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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/btrfs/tree-log.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/btrfs/tree-log.c')
-rw-r--r--fs/btrfs/tree-log.c7562
1 files changed, 7562 insertions, 0 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
new file mode 100644
index 000000000..7c33b28c0
--- /dev/null
+++ b/fs/btrfs/tree-log.c
@@ -0,0 +1,7562 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2008 Oracle. All rights reserved.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/list_sort.h>
+#include <linux/iversion.h>
+#include "misc.h"
+#include "ctree.h"
+#include "tree-log.h"
+#include "disk-io.h"
+#include "locking.h"
+#include "print-tree.h"
+#include "backref.h"
+#include "compression.h"
+#include "qgroup.h"
+#include "block-group.h"
+#include "space-info.h"
+#include "zoned.h"
+#include "inode-item.h"
+
+#define MAX_CONFLICT_INODES 10
+
+/* magic values for the inode_only field in btrfs_log_inode:
+ *
+ * LOG_INODE_ALL means to log everything
+ * LOG_INODE_EXISTS means to log just enough to recreate the inode
+ * during log replay
+ */
+enum {
+ LOG_INODE_ALL,
+ LOG_INODE_EXISTS,
+};
+
+/*
+ * directory trouble cases
+ *
+ * 1) on rename or unlink, if the inode being unlinked isn't in the fsync
+ * log, we must force a full commit before doing an fsync of the directory
+ * where the unlink was done.
+ * ---> record transid of last unlink/rename per directory
+ *
+ * mkdir foo/some_dir
+ * normal commit
+ * rename foo/some_dir foo2/some_dir
+ * mkdir foo/some_dir
+ * fsync foo/some_dir/some_file
+ *
+ * The fsync above will unlink the original some_dir without recording
+ * it in its new location (foo2). After a crash, some_dir will be gone
+ * unless the fsync of some_file forces a full commit
+ *
+ * 2) we must log any new names for any file or dir that is in the fsync
+ * log. ---> check inode while renaming/linking.
+ *
+ * 2a) we must log any new names for any file or dir during rename
+ * when the directory they are being removed from was logged.
+ * ---> check inode and old parent dir during rename
+ *
+ * 2a is actually the more important variant. With the extra logging
+ * a crash might unlink the old name without recreating the new one
+ *
+ * 3) after a crash, we must go through any directories with a link count
+ * of zero and redo the rm -rf
+ *
+ * mkdir f1/foo
+ * normal commit
+ * rm -rf f1/foo
+ * fsync(f1)
+ *
+ * The directory f1 was fully removed from the FS, but fsync was never
+ * called on f1, only its parent dir. After a crash the rm -rf must
+ * be replayed. This must be able to recurse down the entire
+ * directory tree. The inode link count fixup code takes care of the
+ * ugly details.
+ */
+
+/*
+ * stages for the tree walking. The first
+ * stage (0) is to only pin down the blocks we find
+ * the second stage (1) is to make sure that all the inodes
+ * we find in the log are created in the subvolume.
+ *
+ * The last stage is to deal with directories and links and extents
+ * and all the other fun semantics
+ */
+enum {
+ LOG_WALK_PIN_ONLY,
+ LOG_WALK_REPLAY_INODES,
+ LOG_WALK_REPLAY_DIR_INDEX,
+ LOG_WALK_REPLAY_ALL,
+};
+
+static int btrfs_log_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ int inode_only,
+ struct btrfs_log_ctx *ctx);
+static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 objectid);
+static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ u64 dirid, int del_all);
+static void wait_log_commit(struct btrfs_root *root, int transid);
+
+/*
+ * tree logging is a special write ahead log used to make sure that
+ * fsyncs and O_SYNCs can happen without doing full tree commits.
+ *
+ * Full tree commits are expensive because they require commonly
+ * modified blocks to be recowed, creating many dirty pages in the
+ * extent tree an 4x-6x higher write load than ext3.
+ *
+ * Instead of doing a tree commit on every fsync, we use the
+ * key ranges and transaction ids to find items for a given file or directory
+ * that have changed in this transaction. Those items are copied into
+ * a special tree (one per subvolume root), that tree is written to disk
+ * and then the fsync is considered complete.
+ *
+ * After a crash, items are copied out of the log-tree back into the
+ * subvolume tree. Any file data extents found are recorded in the extent
+ * allocation tree, and the log-tree freed.
+ *
+ * The log tree is read three times, once to pin down all the extents it is
+ * using in ram and once, once to create all the inodes logged in the tree
+ * and once to do all the other items.
+ */
+
+/*
+ * start a sub transaction and setup the log tree
+ * this increments the log tree writer count to make the people
+ * syncing the tree wait for us to finish
+ */
+static int start_log_trans(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_root *tree_root = fs_info->tree_root;
+ const bool zoned = btrfs_is_zoned(fs_info);
+ int ret = 0;
+ bool created = false;
+
+ /*
+ * First check if the log root tree was already created. If not, create
+ * it before locking the root's log_mutex, just to keep lockdep happy.
+ */
+ if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state)) {
+ mutex_lock(&tree_root->log_mutex);
+ if (!fs_info->log_root_tree) {
+ ret = btrfs_init_log_root_tree(trans, fs_info);
+ if (!ret) {
+ set_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state);
+ created = true;
+ }
+ }
+ mutex_unlock(&tree_root->log_mutex);
+ if (ret)
+ return ret;
+ }
+
+ mutex_lock(&root->log_mutex);
+
+again:
+ if (root->log_root) {
+ int index = (root->log_transid + 1) % 2;
+
+ if (btrfs_need_log_full_commit(trans)) {
+ ret = BTRFS_LOG_FORCE_COMMIT;
+ goto out;
+ }
+
+ if (zoned && atomic_read(&root->log_commit[index])) {
+ wait_log_commit(root, root->log_transid - 1);
+ goto again;
+ }
+
+ if (!root->log_start_pid) {
+ clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
+ root->log_start_pid = current->pid;
+ } else if (root->log_start_pid != current->pid) {
+ set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
+ }
+ } else {
+ /*
+ * This means fs_info->log_root_tree was already created
+ * for some other FS trees. Do the full commit not to mix
+ * nodes from multiple log transactions to do sequential
+ * writing.
+ */
+ if (zoned && !created) {
+ ret = BTRFS_LOG_FORCE_COMMIT;
+ goto out;
+ }
+
+ ret = btrfs_add_log_tree(trans, root);
+ if (ret)
+ goto out;
+
+ set_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state);
+ clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
+ root->log_start_pid = current->pid;
+ }
+
+ atomic_inc(&root->log_writers);
+ if (!ctx->logging_new_name) {
+ int index = root->log_transid % 2;
+ list_add_tail(&ctx->list, &root->log_ctxs[index]);
+ ctx->log_transid = root->log_transid;
+ }
+
+out:
+ mutex_unlock(&root->log_mutex);
+ return ret;
+}
+
+/*
+ * returns 0 if there was a log transaction running and we were able
+ * to join, or returns -ENOENT if there were not transactions
+ * in progress
+ */
+static int join_running_log_trans(struct btrfs_root *root)
+{
+ const bool zoned = btrfs_is_zoned(root->fs_info);
+ int ret = -ENOENT;
+
+ if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state))
+ return ret;
+
+ mutex_lock(&root->log_mutex);
+again:
+ if (root->log_root) {
+ int index = (root->log_transid + 1) % 2;
+
+ ret = 0;
+ if (zoned && atomic_read(&root->log_commit[index])) {
+ wait_log_commit(root, root->log_transid - 1);
+ goto again;
+ }
+ atomic_inc(&root->log_writers);
+ }
+ mutex_unlock(&root->log_mutex);
+ return ret;
+}
+
+/*
+ * This either makes the current running log transaction wait
+ * until you call btrfs_end_log_trans() or it makes any future
+ * log transactions wait until you call btrfs_end_log_trans()
+ */
+void btrfs_pin_log_trans(struct btrfs_root *root)
+{
+ atomic_inc(&root->log_writers);
+}
+
+/*
+ * indicate we're done making changes to the log tree
+ * and wake up anyone waiting to do a sync
+ */
+void btrfs_end_log_trans(struct btrfs_root *root)
+{
+ if (atomic_dec_and_test(&root->log_writers)) {
+ /* atomic_dec_and_test implies a barrier */
+ cond_wake_up_nomb(&root->log_writer_wait);
+ }
+}
+
+static void btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
+{
+ filemap_fdatawait_range(buf->pages[0]->mapping,
+ buf->start, buf->start + buf->len - 1);
+}
+
+/*
+ * the walk control struct is used to pass state down the chain when
+ * processing the log tree. The stage field tells us which part
+ * of the log tree processing we are currently doing. The others
+ * are state fields used for that specific part
+ */
+struct walk_control {
+ /* should we free the extent on disk when done? This is used
+ * at transaction commit time while freeing a log tree
+ */
+ int free;
+
+ /* pin only walk, we record which extents on disk belong to the
+ * log trees
+ */
+ int pin;
+
+ /* what stage of the replay code we're currently in */
+ int stage;
+
+ /*
+ * Ignore any items from the inode currently being processed. Needs
+ * to be set every time we find a BTRFS_INODE_ITEM_KEY and we are in
+ * the LOG_WALK_REPLAY_INODES stage.
+ */
+ bool ignore_cur_inode;
+
+ /* the root we are currently replaying */
+ struct btrfs_root *replay_dest;
+
+ /* the trans handle for the current replay */
+ struct btrfs_trans_handle *trans;
+
+ /* the function that gets used to process blocks we find in the
+ * tree. Note the extent_buffer might not be up to date when it is
+ * passed in, and it must be checked or read if you need the data
+ * inside it
+ */
+ int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
+ struct walk_control *wc, u64 gen, int level);
+};
+
+/*
+ * process_func used to pin down extents, write them or wait on them
+ */
+static int process_one_buffer(struct btrfs_root *log,
+ struct extent_buffer *eb,
+ struct walk_control *wc, u64 gen, int level)
+{
+ struct btrfs_fs_info *fs_info = log->fs_info;
+ int ret = 0;
+
+ /*
+ * If this fs is mixed then we need to be able to process the leaves to
+ * pin down any logged extents, so we have to read the block.
+ */
+ if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
+ ret = btrfs_read_extent_buffer(eb, gen, level, NULL);
+ if (ret)
+ return ret;
+ }
+
+ if (wc->pin) {
+ ret = btrfs_pin_extent_for_log_replay(wc->trans, eb->start,
+ eb->len);
+ if (ret)
+ return ret;
+
+ if (btrfs_buffer_uptodate(eb, gen, 0) &&
+ btrfs_header_level(eb) == 0)
+ ret = btrfs_exclude_logged_extents(eb);
+ }
+ return ret;
+}
+
+static int do_overwrite_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct extent_buffer *eb, int slot,
+ struct btrfs_key *key)
+{
+ int ret;
+ u32 item_size;
+ u64 saved_i_size = 0;
+ int save_old_i_size = 0;
+ unsigned long src_ptr;
+ unsigned long dst_ptr;
+ int overwrite_root = 0;
+ bool inode_item = key->type == BTRFS_INODE_ITEM_KEY;
+
+ if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
+ overwrite_root = 1;
+
+ item_size = btrfs_item_size(eb, slot);
+ src_ptr = btrfs_item_ptr_offset(eb, slot);
+
+ /* Our caller must have done a search for the key for us. */
+ ASSERT(path->nodes[0] != NULL);
+
+ /*
+ * And the slot must point to the exact key or the slot where the key
+ * should be at (the first item with a key greater than 'key')
+ */
+ if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) {
+ struct btrfs_key found_key;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
+ ret = btrfs_comp_cpu_keys(&found_key, key);
+ ASSERT(ret >= 0);
+ } else {
+ ret = 1;
+ }
+
+ if (ret == 0) {
+ char *src_copy;
+ char *dst_copy;
+ u32 dst_size = btrfs_item_size(path->nodes[0],
+ path->slots[0]);
+ if (dst_size != item_size)
+ goto insert;
+
+ if (item_size == 0) {
+ btrfs_release_path(path);
+ return 0;
+ }
+ dst_copy = kmalloc(item_size, GFP_NOFS);
+ src_copy = kmalloc(item_size, GFP_NOFS);
+ if (!dst_copy || !src_copy) {
+ btrfs_release_path(path);
+ kfree(dst_copy);
+ kfree(src_copy);
+ return -ENOMEM;
+ }
+
+ read_extent_buffer(eb, src_copy, src_ptr, item_size);
+
+ dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
+ read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
+ item_size);
+ ret = memcmp(dst_copy, src_copy, item_size);
+
+ kfree(dst_copy);
+ kfree(src_copy);
+ /*
+ * they have the same contents, just return, this saves
+ * us from cowing blocks in the destination tree and doing
+ * extra writes that may not have been done by a previous
+ * sync
+ */
+ if (ret == 0) {
+ btrfs_release_path(path);
+ return 0;
+ }
+
+ /*
+ * We need to load the old nbytes into the inode so when we
+ * replay the extents we've logged we get the right nbytes.
+ */
+ if (inode_item) {
+ struct btrfs_inode_item *item;
+ u64 nbytes;
+ u32 mode;
+
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_item);
+ nbytes = btrfs_inode_nbytes(path->nodes[0], item);
+ item = btrfs_item_ptr(eb, slot,
+ struct btrfs_inode_item);
+ btrfs_set_inode_nbytes(eb, item, nbytes);
+
+ /*
+ * If this is a directory we need to reset the i_size to
+ * 0 so that we can set it up properly when replaying
+ * the rest of the items in this log.
+ */
+ mode = btrfs_inode_mode(eb, item);
+ if (S_ISDIR(mode))
+ btrfs_set_inode_size(eb, item, 0);
+ }
+ } else if (inode_item) {
+ struct btrfs_inode_item *item;
+ u32 mode;
+
+ /*
+ * New inode, set nbytes to 0 so that the nbytes comes out
+ * properly when we replay the extents.
+ */
+ item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
+ btrfs_set_inode_nbytes(eb, item, 0);
+
+ /*
+ * If this is a directory we need to reset the i_size to 0 so
+ * that we can set it up properly when replaying the rest of
+ * the items in this log.
+ */
+ mode = btrfs_inode_mode(eb, item);
+ if (S_ISDIR(mode))
+ btrfs_set_inode_size(eb, item, 0);
+ }
+insert:
+ btrfs_release_path(path);
+ /* try to insert the key into the destination tree */
+ path->skip_release_on_error = 1;
+ ret = btrfs_insert_empty_item(trans, root, path,
+ key, item_size);
+ path->skip_release_on_error = 0;
+
+ /* make sure any existing item is the correct size */
+ if (ret == -EEXIST || ret == -EOVERFLOW) {
+ u32 found_size;
+ found_size = btrfs_item_size(path->nodes[0],
+ path->slots[0]);
+ if (found_size > item_size)
+ btrfs_truncate_item(path, item_size, 1);
+ else if (found_size < item_size)
+ btrfs_extend_item(path, item_size - found_size);
+ } else if (ret) {
+ return ret;
+ }
+ dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
+ path->slots[0]);
+
+ /* don't overwrite an existing inode if the generation number
+ * was logged as zero. This is done when the tree logging code
+ * is just logging an inode to make sure it exists after recovery.
+ *
+ * Also, don't overwrite i_size on directories during replay.
+ * log replay inserts and removes directory items based on the
+ * state of the tree found in the subvolume, and i_size is modified
+ * as it goes
+ */
+ if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
+ struct btrfs_inode_item *src_item;
+ struct btrfs_inode_item *dst_item;
+
+ src_item = (struct btrfs_inode_item *)src_ptr;
+ dst_item = (struct btrfs_inode_item *)dst_ptr;
+
+ if (btrfs_inode_generation(eb, src_item) == 0) {
+ struct extent_buffer *dst_eb = path->nodes[0];
+ const u64 ino_size = btrfs_inode_size(eb, src_item);
+
+ /*
+ * For regular files an ino_size == 0 is used only when
+ * logging that an inode exists, as part of a directory
+ * fsync, and the inode wasn't fsynced before. In this
+ * case don't set the size of the inode in the fs/subvol
+ * tree, otherwise we would be throwing valid data away.
+ */
+ if (S_ISREG(btrfs_inode_mode(eb, src_item)) &&
+ S_ISREG(btrfs_inode_mode(dst_eb, dst_item)) &&
+ ino_size != 0)
+ btrfs_set_inode_size(dst_eb, dst_item, ino_size);
+ goto no_copy;
+ }
+
+ if (overwrite_root &&
+ S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
+ S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
+ save_old_i_size = 1;
+ saved_i_size = btrfs_inode_size(path->nodes[0],
+ dst_item);
+ }
+ }
+
+ copy_extent_buffer(path->nodes[0], eb, dst_ptr,
+ src_ptr, item_size);
+
+ if (save_old_i_size) {
+ struct btrfs_inode_item *dst_item;
+ dst_item = (struct btrfs_inode_item *)dst_ptr;
+ btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
+ }
+
+ /* make sure the generation is filled in */
+ if (key->type == BTRFS_INODE_ITEM_KEY) {
+ struct btrfs_inode_item *dst_item;
+ dst_item = (struct btrfs_inode_item *)dst_ptr;
+ if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
+ btrfs_set_inode_generation(path->nodes[0], dst_item,
+ trans->transid);
+ }
+ }
+no_copy:
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ btrfs_release_path(path);
+ return 0;
+}
+
+/*
+ * Item overwrite used by replay and tree logging. eb, slot and key all refer
+ * to the src data we are copying out.
+ *
+ * root is the tree we are copying into, and path is a scratch
+ * path for use in this function (it should be released on entry and
+ * will be released on exit).
+ *
+ * If the key is already in the destination tree the existing item is
+ * overwritten. If the existing item isn't big enough, it is extended.
+ * If it is too large, it is truncated.
+ *
+ * If the key isn't in the destination yet, a new item is inserted.
+ */
+static int overwrite_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct extent_buffer *eb, int slot,
+ struct btrfs_key *key)
+{
+ int ret;
+
+ /* Look for the key in the destination tree. */
+ ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+ if (ret < 0)
+ return ret;
+
+ return do_overwrite_item(trans, root, path, eb, slot, key);
+}
+
+static int read_alloc_one_name(struct extent_buffer *eb, void *start, int len,
+ struct fscrypt_str *name)
+{
+ char *buf;
+
+ buf = kmalloc(len, GFP_NOFS);
+ if (!buf)
+ return -ENOMEM;
+
+ read_extent_buffer(eb, buf, (unsigned long)start, len);
+ name->name = buf;
+ name->len = len;
+ return 0;
+}
+
+/*
+ * simple helper to read an inode off the disk from a given root
+ * This can only be called for subvolume roots and not for the log
+ */
+static noinline struct inode *read_one_inode(struct btrfs_root *root,
+ u64 objectid)
+{
+ struct inode *inode;
+
+ inode = btrfs_iget(root->fs_info->sb, objectid, root);
+ if (IS_ERR(inode))
+ inode = NULL;
+ return inode;
+}
+
+/* replays a single extent in 'eb' at 'slot' with 'key' into the
+ * subvolume 'root'. path is released on entry and should be released
+ * on exit.
+ *
+ * extents in the log tree have not been allocated out of the extent
+ * tree yet. So, this completes the allocation, taking a reference
+ * as required if the extent already exists or creating a new extent
+ * if it isn't in the extent allocation tree yet.
+ *
+ * The extent is inserted into the file, dropping any existing extents
+ * from the file that overlap the new one.
+ */
+static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct extent_buffer *eb, int slot,
+ struct btrfs_key *key)
+{
+ struct btrfs_drop_extents_args drop_args = { 0 };
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ int found_type;
+ u64 extent_end;
+ u64 start = key->offset;
+ u64 nbytes = 0;
+ struct btrfs_file_extent_item *item;
+ struct inode *inode = NULL;
+ unsigned long size;
+ int ret = 0;
+
+ item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
+ found_type = btrfs_file_extent_type(eb, item);
+
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ nbytes = btrfs_file_extent_num_bytes(eb, item);
+ extent_end = start + nbytes;
+
+ /*
+ * We don't add to the inodes nbytes if we are prealloc or a
+ * hole.
+ */
+ if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
+ nbytes = 0;
+ } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ size = btrfs_file_extent_ram_bytes(eb, item);
+ nbytes = btrfs_file_extent_ram_bytes(eb, item);
+ extent_end = ALIGN(start + size,
+ fs_info->sectorsize);
+ } else {
+ ret = 0;
+ goto out;
+ }
+
+ inode = read_one_inode(root, key->objectid);
+ if (!inode) {
+ ret = -EIO;
+ goto out;
+ }
+
+ /*
+ * first check to see if we already have this extent in the
+ * file. This must be done before the btrfs_drop_extents run
+ * so we don't try to drop this extent.
+ */
+ ret = btrfs_lookup_file_extent(trans, root, path,
+ btrfs_ino(BTRFS_I(inode)), start, 0);
+
+ if (ret == 0 &&
+ (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
+ struct btrfs_file_extent_item cmp1;
+ struct btrfs_file_extent_item cmp2;
+ struct btrfs_file_extent_item *existing;
+ struct extent_buffer *leaf;
+
+ leaf = path->nodes[0];
+ existing = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+
+ read_extent_buffer(eb, &cmp1, (unsigned long)item,
+ sizeof(cmp1));
+ read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
+ sizeof(cmp2));
+
+ /*
+ * we already have a pointer to this exact extent,
+ * we don't have to do anything
+ */
+ if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
+ btrfs_release_path(path);
+ goto out;
+ }
+ }
+ btrfs_release_path(path);
+
+ /* drop any overlapping extents */
+ drop_args.start = start;
+ drop_args.end = extent_end;
+ drop_args.drop_cache = true;
+ ret = btrfs_drop_extents(trans, root, BTRFS_I(inode), &drop_args);
+ if (ret)
+ goto out;
+
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ u64 offset;
+ unsigned long dest_offset;
+ struct btrfs_key ins;
+
+ if (btrfs_file_extent_disk_bytenr(eb, item) == 0 &&
+ btrfs_fs_incompat(fs_info, NO_HOLES))
+ goto update_inode;
+
+ ret = btrfs_insert_empty_item(trans, root, path, key,
+ sizeof(*item));
+ if (ret)
+ goto out;
+ dest_offset = btrfs_item_ptr_offset(path->nodes[0],
+ path->slots[0]);
+ copy_extent_buffer(path->nodes[0], eb, dest_offset,
+ (unsigned long)item, sizeof(*item));
+
+ ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
+ ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
+ ins.type = BTRFS_EXTENT_ITEM_KEY;
+ offset = key->offset - btrfs_file_extent_offset(eb, item);
+
+ /*
+ * Manually record dirty extent, as here we did a shallow
+ * file extent item copy and skip normal backref update,
+ * but modifying extent tree all by ourselves.
+ * So need to manually record dirty extent for qgroup,
+ * as the owner of the file extent changed from log tree
+ * (doesn't affect qgroup) to fs/file tree(affects qgroup)
+ */
+ ret = btrfs_qgroup_trace_extent(trans,
+ btrfs_file_extent_disk_bytenr(eb, item),
+ btrfs_file_extent_disk_num_bytes(eb, item),
+ GFP_NOFS);
+ if (ret < 0)
+ goto out;
+
+ if (ins.objectid > 0) {
+ struct btrfs_ref ref = { 0 };
+ u64 csum_start;
+ u64 csum_end;
+ LIST_HEAD(ordered_sums);
+
+ /*
+ * is this extent already allocated in the extent
+ * allocation tree? If so, just add a reference
+ */
+ ret = btrfs_lookup_data_extent(fs_info, ins.objectid,
+ ins.offset);
+ if (ret < 0) {
+ goto out;
+ } else if (ret == 0) {
+ btrfs_init_generic_ref(&ref,
+ BTRFS_ADD_DELAYED_REF,
+ ins.objectid, ins.offset, 0);
+ btrfs_init_data_ref(&ref,
+ root->root_key.objectid,
+ key->objectid, offset, 0, false);
+ ret = btrfs_inc_extent_ref(trans, &ref);
+ if (ret)
+ goto out;
+ } else {
+ /*
+ * insert the extent pointer in the extent
+ * allocation tree
+ */
+ ret = btrfs_alloc_logged_file_extent(trans,
+ root->root_key.objectid,
+ key->objectid, offset, &ins);
+ if (ret)
+ goto out;
+ }
+ btrfs_release_path(path);
+
+ if (btrfs_file_extent_compression(eb, item)) {
+ csum_start = ins.objectid;
+ csum_end = csum_start + ins.offset;
+ } else {
+ csum_start = ins.objectid +
+ btrfs_file_extent_offset(eb, item);
+ csum_end = csum_start +
+ btrfs_file_extent_num_bytes(eb, item);
+ }
+
+ ret = btrfs_lookup_csums_range(root->log_root,
+ csum_start, csum_end - 1,
+ &ordered_sums, 0, false);
+ if (ret)
+ goto out;
+ /*
+ * Now delete all existing cums in the csum root that
+ * cover our range. We do this because we can have an
+ * extent that is completely referenced by one file
+ * extent item and partially referenced by another
+ * file extent item (like after using the clone or
+ * extent_same ioctls). In this case if we end up doing
+ * the replay of the one that partially references the
+ * extent first, and we do not do the csum deletion
+ * below, we can get 2 csum items in the csum tree that
+ * overlap each other. For example, imagine our log has
+ * the two following file extent items:
+ *
+ * key (257 EXTENT_DATA 409600)
+ * extent data disk byte 12845056 nr 102400
+ * extent data offset 20480 nr 20480 ram 102400
+ *
+ * key (257 EXTENT_DATA 819200)
+ * extent data disk byte 12845056 nr 102400
+ * extent data offset 0 nr 102400 ram 102400
+ *
+ * Where the second one fully references the 100K extent
+ * that starts at disk byte 12845056, and the log tree
+ * has a single csum item that covers the entire range
+ * of the extent:
+ *
+ * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
+ *
+ * After the first file extent item is replayed, the
+ * csum tree gets the following csum item:
+ *
+ * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
+ *
+ * Which covers the 20K sub-range starting at offset 20K
+ * of our extent. Now when we replay the second file
+ * extent item, if we do not delete existing csum items
+ * that cover any of its blocks, we end up getting two
+ * csum items in our csum tree that overlap each other:
+ *
+ * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
+ * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
+ *
+ * Which is a problem, because after this anyone trying
+ * to lookup up for the checksum of any block of our
+ * extent starting at an offset of 40K or higher, will
+ * end up looking at the second csum item only, which
+ * does not contain the checksum for any block starting
+ * at offset 40K or higher of our extent.
+ */
+ while (!list_empty(&ordered_sums)) {
+ struct btrfs_ordered_sum *sums;
+ struct btrfs_root *csum_root;
+
+ sums = list_entry(ordered_sums.next,
+ struct btrfs_ordered_sum,
+ list);
+ csum_root = btrfs_csum_root(fs_info,
+ sums->bytenr);
+ if (!ret)
+ ret = btrfs_del_csums(trans, csum_root,
+ sums->bytenr,
+ sums->len);
+ if (!ret)
+ ret = btrfs_csum_file_blocks(trans,
+ csum_root,
+ sums);
+ list_del(&sums->list);
+ kfree(sums);
+ }
+ if (ret)
+ goto out;
+ } else {
+ btrfs_release_path(path);
+ }
+ } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ /* inline extents are easy, we just overwrite them */
+ ret = overwrite_item(trans, root, path, eb, slot, key);
+ if (ret)
+ goto out;
+ }
+
+ ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode), start,
+ extent_end - start);
+ if (ret)
+ goto out;
+
+update_inode:
+ btrfs_update_inode_bytes(BTRFS_I(inode), nbytes, drop_args.bytes_found);
+ ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
+out:
+ iput(inode);
+ return ret;
+}
+
+static int unlink_inode_for_log_replay(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *dir,
+ struct btrfs_inode *inode,
+ const struct fscrypt_str *name)
+{
+ int ret;
+
+ ret = btrfs_unlink_inode(trans, dir, inode, name);
+ if (ret)
+ return ret;
+ /*
+ * Whenever we need to check if a name exists or not, we check the
+ * fs/subvolume tree. So after an unlink we must run delayed items, so
+ * that future checks for a name during log replay see that the name
+ * does not exists anymore.
+ */
+ return btrfs_run_delayed_items(trans);
+}
+
+/*
+ * when cleaning up conflicts between the directory names in the
+ * subvolume, directory names in the log and directory names in the
+ * inode back references, we may have to unlink inodes from directories.
