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>
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 52ed567..0055b81 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -48,6 +48,9 @@
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 @@
.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 @@
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;