| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Mon, 10 Jan 2011 11:27:49 -0800 (PST)
From: Luben Tuikov <ltuikov@...oo.com>
To: Jens Axboe <jaxboe@...ionio.com>
Cc: "linux-scsi@...r.kernel.org" <linux-scsi@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] [BLOCK] Allow tag 0 to be generated
--- On Mon, 1/10/11, Jens Axboe <jaxboe@...ionio.com> wrote:
> > That commit isn't a valid sha in my tree. What commit
> do you mean?
> >
> >> skipped tag 0 by virtue of setting last_tag to
> >> 0. This commit sets it to -1, in order to start
> >> and loop over from 0, thus generating tags
> >> [0,max_tag-1], instead of [1,max_tag-1].
> >
> > Irregardless, patch looks good. That's definitely a
> bug. Thanks!
>
> But not in my kernel, what tree are you looking at? I don't
> remember
> seeing any tag patches, and they should be in my tree if
> there are.
It applies on top of this patch:
>From 67869fb9fdfa04503b250d59e086c15f1698aea0 Mon Sep 17 00:00:00 2001
From: Luben Tuikov <ltuikov@...oo.com>
Date: Wed, 24 Nov 2010 14:18:27 -0800
Subject: [PATCH] [BLOCK] Preliminary increasing tag sequence implementation
Signed-off-by: Luben Tuikov <ltuikov@...oo.com>
---
block/blk-tag.c | 15 +++++++++++++--
include/linux/blkdev.h | 1 +
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/block/blk-tag.c b/block/blk-tag.c
index ece65fc..f792e98 100644
--- a/block/blk-tag.c
+++ b/block/blk-tag.c
@@ -130,6 +130,7 @@ init_tag_map(struct request_queue *q, struct blk_queue_tag *tags, int depth)
tags->max_depth = depth;
tags->tag_index = tag_index;
tags->tag_map = tag_map;
+ tags->last_tag = 0;
return 0;
fail:
@@ -222,7 +223,7 @@ int blk_queue_resize_tags(struct request_queue *q, int new_depth)
struct blk_queue_tag *bqt = q->queue_tags;
struct request **tag_index;
unsigned long *tag_map;
- int max_depth, nr_ulongs;
+ int max_depth, nr_ulongs, last_tag;
if (!bqt)
return -ENXIO;
@@ -251,6 +252,7 @@ int blk_queue_resize_tags(struct request_queue *q, int new_depth)
tag_index = bqt->tag_index;
tag_map = bqt->tag_map;
max_depth = bqt->real_max_depth;
+ last_tag = bqt->last_tag;
if (init_tag_map(q, bqt, new_depth))
return -ENOMEM;
@@ -258,6 +260,7 @@ int blk_queue_resize_tags(struct request_queue *q, int new_depth)
memcpy(bqt->tag_index, tag_index, max_depth * sizeof(struct request *));
nr_ulongs = ALIGN(max_depth, BITS_PER_LONG) / BITS_PER_LONG;
memcpy(bqt->tag_map, tag_map, nr_ulongs * sizeof(unsigned long));
+ bqt->last_tag = last_tag;
kfree(tag_index);
kfree(tag_map);
@@ -364,12 +367,20 @@ int blk_queue_start_tag(struct request_queue *q, struct request *rq)
return 1;
}
+ if (bqt->last_tag == bqt->max_depth-1)
+ bqt->last_tag = 0;
+
do {
- tag = find_first_zero_bit(bqt->tag_map, max_depth);
+ tag = find_next_zero_bit(bqt->tag_map,
+ max_depth,
+ bqt->last_tag+1);
if (tag >= max_depth)
return 1;
} while (test_and_set_bit_lock(tag, bqt->tag_map));
+
+ bqt->last_tag = tag;
+
/*
* We need lock ordering semantics given by test_and_set_bit_lock.
* See blk_queue_end_tag for details.
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index aae86fd..228efcc 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -224,6 +224,7 @@ struct blk_queue_tag {
int max_depth; /* what we will send to device */
int real_max_depth; /* what the array can hold */
atomic_t refcnt; /* map can be shared */
+ int last_tag;
};
#define BLK_SCSI_MAX_CMDS (256)
--
1.7.2.2.165.gbc382
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists