vmscan: fix shrinker callback bug in fs/super.c
[linux-2.6.git] / fs / ecryptfs / crypto.c
index f48c498..58609bd 100644 (file)
@@ -1024,25 +1024,25 @@ out:
 }
 
 /**
- * contains_ecryptfs_marker - check for the ecryptfs marker
+ * ecryptfs_validate_marker - check for the ecryptfs marker
  * @data: The data block in which to check
  *
- * Returns one if marker found; zero if not found
+ * Returns zero if marker found; -EINVAL if not found
  */
-static int contains_ecryptfs_marker(char *data)
+static int ecryptfs_validate_marker(char *data)
 {
        u32 m_1, m_2;
 
        m_1 = get_unaligned_be32(data);
        m_2 = get_unaligned_be32(data + 4);
        if ((m_1 ^ MAGIC_ECRYPTFS_MARKER) == m_2)
-               return 1;
+               return 0;
        ecryptfs_printk(KERN_DEBUG, "m_1 = [0x%.8x]; m_2 = [0x%.8x]; "
                        "MAGIC_ECRYPTFS_MARKER = [0x%.8x]\n", m_1, m_2,
                        MAGIC_ECRYPTFS_MARKER);
        ecryptfs_printk(KERN_DEBUG, "(m_1 ^ MAGIC_ECRYPTFS_MARKER) = "
                        "[0x%.8x]\n", (m_1 ^ MAGIC_ECRYPTFS_MARKER));
-       return 0;
+       return -EINVAL;
 }
 
 struct ecryptfs_flag_map_elem {
@@ -1201,27 +1201,19 @@ int ecryptfs_cipher_code_to_string(char *str, u8 cipher_code)
        return rc;
 }
 
-int ecryptfs_read_and_validate_header_region(char *data,
-                                            struct inode *ecryptfs_inode)
+int ecryptfs_read_and_validate_header_region(struct inode *inode)
 {
-       struct ecryptfs_crypt_stat *crypt_stat =
-               &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat);
+       u8 file_size[ECRYPTFS_SIZE_AND_MARKER_BYTES];
+       u8 *marker = file_size + ECRYPTFS_FILE_SIZE_BYTES;
        int rc;
 
-       if (crypt_stat->extent_size == 0)
-               crypt_stat->extent_size = ECRYPTFS_DEFAULT_EXTENT_SIZE;
-       rc = ecryptfs_read_lower(data, 0, crypt_stat->extent_size,
-                                ecryptfs_inode);
-       if (rc < 0) {
-               printk(KERN_ERR "%s: Error reading header region; rc = [%d]\n",
-                      __func__, rc);
-               goto out;
-       }
-       if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) {
-               rc = -EINVAL;
-       } else
-               rc = 0;
-out:
+       rc = ecryptfs_read_lower(file_size, 0, ECRYPTFS_SIZE_AND_MARKER_BYTES,
+                                inode);
+       if (rc < ECRYPTFS_SIZE_AND_MARKER_BYTES)
+               return rc >= 0 ? -EINVAL : rc;
+       rc = ecryptfs_validate_marker(marker);
+       if (!rc)
+               ecryptfs_i_size_init(file_size, inode);
        return rc;
 }
 
@@ -1242,8 +1234,7 @@ ecryptfs_write_header_metadata(char *virt,
        (*written) = 6;
 }
 
-struct kmem_cache *ecryptfs_header_cache_1;
-struct kmem_cache *ecryptfs_header_cache_2;
+struct kmem_cache *ecryptfs_header_cache;
 
 /**
  * ecryptfs_write_headers_virt
@@ -1496,11 +1487,9 @@ static int ecryptfs_read_headers_virt(char *page_virt,
        crypt_stat->mount_crypt_stat = &ecryptfs_superblock_to_private(
                ecryptfs_dentry->d_sb)->mount_crypt_stat;
        offset = ECRYPTFS_FILE_SIZE_BYTES;
-       rc = contains_ecryptfs_marker(page_virt + offset);
-       if (rc == 0) {
-               rc = -EINVAL;
+       rc = ecryptfs_validate_marker(page_virt + offset);
+       if (rc)
                goto out;
-       }
        if (!(crypt_stat->flags & ECRYPTFS_I_SIZE_INITIALIZED))
                ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode);
        offset += MAGIC_ECRYPTFS_MARKER_SIZE_BYTES;
@@ -1567,20 +1556,21 @@ out:
        return rc;
 }
 
-int ecryptfs_read_and_validate_xattr_region(char *page_virt,
+int ecryptfs_read_and_validate_xattr_region(struct dentry *dentry,
                                            struct inode *inode)
 {
+       u8 file_size[ECRYPTFS_SIZE_AND_MARKER_BYTES];
+       u8 *marker = file_size + ECRYPTFS_FILE_SIZE_BYTES;
        int rc;
 
-       rc = ecryptfs_read_xattr_region(page_virt, inode);
-       if (rc)
-               goto out;
-       if (!contains_ecryptfs_marker(page_virt + ECRYPTFS_FILE_SIZE_BYTES)) {
-               printk(KERN_WARNING "Valid data found in [%s] xattr, but "
-                       "the marker is invalid\n", ECRYPTFS_XATTR_NAME);
-               rc = -EINVAL;
-       }
-out:
+       rc = ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry),
+                                    ECRYPTFS_XATTR_NAME, file_size,
+                                    ECRYPTFS_SIZE_AND_MARKER_BYTES);
+       if (rc < ECRYPTFS_SIZE_AND_MARKER_BYTES)
+               return rc >= 0 ? -EINVAL : rc;
+       rc = ecryptfs_validate_marker(marker);
+       if (!rc)
+               ecryptfs_i_size_init(file_size, inode);
        return rc;
 }
 
@@ -1610,7 +1600,7 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry)
        ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat,
                                                      mount_crypt_stat);
        /* Read the first page from the underlying file */
-       page_virt = kmem_cache_alloc(ecryptfs_header_cache_1, GFP_USER);
+       page_virt = kmem_cache_alloc(ecryptfs_header_cache, GFP_USER);
        if (!page_virt) {
                rc = -ENOMEM;
                printk(KERN_ERR "%s: Unable to allocate page_virt\n",
@@ -1655,7 +1645,7 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry)
 out:
        if (page_virt) {
                memset(page_virt, 0, PAGE_CACHE_SIZE);
-               kmem_cache_free(ecryptfs_header_cache_1, page_virt);
+               kmem_cache_free(ecryptfs_header_cache, page_virt);
        }
        return rc;
 }