>On 6/22/26 10:38, Sunmin Jeong wrote: >> 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. > >It's good catch! > >> >> 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 >> > >Fixes and Cc stable line. > >> Reviewed-by: Yunji Kang <[email protected]> >> Reviewed-by: Yeongjin Gil <[email protected]> >> Reviewed-by: Sungjong Seo <[email protected]> >> Signed-off-by: Sunmin Jeong <[email protected]> >> --- >> fs/f2fs/file.c | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index >> 2c4880f24b54..3954aea43bd9 100644 >> --- a/fs/f2fs/file.c >> +++ b/fs/f2fs/file.c >> @@ -1906,8 +1906,13 @@ static int f2fs_expand_inode_data(struct inode >> *inode, loff_t offset, >> >> if (f2fs_is_pinned_file(inode)) { >> block_t sec_blks = CAP_BLKS_PER_SEC(sbi); >> - block_t sec_len = roundup(map.m_len, sec_blks); >> + 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; > >If pg_end is aligned to sec_blks, but off_end is non-zero, is there off-by- >one issue? > >Thanks,
Thanks for your quick reply. I'll send a v2 patch. > >> + } >> + sec_len = roundup(map.m_len, sec_blks); >> map.m_len = sec_blks; >> next_alloc: >> f2fs_down_write(&sbi->pin_sem); _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
