linux/drivers/md, branch v2.6.28

md: Don't read past end of bitmap when reading bitmap.

2008-12-19T05:25:01Z

When we read the write-intent-bitmap off the device, we currently read a whole number of pages. When PAGE_SIZE is 4K, this works due to the alignment we enforce on the superblock and bitmap. When PAGE_SIZE is 64K, this case read past the end-of-device which causes an error. When we write the superblock, we ensure to clip the last page to just be the required size. Copy that code into the read path to just read the required number of sectors. Signed-off-by: Neil Brown Cc: stable@kernel.org

block: fix setting of max_segment_size and seg_boundary mask

2008-12-03T11:55:55Z

Fix setting of max_segment_size and seg_boundary mask for stacked md/dm devices. When stacking devices (LVM over MD over SCSI) some of the request queue parameters are not set up correctly in some cases by default, namely max_segment_size and and seg_boundary mask. If you create MD device over SCSI, these attributes are zeroed. Problem become when there is over this mapping next device-mapper mapping - queue attributes are set in DM this way: request_queue max_segment_size seg_boundary_mask SCSI 65536 0xffffffff MD RAID1 0 0 LVM 65536 -1 (64bit) Unfortunately bio_add_page (resp. bio_phys_segments) calculates number of physical segments according to these parameters. During the generic_make_request() is segment cout recalculated and can increase bio->bi_phys_segments count over the allowed limit. (After bio_clone() in stack operation.) Thi is specially problem in CCISS driver, where it produce OOPS here BUG_ON(creq->nr_phys_segments > MAXSGENTRIES); (MAXSEGENTRIES is 31 by default.) Sometimes even this command is enough to cause oops: dd iflag=direct if=/dev// of=/dev/null bs=128000 count=10 This command generates bios with 250 sectors, allocated in 32 4k-pages (last page uses only 1024 bytes). For LVM layer, it allocates bio with 31 segments (still OK for CCISS), unfortunatelly on lower layer it is recalculated to 32 segments and this violates CCISS restriction and triggers BUG_ON(). The patch tries to fix it by: * initializing attributes above in queue request constructor blk_queue_make_request() * make sure that blk_queue_stack_limits() inherits setting (DM uses its own function to set the limits because it blk_queue_stack_limits() was introduced later. It should probably switch to use generic stack limit function too.) * sets the default seg_boundary value in one place (blkdev.h) * use this mask as default in DM (instead of -1, which differs in 64bit) Bugs related to this: https://bugzilla.redhat.com/show_bug.cgi?id=471639 http://bugzilla.kernel.org/show_bug.cgi?id=8672 Signed-off-by: Milan Broz Reviewed-by: Alasdair G Kergon Cc: Neil Brown Cc: FUJITA Tomonori Cc: Tejun Heo Cc: Mike Miller Signed-off-by: Jens Axboe

dm: avoid destroying table in dm_any_congested

2008-11-13T23:39:14Z

dm_any_congested() just checks for the DMF_BLOCK_IO and has no code to make sure that suspend waits for dm_any_congested() to complete. This patch adds such a check. Without it, a race can occur with dm_table_put() attempting to destroying the table in the wrong thread, the one running dm_any_congested() which is meant to be quick and return immediately. Two examples of problems: 1. Sleeping functions called from congested code, the caller of which holds a spin lock. 2. An ABBA deadlock between pdflush and multipathd. The two locks in contention are inode lock and kernel lock. Signed-off-by: Chandra Seetharaman Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon

dm: move pending queue wake_up end_io_acct

2008-11-13T23:39:10Z

This doesn't fix any bug, just moves wake_up immediately after decrementing md->pending, for better code readability. It must be clear to anyone manipulating md->pending to wake up the queue if md->pending reaches zero, so move the wakeup as close to the decrementing as possible. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon

dm mpath: warn if args ignored

2008-11-13T23:39:06Z

Currently dm ignores the parameters provided to hardware handlers without providing any notifications to the user. This patch just prints a warning message so that the user knows that the arguments are ignored. Signed-off-by: Chandra Seetharaman Signed-off-by: Alasdair G Kergon

dm mpath: avoid attempting to activate null path

2008-11-13T23:39:00Z

Path activation code is called even when the pgpath is NULL. This could lead to a panic in activate_path(). Such a panic is seen in -rt kernel. This problem has been there before the pg_init() was moved to a workqueue. Signed-off-by: Chandra Seetharaman Signed-off-by: Alasdair G Kergon

dm stripe: fix init failure

2008-11-13T23:38:56Z

Don't proceed if dm_stripe_init() fails to register itself as a dm target. Signed-off-by: Heinz Mauelshagen Signed-off-by: Alasdair G Kergon

dm raid1: flush workqueue before destruction

2008-11-13T23:38:52Z

We queue work on keventd queue --- so this queue must be flushed in the destructor. Otherwise, keventd could access mirror_set after it was freed. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon Cc: stable@kernel.org

md: linear: Fix a division by zero bug for very small arrays.

2008-11-06T08:41:24Z

We currently oops with a divide error on starting a linear software raid array consisting of at least two very small (< 500K) devices. The bug is caused by the calculation of the hash table size which tries to compute sector_div(sz, base) with "base" being zero due to the small size of the component devices of the array. Fix this by requiring the hash spacing to be at least one which implies that also "base" is non-zero. This bug has existed since about 2.6.14. Cc: stable@kernel.org Signed-off-by: Andre Noll Signed-off-by: NeilBrown

md: fix bug in raid10 recovery.

2008-11-06T06:28:20Z

Adding a spare to a raid10 doesn't cause recovery to start. This is due to an silly type in commit 6c2fce2ef6b4821c21b5c42c7207cb9cf8c87eda and so is a bug in 2.6.27 and .28-rc. Thanks to Thomas Backlund for bisecting to find this. Cc: Thomas Backlund Cc: stable@kernel.org Signed-off-by: NeilBrown