ext4 crypto: encrypt tmpfile located in encryption protected directory

Factor out calls to ext4_inherit_context() and move them to
__ext4_new_inode(); this fixes a problem where ext4_tmpfile() wasn't
calling calling ext4_inherit_context(), so the temporary file wasn't
getting protected.  Since the blocks for the tmpfile could end up on
disk, they really should be protected if the tmpfile is created within
the context of an encrypted directory.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

1 files changed, 20 insertions, 6 deletions

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index ddca1697ad86..173c1ae21395 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -726,11 +726,25 @@ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
         ext4_group_t i;
         ext4_group_t flex_group;
         struct ext4_group_info *grp;
+        int encrypt = 0;
 
         /* Cannot create files in a deleted directory */
         if (!dir || !dir->i_nlink)
                 return ERR_PTR(-EPERM);
 
+        if ((ext4_encrypted_inode(dir) ||
+             DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) &&
+            (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
+                err = ext4_get_encryption_info(dir);
+                if (err)
+                        return ERR_PTR(err);
+                if (ext4_encryption_info(dir) == NULL)
+                        return ERR_PTR(-EPERM);
+                if (!handle)
+                        nblocks += EXT4_DATA_TRANS_BLOCKS(dir->i_sb);
+                encrypt = 1;
+        }
+
         sb = dir->i_sb;
         ngroups = ext4_get_groups_count(sb);
         trace_ext4_request_inode(dir, mode);
@@ -996,12 +1010,6 @@ got:
         ei->i_block_group = group;
         ei->i_last_alloc_group = ~0;
 
-        /* If the directory encrypted, then we should encrypt the inode. */
-        if ((S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) &&
-            (ext4_encrypted_inode(dir) ||
-             DUMMY_ENCRYPTION_ENABLED(sbi)))
-                ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
-
         ext4_set_inode_flags(inode);
         if (IS_DIRSYNC(inode))
                 ext4_handle_sync(handle);
@@ -1063,6 +1071,12 @@ got:
                 ei->i_datasync_tid = handle->h_transaction->t_tid;
         }
 
+        if (encrypt) {
+                err = ext4_inherit_context(dir, inode);
+                if (err)
+                        goto fail_free_drop;
+        }
+
         err = ext4_mark_inode_dirty(handle, inode);
         if (err) {
                 ext4_std_error(sb, err);