4 files changed, 42 insertions, 13 deletions

diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index b4a0cccfdd7c..b0727f91454e 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -235,6 +235,7 @@ struct ecryptfs_crypt_stat {
 #define ECRYPTFS_METADATA_IN_XATTR  0x00000100
 #define ECRYPTFS_VIEW_AS_ENCRYPTED  0x00000200
 #define ECRYPTFS_KEY_SET            0x00000400
+#define ECRYPTFS_DELAY_PERSISTENT   0x00000800
         u32 flags;
         unsigned int file_version;
         size_t iv_bytes;
@@ -574,9 +575,11 @@ struct ecryptfs_open_req {
         struct list_head kthread_ctl_list;
 };
 
+#define ECRYPTFS_INTERPOSE_FLAG_D_ADD                 0x00000001
+#define ECRYPTFS_INTERPOSE_FLAG_DELAY_PERSISTENT_FILE 0x00000002
 int ecryptfs_interpose(struct dentry *hidden_dentry,
                        struct dentry *this_dentry, struct super_block *sb,
-                       int flag);
+                       u32 flags);
 int ecryptfs_fill_zeros(struct file *file, loff_t new_length);
 int ecryptfs_decode_filename(struct ecryptfs_crypt_stat *crypt_stat,
                              const char *name, int length,
@@ -709,5 +712,6 @@ void ecryptfs_destroy_kthread(void);
 int ecryptfs_privileged_open(struct file **lower_file,
                              struct dentry *lower_dentry,
                              struct vfsmount *lower_mnt);
+int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry);
 
 #endif /* #ifndef ECRYPTFS_KERNEL_H */
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index f0be29051528..2c2d60df3f60 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -199,6 +199,20 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
                        "file must hence be opened RO\n", __func__);
                 goto out;
         }
+        if (!ecryptfs_inode_to_private(inode)->lower_file) {
+                BUG_ON(!(crypt_stat->flags & ECRYPTFS_DELAY_PERSISTENT));
+                mutex_lock(&crypt_stat->cs_mutex);
+                crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
+                mutex_unlock(&crypt_stat->cs_mutex);
+                rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
+                if (rc) {
+                        printk(KERN_ERR "%s: Error attempting to initialize "
+                               "the persistent file for the dentry with name "
+                               "[%s]; rc = [%d]\n", __func__,
+                               ecryptfs_dentry->d_name.name, rc);
+                        goto out;
+                }
+        }
         ecryptfs_set_file_lower(
                 file, ecryptfs_inode_to_private(inode)->lower_file);
         if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 7315547193ea..26090878c930 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -308,7 +308,8 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
                 d_add(dentry, NULL);
                 goto out;
         }
-        rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 1);
+        rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb,
+                                ECRYPTFS_INTERPOSE_FLAG_D_ADD);
         if (rc) {
                 ecryptfs_printk(KERN_ERR, "Error interposing\n");
                 goto out_dput;
@@ -537,7 +538,8 @@ ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
         rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
         if (rc || !lower_dentry->d_inode)
                 goto out;
-        rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
+        rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb,
+                                ECRYPTFS_INTERPOSE_FLAG_DELAY_PERSISTENT_FILE);
         if (rc)
                 goto out;
         fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 10475d93ff53..ee4f84b20410 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -117,7 +117,7 @@ void __ecryptfs_printk(const char *fmt, ...)
  *
  * 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 @@ static int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
  * @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 @@ int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
                 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 @@ int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
         /* 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;