6453345 devfs_getattr violates devfs locking rules

6527396 devfsadm -C taking hours after reconfiguration reboot
6661843 i_ddi_di_cache_invalidate() should only use taskq_dispatch on valid->invalid
6662461 reserved_links_exist() should be optimized

6 files changed, 85 insertions, 40 deletions

diff --git a/usr/src/uts/common/fs/dev/sdev_subr.c b/usr/src/uts/common/fs/dev/sdev_subr.c
index 0159fc568e..77f47f4535 100644
--- a/usr/src/uts/common/fs/dev/sdev_subr.c
+++ b/usr/src/uts/common/fs/dev/sdev_subr.c
@@ -521,7 +521,7 @@ sdev_get_moduleops(struct sdev_node *dv)
 		if (map->dir_invalid) {
 			if (map->dir_module && map->dir_newmodule &&
 			    (strcmp(map->dir_module,
-					map->dir_newmodule) == 0)) {
+			    map->dir_newmodule) == 0)) {
 				load = 0;
 			}
 			sdev_replace_nsmap(map, map->dir_newmodule,
@@ -1230,7 +1230,7 @@ sdev_rnmnode(struct sdev_node *oddv, struct sdev_node *odv,
 			(void) sdev_dirdelete(nddv, *ndvp);
 			*ndvp = NULL;
 			error = VOP_RMDIR(nddv->sdev_attrvp, nnm,
-				    nddv->sdev_attrvp, cred, NULL, 0);
+			    nddv->sdev_attrvp, cred, NULL, 0);
 			if (error)
 				goto err_out;
 		} else {
@@ -1254,7 +1254,7 @@ sdev_rnmnode(struct sdev_node *oddv, struct sdev_node *odv,
 				error = VOP_REMOVE(nddv->sdev_attrvp,
 				    nnm, cred, NULL, 0);
 				if (error)
-				    goto err_out;
+					goto err_out;
 			}
 		}
 	}
@@ -1811,7 +1811,7 @@ sdev_call_devfsadmd(struct sdev_node *ddv, struct sdev_node *dv, char *nm)
 		error = 0;
 	} else if (!DEVNAME_DEVFSADM_HAS_RUN(devfsadm_state)) {
 		sdcmn_err6(("lookup %s/%s starting devfsadm, 0x%x\n",
-			ddv->sdev_name, nm, devfsadm_state));
+		    ddv->sdev_name, nm, devfsadm_state));
 
 		sdev_devfsadmd_thread(ddv, dv, kcred);
 		mutex_enter(&dv->sdev_lookup_lock);
@@ -3026,7 +3026,7 @@ sdev_modctl_lookup(const char *path, vnode_t **r_vp)
 
 int
 sdev_modctl_readdir(const char *dir, char ***dirlistp,
-	int *npathsp, int *npathsp_alloc)
+	int *npathsp, int *npathsp_alloc, int checking_empty)
 {
 	char	**pathlist = NULL;
 	char	**newlist = NULL;
@@ -3081,18 +3081,17 @@ sdev_modctl_readdir(const char *dir, char ***dirlistp,
 			break;
 
 		for (dp = dbuf; ((intptr_t)dp < (intptr_t)dbuf + dbuflen);
-			dp = (dirent64_t *)((intptr_t)dp + dp->d_reclen)) {
+		    dp = (dirent64_t *)((intptr_t)dp + dp->d_reclen)) {
 
 			nm = dp->d_name;
 
 			if (strcmp(nm, ".") == 0 || strcmp(nm, "..") == 0)
 				continue;
-
 			if (npaths == npaths_alloc) {
 				npaths_alloc += 64;
 				newlist = (char **)
 				    kmem_zalloc((npaths_alloc + 1) *
-					sizeof (char *), KM_SLEEP);
+				    sizeof (char *), KM_SLEEP);
 				if (pathlist) {
 					bcopy(pathlist, newlist,
 					    npaths * sizeof (char *));
@@ -3106,6 +3105,12 @@ sdev_modctl_readdir(const char *dir, char ***dirlistp,
 			bcopy(nm, s, n);
 			pathlist[npaths++] = s;
 			sdcmn_err11(("  %s/%s\n", dir, s));
+
+			/* if checking empty, one entry is as good as many */
+			if (checking_empty) {
+				eof = 1;
+				break;
+			}
 		}
 	}
 
diff --git a/usr/src/uts/common/fs/devfs/devfs_vnops.c b/usr/src/uts/common/fs/devfs/devfs_vnops.c
index d459929000..5361b7e00d 100644
--- a/usr/src/uts/common/fs/devfs/devfs_vnops.c
+++ b/usr/src/uts/common/fs/devfs/devfs_vnops.c
@@ -19,7 +19,7 @@
  * CDDL HEADER END
  */
 /*
- * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
@@ -180,6 +180,7 @@ devfs_getattr(struct vnode *vp, struct vattr *vap, int flags, struct cred *cr,
 		return (ENOENT);
 	}
 
