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2009-12-10dm: add request based barrier supportKiyoshi Ueda
This patch adds barrier support for request-based dm. CORE DESIGN The design is basically same as bio-based dm, which emulates barrier by mapping empty barrier bios before/after a barrier I/O. But request-based dm has been using struct request_queue for I/O queueing, so the block-layer's barrier mechanism can be used. o Summary of the block-layer's behavior (which is depended by dm-core) Request-based dm uses QUEUE_ORDERED_DRAIN_FLUSH ordered mode for I/O barrier. It means that when an I/O requiring barrier is found in the request_queue, the block-layer makes pre-flush request and post-flush request just before and just after the I/O respectively. After the ordered sequence starts, the block-layer waits for all in-flight I/Os to complete, then gives drivers the pre-flush request, the barrier I/O and the post-flush request one by one. It means that the request_queue is stopped automatically by the block-layer until drivers complete each sequence. o dm-core For the barrier I/O, treats it as a normal I/O, so no additional code is needed. For the pre/post-flush request, flushes caches by the followings: 1. Make the number of empty barrier requests required by target's num_flush_requests, and map them (dm_rq_barrier()). 2. Waits for the mapped barriers to complete (dm_rq_barrier()). If error has occurred, save the error value to md->barrier_error (dm_end_request()). (*) Basically, the first reported error is taken. But -EOPNOTSUPP supersedes any error and DM_ENDIO_REQUEUE follows. 3. Requeue the pre/post-flush request if the error value is DM_ENDIO_REQUEUE. Otherwise, completes with the error value (dm_rq_barrier_work()). The pre/post-flush work above is done in the kernel thread (kdmflush) context, since memory allocation which might sleep is needed in dm_rq_barrier() but sleep is not allowed in dm_request_fn(), which is an irq-disabled context. Also, clones of the pre/post-flush request share an original, so such clones can't be completed using the softirq context. Instead, complete them in the context of underlying device drivers. It should be safe since there is no I/O dispatching during the completion of such clones. For suspend, the workqueue of kdmflush needs to be flushed after the request_queue has been stopped. Otherwise, the next flush work can be kicked even after the suspend completes. TARGET INTERFACE No new interface is added. Just use the existing num_flush_requests in struct target_type as same as bio-based dm. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm: move dm_end_requestKiyoshi Ueda
This patch moves dm_end_request() to make the next patch more readable. No functional change. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm: refactor request based completion functionsKiyoshi Ueda
This patch factors out the clone completion code, dm_done(), from dm_softirq_done() in preparation for a subsequent patch. No functional change. dm_done() will be used in barrier completion, which can't use and doesn't need softirq. The softirq_done callback needs to get a clone from an original request but it can't in the case of barrier, where an original request is shared by multiple clones. On the other hand, the completion of barrier clones doesn't involve re-submitting requests, which was the primary reason of the need for softirq. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm: use md pending for in flight IO countingKiyoshi Ueda
This patch changes the counter for the number of in_flight I/Os to md->pending from q->in_flight in preparation for a later patch. No functional change. Request-based dm used q->in_flight to count the number of in-flight clones assuming the counter is always incremented for an in-flight original request and original:clone is 1:1 relationship. However, it this no longer true for barrier requests. So use md->pending to count the number of in-flight clones. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm: simplify request based suspendKiyoshi Ueda
The semantics of bio-based dm were changed recently in the case of suspend with "--nolockfs" but without "--noflush". Before 2.6.30, I/Os submitted before the suspend invocation were always flushed. From 2.6.30 onwards, I/Os submitted before the suspend invocation might not be flushed. (For details, see http://marc.info/?t=123994433400003&r=1&w=2) This patch brings the behaviour of request-based dm into line with bio-based dm, simplifying the code and preparing for a subsequent patch that will wait for all in_flight I/Os to complete without stopping request_queue and use dm_wait_for_completion() for it. This change in semantics simplifies the suspend code as follows: o Suspend is implemented as stopping request_queue in request-based dm, and all I/Os are queued in the request_queue even after suspend is invoked. o In the old semantics, we had to track whether I/Os were queued before or after the suspend invocation, so a special barrier-like request called 'suspend marker' was introduced. o With the new semantics, we don't need to flush any I/O so we can remove the marker and the code related to the marker handling and I/O flushing. After removing this codes, the suspend sequence is now: 1. Flush all I/Os by lock_fs() if needed. 2. Stop dispatching any I/O by stopping the request_queue. 3. Wait for all in-flight I/Os to be completed or requeued. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm: abstract clone_rqKiyoshi Ueda
This patch factors out the request cloning code in dm_prep_fn() as clone_rq(). No functional change. This patch is a preparation for a later patch in this series which needs to make clones from an original barrier request. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm: pass gfp_mask to alloc_rq_tioKiyoshi Ueda
This patch adds the gfp_mask argument to alloc_rq_tio(). No functional change. This patch is a preparation for a later patch in this series which needs to allocate tio (for barrier I/O) with different allocation flag (GFP_NOIO) from the one in the normal I/O code path. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm: use clone in map_request functionKiyoshi Ueda
This patch changes the argument of map_request() to clone request from original request. No functional change. This patch is a preparation for PATCH 9, which needs to use map_request() for clones sharing an original barrier request. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm: abstract dm_in_flight functionKiyoshi Ueda
This patch adds md_in_flight() to get the number of in_flight I/Os. No functional change. This patch is a preparation for a later patch in this series, which changes I/O counter to md->pending from q->in_flight in request-based dm. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm kcopyd: accept zero size jobsMikulas Patocka
dm-kcopyd: accept zero-size jobs This patch changes dm-kcopyd so that it accepts zero-size jobs and completes them immediatelly via its completion thread. It is needed for multisnapshots snapshot resizing. When we are writing to a chunk beyond origin end, no copying is done. To simplify the code, we submit an empty request to kcopyd and let kcopyd complete it. If we didn't submit a request to kcopyd and called the completion routine immediatelly, it would violate the principle that completion is called only from one thread and it would need additional locking. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm snapshot: track suspended state in targetMike Snitzer
Keep track of whether or not the device is suspended within the snapshot target module, the same as we do in dm-raid1. We will use this later to enforce the correct sequence of ioctls to transfer the in-core exceptions from a snapshot target instance in one table to a replacement one capable of merging them back into the origin. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm snapshot: move cow ref from exception store to snap coreMike Snitzer
Store the reference to the snapshot cow device in the core snapshot code instead of each exception store. It can be accessed through the new function dm_snap_cow(). Exception stores should each now maintain a reference to their parent snapshot struct. This is cleaner and makes part of the forthcoming snapshot merge code simpler. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Reviewed-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Mikulas Patocka <mpatocka@redhat.com>
2009-12-10dm snapshot: add allocated metadata to snapshot statusMike Snitzer
Add number of sectors used by metadata to the end of the snapshot's status line. Renamed dm_exception_store_type's 'fraction_full' to 'usage'. Renamed arguments to be clearer about what is being returned. Also added 'metadata_sectors'. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm snapshot: rename exception functionsJon Brassow
Rename exception functions. Preparing to pull them out of dm-snap.c for broader use. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm snapshot: rename exception_table to dm_exception_tableJon Brassow
Rename exception_table for broader use outside dm-snap.c Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm snapshot: rename dm_snap_exception to dm_exceptionJon Brassow
The exception structure is not necessarily just a snapshot element (especially after we pull it out of dm-snap.c). Renaming appropriately. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm snapshot: consolidate insert exception functionsJon Brassow
Consolidate the insert_*exception functions. 'insert_completed_exception' already contains all the logic to handle 'insert_exception' (via check for a hash_shift of 0), so remove redundant function. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm snapshot: abstract minimum_chunk_size fnMikulas Patocka
The origin needs to find minimum chunksize of all snapshots. This logic is moved to a separate function because it will be used at another place in the snapshot merge patches. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm snapshot: simplify sector_to_chunk expressionMikulas Patocka
Removed unnecessary 'and' masking: The right shift discards the lower bits so there is no need to clear them. (A later patch needs this change to support a 32-bit chunk_mask.) Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm snapshot: avoid else clause in persistent_read_metadataJon Brassow
Minor code touch-up. We don't need the 'else'. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm ioctl: prefer strlcpy over strncpyRoel Kluin
strlcpy() will always null terminate the string. The code should already guarantee this as the last bytes are already NULs and the string lengths were restricted before being stored in hc. Removing the '-1' becomes necessary so strlcpy() doesn't lose the last character of a maximum-length string. - agk Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm raid1: explicitly initialise bio_listsMikulas Patocka
