Re: [PATCH][FAT] FAT dirent scan with hin take #3

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi,

Pekka Enberg wrote:
Hi,

On 8/31/05, Machida, Hiroyuki <[email protected]> wrote:

+inline
+static int hint_allocate(struct inode *dir)
+{
+       loff_t *hints;
+       int err = 0;
+
+       if (!MSDOS_I(dir)->scan_hints) {
+               hints = kcalloc(FAT_SCAN_NWAY, sizeof(loff_t), GFP_KERNEL);
+               if (!hints)
+                       err = -ENOMEM;


Better to bail out here as...


+
+               down(&MSDOS_I(dir)->scan_lock);
+               if (MSDOS_I(dir)->scan_hints)
+                       err = -EINVAL;


...you might overwrite -ENOMEM here masking the real problem.


It's ok. If MSDOS_I(dir)->scan_hints isn't NULL, it's not error case.
We need just kfree(hints) and return 0.(Assuming  kfree() accepts NULL)
I think EINVAL confuse you.

+               if (!err)
+                       MSDOS_I(dir)->scan_hints = hints;
+               up(&MSDOS_I(dir)->scan_lock);
+               if (err == -EINVAL) {


Gotos would make error handling much cleaner.

How about this ?

	if (!MSDOS_I(dir)->scan_hints) {
		hints  = kcalllo(....);

		down
		if (MSDOS_I(dir)->scan_hints) {
			up
			goto already_allocated;
		}
		if (hints)
			MSDOS_I(dir)->scan_hints = hints;
		up
	}
	return (hints == 0) ? -ENOMEM : 0;

already_allocated:
	kfree(hints); /* kfree accepts NULL */
	return 0;
		



+inline
+static int hint_index_body(const unsigned char *name, int name_len, int check_null)


Please consider calling this __hint_index() instead as per normal
naming conventions.

Agree.


+{
+       int i;
+       int val = 0;
+       unsigned char *p = (unsigned char *) name;
+       int id = current->pid;
+
+       for (i=0; i<name_len; i++) {
+               if (check_null && !*p) break;


Please put break on separate line. You still have quite a few of these.

Agree



+               val = ((val << 1) & 0xfe) | ((val & 0x80) ? 1 : 0);
+               val ^= *p;
+               p ++;
+       }
+       id = ((id >> 8) & 0xf) ^ (id & 0xf);
+       val = (val << 1) | (id & 1);
+       return val & (FAT_SCAN_NWAY-1);
+}


                              Pekka


--
Hiroyuki Machida		[email protected]		
SSW Dept. HENC, Sony Corp.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]
  Powered by Linux