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. 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-c...@kernel.org/ Fixes: c4020b2da4c9 ("f2fs: support F2FS_IOC_PRECACHE_EXTENTS") Signed-off-by: wangzijie <wangzij...@honor.com> --- Rebased on: https://lore.kernel.org/linux-f2fs-devel/20250912081250.44383-1-c...@kernel.org/ v1: https://lore.kernel.org/linux-f2fs-devel/20250912103915.3597413-1-wangzij...@honor.com --- fs/f2fs/data.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 838eae39d..7a5170b32 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1778,9 +1778,10 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, int flag) if (map->m_flags & F2FS_MAP_MAPPED) { unsigned int ofs = start_pgofs - map->m_lblk; - f2fs_update_read_extent_cache_range(&dn, - start_pgofs, map->m_pblk + ofs, - map->m_len - ofs); + if (map->m_len - ofs > 0) + f2fs_update_read_extent_cache_range(&dn, + start_pgofs, map->m_pblk + ofs, + map->m_len - ofs); } if (map->m_next_extent) *map->m_next_extent = is_hole ? pgofs + 1 : pgofs; -- 2.25.1 _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
