[PATCH] Vectorize aio_read/aio_write fileop methods

This patch vectorizes aio_read() and aio_write() methods to prepare for
collapsing all aio & vectored operations into one interface - which is
aio_read()/aio_write().

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Michael Holzheu <HOLZHEU@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 38 insertions, 22 deletions

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 377839bed17..9f7f8b9ea1e 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -707,8 +707,8 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, siz
 /**
  * nfs_file_direct_read - file direct read operation for NFS files
  * @iocb: target I/O control block
- * @buf: user's buffer into which to read data
- * @count: number of bytes to read
+ * @iov: vector of user buffers into which to read data
+ * @nr_segs: size of iov vector
  * @pos: byte offset in file where reading starts
  *
  * We use this function for direct reads instead of calling
@@ -725,17 +725,24 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, siz
  * client must read the updated atime from the server back into its
  * cache.
  */
-ssize_t nfs_file_direct_read(struct kiocb *iocb, char __user *buf, size_t count, loff_t pos)
+ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov,
+				unsigned long nr_segs, loff_t pos)
 {
 	ssize_t retval = -EINVAL;
 	struct file *file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;
+	/* XXX: temporary */
+	const char __user *buf = iov[0].iov_base;
+	size_t count = iov[0].iov_len;
 
 	dprintk("nfs: direct read(%s/%s, %lu@%Ld)\n",
 		file->f_dentry->d_parent->d_name.name,
 		file->f_dentry->d_name.name,
 		(unsigned long) count, (long long) pos);
 
+	if (nr_segs != 1)
+		return -EINVAL;
+
 	if (count < 0)
 		goto out;
 	retval = -EFAULT;
@@ -760,8 +767,8 @@ out:
 /**
  * nfs_file_direct_write - file direct write operation for NFS files
  * @iocb: target I/O control block
- * @buf: user's buffer from which to write data
- * @count: number of bytes to write
+ * @iov: vector of user buffers from which to write data
+ * @nr_segs: size of iov vector
  * @pos: byte offset in file where writing starts
  *
  * We use this function for direct writes instead of calling
@@ -782,17 +789,24 @@ out:
  * Note that O_APPEND is not supported for NFS direct writes, as there
  * is no atomic O_APPEND write facility in the NFS protocol.
  */
-ssize_t nfs_file_direct_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos)
+ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
+				unsigned long nr_segs, loff_t pos)
 {
 	ssize_t retval;
 	struct file *file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;
+	/* XXX: temporary */
+	const char __user *buf = iov[0].iov_base;
+	size_t count = iov[0].iov_len;
 
 	dfprintk(VFS, "nfs: direct write(%s/%s, %lu@%Ld)\n",
 		file->f_dentry->d_parent->d_name.name,
 		file->f_dentry->d_name.name,
 		(unsigned long) count, (long long) pos);
 
+	if (nr_segs != 1)
+		return -EINVAL;
+
 	retval = generic_write_checks(file, &pos, &count, 0);
 	if (retval)
 		goto out;
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index be997d64912..cc93865cea9 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -41,8 +41,10 @@ static int nfs_file_release(struct inode *, struct file *);
 static loff_t nfs_file_llseek(struct file *file, loff_t offset, int origin);
 static int  nfs_file_mmap(struct file *, struct vm_area_struct *);
 static ssize_t nfs_file_sendfile(struct file *, loff_t *, size_t, read_actor_t, void *);
-static ssize_t nfs_file_read(struct kiocb *, char __user *, size_t, loff_t);
-static ssize_t nfs_file_write(struct kiocb *, const char __user *, size_t, loff_t);
+static ssize_t nfs_file_read(struct kiocb *, const struct iovec *iov,
+				unsigned long nr_segs, loff_t pos);
+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);
 static int  nfs_fsync(struct file *, struct dentry *dentry, int datasync);
 static int nfs_check_flags(int flags);
@@ -53,8 +55,8 @@ const struct file_operations nfs_file_operations = {
 	.llseek		= nfs_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read		= nfs_file_read,
-	.aio_write		= nfs_file_write,
+	.aio_read	= nfs_file_read,
+	.aio_write	= nfs_file_write,
 	.mmap		= nfs_file_mmap,
 	.open		= nfs_file_open,
 	.flush		= nfs_file_flush,
@@ -196,15 +198,17 @@ nfs_file_flush(struct file *file, fl_owner_t id)
 }
 
 static ssize_t
-nfs_file_read(struct kiocb *iocb, char __user * buf, size_t count, loff_t pos)
+nfs_file_read(struct kiocb *iocb, const struct iovec *iov,
+		unsigned long nr_segs, loff_t pos)
 {
 	struct dentry * dentry = iocb->ki_filp->f_dentry;
 	struct inode * inode = dentry->d_inode;
 	ssize_t result;
+	size_t count = iov_length(iov, nr_segs);
 
 #ifdef CONFIG_NFS_DIRECTIO
 	if (iocb->ki_filp->f_flags & O_DIRECT)
-		return nfs_file_direct_read(iocb, buf, count, pos);
+		return nfs_file_direct_read(iocb, iov, nr_segs, pos);
 #endif
 
 	dfprintk(VFS, "nfs: read(%s/%s, %lu@%lu)\n",
@@ -214,7 +218,7 @@ nfs_file_read(struct kiocb *iocb, char __user * buf, size_t count, loff_t pos)
 	result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping);
 	nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, count);
 	if (!result)
-		result = generic_file_aio_read(iocb, buf, count, pos);
+		result = generic_file_aio_read(iocb, iov, nr_segs, pos);
 	return result;
 }
 
@@ -336,24 +340,22 @@ const struct address_space_operations nfs_file_aops = {
 #endif
 };
 
-/* 
- * Write to a file (through the page cache).
- */
-static ssize_t
-nfs_file_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos)
+static ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
+				unsigned long nr_segs, loff_t pos)
 {
 	struct dentry * dentry = iocb->ki_filp->f_dentry;
 	struct inode * inode = dentry->d_inode;
 	ssize_t result;
+	size_t count = iov_length(iov, nr_segs);
 
 #ifdef CONFIG_NFS_DIRECTIO
 	if (iocb->ki_filp->f_flags & O_DIRECT)
-		return nfs_file_direct_write(iocb, buf, count, pos);
+		return nfs_file_direct_write(iocb, iov, nr_segs, pos);
 #endif
 
-	dfprintk(VFS, "nfs: write(%s/%s(%ld), %lu@%lu)\n",
+	dfprintk(VFS, "nfs: write(%s/%s(%ld), %lu@%Ld)\n",
 		dentry->d_parent->d_name.name, dentry->d_name.name,
-		inode->i_ino, (unsigned long) count, (unsigned long) pos);
+		inode->i_ino, (unsigned long) count, (long long) pos);
 
 	result = -EBUSY;
 	if (IS_SWAPFILE(inode))
@@ -372,7 +374,7 @@ nfs_file_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t
 		goto out;
 
 	nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count);
-	result = generic_file_aio_write(iocb, buf, count, pos);
+	result = generic_file_aio_write(iocb, iov, nr_segs, pos);
 out:
 	return result;