eCryptfs: Fix metadata in xattr feature regression
Fixes regression in 8faece5f906725c10e7a1f6caf84452abadbdc7b
When using the ecryptfs_xattr_metadata mount option, eCryptfs stores the
metadata (normally stored at the front of the file) in the user.ecryptfs
xattr. This causes ecryptfs_crypt_stat.num_header_bytes_at_front to be
0, since there is no header data at the front of the file. This results
in too much memory being requested and ENOMEM being returned from
ecryptfs_write_metadata().
This patch fixes the problem by using the num_header_bytes_at_front
variable for specifying the max size of the metadata, despite whether it
is stored in the header or xattr.
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 7cb0a59..c907f6f 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -381,8 +381,8 @@
static void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num,
struct ecryptfs_crypt_stat *crypt_stat)
{
- (*offset) = (crypt_stat->num_header_bytes_at_front
- + (crypt_stat->extent_size * extent_num));
+ (*offset) = ecryptfs_lower_header_size(crypt_stat)
+ + (crypt_stat->extent_size * extent_num);
}
/**
@@ -834,7 +834,8 @@
set_extent_mask_and_shift(crypt_stat);
crypt_stat->iv_bytes = ECRYPTFS_DEFAULT_IV_BYTES;
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
- crypt_stat->num_header_bytes_at_front = 0;
+ crypt_stat->num_header_bytes_at_front =
+ ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
else {
if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)
crypt_stat->num_header_bytes_at_front =
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 542f625..8456f70 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -464,6 +464,14 @@
extern struct mutex ecryptfs_daemon_hash_mux;
+static inline size_t
+ecryptfs_lower_header_size(struct ecryptfs_crypt_stat *crypt_stat)
+{
+ if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
+ return 0;
+ return crypt_stat->num_header_bytes_at_front;
+}
+
static inline struct ecryptfs_file_info *
ecryptfs_file_to_private(struct file *file)
{
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 4a430ab..1a73953 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -768,7 +768,7 @@
{
loff_t lower_size;
- lower_size = crypt_stat->num_header_bytes_at_front;
+ lower_size = ecryptfs_lower_header_size(crypt_stat);
if (upper_size != 0) {
loff_t num_extents;
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index df4ce99d..5a30e01 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -97,19 +97,6 @@
* (big-endian)
* Octet 26: Begin RFC 2440 authentication token packet set
*/
-static void set_header_info(char *page_virt,
- struct ecryptfs_crypt_stat *crypt_stat)
-{
- size_t written;
- size_t save_num_header_bytes_at_front =
- crypt_stat->num_header_bytes_at_front;
-
- crypt_stat->num_header_bytes_at_front =
- ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
- ecryptfs_write_header_metadata(page_virt + 20, crypt_stat, &written);
- crypt_stat->num_header_bytes_at_front =
- save_num_header_bytes_at_front;
-}
/**
* ecryptfs_copy_up_encrypted_with_header
@@ -146,9 +133,13 @@
memset(page_virt, 0, PAGE_CACHE_SIZE);
/* TODO: Support more than one header extent */
if (view_extent_num == 0) {
+ size_t written;
+
rc = ecryptfs_read_xattr_region(
page_virt, page->mapping->host);
- set_header_info(page_virt, crypt_stat);
+ ecryptfs_write_header_metadata(page_virt + 20,
+ crypt_stat,
+ &written);
}
kunmap_atomic(page_virt, KM_USER0);
flush_dcache_page(page);