block: support hierarchical mount/umount

This is needed when e.g. sda1 needs to be mounted to /mnt and sda2
/mnt/srv.  We need to make sure sda1 was mounted first.

"devices" is now an ordered list with elements pointing to both "struct
probe_info" and "struct mount".  The order is firstly on presence of
mount info, then strlen(mount.target), then strcmp(probe_info.dev)

Resolves FS#2214

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

diff --git a/block.c b/block.c
index 99672fb5d86cd978f4bdbe1656eafc856a9412ff..66dcf9c09294285481fcc7c341e7f05d8cbe727c 100644 (file)
--- a/block.c
+++ b/block.c
@@ -82,9 +82,20 @@ struct mount {
        unsigned int prio;
 };
 
-static struct vlist_tree mounts;
+struct device {
+       struct vlist_node node;
+
+       struct probe_info *pr;
+       struct mount *m;
+};
+
+static void vlist_nop_update(struct vlist_tree *tree, struct vlist_node *node_new,
+                         struct vlist_node *node_old);
+static int devices_cmp(const void *k1, const void *k2, void *ptr);
+
 static struct blob_buf b;
-static LIST_HEAD(devices);
+static VLIST_TREE(mounts, avl_strcmp, vlist_nop_update, false, false);
+static VLIST_TREE(devices, devices_cmp, vlist_nop_update, false, false);
 static int anon_mount, anon_swap, auto_mount, auto_swap, check_fs;
 static unsigned int delay_root;
 
@@ -409,9 +420,10 @@ static struct mount* find_block(const char *uuid, const char *label, const char
        return NULL;
 }
 
-static void mounts_update(struct vlist_tree *tree, struct vlist_node *node_new,
+static void vlist_nop_update(struct vlist_tree *tree, struct vlist_node *node_new,
                          struct vlist_node *node_old)
 {
+       // NOTE: free on delete skipped
 }
 
 static struct uci_package * config_try_load(struct uci_context *ctx, char *path)
@@ -442,8 +454,6 @@ static int config_load(char *cfg)
        struct uci_element *e;
        char path[64];
 
-       vlist_init(&mounts, avl_strcmp, mounts_update);
-
        if (cfg) {
                snprintf(path, sizeof(path), "%s/upper/etc/config/fstab", cfg);
                pkg = config_try_load(ctx, path);
@@ -482,15 +492,15 @@ static int config_load(char *cfg)
 
 static struct probe_info* _probe_path(char *path)
 {
-       struct probe_info *pr;
+       struct device *dev;
        char tmppath[64];
 
        /* skip ubi device if ubiblock device is present */
        if (path[5] == 'u' && path[6] == 'b' && path[7] == 'i' &&
            path[8] >= '0' && path[8] <= '9' ) {
                snprintf(tmppath, sizeof(tmppath), "/dev/ubiblock%s", path + 8);
-               list_for_each_entry(pr, &devices, list)
-                       if (!strcasecmp(pr->dev, tmppath))
+               vlist_for_each_element(&devices, dev, node)
+                       if (!strcasecmp(dev->pr->dev, tmppath))
                                return NULL;
        }
 
@@ -502,14 +512,20 @@ static int _cache_load(const char *path)
        int gl_flags = GLOB_NOESCAPE | GLOB_MARK;
        int j;
        glob_t gl;
+       struct device *dev;
 
        if (glob(path, gl_flags, NULL, &gl) < 0)
                return -1;
 
        for (j = 0; j < gl.gl_pathc; j++) {
                struct probe_info *pr = _probe_path(gl.gl_pathv[j]);
-               if (pr)
-                       list_add_tail(&pr->list, &devices);
+               if (pr) {
+                       dev = malloc(sizeof(struct device));
+                       dev->pr = pr;
+                       dev->m = find_block(pr->uuid, pr->label,
+                                       basename(pr->dev), NULL);
+                       vlist_add(&devices, &dev->node, dev);
+               }
        }
 
        globfree(&gl);
@@ -517,8 +533,30 @@ static int _cache_load(const char *path)
        return 0;
 }
 
+static int devices_cmp(const void *k1, const void *k2, void *ptr)
+{
+       struct device *dev1 = (struct device *)k1;
+       struct device *dev2 = (struct device *)k2;
+
+       if (dev1->m) {
+               if (!dev2->m)
+                       return -1;
+               if (dev1->m->type == TYPE_MOUNT && dev2->m->type == TYPE_MOUNT &&
+                               dev1->m->target && dev2->m->target) {
+                       int len1 = strlen(dev1->m->target);
+                       int len2 = strlen(dev2->m->target);
+                       if (len1 != len2)
+                               return len1 - len2;
+               }
+       } else if (dev2->m) {
+               return 1;
+       }
+       return strcmp(dev1->pr->dev, dev2->pr->dev);
+}
+
 static void cache_load(int mtd)
 {
+       vlist_update(&devices);
        if (mtd) {
                _cache_load("/dev/mtdblock*");
                _cache_load("/dev/ubiblock*");
@@ -533,6 +571,7 @@ static void cache_load(int mtd)
        _cache_load("/dev/vd*");
        _cache_load("/dev/xvd*");
        _cache_load("/dev/mapper/*");
+       vlist_flush(&devices);
 }
 
