kernel/linux.git/fs/f2fs/super.c, branch v6.12.91

f2fs: fix false alarm of lockdep on cp_global_sem lock

2026-05-23T11:05:01+00:00

[ Upstream commit 6a5e3de9c2bb0b691d16789a5d19e9276a09b308 ] lockdep reported a potential deadlock: a) TCMU device removal context: - call del_gendisk() to get q->q_usage_counter - call start_flush_work() to get work_completion of wb->dwork b) f2fs writeback context: - in wb_workfn(), which holds work_completion of wb->dwork - call f2fs_balance_fs() to get sbi->gc_lock c) f2fs vfs_write context: - call f2fs_gc() to get sbi->gc_lock - call f2fs_write_checkpoint() to get sbi->cp_global_sem d) f2fs mount context: - call recover_fsync_data() to get sbi->cp_global_sem - call f2fs_check_and_fix_write_pointer() to call blkdev_report_zones() that goes down to blk_mq_alloc_request and get q->q_usage_counter Original callstack is in Closes tag. However, I think this is a false alarm due to before mount returns successfully (context d), we can not access file therein via vfs_write (context c). Let's introduce per-sb cp_global_sem_key, and assign the key for cp_global_sem, so that lockdep can recognize cp_global_sem from different super block correctly. A lot of work are done by Shin'ichiro Kawasaki, thanks a lot for the work. Fixes: c426d99127b1 ("f2fs: Check write pointer consistency of open zones") Cc: stable@kernel.org Reported-and-tested-by: Shin'ichiro Kawasaki Closes: https://lore.kernel.org/linux-f2fs-devel/20260218125237.3340441-1-shinichiro.kawasaki@wdc.com Signed-off-by: Shin'ichiro Kawasaki Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim [ adapted context to use `init_f2fs_rwsem()` instead of the not-yet-backported `init_f2fs_rwsem_trace()` macro ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

f2fs: fix to do sanity check on dcc->discard_cmd_cnt conditionally

2026-05-07T04:09:43+00:00

[ Upstream commit 6af249c996f7d73a3435f9e577956fa259347d18 ] Syzbot reported a f2fs bug as below: ------------[ cut here ]------------ kernel BUG at fs/f2fs/segment.c:1900! Oops: invalid opcode: 0000 [#1] SMP KASAN PTI CPU: 1 UID: 0 PID: 6527 Comm: syz.5.110 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:f2fs_issue_discard_timeout+0x59b/0x5a0 fs/f2fs/segment.c:1900 Code: d9 80 e1 07 80 c1 03 38 c1 0f 8c d6 fe ff ff 48 89 df e8 a8 5e fa fd e9 c9 fe ff ff e8 4e 46 94 fd 90 0f 0b e8 46 46 94 fd 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 RSP: 0018:ffffc9000494f940 EFLAGS: 00010283 RAX: ffffffff843009ca RBX: 0000000000000001 RCX: 0000000000080000 RDX: ffffc9001ca78000 RSI: 00000000000029f3 RDI: 00000000000029f4 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed100893a431 R12: 1ffff1100893a430 R13: 1ffff1100c2b702c R14: dffffc0000000000 R15: ffff8880449d2160 FS: 00007ffa35fed6c0(0000) GS:ffff88812643d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2b68634000 CR3: 0000000039f62000 CR4: 00000000003526f0 Call Trace: __f2fs_remount fs/f2fs/super.c:2960 [inline] f2fs_reconfigure+0x108a/0x1710 fs/f2fs/super.c:5443 reconfigure_super+0x227/0x8a0 fs/super.c:1080 do_remount fs/namespace.c:3391 [inline] path_mount+0xdc5/0x10e0 fs/namespace.c:4151 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4338 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffa37dbda0a The root cause is there will be race condition in between f2fs_ioc_fitrim() and f2fs_remount(): - f2fs_remount - f2fs_ioc_fitrim - f2fs_issue_discard_timeout - __issue_discard_cmd - __drop_discard_cmd - __wait_all_discard_cmd - f2fs_trim_fs - f2fs_write_checkpoint - f2fs_clear_prefree_segments - f2fs_issue_discard - __issue_discard_async - __queue_discard_cmd - __update_discard_tree_range - __insert_discard_cmd - __create_discard_cmd : atomic_inc(&dcc->discard_cmd_cnt); - sanity check on dcc->discard_cmd_cnt (expect discard_cmd_cnt to be zero) This will only happen when fitrim races w/ remount rw, if we remount to readonly filesystem, remount will wait until mnt_pcp.mnt_writers to zero, that means fitrim is not in process at that time. Cc: stable@kernel.org Fixes: 2482c4325dfe ("f2fs: detect bug_on in f2fs_wait_discard_bios") Reported-by: syzbot+62538b67389ee582837a@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-f2fs-devel/69b07d7c.050a0220.8df7.09a1.GAE@google.com Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim [ dereferenced flags pointer (`*flags & SB_RDONLY`) to match `int *flags` remount signature ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

f2fs: fix to propagate error from f2fs_enable_checkpoint()

