kernel/linux.git/fs/f2fs/file.c, branch v6.12.102

f2fs: fix to round down start offset of fallocate for pin file

2026-07-04T11:43:33+00:00

commit 4275b59673eb60b02eec3997816c83f1f4b909c4 upstream. Currently, the length of fallocate for pin file is section-aligned to keep allocated sections from being selected as victims of GC. However, for the case that the start offset of fallocate is not aligned in section, the allocated sections can't be fully utilized. It's because a new section is allocated by f2fs_allocate_pinning_section() after using blks_per_sec blocks regardless of the start offset. As a result, several unexpected dirty segments may be created, including blocks assigned to the pinned file. To address this issue, let's round down the start offset of fallocate to the length of section. The reproducing scenario is as below chunk=$(((2<<20)+4096)) # 2MB + 4KB touch test f2fs_io pinfile set test f2fs_io fallocate 0 0 $chunk test f2fs_io fallocate 0 $chunk $chunk test f2fs_io fallocate 0 $((chunk*2)) $chunk test f2fs_io fiemap 0 $((chunk*3)) test Fiemap: offset = 0 len = 12288 logical addr. physical addr. length flags 0 0000000000000000 000000068c600000 0000000000400000 00001088 1 0000000000400000 000000003d400000 0000000000001000 00001088 2 0000000000401000 00000003eb200000 0000000000200000 00001088 3 0000000000601000 00000005e4200000 0000000000001000 00001088 4 0000000000602000 0000000605400000 0000000000200000 00001089 Cc: stable@vger.kernel.org Fixes: f5a53edcf01e ("f2fs: support aligned pinned file") Reviewed-by: Yunji Kang Reviewed-by: Yeongjin Gil Reviewed-by: Sungjong Seo Signed-off-by: Sunmin Jeong Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim 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: fix to avoid updating zero-sized extent in extent cache

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

commit 7c37c79510329cd951a4dedf3f7bf7e2b18dccec upstream. As syzbot reported: F2FS-fs (loop0): __update_extent_tree_range: extent len is zero, type: 0, extent [0, 0, 0], age [0, 0] ------------[ cut here ]------------ kernel BUG at fs/f2fs/extent_cache.c:678! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5336 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:__update_extent_tree_range+0x13bc/0x1500 fs/f2fs/extent_cache.c:678 Call Trace: f2fs_update_read_extent_cache_range+0x192/0x3e0 fs/f2fs/extent_cache.c:1085 f2fs_do_zero_range fs/f2fs/file.c:1657 [inline] f2fs_zero_range+0x10c1/0x1580 fs/f2fs/file.c:1737 f2fs_fallocate+0x583/0x990 fs/f2fs/file.c:2030 vfs_fallocate+0x669/0x7e0 fs/open.c:342 ioctl_preallocate fs/ioctl.c:289 [inline] file_ioctl+0x611/0x780 fs/ioctl.c:-1 do_vfs_ioctl+0xb33/0x1430 fs/ioctl.c:576 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f07bc58eec9 In error path of f2fs_zero_range(), it may add a zero-sized extent into extent cache, it should be avoided. Fixes: 6e9619499f53 ("f2fs: support in batch fzero in dnode page") Cc: stable@kernel.org Reported-by: syzbot+24124df3170c3638b35f@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-f2fs-devel/68e5d698.050a0220.256323.0032.GAE@google.com Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

f2fs: introduce reserved_pin_section sysfs entry

2025-12-18T12:55:16+00:00

[ Upstream commit 59c1c89e9ba8cefff05aa982dd9e6719f25e8ec5 ] This patch introduces /sys/fs/f2fs//reserved_pin_section for tuning @needed parameter of has_not_enough_free_secs(), if we configure it w/ zero, it can avoid f2fs_gc() as much as possible while fallocating on pinned file. Signed-off-by: Chao Yu Reviewed-by: wangzijie Signed-off-by: Jaegeuk Kim Stable-dep-of: e462fc48ceb8 ("f2fs: maintain one time GC mode is enabled during whole zoned GC cycle") Signed-off-by: Sasha Levin

f2fs: fix to avoid running out of free segments

2025-12-18T12:55:15+00:00

[ Upstream commit f7f8932ca6bb22494ef6db671633ad3b4d982271 ] If checkpoint is disabled, GC can not reclaim any segments, we need to detect such condition and bail out from fallocate() of a pinfile, rather than letting allocator running out of free segment, which may cause f2fs to be shutdown. reproducer: mkfs.f2fs -f /dev/vda 16777216 mount -o checkpoint=disable:10% /dev/vda /mnt/f2fs for ((i=0;i<4096;i++)) do { dd if=/dev/zero of=/mnt/f2fs/$i bs=1M count=1; } done sync for ((i=0;i<4096;i+=2)) do { rm /mnt/f2fs/$i; } done sync touch /mnt/f2fs/pinfile f2fs_io pinfile set /mnt/f2fs/pinfile f2fs_io fallocate 0 0 4201644032 /mnt/f2fs/pinfile cat /sys/kernel/debug/f2fs/status output: - Free: 0 (0) Fixes: f5a53edcf01e ("f2fs: support aligned pinned file") Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Stable-dep-of: e462fc48ceb8 ("f2fs: maintain one time GC mode is enabled during whole zoned GC cycle") Signed-off-by: Sasha Levin

