[CIFS] Allow to set extended attribute cifs_acl (try #2)

Allow setting cifs_acl on the server.
Pass on to the server the ACL blob generated by an application.
cifs is just a pass-through, it does not monitor or inspect the contents
of the blob, server decides whether to enforce/apply the ACL blob composed
by an application.
If setting of ACL is succeessful, mark the inode for revalidation.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/fs/cifs/xattr.c b/fs/cifs/xattr.c
index eae2a1491608..912995e013ec 100644
--- a/fs/cifs/xattr.c
+++ b/fs/cifs/xattr.c
@@ -112,6 +112,7 @@ int cifs_setxattr(struct dentry *direntry, const char *ea_name,
         struct cifsTconInfo *pTcon;
         struct super_block *sb;
         char *full_path;
+        struct cifs_ntsd *pacl;
 
         if (direntry == NULL)
                 return -EIO;
@@ -166,6 +167,25 @@ int cifs_setxattr(struct dentry *direntry, const char *ea_name,
                 rc = CIFSSMBSetEA(xid, pTcon, full_path, ea_name, ea_value,
                         (__u16)value_size, cifs_sb->local_nls,
                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
+        } else if (strncmp(ea_name, CIFS_XATTR_CIFS_ACL,
+                        strlen(CIFS_XATTR_CIFS_ACL)) == 0) {
+                pacl = kmalloc(value_size, GFP_KERNEL);
+                if (!pacl) {
+                        cFYI(1, "%s: Can't allocate memory for ACL",
+                                        __func__);
+                        rc = -ENOMEM;
+                } else {
+#ifdef CONFIG_CIFS_ACL
+                        memcpy(pacl, ea_value, value_size);
+                        rc = set_cifs_acl(pacl, value_size,
+                                direntry->d_inode, full_path);
+                        if (rc == 0) /* force revalidate of the inode */
+                                CIFS_I(direntry->d_inode)->time = 0;
+                        kfree(pacl);
+#else
+                        cFYI(1, "Set CIFS ACL not supported yet");
+#endif /* CONFIG_CIFS_ACL */
+                }
         } else {
                 int temp;
                 temp = strncmp(ea_name, POSIX_ACL_XATTR_ACCESS,