Commit 6a912213 authored by Josef Bacik's avatar Josef Bacik Committed by Chris Mason
Browse files

Btrfs: use dget_parent where we can UPDATED 



There are lots of places where we do dentry->d_parent->d_inode without holding
the dentry->d_lock.  This could cause problems with rename.  So instead we need
to use dget_parent() and hold the reference to the parent as long as we are
going to use it's inode and then dput it at the end.

Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
Cc: raven@themaw.net
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 76195853

fs/btrfs/inode.c

+6 −3
Original line number Diff line number Diff line
@@ -4811,10 +4811,12 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir, 
	if (err) {

		drop_inode = 1;

	} else {

		struct dentry *parent = dget_parent(dentry);

		btrfs_update_inode_block_group(trans, dir);

		err = btrfs_update_inode(trans, root, inode);

		BUG_ON(err);

		btrfs_log_new_name(trans, inode, NULL, dentry->d_parent);

		btrfs_log_new_name(trans, inode, NULL, parent);

		dput(parent);

	}



	nr = trans->blocks_used;
@@ -6768,8 +6770,9 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, 
	BUG_ON(ret);



	if (old_inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {

		btrfs_log_new_name(trans, old_inode, old_dir,

				   new_dentry->d_parent);

		struct dentry *parent = dget_parent(new_dentry);

		btrfs_log_new_name(trans, old_inode, old_dir, parent);

		dput(parent);

		btrfs_end_log_trans(root);

	}

out_fail:

fs/btrfs/ioctl.c

+16 −4
Original line number Diff line number Diff line
@@ -233,7 +233,8 @@ static noinline int create_subvol(struct btrfs_root *root, 
	struct btrfs_inode_item *inode_item;

	struct extent_buffer *leaf;

	struct btrfs_root *new_root;

	struct inode *dir = dentry->d_parent->d_inode;

	struct dentry *parent = dget_parent(dentry);

	struct inode *dir;

	int ret;

	int err;

	u64 objectid;
@@ -242,8 +243,13 @@ static noinline int create_subvol(struct btrfs_root *root, 


	ret = btrfs_find_free_objectid(NULL, root->fs_info->tree_root,

				       0, &objectid);

	if (ret)

	if (ret) {

		dput(parent);

		return ret;

	}



	dir = parent->d_inode;



	/*

	 * 1 - inode item

	 * 2 - refs
@@ -251,8 +257,10 @@ static noinline int create_subvol(struct btrfs_root *root, 
	 * 2 - dir items

	 */

	trans = btrfs_start_transaction(root, 6);

	if (IS_ERR(trans))

	if (IS_ERR(trans)) {

		dput(parent);

		return PTR_ERR(trans);

	}



	leaf = btrfs_alloc_free_block(trans, root, root->leafsize,

				      0, objectid, NULL, 0, 0, 0);
@@ -339,6 +347,7 @@ static noinline int create_subvol(struct btrfs_root *root, 


	d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));

fail:

	dput(parent);

	if (async_transid) {

		*async_transid = trans->transid;

		err = btrfs_commit_transaction_async(trans, root, 1);
@@ -354,6 +363,7 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry, 
			   char *name, int namelen, u64 *async_transid)

{

	struct inode *inode;

	struct dentry *parent;

	struct btrfs_pending_snapshot *pending_snapshot;

	struct btrfs_trans_handle *trans;

	int ret;
@@ -396,7 +406,9 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry, 


	btrfs_orphan_cleanup(pending_snapshot->snap);



	inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);

	parent = dget_parent(dentry);

	inode = btrfs_lookup_dentry(parent->d_inode, dentry);

	dput(parent);

	if (IS_ERR(inode)) {

		ret = PTR_ERR(inode);

		goto fail;

fs/btrfs/transaction.c

+4 −1
Original line number Diff line number Diff line
@@ -902,6 +902,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 
	struct btrfs_root *root = pending->root;

	struct btrfs_root *parent_root;

	struct inode *parent_inode;

	struct dentry *parent;

	struct dentry *dentry;

	struct extent_buffer *tmp;

	struct extent_buffer *old;
@@ -941,7 +942,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 
	trans->block_rsv = &pending->block_rsv;



	dentry = pending->dentry;

	parent_inode = dentry->d_parent->d_inode;

	parent = dget_parent(dentry);

	parent_inode = parent->d_inode;

	parent_root = BTRFS_I(parent_inode)->root;

	record_root_in_trans(trans, parent_root);
@@ -989,6 +991,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 
				 parent_inode->i_ino, index,

				 dentry->d_name.name, dentry->d_name.len);

	BUG_ON(ret);

	dput(parent);



	key.offset = (u64)-1;

	pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);

fs/btrfs/tree-log.c

+17 −4
Original line number Diff line number Diff line
@@ -2869,6 +2869,7 @@ static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans, 
{

	int ret = 0;

	struct btrfs_root *root;

	struct dentry *old_parent = NULL;



	/*

	 * for regular files, if its inode is already on disk, we don't
@@ -2910,10 +2911,13 @@ static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans, 
		if (IS_ROOT(parent))

			break;



		parent = parent->d_parent;

		parent = dget_parent(parent);

		dput(old_parent);

		old_parent = parent;

		inode = parent->d_inode;



	}

	dput(old_parent);

out:

	return ret;

}
@@ -2945,6 +2949,7 @@ int btrfs_log_inode_parent(struct btrfs_trans_handle *trans, 
{

	int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL;

	struct super_block *sb;

	struct dentry *old_parent = NULL;

	int ret = 0;

	u64 last_committed = root->fs_info->last_trans_committed;
@@ -3016,10 +3021,13 @@ int btrfs_log_inode_parent(struct btrfs_trans_handle *trans, 
		if (IS_ROOT(parent))

			break;



		parent = parent->d_parent;

		parent = dget_parent(parent);

		dput(old_parent);

		old_parent = parent;

	}

	ret = 0;

end_trans:

	dput(old_parent);

	if (ret < 0) {

		BUG_ON(ret != -ENOSPC);

		root->fs_info->last_trans_log_full_commit = trans->transid;
@@ -3039,8 +3047,13 @@ end_no_trans: 
int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,

			  struct btrfs_root *root, struct dentry *dentry)

{

	return btrfs_log_inode_parent(trans, root, dentry->d_inode,

				      dentry->d_parent, 0);

	struct dentry *parent = dget_parent(dentry);

	int ret;



	ret = btrfs_log_inode_parent(trans, root, dentry->d_inode, parent, 0);

	dput(parent);



	return ret;

}



/*

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