1.\" -*- nroff -*- 2.\" 3.\" Copyright (c) 1996 Doug Rabson 4.\" 5.\" All rights reserved. 6.\" 7.\" This program is free software. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 19.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 22.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28.\" 29.\" $FreeBSD$ 30.\" 31.Dd July 24, 1996 32.Os 33.Dt VOP_FSYNC 9 34.Sh NAME 35.Nm VOP_FSYNC 36.Nd flush file system buffers for a file 37.Sh SYNOPSIS 38.In sys/param.h 39.In sys/vnode.h 40.Ft int 41.Fn VOP_FSYNC "struct vnode *vp" "int waitfor" "struct thread *td" 42.Sh DESCRIPTION 43This call flushes any dirty file system buffers for the file. 44It is used to implement the 45.Xr sync 2 46and 47.Xr fsync 2 48system calls. 49.Pp 50Its arguments are: 51.Bl -tag -width waitfor 52.It Fa vp 53The vnode of the file. 54.It Fa waitfor 55Whether the function should wait for I/O to complete. 56Possible values are: 57.Bl -tag -width MNT_NOWAIT 58.It Dv MNT_WAIT 59Synchronously wait for I/O to complete. 60.It Dv MNT_NOWAIT 61Start all I/O, but do not wait for it. 62.It Dv MNT_LAZY 63Push data not written by file system syncer. 64.El 65.It Fa td 66The calling thread. 67.El 68.Pp 69The argument 70.Fa waitfor 71is either 72.Dv MNT_WAIT 73or 74.Dv MNT_NOWAIT 75and specifies whether or not the function should wait for the writes 76to finish before returning. 77.Sh LOCKS 78The file should be locked on entry. 79.Sh RETURN VALUES 80Zero is returned if the call is successful, otherwise an appropriate 81error code is returned. 82.Sh PSEUDOCODE 83.Bd -literal 84int 85vop_fsync(struct vnode *vp, int waitfor, struct thread *td) 86{ 87 struct buf *bp; 88 struct buf *nbp; 89 struct timeval tv; 90 int s; 91 92loop: 93 s = splbio(); 94 for (bp = vp->v_dirtyblkhd.lh_first; bp; bp = nbp) { 95 nbp = bp->b_vnbufs.le_next; 96 97 /* 98 * Ignore buffers which are already being written. 99 */ 100 if (bp->b_flags & B_BUSY) 101 continue; 102 103 /* 104 * Make sure the buffer is dirty. 105 */ 106 if ((bp->b_flags & B_DELWRI) == 0) 107 panic("vop_fsync: not dirty"); 108 109 vfs_bio_awrite(bp); 110 splx(s); 111 goto loop; 112 } 113 splx(s); 114 115 if (waitfor == MNT_WAIT) { 116 s = splbio(); 117 while (vp->v_numoutput) { 118 vp->v_flag |= VBWAIT; 119 tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1, "vopfsn"); 120 } 121 splx(s); 122#ifdef DIAGNOSTIC 123 if (vp->v_dirtyblkhd.lh_first) { 124 vprint("vop_fsync: dirty", vp); 125 goto loop; 126 } 127#endif 128 } 129 130 /* 131 * Write out the on-disc version of the vnode. 132 */ 133 tv = time; 134 return VOP_UPDATE(vp, &tv, &tv, waitfor == MNT_WAIT); 135} 136.Ed 137.Sh ERRORS 138.Bl -tag -width Er 139.It Bq Er ENOSPC 140The file system is full. 141.It Bq Er EDQUOT 142Quota exceeded. 143.El 144.Sh SEE ALSO 145.Xr vnode 9 146.Sh AUTHORS 147This manual page was written by 148.An Doug Rabson . 149