 
@@ -553,24 +592,24 @@ static int print_block_uci(struct probe_info *pr)
        return 0;
 }
 
-static struct probe_info* find_block_info(char *uuid, char *label, char *path)
+static struct device* find_block_device(char *uuid, char *label, char *path)
 {
-       struct probe_info *pr = NULL;
+       struct device *dev;
 
        if (uuid)
-               list_for_each_entry(pr, &devices, list)
-                       if (pr->uuid && !strcasecmp(pr->uuid, uuid))
-                               return pr;
+               vlist_for_each_element(&devices, dev, node)
+                       if (dev->pr->uuid && !strcasecmp(dev->pr->uuid, uuid))
+                               return dev;
 
        if (label)
-               list_for_each_entry(pr, &devices, list)
-                       if (pr->label && !strcmp(pr->label, label))
-                               return pr;
+               vlist_for_each_element(&devices, dev, node)
+                       if (dev->pr->label && !strcmp(dev->pr->label, label))
+                               return dev;
 
        if (path)
-               list_for_each_entry(pr, &devices, list)
-                       if (pr->dev && !strcmp(basename(pr->dev), basename(path)))
-                               return pr;
+               vlist_for_each_element(&devices, dev, node)
+                       if (dev->pr->dev && !strcmp(basename(dev->pr->dev), basename(path)))
+                               return dev;
 
        return NULL;
 }
@@ -1022,18 +1061,20 @@ static int blockd_notify(char *device, struct mount *m, struct probe_info *pr)
        return err;
 }
 
-static int mount_device(struct probe_info *pr, int type)
+static int mount_device(struct device *dev, int type)
 {
        struct mount *m;
+       struct probe_info *pr;
        char _target[32];
        char *target;
        char *device;
        char *mp;
        int err;
 
-       if (!pr)
+       if (!dev)
                return -1;
 
+       pr = dev->pr;
        device = basename(pr->dev);
 
        if (!strcmp(pr->type, "swap")) {
@@ -1053,7 +1094,7 @@ static int mount_device(struct probe_info *pr, int type)
                return -1;
        }
 
-       m = find_block(pr->uuid, pr->label, device, NULL);
+       m = dev->m;
        if (m && m->extroot)
                return -1;
 
@@ -1170,7 +1211,7 @@ static int mount_action(char *action, char *device, int type)
                return -1;
        cache_load(0);
 
-       return mount_device(find_block_info(NULL, NULL, path), type);
+       return mount_device(find_block_device(NULL, NULL, path), type);
 }
 
 static int main_hotplug(int argc, char **argv)
@@ -1186,19 +1227,21 @@ static int main_autofs(int argc, char **argv)
                return -1;
 
        if (!strcmp(argv[2], "start")) {
+               struct device *dev;
                struct probe_info *pr;
 
                if (config_load(NULL))
                        return -1;
 
                cache_load(0);
-               list_for_each_entry(pr, &devices, list) {
+               vlist_for_each_element(&devices, dev, node) {
                        struct mount *m;
 
+                       pr = dev->pr;
                        if (!strcmp(pr->type, "swap"))
                                continue;
 
-                       m = find_block(pr->uuid, pr->label, NULL, NULL);
+                       m = dev->m;
                        if (m && m->extroot)
                                continue;
 
@@ -1362,7 +1405,8 @@ static int test_fs_support(const char *name)
 
 static int check_extroot(char *path)
 {
-       struct probe_info *pr = NULL;
+       struct device *dev;
+       struct probe_info *pr;
        char devpath[32];
 
 #ifdef UBIFS_EXTROOT
@@ -1385,7 +1429,8 @@ static int check_extroot(char *path)
        }
 #endif
 
-       list_for_each_entry(pr, &devices, list) {
+       vlist_for_each_element(&devices, dev, node) {
+               pr = dev->pr;
                if (!strcmp(pr->dev, devpath)) {
                        struct stat s;
                        FILE *fp = NULL;
@@ -1443,6 +1488,7 @@ static int mount_extroot(char *cfg)
        char overlay[] = "/tmp/extroot/overlay";
        char mnt[] = "/tmp/extroot/mnt";
        char *path = mnt;
+       struct device *dev;
        struct probe_info *pr;
        struct mount *m;
        int err = -1;
@@ -1463,16 +1509,17 @@ static int mount_extroot(char *cfg)
        }
 
        /* Find block device pointed by the mount config */
-       pr = find_block_info(m->uuid, m->label, m->device);
+       dev = find_block_device(m->uuid, m->label, m->device);
 
