kernel/linux.git/fs/f2fs/data.c, branch v6.6.132

f2fs: fix to avoid mapping wrong physical block for swapfile

2026-02-19T15:28:27+00:00

[ Upstream commit 5c145c03188bc9ba1c29e0bc4d527a5978fc47f9 ] Xiaolong Guo reported a f2fs bug in bugzilla [1] [1] https://bugzilla.kernel.org/show_bug.cgi?id=220951 Quoted: "When using stress-ng's swap stress test on F2FS filesystem with kernel 6.6+, the system experiences data corruption leading to either: 1 dm-verity corruption errors and device reboot 2 F2FS node corruption errors and boot hangs The issue occurs specifically when: 1 Using F2FS filesystem (ext4 is unaffected) 2 Swapfile size is less than F2FS section size (2MB) 3 Swapfile has fragmented physical layout (multiple non-contiguous extents) 4 Kernel version is 6.6+ (6.1 is unaffected) The root cause is in check_swap_activate() function in fs/f2fs/data.c. When the first extent of a small swapfile (< 2MB) is not aligned to section boundaries, the function incorrectly treats it as the last extent, failing to map subsequent extents. This results in incorrect swap_extent creation where only the first extent is mapped, causing subsequent swap writes to overwrite wrong physical locations (other files' data). Steps to Reproduce 1 Setup a device with F2FS-formatted userdata partition 2 Compile stress-ng from https://github.com/ColinIanKing/stress-ng 3 Run swap stress test: (Android devices) adb shell "cd /data/stressng; ./stress-ng-64 --metrics-brief --timeout 60 --swap 0" Log: 1 Ftrace shows in kernel 6.6, only first extent is mapped during second f2fs_map_blocks call in check_swap_activate(): stress-ng-swap-8990: f2fs_map_blocks: ino=11002, file offset=0, start blkaddr=0x43143, len=0x1 (Only 4KB mapped, not the full swapfile) 2 in kernel 6.1, both extents are correctly mapped: stress-ng-swap-5966: f2fs_map_blocks: ino=28011, file offset=0, start blkaddr=0x13cd4, len=0x1 stress-ng-swap-5966: f2fs_map_blocks: ino=28011, file offset=1, start blkaddr=0x60c84b, len=0xff The problematic code is in check_swap_activate(): if ((pblock - SM_I(sbi)->main_blkaddr) % blks_per_sec || nr_pblocks % blks_per_sec || !f2fs_valid_pinned_area(sbi, pblock)) { bool last_extent = false; not_aligned++; nr_pblocks = roundup(nr_pblocks, blks_per_sec); if (cur_lblock + nr_pblocks > sis->max) nr_pblocks -= blks_per_sec; /* this extent is last one */ if (!nr_pblocks) { nr_pblocks = last_lblock - cur_lblock; last_extent = true; } ret = f2fs_migrate_blocks(inode, cur_lblock, nr_pblocks); if (ret) { if (ret == -ENOENT) ret = -EINVAL; goto out; } if (!last_extent) goto retry; } When the first extent is unaligned and roundup(nr_pblocks, blks_per_sec) exceeds sis->max, we subtract blks_per_sec resulting in nr_pblocks = 0. The code then incorrectly assumes this is the last extent, sets nr_pblocks = last_lblock - cur_lblock (entire swapfile), and performs migration. After migration, it doesn't retry mapping, so subsequent extents are never processed. " In order to fix this issue, we need to lookup block mapping info after we migrate all blocks in the tail of swapfile. Cc: stable@kernel.org Fixes: 9703d69d9d15 ("f2fs: support file pinning for zoned devices") Cc: Daeho Jeong Reported-and-tested-by: Xiaolong Guo Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220951 Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim [ f2fs_is_sequential_zone_area() => !f2fs_valid_pinned_area() ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

f2fs: fix to avoid UAF in f2fs_write_end_io()

2026-02-19T15:28:27+00:00

[ Upstream commit ce2739e482bce8d2c014d76c4531c877f382aa54 ] As syzbot reported an use-after-free issue in f2fs_write_end_io(). It is caused by below race condition: loop device umount - worker_thread - loop_process_work - do_req_filebacked - lo_rw_aio - lo_rw_aio_complete - blk_mq_end_request - blk_update_request - f2fs_write_end_io - dec_page_count - folio_end_writeback - kill_f2fs_super - kill_block_super - f2fs_put_super : free(sbi) : get_pages(, F2FS_WB_CP_DATA) accessed sbi which is freed In kill_f2fs_super(), we will drop all page caches of f2fs inodes before call free(sbi), it guarantee that all folios should end its writeback, so it should be safe to access sbi before last folio_end_writeback(). Let's relocate ckpt thread wakeup flow before folio_end_writeback() to resolve this issue. Cc: stable@kernel.org Fixes: e234088758fc ("f2fs: avoid wait if IO end up when do_checkpoint for better performance") Reported-by: syzbot+b4444e3c972a7a124187@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=b4444e3c972a7a124187 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 to avoid updating compression context during writeback

2026-01-11T14:22:27+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 [ Adjust context ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

f2fs: fix wrong block mapping for multi-devices

2025-10-23T14:16:23+00:00

commit 9d5c4f5c7a2c7677e1b3942772122b032c265aae upstream. Assuming the disk layout as below, disk0: 0 --- 0x00035abfff disk1: 0x00035ac000 --- 0x00037abfff disk2: 0x00037ac000 --- 0x00037ebfff and we want to read data from offset=13568 having len=128 across the block devices, we can illustrate the block addresses like below. 0 .. 0x00037ac000 ------------------- 0x00037ebfff, 0x00037ec000 ------- | ^ ^ ^ | fofs 0 13568 13568+128 | ------------------------------------------------------ | LBA 0x37e8aa9 0x37ebfa9 0x37ec029 --- map 0x3caa9 0x3ffa9 In this example, we should give the relative map of the target block device ranging from 0x3caa9 to 0x3ffa9 where the length should be calculated by 0x37ebfff + 1 - 0x37ebfa9. In the below equation, however, map->m_pblk was supposed to be the original address instead of the one from the target block address. - map->m_len = min(map->m_len, dev->end_blk + 1 - map->m_pblk); Cc: stable@vger.kernel.org Fixes: 71f2c8206202 ("f2fs: multidevice: support direct IO") Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

f2fs: fix zero-sized extent for precache extents

2025-10-15T09:58:02+00:00

[ Upstream commit 8175c864391753b210f3dcfae1aeed686a226ebb ] Script to reproduce: f2fs_io write 1 0 1881 rand dsync testfile f2fs_io fallocate 0 7708672 4096 testfile f2fs_io write 1 1881 1 rand buffered testfile fsync testfile umount mount f2fs_io precache_extents testfile When the data layout is something like this: dnode1: dnode2: [0] A [0] NEW_ADDR [1] A+1 [1] 0x0 ... [1016] A+1016 [1017] B (B!=A+1017) [1017] 0x0 During precache_extents, we map the last block(valid blkaddr) in dnode1: map->m_flags |= F2FS_MAP_MAPPED; map->m_pblk = blkaddr(valid blkaddr); map->m_len = 1; then we goto next_dnode, meet the first block in dnode2(hole), goto sync_out: map->m_flags & F2FS_MAP_MAPPED == true, and we make zero-sized extent: map->m_len = 1 ofs = start_pgofs - map->m_lblk = 1882 - 1881 = 1 ei.fofs = start_pgofs = 1882 ei.len = map->m_len - ofs = 1 - 1 = 0 Rebased on patch[1], this patch can cover these cases to avoid zero-sized extent: A,B,C is valid blkaddr case1: dnode1: dnode2: [0] A [0] NEW_ADDR [1] A+1 [1] 0x0 ... .... [1016] A+1016 [1017] B (B!=A+1017) [1017] 0x0 case2: dnode1: dnode2: [0] A [0] C (C!=B+1) [1] A+1 [1] C+1 ... .... [1016] A+1016 [1017] B (B!=A+1017) [1017] 0x0 case3: dnode1: dnode2: [0] A [0] C (C!=B+2) [1] A+1 [1] C+1 ... .... [1015] A+1015 [1016] B (B!=A+1016) [1017] B+1 [1017] 0x0 [1] https://lore.kernel.org/linux-f2fs-devel/20250912081250.44383-1-chao@kernel.org/ Fixes: c4020b2da4c9 ("f2fs: support F2FS_IOC_PRECACHE_EXTENTS") Signed-off-by: wangzijie Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: fix to update map->m_next_extent correctly in f2fs_map_blocks()

