2015-09-04 19:24:11

by Trond Myklebust

Subject: [PATCH 1/2] NFS: Optimise away the close-to-open getattr if there is no cached data

If there is no cached data, then there is no need to track the file
change attribute on close.

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/inode.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 99a68bd9c178..ebaf991e4b02 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -766,6 +766,7 @@ EXPORT_SYMBOL_GPL(nfs_put_lock_context);
*/
void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
{
+ struct nfs_inode *nfsi;
struct inode *inode;
struct nfs_server *server;

@@ -774,7 +775,12 @@ void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
if (!is_sync)
return;
inode = d_inode(ctx->dentry);
- if (!list_empty(&NFS_I(inode)->open_files))
+ nfsi = NFS_I(inode);
+ if (inode->i_mapping->nrpages == 0)
+ return;
+ if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
+ return;
+ if (!list_empty(&nfsi->open_files))
return;
server = NFS_SERVER(inode);
if (server->flags & NFS_MOUNT_NOCTO)
--
2.4.3

2015-09-04 19:24:12

by Trond Myklebust

Subject: [PATCH 2/2] Revert "NFS: Make close(2) asynchronous when closing NFS O_DIRECT files"

This reverts commit f895c53f8ace3c3e49ebf9def90e63fc6d46d2bf.

This commit causes a NFSv4 regression in that close()+unlink() can end
up failing. The reason is that we no longer have a guarantee that the
CLOSE has completed on the server, meaning that the subsequent call to
REMOVE may fail with NFS4ERR_FILE_OPEN if the server implements Windows
unlink() semantics.

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/inode.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index ebaf991e4b02..54eb47799a41 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -852,6 +852,11 @@ void put_nfs_open_context(struct nfs_open_context *ctx)
}
EXPORT_SYMBOL_GPL(put_nfs_open_context);

+static void put_nfs_open_context_sync(struct nfs_open_context *ctx)
+{
+ __put_nfs_open_context(ctx, 1);
+}
+
/*
* Ensure that mmap has a recent RPC credential for use when writing out
* shared pages
@@ -907,7 +912,7 @@ void nfs_file_clear_open_context(struct file *filp)
spin_lock(&inode->i_lock);
list_move_tail(&ctx->list, &NFS_I(inode)->open_files);
spin_unlock(&inode->i_lock);
- __put_nfs_open_context(ctx, filp->f_flags & O_DIRECT ? 0 : 1);
+ put_nfs_open_context_sync(ctx);
}
}

--
2.4.3

2015-09-04 19:38:38

by Chuck Lever III

Subject: Re: [PATCH 1/2] NFS: Optimise away the close-to-open getattr if there is no cached data

On Sep 4, 2015, at 3:24 PM, Trond Myklebust <[email protected]> wrote:

> If there is no cached data, then there is no need to track the file
> change attribute on close.

This makes sense. nfs_close_context() is only used by NFSv2
and NFSv3.

Should you update the documenting comment?


> Signed-off-by: Trond Myklebust <[email protected]>
> ---
> fs/nfs/inode.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
> index 99a68bd9c178..ebaf991e4b02 100644
> --- a/fs/nfs/inode.c
> +++ b/fs/nfs/inode.c
> @@ -766,6 +766,7 @@ EXPORT_SYMBOL_GPL(nfs_put_lock_context);
> */
> void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
> {
> + struct nfs_inode *nfsi;
> struct inode *inode;
> struct nfs_server *server;
>
> @@ -774,7 +775,12 @@ void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
> if (!is_sync)
> return;
> inode = d_inode(ctx->dentry);
> - if (!list_empty(&NFS_I(inode)->open_files))
> + nfsi = NFS_I(inode);
> + if (inode->i_mapping->nrpages == 0)
> + return;
> + if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
> + return;
> + if (!list_empty(&nfsi->open_files))
> return;
> server = NFS_SERVER(inode);
> if (server->flags & NFS_MOUNT_NOCTO)
> --
> 2.4.3
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

--
Chuck Lever

2015-09-04 20:39:45

by Trond Myklebust

Subject: Re: [PATCH 1/2] NFS: Optimise away the close-to-open getattr if there is no cached data

On Fri, Sep 4, 2015 at 3:38 PM, Chuck Lever <[email protected]> wrote:
>
> On Sep 4, 2015, at 3:24 PM, Trond Myklebust <[email protected]> wrote:
>
>> If there is no cached data, then there is no need to track the file
>> change attribute on close.
>
> This makes sense. nfs_close_context() is only used by NFSv2
> and NFSv3.
>
> Should you update the documenting comment?

Good point. I'll do that...