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2011-08-01md: avoid endless recovery loop when waiting for fail device to complete.NeilBrown
commit 4274215d24633df7302069e51426659d4759c5ed upstream. If a device fails in a way that causes pending request to take a while to complete, md will not be able to immediately remove it from the array in remove_and_add_spares. It will then incorrectly look like a spare device and md will try to recover it even though it is failed. This leads to a recovery process starting and instantly aborting over and over again. We should check if the device is faulty before considering it to be a spare. This will avoid trying to start a recovery that cannot proceed. This bug was introduced in 2.6.26 so that patch is suitable for any kernel since then. Reported-by: Jim Paradis <james.paradis@stratus.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-08-01md/raid5: fix raid5_set_bi_hw_segmentsNamhyung Kim
commit 9b2dc8b665932a8e681a7ab3237f60475e75e161 upstream. The @bio->bi_phys_segments consists of active stripes count in the lower 16 bits and processed stripes count in the upper 16 bits. So logical-OR operator should be bitwise one. This bug has been present since 2.6.27 and the fix is suitable for any -stable kernel since then. Fortunately the bad code is only used on error paths and is relatively unlikely to be hit. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-08-01md: check ->hot_remove_disk when removing diskNamhyung Kim
commit 01393f3d5836b7d62e925e6f4658a7eb22b83a11 upstream. Check pers->hot_remove_disk instead of pers->hot_add_disk in slot_store() during disk removal. The linear personality only has ->hot_add_disk and no ->hot_remove_disk, so that removing disk in the array resulted to following kernel bug: $ sudo mdadm --create /dev/md0 --level=linear --raid-devices=4 /dev/loop[0-3] $ echo none | sudo tee /sys/block/md0/md/dev-loop2/slot BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD c9f5d067 PUD 8575a067 PMD 0 Oops: 0010 [#1] SMP CPU 2 Modules linked in: linear loop bridge stp llc kvm_intel kvm asus_atk0110 sr_mod cdrom sg Pid: 10450, comm: tee Not tainted 3.0.0-rc1-leonard+ #173 System manufacturer System Product Name/P5G41TD-M PRO RIP: 0010:[<0000000000000000>] [< (null)>] (null) RSP: 0018:ffff880085757df0 EFLAGS: 00010282 RAX: ffffffffa00168e0 RBX: ffff8800d1431800 RCX: 000000000000006e RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff88008543c000 RBP: ffff880085757e48 R08: 0000000000000002 R09: 000000000000000a R10: 0000000000000000 R11: ffff88008543c2e0 R12: 00000000ffffffff R13: ffff8800b4641000 R14: 0000000000000005 R15: 0000000000000000 FS: 00007fe8c9e05700(0000) GS:ffff88011fa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 00000000b4502000 CR4: 00000000000406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process tee (pid: 10450, threadinfo ffff880085756000, task ffff8800c9f08000) Stack: ffffffff8138496a ffff8800b4641000 ffff88008543c268 0000000000000000 ffff8800b4641000 ffff88008543c000 ffff8800d1431868 ffffffff81a78a90 ffff8800b4641000 ffff88008543c000 ffff8800d1431800 ffff880085757e98 Call Trace: [<ffffffff8138496a>] ? slot_store+0xaa/0x265 [<ffffffff81384bae>] rdev_attr_store+0x89/0xa8 [<ffffffff8115a96a>] sysfs_write_file+0x108/0x144 [<ffffffff81106b87>] vfs_write+0xb1/0x10d [<ffffffff8106e6c0>] ? trace_hardirqs_on_caller+0x111/0x135 [<ffffffff81106cac>] sys_write+0x4d/0x77 [<ffffffff814fe702>] system_call_fastpath+0x16/0x1b Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff880085757df0> CR2: 0000000000000000 ---[ end trace ba5fc64319a826fb ]--- Signed-off-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-08-01dm table: reject devices without request fnsMilan Broz
commit f4808ca99a203f20b4475601748e44b25a65bdec upstream. This patch adds a check that a block device has a request function defined before it is used. Otherwise, misconfiguration can cause an oops. Because we are allowing devices with zero size e.g. an offline multipath device as in commit 2cd54d9bedb79a97f014e86c0da393416b264eb3 ("dm: allow offline devices") there needs to be an additional check to ensure devices are initialised. Some block devices, like a loop device without a backing file, exist but have no request function. Reproducer is trivial: dm-mirror on unbound loop device (no backing file on loop devices) dmsetup create x --table "0 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0" and mirror resync will immediatelly cause OOps. BUG: unable to handle kernel NULL pointer dereference at (null) ? generic_make_request+0x2bd/0x590 ? kmem_cache_alloc+0xad/0x190 submit_bio+0x53/0xe0 ? bio_add_page+0x3b/0x50 dispatch_io+0x1ca/0x210 [dm_mod] ? read_callback+0x0/0xd0 [dm_mirror] dm_io+0xbb/0x290 [dm_mod] do_mirror+0x1e0/0x748 [dm_mirror] Signed-off-by: Milan Broz <mbroz@redhat.com> Reported-by: Zdenek Kabelac <zkabelac@redhat.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-03-31md: Fix - again - partition detection when array becomes activeNeilBrown
[ upstream commit f0b4f7e2f29af678bd9af43422c537dcb6008603 ] Revert b821eaa572fd737faaf6928ba046e571526c36c6 and f3b99be19ded511a1bf05a148276239d9f13eefa When I wrote the first of these I had a wrong idea about the lifetime of 'struct block_device'. It can disappear at any time that the block device is not open if it falls out of the inode cache. So relying on the 'size' recorded with it to detect when the device size has changed and so we need to revalidate, is wrong. Rather, we really do need the 'changed' attribute stored directly in the mddev and set/tested as appropriate. Without this patch, a sequence of: mknod / open / close / unlink (which can cause a block_device to be created and then destroyed) will result in a rescan of the partition table and consequence removal and addition of partitions. Several of these in a row can get udev racing to create and unlink and other code can get confused. With the patch, the rescan is only performed when needed and so there are no races. This is suitable for any stable kernel from 2.6.35. Reported-by: "Wojcik, Krzysztof" <krzysztof.wojcik@intel.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: stable@kernel.org
2011-03-31md: correctly handle probe of an 'mdp' device.NeilBrown
commit 8f5f02c460b7ca74ce55ce126ce0c1e58a3f923d upstream. 'mdp' devices are md devices with preallocated device numbers for partitions. As such it is possible to mknod and open a partition before opening the whole device. this causes md_probe() to be called with a device number of a partition, which in-turn calls mddev_find with such a number. However mddev_find expects the number of a 'whole device' and does the wrong thing with partition numbers. So add code to mddev_find to remove the 'partition' part of a device number and just work with the 'whole device'. This patch addresses https://bugzilla.kernel.org/show_bug.cgi?id=28652 Reported-by: hkmaly@bigfoot.com Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-03-31dm mpath: disable blk_abort_queueMike Snitzer
commit 09c9d4c9b6a2b5909ae3c6265e4cd3820b636863 upstream. Revert commit 224cb3e981f1b2f9f93dbd49eaef505d17d894c2 dm: Call blk_abort_queue on failed paths Multipath began to use blk_abort_queue() to allow for lower latency path deactivation. This was found to cause list corruption: the cmd gets blk_abort_queued/timedout run on it and the scsi eh somehow is able to complete and run scsi_queue_insert while scsi_request_fn is still trying to process the request. https://www.redhat.com/archives/dm-devel/2010-November/msg00085.html Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Mike Anderson <andmike@linux.vnet.ibm.com> Cc: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-31dm: dont take i_mutex to change device sizeMike Snitzer
commit c217649bf2d60ac119afd71d938278cffd55962b upstream. No longer needlessly hold md->bdev->bd_inode->i_mutex when changing the size of a DM device. This additional locking is unnecessary because i_size_write() is already protected by the existing critical section in dm_swap_table(). DM already has a reference on md->bdev so the associated bd_inode may be changed without lifetime concerns. A negative side-effect of having held md->bdev->bd_inode->i_mutex was that a concurrent DM device resize and flush (via fsync) would deadlock. Dropping md->bdev->bd_inode->i_mutex eliminates this potential for deadlock. The following reproducer no longer deadlocks: https://www.redhat.com/archives/dm-devel/2009-July/msg00284.html Signed-off-by: Mike Snitzer <snitzer@redhat.com> 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> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-03-31md: fix regression with re-adding devices to arrays with no metadataNeilBrown
commit bf572541ab44240163eaa2d486b06f306a31d45a upstream. Commit 1a855a0606 (2.6.37-rc4) fixed a problem where devices were re-added when they shouldn't be but caused a regression in a less common case that means sometimes devices cannot be re-added when they should be. In particular, when re-adding a device to an array without metadata we should always access the device, but after the above commit we didn't. This patch sets the In_sync flag in that case so that the re-add succeeds. This patch is suitable for any -stable kernel to which 1a855a0606 was applied. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-02-06block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits insteadMartin K. Petersen
commit e692cb668fdd5a712c6ed2a2d6f2a36ee83997b4 upstream. When stacking devices, a request_queue is not always available. This forced us to have a no_cluster flag in the queue_limits that could be used as a carrier until the request_queue had been set up for a metadevice. There were several problems with that approach. First of all it was up to the stacking device to remember to set queue flag after stacking had completed. Also, the queue flag and the queue limits had to be kept in sync at all times. We got that wrong, which could lead to us issuing commands that went beyond the max scatterlist limit set by the driver. The proper fix is to avoid having two flags for tracking the same thing. We deprecate QUEUE_FLAG_CLUSTER and use the queue limit directly in the block layer merging functions. The queue_limit 'no_cluster' is turned into 'cluster' to avoid double negatives and to ease stacking. Clustering defaults to being enabled as before. The queue flag logic is removed from the stacking function, and explicitly setting the cluster flag is no longer necessary in DM and MD. Reported-by: Ed Lin <ed.lin@promise.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-02-06md: protect against NULL reference when waiting to start a raid10.NeilBrown
commit 589a594be1fb8815b3f18e517be696c48664f728 upstream. When we fail to start a raid10 for some reason, we call md_unregister_thread to kill the thread that was created. Unfortunately md_thread() will then make one call into the handler (raid10d) even though md_wakeup_thread has not been called. This is not safe and as md_unregister_thread is called after mddev->private has been set to NULL, it will definitely cause a NULL dereference. So fix this at both ends: - md_thread should only call the handler if THREAD_WAKEUP has been set. - raid10 should call md_unregister_thread before setting things to NULL just like all the other raid modules do. This is applicable to 2.6.35 and later. Reported-by: "Citizen" <citizen_lee@thecus.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-02-06md: fix bug with re-adding of partially recovered device.NeilBrown
commit 1a855a0606653d2d82506281e2c686bacb4b2f45 upstream. With v0.90 metadata, a hot-spare does not become a full member of the array until recovery is complete. So if we re-add such a device to the array, we know that all of it is as up-to-date as the event count would suggest, and so it a bitmap-based recovery is possible. However with v1.x metadata, the hot-spare immediately becomes a full member of the array, but it record how much of the device has been recovered. If the array is stopped and re-assembled recovery starts from this point. When such a device is hot-added to an array we currently lose the 'how much is recovered' information and incorrectly included it as a full in-sync member (after bitmap-based fixup). This is wrong and unsafe and could corrupt data. So be more careful about setting saved_raid_disk - which is what guides the re-adding of devices back into an array. The new code matches the code in slot_store which does a similar thing, which is encouraging. This is suitable for any -stable kernel. Reported-by: "Dailey, Nate" <Nate.Dailey@stratus.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2010-12-14md: fix return value of rdev_size_change()Justin Maggard
commit c26a44ed1e552aaa1d4ceb71842002d235fe98d7 upstream. When trying to grow an array by enlarging component devices, rdev_size_store() expects the return value of rdev_size_change() to be in sectors, but the actual value is returned in KBs. This functionality was broken by commit dd8ac336c13fd8afdb082ebacb1cddd5cf727889 so this patch is suitable for any kernel since 2.6.30. Signed-off-by: Justin Maggard <jmaggard10@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2010-12-14md/raid1: really fix recovery looping when single good device fails.NeilBrown
commit 8f9e0ee38f75d4740daa9e42c8af628d33d19a02 upstream. Commit 4044ba58dd15cb01797c4fd034f39ef4a75f7cc3 supposedly fixed a problem where if a raid1 with just one good device gets a read-error during recovery, the recovery would abort and immediately restart in an infinite loop. However it depended on raid1_remove_disk removing the spare device from the array. But that does not happen in this case. So add a test so that in the 'recovery_disabled' case, the device will be removed. This suitable for any kernel since 2.6.29 which is when recovery_disabled was introduced. Reported-by: Sebastian Färber <faerber@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2010-08-26dm: separate device deletion from dm_putKiyoshi Ueda
commit 3f77316de0ec0fd208467fbee8d9edc70e2c73b2 upstream. This patch separates the device deletion code from dm_put() to make sure the deletion happens in the process context. By this patch, device deletion always occurs in an ioctl (process) context and dm_put() can be called in interrupt context. As a result, the request-based dm's bad dm_put() usage pointed out by Mikulas below disappears. http://marc.info/?l=dm-devel&m=126699981019735&w=2 Without this patch, I confirmed there is a case to crash the system: dm_put() => dm_table_destroy() => vfree() => BUG_ON(in_interrupt()) Some more backgrounds and details: In request-based dm, a device opener can remove a mapped_device while the last request is still completing, because bios in the last request complete first and then the device opener can close and remove the mapped_device before the last request completes: CPU0 CPU1 ================================================================= <<INTERRUPT>> blk_end_request_all(clone_rq) blk_update_request(clone_rq) bio_endio(clone_bio) == end_clone_bio blk_update_request(orig_rq) bio_endio(orig_bio) <<I/O completed>> dm_blk_close() dev_remove() dm_put(md) <<Free