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Diffstat (limited to 'include/linux/dlm.h')
| -rw-r--r-- | include/linux/dlm.h | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/include/linux/dlm.h b/include/linux/dlm.h new file mode 100644 index 00000000..d4e02f53 --- /dev/null +++ b/include/linux/dlm.h @@ -0,0 +1,172 @@ +/****************************************************************************** +******************************************************************************* +** +** 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 + * -DLM_EUNLOCK if unlock request was successful + * -DLM_ECANCEL if a cancel completed successfully + * -EDEADLK if a deadlock was detected + * -ETIMEDOUT if the lock request was canceled due to a timeout + */ + +#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__ */ + |