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2017-02-21Merge branch 'locking-core-for-linus' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "The main changes in this cycle were: - Implement wraparound-safe refcount_t and kref_t types based on generic atomic primitives (Peter Zijlstra) - Improve and fix the ww_mutex code (Nicolai Hähnle) - Add self-tests to the ww_mutex code (Chris Wilson) - Optimize percpu-rwsems with the 'rcuwait' mechanism (Davidlohr Bueso) - Micro-optimize the current-task logic all around the core kernel (Davidlohr Bueso) - Tidy up after recent optimizations: remove stale code and APIs, clean up the code (Waiman Long) - ... plus misc fixes, updates and cleanups" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits) fork: Fix task_struct alignment locking/spinlock/debug: Remove spinlock lockup detection code lockdep: Fix incorrect condition to print bug msgs for MAX_LOCKDEP_CHAIN_HLOCKS lkdtm: Convert to refcount_t testing kref: Implement 'struct kref' using refcount_t refcount_t: Introduce a special purpose refcount type sched/wake_q: Clarify queue reinit comment sched/wait, rcuwait: Fix typo in comment locking/mutex: Fix lockdep_assert_held() fail locking/rtmutex: Flip unlikely() branch to likely() in __rt_mutex_slowlock() locking/rwsem: Reinit wake_q after use locking/rwsem: Remove unnecessary atomic_long_t casts jump_labels: Move header guard #endif down where it belongs locking/atomic, kref: Implement kref_put_lock() locking/ww_mutex: Turn off __must_check for now locking/atomic, kref: Avoid more abuse locking/atomic, kref: Use kref_get_unless_zero() more locking/atomic, kref: Kill kref_sub() locking/atomic, kref: Add kref_read() locking/atomic, kref: Add KREF_INIT() ...
2017-02-03dm crypt: replace RCU read-side section with rwsemOndrej Kozina1-4/+4
The lockdep splat below hints at a bug in RCU usage in dm-crypt that was introduced with commit c538f6ec9f56 ("dm crypt: add ability to use keys from the kernel key retention service"). The kernel keyring function user_key_payload() is in fact a wrapper for rcu_dereference_protected() which must not be called with only rcu_read_lock() section mark. Unfortunately the kernel keyring subsystem doesn't currently provide an interface that allows the use of an RCU read-side section. So for now we must drop RCU in favour of rwsem until a proper function is made available in the kernel keyring subsystem. =============================== [ INFO: suspicious RCU usage. ] 4.10.0-rc5 #2 Not tainted ------------------------------- ./include/keys/user-type.h:53 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by cryptsetup/6464: #0: (&md->type_lock){+.+.+.}, at: [<ffffffffa02472a2>] dm_lock_md_type+0x12/0x20 [dm_mod] #1: (rcu_read_lock){......}, at: [<ffffffffa02822f8>] crypt_set_key+0x1d8/0x4b0 [dm_crypt] stack backtrace: CPU: 1 PID: 6464 Comm: cryptsetup Not tainted 4.10.0-rc5 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014 Call Trace: dump_stack+0x67/0x92 lockdep_rcu_suspicious+0xc5/0x100 crypt_set_key+0x351/0x4b0 [dm_crypt] ? crypt_set_key+0x1d8/0x4b0 [dm_crypt] crypt_ctr+0x341/0xa53 [dm_crypt] dm_table_add_target+0x147/0x330 [dm_mod] table_load+0x111/0x350 [dm_mod] ? retrieve_status+0x1c0/0x1c0 [dm_mod] ctl_ioctl+0x1f5/0x510 [dm_mod] dm_ctl_ioctl+0xe/0x20 [dm_mod] do_vfs_ioctl+0x8e/0x690 ? ____fput+0x9/0x10 ? task_work_run+0x7e/0xa0 ? trace_hardirqs_on_caller+0x122/0x1b0 SyS_ioctl+0x3c/0x70 entry_SYSCALL_64_fastpath+0x18/0xad RIP: 0033:0x7f392c9a4ec7 RSP: 002b:00007ffef6383378 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffef63830a0 RCX: 00007f392c9a4ec7 RDX: 000000000124fcc0 RSI: 00000000c138fd09 RDI: 0000000000000005 RBP: 00007ffef6383090 R08: 00000000ffffffff R09: 00000000012482b0 R10: 2a28205d34383336 R11: 0000000000000246 R12: 00007f392d803a08 R13: 00007ffef63831e0 R14: 0000000000000000 R15: 00007f392d803a0b Fixes: c538f6ec9f56 ("dm crypt: add ability to use keys from the kernel key retention service") Reported-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Ondrej Kozina <okozina@redhat.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-01-14sched/core: Remove set_task_state()Davidlohr Bueso1-2/+2
This is a nasty interface and setting the state of a foreign task must not be done. As of the following commit: be628be0956 ("bcache: Make gc wakeup sane, remove set_task_state()") ... everyone in the kernel calls set_task_state() with current, allowing the helper to be removed. However, as the comment indicates, it is still around for those archs where computing current is more expensive than using a pointer, at least in theory. An important arch that is affected is arm64, however this has been addressed now [1] and performance is up to par making no difference with either calls. Of all the callers, if any, it's the locking bits that would care most about this -- ie: we end up passing a tsk pointer to a lot of the lock slowpath, and setting ->state on that. The following numbers are based on two tests: a custom ad-hoc microbenchmark that