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path: root/drivers/md
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2009-07-30md: avoid dereferencing NULL pointer when accessing suspend_* sysfs attributes.NeilBrown
commit b8d966efd9a46a9a35beac50cbff6e30565125ef upstream. If we try to modify one of the md/ sysfs files suspend_lo or suspend_hi when the array is not active, we dereference a NULL. Protect against that. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-19Revert "dm: sysfs skip output when device is being destroyed"Greg Kroah-Hartman
This reverts commit 9fad9f263a7065be94bf77519346d0d854ff3b92. It is really commit 4d89b7b4e4726893453d0fb4ddbb5b3e16353994 that is being reverted here, it's a patch that should not have been applied to the .27 tree. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-02dm: sysfs skip output when device is being destroyedMilan Broz
commit 4d89b7b4e4726893453d0fb4ddbb5b3e16353994 upstream. Do not process sysfs attributes when device is being destroyed. Otherwise code can cause BUG_ON(test_bit(DMF_FREEING, &md->flags)); in dm_put() call. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-02dm mpath: validate table argument countMikulas Patocka
commit 0e0497c0c017664994819f4602dc07fd95896c52 upstream. The parser reads the argument count as a number but doesn't check that sufficient arguments are supplied. This command triggers the bug: dmsetup create mpath --table "0 `blockdev --getsize /dev/mapper/cr0` multipath 0 0 2 1 round-robin 1000 0 1 1 /dev/mapper/cr0 round-robin 0 1 1 /dev/mapper/cr1 1000" kernel BUG at drivers/md/dm-mpath.c:530! Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-02dm mpath: validate hw_handler argument countMikulas Patocka
commit e094f4f15f5169526c7200b9bde44b900548a81e upstream. Fix arg count parsing error in hw handlers. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-02md/raid5: add missing call to schedule() after prepare_to_wait()Dan Williams
commit 7a3ab908948b6296ee7e81d42f7c176361c51975 upstream. In the unlikely event that reshape progresses past the current request while it is waiting for a stripe we need to schedule() before retrying for 2 reasons: 1/ Prevent list corruption from duplicated list_add() calls without intervening list_del(). 2/ Give the reshape code a chance to make some progress to resolve the conflict. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-19md: remove ability to explicit set an inactive array to 'clean'.NeilBrown
commit 5bf295975416f8e97117bbbcfb0191c00bc3e2b4 upstream. Being able to write 'clean' to an 'array_state' of an inactive array to activate it in 'clean' mode is both unnecessary and inconvenient. It is unnecessary because the same can be achieved by writing 'active'. This activates and array, but it still remains 'clean' until the first write. It is inconvenient because writing 'clean' is more often used to cause an 'active' array to revert to 'clean' mode (thus blocking any writes until a 'write-pending' is promoted to 'active'). Allowing 'clean' to both activate an array and mark an active array as clean can lead to races: One program writes 'clean' to mark the active array as clean at the same time as another program writes 'inactive' to deactivate (stop) and active array. Depending on which writes first, the array could be deactivated and immediately reactivated which isn't what was desired. So just disable the use of 'clean' to activate an array. This avoids a race that can be triggered with mdadm-3.0 and external metadata, so it suitable for -stable. Reported-by: Rafal Marszewski <rafal.marszewski@intel.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-19md/raid10: don't clear bitmap during recovery if array will still be degraded.NeilBrown
commit 18055569127253755d01733f6ecc004ed02f88d0 upstream. If we have a raid10 with multiple missing devices, and we recover just one of these to a spare, then we risk (depending on the bitmap and array chunk size) clearing bits of the bitmap for which recovery isn't complete (because a device is still missing). This can lead to a subsequent "re-add" being recovered without any IO happening, which would result in loss of data. This patch takes the safe approach of not clearing bitmap bits if the array will still be degraded. This patch is suitable for all active -stable kernels. Cc: stable@kernel.org Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-19md: fix some (more) errors with bitmaps on devices larger than 2TB.NeilBrown
