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eCryptfs: Fix metadata in xattr feature regression 

Fixes regression in 8faece5f90

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>
This commit is contained in:
Tyler Hicks 2010-02-11 07:10:38 -06:00
parent 220bf991b0
commit 157f107135
4 changed files with 18 additions and 18 deletions
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7
fs/ecryptfs/crypto.c
View File

@ -381,8 +381,8 @@ out:
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 @@ void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat)
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 =

8
fs/ecryptfs/ecryptfs_kernel.h
View File

@ -464,6 +464,14 @@ struct ecryptfs_daemon {
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)
{

2
fs/ecryptfs/inode.c
View File

@ -768,7 +768,7 @@ upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
{
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;

19
fs/ecryptfs/mmap.c
View File

@ -97,19 +97,6 @@ out:
* (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 @@ ecryptfs_copy_up_encrypted_with_header(struct page *page,
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);