just measures latencies (for ~65 million calls) between get_task_state() vs get_current_state(). Secondly for a higher overview, an unlink microbenchmark was used, which pounds on a single file with open, close,unlink combos with increasing thread counts (up to 4x ncpus). While the workload is quite unrealistic, it does contend a lot on the inode mutex or now rwsem. [1] https://lkml.kernel.org/r/1483468021-8237-1-git-send-email-mark.rutland@arm.com == 1. x86-64 == Avg runtime set_task_state(): 601 msecs Avg runtime set_current_state(): 552 msecs vanilla dirty Hmean unlink1-processes-2 36089.26 ( 0.00%) 38977.33 ( 8.00%) Hmean unlink1-processes-5 28555.01 ( 0.00%) 29832.55 ( 4.28%) Hmean unlink1-processes-8 37323.75 ( 0.00%) 44974.57 ( 20.50%) Hmean unlink1-processes-12 43571.88 ( 0.00%) 44283.01 ( 1.63%) Hmean unlink1-processes-21 34431.52 ( 0.00%) 38284.45 ( 11.19%) Hmean unlink1-processes-30 34813.26 ( 0.00%) 37975.17 ( 9.08%) Hmean unlink1-processes-48 37048.90 ( 0.00%) 39862.78 ( 7.59%) Hmean unlink1-processes-79 35630.01 ( 0.00%) 36855.30 ( 3.44%) Hmean unlink1-processes-110 36115.85 ( 0.00%) 39843.91 ( 10.32%) Hmean unlink1-processes-141 32546.96 ( 0.00%) 35418.52 ( 8.82%) Hmean unlink1-processes-172 34674.79 ( 0.00%) 36899.21 ( 6.42%) Hmean unlink1-processes-203 37303.11 ( 0.00%) 36393.04 ( -2.44%) Hmean unlink1-processes-224 35712.13 ( 0.00%) 36685.96 ( 2.73%) == 2. ppc64le == Avg runtime set_task_state(): 938 msecs Avg runtime set_current_state: 940 msecs vanilla dirty Hmean unlink1-processes-2 19269.19 ( 0.00%) 30704.50 ( 59.35%) Hmean unlink1-processes-5 20106.15 ( 0.00%) 21804.15 ( 8.45%) Hmean unlink1-processes-8 17496.97 ( 0.00%) 17243.28 ( -1.45%) Hmean unlink1-processes-12 14224.15 ( 0.00%) 17240.21 ( 21.20%) Hmean unlink1-processes-21 14155.66 ( 0.00%) 15681.23 ( 10.78%) Hmean unlink1-processes-30 14450.70 ( 0.00%) 15995.83 ( 10.69%) Hmean unlink1-processes-48 16945.57 ( 0.00%) 16370.42 ( -3.39%) Hmean unlink1-processes-79 15788.39 ( 0.00%) 14639.27 ( -7.28%) Hmean unlink1-processes-110 14268.48 ( 0.00%) 14377.40 ( 0.76%) Hmean unlink1-processes-141 14023.65 ( 0.00%) 16271.69 ( 16.03%) Hmean unlink1-processes-172 13417.62 ( 0.00%) 16067.55 ( 19.75%) Hmean unlink1-processes-203 15293.08 ( 0.00%) 15440.40 ( 0.96%) Hmean unlink1-processes-234 13719.32 ( 0.00%) 16190.74 ( 18.01%) Hmean unlink1-processes-265 16400.97 ( 0.00%) 16115.22 ( -1.74%) Hmean unlink1-processes-296 14388.60 ( 0.00%) 16216.13 ( 12.70%) Hmean unlink1-processes-320 15771.85 ( 0.00%) 15905.96 ( 0.85%) x86-64 (known to be fast for get_current()/this_cpu_read_stable() caching) and ppc64 (with paca) show similar improvements in the unlink microbenches. The small delta for ppc64 (2ms), does not represent the gains on the unlink runs. In the case of x86, there was a decent amount of variation in the latency runs, but always within a 20 to 50ms increase), ppc was more constant. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@stgolabs.net Cc: mark.rutland@arm.com Link: http://lkml.kernel.org/r/1483479794-14013-5-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-14Merge tag 'dm-4.10-changes' of ↵Linus Torvalds1-33/+181
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - various fixes and improvements to request-based DM and DM multipath - some locking improvements in DM bufio - add Kconfig option to disable the DM block manager's extra locking which mainly serves as a developer tool - a few bug fixes to DM's persistent-data - a couple changes to prepare for multipage biovec support in the block layer - various improvements and cleanups in the DM core, DM cache, DM raid and DM crypt - add ability to have DM crypt use keys from the kernel key retention service - add a new "error_writes" feature to the DM flakey target, reads are left unchanged in this mode * tag 'dm-4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (40 commits) dm flakey: introduce "error_writes" feature dm cache policy smq: use hash_32() instead of hash_32_generic() dm crypt: reject key strings containing whitespace chars dm space map: always set ev if sm_ll_mutate() succeeds dm space map metadata: skip useless memcpy in metadata_ll_init_index() dm space map metadata: fix 'struct sm_metadata' leak on failed create Documentation: dm raid: define data_offset status field dm raid: fix discard support regression dm raid: don't allow "write behind" with raid4/5/6 dm mpath: use hw_handler_params if attached hw_handler is same as requested dm crypt: add ability to use keys from the kernel key retention service dm array: remove a dead assignment in populate_ablock_with_values() dm ioctl: use offsetof() instead of open-coding it dm rq: simplify use_blk_mq initialization dm: use blk_set_queue_dying() in __dm_destroy() dm bufio: drop the lock when doing GFP_NOIO allocation dm bufio: don't take the lock in dm_bufio_shrink_count dm bufio: avoid sleeping while holding the dm_bufio lock dm table: simplify dm_table_determine_type() dm table: an 'all_blk_mq' table must be loaded for a blk-mq DM device ...
2016-12-08dm crypt: reject key strings containing whitespace charsOndrej Kozina1-0/+18
Unfortunately key_string may theoretically contain whitespace even after it's processed by dm_split_args(). The reason for this is DM core supports escaping of almost all chars including any whitespace. If userspace passes a key to the kernel in format ":32:logon:my_prefix:my\ key" dm-crypt will look up key "my_prefix:my key" in kernel keyring service. So far everything's fine. Unfortunately if userspace later calls DM_TABLE_STATUS ioctl, it will not receive back expected ":32:logon:my_prefix:my\ key" but the unescaped version instead. Also userpace (most notably cryptsetup) is not ready to parse single target argument containing (even escaped) whitespace chars and any whitespace is simply taken as delimiter of another argument. This effect is mitigated by the fact libdevmapper curently performs double escaping of '\' char. Any user input in format "x\ x" is transformed into "x\\ x" before being passed to the kernel. Nonetheless dm-crypt may be used without libdevmapper. Therefore the near-term solution to this is to reject any key string containing whitespace. Signed-off-by: Ondrej Kozina <okozina@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08dm crypt: add ability to use keys from the kernel key retention serviceOndrej Kozina1-13/+146
The kernel key service is a generic way to store keys for the use of other subsystems. Currently there is no way to use kernel keys in dm-crypt. This patch aims to fix that. Instead of key userspace may pass a key description with preceding ':'. So message that constructs encryption mapping now looks like this: <cipher> [<key>|:<key_string>] <iv_offset> <dev_path> <start> [<#opt_params> <opt_params>] where <key_string> is in format: <key_size>:<key_type>:<key_description> Currently we only support two elementary key types: 'user' and 'logon'. Keys may be loaded in dm-crypt either via <key_string> or using classical method and pass the key in hex representation directly. dm-crypt device initialised with a key passed in hex representation may be replaced with key passed in key_string format and vice versa. (Based on original work by Andrey Ryabinin) Signed-off-by: Ondrej Kozina <okozina@redhat.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21dm crypt: constify crypt_iv_operations structuresJulia Lawall1-8/+8
The crypt_iv_operations are never modified, so declare them as const. Done with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21dm crypt: rename crypt_setkey_allcpus to crypt_setkeyMikulas Patocka1-3/+3
In the past, dm-crypt used per-cpu crypto context. This has been removed in the kernel 3.15 and the crypto context is shared between all cpus. This patch renames the function crypt_setkey_allcpus to crypt_setkey, because there is really no activity that is done for all cpus. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21dm crypt: mark key as invalid until properly loadedOndrej Kozina1-2/+5
In crypt_set_key(), if a failure occurs while replacing the old key (e.g. tfm->setkey() fails) the key must not have DM_CRYPT_KEY_VALID flag set. Otherwise, the crypto layer would have an invalid key that still has DM_CRYPT_KEY_VALID flag set. Cc: stable@vger.kernel.org Signed-off-by: Ondrej Kozina <okozina@redhat.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-11-21dm crypt: use bio_add_page()Ming Lei1-7/+1
Use bio_add_page(), the standard interface for adding a page to a bio, rather than open-coding the same. It should be noted that the 'clone' bio that is allocated using bio_alloc_bioset(), in crypt_alloc_buffer(), does _not_ set the bio's BIO_CLONED flag. As such, bio_add_page()'s early return for true bio clones (those with BIO_CLONED set) isn't applicable. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-10-28block: better op and flags encodingChristoph Hellwig1-1/+1
Now that we don't need the common flags to overflow outside the range of a 32-bit type we can encode them the same way for both the bio and request fields. This in addition allows us to place the operation first (and make some room for more ops while we're at it) and to stop having to shift around the operation values. In addition this allows passing around only one value in the block layer instead of two (and eventuall also in the file systems, but we can do that later) and thus clean up a lot of code. Last but not least this allows decreasing the size of the cmd_flags field in struct request to 32-bits. Various functions passing this value could also be updated, but I'd like to avoid the churn for now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-10Merge tag 'dm-4.9-changes' of ↵Linus Torvalds1-14/+10
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - various fixes and cleanups for request-based DM core - add support for delaying the requeue of requests; used by DM multipath when all paths have failed and 'queue_if_no_path' is enabled - DM cache improvements to speedup the loading metadata and the writing of the hint array - fix potential for a dm-crypt crash on device teardown - remove dm_bufio_cond_resched() and just using cond_resched() - change DM multipath to return a reservation conflict error immediately; rather than failing the path and retrying (potentially indefinitely) * tag 'dm-4.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (24 commits) dm mpath: always return reservation conflict without failing over dm bufio: remove dm_bufio_cond_resched() dm crypt: fix crash on exit dm cache metadata: switch to using the new cursor api for loading metadata dm array: introduce cursor api dm btree: introduce cursor api dm cache policy smq: distribute entries to random levels when switching to smq dm cache: speed up writing of the hint array dm array: add dm_array_new() dm mpath: delay the requeue of blk-mq requests while all paths down dm mpath: use dm_mq_kick_requeue_list() dm rq: introduce dm_mq_kick_requeue_list() dm rq: reduce arguments passed to map_request() and dm_requeue_original_request() dm rq: add DM_MAPIO_DELAY_REQUEUE to delay requeue of blk-mq requests dm: convert wait loops to use autoremove_wake_function() dm: use signal_pending_state() in dm_wait_for_completion() dm: rename task state function arguments dm: add two lockdep_assert_held() statements dm rq: simplify dm_old_stop_queue() dm mpath: check if path's request_queue is dying in activate_path() ...
2016-10-08Merge branch 'for-4.9/block' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+1
Pull block layer updates from Jens Axboe: "This is the main pull request for block layer changes in 4.9. As mentioned at the last merge window, I've changed things up and now do just one branch for core block layer changes, and driver changes. This avoids dependencies between the two branches. Outside of this main pull request, there are two topical branches coming as well. This pull request contains: - A set of fixes, and a conversion to blk-mq, of nbd. From Josef. - Set of fixes and updates for lightnvm from Matias, Simon, and Arnd. Followup dependency fix from Geert. - General fixes from Bart, Baoyou, Guoqing, and Linus W. - CFQ async write starvation fix from Glauber. - Add supprot for delayed kick of the requeue list, from Mike. - Pull out the scalable bitmap code from blk-mq-tag.c and make it generally available under the name of sbitmap. Only blk-mq-tag uses it for now, but the blk-mq scheduling bits will use it as well. From Omar. - bdev thaw error progagation from Pierre. - Improve the blk polling statistics, and allow the user to clear them. From Stephen. - Set of minor cleanups from Christoph in block/blk-mq. - Set of cleanups and optimizations from me for block/blk-mq. - Various nvme/nvmet/nvmeof fixes from the various folks" * 'for-4.9/block' of git://git.kernel.dk/linux-block: (54 commits) fs/block_dev.c: return the right error in thaw_bdev() nvme: Pass pointers, not dma addresses, to nvme_get/set_features() nvme/scsi: Remove power management support nvmet: Make dsm number of ranges zero based nvmet: Use direct IO for writes admin-cmd: Added smart-log command support. nvme-fabrics: Add host_traddr options field to host infrastructure nvme-fabrics: revise host transport option descriptions nvme-fabrics: rework nvmf_get_address() for variable options nbd: use BLK_MQ_F_BLOCKING blkcg: Annotate blkg_hint correctly cfq: fix starvation of asynchronous writes blk-mq: add flag for drivers wanting blocking ->queue_rq() blk-mq: remove non-blocking pass in blk_mq_map_request blk-mq: get rid of manual run of queue with __blk_mq_run_hw_queue() block: export bio_free_pages to other modules lightnvm: propagate device_add() error code lightnvm: expose device geometry through sysfs lightnvm: control life of nvm_dev in driver blk-mq: register device instead of disk ...
