[PATCH] Streamline generic_file_* interfaces and filemap cleanups

This patch cleans up generic_file_*_read/write() interfaces.  Christoph
Hellwig gave me the idea for this clean ups.

In a nutshell, all filesystems should set .aio_read/.aio_write methods and use
do_sync_read/ do_sync_write() as their .read/.write methods.  This allows us
to cleanup all variants of generic_file_* routines.

Final available interfaces:

generic_file_aio_read() - read handler
generic_file_aio_write() - write handler
generic_file_aio_write_nolock() - no lock write handler

__generic_file_aio_write_nolock() - internal worker routine

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

1 files changed, 4 insertions, 83 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index 48497094ae83..ec469235985d 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1149,13 +1149,14 @@ success:
  * that can use the page cache directly.
  */
 ssize_t
-__generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
-		unsigned long nr_segs, loff_t *ppos)
+generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
+		unsigned long nr_segs, loff_t pos)
 {
 	struct file *filp = iocb->ki_filp;
 	ssize_t retval;
 	unsigned long seg;
 	size_t count;
+	loff_t *ppos = &iocb->ki_pos;
 
 	count = 0;
 	for (seg = 0; seg < nr_segs; seg++) {
@@ -1179,7 +1180,7 @@ __generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 
 	/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
 	if (filp->f_flags & O_DIRECT) {
-		loff_t pos = *ppos, size;
+		loff_t size;
 		struct address_space *mapping;
 		struct inode *inode;
 
@@ -1223,32 +1224,8 @@ __generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 out:
 	return retval;
 }
-EXPORT_SYMBOL(__generic_file_aio_read);
-
-ssize_t
-generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
-		unsigned long nr_segs, loff_t pos)
-{
-	BUG_ON(iocb->ki_pos != pos);
-	return __generic_file_aio_read(iocb, iov, nr_segs, &iocb->ki_pos);
-}
 EXPORT_SYMBOL(generic_file_aio_read);
 
-ssize_t
-generic_file_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
-{
-	struct iovec local_iov = { .iov_base = buf, .iov_len = count };
-	struct kiocb kiocb;
-	ssize_t ret;
-
-	init_sync_kiocb(&kiocb, filp);
-	ret = __generic_file_aio_read(&kiocb, &local_iov, 1, ppos);
-	if (-EIOCBQUEUED == ret)
-		ret = wait_on_sync_kiocb(&kiocb);
-	return ret;
-}
-EXPORT_SYMBOL(generic_file_read);
-
 int file_send_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size)
 {
 	ssize_t written;
@@ -2339,38 +2316,6 @@ ssize_t generic_file_aio_write_nolock(struct kiocb *iocb,
 }
 EXPORT_SYMBOL(generic_file_aio_write_nolock);
 
-static ssize_t
-__generic_file_write_nolock(struct file *file, const struct iovec *iov,
-				unsigned long nr_segs, loff_t *ppos)
-{
-	struct kiocb kiocb;
-	ssize_t ret;
-
-	init_sync_kiocb(&kiocb, file);
-	kiocb.ki_pos = *ppos;
-	ret = __generic_file_aio_write_nolock(&kiocb, iov, nr_segs, ppos);
-	if (-EIOCBQUEUED == ret)
-		ret = wait_on_sync_kiocb(&kiocb);
-	return ret;
-}
-
-ssize_t
-generic_file_write_nolock(struct file *file, const struct iovec *iov,
-				unsigned long nr_segs, loff_t *ppos)
-{
-	struct kiocb kiocb;
-	ssize_t ret;
-
-	init_sync_kiocb(&kiocb, file);
-	kiocb.ki_pos = *ppos;
-	ret = generic_file_aio_write_nolock(&kiocb, iov, nr_segs, *ppos);
-	if (-EIOCBQUEUED == ret)
-		ret = wait_on_sync_kiocb(&kiocb);
-	*ppos = kiocb.ki_pos;
-	return ret;
-}
-EXPORT_SYMBOL(generic_file_write_nolock);
-
 ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 		unsigned long nr_segs, loff_t pos)
 {
@@ -2397,30 +2342,6 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 }
 EXPORT_SYMBOL(generic_file_aio_write);
 
-ssize_t generic_file_write(struct file *file, const char __user *buf,
-			   size_t count, loff_t *ppos)
-{
-	struct address_space *mapping = file->f_mapping;
-	struct inode *inode = mapping->host;
-	ssize_t	ret;
-	struct iovec local_iov = { .iov_base = (void __user *)buf,
-					.iov_len = count };
-
-	mutex_lock(&inode->i_mutex);
-	ret = __generic_file_write_nolock(file, &local_iov, 1, ppos);
-	mutex_unlock(&inode->i_mutex);
-
-	if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
-		ssize_t err;
-
-		err = sync_page_range(inode, mapping, *ppos - ret, ret);
-		if (err < 0)
-			ret = err;
-	}
-	return ret;
-}
-EXPORT_SYMBOL(generic_file_write);
-
 /*
  * Called under i_mutex for writes to S_ISREG files.   Returns -EIO if something
  * went wrong during pagecache shootdown.