2 files changed, 36 insertions, 62 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index e472441..1f2b99c 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -448,7 +448,7 @@ 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;
 
@@ -1675,27 +1675,22 @@ again:
 }
 
 static ssize_t __btrfs_direct_write(struct kiocb *iocb,
-				    const struct iovec *iov,
-				    unsigned long nr_segs, loff_t pos,
-				    size_t count, size_t ocount)
+				    struct iov_iter *from,
+				    loff_t pos)
 {
 	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,
-					    count, ocount);
+	written = generic_file_direct_write(iocb, from, pos);
 
-	if (written < 0 || written == count)
+	if (written < 0 || !iov_iter_count(from))
 		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, from, pos);
 	if (written_buffered < 0) {
 		err = written_buffered;
 		goto out;
@@ -1730,9 +1725,8 @@ 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 *from)
 {
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file_inode(file);
@@ -1741,18 +1735,12 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
 	u64 end_pos;
 	ssize_t num_written = 0;
 	ssize_t err = 0;
-	size_t count, ocount;
+	size_t count = iov_iter_count(from);
 	bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
+	loff_t pos = iocb->ki_pos;
 
 	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;
-
 	current->backing_dev_info = inode->i_mapping->backing_dev_info;
 	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
 	if (err) {
@@ -1765,6 +1753,8 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
 		goto out;
 	}
 
+	iov_iter_truncate(from, count);
+
 	err = file_remove_suid(file);
 	if (err) {
 		mutex_unlock(&inode->i_mutex);
@@ -1806,14 +1796,9 @@ 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, count, ocount);
+		num_written = __btrfs_direct_write(iocb, from, pos);
 	} 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, from, pos);
 		if (num_written > 0)
 			iocb->ki_pos = pos + num_written;
 	}
@@ -2740,11 +2725,11 @@ out:
 
 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,
+	.read		= new_sync_read,
+	.write		= new_sync_write,
+	.read_iter      = generic_file_read_iter,
 	.splice_read	= generic_file_splice_read,
-	.aio_write	= btrfs_file_aio_write,
+	.write_iter	= btrfs_file_write_iter,
 	.mmap		= btrfs_file_mmap,
 	.open		= generic_file_open,
 	.release	= btrfs_release_file,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7fa5f7f..8925f66 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7445,39 +7445,30 @@ free_ordered:
 }
 
 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
-			const struct iovec *iov, loff_t offset,
-			unsigned long nr_segs)
+			const struct iov_iter *iter, loff_t offset)
 {
 	int seg;
 	int i;
-	size_t size;
-	unsigned long addr;
 	unsigned blocksize_mask = root->sectorsize - 1;
 	ssize_t retval = -EINVAL;
-	loff_t end = offset;
 
 	if (offset & blocksize_mask)
 		goto out;
 
-	/* Check the memory alignment.  Blocks cannot straddle pages */
-	for (seg = 0; seg < nr_segs; seg++) {
-		addr = (unsigned long)iov[seg].iov_base;
-		size = iov[seg].iov_len;
-		end += size;
-		if ((addr & blocksize_mask) || (size & blocksize_mask))
-			goto out;
-
-		/* If this is a write we don't need to check anymore */
-		if (rw & WRITE)
-			continue;
+	if (iov_iter_alignment(iter) & blocksize_mask)
+		goto out;
 
-		/*
-		 * Check to make sure we don't have duplicate iov_base's in this
-		 * iovec, if so return EINVAL, otherwise we'll get csum errors
-		 * when reading back.
-		 */
-		for (i = seg + 1; i < nr_segs; i++) {
-			if (iov[seg].iov_base == iov[i].iov_base)
+	/* If this is a write we don't need to check anymore */
+	if (rw & WRITE)
+		return 0;
+	/*
+	 * Check to make sure we don't have duplicate iov_base's in this
+	 * iovec, if so return EINVAL, otherwise we'll get csum errors
+	 * when reading back.
+	 */
+	for (seg = 0; seg < iter->nr_segs; seg++) {
+		for (i = seg + 1; i < iter->nr_segs; i++) {
+			if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
 				goto out;
 		}
 	}
@@ -7487,8 +7478,7 @@ out:
 }
 
 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
-			const struct iovec *iov, loff_t offset,
-			unsigned long nr_segs)
+			struct iov_iter *iter, loff_t offset)
 {
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file->f_mapping->host;
@@ -7498,8 +7488,7 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
 	bool relock = false;
 	ssize_t ret;
 
-	if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
-			    offset, nr_segs))
+	if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iter, offset))
 		return 0;
 
 	atomic_inc(&inode->i_dio_count);
@@ -7511,7 +7500,7 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
 	 * we need to flush the dirty pages again to make absolutely sure
 	 * that any outstanding dirty pages are on disk.
 	 */
-	count = iov_length(iov, nr_segs);
+	count = iov_iter_count(iter);
 	if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
 		     &BTRFS_I(inode)->runtime_flags))
 		filemap_fdatawrite_range(inode->i_mapping, offset, count);
@@ -7538,7 +7527,7 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
 
 	ret = __blockdev_direct_IO(rw, iocb, inode,
 			BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
-			iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
+			iter, offset, btrfs_get_blocks_direct, NULL,
 			btrfs_submit_direct, flags);
 	if (rw & WRITE) {
 		if (ret < 0 && ret != -EIOCBQUEUED)