2016-09-22dm crypt: fix crash on exitRabin Vincent1-14/+10
As the documentation for kthread_stop() says, "if threadfn() may call do_exit() itself, the caller must ensure task_struct can't go away". dm-crypt does not ensure this and therefore crashes when crypt_dtr() calls kthread_stop(). The crash is trivially reproducible by adding a delay before the call to kthread_stop() and just opening and closing a dm-crypt device. general protection fault: 0000 [#1] PREEMPT SMP CPU: 0 PID: 533 Comm: cryptsetup Not tainted 4.8.0-rc7+ #7 task: ffff88003bd0df40 task.stack: ffff8800375b4000 RIP: 0010: kthread_stop+0x52/0x300 Call Trace: crypt_dtr+0x77/0x120 dm_table_destroy+0x6f/0x120 __dm_destroy+0x130/0x250 dm_destroy+0x13/0x20 dev_remove+0xe6/0x120 ? dev_suspend+0x250/0x250 ctl_ioctl+0x1fc/0x530 ? __lock_acquire+0x24f/0x1b10 dm_ctl_ioctl+0x13/0x20 do_vfs_ioctl+0x91/0x6a0 ? ____fput+0xe/0x10 ? entry_SYSCALL_64_fastpath+0x5/0xbd ? trace_hardirqs_on_caller+0x151/0x1e0 SyS_ioctl+0x41/0x70 entry_SYSCALL_64_fastpath+0x1f/0xbd This problem was introduced by bcbd94ff481e ("dm crypt: fix a possible hang due to race condition on exit"). Looking at the description of that patch (excerpted below), it seems like the problem it addresses can be solved by just using set_current_state instead of __set_current_state, since we obviously need the memory barrier. | dm crypt: fix a possible hang due to race condition on exit | | A kernel thread executes __set_current_state(TASK_INTERRUPTIBLE), | __add_wait_queue, spin_unlock_irq and then tests kthread_should_stop(). | It is possible that the processor reorders memory accesses so that | kthread_should_stop() is executed before __set_current_state(). If | such reordering happens, there is a possible race on thread | termination: [...] So this patch just reverts the aforementioned patch and changes the __set_current_state(TASK_INTERRUPTIBLE) to set_current_state(...). This fixes the crash and should also fix the potential hang. Fixes: bcbd94ff481e ("dm crypt: fix a possible hang due to race condition on exit") Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org # v4.0+ Signed-off-by: Rabin Vincent <rabinv@axis.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-09-14block, dm-crypt, btrfs: Introduce bio_flags()Bart Van Assche1-1/+1
Introduce the bio_flags() macro. Ensure that the second argument of bio_set_op_attrs() only contains flags and no operation. This patch does not change any functionality. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Mike Christie <mchristi@redhat.com> Cc: Chris Mason <clm@fb.com> (maintainer:BTRFS FILE SYSTEM) Cc: Josef Bacik <jbacik@fb.com> (maintainer:BTRFS FILE SYSTEM) Cc: Mike Snitzer <snitzer@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Damien Le Moal <damien.lemoal@hgst.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-31dm crypt: fix free of bad values after tfm allocation failureEric Biggers1-1/+1
If crypt_alloc_tfms() had to allocate multiple tfms and it failed before the last allocation, then it would call crypt_free_tfms() and could free pointers from uninitialized memory -- due to the crypt_free_tfms() check for non-zero cc->tfms[i]. Fix by allocating zeroed memory. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
2016-08-31dm crypt: fix error with too large biosMikulas Patocka1-0/+7
When dm-crypt processes writes, it allocates a new bio in crypt_alloc_buffer(). The bio is allocated from a bio set and it can have at most BIO_MAX_PAGES vector entries, however the incoming bio can be larger (e.g. if it was allocated by bcache). If the incoming bio is larger, bio_alloc_bioset() fails and an error is returned. To avoid the error, we test for a too large bio in the function crypt_map() and use dm_accept_partial_bio() to split the bio. dm_accept_partial_bio() trims the current bio to the desired size and asks DM core to send another bio with the rest of the data. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # v3.16+
2016-08-15dm crypt: increase mempool reserve to better support swappingMikulas Patocka1-1/+1
Increase mempool size from 16 to 64 entries. This increase improves swap on dm-crypt performance. When swapping to dm-crypt, all available memory is temporarily exhausted and dm-crypt can only use the mempool reserve. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-08-07block: rename bio bi_rw to bi_opfJens Axboe1-2/+2
Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower portion and the op code in the higher portions. This means that old code that relies on manually setting bi_rw is most likely going to be broken. Instead of letting that brokeness linger, rename the member, to force old and out-of-tree code to break at compile time instead of at runtime. No intended functional changes in this commit. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-01dm crypt: Fix sparse complaintsBart Van Assche1-2/+2
Avoid that sparse complains about assigning a __le64 value to a u64 variable. Remove the (u64) casts since these are superfluous. This patch does not change the behavior of the source code. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-06-07block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSHMike Christie1-3/+4
To avoid confusion between REQ_OP_FLUSH, which is handled by request_fn drivers, and upper layers requesting the block layer perform a flush sequence along with possibly a WRITE, this patch renames REQ_FLUSH to REQ_PREFLUSH. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07dm: use bio op accessorsMike Christie1-4/+4
Separate the op from the rq_flag_bits and have dm set/get the bio using bio_set_op_attrs/bio_op. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-17Merge branch 'linus' of ↵Linus Torvalds1-45/+48
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto update from Herbert Xu: "Here is the crypto update for 4.6: API: - Convert remaining crypto_hash users to shash or ahash, also convert blkcipher/ablkcipher users to skcipher. - Remove crypto_hash interface. - Remove crypto_pcomp interface. - Add crypto engine for async cipher drivers. - Add akcipher documentation. - Add skcipher documentation. Algorithms: - Rename crypto/crc32 to avoid name clash with lib/crc32. - Fix bug in keywrap where we zero the wrong pointer. Drivers: - Support T5/M5, T7/M7 SPARC CPUs in n2 hwrng driver. - Add PIC32 hwrng driver. - Support BCM6368 in bcm63xx hwrng driver. - Pack structs for 32-bit compat users in qat. - Use crypto engine in omap-aes. - Add support for sama5d2x SoCs in atmel-sha. - Make atmel-sha available again. - Make sahara hashing available again. - Make ccp hashing available again. - Make sha1-mb available again. - Add support for multiple devices in ccp. - Improve DMA performance in caam. - Add hashing support to rockchip" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (116 commits) crypto: qat - remove redundant arbiter configuration crypto: ux500 - fix checks of error code returned by devm_ioremap_resource() crypto: atmel - fix checks of error code returned by devm_ioremap_resource() crypto: qat - Change the definition of icp_qat_uof_regtype hwrng: exynos - use __maybe_unused to hide pm functions crypto: ccp - Add abstraction for device-specific calls crypto: ccp - CCP versioning support crypto: ccp - Support for multiple CCPs crypto: ccp - Remove check for x86 family and model crypto: ccp - memset request context to zero during import lib/mpi: use "static inline" instead of "extern inline" lib/mpi: avoid assembler warning hwrng: bcm63xx - fix non device tree compatibility crypto: testmgr - allow rfc3686 aes-ctr variants in fips mode. crypto: qat - The AE id should be less than the maximal AE number lib/mpi: Endianness fix crypto: rockchip - add hash support for crypto engine in rk3288 crypto: xts - fix compile errors crypto: doc - add skcipher API documentation crypto: doc - update AEAD AD handling ...
