From 2ffd2a6ad1d3a8213bb5805f45f49098fe615db1 Mon Sep 17 00:00:00 2001 From: Kemeng Shi Date: Fri, 5 Jan 2024 17:21:01 +0800 Subject: ext4: remove unnecessary parameter "needed" in ext4_discard_preallocations The "needed" controls the number of ext4_prealloc_space to discard in ext4_discard_preallocations. Function ext4_discard_preallocations is supposed to discard all non-used preallocated blocks when "needed" is 0 and now ext4_discard_preallocations is always called with "needed" = 0. Remove unnecessary parameter "needed" and remove all non-used preallocated spaces in ext4_discard_preallocations to simplify the code. Note: If count of non-used preallocated spaces could be more than UINT_MAX, there was a memory leak as some non-used preallocated spaces are left ununsed and this commit will fix it. Otherwise, there is no behavior change. Signed-off-by: Kemeng Shi Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20240105092102.496631-9-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o --- fs/ext4/extents.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'fs/ext4/extents.c') diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 01299b55a567..9106715254ac 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -100,7 +100,7 @@ static int ext4_ext_trunc_restart_fn(struct inode *inode, int *dropped) * i_rwsem. So we can safely drop the i_data_sem here. */ BUG_ON(EXT4_JOURNAL(inode) == NULL); - ext4_discard_preallocations(inode, 0); + ext4_discard_preallocations(inode); up_write(&EXT4_I(inode)->i_data_sem); *dropped = 1; return 0; @@ -4313,7 +4313,7 @@ got_allocated_blocks: * not a good idea to call discard here directly, * but otherwise we'd need to call it every free(). */ - ext4_discard_preallocations(inode, 0); + ext4_discard_preallocations(inode); if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) fb_flags = EXT4_FREE_BLOCKS_NO_QUOT_UPDATE; ext4_free_blocks(handle, inode, NULL, newblock, @@ -5357,7 +5357,7 @@ static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len) ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle); down_write(&EXT4_I(inode)->i_data_sem); - ext4_discard_preallocations(inode, 0); + ext4_discard_preallocations(inode); ext4_es_remove_extent(inode, punch_start, EXT_MAX_BLOCKS - punch_start); ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1); @@ -5365,7 +5365,7 @@ static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len) up_write(&EXT4_I(inode)->i_data_sem); goto out_stop; } - ext4_discard_preallocations(inode, 0); + ext4_discard_preallocations(inode); ret = ext4_ext_shift_extents(inode, handle, punch_stop, punch_stop - punch_start, SHIFT_LEFT); @@ -5497,7 +5497,7 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len) goto out_stop; down_write(&EXT4_I(inode)->i_data_sem); - ext4_discard_preallocations(inode, 0); + ext4_discard_preallocations(inode); path = ext4_find_extent(inode, offset_lblk, NULL, 0); if (IS_ERR(path)) { -- cgit v1.2.3 From 6430dea07e85958fa87d0276c0c4388dd51e630b Mon Sep 17 00:00:00 2001 From: Zhang Yi Date: Sat, 27 Jan 2024 09:58:02 +0800 Subject: ext4: correct the hole length returned by ext4_map_blocks() In ext4_map_blocks(), if we can't find a range of mapping in the extents cache, we are calling ext4_ext_map_blocks() to search the real path and ext4_ext_determine_hole() to determine the hole range. But if the querying range was partially or completely overlaped by a delalloc extent, we can't find it in the real extent path, so the returned hole length could be incorrect. Fortunately, ext4_ext_put_gap_in_cache() have already handle delalloc extent, but it searches start from the expanded hole_start, doesn't start from the querying range, so the delalloc extent found could not be the one that overlaped the querying range, plus, it also didn't adjust the hole length. Let's just remove ext4_ext_put_gap_in_cache(), handle delalloc and insert adjusted hole extent in ext4_ext_determine_hole(). Signed-off-by: Zhang Yi Suggested-by: Jan Kara Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20240127015825.1608160-4-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o --- fs/ext4/extents.c | 111 ++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 70 insertions(+), 41 deletions(-) (limited to 'fs/ext4/extents.c') diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 9106715254ac..c5b54fb9eb8b 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2229,7 +2229,7 @@ static int ext4_fill_es_cache_info(struct inode *inode, /* - * ext4_ext_determine_hole - determine hole around given block + * ext4_ext_find_hole - find hole around given block according to the given path * @inode: inode we lookup in * @path: path in extent tree to @lblk * @lblk: pointer to logical block around which we want to determine hole @@ -2241,9 +2241,9 @@ static int ext4_fill_es_cache_info(struct inode *inode, * The function returns the length of a hole starting at @lblk. We update @lblk * to the beginning of the hole if we managed to find it. */ -static ext4_lblk_t ext4_ext_determine_hole(struct inode *inode, - struct ext4_ext_path *path, - ext4_lblk_t *lblk) +static ext4_lblk_t ext4_ext_find_hole(struct inode *inode, + struct ext4_ext_path *path, + ext4_lblk_t *lblk) { int depth = ext_depth(inode); struct ext4_extent *ex; @@ -2270,30 +2270,6 @@ static ext4_lblk_t ext4_ext_determine_hole(struct inode *inode, return len; } -/* - * ext4_ext_put_gap_in_cache: - * calculate boundaries of the gap that the requested block fits into - * and cache this gap - */ -static void -ext4_ext_put_gap_in_cache(struct inode *inode, ext4_lblk_t hole_start, - ext4_lblk_t hole_len) -{ - struct extent_status es; - - ext4_es_find_extent_range(inode, &ext4_es_is_delayed, hole_start, - hole_start + hole_len - 1, &es); - if (es.es_len) { - /* There's delayed extent containing lblock? */ - if (es.es_lblk <= hole_start) - return; - hole_len = min(es.es_lblk - hole_start, hole_len); - } - ext_debug(inode, " -> %u:%u\n", hole_start, hole_len); - ext4_es_insert_extent(inode, hole_start, hole_len, ~0, - EXTENT_STATUS_HOLE); -} - /* * ext4_ext_rm_idx: * removes index from the index block. @@ -4062,6 +4038,69 @@ static int get_implied_cluster_alloc(struct super_block *sb, return 0; } +/* + * Determine hole length around the given logical block, first try to + * locate and expand the hole from the given @path, and then adjust it + * if it's partially or completely converted to delayed extents, insert + * it into the extent cache tree if it's indeed a hole, finally return + * the length of the determined extent. + */ +static ext4_lblk_t ext4_ext_determine_insert_hole(struct inode *inode, + struct ext4_ext_path *path, + ext4_lblk_t lblk) +{ + ext4_lblk_t hole_start, len; + struct extent_status es; + + hole_start = lblk; + len = ext4_ext_find_hole(inode, path, &hole_start); +again: + ext4_es_find_extent_range(inode, &ext4_es_is_delayed, hole_start, + hole_start + len - 1, &es); + if (!es.es_len) + goto insert_hole; + + /* + * There's a delalloc extent in the hole, handle it if the delalloc + * extent is in front of, behind and straddle the queried range. + */ + if (lblk >= es.es_lblk + es.es_len) { + /* + * The delalloc extent is in front of the queried range, + * find again from the queried start block. + */ + len -= lblk - hole_start; + hole_start = lblk; + goto again; + } else if (in_range(lblk, es.es_lblk, es.es_len)) { + /* + * The delalloc extent containing lblk, it must have been + * added after ext4_map_blocks() checked the extent status + * tree, adjust the length to the delalloc extent's after + * lblk. + */ + len = es.es_lblk + es.es_len - lblk; + return len; + } else { + /* + * The delalloc extent is partially or