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authorNeilBrown <neilb@suse.de>2011-07-28 11:31:48 +1000
committerNeilBrown <neilb@suse.de>2011-07-28 11:31:48 +1000
commitd2eb35acfdccbe2a3622ed6cc441a5482148423b (patch)
tree77600cab29fc9e1fd39d612773086a456fc32d88 /drivers/md/md.h
parent9f2f3830789a4c9c1af2d1437d407c43e05136e6 (diff)
downloadop-kernel-dev-d2eb35acfdccbe2a3622ed6cc441a5482148423b.zip
op-kernel-dev-d2eb35acfdccbe2a3622ed6cc441a5482148423b.tar.gz
md/raid1: avoid reading from known bad blocks.
Now that we have a bad block list, we should not read from those blocks. There are several main parts to this: 1/ read_balance needs to check for bad blocks, and return not only the chosen device, but also how many good blocks are available there. 2/ fix_read_error needs to avoid trying to read from bad blocks. 3/ read submission must be ready to issue multiple reads to different devices as different bad blocks on different devices could mean that a single large read cannot be served by any one device, but can still be served by the array. This requires keeping count of the number of outstanding requests per bio. This count is stored in 'bi_phys_segments' 4/ retrying a read needs to also be ready to submit a smaller read and queue another request for the rest. This does not yet handle bad blocks when reading to perform resync, recovery, or check. 'md_trim_bio' will also be used for RAID10, so put it in md.c and export it. Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md/md.h')
-rw-r--r--drivers/md/md.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/md/md.h b/drivers/md/md.h
index aea9e9f..7c3192c 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -575,4 +575,5 @@ extern struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
mddev_t *mddev);
extern int mddev_check_plugged(mddev_t *mddev);
+extern void md_trim_bio(struct bio *bio, int offset, int size);
#endif /* _MD_MD_H */
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