2016-02-23dm: rename target's per_bio_data_size to per_io_data_sizeMike Snitzer1-1/+1
Request-based DM will also make use of per_bio_data_size. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-01-27dm crypt: Use skcipher and ahashHerbert Xu1-45/+48
This patch replaces uses of ablkcipher with skcipher, and the long obsolete hash interface with ahash. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-11-19dm crypt: fix a possible hang due to race condition on exitMikulas Patocka1-9/+13
A kernel thread executes __set_current_state(TASK_INTERRUPTIBLE), __add_wait_queue, spin_unlock_irq and then tests kthread_should_stop(). It is possible that the processor reorders memory accesses so that kthread_should_stop() is executed before __set_current_state(). If such reordering happens, there is a possible race on thread termination: CPU 0: calls kthread_should_stop() it tests KTHREAD_SHOULD_STOP bit, returns false CPU 1: calls kthread_stop(cc->write_thread) sets the KTHREAD_SHOULD_STOP bit calls wake_up_process on the kernel thread, that sets the thread state to TASK_RUNNING CPU 0: sets __set_current_state(TASK_INTERRUPTIBLE) spin_unlock_irq(&cc->write_thread_wait.lock) schedule() - and the process is stuck and never terminates, because the state is TASK_INTERRUPTIBLE and wake_up_process on CPU 1 already terminated Fix this race condition by using a new flag DM_CRYPT_EXIT_THREAD to signal that the kernel thread should exit. The flag is set and tested while holding cc->write_thread_wait.lock, so there is no possibility of racy access to the flag. Also, remove the unnecessary set_task_state(current, TASK_RUNNING) following the schedule() call. When the process was woken up, its state was already set to TASK_RUNNING. Other kernel code also doesn't set the state to TASK_RUNNING following schedule() (for example, do_wait_for_common in completion.c doesn't do it). Fixes: dc2676210c42 ("dm crypt: offload writes to thread") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org # v4.0+ Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-11-07mm, page_alloc: distinguish between being unable to sleep, unwilling to ↵Mel Gorman1-3/+3
sleep and avoiding waking kswapd __GFP_WAIT has been used to identify atomic context in callers that hold spinlocks or are in interrupts. They are expected to be high priority and have access one of two watermarks lower than "min" which can be referred to as the "atomic reserve". __GFP_HIGH users get access to the first lower watermark and can be called the "high priority reserve". Over time, callers had a requirement to not block when fallback options were available. Some have abused __GFP_WAIT leading to a situation where an optimisitic allocation with a fallback option can access atomic reserves. This patch uses __GFP_ATOMIC to identify callers that are truely atomic, cannot sleep and have no alternative. High priority users continue to use __GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers that want to wake kswapd for background reclaim. __GFP_WAIT is redefined as a caller that is willing to enter direct reclaim and wake kswapd for background reclaim. This patch then converts a number of sites o __GFP_ATOMIC is used by callers that are high priority and have memory pools for those requests. GFP_ATOMIC uses this flag. o Callers that have a limited mempool to guarantee forward progress clear __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall into this category where kswapd will still be woken but atomic reserves are not used as there is a one-entry mempool to guarantee progress. o Callers that are checking if they are non-blocking should use the helper gfpflags_allow_blocking() where possible. This is because checking for __GFP_WAIT as was done historically now can trigger false positives. Some exceptions like dm-crypt.c exist where the code intent is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to flag manipulations. o Callers that built their own GFP flags instead of starting with GFP_KERNEL and friends now also need to specify __GFP_KSWAPD_RECLAIM. The first key hazard to watch out for is callers that removed __GFP_WAIT and was depending on access to atomic reserves for inconspicuous reasons. In some cases it may be appropriate for them to use __GFP_HIGH. The second key hazard is callers that assembled their own combination of GFP flags instead of starting with something like GFP_KERNEL. They may now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless if it's missed in most cases as other activity will wake kswapd. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-01dm: drop NULL test before kmem_cache_destroy() and mempool_destroy()Julia Lawall1-4/+2
Remove DM's unneeded NULL tests before calling these destroy functions, now that they check for NULL, thanks to these v4.3 commits: 3942d2991 ("mm/slab_common: allow NULL cache pointer in kmem_cache_destroy()") 4e3ca3e03 ("mm/mempool: allow NULL `pool' pointer in mempool_destroy()") The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression x; @@ -if (x != NULL) \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x); // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-09-14dm crypt: constrain crypt device's max_segment_size to PAGE_SIZEMike Snitzer1-2/+15
Setting the dm-crypt device's max_segment_size to PAGE_SIZE is an unfortunate constraint that is required to avoid the potential for exceeding dm-crypt's underlying device's max_segments limits -- due to crypt_alloc_buffer() possibly allocating pages for the encryption bio that are not as physically contiguous as the original bio. It is interesting to note that this problem was already fixed back in 2007 via commit 91e106259 ("dm crypt: use bio_add_page"). But Linux 4.0 commit cf2f1abfb ("dm crypt: don't allocate pages for a partial request") regressed dm-crypt back to _not_ using bio_add_page(). But given dm-crypt's cpu parallelization changes all depend on commit cf2f1abfb's abandoning of the more complex io fragments processing that dm-crypt previously had we cannot easily go back to using bio_add_page(). So all said the cleanest way to resolve this issue is to fix dm-crypt to properly constrain the original bios entering dm-crypt so the encryption bios that dm-crypt generates from the original bios are always compatible with the underlying device's max_segments queue limits. It should be noted that technically Linux 4.3 does _not_ need this fix because of the block core's new late bio-splitting capability. But, it is reasoned, there is little to be gained by having the block core split the encrypted bio that is composed of PAGE_SIZE segments. That said, in the future we may revert this change. Fixes: cf2f1abfb ("dm crypt: don't allocate pages for a partial request") Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=104421 Suggested-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 4.0+
2015-09-03Merge tag 'dm-4.3-changes' of ↵Linus Torvalds1-1/+3
