/****************************************************************************** ******************************************************************************* ** ** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. ** Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. ** ** This copyrighted material is made available to anyone wishing to use, ** modify, copy, or redistribute it subject to the terms and conditions ** of the GNU General Public License v.2. ** ******************************************************************************* ******************************************************************************/ #ifndef __DLM_DOT_H__ #define __DLM_DOT_H__ /* * Interface to Distributed Lock Manager (DLM) * routines and structures to use DLM lockspaces */ /* Lock levels and flags are here */ #include <linux/dlmconstants.h> #include <linux/types.h> typedef void dlm_lockspace_t; /* * Lock status block * * Use this structure to specify the contents of the lock value block. For a * conversion request, this structure is used to specify the lock ID of the * lock. DLM writes the status of the lock request and the lock ID assigned * to the request in the lock status block. * * sb_lkid: the returned lock ID. It is set on new (non-conversion) requests. * It is available when dlm_lock returns. * * sb_lvbptr: saves or returns the contents of the lock's LVB according to rules * shown for the DLM_LKF_VALBLK flag. * * sb_flags: DLM_SBF_DEMOTED is returned if in the process of promoting a lock, * it was first demoted to NL to avoid conversion deadlock. * DLM_SBF_VALNOTVALID is returned if the resource's LVB is marked invalid. * * sb_status: the returned status of the lock request set prior to AST * execution. Possible return values: * * 0 if lock request was successful * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE * -ENOMEM if there is no memory to process request * -EINVAL if there are invalid parameters * -DLM_EUNLOCK if unlock request was successful * -DLM_ECANCEL if a cancel completed successfully */ #define DLM_SBF_DEMOTED 0x01 #define DLM_SBF_VALNOTVALID 0x02 #define DLM_SBF_ALTMODE 0x04 struct dlm_lksb { int sb_status; __u32 sb_lkid; char sb_flags; char * sb_lvbptr; }; /* dlm_new_lockspace() flags */ #define DLM_LSFL_NODIR 0x00000001 #define DLM_LSFL_TIMEWARN 0x00000002 #define DLM_LSFL_FS 0x00000004 #define DLM_LSFL_NEWEXCL 0x00000008 #ifdef __KERNEL__ /* * dlm_new_lockspace * * Starts a lockspace with the given name. If the named lockspace exists in * the cluster, the calling node joins it. */ int dlm_new_lockspace(const char *name, int namelen, dlm_lockspace_t **lockspace, uint32_t flags, int lvblen); /* * dlm_release_lockspace * * Stop a lockspace. */ int dlm_release_lockspace(dlm_lockspace_t *lockspace, int force); /* * dlm_lock * * Make an asyncronous request to acquire or convert a lock on a named * resource. * * lockspace: context for the request * mode: the requested mode of the lock (DLM_LOCK_) * lksb: lock status block for input and async return values * flags: input flags (DLM_LKF_) * name: name of the resource to lock, can be binary * namelen: the length in bytes of the resource name (MAX_RESNAME_LEN) * parent: the lock ID of a parent lock or 0 if none * lockast: function DLM executes when it completes processing the request * astarg: argument passed to lockast and bast functions * bast: function DLM executes when this lock later blocks another request * * Returns: * 0 if request is successfully queued for processing * -EINVAL if any input parameters are invalid * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE * -ENOMEM if there is no memory to process request * -ENOTCONN if there is a communication error * * If the call to dlm_lock returns an error then the operation has failed and * the AST routine will not be called. If dlm_lock returns 0 it is still * possible that the lock operation will fail. The AST routine will be called * when the locking is complete and the status is returned in the lksb. * * If the AST routines or parameter are passed to a conversion operation then * they will overwrite those values that were passed to a previous dlm_lock * call. * * AST routines should not block (at least not for long), but may make * any locking calls they please. */ int dlm_lock(dlm_lockspace_t *lockspace, int mode, struct dlm_lksb *lksb, uint32_t flags, void *name, unsigned int namelen, uint32_t parent_lkid, void (*lockast) (void *astarg), void *astarg, void (*bast) (void *astarg, int mode)); /* * dlm_unlock * * Asynchronously release a lock on a resource. The AST routine is called * when the resource is successfully unlocked. * * lockspace: context for the request * lkid: the lock ID as returned in the lksb * flags: input flags (DLM_LKF_) * lksb: if NULL the lksb parameter passed to last lock request is used * astarg: the arg used with the completion ast for the unlock * * Returns: * 0 if request is successfully queued for processing * -EINVAL if any input parameters are invalid * -ENOTEMPTY if the lock still has sublocks * -EBUSY if the lock is waiting for a remote lock operation * -ENOTCONN if there is a communication error */ int dlm_unlock(dlm_lockspace_t *lockspace, uint32_t lkid, uint32_t flags, struct dlm_lksb *lksb, void *astarg); #endif /* __KERNEL__ */ #endif /* __DLM_DOT_H__ */