[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>

diff --git a/fs/ecryptfs/dentry.c b/fs/ecryptfs/dentry.c
index f0d2a433242b58757f33483fec2a301410ce2aab..0b9992ab990f4cab4983a89aa4eb4f4026a1820b 100644 (file)
--- 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 2f2c6cf972f77152bf6ab78dd43e74b2c05fbcac..ff4865d24f0f1061dcc7dbd47fd169330f136869 100644 (file)
--- 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;
 }