kernel/linux.git/fs/ocfs2/suballoc.h, branch v6.12.80

ocfs2: fix the issue with discontiguous allocation in the global_bitmap

2025-05-18T06:24:54+00:00

commit bd1261b16d9131d79723d982d54295e7f309797a upstream. commit 4eb7b93e0310 ("ocfs2: improve write IO performance when fragmentation is high") introduced another regression. The following ocfs2-test case can trigger this issue: > discontig_runner.sh => activate_discontig_bg.sh => resv_unwritten: > ${RESV_UNWRITTEN_BIN} -f ${WORK_PLACE}/large_testfile -s 0 -l \ > $((${FILE_MAJOR_SIZE_M}*1024*1024)) In my env, test disk size (by "fdisk -l "): > 53687091200 bytes, 104857600 sectors. Above command is: > /usr/local/ocfs2-test/bin/resv_unwritten -f \ > /mnt/ocfs2/ocfs2-activate-discontig-bg-dir/large_testfile -s 0 -l \ > 53187969024 Error log: > [*] Reserve 50724M space for a LARGE file, reserve 200M space for future test. > ioctl error 28: "No space left on device" > resv allocation failed Unknown error -1 > reserve unwritten region from 0 to 53187969024. Call flow: __ocfs2_change_file_space //by ioctl OCFS2_IOC_RESVSP64 ocfs2_allocate_unwritten_extents //start:0 len:53187969024 while() + ocfs2_get_clusters //cpos:0, alloc_size:1623168 (cluster number) + ocfs2_extend_allocation + ocfs2_lock_allocators | + choose OCFS2_AC_USE_MAIN & ocfs2_cluster_group_search | + ocfs2_add_inode_data ocfs2_add_clusters_in_btree __ocfs2_claim_clusters ocfs2_claim_suballoc_bits + During the allocation of the final part of the large file (after ~47GB), no chain had the required contiguous bits_wanted. Consequently, the allocation failed. How to fix: When OCFS2 is encountering fragmented allocation, the file system should stop attempting bits_wanted contiguous allocation and instead provide the largest available contiguous free bits from the cluster groups. Link: https://lkml.kernel.org/r/20250414060125.19938-2-heming.zhao@suse.com Fixes: 4eb7b93e0310 ("ocfs2: improve write IO performance when fragmentation is high") Signed-off-by: Heming Zhao Reported-by: Gautham Ananthakrishna Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

ocfs2: improve write IO performance when fragmentation is high

2024-04-26T04:07:03+00:00

The group_search function ocfs2_cluster_group_search() should bypass groups with insufficient space to avoid unnecessary searches. This patch is particularly useful when ocfs2 is handling huge number small files, and volume fragmentation is very high. In this case, ocfs2 is busy with looking up available la window from //global_bitmap. This patch introduces a new member in the Group Description (gd) struct called 'bg_contig_free_bits', representing the max contigous free bits in this gd. When ocfs2 allocates a new la window from //global_bitmap, 'bg_contig_free_bits' helps expedite the search process. Let's image below path. 1. la state (->local_alloc_state) is set THROTTLED or DISABLED. 2. when user delete a large file and trigger ocfs2_local_alloc_seen_free_bits set osb->local_alloc_state unconditionally. 3. a write IOs thread run and trigger the worst performance path ``` ocfs2_reserve_clusters_with_limit ocfs2_reserve_local_alloc_bits ocfs2_local_alloc_slide_window //[1] + ocfs2_local_alloc_reserve_for_window //[2] + ocfs2_local_alloc_new_window //[3] ocfs2_recalc_la_window ``` [1]: will be called when la window bits used up. [2]: under la state is ENABLED, and this func only check global_bitmap free bits, it will succeed in general. [3]: will use the default la window size to search clusters then fail. ocfs2_recalc_la_window attempts other la window sizes. the timing complexity is O(n^4), resulting in a significant time cost for scanning global bitmap. This leads to a dramatic slowdown in write I/Os (e.g., user space 'dd'). i.e. an ocfs2 partition size: 1.45TB, cluster size: 4KB, la window default size: 106MB. The partition is fragmentation by creating & deleting huge mount of small files. before this patch, the timing of [3] should be (the number got from real world): - la window size change order (size: MB): 106, 53, 26.5, 13, 6.5, 3.25, 1.6, 0.8 only 0.8MB succeed, 0.8MB also triggers la window to disable. ocfs2_local_alloc_new_window retries 8 times, first 7 times totally runs in worst case. - group chain number: 242 ocfs2_claim_suballoc_bits calls for-loop 242 times - each chain has 49 block group ocfs2_search_chain calls while-loop 49 times - each bg has 32256 blocks ocfs2_block_group_find_clear_bits calls while-loop for 32256 bits. for ocfs2_find_next_zero_bit uses ffz() to find zero bit, let's use (32256/64) (this is not worst value) for timing calucation. the loop times: 7*242*49*(32256/64) = 41835024 (~42 million times) In the worst case, user space writes 1MB data will trigger 42M scanning times. under this patch, the timing is '7*242*49 = 83006', reduced by three orders of magnitude. Link: https://lkml.kernel.org/r/20240328125203.20892-2-heming.zhao@suse.com Signed-off-by: Heming Zhao Reviewed-by: Joseph Qi Cc: Changwei Ge Cc: Gang He Cc: Joel Becker Cc: Jun Piao Cc: Junxiao Bi Cc: Mark Fasheh Signed-off-by: Andrew Morton

