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-rw-r--r--fs/btrfs/btrfs_inode.h439
1 files changed, 439 insertions, 0 deletions
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
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+++ b/fs/btrfs/btrfs_inode.h
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+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ */
+
+#ifndef BTRFS_INODE_H
+#define BTRFS_INODE_H
+
+#include <linux/hash.h>
+#include <linux/refcount.h>
+#include "extent_map.h"
+#include "extent_io.h"
+#include "ordered-data.h"
+#include "delayed-inode.h"
+
+/*
+ * Since we search a directory based on f_pos (struct dir_context::pos) we have
+ * to start at 2 since '.' and '..' have f_pos of 0 and 1 respectively, so
+ * everybody else has to start at 2 (see btrfs_real_readdir() and dir_emit_dots()).
+ */
+#define BTRFS_DIR_START_INDEX 2
+
+/*
+ * ordered_data_close is set by truncate when a file that used
+ * to have good data has been truncated to zero. When it is set
+ * the btrfs file release call will add this inode to the
+ * ordered operations list so that we make sure to flush out any
+ * new data the application may have written before commit.
+ */
+enum {
+ BTRFS_INODE_FLUSH_ON_CLOSE,
+ BTRFS_INODE_DUMMY,
+ BTRFS_INODE_IN_DEFRAG,
+ BTRFS_INODE_HAS_ASYNC_EXTENT,
+ /*
+ * Always set under the VFS' inode lock, otherwise it can cause races
+ * during fsync (we start as a fast fsync and then end up in a full
+ * fsync racing with ordered extent completion).
+ */
+ BTRFS_INODE_NEEDS_FULL_SYNC,
+ BTRFS_INODE_COPY_EVERYTHING,
+ BTRFS_INODE_IN_DELALLOC_LIST,
+ BTRFS_INODE_HAS_PROPS,
+ BTRFS_INODE_SNAPSHOT_FLUSH,
+ /*
+ * Set and used when logging an inode and it serves to signal that an
+ * inode does not have xattrs, so subsequent fsyncs can avoid searching
+ * for xattrs to log. This bit must be cleared whenever a xattr is added
+ * to an inode.
+ */
+ BTRFS_INODE_NO_XATTRS,
+ /*
+ * Set when we are in a context where we need to start a transaction and
+ * have dirty pages with the respective file range locked. This is to
+ * ensure that when reserving space for the transaction, if we are low
+ * on available space and need to flush delalloc, we will not flush
+ * delalloc for this inode, because that could result in a deadlock (on
+ * the file range, inode's io_tree).
+ */
+ BTRFS_INODE_NO_DELALLOC_FLUSH,
+ /*
+ * Set when we are working on enabling verity for a file. Computing and
+ * writing the whole Merkle tree can take a while so we want to prevent
+ * races where two separate tasks attempt to simultaneously start verity
+ * on the same file.
+ */
+ BTRFS_INODE_VERITY_IN_PROGRESS,
+ /* Set when this inode is a free space inode. */
+ BTRFS_INODE_FREE_SPACE_INODE,
+};
+
+/* in memory btrfs inode */
+struct btrfs_inode {
+ /* which subvolume this inode belongs to */
+ struct btrfs_root *root;
+
+ /* key used to find this inode on disk. This is used by the code
+ * to read in roots of subvolumes
+ */
+ struct btrfs_key location;
+
+ /*
+ * Lock for counters and all fields used to determine if the inode is in
+ * the log or not (last_trans, last_sub_trans, last_log_commit,
+ * logged_trans), to access/update new_delalloc_bytes and to update the
+ * VFS' inode number of bytes used.
