Re: *FAT problem in 2.6.0-test8

[Andries Brouwer <aebr@win.tue.nl>]

On Sat, Oct 25, 2003 at 07:18:03PM +0900, OGAWA Hirofumi wrote:

> It looks like it doesn't conform to Microsoft's or SmartMedia's
> specifications.
> 
> Yes. It will be important to know how it was formated. 

Yesterday I wondered whether I should propose a patch,
say something like

--- /linux/2.6/linux-2.6.0test6/linux/fs/fat/inode.c    Sat Aug  9 22:16:54 2003
+++ ./inode.c   Sat Oct 25 00:04:18 2003
@@ -931,13 +931,17 @@
                error = first;
                goto out_fail;
        }
-       if (FAT_FIRST_ENT(sb, media) != first
-           && (media != 0xf8 || FAT_FIRST_ENT(sb, 0xfe) != first)) {
-               if (!silent) {
+       if (FAT_FIRST_ENT(sb, media) == first) {
+               /* all is as it should be */
+       } else if (media == 0xf8 && FAT_FIRST_ENT(sb, 0xfe) == first) {
+               /* bad, reported on pc9800 */
+       } else if (first == 0) {
+               /* bad, reported once with a SmartMedia card */
+       } else {
+               if (!silent)
                        printk(KERN_ERR "FAT: invalid first entry of FAT "
                               "(0x%x != 0x%x)\n",
                               FAT_FIRST_ENT(sb, media), first);
-               }
                goto out_invalid;
        }
 
but maybe a single report does not suffice. It would be good to confirm
that certain devices write 0 there. (I would have asked the reporter
to do "dd if=/dev/zero of=/dev/something" and reinsert the card into
the camera, but fiddling with smartmedia cards is a bit dangerous -
not all readers and not all cameras are able to recover from such a
situation, so the card might become unusable without access to other
readers or other cameras.)

Andries

[BTW - Does anyone have more information about this other nonstandard
value, apparently found on pc9800?]