fs/ocfs2/suballoc.h: fix spelling typo in comment

2022-10-03T21:21:42+00:00

Fix spelling typo in comment. Link: https://lkml.kernel.org/r/20220905061656.1829179-1-13667453960@163.com Signed-off-by: Jiangshan Yi Reported-by: k2ci Acked-by: Joseph Qi Signed-off-by: Andrew Morton

treewide: remove editor modelines and cruft

2021-05-07T07:26:34+00:00

The section "19) Editor modelines and other cruft" in Documentation/process/coding-style.rst clearly says, "Do not include any of these in source files." I recently receive a patch to explicitly add a new one. Let's do treewide cleanups, otherwise some people follow the existing code and attempt to upstream their favoriate editor setups. It is even nicer if scripts/checkpatch.pl can check it. If we like to impose coding style in an editor-independent manner, I think editorconfig (patch [1]) is a saner solution. [1] https://lore.kernel.org/lkml/20200703073143.423557-1-danny@kdrag0n.dev/ Link: https://lkml.kernel.org/r/20210324054457.1477489-1-masahiroy@kernel.org Signed-off-by: Masahiro Yamada Acked-by: Geert Uytterhoeven Reviewed-by: Miguel Ojeda [auxdisplay] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ocfs2: suballoc.h: delete a duplicated word

2020-08-07T18:33:21+00:00

Drop the repeated word "is" in a comment. Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Acked-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Joseph Qi Link: http://lkml.kernel.org/r/20200720001421.28823-1-rdunlap@infradead.org Signed-off-by: Linus Torvalds

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 145

2019-05-30T18:25:18+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 021110 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 84 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Richard Fontana Reviewed-by: Allison Randal Reviewed-by: Kate Stewart Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190524100844.756442981@linutronix.de Signed-off-by: Greg Kroah-Hartman

ocfs2: rollback alloc_dinode counts when ocfs2_block_group_set_bits() failed

2014-04-03T23:20:56+00:00

After updating alloc_dinode counts in ocfs2_alloc_dinode_update_counts(), if ocfs2_alloc_dinode_update_bitmap() failed, there is a rare case that some space may be lost. So, roll back alloc_dinode counts when ocfs2_block_group_set_bits() failed. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Younger Liu Reviewed-by: Mark Fasheh Cc: Joel Becker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ocfs2: remove redundant ocfs2_alloc_dinode_update_counts() and ocfs2_block_group_set_bits()

2014-01-22T00:19:42+00:00

ocfs2_alloc_dinode_update_counts() and ocfs2_block_group_set_bits() are already provided in suballoc.c. So, the same functions in move_extents.c are not needed any more. Declare the functions in suballoc.h and remove redundant functions in move_extents.c. Signed-off-by: Younger Liu Cc: Younger Liu Cc: Mark Fasheh Cc: Joel Becker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ocfs2: ac->ac_allow_chain_relink=0 won't disable group relink

2013-02-28T03:10:09+00:00

ocfs2_block_group_alloc_discontig() disables chain relink by setting ac->ac_allow_chain_relink = 0 because it grabs clusters from multiple cluster groups. It doesn't keep the credits for all chain relink,but ocfs2_claim_suballoc_bits overrides this in this call trace: ocfs2_block_group_claim_bits()->ocfs2_claim_clusters()-> __ocfs2_claim_clusters()->ocfs2_claim_suballoc_bits() ocfs2_claim_suballoc_bits set ac->ac_allow_chain_relink = 1; then call ocfs2_search_chain() one time and disable it again, and then we run out of credits. Fix is to allow relink by default and disable it in ocfs2_block_group_alloc_discontig. Without this patch, End-users will run into a crash due to run out of credits, backtrace like this: RIP: 0010:[] [] jbd2_journal_dirty_metadata+0x164/0x170 [jbd2] RSP: 0018:ffff8801b919b5b8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88022139ddc0 RCX: ffff880159f652d0 RDX: ffff880178aa3000 RSI: ffff880159f652d0 RDI: ffff880087f09bf8 RBP: ffff8801b919b5e8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000001e00 R11: 00000000000150b0 R12: ffff880159f652d0 R13: ffff8801a0cae908 R14: ffff880087f09bf8 R15: ffff88018d177800 FS: 00007fc9b0b6b6e0(0000) GS:ffff88022fd40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 000000000040819c CR3: 0000000184017000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process dd (pid: 9945, threadinfo ffff8801b919a000, task ffff880149a264c0) Call Trace: ocfs2_journal_dirty+0x2f/0x70 [ocfs2] ocfs2_relink_block_group+0x111/0x480 [ocfs2] ocfs2_search_chain+0x455/0x9a0 [ocfs2] ... Signed-off-by: Xiaowei.Hu Reviewed-by: Srinivas Eeda Cc: Mark Fasheh Cc: Joel Becker Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ocfs2: allow return of new inode block location before allocation of the inode

2010-09-08T06:25:59+00:00

This allows code which needs to know the eventual block number of an inode but can't allocate it yet due to transaction or lock ordering. For example, ocfs2_create_inode_in_orphan() currently gives a junk blkno for preparation of the orphan dir because it can't yet know where the actual inode is placed - that code is actually in ocfs2_mknod_locked. This is a problem when the orphan dirs are indexed as the junk inode number will create an index entry which goes unused (and fails the later removal from the orphan dir). Now with these interfaces, ocfs2_create_inode_in_orphan() can run the block group search (and get back the inode block number) *before* any actual allocation occurs. Signed-off-by: Mark Fasheh Signed-off-by: Tao Ma