2015-02-28 04:16:20

by Trond Myklebust

Subject: [PATCH] NFS: Ensure that buffered writes wait for O_DIRECT writes to complete

The O_DIRECT code will grab the inode->i_mutex and flush out buffered
writes, before scheduling a read or a write. However there is no
equivalent in the buffered write code to wait for O_DIRECT to complete.

Fixes a reported issue in xfstests generic/133, when first performing an
O_DIRECT write followed by a buffered write.

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/file.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 94712fc781fa..c045c7169fa0 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -372,6 +372,10 @@ start:
nfs_wait_bit_killable, TASK_KILLABLE);
if (ret)
return ret;
+ /*
+ * Wait for O_DIRECT to complete
+ */
+ nfs_inode_dio_wait(mapping->host);

page = grab_cache_page_write_begin(mapping, index, flags);
if (!page)
--
2.1.0

2015-03-02 21:05:08

by Weston Andros Adamson

Subject: Re: [PATCH] NFS: Ensure that buffered writes wait for O_DIRECT writes to complete

Looks good to me.

-dros



> On Feb 27, 2015, at 11:16 PM, Trond Myklebust <[email protected]> wrote:
>
> The O_DIRECT code will grab the inode->i_mutex and flush out buffered
> writes, before scheduling a read or a write. However there is no
> equivalent in the buffered write code to wait for O_DIRECT to complete.
>
> Fixes a reported issue in xfstests generic/133, when first performing an
> O_DIRECT write followed by a buffered write.
>
> Signed-off-by: Trond Myklebust <[email protected]>
> ---
> fs/nfs/file.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/fs/nfs/file.c b/fs/nfs/file.c
> index 94712fc781fa..c045c7169fa0 100644
> --- a/fs/nfs/file.c
> +++ b/fs/nfs/file.c
> @@ -372,6 +372,10 @@ start:
> nfs_wait_bit_killable, TASK_KILLABLE);
> if (ret)
> return ret;
> + /*
> + * Wait for O_DIRECT to complete
> + */
> + nfs_inode_dio_wait(mapping->host);
>
> page = grab_cache_page_write_begin(mapping, index, flags);
> if (!page)
> --
> 2.1.0
>
> --
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