md>> blk_finish_request(clone_rq) .... dm_end_request(clone_rq) free_rq_clone(clone_rq) blk_end_request_all(orig_rq) rq_completed(md) So request-based dm used dm_get()/dm_put() to hold md for each I/O until its request completion handling is fully done. However, the final dm_put() can call the device deletion code which must not be run in interrupt context and may cause kernel panic. To solve the problem, this patch moves the device deletion code, dm_destroy(), to predetermined places that is actually deleting the mapped_device in ioctl (process) context, and changes dm_put() just to decrement the reference count of the mapped_device. By this change, dm_put() can be used in any context and the symmetric model below is introduced: dm_create(): create a mapped_device dm_destroy(): destroy a mapped_device dm_get(): increment the reference count of a mapped_device dm_put(): decrement the reference count of a mapped_device dm_destroy() waits for all references of the mapped_device to disappear, then deletes the mapped_device. dm_destroy() uses active waiting with msleep(1), since deleting the mapped_device isn't performance-critical task. And since at this point, nobody opens the mapped_device and no new reference will be taken, the pending counts are just for racing completing activity and will eventually decrease to zero. For the unlikely case of the forced module unload, dm_destroy_immediate(), which doesn't wait and forcibly deletes the mapped_device, is also introduced and used in dm_hash_remove_all(). Otherwise, "rmmod -f" may be stuck and never return. And now, because the mapped_device is deleted at this point, subsequent accesses to the mapped_device may cause NULL pointer references. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-26dm ioctl: release _hash_lock between devices in remove_allKiyoshi Ueda
commit 98f332855effef02aeb738e4d62e9a5b903c52fd upstream. This patch changes dm_hash_remove_all() to release _hash_lock when removing a device. After removing the device, dm_hash_remove_all() takes _hash_lock and searches the hash from scratch again. This patch is a preparation for the next patch, which changes device deletion code to wait for md reference to be 0. Without this patch, the wait in the next patch may cause AB-BA deadlock: CPU0 CPU1 ----------------------------------------------------------------------- dm_hash_remove_all() down_write(_hash_lock) table_status() md = find_device() dm_get(md) <increment md->holders> dm_get_live_or_inactive_table() dm_get_inactive_table() down_write(_hash_lock) <in the md deletion code> <wait for md->holders to be 0> Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-26dm: prevent access to md being deletedKiyoshi Ueda
commit abdc568b0540bec6d3e0afebac496adef1189b77 upstream. This patch prevents access to mapped_device which is being deleted. Currently, even after a mapped_device has been removed from the hash, it could be accessed through idr_find() using minor number. That could cause a race and NULL pointer reference below: CPU0 CPU1 ------------------------------------------------------------------ dev_remove(param) down_write(_hash_lock) dm_lock_for_deletion(md) spin_lock(_minor_lock) set_bit(DMF_DELETING) spin_unlock(_minor_lock) __hash_remove(hc) up_write(_hash_lock) dev_status(param) md = find_device(param) down_read(_hash_lock) __find_device_hash_cell(param) dm_get_md(param->dev) md = dm_find_md(dev) spin_lock(_minor_lock) md = idr_find(MINOR(dev)) spin_unlock(_minor_lock) dm_put(md) free_dev(md) dm_get(md) up_read(_hash_lock) __dev_status(md, param) dm_put(md) This patch fixes such problems. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-26dm snapshot: test chunk size against both origin and snapshotMikulas Patocka
commit c24110450650f17f7d3ba4fbe01f01ac5a115456 upstream. Validate chunk size against both origin and snapshot sector size Don't allow chunk size smaller than either origin or snapshot logical sector size. Reading or writing data not aligned to sector size is not allowed and causes immediate errors. This requires us to open the origin before initialising the exception store and to export dm_snap_origin. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-26dm snapshot: iterate origin and cow devicesMikulas Patocka
commit 1e5554c8428bc7209a83e2d07ca724be4d981ce3 upstream. Iterate both origin and snapshot devices iterate_devices method should call the callback for all the devices where the bio may be remapped. Thus, snapshot_iterate_devices should call the callback for both snapshot and origin underlying devices because it remaps some bios to the snapshot and some to the origin. snapshot_iterate_devices called the callback only for the origin device. This led to badly calculated device limits if snapshot and origin were placed on different types of disks. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-13md/raid10: fix deadlock with unaligned read during resyncNeilBrown
commit 51e9ac77035a3dfcb6fc0a88a0d80b6f99b5edb1 upstream. If the 'bio_split' path in raid10-read is used while resync/recovery is happening it is possible to deadlock. Fix this be elevating ->nr_waiting for the duration of both parts of the split request. This fixes a bug that has been present since 2.6.22 but has only started manifesting recently for unknown reasons. It is suitable for and -stable since then. Reported-by: Justin Bronder <jsbronder@gentoo.org> Tested-by: Justin Bronder <jsbronder@gentoo.org> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-13md: fix another deadlock with removing sysfs attributes.NeilBrown
commit bb4f1e9d0e2ef93de8e36ca0f5f26625fcd70b7d upstream. Move the deletion of sysfs attributes from reconfig_mutex to open_mutex didn't really help as a process can try to take open_mutex while holding reconfig_mutex, so the same deadlock can happen, just requiring one more process to be involved in the chain. I looks like I cannot easily use locking to wait for the sysfs deletion to complete, so don't. The only things that we cannot do while the deletions are still pending is other things which can change the sysfs namespace: run, takeover, stop. Each of these can fail with -EBUSY. So set a flag while doing a sysfs deletion, and fail run, takeover, stop if that flag is set. This is suitable for 2.6.35.x Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-13md: move revalidate_disk() back outside open_mutexDan Williams
commit 147e0b6a639ac581ca3bf627bedc3f4a6d3eca66 upstream. Commit b821eaa5 "md: remove ->changed and related code" moved revalidate_disk() under open_mutex, and lockdep noticed. [ INFO: possible circular locking dependency detected ] 2.6.32-mdadm-locking #1 ------------------------------------------------------- mdadm/3640 is trying to acquire lock: (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff811acecb>] revalidate_disk+0x5b/0x90 but task is already holding lock: (&mddev->open_mutex){+.+...}, at: [<ffffffffa055e07a>] do_md_stop+0x4a/0x4d0 [md_mod] which lock already depends on the new lock. It is suitable for 2.6.35.x Reported-by: Przemyslaw Czarnowski <przemyslaw.hawrylewicz.czarnowski@intel.com> 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>
2010-06-24md/raid5: don't include 'spare' drives when reshaping to fewer devices.NeilBrown
There are few situations where it would make any sense to add a spare when reducing the number of devices in an array, but it is conceivable: A 6 drive RAID6 with two missing devices could be reshaped to a 5 drive RAID6, and a spare could become available just in time for the reshape, but not early enough to have been recovered first. 'freezing' recovery can make this easy to do without any races. However doing such a thing is a bad idea. md will not record the partially-recovered state of the 'spare' and when the reshape finished it will think that the spare is still spare. Easiest way to avoid this confusion is to simply disallow it. Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md/raid5: add a missing 'continue' in a loop.NeilBrown
As the comment says, the tail of this loop only applies to devices that are not fully in sync, so if In_sync was set, we should avoid the rest of the loop. This bug will hardly ever cause an actual problem. The worst it can do is allow an array to be assembled that is dirty and degraded, which is not generally a good idea (without warning the sysadmin first). This will only happen if the array is RAID4 or a RAID5/6 in an intermediate state during a reshape and so has one drive that is all 'parity' - no data - while some other device has failed. This is certainly possible, but not at all common. Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md/raid5: Allow recovered part of partially recovered devices to be in-syncNeilBrown
During a recovery of reshape the early part of some devices might be in-sync while the later parts are not. We we know we are looking at an early part it is good to treat that part as in-sync for stripe calculations. This is particularly important for a reshape which suffers device failure. Treating the data as in-sync can mean the difference between data-safety and data-loss. Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md/raid5: More careful check for "has array failed".NeilBrown
When we are reshaping an array, the device failure combinations that cause us to decide that the array as failed are more subtle. In particular, any 'spare' will be fully in-sync in the section of the array that has already been reshaped, thus failures that affect only that section are less critical. So encode this subtlety in a new function and call it as appropriate. The case that showed this problem was a 4 drive RAID5 to 8 drive RAID6 conversion where the last two devices failed. This resulted in: good good good good incomplete good good failed failed while converting a 5-drive RAID6 to 8 drive RAID5 The incomplete device causes the whole array to look bad, bad as it was actually good for the section that had been converted to 8-drives, all the data was actually safe. Reported-by: Terry Morris <tbmorris@tbmorris.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md: Don't update ->recovery_offset when reshaping an array to fewer devices.NeilBrown
When an array is reshaped to have fewer devices, the reshape proceeds from the end of the devices to the beginning. If a device happens to be non-In_sync (which is possible but rare) we would normally update the ->recovery_offset as the reshape progresses. However that would be wrong as the recover_offset records that the early part of the device is in_sync, while in fact it would only be the later part that is in_sync, and in any case the offset number would be measured from the wrong end of the device. Relatedly, if after a reshape a spare is discovered to not be recoverred all the way to the end, not allow spare_active to incorporate it in the array. This becomes relevant in the following sample scenario: A 4 drive RAID5 is converted to a 6 drive RAID6 in a combined operation. The RAID5->RAID6 conversion will cause a 5 drive to be included as a spare, then the 5drive -> 6drive reshape will effectively rebuild that spare as it progresses. The 6th drive is treated as in_sync the whole time as there is never any case that we might consider reading from it, but must not because there is no valid data. If we interrupt this reshape part-way through and reverse it to return to a 5-drive RAID6 (or event a 4-drive RAID5), we don't want to update the recovery_offset - as that would be wrong - and we don't want to include that spare as active in the 5-drive RAID6 when the reversed reshape completed and it will be mostly out-of-sync still. Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md/raid5: avoid oops when number of devices is reduced then increased.NeilBrown
The entries in the stripe_cache maintained by raid5 are enlarged when we increased the number of devices in the array, but not shrunk when we reduce the number of devices. So if entries are added after reducing the number of devices, we much ensure to initialise the whole entry, not just the part that is currently relevant. Otherwise if we enlarge the array again, we will reference uninitialised values. As grow_buffers/shrink_buffer now want to use a count that is stored explicity in the raid_conf, they should get it from there rather than being passed it as a parameter. Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md: enable raid4->raid0 takeoverMaciej Trela
Only level 5 with layout=PARITY_N can be taken over to raid0 now. Lets allow level 4 either. Signed-off-by: Maciej Trela <maciej.trela@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md: clear layout after ->raid0 takeoverMaciej Trela
After takeover from raid5/10 -> raid0 mddev->layout is not cleared. Signed-off-by: Maciej Trela <maciej.trela@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md: fix raid10 takeover: use new_layout for setup_confMaciej Trela
Use mddev->new_layout in setup_conf. Also use new_chunk, and don't set ->degraded in takeover(). That gets set in run() Signed-off-by: Maciej Trela <maciej.trela@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md: fix handling of array level takeover that re-arranges devices.NeilBrown
Most array level changes leave the list of devices largely unchanged, possibly causing one at the end to become redundant. However conversions between RAID0 and RAID10 need to renumber all devices (except 0). This renumbering is currently being done in the ->run method when the new personality takes over. However this is too late as the common code in md.c might already have invalidated some of the devices if they had a ->raid_disk number that appeared to high. Moving it into the ->takeover method is too early as the array is still active at that time and wrong ->raid_disk numbers could cause confusion. So add a ->new_raid_disk field to mdk_rdev_s and use it to communicate the new raid_disk number. Now the common code knows exactly which devices need to be renumbered, and which can be invalidated, and can do it all at a convenient time when the array is suspend. It can also update some symlinks in sysfs which previously were not be updated correctly. Reported-by: Maciej Trela <maciej.trela@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md: raid10: Fix null pointer dereference in fix_read_error()Prasanna S. Panchamukhi
Such NULL pointer dereference can occur when the driver was fixing the read errors/bad blocks and the disk was physically removed causing a system crash. This patch check if the rcu_dereference() returns valid rdev before accessing it in fix_read_error(). Cc: stable@kernel.org Signed-off-by: Prasanna S. Panchamukhi <prasanna.panchamukhi@riverbed.com> Signed-off-by: Rob Becker <rbecker@riverbed.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24Restore partition detection of newly created md arrays.NeilBrown
