Author: mjg Date: Thu Jan 30 02:16:17 2020 New Revision: 357282 URL: https://svnweb.freebsd.org/changeset/base/357282
Log: zfs: fix spurious lock contention during path lookup ZFS tracks if anything denies VEXEC to allow for a quick check for the common case of path traversal. Use it. Differential Revision: https://reviews.freebsd.org/D22224 Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_acl.h head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_acl.c head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_acl.h ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_acl.h Thu Jan 30 02:14:10 2020 (r357281) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_acl.h Thu Jan 30 02:16:17 2020 (r357282) @@ -214,7 +214,10 @@ void zfs_oldace_byteswap(ace_t *, int); void zfs_ace_byteswap(void *, size_t, boolean_t); extern boolean_t zfs_has_access(struct znode *zp, cred_t *cr); extern int zfs_zaccess(struct znode *, int, int, boolean_t, cred_t *); +#ifdef illumos int zfs_fastaccesschk_execute(struct znode *, cred_t *); +#endif +int zfs_freebsd_fastaccesschk_execute(struct vnode *, cred_t *); extern int zfs_zaccess_rwx(struct znode *, mode_t, int, cred_t *); extern int zfs_zaccess_unix(struct znode *, mode_t, cred_t *); extern int zfs_acl_access(struct znode *, int, cred_t *); Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_acl.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_acl.c Thu Jan 30 02:14:10 2020 (r357281) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_acl.c Thu Jan 30 02:16:17 2020 (r357282) @@ -2299,7 +2299,41 @@ zfs_zaccess_append(znode_t *zp, uint32_t *working_mode check_privs, B_FALSE, cr)); } +/* + * Check if VEXEC is allowed. + * + * This routine is based on zfs_fastaccesschk_execute which has slowpath + * calling zfs_zaccess. This would be incorrect on FreeBSD (see + * zfs_freebsd_access for the difference). Thus this variant let's the + * caller handle the slowpath (if necessary). + * + * We only check for ZFS_NO_EXECS_DENIED and fail early. This routine can + * be extended to cover more cases, but the flag covers the majority. + */ int +zfs_freebsd_fastaccesschk_execute(struct vnode *vp, cred_t *cr) +{ + boolean_t is_attr; + znode_t *zdp = VTOZ(vp); + + ASSERT_VOP_LOCKED(vp, __func__); + + if (zdp->z_pflags & ZFS_AV_QUARANTINED) + return (1); + + is_attr = ((zdp->z_pflags & ZFS_XATTR) && + (ZTOV(zdp)->v_type == VDIR)); + if (is_attr) + return (1); + + if (zdp->z_pflags & ZFS_NO_EXECS_DENIED) + return (0); + + return (1); +} + +#ifdef illumos +int zfs_fastaccesschk_execute(znode_t *zdp, cred_t *cr) { boolean_t owner = B_FALSE; @@ -2365,6 +2399,7 @@ slow: ZFS_EXIT(zdp->z_zfsvfs); return (error); } +#endif /* * Determine whether Access should be granted/denied. Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c Thu Jan 30 02:14:10 2020 (r357281) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c Thu Jan 30 02:16:17 2020 (r357282) @@ -4858,6 +4858,11 @@ zfs_freebsd_access(ap) accmode_t accmode; int error = 0; + if (ap->a_accmode == VEXEC) { + if (zfs_freebsd_fastaccesschk_execute(ap->a_vp, ap->a_cred) == 0) + return (0); + } + /* * ZFS itself only knowns about VREAD, VWRITE, VEXEC and VAPPEND, */ _______________________________________________ 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"
