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

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

diff --git a/fs/reiserfs/ioctl.c b/fs/reiserfs/ioctl.c
index e0f0f098a523a8d1c3a41099ab76b411989a23a0..74363a7aacbcb64154c81b1f6bcb832e0fee8727 100644 (file)
--- a/fs/reiserfs/ioctl.c
+++ b/fs/reiserfs/ioctl.c
@@ -4,6 +4,7 @@
 
 #include <linux/capability.h>
 #include <linux/fs.h>
+#include <linux/mount.h>
 #include <linux/reiserfs_fs.h>
 #include <linux/time.h>
 #include <asm/uaccess.h>
@@ -25,6 +26,7 @@ int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
                   unsigned long arg)
 {
        unsigned int flags;
+       int err = 0;
 
        switch (cmd) {
        case REISERFS_IOC_UNPACK:
@@ -48,50 +50,67 @@ int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
                        if (!reiserfs_attrs(inode->i_sb))
                                return -ENOTTY;
 
-                       if (IS_RDONLY(inode))
-                               return -EROFS;
+                       err = mnt_want_write(filp->f_path.mnt);
+                       if (err)
+                               return err;
 
-                       if (!is_owner_or_cap(inode))
-                               return -EPERM;
-
-                       if (get_user(flags, (int __user *)arg))
-                               return -EFAULT;
-
-                       /* Is it quota file? Do not allow user to mess with it. */
-                       if (IS_NOQUOTA(inode))
-                               return -EPERM;
+                       if (!is_owner_or_cap(inode)) {
+                               err = -EPERM;
+                               goto setflags_out;
+                       }
+                       if (get_user(flags, (int __user *)arg)) {
+                               err = -EFAULT;
+                               goto setflags_out;
+                       }
+                       /*
+                        * Is it quota file? Do not allow user to mess with it
+                        */
+                       if (IS_NOQUOTA(inode)) {
+                               err = -EPERM;
+                               goto setflags_out;
+                       }
                        if (((flags ^ REISERFS_I(inode)->
                              i_attrs) & (REISERFS_IMMUTABLE_FL |
                                          REISERFS_APPEND_FL))
-                           && !capable(CAP_LINUX_IMMUTABLE))
-                               return -EPERM;
-
+                           && !capable(CAP_LINUX_IMMUTABLE)) {
+                               err = -EPERM;
+                               goto setflags_out;
+                       }
                        if ((flags & REISERFS_NOTAIL_FL) &&
                            S_ISREG(inode->i_mode)) {
                                int result;
 
                                result = reiserfs_unpack(inode, filp);
-                               if (result)
-                                       return result;
+                               if (result) {
+                                       err = result;
+                                       goto setflags_out;
+                               }
                        }
                        sd_attrs_to_i_attrs(flags, inode);
                        REISERFS_I(inode)->i_attrs = flags;
                        inode->i_ctime = CURRENT_TIME_SEC;
                        mark_inode_dirty(inode);
-                       return 0;
+setflags_out:
+                       mnt_drop_write(filp->f_path.mnt);
+                       return err;
                }
        case REISERFS_IOC_GETVERSION:
                return put_user(inode->i_generation, (int __user *)arg);
        case REISERFS_IOC_SETVERSION:
                if (!is_owner_or_cap(inode))
                        return -EPERM;
-               if (IS_RDONLY(inode))
-                       return -EROFS;
-               if (get_user(inode->i_generation, (int __user *)arg))
-                       return -EFAULT;
+               err = mnt_want_write(filp->f_path.mnt);
+               if (err)
+                       return err;
+               if (get_user(inode->i_generation, (int __user *)arg)) {
+                       err = -EFAULT;
+                       goto setversion_out;
+               }
                inode->i_ctime = CURRENT_TIME_SEC;
                mark_inode_dirty(inode);
-               return 0;
+setversion_out:
+               mnt_drop_write(filp->f_path.mnt);
+               return err;
        default:
                return -ENOTTY;
        }