Explicitly initialize bio lists instead of relying on kzalloc. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Takahiro Yasui <tyasui@redhat.com> Tested-by: Takahiro Yasui <tyasui@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm raid1: hold all write bios when leg failsMikulas Patocka
Hold all write bios when leg fails and errors are handled When using a userspace daemon such as dmeventd to handle errors, we must delay completing bios until it has done its job. This patch prevents the following race: - primary leg fails - write "1" fail, the write is held, secondary leg is set default - write "2" goes straight to the secondary leg Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Takahiro Yasui <tyasui@redhat.com> Tested-by: Takahiro Yasui <tyasui@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm raid1: hold write bios when errors are handledMikulas Patocka
Hold all write bios when errors are handled. Previously the failures list was used only when handling errors with a userspace daemon such as dmeventd. Now, it is always used for all bios. The regions where some writes failed must be marked as nosync. This can only be done in process context (i.e. in raid1 workqueue), not in the write_callback function. Previously the write would succeed if writing to at least one leg succeeded. This is wrong because data from the failed leg may be replicated to the correct leg. Now, if using a userspace daemon, the write with some failures will be held until the daemon has done its job and reconfigured the array. If not using a daemon, the write still succeeds if at least one leg succeeds. This is bad, but it is consistent with current behavior. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Takahiro Yasui <tyasui@redhat.com> Tested-by: Takahiro Yasui <tyasui@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm raid1: remove bio_endio from dm_rh_mark_nosyncMikulas Patocka
Move bio completion out of dm_rh_mark_nosync in preparation for the next patch. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Takahiro Yasui <tyasui@redhat.com> Tested-by: Takahiro Yasui <tyasui@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm raid1: abstract get_valid_mirror functionMikulas Patocka
Move the logic to get a valid mirror leg into a function for re-use in a later patch. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Takahiro Yasui <tyasui@redhat.com> Tested-by: Takahiro Yasui <tyasui@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm raid1: use hold framework in do_failuresMikulas Patocka
Use the hold framework in do_failures. This patch doesn't change the bio processing logic, it just simplifies failure handling and avoids periodically polling the failures list. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Takahiro Yasui <tyasui@redhat.com> Tested-by: Takahiro Yasui <tyasui@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm raid1: add framework to hold bios during suspendMikulas Patocka
Add framework to delay bios until a suspend and then resubmit them with either DM_ENDIO_REQUEUE (if the suspend was noflush) or complete them with -EIO. I/O barrier support will use this. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Takahiro Yasui <tyasui@redhat.com> Tested-by: Takahiro Yasui <tyasui@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm raid1: report flush errors separately in statusMikulas Patocka
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>
2009-12-10dm raid1: implement mirror_flushMikulas Patocka
Implement flush callee. It uses dm_io to send zero-size barrier synchronously and concurrently to all the mirror legs. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm log: use flush callback fnMikulas Patocka
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>
2009-12-10dm log: add flush callback fnMikulas Patocka
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>
2009-12-10dm log: introduce flush_failed variableMikulas Patocka
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>
2009-12-10dm log: add flush_header functionMikulas Patocka
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>
2009-12-10dm raid1: split touched state into twoMikulas Patocka
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>
2009-12-10dm raid1: support flushMikulas Patocka
Flush support for dm-raid1. When it receives an empty barrier, submit it to all the devices via dm-io. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm io: remove extra bi_io_vec region hackMikulas Patocka
Remove the hack where we allocate an extra bi_io_vec to store additional private data. This hack prevents us from supporting barriers in dm-raid1 without first making another little block layer change. Instead of doing that, this patch eliminates the bi_io_vec abuse by storing the region number directly in the low bits of bi_private. We need to store two things for each bio, the pointer to the main io structure and, if parallel writes were requested, an index indicating which of these writes this bio belongs to. There can be at most BITS_PER_LONG regions - 32 or 64. The index (region number) was stored in the last (hidden) bio vector and the pointer to struct io was stored in bi_private. This patch now aligns "struct io" on BITS_PER_LONG bytes and stores the region number in the low BITS_PER_LONG bits of bi_private. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm io: use slab for struct ioMikulas Patocka
