summaryrefslogtreecommitdiffstats
path: root/fs/ext4/extents_status.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/ext4/extents_status.c')
-rw-r--r--fs/ext4/extents_status.c2317
1 files changed, 2317 insertions, 0 deletions
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
new file mode 100644
index 000000000..470d29fb4
--- /dev/null
+++ b/fs/ext4/extents_status.c
@@ -0,0 +1,2317 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/ext4/extents_status.c
+ *
+ * Written by Yongqiang Yang <xiaoqiangnk@gmail.com>
+ * Modified by
+ * Allison Henderson <achender@linux.vnet.ibm.com>
+ * Hugh Dickins <hughd@google.com>
+ * Zheng Liu <wenqing.lz@taobao.com>
+ *
+ * Ext4 extents status tree core functions.
+ */
+#include <linux/list_sort.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include "ext4.h"
+
+#include <trace/events/ext4.h>
+
+/*
+ * According to previous discussion in Ext4 Developer Workshop, we
+ * will introduce a new structure called io tree to track all extent
+ * status in order to solve some problems that we have met
+ * (e.g. Reservation space warning), and provide extent-level locking.
+ * Delay extent tree is the first step to achieve this goal. It is
+ * original built by Yongqiang Yang. At that time it is called delay
+ * extent tree, whose goal is only track delayed extents in memory to
+ * simplify the implementation of fiemap and bigalloc, and introduce
+ * lseek SEEK_DATA/SEEK_HOLE support. That is why it is still called
+ * delay extent tree at the first commit. But for better understand
+ * what it does, it has been rename to extent status tree.
+ *
+ * Step1:
+ * Currently the first step has been done. All delayed extents are
+ * tracked in the tree. It maintains the delayed extent when a delayed
+ * allocation is issued, and the delayed extent is written out or
+ * invalidated. Therefore the implementation of fiemap and bigalloc
+ * are simplified, and SEEK_DATA/SEEK_HOLE are introduced.
+ *
+ * The following comment describes the implemenmtation of extent
+ * status tree and future works.
+ *
+ * Step2:
+ * In this step all extent status are tracked by extent status tree.
+ * Thus, we can first try to lookup a block mapping in this tree before
+ * finding it in extent tree. Hence, single extent cache can be removed
+ * because extent status tree can do a better job. Extents in status
+ * tree are loaded on-demand. Therefore, the extent status tree may not
+ * contain all of the extents in a file. Meanwhile we define a shrinker
+ * to reclaim memory from extent status tree because fragmented extent
+ * tree will make status tree cost too much memory. written/unwritten/-
+ * hole extents in the tree will be reclaimed by this shrinker when we
+ * are under high memory pressure. Delayed extents will not be
+ * reclimed because fiemap, bigalloc, and seek_data/hole need it.
+ */
+
+/*
+ * Extent status tree implementation for ext4.
+ *
+ *
+ * ==========================================================================
+ * Extent status tree tracks all extent status.
+ *
+ * 1. Why we need to implement extent status tree?
+ *
+ * Without extent status tree, ext4 identifies a delayed extent by looking
+ * up page cache, this has several deficiencies - complicated, buggy,
+ * and inefficient code.
+ *
+ * FIEMAP, SEEK_HOLE/DATA, bigalloc, and writeout all need to know if a
+ * block or a range of blocks are belonged to a delayed extent.
+ *
+ * Let us have a look at how they do without extent status tree.
+ * -- FIEMAP
+ * FIEMAP looks up page cache to identify delayed allocations from holes.
+ *
+ * -- SEEK_HOLE/DATA
+ * SEEK_HOLE/DATA has the same problem as FIEMAP.
+ *
+ * -- bigalloc
+ * bigalloc looks up page cache to figure out if a block is
+ * already under delayed allocation or not to determine whether
+ * quota reserving is needed for the cluster.
+ *
+ * -- writeout
+ * Writeout looks up whole page cache to see if a buffer is
+ * mapped, If there are not very many delayed buffers, then it is
+ * time consuming.
+ *
+ * With extent status tree implementation, FIEMAP, SEEK_HOLE/DATA,
+ * bigalloc and writeout can figure out if a block or a range of
+ * blocks is under delayed allocation(belonged to a delayed extent) or
+ * not by searching the extent tree.
+ *
+ *
+ * ==========================================================================
+ * 2. Ext4 extent status tree impelmentation
+ *
+ * -- extent
+ * A extent is a range of blocks which are contiguous logically and
+ * physically. Unlike extent in extent tree, this extent in ext4 is
+ * a in-memory struct, there is no corresponding on-disk data. There
+ * is no limit on length of extent, so an extent can contain as many
+ * blocks as they are contiguous logically and physically.
+ *
+ * -- extent status tree
+ * Every inode has an extent status tree and all allocation blocks
+ * are added to the tree with different status. The extent in the
+ * tree are ordered by logical block no.
+ *
+ * -- operations on a extent status tree
+ * There are three important operations on a delayed extent tree: find
+ * next extent, adding a extent(a range of blocks) and removing a extent.
+ *
+ * -- race on a extent status tree
+ * Extent status tree is protected by inode->i_es_lock.
+ *
+ * -- memory consumption
+ * Fragmented extent tree will make extent status tree cost too much
+ * memory. Hence, we will reclaim written/unwritten/hole extents from
+ * the tree under a heavy memory pressure.
+ *
+ *
+ * ==========================================================================
+ * 3. Performance analysis
+ *
+ * -- overhead
+ * 1. There is a cache extent for write access, so if writes are
+ * not very random, adding space operaions are in O(1) time.
+ *
+ * -- gain
+ * 2. Code is much simpler, more readable, more maintainable and
+ * more efficient.
+ *
+ *
+ * ==========================================================================
+ * 4. TODO list
+ *
+ * -- Refactor delayed space reservation
+ *
+ * -- Extent-level locking
+ */
+
+static struct kmem_cache *ext4_es_cachep;
+static struct kmem_cache *ext4_pending_cachep;
+
+static int __es_insert_extent(struct inode *inode, struct extent_status *newes,
+ struct extent_status *prealloc);
+static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
+ ext4_lblk_t end, int *reserved,
+ struct extent_status *prealloc);
+static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan);
+static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
+ struct ext4_inode_info *locked_ei);
+static int __revise_pending(struct inode *inode, ext4_lblk_t lblk,
+ ext4_lblk_t len,
+ struct pending_reservation **prealloc);
+
+int __init ext4_init_es(void)
+{
+ ext4_es_cachep = kmem_cache_create("ext4_extent_status",
+ sizeof(struct extent_status),
+ 0, (SLAB_RECLAIM_ACCOUNT), NULL);
+ if (ext4_es_cachep == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
+void ext4_exit_es(void)
+{
+ kmem_cache_destroy(ext4_es_cachep);
+}
+
+void ext4_es_init_tree(struct ext4_es_tree *tree)
+{
+ tree->root = RB_ROOT;
+ tree->cache_es = NULL;
+}
+
+#ifdef ES_DEBUG__
+static void ext4_es_print_tree(struct inode *inode)
+{
+ struct ext4_es_tree *tree;
+ struct rb_node *node;
+
+ printk(KERN_DEBUG "status extents for inode %lu:", inode->i_ino);
+ tree = &EXT4_I(inode)->i_es_tree;
+ node = rb_first(&tree->root);
+ while (node) {
+ struct extent_status *es;
+ es = rb_entry(node, struct extent_status, rb_node);
+ printk(KERN_DEBUG " [%u/%u) %llu %x",
+ es->es_lblk, es->es_len,
+ ext4_es_pblock(es), ext4_es_status(es));
+ node = rb_next(node);
+ }
+ printk(KERN_DEBUG "\n");
+}
+#else
+#define ext4_es_print_tree(inode)
+#endif
+
+static inline ext4_lblk_t ext4_es_end(struct extent_status *es)
+{
+ BUG_ON(es->es_lblk + es->es_len < es->es_lblk);
+ return es->es_lblk + es->es_len - 1;
+}
+
+/*
+ * search through the tree for an delayed extent with a given offset. If
+ * it can't be found, try to find next extent.
+ */
+static struct extent_status *__es_tree_search(struct rb_root *root,
+ ext4_lblk_t lblk)
+{
+ struct rb_node *node = root->rb_node;
+ struct extent_status *es = NULL;
+
+ while (node) {
+ es = rb_entry(node, struct extent_status, rb_node);
+ if (lblk < es->es_lblk)
+ node = node->rb_left;
+ else if (lblk > ext4_es_end(es))
+ node = node->rb_right;
+ else
+ return es;
+ }
+
+ if (es && lblk < es->es_lblk)
+ return es;
+
+ if (es && lblk > ext4_es_end(es)) {
+ node = rb_next(&es->rb_node);
+ return node ? rb_entry(node, struct extent_status, rb_node) :
+ NULL;
+ }
+
+ return NULL;
+}
+
+/*
+ * ext4_es_find_extent_range - find extent with specified status within block
+ * range or next extent following block range in
+ * extents status tree
+ *
+ * @inode - file containing the range
+ * @matching_fn - pointer to function that matches extents with desired status
+ * @lblk - logical block defining start of range
+ * @end - logical block defining end of range
+ * @es - extent found, if any
+ *
+ * Find the first extent within the block range specified by @lblk and @end
+ * in the extents status tree that satisfies @matching_fn. If a match
+ * is found, it's returned in @es. If not, and a matching extent is found
+ * beyond the block range, it's returned in @es. If no match is found, an
+ * extent is returned in @es whose es_lblk, es_len, and es_pblk components
+ * are 0.
