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Commit 6f519564 authored by Liu Bo's avatar Liu Bo Committed by Chris Mason
Browse files

Btrfs: do not run snapshot-aware defragment on error 



If something wrong happens in write endio, running snapshot-aware defragment
can end up with undefined results, maybe a crash, so we should avoid it.

In order to share similar code, this also adds a helper to free the struct for
snapshot-aware defrag.

Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
Signed-off-by: default avatarChris Mason <chris.mason@fusionio.com>
parent 269d040f

fs/btrfs/inode.c

+28 −19
Original line number Diff line number Diff line
@@ -2365,10 +2365,23 @@ static noinline int relink_extent_backref(struct btrfs_path *path, 
	return ret;

}



static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)

{

	struct old_sa_defrag_extent *old, *tmp;



	if (!new)

		return;



	list_for_each_entry_safe(old, tmp, &new->head, list) {

		list_del(&old->list);

		kfree(old);

	}

	kfree(new);

}



static void relink_file_extents(struct new_sa_defrag_extent *new)

{

	struct btrfs_path *path;

	struct old_sa_defrag_extent *old, *tmp;

	struct sa_defrag_extent_backref *backref;

	struct sa_defrag_extent_backref *prev = NULL;

	struct inode *inode;
@@ -2411,16 +2424,11 @@ static void relink_file_extents(struct new_sa_defrag_extent *new) 
	kfree(prev);



	btrfs_free_path(path);



	list_for_each_entry_safe(old, tmp, &new->head, list) {

		list_del(&old->list);

		kfree(old);

	}

out:

	free_sa_defrag_extent(new);



	atomic_dec(&root->fs_info->defrag_running);

	wake_up(&root->fs_info->transaction_wait);



	kfree(new);

}



static struct new_sa_defrag_extent *
@@ -2430,7 +2438,7 @@ record_old_file_extents(struct inode *inode, 
	struct btrfs_root *root = BTRFS_I(inode)->root;

	struct btrfs_path *path;

	struct btrfs_key key;

	struct old_sa_defrag_extent *old, *tmp;

	struct old_sa_defrag_extent *old;

	struct new_sa_defrag_extent *new;

	int ret;
@@ -2478,7 +2486,7 @@ record_old_file_extents(struct inode *inode, 
		if (slot >= btrfs_header_nritems(l)) {

			ret = btrfs_next_leaf(root, path);

			if (ret < 0)

				goto out_free_list;

				goto out_free_path;

			else if (ret > 0)

				break;

			continue;
@@ -2507,7 +2515,7 @@ record_old_file_extents(struct inode *inode, 


		old = kmalloc(sizeof(*old), GFP_NOFS);

		if (!old)

			goto out_free_list;

			goto out_free_path;



		offset = max(new->file_pos, key.offset);

		end = min(new->file_pos + new->len, key.offset + num_bytes);
@@ -2529,15 +2537,10 @@ record_old_file_extents(struct inode *inode, 


	return new;



out_free_list:

	list_for_each_entry_safe(old, tmp, &new->head, list) {

		list_del(&old->list);

		kfree(old);

	}

out_free_path:

	btrfs_free_path(path);

out_kfree:

	kfree(new);

	free_sa_defrag_extent(new);

	return NULL;

}
@@ -2708,8 +2711,14 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent) 
	btrfs_remove_ordered_extent(inode, ordered_extent);



	/* for snapshot-aware defrag */

	if (new)

	if (new) {

		if (ret) {

			free_sa_defrag_extent(new);

			atomic_dec(&root->fs_info->defrag_running);

		} else {

			relink_file_extents(new);

		}

	}



	/* once for us */

	btrfs_put_ordered_extent(ordered_extent);