f2fs: keep POSIX_FADV_NOREUSE ranges

2025-12-18T12:55:15+00:00

[ Upstream commit ef0c333cad8d1940f132a7ce15f15920216a3bd5 ] This patch records POSIX_FADV_NOREUSE ranges for users to reclaim the caches instantly off from LRU. Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Stable-dep-of: e462fc48ceb8 ("f2fs: maintain one time GC mode is enabled during whole zoned GC cycle") Signed-off-by: Sasha Levin

f2fs: fix to avoid panic once fallocation fails for pinfile

2025-11-02T13:15:22+00:00

[ Upstream commit 48ea8b200414ac69ea96f4c231f5c7ef1fbeffef ] syzbot reports a f2fs bug as below: ------------[ cut here ]------------ kernel BUG at fs/f2fs/segment.c:2746! CPU: 0 UID: 0 PID: 5323 Comm: syz.0.0 Not tainted 6.13.0-rc2-syzkaller-00018-g7cb1b4663150 #0 RIP: 0010:get_new_segment fs/f2fs/segment.c:2746 [inline] RIP: 0010:new_curseg+0x1f52/0x1f70 fs/f2fs/segment.c:2876 Call Trace: __allocate_new_segment+0x1ce/0x940 fs/f2fs/segment.c:3210 f2fs_allocate_new_section fs/f2fs/segment.c:3224 [inline] f2fs_allocate_pinning_section+0xfa/0x4e0 fs/f2fs/segment.c:3238 f2fs_expand_inode_data+0x696/0xca0 fs/f2fs/file.c:1830 f2fs_fallocate+0x537/0xa10 fs/f2fs/file.c:1940 vfs_fallocate+0x569/0x6e0 fs/open.c:327 do_vfs_ioctl+0x258c/0x2e40 fs/ioctl.c:885 __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0x80/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Concurrent pinfile allocation may run out of free section, result in panic in get_new_segment(), let's expand pin_sem lock coverage to include f2fs_gc(), so that we can make sure to reclaim enough free space for following allocation. In addition, do below changes to enhance error path handling: - call f2fs_bug_on() only in non-pinfile allocation path in get_new_segment(). - call reset_curseg_fields() to reset all fields of curseg in new_curseg() Fixes: f5a53edcf01e ("f2fs: support aligned pinned file") Reported-by: syzbot+15669ec8c35ddf6c3d43@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-f2fs-devel/675cd64e.050a0220.37aaf.00bb.GAE@google.com Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Rajani Kantha <681739313@139.com> Signed-off-by: Greg Kroah-Hartman

f2fs: fix to mitigate overhead of f2fs_zero_post_eof_page()

2025-10-15T10:00:12+00:00

[ Upstream commit c2f7c32b254006ad48f8e4efb2e7e7bf71739f17 ] f2fs_zero_post_eof_page() may cuase more overhead due to invalidate_lock and page lookup, change as below to mitigate its overhead: - check new_size before grabbing invalidate_lock - lookup and invalidate pages only in range of [old_size, new_size] Fixes: ba8dac350faf ("f2fs: fix to zero post-eof page") Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: fix to truncate first page in error path of f2fs_truncate()

2025-10-15T10:00:11+00:00

[ Upstream commit 9251a9e6e871cb03c4714a18efa8f5d4a8818450 ] syzbot reports a bug as below: loop0: detected capacity change from 0 to 40427 F2FS-fs (loop0): Wrong SSA boundary, start(3584) end(4096) blocks(3072) F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock F2FS-fs (loop0): invalid crc value F2FS-fs (loop0): f2fs_convert_inline_folio: corrupted inline inode ino=3, i_addr[0]:0x1601, run fsck to fix. ------------[ cut here ]------------ kernel BUG at fs/inode.c:753! RIP: 0010:clear_inode+0x169/0x190 fs/inode.c:753 Call Trace: evict+0x504/0x9c0 fs/inode.c:810 f2fs_fill_super+0x5612/0x6fa0 fs/f2fs/super.c:5047 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808 do_mount fs/namespace.c:4136 [inline] __do_sys_mount fs/namespace.c:4347 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4324 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f During f2fs_evict_inode(), clear_inode() detects that we missed to truncate all page cache before destorying inode, that is because in below path, we will create page #0 in cache, but missed to drop it in error path, let's fix it. - evict - f2fs_evict_inode - f2fs_truncate - f2fs_convert_inline_inode - f2fs_grab_cache_folio : create page #0 in cache - f2fs_convert_inline_folio : sanity check failed, return -EFSCORRUPTED - clear_inode detects that inode->i_data.nrpages is not zero Fixes: 92dffd01790a ("f2fs: convert inline_data when i_size becomes large") Reported-by: syzbot+90266696fe5daacebd35@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-f2fs-devel/68c09802.050a0220.3c6139.000e.GAE@google.com Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin