Re: [PATCH] NULL pointer in raid1_make_request passed to bio_trim when adding md as bcache caching dev
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From: Eric Wheeler <hidden>
Date: 2016-08-11 06:52:16
Also in:
linux-bcache, linux-raid
On Wed, 10 Aug 2016, Eric Wheeler wrote:
quoted hunk ↗ jump to hunk
On Sun, 10 Apr 2016 20:01:30 +0200, Sebastian Roesner wrote:quoted
Am 01.04.2016 um 20:14 schrieb Eric Wheeler:quoted
On Mon, 28 Mar 2016, Shaohua Li wrote:quoted
On Sat, Mar 26, 2016 at 05:46:16PM +0100, Sebastian Roesner wrote:quoted
Hello Ming, Eric, Am 26.03.2016 um 16:40 schrieb Ming Lei: I was able to reproduce it on a non-productive system, but only after copying the bcache superblocks/partition starts from the original system, with new created ones it worked fine.320 bvecs exceeds what bio-clone_set can handle. Could you please try below patch?Hey Sebastian, Have you had a chance to test the patch below from Shaohua Li?I just tried the patch and it did not crash anymore.It doesn't look like this made it into v4.8-rc1 and it is known to fix at least Sebastian's issue. commit 92761dad7ff6e1bf25de247e0064dd398e797599 Author: Shaohua Li [off-list ref] Date: Mon Mar 28 10:54:35 2016 -0700 block: don't make BLK_DEF_MAX_SECTORS too big bio_alloc_bioset() allocates bvecs from bvec_slabs which can only allocate maximum 256 bvec (eg, 1M for 4k pages). We can't bump BLK_DEF_MAX_SECTORS to exceed this value otherwise bio_alloc_bioset will fail. This fixes commit 30e2bc08b2bb7c069. We probably should make the bvec_slabs hold bigger bvecs if bigger bio size is required. Signed-off-by: Shaohua Li [off-list ref]diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 7e5d7e0..da64325 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h@@ -1153,7 +1153,11 @@ extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); enum blk_default_limits { BLK_MAX_SEGMENTS = 128, BLK_SAFE_MAX_SECTORS = 255, - BLK_DEF_MAX_SECTORS = 2560, + /* + * if you change this, please also change bvec_alloc and BIO_MAX_PAGES. + * Otherwise bio_alloc_bioset will break. + */ + BLK_DEF_MAX_SECTORS = BIO_MAX_SECTORS,
It seems that I spoke too soon, as BIO_MAX_SECTORS was removed for v4.8. What should BLK_DEF_MAX_SECTORS be defined as? Something like this? - BLK_DEF_MAX_SECTORS = 2560, + BLK_DEF_MAX_SECTORS = (BIO_MAX_PAGES << (PAGE_SHIFT-9) Or was this issue patched by Shaohua Li solved in some other way? It appears that BLK_DEF_MAX_SECTORS is still used: $ git grep BLK_DEF_MAX_SECTORS block/blk-settings.c: max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS); drivers/block/aoe/aoeblk.c: blk_queue_max_hw_sectors(q, BLK_DEF_MAX_SECTORS); drivers/scsi/sd.c: rw_max = BLK_DEF_MAX_SECTORS; -- Eric Wheeler
BLK_MAX_SEGMENT_SIZE = 65536, BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, }; -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html