Commit c99f1b0c authored by Zhao Lei's avatar Zhao Lei Committed by Chris Mason
Browse files

btrfs: Support busy loop of write and delete 



Reproduce:
 while true; do
   dd if=/dev/zero of=/mnt/btrfs/file count=[75% fs_size]
   rm /mnt/btrfs/file
 done
 Then we can see above loop failed on NO_SPACE.

It it long-term problem since very beginning, because delayed-iput
after rm are not run.

We already have commit_transaction() in alloc_space code, but it is
not triggered in above case.
This patch trigger commit_transaction() to run delayed-iput and
reflash pinned-space to to make write success.

It is based on previous fix of delayed-iput in commit_transaction(),
need to be applied on top of:
btrfs: Fix NO_SPACE bug caused by delayed-iput

Signed-off-by: default avatarZhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent d7c15171

fs/btrfs/extent-tree.c

+14 −12
Original line number Original line Diff line number Diff line
@@ -3858,14 +3858,14 @@ int btrfs_check_data_free_space(struct inode *inode, u64 bytes) 
	struct btrfs_fs_info *fs_info = root->fs_info;

	struct btrfs_fs_info *fs_info = root->fs_info;

	u64 used;

	u64 used;

	int ret = 0;

	int ret = 0;

	int committed = 0;

	int need_commit = 2;

	int have_pinned_space = 1;

	int have_pinned_space;





	/* make sure bytes are sectorsize aligned */

	/* make sure bytes are sectorsize aligned */

	bytes = ALIGN(bytes, root->sectorsize);

	bytes = ALIGN(bytes, root->sectorsize);





	if (btrfs_is_free_space_inode(inode)) {

	if (btrfs_is_free_space_inode(inode)) {

		committed = 1;

		need_commit = 0;

		ASSERT(current->journal_info);

		ASSERT(current->journal_info);

	}

	}
@@ -3915,9 +3915,11 @@ int btrfs_check_data_free_space(struct inode *inode, u64 bytes) 
			if (ret < 0) {

			if (ret < 0) {

				if (ret != -ENOSPC)

				if (ret != -ENOSPC)

					return ret;

					return ret;

				else

				else {

					have_pinned_space = 1;

					goto commit_trans;

					goto commit_trans;

				}

				}

			}





			if (!data_sinfo)

			if (!data_sinfo)

				data_sinfo = fs_info->data_sinfo;

				data_sinfo = fs_info->data_sinfo;
@@ -3930,23 +3932,23 @@ int btrfs_check_data_free_space(struct inode *inode, u64 bytes) 
		 * allocation, and no removed chunk in current transaction,

		 * allocation, and no removed chunk in current transaction,

		 * don't bother committing the transaction.

		 * don't bother committing the transaction.

		 */

		 */

		if (percpu_counter_compare(&data_sinfo->total_bytes_pinned,

		have_pinned_space = percpu_counter_compare(

					   used + bytes -

			&data_sinfo->total_bytes_pinned,

					   data_sinfo->total_bytes) < 0)

			used + bytes - data_sinfo->total_bytes);

			have_pinned_space = 0;

		spin_unlock(&data_sinfo->lock);

		spin_unlock(&data_sinfo->lock);





		/* commit the current transaction and try again */

		/* commit the current transaction and try again */

commit_trans:

commit_trans:

		if (!committed &&

		if (need_commit &&

		    !atomic_read(&root->fs_info->open_ioctl_trans)) {

		    !atomic_read(&root->fs_info->open_ioctl_trans)) {

			committed = 1;

			need_commit--;





			trans = btrfs_join_transaction(root);

			trans = btrfs_join_transaction(root);

			if (IS_ERR(trans))

			if (IS_ERR(trans))

				return PTR_ERR(trans);

				return PTR_ERR(trans);

			if (have_pinned_space ||

			if (have_pinned_space >= 0 ||

			    trans->transaction->have_free_bgs) {

			    trans->transaction->have_free_bgs ||

			    need_commit > 0) {

				ret = btrfs_commit_transaction(trans, root);

				ret = btrfs_commit_transaction(trans, root);

				if (ret)

				if (ret)

					return ret;

					return ret;