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper update from Mike Snitzer: - a couple small cleanups in dm-cache, dm-verity, persistent-data's dm-btree, and DM core. - a 4.1-stable fix for dm-cache that fixes the leaking of deferred bio prison cells - a 4.2-stable fix that adds feature reporting for the dm-stats features added in 4.2 - improve DM-snapshot to not invalidate the on-disk snapshot if snapshot device write overflow occurs; but a write overflow triggered through the origin device will still invalidate the snapshot. - optimize DM-thinp's async discard submission a bit now that late bio splitting has been included in block core. - switch DM-cache's SMQ policy lock from using a mutex to a spinlock; improves performance on very low latency devices (eg. NVMe SSD). - document DM RAID 4/5/6's discard support [ I did not pull the slab changes, which weren't appropriate for this tree, and weren't obviously the right thing to do anyway. At the very least they need some discussion and explanation before getting merged. Because not pulling the actual tagged commit but doing a partial pull instead, this merge commit thus also obviously is missing the git signature from the original tag ] * tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm cache: fix use after freeing migrations dm cache: small cleanups related to deferred prison cell cleanup dm cache: fix leaking of deferred bio prison cells dm raid: document RAID 4/5/6 discard support dm stats: report precise_timestamps and histogram in @stats_list output dm thin: optimize async discard submission dm snapshot: don't invalidate on-disk image on snapshot write overflow dm: remove unlikely() before IS_ERR() dm: do not override error code returned from dm_get_device() dm: test return value for DM_MAPIO_SUBMITTED dm verity: remove unused mempool dm cache: move wake_waker() from free_migrations() to where it is needed dm btree remove: remove unused function get_nr_entries() dm btree: remove unused "dm_block_t root" parameter in btree_split_sibling() dm cache policy smq: change the mutex to a spinlock
2015-08-13block: kill merge_bvec_fn() completelyKent Overstreet1-16/+0
As generic_make_request() is now able to handle arbitrarily sized bios, it's no longer necessary for each individual block driver to define its own ->merge_bvec_fn() callback. Remove every invocation completely. Cc: Jens Axboe <axboe@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina <jkosina@suse.cz> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@kernel.org> Cc: ceph-devel@vger.kernel.org Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Neil Brown <neilb@suse.de> Cc: linux-raid@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: NeilBrown <neilb@suse.de> (for the 'md' bits) Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [dpark: also remove ->merge_bvec_fn() in dm-thin as well as dm-era-target, and resolve merge conflicts] Signed-off-by: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-12dm: do not override error code returned from dm_get_device()Vivek Goyal1-1/+3
Some of the device mapper targets override the error code returned by dm_get_device() and return either -EINVAL or -ENXIO. There is nothing gained by this override. It is better to propagate the returned error code unchanged to caller. This work was motivated by hitting an issue where the underlying device was busy but -EINVAL was being returned. After this change we get -EBUSY instead and it is easier to figure out the problem. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-08-11block: don't access bio->bi_error after bio_put()Sasha Levin1-3/+5
Commit 4246a0b6 ("block: add a bi_error field to struct bio") has added a few dereferences of 'bio' after a call to bio_put(). This causes use-after-frees such as: [521120.719695] BUG: KASan: use after free in dio_bio_complete+0x2b3/0x320 at addr ffff880f36b38714 [521120.720638] Read of size 4 by task mount.ocfs2/9644 [521120.721212] ============================================================================= [521120.722056] BUG kmalloc-256 (Not tainted): kasan: bad access detected [521120.722968] ----------------------------------------------------------------------------- [521120.722968] [521120.723915] Disabling lock debugging due to kernel taint [521120.724539] INFO: Slab 0xffffea003cdace00 objects=32 used=25 fp=0xffff880f36b38600 flags=0x46fffff80004080 [521120.726037] INFO: Object 0xffff880f36b38700 @offset=1792 fp=0xffff880f36b38800 [521120.726037] [521120.726974] Bytes b4 ffff880f36b386f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.727898] Object ffff880f36b38700: 00 88 b3 36 0f 88 ff ff 00 00 d8 de 0b 88 ff ff ...6............ [521120.728822] Object ffff880f36b38710: 02 00 00 f0 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.729705] Object ffff880f36b38720: 01 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 ................ [521120.730623] Object ffff880f36b38730: 00 00 00 00 00 00 00 00 01 00 00 00 00 02 00 00 ................ [521120.731621] Object ffff880f36b38740: 00 02 00 00 01 00 00 00 d0 f7 87 ad ff ff ff ff ................ [521120.732776] Object ffff880f36b38750: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.733640] Object ffff880f36b38760: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.734508] Object ffff880f36b38770: 01 00 03 00 01 00 00 00 88 87 b3 36 0f 88 ff ff ...........6.... [521120.735385] Object ffff880f36b38780: 00 73 22 ad 02 88 ff ff 40 13 e0 3c 00 ea ff ff .s".....@..<.... [521120.736667] Object ffff880f36b38790: 00 02 00 00 00 04 00 00 00 00 00 00 00 00 00 00 ................ [521120.737596] Object ffff880f36b387a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.738524] Object ffff880f36b387b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.739388] Object ffff880f36b387c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.740277] Object ffff880f36b387d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.741187] Object ffff880f36b387e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.742233] Object ffff880f36b387f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.743229] CPU: 41 PID: 9644 Comm: mount.ocfs2 Tainted: G B 4.2.0-rc6-next-20150810-sasha-00039-gf909086 #2420 [521120.744274] ffff880f36b38000 ffff880d89c8f638 ffffffffb6e9ba8a ffff880101c0e5c0 [521120.745025] ffff880d89c8f668 ffffffffad76a313 ffff880101c0e5c0 ffffea003cdace00 [521120.745908] ffff880f36b38700 ffff880f36b38798 ffff880d89c8f690 ffffffffad772854 [521120.747063] Call Trace: [521120.747520] dump_stack (lib/dump_stack.c:52) [521120.748053] print_trailer (mm/slub.c:653) [521120.748582] object_err (mm/slub.c:660) [521120.749079] kasan_report_error (include/linux/kasan.h:20 mm/kasan/report.c:152 mm/kasan/report.c:194) [521120.750834] __asan_report_load4_noabort (mm/kasan/report.c:250) [521120.753580] dio_bio_complete (fs/direct-io.c:478) [521120.755752] do_blockdev_direct_IO (fs/direct-io.c:494 fs/direct-io.c:1291) [521120.759765] __blockdev_direct_IO (fs/direct-io.c:1322) [521120.761658] blkdev_direct_IO (fs/block_dev.c:162) [521120.762993] generic_file_read_iter (mm/filemap.c:1738) [521120.767405] blkdev_read_iter (fs/block_dev.c:1649) [521120.768556] __vfs_read (fs/read_write.c:423 fs/read_write.c:434) [521120.772126] vfs_read (fs/read_write.c:454) [521120.773118] SyS_pread64 (fs/read_write.c:607 fs/read_write.c:594) [521120.776062] entry_SYSCALL_64_fastpath (arch/x86/entry/entry_64.S:186) [521120.777375] Memory state around the buggy address: [521120.778118] ffff880f36b38600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [521120.779211] ffff880f36b38680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [521120.780315] >ffff880f36b38700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [521120.781465] ^ [521120.782083] ffff880f36b38780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [521120.783717] ffff880f36b38800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [521120.784818] ================================================================== This patch fixes a few of those places that I caught while auditing the patch, but the original patch should be audited further for more occurences of this issue since I'm not too familiar with the code. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-29block: add a bi_error field to struct bioChristoph Hellwig1-8/+6
Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-29dm crypt: add comments to better describe crypto processing logicMilan Broz1-6/+24
A crypto driver can process requests synchronously or asynchronously and can use an internal driver queue to backlog requests. Add some comments to clarify internal logic and completion return codes. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-05Revert "dm crypt: fix deadlock when async crypto algorithm returns -EBUSY"Rabin Vincent1-6/+6
This reverts Linux 4.1-rc1 commit 0618764cb25f6fa9fb31152995de42a8a0496475. The problem which that commit attempts to fix actually lies in the Freescale CAAM crypto driver not dm-crypt. dm-crypt uses CRYPTO_TFM_REQ_MAY_BACKLOG. This means the the crypto driver should internally backlog requests which arrive when the queue is full and process them later. Until the crypto hw's queue becomes full, the driver returns -EINPROGRESS. When the crypto hw's queue if full, the driver returns -EBUSY, and if CRYPTO_TFM_REQ_MAY_BACKLOG is set, is expected to backlog the request and process it when the hardware has queue space. At the point when the driver takes the request from the backlog and starts processing it, it calls the completion function with a status of -EINPROGRESS. The completion function is called (for a second time, in the case of backlogged requests) with a status/err of 0 when a request is done. Crypto drivers for hardware without hardware queueing use the helpers, crypto_init_queue(), crypto_enqueue_request(), crypto_dequeue_request() and crypto_get_backlog() helpers to implement this behaviour correctly, while others implement this behaviour without these helpers (ccp, for example). dm-crypt (before the patch that needs reverting) uses this API correctly. It queues up as many requests as the hw queues will allow (i.e. as long as it gets back -EINPROGRESS from the request function). Then, when it sees at least one backlogged request (gets -EBUSY), it waits till that backlogged request is handled (completion gets called with -EINPROGRESS), and then continues. The references to af_alg_wait_for_completion() and af_alg_complete() in that commit's commit message are irrelevant because those functions only handle one request at a time, unlink dm-crypt. The problem is that the Freescale CAAM driver, which that commit describes as having being tested with, fails to implement the backlogging behaviour correctly. In cam_jr_enqueue(), if the hardware queue is full, it simply returns -EBUSY without backlogging the request. What the observed deadlock was is not described in the commit message but it is obviously the wait_for_completion() in crypto_convert() where dm-crypto would wait for the completion being called with -EINPROGRESS in the case of backlogged requests. This completion will never be completed due to the bug in the CAAM driver. Commit 0618764cb25 incorrectly made dm-crypt wait for every request, even when the driver/hardware queues are not full, which means that dm-crypt will never see -EBUSY. This means that that commit will cause a performance regression on all crypto drivers which implement the API correctly. Revert it. Correct backlog handling should be implemented in the CAAM driver instead. Cc'ing stable purely because commit 0618764cb25 did. If for some reason a stable@ kernel did pick up commit 0618764cb25 it should get reverted. Signed-off-by: Rabin Vincent <rabin.vincent@axis.com> Reviewed-by: Horia Geanta <horia.geanta@freescale.com> Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-04-17dm crypt: fix missing error code return from crypt_ctr error pathWei Yongjun1-0/+1
Fix to return a negative error code from crypt_ctr()'s optional parameter processing error path. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-04-15dm crypt: fix deadlock when async crypto algorithm returns -EBUSYBen Collins1-6/+6
I suspect this doesn't show up for most anyone because software algorithms typically don't have a sense of being too busy. However, when working with the Freescale CAAM driver it will return -EBUSY on occasion under heavy -- which resulted in dm-crypt deadlock. After checking the logic in some other drivers, the scheme for crypt_convert() and it's callback, kcryptd_async_done(), were not correctly laid out to properly handle -EBUSY or -EINPROGRESS. Fix this by using the completion for both -EBUSY and -EINPROGRESS. Now crypt_convert()'s use of completion is comparable to af_alg_wait_for_completion(). Similarly, kcryptd_async_done() follows the pattern used in af_alg_complete(). Before this fix dm-crypt would lockup within 1-2 minutes running with the CAAM driver. Fix was regression tested against software algorithms on PPC32 and x86_64, and things seem perfectly happy there as well. Signed-off-by: Ben Collins <ben.c@servergy.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
2015-04-15dm crypt: leverage immutable biovecs when decrypting on readMike Snitzer1-5/+5
Commit 003b5c571 ("block: Convert drivers to immutable biovecs") stopped short of changing dm-crypt to leverage the fact that the biovec array of a bio will no longer be modified. Switch to using bio_clone_fast() when cloning bios for decryption after read. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-04-15dm crypt: update URLs to new cryptsetup project pageMilan Broz1-1/+1
Cryptsetup home page moved to GitLab. Also remove link to abandonded Truecrypt page. Signed-off-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-02-16dm crypt: sort writesMikulas Patocka1-15/+36
Write requests are sorted in a red-black tree structure and are submitted in the sorted order. In theory the sorting should be performed by the underlying disk scheduler, however, in practice the disk scheduler only accepts and sorts a finite number of requests. To allow the sorting of all requests, dm-crypt needs to implement its own sorting. The overhead associated with rbtree-based sorting is considered negligible so it is not used conditionally. Even on SSD sorting can be beneficial since in-order request dispatch promotes lower latency IO completion to the upper layers. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-02-16dm crypt: add 'submit_from_crypt_cpus' optionMikulas Patocka1-2/+14
