vop_fsync(9)

NAME

VOP_FSYNC - flush file system buffers for a file

#include <sys/param.h>
#include <sys/vnode.h>
int
VOP_FSYNC(struct vnode *vp, struct ucred *cred, int waitfor,
        struct thread *td);

This call flushes any dirty file system buffers for the
file. It is used to implement the sync(2) and fsync(2) system calls.
Its arguments are:
vp The vnode of the file.
cred The caller's credentials.
waitfor Whether the function should wait for I/O to com
plete. Possible: values are:; MNT_WAIT Synchronously wait for I/O to complete.; MNT_NOWAIT Start all I/O, but do not wait for it.; MNT_LAZY Push data not written by file system; syncer.
td The calling thread.
The argument waitfor is either MNT_WAIT or MNT_NOWAIT and
specifies whether or not the function should wait for the writes to
finish before returning.

The file should be locked on entry.

int
vop_fsync(struct vnode *vp, struct ucred *cred, int waitfor,
struct thread *td) {: struct buf *bp;
struct buf *nbp;
struct timeval tv;
int s;
loop:: s = splbio();
for (bp = vp->v_dirtyblkhd.lh_first; bp; bp = nbp) {
nbp = bp->b_vnbufs.le_next;

/*
* Ignore buffers which are already being written.
*/

if (bp->b_flags & B_BUSY)

continue;

/*

* Make sure the buffer is dirty.
*/

if ((bp->b_flags & B_DELWRI) == 0)

panic("vop_fsync: not dirty");

vfs_bio_awrite(bp);
splx(s);
goto loop;; }
splx(s);; if (waitfor == MNT_WAIT) {
s = splbio();
while (vp->v_numoutput) {
vp->v_flag |= VBWAIT;
tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1,

"vopfsn");

}
splx(s);; #ifdef DIAGNOSTIC
if (vp->v_dirtyblkhd.lh_first) {
vprint("vop_fsync: dirty", vp);
goto loop;

}; #endif
}

/*
* Write out the on-disc version of the vnode.
*/

tv = time;
return VOP_UPDATE(vp, &tv, &tv, waitfor == MNT_WAIT);; }

[ENOSPC] The file system is full.

[EDQUOT] Quota exceeded.