233 строки
7.7 KiB
C
233 строки
7.7 KiB
C
/******************************************************************************
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*******************************************************************************
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**
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** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
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** Copyright (C) 2004-2011 Red Hat, Inc. All rights reserved.
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**
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** This copyrighted material is made available to anyone wishing to use,
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** modify, copy, or redistribute it subject to the terms and conditions
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** of the GNU General Public License v.2.
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**
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*******************************************************************************
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******************************************************************************/
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#ifndef __DLM_DOT_H__
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#define __DLM_DOT_H__
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/*
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* Interface to Distributed Lock Manager (DLM)
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* routines and structures to use DLM lockspaces
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*/
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/* Lock levels and flags are here */
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#include <linux/dlmconstants.h>
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#include <linux/types.h>
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typedef void dlm_lockspace_t;
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/*
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* Lock status block
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*
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* Use this structure to specify the contents of the lock value block. For a
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* conversion request, this structure is used to specify the lock ID of the
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* lock. DLM writes the status of the lock request and the lock ID assigned
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* to the request in the lock status block.
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*
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* sb_lkid: the returned lock ID. It is set on new (non-conversion) requests.
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* It is available when dlm_lock returns.
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*
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* sb_lvbptr: saves or returns the contents of the lock's LVB according to rules
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* shown for the DLM_LKF_VALBLK flag.
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*
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* sb_flags: DLM_SBF_DEMOTED is returned if in the process of promoting a lock,
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* it was first demoted to NL to avoid conversion deadlock.
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* DLM_SBF_VALNOTVALID is returned if the resource's LVB is marked invalid.
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*
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* sb_status: the returned status of the lock request set prior to AST
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* execution. Possible return values:
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*
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* 0 if lock request was successful
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* -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE
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* -DLM_EUNLOCK if unlock request was successful
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* -DLM_ECANCEL if a cancel completed successfully
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* -EDEADLK if a deadlock was detected
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* -ETIMEDOUT if the lock request was canceled due to a timeout
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*/
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#define DLM_SBF_DEMOTED 0x01
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#define DLM_SBF_VALNOTVALID 0x02
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#define DLM_SBF_ALTMODE 0x04
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struct dlm_lksb {
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int sb_status;
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__u32 sb_lkid;
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char sb_flags;
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char * sb_lvbptr;
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};
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/* dlm_new_lockspace() flags */
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#define DLM_LSFL_TIMEWARN 0x00000002
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#define DLM_LSFL_FS 0x00000004
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#define DLM_LSFL_NEWEXCL 0x00000008
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#ifdef __KERNEL__
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struct dlm_slot {
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int nodeid; /* 1 to MAX_INT */
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int slot; /* 1 to MAX_INT */
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};
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/*
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* recover_prep: called before the dlm begins lock recovery.
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* Notfies lockspace user that locks from failed members will be granted.
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* recover_slot: called after recover_prep and before recover_done.
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* Identifies a failed lockspace member.
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* recover_done: called after the dlm completes lock recovery.
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* Identifies lockspace members and lockspace generation number.
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*/
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struct dlm_lockspace_ops {
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void (*recover_prep) (void *ops_arg);
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void (*recover_slot) (void *ops_arg, struct dlm_slot *slot);
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void (*recover_done) (void *ops_arg, struct dlm_slot *slots,
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int num_slots, int our_slot, uint32_t generation);
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};
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/*
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* dlm_new_lockspace
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*
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* Create/join a lockspace.
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*
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* name: lockspace name, null terminated, up to DLM_LOCKSPACE_LEN (not
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* including terminating null).
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*
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* cluster: cluster name, null terminated, up to DLM_LOCKSPACE_LEN (not
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* including terminating null). Optional. When cluster is null, it
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* is not used. When set, dlm_new_lockspace() returns -EBADR if cluster
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* is not equal to the dlm cluster name.
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*
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* flags:
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* DLM_LSFL_NODIR
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* The dlm should not use a resource directory, but statically assign
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* resource mastery to nodes based on the name hash that is otherwise
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* used to select the directory node. Must be the same on all nodes.
