--- /dev/null
+/*
+ * Copyright (c) 2012 Apple Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ */
+
+#include <kern/assert.h>
+#include <kern/debug.h>
+#include <libkern/libkern.h>
+#include <miscfs/mockfs/mockfs.h>
+#include <miscfs/mockfs/mockfs_fsnode.h>
+#include <miscfs/mockfs/mockfs_vnops.h>
+#include <miscfs/specfs/specdev.h>
+#include <sys/disk.h>
+#include <sys/errno.h>
+#include <sys/malloc.h>
+#include <sys/mount_internal.h>
+#include <sys/vnode_internal.h>
+
+lck_attr_t * mockfs_mtx_attr = (lck_attr_t *) 0;
+lck_grp_attr_t * mockfs_grp_attr = (lck_grp_attr_t *) 0;
+lck_grp_t * mockfs_mtx_grp = (lck_grp_t *) 0;
+
+int mockfs_mountroot(mount_t mp, vnode_t rvp, __unused vfs_context_t ctx);
+
+/*
+ * Functions that are part of the mockfs_vfsops structure.
+ */
+int mockfs_unmount(__unused struct mount *mp, __unused int mntflags, __unused vfs_context_t ctx);
+int mockfs_root(mount_t mp, vnode_t * vpp, __unused vfs_context_t ctx);
+int mockfs_sync(__unused struct mount *mp, __unused int waitfor, __unused vfs_context_t ctx);
+int mockfs_init(__unused struct vfsconf * vfsc);
+
+/*
+ * mockfs_mountroot:
+ * Given a mount (mp) and a vnode for the root device (rvp), builds a fake filesystem for rvp. This consists
+ * of three nodes; a directory node (to serve as a mountpoint for devfs), a file node meant to serve as an
+ * executable frontend for rootvp (we will assume that rootvp is an executable, that the kernel can subsequently
+ * run), and the root node for the mockfs filesystem. The structure of mockfs is memory-backed; only the
+ * contents of the file node refer to the backing device.
+ *
+ * Returns 0 on success, or an error.
+ */
+int mockfs_mountroot(mount_t mp, vnode_t rvp, __unused vfs_context_t ctx)
+{
+ int rvalue = 0;
+ mockfs_fsnode_t root_fsnode = NULL;
+ mockfs_fsnode_t dev_fsnode = NULL;
+ mockfs_fsnode_t file_fsnode = NULL;
+ mockfs_mount_t mockfs_mount_data = NULL;
+ dk_memdev_info_t memdev_info;
+
+ /*
+ * TODO: Validate that the device at least LOOKS like a mach-o (has a sane header); this would prevent us
+ * from causing EBADMACHO panics further along the boot path.
+ */
+
+ /*
+ * There are no M_MOCKFS* definitions at the moment, just use M_TEMP.
+ */
+
+ MALLOC(mockfs_mount_data, mockfs_mount_t, sizeof(*mockfs_mount_data), M_TEMP, M_WAITOK | M_ZERO);
+ mockfs_fsnode_create(mp, MOCKFS_ROOT, &root_fsnode);
+ mockfs_fsnode_create(mp, MOCKFS_DEV, &dev_fsnode);
+ mockfs_fsnode_create(mp, MOCKFS_FILE, &file_fsnode);
+
+ if (!mockfs_mount_data || !root_fsnode || !dev_fsnode || !file_fsnode) {
+ rvalue = ENOMEM;
+ goto done;
+ }
+
+ /*
+ * If rvp is a memory device (with a few caveats), we can point to the same physical memory as the device
+ * and avoid pointless paging/copying; query the device node for the information we need to determine
+ * if we can do this.
+ */
+ bzero(&memdev_info, sizeof(memdev_info));
+
+ if (!VNOP_IOCTL(rvp, DKIOCGETMEMDEVINFO, (caddr_t)&memdev_info, 0, NULL)) {
+ /*
+ * For the moment, we won't try to optimize when mi_phys is true.
+ */
+ if (!mockfs_mount_data->mockfs_physical_memory) {
+ mockfs_mount_data->mockfs_memory_backed = memdev_info.mi_mdev;
+ mockfs_mount_data->mockfs_physical_memory = memdev_info.mi_phys;
+ mockfs_mount_data->mockfs_memdev_base = memdev_info.mi_base;
+ mockfs_mount_data->mockfs_memdev_size = memdev_info.mi_size;
+ }
+ }
+
+ lck_mtx_init(&mockfs_mount_data->mockfs_mnt_mtx, mockfs_mtx_grp, mockfs_mtx_attr);
+
+ /*
+ * All of the needed nodes/structures have been set up; now we just need to establish the relationships
+ * between the various mockfs nodes.
+ */
+ if ((rvalue = mockfs_fsnode_adopt(root_fsnode, dev_fsnode)))
+ goto done;
+
+ if ((rvalue = mockfs_fsnode_adopt(root_fsnode, file_fsnode)))
+ goto done;
+
+ mockfs_mount_data->mockfs_root = root_fsnode;
+ mp->mnt_data = (typeof(mp->mnt_data)) mockfs_mount_data;
+
+done:
+ if (rvalue) {
+ if (file_fsnode)
+ mockfs_fsnode_destroy(file_fsnode);
+ if (dev_fsnode)
+ mockfs_fsnode_destroy(dev_fsnode);
+ if (root_fsnode)
+ mockfs_fsnode_destroy(root_fsnode);
+ if (mockfs_mount_data) {
+ lck_mtx_destroy(&mockfs_mount_data->mockfs_mnt_mtx, mockfs_mtx_grp);
+ FREE(mockfs_mount_data, M_TEMP);
+ }
+ }
+
+ return rvalue;
+}
+
+/*
+ * mockfs_unmount:
+ * Given a mount (mp), and associated flags (mntflags), performs the necessary teardown to destroy the mount.
+ *
+ * Returns 0 on success, or an error.
+ */
+int mockfs_unmount(struct mount *mp, int mntflags, __unused vfs_context_t ctx)
+{
+ int rvalue;
+ int vflush_flags;
+ mockfs_fsnode_t root_fsnode;
+ mockfs_mount_t mockfs_mnt;
+
+ vflush_flags = 0;
+ mockfs_mnt = (mockfs_mount_t) mp->mnt_data;
+
+ /*
+ * Reclaim the vnodes for the mount (forcibly, if requested; given that mockfs only support mountroot
+ * at the moment, this should ALWAYS be forced),
+ */
+ if (mntflags & MNT_FORCE) {
+ vflush_flags |= FORCECLOSE;
+ }
+
+ rvalue = vflush(mp, NULL, vflush_flags);
+
+ if (rvalue)
+ return rvalue;
+
+ /*
+ * Past this point, errors are likely to be unrecoverable, so panic if we're given any excuse; we
+ * need to teardown the mockfs_mnt data now, so that VFS can cleanup the mount structure. Note
+ * that clearing mockfs_root before destroying the fsnode tree is related to an implementation
+ * detail of mockfs_fsnode_destroy (which will refuse to destroy the root node).
+ */
+ root_fsnode = mockfs_mnt->mockfs_root;
+ mockfs_mnt->mockfs_root = NULL;
+ rvalue = mockfs_fsnode_destroy(root_fsnode);
+
+ if (rvalue)
+ panic("mockfs_unmount: Failed to destroy the fsnode tree");
+
+ lck_mtx_destroy(&mockfs_mnt->mockfs_mnt_mtx, mockfs_mtx_grp);
+ FREE(mockfs_mnt, M_TEMP);
+ mp->mnt_data = NULL;
+
+ return rvalue;
+}
+
+/*
+ * mockfs_root:
+ * Given a mount (mp), returns the root vnode (*vpp) for that mount with an iocount.
+ *
+ * Returns 0 on success, or an error.
+ */
+int mockfs_root(mount_t mp, vnode_t * vpp, __unused vfs_context_t ctx)
+{
+ int rvalue;
+
+ rvalue = mockfs_fsnode_vnode(((mockfs_mount_t) mp->mnt_data)->mockfs_root, vpp);
+ return rvalue;
+}
+
+/*
+ * mockfs_sync:
+ * Returns success because we're a read-only filesystem.
+ *
+ * Returns 0.
+ */
+int mockfs_sync(__unused struct mount *mp, __unused int waitfor, __unused vfs_context_t ctx)
+{
+ return (0);
+}
+
+/*
+ * mockfs_init:
+ * Run once (during VFS initialization); takes care of generic mockfs initialization (which for now, means
+ * global lock information).
+ *
+ * Returns 0 on success, or an error.
+ */
+int mockfs_init(__unused struct vfsconf * vfsc)
+{
+ mockfs_mtx_attr = lck_attr_alloc_init();
+ mockfs_grp_attr = lck_grp_attr_alloc_init();
+ mockfs_mtx_grp = lck_grp_alloc_init("mockfs-mutex", mockfs_grp_attr);
+
+ /*
+ * If we've failed to allocate this early in boot, something is horrendously wrong; it should be fine to
+ * panic (for now).
+ */
+ if (!mockfs_mtx_attr || !mockfs_grp_attr || !mockfs_mtx_grp) {
+ panic("mockfs_init failed to allocate lock information");
+ }
+
+ return (0);
+}
+
+struct vfsops mockfs_vfsops = {
+ NULL, /* mount */
+ NULL, /* start */
+ mockfs_unmount, /* unmount */
+ mockfs_root, /* root */
+ NULL, /* quotactl */
+ NULL, /* getattr */
+ mockfs_sync, /* sync */
+ NULL, /* vget */
+ NULL, /* fhtovp */
+ NULL, /* vptofh */
+ mockfs_init, /* init */
+ NULL, /* sysctl */
+ NULL, /* setattr */
+ {NULL}
+};
+
projects / apple / xnu.git / blobdiff