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Decrease stack usage in mdraid 0.9x.

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We have only 92K of stack and using over 4K per frame is wasteful

	* grub-core/disk/mdraid_linux.c (grub_mdraid_detect): Allocate on heap
	rather than stack.
This commit is contained in:
Vladimir Serbinenko 2013-11-16 16:16:48 +01:00
parent 1a454efe89
commit e6a6182d95
2 changed files with 50 additions and 30 deletions
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9
ChangeLog
View file

@ -1,3 +1,12 @@
2013-11-16 Vladimir Serbinenko <phcoder@gmail.com>
Decrease stack usage in mdraid 0.9x.
We have only 92K of stack and using over 4K per frame is wasteful
* grub-core/disk/mdraid_linux.c (grub_mdraid_detect): Allocate on heap
rather than stack.
2013-11-16 Vladimir Serbinenko <phcoder@gmail.com>
Decrease stack usage in BtrFS.

67
grub-core/disk/mdraid_linux.c
View file

@ -184,9 +184,10 @@ grub_mdraid_detect (grub_disk_t disk,
{
grub_disk_addr_t sector;
grub_uint64_t size;
struct grub_raid_super_09 sb;
struct grub_raid_super_09 *sb = NULL;
grub_uint32_t *uuid;
grub_uint32_t level;
struct grub_diskfilter_vg *ret;
/* The sector where the mdraid 0.90 superblock is stored, if available. */
size = grub_disk_get_size (disk);
@ -195,27 +196,31 @@ grub_mdraid_detect (grub_disk_t disk,
return NULL;
sector = NEW_SIZE_SECTORS (size);
if (grub_disk_read (disk, sector, 0, SB_BYTES, &sb))
sb = grub_malloc (sizeof (*sb));
if (!sb)
return NULL;
if (grub_disk_read (disk, sector, 0, SB_BYTES, sb))
goto fail;
/* Look whether there is a mdraid 0.90 superblock. */
if (sb.md_magic != grub_cpu_to_md32_compile_time (SB_MAGIC))
if (sb->md_magic != grub_cpu_to_md32_compile_time (SB_MAGIC))
/* not 0.9x raid. */
return NULL;
goto fail;
if (sb.major_version != grub_cpu_to_md32_compile_time (0)
|| sb.minor_version != grub_cpu_to_md32_compile_time (90))
if (sb->major_version != grub_cpu_to_md32_compile_time (0)
|| sb->minor_version != grub_cpu_to_md32_compile_time (90))
/* Unsupported version. */
return NULL;
goto fail;
/* No need for explicit check that sb.size is 0 (unspecified) since
/* No need for explicit check that sb->size is 0 (unspecified) since
0 >= non-0 is false. */
if (((grub_disk_addr_t) grub_md_to_cpu32 (sb.size)) * 2 >= size)
return NULL;
if (((grub_disk_addr_t) grub_md_to_cpu32 (sb->size)) * 2 >= size)
goto fail;
/* FIXME: Check the checksum. */
level = grub_md_to_cpu32 (sb.level);
level = grub_md_to_cpu32 (sb->level);
/* Multipath. */
if ((int) level == -4)
level = 1;
@ -225,37 +230,43 @@ grub_mdraid_detect (grub_disk_t disk,
{
grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"unsupported RAID level: %d", level);
return NULL;
goto fail;
}
if (grub_md_to_cpu32 (sb.this_disk.number) == 0xffff
|| grub_md_to_cpu32 (sb.this_disk.number) == 0xfffe)
if (grub_md_to_cpu32 (sb->this_disk.number) == 0xffff
|| grub_md_to_cpu32 (sb->this_disk.number) == 0xfffe)
/* Spares aren't implemented. */
return NULL;
goto fail;
uuid = grub_malloc (16);
if (!uuid)
return NULL;
goto fail;
uuid[0] = grub_swap_bytes32 (sb.set_uuid0);
uuid[1] = grub_swap_bytes32 (sb.set_uuid1);
uuid[2] = grub_swap_bytes32 (sb.set_uuid2);
uuid[3] = grub_swap_bytes32 (sb.set_uuid3);
uuid[0] = grub_swap_bytes32 (sb->set_uuid0);
uuid[1] = grub_swap_bytes32 (sb->set_uuid1);
uuid[2] = grub_swap_bytes32 (sb->set_uuid2);
uuid[3] = grub_swap_bytes32 (sb->set_uuid3);
*start_sector = 0;
id->uuidlen = 0;
id->id = grub_md_to_cpu32 (sb.this_disk.number);
id->id = grub_md_to_cpu32 (sb->this_disk.number);
char buf[32];
grub_snprintf (buf, sizeof (buf), "md%d", grub_md_to_cpu32 (sb.md_minor));
return grub_diskfilter_make_raid (16, (char *) uuid,
grub_md_to_cpu32 (sb.raid_disks), buf,
(sb.size) ? ((grub_disk_addr_t)
grub_md_to_cpu32 (sb.size)) * 2
grub_snprintf (buf, sizeof (buf), "md%d", grub_md_to_cpu32 (sb->md_minor));
ret = grub_diskfilter_make_raid (16, (char *) uuid,
grub_md_to_cpu32 (sb->raid_disks), buf,
(sb->size) ? ((grub_disk_addr_t)
grub_md_to_cpu32 (sb->size)) * 2
: sector,
grub_md_to_cpu32 (sb.chunk_size) >> 9,
grub_md_to_cpu32 (sb.layout),
grub_md_to_cpu32 (sb->chunk_size) >> 9,
grub_md_to_cpu32 (sb->layout),
level);
grub_free (sb);
return ret;
fail:
grub_free (sb);
return NULL;
}
static struct grub_diskfilter grub_mdraid_dev = {