380 lines
9.9 KiB
C
380 lines
9.9 KiB
C
/* $OpenBSD: tmpfs_vfsops.c,v 1.19 2021/10/24 15:41:47 patrick Exp $ */
|
|
/* $NetBSD: tmpfs_vfsops.c,v 1.52 2011/09/27 01:10:43 christos Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 2005, 2006, 2007 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/param.h>
|
|
#include <sys/mount.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/vnode.h>
|
|
#include <sys/malloc.h>
|
|
|
|
#include <tmpfs/tmpfs.h>
|
|
|
|
/* MODULE(MODULE_CLASS_VFS, tmpfs, NULL); */
|
|
|
|
struct pool tmpfs_dirent_pool;
|
|
struct pool tmpfs_node_pool;
|
|
|
|
int tmpfs_mount(struct mount *, const char *, void *, struct nameidata *,
|
|
struct proc *);
|
|
int tmpfs_start(struct mount *, int, struct proc *);
|
|
int tmpfs_unmount(struct mount *, int, struct proc *);
|
|
int tmpfs_root(struct mount *, struct vnode **);
|
|
int tmpfs_vget(struct mount *, ino_t, struct vnode **);
|
|
int tmpfs_fhtovp(struct mount *, struct fid *, struct vnode **);
|
|
int tmpfs_vptofh(struct vnode *, struct fid *);
|
|
int tmpfs_statfs(struct mount *, struct statfs *, struct proc *);
|
|
int tmpfs_sync(struct mount *, int, int, struct ucred *, struct proc *);
|
|
int tmpfs_init(struct vfsconf *);
|
|
int tmpfs_mount_update(struct mount *);
|
|
|
|
int
|
|
tmpfs_init(struct vfsconf *vfsp)
|
|
{
|
|
|
|
pool_init(&tmpfs_dirent_pool, sizeof(tmpfs_dirent_t), 0, IPL_NONE,
|
|
PR_WAITOK, "tmpfs_dirent", NULL);
|
|
pool_init(&tmpfs_node_pool, sizeof(tmpfs_node_t), 0, IPL_NONE,
|
|
PR_WAITOK, "tmpfs_node", NULL);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
tmpfs_mount_update(struct mount *mp)
|
|
{
|
|
tmpfs_mount_t *tmp;
|
|
struct vnode *rootvp;
|
|
int error;
|
|
|
|
if ((mp->mnt_flag & MNT_RDONLY) == 0)
|
|
return EOPNOTSUPP;
|
|
|
|
/* ro->rw transition: nothing to do? */
|
|
if (mp->mnt_flag & MNT_WANTRDWR)
|
|
return 0;
|
|
|
|
tmp = mp->mnt_data;
|
|
rootvp = tmp->tm_root->tn_vnode;
|
|
|
|
/* Lock root to prevent lookups. */
|
|
error = vn_lock(rootvp, LK_EXCLUSIVE | LK_RETRY);
|
|
if (error)
|
|
return error;
|
|
|
|
/* Lock mount point to prevent nodes from being added/removed. */
|
|
rw_enter_write(&tmp->tm_lock);
|
|
|
|
/* Flush files opened for writing; skip rootvp. */
|
|
error = vflush(mp, rootvp, WRITECLOSE);
|
|
|
|
rw_exit_write(&tmp->tm_lock);
|
|
VOP_UNLOCK(rootvp);
|
|
|
|
return error;
|
|
}
|
|
|
|
int
|
|
tmpfs_mount(struct mount *mp, const char *path, void *data,
|
|
struct nameidata *ndp, struct proc *p)
|
|
{
|
|
struct tmpfs_args *args = data;
|
|
tmpfs_mount_t *tmp;
|
|
tmpfs_node_t *root;
|
|
uint64_t memlimit;
|
|
uint64_t nodes;
|
|
int error;
|
|
|
|
if (mp->mnt_flag & MNT_UPDATE)
|
|
return (tmpfs_mount_update(mp));
|
|
|
|
/* Prohibit mounts if there is not enough memory. */
|
|
if (tmpfs_mem_info(1) < TMPFS_PAGES_RESERVED)
|
|
return EINVAL;
|
|
|
|
if (args->ta_root_uid == VNOVAL || args->ta_root_gid == VNOVAL ||
|
|
args->ta_root_mode == VNOVAL)
|
|
return EINVAL;
|
|
|
|
/* Get the memory usage limit for this file-system. */
|
|
if (args->ta_size_max < PAGE_SIZE) {
|
|
memlimit = UINT64_MAX;
|
|
} else {
|
|
memlimit = args->ta_size_max;
|
|
}
|
|
KASSERT(memlimit > 0);
|
|
|
|
if (args->ta_nodes_max <= 3) {
|
|
nodes = 3 + (memlimit / 1024);
|
|
} else {
|
|
nodes = args->ta_nodes_max;
|
|
}
|
|
nodes = MIN(nodes, INT_MAX);
|
|
KASSERT(nodes >= 3);
|
|
|
|
/* Allocate the tmpfs mount structure and fill it. */
|
|
tmp = malloc(sizeof(tmpfs_mount_t), M_MISCFSMNT, M_WAITOK);
|
|
|
|
tmp->tm_nodes_max = (ino_t)nodes;
|
|
tmp->tm_nodes_cnt = 0;
|
|
tmp->tm_highest_inode = 1;
|
|
LIST_INIT(&tmp->tm_nodes);
|
|
|
|
rw_init(&tmp->tm_lock, "tmplk");
|
|
tmpfs_mntmem_init(tmp, memlimit);
|
|
|
|
/* Allocate the root node. */
|
|
error = tmpfs_alloc_node(tmp, VDIR, args->ta_root_uid,
|
|
args->ta_root_gid, args->ta_root_mode & ALLPERMS, NULL,
|
|
VNOVAL, &root);
|
|
KASSERT(error == 0 && root != NULL);
|
|
|
|
/*
|
|
* Parent of the root inode is itself. Also, root inode has no
|
|
* directory entry (i.e. is never attached), thus hold an extra
|
|
* reference (link) for it.
