* [PATCH] quota: add missing use of dq_data_lock in __dquot_initialize
@ 2013-02-27 19:43 Jeff Mahoney
2013-03-01 9:35 ` Jan Kara
0 siblings, 1 reply; 2+ messages in thread
From: Jeff Mahoney @ 2013-02-27 19:43 UTC (permalink / raw)
To: Linux FS Maling List; +Cc: Jan Kara
The bulk of __dquot_initialize runs under the dqptr_sem which
protects the inode->i_dquot pointers. It doesn't protect the
dereferenced contents, though. Those are protected by the
dq_data_lock, which is missing around the dquot_resv_space call.
Cc: Jan Kara <jack@suse.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
--
fs/quota/dquot.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -1439,8 +1439,11 @@ static void __dquot_initialize(struct in
* did a write before quota was turned on
*/
rsv = inode_get_rsv_space(inode);
- if (unlikely(rsv))
+ if (unlikely(rsv)) {
+ spin_lock(&dq_data_lock);
dquot_resv_space(inode->i_dquot[cnt], rsv);
+ spin_unlock(&dq_data_lock);
+ }
}
}
out_err:
--
Jeff Mahoney
SUSE Labs
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [PATCH] quota: add missing use of dq_data_lock in __dquot_initialize
2013-02-27 19:43 [PATCH] quota: add missing use of dq_data_lock in __dquot_initialize Jeff Mahoney
@ 2013-03-01 9:35 ` Jan Kara
0 siblings, 0 replies; 2+ messages in thread
From: Jan Kara @ 2013-03-01 9:35 UTC (permalink / raw)
To: Jeff Mahoney; +Cc: Linux FS Maling List, Jan Kara
On Wed 27-02-13 14:43:09, Jeff Mahoney wrote:
> The bulk of __dquot_initialize runs under the dqptr_sem which
> protects the inode->i_dquot pointers. It doesn't protect the
> dereferenced contents, though. Those are protected by the
> dq_data_lock, which is missing around the dquot_resv_space call.
>
> Cc: Jan Kara <jack@suse.com>
> Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Thanks! I've merged the patch. Just one small nitpick - git(1) expects
diffstat to be separated by three dashes (not two) so I had to fix that up
so that it doesn't appear in the commit message. Not sure how that happened
in your submission but I wanted to point that out just in case it was some
systematic error...
Honza
> --
>
> fs/quota/dquot.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> --- a/fs/quota/dquot.c
> +++ b/fs/quota/dquot.c
> @@ -1439,8 +1439,11 @@ static void __dquot_initialize(struct in
> * did a write before quota was turned on
> */
> rsv = inode_get_rsv_space(inode);
> - if (unlikely(rsv))
> + if (unlikely(rsv)) {
> + spin_lock(&dq_data_lock);
> dquot_resv_space(inode->i_dquot[cnt], rsv);
> + spin_unlock(&dq_data_lock);
> + }
> }
> }
> out_err:
>
> --
> Jeff Mahoney
> SUSE Labs
> --
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--
Jan Kara <jack@suse.cz>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 2+ messages in thread
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