freebsd-skq/sys/sys/alq.h
rwatson 04a7b2d379 Modify the alq(9) alq_open() API to accept a file creation mode, rather
than defaulting the cmode argument to vn_open() to 0.  Supply a default
argument of ALQ_DEFAULT_CMODE (0600) in current callers.

Discussed with/pointed out by:	hmp
Reveiwed by:	jeff, hmp
MFC after:	3 days
2005-04-16 12:12:27 +00:00

128 lines
3.6 KiB
C

/*-
* Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*
*/
#ifndef _SYS_ALQ_H_
#define _SYS_ALQ_H_
/*
* Opaque type for the Async. Logging Queue
*/
struct alq;
/* The thread for the logging daemon */
extern struct thread *ald_thread;
/*
* Async. Logging Entry
*/
struct ale {
struct ale *ae_next; /* Next Entry */
char *ae_data; /* Entry buffer */
int ae_flags; /* Entry flags */
};
#define AE_VALID 0x0001 /* Entry has valid data */
/* waitok options */
#define ALQ_NOWAIT 0x0001
#define ALQ_WAITOK 0x0002
/* Suggested mode for file creation. */
#define ALQ_DEFAULT_CMODE 0600
/*
* alq_open: Creates a new queue
*
* Arguments:
* alq Storage for a pointer to the newly created queue.
* file The filename to open for logging.
* cred Credential to authorize open and I/O with.
* cmode Creation mode for file, if new.
* size The size of each entry in the queue.
* count The number of items in the buffer, this should be large enough
* to store items over the period of a disk write.
* Returns:
* error from open or 0 on success
*/
struct ucred;
int alq_open(struct alq **, const char *file, struct ucred *cred, int cmode,
int size, int count);
/*
* alq_write: Write data into the queue
*
* Arguments:
* alq The queue we're writing to
* data The entry to be recorded
* waitok Are we permitted to wait?
*
* Returns:
* EWOULDBLOCK if:
* Waitok is ALQ_NOWAIT and the queue is full.
* The system is shutting down.
* 0 on success.
*/
int alq_write(struct alq *alq, void *data, int waitok);
/*
* alq_flush: Flush the queue out to disk
*/
void alq_flush(struct alq *alq);
/*
* alq_close: Flush the queue and free all resources.
*/
void alq_close(struct alq *alq);
/*
* alq_get: Return an entry for direct access
*
* Arguments:
* alq The queue to retrieve an entry from
* waitok Are we permitted to wait?
*
* Returns:
* The next available ale on success.
* NULL if:
* Waitok is ALQ_NOWAIT and the queue is full.
* The system is shutting down.
*
* This leaves the queue locked until a subsequent alq_post.
*/
struct ale *alq_get(struct alq *alq, int waitok);
/*
* alq_post: Schedule the ale retrieved by alq_get for writing.
* alq The queue to post the entry to.
* ale An asynch logging entry returned by alq_get.
*/
void alq_post(struct alq *, struct ale *);
#endif /* _SYS_ALQ_H_ */