[PATCH 1/8] fs: Export generic_file_buffered_read()

Goldwyn Rodrigues
2019-12-10T23:02:15Z

From: Goldwyn Rodrigues <rgoldwyn@suse.com>

Export generic_file_buffered_read() to be used to
supplement incomplete direct reads.

While we are at it, correct the comments and variable names.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
include/linux/fs.h | 2 ++
mm/filemap.c | 13 +++++++------
2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 98e0349adb52..3883adaa0e01 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3098,6 +3098,8 @@ extern int generic_file_rw_checks(struct file *file_in, struct file *file_out);
extern int generic_copy_file_checks(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
size_t *count, unsigned int flags);
+extern ssize_t generic_file_buffered_read(struct kiocb *iocb,
+ struct iov_iter *to, ssize_t already_read);
extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);
extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
diff --git a/mm/filemap.c b/mm/filemap.c
index bf6aa30be58d..dc2c7e3472a0 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1994,7 +1994,7 @@ static void shrink_readahead_size_eio(struct file *filp,
* generic_file_buffered_read - generic file read routine
* @iocb: the iocb to read
* @iter: data destination
- * @written: already copied
+ * @copied: already copied
*
* This is a generic file read routine, and uses the
* mapping->a_ops->readpage() function for the actual low-level stuff.
@@ -2003,11 +2003,11 @@ static void shrink_readahead_size_eio(struct file *filp,
* of the logic when it comes to error handling etc.
*
* Return:
- * * total number of bytes copied, including those the were already @written
+ * * total number of bytes copied, including those that were @copied
* * negative error code if nothing was copied
*/
-static ssize_t generic_file_buffered_read(struct kiocb *iocb,
- struct iov_iter *iter, ssize_t written)
+ssize_t generic_file_buffered_read(struct kiocb *iocb,
+ struct iov_iter *iter, ssize_t copied)
{
struct file *filp = iocb->ki_filp;
struct address_space *mapping = filp->f_mapping;
@@ -2148,7 +2148,7 @@ static ssize_t generic_file_buffered_read(struct kiocb *iocb,
prev_offset = offset;

put_page(page);
- written += ret;
+ copied += ret;
if (!iov_iter_count(iter))
goto out;
if (ret < nr) {
@@ -2256,8 +2256,9 @@ static ssize_t generic_file_buffered_read(struct kiocb *iocb,

*ppos = ((loff_t)index << PAGE_SHIFT) + offset;
file_accessed(filp);
- return written ? written : error;
+ return copied ? copied : error;
}
+EXPORT_SYMBOL_GPL(generic_file_buffered_read);

/**
* generic_file_read_iter - generic filesystem read routine
--
2.16.4