summaryrefslogtreecommitdiff
path: root/fs/dlm/lock.c
AgeCommit message (Collapse)Author
2011-07-15dlm: use workqueue for callbacksDavid Teigland
Instead of creating our own kthread (dlm_astd) to deliver callbacks for all lockspaces, use a per-lockspace workqueue to deliver the callbacks. This eliminates complications and slowdowns from many lockspaces sharing the same thread. Signed-off-by: David Teigland <teigland@redhat.com>
2011-07-14dlm: remove deadlock debug printDavid Teigland
gfs2 recently began using this feature heavily, creating more debug output than we want to see. Signed-off-by: David Teigland <teigland@redhat.com>
2011-07-12dlm: improve rsb searchesDavid Teigland
By pre-allocating rsb structs before searching the hash table, they can be inserted immediately. This avoids always having to repeat the search when adding the struct to hash list. This also adds space to the rsb struct for a max resource name, so an rsb allocation can be used by any request. The constant size also allows us to finally use a slab for the rsb structs. Signed-off-by: David Teigland <teigland@redhat.com>
2011-07-11dlm: keep lkbs in idrDavid Teigland
This is simpler and quicker than the hash table, and avoids needing to search the hash list for every new lkid to check if it's used. Signed-off-by: David Teigland <teigland@redhat.com>
2011-07-11dlm: fix kmalloc argsDavid Teigland
The gfp and size args were switched. Signed-off-by: David Teigland <teigland@redhat.com>
2011-07-11dlm: don't do pointless NULL check, use kzalloc and fix order of argumentsJesper Juhl
In fs/dlm/lock.c in the dlm_scan_waiters() function there are 3 small issues: 1) There's no need to test the return value of the allocation and do a memset if is succeedes. Just use kzalloc() to obtain zeroed memory. 2) Since kfree() handles NULL pointers gracefully, the test of 'warned' against NULL before the kfree() after the loop is completely pointless. Remove it. 3) The arguments to kmalloc() (now kzalloc()) were swapped. Thanks to Dr. David Alan Gilbert for pointing this out. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: David Teigland <teigland@redhat.com>
2011-05-24Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm: dlm: make plock operation killable dlm: remove shared message stub for recovery dlm: delayed reply message warning dlm: Remove superfluous call to recalc_sigpending()
2011-04-05dlm: remove shared message stub for recoveryDavid Teigland
kmalloc a stub message struct during recovery instead of sharing the struct in the lockspace. This leaves the lockspace stub_ms only for faking downconvert replies, where it is never modified and sharing is not a problem. Also improve the debug messages in the same recovery function. Signed-off-by: David Teigland <teigland@redhat.com>
2011-04-01dlm: delayed reply message warningDavid Teigland
Add an option (disabled by default) to print a warning message when a lock has been waiting a configurable amount of time for a reply message from another node. This is mainly for debugging. Signed-off-by: David Teigland <teigland@redhat.com>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-10dlm: record full callback stateDavid Teigland
Change how callbacks are recorded for locks. Previously, information about multiple callbacks was combined into a couple of variables that indicated what the end result should be. In some situations, we could not tell from this combined state what the exact sequence of callbacks were, and would end up either delivering the callbacks in the wrong order, or suppress redundant callbacks incorrectly. This new approach records all the data for each callback, leaving no uncertainty about what needs to be delivered. Signed-off-by: David Teigland <teigland@redhat.com>
2010-09-03dlm: Don't send callback to node making lock request when "try 1cb" failsSteven Whitehouse
When converting a lock, an lkb is in the granted state and also being used to request a new state. In the case that the conversion was a "try 1cb" type which has failed, and if the new state was incompatible with the old state, a callback was being generated to the requesting node. This is incorrect as callbacks should only be sent to all the other nodes holding blocking locks. The requesting node should receive the normal (failed) response to its "try 1cb" conversion request only. This was discovered while debugging a performance problem on GFS2, however this fix also speeds up GFS as well. In the GFS2 case the performance gain is over 10x for cases of write activity to an inode whose glock is cached on another, idle (wrt that glock) node. (comment added, dct) Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Tested-by: Abhijith Das <adas@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2010-04-30dlm: cleanup remove unused codeDan Carpenter
