1 files changed, 52 insertions, 48 deletions

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index ddbd096c7406..605f514f3b47 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -648,38 +648,17 @@ out_lock:
         return rc;
 }
 
-static int
-ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
+static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
+                                   size_t *bufsiz)
 {
+        struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
         char *lower_buf;
-        size_t lower_bufsiz;
-        struct dentry *lower_dentry;
-        struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
-        char *plaintext_name;
-        size_t plaintext_name_size;
+        size_t lower_bufsiz = PATH_MAX;
         mm_segment_t old_fs;
         int rc;
 
-        lower_dentry = ecryptfs_dentry_to_lower(dentry);
-        if (!lower_dentry->d_inode->i_op->readlink) {
-                rc = -EINVAL;
-                goto out;
-        }
-        mount_crypt_stat = &ecryptfs_superblock_to_private(
-                                                dentry->d_sb)->mount_crypt_stat;
-        /*
-         * If the lower filename is encrypted, it will result in a significantly
-         * longer name.  If needed, truncate the name after decode and decrypt.
-         */
-        if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
-                lower_bufsiz = PATH_MAX;
-        else
-                lower_bufsiz = bufsiz;
-        /* Released in this function */
         lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
-        if (lower_buf == NULL) {
-                printk(KERN_ERR "%s: Out of memory whilst attempting to "
-                       "kmalloc [%zd] bytes\n", __func__, lower_bufsiz);
+        if (!lower_buf) {
                 rc = -ENOMEM;
                 goto out;
         }
@@ -689,29 +668,31 @@ ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
                                                    (char __user *)lower_buf,
                                                    lower_bufsiz);
         set_fs(old_fs);
-        if (rc >= 0) {
-                rc = ecryptfs_decode_and_decrypt_filename(&plaintext_name,
-                                                          &plaintext_name_size,
-                                                          dentry, lower_buf,
-                                                          rc);
-                if (rc) {
-                        printk(KERN_ERR "%s: Error attempting to decode and "
-                               "decrypt filename; rc = [%d]\n", __func__,
-                                rc);
-                        goto out_free_lower_buf;
-                }
-                /* Check for bufsiz <= 0 done in sys_readlinkat() */
-                rc = copy_to_user(buf, plaintext_name,
-                                  min((size_t) bufsiz, plaintext_name_size));
-                if (rc)
-                        rc = -EFAULT;
-                else
-                        rc = plaintext_name_size;
-                kfree(plaintext_name);
-                fsstack_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode);
-        }
-out_free_lower_buf:
+        if (rc < 0)
+                goto out;
+        lower_bufsiz = rc;
+        rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry,
+                                                  lower_buf, lower_bufsiz);
+out:
         kfree(lower_buf);
+        return rc;
+}
+
+static int
+ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
+{
+        char *kbuf;
+        size_t kbufsiz, copied;
+        int rc;
+
+        rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz);
+        if (rc)
+                goto out;
+        copied = min_t(size_t, bufsiz, kbufsiz);
+        rc = copy_to_user(buf, kbuf, copied) ? -EFAULT : copied;
+        kfree(kbuf);
+        fsstack_copy_attr_atime(dentry->d_inode,
+                                ecryptfs_dentry_to_lower(dentry)->d_inode);
 out:
         return rc;
 }
@@ -1016,6 +997,28 @@ out:
         return rc;
 }
 
+int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
+                          struct kstat *stat)
+{
+        struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+        int rc = 0;
+
+        mount_crypt_stat = &ecryptfs_superblock_to_private(
+                                                dentry->d_sb)->mount_crypt_stat;
+        generic_fillattr(dentry->d_inode, stat);
+        if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
+                char *target;
+                size_t targetsiz;
+
+                rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
+                if (!rc) {
+                        kfree(target);
+                        stat->size = targetsiz;
+                }
+        }
+        return rc;
+}
+
 int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
                      struct kstat *stat)
 {
@@ -1133,6 +1136,7 @@ const struct inode_operations ecryptfs_symlink_iops = {
         .put_link = ecryptfs_put_link,
         .permission = ecryptfs_permission,
         .setattr = ecryptfs_setattr,
+        .getattr = ecryptfs_getattr_link,
         .setxattr = ecryptfs_setxattr,
         .getxattr = ecryptfs_getxattr,
         .listxattr = ecryptfs_listxattr,