Allocate "struct io" from a slab. This patch changes dm-io, so that "struct io" is allocated from a slab cache. It used to be allocated with kmalloc. Allocating from a slab will be needed for the next patch, because it requires a special alignment of "struct io" and kmalloc cannot meet this alignment. Signed-off-by: Mikulas Patocka <mpatocka@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>
2009-12-10dm snapshot: cope with chunk size larger than originMikulas Patocka
Under some special conditions the snapshot hash_size is calculated as zero. This patch instead sets a minimum value of 64, the same as for the pending exception table. rounddown_pow_of_two(0) is an undefined operation (it expands to shift by -1). init_exception_table with an argument of 0 would fail with -ENOMEM. The way to trigger the problem is to create a snapshot with a chunk size that is larger than the origin device. Cc: stable@kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm snapshot: only take lock for statustype info not tableMikulas Patocka
Take snapshot lock only for STATUSTYPE_INFO, not STATUSTYPE_TABLE. Commit 4c6fff445d7aa753957856278d4d93bcad6e2c14 (dm-snapshot-lock-snapshot-while-supplying-status.patch) introduced this use of the lock, but userspace applications using libdevmapper have been found to request STATUSTYPE_TABLE while the device is suspended and the lock is already held, leading to deadlock. Since the lock is not necessary in this case, don't try to take it. Cc: stable@kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm: sysfs add empty release function to avoid debug warningMilan Broz
This patch just removes an unnecessary warning: kobject: 'dm': does not have a release() function, it is broken and must be fixed. The kobject is embedded in mapped device struct, so code does not need to release memory explicitly here. Cc: stable@kernel.org Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm exception store: free tmp_store on persistent flag errorJulia Lawall
Error handling code following a kmalloc should free the allocated data. Cc: stable@kernel.org Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10dm: avoid _hash_lock deadlockMikulas Patocka
Fix a reported deadlock if there are still unprocessed multipath events on a device that is being removed. _hash_lock is held during dev_remove while trying to send the outstanding events. Sending the events requests the _hash_lock again in dm_copy_name_and_uuid. This patch introduces a separate lock around regions that modify the link to the hash table (dm_set_mdptr) or the name or uuid so that dm_copy_name_and_uuid no longer needs _hash_lock. Additionally, dm_copy_name_and_uuid can only be called if md exists so we can drop the dm_get() and dm_put() which can lead to a BUG() while md is being freed. The deadlock: #0 [ffff8106298dfb48] schedule at ffffffff80063035 #1 [ffff8106298dfc20] __down_read at ffffffff8006475d #2 [ffff8106298dfc60] dm_copy_name_and_uuid at ffffffff8824f740 #3 [ffff8106298dfc90] dm_send_uevents at ffffffff88252685 #4 [ffff8106298dfcd0] event_callback at ffffffff8824c678 #5 [ffff8106298dfd00] dm_table_event at ffffffff8824dd01 #6 [ffff8106298dfd10] __hash_remove at ffffffff882507ad #7 [ffff8106298dfd30] dev_remove at ffffffff88250865 #8 [ffff8106298dfd60] ctl_ioctl at ffffffff88250d80 #9 [ffff8106298dfee0] do_ioctl at ffffffff800418c4 #10 [ffff8106298dff00] vfs_ioctl at ffffffff8002fab9 #11 [ffff8106298dff40] sys_ioctl at ffffffff8004bdaf #12 [ffff8106298dff80] tracesys at ffffffff8005d28d (via system_call) Cc: stable@kernel.org Reported-by: guy keren <choo@actcom.co.il> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-09Merge branch 'acpica' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 * 'acpica' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: ACPICA: Update version to 20091112. ACPICA: Add additional module-level code support ACPICA: Deploy new create integer interface where appropriate ACPICA: New internal utility function to create Integer objects ACPICA: Add repair for predefined methods that must return sorted lists ACPICA: Fix possible fault if return Package objects contain NULL elements ACPICA: Add post-order callback to acpi_walk_namespace ACPICA: Change package length error message to an info message ACPICA: Reduce severity of predefined repair messages, Warning to Info ACPICA: Update version to 20091013 ACPICA: Fix possible memory leak for Scope ASL operator ACPICA: Remove possibility of executing _REG methods twice ACPICA: Add repair for bad _MAT buffers ACPICA: Add repair for bad _BIF/_BIX packages
2009-12-09Merge branch 'hwmon-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging * 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging: (41 commits) hwmon: (adt7475) Add VID support for the ADT7476 hwmon: (adt7475) Add an entry in MAINTAINERS hwmon: (adt7475) Add support for the ADT7476 hwmon: (adt7475) Voltage attenuators can be bypassed hwmon: (adt7475) Print device information on probe hwmon: (adt7475) Handle alternative pin functions hwmon: (adt7475) Move sysfs files removal to a separate function hwmon: (adt7475) Add support for the ADT7490 hwmon: (adt7475) Improve device detection hwmon: (adt7475) Add missing static marker hwmon: (adt7475) Rework voltage inputs handling hwmon: (adt7475) Implement pwm_use_point2_pwm_at_crit hwmon: (adt7475) New documentation hwmon: (adt7475) Add support for the ADT7473 hwmon: (f71882fg) Add support for the f71889fg (version 2) hwmon: (f71882fg) Fix sysfs file removal hwmon: (f71882fg) Cleanup sysfs attr creation 2/2 hwmon: (f71882fg) Cleanup sysfs attr creation 1/2 hwmon: (thmc50) Stop using I2C_CLIENT_MODULE_PARM hwmon: Add Freescale MC13783 ADC driver ...