commit db305e507d554430a69ede901a6308e6ecb72349 upstream. If a write intent bitmap covers more than 2TB, we sometimes work with values beyond 32bit, so these need to be sector_t. This patches add the required casts to some unsigned longs that are being shifted up. This will affect any raid10 larger than 2TB, or any raid1/4/5/6 with member devices that are larger than 2TB. Signed-off-by: NeilBrown <neilb@suse.de> Reported-by: "Mario 'BitKoenig' Holbe" <Mario.Holbe@TU-Ilmenau.DE> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-19md: fix loading of out-of-date bitmap.NeilBrown
commit b74fd2826c5acce20e6f691437b2d19372bc2057 upstream. When md is loading a bitmap which it knows is out of date, it fills each page with 1s and writes it back out again. However the write_page call makes used of bitmap->file_pages and bitmap->last_page_size which haven't been set correctly yet. So this can sometimes fail. Move the setting of file_pages and last_page_size to before the call to write_page. This bug can cause the assembly on an array to fail, thus making the data inaccessible. Hence I think it is a suitable candidate for -stable. Reported-by: Vojtech Pavlik <vojtech@suse.cz> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-23dm io: respect BIO_MAX_PAGES limitMikulas Patocka
commit d659e6cc98766a1a61d6bdd283f95d149abd7719 upstream. dm-io calls bio_get_nr_vecs to get the maximum number of pages to use for a given device. It allocates one additional bio_vec to use internally but failed to respect BIO_MAX_PAGES, so fix this. This was the likely cause of: https://bugzilla.redhat.com/show_bug.cgi?id=173153 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-23dm ioctl: validate name length when renamingMilan Broz
commit bc0fd67feba2e0770aad85393500ba77c6489f1c upstream. When renaming a mapped device validate the length of the new name. The rename ioctl accepted any correctly-terminated string enclosed within the data passed from userspace. The other ioctls enforce a size limit of DM_NAME_LEN. If the name is changed and becomes longer than that, the device can no longer be addressed by name. Fix it by properly checking for device name length (including terminating zero). Signed-off-by: Milan Broz <mbroz@redhat.com> Reviewed-by: Jonathan Brassow <jbrassow@redhat.com> Reviewed-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-23dm crypt: fix kcryptd_async_done parameterHuang Ying
commit b2174eebd1fadb76454dad09a1dacbc17081e6b0 upstream. In the async encryption-complete function (kcryptd_async_done), the crypto_async_request passed in may be different from the one passed to crypto_ablkcipher_encrypt/decrypt. Only crypto_async_request->data is guaranteed to be same as the one passed in. The current kcryptd_async_done uses the passed-in crypto_async_request directly which may cause the AES-NI-based AES algorithm implementation to panic. This patch fixes this bug by only using crypto_async_request->data, which points to dm_crypt_request, the crypto_async_request passed in. The original data (convert_context) is gotten from dm_crypt_request. [mbroz@redhat.com: reworked] Signed-off-by: Huang Ying <ying.huang@intel.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-16md/raid10: Don't skip more than 1 bitmap-chunk at a time during recovery.NeilBrown
commit 09b4068a7fe442efc40e9dcbcf5ff37c3338ab15 upstream. When doing recovery on a raid10 with a write-intent bitmap, we only need to recovery chunks that are flagged in the bitmap. However if we choose to skip a chunk as it isn't flag, the code currently skips the whole raid10-chunk, thus it might not recovery some blocks that need recovering. This patch fixes it. In case that is confusing, it might help to understand that there is a 'raid10 chunk size' which guides how data is distributed across the devices, and a 'bitmap chunk size' which says how much data corresponds to a single bit in the bitmap. This bug only affects cases where the bitmap chunk size is smaller than the raid10 chunk size. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-16md/raid10: Don't call bitmap_cond_end_sync when we are doing recovery.NeilBrown
commit 78200d45cde2a79c0d0ae0407883bb264caa3c18 upstream. For raid1/4/5/6, resync (fixing inconsistencies between devices) is very similar to recovery (rebuilding a failed device onto a spare). The both walk through the device addresses in order. For raid10 it can be quite different. resync follows the 'array' address, and makes sure all copies are the same. Recover walks through 'device' addresses and recreates each missing block. The 'bitmap_cond_end_sync' function allows the write-intent-bitmap (When present) to be updated to reflect a partially completed resync. It makes assumptions which mean that it does not work correctly for raid10 recovery at all. In particularly, it can cause bitmap-directed recovery of a raid10 to not recovery some of the blocks that need to be recovered. So move the call to bitmap_cond_end_sync into the resync path, rather than being in the common "resync or recovery" path. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-16md: avoid races when stopping resync.NeilBrown
commit 73d5c38a9536142e062c35997b044e89166e063b upstream. There has been a race in raid10 and raid1 for a long time which has only recently started showing up due to a scheduler changed. When a sync_read request finishes, as soon as reschedule_retry is called, another thread can mark the resync request as having completed, so md_do_sync can finish, ->stop can be called, and ->conf can be freed. So using conf after reschedule_retry is not safe. Similarly, when finishing a sync_write, calling md_done_sync must be the last thing we do, as it allows a chain of events which will free conf and other data structures. The first of these requires action in raid10.c The second requires action in raid1.c and raid10.c Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-02-12dm mpath: avoid attempting to activate null pathChandra Seetharaman
commit b81aa1c79201cb424114fd198607951900babe18 upstream. 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 <sekharan@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-02-12md: Allow metadata_version to be updated for externally managed metadata.NeilBrown
commit ea43ddd8491feccf36267349748ea91b1194481e upstream. For externally managed metadata, the 'metadata_version' sysfs attribute is really just a channel for user-space programs to communicate about how the array is being managed. It can be useful for this to be changed while the array is active. Normally changes to metadata_version are not permitted while the array is active. Change that so that if the metadata is externally managed, the metadata_version can be changed to a different flavour of external management. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-02-12md: Don't try to set an array to 'read-auto' if it is already in that state.NeilBrown
commit 80268ee9270ebe4847365a7426de91d179e870d0 upstream. 'read-auto' is a variant of 'readonly' which will switch to writable on the first write attempt. Calling do_md_stop to set the array readonly when it is already readonly returns an error. So make sure not to do that. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-02-12md: Ensure an md array never has too many devices.NeilBrown
commit de01dfadf25bf83cfe3d85c163005c4320532658 upstream. Each different metadata format supported by md supports a different maximum number of devices. We really should be enforcing this maximum in the kernel, but we aren't quite doing that properly. We currently only enforce it at the 'hot_add' point, which is an older interface which is not used by current userspace. We need to also enforce it at 'add_new_disk' time for active arrays and at 'do_md_run' time when starting a new array. So move the test from 'hot_add' into 'bind_rdev_to_array' which is called from both 'hot_add' and 'add_new_disk, and add a new test in 'analyse_sbs' which is called from 'do_md_run'. This bug (or missing feature) has been around "forever" and so the patch is suitable for any -stable that is currently maintained. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-18md: fix bitmap-on-external-file bug.NeilBrown
commit 538452700d95480c16e7aa6b10ff77cd937d33f4 upstream. commit a2ed9615e3222645007fc19991aedf30eed3ecfd fixed a bug with 'internal' bitmaps, but in the process broke 'in a file' bitmaps. So they are broken in 2.6.28 This fixes it, and needs to go in 2.6.28-stable. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-18dm raid1: fix error countJonathan Brassow
commit d460c65a6a9ec9e0d284864ec3a9a2d1b73f0e43 upstream. Always increase the error count when I/O on a leg of a mirror fails. The error count is used to decide whether to select an alternative mirror leg. If the target doesn't use the "handle_errors" feature, the error count is not updated and the bio can get requeued forever by the read callback. Fix it by increasing error_count before the handle_errors feature checking. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-18dm log: fix dm_io_client leak on error pathsTakahiro Yasui
commit c7a2bd19b7c1e0bd2c7604c53d2583e91e536948 upstream. In create_log_context function, dm_io_client_destroy function needs to be called, when memory allocation of disk_header, sync_bits and recovering_bits failed, but dm_io_client_destroy is not called. Signed-off-by: Takahiro Yasui <tyasui@redhat.com> Acked-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-14md: Don't read past end of bitmap when reading bitmap.NeilBrown
commit a2ed9615e3222645007fc19991aedf30eed3ecfd upstream. 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 <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-11-20dm raid1: flush workqueue before destructionMikulas Patocka
commit 18776c7316545482a02bfaa2629a2aa1afc48357 upstream. 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 <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-11-13md: fix bug in raid10 recovery.Neil Brown
commit a53a6c85756339f82ff19e001e90cfba2d6299a8 upstream 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 <tmb@mandriva.org> Cc: George Spelvin <linux@horizon.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-11-13md: linear: Fix a division by zero bug for very small arrays.Andre Noll
commit f1cd14ae52985634d0389e934eba25b5ecf24565 upstream Date: Thu, 6 Nov 2008 19:41:24 +1100 Subject: md: linear: Fix a division by zero bug for very small arrays. 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. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-25dm snapshot: fix primary_pe raceMikulas Patocka
commit 7c5f78b9d7f21937e46c26db82976df4b459c95c upstream Fix a race condition with primary_pe ref_count handling. put_pending_exception runs under dm_snapshot->lock, it does atomic_dec_and_test on primary_pe->ref_count, and later does atomic_read primary_pe->ref_count. __origin_write does atomic_dec_and_test on primary_pe->ref_count without holding dm_snapshot->lock. This opens the following race condition: Assume two CPUs, CPU1 is executing put_pending_exception (and holding dm_snapshot->lock). CPU2 is executing __origin_write in parallel. primary_pe->ref_count == 2. CPU1: if (primary_pe && atomic_dec_and_test(&primary_pe->ref_count)) origin_bios = bio_list_get(&primary_pe->origin_bios); .. decrements primary_pe->ref_count to 1. Doesn't load origin_bios CPU2: if (first && atomic_dec_and_test(&primary_pe->ref_count)) { flush_bios(bio_list_get(&primary_pe->origin_bios)); free_pending_exception(primary_pe); /* If we got here, pe_queue is necessarily empty. */ return r; } .. decrements primary_pe->ref_count to 0, submits pending bios, frees primary_pe. CPU1: if (!primary_pe || primary_pe != pe) free_pending_exception(pe); .. this has no effect. if (primary_pe && !atomic_read(&primary_pe->ref_count)) free_pending_exception(primary_pe); .. sees ref_count == 0 (written by CPU 2), does double free !! This bug can happen only if someone is simultaneously writing to both the origin and the snapshot. If someone is writing only to the origin, __origin_write will submit kcopyd request after it decrements primary_pe->ref_count (so it can't happen that the finished copy races with primary_pe->ref_count decrementation). If someone is writing only to the snapshot, __origin_write isn't invoked at all and the race can't happen. The race happens when someone writes to the snapshot --- this creates pending_exception with primary_pe == NULL and starts copying. Then, someone writes to the same chunk in the snapshot, and __origin_write races with termination of already submitted request in pending_complete (that calls put_pending_exception). This race may be reason for bugs: http://bugzilla.kernel.org/show_bug.cgi?id=11636 https://bugzilla.redhat.com/show_bug.cgi?id=465825 The patch fixes the code to make sure that: 1. If atomic_dec_and_test(&primary_pe->ref_count) returns false, the process must no longer dereference primary_pe (because someone else may free it under us). 2. If atomic_dec_and_test(&primary_pe->ref_count) returns true, the process is responsible for freeing primary_pe. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-25dm kcopyd: avoid queue shuffleKazuo Ito
