NetBSD/sys/fs/tmpfs/tmpfs_vfsops.c
jmmv 064fbe7e18 Do not use unnamed structures/unions without instances; they break the
build under vax because of gcc 2.95.  Found by he@.
2006-02-16 14:57:50 +00:00

466 lines
13 KiB
C

/* $NetBSD: tmpfs_vfsops.c,v 1.11 2006/02/16 14:57:50 jmmv Exp $ */
/*
* Copyright (c) 2005, 2006 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 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>
__KERNEL_RCSID(0, "$NetBSD: tmpfs_vfsops.c,v 1.11 2006/02/16 14:57:50 jmmv Exp $");
#include <sys/param.h>
#include <sys/types.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <fs/tmpfs/tmpfs.h>
MALLOC_DEFINE(M_TMPFSMNT, "tmpfs mount", "tmpfs mount structures");
/* --------------------------------------------------------------------- */
static int tmpfs_mount(struct mount *, const char *, void *,
struct nameidata *, struct lwp *);
static int tmpfs_start(struct mount *, int, struct lwp *);
static int tmpfs_unmount(struct mount *, int, struct lwp *);
static int tmpfs_root(struct mount *, struct vnode **);
static int tmpfs_quotactl(struct mount *, int, uid_t, void *,
struct lwp *);
static int tmpfs_vget(struct mount *, ino_t, struct vnode **);
static int tmpfs_fhtovp(struct mount *, struct fid *, struct vnode **);
static int tmpfs_vptofh(struct vnode *, struct fid *);
static int tmpfs_statvfs(struct mount *, struct statvfs *, struct lwp *);
static int tmpfs_sync(struct mount *, int, struct ucred *, struct lwp *);
static void tmpfs_init(void);
static void tmpfs_done(void);
static int tmpfs_snapshot(struct mount *, struct vnode *,
struct timespec *);
/* --------------------------------------------------------------------- */
static int
tmpfs_mount(struct mount *mp, const char *path, void *data,
struct nameidata *ndp, struct lwp *l)
{
int error;
ino_t nodes;
size_t pages;
struct tmpfs_mount *tmp;
struct tmpfs_node *root;
struct tmpfs_args args;
/* Handle retrieval of mount point arguments. */
if (mp->mnt_flag & MNT_GETARGS) {
if (mp->mnt_data == NULL)
return EIO;
tmp = VFS_TO_TMPFS(mp);
args.ta_version = TMPFS_ARGS_VERSION;
args.ta_nodes_max = tmp->tm_nodes_max;
args.ta_size_max = tmp->tm_pages_max * PAGE_SIZE;
root = tmp->tm_root;
args.ta_root_uid = root->tn_uid;
args.ta_root_gid = root->tn_gid;
args.ta_root_mode = root->tn_mode;
return copyout(&args, data, sizeof(args));
}
/* Verify that we have parameters, as they are required. */
if (data == NULL)
return EINVAL;
/* Get the mount parameters. */
error = copyin(data, &args, sizeof(args));
if (error != 0)
return error;
if (mp->mnt_flag & MNT_UPDATE) {
/* XXX: There is no support yet to update file system
* settings. Should be added. */
return EOPNOTSUPP;
}
if (args.ta_version != TMPFS_ARGS_VERSION)
return EINVAL;
/* Do not allow mounts if we do not have enough memory to preserve
* the minimum reserved pages. */
if (tmpfs_mem_info(TRUE) < TMPFS_PAGES_RESERVED)
return EINVAL;
/* 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 (args.ta_size_max < PAGE_SIZE || args.ta_size_max >= SIZE_MAX)
pages = SIZE_MAX;
else
pages = args.ta_size_max / PAGE_SIZE +
(args.ta_size_max % PAGE_SIZE == 0 ? 0 : 1);
KASSERT(pages > 0);
if (args.ta_nodes_max <= 3)
nodes = 3 + pages * PAGE_SIZE / 1024;
else
nodes = args.ta_nodes_max;
KASSERT(nodes >= 3);
/* Allocate the tmpfs mount structure and fill it. */
tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount),
M_TMPFSMNT, M_WAITOK);
KASSERT(tmp != NULL);
tmp->tm_nodes_max = nodes;
tmp->tm_nodes_last = 2;
LIST_INIT(&tmp->tm_nodes_used);
LIST_INIT(&tmp->tm_nodes_avail);
tmp->tm_pages_max = pages;
tmp->tm_pages_used = 0;
tmpfs_pool_init(&tmp->tm_dirent_pool, sizeof(struct tmpfs_dirent),
"dirent", tmp);
tmpfs_pool_init(&tmp->tm_node_pool, sizeof(struct tmpfs_node),
"node", tmp);
tmpfs_str_pool_init(&tmp->tm_str_pool, tmp);
/* Allocate the root node. */
error = tmpfs_alloc_node(tmp, VDIR, args.ta_root_uid,
args.ta_root_gid, args.ta_root_mode & ALLPERMS, NULL, NULL,
VNOVAL, l->l_proc, &root);
KASSERT(error == 0 && root != NULL);
tmp->tm_root = root;
mp->mnt_data = tmp;
mp->mnt_flag |= MNT_LOCAL;
mp->mnt_stat.f_namemax = MAXNAMLEN;
vfs_getnewfsid(mp);
return set_statvfs_info(path, UIO_USERSPACE, "tmpfs", UIO_SYSSPACE,
mp, l);
}
/* --------------------------------------------------------------------- */
static int
tmpfs_start(struct mount *mp, int flags, struct lwp *l)
{
return 0;
}
/* --------------------------------------------------------------------- */
/* ARGSUSED2 */
static int
tmpfs_unmount(struct mount *mp, int mntflags, struct lwp *l)
{
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, NULL, flags);
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) {
struct tmpfs_dirent *de;
de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir);
while (de != NULL) {
struct tmpfs_dirent *nde;
nde = TAILQ_NEXT(de, td_entries);
tmpfs_free_dirent(tmp, de, FALSE);
de = nde;
node->tn_size -= sizeof(struct tmpfs_dirent);
}
}
next = LIST_NEXT(node, tn_entries);
tmpfs_free_node(tmp, node);
node = next;
}
node = LIST_FIRST(&tmp->tm_nodes_avail);
while (node != NULL) {
struct tmpfs_node *next;
next = LIST_NEXT(node, tn_entries);
LIST_REMOVE(node, tn_entries);
TMPFS_POOL_PUT(&tmp->tm_node_pool, node);
node = next;
}
tmpfs_pool_destroy(&tmp->tm_dirent_pool);
tmpfs_pool_destroy(&tmp->tm_node_pool);
tmpfs_str_pool_destroy(&tmp->tm_str_pool);
KASSERT(tmp->tm_pages_used == 0);
/* Throw away the tmpfs_mount structure. */
free(mp->mnt_data, M_TMPFSMNT);
mp->mnt_data = NULL;
return 0;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_root(struct mount *mp, struct vnode **vpp)
{
return tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, vpp);
}
/* --------------------------------------------------------------------- */
static int
tmpfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg,
struct lwp *l)
{
printf("tmpfs_quotactl called; need for it unknown yet\n");
return EOPNOTSUPP;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp)
{
printf("tmpfs_vget called; need for it unknown yet\n");
return EOPNOTSUPP;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_fhtovp(struct mount *mp, struct fid *fhp, 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;
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;
}
}
return found ? tmpfs_alloc_vp(mp, node, vpp) : EINVAL;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_vptofh(struct vnode *vp, struct fid *fhp)
{
struct tmpfs_fid *tfhp;
struct tmpfs_node *node;
tfhp = (struct tmpfs_fid *)fhp;
node = VP_TO_TMPFS_NODE(vp);
tfhp->tf_len = sizeof(struct tmpfs_fid);
tfhp->tf_id = node->tn_id;
tfhp->tf_gen = node->tn_gen;
return 0;
}
/* --------------------------------------------------------------------- */
/* ARGSUSED2 */
static int
tmpfs_statvfs(struct mount *mp, struct statvfs *sbp, struct lwp *l)
{
fsfilcnt_t freenodes, usednodes;
struct tmpfs_mount *tmp;
struct tmpfs_node *dummy;
tmp = VFS_TO_TMPFS(mp);
sbp->f_iosize = sbp->f_frsize = sbp->f_bsize = PAGE_SIZE;
sbp->f_blocks = TMPFS_PAGES_MAX(tmp);
sbp->f_bavail = sbp->f_bfree = TMPFS_PAGES_AVAIL(tmp);
sbp->f_bresvd = 0;
freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_last,
TMPFS_PAGES_AVAIL(tmp) * PAGE_SIZE / sizeof(struct tmpfs_node));
LIST_FOREACH(dummy, &tmp->tm_nodes_avail, tn_entries)
freenodes++;
usednodes = 0;
LIST_FOREACH(dummy, &tmp->tm_nodes_used, tn_entries)
usednodes++;
sbp->f_files = freenodes + usednodes;
sbp->f_favail = sbp->f_ffree = freenodes;
sbp->f_fresvd = 0;
copy_statvfs_info(sbp, mp);
return 0;
}
/* --------------------------------------------------------------------- */
/* ARGSUSED0 */
static int
tmpfs_sync(struct mount *mp, int waitfor, struct ucred *uc, struct lwp *l)
{
return 0;
}
/* --------------------------------------------------------------------- */
static void
tmpfs_init(void)
{
#ifdef _LKM
malloc_type_attach(M_TMPFSMNT);
#endif
}
/* --------------------------------------------------------------------- */
static void
tmpfs_done(void)
{
#ifdef _LKM
malloc_type_detach(M_TMPFSMNT);
#endif
}
/* --------------------------------------------------------------------- */
static int
tmpfs_snapshot(struct mount *mp, struct vnode *vp, struct timespec *ctime)
{
return EOPNOTSUPP;
}
/* --------------------------------------------------------------------- */
/*
* tmpfs vfs operations.
*/
extern const struct vnodeopv_desc tmpfs_fifoop_opv_desc;
extern const struct vnodeopv_desc tmpfs_specop_opv_desc;
extern const struct vnodeopv_desc tmpfs_vnodeop_opv_desc;
const struct vnodeopv_desc * const tmpfs_vnodeopv_descs[] = {
&tmpfs_fifoop_opv_desc,
&tmpfs_specop_opv_desc,
&tmpfs_vnodeop_opv_desc,
NULL,
};
struct vfsops tmpfs_vfsops = {
MOUNT_TMPFS, /* vfs_name */
tmpfs_mount, /* vfs_mount */
tmpfs_start, /* vfs_start */
tmpfs_unmount, /* vfs_unmount */
tmpfs_root, /* vfs_root */
tmpfs_quotactl, /* vfs_quotactl */
tmpfs_statvfs, /* vfs_statvfs */
tmpfs_sync, /* vfs_sync */
tmpfs_vget, /* vfs_vget */
tmpfs_fhtovp, /* vfs_fhtovp */
tmpfs_vptofh, /* vfs_vptofh */
tmpfs_init, /* vfs_init */
NULL, /* vfs_reinit */
tmpfs_done, /* vfs_done */
NULL, /* vfs_mountroot */
tmpfs_snapshot, /* vfs_snapshot */
vfs_stdextattrctl, /* vfs_extattrctl */
tmpfs_vnodeopv_descs,
};
VFS_ATTACH(tmpfs_vfsops);