[Concept] [PATCH 08/17] ext4l: bring in extents_status, fsync, and hash

From: Simon Glass <simon.glass@canonical.com> Copy extents_status.c, extents_status.h, fsync.c, and hash.c from Linux v6.18 fs/ext4 directory. - extents_status: extent status tree for tracking extent state - fsync: file synchronization operations - hash: directory entry hashing for htree directories Co-developed-by: Claude Opus 4.5 <noreply@anthropic.com> --- fs/ext4l/extents_status.c | 2306 +++++++++++++++++++++++++++++++++++++ fs/ext4l/extents_status.h | 254 ++++ fs/ext4l/fsync.c | 177 +++ fs/ext4l/hash.c | 323 ++++++ 4 files changed, 3060 insertions(+) create mode 100644 fs/ext4l/extents_status.c create mode 100644 fs/ext4l/extents_status.h create mode 100644 fs/ext4l/fsync.c create mode 100644 fs/ext4l/hash.c diff --git a/fs/ext4l/extents_status.c b/fs/ext4l/extents_status.c new file mode 100644 index 00000000000..31dc0496f8d --- /dev/null +++ b/fs/ext4l/extents_status.c @@ -0,0 +1,2306 @@ +// 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. Assurance of Ext4 extent status tree consistency + * + * When mapping blocks, Ext4 queries the extent status tree first and should + * always trusts that the extent status tree is consistent and up to date. + * Therefore, it is important to adheres to the following rules when createing, + * modifying and removing extents. + * + * 1. Besides fastcommit replay, when Ext4 creates or queries block mappings, + * the extent information should always be processed through the extent + * status tree instead of being organized manually through the on-disk + * extent tree. + * + * 2. When updating the extent tree, Ext4 should acquire the i_data_sem + * exclusively and update the extent status tree atomically. If the extents + * to be modified are large enough to exceed the range that a single + * i_data_sem can process (as ext4_datasem_ensure_credits() may drop + * i_data_sem to restart a transaction), it must (e.g. as ext4_punch_hole() + * does): + * + * a) Hold the i_rwsem and invalidate_lock exclusively. This ensures + * exclusion against page faults, as well as reads and writes that may + * concurrently modify the extent status tree. + * b) Evict all page cache in the affected range and recommend rebuilding + * or dropping the extent status tree after modifying the on-disk + * extent tree. This ensures exclusion against concurrent writebacks + * that do not hold those locks but only holds a folio lock. + * + * 3. Based on the rules above, when querying block mappings, Ext4 should at + * least hold the i_rwsem or invalidate_lock or folio lock(s) for the + * specified querying range. + * + * ========================================================================== + * 4. 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. + * + * + * ========================================================================== + * 5. 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(extent_status, SLAB_RECLAIM_ACCOUNT); + 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) +{ + es->es_lblk = es->es_len = es->es_pblk = 0; + + 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 */ + if (ext4_es_is_delayed(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. + */ +void ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk, + ext4_lblk_t len, ext4_fsblk_t pblk, + unsigned int status, bool delalloc_reserve_used) +{ + struct extent_status newes; + ext4_lblk_t end = lblk + len - 1; + int err1 = 0, err2 = 0, err3 = 0; + int resv_used = 0, pending = 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; + + es_debug("add [%u/%u) %llu %x %d to extent status tree of inode %lu\n", + lblk, len, pblk, status, delalloc_reserve_used, inode->i_ino); + + if (!len) + return; + + BUG_ON(end < lblk); + WARN_ON_ONCE(status & EXTENT_STATUS_DELAYED); + + 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 < 0) && revise_pending && !pr) + pr = __alloc_pending(true); + write_lock(&EXT4_I(inode)->i_es_lock); + + err1 = __es_remove_extent(inode, lblk, end, &resv_used, 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; + } + pending = err3; + } +error: + write_unlock(&EXT4_I(inode)->i_es_lock); + /* + * Reduce the reserved cluster count to reflect successful deferred + * allocation of delayed allocated clusters or direct allocation of + * clusters discovered to be delayed allocated. Once allocated, a + * cluster is not included in the reserved count. + * + * When direct allocating (from fallocate, filemap, DIO, or clusters + * allocated when delalloc has been disabled by ext4_nonda_switch()) + * an extent either 1) contains delayed blocks but start with + * non-delayed allocated blocks (e.g. hole) or 2) contains non-delayed + * allocated blocks which belong to delayed allocated clusters when + * bigalloc feature is enabled, quota has already been claimed by + * ext4_mb_new_blocks(), so release the quota reservations made for + * any previously delayed allocated clusters instead of claim them + * again. + */ + resv_used += pending; + if (resv_used) + ext4_da_update_reserve_space(inode, resv_used, + delalloc_reserve_used); + + if (err1 || err2 || err3 < 0) + goto retry; + + ext4_es_print_tree(inode); + return; +} + +/* + * 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 ndelayed; + 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->ndelayed = 0; + + /* + * for bigalloc, note the first delayed 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 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_delayed(es)) + return; + + WARN_ON(len <= 0); + + if (sbi->s_cluster_ratio == 1) { + rc->ndelayed += (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 delayed 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->ndelayed++; + 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->ndelayed++; + rc->partial = false; + i = EXT4_LBLK_CFILL(sbi, i) + 1; + } + } + + /* + * if the current cluster starts on a cluster boundary, count the + * number of whole delayed clusters in the extent + */ + if ((i + sbi->s_cluster_ratio - 1) <= end) { + nclu = (end - i + 1) >> sbi->s_cluster_bits; + rc->ndelayed += 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 blocks within the range, minus the number of + * clusters still containing delayed 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_delayed, right_delayed, count_pending; + struct extent_status *es; + + if (sbi->s_cluster_ratio > 1) { + /* count any remaining partial cluster */ + if (rc->partial) + rc->ndelayed++; + + if (rc->ndelayed == 0) + return 0; + + first_lclu = EXT4_B2C(sbi, rc->first_do_lblk); + last_lclu = EXT4_B2C(sbi, rc->last_do_lblk); + + /* + * decrease the delayed count by the number of clusters at the + * ends of the range that still contain delayed blocks - + * these clusters still need to be reserved + */ + left_delayed = right_delayed = false; + + es = rc->left_es; + while (es && ext4_es_end(es) >= + EXT4_LBLK_CMASK(sbi, rc->first_do_lblk)) { + if (ext4_es_is_delayed(es)) { + rc->ndelayed--; + left_delayed = true; + break; + } + node = rb_prev(&es->rb_node); + if (!node) + break; + es = rb_entry(node, struct extent_status, rb_node); + } + if (right_es && (!left_delayed || 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_delayed(es)) { + rc->ndelayed--; + right_delayed = 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 delayed 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_delayed | right_delayed) + count_pending = false; + else + count_pending = true; + } else { + if (left_delayed) + first_lclu++; + if (right_delayed) + 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 + * delayed block, so the delayed 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->ndelayed--; + 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->ndelayed; +} + + +/* + * __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. + */ +void 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; + + 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; + + 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); +} + +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 = shrink->private_data; + 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 = shrink->private_data; + 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 = shrinker_alloc(0, "ext4-es:%s", sbi->s_sb->s_id); + if (!sbi->s_es_shrinker) { + err = -ENOMEM; + goto err4; + } + + sbi->s_es_shrinker->scan_objects = ext4_es_scan; + sbi->s_es_shrinker->count_objects = ext4_es_count; + sbi->s_es_shrinker->private_data = sbi; + + shrinker_register(sbi->s_es_shrinker); + + 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); + shrinker_free(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(pending_reservation, SLAB_RECLAIM_ACCOUNT); + 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 1 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); + ret = 1; + +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_extent - adds some delayed blocks to the extents + * status tree, adding a pending reservation + * where needed + * + * @inode - file containing the newly added block + * @lblk - start logical block to be added + * @len - length of blocks to be added + * @lclu_allocated/end_allocated - indicates whether a physical cluster has + * been allocated for the logical cluster + * that contains the start/end block. Note that + * end_allocated should always be set to false + * if the start and the end block are in the + * same cluster + */ +void ext4_es_insert_delayed_extent(struct inode *inode, ext4_lblk_t lblk, + ext4_lblk_t len, bool lclu_allocated, + bool end_allocated) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + struct extent_status newes; + ext4_lblk_t end = lblk + len - 1; + int err1 = 0, err2 = 0, err3 = 0; + struct extent_status *es1 = NULL; + struct extent_status *es2 = NULL; + struct pending_reservation *pr1 = NULL; + struct pending_reservation *pr2 = NULL; + + if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY) + return; + + es_debug("add [%u/%u) delayed to extent status tree of inode %lu\n", + lblk, len, inode->i_ino); + if (!len) + return; + + WARN_ON_ONCE((EXT4_B2C(sbi, lblk) == EXT4_B2C(sbi, end)) && + end_allocated); + + newes.es_lblk = lblk; + newes.es_len = len; + ext4_es_store_pblock_status(&newes, ~0, EXTENT_STATUS_DELAYED); + trace_ext4_es_insert_delayed_extent(inode, &newes, lclu_allocated, + end_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 < 0) { + if (lclu_allocated && !pr1) + pr1 = __alloc_pending(true); + if (end_allocated && !pr2) + pr2 = __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 != 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 (lclu_allocated) { + err3 = __insert_pending(inode, lblk, &pr1); + if (err3 < 0) + goto error; + if (pr1) { + __free_pending(pr1); + pr1 = NULL; + } + } + if (end_allocated) { + err3 = __insert_pending(inode, end, &pr2); + if (err3 < 0) + goto error; + if (pr2) { + __free_pending(pr2); + pr2 = NULL; + } + } +error: + write_unlock(&EXT4_I(inode)->i_es_lock); + if (err1 || err2 || err3 < 0) + goto retry; + + ext4_es_print_tree(inode); + ext4_print_pending_tree(inode); + return; +} + +/* + * __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. Returns number of new + * inserts pending cluster on insert pendings, returns 0 on remove pendings, + * return -ENOMEM on failure. + */ +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 pendings = 0; + 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_delayed, + first, lblk - 1); + if (f_del) { + ret = __insert_pending(inode, first, prealloc); + if (ret < 0) + goto out; + pendings += ret; + } else { + last = EXT4_LBLK_CMASK(sbi, end) + + sbi->s_cluster_ratio - 1; + if (last != end) + l_del = __es_scan_range(inode, + &ext4_es_is_delayed, + end + 1, last); + if (l_del) { + ret = __insert_pending(inode, last, prealloc); + if (ret < 0) + goto out; + pendings += ret; + } else + __remove_pending(inode, last); + } + } else { + first = EXT4_LBLK_CMASK(sbi, lblk); + if (first != lblk) + f_del = __es_scan_range(inode, &ext4_es_is_delayed, + first, lblk - 1); + if (f_del) { + ret = __insert_pending(inode, first, prealloc); + if (ret < 0) + goto out; + pendings += ret; + } 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_delayed, + end + 1, last); + if (l_del) { + ret = __insert_pending(inode, last, prealloc); + if (ret < 0) + goto out; + pendings += ret; + } else + __remove_pending(inode, last); + } +out: + return (ret < 0) ? ret : pendings; +} diff --git a/fs/ext4l/extents_status.h b/fs/ext4l/extents_status.h new file mode 100644 index 00000000000..8f9c008d11e --- /dev/null +++ b/fs/ext4l/extents_status.h @@ -0,0 +1,254 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * fs/ext4/extents_status.h + * + * Written by Yongqiang Yang <xiaoqiangnk@gmail.com> + * Modified by + * Allison Henderson <achender@linux.vnet.ibm.com> + * Zheng Liu <wenqing.lz@taobao.com> + * + */ + +#ifndef _EXT4_EXTENTS_STATUS_H +#define _EXT4_EXTENTS_STATUS_H + +/* + * Turn on ES_DEBUG__ to get lots of info about extent status operations. + */ +#ifdef ES_DEBUG__ +#define es_debug(fmt, ...) printk(fmt, ##__VA_ARGS__) +#else +#define es_debug(fmt, ...) no_printk(fmt, ##__VA_ARGS__) +#endif + +/* + * With ES_AGGRESSIVE_TEST defined, the result of es caching will be + * checked with old map_block's result. + */ +#define ES_AGGRESSIVE_TEST__ + +/* + * These flags live in the high bits of extent_status.es_pblk + */ +enum { + ES_WRITTEN_B, + ES_UNWRITTEN_B, + ES_DELAYED_B, + ES_HOLE_B, + ES_REFERENCED_B, + ES_FLAGS +}; + +#define ES_SHIFT (sizeof(ext4_fsblk_t)*8 - ES_FLAGS) +#define ES_MASK (~((ext4_fsblk_t)0) << ES_SHIFT) + +/* + * Besides EXTENT_STATUS_REFERENCED, all these extent type masks + * are exclusive, only one type can be set at a time. + */ +#define EXTENT_STATUS_WRITTEN (1 << ES_WRITTEN_B) +#define EXTENT_STATUS_UNWRITTEN (1 << ES_UNWRITTEN_B) +#define EXTENT_STATUS_DELAYED (1 << ES_DELAYED_B) +#define EXTENT_STATUS_HOLE (1 << ES_HOLE_B) +#define EXTENT_STATUS_REFERENCED (1 << ES_REFERENCED_B) + +#define ES_TYPE_MASK ((ext4_fsblk_t)(EXTENT_STATUS_WRITTEN | \ + EXTENT_STATUS_UNWRITTEN | \ + EXTENT_STATUS_DELAYED | \ + EXTENT_STATUS_HOLE)) + +#define ES_TYPE_VALID(type) ((type) && !((type) & ((type) - 1))) + +struct ext4_sb_info; +struct ext4_extent; + +struct extent_status { + struct rb_node rb_node; + ext4_lblk_t es_lblk; /* first logical block extent covers */ + ext4_lblk_t es_len; /* length of extent in block */ + ext4_fsblk_t es_pblk; /* first physical block */ +}; + +struct ext4_es_tree { + struct rb_root root; + struct extent_status *cache_es; /* recently accessed extent */ +}; + +struct ext4_es_stats { + unsigned long es_stats_shrunk; + struct percpu_counter es_stats_cache_hits; + struct percpu_counter es_stats_cache_misses; + u64 es_stats_scan_time; + u64 es_stats_max_scan_time; + struct percpu_counter es_stats_all_cnt; + struct percpu_counter es_stats_shk_cnt; +}; + +/* + * Pending cluster reservations for bigalloc file systems + * + * A cluster with a pending reservation is a logical cluster shared by at + * least one extent in the extents status tree with delayed and unwritten + * status and at least one other written or unwritten extent. The + * reservation is said to be pending because a cluster reservation would + * have to be taken in the event all blocks in the cluster shared with + * written or unwritten extents were deleted while the delayed and + * unwritten blocks remained. + * + * The set of pending cluster reservations is an auxiliary data structure + * used with the extents status tree to implement reserved cluster/block + * accounting for bigalloc file systems. The set is kept in memory and + * records all pending cluster reservations. + * + * Its primary function is to avoid the need to read extents from the + * disk when invalidating pages as a result of a truncate, punch hole, or + * collapse range operation. Page invalidation requires a decrease in the + * reserved cluster count if it results in the removal of all delayed + * and unwritten extents (blocks) from a cluster that is not shared with a + * written or unwritten extent, and no decrease otherwise. Determining + * whether the cluster is shared can be done by searching for a pending + * reservation on it. + * + * Secondarily, it provides a potentially faster method for determining + * whether the reserved cluster count should be increased when a physical + * cluster is deallocated as a result of a truncate, punch hole, or + * collapse range operation. The necessary information is also present + * in the extents status tree, but might be more rapidly accessed in + * the pending reservation set in many cases due to smaller size. + * + * The pending cluster reservation set is implemented as a red-black tree + * with the goal of minimizing per page search time overhead. + */ + +struct pending_reservation { + struct rb_node rb_node; + ext4_lblk_t lclu; +}; + +struct ext4_pending_tree { + struct rb_root root; +}; + +extern int __init ext4_init_es(void); +extern void ext4_exit_es(void); +extern void ext4_es_init_tree(struct ext4_es_tree *tree); + +extern void ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk, + ext4_lblk_t len, ext4_fsblk_t pblk, + unsigned int status, + bool delalloc_reserve_used); +extern void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk, + ext4_lblk_t len, ext4_fsblk_t pblk, + unsigned int status); +extern void ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk, + ext4_lblk_t len); +extern void ext4_es_find_extent_range(struct inode *inode, + int (*match_fn)(struct extent_status *es), + ext4_lblk_t lblk, ext4_lblk_t end, + struct extent_status *es); +extern int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk, + ext4_lblk_t *next_lblk, + struct extent_status *es); +extern bool ext4_es_scan_range(struct inode *inode, + int (*matching_fn)(struct extent_status *es), + ext4_lblk_t lblk, ext4_lblk_t end); +extern bool ext4_es_scan_clu(struct inode *inode, + int (*matching_fn)(struct extent_status *es), + ext4_lblk_t lblk); + +static inline unsigned int ext4_es_status(struct extent_status *es) +{ + return es->es_pblk >> ES_SHIFT; +} + +static inline unsigned int ext4_es_type(struct extent_status *es) +{ + return (es->es_pblk >> ES_SHIFT) & ES_TYPE_MASK; +} + +static inline int ext4_es_is_written(struct extent_status *es) +{ + return (ext4_es_type(es) & EXTENT_STATUS_WRITTEN) != 0; +} + +static inline int ext4_es_is_unwritten(struct extent_status *es) +{ + return (ext4_es_type(es) & EXTENT_STATUS_UNWRITTEN) != 0; +} + +static inline int ext4_es_is_delayed(struct extent_status *es) +{ + return (ext4_es_type(es) & EXTENT_STATUS_DELAYED) != 0; +} + +static inline int ext4_es_is_hole(struct extent_status *es) +{ + return (ext4_es_type(es) & EXTENT_STATUS_HOLE) != 0; +} + +static inline int ext4_es_is_mapped(struct extent_status *es) +{ + return (ext4_es_is_written(es) || ext4_es_is_unwritten(es)); +} + +static inline void ext4_es_set_referenced(struct extent_status *es) +{ + es->es_pblk |= ((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT; +} + +static inline void ext4_es_clear_referenced(struct extent_status *es) +{ + es->es_pblk &= ~(((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT); +} + +static inline int ext4_es_is_referenced(struct extent_status *es) +{ + return (ext4_es_status(es) & EXTENT_STATUS_REFERENCED) != 0; +} + +static inline ext4_fsblk_t ext4_es_pblock(struct extent_status *es) +{ + return es->es_pblk & ~ES_MASK; +} + +static inline ext4_fsblk_t ext4_es_show_pblock(struct extent_status *es) +{ + ext4_fsblk_t pblock = ext4_es_pblock(es); + return pblock == ~ES_MASK ? 0 : pblock; +} + +static inline void ext4_es_store_pblock(struct extent_status *es, + ext4_fsblk_t pb) +{ + ext4_fsblk_t block; + + block = (pb & ~ES_MASK) | (es->es_pblk & ES_MASK); + es->es_pblk = block; +} + +static inline void ext4_es_store_pblock_status(struct extent_status *es, + ext4_fsblk_t pb, + unsigned int status) +{ + WARN_ON_ONCE(!ES_TYPE_VALID(status & ES_TYPE_MASK)); + + es->es_pblk = (((ext4_fsblk_t)status << ES_SHIFT) & ES_MASK) | + (pb & ~ES_MASK); +} + +extern int ext4_es_register_shrinker(struct ext4_sb_info *sbi); +extern void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi); + +extern int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v); + +extern int __init ext4_init_pending(void); +extern void ext4_exit_pending(void); +extern void ext4_init_pending_tree(struct ext4_pending_tree *tree); +extern void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk); +extern bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk); +extern void ext4_es_insert_delayed_extent(struct inode *inode, ext4_lblk_t lblk, + ext4_lblk_t len, bool lclu_allocated, + bool end_allocated); +extern void ext4_clear_inode_es(struct inode *inode); + +#endif /* _EXT4_EXTENTS_STATUS_H */ diff --git a/fs/ext4l/fsync.c b/fs/ext4l/fsync.c new file mode 100644 index 00000000000..e476c6de307 --- /dev/null +++ b/fs/ext4l/fsync.c @@ -0,0 +1,177 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/ext4/fsync.c + * + * Copyright (C) 1993 Stephen Tweedie (sct@redhat.com) + * from + * Copyright (C) 1992 Remy Card (card@masi.ibp.fr) + * Laboratoire MASI - Institut Blaise Pascal + * Universite Pierre et Marie Curie (Paris VI) + * from + * linux/fs/minix/truncate.c Copyright (C) 1991, 1992 Linus Torvalds + * + * ext4fs fsync primitive + * + * Big-endian to little-endian byte-swapping/bitmaps by + * David S. Miller (davem@caip.rutgers.edu), 1995 + * + * Removed unnecessary code duplication for little endian machines + * and excessive __inline__s. + * Andi Kleen, 1997 + * + * Major simplications and cleanup - we only need to do the metadata, because + * we can depend on generic_block_fdatasync() to sync the data blocks. + */ + +#include <linux/time.h> +#include <linux/fs.h> +#include <linux/sched.h> +#include <linux/writeback.h> +#include <linux/blkdev.h> +#include <linux/buffer_head.h> + +#include "ext4.h" +#include "ext4_jbd2.h" + +#include <trace/events/ext4.h> + +/* + * If we're not journaling and this is a just-created file, we have to + * sync our parent directory (if it was freshly created) since + * otherwise it will only be written by writeback, leaving a huge + * window during which a crash may lose the file. This may apply for + * the parent directory's parent as well, and so on recursively, if + * they are also freshly created. + */ +static int ext4_sync_parent(struct inode *inode) +{ + struct dentry *dentry, *next; + int ret = 0; + + if (!ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) + return 0; + dentry = d_find_any_alias(inode); + if (!dentry) + return 0; + while (ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) { + ext4_clear_inode_state(inode, EXT4_STATE_NEWENTRY); + + next = dget_parent(dentry); + dput(dentry); + dentry = next; + inode = dentry->d_inode; + + /* + * The directory inode may have gone through rmdir by now. But + * the inode itself and its blocks are still allocated (we hold + * a reference to the inode via its dentry), so it didn't go + * through ext4_evict_inode()) and so we are safe to flush + * metadata blocks and the inode. + */ + ret = sync_mapping_buffers(inode->i_mapping); + if (ret) + break; + ret = sync_inode_metadata(inode, 1); + if (ret) + break; + } + dput(dentry); + return ret; +} + +static int ext4_fsync_nojournal(struct file *file, loff_t start, loff_t end, + int datasync, bool *needs_barrier) +{ + struct inode *inode = file->f_inode; + int ret; + + ret = generic_buffers_fsync_noflush(file, start, end, datasync); + if (!ret) + ret = ext4_sync_parent(inode); + if (test_opt(inode->i_sb, BARRIER)) + *needs_barrier = true; + + return ret; +} + +static int ext4_fsync_journal(struct inode *inode, bool datasync, + bool *needs_barrier) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; + tid_t commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid; + + /* + * Fastcommit does not really support fsync on directories or other + * special files. Force a full commit. + */ + if (!S_ISREG(inode->i_mode)) + return ext4_force_commit(inode->i_sb); + + if (journal->j_flags & JBD2_BARRIER && + !jbd2_trans_will_send_data_barrier(journal, commit_tid)) + *needs_barrier = true; + + return ext4_fc_commit(journal, commit_tid); +} + +/* + * akpm: A new design for ext4_sync_file(). + * + * This is only called from sys_fsync(), sys_fdatasync() and sys_msync(). + * There cannot be a transaction open by this task. + * Another task could have dirtied this inode. Its data can be in any + * state in the journalling system. + * + * What we do is just kick off a commit and wait on it. This will snapshot the + * inode to disk. + */ +int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync) +{ + int ret = 0, err; + bool needs_barrier = false; + struct inode *inode = file->f_mapping->host; + + ret = ext4_emergency_state(inode->i_sb); + if (unlikely(ret)) + return ret; + + ASSERT(ext4_journal_current_handle() == NULL); + + trace_ext4_sync_file_enter(file, datasync); + + if (sb_rdonly(inode->i_sb)) + goto out; + + if (!EXT4_SB(inode->i_sb)->s_journal) { + ret = ext4_fsync_nojournal(file, start, end, datasync, + &needs_barrier); + if (needs_barrier) + goto issue_flush; + goto out; + } + + ret = file_write_and_wait_range(file, start, end); + if (ret) + goto out; + + /* + * The caller's filemap_fdatawrite()/wait will sync the data. + * Metadata is in the journal, we wait for proper transaction to + * commit here. + */ + ret = ext4_fsync_journal(inode, datasync, &needs_barrier); + +issue_flush: + if (needs_barrier) { + err = blkdev_issue_flush(inode->i_sb->s_bdev); + if (!ret) + ret = err; + } +out: + err = file_check_and_advance_wb_err(file); + if (ret == 0) + ret = err; + trace_ext4_sync_file_exit(inode, ret); + return ret; +} diff --git a/fs/ext4l/hash.c b/fs/ext4l/hash.c new file mode 100644 index 00000000000..33cd5b6b02d --- /dev/null +++ b/fs/ext4l/hash.c @@ -0,0 +1,323 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/ext4/hash.c + * + * Copyright (C) 2002 by Theodore Ts'o + */ + +#include <linux/fs.h> +#include <linux/unicode.h> +#include <linux/compiler.h> +#include <linux/bitops.h> +#include "ext4.h" + +#define DELTA 0x9E3779B9 + +static void TEA_transform(__u32 buf[4], __u32 const in[]) +{ + __u32 sum = 0; + __u32 b0 = buf[0], b1 = buf[1]; + __u32 a = in[0], b = in[1], c = in[2], d = in[3]; + int n = 16; + + do { + sum += DELTA; + b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b); + b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d); + } while (--n); + + buf[0] += b0; + buf[1] += b1; +} + +/* F, G and H are basic MD4 functions: selection, majority, parity */ +#define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z)))) +#define G(x, y, z) (((x) & (y)) + (((x) ^ (y)) & (z))) +#define H(x, y, z) ((x) ^ (y) ^ (z)) + +/* + * The generic round function. The application is so specific that + * we don't bother protecting all the arguments with parens, as is generally + * good macro practice, in favor of extra legibility. + * Rotation is separate from addition to prevent recomputation + */ +#define ROUND(f, a, b, c, d, x, s) \ + (a += f(b, c, d) + x, a = rol32(a, s)) +#define K1 0 +#define K2 013240474631UL +#define K3 015666365641UL + +/* + * Basic cut-down MD4 transform. Returns only 32 bits of result. + */ +static __u32 half_md4_transform(__u32 buf[4], __u32 const in[8]) +{ + __u32 a = buf[0], b = buf[1], c = buf[2], d = buf[3]; + + /* Round 1 */ + ROUND(F, a, b, c, d, in[0] + K1, 3); + ROUND(F, d, a, b, c, in[1] + K1, 7); + ROUND(F, c, d, a, b, in[2] + K1, 11); + ROUND(F, b, c, d, a, in[3] + K1, 19); + ROUND(F, a, b, c, d, in[4] + K1, 3); + ROUND(F, d, a, b, c, in[5] + K1, 7); + ROUND(F, c, d, a, b, in[6] + K1, 11); + ROUND(F, b, c, d, a, in[7] + K1, 19); + + /* Round 2 */ + ROUND(G, a, b, c, d, in[1] + K2, 3); + ROUND(G, d, a, b, c, in[3] + K2, 5); + ROUND(G, c, d, a, b, in[5] + K2, 9); + ROUND(G, b, c, d, a, in[7] + K2, 13); + ROUND(G, a, b, c, d, in[0] + K2, 3); + ROUND(G, d, a, b, c, in[2] + K2, 5); + ROUND(G, c, d, a, b, in[4] + K2, 9); + ROUND(G, b, c, d, a, in[6] + K2, 13); + + /* Round 3 */ + ROUND(H, a, b, c, d, in[3] + K3, 3); + ROUND(H, d, a, b, c, in[7] + K3, 9); + ROUND(H, c, d, a, b, in[2] + K3, 11); + ROUND(H, b, c, d, a, in[6] + K3, 15); + ROUND(H, a, b, c, d, in[1] + K3, 3); + ROUND(H, d, a, b, c, in[5] + K3, 9); + ROUND(H, c, d, a, b, in[0] + K3, 11); + ROUND(H, b, c, d, a, in[4] + K3, 15); + + buf[0] += a; + buf[1] += b; + buf[2] += c; + buf[3] += d; + + return buf[1]; /* "most hashed" word */ +} +#undef ROUND +#undef K1 +#undef K2 +#undef K3 +#undef F +#undef G +#undef H + +/* The old legacy hash */ +static __u32 dx_hack_hash_unsigned(const char *name, int len) +{ + __u32 hash, hash0 = 0x12a3fe2d, hash1 = 0x37abe8f9; + const unsigned char *ucp = (const unsigned char *) name; + + while (len--) { + hash = hash1 + (hash0 ^ (((int) *ucp++) * 7152373)); + + if (hash & 0x80000000) + hash -= 0x7fffffff; + hash1 = hash0; + hash0 = hash; + } + return hash0 << 1; +} + +static __u32 dx_hack_hash_signed(const char *name, int len) +{ + __u32 hash, hash0 = 0x12a3fe2d, hash1 = 0x37abe8f9; + const signed char *scp = (const signed char *) name; + + while (len--) { + hash = hash1 + (hash0 ^ (((int) *scp++) * 7152373)); + + if (hash & 0x80000000) + hash -= 0x7fffffff; + hash1 = hash0; + hash0 = hash; + } + return hash0 << 1; +} + +static void str2hashbuf_signed(const char *msg, int len, __u32 *buf, int num) +{ + __u32 pad, val; + int i; + const signed char *scp = (const signed char *) msg; + + pad = (__u32)len | ((__u32)len << 8); + pad |= pad << 16; + + val = pad; + if (len > num*4) + len = num * 4; + for (i = 0; i < len; i++) { + val = ((int) scp[i]) + (val << 8); + if ((i % 4) == 3) { + *buf++ = val; + val = pad; + num--; + } + } + if (--num >= 0) + *buf++ = val; + while (--num >= 0) + *buf++ = pad; +} + +static void str2hashbuf_unsigned(const char *msg, int len, __u32 *buf, int num) +{ + __u32 pad, val; + int i; + const unsigned char *ucp = (const unsigned char *) msg; + + pad = (__u32)len | ((__u32)len << 8); + pad |= pad << 16; + + val = pad; + if (len > num*4) + len = num * 4; + for (i = 0; i < len; i++) { + val = ((int) ucp[i]) + (val << 8); + if ((i % 4) == 3) { + *buf++ = val; + val = pad; + num--; + } + } + if (--num >= 0) + *buf++ = val; + while (--num >= 0) + *buf++ = pad; +} + +/* + * Returns the hash of a filename. If len is 0 and name is NULL, then + * this function can be used to test whether or not a hash version is + * supported. + * + * The seed is an 4 longword (32 bits) "secret" which can be used to + * uniquify a hash. If the seed is all zero's, then some default seed + * may be used. + * + * A particular hash version specifies whether or not the seed is + * represented, and whether or not the returned hash is 32 bits or 64 + * bits. 32 bit hashes will return 0 for the minor hash. + */ +static int __ext4fs_dirhash(const struct inode *dir, const char *name, int len, + struct dx_hash_info *hinfo) +{ + __u32 hash; + __u32 minor_hash = 0; + const char *p; + int i; + __u32 in[8], buf[4]; + void (*str2hashbuf)(const char *, int, __u32 *, int) = + str2hashbuf_signed; + + /* Initialize the default seed for the hash checksum functions */ + buf[0] = 0x67452301; + buf[1] = 0xefcdab89; + buf[2] = 0x98badcfe; + buf[3] = 0x10325476; + + /* Check to see if the seed is all zero's */ + if (hinfo->seed) { + for (i = 0; i < 4; i++) { + if (hinfo->seed[i]) { + memcpy(buf, hinfo->seed, sizeof(buf)); + break; + } + } + } + + switch (hinfo->hash_version) { + case DX_HASH_LEGACY_UNSIGNED: + hash = dx_hack_hash_unsigned(name, len); + break; + case DX_HASH_LEGACY: + hash = dx_hack_hash_signed(name, len); + break; + case DX_HASH_HALF_MD4_UNSIGNED: + str2hashbuf = str2hashbuf_unsigned; + fallthrough; + case DX_HASH_HALF_MD4: + p = name; + while (len > 0) { + (*str2hashbuf)(p, len, in, 8); + half_md4_transform(buf, in); + len -= 32; + p += 32; + } + minor_hash = buf[2]; + hash = buf[1]; + break; + case DX_HASH_TEA_UNSIGNED: + str2hashbuf = str2hashbuf_unsigned; + fallthrough; + case DX_HASH_TEA: + p = name; + while (len > 0) { + (*str2hashbuf)(p, len, in, 4); + TEA_transform(buf, in); + len -= 16; + p += 16; + } + hash = buf[0]; + minor_hash = buf[1]; + break; + case DX_HASH_SIPHASH: + { + struct qstr qname = QSTR_INIT(name, len); + __u64 combined_hash; + + if (fscrypt_has_encryption_key(dir)) { + combined_hash = fscrypt_fname_siphash(dir, &qname); + } else { + ext4_warning_inode(dir, "Siphash requires key"); + return -1; + } + + hash = (__u32)(combined_hash >> 32); + minor_hash = (__u32)combined_hash; + break; + } + default: + hinfo->hash = 0; + hinfo->minor_hash = 0; + ext4_warning(dir->i_sb, + "invalid/unsupported hash tree version %u", + hinfo->hash_version); + return -EINVAL; + } + hash = hash & ~1; + if (hash == (EXT4_HTREE_EOF_32BIT << 1)) + hash = (EXT4_HTREE_EOF_32BIT - 1) << 1; + hinfo->hash = hash; + hinfo->minor_hash = minor_hash; + return 0; +} + +int ext4fs_dirhash(const struct inode *dir, const char *name, int len, + struct dx_hash_info *hinfo) +{ +#if IS_ENABLED(CONFIG_UNICODE) + const struct unicode_map *um = dir->i_sb->s_encoding; + int r, dlen; + unsigned char *buff; + struct qstr qstr = {.name = name, .len = len }; + + if (len && IS_CASEFOLDED(dir) && + (!IS_ENCRYPTED(dir) || fscrypt_has_encryption_key(dir))) { + buff = kzalloc(PATH_MAX, GFP_KERNEL); + if (!buff) + return -ENOMEM; + + dlen = utf8_casefold(um, &qstr, buff, PATH_MAX); + if (dlen < 0) { + kfree(buff); + goto opaque_seq; + } + + r = __ext4fs_dirhash(dir, buff, dlen, hinfo); + + kfree(buff); + return r; + } +opaque_seq: +#endif + return __ext4fs_dirhash(dir, name, len, hinfo); +} -- 2.43.0