* [f2fs-dev] [PATCH] f2fs: add READ_ONCE() for i_blocks in f2fs_update_inode()
@ 2026-03-17 11:42 ` Cen Zhang
0 siblings, 0 replies; 6+ messages in thread
From: Cen Zhang @ 2026-03-17 11:42 UTC (permalink / raw)
To: jaegeuk, chao
Cc: gality369, zhenghaoran154, linux-kernel, linux-f2fs-devel,
baijiaju1990, Cen Zhang, ziyuzhang201, r33s3n6, hanguidong02
f2fs_update_inode() reads inode->i_blocks without holding i_lock to
serialize it to the on-disk inode, while concurrent truncate or
allocation paths may modify i_blocks under i_lock. Since blkcnt_t is
u64, this risks torn reads on 32-bit architectures.
Following the approach in ext4_inode_blocks_set(), add READ_ONCE() to prevent
potential compiler-induced tearing.
Signed-off-by: Cen Zhang <zzzccc427@gmail.com>
---
fs/f2fs/inode.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 078874db918c..73b913dbe02a 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -694,7 +694,7 @@ void f2fs_update_inode(struct inode *inode, struct folio *node_folio)
ri->i_uid = cpu_to_le32(i_uid_read(inode));
ri->i_gid = cpu_to_le32(i_gid_read(inode));
ri->i_links = cpu_to_le32(inode->i_nlink);
- ri->i_blocks = cpu_to_le64(SECTOR_TO_BLOCK(inode->i_blocks) + 1);
+ ri->i_blocks = cpu_to_le64(SECTOR_TO_BLOCK(READ_ONCE(inode->i_blocks)) + 1);
if (!f2fs_is_atomic_file(inode) ||
is_inode_flag_set(inode, FI_ATOMIC_COMMITTED))
--
2.34.1
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH] f2fs: add READ_ONCE() for i_blocks in f2fs_update_inode()
@ 2026-03-17 11:42 ` Cen Zhang
0 siblings, 0 replies; 6+ messages in thread
From: Cen Zhang @ 2026-03-17 11:42 UTC (permalink / raw)
To: jaegeuk, chao
Cc: linux-f2fs-devel, linux-kernel, baijiaju1990, r33s3n6, gality369,
zhenghaoran154, hanguidong02, ziyuzhang201, Cen Zhang
f2fs_update_inode() reads inode->i_blocks without holding i_lock to
serialize it to the on-disk inode, while concurrent truncate or
allocation paths may modify i_blocks under i_lock. Since blkcnt_t is
u64, this risks torn reads on 32-bit architectures.
Following the approach in ext4_inode_blocks_set(), add READ_ONCE() to prevent
potential compiler-induced tearing.
Signed-off-by: Cen Zhang <zzzccc427@gmail.com>
---
fs/f2fs/inode.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 078874db918c..73b913dbe02a 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -694,7 +694,7 @@ void f2fs_update_inode(struct inode *inode, struct folio *node_folio)
ri->i_uid = cpu_to_le32(i_uid_read(inode));
ri->i_gid = cpu_to_le32(i_gid_read(inode));
ri->i_links = cpu_to_le32(inode->i_nlink);
- ri->i_blocks = cpu_to_le64(SECTOR_TO_BLOCK(inode->i_blocks) + 1);
+ ri->i_blocks = cpu_to_le64(SECTOR_TO_BLOCK(READ_ONCE(inode->i_blocks)) + 1);
if (!f2fs_is_atomic_file(inode) ||
is_inode_flag_set(inode, FI_ATOMIC_COMMITTED))
--
2.34.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [f2fs-dev] [PATCH] f2fs: add READ_ONCE() for i_blocks in f2fs_update_inode()
2026-03-17 11:42 ` Cen Zhang
@ 2026-03-18 5:56 ` Chao Yu
-1 siblings, 0 replies; 6+ messages in thread
From: Chao Yu via Linux-f2fs-devel @ 2026-03-18 5:56 UTC (permalink / raw)
To: Cen Zhang, jaegeuk
Cc: gality369, zhenghaoran154, linux-kernel, linux-f2fs-devel,
baijiaju1990, ziyuzhang201, r33s3n6, hanguidong02
On 2026/3/17 19:42, Cen Zhang wrote:
> f2fs_update_inode() reads inode->i_blocks without holding i_lock to
> serialize it to the on-disk inode, while concurrent truncate or
> allocation paths may modify i_blocks under i_lock. Since blkcnt_t is
> u64, this risks torn reads on 32-bit architectures.
>
> Following the approach in ext4_inode_blocks_set(), add READ_ONCE() to prevent
> potential compiler-induced tearing.
>
Need a Fixes line and Cc stable@kernel.org?
Otherwise, it looks good to me.