2025-10-15T09:58:01+00:00

[ Upstream commit 869833f54e8306326b85ca3ed08979b7ad412a4a ] Script to reproduce: mkfs.f2fs -O extra_attr,compression /dev/vdb -f mount /dev/vdb /mnt/f2fs -o mode=lfs,noextent_cache cd /mnt/f2fs f2fs_io write 1 0 1024 rand dsync testfile xfs_io testfile -c "fsync" f2fs_io write 1 0 512 rand dsync testfile xfs_io testfile -c "fsync" cd / umount /mnt/f2fs mount /dev/vdb /mnt/f2fs f2fs_io precache_extents /mnt/f2fs/testfile umount /mnt/f2fs Tracepoint output: f2fs_update_read_extent_tree_range: dev = (253,16), ino = 4, pgofs = 0, len = 512, blkaddr = 1055744, c_len = 0 f2fs_update_read_extent_tree_range: dev = (253,16), ino = 4, pgofs = 513, len = 351, blkaddr = 17921, c_len = 0 f2fs_update_read_extent_tree_range: dev = (253,16), ino = 4, pgofs = 864, len = 160, blkaddr = 18272, c_len = 0 During precache_extents, there is off-by-one issue, we should update map->m_next_extent to pgofs rather than pgofs + 1, if last blkaddr is valid and not contiguous to previous extent. Fixes: c4020b2da4c9 ("f2fs: support F2FS_IOC_PRECACHE_EXTENTS") Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: fix to trigger foreground gc during f2fs_map_blocks() in lfs mode

2025-08-15T10:08:59+00:00

[ Upstream commit 1005a3ca28e90c7a64fa43023f866b960a60f791 ] w/ "mode=lfs" mount option, generic/299 will cause system panic as below: ------------[ cut here ]------------ kernel BUG at fs/f2fs/segment.c:2835! Call Trace: f2fs_allocate_data_block+0x6f4/0xc50 f2fs_map_blocks+0x970/0x1550 f2fs_iomap_begin+0xb2/0x1e0 iomap_iter+0x1d6/0x430 __iomap_dio_rw+0x208/0x9a0 f2fs_file_write_iter+0x6b3/0xfa0 aio_write+0x15d/0x2e0 io_submit_one+0x55e/0xab0 __x64_sys_io_submit+0xa5/0x230 do_syscall_64+0x84/0x2f0 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0010:new_curseg+0x70f/0x720 The root cause of we run out-of-space is: in f2fs_map_blocks(), f2fs may trigger foreground gc only if it allocates any physical block, it will be a little bit later when there is multiple threads writing data w/ aio/dio/bufio method in parallel, since we always use OPU in lfs mode, so f2fs_map_blocks() does block allocations aggressively. In order to fix this issue, let's give a chance to trigger foreground gc in prior to block allocation in f2fs_map_blocks(). Fixes: 36abef4e796d ("f2fs: introduce mode=lfs mount option") Cc: Daeho Jeong Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: vm_unmap_ram() may be called from an invalid context

