[PATCH] eCryptfs: Fix handling of lower d_count

Fix the use of dget/dput calls to balance out on the lower filesystem.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 27 insertions, 43 deletions

diff --git a/fs/ecryptfs/dentry.c b/fs/ecryptfs/dentry.c
index f0d2a433242b..0b9992ab990f 100644
--- a/fs/ecryptfs/dentry.c
+++ b/fs/ecryptfs/dentry.c
@@ -24,6 +24,7 @@
 
 #include <linux/dcache.h>
 #include <linux/namei.h>
+#include <linux/mount.h>
 #include "ecryptfs_kernel.h"
 
 /**
@@ -76,8 +77,13 @@ static void ecryptfs_d_release(struct dentry *dentry)
         if (ecryptfs_dentry_to_private(dentry))
                 kmem_cache_free(ecryptfs_dentry_info_cache,
                                 ecryptfs_dentry_to_private(dentry));
-        if (lower_dentry)
+        if (lower_dentry) {
+                struct vfsmount *lower_mnt =
+                        ecryptfs_dentry_to_lower_mnt(dentry);
+
+                mntput(lower_mnt);
                 dput(lower_dentry);
+        }
         return;
 }
 
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 2f2c6cf972f7..ff4865d24f0f 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -325,7 +325,6 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
         struct dentry *lower_dir_dentry;
         struct dentry *lower_dentry;
         struct vfsmount *lower_mnt;
-        struct dentry *tlower_dentry = NULL;
         char *encoded_name;
         unsigned int encoded_namelen;
         struct ecryptfs_crypt_stat *crypt_stat = NULL;
@@ -336,27 +335,32 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
         lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent);
         dentry->d_op = &ecryptfs_dops;
         if ((dentry->d_name.len == 1 && !strcmp(dentry->d_name.name, "."))
-            || (dentry->d_name.len == 2 && !strcmp(dentry->d_name.name, "..")))
-                goto out_drop;
+            || (dentry->d_name.len == 2
+                && !strcmp(dentry->d_name.name, ".."))) {
+                d_drop(dentry);
+                goto out;
+        }
         encoded_namelen = ecryptfs_encode_filename(crypt_stat,
                                                    dentry->d_name.name,
                                                    dentry->d_name.len,
                                                    &encoded_name);
         if (encoded_namelen < 0) {
                 rc = encoded_namelen;
-                goto out_drop;
+                d_drop(dentry);
+                goto out;
         }
         ecryptfs_printk(KERN_DEBUG, "encoded_name = [%s]; encoded_namelen "
                         "= [%d]\n", encoded_name, encoded_namelen);
         lower_dentry = lookup_one_len(encoded_name, lower_dir_dentry,
                                       encoded_namelen - 1);
         kfree(encoded_name);
-        lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
         if (IS_ERR(lower_dentry)) {
                 ecryptfs_printk(KERN_ERR, "ERR from lower_dentry\n");
                 rc = PTR_ERR(lower_dentry);
-                goto out_drop;
+                d_drop(dentry);
+                goto out;
         }
+        lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
         ecryptfs_printk(KERN_DEBUG, "lower_dentry = [%p]; lower_dentry->"
                 "d_name.name = [%s]\n", lower_dentry,
                 lower_dentry->d_name.name);
@@ -397,12 +401,6 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
                                 "as we *think* we are about to unlink\n");
                 goto out;
         }
-        tlower_dentry = dget(lower_dentry);
-        if (!tlower_dentry || IS_ERR(tlower_dentry)) {
-                rc = -ENOMEM;
-                ecryptfs_printk(KERN_ERR, "Cannot dget lower_dentry\n");
-                goto out_dput;
-        }
         /* Released in this function */
         page_virt =
             (char *)kmem_cache_alloc(ecryptfs_header_cache_2,
@@ -414,7 +412,7 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
                 goto out_dput;
         }
         memset(page_virt, 0, PAGE_CACHE_SIZE);
-        rc = ecryptfs_read_header_region(page_virt, tlower_dentry, nd->mnt);
+        rc = ecryptfs_read_header_region(page_virt, lower_dentry, nd->mnt);
         crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
         if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED))
                 ecryptfs_set_default_sizes(crypt_stat);
@@ -437,9 +435,6 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
 
 out_dput:
         dput(lower_dentry);
-        if (tlower_dentry)
-                dput(tlower_dentry);
-out_drop:
         d_drop(dentry);
 out:
         return ERR_PTR(rc);
@@ -475,8 +470,8 @@ out_lock:
         unlock_dir(lower_dir_dentry);
         dput(lower_new_dentry);
         dput(lower_old_dentry);
-        if (!new_dentry->d_inode)
-                d_drop(new_dentry);
+        d_drop(new_dentry);
+        d_drop(old_dentry);
         return rc;
 }
 
@@ -565,41 +560,24 @@ out:
 
 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
 {
-        int rc = 0;
-        struct dentry *tdentry = NULL;
         struct dentry *lower_dentry;
-        struct dentry *tlower_dentry = NULL;
         struct dentry *lower_dir_dentry;
+        int rc;
 
         lower_dentry = ecryptfs_dentry_to_lower(dentry);
-        if (!(tdentry = dget(dentry))) {
-                rc = -EINVAL;
-                ecryptfs_printk(KERN_ERR, "Error dget'ing dentry [%p]\n",
-                                dentry);
-                goto out;
-        }
+        dget(dentry);
         lower_dir_dentry = lock_parent(lower_dentry);
-        if (!(tlower_dentry = dget(lower_dentry))) {
-                rc = -EINVAL;
-                ecryptfs_printk(KERN_ERR, "Error dget'ing lower_dentry "
-                                "[%p]\n", lower_dentry);
-                goto out;
-        }
+        dget(lower_dentry);
         rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
-        if (!rc) {
-                d_delete(tlower_dentry);
-                tlower_dentry = NULL;
-        }
+        dput(lower_dentry);
+        if (!rc)
+                d_delete(lower_dentry);
         ecryptfs_copy_attr_times(dir, lower_dir_dentry->d_inode);
         dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
         unlock_dir(lower_dir_dentry);
         if (!rc)
                 d_drop(dentry);
-out:
-        if (tdentry)
-                dput(tdentry);
-        if (tlower_dentry)
-                dput(tlower_dentry);
+        dput(dentry);
         return rc;
 }