2026-01-08T09:14:59+00:00

[ Upstream commit be112e7449a6e1b54aa9feac618825d154b3a5c7 ] In order to let userspace detect such error rather than suffering silent failure. Fixes: 4354994f097d ("f2fs: checkpoint disabling") Cc: stable@kernel.org Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

f2fs: dump more information for f2fs_{enable,disable}_checkpoint()

2026-01-08T09:14:59+00:00

[ Upstream commit 80b6d1d2535a343e43d658777a46f1ebce8f3413 ] Changes as below: - print more logs for f2fs_{enable,disable}_checkpoint() - account and dump time stats for f2fs_enable_checkpoint() Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Stable-dep-of: be112e7449a6 ("f2fs: fix to propagate error from f2fs_enable_checkpoint()") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

f2fs: add timeout in f2fs_enable_checkpoint()

2026-01-08T09:14:59+00:00

[ Upstream commit 4bc347779698b5e67e1514bab105c2c083e55502 ] During f2fs_enable_checkpoint() in remount(), if we flush a large amount of dirty pages into slow device, it may take long time which will block write IO, let's add a timeout machanism during dirty pages flush to avoid long time block in f2fs_enable_checkpoint(). Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Stable-dep-of: be112e7449a6 ("f2fs: fix to propagate error from f2fs_enable_checkpoint()") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

f2fs: clear SBI_POR_DOING before initing inmem curseg

2026-01-08T09:14:59+00:00

[ Upstream commit f88c7904b5c7e35ab8037e2a59e10d80adf6fd7e ] SBI_POR_DOING can be cleared after recovery is completed, so that changes made before recovery can be persistent, and subsequent errors can be recorded into cp/sb. Signed-off-by: Song Feng Signed-off-by: Yongpeng Yang Signed-off-by: Sheng Yong Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Stable-dep-of: be112e7449a6 ("f2fs: fix to propagate error from f2fs_enable_checkpoint()") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

f2fs: fix to avoid updating compression context during writeback

2026-01-08T09:14:57+00:00

[ Upstream commit 10b591e7fb7cdc8c1e53e9c000dc0ef7069aaa76 ] Bai, Shuangpeng reported a bug as below: Oops: divide error: 0000 [#1] SMP KASAN PTI CPU: 0 UID: 0 PID: 11441 Comm: syz.0.46 Not tainted 6.17.0 #1 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:f2fs_all_cluster_page_ready+0x106/0x550 fs/f2fs/compress.c:857 Call Trace: f2fs_write_cache_pages fs/f2fs/data.c:3078 [inline] __f2fs_write_data_pages fs/f2fs/data.c:3290 [inline] f2fs_write_data_pages+0x1c19/0x3600 fs/f2fs/data.c:3317 do_writepages+0x38e/0x640 mm/page-writeback.c:2634 filemap_fdatawrite_wbc mm/filemap.c:386 [inline] __filemap_fdatawrite_range mm/filemap.c:419 [inline] file_write_and_wait_range+0x2ba/0x3e0 mm/filemap.c:794 f2fs_do_sync_file+0x6e6/0x1b00 fs/f2fs/file.c:294 generic_write_sync include/linux/fs.h:3043 [inline] f2fs_file_write_iter+0x76e/0x2700 fs/f2fs/file.c:5259 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x7e9/0xe00 fs/read_write.c:686 ksys_write+0x19d/0x2d0 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf7/0x470 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The bug was triggered w/ below race condition: fsync setattr ioctl - f2fs_do_sync_file - file_write_and_wait_range - f2fs_write_cache_pages : inode is non-compressed : cc.cluster_size = F2FS_I(inode)->i_cluster_size = 0 - tag_pages_for_writeback - f2fs_setattr - truncate_setsize - f2fs_truncate - f2fs_fileattr_set - f2fs_setflags_common - set_compress_context : F2FS_I(inode)->i_cluster_size = 4 : set_inode_flag(inode, FI_COMPRESSED_FILE) - f2fs_compressed_file : return true - f2fs_all_cluster_page_ready : "pgidx % cc->cluster_size" trigger dividing 0 issue Let's change as below to fix this issue: - introduce a new atomic type variable .writeback in structure f2fs_inode_info to track the number of threads which calling f2fs_write_cache_pages(). - use .i_sem lock to protect .writeback update. - check .writeback before update compression context in f2fs_setflags_common() to avoid race w/ ->writepages. Fixes: 4c8ff7095bef ("f2fs: support data compression") Cc: stable@kernel.org Reported-by: Bai, Shuangpeng Tested-by: Bai, Shuangpeng Closes: https://lore.kernel.org/lkml/44D8F7B3-68AD-425F-9915-65D27591F93F@psu.edu Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

f2fs: drop inode from the donation list when the last file is closed

2026-01-08T09:14:57+00:00

[ Upstream commit 078cad8212ce4f4ebbafcc0936475b8215e1ca2a ] Let's drop the inode from the donation list when there is no other open file. Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Stable-dep-of: 10b591e7fb7c ("f2fs: fix to avoid updating compression context during writeback") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

