ceph: reduce parse_mount_args stack usage

Since we've increased the max mon count, we shouldn't put the addr array
on the parse_mount_args stack.  Put it on the heap instead.

Signed-off-by: Sage Weil <sage@newdream.net>

diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 81916250f0b61090ceff0d75061fc81e66be84ff..deb51bd6ed8378b9ba12ab7bcba001e560d09e2e 100644 (file)
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -314,12 +314,16 @@ static int parse_mount_args(struct ceph_client *client,
        int err;
        substring_t argstr[MAX_OPT_ARGS];
        int num_mon;
-       struct ceph_entity_addr mon_addr[CEPH_MAX_MON];
+       struct ceph_entity_addr *mon_addr;
        int i;
 
        dout("parse_mount_args dev_name '%s'\n", dev_name);
        memset(args, 0, sizeof(*args));
 
+       mon_addr = kcalloc(CEPH_MAX_MON, sizeof(*mon_addr), GFP_KERNEL);
+       if (!mon_addr)
+               return -ENOMEM;
+
        /* start with defaults */
        args->sb_flags = flags;
        args->flags = CEPH_OPT_DEFAULT;
@@ -333,27 +337,29 @@ static int parse_mount_args(struct ceph_client *client,
        args->max_readdir = 1024;
 
        /* ip1[:port1][,ip2[:port2]...]:/subdir/in/fs */
+       err = -EINVAL;
        if (!dev_name)
-               return -EINVAL;
+               goto out;
        *path = strstr(dev_name, ":/");
        if (*path == NULL) {
                pr_err("device name is missing path (no :/ in %s)\n",
                       dev_name);
-               return -EINVAL;
+               goto out;
        }
 
        /* get mon ip(s) */
        err = ceph_parse_ips(dev_name, *path, mon_addr,
                             CEPH_MAX_MON, &num_mon);
        if (err < 0)
-               return err;
+               goto out;
 
        /* build initial monmap */
+       err = -ENOMEM;
        client->monc.monmap = kzalloc(sizeof(*client->monc.monmap) +
                               num_mon*sizeof(client->monc.monmap->mon_inst[0]),
                               GFP_KERNEL);
        if (!client->monc.monmap)
-               return -ENOMEM;
+               goto out;
        for (i = 0; i < num_mon; i++) {
                client->monc.monmap->mon_inst[i].addr = mon_addr[i];
                client->monc.monmap->mon_inst[i].addr.erank = 0;
@@ -374,11 +380,11 @@ static int parse_mount_args(struct ceph_client *client,
                int token, intval, ret;
                if (!*c)
                        continue;
+               err = -EINVAL;
                token = match_token((char *)c, arg_tokens, argstr);
                if (token < 0) {
                        pr_err("bad mount option at '%s'\n", c);
-                       return -EINVAL;
-
+                       goto out;
                }
                if (token < Opt_ip) {
                        ret = match_int(&argstr[0], &intval);
@@ -468,8 +474,11 @@ static int parse_mount_args(struct ceph_client *client,
                        BUG_ON(token);
                }
        }
+       err = 0;
 
-       return 0;
+out:
+       kfree(mon_addr);
+       return err;
 }
 
 static void release_mount_args(struct ceph_mount_args *args)