2009-07-06 09:16:18

by Cong Wang

Subject: [Patch v3] btrfs: use file_remove_suid() after i_mutex is held

V2 -> V3:
set 'err' to -ENOMEM when kmalloc() fails. Thanks to Tao.

V1 -> V2:
Move kmalloc() before mutex_lock(), suggested by Arjan.

file_remove_suid() should be called with i_mutex held,
file_update_time() too. So move them after mutex_lock().

Plus, check the return value of kmalloc().

Signed-off-by: WANG Cong <[email protected]>
Cc: Arjan <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: Yan Zheng <[email protected]>
Cc: Sven Wegener <[email protected]>
Cc: Josef Bacik <[email protected]>
Cc: Jeff Mahoney <[email protected]>
Cc: Tao Ma <[email protected]>

---
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 7c3cd24..e7b0d81 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -944,14 +944,19 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
if (count == 0)
goto out_nolock;

+ pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
+ if (!pages) {
+ err = -ENOMEM;
+ goto out_nolock;
+ }
+
+ mutex_lock(&inode->i_mutex);
+
err = file_remove_suid(file);
if (err)
- goto out_nolock;
+ goto out;
file_update_time(file);

- pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
-
- mutex_lock(&inode->i_mutex);
BTRFS_I(inode)->sequence++;
first_index = pos >> PAGE_CACHE_SHIFT;
last_index = (pos + count) >> PAGE_CACHE_SHIFT;

2009-07-06 11:42:56

by Josef Bacik

Subject: Re: [Patch v3] btrfs: use file_remove_suid() after i_mutex is held

On Mon, Jul 06, 2009 at 05:15:33AM -0400, Amerigo Wang wrote:
>
> V2 -> V3:
> set 'err' to -ENOMEM when kmalloc() fails. Thanks to Tao.
>
> V1 -> V2:
> Move kmalloc() before mutex_lock(), suggested by Arjan.
>
> file_remove_suid() should be called with i_mutex held,
> file_update_time() too. So move them after mutex_lock().
>
> Plus, check the return value of kmalloc().
>
> Signed-off-by: WANG Cong <[email protected]>
> Cc: Arjan <[email protected]>
> Cc: Chris Mason <[email protected]>
> Cc: Yan Zheng <[email protected]>
> Cc: Sven Wegener <[email protected]>
> Cc: Josef Bacik <[email protected]>
> Cc: Jeff Mahoney <[email protected]>
> Cc: Tao Ma <[email protected]>
>
> ---
> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
> index 7c3cd24..e7b0d81 100644
> --- a/fs/btrfs/file.c
> +++ b/fs/btrfs/file.c
> @@ -944,14 +944,19 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
> if (count == 0)
> goto out_nolock;
>
> + pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
> + if (!pages) {
> + err = -ENOMEM;
> + goto out_nolock;
> + }
> +
> + mutex_lock(&inode->i_mutex);
> +
> err = file_remove_suid(file);
> if (err)
> - goto out_nolock;
> + goto out;
> file_update_time(file);
>
> - pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
> -
> - mutex_lock(&inode->i_mutex);
> BTRFS_I(inode)->sequence++;
> first_index = pos >> PAGE_CACHE_SHIFT;
> last_index = (pos + count) >> PAGE_CACHE_SHIFT;

Acked-by: Josef Bacik <[email protected]>

Thanks,

Josef