+	rw_enter(&dv->dv_contents, RW_READER);
 	if (dv->dv_attr) {
 		/*
 		 * obtain from the memory version of attribute.
@@ -195,6 +196,7 @@ devfs_getattr(struct vnode *vp, struct vattr *vap, int flags, struct cred *cr,
 		dsysdebug(error, ("vop_getattr %s %d\n", dv->dv_name, error));
 		dv_vattr_merge(dv, vap);
 	}
+	rw_exit(&dv->dv_contents);
 
 	/*
 	 * Restrict the permissions of the node fronting the console
@@ -241,7 +243,7 @@ devfs_setattr_dir(
 again:	if (dv->dv_attr) {
 
 		error = secpolicy_vnode_setattr(cr, vp, vap,
-				dv->dv_attr, flags, devfs_unlocked_access, dv);
+		    dv->dv_attr, flags, devfs_unlocked_access, dv);
 
 		if (error)
 			goto out;
@@ -281,9 +283,9 @@ again:	if (dv->dv_attr) {
 		if (vap->va_mask & (AT_MODE|AT_UID|AT_GID|AT_ATIME|AT_MTIME)) {
 			/* Set the attributes */
 			error = VOP_SETATTR(dv->dv_attrvp,
-				vap, flags, cr, NULL);
+			    vap, flags, cr, NULL);
 			dsysdebug(error,
-				("vop_setattr %s %d\n", dv->dv_name, error));
+			    ("vop_setattr %s %d\n", dv->dv_name, error));
 
 			/*
 			 * Some file systems may return EROFS for a setattr
@@ -459,8 +461,7 @@ devfs_setattr(
 		ASSERT(vp->v_type != VDIR);
 		*vattrp = dv_vattr_file;
 		error = VOP_GETATTR(dv->dv_attrvp, vattrp, 0, cr, ct);
-		dsysdebug(error, ("vop_getattr %s %d\n",
-			dv->dv_name, error));
+		dsysdebug(error, ("vop_getattr %s %d\n", dv->dv_name, error));
 		if (error)
 			goto out;
 		dv->dv_attr = vattrp;
@@ -469,10 +470,10 @@ devfs_setattr(
 	}
 
 	error = secpolicy_vnode_setattr(cr, vp, vap, dv->dv_attr,
-					flags, devfs_unlocked_access, dv);
+	    flags, devfs_unlocked_access, dv);
 	if (error) {
 		dsysdebug(error, ("devfs_setattr %s secpolicy error %d\n",
-			dv->dv_name, error));
+		    dv->dv_name, error));
 		goto out;
 	}
 
@@ -530,13 +531,13 @@ devfs_setattr(
 		} else {
 			if (mask & AT_MODE)
 				dcmn_err5(("%s persisting mode 0%o\n",
-					dv->dv_name, vap->va_mode));
+				    dv->dv_name, vap->va_mode));
 			if (mask & AT_UID)
 				dcmn_err5(("%s persisting uid %d\n",
-					dv->dv_name, vap->va_uid));
+				    dv->dv_name, vap->va_uid));
 			if (mask & AT_GID)
 				dcmn_err5(("%s persisting gid %d\n",
-					dv->dv_name, vap->va_gid));
+				    dv->dv_name, vap->va_gid));
 
 			if (dv->dv_attrvp == NULL) {
 				dvp = DVTOV(dv->dv_dotdot);
@@ -734,16 +735,14 @@ devfs_access(struct vnode *vp, int mode, int flags, struct cred *cr,
 		return (EACCES);
 	}
 
+	rw_enter(&dv->dv_contents, RW_READER);
 	if (dv->dv_attr && ((dv->dv_flags & DV_ACL) == 0)) {
-		rw_enter(&dv->dv_contents, RW_READER);
-		if (dv->dv_attr) {
-			res = devfs_unlocked_access(dv, mode, cr);
-			rw_exit(&dv->dv_contents);
-			return (res);
-		}
-		rw_exit(&dv->dv_contents);
+		res = devfs_unlocked_access(dv, mode, cr);
+	} else {
+		res = VOP_ACCESS(dv->dv_attrvp, mode, flags, cr, ct);
 	}
-	return (VOP_ACCESS(dv->dv_attrvp, mode, flags, cr, ct));
+	rw_exit(&dv->dv_contents);
+	return (res);
 }
 
 /*
diff --git a/usr/src/uts/common/os/devcfg.c b/usr/src/uts/common/os/devcfg.c
index bfc829934f..ff837895fb 100644
--- a/usr/src/uts/common/os/devcfg.c
+++ b/usr/src/uts/common/os/devcfg.c
@@ -7314,7 +7314,7 @@ i_ddi_di_cache_free(struct di_cache *cache)
 void
 i_ddi_di_cache_invalidate(int kmflag)
 {
-	uint_t	flag;
+	int	cache_valid;
 
 	if (!modrootloaded || !i_ddi_io_initialized()) {
 		if (di_cache_debug)
@@ -7322,16 +7322,15 @@ i_ddi_di_cache_invalidate(int kmflag)
 		return;
 	}
 
-	/*
-	 * Invalidate the in-core cache and
-	 * increment devtree generation number
-	 */
-	atomic_and_32(&di_cache.cache_valid, 0);
+	/* Increment devtree generation number. */
 	atomic_inc_ulong(&devtree_gen);
 
-	flag = (kmflag == KM_SLEEP) ? TQ_SLEEP : TQ_NOSLEEP;
-
-	(void) taskq_dispatch(system_taskq, free_cache_task, NULL, flag);
+	/* Invalidate the in-core cache and dispatch free on valid->invalid */
+	cache_valid = atomic_swap_uint(&di_cache.cache_valid, 0);
+	if (cache_valid) {
+		(void) taskq_dispatch(system_taskq, free_cache_task, NULL,
+		    (kmflag == KM_SLEEP) ? TQ_SLEEP : TQ_NOSLEEP);
+	}
 
 	if (di_cache_debug) {
 		cmn_err(CE_NOTE, "invalidation with km_flag: %s",
diff --git a/usr/src/uts/common/os/modctl.c b/usr/src/uts/common/os/modctl.c
index b4b0751d23..501cb7ba09 100644
--- a/usr/src/uts/common/os/modctl.c
+++ b/usr/src/uts/common/os/modctl.c
@@ -20,7 +20,7 @@
  */
 
 /*
- * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
@@ -2046,7 +2046,7 @@ modctl_devreaddir(const char *udir, int udirlen,
 		goto err;
 
 	if ((ret = sdev_modctl_readdir(dir, &dirlist,
-	    &npaths, &npaths_alloc)) != 0) {
+	    &npaths, &npaths_alloc, 0)) != 0) {
 		ASSERT(dirlist == NULL);
 		goto err;
 	}
@@ -2093,6 +2093,42 @@ err:
 	return (ret);
 }
 
+static int
+modctl_devemptydir(const char *udir, int udirlen, int *uempty)
+{
+	char	*dir;
+	int	ret;
+	char	**dirlist = NULL;
+	int	npaths;
+	int	npaths_alloc;
+	int	empty;
+
+	/*
+	 * copyin the /dev path including terminating null
+	 */
+	udirlen++;
+	if (udirlen <= 1 || udirlen > MAXPATHLEN)
+		return (EINVAL);
+	dir = kmem_zalloc(udirlen + 1, KM_SLEEP);
+	if ((ret = copyinstr(udir, dir, udirlen, NULL)) != 0)
+		goto err;
+
+	if ((ret = sdev_modctl_readdir(dir, &dirlist,
+	    &npaths, &npaths_alloc, 1)) != 0) {
+		goto err;
+	}
+
+	empty = npaths ? 0 : 1;
+	if (copyout(&empty, uempty, sizeof (empty)))
+		ret = EFAULT;
+
+err:
+	if (dirlist)
+		sdev_modctl_readdir_free(dirlist, npaths, npaths_alloc);
+	kmem_free(dir, udirlen + 1);
+	return (ret);
+}
+
 int
 modctl_moddevname(int subcmd, uintptr_t a1, uintptr_t a2)
 {
@@ -2347,6 +2383,11 @@ modctl(int cmd, uintptr_t a1, uintptr_t a2, uintptr_t a3, uintptr_t a4,
 		    (char *)a3, (int64_t *)a4);
 		break;
 
+	case MODDEVEMPTYDIR:	/* non-reconfiguring /dev emptydir */
+		error = modctl_devemptydir((const char *)a1, (size_t)a2,
+		    (int *)a3);
+		break;
+
 	case MODDEVNAME:
 		error = modctl_moddevname((int)a1, a2, a3);
 		break;
diff --git a/usr/src/uts/common/sys/fs/sdev_impl.h b/usr/src/uts/common/sys/fs/sdev_impl.h
index 7e5f75d7f7..33142fe703 100644
--- a/usr/src/uts/common/sys/fs/sdev_impl.h
+++ b/usr/src/uts/common/sys/fs/sdev_impl.h
@@ -624,7 +624,7 @@ extern void *sdev_get_vtor(struct sdev_node *dv);
 /*
  * devinfo helpers
  */
-extern int sdev_modctl_readdir(const char *, char ***, int *, int *);
+extern int sdev_modctl_readdir(const char *, char ***, int *, int *, int);
 extern void sdev_modctl_readdir_free(char **, int, int);
 extern int sdev_modctl_devexists(const char *);
 
diff --git a/usr/src/uts/common/sys/modctl.h b/usr/src/uts/common/sys/modctl.h
index 818572a94d..0ff7ddc42c 100644
--- a/usr/src/uts/common/sys/modctl.h
+++ b/usr/src/uts/common/sys/modctl.h
@@ -19,7 +19,7 @@
  * CDDL HEADER END
  */
 /*
- * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
@@ -269,6 +269,7 @@ struct modlinkage {
 #define	MODRETIRE		40
 #define	MODUNRETIRE		41
 #define	MODISRETIRED		42
+#define	MODDEVEMPTYDIR		43
 
 /*
  * sub cmds for MODEVENTS