From 82397d791966b09d344251bc709cd9db2b3a1902 Mon Sep 17 00:00:00 2001 From: Mateusz Guzik Date: Fri, 1 Jan 2021 04:10:12 +0100 Subject: [PATCH] vfs: denote vnode being a mount point with VIRF_MOUNTPOINT Reviewed by: kib (previous version) Differential Revision: https://reviews.freebsd.org/D27794 --- sys/contrib/openzfs/module/os/freebsd/spl/spl_vfs.c | 4 ++-- sys/kern/vfs_cache.c | 13 +------------ sys/kern/vfs_mount.c | 8 ++++++-- sys/kern/vfs_mountroot.c | 9 ++++++++- sys/kern/vfs_subr.c | 4 +++- sys/sys/vnode.h | 1 + 6 files changed, 21 insertions(+), 18 deletions(-) diff --git a/sys/contrib/openzfs/module/os/freebsd/spl/spl_vfs.c b/sys/contrib/openzfs/module/os/freebsd/spl/spl_vfs.c index 991a11fe2baf..9e16c0029087 100644 --- a/sys/contrib/openzfs/module/os/freebsd/spl/spl_vfs.c +++ b/sys/contrib/openzfs/module/os/freebsd/spl/spl_vfs.c @@ -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); diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c index 2773ed76036c..767b7136c580 100644 --- a/sys/kern/vfs_cache.c +++ b/sys/kern/vfs_cache.c @@ -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); } /* diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c index b3555f0a43e5..b3870e46c5e9 100644 --- a/sys/kern/vfs_mount.c +++ b/sys/kern/vfs_mount.c @@ -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); } diff --git a/sys/kern/vfs_mountroot.c b/sys/kern/vfs_mountroot.c index b07457693968..3b968fd19bbd 100644 --- a/sys/kern/vfs_mountroot.c +++ b/sys/kern/vfs_mountroot.c @@ -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); diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c index 8896b542a499..680475c00d52 100644 --- a/sys/kern/vfs_subr.c +++ b/sys/kern/vfs_subr.c @@ -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)); diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h index 107cf45f9602..9be22f02e8d4 100644 --- a/sys/sys/vnode.h +++ b/sys/sys/vnode.h @@ -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 */