2020-09-18 03:08:48

by Chao Yu

Subject: [PATCH] f2fs: compress: fix to disallow enabling compress on non-empty file

Compressed inode and normal inode has different layout, so we should
disallow enabling compress on non-empty file to avoid race condition
during inode .i_addr array parsing and updating.

Signed-off-by: Chao Yu <[email protected]>
---
fs/f2fs/file.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 58e464cc15f0..139fdfc1dc55 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1821,6 +1821,8 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask)
if (iflags & F2FS_COMPR_FL) {
if (!f2fs_may_compress(inode))
return -EINVAL;
+ if (inode->i_size)
+ return -EINVAL;

set_compress_context(inode);
}
--
2.26.2

2020-09-24 20:07:27

by Jaegeuk Kim

Subject: Re: [PATCH] f2fs: compress: fix to disallow enabling compress on non-empty file

On 09/18, Chao Yu wrote:
> Compressed inode and normal inode has different layout, so we should
> disallow enabling compress on non-empty file to avoid race condition
> during inode .i_addr array parsing and updating.
>
> Signed-off-by: Chao Yu <[email protected]>
> ---
> fs/f2fs/file.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 58e464cc15f0..139fdfc1dc55 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -1821,6 +1821,8 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask)
> if (iflags & F2FS_COMPR_FL) {
> if (!f2fs_may_compress(inode))
> return -EINVAL;
> + if (inode->i_size)

Changed like this.

+ if (S_ISREG(inode->i_mode) && inode->i_size)


> + return -EINVAL;
>
> set_compress_context(inode);
> }
> --
> 2.26.2

2020-09-25 00:59:31

by Chao Yu

Subject: Re: [PATCH] f2fs: compress: fix to disallow enabling compress on non-empty file

On 2020/9/25 4:03, Jaegeuk Kim wrote:
> On 09/18, Chao Yu wrote:
>> Compressed inode and normal inode has different layout, so we should
>> disallow enabling compress on non-empty file to avoid race condition
>> during inode .i_addr array parsing and updating.
>>
>> Signed-off-by: Chao Yu <[email protected]>
>> ---
>> fs/f2fs/file.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>> index 58e464cc15f0..139fdfc1dc55 100644
>> --- a/fs/f2fs/file.c
>> +++ b/fs/f2fs/file.c
>> @@ -1821,6 +1821,8 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask)
>> if (iflags & F2FS_COMPR_FL) {
>> if (!f2fs_may_compress(inode))
>> return -EINVAL;
>> + if (inode->i_size)
>
> Changed like this.
>
> + if (S_ISREG(inode->i_mode) && inode->i_size)

My bad, thanks for fixing this. :)

Thanks,

>
>
>> + return -EINVAL;
>>
>> set_compress_context(inode);
>> }
>> --
>> 2.26.2
> .
>