+ *
+ * This is a helper function to do the unlink of a specific directory
+ * item
+ */
+static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
+ struct btrfs_path *path,
+ struct btrfs_inode *dir,
+ struct btrfs_dir_item *di)
+{
+ struct btrfs_root *root = dir->root;
+ struct inode *inode;
+ struct fscrypt_str name;
+ struct extent_buffer *leaf;
+ struct btrfs_key location;
+ int ret;
+
+ leaf = path->nodes[0];
+
+ btrfs_dir_item_key_to_cpu(leaf, di, &location);
+ ret = read_alloc_one_name(leaf, di + 1, btrfs_dir_name_len(leaf, di), &name);
+ if (ret)
+ return -ENOMEM;
+
+ btrfs_release_path(path);
+
+ inode = read_one_inode(root, location.objectid);
+ if (!inode) {
+ ret = -EIO;
+ goto out;
+ }
+
+ ret = link_to_fixup_dir(trans, root, path, location.objectid);
+ if (ret)
+ goto out;
+
+ ret = unlink_inode_for_log_replay(trans, dir, BTRFS_I(inode), &name);
+out:
+ kfree(name.name);
+ iput(inode);
+ return ret;
+}
+
+/*
+ * See if a given name and sequence number found in an inode back reference are
+ * already in a directory and correctly point to this inode.
+ *
+ * Returns: < 0 on error, 0 if the directory entry does not exists and 1 if it
+ * exists.
+ */
+static noinline int inode_in_dir(struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 dirid, u64 objectid, u64 index,
+ struct fscrypt_str *name)
+{
+ struct btrfs_dir_item *di;
+ struct btrfs_key location;
+ int ret = 0;
+
+ di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
+ index, name, 0);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto out;
+ } else if (di) {
+ btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
+ if (location.objectid != objectid)
+ goto out;
+ } else {
+ goto out;
+ }
+
+ btrfs_release_path(path);
+ di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, 0);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto out;
+ } else if (di) {
+ btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
+ if (location.objectid == objectid)
+ ret = 1;
+ }
+out:
+ btrfs_release_path(path);
+ return ret;
+}
+
+/*
+ * helper function to check a log tree for a named back reference in
+ * an inode. This is used to decide if a back reference that is
+ * found in the subvolume conflicts with what we find in the log.
+ *
+ * inode backreferences may have multiple refs in a single item,
+ * during replay we process one reference at a time, and we don't
+ * want to delete valid links to a file from the subvolume if that
+ * link is also in the log.
+ */
+static noinline int backref_in_log(struct btrfs_root *log,
+ struct btrfs_key *key,
+ u64 ref_objectid,
+ const struct fscrypt_str *name)
+{
+ struct btrfs_path *path;
+ int ret;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
+ if (ret < 0) {
+ goto out;
+ } else if (ret == 1) {
+ ret = 0;
+ goto out;
+ }
+
+ if (key->type == BTRFS_INODE_EXTREF_KEY)
+ ret = !!btrfs_find_name_in_ext_backref(path->nodes[0],
+ path->slots[0],
+ ref_objectid, name);
+ else
+ ret = !!btrfs_find_name_in_backref(path->nodes[0],
+ path->slots[0], name);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_root *log_root,
+ struct btrfs_inode *dir,
+ struct btrfs_inode *inode,
+ u64 inode_objectid, u64 parent_objectid,
+ u64 ref_index, struct fscrypt_str *name)
+{
+ int ret;
+ struct extent_buffer *leaf;
+ struct btrfs_dir_item *di;
+ struct btrfs_key search_key;
+ struct btrfs_inode_extref *extref;
+
+again:
+ /* Search old style refs */
+ search_key.objectid = inode_objectid;
+ search_key.type = BTRFS_INODE_REF_KEY;
+ search_key.offset = parent_objectid;
+ ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+ if (ret == 0) {
+ struct btrfs_inode_ref *victim_ref;
+ unsigned long ptr;
+ unsigned long ptr_end;
+
+ leaf = path->nodes[0];
+
+ /* are we trying to overwrite a back ref for the root directory
+ * if so, just jump out, we're done
+ */
+ if (search_key.objectid == search_key.offset)
+ return 1;
+
+ /* check all the names in this back reference to see
+ * if they are in the log. if so, we allow them to stay
+ * otherwise they must be unlinked as a conflict
+ */
+ ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+ ptr_end = ptr + btrfs_item_size(leaf, path->slots[0]);
+ while (ptr < ptr_end) {
+ struct fscrypt_str victim_name;
+
+ victim_ref = (struct btrfs_inode_ref *)ptr;
+ ret = read_alloc_one_name(leaf, (victim_ref + 1),
+ btrfs_inode_ref_name_len(leaf, victim_ref),
+ &victim_name);
+ if (ret)
+ return ret;
+
+ ret = backref_in_log(log_root, &search_key,
+ parent_objectid, &victim_name);
+ if (ret < 0) {
+ kfree(victim_name.name);
+ return ret;
+ } else if (!ret) {
+ inc_nlink(&inode->vfs_inode);
+ btrfs_release_path(path);
+
+ ret = unlink_inode_for_log_replay(trans, dir, inode,
+ &victim_name);
+ kfree(victim_name.name);
+ if (ret)
+ return ret;
+ goto again;
+ }
+ kfree(victim_name.name);
+
+ ptr = (unsigned long)(victim_ref + 1) + victim_name.len;
+ }
+ }
+ btrfs_release_path(path);
+
+ /* Same search but for extended refs */
+ extref = btrfs_lookup_inode_extref(NULL, root, path, name,
+ inode_objectid, parent_objectid, 0,
+ 0);
+ if (IS_ERR(extref)) {
+ return PTR_ERR(extref);
+ } else if (extref) {
+ u32 item_size;
+ u32 cur_offset = 0;
+ unsigned long base;
+ struct inode *victim_parent;
+
+ leaf = path->nodes[0];
+
+ item_size = btrfs_item_size(leaf, path->slots[0]);
+ base = btrfs_item_ptr_offset(leaf, path->slots[0]);
+
+ while (cur_offset < item_size) {
+ struct fscrypt_str victim_name;
+
+ extref = (struct btrfs_inode_extref *)(base + cur_offset);
+
+ if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
+ goto next;
+
+ ret = read_alloc_one_name(leaf, &extref->name,
+ btrfs_inode_extref_name_len(leaf, extref),
+ &victim_name);
+ if (ret)
+ return ret;
+
+ search_key.objectid = inode_objectid;
+ search_key.type = BTRFS_INODE_EXTREF_KEY;
+ search_key.offset = btrfs_extref_hash(parent_objectid,
+ victim_name.name,
+ victim_name.len);
+ ret = backref_in_log(log_root, &search_key,
+ parent_objectid, &victim_name);
+ if (ret < 0) {
+ kfree(victim_name.name);
+ return ret;
+ } else if (!ret) {
+ ret = -ENOENT;
+ victim_parent = read_one_inode(root,
+ parent_objectid);
+ if (victim_parent) {
+ inc_nlink(&inode->vfs_inode);
+ btrfs_release_path(path);
+
+ ret = unlink_inode_for_log_replay(trans,
+ BTRFS_I(victim_parent),
+ inode, &victim_name);
+ }
+ iput(victim_parent);
+ kfree(victim_name.name);
+ if (ret)
+ return ret;
+ goto again;
+ }
+ kfree(victim_name.name);
+next:
+ cur_offset += victim_name.len + sizeof(*extref);
+ }
+ }
+ btrfs_release_path(path);
+
+ /* look for a conflicting sequence number */
+ di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
+ ref_index, name, 0);
+ if (IS_ERR(di)) {
+ return PTR_ERR(di);
+ } else if (di) {
+ ret = drop_one_dir_item(trans, path, dir, di);
+ if (ret)
+ return ret;
+ }
+ btrfs_release_path(path);
+
+ /* look for a conflicting name */
+ di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir), name, 0);
+ if (IS_ERR(di)) {
+ return PTR_ERR(di);
+ } else if (di) {
+ ret = drop_one_dir_item(trans, path, dir, di);
+ if (ret)
+ return ret;
+ }
+ btrfs_release_path(path);
+
+ return 0;
+}
+
+static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
+ struct fscrypt_str *name, u64 *index,
+ u64 *parent_objectid)
+{
+ struct btrfs_inode_extref *extref;
+ int ret;
+
+ extref = (struct btrfs_inode_extref *)ref_ptr;
+
+ ret = read_alloc_one_name(eb, &extref->name,
+ btrfs_inode_extref_name_len(eb, extref), name);
+ if (ret)
+ return ret;
+
+ if (index)
+ *index = btrfs_inode_extref_index(eb, extref);
+ if (parent_objectid)
+ *parent_objectid = btrfs_inode_extref_parent(eb, extref);
+
+ return 0;
+}
+
+static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
+ struct fscrypt_str *name, u64 *index)
+{
+ struct btrfs_inode_ref *ref;
+ int ret;
+
+ ref = (struct btrfs_inode_ref *)ref_ptr;
+
+ ret = read_alloc_one_name(eb, ref + 1, btrfs_inode_ref_name_len(eb, ref),
+ name);
+ if (ret)
+ return ret;
+
+ if (index)
+ *index = btrfs_inode_ref_index(eb, ref);
+
+ return 0;
+}
+
+/*
+ * Take an inode reference item from the log tree and iterate all names from the
+ * inode reference item in the subvolume tree with the same key (if it exists).
+ * For any name that is not in the inode reference item from the log tree, do a
+ * proper unlink of that name (that is, remove its entry from the inode
+ * reference item and both dir index keys).
+ */
+static int unlink_old_inode_refs(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_inode *inode,
+ struct extent_buffer *log_eb,
+ int log_slot,
+ struct btrfs_key *key)
+{
+ int ret;
+ unsigned long ref_ptr;
+ unsigned long ref_end;
+ struct extent_buffer *eb;
+
+again:
+ btrfs_release_path(path);
+ ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+ if (ret > 0) {
+ ret = 0;
+ goto out;
+ }
+ if (ret < 0)
+ goto out;
+
+ eb = path->nodes[0];
+ ref_ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
+ ref_end = ref_ptr + btrfs_item_size(eb, path->slots[0]);
+ while (ref_ptr < ref_end) {
+ struct fscrypt_str name;
+ u64 parent_id;
+
+ if (key->type == BTRFS_INODE_EXTREF_KEY) {
+ ret = extref_get_fields(eb, ref_ptr, &name,
+ NULL, &parent_id);
+ } else {
+ parent_id = key->offset;
+ ret = ref_get_fields(eb, ref_ptr, &name, NULL);
+ }
+ if (ret)
+ goto out;
+
+ if (key->type == BTRFS_INODE_EXTREF_KEY)
+ ret = !!btrfs_find_name_in_ext_backref(log_eb, log_slot,
+ parent_id, &name);
+ else
+ ret = !!btrfs_find_name_in_backref(log_eb, log_slot, &name);
+
+ if (!ret) {
+ struct inode *dir;
+
+ btrfs_release_path(path);
+ dir = read_one_inode(root, parent_id);
+ if (!dir) {
+ ret = -ENOENT;
+ kfree(name.name);
+ goto out;
+ }
+ ret = unlink_inode_for_log_replay(trans, BTRFS_I(dir),
+ inode, &name);
+ kfree(name.name);
+ iput(dir);
+ if (ret)
+ goto out;
+ goto again;
+ }
+
+ kfree(name.name);
+ ref_ptr += name.len;
+ if (key->type == BTRFS_INODE_EXTREF_KEY)
+ ref_ptr += sizeof(struct btrfs_inode_extref);
+ else
+ ref_ptr += sizeof(struct btrfs_inode_ref);
+ }
+ ret = 0;
+ out:
+ btrfs_release_path(path);
+ return ret;
+}
+
+/*
+ * replay one inode back reference item found in the log tree.
+ * eb, slot and key refer to the buffer and key found in the log tree.
+ * root is the destination we are replaying into, and path is for temp
+ * use by this function. (it should be released on return).
+ */
+static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ struct extent_buffer *eb, int slot,
+ struct btrfs_key *key)
+{
+ struct inode *dir = NULL;
+ struct inode *inode = NULL;
+ unsigned long ref_ptr;
+ unsigned long ref_end;
+ struct fscrypt_str name;
+ int ret;
+ int log_ref_ver = 0;
+ u64 parent_objectid;
+ u64 inode_objectid;
+ u64 ref_index = 0;
+ int ref_struct_size;
+
+ ref_ptr = btrfs_item_ptr_offset(eb, slot);
+ ref_end = ref_ptr + btrfs_item_size(eb, slot);
+
+ if (key->type == BTRFS_INODE_EXTREF_KEY) {
+ struct btrfs_inode_extref *r;
+
+ ref_struct_size = sizeof(struct btrfs_inode_extref);
+ log_ref_ver = 1;
+ r = (struct btrfs_inode_extref *)ref_ptr;
+ parent_objectid = btrfs_inode_extref_parent(eb, r);
+ } else {
+ ref_struct_size = sizeof(struct btrfs_inode_ref);
+ parent_objectid = key->offset;
+ }
+ inode_objectid = key->objectid;
+
+ /*
+ * it is possible that we didn't log all the parent directories
+ * for a given inode. If we don't find the dir, just don't
+ * copy the back ref in. The link count fixup code will take
+ * care of the rest
+ */
+ dir = read_one_inode(root, parent_objectid);
+ if (!dir) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ inode = read_one_inode(root, inode_objectid);
+ if (!inode) {
+ ret = -EIO;
+ goto out;
+ }
+
+ while (ref_ptr < ref_end) {
+ if (log_ref_ver) {
+ ret = extref_get_fields(eb, ref_ptr, &name,
+ &ref_index, &parent_objectid);
+ /*
+ * parent object can change from one array
+ * item to another.
+ */
+ if (!dir)
+ dir = read_one_inode(root, parent_objectid);
+ if (!dir) {
+ ret = -ENOENT;
+ goto out;
+ }
+ } else {
+ ret = ref_get_fields(eb, ref_ptr, &name, &ref_index);
+ }
+ if (ret)
+ goto out;
+
+ ret = inode_in_dir(root, path, btrfs_ino(BTRFS_I(dir)),
+ btrfs_ino(BTRFS_I(inode)), ref_index, &name);
+ if (ret < 0) {
+ goto out;
+ } else if (ret == 0) {
+ /*
+ * look for a conflicting back reference in the
+ * metadata. if we find one we have to unlink that name
+ * of the file before we add our new link. Later on, we
+ * overwrite any existing back reference, and we don't
+ * want to create dangling pointers in the directory.
+ */
+ ret = __add_inode_ref(trans, root, path, log,
+ BTRFS_I(dir), BTRFS_I(inode),
+ inode_objectid, parent_objectid,
+ ref_index, &name);
+ if (ret) {
+ if (ret == 1)
+ ret = 0;
+ goto out;
+ }
+
+ /* insert our name */
+ ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
+ &name, 0, ref_index);
+ if (ret)
+ goto out;
+
+ ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
+ if (ret)
+ goto out;
+ }
+ /* Else, ret == 1, we already have a perfect match, we're done. */
+
+ ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + name.len;
+ kfree(name.name);
+ name.name = NULL;
+ if (log_ref_ver) {
+ iput(dir);
+ dir = NULL;
+ }
+ }
+
+ /*
+ * Before we overwrite the inode reference item in the subvolume tree
+ * with the item from the log tree, we must unlink all names from the
+ * parent directory that are in the subvolume's tree inode reference
+ * item, otherwise we end up with an inconsistent subvolume tree where
+ * dir index entries exist for a name but there is no inode reference
+ * item with the same name.
+ */
+ ret = unlink_old_inode_refs(trans, root, path, BTRFS_I(inode), eb, slot,
+ key);
+ if (ret)
+ goto out;
+
+ /* finally write the back reference in the inode */
+ ret = overwrite_item(trans, root, path, eb, slot, key);
+out:
+ btrfs_release_path(path);
+ kfree(name.name);
+ iput(dir);
+ iput(inode);
+ return ret;
+}
+
+static int count_inode_extrefs(struct btrfs_root *root,
+ struct btrfs_inode *inode, struct btrfs_path *path)
+{
+ int ret = 0;
+ int name_len;
+ unsigned int nlink = 0;
+ u32 item_size;
+ u32 cur_offset = 0;
+ u64 inode_objectid = btrfs_ino(inode);
+ u64 offset = 0;
+ unsigned long ptr;
+ struct btrfs_inode_extref *extref;
+ struct extent_buffer *leaf;
+
+ while (1) {
+ ret = btrfs_find_one_extref(root, inode_objectid, offset, path,
+ &extref, &offset);
+ if (ret)
+ break;
+
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size(leaf, path->slots[0]);
+ ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+ cur_offset = 0;
+
+ while (cur_offset < item_size) {
+ extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
+ name_len = btrfs_inode_extref_name_len(leaf, extref);
+
+ nlink++;
+
+ cur_offset += name_len + sizeof(*extref);
+ }
+
+ offset++;
+ btrfs_release_path(path);
+ }
+ btrfs_release_path(path);
+
+ if (ret < 0 && ret != -ENOENT)
+ return ret;
+ return nlink;
+}
+
+static int count_inode_refs(struct btrfs_root *root,
+ struct btrfs_inode *inode, struct btrfs_path *path)
+{
+ int ret;
+ struct btrfs_key key;
+ unsigned int nlink = 0;
+ unsigned long ptr;
+ unsigned long ptr_end;
+ int name_len;
+ u64 ino = btrfs_ino(inode);
+
+ key.objectid = ino;
+ key.type = BTRFS_INODE_REF_KEY;
+ key.offset = (u64)-1;
+
+ while (1) {
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ break;
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ break;
+ path->slots[0]--;
+ }
+process_slot:
+ btrfs_item_key_to_cpu(path->nodes[0], &key,
+ path->slots[0]);
+ if (key.objectid != ino ||
+ key.type != BTRFS_INODE_REF_KEY)
+ break;
+ ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
+ ptr_end = ptr + btrfs_item_size(path->nodes[0],
+ path->slots[0]);
+ while (ptr < ptr_end) {
+ struct btrfs_inode_ref *ref;
+
+ ref = (struct btrfs_inode_ref *)ptr;
+ name_len = btrfs_inode_ref_name_len(path->nodes[0],
+ ref);
+ ptr = (unsigned long)(ref + 1) + name_len;
+ nlink++;
+ }
+
+ if (key.offset == 0)
+ break;
+ if (path->slots[0] > 0) {
+ path->slots[0]--;
+ goto process_slot;
+ }
+ key.offset--;
+ btrfs_release_path(path);
+ }
+ btrfs_release_path(path);
+
+ return nlink;
+}
+
+/*
+ * There are a few corners where the link count of the file can't
+ * be properly maintained during replay. So, instead of adding
+ * lots of complexity to the log code, we just scan the backrefs
+ * for any file that has been through replay.
+ *
+ * The scan will update the link count on the inode to reflect the
+ * number of back refs found. If it goes down to zero, the iput
+ * will free the inode.
+ */
+static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode)
+{
+ struct btrfs_path *path;
+ int ret;
+ u64 nlink = 0;
+ u64 ino = btrfs_ino(BTRFS_I(inode));
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = count_inode_refs(root, BTRFS_I(inode), path);
+ if (ret < 0)
+ goto out;
+
+ nlink = ret;
+
+ ret = count_inode_extrefs(root, BTRFS_I(inode), path);
+ if (ret < 0)
+ goto out;
+
+ nlink += ret;
+
+ ret = 0;
+
+ if (nlink != inode->i_nlink) {
+ set_nlink(inode, nlink);
+ ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
+ if (ret)
+ goto out;
+ }
+ BTRFS_I(inode)->index_cnt = (u64)-1;
+
+ if (inode->i_nlink == 0) {
+ if (S_ISDIR(inode->i_mode)) {
+ ret = replay_dir_deletes(trans, root, NULL, path,
+ ino, 1);
+ if (ret)
+ goto out;
+ }
+ ret = btrfs_insert_orphan_item(trans, root, ino);
+ if (ret == -EEXIST)
+ ret = 0;
+ }
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path)
+{
+ int ret;
+ struct btrfs_key key;
+ struct inode *inode;
+
+ key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
+ key.type = BTRFS_ORPHAN_ITEM_KEY;
+ key.offset = (u64)-1;
+ while (1) {
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0)
+ break;
+
+ if (ret == 1) {
+ ret = 0;
+ if (path->slots[0] == 0)
+ break;
+ path->slots[0]--;
+ }
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+ if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
+ key.type != BTRFS_ORPHAN_ITEM_KEY)
+ break;
+
+ ret = btrfs_del_item(trans, root, path);
+ if (ret)
+ break;
+
+ btrfs_release_path(path);
+ inode = read_one_inode(root, key.offset);
+ if (!inode) {
+ ret = -EIO;
+ break;
+ }
+
+ ret = fixup_inode_link_count(trans, root, inode);
+ iput(inode);
+ if (ret)
+ break;
+
+ /*
+ * fixup on a directory may create new entries,
+ * make sure we always look for the highset possible
+ * offset
+ */
+ key.offset = (u64)-1;
+ }
+ btrfs_release_path(path);
+ return ret;
+}
+
+
+/*
+ * record a given inode in the fixup dir so we can check its link
+ * count when replay is done. The link count is incremented here
+ * so the inode won't go away until we check it
+ */
+static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 objectid)
+{
+ struct btrfs_key key;
+ int ret = 0;
+ struct inode *inode;
+
+ inode = read_one_inode(root, objectid);
+ if (!inode)
+ return -EIO;
+
+ key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
+ key.type = BTRFS_ORPHAN_ITEM_KEY;
+ key.offset = objectid;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
+
+ btrfs_release_path(path);
+ if (ret == 0) {
+ if (!inode->i_nlink)
+ set_nlink(inode, 1);
+ else
+ inc_nlink(inode);
+ ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
+ } else if (ret == -EEXIST) {
+ ret = 0;
+ }
+ iput(inode);
+
+ return ret;
+}
+
+/*
+ * when replaying the log for a directory, we only insert names
+ * for inodes that actually exist. This means an fsync on a directory
+ * does not implicitly fsync all the new files in it
+ */
+static noinline int insert_one_name(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 dirid, u64 index,
+ const struct fscrypt_str *name,
+ struct btrfs_key *location)
+{
+ struct inode *inode;
+ struct inode *dir;
+ int ret;
+
+ inode = read_one_inode(root, location->objectid);
+ if (!inode)
+ return -ENOENT;
+
+ dir = read_one_inode(root, dirid);
+ if (!dir) {
+ iput(inode);
+ return -EIO;
+ }
+
+ ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), name,
+ 1, index);
+
+ /* FIXME, put inode into FIXUP list */
+
+ iput(inode);
+ iput(dir);
+ return ret;
+}
+
+static int delete_conflicting_dir_entry(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *dir,
+ struct btrfs_path *path,
+ struct btrfs_dir_item *dst_di,
+ const struct btrfs_key *log_key,
+ u8 log_type,
+ bool exists)
+{
+ struct btrfs_key found_key;
+
+ btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
+ /* The existing dentry points to the same inode, don't delete it. */
+ if (found_key.objectid == log_key->objectid &&
+ found_key.type == log_key->type &&
+ found_key.offset == log_key->offset &&
+ btrfs_dir_type(path->nodes[0], dst_di) == log_type)
+ return 1;
+
+ /*
+ * Don't drop the conflicting directory entry if the inode for the new
+ * entry doesn't exist.
+ */
+ if (!exists)
+ return 0;
+
+ return drop_one_dir_item(trans, path, dir, dst_di);
+}
+
+/*
+ * take a single entry in a log directory item and replay it into
+ * the subvolume.
+ *
+ * if a conflicting item exists in the subdirectory already,
+ * the inode it points to is unlinked and put into the link count
+ * fix up tree.
+ *
+ * If a name from the log points to a file or directory that does
+ * not exist in the FS, it is skipped. fsyncs on directories
+ * do not force down inodes inside that directory, just changes to the
+ * names or unlinks in a directory.
+ *
+ * Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a
+ * non-existing inode) and 1 if the name was replayed.
+ */
+static noinline int replay_one_name(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct extent_buffer *eb,
+ struct btrfs_dir_item *di,
+ struct btrfs_key *key)
+{
+ struct fscrypt_str name;
+ struct btrfs_dir_item *dir_dst_di;
+ struct btrfs_dir_item *index_dst_di;
+ bool dir_dst_matches = false;
+ bool index_dst_matches = false;
+ struct btrfs_key log_key;
+ struct btrfs_key search_key;
+ struct inode *dir;
+ u8 log_type;
+ bool exists;
+ int ret;
+ bool update_size = true;
+ bool name_added = false;
+
+ dir = read_one_inode(root, key->objectid);
+ if (!dir)
+ return -EIO;
+
+ ret = read_alloc_one_name(eb, di + 1, btrfs_dir_name_len(eb, di), &name);
+ if (ret)
+ goto out;
+
+ log_type = btrfs_dir_type(eb, di);
+ btrfs_dir_item_key_to_cpu(eb, di, &log_key);
+ ret = btrfs_lookup_inode(trans, root, path, &log_key, 0);
+ btrfs_release_path(path);
+ if (ret < 0)
+ goto out;
+ exists = (ret == 0);
+ ret = 0;
+
+ dir_dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
+ &name, 1);
+ if (IS_ERR(dir_dst_di)) {
+ ret = PTR_ERR(dir_dst_di);
+ goto out;
+ } else if (dir_dst_di) {
+ ret = delete_conflicting_dir_entry(trans, BTRFS_I(dir), path,
+ dir_dst_di, &log_key, log_type,
+ exists);
+ if (ret < 0)
+ goto out;
+ dir_dst_matches = (ret == 1);
+ }
+
+ btrfs_release_path(path);
+
+ index_dst_di = btrfs_lookup_dir_index_item(trans, root, path,
+ key->objectid, key->offset,
+ &name, 1);
+ if (IS_ERR(index_dst_di)) {
+ ret = PTR_ERR(index_dst_di);
+ goto out;
+ } else if (index_dst_di) {
+ ret = delete_conflicting_dir_entry(trans, BTRFS_I(dir), path,
+ index_dst_di, &log_key,
+ log_type, exists);
+ if (ret < 0)
+ goto out;
+ index_dst_matches = (ret == 1);
+ }
+
+ btrfs_release_path(path);
+
+ if (dir_dst_matches && index_dst_matches) {
+ ret = 0;
+ update_size = false;
+ goto out;
+ }
+
+ /*
+ * Check if the inode reference exists in the log for the given name,
+ * inode and parent inode
+ */
+ search_key.objectid = log_key.objectid;
+ search_key.type = BTRFS_INODE_REF_KEY;
+ search_key.offset = key->objectid;
+ ret = backref_in_log(root->log_root, &search_key, 0, &name);
+ if (ret < 0) {
+ goto out;
+ } else if (ret) {
+ /* The dentry will be added later. */
+ ret = 0;
+ update_size = false;
+ goto out;
+ }
+
+ search_key.objectid = log_key.objectid;
+ search_key.type = BTRFS_INODE_EXTREF_KEY;
+ search_key.offset = key->objectid;
+ ret = backref_in_log(root->log_root, &search_key, key->objectid, &name);
+ if (ret < 0) {
+ goto out;
+ } else if (ret) {
+ /* The dentry will be added later. */
+ ret = 0;
+ update_size = false;
+ goto out;
+ }
+ btrfs_release_path(path);
+ ret = insert_one_name(trans, root, key->objectid, key->offset,
+ &name, &log_key);
+ if (ret && ret != -ENOENT && ret != -EEXIST)
+ goto out;
+ if (!ret)
+ name_added = true;
+ update_size = false;
+ ret = 0;
+
+out:
+ if (!ret && update_size) {
+ btrfs_i_size_write(BTRFS_I(dir), dir->i_size + name.len * 2);
+ ret = btrfs_update_inode(trans, root, BTRFS_I(dir));
+ }
+ kfree(name.name);
+ iput(dir);
+ if (!ret && name_added)
+ ret = 1;
+ return ret;
+}
+
+/* Replay one dir item from a BTRFS_DIR_INDEX_KEY key. */
+static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct extent_buffer *eb, int slot,
+ struct btrfs_key *key)
+{
+ int ret;
+ struct btrfs_dir_item *di;
+
+ /* We only log dir index keys, which only contain a single dir item. */
+ ASSERT(key->type == BTRFS_DIR_INDEX_KEY);
+
+ di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
+ ret = replay_one_name(trans, root, path, eb, di, key);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * If this entry refers to a non-directory (directories can not have a
+ * link count > 1) and it was added in the transaction that was not
+ * committed, make sure we fixup the link count of the inode the entry
+ * points to. Otherwise something like the following would result in a
+ * directory pointing to an inode with a wrong link that does not account
+ * for this dir entry:
+ *
+ * mkdir testdir
+ * touch testdir/foo
+ * touch testdir/bar
+ * sync
+ *
+ * ln testdir/bar testdir/bar_link
+ * ln testdir/foo testdir/foo_link
+ * xfs_io -c "fsync" testdir/bar
+ *
+ * <power failure>
+ *
+ * mount fs, log replay happens
+ *
+ * File foo would remain with a link count of 1 when it has two entries
+ * pointing to it in the directory testdir. This would make it impossible
+ * to ever delete the parent directory has it would result in stale
+ * dentries that can never be deleted.