+ */
+static void __es_find_extent_range(struct inode *inode,
+ int (*matching_fn)(struct extent_status *es),
+ ext4_lblk_t lblk, ext4_lblk_t end,
+ struct extent_status *es)
+{
+ struct ext4_es_tree *tree = NULL;
+ struct extent_status *es1 = NULL;
+ struct rb_node *node;
+
+ WARN_ON(es == NULL);
+ WARN_ON(end < lblk);
+
+ tree = &EXT4_I(inode)->i_es_tree;
+
+ /* see if the extent has been cached */
+ es->es_lblk = es->es_len = es->es_pblk = 0;
+ es1 = READ_ONCE(tree->cache_es);
+ if (es1 && in_range(lblk, es1->es_lblk, es1->es_len)) {
+ es_debug("%u cached by [%u/%u) %llu %x\n",
+ lblk, es1->es_lblk, es1->es_len,
+ ext4_es_pblock(es1), ext4_es_status(es1));
+ goto out;
+ }
+
+ es1 = __es_tree_search(&tree->root, lblk);
+
+out:
+ if (es1 && !matching_fn(es1)) {
+ while ((node = rb_next(&es1->rb_node)) != NULL) {
+ es1 = rb_entry(node, struct extent_status, rb_node);
+ if (es1->es_lblk > end) {
+ es1 = NULL;
+ break;
+ }
+ if (matching_fn(es1))
+ break;
+ }
+ }
+
+ if (es1 && matching_fn(es1)) {
+ WRITE_ONCE(tree->cache_es, es1);
+ es->es_lblk = es1->es_lblk;
+ es->es_len = es1->es_len;
+ es->es_pblk = es1->es_pblk;
+ }
+
+}
+
+/*
+ * Locking for __es_find_extent_range() for external use
+ */
+void ext4_es_find_extent_range(struct inode *inode,
+ int (*matching_fn)(struct extent_status *es),
+ ext4_lblk_t lblk, ext4_lblk_t end,
+ struct extent_status *es)
+{
+ if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
+ return;
+
+ trace_ext4_es_find_extent_range_enter(inode, lblk);
+
+ read_lock(&EXT4_I(inode)->i_es_lock);
+ __es_find_extent_range(inode, matching_fn, lblk, end, es);
+ read_unlock(&EXT4_I(inode)->i_es_lock);
+
+ trace_ext4_es_find_extent_range_exit(inode, es);
+}
+
+/*
+ * __es_scan_range - search block range for block with specified status
+ * in extents status tree
+ *
+ * @inode - file containing the range
+ * @matching_fn - pointer to function that matches extents with desired status
+ * @lblk - logical block defining start of range
+ * @end - logical block defining end of range
+ *
+ * Returns true if at least one block in the specified block range satisfies
+ * the criterion specified by @matching_fn, and false if not. If at least
+ * one extent has the specified status, then there is at least one block
+ * in the cluster with that status. Should only be called by code that has
+ * taken i_es_lock.
+ */
+static bool __es_scan_range(struct inode *inode,
+ int (*matching_fn)(struct extent_status *es),
+ ext4_lblk_t start, ext4_lblk_t end)
+{
+ struct extent_status es;
+
+ __es_find_extent_range(inode, matching_fn, start, end, &es);
+ if (es.es_len == 0)
+ return false; /* no matching extent in the tree */
+ else if (es.es_lblk <= start &&
+ start < es.es_lblk + es.es_len)
+ return true;
+ else if (start <= es.es_lblk && es.es_lblk <= end)
+ return true;
+ else
+ return false;
+}
+/*
+ * Locking for __es_scan_range() for external use
+ */
+bool ext4_es_scan_range(struct inode *inode,
+ int (*matching_fn)(struct extent_status *es),
+ ext4_lblk_t lblk, ext4_lblk_t end)
+{
+ bool ret;
+
+ if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
+ return false;
+
+ read_lock(&EXT4_I(inode)->i_es_lock);
+ ret = __es_scan_range(inode, matching_fn, lblk, end);
+ read_unlock(&EXT4_I(inode)->i_es_lock);
+
+ return ret;
+}
+
+/*
+ * __es_scan_clu - search cluster for block with specified status in
+ * extents status tree
+ *
+ * @inode - file containing the cluster
+ * @matching_fn - pointer to function that matches extents with desired status
+ * @lblk - logical block in cluster to be searched
+ *
+ * Returns true if at least one extent in the cluster containing @lblk
+ * satisfies the criterion specified by @matching_fn, and false if not. If at
+ * least one extent has the specified status, then there is at least one block
+ * in the cluster with that status. Should only be called by code that has
+ * taken i_es_lock.
+ */
+static bool __es_scan_clu(struct inode *inode,
+ int (*matching_fn)(struct extent_status *es),
+ ext4_lblk_t lblk)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ ext4_lblk_t lblk_start, lblk_end;
+
+ lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
+ lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
+
+ return __es_scan_range(inode, matching_fn, lblk_start, lblk_end);
+}
+
+/*
+ * Locking for __es_scan_clu() for external use
+ */
+bool ext4_es_scan_clu(struct inode *inode,
+ int (*matching_fn)(struct extent_status *es),
+ ext4_lblk_t lblk)
+{
+ bool ret;
+
+ if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
+ return false;
+
+ read_lock(&EXT4_I(inode)->i_es_lock);
+ ret = __es_scan_clu(inode, matching_fn, lblk);
+ read_unlock(&EXT4_I(inode)->i_es_lock);
+
+ return ret;
+}
+
+static void ext4_es_list_add(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+
+ if (!list_empty(&ei->i_es_list))
+ return;
+
+ spin_lock(&sbi->s_es_lock);
+ if (list_empty(&ei->i_es_list)) {
+ list_add_tail(&ei->i_es_list, &sbi->s_es_list);
+ sbi->s_es_nr_inode++;
+ }
+ spin_unlock(&sbi->s_es_lock);
+}
+
+static void ext4_es_list_del(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+
+ spin_lock(&sbi->s_es_lock);
+ if (!list_empty(&ei->i_es_list)) {
+ list_del_init(&ei->i_es_list);
+ sbi->s_es_nr_inode--;
+ WARN_ON_ONCE(sbi->s_es_nr_inode < 0);
+ }
+ spin_unlock(&sbi->s_es_lock);
+}
+
+static inline struct pending_reservation *__alloc_pending(bool nofail)
+{
+ if (!nofail)
+ return kmem_cache_alloc(ext4_pending_cachep, GFP_ATOMIC);
+
+ return kmem_cache_zalloc(ext4_pending_cachep, GFP_KERNEL | __GFP_NOFAIL);
+}
+
+static inline void __free_pending(struct pending_reservation *pr)
+{
+ kmem_cache_free(ext4_pending_cachep, pr);
+}
+
+/*
+ * Returns true if we cannot fail to allocate memory for this extent_status
+ * entry and cannot reclaim it until its status changes.
+ */
+static inline bool ext4_es_must_keep(struct extent_status *es)
+{
+ /* fiemap, bigalloc, and seek_data/hole need to use it. */
+ if (ext4_es_is_delayed(es))
+ return true;
+
+ return false;
+}
+
+static inline struct extent_status *__es_alloc_extent(bool nofail)
+{
+ if (!nofail)
+ return kmem_cache_alloc(ext4_es_cachep, GFP_ATOMIC);
+
+ return kmem_cache_zalloc(ext4_es_cachep, GFP_KERNEL | __GFP_NOFAIL);
+}
+
+static void ext4_es_init_extent(struct inode *inode, struct extent_status *es,
+ ext4_lblk_t lblk, ext4_lblk_t len, ext4_fsblk_t pblk)
+{
+ es->es_lblk = lblk;
+ es->es_len = len;
+ es->es_pblk = pblk;
+
+ /* We never try to reclaim a must kept extent, so we don't count it. */
+ if (!ext4_es_must_keep(es)) {
+ if (!EXT4_I(inode)->i_es_shk_nr++)
+ ext4_es_list_add(inode);
+ percpu_counter_inc(&EXT4_SB(inode->i_sb)->
+ s_es_stats.es_stats_shk_cnt);
+ }
+
+ EXT4_I(inode)->i_es_all_nr++;
+ percpu_counter_inc(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt);
+}
+
+static inline void __es_free_extent(struct extent_status *es)
+{
+ kmem_cache_free(ext4_es_cachep, es);
+}
+
+static void ext4_es_free_extent(struct inode *inode, struct extent_status *es)
+{
+ EXT4_I(inode)->i_es_all_nr--;
+ percpu_counter_dec(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt);
+
+ /* Decrease the shrink counter when we can reclaim the extent. */
+ if (!ext4_es_must_keep(es)) {
+ BUG_ON(EXT4_I(inode)->i_es_shk_nr == 0);
+ if (!--EXT4_I(inode)->i_es_shk_nr)
+ ext4_es_list_del(inode);
+ percpu_counter_dec(&EXT4_SB(inode->i_sb)->
+ s_es_stats.es_stats_shk_cnt);
+ }
+
+ __es_free_extent(es);
+}
+
+/*
+ * Check whether or not two extents can be merged
+ * Condition:
+ * - logical block number is contiguous
+ * - physical block number is contiguous
+ * - status is equal
+ */
+static int ext4_es_can_be_merged(struct extent_status *es1,
+ struct extent_status *es2)
+{
+ if (ext4_es_type(es1) != ext4_es_type(es2))
+ return 0;
+
+ if (((__u64) es1->es_len) + es2->es_len > EXT_MAX_BLOCKS) {
+ pr_warn("ES assertion failed when merging extents. "
+ "The sum of lengths of es1 (%d) and es2 (%d) "
+ "is bigger than allowed file size (%d)\n",
+ es1->es_len, es2->es_len, EXT_MAX_BLOCKS);
+ WARN_ON(1);
+ return 0;
+ }
+
+ if (((__u64) es1->es_lblk) + es1->es_len != es2->es_lblk)
+ return 0;
+
+ if ((ext4_es_is_written(es1) || ext4_es_is_unwritten(es1)) &&
+ (ext4_es_pblock(es1) + es1->es_len == ext4_es_pblock(es2)))
+ return 1;
+
+ if (ext4_es_is_hole(es1))
+ return 1;
+
+ /* we need to check delayed extent is without unwritten status */
+ if (ext4_es_is_delayed(es1) && !ext4_es_is_unwritten(es1))
+ return 1;
+
+ return 0;
+}
+
+static struct extent_status *
+ext4_es_try_to_merge_left(struct inode *inode, struct extent_status *es)
+{
+ struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
+ struct extent_status *es1;
+ struct rb_node *node;
+
+ node = rb_prev(&es->rb_node);
+ if (!node)
+ return es;
+
+ es1 = rb_entry(node, struct extent_status, rb_node);
+ if (ext4_es_can_be_merged(es1, es)) {
+ es1->es_len += es->es_len;
+ if (ext4_es_is_referenced(es))
+ ext4_es_set_referenced(es1);
+ rb_erase(&es->rb_node, &tree->root);
+ ext4_es_free_extent(inode, es);
+ es = es1;
+ }
+
+ return es;
+}
+
+static struct extent_status *
+ext4_es_try_to_merge_right(struct inode *inode, struct extent_status *es)
+{
+ struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
+ struct extent_status *es1;
+ struct rb_node *node;
+
+ node = rb_next(&es->rb_node);
+ if (!node)
+ return es;
+
+ es1 = rb_entry(node, struct extent_status, rb_node);
+ if (ext4_es_can_be_merged(es, es1)) {
+ es->es_len += es1->es_len;
+ if (ext4_es_is_referenced(es1))
+ ext4_es_set_referenced(es);
+ rb_erase(node, &tree->root);
+ ext4_es_free_extent(inode, es1);
+ }
+
+ return es;
+}
+
+#ifdef ES_AGGRESSIVE_TEST
+#include "ext4_extents.h" /* Needed when ES_AGGRESSIVE_TEST is defined */
+
+static void ext4_es_insert_extent_ext_check(struct inode *inode,
+ struct extent_status *es)
+{
+ struct ext4_ext_path *path = NULL;
+ struct ext4_extent *ex;
+ ext4_lblk_t ee_block;
+ ext4_fsblk_t ee_start;
+ unsigned short ee_len;
+ int depth, ee_status, es_status;
+
+ path = ext4_find_extent(inode, es->es_lblk, NULL, EXT4_EX_NOCACHE);
+ if (IS_ERR(path))
+ return;
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+
+ if (ex) {
+
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_start = ext4_ext_pblock(ex);
+ ee_len = ext4_ext_get_actual_len(ex);
+
+ ee_status = ext4_ext_is_unwritten(ex) ? 1 : 0;
+ es_status = ext4_es_is_unwritten(es) ? 1 : 0;
+
+ /*
+ * Make sure ex and es are not overlap when we try to insert
+ * a delayed/hole extent.
