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2008-02-08dm raid1: report fault statusJonathan Brassow
This patch adds extra information to the mirror status output, so that it can be determined which device(s) have failed. For each mirror device, a character is printed indicating the most severe error encountered. The characters are: * A => Alive - No failures * D => Dead - A write failure occurred leaving mirror out-of-sync * S => Sync - A sychronization failure occurred, mirror out-of-sync * R => Read - A read failure occurred, mirror data unaffected This allows userspace to properly reconfigure the mirror set. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm raid1: handle read failuresJonathan Brassow
This patch gives the ability to respond-to/record device failures that happen during read operations. It also adds the ability to read from mirror devices that are not the primary if they are in-sync. There are essentially two read paths in mirroring; the direct path and the queued path. When a read request is mapped, if the region is 'in-sync' the direct path is taken; otherwise the queued path is taken. If the direct path is taken, we must record bio information so that if the read fails we can retry it. We then discover the status of a direct read through mirror_end_io. If the read has failed, we will mark the device from which the read was attempted as failed (so we don't try to read from it again), restore the bio and try again. If the queued path is taken, we discover the results of the read from 'read_callback'. If the device failed, we will mark the device as failed and attempt the read again if there is another device where this region is known to be 'in-sync'. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm raid1: fix EIO after log failureJonathan Brassow
This patch adds the ability to requeue write I/O to core device-mapper when there is a log device failure. If a write to the log produces and error, the pending writes are put on the "failures" list. Since the log is marked as failed, they will stay on the failures list until a suspend happens. Suspends come in two phases, presuspend and postsuspend. We must make sure that all the writes on the failures list are requeued in the presuspend phase (a requirement of dm core). This means that recovery must be complete (because writes may be delayed behind it) and the failures list must be requeued before we return from presuspend. The mechanisms to ensure recovery is complete (or stopped) was already in place, but needed to be moved from postsuspend to presuspend. We rely on 'flush_workqueue' to ensure that the mirror thread is complete and therefore, has requeued all writes in the failures list. Because we are using flush_workqueue, we must ensure that no additional 'queue_work' calls will produce additional I/O that we need to requeue (because once we return from presuspend, we are unable to do anything about it). 'queue_work' is called in response to the following functions: - complete_resync_work = NA, recovery is stopped - rh_dec (mirror_end_io) = NA, only calls 'queue_work' if it is ready to recover the region (recovery is stopped) or it needs to clear the region in the log* **this doesn't get called while suspending** - rh_recovery_end = NA, recovery is stopped - rh_recovery_start = NA, recovery is stopped - write_callback = 1) Writes w/o failures simply call bio_endio -> mirror_end_io -> rh_dec (see rh_dec above) 2) Writes with failures are put on the failures list and queue_work is called** ** write_callbacks don't happen during suspend ** - do_failures = NA, 'queue_work' not called if suspending - add_mirror (initialization) = NA, only done on mirror creation - queue_bio = NA, 1) delayed I/O scheduled before flush_workqueue is called. 2) No more I/Os are being issued. 3) Re-attempted READs can still be handled. (Write completions are handled through rh_dec/ write_callback - mention above - and do not use queue_bio.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm raid1: handle recovery failuresJonathan Brassow
This patch adds the calls to 'fail_mirror' if an error occurs during mirror recovery (aka resynchronization). 'fail_mirror' is responsible for recording the type of error by mirror device and ensuring an event gets raised for the purpose of notifying userspace. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm raid1: handle write failuresJonathan Brassow
This patch gives mirror the ability to handle device failures during normal write operations. The 'write_callback' function is called when a write completes. If all the writes failed or succeeded, we report failure or success respectively. If some of the writes failed, we call fail_mirror; which increments the error count for the device, notes the type of error encountered (DM_RAID1_WRITE_ERROR), and selects a new primary (if necessary). Note that the primary device can never change while the mirror is not in-sync (IOW, while recovery is happening.) This means that the scenario where a failed write changes the primary and gives recovery_complete a chance to misread the primary never happens. The fact that the primary can change has necessitated the change to the default_mirror field. We need to protect against reading garbage while the primary changes. We then add the bio to a new list in the mirror set, 'failures'. For every bio in the 'failures' list, we call a new function, '__bio_mark_nosync', where we mark the region 'not-in-sync' in the log and properly set the region state as, RH_NOSYNC. Userspace must also be notified of the failure. This is done by 'raising an event' (dm_table_event()). If fail_mirror is called in process context the event can be raised right away. If in interrupt context, the event is deferred to the kmirrord thread - which raises the event if 'event_waiting' is set. Backwards compatibility is maintained by ignoring errors if the DM_FEATURES_HANDLE_ERRORS flag is not present. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm snapshot: combine consecutive exceptions in memoryMilan Broz