+ */
+ if (ret == 1 && btrfs_dir_type(eb, di) != BTRFS_FT_DIR) {
+ struct btrfs_path *fixup_path;
+ struct btrfs_key di_key;
+
+ fixup_path = btrfs_alloc_path();
+ if (!fixup_path)
+ return -ENOMEM;
+
+ btrfs_dir_item_key_to_cpu(eb, di, &di_key);
+ ret = link_to_fixup_dir(trans, root, fixup_path, di_key.objectid);
+ btrfs_free_path(fixup_path);
+ }
+
+ return ret;
+}
+
+/*
+ * directory replay has two parts. There are the standard directory
+ * items in the log copied from the subvolume, and range items
+ * created in the log while the subvolume was logged.
+ *
+ * The range items tell us which parts of the key space the log
+ * is authoritative for. During replay, if a key in the subvolume
+ * directory is in a logged range item, but not actually in the log
+ * that means it was deleted from the directory before the fsync
+ * and should be removed.
+ */
+static noinline int find_dir_range(struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 dirid,
+ u64 *start_ret, u64 *end_ret)
+{
+ struct btrfs_key key;
+ u64 found_end;
+ struct btrfs_dir_log_item *item;
+ int ret;
+ int nritems;
+
+ if (*start_ret == (u64)-1)
+ return 1;
+
+ key.objectid = dirid;
+ key.type = BTRFS_DIR_LOG_INDEX_KEY;
+ key.offset = *start_ret;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ goto out;
+ path->slots[0]--;
+ }
+ if (ret != 0)
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+
+ if (key.type != BTRFS_DIR_LOG_INDEX_KEY || key.objectid != dirid) {
+ ret = 1;
+ goto next;
+ }
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_dir_log_item);
+ found_end = btrfs_dir_log_end(path->nodes[0], item);
+
+ if (*start_ret >= key.offset && *start_ret <= found_end) {
+ ret = 0;
+ *start_ret = key.offset;
+ *end_ret = found_end;
+ goto out;
+ }
+ ret = 1;
+next:
+ /* check the next slot in the tree to see if it is a valid item */
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ path->slots[0]++;
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ goto out;
+ }
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+
+ if (key.type != BTRFS_DIR_LOG_INDEX_KEY || key.objectid != dirid) {
+ ret = 1;
+ goto out;
+ }
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_dir_log_item);
+ found_end = btrfs_dir_log_end(path->nodes[0], item);
+ *start_ret = key.offset;
+ *end_ret = found_end;
+ ret = 0;
+out:
+ btrfs_release_path(path);
+ return ret;
+}
+
+/*
+ * this looks for a given directory item in the log. If the directory
+ * item is not in the log, the item is removed and the inode it points
+ * to is unlinked
+ */
+static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ struct btrfs_path *log_path,
+ struct inode *dir,
+ struct btrfs_key *dir_key)
+{
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ int ret;
+ struct extent_buffer *eb;
+ int slot;
+ struct btrfs_dir_item *di;
+ struct fscrypt_str name;
+ struct inode *inode = NULL;
+ struct btrfs_key location;
+
+ /*
+ * Currently we only log dir index keys. Even if we replay a log created
+ * by an older kernel that logged both dir index and dir item keys, all
+ * we need to do is process the dir index keys, we (and our caller) can
+ * safely ignore dir item keys (key type BTRFS_DIR_ITEM_KEY).
+ */
+ ASSERT(dir_key->type == BTRFS_DIR_INDEX_KEY);
+
+ eb = path->nodes[0];
+ slot = path->slots[0];
+ di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
+ ret = read_alloc_one_name(eb, di + 1, btrfs_dir_name_len(eb, di), &name);
+ if (ret)
+ goto out;
+
+ if (log) {
+ struct btrfs_dir_item *log_di;
+
+ log_di = btrfs_lookup_dir_index_item(trans, log, log_path,
+ dir_key->objectid,
+ dir_key->offset, &name, 0);
+ if (IS_ERR(log_di)) {
+ ret = PTR_ERR(log_di);
+ goto out;
+ } else if (log_di) {
+ /* The dentry exists in the log, we have nothing to do. */
+ ret = 0;
+ goto out;
+ }
+ }
+
+ btrfs_dir_item_key_to_cpu(eb, di, &location);
+ btrfs_release_path(path);
+ btrfs_release_path(log_path);
+ inode = read_one_inode(root, location.objectid);
+ if (!inode) {
+ ret = -EIO;
+ goto out;
+ }
+
+ ret = link_to_fixup_dir(trans, root, path, location.objectid);
+ if (ret)
+ goto out;
+
+ inc_nlink(inode);
+ ret = unlink_inode_for_log_replay(trans, BTRFS_I(dir), BTRFS_I(inode),
+ &name);
+ /*
+ * Unlike dir item keys, dir index keys can only have one name (entry) in
+ * them, as there are no key collisions since each key has a unique offset
+ * (an index number), so we're done.
+ */
+out:
+ btrfs_release_path(path);
+ btrfs_release_path(log_path);
+ kfree(name.name);
+ iput(inode);
+ return ret;
+}
+
+static int replay_xattr_deletes(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ const u64 ino)
+{
+ struct btrfs_key search_key;
+ struct btrfs_path *log_path;
+ int i;
+ int nritems;
+ int ret;
+
+ log_path = btrfs_alloc_path();
+ if (!log_path)
+ return -ENOMEM;
+
+ search_key.objectid = ino;
+ search_key.type = BTRFS_XATTR_ITEM_KEY;
+ search_key.offset = 0;
+again:
+ ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+process_leaf:
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ for (i = path->slots[0]; i < nritems; i++) {
+ struct btrfs_key key;
+ struct btrfs_dir_item *di;
+ struct btrfs_dir_item *log_di;
+ u32 total_size;
+ u32 cur;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, i);
+ if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) {
+ ret = 0;
+ goto out;
+ }
+
+ di = btrfs_item_ptr(path->nodes[0], i, struct btrfs_dir_item);
+ total_size = btrfs_item_size(path->nodes[0], i);
+ cur = 0;
+ while (cur < total_size) {
+ u16 name_len = btrfs_dir_name_len(path->nodes[0], di);
+ u16 data_len = btrfs_dir_data_len(path->nodes[0], di);
+ u32 this_len = sizeof(*di) + name_len + data_len;
+ char *name;
+
+ name = kmalloc(name_len, GFP_NOFS);
+ if (!name) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ read_extent_buffer(path->nodes[0], name,
+ (unsigned long)(di + 1), name_len);
+
+ log_di = btrfs_lookup_xattr(NULL, log, log_path, ino,
+ name, name_len, 0);
+ btrfs_release_path(log_path);
+ if (!log_di) {
+ /* Doesn't exist in log tree, so delete it. */
+ btrfs_release_path(path);
+ di = btrfs_lookup_xattr(trans, root, path, ino,
+ name, name_len, -1);
+ kfree(name);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto out;
+ }
+ ASSERT(di);
+ ret = btrfs_delete_one_dir_name(trans, root,
+ path, di);
+ if (ret)
+ goto out;
+ btrfs_release_path(path);
+ search_key = key;
+ goto again;
+ }
+ kfree(name);
+ if (IS_ERR(log_di)) {
+ ret = PTR_ERR(log_di);
+ goto out;
+ }
+ cur += this_len;
+ di = (struct btrfs_dir_item *)((char *)di + this_len);
+ }
+ }
+ ret = btrfs_next_leaf(root, path);
+ if (ret > 0)
+ ret = 0;
+ else if (ret == 0)
+ goto process_leaf;
+out:
+ btrfs_free_path(log_path);
+ btrfs_release_path(path);
+ return ret;
+}
+
+
+/*
+ * deletion replay happens before we copy any new directory items
+ * out of the log or out of backreferences from inodes. It
+ * scans the log to find ranges of keys that log is authoritative for,
+ * and then scans the directory to find items in those ranges that are
+ * not present in the log.
+ *
+ * Anything we don't find in the log is unlinked and removed from the
+ * directory.
+ */
+static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ u64 dirid, int del_all)
+{
+ u64 range_start;
+ u64 range_end;
+ int ret = 0;
+ struct btrfs_key dir_key;
+ struct btrfs_key found_key;
+ struct btrfs_path *log_path;
+ struct inode *dir;
+
+ dir_key.objectid = dirid;
+ dir_key.type = BTRFS_DIR_INDEX_KEY;
+ log_path = btrfs_alloc_path();
+ if (!log_path)
+ return -ENOMEM;
+
+ dir = read_one_inode(root, dirid);
+ /* it isn't an error if the inode isn't there, that can happen
+ * because we replay the deletes before we copy in the inode item
+ * from the log
+ */
+ if (!dir) {
+ btrfs_free_path(log_path);
+ return 0;
+ }
+
+ range_start = 0;
+ range_end = 0;
+ while (1) {
+ if (del_all)
+ range_end = (u64)-1;
+ else {
+ ret = find_dir_range(log, path, dirid,
+ &range_start, &range_end);
+ if (ret < 0)
+ goto out;
+ else if (ret > 0)
+ break;
+ }
+
+ dir_key.offset = range_start;
+ while (1) {
+ int nritems;
+ ret = btrfs_search_slot(NULL, root, &dir_key, path,
+ 0, 0);
+ if (ret < 0)
+ goto out;
+
+ nritems = btrfs_header_nritems(path->nodes[0]);
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 1)
+ break;
+ else if (ret < 0)
+ goto out;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+ if (found_key.objectid != dirid ||
+ found_key.type != dir_key.type) {
+ ret = 0;
+ goto out;
+ }
+
+ if (found_key.offset > range_end)
+ break;
+
+ ret = check_item_in_log(trans, log, path,
+ log_path, dir,
+ &found_key);
+ if (ret)
+ goto out;
+ if (found_key.offset == (u64)-1)
+ break;
+ dir_key.offset = found_key.offset + 1;
+ }
+ btrfs_release_path(path);
+ if (range_end == (u64)-1)
+ break;
+ range_start = range_end + 1;
+ }
+ ret = 0;
+out:
+ btrfs_release_path(path);
+ btrfs_free_path(log_path);
+ iput(dir);
+ return ret;
+}
+
+/*
+ * the process_func used to replay items from the log tree. This
+ * gets called in two different stages. The first stage just looks
+ * for inodes and makes sure they are all copied into the subvolume.
+ *
+ * The second stage copies all the other item types from the log into
+ * the subvolume. The two stage approach is slower, but gets rid of
+ * lots of complexity around inodes referencing other inodes that exist
+ * only in the log (references come from either directory items or inode
+ * back refs).
+ */
+static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
+ struct walk_control *wc, u64 gen, int level)
+{
+ int nritems;
+ struct btrfs_path *path;
+ struct btrfs_root *root = wc->replay_dest;
+ struct btrfs_key key;
+ int i;
+ int ret;
+
+ ret = btrfs_read_extent_buffer(eb, gen, level, NULL);
+ if (ret)
+ return ret;
+
+ level = btrfs_header_level(eb);
+
+ if (level != 0)
+ return 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ nritems = btrfs_header_nritems(eb);
+ for (i = 0; i < nritems; i++) {
+ btrfs_item_key_to_cpu(eb, &key, i);
+
+ /* inode keys are done during the first stage */
+ if (key.type == BTRFS_INODE_ITEM_KEY &&
+ wc->stage == LOG_WALK_REPLAY_INODES) {
+ struct btrfs_inode_item *inode_item;
+ u32 mode;
+
+ inode_item = btrfs_item_ptr(eb, i,
+ struct btrfs_inode_item);
+ /*
+ * If we have a tmpfile (O_TMPFILE) that got fsync'ed
+ * and never got linked before the fsync, skip it, as
+ * replaying it is pointless since it would be deleted
+ * later. We skip logging tmpfiles, but it's always
+ * possible we are replaying a log created with a kernel
+ * that used to log tmpfiles.
+ */
+ if (btrfs_inode_nlink(eb, inode_item) == 0) {
+ wc->ignore_cur_inode = true;
+ continue;
+ } else {
+ wc->ignore_cur_inode = false;
+ }
+ ret = replay_xattr_deletes(wc->trans, root, log,
+ path, key.objectid);
+ if (ret)
+ break;
+ mode = btrfs_inode_mode(eb, inode_item);
+ if (S_ISDIR(mode)) {
+ ret = replay_dir_deletes(wc->trans,
+ root, log, path, key.objectid, 0);
+ if (ret)
+ break;
+ }
+ ret = overwrite_item(wc->trans, root, path,
+ eb, i, &key);
+ if (ret)
+ break;
+
+ /*
+ * Before replaying extents, truncate the inode to its
+ * size. We need to do it now and not after log replay
+ * because before an fsync we can have prealloc extents
+ * added beyond the inode's i_size. If we did it after,
+ * through orphan cleanup for example, we would drop
+ * those prealloc extents just after replaying them.
+ */
+ if (S_ISREG(mode)) {
+ struct btrfs_drop_extents_args drop_args = { 0 };
+ struct inode *inode;
+ u64 from;
+
+ inode = read_one_inode(root, key.objectid);
+ if (!inode) {
+ ret = -EIO;
+ break;
+ }
+ from = ALIGN(i_size_read(inode),
+ root->fs_info->sectorsize);
+ drop_args.start = from;
+ drop_args.end = (u64)-1;
+ drop_args.drop_cache = true;
+ ret = btrfs_drop_extents(wc->trans, root,
+ BTRFS_I(inode),
+ &drop_args);
+ if (!ret) {
+ inode_sub_bytes(inode,
+ drop_args.bytes_found);
+ /* Update the inode's nbytes. */
+ ret = btrfs_update_inode(wc->trans,
+ root, BTRFS_I(inode));
+ }
+ iput(inode);
+ if (ret)
+ break;
+ }
+
+ ret = link_to_fixup_dir(wc->trans, root,
+ path, key.objectid);
+ if (ret)
+ break;
+ }
+
+ if (wc->ignore_cur_inode)
+ continue;
+
+ if (key.type == BTRFS_DIR_INDEX_KEY &&
+ wc->stage == LOG_WALK_REPLAY_DIR_INDEX) {
+ ret = replay_one_dir_item(wc->trans, root, path,
+ eb, i, &key);
+ if (ret)
+ break;
+ }
+
+ if (wc->stage < LOG_WALK_REPLAY_ALL)
+ continue;
+
+ /* these keys are simply copied */
+ if (key.type == BTRFS_XATTR_ITEM_KEY) {
+ ret = overwrite_item(wc->trans, root, path,
+ eb, i, &key);
+ if (ret)
+ break;
+ } else if (key.type == BTRFS_INODE_REF_KEY ||
+ key.type == BTRFS_INODE_EXTREF_KEY) {
+ ret = add_inode_ref(wc->trans, root, log, path,
+ eb, i, &key);
+ if (ret && ret != -ENOENT)
+ break;
+ ret = 0;
+ } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
+ ret = replay_one_extent(wc->trans, root, path,
+ eb, i, &key);
+ if (ret)
+ break;
+ }
+ /*
+ * We don't log BTRFS_DIR_ITEM_KEY keys anymore, only the
+ * BTRFS_DIR_INDEX_KEY items which we use to derive the
+ * BTRFS_DIR_ITEM_KEY items. If we are replaying a log from an
+ * older kernel with such keys, ignore them.
+ */
+ }
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * Correctly adjust the reserved bytes occupied by a log tree extent buffer
+ */
+static void unaccount_log_buffer(struct btrfs_fs_info *fs_info, u64 start)
+{
+ struct btrfs_block_group *cache;
+
+ cache = btrfs_lookup_block_group(fs_info, start);
+ if (!cache) {
+ btrfs_err(fs_info, "unable to find block group for %llu", start);
+ return;
+ }
+
+ spin_lock(&cache->space_info->lock);
+ spin_lock(&cache->lock);
+ cache->reserved -= fs_info->nodesize;
+ cache->space_info->bytes_reserved -= fs_info->nodesize;
+ spin_unlock(&cache->lock);
+ spin_unlock(&cache->space_info->lock);
+
+ btrfs_put_block_group(cache);
+}
+
+static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int *level,
+ struct walk_control *wc)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ u64 bytenr;
+ u64 ptr_gen;
+ struct extent_buffer *next;
+ struct extent_buffer *cur;
+ u32 blocksize;
+ int ret = 0;
+
+ while (*level > 0) {
+ struct btrfs_key first_key;
+
+ cur = path->nodes[*level];
+
+ WARN_ON(btrfs_header_level(cur) != *level);
+
+ if (path->slots[*level] >=
+ btrfs_header_nritems(cur))
+ break;
+
+ bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
+ ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
+ btrfs_node_key_to_cpu(cur, &first_key, path->slots[*level]);
+ blocksize = fs_info->nodesize;
+
+ next = btrfs_find_create_tree_block(fs_info, bytenr,
+ btrfs_header_owner(cur),
+ *level - 1);
+ if (IS_ERR(next))
+ return PTR_ERR(next);
+
+ if (*level == 1) {
+ ret = wc->process_func(root, next, wc, ptr_gen,
+ *level - 1);
+ if (ret) {
+ free_extent_buffer(next);
+ return ret;
+ }
+
+ path->slots[*level]++;
+ if (wc->free) {
+ ret = btrfs_read_extent_buffer(next, ptr_gen,
+ *level - 1, &first_key);
+ if (ret) {
+ free_extent_buffer(next);
+ return ret;
+ }
+
+ if (trans) {
+ btrfs_tree_lock(next);
+ btrfs_clean_tree_block(next);
+ btrfs_wait_tree_block_writeback(next);
+ btrfs_tree_unlock(next);
+ ret = btrfs_pin_reserved_extent(trans,
+ bytenr, blocksize);
+ if (ret) {
+ free_extent_buffer(next);
+ return ret;
+ }
+ btrfs_redirty_list_add(
+ trans->transaction, next);
+ } else {
+ if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
+ clear_extent_buffer_dirty(next);
+ unaccount_log_buffer(fs_info, bytenr);
+ }
+ }
+ free_extent_buffer(next);
+ continue;
+ }
+ ret = btrfs_read_extent_buffer(next, ptr_gen, *level - 1, &first_key);
+ if (ret) {
+ free_extent_buffer(next);
+ return ret;
+ }
+
+ if (path->nodes[*level-1])
+ free_extent_buffer(path->nodes[*level-1]);
+ path->nodes[*level-1] = next;
+ *level = btrfs_header_level(next);
+ path->slots[*level] = 0;
+ cond_resched();
+ }
+ path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
+
+ cond_resched();
+ return 0;
+}
+
+static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, int *level,
+ struct walk_control *wc)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ int i;
+ int slot;
+ int ret;
+
+ for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
+ slot = path->slots[i];
+ if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
+ path->slots[i]++;
+ *level = i;
+ WARN_ON(*level == 0);
+ return 0;
+ } else {
+ ret = wc->process_func(root, path->nodes[*level], wc,
+ btrfs_header_generation(path->nodes[*level]),
+ *level);
+ if (ret)
+ return ret;
+
+ if (wc->free) {
+ struct extent_buffer *next;
+
+ next = path->nodes[*level];
+
+ if (trans) {
+ btrfs_tree_lock(next);
+ btrfs_clean_tree_block(next);
+ btrfs_wait_tree_block_writeback(next);
+ btrfs_tree_unlock(next);
+ ret = btrfs_pin_reserved_extent(trans,
+ path->nodes[*level]->start,
+ path->nodes[*level]->len);
+ if (ret)
+ return ret;
+ btrfs_redirty_list_add(trans->transaction,
+ next);
+ } else {
+ if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
+ clear_extent_buffer_dirty(next);
+
+ unaccount_log_buffer(fs_info,
+ path->nodes[*level]->start);
+ }
+ }
+ free_extent_buffer(path->nodes[*level]);
+ path->nodes[*level] = NULL;
+ *level = i + 1;
+ }
+ }
+ return 1;
+}
+
+/*
+ * drop the reference count on the tree rooted at 'snap'. This traverses
+ * the tree freeing any blocks that have a ref count of zero after being
+ * decremented.
+ */
+static int walk_log_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log, struct walk_control *wc)
+{
+ struct btrfs_fs_info *fs_info = log->fs_info;
+ int ret = 0;
+ int wret;
+ int level;
+ struct btrfs_path *path;
+ int orig_level;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ level = btrfs_header_level(log->node);
+ orig_level = level;
+ path->nodes[level] = log->node;
+ atomic_inc(&log->node->refs);
+ path->slots[level] = 0;
+
+ while (1) {
+ wret = walk_down_log_tree(trans, log, path, &level, wc);
+ if (wret > 0)
+ break;
+ if (wret < 0) {
+ ret = wret;
+ goto out;
+ }
+
+ wret = walk_up_log_tree(trans, log, path, &level, wc);
+ if (wret > 0)
+ break;
+ if (wret < 0) {
+ ret = wret;
+ goto out;
+ }
+ }
+
+ /* was the root node processed? if not, catch it here */
+ if (path->nodes[orig_level]) {
+ ret = wc->process_func(log, path->nodes[orig_level], wc,
+ btrfs_header_generation(path->nodes[orig_level]),
+ orig_level);
+ if (ret)
+ goto out;
+ if (wc->free) {
+ struct extent_buffer *next;
+
+ next = path->nodes[orig_level];
+
+ if (trans) {
+ btrfs_tree_lock(next);
+ btrfs_clean_tree_block(next);
+ btrfs_wait_tree_block_writeback(next);
+ btrfs_tree_unlock(next);
+ ret = btrfs_pin_reserved_extent(trans,
+ next->start, next->len);
+ if (ret)
+ goto out;
+ btrfs_redirty_list_add(trans->transaction, next);
+ } else {
+ if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
+ clear_extent_buffer_dirty(next);
+ unaccount_log_buffer(fs_info, next->start);
+ }
+ }
+ }
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * helper function to update the item for a given subvolumes log root
+ * in the tree of log roots
+ */
+static int update_log_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log,
+ struct btrfs_root_item *root_item)
+{
+ struct btrfs_fs_info *fs_info = log->fs_info;
+ int ret;
+
+ if (log->log_transid == 1) {
+ /* insert root item on the first sync */
+ ret = btrfs_insert_root(trans, fs_info->log_root_tree,
+ &log->root_key, root_item);
+ } else {
+ ret = btrfs_update_root(trans, fs_info->log_root_tree,
+ &log->root_key, root_item);
+ }
+ return ret;
+}
+
+static void wait_log_commit(struct btrfs_root *root, int transid)
+{
+ DEFINE_WAIT(wait);
+ int index = transid % 2;
+
+ /*
+ * we only allow two pending log transactions at a time,
+ * so we know that if ours is more than 2 older than the
+ * current transaction, we're done
+ */
+ for (;;) {
+ prepare_to_wait(&root->log_commit_wait[index],
+ &wait, TASK_UNINTERRUPTIBLE);
+
+ if (!(root->log_transid_committed < transid &&
+ atomic_read(&root->log_commit[index])))
+ break;
+
+ mutex_unlock(&root->log_mutex);
+ schedule();
+ mutex_lock(&root->log_mutex);
+ }
+ finish_wait(&root->log_commit_wait[index], &wait);
+}
+
+static void wait_for_writer(struct btrfs_root *root)
+{
+ DEFINE_WAIT(wait);
+
+ for (;;) {
+ prepare_to_wait(&root->log_writer_wait, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (!atomic_read(&root->log_writers))
+ break;
+
+ mutex_unlock(&root->log_mutex);
+ schedule();
+ mutex_lock(&root->log_mutex);
+ }
+ finish_wait(&root->log_writer_wait, &wait);
+}
+
+static inline void btrfs_remove_log_ctx(struct btrfs_root *root,
+ struct btrfs_log_ctx *ctx)
+{
+ mutex_lock(&root->log_mutex);
+ list_del_init(&ctx->list);
+ mutex_unlock(&root->log_mutex);
+}
+
+/*
+ * Invoked in log mutex context, or be sure there is no other task which
+ * can access the list.
+ */
+static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root,
+ int index, int error)
+{
+ struct btrfs_log_ctx *ctx;
+ struct btrfs_log_ctx *safe;
+
+ list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) {
+ list_del_init(&ctx->list);
+ ctx->log_ret = error;
+ }
+}
+
+/*
+ * btrfs_sync_log does sends a given tree log down to the disk and
+ * updates the super blocks to record it. When this call is done,
+ * you know that any inodes previously logged are safely on disk only
+ * if it returns 0.
+ *
+ * Any other return value means you need to call btrfs_commit_transaction.
+ * Some of the edge cases for fsyncing directories that have had unlinks
+ * or renames done in the past mean that sometimes the only safe
+ * fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN,
+ * that has happened.
+ */
+int btrfs_sync_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_log_ctx *ctx)
+{
+ int index1;
+ int index2;
+ int mark;
+ int ret;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_root *log = root->log_root;
+ struct btrfs_root *log_root_tree = fs_info->log_root_tree;
+ struct btrfs_root_item new_root_item;
+ int log_transid = 0;
+ struct btrfs_log_ctx root_log_ctx;
+ struct blk_plug plug;
+ u64 log_root_start;
+ u64 log_root_level;
+
+ mutex_lock(&root->log_mutex);
+ log_transid = ctx->log_transid;
+ if (root->log_transid_committed >= log_transid) {
+ mutex_unlock(&root->log_mutex);
+ return ctx->log_ret;
+ }
+
+ index1 = log_transid % 2;
+ if (atomic_read(&root->log_commit[index1])) {
+ wait_log_commit(root, log_transid);
+ mutex_unlock(&root->log_mutex);
+ return ctx->log_ret;
+ }
+ ASSERT(log_transid == root->log_transid);
+ atomic_set(&root->log_commit[index1], 1);
+
+ /* wait for previous tree log sync to complete */
+ if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
+ wait_log_commit(root, log_transid - 1);
+
+ while (1) {
+ int batch = atomic_read(&root->log_batch);
+ /* when we're on an ssd, just kick the log commit out */
+ if (!btrfs_test_opt(fs_info, SSD) &&
+ test_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state)) {
+ mutex_unlock(&root->log_mutex);
+ schedule_timeout_uninterruptible(1);
+ mutex_lock(&root->log_mutex);
+ }
+ wait_for_writer(root);
+ if (batch == atomic_read(&root->log_batch))
+ break;
+ }
+
+ /* bail out if we need to do a full commit */
+ if (btrfs_need_log_full_commit(trans)) {
+ ret = BTRFS_LOG_FORCE_COMMIT;
+ mutex_unlock(&root->log_mutex);
+ goto out;
+ }
+
+ if (log_transid % 2 == 0)
+ mark = EXTENT_DIRTY;
+ else
+ mark = EXTENT_NEW;
+
+ /* we start IO on all the marked extents here, but we don't actually
+ * wait for them until later.
+ */
+ blk_start_plug(&plug);
+ ret = btrfs_write_marked_extents(fs_info, &log->dirty_log_pages, mark);
+ /*
+ * -EAGAIN happens when someone, e.g., a concurrent transaction
+ * commit, writes a dirty extent in this tree-log commit. This
+ * concurrent write will create a hole writing out the extents,
+ * and we cannot proceed on a zoned filesystem, requiring
+ * sequential writing. While we can bail out to a full commit
+ * here, but we can continue hoping the concurrent writing fills
+ * the hole.
+ */
+ if (ret == -EAGAIN && btrfs_is_zoned(fs_info))
+ ret = 0;
+ if (ret) {
+ blk_finish_plug(&plug);
+ btrfs_set_log_full_commit(trans);
+ mutex_unlock(&root->log_mutex);
+ goto out;
+ }
+
+ /*
+ * We _must_ update under the root->log_mutex in order to make sure we
+ * have a consistent view of the log root we are trying to commit at
+ * this moment.
+ *
+ * We _must_ copy this into a local copy, because we are not holding the
+ * log_root_tree->log_mutex yet. This is important because when we
+ * commit the log_root_tree we must have a consistent view of the
+ * log_root_tree when we update the super block to point at the
+ * log_root_tree bytenr. If we update the log_root_tree here we'll race
+ * with the commit and possibly point at the new block which we may not
+ * have written out.