f2fs: use global inline_xattr_slab instead of per-sb slab cache

2026-01-08T09:14:57+00:00

[ Upstream commit 1f27ef42bb0b7c0740c5616ec577ec188b8a1d05 ] As Hong Yun reported in mailing list: loop7: detected capacity change from 0 to 131072 ------------[ cut here ]------------ kmem_cache of name 'f2fs_xattr_entry-7:7' already exists WARNING: CPU: 0 PID: 24426 at mm/slab_common.c:110 kmem_cache_sanity_check mm/slab_common.c:109 [inline] WARNING: CPU: 0 PID: 24426 at mm/slab_common.c:110 __kmem_cache_create_args+0xa6/0x320 mm/slab_common.c:307 CPU: 0 UID: 0 PID: 24426 Comm: syz.7.1370 Not tainted 6.17.0-rc4 #1 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:kmem_cache_sanity_check mm/slab_common.c:109 [inline] RIP: 0010:__kmem_cache_create_args+0xa6/0x320 mm/slab_common.c:307 Call Trace: __kmem_cache_create include/linux/slab.h:353 [inline] f2fs_kmem_cache_create fs/f2fs/f2fs.h:2943 [inline] f2fs_init_xattr_caches+0xa5/0xe0 fs/f2fs/xattr.c:843 f2fs_fill_super+0x1645/0x2620 fs/f2fs/super.c:4918 get_tree_bdev_flags+0x1fb/0x260 fs/super.c:1692 vfs_get_tree+0x43/0x140 fs/super.c:1815 do_new_mount+0x201/0x550 fs/namespace.c:3808 do_mount fs/namespace.c:4136 [inline] __do_sys_mount fs/namespace.c:4347 [inline] __se_sys_mount+0x298/0x2f0 fs/namespace.c:4324 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x8e/0x3a0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e The bug can be reproduced w/ below scripts: - mount /dev/vdb /mnt1 - mount /dev/vdc /mnt2 - umount /mnt1 - mounnt /dev/vdb /mnt1 The reason is if we created two slab caches, named f2fs_xattr_entry-7:3 and f2fs_xattr_entry-7:7, and they have the same slab size. Actually, slab system will only create one slab cache core structure which has slab name of "f2fs_xattr_entry-7:3", and two slab caches share the same structure and cache address. So, if we destroy f2fs_xattr_entry-7:3 cache w/ cache address, it will decrease reference count of slab cache, rather than release slab cache entirely, since there is one more user has referenced the cache. Then, if we try to create slab cache w/ name "f2fs_xattr_entry-7:3" again, slab system will find that there is existed cache which has the same name and trigger the warning. Let's changes to use global inline_xattr_slab instead of per-sb slab cache for fixing. Fixes: a999150f4fe3 ("f2fs: use kmem_cache pool during inline xattr lookups") Cc: stable@kernel.org Reported-by: Hong Yun Tested-by: Hong Yun Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim [ folio => page ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

f2fs: fix return value of f2fs_recover_fsync_data()

2026-01-08T09:14:20+00:00

commit 01fba45deaddcce0d0b01c411435d1acf6feab7b upstream. With below scripts, it will trigger panic in f2fs: mkfs.f2fs -f /dev/vdd mount /dev/vdd /mnt/f2fs touch /mnt/f2fs/foo sync echo 111 >> /mnt/f2fs/foo f2fs_io fsync /mnt/f2fs/foo f2fs_io shutdown 2 /mnt/f2fs umount /mnt/f2fs mount -o ro,norecovery /dev/vdd /mnt/f2fs or mount -o ro,disable_roll_forward /dev/vdd /mnt/f2fs F2FS-fs (vdd): f2fs_recover_fsync_data: recovery fsync data, check_only: 0 F2FS-fs (vdd): Mounted with checkpoint version = 7f5c361f F2FS-fs (vdd): Stopped filesystem due to reason: 0 F2FS-fs (vdd): f2fs_recover_fsync_data: recovery fsync data, check_only: 1 Filesystem f2fs get_tree() didn't set fc->root, returned 1 ------------[ cut here ]------------ kernel BUG at fs/super.c:1761! Oops: invalid opcode: 0000 [#1] SMP PTI CPU: 3 UID: 0 PID: 722 Comm: mount Not tainted 6.18.0-rc2+ #721 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:vfs_get_tree.cold+0x18/0x1a Call Trace: fc_mount+0x13/0xa0 path_mount+0x34e/0xc50 __x64_sys_mount+0x121/0x150 do_syscall_64+0x84/0x800 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fa6cc126cfe The root cause is we missed to handle error number returned from f2fs_recover_fsync_data() when mounting image w/ ro,norecovery or ro,disable_roll_forward mount option, result in returning a positive error number to vfs_get_tree(), fix it. Cc: stable@kernel.org Fixes: 6781eabba1bd ("f2fs: give -EINVAL for norecovery and rw mount") Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman