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| author | kib <kib@FreeBSD.org> | 2016-11-27 09:10:33 +0000 |
|---|---|---|
| committer | kib <kib@FreeBSD.org> | 2016-11-27 09:10:33 +0000 |
| commit | d6471013890dc459dd941fa7871c1c0893df21e9 (patch) | |
| tree | 984af61cd17ae369bf7736ecb5c60112edb90148 /sys/kern | |
| parent | 593ac3706b39851cbc3bd96af1f392264c03be3c (diff) | |
| download | FreeBSD-src-d6471013890dc459dd941fa7871c1c0893df21e9.zip FreeBSD-src-d6471013890dc459dd941fa7871c1c0893df21e9.tar.gz | |
MFC r308618:
Provide simple mutual exclusion between mount point update and unmount.
In the update path in ffs_mount(), drop vfs_busy() reference around namei().
Diffstat (limited to 'sys/kern')
| -rw-r--r-- | sys/kern/vfs_mount.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c index 7e7bf4c..945fe21 100644 --- a/sys/kern/vfs_mount.c +++ b/sys/kern/vfs_mount.c @@ -934,6 +934,11 @@ vfs_domount_update( VOP_UNLOCK(vp, 0); MNT_ILOCK(mp); + if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { + MNT_IUNLOCK(mp); + error = EBUSY; + goto end; + } mp->mnt_flag &= ~MNT_UPDATEMASK; mp->mnt_flag |= fsflags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT | MNT_ROOTFS | MNT_UPDATEMASK | MNT_RDONLY); @@ -1293,6 +1298,7 @@ dounmount(struct mount *mp, int flags, struct thread *td) vn_start_write(NULL, &mp, V_WAIT | V_MNTREF); MNT_ILOCK(mp); if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 || + (mp->mnt_flag & MNT_UPDATE) != 0 || !TAILQ_EMPTY(&mp->mnt_uppers)) { dounmount_cleanup(mp, coveredvp, 0); return (EBUSY); |
