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 filesystem buffers for a file 37.Sh SYNOPSIS 38.Fd #include <sys/param.h> 39.Fd #include <sys/vnode.h> 40.Ft int 41.Fn VOP_FSYNC "struct vnode *vp" "struct ucred *cred" "int waitfor" "struct proc *p" 42.Sh DESCRIPTION 43This call flushes any dirty filesystem 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 Ar vp 53the vnode of the file 54.It Ar cred 55the caller's credentials 56.It Ar waitfor 57whether the function should wait for I/O to complete 58.It Ar p 59the calling process 60.El 61.Pp 62The argument 63.Fa waitfor 64is either 65.Dv MNT_WAIT 66or 67.Dv MNT_NOWAIT 68and specifies whether or not the function should wait for the writes 69to finish before returning. 70.Sh LOCKS 71The file should be locked on entry. 72.Sh RETURN VALUES 73Zero is returned if the call is successful, otherwise an appropriate 74error code is returned. 75.Sh PSEUDOCODE 76.Bd -literal 77int 78vop_fsync(struct vnode *vp, struct ucred *cred, int waitfor, struct proc *p) 79{ 80 struct buf *bp; 81 struct buf *nbp; 82 struct timeval tv; 83 int s; 84 85loop: 86 s = splbio(); 87 for (bp = vp->v_dirtyblkhd.lh_first; bp; bp = nbp) { 88 nbp = bp->b_vnbufs.le_next; 89 90 /* 91 * Ignore buffers which are already being written. 92 */ 93 if (bp->b_flags & B_BUSY) 94 continue; 95 96 /* 97 * Make sure the buffer is dirty. 98 */ 99 if ((bp->b_flags & B_DELWRI) == 0) 100 panic("vop_fsync: not dirty"); 101 102 vfs_bio_awrite(bp); 103 splx(s); 104 goto loop; 105 } 106 splx(s); 107 108 if (waitfor == MNT_WAIT) { 109 s = splbio(); 110 while (vp->v_numoutput) { 111 vp->v_flag |= VBWAIT; 112 tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1, "vopfsn"); 113 } 114 splx(s); 115#ifdef DIAGNOSTIC 116 if (vp->v_dirtyblkhd.lh_first) { 117 vprint("vop_fsync: dirty", vp); 118 goto loop; 119 } 120#endif 121 } 122 123 /* 124 * Write out the on-disc version of the vnode. 125 */ 126 tv = time; 127 return VOP_UPDATE(vp, &tv, &tv, waitfor == MNT_WAIT); 128} 129.Ed 130.Sh ERRORS 131.Bl -tag -width Er 132.It Bq Er ENOSPC 133The filesystem is full. 134.It Bq Er EDQUOT 135Quota exceeded. 136.El 137.Sh SEE ALSO 138.Xr vnode 9 139.Sh AUTHORS 140This man page was written by 141.An Doug Rabson . 142