#include <sys/filedesc.h>
#include <sys/vnode_internal.h>
#include <sys/imageboot.h>
+#include <kern/assert.h>
#include <pexpert/pexpert.h>
#endif
extern int di_root_image(const char *path, char devname[], dev_t *dev_p);
+static boolean_t imageboot_setup_new(void);
#define kIBFilePrefix "file://"
-int
+__private_extern__ int
+imageboot_format_is_valid(const char *root_path)
+{
+ return (strncmp(root_path, kIBFilePrefix,
+ strlen(kIBFilePrefix)) == 0);
+}
+
+static void
+vnode_get_and_drop_always(vnode_t vp)
+{
+ vnode_getalways(vp);
+ vnode_rele(vp);
+ vnode_put(vp);
+}
+
+__private_extern__ int
imageboot_needed(void)
{
int result = 0;
char *root_path = NULL;
-
+
DBG_TRACE("%s: checking for presence of root path\n", __FUNCTION__);
MALLOC_ZONE(root_path, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK);
if (root_path == NULL)
panic("%s: M_NAMEI zone exhausted", __FUNCTION__);
- if(PE_parse_boot_argn("rp", root_path, MAXPATHLEN) == TRUE) {
- /* Got it, now verify scheme */
+ /* Check for first layer */
+ if (!(PE_parse_boot_argn("rp0", root_path, MAXPATHLEN) ||
+ PE_parse_boot_argn("rp", root_path, MAXPATHLEN) ||
+ PE_parse_boot_argn(IMAGEBOOT_ROOT_ARG, root_path, MAXPATHLEN))) {
+ goto out;
+ }
+
+ /* Sanity-check first layer */
+ if (imageboot_format_is_valid(root_path)) {
+ DBG_TRACE("%s: Found %s\n", __FUNCTION__, root_path);
+ } else {
+ goto out;
+ }
+
+ result = 1;
- if (strncmp(root_path, kIBFilePrefix,
- strlen(kIBFilePrefix)) == 0) {
- DBG_TRACE("%s: Found %s\n", __FUNCTION__, root_path);
- result = 1;
- } else {
- DBG_TRACE("%s: Invalid URL scheme for %s\n",
- __FUNCTION__, root_path);
- }
+ /* Check for second layer */
+ if (!(PE_parse_boot_argn("rp1", root_path, MAXPATHLEN) ||
+ PE_parse_boot_argn(IMAGEBOOT_CONTAINER_ARG, root_path, MAXPATHLEN))) {
+ goto out;
}
+
+ /* Sanity-check second layer */
+ if (imageboot_format_is_valid(root_path)) {
+ DBG_TRACE("%s: Found %s\n", __FUNCTION__, root_path);
+ } else {
+ panic("%s: Invalid URL scheme for %s\n",
+ __FUNCTION__, root_path);
+ }
+
+out:
FREE_ZONE(root_path, MAXPATHLEN, M_NAMEI);
return (result);
/*
- * We know there's an image. Attach it, and
- * switch over to root off it
- *
- * NB: p is always kernproc
+ * Swaps in new root filesystem based on image path.
+ * Current root filesystem is removed from mount list and
+ * tagged MNTK_BACKS_ROOT, MNT_ROOTFS is cleared on it, and
+ * "rootvnode" is reset. Root vnode of currentroot filesystem
+ * is returned with usecount (no iocount).
*/
+__private_extern__ int
+imageboot_mount_image(const char *root_path, int height)
+{
+ dev_t dev;
+ int error;
+ vnode_t old_rootvnode = NULL;
+ vnode_t newdp;
+ mount_t new_rootfs;
+
+ error = di_root_image(root_path, rootdevice, &dev);
+ if (error) {
+ panic("%s: di_root_image failed: %d\n", __FUNCTION__, error);
+ }
+
+ rootdev = dev;
+ mountroot = NULL;
+ printf("%s: root device 0x%x\n", __FUNCTION__, rootdev);
+ error = vfs_mountroot();
+ if (error != 0) {
+ panic("vfs_mountroot() failed.\n");
+ }
+
+ /*
+ * Get the vnode for '/'.
+ * Set fdp->fd_fd.fd_cdir to reference it.
