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path: root/drivers/md/dm-crypt.c
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2012-01-06Revert "dm crypt: scale to multiple cpus"Kasoju Mallikarjun
This reverts commit c029772125594e31eb1a5ad9e0913724ed9891f2. Change-Id: Id9ad9be437cd79db20362e1cc4b81b7380ee7f3d Reviewed-on: http://git-master/r/72237 Reviewed-by: Automatic_Commit_Validation_User Reviewed-by: Mallikarjun Kasoju <mkasoju@nvidia.com> Tested-by: Mallikarjun Kasoju <mkasoju@nvidia.com> Tested-by: Ahung Cheng <ahcheng@nvidia.com> Reviewed-by: Venkat Moganty <vmoganty@nvidia.com>
2012-01-06Revert "dm crypt: use io thread for reads only if mempool exhausted"Kasoju Mallikarjun
This reverts commit 20c82538e4f5ede51bc2b4795bc6e5cae772796d. Conflicts: drivers/md/dm-crypt.c Change-Id: Id6c1f774c735836652c07ee279fb81093e732372 Reviewed-on: http://git-master/r/72236 Reviewed-by: Automatic_Commit_Validation_User Reviewed-by: Mallikarjun Kasoju <mkasoju@nvidia.com> Tested-by: Mallikarjun Kasoju <mkasoju@nvidia.com> Tested-by: Ahung Cheng <ahcheng@nvidia.com> Reviewed-by: Venkat Moganty <vmoganty@nvidia.com>
2012-01-06Revert "dm crypt: add post iv call to iv generator"Kasoju Mallikarjun
This reverts commit 2dc5327d3acb3340ab6fa3981401b076b78a51f4. Change-Id: I58ed3f6e8f9d053cb2ae9cfb0ae57528055a902b Reviewed-on: http://git-master/r/72235 Reviewed-by: Automatic_Commit_Validation_User Reviewed-by: Mallikarjun Kasoju <mkasoju@nvidia.com> Tested-by: Mallikarjun Kasoju <mkasoju@nvidia.com> Tested-by: Ahung Cheng <ahcheng@nvidia.com> Reviewed-by: Venkat Moganty <vmoganty@nvidia.com>
2012-01-06Revert "dm crypt: add multi key capability"Kasoju Mallikarjun
This reverts commit d1f9642381847e2b94caa34c3533211cf36ffcf4. Change-Id: If1879b331c1f0e3dea7433c5de53ac653743d9c2 Reviewed-on: http://git-master/r/72234 Reviewed-by: Automatic_Commit_Validation_User Reviewed-by: Mallikarjun Kasoju <mkasoju@nvidia.com> Tested-by: Mallikarjun Kasoju <mkasoju@nvidia.com> Tested-by: Ahung Cheng <ahcheng@nvidia.com> Reviewed-by: Venkat Moganty <vmoganty@nvidia.com>
2012-01-06Revert "dm crypt: add loop aes iv generator"Kasoju Mallikarjun
This reverts commit 34745785937a2003c144c0d4802fa637470d87af. Change-Id: Ic1ee80202b92a5ceb4e04ceb041adfbb40274ca0 Reviewed-on: http://git-master/r/72233 Reviewed-by: Automatic_Commit_Validation_User Reviewed-by: Mallikarjun Kasoju <mkasoju@nvidia.com> Tested-by: Mallikarjun Kasoju <mkasoju@nvidia.com> Tested-by: Ahung Cheng <ahcheng@nvidia.com> Reviewed-by: Venkat Moganty <vmoganty@nvidia.com>
2012-01-06Revert "dm crypt: wipe keys string immediately after key is set"Kasoju Mallikarjun
This reverts commit de8be5ac70f50a2340f24fd769a1aafa5a51ae34. Change-Id: I4d2788550ab382ec248c7a2fa10b4cb4e2766283 Reviewed-on: http://git-master/r/72232 Reviewed-by: Automatic_Commit_Validation_User Reviewed-by: Mallikarjun Kasoju <mkasoju@nvidia.com> Tested-by: Mallikarjun Kasoju <mkasoju@nvidia.com> Tested-by: Ahung Cheng <ahcheng@nvidia.com> Reviewed-by: Venkat Moganty <vmoganty@nvidia.com>
2011-09-25dm crypt: always disable discard_zeroes_dataMilan Broz
If optional discard support in dm-crypt is enabled, discards requests bypass the crypt queue and blocks of the underlying device are discarded. For the read path, discarded blocks are handled the same as normal ciphertext blocks, thus decrypted. So if the underlying device announces discarded regions return zeroes, dm-crypt must disable this flag because after decryption there is just random noise instead of zeroes. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02dm crypt: optionally support discard requestsMilan Broz
Add optional parameter field to dmcrypt table and support "allow_discards" option. Discard requests bypass crypt queue processing. Bio is simple remapped to underlying device. Note that discard will be never enabled by default because of security consequences. It is up to the administrator to enable it for encrypted devices. (Note that userspace cryptsetup does not understand new optional parameters yet. Support for this will come later. Until then, you should use 'dmsetup' to enable and disable this.) Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02dm table: share target argument parsing functionsMike Snitzer
Move multipath target argument parsing code into dm-table so other targets can share it. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02dm: suppress endian warningsAlasdair G Kergon
Suppress sparse warnings about cpu_to_le32() by using __le32 types for on-disk data etc. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-07-26atomic: use <linux/atomic.h>Arun Sharma
This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dmLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: dm stripe: implement merge method dm mpath: allow table load with no priority groups dm mpath: fail message ioctl if specified path is not valid dm ioctl: add flag to wipe buffers for secure data dm ioctl: prepare for crypt key wiping dm crypt: wipe keys string immediately after key is set dm: add flakey target dm: fix opening log and cow devices for read only tables
2011-03-24dm crypt: wipe keys string immediately after key is setMilan Broz
Always wipe the original copy of the key after processing it in crypt_set_key(). Signed-off-by: Milan Broz <mbroz@redhat.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-03-10block: remove per-queue pluggingJens Axboe
Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-01-13dm crypt: add loop aes iv generatorMilan Broz
This patch adds a compatible implementation of the block chaining mode used by the Loop-AES block device encryption system (http://loop-aes.sourceforge.net/) designed by Jari Ruusu. It operates on full 512 byte sectors and uses CBC with an IV derived from the sector number, the data and optionally extra IV seed. This means that after CBC decryption the first block of sector must be tweaked according to decrypted data. Loop-AES can use three encryption schemes: version 1: is plain aes-cbc mode (already compatible) version 2: uses 64 multikey scheme with own IV generator version 3: the same as version 2 with additional IV seed (it uses 65 keys, last key is used as IV seed) The IV generator is here named lmk (Loop-AES multikey) and for the cipher specification looks like: aes:64-cbc-lmk Version 2 and 3 is recognised according to length of provided multi-key string (which is just hexa encoded "raw key" used in original Loop-AES ioctl). Configuration of the device and decoding key string will be done in userspace (cryptsetup). (Loop-AES stores keys in gpg encrypted file, raw keys are output of simple hashing of lines in this file). Based on an implementation by Max Vozeler: http://article.gmane.org/gmane.linux.kernel.cryptoapi/3752/ Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> CC: Max Vozeler <max@hinterhof.net>
2011-01-13dm crypt: add multi key capabilityMilan Broz
This patch adds generic multikey handling to be used in following patch for Loop-AES mode compatibility. This patch extends mapping table to optional keycount and implements generic multi-key capability. With more keys defined the <key> string is divided into several <keycount> sections and these are used for tfms. The tfm is used according to sector offset (sector 0->tfm[0], sector 1->tfm[1], sector N->tfm[N modulo keycount]) (only power of two values supported for keycount here). Because of tfms per-cpu allocation, this mode can be take a lot of memory on large smp systems. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Max Vozeler <max@hinterhof.net>
2011-01-13dm crypt: add post iv call to iv generatorMilan Broz
IV (initialisation vector) can in principle depend not only on sector but also on plaintext data (or other attributes). Change IV generator interface to work directly with dmreq structure to allow such dependence in generator. Also add post() function which is called after the crypto operation. This allows tricky modification of decrypted data or IV internals. In asynchronous mode the post() can be called after ctx->sector count was increased so it is needed to add iv_sector copy directly to dmreq structure. (N.B. dmreq always include only one sector in scatterlists) Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13dm crypt: use io thread for reads only if mempool exhaustedMilan Broz
If there is enough memory, code can directly submit bio instead queing this operation in separate thread. Try to alloc bio clone with GFP_NOWAIT and only if it fails use separate queue (map function cannot block here). Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13dm crypt: scale to multiple cpusAndi Kleen
Currently dm-crypt does all the encryption work for a single dm-crypt mapping in a single workqueue. This does not scale well when multiple CPUs are submitting IO at a high rate. The single CPU running the single thread cannot keep up with the encryption and encrypted IO performance tanks. This patch changes the crypto workqueue to be per CPU. This means that as long as the IO submitter (or the interrupt target CPUs for reads) runs on different CPUs the encryption work will be also parallel. To avoid a bottleneck on the IO worker I also changed those to be per-CPU threads. There is still some shared data, so I suspect some bouncing cache lines. But I haven't done a detailed study on that yet. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13dm crypt: simplify compatible table outputMilan Broz
Rename cc->cipher_mode to cc->cipher_string and store the whole of the cipher information so it can easily be printed when processing the DM_DEV_STATUS ioctl. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13dm crypt: set key size earlyMilan Broz
Simplify key size verification (hexadecimal string) and set key size early in constructor. (Patch required by later changes.) Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-09-10dm: implement REQ_FLUSH/FUA support for bio-based dmTejun Heo
This patch converts bio-based dm to support REQ_FLUSH/FUA instead of now deprecated REQ_HARDBARRIER. * -EOPNOTSUPP handling logic dropped. * Preflush is handled as before but postflush is dropped and replaced with passing down REQ_FUA to member request_queues. This replaces one array wide cache flush w/ member specific FUA writes. * __split_and_process_bio() now calls __clone_and_map_flush() directly for flushes and guarantees all FLUSH bio's going to targets are zero ` length. * It's now guaranteed that all FLUSH bio's which are passed onto dm targets are zero length. bio_empty_barrier() tests are replaced with REQ_FLUSH tests. * Empty WRITE_BARRIERs are replaced with WRITE_FLUSHes. * Dropped unlikely() around REQ_FLUSH tests. Flushes are not unlikely enough to be marked with unlikely(). * Block layer now filters out REQ_FLUSH/FUA bio's if the request_queue doesn't support cache flushing. Advertise REQ_FLUSH | REQ_FUA capability. * Request based dm isn't converted yet. dm_init_request_based_queue() resets flush support to 0 for now. To avoid disturbing request based dm code, dm->flush_error is added for bio based dm while requested based dm continues to use dm->barrier_error. Lightly tested linear, stripe, raid1, snap and crypt targets. Please proceed with caution as I'm not familiar with the code base. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: dm-devel@redhat.com Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-12dm: use dm_target_offset macroAlasdair G Kergon
Use new dm_target_offset() macro to avoid most references to ti->begin in dm targets. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12dm crypt: simplify crypt_ctrMilan Broz
Allocate cipher strings indpendently of struct crypt_config and move cipher parsing and allocation into a separate function to prepare for supporting the cryptoapi format e.g. "xts(aes)". No functional change in this patch. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12dm crypt: simplify crypt_config destruction logicMilan Broz
Use just one label and reuse common destructor for crypt target. Parse remaining argv arguments in logic order. Also do not ignore error values from IV init and set key functions. No functional change in this patch except changed return codes based on above. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12dm crypt: use kstrdupJulia Lawall
Use kstrdup when the goal of an allocation is copy a string into the allocated region. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression from,to; expression flag,E1,E2; statement S; @@ - to = kmalloc(strlen(from) + 1,flag); + to = kstrdup(from, flag); ... when != \(from = E1 \| to = E1 \) if (to==NULL || ...) S ... when != \(from = E2 \| to = E2 \) - strcpy(to, from); // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06dm table: remove unused dm_get_device range parametersNikanth Karthikesan
Remove unused parameters(start and len) of dm_get_device() and fix the callers. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm crypt: add plain64 ivMilan Broz
The default plain IV is 32-bit only. This plain64 IV provides a compatible mode for encrypted devices bigger than 4TB. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm crypt: make wipe message also wipe essiv keyMilan Broz
The "wipe key" message is used to wipe the volume key from memory temporarily, for example when suspending to RAM. But the initialisation vector in ESSIV mode is calculated from the hashed volume key, so the wipe message should wipe this IV key too and reinitialise it when the volume key is reinstated. This patch adds an IV wipe method called from a wipe message callback. ESSIV is then reinitialised using the init function added by the last patch. Cc: stable@kernel.org Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm crypt: separate essiv allocation from initialisationMilan Broz
This patch separates the construction of IV from its initialisation. (For ESSIV it is a hash calculation based on volume key.) Constructor code now preallocates hash tfm and salt array and saves it in a private IV structure. The next patch requires this to reinitialise the wiped IV without reallocating memory when resuming a suspended device. Cc: stable@kernel.org Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm crypt: restructure essiv error pathMilan Broz
Use kzfree for salt deallocation because it is derived from the volume key. Use a common error path in ESSIV constructor. Required by a later patch which fixes the way key material is wiped from memory. Cc: stable@kernel.org Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm crypt: move private iv fields to structsMilan Broz
Define private structures for IV so it's easy to add further attributes in a following patch which fixes the way key material is wiped from memory. Also move ESSIV destructor and remove unnecessary 'status' operation. There are no functional changes in this patch. Cc: stable@kernel.org Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm crypt: make wipe message also wipe tfm keyMilan Broz
The "wipe key" message is used to wipe a volume key from memory temporarily, for example when suspending to RAM. There are two instances of the key in memory (inside crypto tfm) but only one got wiped. This patch wipes them both. Cc: stable@kernel.org Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-11-09tree-wide: fix a very frequent spelling mistakeDirk Hohndel
something-bility is spelled as something-blity so a grep for 'blit' would find these lines this is so trivial that I didn't split it by subsystem / copy additional maintainers - all changes are to comments The only purpose is to get fewer false positives when grepping around the kernel sources. Signed-off-by: Dirk Hohndel <hohndel@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-07-23dm table: pass correct dev area size to device_area_is_validMike Snitzer
Incorrect device area lengths are being passed to device_area_is_valid(). The regression appeared in 2.6.31-rc1 through commit 754c5fc7ebb417b23601a6222a6005cc2e7f2913. With the dm-stripe target, the size of the target (ti->len) was used instead of the stripe_width (ti->len/#stripes). An example of a consequent incorrect error message is: device-mapper: table: 254:0: sdb too small for target Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-07-10Fix congestion_wait() sync/async vs read/write confusionJens Axboe
Commit 1faa16d22877f4839bd433547d770c676d1d964c accidentally broke the bdi congestion wait queue logic, causing us to wait on congestion for WRITE (== 1) when we really wanted BLK_RW_ASYNC (== 0) instead. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-06-22dm target:s introduce iterate devices fnMike Snitzer
Add .iterate_devices to 'struct target_type' to allow a function to be called for all devices in a DM target. Implemented it for all targets except those in dm-snap.c (origin and snapshot). (The raid1 version number jumps to 1.12 because we originally reserved 1.1 to 1.11 for 'block_on_error' but ended up using 'handle_errors' instead.) Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: martin.petersen@oracle.com
2009-06-22dm crypt: support flushMikulas Patocka
Flush support for dm-crypt target. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-04-02dm crypt: use kzfreeJohannes Weiner
Use kzfree() instead of memset() + kfree(). Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-03-16dm crypt: wait for endio to complete before destructionMilan Broz
The following oops has been reported when dm-crypt runs over a loop device. ... [ 70.381058] Process loop0 (pid: 4268, ti=cf3b2000 task=cf1cc1f0 task.ti=cf3b2000) ... [ 70.381058] Call Trace: [ 70.381058] [<d0d76601>] ? crypt_dec_pending+0x5e/0x62 [dm_crypt] [ 70.381058] [<d0d767b8>] ? crypt_endio+0xa2/0xaa [dm_crypt] [ 70.381058] [<d0d76716>] ? crypt_endio+0x0/0xaa [dm_crypt] [ 70.381058] [<c01a2f24>] ? bio_endio+0x2b/0x2e [ 70.381058] [<d0806530>] ? dec_pending+0x224/0x23b [dm_mod] [ 70.381058] [<d08066e4>] ? clone_endio+0x79/0xa4 [dm_mod] [ 70.381058] [<d080666b>] ? clone_endio+0x0/0xa4 [dm_mod] [ 70.381058] [<c01a2f24>] ? bio_endio+0x2b/0x2e [ 70.381058] [<c02bad86>] ? loop_thread+0x380/0x3b7 [ 70.381058] [<c02ba8a1>] ? do_lo_send_aops+0x0/0x165 [ 70.381058] [<c013754f>] ? autoremove_wake_function+0x0/0x33 [ 70.381058] [<c02baa06>] ? loop_thread+0x0/0x3b7 When a table is being replaced, it waits for I/O to complete before destroying the mempool, but the endio function doesn't call mempool_free() until after completing the bio. Fix it by swapping the order of those two operations. The same problem occurs in dm.c with md referenced after dec_pending. Again, we swap the order. Cc: stable@kernel.org Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-03-16dm crypt: fix kcryptd_async_done parameterHuang Ying
In the async encryption-complete function (kcryptd_async_done), the crypto_async_request passed in may be different from the one passed to crypto_ablkcipher_encrypt/decrypt. Only crypto_async_request->data is guaranteed to be same as the one passed in. The current kcryptd_async_done uses the passed-in crypto_async_request directly which may cause the AES-NI-based AES algorithm implementation to panic. This patch fixes this bug by only using crypto_async_request->data, which points to dm_crypt_request, the crypto_async_request passed in. The original data (convert_context) is gotten from dm_crypt_request. [mbroz@redhat.com: reworked] Cc: stable@kernel.org Signed-off-by: Huang Ying <ying.huang@intel.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-01-06dm: consolidate target deregistration error handlingMikulas Patocka
