Author: kib Date: Thu Nov 26 18:16:32 2020 New Revision: 368077 URL: https://svnweb.freebsd.org/changeset/base/368077
Log: nullfs: provide custom bypass for VOP_READ_PGCACHE(). Normal bypass expects locked vnode, which is not true for VOP_READ_PGCACHE(). Ensure liveness of the lower vnode by taking the upper vnode interlock, which is also taked by null_reclaim() when setting v_data to NULL. Reported and tested by: pho Reviewed by: markj, mjg Sponsored by: The FreeBSD Foundation Differential revision: https://reviews.freebsd.org/D27327 Modified: head/sys/fs/nullfs/null_vnops.c Modified: head/sys/fs/nullfs/null_vnops.c ============================================================================== --- head/sys/fs/nullfs/null_vnops.c Thu Nov 26 18:13:33 2020 (r368076) +++ head/sys/fs/nullfs/null_vnops.c Thu Nov 26 18:16:32 2020 (r368077) @@ -947,6 +947,28 @@ null_vptocnp(struct vop_vptocnp_args *ap) return (error); } +static int +null_read_pgcache(struct vop_read_pgcache_args *ap) +{ + struct vnode *lvp, *vp; + struct null_node *xp; + int error; + + vp = ap->a_vp; + VI_LOCK(vp); + xp = VTONULL(vp); + if (xp == NULL) { + VI_UNLOCK(vp); + return (EJUSTRETURN); + } + lvp = xp->null_lowervp; + vref(lvp); + VI_UNLOCK(vp); + error = VOP_READ_PGCACHE(lvp, ap->a_uio, ap->a_ioflag, ap->a_cred); + vrele(lvp); + return (error); +} + /* * Global vfs data structures */ @@ -966,6 +988,7 @@ struct vop_vector null_vnodeops = { .vop_lookup = null_lookup, .vop_open = null_open, .vop_print = null_print, + .vop_read_pgcache = null_read_pgcache, .vop_reclaim = null_reclaim, .vop_remove = null_remove, .vop_rename = null_rename, _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
