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Diffstat (limited to 'fs/ecryptfs/inode.c')
-rw-r--r--fs/ecryptfs/inode.c84
1 files changed, 53 insertions, 31 deletions
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 18426f4855f1..e23752d9a79f 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -128,13 +128,20 @@ static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
struct inode *inode)
{
struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
- struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
struct dentry *lower_dir_dentry;
+ struct inode *lower_dir_inode;
int rc;
- dget(lower_dentry);
- lower_dir_dentry = lock_parent(lower_dentry);
- rc = vfs_unlink(lower_dir_inode, lower_dentry, NULL);
+ lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent);
+ lower_dir_inode = d_inode(lower_dir_dentry);
+ inode_lock_nested(lower_dir_inode, I_MUTEX_PARENT);
+ dget(lower_dentry); // don't even try to make the lower negative
+ if (lower_dentry->d_parent != lower_dir_dentry)
+ rc = -EINVAL;
+ else if (d_unhashed(lower_dentry))
+ rc = -EINVAL;
+ else
+ rc = vfs_unlink(lower_dir_inode, lower_dentry, NULL);
if (rc) {
printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
goto out_unlock;
@@ -142,10 +149,11 @@ static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
fsstack_copy_attr_times(dir, lower_dir_inode);
set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
inode->i_ctime = dir->i_ctime;
- d_drop(dentry);
out_unlock:
- unlock_dir(lower_dir_dentry);
dput(lower_dentry);
+ inode_unlock(lower_dir_inode);
+ if (!rc)
+ d_drop(dentry);
return rc;
}
@@ -311,9 +319,9 @@ static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
static struct dentry *ecryptfs_lookup_interpose(struct dentry *dentry,
struct dentry *lower_dentry)
{
- struct inode *inode, *lower_inode = d_inode(lower_dentry);
+ struct path *path = ecryptfs_dentry_to_lower_path(dentry->d_parent);
+ struct inode *inode, *lower_inode;
struct ecryptfs_dentry_info *dentry_info;
- struct vfsmount *lower_mnt;
int rc = 0;
dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
@@ -322,16 +330,23 @@ static struct dentry *ecryptfs_lookup_interpose(struct dentry *dentry,
return ERR_PTR(-ENOMEM);
}
- lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
fsstack_copy_attr_atime(d_inode(dentry->d_parent),
- d_inode(lower_dentry->d_parent));
+ d_inode(path->dentry));
BUG_ON(!d_count(lower_dentry));
ecryptfs_set_dentry_private(dentry, dentry_info);
- dentry_info->lower_path.mnt = lower_mnt;
+ dentry_info->lower_path.mnt = mntget(path->mnt);
dentry_info->lower_path.dentry = lower_dentry;
- if (d_really_is_negative(lower_dentry)) {
+ /*
+ * negative dentry can go positive under us here - its parent is not
+ * locked. That's OK and that could happen just as we return from
+ * ecryptfs_lookup() anyway. Just need to be careful and fetch
+ * ->d_inode only once - it's not stable here.
+ */
+ lower_inode = READ_ONCE(lower_dentry->d_inode);
+
+ if (!lower_inode) {
/* We want to add because we couldn't find in lower */
d_add(dentry, NULL);
return NULL;
@@ -512,22 +527,30 @@ static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct dentry *lower_dentry;
struct dentry *lower_dir_dentry;
+ struct inode *lower_dir_inode;
int rc;
lower_dentry = ecryptfs_dentry_to_lower(dentry);
- dget(dentry);
- lower_dir_dentry = lock_parent(lower_dentry);
- dget(lower_dentry);
- rc = vfs_rmdir(d_inode(lower_dir_dentry), lower_dentry);
- dput(lower_dentry);
- if (!rc && d_really_is_positive(dentry))
+ lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent);
+ lower_dir_inode = d_inode(lower_dir_dentry);
+
+ inode_lock_nested(lower_dir_inode, I_MUTEX_PARENT);
+ dget(lower_dentry); // don't even try to make the lower negative
+ if (lower_dentry->d_parent != lower_dir_dentry)
+ rc = -EINVAL;
+ else if (d_unhashed(lower_dentry))
+ rc = -EINVAL;
+ else
+ rc = vfs_rmdir(lower_dir_inode, lower_dentry);
+ if (!rc) {
clear_nlink(d_inode(dentry));
- fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
- set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
- unlock_dir(lower_dir_dentry);
+ fsstack_copy_attr_times(dir, lower_dir_inode);
+ set_nlink(dir, lower_dir_inode->i_nlink);
+ }
+ dput(lower_dentry);
+ inode_unlock(lower_dir_inode);
if (!rc)
d_drop(dentry);
- dput(dentry);
return rc;
}
@@ -565,20 +588,22 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct dentry *lower_new_dentry;
struct dentry *lower_old_dir_dentry;
struct dentry *lower_new_dir_dentry;
- struct dentry *trap = NULL;
+ struct dentry *trap;
struct inode *target_inode;
if (flags)
return -EINVAL;
+ lower_old_dir_dentry = ecryptfs_dentry_to_lower(old_dentry->d_parent);
+ lower_new_dir_dentry = ecryptfs_dentry_to_lower(new_dentry->d_parent);
+
lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
- dget(lower_old_dentry);
- dget(lower_new_dentry);
- lower_old_dir_dentry = dget_parent(lower_old_dentry);
- lower_new_dir_dentry = dget_parent(lower_new_dentry);
+
target_inode = d_inode(new_dentry);
+
trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
+ dget(lower_new_dentry);
rc = -EINVAL;
if (lower_old_dentry->d_parent != lower_old_dir_dentry)
goto out_lock;
@@ -606,11 +631,8 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
if (new_dir != old_dir)
fsstack_copy_attr_all(old_dir, d_inode(lower_old_dir_dentry));
out_lock:
- unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
- dput(lower_new_dir_dentry);
- dput(lower_old_dir_dentry);
dput(lower_new_dentry);
- dput(lower_old_dentry);
+ unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
return rc;
}