* [f2fs-dev] [PATCH v3 2/2] f2fs: fix infinite loop in __insert_extent_tree()
2025-09-17 2:36 [f2fs-dev] [PATCH v3 1/2] f2fs: fix zero-sized extent for precache extents wangzijie
@ 2025-09-17 2:36 ` wangzijie
2025-09-17 6:48 ` Chao Yu
2025-09-17 6:41 ` [f2fs-dev] [PATCH v3 1/2] f2fs: fix zero-sized extent for precache extents Chao Yu
` (2 subsequent siblings)
3 siblings, 1 reply; 6+ messages in thread
From: wangzijie @ 2025-09-17 2:36 UTC (permalink / raw)
To: jaegeuk, chao
Cc: linux-f2fs-devel, linux-kernel, bintian.wang, feng.han, wangzijie
When we get wrong extent info data, and look up extent_node in rb tree,
it will cause infinite loop (CONFIG_F2FS_CHECK_FS=n). Avoiding this by
return NULL and print some kernel messages in that case.
Signed-off-by: wangzijie <wangzijie1@honor.com>
---
v3:
- followed by Jaegeuk's suggestion to print some kernel messages
---
fs/f2fs/extent_cache.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index 199c1e7a8..ba0a07bfd 100644
--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -604,7 +604,13 @@ static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
p = &(*p)->rb_right;
leftmost = false;
} else {
+ f2fs_err_ratelimited(sbi, "%s: corrupted extent, type: %d, "
+ "extent node in rb tree [%u, %u, %u], age [%llu, %llu], "
+ "extent node to insert [%u, %u, %u], age [%llu, %llu]",
+ __func__, et->type, en->ei.fofs, en->ei.blk, en->ei.len, en->ei.age,
+ en->ei.last_blocks, ei->fofs, ei->blk, ei->len, ei->age, ei->last_blocks);
f2fs_bug_on(sbi, 1);
+ return NULL;
}
}
--
2.25.1
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [f2fs-dev] [PATCH v3 2/2] f2fs: fix infinite loop in __insert_extent_tree()
2025-09-17 2:36 ` [f2fs-dev] [PATCH v3 2/2] f2fs: fix infinite loop in __insert_extent_tree() wangzijie
@ 2025-09-17 6:48 ` Chao Yu
0 siblings, 0 replies; 6+ messages in thread
From: Chao Yu @ 2025-09-17 6:48 UTC (permalink / raw)
To: wangzijie, jaegeuk
Cc: chao, linux-f2fs-devel, linux-kernel, bintian.wang, feng.han
On 9/17/25 10:36, wangzijie wrote:
> When we get wrong extent info data, and look up extent_node in rb tree,
> it will cause infinite loop (CONFIG_F2FS_CHECK_FS=n). Avoiding this by
> return NULL and print some kernel messages in that case.
>
> Signed-off-by: wangzijie <wangzijie1@honor.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Thanks,
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [f2fs-dev] [PATCH v3 1/2] f2fs: fix zero-sized extent for precache extents
2025-09-17 2:36 [f2fs-dev] [PATCH v3 1/2] f2fs: fix zero-sized extent for precache extents wangzijie
2025-09-17 2:36 ` [f2fs-dev] [PATCH v3 2/2] f2fs: fix infinite loop in __insert_extent_tree() wangzijie
@ 2025-09-17 6:41 ` Chao Yu
2025-09-17 15:59 ` Jaegeuk Kim
2025-09-29 22:30 ` patchwork-bot+f2fs
3 siblings, 0 replies; 6+ messages in thread
From: Chao Yu @ 2025-09-17 6:41 UTC (permalink / raw)
To: wangzijie, jaegeuk
Cc: chao, linux-f2fs-devel, linux-kernel, bintian.wang, feng.han
On 9/17/25 10:36, wangzijie wrote:
> 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 <wangzijie1@honor.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Thanks,
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [f2fs-dev] [PATCH v3 1/2] f2fs: fix zero-sized extent for precache extents
2025-09-17 2:36 [f2fs-dev] [PATCH v3 1/2] f2fs: fix zero-sized extent for precache extents wangzijie
2025-09-17 2:36 ` [f2fs-dev] [PATCH v3 2/2] f2fs: fix infinite loop in __insert_extent_tree() wangzijie
2025-09-17 6:41 ` [f2fs-dev] [PATCH v3 1/2] f2fs: fix zero-sized extent for precache extents Chao Yu
@ 2025-09-17 15:59 ` Jaegeuk Kim
2025-09-29 22:30 ` patchwork-bot+f2fs
3 siblings, 0 replies; 6+ messages in thread
From: Jaegeuk Kim @ 2025-09-17 15:59 UTC (permalink / raw)
To: wangzijie; +Cc: chao, linux-f2fs-devel, linux-kernel, bintian.wang, feng.han
On 09/17, wangzijie wrote:
> 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 <wangzijie1@honor.com>
> ---
> Rebased on:
> https://lore.kernel.org/linux-f2fs-devel/20250912081250.44383-1-chao@kernel.org/
> v2:
> https://lore.kernel.org/linux-f2fs-devel/20250915035246.98055-1-wangzijie1@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)
Applied with
if (map->m_len > ofs)
> + 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
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [f2fs-dev] [PATCH v3 1/2] f2fs: fix zero-sized extent for precache extents
2025-09-17 2:36 [f2fs-dev] [PATCH v3 1/2] f2fs: fix zero-sized extent for precache extents wangzijie
` (2 preceding siblings ...)
2025-09-17 15:59 ` Jaegeuk Kim
@ 2025-09-29 22:30 ` patchwork-bot+f2fs
3 siblings, 0 replies; 6+ messages in thread
From: patchwork-bot+f2fs @ 2025-09-29 22:30 UTC (permalink / raw)
To: wangzijie; +Cc: jaegeuk, chao, linux-kernel, feng.han, linux-f2fs-devel
Hello:
This series was applied to jaegeuk/f2fs.git (dev)
by Jaegeuk Kim <jaegeuk@kernel.org>:
On Wed, 17 Sep 2025 10:36:21 +0800 you wrote:
> 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
>
> [...]
Here is the summary with links:
- [f2fs-dev,v3,1/2] f2fs: fix zero-sized extent for precache extents
(no matching commit)
- [f2fs-dev,v3,2/2] f2fs: fix infinite loop in __insert_extent_tree()
https://git.kernel.org/jaegeuk/f2fs/c/23361bd54966
You are awesome, thank you!
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^ permalink raw reply [flat|nested] 6+ messages in thread