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Diffstat (limited to 'usr/src/cmd/dlmgmtd/dlmgmt_db.c')
-rw-r--r--usr/src/cmd/dlmgmtd/dlmgmt_db.c122
1 files changed, 106 insertions, 16 deletions
diff --git a/usr/src/cmd/dlmgmtd/dlmgmt_db.c b/usr/src/cmd/dlmgmtd/dlmgmt_db.c
index 99307dbc03..6ccd9d97b8 100644
--- a/usr/src/cmd/dlmgmtd/dlmgmt_db.c
+++ b/usr/src/cmd/dlmgmtd/dlmgmt_db.c
@@ -21,6 +21,7 @@
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2016 Joyent, Inc.
*/
#include <assert.h>
@@ -43,6 +44,7 @@
#include <libcontract.h>
#include <libcontract_priv.h>
#include <sys/contract/process.h>
+#include <zone.h>
#include "dlmgmt_impl.h"
typedef enum dlmgmt_db_op {
@@ -552,6 +554,10 @@ dlmgmt_db_update(dlmgmt_db_op_t op, const char *entryname, dlmgmt_link_t *linkp,
linkp->ll_zoneid, flags, &err)) == NULL)
return (err);
+ /* If transient op and onloan, use the global zone cache file. */
+ if (flags == DLMGMT_ACTIVE && linkp->ll_onloan)
+ req->ls_zoneid = GLOBAL_ZONEID;
+
/*
* If the return error is EINPROGRESS, this request is handled
* asynchronously; return success.
@@ -714,11 +720,13 @@ parse_linkprops(char *buf, dlmgmt_link_t *linkp)
char attr_name[MAXLINKATTRLEN];
size_t attr_buf_len = 0;
void *attr_buf = NULL;
+ boolean_t rename;
curr = buf;
len = strlen(buf);
attr_name[0] = '\0';
for (i = 0; i < len; i++) {
+ rename = B_FALSE;
char c = buf[i];
boolean_t match = (c == '=' ||
(c == ',' && !found_type) || c == ';');
@@ -768,6 +776,21 @@ parse_linkprops(char *buf, dlmgmt_link_t *linkp)
goto parse_fail;
linkp->ll_media =
(uint32_t)*(int64_t *)attr_buf;
+ } else if (strcmp(attr_name, "zone") == 0) {
+ if (read_str(curr, &attr_buf) == 0)
+ goto parse_fail;
+ linkp->ll_zoneid = getzoneidbyname(attr_buf);
+ if (linkp->ll_zoneid == -1) {
+ if (errno == EFAULT)
+ abort();
+ /*
+ * If we can't find the zone, assign the
+ * link to the GZ and mark it for being
+ * renamed.
+ */
+ linkp->ll_zoneid = 0;
+ rename = B_TRUE;
+ }
} else {
attr_buf_len = translators[type].read_func(curr,
&attr_buf);
@@ -811,6 +834,16 @@ parse_linkprops(char *buf, dlmgmt_link_t *linkp)
(void) snprintf(attr_name, MAXLINKATTRLEN, "%s", curr);
}
+
+ /*
+ * The zone that this link belongs to has died, we are
+ * reparenting it to the GZ and renaming it to avoid name
+ * collisions.
+ */
+ if (rename == B_TRUE) {
+ (void) snprintf(linkp->ll_link, MAXLINKNAMELEN,
+ "SUNWorphan%u", (uint16_t)(gethrtime() / 1000));
+ }
curr = buf + i + 1;
}
@@ -1222,12 +1255,19 @@ generate_link_line(dlmgmt_link_t *linkp, boolean_t persist, char *buf)
ptr += snprintf(ptr, BUFLEN(lim, ptr), "%s\t", linkp->ll_link);
if (!persist) {
+ char zname[ZONENAME_MAX];
/*
- * We store the linkid in the active database so that dlmgmtd
- * can recover in the event that it is restarted.
+ * We store the linkid and the zone name in the active database
+ * so that dlmgmtd can recover in the event that it is
+ * restarted.