+ */
+ if (!ext4_es_is_written(es) && !ext4_es_is_unwritten(es)) {
+ if (in_range(es->es_lblk, ee_block, ee_len)) {
+ pr_warn("ES insert assertion failed for "
+ "inode: %lu we can find an extent "
+ "at block [%d/%d/%llu/%c], but we "
+ "want to add a delayed/hole extent "
+ "[%d/%d/%llu/%x]\n",
+ inode->i_ino, ee_block, ee_len,
+ ee_start, ee_status ? 'u' : 'w',
+ es->es_lblk, es->es_len,
+ ext4_es_pblock(es), ext4_es_status(es));
+ }
+ goto out;
+ }
+
+ /*
+ * We don't check ee_block == es->es_lblk, etc. because es
+ * might be a part of whole extent, vice versa.
+ */
+ if (es->es_lblk < ee_block ||
+ ext4_es_pblock(es) != ee_start + es->es_lblk - ee_block) {
+ pr_warn("ES insert assertion failed for inode: %lu "
+ "ex_status [%d/%d/%llu/%c] != "
+ "es_status [%d/%d/%llu/%c]\n", inode->i_ino,
+ ee_block, ee_len, ee_start,
+ ee_status ? 'u' : 'w', es->es_lblk, es->es_len,
+ ext4_es_pblock(es), es_status ? 'u' : 'w');
+ goto out;
+ }
+
+ if (ee_status ^ es_status) {
+ pr_warn("ES insert assertion failed for inode: %lu "
+ "ex_status [%d/%d/%llu/%c] != "
+ "es_status [%d/%d/%llu/%c]\n", inode->i_ino,
+ ee_block, ee_len, ee_start,
+ ee_status ? 'u' : 'w', es->es_lblk, es->es_len,
+ ext4_es_pblock(es), es_status ? 'u' : 'w');
+ }
+ } else {
+ /*
+ * We can't find an extent on disk. So we need to make sure
+ * that we don't want to add an written/unwritten extent.
+ */
+ if (!ext4_es_is_delayed(es) && !ext4_es_is_hole(es)) {
+ pr_warn("ES insert assertion failed for inode: %lu "
+ "can't find an extent at block %d but we want "
+ "to add a written/unwritten extent "
+ "[%d/%d/%llu/%x]\n", inode->i_ino,
+ es->es_lblk, es->es_lblk, es->es_len,
+ ext4_es_pblock(es), ext4_es_status(es));
+ }
+ }
+out:
+ ext4_free_ext_path(path);
+}
+
+static void ext4_es_insert_extent_ind_check(struct inode *inode,
+ struct extent_status *es)
+{
+ struct ext4_map_blocks map;
+ int retval;
+
+ /*
+ * Here we call ext4_ind_map_blocks to lookup a block mapping because
+ * 'Indirect' structure is defined in indirect.c. So we couldn't
+ * access direct/indirect tree from outside. It is too dirty to define
+ * this function in indirect.c file.
+ */
+
+ map.m_lblk = es->es_lblk;
+ map.m_len = es->es_len;
+
+ retval = ext4_ind_map_blocks(NULL, inode, &map, 0);
+ if (retval > 0) {
+ if (ext4_es_is_delayed(es) || ext4_es_is_hole(es)) {
+ /*
+ * We want to add a delayed/hole extent but this
+ * block has been allocated.
+ */
+ pr_warn("ES insert assertion failed for inode: %lu "
+ "We can find blocks but we want to add a "
+ "delayed/hole extent [%d/%d/%llu/%x]\n",
+ inode->i_ino, es->es_lblk, es->es_len,
+ ext4_es_pblock(es), ext4_es_status(es));
+ return;
+ } else if (ext4_es_is_written(es)) {
+ if (retval != es->es_len) {
+ pr_warn("ES insert assertion failed for "
+ "inode: %lu retval %d != es_len %d\n",
+ inode->i_ino, retval, es->es_len);
+ return;
+ }
+ if (map.m_pblk != ext4_es_pblock(es)) {
+ pr_warn("ES insert assertion failed for "
+ "inode: %lu m_pblk %llu != "
+ "es_pblk %llu\n",
+ inode->i_ino, map.m_pblk,
+ ext4_es_pblock(es));
+ return;
+ }
+ } else {
+ /*
+ * We don't need to check unwritten extent because
+ * indirect-based file doesn't have it.
+ */
+ BUG();
+ }
+ } else if (retval == 0) {
+ if (ext4_es_is_written(es)) {
+ pr_warn("ES insert assertion failed for inode: %lu "
+ "We can't find the block but we want to add "
+ "a written extent [%d/%d/%llu/%x]\n",
+ inode->i_ino, es->es_lblk, es->es_len,
+ ext4_es_pblock(es), ext4_es_status(es));
+ return;
+ }
+ }
+}
+
+static inline void ext4_es_insert_extent_check(struct inode *inode,
+ struct extent_status *es)
+{
+ /*
+ * We don't need to worry about the race condition because
+ * caller takes i_data_sem locking.
+ */
+ BUG_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
+ if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ ext4_es_insert_extent_ext_check(inode, es);
+ else
+ ext4_es_insert_extent_ind_check(inode, es);
+}
+#else
+static inline void ext4_es_insert_extent_check(struct inode *inode,
+ struct extent_status *es)
+{
+}
+#endif
+
+static int __es_insert_extent(struct inode *inode, struct extent_status *newes,
+ struct extent_status *prealloc)
+{
+ struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
+ struct rb_node **p = &tree->root.rb_node;
+ struct rb_node *parent = NULL;
+ struct extent_status *es;
+
+ while (*p) {
+ parent = *p;
+ es = rb_entry(parent, struct extent_status, rb_node);
+
+ if (newes->es_lblk < es->es_lblk) {
+ if (ext4_es_can_be_merged(newes, es)) {
+ /*
+ * Here we can modify es_lblk directly
+ * because it isn't overlapped.
+ */
+ es->es_lblk = newes->es_lblk;
+ es->es_len += newes->es_len;
+ if (ext4_es_is_written(es) ||
+ ext4_es_is_unwritten(es))
+ ext4_es_store_pblock(es,
+ newes->es_pblk);
+ es = ext4_es_try_to_merge_left(inode, es);
+ goto out;
+ }
+ p = &(*p)->rb_left;
+ } else if (newes->es_lblk > ext4_es_end(es)) {
+ if (ext4_es_can_be_merged(es, newes)) {
+ es->es_len += newes->es_len;
+ es = ext4_es_try_to_merge_right(inode, es);
+ goto out;
+ }
+ p = &(*p)->rb_right;
+ } else {
+ BUG();
+ return -EINVAL;
+ }
+ }
+
+ if (prealloc)
+ es = prealloc;
+ else
+ es = __es_alloc_extent(false);
+ if (!es)
+ return -ENOMEM;
+ ext4_es_init_extent(inode, es, newes->es_lblk, newes->es_len,
+ newes->es_pblk);
+
+ rb_link_node(&es->rb_node, parent, p);
+ rb_insert_color(&es->rb_node, &tree->root);
+
+out:
+ tree->cache_es = es;
+ return 0;
+}
+
+/*
+ * ext4_es_insert_extent() adds information to an inode's extent
+ * status tree.