Smatch complains because "lkb" is never NULL. Looking at it, the original code actually adds the new element to the end of the list fine, so we can just get rid of the if condition. This code is four years old and no one has complained so it must work. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: David Teigland <teigland@redhat.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-02-26dlm: use bastmode in debugfs outputDavid Teigland
The bast mode that appears in the debugfs output should be useful on both master and process nodes. lkb_highbast is currently printed, and is only useful on the master node. lkb_bastmode is only useful on the process node. This patch sets lkb_bastmode on the master node as well, and uses that value in the debugfs print. Signed-off-by: David Teigland <teigland@redhat.com>
2010-02-26dlm: send reply before bastDavid Teigland
When the lock master processes a successful operation (request, convert, cancel, or unlock), it will process the effects of the change before sending the reply for the operation. The "effects" of the operation are: - blocking callbacks (basts) for any newly granted locks - waiting or converting locks that can now be granted The cast is queued on the local node when the reply from the lock master is received. This means that a lock holder can receive a bast for a lock mode that is doesn't yet know has been granted. Signed-off-by: David Teigland <teigland@redhat.com>
2010-02-24dlm: fix ordering of bast and castDavid Teigland
When both blocking and completion callbacks are queued for lock, the dlm would always deliver the completion callback (cast) first. In some cases the blocking callback (bast) is queued before the cast, though, and should be delivered first. This patch keeps track of the order in which they were queued and delivers them in that order. This patch also keeps track of the granted mode in the last cast and eliminates the following bast if the bast mode is compatible with the preceding cast mode. This happens when a remotely mastered lock is demoted, e.g. EX->NL, in which case the local node queues a cast immediately after sending the demote message. In this way a cast can be queued for a mode, e.g. NL, that makes an in-transit bast extraneous. Signed-off-by: David Teigland <teigland@redhat.com>
2009-11-30dlm: always use GFP_NOFSDavid Teigland
Replace all GFP_KERNEL and ls_allocation with GFP_NOFS. ls_allocation would be GFP_KERNEL for userland lockspaces and GFP_NOFS for file system lockspaces. It was discovered that any lockspaces on the system can affect all others by triggering memory reclaim in the file system which could in turn call back into the dlm to acquire locks, deadlocking dlm threads that were shared by all lockspaces, like dlm_recv. Signed-off-by: David Teigland <teigland@redhat.com>
2009-06-17dlm: Fix uninitialised variable warning in lock.cSteven Whitehouse
CC [M] fs/dlm/lock.o fs/dlm/lock.c: In function ‘find_rsb’: fs/dlm/lock.c:438: warning: ‘r’ may be used uninitialized in this function Since r is used on the error path to set r_ret, set it to NULL. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2009-03-11dlm: ignore cancel on granted lockDavid Teigland
Return immediately from dlm_unlock(CANCEL) if the lock is granted and not being converted; there's nothing to cancel. Signed-off-by: David Teigland <teigland@redhat.com>
2009-03-11dlm: clear defunct cancel stateDavid Teigland
When a conversion completes successfully and finds that a cancel of the convert is still in progress (which is now a moot point), preemptively clear the state associated with outstanding cancel. That state could cause a subsequent conversion to be ignored. Also, improve the consistency and content of error and debug messages in this area. Signed-off-by: David Teigland <teigland@redhat.com>
2009-01-08dlm: change rsbtbl rwlock to spinlockDavid Teigland
The rwlock is almost always used in write mode, so there's no reason to not use a spinlock instead. Signed-off-by: David Teigland <teigland@redhat.com>
2008-12-23dlm: add time stamp of blocking callbackDavid Teigland
Record the time the latest blocking callback was queued for a lock. This will be used for debugging in combination with lock queue timestamp changes in the previous patch. Signed-off-by: David Teigland <teigland@redhat.com>
2008-12-23dlm: change lock time stampingDavid Teigland
Use ktime instead of jiffies for timestamping lkb's. Also stamp the time on every lkb whenever it's added to a resource queue, instead of just stamping locks subject to timeouts. This will allow us to use timestamps more widely for debugging all locks. Signed-off-by: David Teigland <teigland@redhat.com>
