2014-11-04 21:26:41

by Fabian Frédérick

[permalink] [raw]
Subject: [PATCH V2 linux-next] fs/affs/file.c: adding support to O_DIRECT

Based on ext2_direct_IO

Tested with O_DIRECT file open and sysbench/mariadb with 1%
written queries improvement (update_non_index test) on a volume
created with mkaffs.

Cc: Al Viro <[email protected]>
Cc: Andrew Morton <[email protected]>
Signed-off-by: Fabian Frederick <[email protected]>
---
V2: Adding test results (suggested by Andrew Morton)

fs/affs/file.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/fs/affs/file.c b/fs/affs/file.c
index 8e51085..05005bd 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -12,6 +12,7 @@
* affs regular file handling primitives
*/

+#include <linux/aio.h>
#include "affs.h"

#if PAGE_SIZE < 4096
@@ -392,6 +393,22 @@ static void affs_write_failed(struct address_space *mapping, loff_t to)
}
}

+static ssize_t
+affs_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter,
+ loff_t offset)
+{
+ struct file *file = iocb->ki_filp;
+ struct address_space *mapping = file->f_mapping;
+ struct inode *inode = mapping->host;
+ size_t count = iov_iter_count(iter);
+ ssize_t ret;
+
+ ret = blockdev_direct_IO(rw, iocb, inode, iter, offset, affs_get_block);
+ if (ret < 0 && (rw & WRITE))
+ affs_write_failed(mapping, offset + count);
+ return ret;
+}
+
static int affs_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
@@ -418,6 +435,7 @@ const struct address_space_operations affs_aops = {
.writepage = affs_writepage,
.write_begin = affs_write_begin,
.write_end = generic_write_end,
+ .direct_IO = affs_direct_IO,
.bmap = _affs_bmap
};

--
1.9.3