>>On 9/12/2025 11:36 AM, wangzijie wrote: >>>> On 9/11/2025 5:07 PM, wangzijie wrote: >>>>>> On 9/10/25 21:58, wangzijie wrote: >>>>>>> When the data layout is like this: >>>>>>> dnode1: dnode2: >>>>>>> [0] A [0] NEW_ADDR >>>>>>> [1] A+1 [1] 0x0 >>>>>>> ... .... >>>>>>> [1016] A+1016 >>>>>>> [1017] B (B!=A+1017) [1017] 0x0 >>>>>>> >>>>>>> We can build this kind of layout by following steps(with >>>>>>> i_extra_isize:36): >>>>>>> ./f2fs_io write 1 0 1881 rand dsync testfile >>>>>>> ./f2fs_io write 1 1881 1 rand buffered testfile >>>>>>> ./f2fs_io fallocate 0 7708672 4096 testfile >>>>>>> >>>>>>> And when we map first data block in dnode2, we will get wrong >>>>>>> extent_info data: >>>>>>> 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 >>>>>>> >>>>>>> Fix it by skipping updating this kind of extent info. >>>>>>> >>>>>>> Signed-off-by: wangzijie <[email protected]> >>>>>>> --- >>>>>>> fs/f2fs/data.c | 3 +++ >>>>>>> 1 file changed, 3 insertions(+) >>>>>>> >>>>>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c >>>>>>> index 7961e0ddf..b8bb71852 100644 >>>>>>> --- a/fs/f2fs/data.c >>>>>>> +++ b/fs/f2fs/data.c >>>>>>> @@ -1649,6 +1649,9 @@ int f2fs_map_blocks(struct inode *inode, struct >>>>>>> f2fs_map_blocks *map, int flag) >>>>>>> >>>>>>> switch (flag) { >>>>>>> case F2FS_GET_BLOCK_PRECACHE: >>>>>>> + if (__is_valid_data_blkaddr(map->m_pblk) && >>>>>>> + start_pgofs - map->m_lblk == map->m_len) >>>>>>> + map->m_flags &= ~F2FS_MAP_MAPPED; >>>>>> >>>>>> It looks we missed to reset value for map variable in >>>>>> f2fs_precache_extents(), >>>>>> what do you think of this? >>>>>> >>>>>> --- >>>>>> fs/f2fs/file.c | 4 +++- >>>>>> 1 file changed, 3 insertions(+), 1 deletion(-) >>>>>> >>>>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c >>>>>> index 1aae4361d0a8..2b14151d4130 100644 >>>>>> --- a/fs/f2fs/file.c >>>>>> +++ b/fs/f2fs/file.c >>>>>> @@ -3599,7 +3599,7 @@ static int f2fs_ioc_io_prio(struct file *filp, >>>>>> unsigned long arg) >>>>>> int f2fs_precache_extents(struct inode *inode) >>>>>> { >>>>>> struct f2fs_inode_info *fi = F2FS_I(inode); >>>>>> - struct f2fs_map_blocks map; >>>>>> + struct f2fs_map_blocks map = { 0 }; >>>>>> pgoff_t m_next_extent; >>>>>> loff_t end; >>>>>> int err; >>>>>> @@ -3617,6 +3617,8 @@ int f2fs_precache_extents(struct inode *inode) >>>>>> >>>>>> while (map.m_lblk < end) { >>>>>> map.m_len = end - map.m_lblk; >>>>>> + map.m_pblk = 0; >>>>>> + map.m_flags = 0; >>>>>> >>>>>> f2fs_down_write(&fi->i_gc_rwsem[WRITE]); >>>>>> err = f2fs_map_blocks(inode, &map, >>>>>> F2FS_GET_BLOCK_PRECACHE); >>>>>> -- >>>>>> 2.49.0 >>>>>> >>>>>> Thanks, >>>>>> >>>>>>> goto sync_out; >>>>>>> case F2FS_GET_BLOCK_BMAP: >>>>>>> map->m_pblk = 0; >>>>> >>>>> >>>>> We have already reset m_flags (map->m_flags = 0) in f2fs_map_blocks(). >>>> >>>> Zijie: >>>> >>>> Oops, that's right, thanks for correcting me. >>>> >>>>> >>>>> I think that this bug is caused by we missed to reset m_flags when we >>>>> goto next_dnode in below caseļ¼ >>>>> >>>>> 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 >>>>> >>>>> 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 