add delay for root partition when extroot is used

This patch adds a new option called delay_root to /etc/config/fstab. This option defines
how long mount_root should wait (in seconds) for an external storage to show up.

Signed-off-by: Peter Wagner <tripolar@gmx.at>

diff --git a/block.c b/block.c
index e3363ae39128a2182a1965bbab60adedaa18acc2..4bbfeb0f98257bbab1e4896309dfdfc00b5861e9 100644 (file)
--- a/block.c
+++ b/block.c
@@ -58,12 +58,14 @@ static struct vlist_tree mounts;
 static struct blob_buf b;
 static LIST_HEAD(devices);
 static int anon_mount, anon_swap, auto_mount, auto_swap;
+static unsigned int delay_root;
 
 enum {
        CFG_ANON_MOUNT,
        CFG_ANON_SWAP,
        CFG_AUTO_MOUNT,
        CFG_AUTO_SWAP,
+       CFG_DELAY_ROOT,
        __CFG_MAX
 };
 
@@ -72,6 +74,7 @@ static const struct blobmsg_policy config_policy[__CFG_MAX] = {
        [CFG_ANON_MOUNT] = { .name = "anon_mount", .type = BLOBMSG_TYPE_INT32 },
        [CFG_AUTO_SWAP] = { .name = "auto_swap", .type = BLOBMSG_TYPE_INT32 },
        [CFG_AUTO_MOUNT] = { .name = "auto_mount", .type = BLOBMSG_TYPE_INT32 },
+       [CFG_DELAY_ROOT] = { .name = "delay_root", .type = BLOBMSG_TYPE_INT32 },
 };
 
 enum {
@@ -215,6 +218,9 @@ static int global_add(struct uci_section *s)
        if ((tb[CFG_AUTO_SWAP]) && blobmsg_get_u32(tb[CFG_AUTO_SWAP]))
                auto_swap = 1;
 
+       if (tb[CFG_DELAY_ROOT])
+               delay_root = blobmsg_get_u32(tb[CFG_DELAY_ROOT]);
+
        return 0;
 }
 
@@ -651,6 +657,12 @@ static int mount_extroot(char *cfg)
                return -1;
 
        pr = find_block_info(m->uuid, m->label, NULL);
+
+       if (!pr && delay_root){
+               fprintf(stderr, "extroot: is not ready yet, retrying in %ui seconds\n", delay_root);
+               sleep(delay_root);
+               pr = find_block_info(m->uuid, m->label, NULL);
+       }
        if (pr) {
                if (strncmp(pr->id->name, "ext", 3)) {
                        fprintf(stderr, "extroot: %s is not supported, try ext4\n", pr->id->name);
@@ -760,6 +772,7 @@ static int main_detect(int argc, char **argv)
        printf("\toption\tanon_mount\t'0'\n");
        printf("\toption\tauto_swap\t'1'\n");
        printf("\toption\tauto_mount\t'1'\n\n");
+       printf("\toption\tdelay_root\t'0'\n\n");
        list_for_each_entry(pr, &devices, list)
                print_block_uci(pr);