Provided sector_t is 64 bits, reduce the in-memory footprint of the snapshot exception table by the simple method of using unused bits of the chunk number to combine consecutive entries. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: stripe enhanced status returnBrian Wood
This patch adds additional information to the status line. It is added at the end of the returned text so it will not interfere with existing implementations using this data. The addition of this information will allow for a common return interface to match that returned with the dm-raid1.c status line (with Jonathan Brassow's patches). Here is a sample of what is returned with a mirror "status" call: isw_eeaaabgfg_mirror: 0 488390920 mirror 2 8:16 8:32 3727/3727 1 AA 1 core Here's what's returned with this patch for a stripe "status" call: isw_dheeijjdej_stripe: 0 976783872 striped 2 8:16 8:32 1 AA Signed-off-by: Brian Wood <brian.j.wood@intel.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: stripe trigger event on failureBrian Wood
This patch adds the stripe_end_io function to process errors that might occur after an IO operation. As part of this there are a number of enhancements made to record and trigger events: - New atomic variable in struct stripe to record the number of errors each stripe volume device has experienced (could be used later with uevents to report back directly to userspace) - New workqueue/work struct setup to process the trigger_event function - New end_io function. It is here that testing for BIO error conditions take place. It determines the exact stripe that cause the error, records this in the new atomic variable, and calls the queue_work() function - New trigger_event function to process failure events. This calls dm_table_event() Signed-off-by: Brian Wood <brian.j.wood@intel.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm log: auto load modulesJonathan Brassow
If the log type is not recognised, attempt to load the module 'dm-log-<type>.ko'. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: move deferred bio flushing to workqueueMilan Broz
Add a single-thread workqueue for each mapped device and move flushing of the lists of pushback and deferred bios to this new workqueue. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: use async cryptoMilan Broz
dm-crypt: Use crypto ablkcipher interface Move encrypt/decrypt core to async crypto call. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: prepare async callback fnMilan Broz
dm-crypt: Use crypto ablkcipher interface Prepare callback function for async crypto operation. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: add completion for asyncMilan Broz
dm-crypt: Use crypto ablkcipher interface Prepare completion for async crypto request. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: add async request mempoolMilan Broz
dm-crypt: Use crypto ablkcipher interface Introduce mempool for async crypto requests. cc->req is used mainly during synchronous operations (to prevent allocation and deallocation of the same object). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: extract scatterlist processingMilan Broz
dm-crypt: Use crypto ablkcipher interface Move scatterlists to separate dm_crypt_struct and pick out block processing from crypt_convert. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: tidy io ref countingMilan Broz
Make io reference counting more obvious. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: introduce crypt_write_io_loopMilan Broz
Introduce crypt_write_io_loop(). Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: abstract crypt_write_doneMilan Broz
Process write request in separate function and queue final bio through io workqueue. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: store sector mapping in dm_crypt_ioMilan Broz
Add sector into dm_crypt_io instead of using local variable. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: move queue functionsAlasdair G Kergon
Reorder kcryptd functions for clarity. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: adjust io processing functionsMilan Broz
Rename functions to follow calling convention. Prepare write io error processing function skeleton. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: tidy crypt_endioMilan Broz
Simplify crypt_endio function. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: move error setting outside crypt_dec_pendingMilan Broz
Move error code setting outside of crypt_dec_pending function. Use -EIO if crypt_convert_scatterlist() fails. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: remove unnecessary crypt_context write parmMilan Broz
Remove write attribute from convert_context and use bio flag instead. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm crypt: move convert_context inside dm_crypt_ioMilan Broz
Move convert_context inside dm_crypt_io. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm mpath: add missing staticAlasdair G Kergon
A static declaration missing. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: targets no longer experimentalAlasdair G Kergon
Drop the EXPERIMENTAL tag from well-established device-mapper targets, so the newer ones stand out better. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: refactor dm_suspend completion waitMilan Broz
Move completion wait to separate function Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: split dm_suspend io_lock hold into twoMilan Broz