+ *
+ * Return 0 on success, error code on failure.
+ */
+int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
+ ext4_lblk_t len, ext4_fsblk_t pblk,
+ unsigned int status)
+{
+ struct extent_status newes;
+ ext4_lblk_t end = lblk + len - 1;
+ int err1 = 0, err2 = 0, err3 = 0;
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct extent_status *es1 = NULL;
+ struct extent_status *es2 = NULL;
+ struct pending_reservation *pr = NULL;
+ bool revise_pending = false;
+
+ if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
+ return 0;
+
+ es_debug("add [%u/%u) %llu %x to extent status tree of inode %lu\n",
+ lblk, len, pblk, status, inode->i_ino);
+
+ if (!len)
+ return 0;
+
+ BUG_ON(end < lblk);
+
+ if ((status & EXTENT_STATUS_DELAYED) &&
+ (status & EXTENT_STATUS_WRITTEN)) {
+ ext4_warning(inode->i_sb, "Inserting extent [%u/%u] as "
+ " delayed and written which can potentially "
+ " cause data loss.", lblk, len);
+ WARN_ON(1);
+ }
+
+ newes.es_lblk = lblk;
+ newes.es_len = len;
+ ext4_es_store_pblock_status(&newes, pblk, status);
+ trace_ext4_es_insert_extent(inode, &newes);
+
+ ext4_es_insert_extent_check(inode, &newes);
+
+ revise_pending = sbi->s_cluster_ratio > 1 &&
+ test_opt(inode->i_sb, DELALLOC) &&
+ (status & (EXTENT_STATUS_WRITTEN |
+ EXTENT_STATUS_UNWRITTEN));
+retry:
+ if (err1 && !es1)
+ es1 = __es_alloc_extent(true);
+ if ((err1 || err2) && !es2)
+ es2 = __es_alloc_extent(true);
+ if ((err1 || err2 || err3) && revise_pending && !pr)
+ pr = __alloc_pending(true);
+ write_lock(&EXT4_I(inode)->i_es_lock);
+
+ err1 = __es_remove_extent(inode, lblk, end, NULL, es1);
+ if (err1 != 0)
+ goto error;
+ /* Free preallocated extent if it didn't get used. */
+ if (es1) {
+ if (!es1->es_len)
+ __es_free_extent(es1);
+ es1 = NULL;
+ }
+
+ err2 = __es_insert_extent(inode, &newes, es2);
+ if (err2 == -ENOMEM && !ext4_es_must_keep(&newes))
+ err2 = 0;
+ if (err2 != 0)
+ goto error;
+ /* Free preallocated extent if it didn't get used. */
+ if (es2) {
+ if (!es2->es_len)
+ __es_free_extent(es2);
+ es2 = NULL;
+ }
+
+ if (revise_pending) {
+ err3 = __revise_pending(inode, lblk, len, &pr);
+ if (err3 != 0)
+ goto error;
+ if (pr) {
+ __free_pending(pr);
+ pr = NULL;
+ }
+ }
+error:
+ write_unlock(&EXT4_I(inode)->i_es_lock);
+ if (err1 || err2 || err3)
+ goto retry;
+
+ ext4_es_print_tree(inode);
+ return 0;
+}
+
+/*
+ * ext4_es_cache_extent() inserts information into the extent status
+ * tree if and only if there isn't information about the range in
+ * question already.
+ */
+void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
+ ext4_lblk_t len, ext4_fsblk_t pblk,
+ unsigned int status)
+{
+ struct extent_status *es;
+ struct extent_status newes;
+ ext4_lblk_t end = lblk + len - 1;
+
+ if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
+ return;
+
+ newes.es_lblk = lblk;
+ newes.es_len = len;
+ ext4_es_store_pblock_status(&newes, pblk, status);
+ trace_ext4_es_cache_extent(inode, &newes);
+
+ if (!len)
+ return;
+
+ BUG_ON(end < lblk);
+
+ write_lock(&EXT4_I(inode)->i_es_lock);
+
+ es = __es_tree_search(&EXT4_I(inode)->i_es_tree.root, lblk);
+ if (!es || es->es_lblk > end)
+ __es_insert_extent(inode, &newes, NULL);
+ write_unlock(&EXT4_I(inode)->i_es_lock);
+}
+
+/*
+ * ext4_es_lookup_extent() looks up an extent in extent status tree.
+ *
+ * ext4_es_lookup_extent is called by ext4_map_blocks/ext4_da_map_blocks.
+ *
+ * Return: 1 on found, 0 on not
+ */
+int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
+ ext4_lblk_t *next_lblk,
+ struct extent_status *es)
+{
+ struct ext4_es_tree *tree;
+ struct ext4_es_stats *stats;
+ struct extent_status *es1 = NULL;
+ struct rb_node *node;
+ int found = 0;
+
+ if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
+ return 0;
+
+ trace_ext4_es_lookup_extent_enter(inode, lblk);
+ es_debug("lookup extent in block %u\n", lblk);
+
+ tree = &EXT4_I(inode)->i_es_tree;
+ read_lock(&EXT4_I(inode)->i_es_lock);
+
+ /* find extent in cache firstly */
+ es->es_lblk = es->es_len = es->es_pblk = 0;
+ es1 = READ_ONCE(tree->cache_es);
+ if (es1 && in_range(lblk, es1->es_lblk, es1->es_len)) {
+ es_debug("%u cached by [%u/%u)\n",
+ lblk, es1->es_lblk, es1->es_len);
+ found = 1;
+ goto out;
+ }
+
+ node = tree->root.rb_node;
+ while (node) {
+ es1 = rb_entry(node, struct extent_status, rb_node);
+ if (lblk < es1->es_lblk)
+ node = node->rb_left;
+ else if (lblk > ext4_es_end(es1))
+ node = node->rb_right;
+ else {
+ found = 1;
+ break;
+ }
+ }
+
+out:
+ stats = &EXT4_SB(inode->i_sb)->s_es_stats;
+ if (found) {
+ BUG_ON(!es1);
+ es->es_lblk = es1->es_lblk;
+ es->es_len = es1->es_len;
+ es->es_pblk = es1->es_pblk;
+ if (!ext4_es_is_referenced(es1))
+ ext4_es_set_referenced(es1);
+ percpu_counter_inc(&stats->es_stats_cache_hits);
+ if (next_lblk) {
+ node = rb_next(&es1->rb_node);
+ if (node) {
+ es1 = rb_entry(node, struct extent_status,
+ rb_node);
+ *next_lblk = es1->es_lblk;
+ } else
+ *next_lblk = 0;
+ }
+ } else {
+ percpu_counter_inc(&stats->es_stats_cache_misses);
+ }
+
+ read_unlock(&EXT4_I(inode)->i_es_lock);
+
+ trace_ext4_es_lookup_extent_exit(inode, es, found);
+ return found;
+}
+
+struct rsvd_count {
+ int ndelonly;
+ bool first_do_lblk_found;
+ ext4_lblk_t first_do_lblk;
+ ext4_lblk_t last_do_lblk;
+ struct extent_status *left_es;
+ bool partial;
+ ext4_lblk_t lclu;
+};
+
+/*
+ * init_rsvd - initialize reserved count data before removing block range
+ * in file from extent status tree
+ *
+ * @inode - file containing range
+ * @lblk - first block in range
+ * @es - pointer to first extent in range
+ * @rc - pointer to reserved count data
+ *
+ * Assumes es is not NULL
+ */
+static void init_rsvd(struct inode *inode, ext4_lblk_t lblk,
+ struct extent_status *es, struct rsvd_count *rc)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct rb_node *node;
+
+ rc->ndelonly = 0;
+
+ /*
+ * for bigalloc, note the first delonly block in the range has not
+ * been found, record the extent containing the block to the left of
+ * the region to be removed, if any, and note that there's no partial
+ * cluster to track
+ */
+ if (sbi->s_cluster_ratio > 1) {
+ rc->first_do_lblk_found = false;
+ if (lblk > es->es_lblk) {
+ rc->left_es = es;
+ } else {
+ node = rb_prev(&es->rb_node);
+ rc->left_es = node ? rb_entry(node,
+ struct extent_status,
+ rb_node) : NULL;
+ }
+ rc->partial = false;
+ }
+}
+
+/*
+ * count_rsvd - count the clusters containing delayed and not unwritten
+ * (delonly) blocks in a range within an extent and add to
+ * the running tally in rsvd_count
+ *
+ * @inode - file containing extent
+ * @lblk - first block in range
+ * @len - length of range in blocks
+ * @es - pointer to extent containing clusters to be counted
+ * @rc - pointer to reserved count data
+ *
+ * Tracks partial clusters found at the beginning and end of extents so
+ * they aren't overcounted when they span adjacent extents
+ */
+static void count_rsvd(struct inode *inode, ext4_lblk_t lblk, long len,
+ struct extent_status *es, struct rsvd_count *rc)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ ext4_lblk_t i, end, nclu;
+
+ if (!ext4_es_is_delonly(es))
+ return;
+
+ WARN_ON(len <= 0);
+
+ if (sbi->s_cluster_ratio == 1) {
+ rc->ndelonly += (int) len;
+ return;
+ }
+
+ /* bigalloc */
+
+ i = (lblk < es->es_lblk) ? es->es_lblk : lblk;
+ end = lblk + (ext4_lblk_t) len - 1;
+ end = (end > ext4_es_end(es)) ? ext4_es_end(es) : end;
+
+ /* record the first block of the first delonly extent seen */
+ if (!rc->first_do_lblk_found) {
+ rc->first_do_lblk = i;
+ rc->first_do_lblk_found = true;
+ }
+
+ /* update the last lblk in the region seen so far */
+ rc->last_do_lblk = end;
+
+ /*
+ * if we're tracking a partial cluster and the current extent
+ * doesn't start with it, count it and stop tracking
+ */
+ if (rc->partial && (rc->lclu != EXT4_B2C(sbi, i))) {
+ rc->ndelonly++;
+ rc->partial = false;
+ }
+
+ /*
+ * if the first cluster doesn't start on a cluster boundary but
+ * ends on one, count it
+ */
+ if (EXT4_LBLK_COFF(sbi, i) != 0) {
+ if (end >= EXT4_LBLK_CFILL(sbi, i)) {
+ rc->ndelonly++;
+ rc->partial = false;
+ i = EXT4_LBLK_CFILL(sbi, i) + 1;
+ }
+ }
+
+ /*
+ * if the current cluster starts on a cluster boundary, count the
+ * number of whole delonly clusters in the extent
+ */
+ if ((i + sbi->s_cluster_ratio - 1) <= end) {
+ nclu = (end - i + 1) >> sbi->s_cluster_bits;
+ rc->ndelonly += nclu;
+ i += nclu << sbi->s_cluster_bits;
+ }
+
+ /*
+ * start tracking a partial cluster if there's a partial at the end
+ * of the current extent and we're not already tracking one
+ */
+ if (!rc->partial && i <= end) {
+ rc->partial = true;
+ rc->lclu = EXT4_B2C(sbi, i);
+ }
+}
+
+/*
+ * __pr_tree_search - search for a pending cluster reservation
+ *
+ * @root - root of pending reservation tree
+ * @lclu - logical cluster to search for
+ *
+ * Returns the pending reservation for the cluster identified by @lclu
+ * if found. If not, returns a reservation for the next cluster if any,
+ * and if not, returns NULL.