Change dm_unregister_target to return void and use BUG() for error reporting. dm_unregister_target can only fail because of programming bug in the target driver. It can't fail because of user's behavior or disk errors. This patch changes unregister_target to return void and use BUG if someone tries to unregister non-registered target or unregister target that is in use. This patch removes code duplication (testing of error codes in all dm targets) and reports bugs in just one place, in dm_unregister_target. In some target drivers, these return codes were ignored, which could lead to a situation where bugs could be missed. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-12-29bio: allow individual slabs in the bio_setJens Axboe
Instead of having a global bio slab cache, add a reference to one in each bio_set that is created. This allows for personalized slabs in each bio_set, so that they can have bios of different sizes. This means we can personalize the bios we return. File systems may want to embed the bio inside another structure, to avoid allocation more items (and stuffing them in ->bi_private) after the get a bio. Or we may want to embed a number of bio_vecs directly at the end of a bio, to avoid doing two allocations to return a bio. This is now possible. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-21dm crypt: remove waitqueueMilan Broz
Remove waitqueue no longer needed with the async crypto interface. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-10-21dm crypt: fix async splitMilan Broz
When writing io, dm-crypt has to allocate a new cloned bio and encrypt the data into newly-allocated pages attached to this bio. In rare cases, because of hw restrictions (e.g. physical segment limit) or memory pressure, sometimes more than one cloned bio has to be used, each processing a different fragment of the original. Currently there is one waitqueue which waits for one fragment to finish and continues processing the next fragment. But when using asynchronous crypto this doesn't work, because several fragments may be processed asynchronously or in parallel and there is only one crypt context that cannot be shared between the bio fragments. The result may be corruption of the data contained in the encrypted bio. The patch fixes this by allocating new dm_crypt_io structs (with new crypto contexts) and running them independently. The fragments contains a pointer to the base dm_crypt_io struct to handle reference counting, so the base one is properly deallocated after all the fragments are finished. In a low memory situation, this only uses one additional object from the mempool. If the mempool is empty, the next allocation simple waits for previous fragments to complete. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-10-21dm crypt: tidy sectorMilan Broz
Prepare local sector variable (offset) for later patch. Do not update io->sector for still-running I/O. No functional change. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-10-21dm: remove dm header from targetsMikulas Patocka
Change #include "dm.h" to #include <linux/device-mapper.h> in all targets. Targets should not need direct access to internal DM structures. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-10-10dm crypt: avoid unnecessary wait when splitting bioMilan Broz
Don't wait between submitting crypt requests for a bio unless we are short of memory. There are two situations when we must split an encrypted bio: 1) there are no free pages; 2) the new bio would violate underlying device restrictions (e.g. max hw segments). In case (2) we do not need to wait. Add output variable to crypt_alloc_buffer() to distinguish between these cases. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-10-10dm crypt: tidy ctx pendingMilan Broz
Move the initialisation of ctx->pending into one place, at the start of crypt_convert(). Introduce crypt_finished to indicate whether or not the encryption is finished, for use in a later patch. No functional change. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-10-10dm crypt: fix async inc_pendingMilan Broz
The pending reference count must be incremented *before* the async work is queued to another thread, not after. Otherwise there's a race if the work completes and decrements the reference count before it gets incremented. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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