Don't close and reopen all pipes on every DNOTIFY signal.
authorneilbrown <neilbrown>
Tue, 28 Mar 2006 00:50:44 +0000 (00:50 +0000)
committerneilbrown <neilbrown>
Tue, 28 Mar 2006 00:50:44 +0000 (00:50 +0000)
From: Vince Busam <vbusam@google.com>
Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
Don't unnecessarily close and re-open all pipes after every DNOTIFY
signal.  These unnecessary closes were triggering a kernel Oops.
Original patch modified to correct segfault when unmounting last
NFSv4 mount.

ChangeLog
utils/gssd/gssd_proc.c

index 437660a..74808aa 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,16 @@
 2006-03-28 kwc@citi.umich.edu
+       
+       Don't close and reopen all pipes on every DNOTIFY signal.
+       
+       From: Vince Busam <vbusam@google.com>
+       Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
+       
+       Don't unnecessarily close and re-open all pipes after every DNOTIFY
+       signal.  These unnecessary closes were triggering a kernel Oops.
+       Original patch modified to correct segfault when unmounting last
+       NFSv4 mount.
+       
+2006-03-28 kwc@citi.umich.edu
        Add option to specify directory to search for credentials cache files
        
        
index 4c3d85d..8b456b0 100644 (file)
@@ -178,6 +178,12 @@ fail:
 static void
 destroy_client(struct clnt_info *clp)
 {
+       if (clp->krb5_poll_index != -1)
+               memset(&pollarray[clp->krb5_poll_index], 0,
+                                       sizeof(struct pollfd));
+       if (clp->spkm3_poll_index != -1)
+               memset(&pollarray[clp->spkm3_poll_index], 0,
+                                       sizeof(struct pollfd));
        if (clp->dir_fd != -1) close(clp->dir_fd);
        if (clp->krb5_fd != -1) close(clp->krb5_fd);
        if (clp->spkm3_fd != -1) close(clp->spkm3_fd);
@@ -216,15 +222,20 @@ process_clnt_dir_files(struct clnt_info * clp)
        char    sname[32];
        char    info_file_name[32];
 
-       snprintf(kname, sizeof(kname), "%s/krb5", clp->dirname);
-       clp->krb5_fd = open(kname, O_RDWR);
-       snprintf(sname, sizeof(sname), "%s/spkm3", clp->dirname);
-       clp->spkm3_fd = open(sname, O_RDWR);
+       if (clp->krb5_fd == -1) {
+               snprintf(kname, sizeof(kname), "%s/krb5", clp->dirname);
+               clp->krb5_fd = open(kname, O_RDWR);
+       }
+       if (clp->spkm3_fd == -1) {
+               snprintf(sname, sizeof(sname), "%s/spkm3", clp->dirname);
+               clp->spkm3_fd = open(sname, O_RDWR);
+       }
        if((clp->krb5_fd == -1) && (clp->spkm3_fd == -1))
                return -1;
        snprintf(info_file_name, sizeof(info_file_name), "%s/info",
                        clp->dirname);
-       if (read_service_info(info_file_name, &clp->servicename,
+       if ((clp->servicename == NULL) &&
+            read_service_info(info_file_name, &clp->servicename,
                                &clp->servername, &clp->prog, &clp->vers,
                                &clp->protocol))
                return -1;
@@ -250,6 +261,31 @@ get_poll_index(int *ind)
        return 0;
 }
 
+
+static int
+insert_clnt_poll(struct clnt_info *clp)
+{
+       if ((clp->krb5_fd != -1) && (clp->krb5_poll_index == -1)) {
+               if (get_poll_index(&clp->krb5_poll_index)) {
+                       printerr(0, "ERROR: Too many krb5 clients\n");
+                       return -1;
+               }
+               pollarray[clp->krb5_poll_index].fd = clp->krb5_fd;
+               pollarray[clp->krb5_poll_index].events |= POLLIN;
+       }
+
+       if ((clp->spkm3_fd != -1) && (clp->spkm3_poll_index == -1)) {
+               if (get_poll_index(&clp->spkm3_poll_index)) {
+                       printerr(0, "ERROR: Too many spkm3 clients\n");
+                       return -1;
+               }
+               pollarray[clp->spkm3_poll_index].fd = clp->spkm3_fd;
+               pollarray[clp->spkm3_poll_index].events |= POLLIN;
+       }
+
+       return 0;
+}
+
 static void
 process_clnt_dir(char *dir)
 {
@@ -273,23 +309,8 @@ process_clnt_dir(char *dir)
        if (process_clnt_dir_files(clp))
                goto fail_keep_client;
 
-       if(clp->krb5_fd != -1) {
-               if (get_poll_index(&clp->krb5_poll_index)) {
-                       printerr(0, "ERROR: Too many krb5 clients\n");
-                       goto fail_destroy_client;
-               }
-               pollarray[clp->krb5_poll_index].fd = clp->krb5_fd;
-               pollarray[clp->krb5_poll_index].events |= POLLIN;
-       }
-
-       if(clp->spkm3_fd != -1) {
-               if (get_poll_index(&clp->spkm3_poll_index)) {
-                       printerr(0, "ERROR: Too many spkm3 clients\n");
-                       goto fail_destroy_client;
-               }
-               pollarray[clp->spkm3_poll_index].fd = clp->spkm3_fd;
-               pollarray[clp->spkm3_poll_index].events |= POLLIN;
-       }
+       if (insert_clnt_poll(clp))
+               goto fail_destroy_client;
 
        return;
 
@@ -314,18 +335,50 @@ init_client_list(void)
        pollarray = calloc(pollsize, sizeof(struct pollfd));
 }
 
+/*
+ * This is run after a DNOTIFY signal, and should clear up any
+ * directories that are no longer around, and re-scan any existing
+ * directories, since the DNOTIFY could have been in there.
+ */
 static void
-destroy_client_list(void)
+update_old_clients(struct dirent **namelist, int size)
 {
-       struct clnt_info        *clp;
+       struct clnt_info *clp;
+       void *saveprev;
+       int i, stillhere;
+
+       for (clp = clnt_list.tqh_first; clp != NULL; clp = clp->list.tqe_next) {
+               stillhere = 0;
+               for (i=0; i < size; i++) {
+                       if (!strcmp(clp->dirname, namelist[i]->d_name)) {
+                               stillhere = 1;
+                               break;
+                       }
+               }
+               if (!stillhere) {
+                       printerr(2, "destroying client %s\n", clp->dirname);
+                       saveprev = clp->list.tqe_prev;
+                       TAILQ_REMOVE(&clnt_list, clp, list);
+                       destroy_client(clp);
+                       clp = saveprev;
+               }
+       }
+       for (clp = clnt_list.tqh_first; clp != NULL; clp = clp->list.tqe_next) {
+               if (!process_clnt_dir_files(clp))
+                       insert_clnt_poll(clp);
+       }
+}
 
-       printerr(1, "processing client list\n");
+/* Search for a client by directory name, return 1 if found, 0 otherwise */
+static int
+find_client(char *dirname)
+{
+       struct clnt_info        *clp;
 
-       while (clnt_list.tqh_first != NULL) {
-               clp = clnt_list.tqh_first;
-               TAILQ_REMOVE(&clnt_list, clp, list);
-               destroy_client(clp);
-       }
+       for (clp = clnt_list.tqh_first; clp != NULL; clp = clp->list.tqe_next)
+               if (!strcmp(clp->dirname, dirname))
+                       return 1;
+       return 0;
 }
 
 /* Used to read (and re-read) list of clients, set up poll array. */
@@ -333,9 +386,7 @@ int
 update_client_list(void)
 {
        struct dirent **namelist;
-       int i,j;
-
-       destroy_client_list();
+       int i, j;
 
        if (chdir(pipefsdir) < 0) {
                printerr(0, "ERROR: can't chdir to %s: %s\n",
@@ -343,17 +394,17 @@ update_client_list(void)
                return -1;
        }
 
-       memset(pollarray, 0, pollsize * sizeof(struct pollfd));
-
        j = scandir(pipefsdir, &namelist, NULL, alphasort);
        if (j < 0) {
                printerr(0, "ERROR: can't scandir %s: %s\n",
                         pipefsdir, strerror(errno));
                return -1;
        }
+       update_old_clients(namelist, j);
        for (i=0; i < j; i++) {
                if (i < FD_ALLOC_BLOCK
-                               && !strncmp(namelist[i]->d_name, "clnt", 4))
+                               && !strncmp(namelist[i]->d_name, "clnt", 4)
+                               && !find_client(namelist[i]->d_name))
                        process_clnt_dir(namelist[i]->d_name);
                free(namelist[i]);
        }