Commit b821eaa572fd737faaf6928ba046e571526c36c6 broke partition detection for md arrays. The logic was almost right. However if revalidate_disk is called when the device is not yet open, bdev->bd_disk won't be set, so the flush_disk() Call will not set bd_invalidated. So when md_open is called we still need to ensure that ->bd_invalidated gets set. This is easily done with a call to check_disk_size_change in the place where the offending commit removed check_disk_change. At the important times, the size will have changed from 0 to non-zero, so check_disk_size_change will set bd_invalidated. Tested-by: Duncan <1i5t5.duncan@cox.net> Reported-by: Duncan <1i5t5.duncan@cox.net> Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-27md: convert cpu notifier to return encapsulate errno valueAkinobu Mita
By the previous modification, the cpu notifier can return encapsulate errno value. This converts the cpu notifiers for raid5. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-21Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (69 commits) fix handling of offsets in cris eeprom.c, get rid of fake on-stack files get rid of home-grown mutex in cris eeprom.c switch ecryptfs_write() to struct inode *, kill on-stack fake files switch ecryptfs_get_locked_page() to struct inode * simplify access to ecryptfs inodes in ->readpage() and friends AFS: Don't put struct file on the stack Ban ecryptfs over ecryptfs logfs: replace inode uid,gid,mode initialization with helper function ufs: replace inode uid,gid,mode initialization with helper function udf: replace inode uid,gid,mode init with helper ubifs: replace inode uid,gid,mode initialization with helper function sysv: replace inode uid,gid,mode initialization with helper function reiserfs: replace inode uid,gid,mode initialization with helper function ramfs: replace inode uid,gid,mode initialization with helper function omfs: replace inode uid,gid,mode initialization with helper function bfs: replace inode uid,gid,mode initialization with helper function ocfs2: replace inode uid,gid,mode initialization with helper function nilfs2: replace inode uid,gid,mode initialization with helper function minix: replace inode uid,gid,mode init with helper ext4: replace inode uid,gid,mode init with helper ... Trivial conflict in fs/fs-writeback.c (mark bitfields unsigned)
2010-05-22Merge commit '3ff195b011d7decf501a4d55aeed312731094796' into for-linusNeilBrown
Conflicts: drivers/md/md.c - Resolved conflict in md_update_sb - Added extra 'NULL' arg to new instance of sysfs_get_dirent. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-21sanitize vfs_fsync calling conventionsChristoph Hellwig
Now that the last user passing a NULL file pointer is gone we can remove the redundant dentry argument and associated hacks inside vfs_fsynmc_range. The next step will be removig the dentry argument from ->fsync, but given the luck with the last round of method prototype changes I'd rather defer this until after the main merge window. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21sysfs: Implement sysfs tagged directory support.Eric W. Biederman
The problem. When implementing a network namespace I need to be able to have multiple network devices with the same name. Currently this is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and potentially a few other directories of the form /sys/ ... /net/*. What this patch does is to add an additional tag field to the sysfs dirent structure. For directories that should show different contents depending on the context such as /sys/class/net/, and /sys/devices/virtual/net/ this tag field is used to specify the context in which those directories should be visible. Effectively this is the same as creating multiple distinct directories with the same name but internally to sysfs the result is nicer. I am calling the concept of a single directory that looks like multiple directories all at the same path in the filesystem tagged directories. For the networking namespace the set of directories whose contents I need to filter with tags can depend on the presence or absence of hotplug hardware or which modules are currently loaded. Which means I need a simple race free way to setup those directories as tagged. To achieve a reace free design all tagged directories are created and managed by sysfs itself. Users of this interface: - define a type in the sysfs_tag_type enumeration. - call sysfs_register_ns_types with the type and it's operations - sysfs_exit_ns when an individual tag is no longer valid - Implement mount_ns() which returns the ns of the calling process so we can attach it to a sysfs superblock. - Implement ktype.namespace() which returns the ns of a syfs kobject. Everything else is left up to sysfs and the driver layer. For the network namespace mount_ns and namespace() are essentially one line functions, and look to remain that. Tags are currently represented a const void * pointers as that is both generic, prevides enough information for equality comparisons, and is trivial to create for current users, as it is just the existing namespace pointer. The work needed in sysfs is more extensive. At each directory or symlink creating I need to check if the directory it is being created in is a tagged directory and if so generate the appropriate tag to place on the sysfs_dirent. Likewise at each symlink or directory removal I need to check if the sysfs directory it is being removed from is a tagged directory and if so figure out which tag goes along with the name I am deleting. Currently only directories which hold kobjects, and symlinks are supported. There is not enough information in the current file attribute interfaces to give us anything to discriminate on which makes it useless, and there are no potential users which makes it an uninteresting problem to solve. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-18md: don't insist on valid event count for spare devices.NeilBrown
Devices which know that they are spares do not really need to have an event count that matches the rest of the array, so there are no data-in-sync issues. It is enough that the uuid matches. So remove the requirement that the event count is up-to-date. We currently still write out and event count on spares, but this allows us in a year or 3 to stop doing that completely. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: simplify updating of event count to sometimes avoid updating spares.NeilBrown
When updating the event count for a simple clean <-> dirty transition, we try to avoid updating the spares so they can safely spin-down. As the event_counts across an array must be +/- 1, this means decrementing the event_count on a dirty->clean transition. This is not always safe and we have to avoid the unsafe time. We current do this with a misguided idea about it being safe or not depending on whether the event_count is odd or even. This approach only works reliably in a few common instances, but easily falls down. So instead, simply keep internal state concerning whether it is safe or not, and always assume it is not safe when an array is first assembled. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md/raid6: Fix raid-6 read-error correction in degraded stateGabriele A. Trombetti
Fix: Raid-6 was not trying to correct a read-error when in singly-degraded state and was instead dropping one more device, going to doubly-degraded state. This patch fixes this behaviour. Tested-by: Janos Haar <janos.haar@netcenter.hu> Signed-off-by: Gabriele A. Trombetti <g.trombetti.lkrnl1213@logicschema.com> Reported-by: Janos Haar <janos.haar@netcenter.hu> Signed-off-by: NeilBrown <neilb@suse.de> Cc: stable@kernel.org
2010-05-18md: restore ability of spare drives to spin down.NeilBrown
Some time ago we stopped the clean/active metadata updates from being written to a 'spare' device in most cases so that it could spin down and say spun down. Device failure/removal etc are still recorded on spares. However commit 51d5668cb2e3fd1827a55 broke this 50% of the time, depending on whether the event count is even or odd. The change log entry said: This means that the alignment between 'odd/even' and 'clean/dirty' might take a little longer to attain, how ever the code makes no attempt to create that alignment, so it could take arbitrarily long. So when we find that clean/dirty is not aligned with odd/even, force a second metadata-update immediately. There are already cases where a second metadata-update is needed immediately (e.g. when a device fails during the metadata update). We just piggy-back on that. Reported-by: Joe Bryant <tenminjoe@yahoo.com> Signed-off-by: NeilBrown <neilb@suse.de> Cc: stable@kernel.org
2010-05-18md: Fix read balancing in RAID1 and RAID10 on drives > 2TBNeilBrown
read_balance uses a "unsigned long" for a sector number which will get truncated beyond 2TB. This will cause read-balancing to be non-optimal, and can cause data to be read from the 'wrong' branch during a resync. This has a very small chance of returning wrong data. Reported-by: Jordan Russell <jr-list-2010@quo.to> Cc: stable@kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md/linear: standardise all printk messagesNeilBrown
md/linear:mdname: Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md/raid0: tidy up printk messages.NeilBrown
All messages now start md/raid0:md-device-name: Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md/raid10: tidy up printk messages.NeilBrown
All raid10 printk messages now start md/raid10:md-device-name: Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md/raid1: improve printk messagesNeilBrown
Make sure the array name is included in a uniform way in all printk messages. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md/raid5: improve consistency of error messages.NeilBrown
Many 'printk' messages from the raid456 module mention 'raid5' even though it may be a 'raid6' or even 'raid4' array. This can cause confusion. Also the actual array name is not always reported and when it is it is not reported consistently. So change all the messages to start: md/raid:%s: where '%s' becomes e.g. md3 to identify the particular array. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: remove EXPERIMENTAL designation from RAID10NeilBrown
RAID10 has been available for quite a while now and is quite well tested, so we can remove the EXPERIMENTAL designation. Reported-by: Eric MSP Veith <eveith@wwweb-library.net> Signed-off-by: NeilBrown <neilb@suse.de>