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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-18 18:23:53 +08:00
linux-next/include/linux/raid
Raz Ben-Jehuda(caro) 46031f9a38 [PATCH] md: allow reads that have bypassed the cache to be retried on failure
If a bypass-the-cache read fails, we simply try again through the cache.  If
it fails again it will trigger normal recovery precedures.

update 1:

From: NeilBrown <neilb@suse.de>

1/
  chunk_aligned_read and retry_aligned_read assume that
      data_disks == raid_disks - 1
  which is not true for raid6.
  So when an aligned read request bypasses the cache, we can get the wrong data.

2/ The cloned bio is being used-after-free in raid5_align_endio
   (to test BIO_UPTODATE).

3/ We forgot to add rdev->data_offset when submitting
   a bio for aligned-read

4/ clone_bio calls blk_recount_segments and then we change bi_bdev,
   so we need to invalidate the segment counts.

5/ We don't de-reference the rdev when the read completes.
   This means we need to record the rdev to so it is still
   available in the end_io routine.  Fortunately
   bi_next in the original bio is unused at this point so
   we can stuff it in there.

6/ We leak a cloned bio if the target rdev is not usable.

From: NeilBrown <neilb@suse.de>

update 2:

1/ When aligned requests fail (read error) they need to be retried
   via the normal method (stripe cache).  As we cannot be sure that
   we can process a single read in one go (we may not be able to
   allocate all the stripes needed) we store a bio-being-retried
   and a list of bioes-that-still-need-to-be-retried.
   When find a bio that needs to be retried, we should add it to
   the list, not to single-bio...

2/ We were never incrementing 'scnt' when resubmitting failed
   aligned requests.

[akpm@osdl.org: build fix]
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:57:20 -08:00
..
bitmap.h [PATCH] md: endian annotations for the bitmap superblock 2006-10-21 13:35:05 -07:00
Kbuild [HEADERS] One line per header in Kbuild files to reduce conflicts 2006-09-19 12:43:58 +01:00
linear.h [PATCH] md: allow a linear array to have drives added while active 2006-06-26 09:58:37 -07:00
md_k.h [PATCH] md: remove MAX_MD_DEVS which is an arbitrary limit 2006-10-03 08:04:18 -07:00
md_p.h [PATCH] md: endian annotation for v1 superblock access 2006-10-21 13:35:05 -07:00
md_u.h [PATCH] md: the scheduled removal of the START_ARRAY ioctl for md 2006-10-03 08:04:16 -07:00
md.h [PATCH] md: replace magic numbers in sb_dirty with well defined bit flags 2006-10-03 08:04:17 -07:00
multipath.h
raid0.h
raid1.h [PATCH] md: Remove working_disks from raid1 state data 2006-10-03 08:04:17 -07:00
raid5.h [PATCH] md: allow reads that have bypassed the cache to be retried on failure 2006-12-10 09:57:20 -08:00
raid10.h [PATCH] md: remove 'working_disks' from raid10 state 2006-10-03 08:04:17 -07:00
xor.h