Commit 491a6d01 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
Browse files

btrfs: allocate dio_data on stack 



Make use of the new iomap_iter->private field to avoid a memory
allocation per iomap range.

Reviewed-by: default avatarNikolay Borisov <nborisov@suse.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 786f847f

fs/btrfs/inode.c

+11 −23
Original line number Diff line number Diff line
@@ -7546,10 +7546,11 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start, 
		loff_t length, unsigned int flags, struct iomap *iomap,

		struct iomap *srcmap)

{

	struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap);

	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);

	struct extent_map *em;

	struct extent_state *cached_state = NULL;

	struct btrfs_dio_data *dio_data = NULL;

	struct btrfs_dio_data *dio_data = iter->private;

	u64 lockstart, lockend;

	const bool write = !!(flags & IOMAP_WRITE);

	int ret = 0;
@@ -7595,17 +7596,7 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start, 
		}

	}



	if (flags & IOMAP_NOWAIT) {

		dio_data = kzalloc(sizeof(*dio_data), GFP_NOWAIT);

		if (!dio_data)

			return -EAGAIN;

	} else {

		dio_data = kzalloc(sizeof(*dio_data), GFP_NOFS);

		if (!dio_data)

			return -ENOMEM;

	}



	iomap->private = dio_data;

	memset(dio_data, 0, sizeof(*dio_data));



	/*

	 * We always try to allocate data space and must do it before locking
@@ -7769,23 +7760,22 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start, 
		extent_changeset_free(dio_data->data_reserved);

	}



	kfree(dio_data);



	return ret;

}



static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length,

		ssize_t written, unsigned int flags, struct iomap *iomap)

{

	int ret = 0;

	struct btrfs_dio_data *dio_data = iomap->private;

	struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap);

	struct btrfs_dio_data *dio_data = iter->private;

	size_t submitted = dio_data->submitted;

	const bool write = !!(flags & IOMAP_WRITE);

	int ret = 0;



	if (!write && (iomap->type == IOMAP_HOLE)) {

		/* If reading from a hole, unlock and return */

		unlock_extent(&BTRFS_I(inode)->io_tree, pos, pos + length - 1);

		goto out;

		return 0;

	}



	if (submitted < length) {
@@ -7802,10 +7792,6 @@ static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length, 


	if (write)

		extent_changeset_free(dio_data->data_reserved);

out:

	kfree(dio_data);

	iomap->private = NULL;



	return ret;

}
@@ -8041,7 +8027,7 @@ static void btrfs_submit_direct(const struct iomap_iter *iter, 
	int ret;

	blk_status_t status;

	struct btrfs_io_geometry geom;

	struct btrfs_dio_data *dio_data = iter->iomap.private;

	struct btrfs_dio_data *dio_data = iter->private;

	struct extent_map *em = NULL;



	dip = btrfs_create_dio_private(dio_bio, inode, file_offset);
@@ -8166,8 +8152,10 @@ static const struct iomap_dio_ops btrfs_dio_ops = { 


ssize_t btrfs_dio_rw(struct kiocb *iocb, struct iov_iter *iter, size_t done_before)

{

	struct btrfs_dio_data data;



	return iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dio_ops,

			    IOMAP_DIO_PARTIAL, NULL, done_before);

			    IOMAP_DIO_PARTIAL, &data, done_before);

}



static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,