+ */
+ btrfs_set_root_node(&log->root_item, log->node);
+ memcpy(&new_root_item, &log->root_item, sizeof(new_root_item));
+
+ root->log_transid++;
+ log->log_transid = root->log_transid;
+ root->log_start_pid = 0;
+ /*
+ * IO has been started, blocks of the log tree have WRITTEN flag set
+ * in their headers. new modifications of the log will be written to
+ * new positions. so it's safe to allow log writers to go in.
+ */
+ mutex_unlock(&root->log_mutex);
+
+ if (btrfs_is_zoned(fs_info)) {
+ mutex_lock(&fs_info->tree_root->log_mutex);
+ if (!log_root_tree->node) {
+ ret = btrfs_alloc_log_tree_node(trans, log_root_tree);
+ if (ret) {
+ mutex_unlock(&fs_info->tree_root->log_mutex);
+ blk_finish_plug(&plug);
+ goto out;
+ }
+ }
+ mutex_unlock(&fs_info->tree_root->log_mutex);
+ }
+
+ btrfs_init_log_ctx(&root_log_ctx, NULL);
+
+ mutex_lock(&log_root_tree->log_mutex);
+
+ index2 = log_root_tree->log_transid % 2;
+ list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]);
+ root_log_ctx.log_transid = log_root_tree->log_transid;
+
+ /*
+ * Now we are safe to update the log_root_tree because we're under the
+ * log_mutex, and we're a current writer so we're holding the commit
+ * open until we drop the log_mutex.
+ */
+ ret = update_log_root(trans, log, &new_root_item);
+ if (ret) {
+ if (!list_empty(&root_log_ctx.list))
+ list_del_init(&root_log_ctx.list);
+
+ blk_finish_plug(&plug);
+ btrfs_set_log_full_commit(trans);
+ if (ret != -ENOSPC)
+ btrfs_err(fs_info,
+ "failed to update log for root %llu ret %d",
+ root->root_key.objectid, ret);
+ btrfs_wait_tree_log_extents(log, mark);
+ mutex_unlock(&log_root_tree->log_mutex);
+ goto out;
+ }
+
+ if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) {
+ blk_finish_plug(&plug);
+ list_del_init(&root_log_ctx.list);
+ mutex_unlock(&log_root_tree->log_mutex);
+ ret = root_log_ctx.log_ret;
+ goto out;
+ }
+
+ index2 = root_log_ctx.log_transid % 2;
+ if (atomic_read(&log_root_tree->log_commit[index2])) {
+ blk_finish_plug(&plug);
+ ret = btrfs_wait_tree_log_extents(log, mark);
+ wait_log_commit(log_root_tree,
+ root_log_ctx.log_transid);
+ mutex_unlock(&log_root_tree->log_mutex);
+ if (!ret)
+ ret = root_log_ctx.log_ret;
+ goto out;
+ }
+ ASSERT(root_log_ctx.log_transid == log_root_tree->log_transid);
+ atomic_set(&log_root_tree->log_commit[index2], 1);
+
+ if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
+ wait_log_commit(log_root_tree,
+ root_log_ctx.log_transid - 1);
+ }
+
+ /*
+ * now that we've moved on to the tree of log tree roots,
+ * check the full commit flag again
+ */
+ if (btrfs_need_log_full_commit(trans)) {
+ blk_finish_plug(&plug);
+ btrfs_wait_tree_log_extents(log, mark);
+ mutex_unlock(&log_root_tree->log_mutex);
+ ret = BTRFS_LOG_FORCE_COMMIT;
+ goto out_wake_log_root;
+ }
+
+ ret = btrfs_write_marked_extents(fs_info,
+ &log_root_tree->dirty_log_pages,
+ EXTENT_DIRTY | EXTENT_NEW);
+ blk_finish_plug(&plug);
+ /*
+ * As described above, -EAGAIN indicates a hole in the extents. We
+ * cannot wait for these write outs since the waiting cause a
+ * deadlock. Bail out to the full commit instead.
+ */
+ if (ret == -EAGAIN && btrfs_is_zoned(fs_info)) {
+ btrfs_set_log_full_commit(trans);
+ btrfs_wait_tree_log_extents(log, mark);
+ mutex_unlock(&log_root_tree->log_mutex);
+ goto out_wake_log_root;
+ } else if (ret) {
+ btrfs_set_log_full_commit(trans);
+ mutex_unlock(&log_root_tree->log_mutex);
+ goto out_wake_log_root;
+ }
+ ret = btrfs_wait_tree_log_extents(log, mark);
+ if (!ret)
+ ret = btrfs_wait_tree_log_extents(log_root_tree,
+ EXTENT_NEW | EXTENT_DIRTY);
+ if (ret) {
+ btrfs_set_log_full_commit(trans);
+ mutex_unlock(&log_root_tree->log_mutex);
+ goto out_wake_log_root;
+ }
+
+ log_root_start = log_root_tree->node->start;
+ log_root_level = btrfs_header_level(log_root_tree->node);
+ log_root_tree->log_transid++;
+ mutex_unlock(&log_root_tree->log_mutex);
+
+ /*
+ * Here we are guaranteed that nobody is going to write the superblock
+ * for the current transaction before us and that neither we do write
+ * our superblock before the previous transaction finishes its commit
+ * and writes its superblock, because:
+ *
+ * 1) We are holding a handle on the current transaction, so no body
+ * can commit it until we release the handle;
+ *
+ * 2) Before writing our superblock we acquire the tree_log_mutex, so
+ * if the previous transaction is still committing, and hasn't yet
+ * written its superblock, we wait for it to do it, because a
+ * transaction commit acquires the tree_log_mutex when the commit
+ * begins and releases it only after writing its superblock.
+ */
+ mutex_lock(&fs_info->tree_log_mutex);
+
+ /*
+ * The previous transaction writeout phase could have failed, and thus
+ * marked the fs in an error state. We must not commit here, as we
+ * could have updated our generation in the super_for_commit and
+ * writing the super here would result in transid mismatches. If there
+ * is an error here just bail.
+ */
+ if (BTRFS_FS_ERROR(fs_info)) {
+ ret = -EIO;
+ btrfs_set_log_full_commit(trans);
+ btrfs_abort_transaction(trans, ret);
+ mutex_unlock(&fs_info->tree_log_mutex);
+ goto out_wake_log_root;
+ }
+
+ btrfs_set_super_log_root(fs_info->super_for_commit, log_root_start);
+ btrfs_set_super_log_root_level(fs_info->super_for_commit, log_root_level);
+ ret = write_all_supers(fs_info, 1);
+ mutex_unlock(&fs_info->tree_log_mutex);
+ if (ret) {
+ btrfs_set_log_full_commit(trans);
+ btrfs_abort_transaction(trans, ret);
+ goto out_wake_log_root;
+ }
+
+ /*
+ * We know there can only be one task here, since we have not yet set
+ * root->log_commit[index1] to 0 and any task attempting to sync the
+ * log must wait for the previous log transaction to commit if it's
+ * still in progress or wait for the current log transaction commit if
+ * someone else already started it. We use <= and not < because the
+ * first log transaction has an ID of 0.
+ */
+ ASSERT(root->last_log_commit <= log_transid);
+ root->last_log_commit = log_transid;
+
+out_wake_log_root:
+ mutex_lock(&log_root_tree->log_mutex);
+ btrfs_remove_all_log_ctxs(log_root_tree, index2, ret);
+
+ log_root_tree->log_transid_committed++;
+ atomic_set(&log_root_tree->log_commit[index2], 0);
+ mutex_unlock(&log_root_tree->log_mutex);
+
+ /*
+ * The barrier before waitqueue_active (in cond_wake_up) is needed so
+ * all the updates above are seen by the woken threads. It might not be
+ * necessary, but proving that seems to be hard.
+ */
+ cond_wake_up(&log_root_tree->log_commit_wait[index2]);
+out:
+ mutex_lock(&root->log_mutex);
+ btrfs_remove_all_log_ctxs(root, index1, ret);
+ root->log_transid_committed++;
+ atomic_set(&root->log_commit[index1], 0);
+ mutex_unlock(&root->log_mutex);
+
+ /*
+ * The barrier before waitqueue_active (in cond_wake_up) is needed so
+ * all the updates above are seen by the woken threads. It might not be
+ * necessary, but proving that seems to be hard.
+ */
+ cond_wake_up(&root->log_commit_wait[index1]);
+ return ret;
+}
+
+static void free_log_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log)
+{
+ int ret;
+ struct walk_control wc = {
+ .free = 1,
+ .process_func = process_one_buffer
+ };
+
+ if (log->node) {
+ ret = walk_log_tree(trans, log, &wc);
+ if (ret) {
+ /*
+ * We weren't able to traverse the entire log tree, the
+ * typical scenario is getting an -EIO when reading an
+ * extent buffer of the tree, due to a previous writeback
+ * failure of it.
+ */
+ set_bit(BTRFS_FS_STATE_LOG_CLEANUP_ERROR,
+ &log->fs_info->fs_state);
+
+ /*
+ * Some extent buffers of the log tree may still be dirty
+ * and not yet written back to storage, because we may
+ * have updates to a log tree without syncing a log tree,
+ * such as during rename and link operations. So flush
+ * them out and wait for their writeback to complete, so
+ * that we properly cleanup their state and pages.
+ */
+ btrfs_write_marked_extents(log->fs_info,
+ &log->dirty_log_pages,
+ EXTENT_DIRTY | EXTENT_NEW);
+ btrfs_wait_tree_log_extents(log,
+ EXTENT_DIRTY | EXTENT_NEW);
+
+ if (trans)
+ btrfs_abort_transaction(trans, ret);
+ else
+ btrfs_handle_fs_error(log->fs_info, ret, NULL);
+ }
+ }
+
+ clear_extent_bits(&log->dirty_log_pages, 0, (u64)-1,
+ EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT);
+ extent_io_tree_release(&log->log_csum_range);
+
+ btrfs_put_root(log);
+}
+
+/*
+ * free all the extents used by the tree log. This should be called
+ * at commit time of the full transaction
+ */
+int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
+{
+ if (root->log_root) {
+ free_log_tree(trans, root->log_root);
+ root->log_root = NULL;
+ clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state);
+ }
+ return 0;
+}
+
+int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info)
+{
+ if (fs_info->log_root_tree) {
+ free_log_tree(trans, fs_info->log_root_tree);
+ fs_info->log_root_tree = NULL;
+ clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &fs_info->tree_root->state);
+ }
+ return 0;
+}
+
+/*
+ * Check if an inode was logged in the current transaction. This correctly deals
+ * with the case where the inode was logged but has a logged_trans of 0, which
+ * happens if the inode is evicted and loaded again, as logged_trans is an in
+ * memory only field (not persisted).
+ *
+ * Returns 1 if the inode was logged before in the transaction, 0 if it was not,
+ * and < 0 on error.
+ */
+static int inode_logged(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path_in)
+{
+ struct btrfs_path *path = path_in;
+ struct btrfs_key key;
+ int ret;
+
+ if (inode->logged_trans == trans->transid)
+ return 1;
+
+ /*
+ * If logged_trans is not 0, then we know the inode logged was not logged
+ * in this transaction, so we can return false right away.
+ */
+ if (inode->logged_trans > 0)
+ return 0;
+
+ /*
+ * If no log tree was created for this root in this transaction, then
+ * the inode can not have been logged in this transaction. In that case
+ * set logged_trans to anything greater than 0 and less than the current
+ * transaction's ID, to avoid the search below in a future call in case
+ * a log tree gets created after this.
+ */
+ if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &inode->root->state)) {
+ inode->logged_trans = trans->transid - 1;
+ return 0;
+ }
+
+ /*
+ * We have a log tree and the inode's logged_trans is 0. We can't tell
+ * for sure if the inode was logged before in this transaction by looking
+ * only at logged_trans. We could be pessimistic and assume it was, but
+ * that can lead to unnecessarily logging an inode during rename and link
+ * operations, and then further updating the log in followup rename and
+ * link operations, specially if it's a directory, which adds latency
+ * visible to applications doing a series of rename or link operations.
+ *
+ * A logged_trans of 0 here can mean several things:
+ *
+ * 1) The inode was never logged since the filesystem was mounted, and may
+ * or may have not been evicted and loaded again;
+ *
+ * 2) The inode was logged in a previous transaction, then evicted and
+ * then loaded again;
+ *
+ * 3) The inode was logged in the current transaction, then evicted and
+ * then loaded again.
+ *
+ * For cases 1) and 2) we don't want to return true, but we need to detect
+ * case 3) and return true. So we do a search in the log root for the inode
+ * item.
+ */
+ key.objectid = btrfs_ino(inode);
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+
+ if (!path) {
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ }
+
+ ret = btrfs_search_slot(NULL, inode->root->log_root, &key, path, 0, 0);
+
+ if (path_in)
+ btrfs_release_path(path);
+ else
+ btrfs_free_path(path);
+
+ /*
+ * Logging an inode always results in logging its inode item. So if we
+ * did not find the item we know the inode was not logged for sure.
+ */
+ if (ret < 0) {
+ return ret;
+ } else if (ret > 0) {
+ /*
+ * Set logged_trans to a value greater than 0 and less then the
+ * current transaction to avoid doing the search in future calls.
+ */
+ inode->logged_trans = trans->transid - 1;
+ return 0;
+ }
+
+ /*
+ * The inode was previously logged and then evicted, set logged_trans to
+ * the current transacion's ID, to avoid future tree searches as long as
+ * the inode is not evicted again.
+ */
+ inode->logged_trans = trans->transid;
+
+ /*
+ * If it's a directory, then we must set last_dir_index_offset to the
+ * maximum possible value, so that the next attempt to log the inode does
+ * not skip checking if dir index keys found in modified subvolume tree
+ * leaves have been logged before, otherwise it would result in attempts
+ * to insert duplicate dir index keys in the log tree. This must be done
+ * because last_dir_index_offset is an in-memory only field, not persisted
+ * in the inode item or any other on-disk structure, so its value is lost
+ * once the inode is evicted.
+ */
+ if (S_ISDIR(inode->vfs_inode.i_mode))
+ inode->last_dir_index_offset = (u64)-1;
+
+ return 1;
+}
+
+/*
+ * Delete a directory entry from the log if it exists.
+ *
+ * Returns < 0 on error
+ * 1 if the entry does not exists
+ * 0 if the entry existed and was successfully deleted
+ */
+static int del_logged_dentry(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ u64 dir_ino,
+ const struct fscrypt_str *name,
+ u64 index)
+{
+ struct btrfs_dir_item *di;
+
+ /*
+ * We only log dir index items of a directory, so we don't need to look
+ * for dir item keys.
+ */
+ di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
+ index, name, -1);
+ if (IS_ERR(di))
+ return PTR_ERR(di);
+ else if (!di)
+ return 1;
+
+ /*
+ * We do not need to update the size field of the directory's
+ * inode item because on log replay we update the field to reflect
+ * all existing entries in the directory (see overwrite_item()).
+ */
+ return btrfs_delete_one_dir_name(trans, log, path, di);
+}
+
+/*
+ * If both a file and directory are logged, and unlinks or renames are
+ * mixed in, we have a few interesting corners:
+ *
+ * create file X in dir Y
+ * link file X to X.link in dir Y
+ * fsync file X
+ * unlink file X but leave X.link
+ * fsync dir Y
+ *
+ * After a crash we would expect only X.link to exist. But file X
+ * didn't get fsync'd again so the log has back refs for X and X.link.
+ *
+ * We solve this by removing directory entries and inode backrefs from the
+ * log when a file that was logged in the current transaction is
+ * unlinked. Any later fsync will include the updated log entries, and
+ * we'll be able to reconstruct the proper directory items from backrefs.
+ *
+ * This optimizations allows us to avoid relogging the entire inode
+ * or the entire directory.
+ */
+void btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const struct fscrypt_str *name,
+ struct btrfs_inode *dir, u64 index)
+{
+ struct btrfs_path *path;
+ int ret;
+
+ ret = inode_logged(trans, dir, NULL);
+ if (ret == 0)
+ return;
+ else if (ret < 0) {
+ btrfs_set_log_full_commit(trans);
+ return;
+ }
+
+ ret = join_running_log_trans(root);
+ if (ret)
+ return;
+
+ mutex_lock(&dir->log_mutex);
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+
+ ret = del_logged_dentry(trans, root->log_root, path, btrfs_ino(dir),
+ name, index);
+ btrfs_free_path(path);
+out_unlock:
+ mutex_unlock(&dir->log_mutex);
+ if (ret < 0)
+ btrfs_set_log_full_commit(trans);
+ btrfs_end_log_trans(root);
+}
+
+/* see comments for btrfs_del_dir_entries_in_log */
+void btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ const struct fscrypt_str *name,
+ struct btrfs_inode *inode, u64 dirid)
+{
+ struct btrfs_root *log;
+ u64 index;
+ int ret;
+
+ ret = inode_logged(trans, inode, NULL);
+ if (ret == 0)
+ return;
+ else if (ret < 0) {
+ btrfs_set_log_full_commit(trans);
+ return;
+ }
+
+ ret = join_running_log_trans(root);
+ if (ret)
+ return;
+ log = root->log_root;
+ mutex_lock(&inode->log_mutex);
+
+ ret = btrfs_del_inode_ref(trans, log, name, btrfs_ino(inode),
+ dirid, &index);
+ mutex_unlock(&inode->log_mutex);
+ if (ret < 0 && ret != -ENOENT)
+ btrfs_set_log_full_commit(trans);
+ btrfs_end_log_trans(root);
+}
+
+/*
+ * creates a range item in the log for 'dirid'. first_offset and
+ * last_offset tell us which parts of the key space the log should
+ * be considered authoritative for.
+ */
+static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ u64 dirid,
+ u64 first_offset, u64 last_offset)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_dir_log_item *item;
+
+ key.objectid = dirid;
+ key.offset = first_offset;
+ key.type = BTRFS_DIR_LOG_INDEX_KEY;
+ ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
+ /*
+ * -EEXIST is fine and can happen sporadically when we are logging a
+ * directory and have concurrent insertions in the subvolume's tree for
+ * items from other inodes and that result in pushing off some dir items
+ * from one leaf to another in order to accommodate for the new items.
+ * This results in logging the same dir index range key.
+ */
+ if (ret && ret != -EEXIST)
+ return ret;
+
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_dir_log_item);
+ if (ret == -EEXIST) {
+ const u64 curr_end = btrfs_dir_log_end(path->nodes[0], item);
+
+ /*
+ * btrfs_del_dir_entries_in_log() might have been called during
+ * an unlink between the initial insertion of this key and the
+ * current update, or we might be logging a single entry deletion
+ * during a rename, so set the new last_offset to the max value.
+ */
+ last_offset = max(last_offset, curr_end);
+ }
+ btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ btrfs_release_path(path);
+ return 0;
+}
+
+static int flush_dir_items_batch(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct extent_buffer *src,
+ struct btrfs_path *dst_path,
+ int start_slot,
+ int count)
+{
+ struct btrfs_root *log = inode->root->log_root;
+ char *ins_data = NULL;
+ struct btrfs_item_batch batch;
+ struct extent_buffer *dst;
+ unsigned long src_offset;
+ unsigned long dst_offset;
+ u64 last_index;
+ struct btrfs_key key;
+ u32 item_size;
+ int ret;
+ int i;
+
+ ASSERT(count > 0);
+ batch.nr = count;
+
+ if (count == 1) {
+ btrfs_item_key_to_cpu(src, &key, start_slot);
+ item_size = btrfs_item_size(src, start_slot);
+ batch.keys = &key;
+ batch.data_sizes = &item_size;
+ batch.total_data_size = item_size;
+ } else {
+ struct btrfs_key *ins_keys;
+ u32 *ins_sizes;
+
+ ins_data = kmalloc(count * sizeof(u32) +
+ count * sizeof(struct btrfs_key), GFP_NOFS);
+ if (!ins_data)
+ return -ENOMEM;
+
+ ins_sizes = (u32 *)ins_data;
+ ins_keys = (struct btrfs_key *)(ins_data + count * sizeof(u32));
+ batch.keys = ins_keys;
+ batch.data_sizes = ins_sizes;
+ batch.total_data_size = 0;
+
+ for (i = 0; i < count; i++) {
+ const int slot = start_slot + i;
+
+ btrfs_item_key_to_cpu(src, &ins_keys[i], slot);
+ ins_sizes[i] = btrfs_item_size(src, slot);
+ batch.total_data_size += ins_sizes[i];
+ }
+ }
+
+ ret = btrfs_insert_empty_items(trans, log, dst_path, &batch);
+ if (ret)
+ goto out;
+
+ dst = dst_path->nodes[0];
+ /*
+ * Copy all the items in bulk, in a single copy operation. Item data is
+ * organized such that it's placed at the end of a leaf and from right
+ * to left. For example, the data for the second item ends at an offset
+ * that matches the offset where the data for the first item starts, the
+ * data for the third item ends at an offset that matches the offset
+ * where the data of the second items starts, and so on.
+ * Therefore our source and destination start offsets for copy match the
+ * offsets of the last items (highest slots).
+ */
+ dst_offset = btrfs_item_ptr_offset(dst, dst_path->slots[0] + count - 1);
+ src_offset = btrfs_item_ptr_offset(src, start_slot + count - 1);
+ copy_extent_buffer(dst, src, dst_offset, src_offset, batch.total_data_size);
+ btrfs_release_path(dst_path);
+
+ last_index = batch.keys[count - 1].offset;
+ ASSERT(last_index > inode->last_dir_index_offset);
+
+ /*
+ * If for some unexpected reason the last item's index is not greater
+ * than the last index we logged, warn and return an error to fallback
+ * to a transaction commit.
+ */
+ if (WARN_ON(last_index <= inode->last_dir_index_offset))
+ ret = -EUCLEAN;
+ else
+ inode->last_dir_index_offset = last_index;
+out:
+ kfree(ins_data);
+
+ return ret;
+}
+
+static int process_dir_items_leaf(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ struct btrfs_path *dst_path,
+ struct btrfs_log_ctx *ctx,
+ u64 *last_old_dentry_offset)
+{
+ struct btrfs_root *log = inode->root->log_root;
+ struct extent_buffer *src;
+ const int nritems = btrfs_header_nritems(path->nodes[0]);
+ const u64 ino = btrfs_ino(inode);
+ bool last_found = false;
+ int batch_start = 0;
+ int batch_size = 0;
+ int i;
+
+ /*
+ * We need to clone the leaf, release the read lock on it, and use the
+ * clone before modifying the log tree. See the comment at copy_items()
+ * about why we need to do this.
+ */
+ src = btrfs_clone_extent_buffer(path->nodes[0]);
+ if (!src)
+ return -ENOMEM;
+
+ i = path->slots[0];
+ btrfs_release_path(path);
+ path->nodes[0] = src;
+ path->slots[0] = i;
+
+ for (; i < nritems; i++) {
+ struct btrfs_dir_item *di;
+ struct btrfs_key key;
+ int ret;
+
+ btrfs_item_key_to_cpu(src, &key, i);
+
+ if (key.objectid != ino || key.type != BTRFS_DIR_INDEX_KEY) {
+ last_found = true;
+ break;
+ }
+
+ di = btrfs_item_ptr(src, i, struct btrfs_dir_item);
+
+ /*
+ * Skip ranges of items that consist only of dir item keys created
+ * in past transactions. However if we find a gap, we must log a
+ * dir index range item for that gap, so that index keys in that
+ * gap are deleted during log replay.
+ */
+ if (btrfs_dir_transid(src, di) < trans->transid) {
+ if (key.offset > *last_old_dentry_offset + 1) {
+ ret = insert_dir_log_key(trans, log, dst_path,
+ ino, *last_old_dentry_offset + 1,
+ key.offset - 1);
+ if (ret < 0)
+ return ret;
+ }
+
+ *last_old_dentry_offset = key.offset;
+ continue;
+ }
+
+ /* If we logged this dir index item before, we can skip it. */
+ if (key.offset <= inode->last_dir_index_offset)
+ continue;
+
+ /*
+ * We must make sure that when we log a directory entry, the
+ * corresponding inode, after log replay, has a matching link
+ * count. For example:
+ *
+ * touch foo
+ * mkdir mydir
+ * sync
+ * ln foo mydir/bar
+ * xfs_io -c "fsync" mydir
+ * <crash>
+ * <mount fs and log replay>
+ *
+ * Would result in a fsync log that when replayed, our file inode
+ * would have a link count of 1, but we get two directory entries
+ * pointing to the same inode. After removing one of the names,
+ * it would not be possible to remove the other name, which
+ * resulted always in stale file handle errors, and would not be
+ * possible to rmdir the parent directory, since its i_size could
+ * never be decremented to the value BTRFS_EMPTY_DIR_SIZE,
+ * resulting in -ENOTEMPTY errors.
+ */
+ if (!ctx->log_new_dentries) {
+ struct btrfs_key di_key;
+
+ btrfs_dir_item_key_to_cpu(src, di, &di_key);
+ if (di_key.type != BTRFS_ROOT_ITEM_KEY)
+ ctx->log_new_dentries = true;
+ }
+
+ if (batch_size == 0)
+ batch_start = i;
+ batch_size++;
+ }
+
+ if (batch_size > 0) {
+ int ret;
+
+ ret = flush_dir_items_batch(trans, inode, src, dst_path,
+ batch_start, batch_size);
+ if (ret < 0)
+ return ret;
+ }
+
+ return last_found ? 1 : 0;
+}
+
+/*
+ * log all the items included in the current transaction for a given
+ * directory. This also creates the range items in the log tree required
+ * to replay anything deleted before the fsync
+ */
+static noinline int log_dir_items(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ struct btrfs_path *dst_path,
+ struct btrfs_log_ctx *ctx,
+ u64 min_offset, u64 *last_offset_ret)
+{
+ struct btrfs_key min_key;
+ struct btrfs_root *root = inode->root;
+ struct btrfs_root *log = root->log_root;
+ int err = 0;
+ int ret;
+ u64 last_old_dentry_offset = min_offset - 1;
+ u64 last_offset = (u64)-1;
+ u64 ino = btrfs_ino(inode);
+
+ min_key.objectid = ino;
+ min_key.type = BTRFS_DIR_INDEX_KEY;
+ min_key.offset = min_offset;
+
+ ret = btrfs_search_forward(root, &min_key, path, trans->transid);
+
+ /*
+ * we didn't find anything from this transaction, see if there
+ * is anything at all
+ */
+ if (ret != 0 || min_key.objectid != ino ||
+ min_key.type != BTRFS_DIR_INDEX_KEY) {
+ min_key.objectid = ino;
+ min_key.type = BTRFS_DIR_INDEX_KEY;
+ min_key.offset = (u64)-1;
+ btrfs_release_path(path);
+ ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
+ if (ret < 0) {
+ btrfs_release_path(path);
+ return ret;
+ }
+ ret = btrfs_previous_item(root, path, ino, BTRFS_DIR_INDEX_KEY);
+
+ /* if ret == 0 there are items for this type,
+ * create a range to tell us the last key of this type.
+ * otherwise, there are no items in this directory after
+ * *min_offset, and we create a range to indicate that.
+ */
+ if (ret == 0) {
+ struct btrfs_key tmp;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &tmp,
+ path->slots[0]);
+ if (tmp.type == BTRFS_DIR_INDEX_KEY)
+ last_old_dentry_offset = tmp.offset;
+ } else if (ret < 0) {
+ err = ret;
+ }
+
+ goto done;
+ }
+
+ /* go backward to find any previous key */
+ ret = btrfs_previous_item(root, path, ino, BTRFS_DIR_INDEX_KEY);
+ if (ret == 0) {
+ struct btrfs_key tmp;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
+ /*
+ * The dir index key before the first one we found that needs to
+ * be logged might be in a previous leaf, and there might be a
+ * gap between these keys, meaning that we had deletions that
+ * happened. So the key range item we log (key type
+ * BTRFS_DIR_LOG_INDEX_KEY) must cover a range that starts at the
+ * previous key's offset plus 1, so that those deletes are replayed.
+ */
+ if (tmp.type == BTRFS_DIR_INDEX_KEY)
+ last_old_dentry_offset = tmp.offset;
+ } else if (ret < 0) {
+ err = ret;
+ goto done;
+ }
+
+ btrfs_release_path(path);
+
+ /*
+ * Find the first key from this transaction again or the one we were at
+ * in the loop below in case we had to reschedule. We may be logging the
+ * directory without holding its VFS lock, which happen when logging new
+ * dentries (through log_new_dir_dentries()) or in some cases when we
+ * need to log the parent directory of an inode. This means a dir index
+ * key might be deleted from the inode's root, and therefore we may not
+ * find it anymore. If we can't find it, just move to the next key. We
+ * can not bail out and ignore, because if we do that we will simply
+ * not log dir index keys that come after the one that was just deleted
+ * and we can end up logging a dir index range that ends at (u64)-1
+ * (@last_offset is initialized to that), resulting in removing dir
+ * entries we should not remove at log replay time.
