Dave Kleikamp
2013-Oct-16 14:04 UTC
[PATCH V9 25/33] btrfs: add support for read_iter and write_iter
btrfs can use generic_file_read_iter(). Base btrfs_file_write_iter()
on btrfs_file_aio_write(), then have the latter call the former.
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: linux-btrfs@vger.kernel.org
---
fs/btrfs/file.c | 42 ++++++++++++++----------------------------
1 file changed, 14 insertions(+), 28 deletions(-)
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 72da4df..5e70fc2 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -453,7 +453,7 @@ static noinline int btrfs_copy_from_user(loff_t pos, int
num_pages,
write_bytes -= copied;
total_copied += copied;
- /* Return to btrfs_file_aio_write to fault page */
+ /* Return to btrfs_file_write_iter to fault page */
if (unlikely(copied == 0))
break;
@@ -1557,27 +1557,23 @@ static noinline ssize_t __btrfs_buffered_write(struct
file *file,
}
static ssize_t __btrfs_direct_write(struct kiocb *iocb,
- const struct iovec *iov,
- unsigned long nr_segs, loff_t pos,
- loff_t *ppos, size_t count, size_t ocount)
+ struct iov_iter *iter, loff_t pos,
+ loff_t *ppos, size_t count)
{
struct file *file = iocb->ki_filp;
- struct iov_iter i;
ssize_t written;
ssize_t written_buffered;
loff_t endbyte;
int err;
- written = generic_file_direct_write(iocb, iov, &nr_segs, pos, ppos,
- count, ocount);
+ written = generic_file_direct_write_iter(iocb, iter, pos, ppos, count);
if (written < 0 || written == count)
return written;
pos += written;
count -= written;
- iov_iter_init(&i, iov, nr_segs, count, written);
- written_buffered = __btrfs_buffered_write(file, &i, pos);
+ written_buffered = __btrfs_buffered_write(file, iter, pos);
if (written_buffered < 0) {
err = written_buffered;
goto out;
@@ -1612,9 +1608,8 @@ static void update_time_for_write(struct inode *inode)
inode_inc_iversion(inode);
}
-static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
- const struct iovec *iov,
- unsigned long nr_segs, loff_t pos)
+static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
+ struct iov_iter *iter, loff_t pos)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
@@ -1623,17 +1618,12 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
u64 start_pos;
ssize_t num_written = 0;
ssize_t err = 0;
- size_t count, ocount;
+ size_t count;
bool sync = (file->f_flags & O_DSYNC) ||
IS_SYNC(file->f_mapping->host);
mutex_lock(&inode->i_mutex);
- err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
- if (err) {
- mutex_unlock(&inode->i_mutex);
- goto out;
- }
- count = ocount;
+ count = iov_iter_count(iter);
current->backing_dev_info = inode->i_mapping->backing_dev_info;
err = generic_write_checks(file, &pos, &count,
S_ISBLK(inode->i_mode));
@@ -1686,14 +1676,10 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
atomic_inc(&BTRFS_I(inode)->sync_writers);
if (unlikely(file->f_flags & O_DIRECT)) {
- num_written = __btrfs_direct_write(iocb, iov, nr_segs,
- pos, ppos, count, ocount);
+ num_written = __btrfs_direct_write(iocb, iter, pos, ppos,
+ count);
} else {
- struct iov_iter i;
-
- iov_iter_init(&i, iov, nr_segs, count, num_written);
-
- num_written = __btrfs_buffered_write(file, &i, pos);
+ num_written = __btrfs_buffered_write(file, iter, pos);
if (num_written > 0)
*ppos = pos + num_written;
}
@@ -2552,9 +2538,9 @@ const struct file_operations btrfs_file_operations = {
.llseek = btrfs_file_llseek,
.read = do_sync_read,
.write = do_sync_write,
- .aio_read = generic_file_aio_read,
.splice_read = generic_file_splice_read,
- .aio_write = btrfs_file_aio_write,
+ .read_iter = generic_file_read_iter,
+ .write_iter = btrfs_file_write_iter,
.mmap = btrfs_file_mmap,
.open = generic_file_open,
.release = btrfs_release_file,
--
1.8.4