eCryptfs: Cleanup and optimize ecryptfs_lookup_interpose()
ecryptfs_lookup_interpose() has turned into spaghetti code over the
years. This is an effort to clean it up.
- Shorten overly descriptive variable names such as ecryptfs_dentry
- Simplify gotos and error paths
- Create helper function for reading plaintext i_size from metadata
It also includes an optimization when reading i_size from the metadata.
A complete page-sized kmem_cache_alloc() was being done to read in 16
bytes of metadata. The buffer for that is now statically declared.
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 162f9ba..66d8e67 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1201,24 +1201,19 @@
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;
- }
- rc = ecryptfs_validate_marker(data + ECRYPTFS_FILE_SIZE_BYTES);
-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;
}
@@ -1562,19 +1557,21 @@
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;
- rc = ecryptfs_validate_marker(page_virt + ECRYPTFS_FILE_SIZE_BYTES);
- if (rc)
- printk(KERN_WARNING "Valid data found in [%s] xattr, but "
- "the marker is invalid\n", ECRYPTFS_XATTR_NAME);
-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;
}