[PATCH] pipe: skip file_update_time on frozen fs

[PATCH] pipe: skip file_update_time on frozen fs

[Dmitry Monakhov]

Pipe has no data associated with fs so it is not good idea to block
pipe_write() if FS is frozen, but we can not update file's time on such
filesystem. Let's use same idea as we use in touch_atime().

https://bugzilla.kernel.org/show_bug.cgi?id=65701

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Reviewed-by: Jan Kara <jack@suse.cz>

---
 fs/pipe.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/fs/pipe.c b/fs/pipe.c
index d2c45e1..a9acd9a 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -663,10 +663,11 @@ out:
 		wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM);
 		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
 	}
-	if (ret > 0) {
+	if (ret > 0 && sb_start_write_trylock(file_inode(filp)->i_sb)) {
 		int err = file_update_time(filp);
 		if (err)
 			ret = err;
+		sb_end_write(file_inode(filp)->i_sb);
 	}
 	return ret;
 }
-- 
1.7.1

[PATCH] pipe: skip file_update_time on frozen fs

[Dmitry Monakhov]

Pipe has no data associated with fs so it is not good idea to block
pipe_write() if FS is frozen, but we can not update file's time on such
filesystem. Let's use same idea as we use in touch_time().

https://bugzilla.kernel.org/show_bug.cgi?id=65701

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
---
 fs/pipe.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/fs/pipe.c b/fs/pipe.c
index d2c45e1..a9acd9a 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -663,10 +663,11 @@ out:
 		wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM);
 		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
 	}
-	if (ret > 0) {
+	if (ret > 0 && sb_start_write_trylock(file_inode(filp)->i_sb)) {
 		int err = file_update_time(filp);
 		if (err)
 			ret = err;
+		sb_end_write(file_inode(filp)->i_sb);
 	}
 	return ret;
 }
-- 
1.7.1

Re: [PATCH] pipe: skip file_update_time on frozen fs

[Jan Kara]

On Mon 25-11-13 13:43:23, Dmitry Monakhov wrote:
> Pipe has no data associated with fs so it is not good idea to block
> pipe_write() if FS is frozen, but we can not update file's time on such
> filesystem. Let's use same idea as we use in touch_time().
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=65701
> 
> Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
  Looks good. You can add:
Reviewed-by: Jan Kara <jack@suse.cz>

  BTW, please send it to Al Viro. He should be the right guy to merge the
patch and I don't think he is scanning mailing lists for fixes often...

									Honza
> ---
>  fs/pipe.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/fs/pipe.c b/fs/pipe.c
> index d2c45e1..a9acd9a 100644
> --- a/fs/pipe.c
> +++ b/fs/pipe.c
> @@ -663,10 +663,11 @@ out:
>  		wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM);
>  		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
>  	}
> -	if (ret > 0) {
> +	if (ret > 0 && sb_start_write_trylock(file_inode(filp)->i_sb)) {
>  		int err = file_update_time(filp);
>  		if (err)
>  			ret = err;
> +		sb_end_write(file_inode(filp)->i_sb);
>  	}
>  	return ret;
>  }
> -- 
> 1.7.1
> 
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-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR