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path: root/fs/dlm/user.c
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2007-07-09[DLM] canceling deadlocked lockDavid Teigland
Add a function that can be used through libdlm by a system daemon to cancel another process's deadlocked lock. A completion ast with EDEADLK is returned to the process waiting for the lock. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] timeout fixesDavid Teigland
Various fixes related to the new timeout feature: - add_timeout() missed setting TIMEWARN flag on lkb's when the TIMEOUT flag was already set - clear_proc_locks should remove a dead process's locks from the timeout list - the end-of-life calculation for user locks needs to consider that ETIMEDOUT is equivalent to -DLM_ECANCEL - make initial default timewarn_cs config value visible in configfs - change bit position of TIMEOUT_CANCEL flag so it's not copied to a remote master node - set timestamp on remote lkb's so a lock dump will display the time they've been waiting Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] dlm_device interface changes [3/6]David Teigland
Change the user/kernel device interface used by libdlm: - Add ability for userspace to check the version of the interface. libdlm can now adapt to different versions of the kernel interface. - Increase the size of the flags passed in a lock request so all possible flags can be used from userspace. - Add an opaque "xid" value for each lock. This "transaction id" will be used later to associate locks with each other during deadlock detection. - Add a "timeout" value for each lock. This is used along with the DLM_LKF_TIMEOUT flag. Also, remove a fragment of unused code in device_read(). This patch requires updating libdlm which is backward compatible with older kernels. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] add lock timeouts and warnings [2/6]David Teigland
New features: lock timeouts and time warnings. If the DLM_LKF_TIMEOUT flag is set, then the request/conversion will be canceled after waiting the specified number of centiseconds (specified per lock). This feature is only available for locks requested through libdlm (can be enabled for kernel dlm users if there's a use for it.) If the new DLM_LSFL_TIMEWARN flag is set when creating the lockspace, then a warning message will be sent to userspace (using genetlink) after a request/conversion has been waiting for a given number of centiseconds (configurable per node). The time warnings will be used in the future to do deadlock detection in userspace. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] Remove redundant assignmentPatrick Caulfield
This patch removes a redundant (and incorrect) assignment from compat_output Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] interface for purge (2/2)David Teigland
Add code to accept purge commands from userland. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] overlapping cancel and unlockDavid Teigland
Full cancel and force-unlock support. In the past, cancel and force-unlock wouldn't work if there was another operation in progress on the lock. Now, both cancel and unlock-force can overlap an operation on a lock, meaning there may be 2 or 3 operations in progress on a lock in parallel. This support is important not only because cancel and force-unlock are explicit operations that an app can use, but both are used implicitly when a process exits while holding locks. Summary of changes: - add-to and remove-from waiters functions were rewritten to handle situations with more than one remote operation outstanding on a lock - validate_unlock_args detects when an overlapping cancel/unlock-force can be sent and when it needs to be delayed until a request/lookup reply is received - processing request/lookup replies detects when cancel/unlock-force occured during the op, and carries out the delayed cancel/unlock-force - manipulation of the "waiters" (remote operation) state of a lock moved under the standard rsb mutex that protects all the other lock state - the two recovery routines related to locks on the waiters list changed according to the way lkb's are now locked before accessing waiters state - waiters recovery detects when lkb's being recovered have overlapping cancel/unlock-force, and may not recover such locks - revert_lock (cancel) returns a value to distinguish cases where it did nothing vs cases where it actually did a cancel; the cancel completion ast should only be done when cancel did something - orphaned locks put on new list so they can be found later for purging - cancel must be called on a lock when making it an orphan - flag user locks (ENDOFLIFE) at the end of their useful life (to the application) so we can return an error for any further cancel/unlock-force - we weren't setting COMP/BAST ast flags if one was already set, so we'd lose either a completion or blocking ast - clear an unread bast on a lock that's become unlocked Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] Don't delete misc device if lockspace removal failsPatrick Caulfield
Currently if the lockspace removal fails the misc device associated with a lockspace is left deleted. After that there is no way to access the orphaned lockspace from userland. This patch recreates the misc device if th dlm_release_lockspace fails. I believe this is better than attempting to remove the lockspace first because that leaves an unattached device lying around. The potential gap in which there is no access to the lockspace between removing the misc device and recreating it is acceptable ... after all the application is trying to remove it, and only new users of the lockspace will be affected. Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-03-07[DLM] fs/dlm/user.c should #include "user.h"Adrian Bunk
Every file should include the headers containing the prototypes for it's global functions. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-12[PATCH] mark struct file_operations const 6Arjan van de Ven
Many struct file_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-05[DLM] fix user unlockingDavid Teigland
When a user process exits, we clear all the locks it holds. There is a problem, though, with locks that the process had begun unlocking before it exited. We couldn't find the lkb's that were in the process of being unlocked remotely, to flag that they are DEAD. To solve this, we move lkb's being unlocked onto a new list in the per-process structure that tracks what locks the process is holding. We can then go through this list to flag the necessary lkb's when clearing locks for a process when it exits. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-08-31[DLM] force removal of user lockspaceDavid Teigland
Check if the FORCEFREE flag has been provided from user space. If so, set the force option to dlm_release_lockspace() so that any remaining locks will be freed. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-07-21[DLM] fix whitespace damageDavid Teigland
My previous dlm patch added trailing whitespace damage, fix that. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-07-20[DLM] fix leaking user locksDavid Teigland
User NOQUEUE lock requests to a remote node that failed with -EAGAIN were never being removed from a process's list of locks. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-07-13[DLM] dlm: user locksDavid Teigland
This changes the way the dlm handles user locks. The core dlm is now aware of user locks so they can be dealt with more efficiently. There is no more dlm_device module which previously managed its own duplicate copy of every user lock. Signed-off-by: Patrick Caulfield <pcaulfie@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>