-       if (!pr && delay_root){
+       if (!dev && delay_root){
                ULOG_INFO("extroot: device not present, retrying in %u seconds\n", delay_root);
                sleep(delay_root);
                make_devs();
                cache_load(0);
-               pr = find_block_info(m->uuid, m->label, m->device);
+               dev = find_block_device(m->uuid, m->label, m->device);
        }
-       if (pr) {
+       if (dev) {
+               pr = dev->pr;
                if (strncmp(pr->type, "ext", 3) &&
                    strncmp(pr->type, "f2fs", 4) &&
                    strncmp(pr->type, "btrfs", 5) &&
@@ -1516,7 +1563,6 @@ static int mount_extroot(char *cfg)
 
 static int main_extroot(int argc, char **argv)
 {
-       struct probe_info *pr;
        char blkdev_path[32] = { 0 };
        int err = -1;
 #ifdef UBIFS_EXTROOT
@@ -1545,8 +1591,8 @@ static int main_extroot(int argc, char **argv)
        /* Start with looking for MTD partition */
        find_block_mtd("\"rootfs_data\"", blkdev_path, sizeof(blkdev_path));
        if (blkdev_path[0]) {
-               pr = find_block_info(NULL, NULL, blkdev_path);
-               if (pr && !strcmp(pr->type, "jffs2")) {
+               struct device *dev = find_block_device(NULL, NULL, blkdev_path);
+               if (dev && !strcmp(dev->pr->type, "jffs2")) {
                        char cfg[] = "/tmp/jffs_cfg";
 
                        /*
@@ -1592,14 +1638,14 @@ static int main_extroot(int argc, char **argv)
 
 static int main_mount(int argc, char **argv)
 {
-       struct probe_info *pr;
+       struct device *dev;
 
        if (config_load(NULL))
                return -1;
 
        cache_load(1);
-       list_for_each_entry(pr, &devices, list)
-               mount_device(pr, TYPE_DEV);
+       vlist_for_each_element(&devices, dev, node)
+               mount_device(dev, TYPE_DEV);
 
        handle_swapfiles(true);
 
@@ -1608,6 +1654,7 @@ static int main_mount(int argc, char **argv)
 
 static int main_umount(int argc, char **argv)
 {
+       struct device *dev;
        struct probe_info *pr;
        bool all = false;
 
@@ -1621,13 +1668,14 @@ static int main_umount(int argc, char **argv)
        if (argc == 3)
                all = !strcmp(argv[2], "-a");
 
-       list_for_each_entry(pr, &devices, list) {
+       vlist_for_each_element_reverse(&devices, dev, node) {
                struct mount *m;
 
+               pr = dev->pr;
                if (!strcmp(pr->type, "swap"))
                        continue;
 
-               m = find_block(pr->uuid, pr->label, basename(pr->dev), NULL);
+               m = dev->m;
                if (m && m->extroot)
                        continue;
 
@@ -1639,7 +1687,7 @@ static int main_umount(int argc, char **argv)
 
 static int main_detect(int argc, char **argv)
 {
-       struct probe_info *pr;
+       struct device *dev;
 
        cache_load(0);
        printf("config 'global'\n");
@@ -1649,8 +1697,8 @@ static int main_detect(int argc, char **argv)
        printf("\toption\tauto_mount\t'1'\n");
        printf("\toption\tdelay_root\t'5'\n");
        printf("\toption\tcheck_fs\t'0'\n\n");
-       list_for_each_entry(pr, &devices, list)
-               print_block_uci(pr);
+       vlist_for_each_element(&devices, dev, node)
+               print_block_uci(dev->pr);
 
        return 0;
 }
@@ -1658,12 +1706,12 @@ static int main_detect(int argc, char **argv)
 static int main_info(int argc, char **argv)
 {
        int i;
-       struct probe_info *pr;
+       struct device *dev;
 
        cache_load(1);
        if (argc == 2) {
-               list_for_each_entry(pr, &devices, list)
-                       print_block_info(pr);
+               vlist_for_each_element(&devices, dev, node)
+                       print_block_info(dev->pr);
 
                return 0;
        };
@@ -1679,9 +1727,9 @@ static int main_info(int argc, char **argv)
                        ULOG_ERR("%s is not a block device\n", argv[i]);
                        continue;
                }
-               pr = find_block_info(NULL, NULL, argv[i]);
-               if (pr)
-                       print_block_info(pr);
+               dev = find_block_device(NULL, NULL, argv[i]);
+               if (dev)
+                       print_block_info(dev->pr);
        }
 
        return 0;
@@ -1703,6 +1751,7 @@ static int main_swapon(int argc, char **argv)
        FILE *fp;
        char *lineptr;
        size_t s;
+       struct device *dev;
        struct probe_info *pr;
        int flags = 0;
        int pri;
@@ -1727,7 +1776,8 @@ static int main_swapon(int argc, char **argv)
                        return 0;
                case 'a':
                        cache_load(0);
-                       list_for_each_entry(pr, &devices, list) {
+                       vlist_for_each_element(&devices, dev, node) {
+                               pr = dev->pr;
                                if (strcmp(pr->type, "swap"))
                                        continue;
                                if (swapon(pr->dev, 0))