commit b673c3a8192e28f13e2050a4b82c1986be92cc15 upstream Write throughput to LVM snapshot origin volume is an order of magnitude slower than those to LV without snapshots or snapshot target volumes, especially in the case of sequential writes with O_SYNC on. The following patch originally written by Kevin Jamieson and Jan Blunck and slightly modified for the current RCs by myself tries to improve the performance by modifying the behaviour of kcopyd, so that it pushes back an I/O job to the head of the job queue instead of the tail as process_jobs() currently does when it has to wait for free pages. This way, write requests aren't shuffled to cause extra seeks. I tested the patch against 2.6.27-rc5 and got the following results. The test is a dd command writing to snapshot origin followed by fsync to the file just created/updated. A couple of filesystem benchmarks gave me similar results in case of sequential writes, while random writes didn't suffer much. dd if=/dev/zero of=<somewhere on snapshot origin> bs=4096 count=... [conv=notrunc when updating] 1) linux 2.6.27-rc5 without the patch, write to snapshot origin, average throughput (MB/s) 10M 100M 1000M create,dd 511.46 610.72 11.81 create,dd+fsync 7.10 6.77 8.13 update,dd 431.63 917.41 12.75 update,dd+fsync 7.79 7.43 8.12 compared with write throughput to LV without any snapshots, all dd+fsync and 1000 MiB writes perform very poorly. 10M 100M 1000M create,dd 555.03 608.98 123.29 create,dd+fsync 114.27 72.78 76.65 update,dd 152.34 1267.27 124.04 update,dd+fsync 130.56 77.81 77.84 2) linux 2.6.27-rc5 with the patch, write to snapshot origin, average throughput (MB/s) 10M 100M 1000M create,dd 537.06 589.44 46.21 create,dd+fsync 31.63 29.19 29.23 update,dd 487.59 897.65 37.76 update,dd+fsync 34.12 30.07 26.85 Although still not on par with plain LV performance - cannot be avoided because it's copy on write anyway - this simple patch successfully improves throughtput of dd+fsync while not affecting the rest. Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Kazuo Ito <ito.kazuo@oss.ntt.co.jp> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-22md: Fix rdev_size_store with size == 0Chris Webb
commit 7d3c6f8717ee6c2bf6cba5fa0bda3b28fbda6015 upstream Fix rdev_size_store with size == 0. size == 0 means to use the largest size allowed by the underlying device and is used when modifying an active array. This fixes a regression introduced by commit d7027458d68b2f1752a28016dcf2ffd0a7e8f567 Signed-off-by: Chris Webb <chris@arachsys.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-01dm mpath: add missing path switching lockingChandra Seetharaman
Moving the path activation to workqueue along with scsi_dh patches introduced a race. It is due to the fact that the current_pgpath (in the multipath data structure) can be modified if changes happen in any of the paths leading to the lun. If the changes lead to current_pgpath being set to NULL, then it leads to the invalid access which results in the panic below. This patch fixes that by storing the pgpath to activate in the multipath data structure and properly protecting it. Note that if activate_path is called twice in succession with different pgpath, with the second one being called before the first one is done, then activate path will be called twice for the second pgpath, which is fine. Unable to handle kernel paging request for data at address 0x00000020 Faulting instruction address: 0xd000000000aa1844 cpu 0x1: Vector: 300 (Data Access) at [c00000006b987a80] pc: d000000000aa1844: .activate_path+0x30/0x218 [dm_multipath] lr: c000000000087a2c: .run_workqueue+0x114/0x204 sp: c00000006b987d00 msr: 8000000000009032 dar: 20 dsisr: 40000000 current = 0xc0000000676bb3f0 paca = 0xc0000000006f3680 pid = 2528, comm = kmpath_handlerd enter ? for help [c00000006b987da0] c000000000087a2c .run_workqueue+0x114/0x204 [c00000006b987e40] c000000000088b58 .worker_thread+0x120/0x144 [c00000006b987f00] c00000000008ca70 .kthread+0x78/0xc4 [c00000006b987f90] c000000000027cc8 .kernel_thread+0x4c/0x68 Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-10-01dm: cope with access beyond end of device in dm_merge_bvecMikulas Patocka
If for any reason dm_merge_bvec() is given an offset beyond the end of the device, avoid an oops and always allow one page to be added to an empty bio. We'll reject the I/O later after the bio is submitted. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-10-01dm: always allow one page in dm_merge_bvecMikulas Patocka
Some callers assume they can always add at least one page to an empty bio, so dm_merge_bvec should not return 0 in this case: we'll reject the I/O later after the bio is submitted. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-09-19md: Don't wait UNINTERRUPTIBLE for other resync to finishNeilBrown
