user/sven/linux.git/drivers/md, branch v3.10.59

md/raid5: disable 'DISCARD' by default due to safety concerns.

2014-10-09T19:18:43Z

commit 8e0e99ba64c7ba46133a7c8a3e3f7de01f23bd93 upstream. It has come to my attention (thanks Martin) that 'discard_zeroes_data' is only a hint. Some devices in some cases don't do what it says on the label. The use of DISCARD in RAID5 depends on reads from discarded regions being predictably zero. If a write to a previously discarded region performs a read-modify-write cycle it assumes that the parity block was consistent with the data blocks. If all were zero, this would be the case. If some are and some aren't this would not be the case. This could lead to data corruption after a device failure when data needs to be reconstructed from the parity. As we cannot trust 'discard_zeroes_data', ignore it by default and so disallow DISCARD on all raid4/5/6 arrays. As many devices are trustworthy, and as there are benefits to using DISCARD, add a module parameter to over-ride this caution and cause DISCARD to work if discard_zeroes_data is set. If a site want to enable DISCARD on some arrays but not on others they should select DISCARD support at the filesystem level, and set the raid456 module parameter. raid456.devices_handle_discard_safely=Y As this is a data-safety issue, I believe this patch is suitable for -stable. DISCARD support for RAID456 was added in 3.7 Cc: Shaohua Li Cc: "Martin K. Petersen" Cc: Mike Snitzer Cc: Heinz Mauelshagen Acked-by: Martin K. Petersen Acked-by: Mike Snitzer Fixes: 620125f2bf8ff0c4969b79653b54d7bcc9d40637 Signed-off-by: NeilBrown [bwh: Backported to 3.10: adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

md/raid1: fix_read_error should act on all non-faulty devices.

2014-10-05T21:54:14Z

commit b8cb6b4c121e1bf1963c16ed69e7adcb1bc301cd upstream. If a devices is being recovered it is not InSync and is not Faulty. If a read error is experienced on that device, fix_read_error() will be called, but it ignores non-InSync devices. So it will neither fix the error nor fail the device. It is incorrect that fix_read_error() ignores non-InSync devices. It should only ignore Faulty devices. So fix it. This became a bug when we allowed reading from a device that was being recovered. It is suitable for any subsequent -stable kernel. Fixes: da8840a747c0dbf49506ec906757a6b87b9741e9 Reported-by: Alexander Lyakas Tested-by: Alexander Lyakas Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

dm crypt: fix access beyond the end of allocated space

2014-10-05T21:54:12Z

commit d49ec52ff6ddcda178fc2476a109cf1bd1fa19ed upstream. The DM crypt target accesses memory beyond allocated space resulting in a crash on 32 bit x86 systems. This bug is very old (it dates back to 2.6.25 commit 3a7f6c990ad04 "dm crypt: use async crypto"). However, this bug was masked by the fact that kmalloc rounds the size up to the next power of two. This bug wasn't exposed until 3.17-rc1 commit 298a9fa08a ("dm crypt: use per-bio data"). By switching to using per-bio data there was no longer any padding beyond the end of a dm-crypt allocated memory block. To minimize allocation overhead dm-crypt puts several structures into one block allocated with kmalloc. The block holds struct ablkcipher_request, cipher-specific scratch pad (crypto_ablkcipher_reqsize(any_tfm(cc))), struct dm_crypt_request and an initialization vector. The variable dmreq_start is set to offset of struct dm_crypt_request within this memory block. dm-crypt allocates the block with this size: cc->dmreq_start + sizeof(struct dm_crypt_request) + cc->iv_size. When accessing the initialization vector, dm-crypt uses the function iv_of_dmreq, which performs this calculation: ALIGN((unsigned long)(dmreq + 1), crypto_ablkcipher_alignmask(any_tfm(cc)) + 1). dm-crypt allocated "cc->iv_size" bytes beyond the end of dm_crypt_request structure. However, when dm-crypt accesses the initialization vector, it takes a pointer to the end of dm_crypt_request, aligns it, and then uses it as the initialization vector. If the end of dm_crypt_request is not aligned on a crypto_ablkcipher_alignmask(any_tfm(cc)) boundary the alignment causes the initialization vector to point beyond the allocated space. Fix this bug by calculating the variable iv_size_padding and adding it to the allocated size. Also correct the alignment of dm_crypt_request. struct dm_crypt_request is specific to dm-crypt (it isn't used by the crypto subsystem at all), so it is aligned on __alignof__(struct dm_crypt_request). Also align per_bio_data_size on ARCH_KMALLOC_MINALIGN, so that it is aligned as if the block was allocated with kmalloc. Reported-by: Krzysztof Kolasa Tested-by: Milan Broz Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

md/raid1,raid10: always abort recover on write error.