2008-12-23dlm: improve how bast mode handlingDavid Teigland
The lkb bastmode value is set in the context of processing the lock, and read by the dlm_astd thread. Because it's accessed in these two separate contexts, the writing/reading ought to be done under a lock. This is simple to do by setting it and reading it when the lkb is added to and removed from dlm_astd's callback list which is properly locked. Signed-off-by: David Teigland <teigland@redhat.com>
2008-07-14dlm: fix uninitialized variable for search_rsb_list callersBenny Halevy
gcc 4.3.0 correctly emits the following warning. search_rsb_list does not *r_ret if no dlm_rsb is found and _search_rsb may pass the uninitialized value upstream on the error path when both calls to search_rsb_list return non-zero error. The fix sets *r_ret to NULL on search_rsb_list's not-found path. Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: David Teigland <teigland@redhat.com>
2008-07-14dlm: fix basts for granted CW waiting PR/CWDavid Teigland
The fix in commit 3650925893469ccb03dbcc6a440c5d363350f591 was addressing the case of a granted PR lock with waiting PR and CW locks. It's a special case that requires forcing a CW bast. However, that forced CW bast was incorrectly applying to a second condition where the granted lock was CW. So, the holder of a CW lock could receive an extraneous CW bast instead of a PR bast. This fix narrows the original special case to what was intended. Signed-off-by: David Teigland <teigland@redhat.com>
2008-04-21dlm: save master info after failed no-queue requestDavid Teigland
When a NOQUEUE request fails, the rsb res_master field is unnecessarily reset to -1, instead of leaving the valid master setting in place. We want to save the looked-up master values while the rsb is on the "toss list" so that another lookup can be avoided if the rsb is soon reused. The fix is to simply leave res_master value alone. Signed-off-by: David Teigland <teigland@redhat.com>
2008-04-21dlm: make dlm_print_rsb() staticAdrian Bunk
dlm_print_rsb() can now become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David Teigland <teigland@redhat.com>
2008-02-06dlm: eliminate astparam type castingDavid Teigland
Put lkb_astparam in a union with a dlm_user_args pointer to eliminate a lot of type casting. Signed-off-by: David Teigland <teigland@redhat.com>
2008-02-06dlm: proper types for asts and bastsDavid Teigland
Use proper types for ast and bast functions, and use consistent type for ast param. Signed-off-by: David Teigland <teigland@redhat.com>
2008-02-04dlm: fix overflows when copying from ->m_extra to lvbAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Teigland <teigland@redhat.com>
2008-02-04dlm: make find_rsb() fail gracefully when namelen is too largeAl Viro
We *can* get there from receive_request() and dlm_recover_master_copy() with namelen too large if incoming request is invalid; BUG() from DLM_ASSERT() in allocate_rsb() is a bit excessive reaction to that and in case of dlm_recover_master_copy() we would actually oops before that while calculating hash of up to 64Kb worth of data - with data actually being 64 _bytes_ in kmalloc()'ed struct. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Teigland <teigland@redhat.com>
2008-02-04dlm: receive_rcom_lock_args() overflow checkAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Teigland <teigland@redhat.com>
2008-02-04dlm: verify that places expecting rcom_lock have packet long enoughAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Teigland <teigland@redhat.com>
2008-02-04dlm: do not byteswap rcom_lockAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Teigland <teigland@redhat.com>
2008-02-04dlm: dlm_process_incoming_buffer() fixesAl Viro
* check that length is large enough to cover the non-variable part of message or rcom resp. (after checking that it's large enough to cover the header, of course). * kill more pointless casts Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Teigland <teigland@redhat.com>
2008-02-04dlm: use proper C for dlm/requestqueue stuff (and fix alignment bug)Al Viro
a) don't cast the pointer to dlm_header *, we use it as dlm_message * anyway. b) we copy the message into a queue element, then pass the pointer to copy to dlm_receive_message_saved(); declare it properly to make sure that we have the right alignment. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Teigland <teigland@redhat.com>
2008-01-30dlm: keep cached master rsbs during recoveryDavid Teigland
