properly handle return codes

[project/fstools.git] / libfstools / overlay.c

diff --git a/libfstools/overlay.c b/libfstools/overlay.c
index bb506ee..0677c34 100644 (file)
--- a/libfstools/overlay.c
+++ b/libfstools/overlay.c
@@ -14,6 +14,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/mount.h>
+#include <sys/syscall.h>
 
 #include <asm/byteorder.h>
 
@@ -32,6 +33,50 @@
 
 #define SWITCH_JFFS2 "/tmp/.switch_jffs2"
 
+static bool keep_sysupgrade;
+
+static ssize_t
+fs_getxattr(const char *path, const char *name, void *value, size_t size)
+{
+       return syscall(__NR_getxattr, path, name, value, size);
+}
+
+static ssize_t
+fs_setxattr(const char *path, const char *name, const void *value, size_t size, int flags)
+{
+       return syscall(__NR_setxattr, path, name, value, size, flags);
+}
+
+static int
+handle_rmdir(const char *dir)
+{
+       struct dirent *dt;
+       struct stat st;
+       DIR *d;
+       int fd;
+
+       d = opendir(dir);
+       if (!d)
+               return -1;
+
+       fd = dirfd(d);
+
+       while ((dt = readdir(d)) != NULL) {
+               if (fstatat(fd, dt->d_name, &st, AT_SYMLINK_NOFOLLOW) || S_ISDIR(st.st_mode))
+                       continue;
+
+               if (keep_sysupgrade && !strcmp(dt->d_name, "sysupgrade.tgz"))
+                       continue;
+
+               unlinkat(fd, dt->d_name, 0);
+       }
+
+       closedir(d);
+       rmdir(dir);
+
+       return 0;
+}
+
 void
 foreachdir(const char *dir, int (*cb)(const char*))
 {
@@ -51,6 +96,13 @@ foreachdir(const char *dir, int (*cb)(const char*))
        cb(dir);
 }
 
+void
+overlay_delete(const char *dir, bool _keep_sysupgrade)
+{
+       keep_sysupgrade = _keep_sysupgrade;
+       foreachdir(dir, handle_rmdir);
+}
+
 static int
 overlay_mount(struct volume *v, char *fs)
 {
@@ -91,7 +143,10 @@ switch2jffs(struct volume *v)
                return -1;
        }
 
-       system("cp -a /tmp/root/* /rom/overlay"); /**/
+       if (system("cp -a /tmp/root/* /rom/overlay")) {
+               ULOG_ERR("failed - cp -a /tmp/root/* /rom/overlay: %s\n", strerror(errno));
+               return -1;
+       }
 
        if (pivot("/rom", "/mnt")) {
                ULOG_ERR("failed - pivot /rom /mnt: %s\n", strerror(errno));
@@ -196,7 +251,13 @@ jffs2_switch(struct volume *v)
                }
                break;
        }
-       return ret;
+
+       if (ret)
+               return ret;
+
+       sync();
+       fs_state_set("/overlay", FS_STATE_READY);
+       return 0;
 }
 
 static int overlay_mount_fs(struct volume *v)
@@ -216,17 +277,39 @@ static int overlay_mount_fs(struct volume *v)
                break;
        }
 
+       volume_init(v);
+
        if (mount(v->blk, "/tmp/overlay", fstype, MS_NOATIME, NULL)) {
                ULOG_ERR("failed to mount -t %s %s /tmp/overlay: %s\n",
                         fstype, v->blk, strerror(errno));
                return -1;
        }
 
-       volume_init(v);
-
        return -1;
 }
 
+enum fs_state fs_state_get(const char *dir)
+{
+       uint32_t val;
+
+       if (fs_getxattr(dir, "user.fs_state", &val, sizeof(val)) != sizeof(val))
+               return FS_STATE_UNKNOWN;
+
+       if (val > __FS_STATE_LAST)
+               return FS_STATE_UNKNOWN;
+
+       return val;
+}
+
+
+int fs_state_set(const char *dir, enum fs_state state)
+{
+       uint32_t val = state;
+
+       return fs_setxattr(dir, "user.fs_state", &val, sizeof(val), 0);
+}
+
+
 int mount_overlay(struct volume *v)
 {
        char *mp;
@@ -248,7 +331,22 @@ int mount_overlay(struct volume *v)
                return 0;
        }
 
-       ULOG_INFO("switching to overlay\n");
+       switch(fs_state_get("/tmp/overlay")) {
+       case FS_STATE_UNKNOWN:
+               fs_state_set("/tmp/overlay", FS_STATE_PENDING);
+               if (fs_state_get("/tmp/overlay") != FS_STATE_PENDING) {
+                       ULOG_ERR("unable to set filesystem state\n");
+                       break;
+               }
+       case FS_STATE_PENDING:
+               ULOG_INFO("overlay filesystem has not been fully initialized yet\n");
+               overlay_delete("/tmp/overlay", true);
+               break;
+       case FS_STATE_READY:
+               break;
+       }
+
+       ULOG_INFO("switching to jffs2 overlay\n");
        if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
                ULOG_ERR("switching to jffs2 failed - fallback to ramoverlay\n");
                return ramoverlay();