+ */
+search:
+ ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
+ if (ret > 0)
+ ret = btrfs_next_item(root, path);
+ if (ret < 0)
+ err = ret;
+ /* If ret is 1, there are no more keys in the inode's root. */
+ if (ret != 0)
+ goto done;
+
+ /*
+ * we have a block from this transaction, log every item in it
+ * from our directory
+ */
+ while (1) {
+ ret = process_dir_items_leaf(trans, inode, path, dst_path, ctx,
+ &last_old_dentry_offset);
+ if (ret != 0) {
+ if (ret < 0)
+ err = ret;
+ goto done;
+ }
+ path->slots[0] = btrfs_header_nritems(path->nodes[0]);
+
+ /*
+ * look ahead to the next item and see if it is also
+ * from this directory and from this transaction
+ */
+ ret = btrfs_next_leaf(root, path);
+ if (ret) {
+ if (ret == 1)
+ last_offset = (u64)-1;
+ else
+ err = ret;
+ goto done;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &min_key, path->slots[0]);
+ if (min_key.objectid != ino || min_key.type != BTRFS_DIR_INDEX_KEY) {
+ last_offset = (u64)-1;
+ goto done;
+ }
+ if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
+ /*
+ * The next leaf was not changed in the current transaction
+ * and has at least one dir index key.
+ * We check for the next key because there might have been
+ * one or more deletions between the last key we logged and
+ * that next key. So the key range item we log (key type
+ * BTRFS_DIR_LOG_INDEX_KEY) must end at the next key's
+ * offset minus 1, so that those deletes are replayed.
+ */
+ last_offset = min_key.offset - 1;
+ goto done;
+ }
+ if (need_resched()) {
+ btrfs_release_path(path);
+ cond_resched();
+ goto search;
+ }
+ }
+done:
+ btrfs_release_path(path);
+ btrfs_release_path(dst_path);
+
+ if (err == 0) {
+ *last_offset_ret = last_offset;
+ /*
+ * In case the leaf was changed in the current transaction but
+ * all its dir items are from a past transaction, the last item
+ * in the leaf is a dir item and there's no gap between that last
+ * dir item and the first one on the next leaf (which did not
+ * change in the current transaction), then we don't need to log
+ * a range, last_old_dentry_offset is == to last_offset.
+ */
+ ASSERT(last_old_dentry_offset <= last_offset);
+ if (last_old_dentry_offset < last_offset) {
+ ret = insert_dir_log_key(trans, log, path, ino,
+ last_old_dentry_offset + 1,
+ last_offset);
+ if (ret)
+ err = ret;
+ }
+ }
+ return err;
+}
+
+/*
+ * If the inode was logged before and it was evicted, then its
+ * last_dir_index_offset is (u64)-1, so we don't the value of the last index
+ * key offset. If that's the case, search for it and update the inode. This
+ * is to avoid lookups in the log tree every time we try to insert a dir index
+ * key from a leaf changed in the current transaction, and to allow us to always
+ * do batch insertions of dir index keys.
+ */
+static int update_last_dir_index_offset(struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ const struct btrfs_log_ctx *ctx)
+{
+ const u64 ino = btrfs_ino(inode);
+ struct btrfs_key key;
+ int ret;
+
+ lockdep_assert_held(&inode->log_mutex);
+
+ if (inode->last_dir_index_offset != (u64)-1)
+ return 0;
+
+ if (!ctx->logged_before) {
+ inode->last_dir_index_offset = BTRFS_DIR_START_INDEX - 1;
+ return 0;
+ }
+
+ key.objectid = ino;
+ key.type = BTRFS_DIR_INDEX_KEY;
+ key.offset = (u64)-1;
+
+ ret = btrfs_search_slot(NULL, inode->root->log_root, &key, path, 0, 0);
+ /*
+ * An error happened or we actually have an index key with an offset
+ * value of (u64)-1. Bail out, we're done.
+ */
+ if (ret <= 0)
+ goto out;
+
+ ret = 0;
+ inode->last_dir_index_offset = BTRFS_DIR_START_INDEX - 1;
+
+ /*
+ * No dir index items, bail out and leave last_dir_index_offset with
+ * the value right before the first valid index value.
+ */
+ if (path->slots[0] == 0)
+ goto out;
+
+ /*
+ * btrfs_search_slot() left us at one slot beyond the slot with the last
+ * index key, or beyond the last key of the directory that is not an
+ * index key. If we have an index key before, set last_dir_index_offset
+ * to its offset value, otherwise leave it with a value right before the
+ * first valid index value, as it means we have an empty directory.
+ */
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1);
+ if (key.objectid == ino && key.type == BTRFS_DIR_INDEX_KEY)
+ inode->last_dir_index_offset = key.offset;
+
+out:
+ btrfs_release_path(path);
+
+ return ret;
+}
+
+/*
+ * logging directories is very similar to logging inodes, We find all the items
+ * from the current transaction and write them to the log.
+ *
+ * The recovery code scans the directory in the subvolume, and if it finds a
+ * key in the range logged that is not present in the log tree, then it means
+ * that dir entry was unlinked during the transaction.
+ *
+ * In order for that scan to work, we must include one key smaller than
+ * the smallest logged by this transaction and one key larger than the largest
+ * key logged by this transaction.
+ */
+static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ struct btrfs_path *dst_path,
+ struct btrfs_log_ctx *ctx)
+{
+ u64 min_key;
+ u64 max_key;
+ int ret;
+
+ ret = update_last_dir_index_offset(inode, path, ctx);
+ if (ret)
+ return ret;
+
+ min_key = BTRFS_DIR_START_INDEX;
+ max_key = 0;
+
+ while (1) {
+ ret = log_dir_items(trans, inode, path, dst_path,
+ ctx, min_key, &max_key);
+ if (ret)
+ return ret;
+ if (max_key == (u64)-1)
+ break;
+ min_key = max_key + 1;
+ }
+
+ return 0;
+}
+
+/*
+ * a helper function to drop items from the log before we relog an
+ * inode. max_key_type indicates the highest item type to remove.
+ * This cannot be run for file data extents because it does not
+ * free the extents they point to.
+ */
+static int drop_inode_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ struct btrfs_inode *inode,
+ int max_key_type)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ int start_slot;
+
+ key.objectid = btrfs_ino(inode);
+ key.type = max_key_type;
+ key.offset = (u64)-1;
+
+ while (1) {
+ ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
+ BUG_ON(ret == 0); /* Logic error */
+ if (ret < 0)
+ break;
+
+ if (path->slots[0] == 0)
+ break;
+
+ path->slots[0]--;
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+
+ if (found_key.objectid != key.objectid)
+ break;
+
+ found_key.offset = 0;
+ found_key.type = 0;
+ ret = btrfs_bin_search(path->nodes[0], &found_key, &start_slot);
+ if (ret < 0)
+ break;
+
+ ret = btrfs_del_items(trans, log, path, start_slot,
+ path->slots[0] - start_slot + 1);
+ /*
+ * If start slot isn't 0 then we don't need to re-search, we've
+ * found the last guy with the objectid in this tree.
+ */
+ if (ret || start_slot != 0)
+ break;
+ btrfs_release_path(path);
+ }
+ btrfs_release_path(path);
+ if (ret > 0)
+ ret = 0;
+ return ret;
+}
+
+static int truncate_inode_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log_root,
+ struct btrfs_inode *inode,
+ u64 new_size, u32 min_type)
+{
+ struct btrfs_truncate_control control = {
+ .new_size = new_size,
+ .ino = btrfs_ino(inode),
+ .min_type = min_type,
+ .skip_ref_updates = true,
+ };
+
+ return btrfs_truncate_inode_items(trans, log_root, &control);
+}
+
+static void fill_inode_item(struct btrfs_trans_handle *trans,
+ struct extent_buffer *leaf,
+ struct btrfs_inode_item *item,
+ struct inode *inode, int log_inode_only,
+ u64 logged_isize)
+{
+ struct btrfs_map_token token;
+ u64 flags;
+
+ btrfs_init_map_token(&token, leaf);
+
+ if (log_inode_only) {
+ /* set the generation to zero so the recover code
+ * can tell the difference between an logging
+ * just to say 'this inode exists' and a logging
+ * to say 'update this inode with these values'
+ */
+ btrfs_set_token_inode_generation(&token, item, 0);
+ btrfs_set_token_inode_size(&token, item, logged_isize);
+ } else {
+ btrfs_set_token_inode_generation(&token, item,
+ BTRFS_I(inode)->generation);
+ btrfs_set_token_inode_size(&token, item, inode->i_size);
+ }
+
+ btrfs_set_token_inode_uid(&token, item, i_uid_read(inode));
+ btrfs_set_token_inode_gid(&token, item, i_gid_read(inode));
+ btrfs_set_token_inode_mode(&token, item, inode->i_mode);
+ btrfs_set_token_inode_nlink(&token, item, inode->i_nlink);
+
+ btrfs_set_token_timespec_sec(&token, &item->atime,
+ inode->i_atime.tv_sec);
+ btrfs_set_token_timespec_nsec(&token, &item->atime,
+ inode->i_atime.tv_nsec);
+
+ btrfs_set_token_timespec_sec(&token, &item->mtime,
+ inode->i_mtime.tv_sec);
+ btrfs_set_token_timespec_nsec(&token, &item->mtime,
+ inode->i_mtime.tv_nsec);
+
+ btrfs_set_token_timespec_sec(&token, &item->ctime,
+ inode->i_ctime.tv_sec);
+ btrfs_set_token_timespec_nsec(&token, &item->ctime,
+ inode->i_ctime.tv_nsec);
+
+ /*
+ * We do not need to set the nbytes field, in fact during a fast fsync
+ * its value may not even be correct, since a fast fsync does not wait
+ * for ordered extent completion, which is where we update nbytes, it
+ * only waits for writeback to complete. During log replay as we find
+ * file extent items and replay them, we adjust the nbytes field of the
+ * inode item in subvolume tree as needed (see overwrite_item()).
+ */
+
+ btrfs_set_token_inode_sequence(&token, item, inode_peek_iversion(inode));
+ btrfs_set_token_inode_transid(&token, item, trans->transid);
+ btrfs_set_token_inode_rdev(&token, item, inode->i_rdev);
+ flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags,
+ BTRFS_I(inode)->ro_flags);
+ btrfs_set_token_inode_flags(&token, item, flags);
+ btrfs_set_token_inode_block_group(&token, item, 0);
+}
+
+static int log_inode_item(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log, struct btrfs_path *path,
+ struct btrfs_inode *inode, bool inode_item_dropped)
+{
+ struct btrfs_inode_item *inode_item;
+ int ret;
+
+ /*
+ * If we are doing a fast fsync and the inode was logged before in the
+ * current transaction, then we know the inode was previously logged and
+ * it exists in the log tree. For performance reasons, in this case use
+ * btrfs_search_slot() directly with ins_len set to 0 so that we never
+ * attempt a write lock on the leaf's parent, which adds unnecessary lock
+ * contention in case there are concurrent fsyncs for other inodes of the
+ * same subvolume. Using btrfs_insert_empty_item() when the inode item
+ * already exists can also result in unnecessarily splitting a leaf.
+ */
+ if (!inode_item_dropped && inode->logged_trans == trans->transid) {
+ ret = btrfs_search_slot(trans, log, &inode->location, path, 0, 1);
+ ASSERT(ret <= 0);
+ if (ret > 0)
+ ret = -ENOENT;
+ } else {
+ /*
+ * This means it is the first fsync in the current transaction,
+ * so the inode item is not in the log and we need to insert it.
+ * We can never get -EEXIST because we are only called for a fast
+ * fsync and in case an inode eviction happens after the inode was
+ * logged before in the current transaction, when we load again
+ * the inode, we set BTRFS_INODE_NEEDS_FULL_SYNC on its runtime
+ * flags and set ->logged_trans to 0.
+ */
+ ret = btrfs_insert_empty_item(trans, log, path, &inode->location,
+ sizeof(*inode_item));
+ ASSERT(ret != -EEXIST);
+ }
+ if (ret)
+ return ret;
+ inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_item);
+ fill_inode_item(trans, path->nodes[0], inode_item, &inode->vfs_inode,
+ 0, 0);
+ btrfs_release_path(path);
+ return 0;
+}
+
+static int log_csums(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_root *log_root,
+ struct btrfs_ordered_sum *sums)
+{
+ const u64 lock_end = sums->bytenr + sums->len - 1;
+ struct extent_state *cached_state = NULL;
+ int ret;
+
+ /*
+ * If this inode was not used for reflink operations in the current
+ * transaction with new extents, then do the fast path, no need to
+ * worry about logging checksum items with overlapping ranges.
+ */
+ if (inode->last_reflink_trans < trans->transid)
+ return btrfs_csum_file_blocks(trans, log_root, sums);
+
+ /*
+ * Serialize logging for checksums. This is to avoid racing with the
+ * same checksum being logged by another task that is logging another
+ * file which happens to refer to the same extent as well. Such races
+ * can leave checksum items in the log with overlapping ranges.
+ */
+ ret = lock_extent(&log_root->log_csum_range, sums->bytenr, lock_end,
+ &cached_state);
+ if (ret)
+ return ret;
+ /*
+ * Due to extent cloning, we might have logged a csum item that covers a
+ * subrange of a cloned extent, and later we can end up logging a csum
+ * item for a larger subrange of the same extent or the entire range.
+ * This would leave csum items in the log tree that cover the same range
+ * and break the searches for checksums in the log tree, resulting in
+ * some checksums missing in the fs/subvolume tree. So just delete (or
+ * trim and adjust) any existing csum items in the log for this range.
+ */
+ ret = btrfs_del_csums(trans, log_root, sums->bytenr, sums->len);
+ if (!ret)
+ ret = btrfs_csum_file_blocks(trans, log_root, sums);
+
+ unlock_extent(&log_root->log_csum_range, sums->bytenr, lock_end,
+ &cached_state);
+
+ return ret;
+}
+
+static noinline int copy_items(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *dst_path,
+ struct btrfs_path *src_path,
+ int start_slot, int nr, int inode_only,
+ u64 logged_isize)
+{
+ struct btrfs_root *log = inode->root->log_root;
+ struct btrfs_file_extent_item *extent;
+ struct extent_buffer *src;
+ int ret = 0;
+ struct btrfs_key *ins_keys;
+ u32 *ins_sizes;
+ struct btrfs_item_batch batch;
+ char *ins_data;
+ int i;
+ int dst_index;
+ const bool skip_csum = (inode->flags & BTRFS_INODE_NODATASUM);
+ const u64 i_size = i_size_read(&inode->vfs_inode);
+
+ /*
+ * To keep lockdep happy and avoid deadlocks, clone the source leaf and
+ * use the clone. This is because otherwise we would be changing the log
+ * tree, to insert items from the subvolume tree or insert csum items,
+ * while holding a read lock on a leaf from the subvolume tree, which
+ * creates a nasty lock dependency when COWing log tree nodes/leaves:
+ *
+ * 1) Modifying the log tree triggers an extent buffer allocation while
+ * holding a write lock on a parent extent buffer from the log tree.
+ * Allocating the pages for an extent buffer, or the extent buffer
+ * struct, can trigger inode eviction and finally the inode eviction
+ * will trigger a release/remove of a delayed node, which requires
+ * taking the delayed node's mutex;
+ *
+ * 2) Allocating a metadata extent for a log tree can trigger the async
+ * reclaim thread and make us wait for it to release enough space and
+ * unblock our reservation ticket. The reclaim thread can start
+ * flushing delayed items, and that in turn results in the need to
+ * lock delayed node mutexes and in the need to write lock extent
+ * buffers of a subvolume tree - all this while holding a write lock
+ * on the parent extent buffer in the log tree.
+ *
+ * So one task in scenario 1) running in parallel with another task in
+ * scenario 2) could lead to a deadlock, one wanting to lock a delayed
+ * node mutex while having a read lock on a leaf from the subvolume,
+ * while the other is holding the delayed node's mutex and wants to
+ * write lock the same subvolume leaf for flushing delayed items.
+ */
+ src = btrfs_clone_extent_buffer(src_path->nodes[0]);
+ if (!src)
+ return -ENOMEM;
+
+ i = src_path->slots[0];
+ btrfs_release_path(src_path);
+ src_path->nodes[0] = src;
+ src_path->slots[0] = i;
+
+ ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
+ nr * sizeof(u32), GFP_NOFS);
+ if (!ins_data)
+ return -ENOMEM;
+
+ ins_sizes = (u32 *)ins_data;
+ ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
+ batch.keys = ins_keys;
+ batch.data_sizes = ins_sizes;
+ batch.total_data_size = 0;
+ batch.nr = 0;
+
+ dst_index = 0;
+ for (i = 0; i < nr; i++) {
+ const int src_slot = start_slot + i;
+ struct btrfs_root *csum_root;
+ struct btrfs_ordered_sum *sums;
+ struct btrfs_ordered_sum *sums_next;
+ LIST_HEAD(ordered_sums);
+ u64 disk_bytenr;
+ u64 disk_num_bytes;
+ u64 extent_offset;
+ u64 extent_num_bytes;
+ bool is_old_extent;
+
+ btrfs_item_key_to_cpu(src, &ins_keys[dst_index], src_slot);
+
+ if (ins_keys[dst_index].type != BTRFS_EXTENT_DATA_KEY)
+ goto add_to_batch;
+
+ extent = btrfs_item_ptr(src, src_slot,
+ struct btrfs_file_extent_item);
+
+ is_old_extent = (btrfs_file_extent_generation(src, extent) <
+ trans->transid);
+
+ /*
+ * Don't copy extents from past generations. That would make us
+ * log a lot more metadata for common cases like doing only a
+ * few random writes into a file and then fsync it for the first
+ * time or after the full sync flag is set on the inode. We can
+ * get leaves full of extent items, most of which are from past
+ * generations, so we can skip them - as long as the inode has
+ * not been the target of a reflink operation in this transaction,
+ * as in that case it might have had file extent items with old
+ * generations copied into it. We also must always log prealloc
+ * extents that start at or beyond eof, otherwise we would lose
+ * them on log replay.
+ */
+ if (is_old_extent &&
+ ins_keys[dst_index].offset < i_size &&
+ inode->last_reflink_trans < trans->transid)
+ continue;
+
+ if (skip_csum)
+ goto add_to_batch;
+
+ /* Only regular extents have checksums. */
+ if (btrfs_file_extent_type(src, extent) != BTRFS_FILE_EXTENT_REG)
+ goto add_to_batch;
+
+ /*
+ * If it's an extent created in a past transaction, then its
+ * checksums are already accessible from the committed csum tree,
+ * no need to log them.
+ */
+ if (is_old_extent)
+ goto add_to_batch;
+
+ disk_bytenr = btrfs_file_extent_disk_bytenr(src, extent);
+ /* If it's an explicit hole, there are no checksums. */
+ if (disk_bytenr == 0)
+ goto add_to_batch;
+
+ disk_num_bytes = btrfs_file_extent_disk_num_bytes(src, extent);
+
+ if (btrfs_file_extent_compression(src, extent)) {
+ extent_offset = 0;
+ extent_num_bytes = disk_num_bytes;
+ } else {
+ extent_offset = btrfs_file_extent_offset(src, extent);
+ extent_num_bytes = btrfs_file_extent_num_bytes(src, extent);
+ }
+
+ csum_root = btrfs_csum_root(trans->fs_info, disk_bytenr);
+ disk_bytenr += extent_offset;
+ ret = btrfs_lookup_csums_range(csum_root, disk_bytenr,
+ disk_bytenr + extent_num_bytes - 1,
+ &ordered_sums, 0, false);
+ if (ret)
+ goto out;
+
+ list_for_each_entry_safe(sums, sums_next, &ordered_sums, list) {
+ if (!ret)
+ ret = log_csums(trans, inode, log, sums);
+ list_del(&sums->list);
+ kfree(sums);
+ }
+ if (ret)
+ goto out;
+
+add_to_batch:
+ ins_sizes[dst_index] = btrfs_item_size(src, src_slot);
+ batch.total_data_size += ins_sizes[dst_index];
+ batch.nr++;
+ dst_index++;
+ }
+
+ /*
+ * We have a leaf full of old extent items that don't need to be logged,
+ * so we don't need to do anything.
+ */
+ if (batch.nr == 0)
+ goto out;
+
+ ret = btrfs_insert_empty_items(trans, log, dst_path, &batch);
+ if (ret)
+ goto out;
+
+ dst_index = 0;
+ for (i = 0; i < nr; i++) {
+ const int src_slot = start_slot + i;
+ const int dst_slot = dst_path->slots[0] + dst_index;
+ struct btrfs_key key;
+ unsigned long src_offset;
+ unsigned long dst_offset;
+
+ /*
+ * We're done, all the remaining items in the source leaf
+ * correspond to old file extent items.
+ */
+ if (dst_index >= batch.nr)
+ break;
+
+ btrfs_item_key_to_cpu(src, &key, src_slot);
+
+ if (key.type != BTRFS_EXTENT_DATA_KEY)
+ goto copy_item;
+
+ extent = btrfs_item_ptr(src, src_slot,
+ struct btrfs_file_extent_item);
+
+ /* See the comment in the previous loop, same logic. */
+ if (btrfs_file_extent_generation(src, extent) < trans->transid &&
+ key.offset < i_size &&
+ inode->last_reflink_trans < trans->transid)
+ continue;
+
+copy_item:
+ dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0], dst_slot);
+ src_offset = btrfs_item_ptr_offset(src, src_slot);
+
+ if (key.type == BTRFS_INODE_ITEM_KEY) {
+ struct btrfs_inode_item *inode_item;
+
+ inode_item = btrfs_item_ptr(dst_path->nodes[0], dst_slot,
+ struct btrfs_inode_item);
+ fill_inode_item(trans, dst_path->nodes[0], inode_item,
+ &inode->vfs_inode,
+ inode_only == LOG_INODE_EXISTS,
+ logged_isize);
+ } else {
+ copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
+ src_offset, ins_sizes[dst_index]);
+ }
+
+ dst_index++;
+ }
+
+ btrfs_mark_buffer_dirty(dst_path->nodes[0]);
+ btrfs_release_path(dst_path);
+out:
+ kfree(ins_data);
+
+ return ret;
+}
+
+static int extent_cmp(void *priv, const struct list_head *a,
+ const struct list_head *b)
+{
+ const struct extent_map *em1, *em2;
+
+ em1 = list_entry(a, struct extent_map, list);
+ em2 = list_entry(b, struct extent_map, list);
+
+ if (em1->start < em2->start)
+ return -1;
+ else if (em1->start > em2->start)
+ return 1;
+ return 0;
+}
+
+static int log_extent_csums(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_root *log_root,
+ const struct extent_map *em,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_ordered_extent *ordered;
+ struct btrfs_root *csum_root;
+ u64 csum_offset;
+ u64 csum_len;
+ u64 mod_start = em->mod_start;
+ u64 mod_len = em->mod_len;
+ LIST_HEAD(ordered_sums);
+ int ret = 0;
+
+ if (inode->flags & BTRFS_INODE_NODATASUM ||
+ test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
+ em->block_start == EXTENT_MAP_HOLE)
+ return 0;
+
+ list_for_each_entry(ordered, &ctx->ordered_extents, log_list) {
+ const u64 ordered_end = ordered->file_offset + ordered->num_bytes;
+ const u64 mod_end = mod_start + mod_len;
+ struct btrfs_ordered_sum *sums;
+
+ if (mod_len == 0)
+ break;
+
+ if (ordered_end <= mod_start)
+ continue;
+ if (mod_end <= ordered->file_offset)
+ break;
+
+ /*
+ * We are going to copy all the csums on this ordered extent, so
+ * go ahead and adjust mod_start and mod_len in case this ordered
+ * extent has already been logged.
+ */
+ if (ordered->file_offset > mod_start) {
+ if (ordered_end >= mod_end)
+ mod_len = ordered->file_offset - mod_start;
+ /*
+ * If we have this case
+ *
+ * |--------- logged extent ---------|
+ * |----- ordered extent ----|
+ *
+ * Just don't mess with mod_start and mod_len, we'll
+ * just end up logging more csums than we need and it
+ * will be ok.
+ */
+ } else {
+ if (ordered_end < mod_end) {
+ mod_len = mod_end - ordered_end;
+ mod_start = ordered_end;
+ } else {
+ mod_len = 0;
+ }
+ }
+
+ /*
+ * To keep us from looping for the above case of an ordered
+ * extent that falls inside of the logged extent.
+ */
+ if (test_and_set_bit(BTRFS_ORDERED_LOGGED_CSUM, &ordered->flags))
+ continue;
+
+ list_for_each_entry(sums, &ordered->list, list) {
+ ret = log_csums(trans, inode, log_root, sums);
+ if (ret)
+ return ret;
+ }
+ }
+
+ /* We're done, found all csums in the ordered extents. */
+ if (mod_len == 0)
+ return 0;
+
+ /* If we're compressed we have to save the entire range of csums. */
+ if (em->compress_type) {
+ csum_offset = 0;
+ csum_len = max(em->block_len, em->orig_block_len);
+ } else {
+ csum_offset = mod_start - em->start;
+ csum_len = mod_len;
+ }
+
+ /* block start is already adjusted for the file extent offset. */
+ csum_root = btrfs_csum_root(trans->fs_info, em->block_start);
+ ret = btrfs_lookup_csums_range(csum_root,
+ em->block_start + csum_offset,
+ em->block_start + csum_offset +
+ csum_len - 1, &ordered_sums, 0, false);
+ if (ret)
+ return ret;
+
+ while (!list_empty(&ordered_sums)) {
+ struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
+ struct btrfs_ordered_sum,
+ list);
+ if (!ret)
+ ret = log_csums(trans, inode, log_root, sums);
+ list_del(&sums->list);
+ kfree(sums);
+ }
+
+ return ret;
+}
+
+static int log_one_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ const struct extent_map *em,
+ struct btrfs_path *path,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_drop_extents_args drop_args = { 0 };
+ struct btrfs_root *log = inode->root->log_root;
+ struct btrfs_file_extent_item fi = { 0 };
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ u64 extent_offset = em->start - em->orig_start;
+ u64 block_len;
+ int ret;
+
+ btrfs_set_stack_file_extent_generation(&fi, trans->transid);
+ if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
+ btrfs_set_stack_file_extent_type(&fi, BTRFS_FILE_EXTENT_PREALLOC);
+ else
+ btrfs_set_stack_file_extent_type(&fi, BTRFS_FILE_EXTENT_REG);
+
+ block_len = max(em->block_len, em->orig_block_len);
+ if (em->compress_type != BTRFS_COMPRESS_NONE) {
+ btrfs_set_stack_file_extent_disk_bytenr(&fi, em->block_start);
+ btrfs_set_stack_file_extent_disk_num_bytes(&fi, block_len);
+ } else if (em->block_start < EXTENT_MAP_LAST_BYTE) {
+ btrfs_set_stack_file_extent_disk_bytenr(&fi, em->block_start -
+ extent_offset);
+ btrfs_set_stack_file_extent_disk_num_bytes(&fi, block_len);
+ }
+
+ btrfs_set_stack_file_extent_offset(&fi, extent_offset);
+ btrfs_set_stack_file_extent_num_bytes(&fi, em->len);
+ btrfs_set_stack_file_extent_ram_bytes(&fi, em->ram_bytes);
+ btrfs_set_stack_file_extent_compression(&fi, em->compress_type);
+
+ ret = log_extent_csums(trans, inode, log, em, ctx);
+ if (ret)
+ return ret;
+
+ /*
+ * If this is the first time we are logging the inode in the current
+ * transaction, we can avoid btrfs_drop_extents(), which is expensive
+ * because it does a deletion search, which always acquires write locks
+ * for extent buffers at levels 2, 1 and 0. This not only wastes time
+ * but also adds significant contention in a log tree, since log trees
+ * are small, with a root at level 2 or 3 at most, due to their short
+ * life span.
+ */
+ if (ctx->logged_before) {
+ drop_args.path = path;
+ drop_args.start = em->start;
+ drop_args.end = em->start + em->len;
+ drop_args.replace_extent = true;
+ drop_args.extent_item_size = sizeof(fi);
+ ret = btrfs_drop_extents(trans, log, inode, &drop_args);
+ if (ret)
+ return ret;
+ }
+
+ if (!drop_args.extent_inserted) {
+ key.objectid = btrfs_ino(inode);
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = em->start;
+
+ ret = btrfs_insert_empty_item(trans, log, path, &key,
+ sizeof(fi));
+ if (ret)
+ return ret;
+ }
+ leaf = path->nodes[0];
+ write_extent_buffer(leaf, &fi,
+ btrfs_item_ptr_offset(leaf, path->slots[0]),
+ sizeof(fi));
+ btrfs_mark_buffer_dirty(leaf);
+
+ btrfs_release_path(path);
+
+ return ret;
+}
+
+/*
+ * Log all prealloc extents beyond the inode's i_size to make sure we do not
+ * lose them after doing a full/fast fsync and replaying the log. We scan the
+ * subvolume's root instead of iterating the inode's extent map tree because
+ * otherwise we can log incorrect extent items based on extent map conversion.