wrong blkaddr/len for >>>>> extent_info. >>>> >>>> So, can you please add above explanation into commit message? that >>>> should be helpful for understanding the problem more clearly. >>>> >>>> Please take a look at this case w/ your patch: >>>> >>>> mkfs.f2fs -O extra_attr,compression /dev/vdb -f >>>> mount /dev/vdb /mnt/f2fs -o mode=lfs >>>> cd /mnt/f2fs >>>> f2fs_io write 1 0 1883 rand dsync testfile >>>> f2fs_io fallocate 0 7712768 4096 testfile >>>> f2fs_io write 1 1881 1 rand buffered 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 >>>> >>>> f2fs_io-733 [010] ..... 78.134136: >>>> f2fs_update_read_extent_tree_range: dev = (253,16), ino = 4, pgofs = 1882, >>>> len = 0, blkaddr = 17410, c_len = 0 >>>> >>>> I suspect we need this? >>>> >>>> @@ -1784,7 +1781,8 @@ int f2fs_map_blocks(struct inode *inode, struct >>>> f2fs_map_blocks *map, int flag) >>>> } >>>> >>>> if (flag == F2FS_GET_BLOCK_PRECACHE) { >>>> - if (map->m_flags & F2FS_MAP_MAPPED) { >>>> + if ((map->m_flags & F2FS_MAP_MAPPED) && >>>> + (map->m_len - ofs)) { >>>> unsigned int ofs = start_pgofs - map->m_lblk; >>>> >>>> f2fs_update_read_extent_cache_range(&dn, >>> >>> Thanks for pointing out this. Let me find a way to cover these cases and do >>> more test. >>> >>>> BTW, I find another bug, if one blkaddr is adjcent to previous extent, >>>> but and it is valid, we need to set m_next_extent to pgofs rather than >>>> pgofs + 1. >>>> >>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c >>>> index cbf8841642c7..ac88ed68059c 100644 >>>> --- a/fs/f2fs/data.c >>>> +++ b/fs/f2fs/data.c >>>> @@ -1789,8 +1789,11 @@ int f2fs_map_blocks(struct inode *inode, struct >>>> f2fs_map_blocks *map, int flag) >>>> start_pgofs, map->m_pblk + ofs, >>>> map->m_len - ofs); >>>> } >>>> - if (map->m_next_extent) >>>> - *map->m_next_extent = pgofs + 1; >>>> + if (map->m_next_extent) { >>>> + *map->m_next_extent = pgofs; >>>> + if (!__is_valid_data_blkaddr(blkaddr)) >>>> + *map->m_next_extent += 1; >>>> + } >>>> } >>>> f2fs_put_dnode(&dn); >>> >>> Maybe it can be this? >>> if (map->m_next_extent) >>> *map->m_next_extent = is_hole ? pgofs + 1 : pgofs; >> >>It's better, will update, thank you. :) >> >>Thanks, > >Hi Chao, >I test some cases with this change: > >diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c >index 7961e0ddf..7093fdc95 100644 >--- a/fs/f2fs/data.c >+++ b/fs/f2fs/data.c >@@ -1777,13 +1777,13 @@ int f2fs_map_blocks(struct inode *inode, struct >f2fs_map_blocks *map, int flag) > if (flag == F2FS_GET_BLOCK_PRECACHE) { > 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 = pgofs + 1; >+ *map->m_next_extent = is_hole ? pgofs + 1 : pgofs; > } > f2fs_put_dnode(&dn); > unlock_out: > > >test cases: > >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 > >case4: >one blkaddr is adjcent to previous extent, and it is valid. > >And from the result, it seems this change can cover these >situations correctly. >Do we need a patch with this change?
Sorry, with this change, for case1: The first block of dnode2 ([0]:NEW_ADDR) will be skipped. Let me find a better way.... _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
