Commit f248679e authored by Josef Bacik's avatar Josef Bacik Committed by Chris Mason
Browse files

Btrfs: add a delalloc mutex to inodes for delalloc reservations 



I was using i_mutex for this, but we're getting bogus lockdep warnings by doing
that and theres no real way to get rid of those, so just stop using i_mutex to
protect delalloc metadata reservations and use a delalloc mutex instead.  This
shouldn't be contended often at all, only if you are writing and mmap writing to
the file at the same time.  Thanks,

Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
parent 8c2a3ca2

fs/btrfs/btrfs_inode.h

+3 −0
Original line number Diff line number Diff line
@@ -51,6 +51,9 @@ struct btrfs_inode { 
	/* held while logging the inode in tree-log.c */

	struct mutex log_mutex;



	/* held while doing delalloc reservations */

	struct mutex delalloc_mutex;



	/* used to order data wrt metadata */

	struct btrfs_ordered_inode_tree ordered_tree;

fs/btrfs/extent-tree.c

+3 −2
Original line number Diff line number Diff line
@@ -4345,12 +4345,11 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes) 
	/* Need to be holding the i_mutex here if we aren't free space cache */

	if (btrfs_is_free_space_inode(root, inode))

		flush = 0;

	else

		WARN_ON(!mutex_is_locked(&inode->i_mutex));



	if (flush && btrfs_transaction_in_commit(root->fs_info))

		schedule_timeout(1);



	mutex_lock(&BTRFS_I(inode)->delalloc_mutex);

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



	spin_lock(&BTRFS_I(inode)->lock);
@@ -4405,6 +4404,7 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes) 
						      btrfs_ino(inode),

						      to_free, 0);

		}

		mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);

		return ret;

	}
@@ -4415,6 +4415,7 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes) 
	}

	BTRFS_I(inode)->reserved_extents += nr_extents;

	spin_unlock(&BTRFS_I(inode)->lock);

	mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);



	if (to_reserve)

		trace_btrfs_space_reservation(root->fs_info,"delalloc",

fs/btrfs/inode.c

+1 −10
Original line number Diff line number Diff line
@@ -2239,14 +2239,7 @@ int btrfs_orphan_cleanup(struct btrfs_root *root) 
				continue;

			}

			nr_truncate++;

			/*

			 * Need to hold the imutex for reservation purposes, not

			 * a huge deal here but I have a WARN_ON in

			 * btrfs_delalloc_reserve_space to catch offenders.

			 */

			mutex_lock(&inode->i_mutex);

			ret = btrfs_truncate(inode);

			mutex_unlock(&inode->i_mutex);

		} else {

			nr_unlink++;

		}
@@ -6411,10 +6404,7 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 
	u64 page_start;

	u64 page_end;



	/* Need this to keep space reservations serialized */

	mutex_lock(&inode->i_mutex);

	ret  = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);

	mutex_unlock(&inode->i_mutex);

	if (!ret)

		ret = btrfs_update_time(vma->vm_file);

	if (ret) {
@@ -6758,6 +6748,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb) 
	extent_io_tree_init(&ei->io_tree, &inode->i_data);

	extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);

	mutex_init(&ei->log_mutex);

	mutex_init(&ei->delalloc_mutex);

	btrfs_ordered_inode_tree_init(&ei->ordered_tree);

	INIT_LIST_HEAD(&ei->i_orphan);

	INIT_LIST_HEAD(&ei->delalloc_inodes);

fs/btrfs/ioctl.c

+0 −2
Original line number Diff line number Diff line
@@ -868,10 +868,8 @@ static int cluster_pages_for_defrag(struct inode *inode, 
		return 0;

	file_end = (isize - 1) >> PAGE_CACHE_SHIFT;



	mutex_lock(&inode->i_mutex);

	ret = btrfs_delalloc_reserve_space(inode,

					   num_pages << PAGE_CACHE_SHIFT);

	mutex_unlock(&inode->i_mutex);

	if (ret)

		return ret;

again:

fs/btrfs/relocation.c

+0 −2
Original line number Diff line number Diff line
@@ -2949,9 +2949,7 @@ static int relocate_file_extent_cluster(struct inode *inode, 
	index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;

	last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;

	while (index <= last_index) {

		mutex_lock(&inode->i_mutex);

		ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);

		mutex_unlock(&inode->i_mutex);

		if (ret)

			goto out;

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