+ * That can happen due to the fact that extent maps are merged when they
+ * are not in the extent map tree's list of modified extents.
+ */
+static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path)
+{
+ struct btrfs_root *root = inode->root;
+ struct btrfs_key key;
+ const u64 i_size = i_size_read(&inode->vfs_inode);
+ const u64 ino = btrfs_ino(inode);
+ struct btrfs_path *dst_path = NULL;
+ bool dropped_extents = false;
+ u64 truncate_offset = i_size;
+ struct extent_buffer *leaf;
+ int slot;
+ int ins_nr = 0;
+ int start_slot = 0;
+ int ret;
+
+ if (!(inode->flags & BTRFS_INODE_PREALLOC))
+ return 0;
+
+ key.objectid = ino;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = i_size;
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ /*
+ * We must check if there is a prealloc extent that starts before the
+ * i_size and crosses the i_size boundary. This is to ensure later we
+ * truncate down to the end of that extent and not to the i_size, as
+ * otherwise we end up losing part of the prealloc extent after a log
+ * replay and with an implicit hole if there is another prealloc extent
+ * that starts at an offset beyond i_size.
+ */
+ ret = btrfs_previous_item(root, path, ino, BTRFS_EXTENT_DATA_KEY);
+ if (ret < 0)
+ goto out;
+
+ if (ret == 0) {
+ struct btrfs_file_extent_item *ei;
+
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
+
+ if (btrfs_file_extent_type(leaf, ei) ==
+ BTRFS_FILE_EXTENT_PREALLOC) {
+ u64 extent_end;
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ extent_end = key.offset +
+ btrfs_file_extent_num_bytes(leaf, ei);
+
+ if (extent_end > i_size)
+ truncate_offset = extent_end;
+ }
+ } else {
+ ret = 0;
+ }
+
+ while (true) {
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+
+ if (slot >= btrfs_header_nritems(leaf)) {
+ if (ins_nr > 0) {
+ ret = copy_items(trans, inode, dst_path, path,
+ start_slot, ins_nr, 1, 0);
+ if (ret < 0)
+ goto out;
+ ins_nr = 0;
+ }
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ ret = 0;
+ break;
+ }
+ continue;
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.objectid > ino)
+ break;
+ if (WARN_ON_ONCE(key.objectid < ino) ||
+ key.type < BTRFS_EXTENT_DATA_KEY ||
+ key.offset < i_size) {
+ path->slots[0]++;
+ continue;
+ }
+ if (!dropped_extents) {
+ /*
+ * Avoid logging extent items logged in past fsync calls
+ * and leading to duplicate keys in the log tree.
+ */
+ ret = truncate_inode_items(trans, root->log_root, inode,
+ truncate_offset,
+ BTRFS_EXTENT_DATA_KEY);
+ if (ret)
+ goto out;
+ dropped_extents = true;
+ }
+ if (ins_nr == 0)
+ start_slot = slot;
+ ins_nr++;
+ path->slots[0]++;
+ if (!dst_path) {
+ dst_path = btrfs_alloc_path();
+ if (!dst_path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+ }
+ if (ins_nr > 0)
+ ret = copy_items(trans, inode, dst_path, path,
+ start_slot, ins_nr, 1, 0);
+out:
+ btrfs_release_path(path);
+ btrfs_free_path(dst_path);
+ return ret;
+}
+
+static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_ordered_extent *ordered;
+ struct btrfs_ordered_extent *tmp;
+ struct extent_map *em, *n;
+ struct list_head extents;
+ struct extent_map_tree *tree = &inode->extent_tree;
+ int ret = 0;
+ int num = 0;
+
+ INIT_LIST_HEAD(&extents);
+
+ write_lock(&tree->lock);
+
+ list_for_each_entry_safe(em, n, &tree->modified_extents, list) {
+ list_del_init(&em->list);
+ /*
+ * Just an arbitrary number, this can be really CPU intensive
+ * once we start getting a lot of extents, and really once we
+ * have a bunch of extents we just want to commit since it will
+ * be faster.
+ */
+ if (++num > 32768) {
+ list_del_init(&tree->modified_extents);
+ ret = -EFBIG;
+ goto process;
+ }
+
+ if (em->generation < trans->transid)
+ continue;
+
+ /* We log prealloc extents beyond eof later. */
+ if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) &&
+ em->start >= i_size_read(&inode->vfs_inode))
+ continue;
+
+ /* Need a ref to keep it from getting evicted from cache */
+ refcount_inc(&em->refs);
+ set_bit(EXTENT_FLAG_LOGGING, &em->flags);
+ list_add_tail(&em->list, &extents);
+ num++;
+ }
+
+ list_sort(NULL, &extents, extent_cmp);
+process:
+ while (!list_empty(&extents)) {
+ em = list_entry(extents.next, struct extent_map, list);
+
+ list_del_init(&em->list);
+
+ /*
+ * If we had an error we just need to delete everybody from our
+ * private list.
+ */
+ if (ret) {
+ clear_em_logging(tree, em);
+ free_extent_map(em);
+ continue;
+ }
+
+ write_unlock(&tree->lock);
+
+ ret = log_one_extent(trans, inode, em, path, ctx);
+ write_lock(&tree->lock);
+ clear_em_logging(tree, em);
+ free_extent_map(em);
+ }
+ WARN_ON(!list_empty(&extents));
+ write_unlock(&tree->lock);
+
+ if (!ret)
+ ret = btrfs_log_prealloc_extents(trans, inode, path);
+ if (ret)
+ return ret;
+
+ /*
+ * We have logged all extents successfully, now make sure the commit of
+ * the current transaction waits for the ordered extents to complete
+ * before it commits and wipes out the log trees, otherwise we would
+ * lose data if an ordered extents completes after the transaction
+ * commits and a power failure happens after the transaction commit.
+ */
+ list_for_each_entry_safe(ordered, tmp, &ctx->ordered_extents, log_list) {
+ list_del_init(&ordered->log_list);
+ set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags);
+
+ if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
+ spin_lock_irq(&inode->ordered_tree.lock);
+ if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
+ set_bit(BTRFS_ORDERED_PENDING, &ordered->flags);
+ atomic_inc(&trans->transaction->pending_ordered);
+ }
+ spin_unlock_irq(&inode->ordered_tree.lock);
+ }
+ btrfs_put_ordered_extent(ordered);
+ }
+
+ return 0;
+}
+
+static int logged_inode_size(struct btrfs_root *log, struct btrfs_inode *inode,
+ struct btrfs_path *path, u64 *size_ret)
+{
+ struct btrfs_key key;
+ int ret;
+
+ key.objectid = btrfs_ino(inode);
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(NULL, log, &key, path, 0, 0);
+ if (ret < 0) {
+ return ret;
+ } else if (ret > 0) {
+ *size_ret = 0;
+ } else {
+ struct btrfs_inode_item *item;
+
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_item);
+ *size_ret = btrfs_inode_size(path->nodes[0], item);
+ /*
+ * If the in-memory inode's i_size is smaller then the inode
+ * size stored in the btree, return the inode's i_size, so
+ * that we get a correct inode size after replaying the log
+ * when before a power failure we had a shrinking truncate
+ * followed by addition of a new name (rename / new hard link).
+ * Otherwise return the inode size from the btree, to avoid
+ * data loss when replaying a log due to previously doing a
+ * write that expands the inode's size and logging a new name
+ * immediately after.
+ */
+ if (*size_ret > inode->vfs_inode.i_size)
+ *size_ret = inode->vfs_inode.i_size;
+ }
+
+ btrfs_release_path(path);
+ return 0;
+}
+
+/*
+ * At the moment we always log all xattrs. This is to figure out at log replay
+ * time which xattrs must have their deletion replayed. If a xattr is missing
+ * in the log tree and exists in the fs/subvol tree, we delete it. This is
+ * because if a xattr is deleted, the inode is fsynced and a power failure
+ * happens, causing the log to be replayed the next time the fs is mounted,
+ * we want the xattr to not exist anymore (same behaviour as other filesystems
+ * with a journal, ext3/4, xfs, f2fs, etc).
+ */
+static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ struct btrfs_path *dst_path)
+{
+ struct btrfs_root *root = inode->root;
+ int ret;
+ struct btrfs_key key;
+ const u64 ino = btrfs_ino(inode);
+ int ins_nr = 0;
+ int start_slot = 0;
+ bool found_xattrs = false;
+
+ if (test_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags))
+ return 0;
+
+ key.objectid = ino;
+ key.type = BTRFS_XATTR_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ return ret;
+
+ while (true) {
+ int slot = path->slots[0];
+ struct extent_buffer *leaf = path->nodes[0];
+ int nritems = btrfs_header_nritems(leaf);
+
+ if (slot >= nritems) {
+ if (ins_nr > 0) {
+ ret = copy_items(trans, inode, dst_path, path,
+ start_slot, ins_nr, 1, 0);
+ if (ret < 0)
+ return ret;
+ ins_nr = 0;
+ }
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ return ret;
+ else if (ret > 0)
+ break;
+ continue;
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY)
+ break;
+
+ if (ins_nr == 0)
+ start_slot = slot;
+ ins_nr++;
+ path->slots[0]++;
+ found_xattrs = true;
+ cond_resched();
+ }
+ if (ins_nr > 0) {
+ ret = copy_items(trans, inode, dst_path, path,
+ start_slot, ins_nr, 1, 0);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (!found_xattrs)
+ set_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags);
+
+ return 0;
+}
+
+/*
+ * When using the NO_HOLES feature if we punched a hole that causes the
+ * deletion of entire leafs or all the extent items of the first leaf (the one
+ * that contains the inode item and references) we may end up not processing
+ * any extents, because there are no leafs with a generation matching the
+ * current transaction that have extent items for our inode. So we need to find
+ * if any holes exist and then log them. We also need to log holes after any
+ * truncate operation that changes the inode's size.
+ */
+static int btrfs_log_holes(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path)
+{
+ struct btrfs_root *root = inode->root;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_key key;
+ const u64 ino = btrfs_ino(inode);
+ const u64 i_size = i_size_read(&inode->vfs_inode);
+ u64 prev_extent_end = 0;
+ int ret;
+
+ if (!btrfs_fs_incompat(fs_info, NO_HOLES) || i_size == 0)
+ return 0;
+
+ key.objectid = ino;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ return ret;
+
+ while (true) {
+ struct extent_buffer *leaf = path->nodes[0];
+
+ if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ return ret;
+ if (ret > 0) {
+ ret = 0;
+ break;
+ }
+ leaf = path->nodes[0];
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY)
+ break;
+
+ /* We have a hole, log it. */
+ if (prev_extent_end < key.offset) {
+ const u64 hole_len = key.offset - prev_extent_end;
+
+ /*
+ * Release the path to avoid deadlocks with other code
+ * paths that search the root while holding locks on
+ * leafs from the log root.
+ */
+ btrfs_release_path(path);
+ ret = btrfs_insert_hole_extent(trans, root->log_root,
+ ino, prev_extent_end,
+ hole_len);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * Search for the same key again in the root. Since it's
+ * an extent item and we are holding the inode lock, the
+ * key must still exist. If it doesn't just emit warning
+ * and return an error to fall back to a transaction
+ * commit.
+ */
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ return ret;
+ if (WARN_ON(ret > 0))
+ return -ENOENT;
+ leaf = path->nodes[0];
+ }
+
+ prev_extent_end = btrfs_file_extent_end(path);
+ path->slots[0]++;
+ cond_resched();
+ }
+
+ if (prev_extent_end < i_size) {
+ u64 hole_len;
+
+ btrfs_release_path(path);
+ hole_len = ALIGN(i_size - prev_extent_end, fs_info->sectorsize);
+ ret = btrfs_insert_hole_extent(trans, root->log_root, ino,
+ prev_extent_end, hole_len);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * When we are logging a new inode X, check if it doesn't have a reference that
+ * matches the reference from some other inode Y created in a past transaction
+ * and that was renamed in the current transaction. If we don't do this, then at
+ * log replay time we can lose inode Y (and all its files if it's a directory):
+ *
+ * mkdir /mnt/x
+ * echo "hello world" > /mnt/x/foobar
+ * sync
+ * mv /mnt/x /mnt/y
+ * mkdir /mnt/x # or touch /mnt/x
+ * xfs_io -c fsync /mnt/x
+ * <power fail>
+ * mount fs, trigger log replay
+ *
+ * After the log replay procedure, we would lose the first directory and all its
+ * files (file foobar).
+ * For the case where inode Y is not a directory we simply end up losing it:
+ *
+ * echo "123" > /mnt/foo
+ * sync
+ * mv /mnt/foo /mnt/bar
+ * echo "abc" > /mnt/foo
+ * xfs_io -c fsync /mnt/foo
+ * <power fail>
+ *
+ * We also need this for cases where a snapshot entry is replaced by some other
+ * entry (file or directory) otherwise we end up with an unreplayable log due to
+ * attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as
+ * if it were a regular entry:
+ *
+ * mkdir /mnt/x
+ * btrfs subvolume snapshot /mnt /mnt/x/snap
+ * btrfs subvolume delete /mnt/x/snap
+ * rmdir /mnt/x
+ * mkdir /mnt/x
+ * fsync /mnt/x or fsync some new file inside it
+ * <power fail>
+ *
+ * The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in
+ * the same transaction.
+ */
+static int btrfs_check_ref_name_override(struct extent_buffer *eb,
+ const int slot,
+ const struct btrfs_key *key,
+ struct btrfs_inode *inode,
+ u64 *other_ino, u64 *other_parent)
+{
+ int ret;
+ struct btrfs_path *search_path;
+ char *name = NULL;
+ u32 name_len = 0;
+ u32 item_size = btrfs_item_size(eb, slot);
+ u32 cur_offset = 0;
+ unsigned long ptr = btrfs_item_ptr_offset(eb, slot);
+
+ search_path = btrfs_alloc_path();
+ if (!search_path)
+ return -ENOMEM;
+ search_path->search_commit_root = 1;
+ search_path->skip_locking = 1;
+
+ while (cur_offset < item_size) {
+ u64 parent;
+ u32 this_name_len;
+ u32 this_len;
+ unsigned long name_ptr;
+ struct btrfs_dir_item *di;
+ struct fscrypt_str name_str;
+
+ if (key->type == BTRFS_INODE_REF_KEY) {
+ struct btrfs_inode_ref *iref;
+
+ iref = (struct btrfs_inode_ref *)(ptr + cur_offset);
+ parent = key->offset;
+ this_name_len = btrfs_inode_ref_name_len(eb, iref);
+ name_ptr = (unsigned long)(iref + 1);
+ this_len = sizeof(*iref) + this_name_len;
+ } else {
+ struct btrfs_inode_extref *extref;
+
+ extref = (struct btrfs_inode_extref *)(ptr +
+ cur_offset);
+ parent = btrfs_inode_extref_parent(eb, extref);
+ this_name_len = btrfs_inode_extref_name_len(eb, extref);
+ name_ptr = (unsigned long)&extref->name;
+ this_len = sizeof(*extref) + this_name_len;
+ }
+
+ if (this_name_len > name_len) {
+ char *new_name;
+
+ new_name = krealloc(name, this_name_len, GFP_NOFS);
+ if (!new_name) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ name_len = this_name_len;
+ name = new_name;
+ }
+
+ read_extent_buffer(eb, name, name_ptr, this_name_len);
+
+ name_str.name = name;
+ name_str.len = this_name_len;
+ di = btrfs_lookup_dir_item(NULL, inode->root, search_path,
+ parent, &name_str, 0);
+ if (di && !IS_ERR(di)) {
+ struct btrfs_key di_key;
+
+ btrfs_dir_item_key_to_cpu(search_path->nodes[0],
+ di, &di_key);
+ if (di_key.type == BTRFS_INODE_ITEM_KEY) {
+ if (di_key.objectid != key->objectid) {
+ ret = 1;
+ *other_ino = di_key.objectid;
+ *other_parent = parent;
+ } else {
+ ret = 0;
+ }
+ } else {
+ ret = -EAGAIN;
+ }
+ goto out;
+ } else if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto out;
+ }
+ btrfs_release_path(search_path);
+
+ cur_offset += this_len;
+ }
+ ret = 0;
+out:
+ btrfs_free_path(search_path);
+ kfree(name);
+ return ret;
+}
+
+/*
+ * Check if we need to log an inode. This is used in contexts where while
+ * logging an inode we need to log another inode (either that it exists or in
+ * full mode). This is used instead of btrfs_inode_in_log() because the later
+ * requires the inode to be in the log and have the log transaction committed,
+ * while here we do not care if the log transaction was already committed - our
+ * caller will commit the log later - and we want to avoid logging an inode
+ * multiple times when multiple tasks have joined the same log transaction.
+ */
+static bool need_log_inode(const struct btrfs_trans_handle *trans,
+ const struct btrfs_inode *inode)
+{
+ /*
+ * If a directory was not modified, no dentries added or removed, we can
+ * and should avoid logging it.
+ */
+ if (S_ISDIR(inode->vfs_inode.i_mode) && inode->last_trans < trans->transid)
+ return false;
+
+ /*
+ * If this inode does not have new/updated/deleted xattrs since the last
+ * time it was logged and is flagged as logged in the current transaction,
+ * we can skip logging it. As for new/deleted names, those are updated in
+ * the log by link/unlink/rename operations.
+ * In case the inode was logged and then evicted and reloaded, its
+ * logged_trans will be 0, in which case we have to fully log it since
+ * logged_trans is a transient field, not persisted.
+ */
+ if (inode->logged_trans == trans->transid &&
+ !test_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags))
+ return false;
+
+ return true;
+}
+
+struct btrfs_dir_list {
+ u64 ino;
+ struct list_head list;
+};
+
+/*
+ * Log the inodes of the new dentries of a directory.
+ * See process_dir_items_leaf() for details about why it is needed.
+ * This is a recursive operation - if an existing dentry corresponds to a
+ * directory, that directory's new entries are logged too (same behaviour as
+ * ext3/4, xfs, f2fs, reiserfs, nilfs2). Note that when logging the inodes
+ * the dentries point to we do not acquire their VFS lock, otherwise lockdep
+ * complains about the following circular lock dependency / possible deadlock:
+ *
+ * CPU0 CPU1
+ * ---- ----
+ * lock(&type->i_mutex_dir_key#3/2);
+ * lock(sb_internal#2);
+ * lock(&type->i_mutex_dir_key#3/2);
+ * lock(&sb->s_type->i_mutex_key#14);
+ *
+ * Where sb_internal is the lock (a counter that works as a lock) acquired by
+ * sb_start_intwrite() in btrfs_start_transaction().
+ * Not acquiring the VFS lock of the inodes is still safe because:
+ *
+ * 1) For regular files we log with a mode of LOG_INODE_EXISTS. It's possible
+ * that while logging the inode new references (names) are added or removed
+ * from the inode, leaving the logged inode item with a link count that does
+ * not match the number of logged inode reference items. This is fine because
+ * at log replay time we compute the real number of links and correct the
+ * link count in the inode item (see replay_one_buffer() and
+ * link_to_fixup_dir());
+ *
+ * 2) For directories we log with a mode of LOG_INODE_ALL. It's possible that
+ * while logging the inode's items new index items (key type
+ * BTRFS_DIR_INDEX_KEY) are added to fs/subvol tree and the logged inode item
+ * has a size that doesn't match the sum of the lengths of all the logged
+ * names - this is ok, not a problem, because at log replay time we set the
+ * directory's i_size to the correct value (see replay_one_name() and
+ * do_overwrite_item()).
+ */
+static int log_new_dir_dentries(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *start_inode,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_root *root = start_inode->root;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_path *path;
+ LIST_HEAD(dir_list);
+ struct btrfs_dir_list *dir_elem;
+ u64 ino = btrfs_ino(start_inode);
+ int ret = 0;
+
+ /*
+ * If we are logging a new name, as part of a link or rename operation,
+ * don't bother logging new dentries, as we just want to log the names
+ * of an inode and that any new parents exist.
+ */
+ if (ctx->logging_new_name)
+ return 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ while (true) {
+ struct extent_buffer *leaf;
+ struct btrfs_key min_key;
+ bool continue_curr_inode = true;
+ int nritems;
+ int i;
+
+ min_key.objectid = ino;
+ min_key.type = BTRFS_DIR_INDEX_KEY;
+ min_key.offset = 0;
+again:
+ btrfs_release_path(path);
+ ret = btrfs_search_forward(root, &min_key, path, trans->transid);
+ if (ret < 0) {
+ break;
+ } else if (ret > 0) {
+ ret = 0;
+ goto next;
+ }
+
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ for (i = path->slots[0]; i < nritems; i++) {
+ struct btrfs_dir_item *di;
+ struct btrfs_key di_key;
+ struct inode *di_inode;
+ int log_mode = LOG_INODE_EXISTS;
+ int type;
+
+ btrfs_item_key_to_cpu(leaf, &min_key, i);
+ if (min_key.objectid != ino ||
+ min_key.type != BTRFS_DIR_INDEX_KEY) {
+ continue_curr_inode = false;
+ break;
+ }
+
+ di = btrfs_item_ptr(leaf, i, struct btrfs_dir_item);
+ type = btrfs_dir_type(leaf, di);
+ if (btrfs_dir_transid(leaf, di) < trans->transid)
+ continue;
+ btrfs_dir_item_key_to_cpu(leaf, di, &di_key);
+ if (di_key.type == BTRFS_ROOT_ITEM_KEY)
+ continue;
+
+ btrfs_release_path(path);
+ di_inode = btrfs_iget(fs_info->sb, di_key.objectid, root);
+ if (IS_ERR(di_inode)) {
+ ret = PTR_ERR(di_inode);
+ goto out;
+ }
+
+ if (!need_log_inode(trans, BTRFS_I(di_inode))) {
+ btrfs_add_delayed_iput(di_inode);
+ break;
+ }
+
+ ctx->log_new_dentries = false;
+ if (type == BTRFS_FT_DIR)
+ log_mode = LOG_INODE_ALL;
+ ret = btrfs_log_inode(trans, BTRFS_I(di_inode),
+ log_mode, ctx);
+ btrfs_add_delayed_iput(di_inode);
+ if (ret)
+ goto out;
+ if (ctx->log_new_dentries) {
+ dir_elem = kmalloc(sizeof(*dir_elem), GFP_NOFS);
+ if (!dir_elem) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ dir_elem->ino = di_key.objectid;
+ list_add_tail(&dir_elem->list, &dir_list);
+ }
+ break;
+ }
+
+ if (continue_curr_inode && min_key.offset < (u64)-1) {
+ min_key.offset++;
+ goto again;
+ }
+
+next:
+ if (list_empty(&dir_list))
+ break;
+
+ dir_elem = list_first_entry(&dir_list, struct btrfs_dir_list, list);
+ ino = dir_elem->ino;
+ list_del(&dir_elem->list);
+ kfree(dir_elem);
+ }
+out:
+ btrfs_free_path(path);
+ if (ret) {
+ struct btrfs_dir_list *next;
+
+ list_for_each_entry_safe(dir_elem, next, &dir_list, list)
+ kfree(dir_elem);
+ }
+
+ return ret;
+}
+
+struct btrfs_ino_list {
+ u64 ino;
+ u64 parent;
+ struct list_head list;
+};
+
+static void free_conflicting_inodes(struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_ino_list *curr;
+ struct btrfs_ino_list *next;
+
+ list_for_each_entry_safe(curr, next, &ctx->conflict_inodes, list) {
+ list_del(&curr->list);
+ kfree(curr);
+ }
+}
+
+static int conflicting_inode_is_dir(struct btrfs_root *root, u64 ino,
+ struct btrfs_path *path)
+{
+ struct btrfs_key key;
+ int ret;
+
+ key.objectid = ino;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+
+ path->search_commit_root = 1;
+ path->skip_locking = 1;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (WARN_ON_ONCE(ret > 0)) {
+ /*
+ * We have previously found the inode through the commit root
+ * so this should not happen. If it does, just error out and
+ * fallback to a transaction commit.
+ */
+ ret = -ENOENT;
+ } else if (ret == 0) {
+ struct btrfs_inode_item *item;
+
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_item);
+ if (S_ISDIR(btrfs_inode_mode(path->nodes[0], item)))
+ ret = 1;
+ }
+
+ btrfs_release_path(path);
+ path->search_commit_root = 0;
+ path->skip_locking = 0;
+
+ return ret;
+}
+
+static int add_conflicting_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 ino, u64 parent,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_ino_list *ino_elem;
+ struct inode *inode;
+
+ /*
+ * It's rare to have a lot of conflicting inodes, in practice it is not
+ * common to have more than 1 or 2. We don't want to collect too many,
+ * as we could end up logging too many inodes (even if only in
+ * LOG_INODE_EXISTS mode) and slow down other fsyncs or transaction
+ * commits.
+ */
+ if (ctx->num_conflict_inodes >= MAX_CONFLICT_INODES) {
+ btrfs_set_log_full_commit(trans);
+ return BTRFS_LOG_FORCE_COMMIT;
+ }
+
+ inode = btrfs_iget(root->fs_info->sb, ino, root);
+ /*
+ * If the other inode that had a conflicting dir entry was deleted in
+ * the current transaction then we either:
+ *
+ * 1) Log the parent directory (later after adding it to the list) if
+ * the inode is a directory. This is because it may be a deleted
+ * subvolume/snapshot or it may be a regular directory that had
+ * deleted subvolumes/snapshots (or subdirectories that had them),
+ * and at the moment we can't deal with dropping subvolumes/snapshots
+ * during log replay. So we just log the parent, which will result in
+ * a fallback to a transaction commit if we are dealing with those
+ * cases (last_unlink_trans will match the current transaction);
+ *
+ * 2) Do nothing if it's not a directory. During log replay we simply
+ * unlink the conflicting dentry from the parent directory and then
+ * add the dentry for our inode. Like this we can avoid logging the
+ * parent directory (and maybe fallback to a transaction commit in
+ * case it has a last_unlink_trans == trans->transid, due to moving
+ * some inode from it to some other directory).
+ */
+ if (IS_ERR(inode)) {
+ int ret = PTR_ERR(inode);
+
+ if (ret != -ENOENT)
+ return ret;
+
+ ret = conflicting_inode_is_dir(root, ino, path);
+ /* Not a directory or we got an error. */
+ if (ret <= 0)
+ return ret;
+
+ /* Conflicting inode is a directory, so we'll log its parent. */
+ ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
+ if (!ino_elem)
+ return -ENOMEM;
+ ino_elem->ino = ino;
+ ino_elem->parent = parent;
+ list_add_tail(&ino_elem->list, &ctx->conflict_inodes);
+ ctx->num_conflict_inodes++;
+
+ return 0;
+ }
+
+ /*
+ * If the inode was already logged skip it - otherwise we can hit an
+ * infinite loop. Example:
+ *
+ * From the commit root (previous transaction) we have the following
+ * inodes:
+ *
+ * inode 257 a directory
+ * inode 258 with references "zz" and "zz_link" on inode 257
+ * inode 259 with reference "a" on inode 257
+ *
+ * And in the current (uncommitted) transaction we have:
+ *
+ * inode 257 a directory, unchanged
+ * inode 258 with references "a" and "a2" on inode 257
+ * inode 259 with reference "zz_link" on inode 257
+ * inode 261 with reference "zz" on inode 257
+ *
+ * When logging inode 261 the following infinite loop could
+ * happen if we don't skip already logged inodes:
+ *
+ * - we detect inode 258 as a conflicting inode, with inode 261
+ * on reference "zz", and log it;
+ *
+ * - we detect inode 259 as a conflicting inode, with inode 258
+ * on reference "a", and log it;
+ *
+ * - we detect inode 258 as a conflicting inode, with inode 259
+ * on reference "zz_link", and log it - again! After this we
+ * repeat the above steps forever.
+ *
+ * Here we can use need_log_inode() because we only need to log the
+ * inode in LOG_INODE_EXISTS mode and rename operations update the log,
+ * so that the log ends up with the new name and without the old name.