Change io_locking to allow processing flush in separate thread. Because we have DMF_BLOCK_IO already set, any possible new ios are queued in dm_requests now. In the case of interrupting previous wait there can be more ios queued (we unlocked io_lock for a while) but this is safe. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: tidy dm_suspendMilan Broz
Tidy dm_suspend function - change return value logic in dm_suspend - use atomic_read only once. - move DMF_BLOCK_IO clearing into one place Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: refactor deferred bio_list processingMilan Broz
Refactor deferred bio_list processing. - use separate _merge_pushback_list function - move deferred bio list pick up to flush function - use bio_list_pop instead of bio_list_get - simplify noflush flag use No real functional change in this patch. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: tidy alloc_dev labelsMilan Broz
Tidy labels in alloc_dev to make later patches more clear. No functional change in this patch. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm ioctl: use uninitialized_varAndrew Morton
drivers/md/dm-ioctl.c:1405: warning: 'param' may be used uninitialized in this function Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: table use uninitialized_varAndrew Morton
drivers/md/dm-table.c: In function 'dm_get_device': drivers/md/dm-table.c:478: warning: 'dev' may be used uninitialized in this function Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm snapshot: use uninitialized_varAndrew Morton
drivers/md/dm-exception-store.c: In function 'persistent_read_metadata': drivers/md/dm-exception-store.c:452: warning: 'new_snapshot' may be used uninitialized in this function Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: convert suspend_lock semaphore to mutexDaniel Walker
Replace semaphore with mutex. Signed-off-by: Daniel Walker <dwalker@mvista.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm snapshot: use rounddown_pow_of_twoRobert P. J. Day
Since the source file already includes the log2.h header file, it seems pointless to re-invent the necessary routine. Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: table remove unused totalJun'ichi Nomura
"total = 0" does nothing. Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: table use list_for_eachPaul Jimenez
This patch is some minor janitorish cleanup, using some macros from linux/list.h (already #included via dm.h) to improve readability. Signed-off-by: Paul Jimenez <pj@place.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm ioctl: move compat codeMilan Broz
Move compat_ioctl handling into dm-ioctl.c. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm ioctl: remove lock_kernelAlasdair G Kergon
Remove lock_kernel() from the device-mapper ioctls - there should be sufficient internal locking already where required. Also remove some superfluous casts. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: mark function lists staticAlasdair G Kergon
Add a couple of statics. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-08dm: add missing memory barrier to dm_suspendMilan Broz
Add memory barrier to fix atomic_read of pending value. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-02-06md: fix an occasional deadlock in raid5NeilBrown
raid5's 'make_request' function calls generic_make_request on underlying devices and if we run out of stripe heads, it could end up waiting for one of those requests to complete. This is bad as recursive calls to generic_make_request go on a queue and are not even attempted until make_request completes. So: don't make any generic_make_request calls in raid5 make_request until all waiting has been done. We do this by simply setting STRIPE_HANDLE instead of calling handle_stripe(). If we need more stripe_heads, raid5d will get called to process the pending stripe_heads which will call generic_make_request from a This change by itself causes a performance hit. So add a change so that raid5_activate_delayed is only called at unplug time, never in raid5. This seems to bring back the performance numbers. Calling it in raid5d was sometimes too soon... Neil said: How about we queue it for 2.6.25-rc1 and then about when -rc2 comes out, we queue it for 2.6.24.y? Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Neil Brown <neilb@suse.de> Tested-by: dean gaudet <dean@arctic.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06md: change ITERATE_RDEV_GENERIC to rdev_for_each_list, and remove ↵NeilBrown
ITERATE_RDEV_PENDING. Finish ITERATE_ to for_each conversion. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06md: change ITERATE_RDEV to rdev_for_eachNeilBrown
As this is more in line with common practice in the kernel. Also swap the args around to be more like list_for_each. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06md: change INTERATE_MDDEV to for_each_mddevNeilBrown
As this is more consistent with kernel style. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06md: change a few 'int' to 'size_t' in mdNeilBrown
As suggested by Andrew Morton. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06md: fix use-after-free bug when dropping an rdev from an md arrayNeilBrown
Due to possible deadlock issues we need to use a schedule work to kobject_del an 'rdev' object from a different thread. A recent change means that kobject_add no longer gets a refernce, and kobject_del doesn't put a reference. Consequently, we need to explicitly hold a reference to ensure that the last reference isn't dropped before the scheduled work get a chance to call kobject_del. Also, rename delayed_delete to md_delayed_delete to that it is more obvious in a stack trace which code is to blame. Cc: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06md: allow an md array to appear with 0 drives if it has external metadataNeilBrown
Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>