[PATCH 6/6] eCryptfs: Fix handling of lower d_count

Michael Halcrow
2006-10-30T23:41:52Z

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

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>

---

fs/ecryptfs/dentry.c | 8 ++++++
fs/ecryptfs/inode.c | 62 ++++++++++++++++----------------------------------
2 files changed, 27 insertions(+), 43 deletions(-)

0277a301b99c7a2270fcca1e2c2ada96037b6fa1
diff --git a/fs/ecryptfs/dentry.c b/fs/ecryptfs/dentry.c
index f0d2a43..0b9992a 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 de
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 2f2c6cf..ff4865d 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -325,7 +325,6 @@ static struct dentry *ecryptfs_lookup(st
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(st
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(st
"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(st
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(st

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;
}

--
1.3.3