From cfb3c85a600c6aa25a2581b3c1c4db3460f14e46 Mon Sep 17 00:00:00 2001 From: Jeffle Xu Date: Fri, 22 May 2020 12:18:44 +0800 Subject: ext4: fix partial cluster initialization when splitting extent Fix the bug when calculating the physical block number of the first block in the split extent. This bug will cause xfstests shared/298 failure on ext4 with bigalloc enabled occasionally. Ext4 error messages indicate that previously freed blocks are being freed again, and the following fsck will fail due to the inconsistency of block bitmap and bg descriptor. The following is an example case: 1. First, Initialize a ext4 filesystem with cluster size '16K', block size '4K', in which case, one cluster contains four blocks. 2. Create one file (e.g., xxx.img) on this ext4 filesystem. Now the extent tree of this file is like: ... 36864:[0]4:220160 36868:[0]14332:145408 51200:[0]2:231424 ... 3. Then execute PUNCH_HOLE fallocate on this file. The hole range is like: .. ext4_ext_remove_space: dev 254,16 ino 12 since 49506 end 49506 depth 1 ext4_ext_remove_space: dev 254,16 ino 12 since 49544 end 49546 depth 1 ext4_ext_remove_space: dev 254,16 ino 12 since 49605 end 49607 depth 1 ... 4. Then the extent tree of this file after punching is like ... 49507:[0]37:158047 49547:[0]58:158087 ... 5. Detailed procedure of punching hole [49544, 49546] 5.1. The block address space: ``` lblk ~49505 49506 49507~49543 49544~49546 49547~ ---------+------+-------------+----------------+-------- extent | hole | extent | hole | extent ---------+------+-------------+----------------+-------- pblk ~158045 158046 158047~158083 158084~158086 158087~ ``` 5.2. The detailed layout of cluster 39521: ``` cluster 39521 <-------------------------------> hole extent <----------------------><-------- lblk 49544 49545 49546 49547 +-------+-------+-------+-------+ | | | | | +-------+-------+-------+-------+ pblk 158084 1580845 158086 158087 ``` 5.3. The ftrace output when punching hole [49544, 49546]: - ext4_ext_remove_space (start 49544, end 49546) - ext4_ext_rm_leaf (start 49544, end 49546, last_extent [49507(158047), 40], partial [pclu 39522 lblk 0 state 2]) - ext4_remove_blocks (extent [49507(158047), 40], from 49544 to 49546, partial [pclu 39522 lblk 0 state 2] - ext4_free_blocks: (block 158084 count 4) - ext4_mballoc_free (extent 1/6753/1) 5.4. Ext4 error message in dmesg: EXT4-fs error (device vdb): mb_free_blocks:1457: group 1, block 158084:freeing already freed block (bit 6753); block bitmap corrupt. EXT4-fs error (device vdb): ext4_mb_generate_buddy:747: group 1, block bitmap and bg descriptor inconsistent: 19550 vs 19551 free clusters In this case, the whole cluster 39521 is freed mistakenly when freeing pblock 158084~158086 (i.e., the first three blocks of this cluster), although pblock 158087 (the last remaining block of this cluster) has not been freed yet. The root cause of this isuue is that, the pclu of the partial cluster is calculated mistakenly in ext4_ext_remove_space(). The correct partial_cluster.pclu (i.e., the cluster number of the first block in the next extent, that is, lblock 49597 (pblock 158086)) should be 39521 rather than 39522. Fixes: f4226d9ea400 ("ext4: fix partial cluster initialization") Signed-off-by: Jeffle Xu Reviewed-by: Eric Whitney Cc: stable@kernel.org # v3.19+ Link: https://lore.kernel.org/r/1590121124-37096-1-git-send-email-jefflexu@linux.alibaba.com Signed-off-by: Theodore Ts'o --- fs/ext4/extents.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/ext4/extents.c') diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 7d088ff1e902..221f240eae60 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2844,7 +2844,7 @@ again: * in use to avoid freeing it when removing blocks. */ if (sbi->s_cluster_ratio > 1) { - pblk = ext4_ext_pblock(ex) + end - ee_block + 2; + pblk = ext4_ext_pblock(ex) + end - ee_block + 1; partial.pclu = EXT4_B2C(sbi, pblk); partial.state = nofree; } -- cgit From e4d7f2d3593e703a4d58b813f332a5c2aef5106f Mon Sep 17 00:00:00 2001 From: Keyur Patel Date: Wed, 10 Jun 2020 23:19:46 -0400 Subject: ext4: fix spelling mistakes in extents.c Fix spelling issues over the comments in the code. requsted ==> requested deterimined ==> determined insde ==> inside neet ==> need somthing ==> something Signed-off-by: Keyur Patel Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20200611031947.165079-1-iamkeyur96@gmail.