1 files changed, 423 insertions, 0 deletions
diff --git a/sys/fs/tmpfs/tmpfs_vfsops.c b/sys/fs/tmpfs/tmpfs_vfsops.c
new file mode 100644
index 0000000..4d55f51
--- /dev/null
+++ b/sys/fs/tmpfs/tmpfs_vfsops.c
@@ -0,0 +1,423 @@
+/*	$NetBSD: tmpfs_vfsops.c,v 1.10 2005/12/11 12:24:29 christos Exp $	*/
+
+/*-
+ * Copyright (c) 2005 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
+ * 2005 program.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * Efficient memory file system.
+ *
+ * tmpfs is a file system that uses NetBSD's virtual memory sub-system
+ * (the well-known UVM) to store file data and metadata in an efficient
+ * way.  This means that it does not follow the structure of an on-disk
+ * file system because it simply does not need to.  Instead, it uses
+ * memory-specific data structures and algorithms to automatically
+ * allocate and release resources.
+ */
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/limits.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/kernel.h>
+#include <sys/stat.h>
+#include <sys/systm.h>
+#include <sys/sysctl.h>
+
+#include <vm/vm.h>
+#include <vm/vm_object.h>
+#include <vm/vm_param.h>
+
+#include <fs/tmpfs/tmpfs.h>
+
+/*
+ * Default permission for root node
+ */
+#define TMPFS_DEFAULT_ROOT_MODE	(S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH)
+
+MALLOC_DEFINE(M_TMPFSMNT, "tmpfs mount", "tmpfs mount structures");
+MALLOC_DEFINE(M_TMPFSNAME, "tmpfs name", "tmpfs file names");
+
+/* --------------------------------------------------------------------- */
+
+static int	tmpfs_mount(struct mount *);
+static int	tmpfs_unmount(struct mount *, int);
+static int	tmpfs_root(struct mount *, int flags, struct vnode **);
+static int	tmpfs_fhtovp(struct mount *, struct fid *, int,
+		    struct vnode **);
+static int	tmpfs_statfs(struct mount *, struct statfs *);
+
+/* --------------------------------------------------------------------- */
+
+static const char *tmpfs_opts[] = {
+	"from", "size", "maxfilesize", "inodes", "uid", "gid", "mode", "export",
+	"union", NULL
+};
+
+static const char *tmpfs_updateopts[] = {
+	"from", "export", NULL
+};
+
+/* --------------------------------------------------------------------- */
+
+static int
+tmpfs_node_ctor(void *mem, int size, void *arg, int flags)
+{
+	struct tmpfs_node *node = (struct tmpfs_node *)mem;
+
+	node->tn_gen++;
+	node->tn_size = 0;
+	node->tn_status = 0;
+	node->tn_flags = 0;
+	node->tn_links = 0;
+	node->tn_vnode = NULL;
+	node->tn_vpstate = 0;
+
+	return (0);
+}
+
+static void
+tmpfs_node_dtor(void *mem, int size, void *arg)
+{
+	struct tmpfs_node *node = (struct tmpfs_node *)mem;
+	node->tn_type = VNON;
+}
+
+static int
+tmpfs_node_init(void *mem, int size, int flags)
+{
+	struct tmpfs_node *node = (struct tmpfs_node *)mem;
+	node->tn_id = 0;
+
+	mtx_init(&node->tn_interlock, "tmpfs node interlock", NULL, MTX_DEF);
+	node->tn_gen = arc4random();
+
+	return (0);
+}
+
+static void
+tmpfs_node_fini(void *mem, int size)
+{
+	struct tmpfs_node *node = (struct tmpfs_node *)mem;
+
+	mtx_destroy(&node->tn_interlock);
+}
+
+static int
+tmpfs_mount(struct mount *mp)
+{
+	const size_t nodes_per_page = howmany(PAGE_SIZE,
+	    sizeof(struct tmpfs_dirent) + sizeof(struct tmpfs_node));
+	struct tmpfs_mount *tmp;
+	struct tmpfs_node *root;
+	int error;
+	/* Size counters. */
+	u_quad_t pages;
+	off_t nodes_max, size_max, maxfilesize;
+
+	/* Root node attributes. */
+	uid_t root_uid;
+	gid_t root_gid;
+	mode_t root_mode;
+
+	struct vattr va;
+
+	if (vfs_filteropt(mp->mnt_optnew, tmpfs_opts))
+		return (EINVAL);
+
+	if (mp->mnt_flag & MNT_UPDATE) {