+ */
+ if (VFS_ROOT(TAILQ_LAST(&mountlist,mntlist), &newdp, vfs_context_kernel()))
+ panic("%s: cannot find root vnode", __FUNCTION__);
+
+ if (rootvnode != NULL) {
+ /* remember the old rootvnode, but remove it from mountlist */
+ mount_t old_rootfs;
+
+ old_rootvnode = rootvnode;
+ old_rootfs = rootvnode->v_mount;
+
+ mount_list_remove(old_rootfs);
+
+ mount_lock(old_rootfs);
+#ifdef CONFIG_IMGSRC_ACCESS
+ old_rootfs->mnt_kern_flag |= MNTK_BACKS_ROOT;
+#endif /* CONFIG_IMGSRC_ACCESS */
+ old_rootfs->mnt_flag &= ~MNT_ROOTFS;
+ mount_unlock(old_rootfs);
+ }
+
+ /* switch to the new rootvnode */
+ rootvnode = newdp;
+
+ new_rootfs = rootvnode->v_mount;
+ mount_lock(new_rootfs);
+ new_rootfs->mnt_flag |= MNT_ROOTFS;
+ mount_unlock(new_rootfs);
+
+ vnode_ref(newdp);
+ vnode_put(newdp);
+ filedesc0.fd_cdir = newdp;
+ DBG_TRACE("%s: root switched\n", __FUNCTION__);
+
+ if (old_rootvnode != NULL) {
+#ifdef CONFIG_IMGSRC_ACCESS
+ if (height >= 0 && PE_imgsrc_mount_supported()) {
+ imgsrc_rootvnodes[height] = old_rootvnode;
+ } else {
+ vnode_get_and_drop_always(old_rootvnode);
+ }
+#else
+ height = 0; /* keep the compiler from complaining */
+ vnode_get_and_drop_always(old_rootvnode);
+#endif /* CONFIG_IMGSRC_ACCESS */
+ }
+ return 0;
+}
-int
+static boolean_t
+imageboot_setup_new()
+{
+ int error;
+ char *root_path = NULL;
+ int height = 0;
+ boolean_t done = FALSE;
+
+ MALLOC_ZONE(root_path, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK);
+ assert(root_path != NULL);
+
+ if(PE_parse_boot_argn(IMAGEBOOT_CONTAINER_ARG, root_path, MAXPATHLEN) == TRUE) {
+ printf("%s: container image url is %s\n", __FUNCTION__, root_path);
+ error = imageboot_mount_image(root_path, height);
+ if (error != 0) {
+ panic("Failed to mount container image.");
+ }
+
+ height++;
+ }
+
+ if (PE_parse_boot_argn(IMAGEBOOT_ROOT_ARG, root_path, MAXPATHLEN) == FALSE) {
+ if (height > 0) {
+ panic("%s specified without %s?\n", IMAGEBOOT_CONTAINER_ARG, IMAGEBOOT_ROOT_ARG);
+ }
+ goto out;
+
+ }
+
+ printf("%s: root image url is %s\n", __FUNCTION__, root_path);
+
+ error = imageboot_mount_image(root_path, height);
+ if (error != 0) {
+ panic("Failed to mount root image.");
+ }
+
+ done = TRUE;
+
+out:
+ FREE_ZONE(root_path, MAXPATHLEN, M_NAMEI);
+ return done;
+}
+
+__private_extern__ void
imageboot_setup()
{
- dev_t dev;
int error = 0;
char *root_path = NULL;
DBG_TRACE("%s: entry\n", __FUNCTION__);
+ if (rootvnode == NULL) {
+ panic("imageboot_setup: rootvnode is NULL.");
+ }
+
+ /*
+ * New boot-arg scheme:
+ * root-dmg : the dmg that will be the root filesystem.
+ * container-dmg : an optional dmg that contains the root-dmg.
+ */
+ if (imageboot_setup_new()) {
+ return;
+ }
+
MALLOC_ZONE(root_path, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK);
- if (root_path == NULL)
- return (ENOMEM);
+ assert(root_path != NULL);
- if(PE_parse_boot_argn("rp", root_path, MAXPATHLEN) == FALSE) {
- error = ENOENT;
- goto done;
+ /*
+ * Look for outermost disk image to root from. If we're doing a nested boot,
+ * there's some sense in which the outer image never needs to be the root filesystem,
+ * but it does need very similar treatment: it must not be unmounted, needs a fake
+ * device vnode created for it, and should not show up in getfsstat() until exposed
+ * with MNT_IMGSRC. We just make it the temporary root.
+ */
+ if((PE_parse_boot_argn("rp", root_path, MAXPATHLEN) == FALSE) &&
+ (PE_parse_boot_argn("rp0", root_path, MAXPATHLEN) == FALSE)) {
+ panic("%s: no valid path to image.\n", __FUNCTION__);
}
printf("%s: root image url is %s\n", __FUNCTION__, root_path);
- error = di_root_image(root_path, rootdevice, &dev);
- if(error) {
- printf("%s: di_root_image failed: %d\n", __FUNCTION__, error);
- goto done;
+
+ error = imageboot_mount_image(root_path, 0);
+ if (error) {
+ panic("Failed on first stage of imageboot.");
}
- rootdev = dev;
- mountroot = NULL;
- printf("%s: root device 0x%x\n", __FUNCTION__, rootdev);
- error = vfs_mountroot();
+ /*
+ * See if we are rooting from a nested image
+ */
+ if(PE_parse_boot_argn("rp1", root_path, MAXPATHLEN) == FALSE) {
+ goto done;
+ }
+
+ printf("%s: second level root image url is %s\n", __FUNCTION__, root_path);
- if (error == 0 && rootvnode != NULL) {
- struct vnode *tvp;
- struct vnode *newdp;
-
- /*
- * Get the vnode for '/'.
- * Set fdp->fd_fd.fd_cdir to reference it.
- */
- if (VFS_ROOT(TAILQ_LAST(&mountlist,mntlist), &newdp, vfs_context_kernel()))
- panic("%s: cannot find root vnode", __FUNCTION__);
-
- vnode_ref(newdp);
- vnode_put(newdp);
- tvp = rootvnode;
- vnode_rele(tvp);
- filedesc0.fd_cdir = newdp;
- rootvnode = newdp;
- mount_list_lock();
- TAILQ_REMOVE(&mountlist, TAILQ_FIRST(&mountlist), mnt_list);
- mount_list_unlock();
- mountlist.tqh_first->mnt_flag |= MNT_ROOTFS;
- DBG_TRACE("%s: root switched\n", __FUNCTION__);
+ /*
+ * If we fail to set up second image, it's not a given that we
+ * can safely root off the first.
+ */
+ error = imageboot_mount_image(root_path, 1);
+ if (error) {
+ panic("Failed on second stage of imageboot.");
}
+
done:
FREE_ZONE(root_path, MAXPATHLEN, M_NAMEI);
DBG_TRACE("%s: exit\n", __FUNCTION__);
- return (error);
+ return;
}
projects / apple / xnu.git / blobdiff