ext4: split ext4_file_write into buffered IO and direct IO
ext4_file_dio_write is defined in order to split buffered IO and
direct IO in ext4. This patch just refactor some stuff in write path.
CC: Tao Ma <tm@tao.ma>
CC: Eric Sandeen <sandeen@redhat.com>
CC: Robin Dong <hao.bigrat@gmail.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 8c7642a..a10dc77 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -90,34 +90,16 @@
}
static ssize_t
-ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos)
+ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
{
struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
int unaligned_aio = 0;
ssize_t ret;
- /*
- * If we have encountered a bitmap-format file, the size limit
- * is smaller than s_maxbytes, which is for extent-mapped files.
- */
-
- if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
- struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
- size_t length = iov_length(iov, nr_segs);
-
- if ((pos > sbi->s_bitmap_maxbytes ||
- (pos == sbi->s_bitmap_maxbytes && length > 0)))
- return -EFBIG;
-
- if (pos + length > sbi->s_bitmap_maxbytes) {
- nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
- sbi->s_bitmap_maxbytes - pos);
- }
- } else if (unlikely((iocb->ki_filp->f_flags & O_DIRECT) &&
- !is_sync_kiocb(iocb))) {
+ if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
+ !is_sync_kiocb(iocb))
unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos);
- }
/* Unaligned direct AIO must be serialized; see comment above */
if (unaligned_aio) {
@@ -141,6 +123,40 @@
return ret;
}
+static ssize_t
+ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
+{
+ struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
+ ssize_t ret;
+
+ /*
+ * If we have encountered a bitmap-format file, the size limit
+ * is smaller than s_maxbytes, which is for extent-mapped files.
+ */
+
+ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ size_t length = iov_length(iov, nr_segs);
+
+ if ((pos > sbi->s_bitmap_maxbytes ||
+ (pos == sbi->s_bitmap_maxbytes && length > 0)))
+ return -EFBIG;
+
+ if (pos + length > sbi->s_bitmap_maxbytes) {
+ nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
+ sbi->s_bitmap_maxbytes - pos);
+ }
+ }
+
+ if (unlikely(iocb->ki_filp->f_flags & O_DIRECT))
+ ret = ext4_file_dio_write(iocb, iov, nr_segs, pos);
+ else
+ ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
+
+ return ret;
+}
+
static const struct vm_operations_struct ext4_file_vm_ops = {
.fault = filemap_fault,
.page_mkwrite = ext4_page_mkwrite,