kernel/linux.git/include/linux/raid, branch linux-2.6.16.y

md: avoid possible BUG_ON in md bitmap handling

2007-08-23T00:13:17+00:00

md/bitmap tracks how many active write requests are pending on blocks associated with each bit in the bitmap, so that it knows when it can clear the bit (when count hits zero). The counter has 14 bits of space, so if there are ever more than 16383, we cannot cope. Currently the code just calles BUG_ON as "all" drivers have request queue limits much smaller than this. However is seems that some don't. Apparently some multipath configurations can allow more than 16383 concurrent write requests. So, in this unlikely situation, instead of calling BUG_ON we now wait for the count to drop down a bit. This requires a new wait_queue_head, some waiting code, and a wakeup call. Tested by limiting the counter to 20 instead of 16383 (writes go a lot slower in that case...). Signed-off-by: Neil Brown Signed-off-by: Adrian Bunk

md: fix resync speed calculation for restarted resyncs

2007-08-22T22:57:45+00:00

We introduced 'io_sectors' recently so we could count the sectors that causes io during resync separate from sectors which didn't cause IO - there can be a difference if a bitmap is being used to accelerate resync. However when a speed is reported, we find the number of sectors processed recently by subtracting an oldish io_sectors count from a current 'curr_resync' count. This is wrong because curr_resync counts all sectors, not just io sectors. So, add a field to mddev to store the curren io_sectors separately from curr_resync, and use that in the calculations. Signed-off-by: Neil Brown Signed-off-by: Adrian Bunk

md/bitmap: remove dead code from md/bitmap

2007-08-11T23:07:37+00:00

bitmap_active is never called, and the BITMAP_ACTIVE flag is never users or tested, so discard them both. Also remove some out-of-date 'todo' comments. Signed-off-by: Neil Brown Signed-off-by: Adrian Bunk

[PATCH] DM: Fix bug: BIO_RW_BARRIER requests to md/raid1 hang.

2006-03-28T06:47:31+00:00

Both R1BIO_Barrier and R1BIO_Returned are 4 !!!! This means that barrier requests don't get returned (i.e. b_endio called) because it looks like they already have been. Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Chris Wright Signed-off-by: Greg Kroah-Hartman

[PATCH] md: allow sync-speed to be controlled per-device

2006-01-06T16:34:10+00:00

Also export current (average) speed and status in sysfs. Signed-off-by: Neil Brown Acked-by: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] md: count corrected read errors per drive

2006-01-06T16:34:09+00:00

Store this total in superblock (As appropriate), and make it available to userspace via sysfs. Signed-off-by: Neil Brown Acked-by: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] md: allow array level to be set textually via sysfs

2006-01-06T16:34:09+00:00

Signed-off-by: Neil Brown Acked-by: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] md: make a couple of names in md.c static

2006-01-06T16:34:07+00:00

.. because they aren't used outside md.c Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] md: define and use safe_put_page for md

2006-01-06T16:34:07+00:00

md sometimes call put_page on NULL pointers (treating it like kfree). This is not safe, so define and use a 'safe_put_page' which checks for NULL. Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] md: remove personality numbering from md

2006-01-06T16:34:06+00:00

md supports multiple different RAID level, each being implemented by a 'personality' (which is often in a separate module). These personalities have fairly artificial 'numbers'. The numbers are use to: 1- provide an index into an array where the various personalities are recorded 2- identify the module (via an alias) which implements are particular personality. Neither of these uses really justify the existence of personality numbers. The array can be replaced by a linked list which is searched (array lookup only happens very rarely). Module identification can be done using an alias based on level rather than 'personality' number. The current 'raid5' modules support two level (4 and 5) but only one personality. This slight awkwardness (which was handled in the mapping from level to personality) can be better handled by allowing raid5 to register 2 personalities. With this change in place, the core md module does not need to have an exhaustive list of all possible personalities, so other personalities can be added independently. This patch also moves the check for chunksize being non-zero into the ->run routines for the personalities that need it, rather than having it in core-md. This has a side effect of allowing 'faulty' and 'linear' not to have a chunk-size set. Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds