Commit fbe10494 authored by Zheng Liu's avatar Zheng Liu Committed by Theodore Ts'o

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: default avatarZheng Liu <wenqing.lz@taobao.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 62a1391d
......@@ -90,34 +90,16 @@ ext4_unaligned_aio(struct inode *inode, const struct iovec *iov,
}
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 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
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,
......
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