Commit 26ce9114 authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: make can_nocow_extent nowait compatible 



If we have NOWAIT specified on our IOCB and we're writing into a
PREALLOC or NOCOW extent then we need to be able to tell
can_nocow_extent that we don't want to wait on any locks or metadata IO.
Fix can_nocow_extent to allow for NOWAIT.

Reviewed-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarStefan Roesch <shr@fb.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 857bc13f

fs/btrfs/ctree.h

+3 −2
Original line number Diff line number Diff line
@@ -3330,7 +3330,8 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans, 
blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,

				u64 offset, bool one_ordered);

int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,

			     struct list_head *list, int search_commit);

			     struct list_head *list, int search_commit,

			     bool nowait);

void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,

				     const struct btrfs_path *path,

				     struct btrfs_file_extent_item *fi,
@@ -3358,7 +3359,7 @@ int btrfs_check_data_csum(struct inode *inode, struct btrfs_bio *bbio, 
			  u32 bio_offset, struct page *page, u32 pgoff);

noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,

			      u64 *orig_start, u64 *orig_block_len,

			      u64 *ram_bytes, bool strict);

			      u64 *ram_bytes, bool nowait, bool strict);



void __btrfs_del_delalloc_inode(struct btrfs_root *root,

				struct btrfs_inode *inode);

fs/btrfs/extent-tree.c

+6 −0
Original line number Diff line number Diff line
@@ -2220,6 +2220,12 @@ static noinline int check_delayed_ref(struct btrfs_root *root, 
	}



	if (!mutex_trylock(&head->mutex)) {

		if (path->nowait) {

			spin_unlock(&delayed_refs->lock);

			btrfs_put_transaction(cur_trans);

			return -EAGAIN;

		}



		refcount_inc(&head->refs);

		spin_unlock(&delayed_refs->lock);

fs/btrfs/file-item.c

+3 −1
Original line number Diff line number Diff line
@@ -511,7 +511,8 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst 
}



int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,

			     struct list_head *list, int search_commit)

			     struct list_head *list, int search_commit,

			     bool nowait)

{

	struct btrfs_fs_info *fs_info = root->fs_info;

	struct btrfs_key key;
@@ -533,6 +534,7 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end, 
	if (!path)

		return -ENOMEM;



	path->nowait = nowait;

	if (search_commit) {

		path->skip_locking = 1;

		path->reada = READA_FORWARD;

fs/btrfs/file.c

+1 −1
Original line number Diff line number Diff line
@@ -1501,7 +1501,7 @@ int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos, 


	btrfs_lock_and_flush_ordered_range(inode, lockstart, lockend, NULL);

	ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,

			NULL, NULL, NULL, false);

			NULL, NULL, NULL, false, false);

	if (ret <= 0) {

		ret = 0;

		btrfs_drew_write_unlock(&root->snapshot_lock);

fs/btrfs/inode.c

+10 −6
Original line number Diff line number Diff line
@@ -1666,7 +1666,7 @@ static noinline int run_delalloc_zoned(struct btrfs_inode *inode, 
}



static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,

					u64 bytenr, u64 num_bytes)

					u64 bytenr, u64 num_bytes, bool nowait)

{

	struct btrfs_root *csum_root = btrfs_csum_root(fs_info, bytenr);

	struct btrfs_ordered_sum *sums;
@@ -1674,7 +1674,8 @@ static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info, 
	LIST_HEAD(list);



	ret = btrfs_lookup_csums_range(csum_root, bytenr,

				       bytenr + num_bytes - 1, &list, 0);

				       bytenr + num_bytes - 1, &list, 0,

				       nowait);

	if (ret == 0 && list_empty(&list))

		return 0;
@@ -1800,6 +1801,7 @@ static int can_nocow_file_extent(struct btrfs_path *path, 
	u8 extent_type;

	int can_nocow = 0;

	int ret = 0;

	bool nowait = path->nowait;



	fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item);

	extent_type = btrfs_file_extent_type(leaf, fi);
@@ -1876,7 +1878,8 @@ static int can_nocow_file_extent(struct btrfs_path *path, 
	 * Force COW if csums exist in the range. This ensures that csums for a

	 * given extent are either valid or do not exist.

	 */

	ret = csum_exist_in_range(root->fs_info, args->disk_bytenr, args->num_bytes);

	ret = csum_exist_in_range(root->fs_info, args->disk_bytenr, args->num_bytes,

				  nowait);

	WARN_ON_ONCE(ret > 0 && is_freespace_inode);

	if (ret != 0)

		goto out;
@@ -7167,7 +7170,7 @@ static bool btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr) 
 */

noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,

			      u64 *orig_start, u64 *orig_block_len,

			      u64 *ram_bytes, bool strict)

			      u64 *ram_bytes, bool nowait, bool strict)

{

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

	struct can_nocow_file_extent_args nocow_args = { 0 };
@@ -7183,6 +7186,7 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, 
	path = btrfs_alloc_path();

	if (!path)

		return -ENOMEM;

	path->nowait = nowait;



	ret = btrfs_lookup_file_extent(NULL, root, path,

			btrfs_ino(BTRFS_I(inode)), offset, 0);
@@ -7452,7 +7456,7 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map, 
		block_start = em->block_start + (start - em->start);



		if (can_nocow_extent(inode, start, &len, &orig_start,

				     &orig_block_len, &ram_bytes, false) == 1) {

				     &orig_block_len, &ram_bytes, false, false) == 1) {

			bg = btrfs_inc_nocow_writers(fs_info, block_start);

			if (bg)

				can_nocow = true;
@@ -11135,7 +11139,7 @@ static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file, 
		free_extent_map(em);

		em = NULL;



		ret = can_nocow_extent(inode, start, &len, NULL, NULL, NULL, true);

		ret = can_nocow_extent(inode, start, &len, NULL, NULL, NULL, false, true);

		if (ret < 0) {

			goto out;

		} else if (ret) {