2025-08-15T10:08:59+00:00

[ Upstream commit 08a7efc5b02a0620ae16aa9584060e980a69cb55 ] When testing F2FS with xfstests using UFS backed virtual disks the kernel complains sometimes that f2fs_release_decomp_mem() calls vm_unmap_ram() from an invalid context. Example trace from f2fs/007 test: f2fs/007 5s ... [12:59:38][ 8.902525] run fstests f2fs/007 [ 11.468026] BUG: sleeping function called from invalid context at mm/vmalloc.c:2978 [ 11.471849] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 68, name: irq/22-ufshcd [ 11.475357] preempt_count: 1, expected: 0 [ 11.476970] RCU nest depth: 0, expected: 0 [ 11.478531] CPU: 0 UID: 0 PID: 68 Comm: irq/22-ufshcd Tainted: G W 6.16.0-rc5-xfstests-ufs-g40f92e79b0aa #9 PREEMPT(none) [ 11.478535] Tainted: [W]=WARN [ 11.478536] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 11.478537] Call Trace: [ 11.478543] [ 11.478545] dump_stack_lvl+0x4e/0x70 [ 11.478554] __might_resched.cold+0xaf/0xbe [ 11.478557] vm_unmap_ram+0x21/0xb0 [ 11.478560] f2fs_release_decomp_mem+0x59/0x80 [ 11.478563] f2fs_free_dic+0x18/0x1a0 [ 11.478565] f2fs_finish_read_bio+0xd7/0x290 [ 11.478570] blk_update_request+0xec/0x3b0 [ 11.478574] ? sbitmap_queue_clear+0x3b/0x60 [ 11.478576] scsi_end_request+0x27/0x1a0 [ 11.478582] scsi_io_completion+0x40/0x300 [ 11.478583] ufshcd_mcq_poll_cqe_lock+0xa3/0xe0 [ 11.478588] ufshcd_sl_intr+0x194/0x1f0 [ 11.478592] ufshcd_threaded_intr+0x68/0xb0 [ 11.478594] ? __pfx_irq_thread_fn+0x10/0x10 [ 11.478599] irq_thread_fn+0x20/0x60 [ 11.478602] ? __pfx_irq_thread_fn+0x10/0x10 [ 11.478603] irq_thread+0xb9/0x180 [ 11.478605] ? __pfx_irq_thread_dtor+0x10/0x10 [ 11.478607] ? __pfx_irq_thread+0x10/0x10 [ 11.478609] kthread+0x10a/0x230 [ 11.478614] ? __pfx_kthread+0x10/0x10 [ 11.478615] ret_from_fork+0x7e/0xd0 [ 11.478619] ? __pfx_kthread+0x10/0x10 [ 11.478621] ret_from_fork_asm+0x1a/0x30 [ 11.478623] This patch modifies in_task() check inside f2fs_read_end_io() to also check if interrupts are disabled. This ensures that pages are unmapped asynchronously in an interrupt handler. Fixes: bff139b49d9f ("f2fs: handle decompress only post processing in softirq") Signed-off-by: Jan Prusakowski Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: fix to detect gcing page in f2fs_is_cp_guaranteed()

2025-06-19T13:28:12+00:00

[ Upstream commit aa1be8dd64163eca4dde7fd2557eb19927a06a47 ] Jan Prusakowski reported a f2fs bug as below: f2fs/007 will hang kernel during testing w/ below configs: kernel 6.12.18 (from pixel-kernel/android16-6.12) export MKFS_OPTIONS="-O encrypt -O extra_attr -O project_quota -O quota" export F2FS_MOUNT_OPTIONS="test_dummy_encryption,discard,fsync_mode=nobarrier,reserve_root=32768,checkpoint_merge,atgc" cat /proc//stack f2fs_wait_on_all_pages+0xa3/0x130 do_checkpoint+0x40c/0x5d0 f2fs_write_checkpoint+0x258/0x550 kill_f2fs_super+0x14f/0x190 deactivate_locked_super+0x30/0xb0 cleanup_mnt+0xba/0x150 task_work_run+0x59/0xa0 syscall_exit_to_user_mode+0x12d/0x130 do_syscall_64+0x57/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e cat /sys/kernel/debug/f2fs/status - IO_W (CP: -256, Data: 256, Flush: ( 0 0 1), Discard: ( 0 0)) cmd: 0 undiscard: 0 CP IOs reference count becomes negative. The root cause is: After 4961acdd65c9 ("f2fs: fix to tag gcing flag on page during block migration"), we will tag page w/ gcing flag for raw page of cluster during its migration. However, if the inode is both encrypted and compressed, during ioc_decompress(), it will tag page w/ gcing flag, and it increase F2FS_WB_DATA reference count: - f2fs_write_multi_page - f2fs_write_raw_page - f2fs_write_single_page - do_write_page - f2fs_submit_page_write - WB_DATA_TYPE(bio_page, fio->compressed_page) : bio_page is encrypted, so mapping is NULL, and fio->compressed_page is NULL, it returns F2FS_WB_DATA - inc_page_count(.., F2FS_WB_DATA) Then, during end_io(), it decrease F2FS_WB_CP_DATA reference count: - f2fs_write_end_io - f2fs_compress_write_end_io - fscrypt_pagecache_folio : get raw page from encrypted page - WB_DATA_TYPE(&folio->page, false) : raw page has gcing flag, it returns F2FS_WB_CP_DATA - dec_page_count(.., F2FS_WB_CP_DATA) In order to fix this issue, we need to detect gcing flag in raw page in f2fs_is_cp_guaranteed(). Fixes: 4961acdd65c9 ("f2fs: fix to tag gcing flag on page during block migration") Reported-by: Jan Prusakowski Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: clean up w/ fscrypt_is_bounce_page()

2025-06-19T13:28:12+00:00

[ Upstream commit 0c708e35cf26449ca317fcbfc274704660b6d269 ] Just cleanup, no logic changes. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin