diff options
author | kib <kib@FreeBSD.org> | 2013-05-11 11:17:44 +0000 |
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committer | kib <kib@FreeBSD.org> | 2013-05-11 11:17:44 +0000 |
commit | dfd7a7f46d4cb6fa7e3cfa78fcff22319891d343 (patch) | |
tree | eec4ec06bf51508293c37264e9b64bf402c90040 /sys/kern/vfs_subr.c | |
parent | f43ee707dde8c47ed5b7e330f329246e0c77e9fe (diff) | |
download | FreeBSD-src-dfd7a7f46d4cb6fa7e3cfa78fcff22319891d343.zip FreeBSD-src-dfd7a7f46d4cb6fa7e3cfa78fcff22319891d343.tar.gz |
- Fix nullfs vnode reference leak in nullfs_reclaim_lowervp(). The
null_hashget() obtains the reference on the nullfs vnode, which must
be dropped.
- Fix a wart which existed from the introduction of the nullfs
caching, do not unlock lower vnode in the nullfs_reclaim_lowervp().
It should be innocent, but now it is also formally safe. Inform the
nullfs_reclaim() about this using the NULLV_NOUNLOCK flag set on
nullfs inode.
- Add a callback to the upper filesystems for the lower vnode
unlinking. When inactivating a nullfs vnode, check if the lower
vnode was unlinked, indicated by nullfs flag NULLV_DROP or VV_NOSYNC
on the lower vnode, and reclaim upper vnode if so. This allows
nullfs to purge cached vnodes for the unlinked lower vnode, avoiding
excessive caching.
Reported by: G??ran L??wkrantz <goran.lowkrantz@ismobile.com>
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Diffstat (limited to 'sys/kern/vfs_subr.c')
-rw-r--r-- | sys/kern/vfs_subr.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c index d9cbde2..7f72ed1 100644 --- a/sys/kern/vfs_subr.c +++ b/sys/kern/vfs_subr.c @@ -2700,19 +2700,20 @@ vgone(struct vnode *vp) } static void -vgonel_reclaim_lowervp_vfs(struct mount *mp __unused, +notify_lowervp_vfs_dummy(struct mount *mp __unused, struct vnode *lowervp __unused) { } /* - * Notify upper mounts about reclaimed vnode. + * Notify upper mounts about reclaimed or unlinked vnode. */ -static void -vgonel_reclaim_lowervp(struct vnode *vp) +void +vfs_notify_upper(struct vnode *vp, int event) { static struct vfsops vgonel_vfsops = { - .vfs_reclaim_lowervp = vgonel_reclaim_lowervp_vfs + .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, + .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, }; struct mount *mp, *ump, *mmp; @@ -2736,7 +2737,17 @@ vgonel_reclaim_lowervp(struct vnode *vp) } TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); MNT_IUNLOCK(mp); - VFS_RECLAIM_LOWERVP(ump, vp); + switch (event) { + case VFS_NOTIFY_UPPER_RECLAIM: + VFS_RECLAIM_LOWERVP(ump, vp); + break; + case VFS_NOTIFY_UPPER_UNLINK: + VFS_UNLINK_LOWERVP(ump, vp); + break; + default: + KASSERT(0, ("invalid event %d", event)); + break; + } MNT_ILOCK(mp); ump = TAILQ_NEXT(mmp, mnt_upper_link); TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); @@ -2783,7 +2794,7 @@ vgonel(struct vnode *vp) active = vp->v_usecount; oweinact = (vp->v_iflag & VI_OWEINACT); VI_UNLOCK(vp); - vgonel_reclaim_lowervp(vp); + vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); /* * Clean out any buffers associated with the vnode. |