|
|
*/
|
|
root->tn_links++;
|
|
root->tn_spec.tn_dir.tn_parent = root;
|
|
tmp->tm_root = root;
|
|
|
|
mp->mnt_data = tmp;
|
|
mp->mnt_flag |= MNT_LOCAL;
|
|
mp->mnt_stat.f_namemax = TMPFS_MAXNAMLEN;
|
|
vfs_getnewfsid(mp);
|
|
|
|
mp->mnt_stat.mount_info.tmpfs_args = *args;
|
|
|
|
bzero(&mp->mnt_stat.f_mntonname, sizeof(mp->mnt_stat.f_mntonname));
|
|
bzero(&mp->mnt_stat.f_mntfromname, sizeof(mp->mnt_stat.f_mntfromname));
|
|
bzero(&mp->mnt_stat.f_mntfromspec, sizeof(mp->mnt_stat.f_mntfromspec));
|
|
|
|
strlcpy(mp->mnt_stat.f_mntonname, path,
|
|
sizeof(mp->mnt_stat.f_mntonname) - 1);
|
|
strlcpy(mp->mnt_stat.f_mntfromname, "tmpfs",
|
|
sizeof(mp->mnt_stat.f_mntfromname) - 1);
|
|
strlcpy(mp->mnt_stat.f_mntfromspec, "tmpfs",
|
|
sizeof(mp->mnt_stat.f_mntfromspec) - 1);
|
|
|
|
return error;
|
|
}
|
|
|
|
int
|
|
tmpfs_start(struct mount *mp, int flags, struct proc *p)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
tmpfs_unmount(struct mount *mp, int mntflags, struct proc *p)
|
|
{
|
|
tmpfs_mount_t *tmp = VFS_TO_TMPFS(mp);
|
|
tmpfs_node_t *node, *cnode;
|
|
int error, flags = 0;
|
|
|
|
/* Handle forced unmounts. */
|
|
if (mntflags & MNT_FORCE)
|
|
flags |= FORCECLOSE;
|
|
|
|
/* Finalize all pending I/O. */
|
|
error = vflush(mp, NULL, flags);
|
|
if (error != 0)
|
|
return error;
|
|
|
|
/*
|
|
* First round, detach and destroy all directory entries.
|
|
* Also, clear the pointers to the vnodes - they are gone.
|
|
*/
|
|
LIST_FOREACH(node, &tmp->tm_nodes, tn_entries) {
|
|
tmpfs_dirent_t *de;
|
|
|
|
node->tn_vnode = NULL;
|
|
if (node->tn_type != VDIR) {
|
|
continue;
|
|
}
|
|
while ((de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir)) != NULL) {
|
|
cnode = de->td_node;
|
|
if (cnode)
|
|
cnode->tn_vnode = NULL;
|
|
tmpfs_dir_detach(node, de);
|
|
tmpfs_free_dirent(tmp, de);
|
|
}
|
|
}
|
|
|
|
/* Second round, destroy all inodes. */
|
|
while ((node = LIST_FIRST(&tmp->tm_nodes)) != NULL) {
|
|
tmpfs_free_node(tmp, node);
|
|
}
|
|
|
|
/* Throw away the tmpfs_mount structure. */
|
|
tmpfs_mntmem_destroy(tmp);
|
|
/* mutex_destroy(&tmp->tm_lock); */
|
|
/* kmem_free(tmp, sizeof(*tmp)); */
|
|
free(tmp, M_MISCFSMNT, sizeof(tmpfs_mount_t));
|
|
mp->mnt_data = NULL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
tmpfs_root(struct mount *mp, struct vnode **vpp)
|
|
{
|
|
tmpfs_node_t *node = VFS_TO_TMPFS(mp)->tm_root;
|
|
|
|
rw_enter_write(&node->tn_nlock);
|
|
return tmpfs_vnode_get(mp, node, vpp);
|
|
}
|
|
|
|
int
|
|
tmpfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp)
|
|
{
|
|
|
|
printf("tmpfs_vget called; need for it unknown yet\n");
|
|
return EOPNOTSUPP;
|
|
}
|
|
|
|
int
|
|
tmpfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
|
|
{
|
|
tmpfs_mount_t *tmp = VFS_TO_TMPFS(mp);
|
|
tmpfs_node_t *node;
|
|
tmpfs_fid_t tfh;
|
|
|
|
if (fhp->fid_len != sizeof(tmpfs_fid_t)) {
|
|
return EINVAL;
|
|
}
|
|
memcpy(&tfh, fhp, sizeof(tmpfs_fid_t));
|
|
|
|
rw_enter_write(&tmp->tm_lock);
|
|
LIST_FOREACH(node, &tmp->tm_nodes, tn_entries) {
|
|
if (node->tn_id != tfh.tf_id) {
|
|
continue;
|
|
}
|
|
if (TMPFS_NODE_GEN(node) != tfh.tf_gen) {
|
|
continue;
|
|
}
|
|
rw_enter_write(&node->tn_nlock);
|
|
break;
|
|
}
|
|
rw_exit_write(&tmp->tm_lock);
|
|
|
|
/* Will release the tn_nlock. */
|
|
return node ? tmpfs_vnode_get(mp, node, vpp) : ESTALE;
|
|
}
|
|
|
|
int
|
|
tmpfs_vptofh(struct vnode *vp, struct fid *fhp)
|
|
{
|
|
tmpfs_fid_t tfh;
|
|
tmpfs_node_t *node;
|
|
|
|
node = VP_TO_TMPFS_NODE(vp);
|
|
|
|
memset(&tfh, 0, sizeof(tfh));
|
|
tfh.tf_len = sizeof(tmpfs_fid_t);
|
|
tfh.tf_gen = TMPFS_NODE_GEN(node);
|
|
tfh.tf_id = node->tn_id;
|
|
memcpy(fhp, &tfh, sizeof(tfh));
|
|
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
tmpfs_statfs(struct mount *mp, struct statfs *sbp, struct proc *p)
|
|
{
|
|
tmpfs_mount_t *tmp;
|
|
fsfilcnt_t freenodes;
|
|
uint64_t avail;
|
|
|
|
tmp = VFS_TO_TMPFS(mp);
|
|
|
|
sbp->f_iosize = sbp->f_bsize = PAGE_SIZE;
|
|
|
|
rw_enter_write(&tmp->tm_acc_lock);
|
|
avail = tmpfs_pages_avail(tmp);
|
|
sbp->f_blocks = (tmpfs_bytes_max(tmp) >> PAGE_SHIFT);
|
|
sbp->f_bfree = avail;
|
|
sbp->f_bavail = avail & INT64_MAX; /* f_bavail is int64_t */
|
|
|
|
freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_cnt,
|
|
avail * PAGE_SIZE / sizeof(tmpfs_node_t));
|
|
|
|
sbp->f_files = tmp->tm_nodes_cnt + freenodes;
|
|
sbp->f_ffree = freenodes;
|
|
sbp->f_favail = freenodes & INT64_MAX; /* f_favail is int64_t */
|
|
rw_exit_write(&tmp->tm_acc_lock);
|
|
|
|
copy_statfs_info(sbp, mp);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
tmpfs_sync(struct mount *mp, int waitfor, int stall, struct ucred *cred,
|
|
struct proc *p)
|
|
{
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* tmpfs vfs operations.
|
|
*/
|
|
|
|
const struct vfsops tmpfs_vfsops = {
|
|
.vfs_mount = tmpfs_mount,
|
|
.vfs_start = tmpfs_start,
|
|
.vfs_unmount = tmpfs_unmount,
|
|
.vfs_root = tmpfs_root,
|
|
.vfs_quotactl = (void *)eopnotsupp,
|
|
.vfs_statfs = tmpfs_statfs,
|
|
.vfs_sync = tmpfs_sync,
|
|
.vfs_vget = tmpfs_vget,
|
|
.vfs_fhtovp = tmpfs_fhtovp,
|
|
.vfs_vptofh = tmpfs_vptofh,
|
|
.vfs_init = tmpfs_init,
|
|
.vfs_sysctl = (void *)eopnotsupp,
|
|
.vfs_checkexp = (void *)eopnotsupp,
|
|
};
|