Make it possible to disable offloading writes by setting the optional 'submit_from_crypt_cpus' table argument. There are some situations where offloading write bios from the encryption threads to a single thread degrades performance significantly. The default is to offload write bios to the same thread because it benefits CFQ to have writes submitted using the same IO context. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-02-16dm crypt: offload writes to threadMikulas Patocka1-20/+94
Submitting write bios directly in the encryption thread caused serious performance degradation. On a multiprocessor machine, encryption requests finish in a different order than they were submitted. Consequently, write requests would be submitted in a different order and it could cause severe performance degradation. Move the submission of write requests to a separate thread so that the requests can be sorted before submitting. But this commit improves dm-crypt performance even without having dm-crypt perform request sorting (in particular it enables IO schedulers like CFQ to sort more effectively). Note: it is required that a previous commit ("dm crypt: don't allocate pages for a partial request") be applied before applying this patch. Otherwise, this commit could introduce a crash. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-02-16dm crypt: remove unused io_pool and _crypt_io_poolMikulas Patocka1-22/+2
The previous commit ("dm crypt: don't allocate pages for a partial request") stopped using the io_pool slab mempool and backing _crypt_io_pool kmem cache. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-02-16dm crypt: avoid deadlock in mempoolsMikulas Patocka1-5/+36
Fix a theoretical deadlock introduced in the previous commit ("dm crypt: don't allocate pages for a partial request"). The function crypt_alloc_buffer may be called concurrently. If we allocate from the mempool concurrently, there is a possibility of deadlock. For example, if we have mempool of 256 pages, two processes, each wanting 256, pages allocate from the mempool concurrently, it may deadlock in a situation where both processes have allocated 128 pages and the mempool is exhausted. To avoid such a scenario we allocate the pages under a mutex. In order to not degrade performance with excessive locking, we try non-blocking allocations without a mutex first and if that fails, we fallback to a blocking allocations with a mutex. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-02-16dm crypt: don't allocate pages for a partial requestMikulas Patocka1-109/+30
Change crypt_alloc_buffer so that it only ever allocates pages for a full request. This is a prerequisite for the commit "dm crypt: offload writes to thread". This change simplifies the dm-crypt code at the expense of reduced throughput in low memory conditions (where allocation for a partial request is most useful). Note: the next commit ("dm crypt: avoid deadlock in mempools") is needed to fix a theoretical deadlock. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-02-16dm crypt: use unbound workqueue for request processingMikulas Patocka1-15/+34
Use unbound workqueue by default so that work is automatically balanced between available CPUs. The original behavior of encrypting using the same cpu that IO was submitted on can still be enabled by setting the optional 'same_cpu_crypt' table argument. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-12-09Merge tag 'dm-3.19-changes' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - Significant DM thin-provisioning performance improvements to meet performance requirements that were requested by the Gluster distributed filesystem. Specifically, dm-thinp now takes care to aggregate IO that will be issued to the same thinp block before issuing IO to the underlying devices. This really helps improve performance on HW RAID6 devices that have a writeback cache because it avoids RMW in the HW RAID controller. - Some stable fixes: fix leak in DM bufio if integrity profiles were enabled, use memzero_explicit in DM crypt to avoid any potential for information leak, and a DM cache fix to properly mark a cache block dirty if it was promoted to the cache via the overwrite optimization. - A few simple DM persistent data library fixes - DM cache multiqueue policy block promotion improvements. - DM cache discard improvements that take advantage of range (multiblock) discard support in the DM bio-prison. This allows for much more efficient bulk discard processing (e.g. when mkfs.xfs discards the entire device). - Some small optimizations in DM core and RCU deference cleanups - DM core changes to suspend/resume code to introduce the new internal suspend/resume interface that the DM thin-pool target now uses to suspend/resume active thin devices when the thin-pool must suspend/resume. This avoids forcing userspace to track all active thin volumes in a thin-pool when the thin-pool is suspended for the purposes of metadata or data space resize. * tag 'dm-3.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (49 commits) dm crypt: use memzero_explicit for on-stack buffer dm space map metadata: fix sm_bootstrap_get_count() dm space map metadata: fix sm_bootstrap_get_nr_blocks() dm bufio: fix memleak when using a dm_buffer's inline bio dm cache: fix spurious cell_defer when dealing with partial block at end of device dm cache: dirty flag was mistakenly being cleared when promoting via overwrite dm cache: only use overwrite optimisation for promotion when in writeback mode dm cache: discard block size must be a multiple of cache block size dm cache: fix a harmless race when working out if a block is discarded dm cache: when reloading a discard bitset allow for a different discard block size dm cache: fix some issues with the new discard range support dm array: if resizing the array is a noop set the new root to the old one dm: use rcu_dereference_protected instead of rcu_dereference dm thin: fix pool_io_hints to avoid looking at max_hw_sectors dm thin: suspend/resume active thin devices when reloading thin-pool dm: enhance internal suspend and resume interface dm thin: do not allow thin device activation while pool is suspended dm: add presuspend_undo hook to target_type dm: return earlier from dm_blk_ioctl if target doesn't implement .ioctl dm thin: remove stale 'trim' message in block comment above pool_message ...
2014-12-02dm crypt: use memzero_explicit for on-stack bufferMilan Broz1-1/+1
Use memzero_explicit to cleanup sensitive data allocated on stack to prevent the compiler from optimizing and removing memset() calls. Signed-off-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
2014-10-14crypto, dm: LLVMLinux: Remove VLAIS usage from dm-cryptJan-Simon Möller1-20/+14
Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99 compliant equivalent. This patch allocates the appropriate amount of memory using a char array using the SHASH_DESC_ON_STACK macro. The new code can be compiled with both gcc and clang. Signed-off-by: Jan-Simon Möller <dl9pf@gmx.de> Signed-off-by: Behan Webster <behanw@converseincode.com> Reviewed-by: Mark Charlebois <charlebm@gmail.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Cc: pageexec@freemail.hu Cc: gmazyland@gmail.com Cc: "David S. Miller" <davem@davemloft.net>