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path: root/drivers/md/dm-log.c
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* dm: use vzallocJoe Perches2011-08-021-2/+1
| | | | | | | Use vzalloc() instead of vmalloc()+memset(). Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: clean up bit little endian bitopsAkinobu Mita2011-08-021-5/+4
| | | | | | | | | | Using __test_and_{set,clear}_bit_le() with ignoring its return value can be replaced with __{set,clear}_bit_le(). This also removes unnecessary casts. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: suppress endian warningsAlasdair G Kergon2011-08-021-7/+13
| | | | | | | 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>
* dm io: use fixed initial mempool sizeMikulas Patocka2011-05-291-2/+1
| | | | | | | | | | | | | | | | | Replace the arbitrary calculation of an initial io struct mempool size with a constant. The code calculated the number of reserved structures based on the request size and used a "magic" multiplication constant of 4. This patch changes it to reserve a fixed number - itself still chosen quite arbitrarily. Further testing might show if there is a better number to choose. Note that if there is no memory pressure, we can still allocate an arbitrary number of "struct io" structures. One structure is enough to process the whole request. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dmLinus Torvalds2011-03-251-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | * 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
| * dm: fix opening log and cow devices for read only tablesMilan Broz2011-03-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a table is read-only, also open any log and cow devices it uses read-only. Previously, even read-only devices were opened read-write internally. After patch 75f1dc0d076d1c1168f2115f1941ea627d38bd5a block: check bdev_read_only() from blkdev_get() was applied, loading such tables began to fail. The patch was reverted by e51900f7d38cbcfb481d84567fd92540e7e1d23a block: revert block_dev read-only check but this patch fixes this part of the code to work with the original patch. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* | dm: use little-endian bitopsAkinobu Mita2011-03-231-4/+4
|/ | | | | | | | | | | As a preparation for removing ext2 non-atomic bit operations from asm/bitops.h. This converts ext2 non-atomic bit operations to little-endian bit operations. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm log: use PTR_ERR value instead of ENOMEMDan Carpenter2011-01-131-1/+1
| | | | | | | | | | | | | | | It's nicer to return the PTR_ERR() value instead of just returning -ENOMEM. In the current code the PTR_ERR() value is always equal to -ENOMEM so this doesn't actually affect anything, but still... In addition, dm_dirty_log_create() doesn't check for a specific -ENOMEM return. So this change is safe relative to potential for a non -ENOMEM return in the future. Signed-off-by: Dan Carpenter <error27@gmail.com> Acked-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: implement REQ_FLUSH/FUA support for bio-based dmTejun Heo2010-09-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* dm table: remove unused dm_get_device range parametersNikanth Karthikesan2010-03-061-2/+1
| | | | | | | | 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>
* dm raid1: report flush errors separately in statusMikulas Patocka2009-12-101-4/+12
| | | | | | | Report flush errors as 'F' instead of 'D' for log and mirror devices. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: use flush callback fnMikulas Patocka2009-12-101-2/+15
| | | | | | | | | | | Call the flush callback from the log. If flush failed, we have no alternative but to mark the whole log as dirty. Also we set the variable flush_failed to prevent any bits ever being marked as clean again. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: add flush callback fnMikulas Patocka2009-12-101-2/+4
| | | | | | | | | | | | | Introduce a callback pointer from the log to dm-raid1 layer. Before some region is set as "in-sync", we need to flush hardware cache on all the disks. But the log module doesn't have access to the mirror_set structure. So it will use this callback. So far the callback is unused, it will be used in further patches. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: introduce flush_failed variableMikulas Patocka2009-12-101-1/+4
| | | | | | | | | | | | | | | | Introduce "flush failed" variable. When a flush before clearing a bit in the log fails, we don't know anything about which which regions are in-sync and which not. So we need to set all regions as not-in-sync and set the variable "flush_failed" to prevent setting the in-sync bit in the future. A target reload is the only way to get out of this situation. The variable will be set in following patches. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: add flush_header functionMikulas Patocka2009-12-101-1/+22
