2009-05-25 07:02:13

by Suresh Jayaraman

[permalink] [raw]
Subject: [PATCH] [RESEND] nfs: add support for splice writes

Adds support for splice writes. It effectively calls
generic_file_splice_write() to do the writes.

We need not worry about O_APPEND case as the combination of splice()
writes and O_APPEND is disallowed. This patch propagates NFS write
errors back to the caller. The number of bytes written via splice are
being added to NFSIO_NORMALWRITTENBYTES as these are effectively
cached writes.

Signed-off-by: Suresh Jayaraman <[email protected]>
---
fs/nfs/file.c | 31 +++++++++++++++++++++++++++++++
1 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index ec7e27d..3f80c5e 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -48,6 +48,9 @@ static ssize_t nfs_file_splice_read(struct file *filp, loff_t *ppos,
size_t count, unsigned int flags);
static ssize_t nfs_file_read(struct kiocb *, const struct iovec *iov,
unsigned long nr_segs, loff_t pos);
+static ssize_t nfs_file_splice_write(struct pipe_inode_info *pipe,
+ struct file *filp, loff_t *ppos,
+ size_t count, unsigned int flags);
static ssize_t nfs_file_write(struct kiocb *, const struct iovec *iov,
unsigned long nr_segs, loff_t pos);
static int nfs_file_flush(struct file *, fl_owner_t id);
@@ -73,6 +76,7 @@ const struct file_operations nfs_file_operations = {
.lock = nfs_lock,
.flock = nfs_flock,
.splice_read = nfs_file_splice_read,
+ .splice_write = nfs_file_splice_write,
.check_flags = nfs_check_flags,
.setlease = nfs_setlease,
};
@@ -587,6 +591,33 @@ out_swapfile:
goto out;
}

+static ssize_t nfs_file_splice_write(struct pipe_inode_info *pipe,
+ struct file *filp, loff_t *ppos,
+ size_t count, unsigned int flags)
+{
+ struct dentry *dentry = filp->f_path.dentry;
+ struct inode *inode = dentry->d_inode;
+ ssize_t ret;
+
+ dprintk("NFS splice_write(%s/%s, %lu@%llu)\n",
+ dentry->d_parent->d_name.name, dentry->d_name.name,
+ (unsigned long) count, (unsigned long long) *ppos);
+
+ /*
+ * The combination of splice and an O_APPEND destination is disallowed.
+ */
+
+ nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count);
+
+ ret = generic_file_splice_write(pipe, filp, ppos, count, flags);
+ if (ret >= 0 && nfs_need_sync_write(filp, inode)) {
+ int err = nfs_do_fsync(nfs_file_open_context(filp), inode);
+ if (err < 0)
+ ret = err;
+ }
+ return ret;
+}
+
static int do_getlk(struct file *filp, int cmd, struct file_lock *fl)
{
struct inode *inode = filp->f_mapping->host;


2009-05-25 16:59:54

by Myklebust, Trond

[permalink] [raw]
Subject: Re: [PATCH] [RESEND] nfs: add support for splice writes

On Mon, 2009-05-25 at 12:32 +0530, Suresh Jayaraman wrote:
> Adds support for splice writes. It effectively calls
> generic_file_splice_write() to do the writes.
>
> We need not worry about O_APPEND case as the combination of splice()
> writes and O_APPEND is disallowed. This patch propagates NFS write
> errors back to the caller. The number of bytes written via splice are
> being added to NFSIO_NORMALWRITTENBYTES as these are effectively
> cached writes.
>
> Signed-off-by: Suresh Jayaraman <[email protected]>
> ---
> fs/nfs/file.c | 31 +++++++++++++++++++++++++++++++
> 1 files changed, 31 insertions(+), 0 deletions(-)
>
> diff --git a/fs/nfs/file.c b/fs/nfs/file.c
> index ec7e27d..3f80c5e 100644
> --- a/fs/nfs/file.c
> +++ b/fs/nfs/file.c
> @@ -48,6 +48,9 @@ static ssize_t nfs_file_splice_read(struct file *filp, loff_t *ppos,
> size_t count, unsigned int flags);
> static ssize_t nfs_file_read(struct kiocb *, const struct iovec *iov,
> unsigned long nr_segs, loff_t pos);
> +static ssize_t nfs_file_splice_write(struct pipe_inode_info *pipe,
> + struct file *filp, loff_t *ppos,
> + size_t count, unsigned int flags);
> static ssize_t nfs_file_write(struct kiocb *, const struct iovec *iov,
> unsigned long nr_segs, loff_t pos);
> static int nfs_file_flush(struct file *, fl_owner_t id);
> @@ -73,6 +76,7 @@ const struct file_operations nfs_file_operations = {
> .lock = nfs_lock,
> .flock = nfs_flock,
> .splice_read = nfs_file_splice_read,
> + .splice_write = nfs_file_splice_write,
> .check_flags = nfs_check_flags,
> .setlease = nfs_setlease,
> };
> @@ -587,6 +591,33 @@ out_swapfile:
> goto out;
> }
>
> +static ssize_t nfs_file_splice_write(struct pipe_inode_info *pipe,
> + struct file *filp, loff_t *ppos,
> + size_t count, unsigned int flags)
> +{
> + struct dentry *dentry = filp->f_path.dentry;
> + struct inode *inode = dentry->d_inode;
> + ssize_t ret;
> +
> + dprintk("NFS splice_write(%s/%s, %lu@%llu)\n",
> + dentry->d_parent->d_name.name, dentry->d_name.name,
> + (unsigned long) count, (unsigned long long) *ppos);
> +
> + /*
> + * The combination of splice and an O_APPEND destination is disallowed.
> + */
> +
> + nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count);
> +
> + ret = generic_file_splice_write(pipe, filp, ppos, count, flags);
> + if (ret >= 0 && nfs_need_sync_write(filp, inode)) {
> + int err = nfs_do_fsync(nfs_file_open_context(filp), inode);
> + if (err < 0)
> + ret = err;
> + }
> + return ret;
> +}
> +
> static int do_getlk(struct file *filp, int cmd, struct file_lock *fl)
> {
> struct inode *inode = filp->f_mapping->host;

Thanks Suresh! That patch looks good...

Cheers
Trond
--
Trond Myklebust
Linux NFS client maintainer

NetApp
[email protected]
http://www.netapp.com