vfs: denote vnode being a mount point with VIRF_MOUNTPOINT

Reviewed by:	kib (previous version)
Differential Revision:	https://reviews.freebsd.org/D27794
This commit is contained in:
Mateusz Guzik 2021-01-01 04:10:12 +01:00
parent 3e506a67bb
commit 82397d7919
6 changed files with 21 additions and 18 deletions
sys
contrib/openzfs/module/os/freebsd/spl
kern
sys

@ -240,9 +240,9 @@ mount_snapshot(kthread_t *td, vnode_t **vpp, const char *fstype, char *fspath,
#endif
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
vn_irflag_set_locked(vp, VIRF_MOUNTPOINT);
vp->v_mountedhere = mp;
VI_UNLOCK(vp);
/* Put the new filesystem on the mount list. */
mtx_lock(&mountlist_mtx);
TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);

@ -4755,21 +4755,10 @@ cache_fplookup_cross_mount(struct cache_fpl *fpl)
static bool
cache_fplookup_is_mp(struct cache_fpl *fpl)
{
struct mount *mp;
struct vnode *vp;
vp = fpl->tvp;
/*
* Hack: while this is a union, the pointer tends to be NULL so save on
* a branch.
*/
mp = atomic_load_ptr(&vp->v_mountedhere);
if (mp == NULL)
return (false);
if (vp->v_type == VDIR)
return (true);
return (false);
return ((vn_irflag_read(vp) & VIRF_MOUNTPOINT) != 0);
}
/*

@ -1034,8 +1034,9 @@ vfs_domount_first(
cache_purge(vp);
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
vn_irflag_set_locked(vp, VIRF_MOUNTPOINT);
vp->v_mountedhere = mp;
VI_UNLOCK(vp);
/* Place the new filesystem at the end of the mount list. */
mtx_lock(&mountlist_mtx);
TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
@ -1881,8 +1882,11 @@ dounmount(struct mount *mp, int flags, struct thread *td)
mtx_unlock(&mountlist_mtx);
EVENTHANDLER_DIRECT_INVOKE(vfs_unmounted, mp, td);
if (coveredvp != NULL) {
VI_LOCK(coveredvp);
vn_irflag_unset_locked(coveredvp, VIRF_MOUNTPOINT);
coveredvp->v_mountedhere = NULL;
vn_seqc_write_end(coveredvp);
vn_seqc_write_end_locked(coveredvp);
VI_UNLOCK(coveredvp);
VOP_UNLOCK(coveredvp);
vdrop(coveredvp);
}

@ -335,8 +335,9 @@ vfs_mountroot_shuffle(struct thread *td, struct mount *mpdevfs)
VI_LOCK(vporoot);
vporoot->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vporoot);
vn_irflag_unset_locked(vporoot, VIRF_MOUNTPOINT);
vporoot->v_mountedhere = NULL;
VI_UNLOCK(vporoot);
mporoot->mnt_flag &= ~MNT_ROOTFS;
mporoot->mnt_vnodecovered = NULL;
vput(vporoot);
@ -393,11 +394,17 @@ vfs_mountroot_shuffle(struct thread *td, struct mount *mpdevfs)
vpdevfs = mpdevfs->mnt_vnodecovered;
if (vpdevfs != NULL) {
cache_purge(vpdevfs);
VI_LOCK(vpdevfs);
vn_irflag_unset_locked(vpdevfs, VIRF_MOUNTPOINT);
vpdevfs->v_mountedhere = NULL;
VI_UNLOCK(vpdevfs);
vrele(vpdevfs);
}
VI_LOCK(vp);
mpdevfs->mnt_vnodecovered = vp;
vn_irflag_set_locked(vp, VIRF_MOUNTPOINT);
vp->v_mountedhere = mpdevfs;
VI_UNLOCK(vp);
VOP_UNLOCK(vp);
} else
vput(vp);

@ -4042,7 +4042,9 @@ vn_printf(struct vnode *vp, const char *fmt, ...)
strlcat(buf, "|VIRF_DOOMED", sizeof(buf));
if (irflag & VIRF_PGREAD)
strlcat(buf, "|VIRF_PGREAD", sizeof(buf));
flags = irflag & ~(VIRF_DOOMED | VIRF_PGREAD);
if (irflag & VIRF_MOUNTPOINT)
strlcat(buf, "|VIRF_MOUNTPOINT", sizeof(buf));
flags = irflag & ~(VIRF_DOOMED | VIRF_PGREAD | VIRF_MOUNTPOINT);
if (flags != 0) {
snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags);
strlcat(buf, buf2, sizeof(buf));

@ -246,6 +246,7 @@ struct xvnode {
#define VIRF_DOOMED 0x0001 /* This vnode is being recycled */
#define VIRF_PGREAD 0x0002 /* Direct reads from the page cache are permitted,
never cleared once set */
#define VIRF_MOUNTPOINT 0x0004 /* This vnode is mounted on */
#define VI_TEXT_REF 0x0001 /* Text ref grabbed use ref */
#define VI_MOUNT 0x0002 /* Mount in progress */