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path: root/fs/dlm/dlm_internal.h
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2007-10-10[DLM] block dlm_recv in recovery transitionDavid Teigland
Introduce a per-lockspace rwsem that's held in read mode by dlm_recv threads while working in the dlm. This allows dlm_recv activity to be suspended when the lockspace transitions to, from and between recovery cycles. The specific bug prompting this change is one where an in-progress recovery cycle is aborted by a new recovery cycle. While dlm_recv was processing a recovery message, the recovery cycle was aborted and dlm_recoverd began cleaning up. dlm_recv decremented recover_locks_count on an rsb after dlm_recoverd had reset it to zero. This is fixed by suspending dlm_recv (taking write lock on the rwsem) before aborting the current recovery. The transitions to/from normal and recovery modes are simplified by using this new ability to block dlm_recv. The switch from normal to recovery mode means dlm_recv goes from processing locking messages, to saving them for later, and vice versa. Races are avoided by blocking dlm_recv when setting the flag that switches between modes. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] dump more lock valuesDavid Teigland
Add two more output fields (lkb_flags and rsb nodeid) to the new debugfs file that dumps one lock per line. Also, dump all locks instead of just mastered locks. Accordingly, use a suffix of _locks instead of _master. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] variable allocationPatrick Caulfield
Add a new flag, DLM_LSFL_FS, to be used when a file system creates a lockspace. This flag causes the dlm to use GFP_NOFS for allocations instead of GFP_KERNEL. (This updated version of the patch uses gfp_t for ls_allocation.) Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com> Signed-Off-By: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] dumping master locksDavid Teigland
Add a new debugfs file that dumps a compact list of mastered locks. This will be used by a userland daemon to collect state for deadlock detection. Also, for the existing function that prints all lock state, lock the rsb before going through the lock lists since they can be changing in the course of normal dlm activity. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
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] wait for config check during join [6/6]David Teigland
Joining the lockspace should wait for the initial round of inter-node config checks to complete before returning. This way, if there's a configuration mismatch between the joining node and the existing nodes, the join can fail and return an error to the application. 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] add orphan purging code (1/2)David Teigland
Add code for purging orphan locks. A process can also purge all of its own non-orphan locks by passing a pid of zero. Code already exists for processes to create persistent locks that become orphans when the process exits, but the complimentary capability for another process to then purge these orphans has been missing. 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>
2007-02-05[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>
2007-02-05[DLM] add config entry to enable log_debugDavid Teigland
Add a new dlm_config_info field to enable log_debug output and change log_debug() to use it. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05[DLM] fix old rcom messagesDavid Teigland
A reply to a recovery message will often be received after the relevant recovery sequence has aborted and the next recovery sequence has begun. We need to ignore replies to these old messages from the previous recovery. There's already a way to do this for synchronous recovery requests using the rc_id number, but not for async. Each recovery sequence already has a locally unique sequence number associated with it. This patch adds a field to the rcom (recovery message) structure where this recovery sequence number can be placed, rc_seq. When a node sends a reply to a recovery request, it copies the rc_seq number it received into rc_seq_reply. When the first node receives the reply to its recovery message, it will check whether rc_seq_reply matches the current recovery sequence number, ls_recover_seq, and if not then it ignores the old reply. An old, inadequate approach to filtering out old replies (checking if the current stage of recovery has moved back to the start) has been removed from two spots. The protocol version number is changed to reflect the different rcom structures. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-11-30[DLM] don't accept replies to old recovery messagesDavid Teigland
We often abort a recovery after sending a status request to a remote node. We want to ignore any potential status reply we get from the remote node. If we get one of these unwanted replies, we've often moved on to the next recovery message and incremented the message sequence counter, so the reply will be ignored due to the seq number. In some cases, we've not moved on to the next message so the seq number of the reply we want to ignore is still correct, causing the reply to be accepted. The next recovery message will then mistake this old reply as a new one. To fix this, we add the flag RCOM_WAIT to indicate when we can accept a new reply. We clear this flag if we abort recovery while waiting for a reply. Before the flag is set again (to allow new replies) we know that any old replies will be rejected due to their sequence number. We also initialize the recovery-message sequence number to a random value when a lockspace is first created. This makes it clear when messages are being rejected from an old instance of a lockspace that has since been recreated. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-08-23[DLM] down conversion clearing flagsDavid Teigland
The down-conversion optimization was resulting in the lkb flags being cleared because the stub message reply had no flags value set. Copy the current flags into the stub message so they'll be copied back into the lkb as part of processing the fake reply. Also add an assertion to catch this error more directly if it exists elsewhere. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-08-09[DLM] reject replies to old requestsDavid Teigland
When recoveries are aborted by other recoveries we can get replies to status or names requests that we've given up on. This can cause problems if we're making another request and receive an old reply. Add a sequence number to status/names requests and reject replies that don't match. A field already exists for the seq number that's used in other message types. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-08-09[DLM] show nodeid for recovery messageDavid Teigland
To aid debugging, it's useful to be able to see what nodeid the dlm is waiting on for a message reply. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-07-26[DLM] more info through debugfsDavid Teigland
Display more information from debugfs, particularly locks waiting for a master lookup or operations waiting for a remote reply. 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>
2006-05-02[DLM] fix grant_after_purge softlockupDavid Teigland
In dlm_grant_after_purge() we were holding a hash table read_lock while calling put_rsb() which potentially removes the rsb from the hash table, taking the same lock in write. Fix this by flagging rsb's ahead of time that have been purged. Then iteratively read_lock the hash table, find a flagged rsb, unlock, process rsb. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-02-23[DLM] Remove range locks from the DLMDavid Teigland
This patch removes support for range locking from the DLM Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-01-20[DLM] Update DLM to the latest patch levelDavid Teigland
Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steve Whitehouse <swhiteho@redhat.com>
2006-01-18[DLM] The core of the DLM for GFS2/CLVMDavid Teigland
This is the core of the distributed lock manager which is required to use GFS2 as a cluster filesystem. It is also used by CLVM and can be used as a standalone lock manager independantly of either of these two projects. It implements VAX-style locking modes. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steve Whitehouse <swhiteho@redhat.com>