Re: [f2fs-dev] [PATCH] f2fs: use inode mutex to keep atomicity off2fs_falloc

From: Jaegeuk Kim
Date: Tue Jan 28 2014 - 01:01:45 EST


Hi,

2014-01-28 (í), 10:29 +0800, Chao Yu:
> Previously without protection of inode mutex, f2fs_falloc and other data
> correlated operations will interfere with each other.

Could you explain a little bit more what kind of scenarios wrt this?


> So let's use inode mutex to keep atomicity of f2fs_falloc.
>
> Signed-off-by: Chao Yu <chao2.yu@xxxxxxxxxxx>
> ---
> fs/f2fs/file.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 85e91ca..ece380f 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -559,6 +559,8 @@ static long f2fs_fallocate(struct file *file, int mode,
> if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
> return -EOPNOTSUPP;
>
> + mutex_lock(&inode->i_mutex);
> +
> if (mode & FALLOC_FL_PUNCH_HOLE)
> ret = punch_hole(inode, offset, len);
> else
> @@ -568,6 +570,9 @@ static long f2fs_fallocate(struct file *file, int mode,
> inode->i_mtime = inode->i_ctime = CURRENT_TIME;
> mark_inode_dirty(inode);
> }
> +
> + mutex_unlock(&inode->i_mutex);
> +
> trace_f2fs_fallocate(inode, mode, offset, len, ret);
> return ret;
> }

--
Jaegeuk Kim
Samsung

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