[PATCH] r/o bind mounts: elevate write count for ioctls()

[linux-2.6-omap-h63xx.git] / fs / hfsplus / ioctl.c

diff --git a/fs/hfsplus/ioctl.c b/fs/hfsplus/ioctl.c
index b60c0affbec58af68e45fd063692a933949ad457..f457d2ca51ab8e68a3e60cd9028620fa029f8f18 100644 (file)
--- a/fs/hfsplus/ioctl.c
+++ b/fs/hfsplus/ioctl.c
@@ -14,6 +14,7 @@
 
 #include <linux/capability.h>
 #include <linux/fs.h>
+#include <linux/mount.h>
 #include <linux/sched.h>
 #include <linux/xattr.h>
 #include <asm/uaccess.h>
@@ -35,25 +36,32 @@ int hfsplus_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
                        flags |= FS_NODUMP_FL; /* EXT2_NODUMP_FL */
                return put_user(flags, (int __user *)arg);
        case HFSPLUS_IOC_EXT2_SETFLAGS: {
-               if (IS_RDONLY(inode))
-                       return -EROFS;
-
-               if (!is_owner_or_cap(inode))
-                       return -EACCES;
-
-               if (get_user(flags, (int __user *)arg))
-                       return -EFAULT;
-
+               int err = 0;
+               err = mnt_want_write(filp->f_path.mnt);
+               if (err)
+                       return err;
+
+               if (!is_owner_or_cap(inode)) {
+                       err = -EACCES;
+                       goto setflags_out;
+               }
+               if (get_user(flags, (int __user *)arg)) {
+                       err = -EFAULT;
+                       goto setflags_out;
+               }
                if (flags & (FS_IMMUTABLE_FL|FS_APPEND_FL) ||
                    HFSPLUS_I(inode).rootflags & (HFSPLUS_FLG_IMMUTABLE|HFSPLUS_FLG_APPEND)) {
-                       if (!capable(CAP_LINUX_IMMUTABLE))
-                               return -EPERM;
+                       if (!capable(CAP_LINUX_IMMUTABLE)) {
+                               err = -EPERM;
+                               goto setflags_out;
+                       }
                }
 
                /* don't silently ignore unsupported ext2 flags */
-               if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL))
-                       return -EOPNOTSUPP;
-
+               if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) {
+                       err = -EOPNOTSUPP;
+                       goto setflags_out;
+               }
                if (flags & FS_IMMUTABLE_FL) { /* EXT2_IMMUTABLE_FL */
                        inode->i_flags |= S_IMMUTABLE;
                        HFSPLUS_I(inode).rootflags |= HFSPLUS_FLG_IMMUTABLE;
@@ -75,7 +83,9 @@ int hfsplus_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
 
                inode->i_ctime = CURRENT_TIME_SEC;
                mark_inode_dirty(inode);
-               return 0;
+setflags_out:
+               mnt_drop_write(filp->f_path.mnt);
+               return err;
        }
        default:
                return -ENOTTY;