2014-09-17T16:04:01Z

commit 2446dba03f9dabe0b477a126cbeb377854785b47 upstream. Currently we don't abort recovery on a write error if the write error to the recovering device was triggerd by normal IO (as opposed to recovery IO). This means that for one bitmap region, the recovery might write to the recovering device for a few sectors, then not bother for subsequent sectors (as it never writes to failed devices). In this case the bitmap bit will be cleared, but it really shouldn't. The result is that if the recovering device fails and is then re-added (after fixing whatever hardware problem triggerred the failure), the second recovery won't redo the region it was in the middle of, so some of the device will not be recovered properly. If we abort the recovery, the region being processes will be cancelled (bit not cleared) and the whole region will be retried. As the bug can result in data corruption the patch is suitable for -stable. For kernels prior to 3.11 there is a conflict in raid10.c which will require care. Original-from: jiao hui Reported-and-tested-by: jiao hui Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

md/raid10: Fix memory leak when raid10 reshape completes.

2014-09-17T16:04:00Z

commit b39685526f46976bcd13aa08c82480092befa46c upstream. When a raid10 commences a resync/recovery/reshape it allocates some buffer space. When a resync/recovery completes the buffer space is freed. But not when the reshape completes. This can result in a small memory leak. There is a subtle side-effect of this bug. When a RAID10 is reshaped to a larger array (more devices), the reshape is immediately followed by a "resync" of the new space. This "resync" will use the buffer space which was allocated for "reshape". This can cause problems including a "BUG" in the SCSI layer. So this is suitable for -stable. Fixes: 3ea7daa5d7fde47cd41f4d56c2deb949114da9d6 Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

md/raid10: fix memory leak when reshaping a RAID10.

2014-09-17T16:04:00Z

commit ce0b0a46955d1bb389684a2605dbcaa990ba0154 upstream. raid10 reshape clears unwanted bits from a bio->bi_flags using a method which, while clumsy, worked until 3.10 when BIO_OWNS_VEC was added. Since then it clears that bit but shouldn't. This results in a memory leak. So change to used the approved method of clearing unwanted bits. As this causes a memory leak which can consume all of memory the fix is suitable for -stable. Fixes: a38352e0ac02dbbd4fa464dc22d1352b5fbd06fd Reported-by: mdraid.pkoch@dfgh.net (Peter Koch) Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

md/raid6: avoid data corruption during recovery of double-degraded RAID6

2014-09-17T16:04:00Z

commit 9c4bdf697c39805078392d5ddbbba5ae5680e0dd upstream. During recovery of a double-degraded RAID6 it is possible for some blocks not to be recovered properly, leading to corruption. If a write happens to one block in a stripe that would be written to a missing device, and at the same time that stripe is recovering data to the other missing device, then that recovered data may not be written. This patch skips, in the double-degraded case, an optimisation that is only safe for single-degraded arrays. Bug was introduced in 2.6.32 and fix is suitable for any kernel since then. In an older kernel with separate handle_stripe5() and handle_stripe6() functions the patch must change handle_stripe6(). Fixes: 6c0069c0ae9659e3a91b68eaed06a5c6c37f45c8 Cc: Yuri Tikhonov Cc: Dan Williams Reported-by: "Manibalan P" Tested-by: "Manibalan P" Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1090423 Signed-off-by: NeilBrown Acked-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

dm cache metadata: do not allow the data block size to change

2014-07-28T15:00:07Z

commit 048e5a07f282c57815b3901d4a68a77fa131ce0a upstream. The block size for the dm-cache's data device must remained fixed for the life of the cache. Disallow any attempt to change the cache's data block size. Signed-off-by: Mike Snitzer Acked-by: Joe Thornber Signed-off-by: Greg Kroah-Hartman

dm thin metadata: do not allow the data block size to change

2014-07-28T15:00:07Z

commit 9aec8629ec829fc9403788cd959e05dd87988bd1 upstream. The block size for the thin-pool's data device must remained fixed for the life of the thin-pool. Disallow any attempt to change the thin-pool's data block size. It should be noted that attempting to change the data block size via thin-pool table reload will be ignored as a side-effect of the thin-pool handover that the thin-pool target does during thin-pool table reload. Here is an example outcome of attempting to load a thin-pool table that reduced the thin-pool's data block size from 1024K to 512K. Before: kernel: device-mapper: thin: 253:4: growing the data device from 204800 to 409600 blocks After: kernel: device-mapper: thin metadata: changing the data block size (from 2048 to 1024) is not supported kernel: device-mapper: table: 253:4: thin-pool: Error creating metadata object kernel: device-mapper: ioctl: error adding target to table Signed-off-by: Mike Snitzer Acked-by: Joe Thornber Signed-off-by: Greg Kroah-Hartman

dm io: fix a race condition in the wake up code for sync_io

2014-07-17T22:58:02Z

commit 10f1d5d111e8aed46a0f1179faf9a3cf422f689e upstream. There's a race condition between the atomic_dec_and_test(&io->count) in dec_count() and the waking of the sync_io() thread. If the thread is spuriously woken immediately after the decrement it may exit, making the on stack io struct invalid, yet the dec_count could still be using it. Fix this race by using a completion in sync_io() and dec_count(). Reported-by: Minfei Huang Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Acked-by: Mikulas Patocka Signed-off-by: Greg Kroah-Hartman