+ */
+static struct pending_reservation *__pr_tree_search(struct rb_root *root,
+ ext4_lblk_t lclu)
+{
+ struct rb_node *node = root->rb_node;
+ struct pending_reservation *pr = NULL;
+
+ while (node) {
+ pr = rb_entry(node, struct pending_reservation, rb_node);
+ if (lclu < pr->lclu)
+ node = node->rb_left;
+ else if (lclu > pr->lclu)
+ node = node->rb_right;
+ else
+ return pr;
+ }
+ if (pr && lclu < pr->lclu)
+ return pr;
+ if (pr && lclu > pr->lclu) {
+ node = rb_next(&pr->rb_node);
+ return node ? rb_entry(node, struct pending_reservation,
+ rb_node) : NULL;
+ }
+ return NULL;
+}
+
+/*
+ * get_rsvd - calculates and returns the number of cluster reservations to be
+ * released when removing a block range from the extent status tree
+ * and releases any pending reservations within the range
+ *
+ * @inode - file containing block range
+ * @end - last block in range
+ * @right_es - pointer to extent containing next block beyond end or NULL
+ * @rc - pointer to reserved count data
+ *
+ * The number of reservations to be released is equal to the number of
+ * clusters containing delayed and not unwritten (delonly) blocks within
+ * the range, minus the number of clusters still containing delonly blocks
+ * at the ends of the range, and minus the number of pending reservations
+ * within the range.
+ */
+static unsigned int get_rsvd(struct inode *inode, ext4_lblk_t end,
+ struct extent_status *right_es,
+ struct rsvd_count *rc)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct pending_reservation *pr;
+ struct ext4_pending_tree *tree = &EXT4_I(inode)->i_pending_tree;
+ struct rb_node *node;
+ ext4_lblk_t first_lclu, last_lclu;
+ bool left_delonly, right_delonly, count_pending;
+ struct extent_status *es;
+
+ if (sbi->s_cluster_ratio > 1) {
+ /* count any remaining partial cluster */
+ if (rc->partial)
+ rc->ndelonly++;
+
+ if (rc->ndelonly == 0)
+ return 0;
+
+ first_lclu = EXT4_B2C(sbi, rc->first_do_lblk);
+ last_lclu = EXT4_B2C(sbi, rc->last_do_lblk);
+
+ /*
+ * decrease the delonly count by the number of clusters at the
+ * ends of the range that still contain delonly blocks -
+ * these clusters still need to be reserved
+ */
+ left_delonly = right_delonly = false;
+
+ es = rc->left_es;
+ while (es && ext4_es_end(es) >=
+ EXT4_LBLK_CMASK(sbi, rc->first_do_lblk)) {
+ if (ext4_es_is_delonly(es)) {
+ rc->ndelonly--;
+ left_delonly = true;
+ break;
+ }
+ node = rb_prev(&es->rb_node);
+ if (!node)
+ break;
+ es = rb_entry(node, struct extent_status, rb_node);
+ }
+ if (right_es && (!left_delonly || first_lclu != last_lclu)) {
+ if (end < ext4_es_end(right_es)) {
+ es = right_es;
+ } else {
+ node = rb_next(&right_es->rb_node);
+ es = node ? rb_entry(node, struct extent_status,
+ rb_node) : NULL;
+ }
+ while (es && es->es_lblk <=
+ EXT4_LBLK_CFILL(sbi, rc->last_do_lblk)) {
+ if (ext4_es_is_delonly(es)) {
+ rc->ndelonly--;
+ right_delonly = true;
+ break;
+ }
+ node = rb_next(&es->rb_node);
+ if (!node)
+ break;
+ es = rb_entry(node, struct extent_status,
+ rb_node);
+ }
+ }
+
+ /*
+ * Determine the block range that should be searched for
+ * pending reservations, if any. Clusters on the ends of the
+ * original removed range containing delonly blocks are
+ * excluded. They've already been accounted for and it's not
+ * possible to determine if an associated pending reservation
+ * should be released with the information available in the
+ * extents status tree.
+ */
+ if (first_lclu == last_lclu) {
+ if (left_delonly | right_delonly)
+ count_pending = false;
+ else
+ count_pending = true;
+ } else {
+ if (left_delonly)
+ first_lclu++;
+ if (right_delonly)
+ last_lclu--;
+ if (first_lclu <= last_lclu)
+ count_pending = true;
+ else
+ count_pending = false;
+ }
+
+ /*
+ * a pending reservation found between first_lclu and last_lclu
+ * represents an allocated cluster that contained at least one
+ * delonly block, so the delonly total must be reduced by one
+ * for each pending reservation found and released
+ */
+ if (count_pending) {
+ pr = __pr_tree_search(&tree->root, first_lclu);
+ while (pr && pr->lclu <= last_lclu) {
+ rc->ndelonly--;
+ node = rb_next(&pr->rb_node);
+ rb_erase(&pr->rb_node, &tree->root);
+ __free_pending(pr);
+ if (!node)
+ break;
+ pr = rb_entry(node, struct pending_reservation,
+ rb_node);
+ }
+ }
+ }
+ return rc->ndelonly;
+}
+
+
+/*
+ * __es_remove_extent - removes block range from extent status tree
+ *
+ * @inode - file containing range
+ * @lblk - first block in range
+ * @end - last block in range
+ * @reserved - number of cluster reservations released
+ * @prealloc - pre-allocated es to avoid memory allocation failures
+ *
+ * If @reserved is not NULL and delayed allocation is enabled, counts
+ * block/cluster reservations freed by removing range and if bigalloc
+ * enabled cancels pending reservations as needed. Returns 0 on success,
+ * error code on failure.
+ */
+static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
+ ext4_lblk_t end, int *reserved,
+ struct extent_status *prealloc)
+{
+ struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
+ struct rb_node *node;
+ struct extent_status *es;
+ struct extent_status orig_es;
+ ext4_lblk_t len1, len2;
+ ext4_fsblk_t block;
+ int err = 0;
+ bool count_reserved = true;
+ struct rsvd_count rc;
+
+ if (reserved == NULL || !test_opt(inode->i_sb, DELALLOC))
+ count_reserved = false;
+
+ es = __es_tree_search(&tree->root, lblk);
+ if (!es)
+ goto out;
+ if (es->es_lblk > end)
+ goto out;
+
+ /* Simply invalidate cache_es. */
+ tree->cache_es = NULL;
+ if (count_reserved)
+ init_rsvd(inode, lblk, es, &rc);
+
+ orig_es.es_lblk = es->es_lblk;
+ orig_es.es_len = es->es_len;
+ orig_es.es_pblk = es->es_pblk;
+
+ len1 = lblk > es->es_lblk ? lblk - es->es_lblk : 0;
+ len2 = ext4_es_end(es) > end ? ext4_es_end(es) - end : 0;
+ if (len1 > 0)
+ es->es_len = len1;
+ if (len2 > 0) {
+ if (len1 > 0) {
+ struct extent_status newes;
+
+ newes.es_lblk = end + 1;
+ newes.es_len = len2;
+ block = 0x7FDEADBEEFULL;
+ if (ext4_es_is_written(&orig_es) ||
+ ext4_es_is_unwritten(&orig_es))
+ block = ext4_es_pblock(&orig_es) +
+ orig_es.es_len - len2;
+ ext4_es_store_pblock_status(&newes, block,
+ ext4_es_status(&orig_es));
+ err = __es_insert_extent(inode, &newes, prealloc);
+ if (err) {
+ if (!ext4_es_must_keep(&newes))
+ return 0;
+
+ es->es_lblk = orig_es.es_lblk;
+ es->es_len = orig_es.es_len;
+ goto out;
+ }
+ } else {
+ es->es_lblk = end + 1;
+ es->es_len = len2;
+ if (ext4_es_is_written(es) ||
+ ext4_es_is_unwritten(es)) {
+ block = orig_es.es_pblk + orig_es.es_len - len2;
+ ext4_es_store_pblock(es, block);
+ }
+ }
+ if (count_reserved)
+ count_rsvd(inode, orig_es.es_lblk + len1,
+ orig_es.es_len - len1 - len2, &orig_es, &rc);
+ goto out_get_reserved;
+ }
+
+ if (len1 > 0) {
+ if (count_reserved)
+ count_rsvd(inode, lblk, orig_es.es_len - len1,
+ &orig_es, &rc);
+ node = rb_next(&es->rb_node);
+ if (node)
+ es = rb_entry(node, struct extent_status, rb_node);
+ else
+ es = NULL;
+ }
+
+ while (es && ext4_es_end(es) <= end) {
+ if (count_reserved)
+ count_rsvd(inode, es->es_lblk, es->es_len, es, &rc);
+ node = rb_next(&es->rb_node);
+ rb_erase(&es->rb_node, &tree->root);
+ ext4_es_free_extent(inode, es);
+ if (!node) {
+ es = NULL;
+ break;
+ }
+ es = rb_entry(node, struct extent_status, rb_node);
+ }
+
+ if (es && es->es_lblk < end + 1) {
+ ext4_lblk_t orig_len = es->es_len;
+
+ len1 = ext4_es_end(es) - end;
+ if (count_reserved)
+ count_rsvd(inode, es->es_lblk, orig_len - len1,
+ es, &rc);
+ es->es_lblk = end + 1;
+ es->es_len = len1;
+ if (ext4_es_is_written(es) || ext4_es_is_unwritten(es)) {
+ block = es->es_pblk + orig_len - len1;
+ ext4_es_store_pblock(es, block);
+ }
+ }
+
+out_get_reserved:
+ if (count_reserved)
+ *reserved = get_rsvd(inode, end, es, &rc);
+out:
+ return err;
+}
+
+/*
+ * ext4_es_remove_extent - removes block range from extent status tree
+ *
+ * @inode - file containing range
+ * @lblk - first block in range
+ * @len - number of blocks to remove
+ *
+ * Reduces block/cluster reservation count and for bigalloc cancels pending
+ * reservations as needed. Returns 0 on success, error code on failure.
+ */
+int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
+ ext4_lblk_t len)
+{
+ ext4_lblk_t end;
+ int err = 0;
+ int reserved = 0;
+ struct extent_status *es = NULL;
+
+ if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
+ return 0;
+
+ trace_ext4_es_remove_extent(inode, lblk, len);
+ es_debug("remove [%u/%u) from extent status tree of inode %lu\n",
+ lblk, len, inode->i_ino);
+
+ if (!len)
+ return err;
+
+ end = lblk + len - 1;
+ BUG_ON(end < lblk);
+
+retry:
+ if (err && !es)
+ es = __es_alloc_extent(true);
+ /*
+ * ext4_clear_inode() depends on us taking i_es_lock unconditionally
+ * so that we are sure __es_shrink() is done with the inode before it
+ * is reclaimed.
+ */
+ write_lock(&EXT4_I(inode)->i_es_lock);
+ err = __es_remove_extent(inode, lblk, end, &reserved, es);
+ /* Free preallocated extent if it didn't get used. */
+ if (es) {
+ if (!es->es_len)
+ __es_free_extent(es);
+ es = NULL;
+ }
+ write_unlock(&EXT4_I(inode)->i_es_lock);
+ if (err)
+ goto retry;
+
+ ext4_es_print_tree(inode);
+ ext4_da_release_space(inode, reserved);
+ return 0;
+}
+
+static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
+ struct ext4_inode_info *locked_ei)
+{
+ struct ext4_inode_info *ei;
+ struct ext4_es_stats *es_stats;
+ ktime_t start_time;
+ u64 scan_time;
+ int nr_to_walk;
+ int nr_shrunk = 0;
+ int retried = 0, nr_skipped = 0;
+
+ es_stats = &sbi->s_es_stats;
+ start_time = ktime_get();
+
+retry:
+ spin_lock(&sbi->s_es_lock);
+ nr_to_walk = sbi->s_es_nr_inode;
+ while (nr_to_walk-- > 0) {
+ if (list_empty(&sbi->s_es_list)) {
+ spin_unlock(&sbi->s_es_lock);
+ goto out;
+ }
+ ei = list_first_entry(&sbi->s_es_list, struct ext4_inode_info,
+ i_es_list);
+ /* Move the inode to the tail */
+ list_move_tail(&ei->i_es_list, &sbi->s_es_list);
+
+ /*
+ * Normally we try hard to avoid shrinking precached inodes,
+ * but we will as a last resort.
+ */
+ if (!retried && ext4_test_inode_state(&ei->vfs_inode,
+ EXT4_STATE_EXT_PRECACHED)) {
+ nr_skipped++;
+ continue;
+ }
+
+ if (ei == locked_ei || !write_trylock(&ei->i_es_lock)) {
+ nr_skipped++;
+ continue;
+ }
+ /*
+ * Now we hold i_es_lock which protects us from inode reclaim
+ * freeing inode under us
+ */
+ spin_unlock(&sbi->s_es_lock);
+
+ nr_shrunk += es_reclaim_extents(ei, &nr_to_scan);
+ write_unlock(&ei->i_es_lock);
+
+ if (nr_to_scan <= 0)
+ goto out;
+ spin_lock(&sbi->s_es_lock);
+ }
+ spin_unlock(&sbi->s_es_lock);
+
+ /*
+ * If we skipped any inodes, and we weren't able to make any
+ * forward progress, try again to scan precached inodes.
+ */
+ if ((nr_shrunk == 0) && nr_skipped && !retried) {
+ retried++;
+ goto retry;
+ }
+
+ if (locked_ei && nr_shrunk == 0)
+ nr_shrunk = es_reclaim_extents(locked_ei, &nr_to_scan);
+
+out:
+ scan_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
+ if (likely(es_stats->es_stats_scan_time))
+ es_stats->es_stats_scan_time = (scan_time +
+ es_stats->es_stats_scan_time*3) / 4;
+ else
+ es_stats->es_stats_scan_time = scan_time;
+ if (scan_time > es_stats->es_stats_max_scan_time)
+ es_stats->es_stats_max_scan_time = scan_time;
+ if (likely(es_stats->es_stats_shrunk))
+ es_stats->es_stats_shrunk = (nr_shrunk +
+ es_stats->es_stats_shrunk*3) / 4;
+ else
+ es_stats->es_stats_shrunk = nr_shrunk;
+
+ trace_ext4_es_shrink(sbi->s_sb, nr_shrunk, scan_time,
+ nr_skipped, retried);
+ return nr_shrunk;
+}
+
+static unsigned long ext4_es_count(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ unsigned long nr;
+ struct ext4_sb_info *sbi;
+
+ sbi = container_of(shrink, struct ext4_sb_info, s_es_shrinker);
+ nr = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
+ trace_ext4_es_shrink_count(sbi->s_sb, sc->nr_to_scan, nr);
+ return nr;
+}
+
+static unsigned long ext4_es_scan(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct ext4_sb_info *sbi = container_of(shrink,
+ struct ext4_sb_info, s_es_shrinker);
+ int nr_to_scan = sc->nr_to_scan;
+ int ret, nr_shrunk;
+
+ ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
+ trace_ext4_es_shrink_scan_enter(sbi->s_sb, nr_to_scan, ret);
+
+ nr_shrunk = __es_shrink(sbi, nr_to_scan, NULL);
+
+ ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
+ trace_ext4_es_shrink_scan_exit(sbi->s_sb, nr_shrunk, ret);
+ return nr_shrunk;
+}
+
+int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v)
+{
+ struct ext4_sb_info *sbi = EXT4_SB((struct super_block *) seq->private);
+ struct ext4_es_stats *es_stats = &sbi->s_es_stats;
+ struct ext4_inode_info *ei, *max = NULL;
+ unsigned int inode_cnt = 0;
+
+ if (v != SEQ_START_TOKEN)
+ return 0;
+
+ /* here we just find an inode that has the max nr. of objects */
+ spin_lock(&sbi->s_es_lock);
+ list_for_each_entry(ei, &sbi->s_es_list, i_es_list) {
+ inode_cnt++;
+ if (max && max->i_es_all_nr < ei->i_es_all_nr)
+ max = ei;
+ else if (!max)
+ max = ei;
+ }
+ spin_unlock(&sbi->s_es_lock);
+
+ seq_printf(seq, "stats:\n %lld objects\n %lld reclaimable objects\n",
+ percpu_counter_sum_positive(&es_stats->es_stats_all_cnt),
+ percpu_counter_sum_positive(&es_stats->es_stats_shk_cnt));
+ seq_printf(seq, " %lld/%lld cache hits/misses\n",
+ percpu_counter_sum_positive(&es_stats->es_stats_cache_hits),
+ percpu_counter_sum_positive(&es_stats->es_stats_cache_misses));
+ if (inode_cnt)
+ seq_printf(seq, " %d inodes on list\n", inode_cnt);
+
+ seq_printf(seq, "average:\n %llu us scan time\n",
+ div_u64(es_stats->es_stats_scan_time, 1000));
+ seq_printf(seq, " %lu shrunk objects\n", es_stats->es_stats_shrunk);
+ if (inode_cnt)
+ seq_printf(seq,
+ "maximum:\n %lu inode (%u objects, %u reclaimable)\n"
+ " %llu us max scan time\n",
+ max->vfs_inode.i_ino, max->i_es_all_nr, max->i_es_shk_nr,
+ div_u64(es_stats->es_stats_max_scan_time, 1000));
+
+ return 0;
+}
+
+int ext4_es_register_shrinker(struct ext4_sb_info *sbi)
+{
+ int err;
+
+ /* Make sure we have enough bits for physical block number */
+ BUILD_BUG_ON(ES_SHIFT < 48);
+ INIT_LIST_HEAD(&sbi->s_es_list);
+ sbi->s_es_nr_inode = 0;
+ spin_lock_init(&sbi->s_es_lock);
+ sbi->s_es_stats.es_stats_shrunk = 0;
+ err = percpu_counter_init(&sbi->s_es_stats.es_stats_cache_hits, 0,
+ GFP_KERNEL);
+ if (err)
+ return err;
+ err = percpu_counter_init(&sbi->s_es_stats.es_stats_cache_misses, 0,
+ GFP_KERNEL);
+ if (err)
+ goto err1;
+ sbi->s_es_stats.es_stats_scan_time = 0;
+ sbi->s_es_stats.es_stats_max_scan_time = 0;
+ err = percpu_counter_init(&sbi->s_es_stats.es_stats_all_cnt, 0, GFP_KERNEL);
+ if (err)
+ goto err2;
+ err = percpu_counter_init(&sbi->s_es_stats.es_stats_shk_cnt, 0, GFP_KERNEL);
+ if (err)
+ goto err3;
+
+ sbi->s_es_shrinker.scan_objects = ext4_es_scan;
+ sbi->s_es_shrinker.count_objects = ext4_es_count;
+ sbi->s_es_shrinker.seeks = DEFAULT_SEEKS;
+ err = register_shrinker(&sbi->s_es_shrinker, "ext4-es:%s",
+ sbi->s_sb->s_id);
+ if (err)
+ goto err4;
+
+ return 0;
+err4:
+ percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt);
+err3:
+ percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt);
+err2:
+ percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_misses);
+err1:
+ percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_hits);
+ return err;
+}
+
+void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi)
+{
+ percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_hits);
+ percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_misses);
+ percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt);
+ percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt);
+ unregister_shrinker(&sbi->s_es_shrinker);
+}
+
+/*
+ * Shrink extents in given inode from ei->i_es_shrink_lblk till end. Scan at
+ * most *nr_to_scan extents, update *nr_to_scan accordingly.
+ *
+ * Return 0 if we hit end of tree / interval, 1 if we exhausted nr_to_scan.
+ * Increment *nr_shrunk by the number of reclaimed extents. Also update
+ * ei->i_es_shrink_lblk to where we should continue scanning.
+ */
+static int es_do_reclaim_extents(struct ext4_inode_info *ei, ext4_lblk_t end,
+ int *nr_to_scan, int *nr_shrunk)
+{
+ struct inode *inode = &ei->vfs_inode;
+ struct ext4_es_tree *tree = &ei->i_es_tree;
+ struct extent_status *es;
+ struct rb_node *node;
+
+ es = __es_tree_search(&tree->root, ei->i_es_shrink_lblk);
+ if (!es)
+ goto out_wrap;
+
+ while (*nr_to_scan > 0) {
+ if (es->es_lblk > end) {
+ ei->i_es_shrink_lblk = end + 1;
+ return 0;
+ }
+
+ (*nr_to_scan)--;
+ node = rb_next(&es->rb_node);
+
+ if (ext4_es_must_keep(es))
+ goto next;
+ if (ext4_es_is_referenced(es)) {
+ ext4_es_clear_referenced(es);
+ goto next;
+ }
+
+ rb_erase(&es->rb_node, &tree->root);
+ ext4_es_free_extent(inode, es);
+ (*nr_shrunk)++;
+next:
+ if (!node)
+ goto out_wrap;
+ es = rb_entry(node, struct extent_status, rb_node);
+ }
+ ei->i_es_shrink_lblk = es->es_lblk;
+ return 1;
+out_wrap:
+ ei->i_es_shrink_lblk = 0;
+ return 0;
+}
+
+static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan)
+{
+ struct inode *inode = &ei->vfs_inode;
+ int nr_shrunk = 0;
+ ext4_lblk_t start = ei->i_es_shrink_lblk;
+ static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+
+ if (ei->i_es_shk_nr == 0)
+ return 0;
+
+ if (ext4_test_inode_state(inode, EXT4_STATE_EXT_PRECACHED) &&
+ __ratelimit(&_rs))
+ ext4_warning(inode->i_sb, "forced shrink of precached extents");
+
+ if (!es_do_reclaim_extents(ei, EXT_MAX_BLOCKS, nr_to_scan, &nr_shrunk) &&
+ start != 0)
+ es_do_reclaim_extents(ei, start - 1, nr_to_scan, &nr_shrunk);
+
+ ei->i_es_tree.cache_es = NULL;
+ return nr_shrunk;
+}
+
+/*
+ * Called to support EXT4_IOC_CLEAR_ES_CACHE. We can only remove
+ * discretionary entries from the extent status cache. (Some entries
+ * must be present for proper operations.)
+ */
+void ext4_clear_inode_es(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct extent_status *es;
+ struct ext4_es_tree *tree;
+ struct rb_node *node;
+
+ write_lock(&ei->i_es_lock);
+ tree = &EXT4_I(inode)->i_es_tree;
+ tree->cache_es = NULL;
+ node = rb_first(&tree->root);
+ while (node) {
+ es = rb_entry(node, struct extent_status, rb_node);
+ node = rb_next(node);
+ if (!ext4_es_must_keep(es)) {
+ rb_erase(&es->rb_node, &tree->root);
+ ext4_es_free_extent(inode, es);
+ }
+ }
+ ext4_clear_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
+ write_unlock(&ei->i_es_lock);
+}
+
+#ifdef ES_DEBUG__
+static void ext4_print_pending_tree(struct inode *inode)
+{
+ struct ext4_pending_tree *tree;
+ struct rb_node *node;
+ struct pending_reservation *pr;
+
+ printk(KERN_DEBUG "pending reservations for inode %lu:", inode->i_ino);
+ tree = &EXT4_I(inode)->i_pending_tree;
+ node = rb_first(&tree->root);
+ while (node) {
+ pr = rb_entry(node, struct pending_reservation, rb_node);
+ printk(KERN_DEBUG " %u", pr->lclu);
+ node = rb_next(node);
+ }
+ printk(KERN_DEBUG "\n");
+}
+#else
+#define ext4_print_pending_tree(inode)
+#endif
+
+int __init ext4_init_pending(void)
+{
+ ext4_pending_cachep = kmem_cache_create("ext4_pending_reservation",
+ sizeof(struct pending_reservation),
+ 0, (SLAB_RECLAIM_ACCOUNT), NULL);
+ if (ext4_pending_cachep == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
+void ext4_exit_pending(void)
+{
+ kmem_cache_destroy(ext4_pending_cachep);
+}
+
+void ext4_init_pending_tree(struct ext4_pending_tree *tree)
+{
+ tree->root = RB_ROOT;
+}
+
+/*
+ * __get_pending - retrieve a pointer to a pending reservation
+ *
+ * @inode - file containing the pending cluster reservation
+ * @lclu - logical cluster of interest
+ *
+ * Returns a pointer to a pending reservation if it's a member of
+ * the set, and NULL if not. Must be called holding i_es_lock.
+ */
+static struct pending_reservation *__get_pending(struct inode *inode,
+ ext4_lblk_t lclu)
+{
+ struct ext4_pending_tree *tree;
+ struct rb_node *node;
+ struct pending_reservation *pr = NULL;
+
+ tree = &EXT4_I(inode)->i_pending_tree;
+ node = (&tree->root)->rb_node;
+
+ while (node) {
+ pr = rb_entry(node, struct pending_reservation, rb_node);
+ if (lclu < pr->lclu)
+ node = node->rb_left;
+ else if (lclu > pr->lclu)
+ node = node->rb_right;
+ else if (lclu == pr->lclu)
+ return pr;
+ }
+ return NULL;
+}
+
+/*
+ * __insert_pending - adds a pending cluster reservation to the set of
+ * pending reservations
+ *
+ * @inode - file containing the cluster
+ * @lblk - logical block in the cluster to be added
+ * @prealloc - preallocated pending entry
+ *
+ * Returns 0 on successful insertion and -ENOMEM on failure. If the
+ * pending reservation is already in the set, returns successfully.
+ */
+static int __insert_pending(struct inode *inode, ext4_lblk_t lblk,
+ struct pending_reservation **prealloc)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct ext4_pending_tree *tree = &EXT4_I(inode)->i_pending_tree;
+ struct rb_node **p = &tree->root.rb_node;
+ struct rb_node *parent = NULL;
+ struct pending_reservation *pr;
+ ext4_lblk_t lclu;
+ int ret = 0;
+
+ lclu = EXT4_B2C(sbi, lblk);
+ /* search to find parent for insertion */
+ while (*p) {
+ parent = *p;
+ pr = rb_entry(parent, struct pending_reservation, rb_node);
+
+ if (lclu < pr->lclu) {
+ p = &(*p)->rb_left;
+ } else if (lclu > pr->lclu) {
+ p = &(*p)->rb_right;
+ } else {
+ /* pending reservation already inserted */
+ goto out;
+ }
+ }
+
+ if (likely(*prealloc == NULL)) {
+ pr = __alloc_pending(false);
+ if (!pr) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ } else {
+ pr = *prealloc;
+ *prealloc = NULL;
+ }
+ pr->lclu = lclu;
+
+ rb_link_node(&pr->rb_node, parent, p);
+ rb_insert_color(&pr->rb_node, &tree->root);
+
+out:
+ return ret;
+}
+
+/*
+ * __remove_pending - removes a pending cluster reservation from the set
+ * of pending reservations
+ *
+ * @inode - file containing the cluster
+ * @lblk - logical block in the pending cluster reservation to be removed
+ *
+ * Returns successfully if pending reservation is not a member of the set.
