Commit 80f9d241 authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: make btrfs_check_nocow_lock nowait compatible 



Now all the helpers that btrfs_check_nocow_lock uses handle nowait, add
a nowait flag to btrfs_check_nocow_lock so it can be used by the write
path.

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>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent d2c7a19f

fs/btrfs/ctree.h

+1 −1
Original line number Diff line number Diff line
@@ -3525,7 +3525,7 @@ int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages, 
		      struct extent_state **cached, bool noreserve);

int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end);

int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos,

			   size_t *write_bytes);

			   size_t *write_bytes, bool nowait);

void btrfs_check_nocow_unlock(struct btrfs_inode *inode);

bool btrfs_find_delalloc_in_range(struct btrfs_inode *inode, u64 start, u64 end,

				  u64 *delalloc_start_ret, u64 *delalloc_end_ret);

fs/btrfs/file.c

+22 −11
Original line number Diff line number Diff line
@@ -1480,7 +1480,7 @@ lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages, 
 * NOTE: Callers need to call btrfs_check_nocow_unlock() if we return > 0.

 */

int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos,

			   size_t *write_bytes)

			   size_t *write_bytes, bool nowait)

{

	struct btrfs_fs_info *fs_info = inode->root->fs_info;

	struct btrfs_root *root = inode->root;
@@ -1499,16 +1499,21 @@ int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos, 
			   fs_info->sectorsize) - 1;

	num_bytes = lockend - lockstart + 1;



	if (nowait) {

		if (!btrfs_try_lock_ordered_range(inode, lockstart, lockend)) {

			btrfs_drew_write_unlock(&root->snapshot_lock);

			return -EAGAIN;

		}

	} else {

		btrfs_lock_and_flush_ordered_range(inode, lockstart, lockend, NULL);

	}

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

			NULL, NULL, NULL, false, false);

	if (ret <= 0) {

		ret = 0;

			NULL, NULL, NULL, nowait, false);

	if (ret <= 0)

		btrfs_drew_write_unlock(&root->snapshot_lock);

	} else {

	else

		*write_bytes = min_t(size_t, *write_bytes ,

				     num_bytes - pos + lockstart);

	}

	unlock_extent(&inode->io_tree, lockstart, lockend, NULL);



	return ret;
@@ -1665,16 +1670,22 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, 
						  &data_reserved, pos,

						  write_bytes, false);

		if (ret < 0) {

			int can_nocow;



			/*

			 * If we don't have to COW at the offset, reserve

			 * metadata only. write_bytes may get smaller than

			 * requested here.

			 */

			if (btrfs_check_nocow_lock(BTRFS_I(inode), pos,

						   &write_bytes) > 0)

				only_release_metadata = true;

			else

			can_nocow = btrfs_check_nocow_lock(BTRFS_I(inode), pos,

							   &write_bytes, false);

			if (can_nocow < 0)

				ret = can_nocow;

			if (can_nocow > 0)

				ret = 0;

			if (ret)

				break;

			only_release_metadata = true;

		}



		num_pages = DIV_ROUND_UP(write_bytes + offset, PAGE_SIZE);

fs/btrfs/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -4887,7 +4887,7 @@ int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len, 
	ret = btrfs_check_data_free_space(inode, &data_reserved, block_start,

					  blocksize, false);

	if (ret < 0) {

		if (btrfs_check_nocow_lock(inode, block_start, &write_bytes) > 0) {

		if (btrfs_check_nocow_lock(inode, block_start, &write_bytes, false) > 0) {

			/* For nocow case, no need to reserve data space */

			only_release_metadata = true;

		} else {