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authorJosef Bacik <josef@redhat.com>2010-11-20 09:48:00 +0000
committerChris Mason <chris.mason@oracle.com>2010-11-21 22:26:09 -0500
commit6a912213046ecb6511fdf35531a0c7de3de963c9 (patch)
treeb745a07d0ad5c5bedf68c55739200093f9d96c1b /fs/btrfs
parent76195853903ca613ba722203db9b747d70478fc7 (diff)
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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: Josef Bacik <josef@redhat.com> Cc: raven@themaw.net Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/inode.c9
-rw-r--r--fs/btrfs/ioctl.c20
-rw-r--r--fs/btrfs/transaction.c5
-rw-r--r--fs/btrfs/tree-log.c21
4 files changed, 43 insertions, 12 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index fc22f556aa24..c0faf47d0cd9 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -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:
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 6b4bfa72bf8d..f1c9bb4079ed 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -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;
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 1fffbc017bdf..f50e931fc217 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -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);
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index a29f19384a27..054744ac5719 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -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;
}
/*