5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhan Xusheng commit 0f448bb3767ef6119f5cdeabcae3f10d6e75aed6 upstream. From: Zhan Xusheng Commit 4275b59673eb ("f2fs: fix to round down start offset of fallocate for pin file") moved the allocation loop's start down to a section boundary, but the error path still converts @expanded against @pg_start, which holds the unrounded start. @pg_start exists for that conversion: commit 88f2cfc5fa90 ("f2fs: fix to update last i_size if fallocate partially succeeds") added it as an immutable base because map.m_lblk moves every round. Each round now maps exactly sec_blks blocks starting from rounddown(pg_start, sec_blks), so pg_start + expanded overshoots the last allocated block by pg_start % sec_blks, and a partial failure leaves i_size covering a tail that was never allocated. Nothing corrects that afterwards either, since file_dont_truncate() has already cleared FADVISE_TRUNC_BIT. It needs a start offset that is not section aligned plus a fallocate that hits ENOSPC partway, so the error path runs with expanded > 0. On an 80 MiB image with 2 MiB sections: truncate -s 80M img mkfs.f2fs -s 1 -f img mount -o loop img /mnt touch /mnt/pinned f2fs_io pinfile set /mnt/pinned # 2093056 = block 511, so pg_start % sec_blks = 511 f2fs_io fallocate 0 2093056 536870912 /mnt/pinned stat -c %s /mnt/pinned filefrag -v /mnt/pinned The last extent ends at block 10737 either way. Before, i_size is 46075904, block 11249, so 511 blocks of it were never allocated, and filefrag does not mark the last extent eof. After, i_size is 43982848, block 10738, and eof is back. A kernel from before that commit also shows no overshoot. Keep @pg_start pointing at where allocation actually begins. Fixes: 4275b59673eb ("f2fs: fix to round down start offset of fallocate for pin file") Cc: stable@vger.kernel.org Signed-off-by: Zhan Xusheng Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/file.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1685,8 +1685,9 @@ static int expand_inode_data(struct inod block_t sec_len; if (map.m_lblk % sec_blks) { - map.m_lblk = rounddown(map.m_lblk, sec_blks); - map.m_len = pg_end - map.m_lblk; + pg_start = rounddown(map.m_lblk, sec_blks); + map.m_lblk = pg_start; + map.m_len = pg_end - pg_start; if (off_end) map.m_len++; }