completely behind + * the queried range, update hole length until the + * beginning of the delalloc extent. + */ + len = min(es.es_lblk - hole_start, len); + } + +insert_hole: + /* Put just found gap into cache to speed up subsequent requests */ + ext_debug(inode, " -> %u:%u\n", hole_start, len); + ext4_es_insert_extent(inode, hole_start, len, ~0, EXTENT_STATUS_HOLE); + + /* Update hole_len to reflect hole size after lblk */ + if (hole_start != lblk) + len -= lblk - hole_start; + + return len; +} /* * Block allocation/map/preallocation routine for extents based files @@ -4179,22 +4218,12 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, * we couldn't try to create block if create flag is zero */ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { - ext4_lblk_t hole_start, hole_len; + ext4_lblk_t len; - hole_start = map->m_lblk; - hole_len = ext4_ext_determine_hole(inode, path, &hole_start); - /* - * put just found gap into cache to speed up - * subsequent requests - */ - ext4_ext_put_gap_in_cache(inode, hole_start, hole_len); + len = ext4_ext_determine_insert_hole(inode, path, map->m_lblk); - /* Update hole_len to reflect hole size after map->m_lblk */ - if (hole_start != map->m_lblk) - hole_len -= map->m_lblk - hole_start; map->m_pblk = 0; - map->m_len = min_t(unsigned int, map->m_len, hole_len); - + map->m_len = min_t(unsigned int, map->m_len, len); goto out; } -- cgit v1.2.3 From 874eaba96d39334fe9c729ff631e65523616d4d8 Mon Sep 17 00:00:00 2001 From: Zhang Yi Date: Sat, 27 Jan 2024 09:58:04 +0800 Subject: ext4: make ext4_map_blocks() distinguish delalloc only extent Add a new map flag EXT4_MAP_DELAYED to indicate the mapping range is a delayed allocated only (not unwritten) one, and making ext4_map_blocks() can distinguish it, no longer mixing it with holes. Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20240127015825.1608160-6-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o --- fs/ext4/ext4.h | 4 +++- fs/ext4/extents.c | 7 +++++-- fs/ext4/inode.c | 2 ++ 3 files changed, 10 insertions(+), 3 deletions(-) (limited to 'fs/ext4/extents.c') diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 786b6857ab47..023571f8dd1b 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -252,8 +252,10 @@ struct ext4_allocation_request { #define EXT4_MAP_MAPPED BIT(BH_Mapped) #define EXT4_MAP_UNWRITTEN BIT(BH_Unwritten) #define EXT4_MAP_BOUNDARY BIT(BH_Boundary) +#define EXT4_MAP_DELAYED BIT(BH_Delay) #define EXT4_MAP_FLAGS (EXT4_MAP_NEW | EXT4_MAP_MAPPED |\ - EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY) + EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\ + EXT4_MAP_DELAYED) struct ext4_map_blocks { ext4_fsblk_t m_pblk; diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index c5b54fb9eb8b..7669d154c05e 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4076,8 +4076,11 @@ again: /* * The delalloc extent containing lblk, it must have been * added after ext4_map_blocks() checked the extent status - * tree, adjust the length to the delalloc extent's after - * lblk. + * tree so we are not holding i_rwsem and delalloc info is + * only stabilized by i_data_sem we are going to release + * soon. Don't modify the extent status tree and report + * extent as a hole, just adjust the length to the delalloc + * extent's after lblk. */ len = es.es_lblk + es.es_len - lblk; return len; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index af205b416794..60f0d2dc1c37 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -515,6 +515,8 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode, map->m_len = retval; } else if (ext4_es_is_delayed(&es) || ext4_es_is_hole(&es)) { map->m_pblk = 0; + map->m_flags |= ext4_es_is_delayed(&es) ? + EXT4_MAP_DELAYED : 0; retval = es.es_len - (map->m_lblk - es.es_lblk); if (retval > map->m_len) retval = map->m_len; -- cgit v1.2.3