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 221f240eae60..1106ee17aa21 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -1915,7 +1915,7 @@ out: /* * ext4_ext_insert_extent: - * tries to merge requsted extent into the existing extent or + * tries to merge requested extent into the existing extent or * inserts requested extent as new one into the tree, * creating new leaf in the no-space case. */ @@ -3125,7 +3125,7 @@ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) * * * Splits extent [a, b] into two extents [a, @split) and [@split, b], states - * of which are deterimined by split_flag. + * of which are determined by split_flag. * * There are two cases: * a> the extent are splitted into two extent. @@ -3650,7 +3650,7 @@ static int ext4_split_convert_extents(handle_t *handle, eof_block = map->m_lblk + map->m_len; /* * It is safe to convert extent to initialized via explicit - * zeroout only if extent is fully insde i_size or new_size. + * zeroout only if extent is fully inside i_size or new_size. */ depth = ext_depth(inode); ex = path[depth].p_ext; @@ -4495,7 +4495,7 @@ static long ext4_zero_range(struct file *file, loff_t offset, } /* - * Round up offset. This is not fallocate, we neet to zero out + * Round up offset. This is not fallocate, we need to zero out * blocks, so convert interior block aligned part of the range to * unwritten and possibly manually zero out unaligned parts of the * range. @@ -5579,7 +5579,7 @@ ext4_swap_extents(handle_t *handle, struct inode *inode1, } ex1 = path1[path1->p_depth].p_ext; ex2 = path2[path2->p_depth].p_ext; - /* Do we have somthing to swap ? */ + /* Do we have something to swap ? */ if (unlikely(!ex2 || !ex1)) goto finish; -- cgit From e0f49d270d9d04beec113aa7cfacac6bddcb5765 Mon Sep 17 00:00:00 2001 From: Markus Elfring Date: Sat, 13 Jun 2020 19:12:24 +0200 Subject: ext4: delete unnecessary checks before brelse() The brelse() function tests whether its argument is NULL and then returns immediately. Thus remove the tests which are not needed around the shown calls. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring Reviewed-by: Ritesh Harjani Link: https://lore.kernel.org/r/0d713702-072f-a89c-20ec-ca70aa83a432@web.de Signed-off-by: Theodore Ts'o --- fs/ext4/extents.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'fs/ext4/extents.c') diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 1106ee17aa21..4af3f36c8351 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -693,10 +693,8 @@ void ext4_ext_drop_refs(struct ext4_ext_path *path) return; depth = path->p_depth; for (i = 0; i <= depth; i++, path++) { - if (path->p_bh) { - brelse(path->p_bh); - path->p_bh = NULL; - } + brelse(path->p_bh); + path->p_bh = NULL; } } -- cgit From ce9f24cccdc019229b70a5c15e2b09ad9c0ab5d1 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 28 Jul 2020 15:04:34 +0200 Subject: ext4: check journal inode extents more carefully Currently, system zones just track ranges of block, that are "important" fs metadata (bitmaps, group descriptors, journal blocks, etc.). This however complicates how extent tree (or indirect blocks) can be checked for inodes that actually track such metadata - currently the journal inode but arguably we should be treating quota files or resize inode similarly. We cannot run __ext4_ext_check() on such metadata inodes when loading their extents as that would immediately trigger the validity checks and so we just hack around that and special-case the journal inode. This however leads to a situation that a journal inode which has extent tree of depth at least one can have invalid extent tree that gets unnoticed until ext4_cache_extents() crashes. To overcome this limitation, track inode number each system zone belongs to (0 is used for zones not belonging to any inode). We can then verify inode number matches the expected one when verifying extent tree and thus avoid the false errors. With this there's no need to to special-case journal inode during extent tree checking anymore so remove it. Fixes: 0a944e8a6c66 ("ext4: don't perform block validity checks on the journal inode") Reported-by: Wolfgang Frisch Reviewed-by: Lukas Czerner Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20200728130437.7804-4-jack@suse.cz Signed-off-by: Theodore Ts'o --- fs/ext4/extents.