Expand locking around identification of filesystem mount point when

accounting for I/O counts at completion of I/O operation. Also switch
from using global devmtx to vnode mutex to reduce contention.

Suggested and reviewed by: kib
This commit is contained in:
Kirk McKusick 2012-04-08 06:20:21 +00:00
parent 827e334c01
commit 85121b0979

View File

@ -97,6 +97,7 @@ g_vfs_done(struct bio *bip)
int vfslocked, destroy;
struct mount *mp;
struct vnode *vp;
struct cdev *cdevp;
/*
* Collect statistics on synchronous and asynchronous read
@ -106,12 +107,23 @@ g_vfs_done(struct bio *bip)
*/
bp = bip->bio_caller2;
vp = bp->b_vp;
if (vp == NULL)
if (vp == NULL) {
mp = NULL;
else if (vn_isdisk(vp, NULL))
mp = vp->v_rdev->si_mountpt;
else
} else {
/*
* If not a disk vnode, use its associated mount point
* otherwise use the mountpoint associated with the disk.
*/
VI_LOCK(vp);
if (vp->v_type != VCHR ||
(cdevp = vp->v_rdev) == NULL ||
cdevp->si_devsw == NULL ||
(cdevp->si_devsw->d_flags & D_DISK) == 0)
mp = vp->v_mount;
else
mp = cdevp->si_mountpt;
VI_UNLOCK(vp);
}
if (mp != NULL) {
if (bp->b_iocmd == BIO_WRITE) {
if (LK_HOLDER(bp->b_lock.lk_lock) == LK_KERNPROC)