/* SPDX-License-Identifier: GPL-2.0-only */ /****************************************************************************** ******************************************************************************* ** ** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. ** Copyright (C) 2004-2011 Red Hat, Inc. All rights reserved. ** ** ******************************************************************************* ******************************************************************************/ #ifndef __DLM_DOT_H__ #define __DLM_DOT_H__ #include <uapi/linux/dlm.h> struct dlm_slot { … }; /* * recover_prep: called before the dlm begins lock recovery. * Notfies lockspace user that locks from failed members will be granted. * recover_slot: called after recover_prep and before recover_done. * Identifies a failed lockspace member. * recover_done: called after the dlm completes lock recovery. * Identifies lockspace members and lockspace generation number. */ struct dlm_lockspace_ops { … }; /* only relevant for kernel lockspaces, will be removed in future */ #define DLM_LSFL_SOFTIRQ … /* * dlm_new_lockspace * * Create/join a lockspace. * * name: lockspace name, null terminated, up to DLM_LOCKSPACE_LEN (not * including terminating null). * * cluster: cluster name, null terminated, up to DLM_LOCKSPACE_LEN (not * including terminating null). Optional. When cluster is null, it * is not used. When set, dlm_new_lockspace() returns -EBADR if cluster * is not equal to the dlm cluster name. * * flags: * DLM_LSFL_NODIR * The dlm should not use a resource directory, but statically assign * resource mastery to nodes based on the name hash that is otherwise * used to select the directory node. Must be the same on all nodes. * DLM_LSFL_NEWEXCL * dlm_new_lockspace() should return -EEXIST if the lockspace exists. * DLM_LSFL_SOFTIRQ * dlm request callbacks (ast, bast) are softirq safe. Flag should be * preferred by users. Will be default in some future. If set the * strongest context for ast, bast callback is softirq as it avoids * an additional context switch. * * lvblen: length of lvb in bytes. Must be multiple of 8. * dlm_new_lockspace() returns an error if this does not match * what other nodes are using. * * ops: callbacks that indicate lockspace recovery points so the * caller can coordinate its recovery and know lockspace members. * This is only used by the initial dlm_new_lockspace() call. * Optional. * * ops_arg: arg for ops callbacks. * * ops_result: tells caller if the ops callbacks (if provided) will * be used or not. 0: will be used, -EXXX will not be used. * -EOPNOTSUPP: the dlm does not have recovery_callbacks enabled. * * lockspace: handle for dlm functions */ int dlm_new_lockspace(const char *name, const char *cluster, uint32_t flags, int lvblen, const struct dlm_lockspace_ops *ops, void *ops_arg, int *ops_result, dlm_lockspace_t **lockspace); /* * dlm_release_lockspace * * Stop a lockspace. */ int dlm_release_lockspace(dlm_lockspace_t *lockspace, int force); /* * dlm_lock * * Make an asynchronous 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. If DLM_LSFL_SOFTIRQ for kernel * users of dlm_new_lockspace() is passed the ast and bast callbacks * can be processed in softirq context. Also some of the callback * contexts are in the same context as the DLM lock request API, users * must not hold locks while calling dlm lock request API and trying * to acquire this lock in the callback again, this will end in a * lock recursion. For newer implementation the DLM_LSFL_SOFTIRQ * should be used. */ int dlm_lock(dlm_lockspace_t *lockspace, int mode, struct dlm_lksb *lksb, uint32_t flags, const 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 /* __DLM_DOT_H__ */
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