userns: Pass a userns parameter into posix_acl_to_xattr and posix_acl_from_xattr

 - Pass the user namespace the uid and gid values in the xattr are stored
   in into posix_acl_from_xattr.

 - Pass the user namespace kuid and kgid values should be converted into
   when storing uid and gid values in an xattr in posix_acl_to_xattr.

- Modify all callers of posix_acl_from_xattr and posix_acl_to_xattr to
  pass in &init_user_ns.

In the short term this change is not strictly needed but it makes the
code clearer.  In the longer term this change is necessary to be able to
mount filesystems outside of the initial user namespace that natively
store posix acls in the linux xattr format.

Cc: Theodore Tso <tytso@mit.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

2 files changed, 4 insertions, 4 deletions

diff --git a/fs/jfs/acl.c b/fs/jfs/acl.c
index 45559dc3ea2..d254d6d3599 100644
--- a/fs/jfs/acl.c
+++ b/fs/jfs/acl.c
@@ -64,7 +64,7 @@ struct posix_acl *jfs_get_acl(struct inode *inode, int type)
                 else
                         acl = ERR_PTR(size);
         } else {
-                acl = posix_acl_from_xattr(value, size);
+                acl = posix_acl_from_xattr(&init_user_ns, value, size);
         }
         kfree(value);
         if (!IS_ERR(acl))
@@ -100,7 +100,7 @@ static int jfs_set_acl(tid_t tid, struct inode *inode, int type,
                 value = kmalloc(size, GFP_KERNEL);
                 if (!value)
                         return -ENOMEM;
-                rc = posix_acl_to_xattr(acl, value, size);
+                rc = posix_acl_to_xattr(&init_user_ns, acl, value, size);
                 if (rc < 0)
                         goto out;
         }
diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c
index 26683e15b3a..42d67f9757b 100644
--- a/fs/jfs/xattr.c
+++ b/fs/jfs/xattr.c
@@ -685,7 +685,7 @@ static int can_set_system_xattr(struct inode *inode, const char *name,
          * POSIX_ACL_XATTR_ACCESS is tied to i_mode
          */
         if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0) {
-                acl = posix_acl_from_xattr(value, value_len);
+                acl = posix_acl_from_xattr(&init_user_ns, value, value_len);
                 if (IS_ERR(acl)) {
                         rc = PTR_ERR(acl);
                         printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
@@ -710,7 +710,7 @@ static int can_set_system_xattr(struct inode *inode, const char *name,
 
                 return 0;
         } else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0) {
-                acl = posix_acl_from_xattr(value, value_len);
+                acl = posix_acl_from_xattr(&init_user_ns, value, value_len);
                 if (IS_ERR(acl)) {
                         rc = PTR_ERR(acl);
                         printk(KERN_ERR "posix_acl_from_xattr returned %d\n",