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) (limited to 'fs/ext4/extents.c') diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 4af3f36c8351..0eea09aa0f26 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -340,7 +340,7 @@ static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) */ if (lblock + len <= lblock) return 0; - return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len); + return ext4_inode_block_valid(inode, block, len); } static int ext4_valid_extent_idx(struct inode *inode, @@ -348,7 +348,7 @@ static int ext4_valid_extent_idx(struct inode *inode, { ext4_fsblk_t block = ext4_idx_pblock(ext_idx); - return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1); + return ext4_inode_block_valid(inode, block, 1); } static int ext4_valid_extent_entries(struct inode *inode, @@ -507,14 +507,10 @@ __read_extent_tree_block(const char *function, unsigned int line, } if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE)) return bh; - if (!ext4_has_feature_journal(inode->i_sb) || - (inode->i_ino != - le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_journal_inum))) { - err = __ext4_ext_check(function, line, inode, - ext_block_hdr(bh), depth, pblk); - if (err) - goto errout; - } + err = __ext4_ext_check(function, line, inode, + ext_block_hdr(bh), depth, pblk); + if (err) + goto errout; set_buffer_verified(bh); /* * If this is a leaf block, cache all of its entries -- cgit From 27bc446e2def38db3244a6eb4bb1d6312936610a Mon Sep 17 00:00:00 2001 From: brookxu Date: Mon, 17 Aug 2020 15:36:15 +0800 Subject: ext4: limit the length of per-inode prealloc list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In the scenario of writing sparse files, the per-inode prealloc list may be very long, resulting in high overhead for ext4_mb_use_preallocated(). To circumvent this problem, we limit the maximum length of per-inode prealloc list to 512 and allow users to modify it. After patching, we observed that the sys ratio of cpu has dropped, and the system throughput has increased significantly. We created a process to write the sparse file, and the running time of the process on the fixed kernel was significantly reduced, as follows: Running time on unfixed kernel： [root@TENCENT64 ~]# time taskset 0x01 ./sparse /data1/sparce.dat real 0m2.051s user 0m0.008s sys 0m2.026s Running time on fixed kernel： [root@TENCENT64 ~]# time taskset 0x01 ./sparse /data1/sparce.dat real 0m0.471s user 0m0.004s sys 0m0.395s Signed-off-by: Chunguang Xu Link: https://lore.kernel.org/r/d7a98178-056b-6db5-6bce-4ead23f4a257@gmail.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 0eea09aa0f26..a0481582187a 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_mutex. So we can safely drop the i_data_sem here. */ BUG_ON(EXT4_JOURNAL(inode) == NULL); - ext4_discard_preallocations(inode); + ext4_discard_preallocations(inode, 0); up_write(&EXT4_I(inode)->i_data_sem); *dropped = 1; return 0; @@ -4266,7 +4266,7 @@ 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); + ext4_discard_preallocations(inode, 0); if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) fb_flags = EXT4_FREE_BLOCKS_NO_QUOT_UPDATE; ext4_free_blocks(handle, inode, NULL, newblock, @@ -5293,7 +5293,7 @@ static int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len) } down_write(&EXT4_I(inode)->i_data_sem); - ext4_discard_preallocations(inode); + ext4_discard_preallocations(inode, 0); ret = ext4_es_remove_extent(inode, punch_start, EXT_MAX_BLOCKS - punch_start); @@ -5307,7 +5307,7 @@ static int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len) up_write(&EXT4_I(inode)->i_data_sem); goto out_stop; } - ext4_discard_preallocations(inode); + ext4_discard_preallocations(inode, 0); ret = ext4_ext_shift_extents(inode, handle, punch_stop, punch_stop - punch_start, SHIFT_LEFT); @@ -5439,7 +5439,7 @@ static int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len) goto out_stop; down_write(&EXT4_I(inode)->i_data_sem); - ext4_discard_preallocations(inode); + ext4_discard_preallocations(inode, 0); path = ext4_find_extent(inode, offset_lblk, NULL, 0); if (IS_ERR(path)) { -- cgit