+ */
+static void __remove_pending(struct inode *inode, ext4_lblk_t lblk)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct pending_reservation *pr;
+ struct ext4_pending_tree *tree;
+
+ pr = __get_pending(inode, EXT4_B2C(sbi, lblk));
+ if (pr != NULL) {
+ tree = &EXT4_I(inode)->i_pending_tree;
+ rb_erase(&pr->rb_node, &tree->root);
+ __free_pending(pr);
+ }
+}
+
+/*
+ * ext4_remove_pending - removes a pending cluster reservation from the set
+ * of pending reservations
+ *
+ * @inode - file containing the cluster
+ * @lblk - logical block in the pending cluster reservation to be removed
+ *
+ * Locking for external use of __remove_pending.
+ */
+void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+
+ write_lock(&ei->i_es_lock);
+ __remove_pending(inode, lblk);
+ write_unlock(&ei->i_es_lock);
+}
+
+/*
+ * ext4_is_pending - determine whether a cluster has a pending reservation
+ * on it
+ *
+ * @inode - file containing the cluster
+ * @lblk - logical block in the cluster
+ *
+ * Returns true if there's a pending reservation for the cluster in the
+ * set of pending reservations, and false if not.
+ */
+bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ bool ret;
+
+ read_lock(&ei->i_es_lock);
+ ret = (bool)(__get_pending(inode, EXT4_B2C(sbi, lblk)) != NULL);
+ read_unlock(&ei->i_es_lock);
+
+ return ret;
+}
+
+/*
+ * ext4_es_insert_delayed_block - adds a delayed block to the extents status
+ * tree, adding a pending reservation where
+ * needed
+ *
+ * @inode - file containing the newly added block
+ * @lblk - logical block to be added
+ * @allocated - indicates whether a physical cluster has been allocated for
+ * the logical cluster that contains the block
+ *
+ * Returns 0 on success, negative error code on failure.
+ */
+int ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
+ bool allocated)
+{
+ struct extent_status newes;
+ int err1 = 0, err2 = 0, err3 = 0;
+ struct extent_status *es1 = NULL;
+ struct extent_status *es2 = NULL;
+ struct pending_reservation *pr = NULL;
+
+ if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
+ return 0;
+
+ es_debug("add [%u/1) delayed to extent status tree of inode %lu\n",
+ lblk, inode->i_ino);
+
+ newes.es_lblk = lblk;
+ newes.es_len = 1;
+ ext4_es_store_pblock_status(&newes, ~0, EXTENT_STATUS_DELAYED);
+ trace_ext4_es_insert_delayed_block(inode, &newes, allocated);
+
+ ext4_es_insert_extent_check(inode, &newes);
+
+retry:
+ if (err1 && !es1)
+ es1 = __es_alloc_extent(true);
+ if ((err1 || err2) && !es2)
+ es2 = __es_alloc_extent(true);
+ if ((err1 || err2 || err3) && allocated && !pr)
+ pr = __alloc_pending(true);
+ write_lock(&EXT4_I(inode)->i_es_lock);
+
+ err1 = __es_remove_extent(inode, lblk, lblk, NULL, es1);
+ if (err1 != 0)
+ goto error;
+ /* Free preallocated extent if it didn't get used. */
+ if (es1) {
+ if (!es1->es_len)
+ __es_free_extent(es1);
+ es1 = NULL;
+ }
+
+ err2 = __es_insert_extent(inode, &newes, es2);
+ if (err2 != 0)
+ goto error;
+ /* Free preallocated extent if it didn't get used. */
+ if (es2) {
+ if (!es2->es_len)
+ __es_free_extent(es2);
+ es2 = NULL;
+ }
+
+ if (allocated) {
+ err3 = __insert_pending(inode, lblk, &pr);
+ if (err3 != 0)
+ goto error;
+ if (pr) {
+ __free_pending(pr);
+ pr = NULL;
+ }
+ }
+error:
+ write_unlock(&EXT4_I(inode)->i_es_lock);
+ if (err1 || err2 || err3)
+ goto retry;
+
+ ext4_es_print_tree(inode);
+ ext4_print_pending_tree(inode);
+ return 0;
+}
+
+/*
+ * __es_delayed_clu - count number of clusters containing blocks that
+ * are delayed only
+ *
+ * @inode - file containing block range
+ * @start - logical block defining start of range
+ * @end - logical block defining end of range
+ *
+ * Returns the number of clusters containing only delayed (not delayed
+ * and unwritten) blocks in the range specified by @start and @end. Any
+ * cluster or part of a cluster within the range and containing a delayed
+ * and not unwritten block within the range is counted as a whole cluster.
+ */
+static unsigned int __es_delayed_clu(struct inode *inode, ext4_lblk_t start,
+ ext4_lblk_t end)
+{
+ struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
+ struct extent_status *es;
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct rb_node *node;
+ ext4_lblk_t first_lclu, last_lclu;
+ unsigned long long last_counted_lclu;
+ unsigned int n = 0;
+
+ /* guaranteed to be unequal to any ext4_lblk_t value */
+ last_counted_lclu = ~0ULL;
+
+ es = __es_tree_search(&tree->root, start);
+
+ while (es && (es->es_lblk <= end)) {
+ if (ext4_es_is_delonly(es)) {
+ if (es->es_lblk <= start)
+ first_lclu = EXT4_B2C(sbi, start);
+ else
+ first_lclu = EXT4_B2C(sbi, es->es_lblk);
+
+ if (ext4_es_end(es) >= end)
+ last_lclu = EXT4_B2C(sbi, end);
+ else
+ last_lclu = EXT4_B2C(sbi, ext4_es_end(es));
+
+ if (first_lclu == last_counted_lclu)
+ n += last_lclu - first_lclu;
+ else
+ n += last_lclu - first_lclu + 1;
+ last_counted_lclu = last_lclu;
+ }
+ node = rb_next(&es->rb_node);
+ if (!node)
+ break;
+ es = rb_entry(node, struct extent_status, rb_node);
+ }
+
+ return n;
+}
+
+/*
+ * ext4_es_delayed_clu - count number of clusters containing blocks that
+ * are both delayed and unwritten
+ *
+ * @inode - file containing block range
+ * @lblk - logical block defining start of range
+ * @len - number of blocks in range
+ *
+ * Locking for external use of __es_delayed_clu().
+ */
+unsigned int ext4_es_delayed_clu(struct inode *inode, ext4_lblk_t lblk,
+ ext4_lblk_t len)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ ext4_lblk_t end;
+ unsigned int n;
+
+ if (len == 0)
+ return 0;
+
+ end = lblk + len - 1;
+ WARN_ON(end < lblk);
+
+ read_lock(&ei->i_es_lock);
+
+ n = __es_delayed_clu(inode, lblk, end);
+
+ read_unlock(&ei->i_es_lock);
+
+ return n;
+}
+
+/*
+ * __revise_pending - makes, cancels, or leaves unchanged pending cluster
+ * reservations for a specified block range depending
+ * upon the presence or absence of delayed blocks
+ * outside the range within clusters at the ends of the
+ * range
+ *
+ * @inode - file containing the range
+ * @lblk - logical block defining the start of range
+ * @len - length of range in blocks
+ * @prealloc - preallocated pending entry
+ *
+ * Used after a newly allocated extent is added to the extents status tree.
+ * Requires that the extents in the range have either written or unwritten
+ * status. Must be called while holding i_es_lock.
+ */
+static int __revise_pending(struct inode *inode, ext4_lblk_t lblk,
+ ext4_lblk_t len,
+ struct pending_reservation **prealloc)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ ext4_lblk_t end = lblk + len - 1;
+ ext4_lblk_t first, last;
+ bool f_del = false, l_del = false;
+ int ret = 0;
+
+ if (len == 0)
+ return 0;
+
+ /*
+ * Two cases - block range within single cluster and block range
+ * spanning two or more clusters. Note that a cluster belonging
+ * to a range starting and/or ending on a cluster boundary is treated
+ * as if it does not contain a delayed extent. The new range may
+ * have allocated space for previously delayed blocks out to the
+ * cluster boundary, requiring that any pre-existing pending
+ * reservation be canceled. Because this code only looks at blocks
+ * outside the range, it should revise pending reservations
+ * correctly even if the extent represented by the range can't be
+ * inserted in the extents status tree due to ENOSPC.
+ */
+
+ if (EXT4_B2C(sbi, lblk) == EXT4_B2C(sbi, end)) {
+ first = EXT4_LBLK_CMASK(sbi, lblk);
+ if (first != lblk)
+ f_del = __es_scan_range(inode, &ext4_es_is_delonly,
+ first, lblk - 1);
+ if (f_del) {
+ ret = __insert_pending(inode, first, prealloc);
+ if (ret < 0)
+ goto out;
+ } else {
+ last = EXT4_LBLK_CMASK(sbi, end) +
+ sbi->s_cluster_ratio - 1;
+ if (last != end)
+ l_del = __es_scan_range(inode,
+ &ext4_es_is_delonly,
+ end + 1, last);
+ if (l_del) {
+ ret = __insert_pending(inode, last, prealloc);
+ if (ret < 0)
+ goto out;
+ } else
+ __remove_pending(inode, last);
+ }
+ } else {
+ first = EXT4_LBLK_CMASK(sbi, lblk);
+ if (first != lblk)
+ f_del = __es_scan_range(inode, &ext4_es_is_delonly,
+ first, lblk - 1);
+ if (f_del) {
+ ret = __insert_pending(inode, first, prealloc);
+ if (ret < 0)
+ goto out;
+ } else
+ __remove_pending(inode, first);
+
+ last = EXT4_LBLK_CMASK(sbi, end) + sbi->s_cluster_ratio - 1;
+ if (last != end)
+ l_del = __es_scan_range(inode, &ext4_es_is_delonly,
+ end + 1, last);
+ if (l_del) {
+ ret = __insert_pending(inode, last, prealloc);
+ if (ret < 0)
+ goto out;
+ } else
+ __remove_pending(inode, last);
+ }
+out:
+ return ret;
+}