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 <sjayaraman@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Suresh Jayaraman 2009-06-17 18:02:09 -07:00 committed by Trond Myklebust
parent 5cd973c44a
commit bf40d3435c

View file

@ -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;