| | | | | | | | | | Introduce flush_header and use it to flush the log device. Note that we don't have to flush if all the regions transition from "dirty" to "clean" state. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid1: split touched state into twoMikulas Patocka2009-12-101-7/+11
| | | | | | | | | | | | | | | | | | Split the variable "touched" into two, "touched_dirtied" and "touched_cleaned", set when some region was dirtied or cleaned. This will be used to optimize flushes. After a transition from "dirty" to "clean" state we don't have flush hardware cache on the log device. After a transition from "clean" to "dirty" the cache must be flushed. Before a transition from "clean" to "dirty" state we don't have to flush all the raid legs. Before a transition from "dirty" to "clean" we must flush all the legs to make sure that they are really in sync. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: fix create_log_context to use logical_block_size of log deviceMike Snitzer2009-06-221-3/+4
| | | | | | | | create_log_context() must use the logical_block_size from the log disk, where the I/O happens, not the target's logical_block_size. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: use i_size_readMikulas Patocka2009-06-221-1/+1
| | | | | | | | | | | | | | | Use i_size_read() instead of reading i_size. If someone changes the size of the device simultaneously, i_size_read is guaranteed to return a valid value (either the old one or the new one). i_size can return some intermediate invalid value (on 32-bit computers with 64-bit i_size, the reads to both halves of i_size can be interleaved with updates to i_size, resulting in garbage being returned). Cc: stable@kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* block: Do away with the notion of hardsect_sizeMartin K. Petersen2009-05-221-1/+2
| | | | | | | | | | | | | | Until now we have had a 1:1 mapping between storage device physical block size and the logical block sized used when addressing the device. With SATA 4KB drives coming out that will no longer be the case. The sector size will be 4KB but the logical block size will remain 512-bytes. Hence we need to distinguish between the physical block size and the logical ditto. This patch renames hardsect_size to logical_block_size. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* dm log: remove struct dm_dirty_log_internalMike Snitzer2009-04-021-44/+14
| | | | | | | | | | Remove the 'dm_dirty_log_internal' structure. The resulting cleanup eliminates extra memory allocations. Therefore exposing the internal list_head to the external 'dm_dirty_log_type' structure is a worthwhile compromise. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: use standard kernel module refcountMike Snitzer2009-04-021-16/+3
| | | | | | | | | Avoid private module usage accounting by removing 'use' from dm_dirty_log_internal. The standard module reference counting is sufficient. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: ensure log bitmap fits on log deviceMilan Broz2009-01-061-0/+8
| | | | | | | Check that the log bitmap will fit within the log device. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: move region_size validationMilan Broz2009-01-061-2/+14
| | | | | | | | | Move log size validation from mirror target to log constructor. Removed PAGE_SIZE restriction we no longer think necessary. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: avoid reinitialising io_req on every operationTakahiro Yasui2009-01-061-10/+7
| | | | | | | | | | | | | rw_header function updates three members of io_req data every time when I/O is processed. bi_rw and notify.fn are never modified once they get initialized, and so they can be set in advance. header_to_disk() can also be pulled out of write_header() since only one caller needs it and write_header() can be replaced by rw_header() directly. Signed-off-by: Takahiro Yasui <tyasui@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: fix dm_io_client leak on error pathsTakahiro Yasui2009-01-061-0/+5
| | | | | | | | | | | In create_log_context function, dm_io_client_destroy function needs to be called, when memory allocation of disk_header, sync_bits and recovering_bits failed, but dm_io_client_destroy is not called. Cc: stable@kernel.org Signed-off-by: Takahiro Yasui <tyasui@redhat.com> Acked-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: remove dm header from targetsMikulas Patocka2008-10-211-1/+1
| | | | | | | | 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>
* dm log: make dm_dirty_log init and exit staticAdrian Bunk2008-07-211-2/+2
| | | | | | | | dm_dirty_log_{init,exit}() can now become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: move include filesAlasdair G Kergon2008-04-251-2/+2
| | | | | | Publish the dm-io, dm-log and dm-kcopyd headers in include/linux. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: make module use tracking internalJonathan Brassow2008-04-251-29/+94
| | | | | | | Remove internal module reference fields from the interface. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: move register functionsAlasdair G Kergon2008-04-251-26/+26
| | | | | | Reorder a couple of functions in the file so the next patch is readable. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: clean interfaceHeinz Mauelshagen2008-04-251-44/+45
| | | | | | | Clean up the dm-log interface to prepare for publishing it in include/linux. Signed-off-by: Heinz Mauelshagen <hjm@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm io: clean interfaceHeinz Mauelshagen2008-04-251-1/+1
| | | | | | | Clean up the dm-io interface to prepare for publishing it in include/linux. Signed-off-by: Heinz Mauelshagen <hjm@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: move dirty region log code into separate moduleHeinz Mauelshagen2008-04-251-1/+8
| | | | | | | | Move the dirty region log code into a separate module so other targets can share the code. Signed-off-by: Heinz Mauelshagen <hjm@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: generalise name in messagesHeinz Mauelshagen2008-04-251-7/+8
| | | | | | | | Change dm-log.c messages from "mirror log" to "dirty region log" as a new dm target wants to share this code. Signed-off-by: Heinz Mauelshagen <hjm@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: auto load modulesJonathan Brassow2008-02-081-1/+50
| | | | | | | | 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>
* dm log: split suspendJonathan Brassow2007-10-201-1/+1
| | | | | | | | | | | | | There are now two phases to a suspend in device-mapper - presuspend and postsuspend. This patch removes the single 'suspend' in the logging API and replaces it with 'presuspend' and 'postsuspend' functions to align it better with core device-mapper. A subsequent patch will make use of 'presuspend'. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: fix resume failed log deviceJonathan Brassow2007-05-091-1/+8
| | | | | | | | | | | | | | | | | | This patch removes the possibility of having uninitialized log state if the log device has failed. When a mirror resumes operation, it calls 'resume' on the logging module. If disk based logging is being used, the log device is read to fill in the log state. If the log device has failed, we cannot simply return, because this would leave the in-memory log state uninitialized. Instead, we assume all regions are out-of-sync and reset the log state. Failure to do this could result in the logging code reporting a region as in-sync, even though it isn't; which could result in a corrupted mirror. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm log: update dm io interfaceHeinz Mauelshagen2007-05-091-7/+24
| | | | | | | | | | | This patch ports dm-log.c to the new dm-io interface in order to make it scalable to have a large number of persistent dirty logs active in parallel. Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Cc: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm log: report fault statusJonathan E Brassow2007-05-091-3/+4
| | | | | | | | | | This patch reports the status of the log device so that userspace can detect the error and take appropriate action. Signed-off-by: Jonathan E Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm log: fault detectionJonathan E Brassow2007-05-091-3/+27
| | | | | | | | | | | This patch gives the disk logging code the ability to store the fact that an error occured on the log device. In addition, an event is raised when an error is encountered during I/O to the log device. Signed-off-by: Jonathan E Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] dm: raid1: reset sync_search on resumeJonathan E Brassow2006-12-081-0/+9
| | | | | | | | | | | Reset sync_search on resume. The effect is to retry syncing all out-of-sync regions when a mirror is resumed, including ones that previously failed. Signed-off-by: Jonathan E Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] dm: log: rename complete_resync_workJonathan E Brassow2006-12-081-6/+9
| | | | | | | | | | | | | | The complete_resync_work function only provides the ability to change an out-of-sync region to in-sync. This patch enhances the function to allow us to change the status from in-sync to out-of-sync as well, something that is needed when a mirror write to one of the devices or an initial resync on a given region fails. Signed-off-by: Jonathan E Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] dm: improve error message consistencyAlasdair G Kergon2006-06-261-0/+2
| | | | | | | | | Tidy device-mapper error messages to include context information automatically. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] dm mirror log: sync_count fixAlasdair G Kergon2006-06-261-1/+5
| | | | | | | | | When a mirror is reduced in size, clear the part of the bitmap that is no longer used. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] dm mirror log: bitset_size fixAlasdair G Kergon2006-06-261-2/+2
| | | | | | | | | Fix the 'sizeof' in the region log bitmap size calculation: it's uint32_t, not unsigned long - this breaks on some archs. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] dm mirror log: refactor contextAlasdair G Kergon2006-06-261-50/+63
| | | | | | | | | Refactor the code that creates the core and disk log contexts to avoid the repeated allocation of clean_bits introduced by the last patch. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] dm mirror log: sector size fixKevin Corry2006-06-261-49/+19
| | | | | | | | | | | | | | | | On-disk logs for dm-mirror devices are currently hard-coded to use 512 byte hard-sector-sizes. This patch fixes dm-log so it will work with devices with non-512-byte hard-sector-sizes. To maintain full compatibility, instead of moving the clean-bits bitset to a bitset, and enlarges the disk-header buffer to encompass both the header and the bitset. The I/O routines for the bitset are removed, and the I/O routines for the disk-header now also read/write the bitset. Signed-off-by: Kevin Corry <kevcorry@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] device-mapper log bitset: fix big endian find_next_zero_bitStefan Bader2006-02-021-1/+2
| | | | | | | | | | | | | This is a fix to the device-mapper-log-bitset-fix-endian patch that switched to ext2_* versions of the set and clear bit functions. The find_next_zero_bit function also has to be the ext2 one. Otherwise the mirror target tries to recover non-existent regions beyond the end of device. Signed-off-by: Stefan Bader <shbader@de.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] device-mapper log bitset: fix endianPatrick Caulfield2006-02-011-34/+11
| | | | | | | | | | | | | | | | | | | Clean up the code responsible for the on-disk mirror logs by using the set_le_bit test_le_bit functions of ext2. That makes the BE machines keep the bitmap internally in LE order - it does mean you can't use any other type of operations on the bitmap words but that looks to be OK in this instance. The efficiency tradeoff is very minimal as you would expect for something that ext2 uses. This allows us to remove bits_to_core(), bits_to_disk() and log->disk_bits. Also increment the mirror log disk version transparently to avoid sharing with older kernels that suffered from the 64-bit BE bug. Signed-off-by: Patrick Caulfield <pcaulfie@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] make dm-mirror not issue invalid resync requestsDarrick J. Wong2006-01-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I've been attempting to set up a (Host)RAID mirror with dm_mirror on 2.6.14.3, and I've been having a strange little problem. The configuration in question is a set of 9GB SCSI disks that have 17942584 sectors. I set up the dm_mirror table as such: 0 17942528 mirror core 2 2048 nosync 2 8:48 0 8:64 0 If I'm not mistaken, this sets up a 9GB RAID1 mriror with 1MB stripes across both SCSI disks. The sector count of the dm device is less than the size of the disks, so we shouldn't fall off the end. However, I always get the messages like this in dmesg when I set up the dm table: attempt to access beyond end of device sdd: rw=0, want=17958656, limit=17942584 Clearly, something is trying to read sectors past the end of the drive. I traced it down to the __rh_recovery_prepare function in dm-raid1.c, which gets called when we're putting the mirror set together. This function calls the dirty region log's get_resync_work function to see if there's any resync that needs to be done, and queues up any areas that are out of sync. The log's get_resync_work function is actually a pointer to the core_get_resync_work function in dm-log.c. The core_get_resync_work function queries a bitset lc->sync_bits to find out if there are any regions that are out of date (i.e. the bit is 0), which is where the problem occurs. If every bit in lc->sync_bits is 1 (which is the case when we've just configured a new RAID1 with the nosync option), the find_next_zero_bit does NOT return the size parameter (lc->region_count in this case), it returns the size parameter rounded up to the nearest multiple of 32! I don't know if this is intentional, but i386 and x86_64 both exhibit this behavior. In any case, the statement "if (*region == lc->region_count)" looks like it's supposed to catch the case where are no regions to resync and return 0. Since find_next_zero_bit apparently has a habit of returning a value that's larger than lc->region_count, the enclosed patch changes the equality test to a greater-than test so that we don't try to resync areas outside of the RAID1 region. Seeing as the HostRAID metadata lives just past the end of the RAID1 data, mucking around in that area is not a good idea. I suppose another way to fix this would be to amend find_next_zero_bit so that it doesn't return values larger than "size", but I don't know if there's a reason for the current behavior. Signed-Off-By: Darrick J. Wong <djwong@us.ibm.com> Acked-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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