To prevent the master of an rsb from changing rapidly, an unused rsb is kept on the "toss list" for a period of time to be reused. The toss list was being cleared completely for each recovery, which is unnecessary. Much of the benefit of the toss list can be maintained if nodes keep rsb's in their toss list that they are the master of. These rsb's need to be included when the resource directory is rebuilt during recovery. Signed-off-by: David Teigland <teigland@redhat.com>
2008-01-30dlm: change error message to debugDavid Teigland
The invalid lockspace messages are normal and can appear relatively often. They should be suppressed without debugging enabled. Signed-off-by: David Teigland <teigland@redhat.com>
2008-01-30dlm: limit dir lookup loopDavid Teigland
In a rare case we may need to repeat a local resource directory lookup due to a race with removing the rsb and removing the resdir record. We'll never need to do more than a single additional lookup, though, so the infinite loop around the lookup can be removed. In addition to being unnecessary, the infinite loop is dangerous since some other unknown condition may appear causing the loop to never break. Signed-off-by: David Teigland <teigland@redhat.com>
2008-01-30dlm: reject normal unlock when lock is waiting for lookupDavid Teigland
Non-forced unlocks should be rejected if the lock is waiting on the rsb_lookup list for another lock to establish the master node. Signed-off-by: David Teigland <teigland@redhat.com>
2008-01-30dlm: validate messages before processingDavid Teigland
There was some hit and miss validation of messages that has now been cleaned up and unified. Before processing a message, the new validate_message() function checks that the lkb is the appropriate type, process-copy or master-copy, and that the message is from the correct nodeid for the the given lkb. Other checks and assertions on the lkb type and nodeid have been removed. The assertions were particularly bad since they would panic the machine instead of just ignoring the bad message. Although other recent patches have made processing old message unlikely, it still may be possible for an old message to be processed and caught by these checks. Signed-off-by: David Teigland <teigland@redhat.com>
2008-01-30dlm: reject messages from non-membersDavid Teigland
Messages from nodes that are no longer members of the lockspace should be ignored. When nodes are removed from the lockspace, recovery can sometimes complete quickly enough that messages arrive from a removed node after recovery has completed. When processed, these messages would often cause an error message, and could in some cases change some state, causing problems. Signed-off-by: David Teigland <teigland@redhat.com>
2008-01-30dlm: another call to confirm_master in receive_request_replyDavid Teigland
When a failed request (EBADR or ENOTBLK) is unlocked/canceled instead of retried, there may be other lkb's waiting on the rsb_lookup list for it to complete. A call to confirm_master() is needed to move on to the next waiting lkb since the current one won't be retried. Signed-off-by: David Teigland <teigland@redhat.com>
2008-01-30dlm: recover locks waiting for overlap repliesDavid Teigland
When recovery looks at locks waiting for replies, it fails to consider locks that have already received a reply for their first remote operation, but not received a reply for secondary, overlapping unlock/cancel. The appropriate stub reply needs to be called for these waiters. Appears when we start doing recovery in the presence of a many overlapping unlock/cancel ops. Signed-off-by: David Teigland <teigland@redhat.com>
2008-01-30dlm: clear ast_type when removing from astqueueDavid Teigland
The lkb_ast_type field indicates whether the lkb is on the astqueue list. When clearing locks for a process, lkb's were being removed from the astqueue list without clearing the field. If release_lockspace then happened immediately afterward, it could try to remove the lkb from the list a second time. Appears when process calls libdlm dlm_release_lockspace() which first closes the ls dev triggering clear_proc_locks, and then removes the ls (a write to control dev) causing release_lockspace(). Signed-off-by: David Teigland <teigland@redhat.com>
2008-01-29dlm: use dlm prefix on alloc and free functionsDavid Teigland
The dlm functions in memory.c should use the dlm_ prefix. Also, use kzalloc/kfree directly for dlm_direntry's, removing the wrapper functions. Signed-off-by: David Teigland <teigland@redhat.com>
2008-01-29dlm: don't print common non-errorsDavid Teigland
Change log_error() to log_debug() for conditions that can occur in large number in normal operation. Signed-off-by: David Teigland <teigland@redhat.com>
2008-01-29dlm: proper prototypesAdrian Bunk
This patch adds a proper prototype for some functions in fs/dlm/dlm_internal.h Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David Teigland <teigland@redhat.com>