When two md arrays share some block device (e.g each uses different partitions on the one device), a resync of one array will wait for the resync on the other to finish. This can be a long time and as it currently waits TASK_UNINTERRUPTIBLE, the softlockup code notices and complains. So use TASK_INTERRUPTIBLE instead and make sure to flush signals before calling schedule. Signed-off-by: NeilBrown <neilb@suse.de>
2008-09-01Fix problem with waiting while holding rcu read lock in md/bitmap.cNeilBrown
A recent patch to protect the rdev list with rcu locking leaves us with a problem because we can sleep on memalloc while holding the rcu lock. The rcu lock is only needed while walking the linked list as uninteresting devices (failed or spares) can be removed at any time. So only take the rcu lock while actually walking the linked list. Take a refcount on the rdev during the time when we drop the lock and do the memalloc to start IO. When we return to the locked code, all the interesting devices on the list will not have moved, so we can simply use list_for_each_continue_rcu to pick up where we left off. Signed-off-by: NeilBrown <neilb@suse.de>
2008-09-01Remove invalidate_partition call from do_md_stop.NeilBrown
When stopping an md array, or just switching to read-only, we currently call invalidate_partition while holding the mddev lock. The main reason for this is probably to ensure all dirty buffers are flushed (invalidate_partition calls fsync_bdev). However if any dirty buffers are found, it will almost certainly cause a deadlock as starting writeout will require an update to the superblock, and performing that updates requires taking the mddev lock - which is already held. This deadlock can be demonstrated by running "reboot -f -n" with a root filesystem on md/raid, and some dirty buffers in memory. All other calls to stop an array should already happen after a flush. The normal sequence is to stop using the array (e.g. umount) which will cause __blkdev_put to call sync_blockdev. Then open the array and issue the STOP_ARRAY ioctl while the buffers are all still clean. So this invalidate_partition is normally a no-op, except for one case where it will cause a deadlock. So remove it. This patch possibly addresses the regression recored in http://bugzilla.kernel.org/show_bug.cgi?id=11460 and http://bugzilla.kernel.org/show_bug.cgi?id=11452 though it isn't yet clear how it ever worked. Signed-off-by: NeilBrown <neilb@suse.de>
2008-08-07md: cancel check/repair requests when recovery is neededDan Williams
If a 'repair' is requested when an array is in a position to 'recover' raid1 will perform the repair while md believes a recovery is happening. Address this at both ends, i.e. cancel check/repair requests upon detecting a recover condition and do not call ->spare_active after completing a check/repair. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-08-05Allow raid10 resync to happening in larger chunks.NeilBrown
The raid10 resync/recovery code currently limits the amount of in-flight resync IO to 2Meg. This was copied from raid1 where it seems quite adequate. However for raid10, some layouts require a bit of seeking to perform a resync, and allowing a larger buffer size means that the seeking can be significantly reduced. There is probably no real need to limit the amount of in-flight IO at all. Any shortage of memory will naturally reduce the amount of buffer space available down to a set minimum, and any concurrent normal IO will quickly cause resync IO to back off. The only problem would be that normal IO has to wait for all resync IO to finish, so a very large amount of resync IO could cause unpleasant latency when normal IO starts up. So: increase RESYNC_DEPTH to allow 32Meg of buffer (if memory is available) which seems to be a good amount. Also reduce the amount of memory reserved as there is no need to keep 2Meg just for resync if memory is tight. Thanks to Keld for the suggestion. Cc: Keld Jørn Simonsen <keld@dkuug.dk> Signed-off-by: NeilBrown <neilb@suse.de>
2008-08-05Allow faulty devices to be removed from a readonly array.NeilBrown
Removing faulty devices from an array is a two stage process. First the device is moved from being a part of the active array to being similar to a spare device. Then it can be removed by a request from user space. The first step is currently not performed for read-only arrays, so the second step can never succeed. So allow readonly arrays to remove failed devices (which aren't blocked). Signed-off-by: NeilBrown <neilb@suse.de>
