eCryptfs: do not try to open device files on mknod
When creating device nodes, eCryptfs needs to delay actually opening the lower
persistent file until an application tries to open. Device handles may not be
backed by anything when they first come into existence.
[Valdis.Kletnieks@vt.edu: build fix]
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: <Valdis.Kletnieks@vt.edu}
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 10475d9..ee4f84b 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -117,7 +117,7 @@
*
* Returns zero on success; non-zero otherwise
*/
-static int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
+int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
{
struct ecryptfs_inode_info *inode_info =
ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
@@ -149,14 +149,14 @@
* @lower_dentry: Existing dentry in the lower filesystem
* @dentry: ecryptfs' dentry
* @sb: ecryptfs's super_block
- * @flag: If set to true, then d_add is called, else d_instantiate is called
+ * @flags: flags to govern behavior of interpose procedure
*
* Interposes upper and lower dentries.
*
* Returns zero on success; non-zero otherwise
*/
int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
- struct super_block *sb, int flag)
+ struct super_block *sb, u32 flags)
{
struct inode *lower_inode;
struct inode *inode;
@@ -193,7 +193,7 @@
init_special_inode(inode, lower_inode->i_mode,
lower_inode->i_rdev);
dentry->d_op = &ecryptfs_dops;
- if (flag)
+ if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
d_add(dentry, inode);
else
d_instantiate(dentry, inode);
@@ -201,12 +201,21 @@
/* This size will be overwritten for real files w/ headers and
* other metadata */
fsstack_copy_inode_size(inode, lower_inode);
- rc = ecryptfs_init_persistent_file(dentry);
- if (rc) {
- printk(KERN_ERR "%s: Error attempting to initialize the "
- "persistent file for the dentry with name [%s]; "
- "rc = [%d]\n", __func__, dentry->d_name.name, rc);
- goto out;
+ if (!(flags & ECRYPTFS_INTERPOSE_FLAG_DELAY_PERSISTENT_FILE)) {
+ rc = ecryptfs_init_persistent_file(dentry);
+ if (rc) {
+ printk(KERN_ERR "%s: Error attempting to initialize "
+ "the persistent file for the dentry with name "
+ "[%s]; rc = [%d]\n", __func__,
+ dentry->d_name.name, rc);
+ goto out;
+ }
+ } else {
+ struct ecryptfs_inode_info *inode_info =
+ ecryptfs_inode_to_private(dentry->d_inode);
+
+ inode_info->lower_file = NULL;
+ inode_info->crypt_stat.flags |= ECRYPTFS_DELAY_PERSISTENT;
}
out:
return rc;