+ */
+ spinlock_t lock;
+
+ /* the extent_tree has caches of all the extent mappings to disk */
+ struct extent_map_tree extent_tree;
+
+ /* the io_tree does range state (DIRTY, LOCKED etc) */
+ struct extent_io_tree io_tree;
+
+ /* special utility tree used to record which mirrors have already been
+ * tried when checksums fail for a given block
+ */
+ struct rb_root io_failure_tree;
+ spinlock_t io_failure_lock;
+
+ /*
+ * Keep track of where the inode has extent items mapped in order to
+ * make sure the i_size adjustments are accurate
+ */
+ struct extent_io_tree file_extent_tree;
+
+ /* held while logging the inode in tree-log.c */
+ struct mutex log_mutex;
+
+ /* used to order data wrt metadata */
+ struct btrfs_ordered_inode_tree ordered_tree;
+
+ /* list of all the delalloc inodes in the FS. There are times we need
+ * to write all the delalloc pages to disk, and this list is used
+ * to walk them all.
+ */
+ struct list_head delalloc_inodes;
+
+ /* node for the red-black tree that links inodes in subvolume root */
+ struct rb_node rb_node;
+
+ unsigned long runtime_flags;
+
+ /* Keep track of who's O_SYNC/fsyncing currently */
+ atomic_t sync_writers;
+
+ /* full 64 bit generation number, struct vfs_inode doesn't have a big
+ * enough field for this.
+ */
+ u64 generation;
+
+ /*
+ * transid of the trans_handle that last modified this inode
+ */
+ u64 last_trans;
+
+ /*
+ * transid that last logged this inode
+ */
+ u64 logged_trans;
+
+ /*
+ * log transid when this inode was last modified
+ */
+ int last_sub_trans;
+
+ /* a local copy of root's last_log_commit */
+ int last_log_commit;
+
+ /*
+ * Total number of bytes pending delalloc, used by stat to calculate the
+ * real block usage of the file. This is used only for files.
+ */
+ u64 delalloc_bytes;
+
+ union {
+ /*
+ * Total number of bytes pending delalloc that fall within a file
+ * range that is either a hole or beyond EOF (and no prealloc extent
+ * exists in the range). This is always <= delalloc_bytes and this
+ * is used only for files.
+ */
+ u64 new_delalloc_bytes;
+ /*
+ * The offset of the last dir index key that was logged.
+ * This is used only for directories.
+ */
+ u64 last_dir_index_offset;
+ };
+
+ /*
+ * total number of bytes pending defrag, used by stat to check whether
+ * it needs COW.
+ */
+ u64 defrag_bytes;
+
+ /*
+ * the size of the file stored in the metadata on disk. data=ordered
+ * means the in-memory i_size might be larger than the size on disk
+ * because not all the blocks are written yet.
+ */
+ u64 disk_i_size;
+
+ /*
+ * If this is a directory then index_cnt is the counter for the index
+ * number for new files that are created. For an empty directory, this
+ * must be initialized to BTRFS_DIR_START_INDEX.
+ */
+ u64 index_cnt;
+
+ /* Cache the directory index number to speed the dir/file remove */
+ u64 dir_index;
+
+ /* the fsync log has some corner cases that mean we have to check
+ * directories to see if any unlinks have been done before
+ * the directory was logged. See tree-log.c for all the
+ * details
+ */
+ u64 last_unlink_trans;
+
+ /*
+ * The id/generation of the last transaction where this inode was
+ * either the source or the destination of a clone/dedupe operation.
+ * Used when logging an inode to know if there are shared extents that
+ * need special care when logging checksum items, to avoid duplicate
+ * checksum items in a log (which can lead to a corruption where we end
+ * up with missing checksum ranges after log replay).
+ * Protected by the vfs inode lock.
+ */
+ u64 last_reflink_trans;
+
+ /*
+ * Number of bytes outstanding that are going to need csums. This is
+ * used in ENOSPC accounting.
+ */
+ u64 csum_bytes;
+
+ /* Backwards incompatible flags, lower half of inode_item::flags */
+ u32 flags;
+ /* Read-only compatibility flags, upper half of inode_item::flags */
+ u32 ro_flags;
+
+ /*
+ * Counters to keep track of the number of extent item's we may use due
+ * to delalloc and such. outstanding_extents is the number of extent
+ * items we think we'll end up using, and reserved_extents is the number
+ * of extent items we've reserved metadata for.
+ */
+ unsigned outstanding_extents;
+
+ struct btrfs_block_rsv block_rsv;
+
+ /*
+ * Cached values of inode properties
+ */
+ unsigned prop_compress; /* per-file compression algorithm */
+ /*
+ * Force compression on the file using the defrag ioctl, could be
+ * different from prop_compress and takes precedence if set
+ */
+ unsigned defrag_compress;
+
+ struct btrfs_delayed_node *delayed_node;
+
+ /* File creation time. */
+ struct timespec64 i_otime;
+
+ /* Hook into fs_info->delayed_iputs */
+ struct list_head delayed_iput;
+
+ struct rw_semaphore i_mmap_lock;
+ struct inode vfs_inode;
+};
+
+static inline struct btrfs_inode *BTRFS_I(const struct inode *inode)
+{
+ return container_of(inode, struct btrfs_inode, vfs_inode);
+}
+
+static inline unsigned long btrfs_inode_hash(u64 objectid,
+ const struct btrfs_root *root)
+{
+ u64 h = objectid ^ (root->root_key.objectid * GOLDEN_RATIO_PRIME);
+
+#if BITS_PER_LONG == 32
+ h = (h >> 32) ^ (h & 0xffffffff);
+#endif
+
+ return (unsigned long)h;
+}
+
+#if BITS_PER_LONG == 32
+
+/*
+ * On 32 bit systems the i_ino of struct inode is 32 bits (unsigned long), so
+ * we use the inode's location objectid which is a u64 to avoid truncation.
+ */
+static inline u64 btrfs_ino(const struct btrfs_inode *inode)
+{
+ u64 ino = inode->location.objectid;
+
+ /* type == BTRFS_ROOT_ITEM_KEY: subvol dir */
+ if (inode->location.type == BTRFS_ROOT_ITEM_KEY)
+ ino = inode->vfs_inode.i_ino;
+ return ino;
+}
+
+#else
+
+static inline u64 btrfs_ino(const struct btrfs_inode *inode)
+{
+ return inode->vfs_inode.i_ino;
+}
+
+#endif
+
+static inline void btrfs_i_size_write(struct btrfs_inode *inode, u64 size)
+{
+ i_size_write(&inode->vfs_inode, size);
+ inode->disk_i_size = size;
+}
+
+static inline bool btrfs_is_free_space_inode(struct btrfs_inode *inode)
+{
+ return test_bit(BTRFS_INODE_FREE_SPACE_INODE, &inode->runtime_flags);
+}
+
+static inline bool is_data_inode(struct inode *inode)
+{
+ return btrfs_ino(BTRFS_I(inode)) != BTRFS_BTREE_INODE_OBJECTID;
+}
+
+static inline void btrfs_mod_outstanding_extents(struct btrfs_inode *inode,
+ int mod)
+{
+ lockdep_assert_held(&inode->lock);
+ inode->outstanding_extents += mod;
+ if (btrfs_is_free_space_inode(inode))
+ return;
+ trace_btrfs_inode_mod_outstanding_extents(inode->root, btrfs_ino(inode),
+ mod);
+}
+
+/*
+ * Called every time after doing a buffered, direct IO or memory mapped write.
+ *
+ * This is to ensure that if we write to a file that was previously fsynced in
+ * the current transaction, then try to fsync it again in the same transaction,
+ * we will know that there were changes in the file and that it needs to be
+ * logged.
+ */
+static inline void btrfs_set_inode_last_sub_trans(struct btrfs_inode *inode)
+{
+ spin_lock(&inode->lock);
+ inode->last_sub_trans = inode->root->log_transid;
+ spin_unlock(&inode->lock);
+}
+
+/*
+ * Should be called while holding the inode's VFS lock in exclusive mode or in a
+ * context where no one else can access the inode concurrently (during inode
+ * creation or when loading an inode from disk).