2008-08-05Don't let a blocked_rdev interfere with read request in raid5/6NeilBrown
When we have externally managed metadata, we need to mark a failed device as 'Blocked' and not allow any writes until that device have been marked as faulty in the metadata and the Blocked flag has been removed. However it is perfectly OK to allow read requests when there is a Blocked device, and with a readonly array, there may not be any metadata-handler watching for blocked devices. So in raid5/raid6 only allow a Blocked device to interfere with Write request or resync. Read requests go through untouched. raid1 and raid10 already differentiate between read and write properly. Signed-off-by: NeilBrown <neilb@suse.de>
2008-08-05Fail safely when trying to grow an array with a write-intent bitmap.NeilBrown
We cannot currently change the size of a write-intent bitmap. So if we change the size of an array which has such a bitmap, it tries to set bits beyond the end of the bitmap. For now, simply reject any request to change the size of an array which has a bitmap. mdadm can remove the bitmap and add a new one after the array has changed size. Signed-off-by: NeilBrown <neilb@suse.de>
2008-08-05Restore force switch of md array to readonly at reboot time.NeilBrown
A recent patch allowed do_md_stop to know whether it was being called via an ioctl or not, and thus where to allow for an extra open file descriptor when checking if it is in use. This broke then switch to readonly performed by the shutdown notifier, which needs to work even when the array is still (apparently) active (as md doesn't get told when the filesystem becomes readonly). So restore this feature by pretending that there can be lots of file descriptors open, but we still want do_md_stop to switch to readonly. Signed-off-by: NeilBrown <neilb@suse.de>
2008-08-05Make writes to md/safe_mode_delay immediately effective.NeilBrown
If we reduce the 'safe_mode_delay', it could still wait for the old delay to completely expire before doing anything about safe_mode. Thus the effect if the change is delayed. To make the effect more immediate, run the timeout function immediately if the delay was reduced. This may cause it to run slightly earlier that required, but that is the safer option. Signed-off-by: NeilBrown <neilb@suse.de>
2008-08-01Merge branch 'for-linus' of git://neil.brown.name/mdLinus Torvalds
* 'for-linus' of git://neil.brown.name/md: md: raid10: wake up frozen array md: do not count blocked devices as spares md: do not progress the resync process if the stripe was blocked md: delay notification of 'active_idle' to the recovery thread md: fix merge error md: move async_tx_issue_pending_all outside spin_lock_irq
2008-08-01Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: md: the bitmap code needs to use blk_plug_device_unlocked() block: add a blk_plug_device_unlocked() that grabs the queue lock
2008-08-01md: the bitmap code needs to use blk_plug_device_unlocked()Jens Axboe
It doesn't hold the queue lock, so it's both racey on the queue flags and thus spews a warning. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-08-01[PATCH] switch mtd and dm-table to lookup_bdev()Al Viro
No need to open-code it... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-01md: raid10: wake up frozen arrayArthur Jones
When rescheduling a bio in raid10, we wake up the md thread, but if the array is frozen, this will have no effect. This causes the array to remain frozen for eternity. We add a wake_up to allow the array to de-freeze. This code is nearly identical to the raid1 code, which has this fix already. Signed-off-by: Arthur Jones <ajones@riverbed.com> Signed-off-by: NeilBrown <neilb@suse.de>
2008-07-28md: do not count blocked devices as sparesDan Williams
remove_and_add_spares() assumes that failed devices have been hot-removed from the array. Removal is skipped in the 'blocked' case so do not count a device in this state as 'spare'. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-07-28md: do not progress the resync process if the stripe was blockedDan Williams
handle_stripe will take no action on a stripe when waiting for userspace to unblock the array, so do not report completed sectors. Signed-off-by: Dan Williams <dan.j.williams@intel.com>