*/
u64 = linkp->ll_linkid;
ptr += write_uint64(ptr, BUFLEN(lim, ptr), "linkid", &u64);
+
+ if (getzonenamebyid(linkp->ll_zoneid, zname,
+ sizeof (zname)) != -1) {
+ ptr += write_str(ptr, BUFLEN(lim, ptr), "zone", zname);
+ }
}
u64 = linkp->ll_class;
ptr += write_uint64(ptr, BUFLEN(lim, ptr), "class", &u64);
@@ -1382,38 +1422,88 @@ dlmgmt_db_walk(zoneid_t zoneid, datalink_class_t class, db_walk_func_t *func)
}
/*
+ * Attempt to mitigate one of the deadlocks in the dlmgmtd architecture.
+ *
+ * dlmgmt_db_init() calls dlmgmt_process_db_req() which eventually gets to
+ * dlmgmt_zfop() which tries to fork, enter the zone and read the file.
+ * Because of the upcall architecture of dlmgmtd this can lead to deadlock
+ * with the following scenario:
+ * a) the thread preparing to fork will have acquired the malloc locks
+ * then attempt to suspend every thread in preparation to fork.
+ * b) all of the upcalls will be blocked in door_ucred() trying to malloc()
+ * and get the credentials of their caller.
+ * c) we can't suspend the in-kernel thread making the upcall.
+ *
+ * Thus, we cannot serve door requests because we're blocked in malloc()
+ * which fork() owns, but fork() is in turn blocked on the in-kernel thread
+ * making the door upcall. This is a fundamental architectural problem with
+ * any server handling upcalls and also trying to fork().
+ *
+ * To minimize the chance of this deadlock occuring, we check ahead of time to
+ * see if the file we want to read actually exists in the zone (which it almost
+ * never does), so we don't need fork in that case (i.e. rarely to never).
+ */
+static boolean_t
+zone_file_exists(char *zoneroot, char *filename)
+{
+ struct stat sb;
+ char fname[MAXPATHLEN];
+
+ (void) snprintf(fname, sizeof (fname), "%s/%s", zoneroot, filename);
+
+ if (stat(fname, &sb) == -1)
+ return (B_FALSE);
+
+ return (B_TRUE);
+}
+
+/*
* Initialize the datalink <link name, linkid> mapping and the link's
* attributes list based on the configuration file /etc/dladm/datalink.conf
* and the active configuration cache file
* /etc/svc/volatile/dladm/datalink-management:default.cache.
*/
int
-dlmgmt_db_init(zoneid_t zoneid)
+dlmgmt_db_init(zoneid_t zoneid, char *zoneroot)
{
dlmgmt_db_req_t *req;
int err;
boolean_t boot = B_FALSE;
+ char tdir[MAXPATHLEN];
+ char *path = cachefile;
if ((req = dlmgmt_db_req_alloc(DLMGMT_DB_OP_READ, NULL,
DATALINK_INVALID_LINKID, zoneid, DLMGMT_ACTIVE, &err)) == NULL)
return (err);
- if ((err = dlmgmt_process_db_req(req)) != 0) {
- /*
- * If we get back ENOENT, that means that the active
- * configuration file doesn't exist yet, and is not an error.
- * We'll create it down below after we've loaded the
- * persistent configuration.
- */
- if (err != ENOENT)
- goto done;
+ /* Handle running in a non-native branded zone (i.e. has /native) */
+ if (zone_file_exists(zoneroot, "/native" DLMGMT_TMPFS_DIR)) {
+ (void) snprintf(tdir, sizeof (tdir), "/native%s", cachefile);
+ path = tdir;
+ }
+
+ if (zone_file_exists(zoneroot, path)) {
+ if ((err = dlmgmt_process_db_req(req)) != 0) {
+ /*
+ * If we get back ENOENT, that means that the active
+ * configuration file doesn't exist yet, and is not an
+ * error. We'll create it down below after we've
+ * loaded the persistent configuration.
+ */
+ if (err != ENOENT)
+ goto done;
+ boot = B_TRUE;
+ }
+ } else {
boot = B_TRUE;
}
- req->ls_flags = DLMGMT_PERSIST;
- err = dlmgmt_process_db_req(req);
- if (err != 0 && err != ENOENT)
- goto done;
+ if (zone_file_exists(zoneroot, DLMGMT_PERSISTENT_DB_PATH)) {
+ req->ls_flags = DLMGMT_PERSIST;
+ err = dlmgmt_process_db_req(req);
+ if (err != 0 && err != ENOENT)
+ goto done;
+ }
err = 0;
if (rewrite_needed) {
/*
generated by cgit v1.2.3 (git 2.46.0) at 2025-10-11 01:05:52 +0000