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Btrfs: use dget_parent where we can UPDATED

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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: Josef Bacik <josef@redhat.com>
Cc: raven@themaw.net
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Josef Bacik 2010-11-20 09:48:00 +00:00 committed by Chris Mason
parent 7619585390
commit 6a91221304
4 changed files with 43 additions and 12 deletions
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9
fs/btrfs/inode.c
View file

@ -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:

20
fs/btrfs/ioctl.c
View file

@ -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;

5
fs/btrfs/transaction.c
View file

@ -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);

21
fs/btrfs/tree-log.c
View file

@ -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 @@ int btrfs_log_inode_parent(struct btrfs_trans_handle *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;
}
/*