Thanks,
> Signed-off-by: Cen Zhang <zzzccc427@gmail.com>
> ---
> fs/f2fs/inode.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
> index 078874db918c..73b913dbe02a 100644
> --- a/fs/f2fs/inode.c
> +++ b/fs/f2fs/inode.c
> @@ -694,7 +694,7 @@ void f2fs_update_inode(struct inode *inode, struct folio *node_folio)
> ri->i_uid = cpu_to_le32(i_uid_read(inode));
> ri->i_gid = cpu_to_le32(i_gid_read(inode));
> ri->i_links = cpu_to_le32(inode->i_nlink);
> - ri->i_blocks = cpu_to_le64(SECTOR_TO_BLOCK(inode->i_blocks) + 1);
> + ri->i_blocks = cpu_to_le64(SECTOR_TO_BLOCK(READ_ONCE(inode->i_blocks)) + 1);
>
> if (!f2fs_is_atomic_file(inode) ||
> is_inode_flag_set(inode, FI_ATOMIC_COMMITTED))
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] f2fs: add READ_ONCE() for i_blocks in f2fs_update_inode()
@ 2026-03-18 5:56 ` Chao Yu
0 siblings, 0 replies; 6+ messages in thread
From: Chao Yu @ 2026-03-18 5:56 UTC (permalink / raw)
To: Cen Zhang, jaegeuk
Cc: chao, linux-f2fs-devel, linux-kernel, baijiaju1990, r33s3n6,
gality369, zhenghaoran154, hanguidong02, ziyuzhang201
On 2026/3/17 19:42, Cen Zhang wrote:
> f2fs_update_inode() reads inode->i_blocks without holding i_lock to
> serialize it to the on-disk inode, while concurrent truncate or
> allocation paths may modify i_blocks under i_lock. Since blkcnt_t is
> u64, this risks torn reads on 32-bit architectures.
>
> Following the approach in ext4_inode_blocks_set(), add READ_ONCE() to prevent
> potential compiler-induced tearing.
>
Need a Fixes line and Cc stable@kernel.org?
Otherwise, it looks good to me.
Thanks,
> Signed-off-by: Cen Zhang <zzzccc427@gmail.com>
> ---
> fs/f2fs/inode.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
> index 078874db918c..73b913dbe02a 100644
> --- a/fs/f2fs/inode.c
> +++ b/fs/f2fs/inode.c
> @@ -694,7 +694,7 @@ void f2fs_update_inode(struct inode *inode, struct folio *node_folio)
> ri->i_uid = cpu_to_le32(i_uid_read(inode));
> ri->i_gid = cpu_to_le32(i_gid_read(inode));
> ri->i_links = cpu_to_le32(inode->i_nlink);
> - ri->i_blocks = cpu_to_le64(SECTOR_TO_BLOCK(inode->i_blocks) + 1);
> + ri->i_blocks = cpu_to_le64(SECTOR_TO_BLOCK(READ_ONCE(inode->i_blocks)) + 1);
>
> if (!f2fs_is_atomic_file(inode) ||
> is_inode_flag_set(inode, FI_ATOMIC_COMMITTED))
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [f2fs-dev] [PATCH] f2fs: add READ_ONCE() for i_blocks in f2fs_update_inode()
2026-03-18 5:56 ` Chao Yu
@ 2026-03-18 7:50 ` Cen Zhang
-1 siblings, 0 replies; 6+ messages in thread
From: Cen Zhang @ 2026-03-18 7:50 UTC (permalink / raw)
To: Chao Yu
Cc: gality369, zhenghaoran154, linux-kernel, linux-f2fs-devel,
baijiaju1990, ziyuzhang201, r33s3n6, jaegeuk, hanguidong02
Hi Chao,
Thank you for the review.
On 2026/3/18 13:56, Chao Yu wrote:
> Need a Fixes line and Cc stable@kernel.org?
Good point, added both in v2:
Fixes: 19f99cee206c ("f2fs: add core inode operations")
Cc: stable@vger.kernel.org
> Otherwise, it looks good to me.
Thanks!
Best regards,
Cen
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] f2fs: add READ_ONCE() for i_blocks in f2fs_update_inode()
@ 2026-03-18 7:50 ` Cen Zhang
0 siblings, 0 replies; 6+ messages in thread
From: Cen Zhang @ 2026-03-18 7:50 UTC (permalink / raw)
To: Chao Yu
Cc: jaegeuk, linux-f2fs-devel, linux-kernel, baijiaju1990, r33s3n6,
gality369, zhenghaoran154, hanguidong02, ziyuzhang201
Hi Chao,
Thank you for the review.
On 2026/3/18 13:56, Chao Yu wrote:
> Need a Fixes line and Cc stable@kernel.org?
Good point, added both in v2:
Fixes: 19f99cee206c ("f2fs: add core inode operations")
Cc: stable@vger.kernel.org
> Otherwise, it looks good to me.
Thanks!
Best regards,
Cen
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-03-18 7:50 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-03-17 11:42 [f2fs-dev] [PATCH] f2fs: add READ_ONCE() for i_blocks in f2fs_update_inode() Cen Zhang
2026-03-17 11:42 ` Cen Zhang
2026-03-18 5:56 ` [f2fs-dev] " Chao Yu via Linux-f2fs-devel
2026-03-18 5:56 ` Chao Yu
2026-03-18 7:50 ` [f2fs-dev] " Cen Zhang
2026-03-18 7:50 ` Cen Zhang
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