+		/* Only support update mounts for certain options. */
+		if (vfs_filteropt(mp->mnt_optnew, tmpfs_updateopts) != 0)
+			return (EOPNOTSUPP);
+		if (vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0) !=
+		    ((struct tmpfs_mount *)mp->mnt_data)->tm_ronly)
+			return (EOPNOTSUPP);
+		return (0);
+	}
+
+	vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY);
+	error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred);
+	VOP_UNLOCK(mp->mnt_vnodecovered, 0);
+	if (error)
+		return (error);
+
+	if (mp->mnt_cred->cr_ruid != 0 ||
+	    vfs_scanopt(mp->mnt_optnew, "gid", "%d", &root_gid) != 1)
+		root_gid = va.va_gid;
+	if (mp->mnt_cred->cr_ruid != 0 ||
+	    vfs_scanopt(mp->mnt_optnew, "uid", "%d", &root_uid) != 1)
+		root_uid = va.va_uid;
+	if (mp->mnt_cred->cr_ruid != 0 ||
+	    vfs_scanopt(mp->mnt_optnew, "mode", "%ho", &root_mode) != 1)
+		root_mode = va.va_mode;
+	if (vfs_getopt_size(mp->mnt_optnew, "inodes", &nodes_max) != 0)
+		nodes_max = 0;
+	if (vfs_getopt_size(mp->mnt_optnew, "size", &size_max) != 0)
+		size_max = 0;
+	if (vfs_getopt_size(mp->mnt_optnew, "maxfilesize", &maxfilesize) != 0)
+		maxfilesize = 0;
+
+	/* Do not allow mounts if we do not have enough memory to preserve
+	 * the minimum reserved pages. */
+	if (tmpfs_mem_avail() < TMPFS_PAGES_MINRESERVED)
+		return ENOSPC;
+
+	/* Get the maximum number of memory pages this file system is
+	 * allowed to use, based on the maximum size the user passed in
+	 * the mount structure.  A value of zero is treated as if the
+	 * maximum available space was requested. */
+	if (size_max < PAGE_SIZE || size_max > OFF_MAX - PAGE_SIZE ||
+	    (SIZE_MAX < OFF_MAX && size_max / PAGE_SIZE >= SIZE_MAX))
+		pages = SIZE_MAX;
+	else
+		pages = howmany(size_max, PAGE_SIZE);
+	MPASS(pages > 0);
+
+	if (nodes_max <= 3) {
+		if (pages < INT_MAX / nodes_per_page)
+			nodes_max = pages * nodes_per_page;
+		else
+			nodes_max = INT_MAX;
+	}
+	if (nodes_max > INT_MAX)
+		nodes_max = INT_MAX;
+	MPASS(nodes_max >= 3);
+
+	/* Allocate the tmpfs mount structure and fill it. */
+	tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount),
+	    M_TMPFSMNT, M_WAITOK | M_ZERO);
+
+	mtx_init(&tmp->allnode_lock, "tmpfs allnode lock", NULL, MTX_DEF);
+	tmp->tm_nodes_max = nodes_max;
+	tmp->tm_nodes_inuse = 0;
+	tmp->tm_maxfilesize = maxfilesize > 0 ? maxfilesize : OFF_MAX;
+	LIST_INIT(&tmp->tm_nodes_used);
+
+	tmp->tm_pages_max = pages;
+	tmp->tm_pages_used = 0;
+	tmp->tm_ino_unr = new_unrhdr(2, INT_MAX, &tmp->allnode_lock);
+	tmp->tm_dirent_pool = uma_zcreate("TMPFS dirent",
+	    sizeof(struct tmpfs_dirent),
+	    NULL, NULL, NULL, NULL,
+	    UMA_ALIGN_PTR, 0);
+	tmp->tm_node_pool = uma_zcreate("TMPFS node",
+	    sizeof(struct tmpfs_node),
+	    tmpfs_node_ctor, tmpfs_node_dtor,
+	    tmpfs_node_init, tmpfs_node_fini,
+	    UMA_ALIGN_PTR, 0);
+	tmp->tm_ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
+
+	/* Allocate the root node. */
+	error = tmpfs_alloc_node(tmp, VDIR, root_uid,
+	    root_gid, root_mode & ALLPERMS, NULL, NULL,
+	    VNOVAL, &root);
+
+	if (error != 0 || root == NULL) {
+	    uma_zdestroy(tmp->tm_node_pool);
+	    uma_zdestroy(tmp->tm_dirent_pool);
+	    delete_unrhdr(tmp->tm_ino_unr);
+	    free(tmp, M_TMPFSMNT);
+	    return error;
+	}
+	KASSERT(root->tn_id == 2,
+	    ("tmpfs root with invalid ino: %ju", (uintmax_t)root->tn_id));
+	tmp->tm_root = root;
+
+	MNT_ILOCK(mp);
+	mp->mnt_flag |= MNT_LOCAL;
+	MNT_IUNLOCK(mp);
+
+	mp->mnt_data = tmp;
+	mp->mnt_stat.f_namemax = MAXNAMLEN;
+	vfs_getnewfsid(mp);
+	vfs_mountedfrom(mp, "tmpfs");
+
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+/* ARGSUSED2 */
+static int
+tmpfs_unmount(struct mount *mp, int mntflags)
+{
+	int error;
+	int flags = 0;
+	struct tmpfs_mount *tmp;
+	struct tmpfs_node *node;
+
+	/* Handle forced unmounts. */
+	if (mntflags & MNT_FORCE)
+		flags |= FORCECLOSE;
+
+	/* Finalize all pending I/O. */
+	error = vflush(mp, 0, flags, curthread);
+	if (error != 0)
+		return error;
+
+	tmp = VFS_TO_TMPFS(mp);
+
+	/* Free all associated data.  The loop iterates over the linked list
+	 * we have containing all used nodes.  For each of them that is
+	 * a directory, we free all its directory entries.  Note that after
+	 * freeing a node, it will automatically go to the available list,
+	 * so we will later have to iterate over it to release its items. */
+	node = LIST_FIRST(&tmp->tm_nodes_used);
+	while (node != NULL) {
+		struct tmpfs_node *next;
+
+		if (node->tn_type == VDIR)
+			tmpfs_dir_destroy(tmp, node);
+
+		next = LIST_NEXT(node, tn_entries);
+		tmpfs_free_node(tmp, node);
+		node = next;
+	}
+
+	uma_zdestroy(tmp->tm_dirent_pool);
+	uma_zdestroy(tmp->tm_node_pool);
+	delete_unrhdr(tmp->tm_ino_unr);
+
+	mtx_destroy(&tmp->allnode_lock);
+	MPASS(tmp->tm_pages_used == 0);
+	MPASS(tmp->tm_nodes_inuse == 0);
+
+	/* Throw away the tmpfs_mount structure. */
+	free(mp->mnt_data, M_TMPFSMNT);
+	mp->mnt_data = NULL;
+
+	MNT_ILOCK(mp);
+	mp->mnt_flag &= ~MNT_LOCAL;
+	MNT_IUNLOCK(mp);
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+static int
+tmpfs_root(struct mount *mp, int flags, struct vnode **vpp)
+{
+	int error;
+	error = tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, flags, vpp);
+
+	if (!error)
+		(*vpp)->v_vflag |= VV_ROOT;
+
+	return error;
+}
+
+/* --------------------------------------------------------------------- */
+
+static int
+tmpfs_fhtovp(struct mount *mp, struct fid *fhp, int flags,
+    struct vnode **vpp)
+{
+	boolean_t found;
+	struct tmpfs_fid *tfhp;
+	struct tmpfs_mount *tmp;
+	struct tmpfs_node *node;
+
+	tmp = VFS_TO_TMPFS(mp);
+
+	tfhp = (struct tmpfs_fid *)fhp;
+	if (tfhp->tf_len != sizeof(struct tmpfs_fid))
+		return EINVAL;
+
+	if (tfhp->tf_id >= tmp->tm_nodes_max)
+		return EINVAL;
+
+	found = FALSE;
+
+	TMPFS_LOCK(tmp);
+	LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) {
+		if (node->tn_id == tfhp->tf_id &&
+		    node->tn_gen == tfhp->tf_gen) {
+			found = TRUE;
+			break;
+		}
+	}
+	TMPFS_UNLOCK(tmp);
+
+	if (found)
+		return (tmpfs_alloc_vp(mp, node, LK_EXCLUSIVE, vpp));
+
+	return (EINVAL);
+}
+
+/* --------------------------------------------------------------------- */
+
+/* ARGSUSED2 */
+static int
+tmpfs_statfs(struct mount *mp, struct statfs *sbp)
+{
+	struct tmpfs_mount *tmp;
+	size_t used;
+
+	tmp = VFS_TO_TMPFS(mp);
+
+	sbp->f_iosize = PAGE_SIZE;
+	sbp->f_bsize = PAGE_SIZE;
+
+	used = tmpfs_pages_used(tmp);
+	if (tmp->tm_pages_max != SIZE_MAX)
+		 sbp->f_blocks = tmp->tm_pages_max;
+	else
+		 sbp->f_blocks = used + tmpfs_mem_avail();
+	if (sbp->f_blocks <= used)
+		sbp->f_bavail = 0;
+	else
+		sbp->f_bavail = sbp->f_blocks - used;
+	sbp->f_bfree = sbp->f_bavail;
+	used = tmp->tm_nodes_inuse;
+	sbp->f_files = tmp->tm_nodes_max;
+	if (sbp->f_files <= used)
+		sbp->f_ffree = 0;
+	else
+		sbp->f_ffree = sbp->f_files - used;
+	/* sbp->f_owner = tmp->tn_uid; */
+
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+/*
+ * tmpfs vfs operations.
+ */
+
+struct vfsops tmpfs_vfsops = {
+	.vfs_mount =			tmpfs_mount,
+	.vfs_unmount =			tmpfs_unmount,
+	.vfs_root =			tmpfs_root,
+	.vfs_statfs =			tmpfs_statfs,
+	.vfs_fhtovp =			tmpfs_fhtovp,
+};
+VFS_SET(tmpfs_vfsops, tmpfs, 0);