+ */
+ if (!need_log_inode(trans, BTRFS_I(inode))) {
+ btrfs_add_delayed_iput(inode);
+ return 0;
+ }
+
+ btrfs_add_delayed_iput(inode);
+
+ ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
+ if (!ino_elem)
+ return -ENOMEM;
+ ino_elem->ino = ino;
+ ino_elem->parent = parent;
+ list_add_tail(&ino_elem->list, &ctx->conflict_inodes);
+ ctx->num_conflict_inodes++;
+
+ return 0;
+}
+
+static int log_conflicting_inodes(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ int ret = 0;
+
+ /*
+ * Conflicting inodes are logged by the first call to btrfs_log_inode(),
+ * otherwise we could have unbounded recursion of btrfs_log_inode()
+ * calls. This check guarantees we can have only 1 level of recursion.
+ */
+ if (ctx->logging_conflict_inodes)
+ return 0;
+
+ ctx->logging_conflict_inodes = true;
+
+ /*
+ * New conflicting inodes may be found and added to the list while we
+ * are logging a conflicting inode, so keep iterating while the list is
+ * not empty.
+ */
+ while (!list_empty(&ctx->conflict_inodes)) {
+ struct btrfs_ino_list *curr;
+ struct inode *inode;
+ u64 ino;
+ u64 parent;
+
+ curr = list_first_entry(&ctx->conflict_inodes,
+ struct btrfs_ino_list, list);
+ ino = curr->ino;
+ parent = curr->parent;
+ list_del(&curr->list);
+ kfree(curr);
+
+ inode = btrfs_iget(fs_info->sb, ino, root);
+ /*
+ * If the other inode that had a conflicting dir entry was
+ * deleted in the current transaction, we need to log its parent
+ * directory. See the comment at add_conflicting_inode().
+ */
+ if (IS_ERR(inode)) {
+ ret = PTR_ERR(inode);
+ if (ret != -ENOENT)
+ break;
+
+ inode = btrfs_iget(fs_info->sb, parent, root);
+ if (IS_ERR(inode)) {
+ ret = PTR_ERR(inode);
+ break;
+ }
+
+ /*
+ * Always log the directory, we cannot make this
+ * conditional on need_log_inode() because the directory
+ * might have been logged in LOG_INODE_EXISTS mode or
+ * the dir index of the conflicting inode is not in a
+ * dir index key range logged for the directory. So we
+ * must make sure the deletion is recorded.
+ */
+ ret = btrfs_log_inode(trans, BTRFS_I(inode),
+ LOG_INODE_ALL, ctx);
+ btrfs_add_delayed_iput(inode);
+ if (ret)
+ break;
+ continue;
+ }
+
+ /*
+ * Here we can use need_log_inode() because we only need to log
+ * the inode in LOG_INODE_EXISTS mode and rename operations
+ * update the log, so that the log ends up with the new name and
+ * without the old name.
+ *
+ * We did this check at add_conflicting_inode(), but here we do
+ * it again because if some other task logged the inode after
+ * that, we can avoid doing it again.
+ */
+ if (!need_log_inode(trans, BTRFS_I(inode))) {
+ btrfs_add_delayed_iput(inode);
+ continue;
+ }
+
+ /*
+ * We are safe logging the other inode without acquiring its
+ * lock as long as we log with the LOG_INODE_EXISTS mode. We
+ * are safe against concurrent renames of the other inode as
+ * well because during a rename we pin the log and update the
+ * log with the new name before we unpin it.
+ */
+ ret = btrfs_log_inode(trans, BTRFS_I(inode), LOG_INODE_EXISTS, ctx);
+ btrfs_add_delayed_iput(inode);
+ if (ret)
+ break;
+ }
+
+ ctx->logging_conflict_inodes = false;
+ if (ret)
+ free_conflicting_inodes(ctx);
+
+ return ret;
+}
+
+static int copy_inode_items_to_log(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_key *min_key,
+ const struct btrfs_key *max_key,
+ struct btrfs_path *path,
+ struct btrfs_path *dst_path,
+ const u64 logged_isize,
+ const int inode_only,
+ struct btrfs_log_ctx *ctx,
+ bool *need_log_inode_item)
+{
+ const u64 i_size = i_size_read(&inode->vfs_inode);
+ struct btrfs_root *root = inode->root;
+ int ins_start_slot = 0;
+ int ins_nr = 0;
+ int ret;
+
+ while (1) {
+ ret = btrfs_search_forward(root, min_key, path, trans->transid);
+ if (ret < 0)
+ return ret;
+ if (ret > 0) {
+ ret = 0;
+ break;
+ }
+again:
+ /* Note, ins_nr might be > 0 here, cleanup outside the loop */
+ if (min_key->objectid != max_key->objectid)
+ break;
+ if (min_key->type > max_key->type)
+ break;
+
+ if (min_key->type == BTRFS_INODE_ITEM_KEY) {
+ *need_log_inode_item = false;
+ } else if (min_key->type == BTRFS_EXTENT_DATA_KEY &&
+ min_key->offset >= i_size) {
+ /*
+ * Extents at and beyond eof are logged with
+ * btrfs_log_prealloc_extents().
+ * Only regular files have BTRFS_EXTENT_DATA_KEY keys,
+ * and no keys greater than that, so bail out.
+ */
+ break;
+ } else if ((min_key->type == BTRFS_INODE_REF_KEY ||
+ min_key->type == BTRFS_INODE_EXTREF_KEY) &&
+ (inode->generation == trans->transid ||
+ ctx->logging_conflict_inodes)) {
+ u64 other_ino = 0;
+ u64 other_parent = 0;
+
+ ret = btrfs_check_ref_name_override(path->nodes[0],
+ path->slots[0], min_key, inode,
+ &other_ino, &other_parent);
+ if (ret < 0) {
+ return ret;
+ } else if (ret > 0 &&
+ other_ino != btrfs_ino(BTRFS_I(ctx->inode))) {
+ if (ins_nr > 0) {
+ ins_nr++;
+ } else {
+ ins_nr = 1;
+ ins_start_slot = path->slots[0];
+ }
+ ret = copy_items(trans, inode, dst_path, path,
+ ins_start_slot, ins_nr,
+ inode_only, logged_isize);
+ if (ret < 0)
+ return ret;
+ ins_nr = 0;
+
+ btrfs_release_path(path);
+ ret = add_conflicting_inode(trans, root, path,
+ other_ino,
+ other_parent, ctx);
+ if (ret)
+ return ret;
+ goto next_key;
+ }
+ } else if (min_key->type == BTRFS_XATTR_ITEM_KEY) {
+ /* Skip xattrs, logged later with btrfs_log_all_xattrs() */
+ if (ins_nr == 0)
+ goto next_slot;
+ ret = copy_items(trans, inode, dst_path, path,
+ ins_start_slot,
+ ins_nr, inode_only, logged_isize);
+ if (ret < 0)
+ return ret;
+ ins_nr = 0;
+ goto next_slot;
+ }
+
+ if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
+ ins_nr++;
+ goto next_slot;
+ } else if (!ins_nr) {
+ ins_start_slot = path->slots[0];
+ ins_nr = 1;
+ goto next_slot;
+ }
+
+ ret = copy_items(trans, inode, dst_path, path, ins_start_slot,
+ ins_nr, inode_only, logged_isize);
+ if (ret < 0)
+ return ret;
+ ins_nr = 1;
+ ins_start_slot = path->slots[0];
+next_slot:
+ path->slots[0]++;
+ if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) {
+ btrfs_item_key_to_cpu(path->nodes[0], min_key,
+ path->slots[0]);
+ goto again;
+ }
+ if (ins_nr) {
+ ret = copy_items(trans, inode, dst_path, path,
+ ins_start_slot, ins_nr, inode_only,
+ logged_isize);
+ if (ret < 0)
+ return ret;
+ ins_nr = 0;
+ }
+ btrfs_release_path(path);
+next_key:
+ if (min_key->offset < (u64)-1) {
+ min_key->offset++;
+ } else if (min_key->type < max_key->type) {
+ min_key->type++;
+ min_key->offset = 0;
+ } else {
+ break;
+ }
+
+ /*
+ * We may process many leaves full of items for our inode, so
+ * avoid monopolizing a cpu for too long by rescheduling while
+ * not holding locks on any tree.
+ */
+ cond_resched();
+ }
+ if (ins_nr) {
+ ret = copy_items(trans, inode, dst_path, path, ins_start_slot,
+ ins_nr, inode_only, logged_isize);
+ if (ret)
+ return ret;
+ }
+
+ if (inode_only == LOG_INODE_ALL && S_ISREG(inode->vfs_inode.i_mode)) {
+ /*
+ * Release the path because otherwise we might attempt to double
+ * lock the same leaf with btrfs_log_prealloc_extents() below.
+ */
+ btrfs_release_path(path);
+ ret = btrfs_log_prealloc_extents(trans, inode, dst_path);
+ }
+
+ return ret;
+}
+
+static int insert_delayed_items_batch(struct btrfs_trans_handle *trans,
+ struct btrfs_root *log,
+ struct btrfs_path *path,
+ const struct btrfs_item_batch *batch,
+ const struct btrfs_delayed_item *first_item)
+{
+ const struct btrfs_delayed_item *curr = first_item;
+ int ret;
+
+ ret = btrfs_insert_empty_items(trans, log, path, batch);
+ if (ret)
+ return ret;
+
+ for (int i = 0; i < batch->nr; i++) {
+ char *data_ptr;
+
+ data_ptr = btrfs_item_ptr(path->nodes[0], path->slots[0], char);
+ write_extent_buffer(path->nodes[0], &curr->data,
+ (unsigned long)data_ptr, curr->data_len);
+ curr = list_next_entry(curr, log_list);
+ path->slots[0]++;
+ }
+
+ btrfs_release_path(path);
+
+ return 0;
+}
+
+static int log_delayed_insertion_items(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ const struct list_head *delayed_ins_list,
+ struct btrfs_log_ctx *ctx)
+{
+ /* 195 (4095 bytes of keys and sizes) fits in a single 4K page. */
+ const int max_batch_size = 195;
+ const int leaf_data_size = BTRFS_LEAF_DATA_SIZE(trans->fs_info);
+ const u64 ino = btrfs_ino(inode);
+ struct btrfs_root *log = inode->root->log_root;
+ struct btrfs_item_batch batch = {
+ .nr = 0,
+ .total_data_size = 0,
+ };
+ const struct btrfs_delayed_item *first = NULL;
+ const struct btrfs_delayed_item *curr;
+ char *ins_data;
+ struct btrfs_key *ins_keys;
+ u32 *ins_sizes;
+ u64 curr_batch_size = 0;
+ int batch_idx = 0;
+ int ret;
+
+ /* We are adding dir index items to the log tree. */
+ lockdep_assert_held(&inode->log_mutex);
+
+ /*
+ * We collect delayed items before copying index keys from the subvolume
+ * to the log tree. However just after we collected them, they may have
+ * been flushed (all of them or just some of them), and therefore we
+ * could have copied them from the subvolume tree to the log tree.
+ * So find the first delayed item that was not yet logged (they are
+ * sorted by index number).
+ */
+ list_for_each_entry(curr, delayed_ins_list, log_list) {
+ if (curr->index > inode->last_dir_index_offset) {
+ first = curr;
+ break;
+ }
+ }
+
+ /* Empty list or all delayed items were already logged. */
+ if (!first)
+ return 0;
+
+ ins_data = kmalloc(max_batch_size * sizeof(u32) +
+ max_batch_size * sizeof(struct btrfs_key), GFP_NOFS);
+ if (!ins_data)
+ return -ENOMEM;
+ ins_sizes = (u32 *)ins_data;
+ batch.data_sizes = ins_sizes;
+ ins_keys = (struct btrfs_key *)(ins_data + max_batch_size * sizeof(u32));
+ batch.keys = ins_keys;
+
+ curr = first;
+ while (!list_entry_is_head(curr, delayed_ins_list, log_list)) {
+ const u32 curr_size = curr->data_len + sizeof(struct btrfs_item);
+
+ if (curr_batch_size + curr_size > leaf_data_size ||
+ batch.nr == max_batch_size) {
+ ret = insert_delayed_items_batch(trans, log, path,
+ &batch, first);
+ if (ret)
+ goto out;
+ batch_idx = 0;
+ batch.nr = 0;
+ batch.total_data_size = 0;
+ curr_batch_size = 0;
+ first = curr;
+ }
+
+ ins_sizes[batch_idx] = curr->data_len;
+ ins_keys[batch_idx].objectid = ino;
+ ins_keys[batch_idx].type = BTRFS_DIR_INDEX_KEY;
+ ins_keys[batch_idx].offset = curr->index;
+ curr_batch_size += curr_size;
+ batch.total_data_size += curr->data_len;
+ batch.nr++;
+ batch_idx++;
+ curr = list_next_entry(curr, log_list);
+ }
+
+ ASSERT(batch.nr >= 1);
+ ret = insert_delayed_items_batch(trans, log, path, &batch, first);
+
+ curr = list_last_entry(delayed_ins_list, struct btrfs_delayed_item,
+ log_list);
+ inode->last_dir_index_offset = curr->index;
+out:
+ kfree(ins_data);
+
+ return ret;
+}
+
+static int log_delayed_deletions_full(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ const struct list_head *delayed_del_list,
+ struct btrfs_log_ctx *ctx)
+{
+ const u64 ino = btrfs_ino(inode);
+ const struct btrfs_delayed_item *curr;
+
+ curr = list_first_entry(delayed_del_list, struct btrfs_delayed_item,
+ log_list);
+
+ while (!list_entry_is_head(curr, delayed_del_list, log_list)) {
+ u64 first_dir_index = curr->index;
+ u64 last_dir_index;
+ const struct btrfs_delayed_item *next;
+ int ret;
+
+ /*
+ * Find a range of consecutive dir index items to delete. Like
+ * this we log a single dir range item spanning several contiguous
+ * dir items instead of logging one range item per dir index item.
+ */
+ next = list_next_entry(curr, log_list);
+ while (!list_entry_is_head(next, delayed_del_list, log_list)) {
+ if (next->index != curr->index + 1)
+ break;
+ curr = next;
+ next = list_next_entry(next, log_list);
+ }
+
+ last_dir_index = curr->index;
+ ASSERT(last_dir_index >= first_dir_index);
+
+ ret = insert_dir_log_key(trans, inode->root->log_root, path,
+ ino, first_dir_index, last_dir_index);
+ if (ret)
+ return ret;
+ curr = list_next_entry(curr, log_list);
+ }
+
+ return 0;
+}
+
+static int batch_delete_dir_index_items(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ struct btrfs_log_ctx *ctx,
+ const struct list_head *delayed_del_list,
+ const struct btrfs_delayed_item *first,
+ const struct btrfs_delayed_item **last_ret)
+{
+ const struct btrfs_delayed_item *next;
+ struct extent_buffer *leaf = path->nodes[0];
+ const int last_slot = btrfs_header_nritems(leaf) - 1;
+ int slot = path->slots[0] + 1;
+ const u64 ino = btrfs_ino(inode);
+
+ next = list_next_entry(first, log_list);
+
+ while (slot < last_slot &&
+ !list_entry_is_head(next, delayed_del_list, log_list)) {
+ struct btrfs_key key;
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.objectid != ino ||
+ key.type != BTRFS_DIR_INDEX_KEY ||
+ key.offset != next->index)
+ break;
+
+ slot++;
+ *last_ret = next;
+ next = list_next_entry(next, log_list);
+ }
+
+ return btrfs_del_items(trans, inode->root->log_root, path,
+ path->slots[0], slot - path->slots[0]);
+}
+
+static int log_delayed_deletions_incremental(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ const struct list_head *delayed_del_list,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_root *log = inode->root->log_root;
+ const struct btrfs_delayed_item *curr;
+ u64 last_range_start = 0;
+ u64 last_range_end = 0;
+ struct btrfs_key key;
+
+ key.objectid = btrfs_ino(inode);
+ key.type = BTRFS_DIR_INDEX_KEY;
+ curr = list_first_entry(delayed_del_list, struct btrfs_delayed_item,
+ log_list);
+
+ while (!list_entry_is_head(curr, delayed_del_list, log_list)) {
+ const struct btrfs_delayed_item *last = curr;
+ u64 first_dir_index = curr->index;
+ u64 last_dir_index;
+ bool deleted_items = false;
+ int ret;
+
+ key.offset = curr->index;
+ ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
+ if (ret < 0) {
+ return ret;
+ } else if (ret == 0) {
+ ret = batch_delete_dir_index_items(trans, inode, path, ctx,
+ delayed_del_list, curr,
+ &last);
+ if (ret)
+ return ret;
+ deleted_items = true;
+ }
+
+ btrfs_release_path(path);
+
+ /*
+ * If we deleted items from the leaf, it means we have a range
+ * item logging their range, so no need to add one or update an
+ * existing one. Otherwise we have to log a dir range item.
+ */
+ if (deleted_items)
+ goto next_batch;
+
+ last_dir_index = last->index;
+ ASSERT(last_dir_index >= first_dir_index);
+ /*
+ * If this range starts right after where the previous one ends,
+ * then we want to reuse the previous range item and change its
+ * end offset to the end of this range. This is just to minimize
+ * leaf space usage, by avoiding adding a new range item.
+ */
+ if (last_range_end != 0 && first_dir_index == last_range_end + 1)
+ first_dir_index = last_range_start;
+
+ ret = insert_dir_log_key(trans, log, path, key.objectid,
+ first_dir_index, last_dir_index);
+ if (ret)
+ return ret;
+
+ last_range_start = first_dir_index;
+ last_range_end = last_dir_index;
+next_batch:
+ curr = list_next_entry(last, log_list);
+ }
+
+ return 0;
+}
+
+static int log_delayed_deletion_items(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ const struct list_head *delayed_del_list,
+ struct btrfs_log_ctx *ctx)
+{
+ /*
+ * We are deleting dir index items from the log tree or adding range
+ * items to it.
+ */
+ lockdep_assert_held(&inode->log_mutex);
+
+ if (list_empty(delayed_del_list))
+ return 0;
+
+ if (ctx->logged_before)
+ return log_delayed_deletions_incremental(trans, inode, path,
+ delayed_del_list, ctx);
+
+ return log_delayed_deletions_full(trans, inode, path, delayed_del_list,
+ ctx);
+}
+
+/*
+ * Similar logic as for log_new_dir_dentries(), but it iterates over the delayed
+ * items instead of the subvolume tree.
+ */
+static int log_new_delayed_dentries(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ const struct list_head *delayed_ins_list,
+ struct btrfs_log_ctx *ctx)
+{
+ const bool orig_log_new_dentries = ctx->log_new_dentries;
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ struct btrfs_delayed_item *item;
+ int ret = 0;
+
+ /*
+ * No need for the log mutex, plus to avoid potential deadlocks or
+ * lockdep annotations due to nesting of delayed inode mutexes and log
+ * mutexes.
+ */
+ lockdep_assert_not_held(&inode->log_mutex);
+
+ ASSERT(!ctx->logging_new_delayed_dentries);
+ ctx->logging_new_delayed_dentries = true;
+
+ list_for_each_entry(item, delayed_ins_list, log_list) {
+ struct btrfs_dir_item *dir_item;
+ struct inode *di_inode;
+ struct btrfs_key key;
+ int log_mode = LOG_INODE_EXISTS;
+
+ dir_item = (struct btrfs_dir_item *)item->data;
+ btrfs_disk_key_to_cpu(&key, &dir_item->location);
+
+ if (key.type == BTRFS_ROOT_ITEM_KEY)
+ continue;
+
+ di_inode = btrfs_iget(fs_info->sb, key.objectid, inode->root);
+ if (IS_ERR(di_inode)) {
+ ret = PTR_ERR(di_inode);
+ break;
+ }
+
+ if (!need_log_inode(trans, BTRFS_I(di_inode))) {
+ btrfs_add_delayed_iput(di_inode);
+ continue;
+ }
+
+ if (btrfs_stack_dir_type(dir_item) == BTRFS_FT_DIR)
+ log_mode = LOG_INODE_ALL;
+
+ ctx->log_new_dentries = false;
+ ret = btrfs_log_inode(trans, BTRFS_I(di_inode), log_mode, ctx);
+
+ if (!ret && ctx->log_new_dentries)
+ ret = log_new_dir_dentries(trans, BTRFS_I(di_inode), ctx);
+
+ btrfs_add_delayed_iput(di_inode);
+
+ if (ret)
+ break;
+ }
+
+ ctx->log_new_dentries = orig_log_new_dentries;
+ ctx->logging_new_delayed_dentries = false;
+
+ return ret;
+}
+
+/* log a single inode in the tree log.
+ * At least one parent directory for this inode must exist in the tree
+ * or be logged already.
+ *
+ * Any items from this inode changed by the current transaction are copied
+ * to the log tree. An extra reference is taken on any extents in this
+ * file, allowing us to avoid a whole pile of corner cases around logging
+ * blocks that have been removed from the tree.
+ *
+ * See LOG_INODE_ALL and related defines for a description of what inode_only
+ * does.
+ *
+ * This handles both files and directories.
+ */
+static int btrfs_log_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ int inode_only,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_path *path;
+ struct btrfs_path *dst_path;
+ struct btrfs_key min_key;
+ struct btrfs_key max_key;
+ struct btrfs_root *log = inode->root->log_root;
+ int ret;
+ bool fast_search = false;
+ u64 ino = btrfs_ino(inode);
+ struct extent_map_tree *em_tree = &inode->extent_tree;
+ u64 logged_isize = 0;
+ bool need_log_inode_item = true;
+ bool xattrs_logged = false;
+ bool inode_item_dropped = true;
+ bool full_dir_logging = false;
+ LIST_HEAD(delayed_ins_list);
+ LIST_HEAD(delayed_del_list);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ dst_path = btrfs_alloc_path();
+ if (!dst_path) {
+ btrfs_free_path(path);
+ return -ENOMEM;
+ }
+
+ min_key.objectid = ino;
+ min_key.type = BTRFS_INODE_ITEM_KEY;
+ min_key.offset = 0;
+
+ max_key.objectid = ino;
+
+
+ /* today the code can only do partial logging of directories */
+ if (S_ISDIR(inode->vfs_inode.i_mode) ||
+ (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
+ &inode->runtime_flags) &&
+ inode_only >= LOG_INODE_EXISTS))
+ max_key.type = BTRFS_XATTR_ITEM_KEY;
+ else
+ max_key.type = (u8)-1;
+ max_key.offset = (u64)-1;
+
+ if (S_ISDIR(inode->vfs_inode.i_mode) && inode_only == LOG_INODE_ALL)
+ full_dir_logging = true;
+
+ /*
+ * If we are logging a directory while we are logging dentries of the
+ * delayed items of some other inode, then we need to flush the delayed
+ * items of this directory and not log the delayed items directly. This
+ * is to prevent more than one level of recursion into btrfs_log_inode()
+ * by having something like this:
+ *
+ * $ mkdir -p a/b/c/d/e/f/g/h/...
+ * $ xfs_io -c "fsync" a
+ *
+ * Where all directories in the path did not exist before and are
+ * created in the current transaction.
+ * So in such a case we directly log the delayed items of the main
+ * directory ("a") without flushing them first, while for each of its
+ * subdirectories we flush their delayed items before logging them.
+ * This prevents a potential unbounded recursion like this:
+ *
+ * btrfs_log_inode()
+ * log_new_delayed_dentries()
+ * btrfs_log_inode()
+ * log_new_delayed_dentries()
+ * btrfs_log_inode()
+ * log_new_delayed_dentries()
+ * (...)
+ *
+ * We have thresholds for the maximum number of delayed items to have in
+ * memory, and once they are hit, the items are flushed asynchronously.
+ * However the limit is quite high, so lets prevent deep levels of
+ * recursion to happen by limiting the maximum depth to be 1.
+ */
+ if (full_dir_logging && ctx->logging_new_delayed_dentries) {
+ ret = btrfs_commit_inode_delayed_items(trans, inode);
+ if (ret)
+ goto out;
+ }
+
+ mutex_lock(&inode->log_mutex);
+
+ /*
+ * For symlinks, we must always log their content, which is stored in an
+ * inline extent, otherwise we could end up with an empty symlink after
+ * log replay, which is invalid on linux (symlink(2) returns -ENOENT if
+ * one attempts to create an empty symlink).
+ * We don't need to worry about flushing delalloc, because when we create
+ * the inline extent when the symlink is created (we never have delalloc
+ * for symlinks).
+ */
+ if (S_ISLNK(inode->vfs_inode.i_mode))
+ inode_only = LOG_INODE_ALL;
+
+ /*
+ * Before logging the inode item, cache the value returned by
+ * inode_logged(), because after that we have the need to figure out if
+ * the inode was previously logged in this transaction.
+ */
+ ret = inode_logged(trans, inode, path);
+ if (ret < 0)
+ goto out_unlock;
+ ctx->logged_before = (ret == 1);
+ ret = 0;
+
+ /*
+ * This is for cases where logging a directory could result in losing a
+ * a file after replaying the log. For example, if we move a file from a
+ * directory A to a directory B, then fsync directory A, we have no way
+ * to known the file was moved from A to B, so logging just A would
+ * result in losing the file after a log replay.
+ */
+ if (full_dir_logging && inode->last_unlink_trans >= trans->transid) {
+ btrfs_set_log_full_commit(trans);
+ ret = BTRFS_LOG_FORCE_COMMIT;
+ goto out_unlock;
+ }
+
+ /*
+ * a brute force approach to making sure we get the most uptodate
+ * copies of everything.
+ */
+ if (S_ISDIR(inode->vfs_inode.i_mode)) {
+ clear_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags);
+ if (ctx->logged_before)
+ ret = drop_inode_items(trans, log, path, inode,
+ BTRFS_XATTR_ITEM_KEY);
+ } else {
+ if (inode_only == LOG_INODE_EXISTS && ctx->logged_before) {
+ /*
+ * Make sure the new inode item we write to the log has
+ * the same isize as the current one (if it exists).
+ * This is necessary to prevent data loss after log
+ * replay, and also to prevent doing a wrong expanding
+ * truncate - for e.g. create file, write 4K into offset
+ * 0, fsync, write 4K into offset 4096, add hard link,
+ * fsync some other file (to sync log), power fail - if
+ * we use the inode's current i_size, after log replay
+ * we get a 8Kb file, with the last 4Kb extent as a hole
+ * (zeroes), as if an expanding truncate happened,
+ * instead of getting a file of 4Kb only.
+ */
+ ret = logged_inode_size(log, inode, path, &logged_isize);
+ if (ret)
+ goto out_unlock;
+ }
+ if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
+ &inode->runtime_flags)) {
+ if (inode_only == LOG_INODE_EXISTS) {
+ max_key.type = BTRFS_XATTR_ITEM_KEY;
+ if (ctx->logged_before)
+ ret = drop_inode_items(trans, log, path,
+ inode, max_key.type);
+ } else {
+ clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
+ &inode->runtime_flags);
+ clear_bit(BTRFS_INODE_COPY_EVERYTHING,
+ &inode->runtime_flags);
+ if (ctx->logged_before)
+ ret = truncate_inode_items(trans, log,
+ inode, 0, 0);
+ }
+ } else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING,
+ &inode->runtime_flags) ||
+ inode_only == LOG_INODE_EXISTS) {
+ if (inode_only == LOG_INODE_ALL)
+ fast_search = true;
+ max_key.type = BTRFS_XATTR_ITEM_KEY;
+ if (ctx->logged_before)
+ ret = drop_inode_items(trans, log, path, inode,
+ max_key.type);
+ } else {
+ if (inode_only == LOG_INODE_ALL)
+ fast_search = true;
+ inode_item_dropped = false;
+ goto log_extents;
+ }
+
+ }
+ if (ret)
+ goto out_unlock;
+
+ /*
+ * If we are logging a directory in full mode, collect the delayed items
+ * before iterating the subvolume tree, so that we don't miss any new
+ * dir index items in case they get flushed while or right after we are
+ * iterating the subvolume tree.
+ */
+ if (full_dir_logging && !ctx->logging_new_delayed_dentries)
+ btrfs_log_get_delayed_items(inode, &delayed_ins_list,
+ &delayed_del_list);
+
+ ret = copy_inode_items_to_log(trans, inode, &min_key, &max_key,
+ path, dst_path, logged_isize,
+ inode_only, ctx,
+ &need_log_inode_item);
+ if (ret)
+ goto out_unlock;
+
+ btrfs_release_path(path);
+ btrfs_release_path(dst_path);
+ ret = btrfs_log_all_xattrs(trans, inode, path, dst_path);
+ if (ret)
+ goto out_unlock;
+ xattrs_logged = true;
+ if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) {
+ btrfs_release_path(path);
+ btrfs_release_path(dst_path);
+ ret = btrfs_log_holes(trans, inode, path);
+ if (ret)
+ goto out_unlock;
+ }
+log_extents:
+ btrfs_release_path(path);
+ btrfs_release_path(dst_path);
+ if (need_log_inode_item) {
+ ret = log_inode_item(trans, log, dst_path, inode, inode_item_dropped);
+ if (ret)
+ goto out_unlock;
+ /*
+ * If we are doing a fast fsync and the inode was logged before
+ * in this transaction, we don't need to log the xattrs because
+ * they were logged before. If xattrs were added, changed or
+ * deleted since the last time we logged the inode, then we have
+ * already logged them because the inode had the runtime flag
+ * BTRFS_INODE_COPY_EVERYTHING set.
