[PATCH] Fix floppy ioctls, REVISED edition

From: Alain Knaff (Alain.Knaff@ltnb.lu)
Date: Sat Sep 16 2000 - 12:22:38 EST


The following patch (against 2.4.0-test8) restores floppy ioctl functionality,
which has been broken in 2.4.0-test6-pre7. It now tests for fake
ioctl's, so their should be no interaction with read-only mounts:

--- 2.4.0-test8/linux/drivers/block/floppy.c Mon Sep 11 20:09:28 2000
+++ linux/drivers/block/floppy.c Sat Sep 16 18:57:14 2000
@@ -3435,6 +3435,7 @@
 static int fd_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
                     unsigned long param)
 {
+#define FD_IOCTL_ALLOWED ((filp) && (filp)->private_data)
 #define OUT(c,x) case c: outparam = (const char *) (x); break
 #define IN(c,x,tag) case c: *(x) = inparam. tag ; return 0
 
@@ -3502,7 +3503,7 @@
                 return -EINVAL;
 
         /* permission checks */
- if (((cmd & 0x40) && !(filp->f_mode & 2)) ||
+ if (((cmd & 0x40) && !FD_IOCTL_ALLOWED) ||
             ((cmd & 0x80) && !capable(CAP_SYS_ADMIN)))
                 return -EPERM;
 
@@ -3708,6 +3709,8 @@
                 return -EIO;
         }
 
+ filp->private_data = (void*) 0;
+
         drive = DRIVE(inode->i_rdev);
         if (drive >= N_DRIVE ||
             !(allowed_drive_mask & (1 << drive)) ||
@@ -3774,6 +3777,13 @@
                         buffer_track = -1;
                 invalidate_buffers(MKDEV(FLOPPY_MAJOR,old_dev));
         }
+
+ /* Allow ioctls if we have write-permissions even if read-only open.
+ * Needed so that programs such as fdrawcmd still can work on write
+ * protected disks */
+ if ((filp->f_mode & 2) ||
+ (inode->i_sb && (permission(inode,2) == 0)))
+ filp->private_data = (void*) 8;
 
         if (UFDCS->rawcmd == 1)
                 UFDCS->rawcmd = 2;
-
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