+ */
+static inline void btrfs_set_inode_full_sync(struct btrfs_inode *inode)
+{
+ set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
+ /*
+ * The inode may have been part of a reflink operation in the last
+ * transaction that modified it, and then a fsync has reset the
+ * last_reflink_trans to avoid subsequent fsyncs in the same
+ * transaction to do unnecessary work. So update last_reflink_trans
+ * to the last_trans value (we have to be pessimistic and assume a
+ * reflink happened).
+ *
+ * The ->last_trans is protected by the inode's spinlock and we can
+ * have a concurrent ordered extent completion update it. Also set
+ * last_reflink_trans to ->last_trans only if the former is less than
+ * the later, because we can be called in a context where
+ * last_reflink_trans was set to the current transaction generation
+ * while ->last_trans was not yet updated in the current transaction,
+ * and therefore has a lower value.
+ */
+ spin_lock(&inode->lock);
+ if (inode->last_reflink_trans < inode->last_trans)
+ inode->last_reflink_trans = inode->last_trans;
+ spin_unlock(&inode->lock);
+}
+
+static inline bool btrfs_inode_in_log(struct btrfs_inode *inode, u64 generation)
+{
+ bool ret = false;
+
+ spin_lock(&inode->lock);
+ if (inode->logged_trans == generation &&
+ inode->last_sub_trans <= inode->last_log_commit &&
+ inode->last_sub_trans <= inode->root->last_log_commit)
+ ret = true;
+ spin_unlock(&inode->lock);
+ return ret;
+}
+
+/*
+ * Check if the inode has flags compatible with compression
+ */
+static inline bool btrfs_inode_can_compress(const struct btrfs_inode *inode)
+{
+ if (inode->flags & BTRFS_INODE_NODATACOW ||
+ inode->flags & BTRFS_INODE_NODATASUM)
+ return false;
+ return true;
+}
+
+/*
+ * btrfs_inode_item stores flags in a u64, btrfs_inode stores them in two
+ * separate u32s. These two functions convert between the two representations.
+ */
+static inline u64 btrfs_inode_combine_flags(u32 flags, u32 ro_flags)
+{
+ return (flags | ((u64)ro_flags << 32));
+}
+
+static inline void btrfs_inode_split_flags(u64 inode_item_flags,
+ u32 *flags, u32 *ro_flags)
+{
+ *flags = (u32)inode_item_flags;
+ *ro_flags = (u32)(inode_item_flags >> 32);
+}
+
+/* Array of bytes with variable length, hexadecimal format 0x1234 */
+#define CSUM_FMT "0x%*phN"
+#define CSUM_FMT_VALUE(size, bytes) size, bytes
+
+static inline void btrfs_print_data_csum_error(struct btrfs_inode *inode,
+ u64 logical_start, u8 *csum, u8 *csum_expected, int mirror_num)
+{
+ struct btrfs_root *root = inode->root;
+ const u32 csum_size = root->fs_info->csum_size;
+
+ /* Output minus objectid, which is more meaningful */
+ if (root->root_key.objectid >= BTRFS_LAST_FREE_OBJECTID)
+ btrfs_warn_rl(root->fs_info,
+"csum failed root %lld ino %lld off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
+ root->root_key.objectid, btrfs_ino(inode),
+ logical_start,
+ CSUM_FMT_VALUE(csum_size, csum),
+ CSUM_FMT_VALUE(csum_size, csum_expected),
+ mirror_num);
+ else
+ btrfs_warn_rl(root->fs_info,
+"csum failed root %llu ino %llu off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
+ root->root_key.objectid, btrfs_ino(inode),
+ logical_start,
+ CSUM_FMT_VALUE(csum_size, csum),
+ CSUM_FMT_VALUE(csum_size, csum_expected),
+ mirror_num);
+}
+
+#endif