Here is a patch that fixes a major issue in the raid5/6 code. It seems
that the code:
logical_sector = bi->bi_sector & ~(STRIPE_SECTORS-1);
(sector_t) = (sector_t) & (constant)
that the right side of the & does not get extended correctly when the
constant is promoted to the sector_t type. I have CONFIG_LBD turned on
so sector_t should be 64bits wide. This fails to properly mask the
value of 4294967296 (2TB/512) to 4294967296. in my case it was coming
out 0. this cause the loop following this code to read from 0 to
4294967296 blocks so it could write one character.
As you might imagine this makes a format of a 3.5TB filesystem take a
very long time.
Here is the patch:
Binary files linux-2.6.5/drivers/md/mktables and
linux-2.6.5fixraid/drivers/md/mktables differ
diff -urN -X /home/efelix/.cvsignore linux-2.6.5/drivers/md/raid5.c
linux-2.6.5fixraid/drivers/md/raid5.c
--- linux-2.6.5/drivers/md/raid5.c 2004-04-04 03:36:26.000000000 +0000
+++ linux-2.6.5fixraid/drivers/md/raid5.c 2004-04-06 18:26:05.000000000
+0000
@@ -1334,8 +1334,9 @@
disk_stat_add(mddev->gendisk, read_sectors, bio_sectors(bi));
}
- logical_sector = bi->bi_sector & ~(STRIPE_SECTORS-1);
+ logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
last_sector = bi->bi_sector + (bi->bi_size>>9);
+ PRINTK("Bio: %Lu logical %Lu last
%Lu\n",bi->bi_sector,logical_sector,last_sector);
bi->bi_next = NULL;
bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
diff -urN -X /home/efelix/.cvsignore linux-2.6.5/drivers/md/raid6main.c
linux-2.6.5fixraid/drivers/md/raid6main.c
--- linux-2.6.5/drivers/md/raid6main.c 2004-04-04 03:36:14.000000000
+0000
+++ linux-2.6.5fixraid/drivers/md/raid6main.c 2004-04-06
18:31:30.000000000 +0000
@@ -1496,7 +1496,7 @@
disk_stat_add(mddev->gendisk, read_sectors, bio_sectors(bi));
}
- logical_sector = bi->bi_sector & ~(STRIPE_SECTORS-1);
+ logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
last_sector = bi->bi_sector + (bi->bi_size>>9);
bi->bi_next = NULL;
I have tested this on at least 2 arrays, with ext2 and some long dd's
Evan
--
-------------------------
Evan Felix
Administrator of Supercomputer #5 in Top 500, Nov 2003
Environmental Molecular Sciences Laboratory
Pacific Northwest National Laboratory
Operated for the U.S. DOE by Battelle
Binary files linux-2.6.5/drivers/md/mktables and linux-2.6.5fixraid/drivers/md/mktables differ
diff -urN -X /home/efelix/.cvsignore linux-2.6.5/drivers/md/raid5.c linux-2.6.5fixraid/drivers/md/raid5.c
--- linux-2.6.5/drivers/md/raid5.c 2004-04-04 03:36:26.000000000 +0000
+++ linux-2.6.5fixraid/drivers/md/raid5.c 2004-04-06 18:26:05.000000000 +0000
@@ -1334,8 +1334,9 @@
disk_stat_add(mddev->gendisk, read_sectors, bio_sectors(bi));
}
- logical_sector = bi->bi_sector & ~(STRIPE_SECTORS-1);
+ logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
last_sector = bi->bi_sector + (bi->bi_size>>9);
+ PRINTK("Bio: %Lu logical %Lu last %Lu\n",bi->bi_sector,logical_sector,last_sector);
bi->bi_next = NULL;
bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
diff -urN -X /home/efelix/.cvsignore linux-2.6.5/drivers/md/raid6main.c linux-2.6.5fixraid/drivers/md/raid6main.c
--- linux-2.6.5/drivers/md/raid6main.c 2004-04-04 03:36:14.000000000 +0000
+++ linux-2.6.5fixraid/drivers/md/raid6main.c 2004-04-06 18:31:30.000000000 +0000
@@ -1496,7 +1496,7 @@
disk_stat_add(mddev->gendisk, read_sectors, bio_sectors(bi));
}
- logical_sector = bi->bi_sector & ~(STRIPE_SECTORS-1);
+ logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
last_sector = bi->bi_sector + (bi->bi_size>>9);
bi->bi_next = NULL;