+ */
+ if (!xattrs_logged && inode->logged_trans < trans->transid) {
+ ret = btrfs_log_all_xattrs(trans, inode, path, dst_path);
+ if (ret)
+ goto out_unlock;
+ btrfs_release_path(path);
+ }
+ }
+ if (fast_search) {
+ ret = btrfs_log_changed_extents(trans, inode, dst_path, ctx);
+ if (ret)
+ goto out_unlock;
+ } else if (inode_only == LOG_INODE_ALL) {
+ struct extent_map *em, *n;
+
+ write_lock(&em_tree->lock);
+ list_for_each_entry_safe(em, n, &em_tree->modified_extents, list)
+ list_del_init(&em->list);
+ write_unlock(&em_tree->lock);
+ }
+
+ if (full_dir_logging) {
+ ret = log_directory_changes(trans, inode, path, dst_path, ctx);
+ if (ret)
+ goto out_unlock;
+ ret = log_delayed_insertion_items(trans, inode, path,
+ &delayed_ins_list, ctx);
+ if (ret)
+ goto out_unlock;
+ ret = log_delayed_deletion_items(trans, inode, path,
+ &delayed_del_list, ctx);
+ if (ret)
+ goto out_unlock;
+ }
+
+ spin_lock(&inode->lock);
+ inode->logged_trans = trans->transid;
+ /*
+ * Don't update last_log_commit if we logged that an inode exists.
+ * We do this for three reasons:
+ *
+ * 1) We might have had buffered writes to this inode that were
+ * flushed and had their ordered extents completed in this
+ * transaction, but we did not previously log the inode with
+ * LOG_INODE_ALL. Later the inode was evicted and after that
+ * it was loaded again and this LOG_INODE_EXISTS log operation
+ * happened. We must make sure that if an explicit fsync against
+ * the inode is performed later, it logs the new extents, an
+ * updated inode item, etc, and syncs the log. The same logic
+ * applies to direct IO writes instead of buffered writes.
+ *
+ * 2) When we log the inode with LOG_INODE_EXISTS, its inode item
+ * is logged with an i_size of 0 or whatever value was logged
+ * before. If later the i_size of the inode is increased by a
+ * truncate operation, the log is synced through an fsync of
+ * some other inode and then finally an explicit fsync against
+ * this inode is made, we must make sure this fsync logs the
+ * inode with the new i_size, the hole between old i_size and
+ * the new i_size, and syncs the log.
+ *
+ * 3) If we are logging that an ancestor inode exists as part of
+ * logging a new name from a link or rename operation, don't update
+ * its last_log_commit - otherwise if an explicit fsync is made
+ * against an ancestor, the fsync considers the inode in the log
+ * and doesn't sync the log, resulting in the ancestor missing after
+ * a power failure unless the log was synced as part of an fsync
+ * against any other unrelated inode.
+ */
+ if (inode_only != LOG_INODE_EXISTS)
+ inode->last_log_commit = inode->last_sub_trans;
+ spin_unlock(&inode->lock);
+
+ /*
+ * Reset the last_reflink_trans so that the next fsync does not need to
+ * go through the slower path when logging extents and their checksums.
+ */
+ if (inode_only == LOG_INODE_ALL)
+ inode->last_reflink_trans = 0;
+
+out_unlock:
+ mutex_unlock(&inode->log_mutex);
+out:
+ btrfs_free_path(path);
+ btrfs_free_path(dst_path);
+
+ if (ret)
+ free_conflicting_inodes(ctx);
+ else
+ ret = log_conflicting_inodes(trans, inode->root, ctx);
+
+ if (full_dir_logging && !ctx->logging_new_delayed_dentries) {
+ if (!ret)
+ ret = log_new_delayed_dentries(trans, inode,
+ &delayed_ins_list, ctx);
+
+ btrfs_log_put_delayed_items(inode, &delayed_ins_list,
+ &delayed_del_list);
+ }
+
+ return ret;
+}
+
+static int btrfs_log_all_parents(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_root *root = inode->root;
+ const u64 ino = btrfs_ino(inode);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ path->skip_locking = 1;
+ path->search_commit_root = 1;
+
+ key.objectid = ino;
+ key.type = BTRFS_INODE_REF_KEY;
+ key.offset = 0;
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ while (true) {
+ struct extent_buffer *leaf = path->nodes[0];
+ int slot = path->slots[0];
+ u32 cur_offset = 0;
+ u32 item_size;
+ unsigned long ptr;
+
+ if (slot >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto out;
+ else if (ret > 0)
+ break;
+ continue;
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ /* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */
+ if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY)
+ break;
+
+ item_size = btrfs_item_size(leaf, slot);
+ ptr = btrfs_item_ptr_offset(leaf, slot);
+ while (cur_offset < item_size) {
+ struct btrfs_key inode_key;
+ struct inode *dir_inode;
+
+ inode_key.type = BTRFS_INODE_ITEM_KEY;
+ inode_key.offset = 0;
+
+ if (key.type == BTRFS_INODE_EXTREF_KEY) {
+ struct btrfs_inode_extref *extref;
+
+ extref = (struct btrfs_inode_extref *)
+ (ptr + cur_offset);
+ inode_key.objectid = btrfs_inode_extref_parent(
+ leaf, extref);
+ cur_offset += sizeof(*extref);
+ cur_offset += btrfs_inode_extref_name_len(leaf,
+ extref);
+ } else {
+ inode_key.objectid = key.offset;
+ cur_offset = item_size;
+ }
+
+ dir_inode = btrfs_iget(fs_info->sb, inode_key.objectid,
+ root);
+ /*
+ * If the parent inode was deleted, return an error to
+ * fallback to a transaction commit. This is to prevent
+ * getting an inode that was moved from one parent A to
+ * a parent B, got its former parent A deleted and then
+ * it got fsync'ed, from existing at both parents after
+ * a log replay (and the old parent still existing).
+ * Example:
+ *
+ * mkdir /mnt/A
+ * mkdir /mnt/B
+ * touch /mnt/B/bar
+ * sync
+ * mv /mnt/B/bar /mnt/A/bar
+ * mv -T /mnt/A /mnt/B
+ * fsync /mnt/B/bar
+ * <power fail>
+ *
+ * If we ignore the old parent B which got deleted,
+ * after a log replay we would have file bar linked
+ * at both parents and the old parent B would still
+ * exist.
+ */
+ if (IS_ERR(dir_inode)) {
+ ret = PTR_ERR(dir_inode);
+ goto out;
+ }
+
+ if (!need_log_inode(trans, BTRFS_I(dir_inode))) {
+ btrfs_add_delayed_iput(dir_inode);
+ continue;
+ }
+
+ ctx->log_new_dentries = false;
+ ret = btrfs_log_inode(trans, BTRFS_I(dir_inode),
+ LOG_INODE_ALL, ctx);
+ if (!ret && ctx->log_new_dentries)
+ ret = log_new_dir_dentries(trans,
+ BTRFS_I(dir_inode), ctx);
+ btrfs_add_delayed_iput(dir_inode);
+ if (ret)
+ goto out;
+ }
+ path->slots[0]++;
+ }
+ ret = 0;
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static int log_new_ancestors(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_key found_key;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
+
+ while (true) {
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct extent_buffer *leaf = path->nodes[0];
+ int slot = path->slots[0];
+ struct btrfs_key search_key;
+ struct inode *inode;
+ u64 ino;
+ int ret = 0;
+
+ btrfs_release_path(path);
+
+ ino = found_key.offset;
+
+ search_key.objectid = found_key.offset;
+ search_key.type = BTRFS_INODE_ITEM_KEY;
+ search_key.offset = 0;
+ inode = btrfs_iget(fs_info->sb, ino, root);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ if (BTRFS_I(inode)->generation >= trans->transid &&
+ need_log_inode(trans, BTRFS_I(inode)))
+ ret = btrfs_log_inode(trans, BTRFS_I(inode),
+ LOG_INODE_EXISTS, ctx);
+ btrfs_add_delayed_iput(inode);
+ if (ret)
+ return ret;
+
+ if (search_key.objectid == BTRFS_FIRST_FREE_OBJECTID)
+ break;
+
+ search_key.type = BTRFS_INODE_REF_KEY;
+ ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+ if (ret < 0)
+ return ret;
+
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ return ret;
+ else if (ret > 0)
+ return -ENOENT;
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ }
+
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+ if (found_key.objectid != search_key.objectid ||
+ found_key.type != BTRFS_INODE_REF_KEY)
+ return -ENOENT;
+ }
+ return 0;
+}
+
+static int log_new_ancestors_fast(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct dentry *parent,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_root *root = inode->root;
+ struct dentry *old_parent = NULL;
+ struct super_block *sb = inode->vfs_inode.i_sb;
+ int ret = 0;
+
+ while (true) {
+ if (!parent || d_really_is_negative(parent) ||
+ sb != parent->d_sb)
+ break;
+
+ inode = BTRFS_I(d_inode(parent));
+ if (root != inode->root)
+ break;
+
+ if (inode->generation >= trans->transid &&
+ need_log_inode(trans, inode)) {
+ ret = btrfs_log_inode(trans, inode,
+ LOG_INODE_EXISTS, ctx);
+ if (ret)
+ break;
+ }
+ if (IS_ROOT(parent))
+ break;
+
+ parent = dget_parent(parent);
+ dput(old_parent);
+ old_parent = parent;
+ }
+ dput(old_parent);
+
+ return ret;
+}
+
+static int log_all_new_ancestors(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct dentry *parent,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_root *root = inode->root;
+ const u64 ino = btrfs_ino(inode);
+ struct btrfs_path *path;
+ struct btrfs_key search_key;
+ int ret;
+
+ /*
+ * For a single hard link case, go through a fast path that does not
+ * need to iterate the fs/subvolume tree.
+ */
+ if (inode->vfs_inode.i_nlink < 2)
+ return log_new_ancestors_fast(trans, inode, parent, ctx);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ search_key.objectid = ino;
+ search_key.type = BTRFS_INODE_REF_KEY;
+ search_key.offset = 0;
+again:
+ ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ if (ret == 0)
+ path->slots[0]++;
+
+ while (true) {
+ struct extent_buffer *leaf = path->nodes[0];
+ int slot = path->slots[0];
+ struct btrfs_key found_key;
+
+ if (slot >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto out;
+ else if (ret > 0)
+ break;
+ continue;
+ }
+
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+ if (found_key.objectid != ino ||
+ found_key.type > BTRFS_INODE_EXTREF_KEY)
+ break;
+
+ /*
+ * Don't deal with extended references because they are rare
+ * cases and too complex to deal with (we would need to keep
+ * track of which subitem we are processing for each item in
+ * this loop, etc). So just return some error to fallback to
+ * a transaction commit.
+ */
+ if (found_key.type == BTRFS_INODE_EXTREF_KEY) {
+ ret = -EMLINK;
+ goto out;
+ }
+
+ /*
+ * Logging ancestors needs to do more searches on the fs/subvol
+ * tree, so it releases the path as needed to avoid deadlocks.
+ * Keep track of the last inode ref key and resume from that key
+ * after logging all new ancestors for the current hard link.
+ */
+ memcpy(&search_key, &found_key, sizeof(search_key));
+
+ ret = log_new_ancestors(trans, root, path, ctx);
+ if (ret)
+ goto out;
+ btrfs_release_path(path);
+ goto again;
+ }
+ ret = 0;
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * helper function around btrfs_log_inode to make sure newly created
+ * parent directories also end up in the log. A minimal inode and backref
+ * only logging is done of any parent directories that are older than
+ * the last committed transaction
+ */
+static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *inode,
+ struct dentry *parent,
+ int inode_only,
+ struct btrfs_log_ctx *ctx)
+{
+ struct btrfs_root *root = inode->root;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ int ret = 0;
+ bool log_dentries = false;
+
+ if (btrfs_test_opt(fs_info, NOTREELOG)) {
+ ret = BTRFS_LOG_FORCE_COMMIT;
+ goto end_no_trans;
+ }
+
+ if (btrfs_root_refs(&root->root_item) == 0) {
+ ret = BTRFS_LOG_FORCE_COMMIT;
+ goto end_no_trans;
+ }
+
+ /*
+ * Skip already logged inodes or inodes corresponding to tmpfiles
+ * (since logging them is pointless, a link count of 0 means they
+ * will never be accessible).
+ */
+ if ((btrfs_inode_in_log(inode, trans->transid) &&
+ list_empty(&ctx->ordered_extents)) ||
+ inode->vfs_inode.i_nlink == 0) {
+ ret = BTRFS_NO_LOG_SYNC;
+ goto end_no_trans;
+ }
+
+ ret = start_log_trans(trans, root, ctx);
+ if (ret)
+ goto end_no_trans;
+
+ ret = btrfs_log_inode(trans, inode, inode_only, ctx);
+ if (ret)
+ goto end_trans;
+
+ /*
+ * for regular files, if its inode is already on disk, we don't
+ * have to worry about the parents at all. This is because
+ * we can use the last_unlink_trans field to record renames
+ * and other fun in this file.
+ */
+ if (S_ISREG(inode->vfs_inode.i_mode) &&
+ inode->generation < trans->transid &&
+ inode->last_unlink_trans < trans->transid) {
+ ret = 0;
+ goto end_trans;
+ }
+
+ if (S_ISDIR(inode->vfs_inode.i_mode) && ctx->log_new_dentries)
+ log_dentries = true;
+
+ /*
+ * On unlink we must make sure all our current and old parent directory
+ * inodes are fully logged. This is to prevent leaving dangling
+ * directory index entries in directories that were our parents but are
+ * not anymore. Not doing this results in old parent directory being
+ * impossible to delete after log replay (rmdir will always fail with
+ * error -ENOTEMPTY).
+ *
+ * Example 1:
+ *
+ * mkdir testdir
+ * touch testdir/foo
+ * ln testdir/foo testdir/bar
+ * sync
+ * unlink testdir/bar
+ * xfs_io -c fsync testdir/foo
+ * <power failure>
+ * mount fs, triggers log replay
+ *
+ * If we don't log the parent directory (testdir), after log replay the
+ * directory still has an entry pointing to the file inode using the bar
+ * name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and
+ * the file inode has a link count of 1.
+ *
+ * Example 2:
+ *
+ * mkdir testdir
+ * touch foo
+ * ln foo testdir/foo2
+ * ln foo testdir/foo3
+ * sync
+ * unlink testdir/foo3
+ * xfs_io -c fsync foo
+ * <power failure>
+ * mount fs, triggers log replay
+ *
+ * Similar as the first example, after log replay the parent directory
+ * testdir still has an entry pointing to the inode file with name foo3
+ * but the file inode does not have a matching BTRFS_INODE_REF_KEY item
+ * and has a link count of 2.
+ */
+ if (inode->last_unlink_trans >= trans->transid) {
+ ret = btrfs_log_all_parents(trans, inode, ctx);
+ if (ret)
+ goto end_trans;
+ }
+
+ ret = log_all_new_ancestors(trans, inode, parent, ctx);
+ if (ret)
+ goto end_trans;
+
+ if (log_dentries)
+ ret = log_new_dir_dentries(trans, inode, ctx);
+ else
+ ret = 0;
+end_trans:
+ if (ret < 0) {
+ btrfs_set_log_full_commit(trans);
+ ret = BTRFS_LOG_FORCE_COMMIT;
+ }
+
+ if (ret)
+ btrfs_remove_log_ctx(root, ctx);
+ btrfs_end_log_trans(root);
+end_no_trans:
+ return ret;
+}
+
+/*
+ * it is not safe to log dentry if the chunk root has added new
+ * chunks. This returns 0 if the dentry was logged, and 1 otherwise.
+ * If this returns 1, you must commit the transaction to safely get your
+ * data on disk.
+ */
+int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
+ struct dentry *dentry,
+ struct btrfs_log_ctx *ctx)
+{
+ struct dentry *parent = dget_parent(dentry);
+ int ret;
+
+ ret = btrfs_log_inode_parent(trans, BTRFS_I(d_inode(dentry)), parent,
+ LOG_INODE_ALL, ctx);
+ dput(parent);
+
+ return ret;
+}
+
+/*
+ * should be called during mount to recover any replay any log trees
+ * from the FS
+ */
+int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
+{
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_root *log;
+ struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
+ struct walk_control wc = {
+ .process_func = process_one_buffer,
+ .stage = LOG_WALK_PIN_ONLY,
+ };
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ set_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
+
+ trans = btrfs_start_transaction(fs_info->tree_root, 0);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto error;
+ }
+
+ wc.trans = trans;
+ wc.pin = 1;
+
+ ret = walk_log_tree(trans, log_root_tree, &wc);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ goto error;
+ }
+
+again:
+ key.objectid = BTRFS_TREE_LOG_OBJECTID;
+ key.offset = (u64)-1;
+ key.type = BTRFS_ROOT_ITEM_KEY;
+
+ while (1) {
+ ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
+
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, ret);
+ goto error;
+ }
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ break;
+ path->slots[0]--;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+ btrfs_release_path(path);
+ if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
+ break;
+
+ log = btrfs_read_tree_root(log_root_tree, &found_key);
+ if (IS_ERR(log)) {
+ ret = PTR_ERR(log);
+ btrfs_abort_transaction(trans, ret);
+ goto error;
+ }
+
+ wc.replay_dest = btrfs_get_fs_root(fs_info, found_key.offset,
+ true);
+ if (IS_ERR(wc.replay_dest)) {
+ ret = PTR_ERR(wc.replay_dest);
+
+ /*
+ * We didn't find the subvol, likely because it was
+ * deleted. This is ok, simply skip this log and go to
+ * the next one.
+ *
+ * We need to exclude the root because we can't have
+ * other log replays overwriting this log as we'll read
+ * it back in a few more times. This will keep our
+ * block from being modified, and we'll just bail for
+ * each subsequent pass.
+ */
+ if (ret == -ENOENT)
+ ret = btrfs_pin_extent_for_log_replay(trans,
+ log->node->start,
+ log->node->len);
+ btrfs_put_root(log);
+
+ if (!ret)
+ goto next;
+ btrfs_abort_transaction(trans, ret);
+ goto error;
+ }
+
+ wc.replay_dest->log_root = log;
+ ret = btrfs_record_root_in_trans(trans, wc.replay_dest);
+ if (ret)
+ /* The loop needs to continue due to the root refs */
+ btrfs_abort_transaction(trans, ret);
+ else
+ ret = walk_log_tree(trans, log, &wc);
+
+ if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
+ ret = fixup_inode_link_counts(trans, wc.replay_dest,
+ path);
+ if (ret)
+ btrfs_abort_transaction(trans, ret);
+ }
+
+ if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
+ struct btrfs_root *root = wc.replay_dest;
+
+ btrfs_release_path(path);
+
+ /*
+ * We have just replayed everything, and the highest
+ * objectid of fs roots probably has changed in case
+ * some inode_item's got replayed.
+ *
+ * root->objectid_mutex is not acquired as log replay
+ * could only happen during mount.
+ */
+ ret = btrfs_init_root_free_objectid(root);
+ if (ret)
+ btrfs_abort_transaction(trans, ret);
+ }
+
+ wc.replay_dest->log_root = NULL;
+ btrfs_put_root(wc.replay_dest);
+ btrfs_put_root(log);
+
+ if (ret)
+ goto error;
+next:
+ if (found_key.offset == 0)
+ break;
+ key.offset = found_key.offset - 1;
+ }
+ btrfs_release_path(path);
+
+ /* step one is to pin it all, step two is to replay just inodes */
+ if (wc.pin) {
+ wc.pin = 0;
+ wc.process_func = replay_one_buffer;
+ wc.stage = LOG_WALK_REPLAY_INODES;
+ goto again;
+ }
+ /* step three is to replay everything */
+ if (wc.stage < LOG_WALK_REPLAY_ALL) {
+ wc.stage++;
+ goto again;
+ }
+
+ btrfs_free_path(path);
+
+ /* step 4: commit the transaction, which also unpins the blocks */
+ ret = btrfs_commit_transaction(trans);
+ if (ret)
+ return ret;
+
+ log_root_tree->log_root = NULL;
+ clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
+ btrfs_put_root(log_root_tree);
+
+ return 0;
+error:
+ if (wc.trans)
+ btrfs_end_transaction(wc.trans);
+ clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * there are some corner cases where we want to force a full
+ * commit instead of allowing a directory to be logged.
+ *
+ * They revolve around files there were unlinked from the directory, and
+ * this function updates the parent directory so that a full commit is
+ * properly done if it is fsync'd later after the unlinks are done.
+ *
+ * Must be called before the unlink operations (updates to the subvolume tree,
+ * inodes, etc) are done.
+ */
+void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *dir, struct btrfs_inode *inode,
+ int for_rename)
+{
+ /*
+ * when we're logging a file, if it hasn't been renamed
+ * or unlinked, and its inode is fully committed on disk,
+ * we don't have to worry about walking up the directory chain
+ * to log its parents.
+ *
+ * So, we use the last_unlink_trans field to put this transid
+ * into the file. When the file is logged we check it and
+ * don't log the parents if the file is fully on disk.
+ */
+ mutex_lock(&inode->log_mutex);
+ inode->last_unlink_trans = trans->transid;
+ mutex_unlock(&inode->log_mutex);
+
+ /*
+ * if this directory was already logged any new
+ * names for this file/dir will get recorded
+ */
+ if (dir->logged_trans == trans->transid)
+ return;
+
+ /*
+ * if the inode we're about to unlink was logged,
+ * the log will be properly updated for any new names
+ */
+ if (inode->logged_trans == trans->transid)
+ return;
+
+ /*
+ * when renaming files across directories, if the directory
+ * there we're unlinking from gets fsync'd later on, there's
+ * no way to find the destination directory later and fsync it
+ * properly. So, we have to be conservative and force commits
+ * so the new name gets discovered.
+ */
+ if (for_rename)
+ goto record;
+
+ /* we can safely do the unlink without any special recording */
+ return;
+
+record:
+ mutex_lock(&dir->log_mutex);
+ dir->last_unlink_trans = trans->transid;
+ mutex_unlock(&dir->log_mutex);
+}
+
+/*
+ * Make sure that if someone attempts to fsync the parent directory of a deleted
+ * snapshot, it ends up triggering a transaction commit. This is to guarantee
+ * that after replaying the log tree of the parent directory's root we will not
+ * see the snapshot anymore and at log replay time we will not see any log tree
+ * corresponding to the deleted snapshot's root, which could lead to replaying
+ * it after replaying the log tree of the parent directory (which would replay
+ * the snapshot delete operation).
+ *
+ * Must be called before the actual snapshot destroy operation (updates to the
+ * parent root and tree of tree roots trees, etc) are done.
+ */
+void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
+ struct btrfs_inode *dir)
+{
+ mutex_lock(&dir->log_mutex);
+ dir->last_unlink_trans = trans->transid;
+ mutex_unlock(&dir->log_mutex);
+}
+
+/**
+ * Update the log after adding a new name for an inode.
+ *
+ * @trans: Transaction handle.
+ * @old_dentry: The dentry associated with the old name and the old
+ * parent directory.
+ * @old_dir: The inode of the previous parent directory for the case
+ * of a rename. For a link operation, it must be NULL.
+ * @old_dir_index: The index number associated with the old name, meaningful
+ * only for rename operations (when @old_dir is not NULL).
+ * Ignored for link operations.
+ * @parent: The dentry associated with the directory under which the
+ * new name is located.
+ *
+ * Call this after adding a new name for an inode, as a result of a link or
+ * rename operation, and it will properly update the log to reflect the new name.
+ */
+void btrfs_log_new_name(struct btrfs_trans_handle *trans,
+ struct dentry *old_dentry, struct btrfs_inode *old_dir,
+ u64 old_dir_index, struct dentry *parent)
+{
+ struct btrfs_inode *inode = BTRFS_I(d_inode(old_dentry));
+ struct btrfs_root *root = inode->root;
+ struct btrfs_log_ctx ctx;
+ bool log_pinned = false;
+ int ret;
+
+ /*
+ * this will force the logging code to walk the dentry chain
+ * up for the file
+ */
+ if (!S_ISDIR(inode->vfs_inode.i_mode))
+ inode->last_unlink_trans = trans->transid;
+
+ /*
+ * if this inode hasn't been logged and directory we're renaming it
+ * from hasn't been logged, we don't need to log it
+ */
+ ret = inode_logged(trans, inode, NULL);
+ if (ret < 0) {
+ goto out;
+ } else if (ret == 0) {
+ if (!old_dir)
+ return;
+ /*
+ * If the inode was not logged and we are doing a rename (old_dir is not
+ * NULL), check if old_dir was logged - if it was not we can return and
+ * do nothing.
+ */
+ ret = inode_logged(trans, old_dir, NULL);
+ if (ret < 0)
+ goto out;
+ else if (ret == 0)
+ return;
+ }
+ ret = 0;
+
+ /*
+ * If we are doing a rename (old_dir is not NULL) from a directory that
+ * was previously logged, make sure that on log replay we get the old
+ * dir entry deleted. This is needed because we will also log the new
+ * name of the renamed inode, so we need to make sure that after log
+ * replay we don't end up with both the new and old dir entries existing.
+ */
+ if (old_dir && old_dir->logged_trans == trans->transid) {
+ struct btrfs_root *log = old_dir->root->log_root;
+ struct btrfs_path *path;
+ struct fscrypt_name fname;
+
+ ASSERT(old_dir_index >= BTRFS_DIR_START_INDEX);
+
+ ret = fscrypt_setup_filename(&old_dir->vfs_inode,
+ &old_dentry->d_name, 0, &fname);
+ if (ret)
+ goto out;
+ /*
+ * We have two inodes to update in the log, the old directory and
+ * the inode that got renamed, so we must pin the log to prevent
+ * anyone from syncing the log until we have updated both inodes
+ * in the log.
+ */
+ ret = join_running_log_trans(root);
+ /*
+ * At least one of the inodes was logged before, so this should
+ * not fail, but if it does, it's not serious, just bail out and
+ * mark the log for a full commit.
+ */
+ if (WARN_ON_ONCE(ret < 0)) {
+ fscrypt_free_filename(&fname);
+ goto out;
+ }
+
+ log_pinned = true;
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ fscrypt_free_filename(&fname);
+ goto out;
+ }
+
+ /*
+ * Other concurrent task might be logging the old directory,
+ * as it can be triggered when logging other inode that had or
+ * still has a dentry in the old directory. We lock the old
+ * directory's log_mutex to ensure the deletion of the old
+ * name is persisted, because during directory logging we
+ * delete all BTRFS_DIR_LOG_INDEX_KEY keys and the deletion of
+ * the old name's dir index item is in the delayed items, so
+ * it could be missed by an in progress directory logging.
+ */
+ mutex_lock(&old_dir->log_mutex);
+ ret = del_logged_dentry(trans, log, path, btrfs_ino(old_dir),
+ &fname.disk_name, old_dir_index);
+ if (ret > 0) {
+ /*
+ * The dentry does not exist in the log, so record its
+ * deletion.
+ */
+ btrfs_release_path(path);
+ ret = insert_dir_log_key(trans, log, path,
+ btrfs_ino(old_dir),
+ old_dir_index, old_dir_index);
+ }
+ mutex_unlock(&old_dir->log_mutex);
+
+ btrfs_free_path(path);
+ fscrypt_free_filename(&fname);
+ if (ret < 0)
+ goto out;
+ }
+
+ btrfs_init_log_ctx(&ctx, &inode->vfs_inode);
+ ctx.logging_new_name = true;
+ /*
+ * We don't care about the return value. If we fail to log the new name
+ * then we know the next attempt to sync the log will fallback to a full
+ * transaction commit (due to a call to btrfs_set_log_full_commit()), so
+ * we don't need to worry about getting a log committed that has an
+ * inconsistent state after a rename operation.
+ */
+ btrfs_log_inode_parent(trans, inode, parent, LOG_INODE_EXISTS, &ctx);
+ ASSERT(list_empty(&ctx.conflict_inodes));
+out:
+ /*
+ * If an error happened mark the log for a full commit because it's not
+ * consistent and up to date or we couldn't find out if one of the
+ * inodes was logged before in this transaction. Do it before unpinning
+ * the log, to avoid any races with someone else trying to commit it.
+ */
+ if (ret < 0)
+ btrfs_set_log_full_commit(trans);
+ if (log_pinned)
+ btrfs_end_log_trans(root);
+}
+