[PATCH] pc & gpt partmap iterators don't abort when their hook requests it

[Robert Millan <rmh@aybabtu.com>]

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See ChangeLog for description.  I'd really like to receive some review on
this one, since the code it touches is so fragile (although I tested it on a
typical setup and it works).

-- 
Robert Millan

<GPLv2> I know my rights; I want my phone call!
<DRM> What good is a phone call… if you are unable to speak?
(as seen on /.)

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2008-07-01  Robert Millan  <rmh@aybabtu.com>

	This fixes a performance issue when pc & gpt partmap iterators
	didn't abort iteration even after our hook found what it was
	looking for (often causing expensive probes of non-existant drives).

	The probe functions relied on previous buggy behaviour, since they
	would rise an error when their own hook (find_func()) caused early
	abortion of its iteration.

	* kern/device.c (grub_device_open): Improve error message.

	* partmap/pc.c (pc_partition_map_iterate): Abort parent iteration
	when hook requests it, independently of grub_errno.
	(pc_partition_map_probe): Do not fail when find_func() caused
	early abortion of pc_partition_map_iterate().

	* partmap/gpt.c (gpt_partition_map_iterate): Abort parent iteration
	when hook requests it, independently of grub_errno.
	(gpt_partition_map_probe): Do not fail when find_func() caused
	early abortion of gpt_partition_map_iterate().

diff -x debian -x ChangeLog -x configure -x config.h.in -x CVS -x '*~' -x '*.mk' -urp ../grub2/kern/device.c ./kern/device.c
--- ../grub2/kern/device.c	2008-01-10 00:25:54.000000000 +0100
+++ ./kern/device.c	2008-06-30 14:15:19.000000000 +0200
@@ -50,7 +50,7 @@ grub_device_open (const char *name)
   disk = grub_disk_open (name);
   if (! disk)
     {
-      grub_error (GRUB_ERR_BAD_DEVICE, "unknown device");
+      grub_error (GRUB_ERR_BAD_DEVICE, "unknown device %s", name);
       goto fail;
     }
 
diff -x debian -x ChangeLog -x configure -x config.h.in -x CVS -x '*~' -x '*.mk' -urp ../grub2/partmap/gpt.c ./partmap/gpt.c
--- ../grub2/partmap/gpt.c	2008-02-23 21:33:32.000000000 +0100
+++ ./partmap/gpt.c	2008-07-01 15:06:31.000000000 +0200
@@ -102,7 +102,7 @@ gpt_partition_map_iterate (grub_disk_t d
 			i, part.start, part.len);
 
 	  if (hook (disk, &part))
-	    return grub_errno;
+	    return 1;
 	}
 
       last_offset += grub_le_to_cpu32 (gpt.partentry_size);
@@ -150,8 +150,7 @@ gpt_partition_map_probe (grub_disk_t dis
       return 0;
     }
 
-  if (gpt_partition_map_iterate (disk, find_func))
-    goto fail;
+  gpt_partition_map_iterate (disk, find_func);
 
   return p;
 
diff -x debian -x ChangeLog -x configure -x config.h.in -x CVS -x '*~' -x '*.mk' -urp ../grub2/partmap/pc.c ./partmap/pc.c
--- ../grub2/partmap/pc.c	2007-07-22 01:32:30.000000000 +0200
+++ ./partmap/pc.c	2008-07-01 15:06:03.000000000 +0200
@@ -151,7 +151,7 @@ pc_partition_map_iterate (grub_disk_t di
 	      pcdata.dos_part++;
 	      
 	      if (hook (disk, &p))
-		goto finish;
+		return 1;
 
 	      /* Check if this is a BSD partition.  */
 	      if (grub_pc_partition_is_bsd (e->type))
@@ -255,8 +255,7 @@ pc_partition_map_probe (grub_disk_t disk
     return 0;
   
   pcdata = p->data;
-  if (pc_partition_map_iterate (disk, find_func))
-    goto fail;
+  pc_partition_map_iterate (disk, find_func);
 
   if (p->index < 0)
     {