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authorTyler Hicks <tyhicks@linux.vnet.ibm.com>2010-02-11 00:02:32 -0600
committerTyler Hicks <tyhicks@linux.vnet.ibm.com>2010-03-23 12:31:35 -0500
commitf4e60e6b303bc46cdc477d3174dbf9cb5dd013aa (patch)
tree36abefd614efd86f97ac812f57c86a583c7e484a
parent1984c23f9e0cdb432d90a85ecf88b424d36878fc (diff)
downloadlinux-next-f4e60e6b303bc46cdc477d3174dbf9cb5dd013aa.tar.gz
eCryptfs: Strip metadata in xattr flag in encrypted view
The ecryptfs_encrypted_view mount option provides a unified way of viewing encrypted eCryptfs files. If the metadata is stored in a xattr, the metadata is moved to the file header when the file is read inside the eCryptfs mount. Because of this, we should strip the ECRYPTFS_METADATA_IN_XATTR flag from the header's flag section. This allows eCryptfs to treat the file as an eCryptfs file with a header at the front. Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
-rw-r--r--fs/ecryptfs/crypto.c9
-rw-r--r--fs/ecryptfs/ecryptfs_kernel.h3
-rw-r--r--fs/ecryptfs/mmap.c14
3 files changed, 22 insertions, 4 deletions
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 4d9db0ed88ea..fad5bf6a6116 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1107,9 +1107,9 @@ static void write_ecryptfs_marker(char *page_virt, size_t *written)
(*written) = MAGIC_ECRYPTFS_MARKER_SIZE_BYTES;
}
-static void
-write_ecryptfs_flags(char *page_virt, struct ecryptfs_crypt_stat *crypt_stat,
- size_t *written)
+void ecryptfs_write_crypt_stat_flags(char *page_virt,
+ struct ecryptfs_crypt_stat *crypt_stat,
+ size_t *written)
{
u32 flags = 0;
int i;
@@ -1290,7 +1290,8 @@ static int ecryptfs_write_headers_virt(char *page_virt, size_t max,
offset = ECRYPTFS_FILE_SIZE_BYTES;
write_ecryptfs_marker((page_virt + offset), &written);
offset += written;
- write_ecryptfs_flags((page_virt + offset), crypt_stat, &written);
+ ecryptfs_write_crypt_stat_flags((page_virt + offset), crypt_stat,
+ &written);
offset += written;
ecryptfs_write_header_metadata((page_virt + offset), crypt_stat,
&written);
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index d031efd7666b..bc7115403f38 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -659,6 +659,9 @@ int ecryptfs_decrypt_page(struct page *page);
int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry);
int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry);
int ecryptfs_new_file_context(struct dentry *ecryptfs_dentry);
+void ecryptfs_write_crypt_stat_flags(char *page_virt,
+ struct ecryptfs_crypt_stat *crypt_stat,
+ size_t *written);
int ecryptfs_read_and_validate_header_region(char *data,
struct inode *ecryptfs_inode);
int ecryptfs_read_and_validate_xattr_region(char *page_virt,
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 270f42ae7c0d..bea998a25afd 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -82,6 +82,19 @@ out:
return rc;
}
+static void strip_xattr_flag(char *page_virt,
+ struct ecryptfs_crypt_stat *crypt_stat)
+{
+ if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
+ size_t written;
+
+ crypt_stat->flags &= ~ECRYPTFS_METADATA_IN_XATTR;
+ ecryptfs_write_crypt_stat_flags(page_virt, crypt_stat,
+ &written);
+ crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
+ }
+}
+
/**
* Header Extent:
* Octets 0-7: Unencrypted file size (big-endian)
@@ -136,6 +149,7 @@ ecryptfs_copy_up_encrypted_with_header(struct page *page,
rc = ecryptfs_read_xattr_region(
page_virt, page->mapping->host);
+ strip_xattr_flag(page_virt + 16, crypt_stat);
ecryptfs_write_header_metadata(page_virt + 20,
crypt_stat,
&written);