From: Evan Felix <evan.felix@pnl.gov>
To: linux-raid <linux-raid@vger.kernel.org>,
linux-kernel@vger.kernel.org, neilb@cse.unsw.edu.au
Subject: [PATCH] Linux Raid5/6 abover 2 Terabytes
Date: Tue, 06 Apr 2004 14:00:40 -0700 [thread overview]
Message-ID: <1081285240.2219.43.camel@e-linux> (raw)
[-- Attachment #1: Type: text/plain, Size: 2342 bytes --]
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
[-- Attachment #2: fix_block_mask.patch --]
[-- Type: text/x-patch, Size: 1383 bytes --]
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;
next reply other threads:[~2004-04-06 21:00 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-04-06 21:00 Evan Felix [this message]
2004-04-06 23:02 ` [PATCH] Linux Raid5/6 abover 2 Terabytes Andreas Schwab
2004-04-06 23:02 ` Andreas Schwab
[not found] <249C1CB246997C48BB74963CCD361C1B02376A60@pnlmse28.pnl.gov>
2004-04-12 15:53 ` Evan Felix
2004-05-01 7:08 ` Brad Campbell
2004-05-03 17:49 ` Evan Felix
2004-05-04 1:24 ` Neil Brown
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