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* DLM_LSFL_TIMEWARN
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* The dlm should emit netlink messages if locks have been waiting
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* for a configurable amount of time. (Unused.)
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* DLM_LSFL_FS
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* The lockspace user is in the kernel (i.e. filesystem). Enables
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* direct bast/cast callbacks.
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* DLM_LSFL_NEWEXCL
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* dlm_new_lockspace() should return -EEXIST if the lockspace exists.
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*
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* lvblen: length of lvb in bytes. Must be multiple of 8.
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* dlm_new_lockspace() returns an error if this does not match
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* what other nodes are using.
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*
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* ops: callbacks that indicate lockspace recovery points so the
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* caller can coordinate its recovery and know lockspace members.
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* This is only used by the initial dlm_new_lockspace() call.
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* Optional.
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*
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* ops_arg: arg for ops callbacks.
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*
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* ops_result: tells caller if the ops callbacks (if provided) will
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* be used or not. 0: will be used, -EXXX will not be used.
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* -EOPNOTSUPP: the dlm does not have recovery_callbacks enabled.
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*
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* lockspace: handle for dlm functions
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*/
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int dlm_new_lockspace(const char *name, const char *cluster,
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uint32_t flags, int lvblen,
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const struct dlm_lockspace_ops *ops, void *ops_arg,
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int *ops_result, dlm_lockspace_t **lockspace);
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/*
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* dlm_release_lockspace
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*
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* Stop a lockspace.
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*/
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int dlm_release_lockspace(dlm_lockspace_t *lockspace, int force);
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/*
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* dlm_lock
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*
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* Make an asyncronous request to acquire or convert a lock on a named
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* resource.
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*
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* lockspace: context for the request
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* mode: the requested mode of the lock (DLM_LOCK_)
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* lksb: lock status block for input and async return values
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* flags: input flags (DLM_LKF_)
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* name: name of the resource to lock, can be binary
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* namelen: the length in bytes of the resource name (MAX_RESNAME_LEN)
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* parent: the lock ID of a parent lock or 0 if none
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* lockast: function DLM executes when it completes processing the request
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* astarg: argument passed to lockast and bast functions
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* bast: function DLM executes when this lock later blocks another request
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*
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* Returns:
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* 0 if request is successfully queued for processing
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* -EINVAL if any input parameters are invalid
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* -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE
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* -ENOMEM if there is no memory to process request
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* -ENOTCONN if there is a communication error
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*
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* If the call to dlm_lock returns an error then the operation has failed and
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* the AST routine will not be called. If dlm_lock returns 0 it is still
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* possible that the lock operation will fail. The AST routine will be called
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* when the locking is complete and the status is returned in the lksb.
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*
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* If the AST routines or parameter are passed to a conversion operation then
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* they will overwrite those values that were passed to a previous dlm_lock
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* call.
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*
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* AST routines should not block (at least not for long), but may make
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* any locking calls they please.
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*/
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int dlm_lock(dlm_lockspace_t *lockspace,
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int mode,
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struct dlm_lksb *lksb,
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uint32_t flags,
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void *name,
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unsigned int namelen,
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uint32_t parent_lkid,
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void (*lockast) (void *astarg),
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void *astarg,
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void (*bast) (void *astarg, int mode));
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/*
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* dlm_unlock
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*
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* Asynchronously release a lock on a resource. The AST routine is called
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* when the resource is successfully unlocked.
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*
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* lockspace: context for the request
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* lkid: the lock ID as returned in the lksb
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* flags: input flags (DLM_LKF_)
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* lksb: if NULL the lksb parameter passed to last lock request is used
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* astarg: the arg used with the completion ast for the unlock
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*
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* Returns:
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* 0 if request is successfully queued for processing
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* -EINVAL if any input parameters are invalid
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* -ENOTEMPTY if the lock still has sublocks
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* -EBUSY if the lock is waiting for a remote lock operation
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* -ENOTCONN if there is a communication error
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*/
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int dlm_unlock(dlm_lockspace_t *lockspace,
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uint32_t lkid,
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uint32_t flags,
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struct dlm_lksb *lksb,
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void *astarg);
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#endif /* __KERNEL__ */
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#endif /* __DLM_DOT_H__ */
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