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NetBSD/sys/fs/tmpfs/tmpfs.h

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/* $NetBSD: tmpfs.h,v 1.56 2020/05/17 19:39:15 ad Exp $ */
/*
* Copyright (c) 2005, 2006, 2007, 2020 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.
*/
#ifndef _FS_TMPFS_TMPFS_H_
#define _FS_TMPFS_TMPFS_H_
#if !defined(_KERNEL) && !defined(_KMEMUSER)
#error "not supposed to be exposed to userland"
#endif
#include <sys/dirent.h>
#include <sys/mount.h>
#include <sys/pool.h>
#include <sys/queue.h>
#include <sys/vnode.h>
/*
* Internal representation of a tmpfs directory entry.
*
* All fields are protected by vnode lock.
*/
typedef struct tmpfs_dirent {
TAILQ_ENTRY(tmpfs_dirent) td_entries;
/* Pointer to the inode this entry refers to. */
struct tmpfs_node * td_node;
/* Sequence number, see tmpfs_dir_getseq(). */
uint32_t td_seq;
/* Name and its length. */
char * td_name;
uint16_t td_namelen;
} tmpfs_dirent_t;
TAILQ_HEAD(tmpfs_dir, tmpfs_dirent);
/*
* Internal representation of a tmpfs file system node -- inode.
*
* This structure is split in two parts: one holds attributes common
* to all file types and the other holds data that is only applicable to
* a particular type.
*
* All fields are protected by vnode lock. The vnode association itself
* is protected by vcache.
*/
typedef struct tmpfs_node {
LIST_ENTRY(tmpfs_node) tn_entries;
/*
* Each inode has a corresponding vnode. It is a bi-directional
* association. Whenever vnode is allocated, its v_data field is
* set to the inode it reference, and tmpfs_node_t::tn_vnode is
* set to point to the said vnode.
*
* Further attempts to allocate a vnode for this same node will
* result in returning a new reference to the value stored in
* tn_vnode. It may be NULL when the node is unused (that is,
* no vnode has been allocated or it has been reclaimed).
*/
vnode_t * tn_vnode;
/* Prevent node from being reclaimed. */
uint32_t tn_holdcount;
/* Directory entry. Only a hint, since hard link can have multiple. */
tmpfs_dirent_t * tn_dirent_hint;
/* The inode type: VBLK, VCHR, VDIR, VFIFO, VLNK, VREG or VSOCK. */
enum vtype tn_type;
/* Inode identifier and generation number. */
ino_t tn_id;
uint32_t tn_gen;
/* The inode size. */
off_t tn_size;
/* Generic node attributes. */
uid_t tn_uid;
gid_t tn_gid;
mode_t tn_mode;
int tn_flags;
nlink_t tn_links;
unsigned tn_tflags;
struct timespec tn_atime;
struct timespec tn_mtime;
struct timespec tn_ctime;
struct timespec tn_birthtime;
kmutex_t tn_timelock;
/* Head of byte-level lock list (used by tmpfs_advlock). */
struct lockf * tn_lockf;
union {
/* Type case: VBLK or VCHR. */
struct {
dev_t tn_rdev;
} tn_dev;
/* Type case: VDIR. */
struct {
/* Parent directory (root inode points to itself). */
struct tmpfs_node * tn_parent;
/* List of directory entries. */
struct tmpfs_dir tn_dir;
/* Last given sequence number and their arena. */
uint32_t tn_next_seq;
void * tn_seq_arena;
/*
* Pointer of the last directory entry returned
* by the readdir(3) operation.
*/
struct tmpfs_dirent * tn_readdir_lastp;
} tn_dir;
/* Type case: VLNK. */
struct tn_lnk {
/* The link's target. */
char * tn_link;
} tn_lnk;
/* Type case: VREG. */
struct tn_reg {
/* Underlying UVM object to store contents. */
struct uvm_object * tn_aobj;
size_t tn_aobj_pages;
} tn_reg;
} tn_spec;
} tmpfs_node_t;
#if defined(_KERNEL)
VFS_PROTOS(tmpfs);
LIST_HEAD(tmpfs_node_list, tmpfs_node);
#define TMPFS_MAXNAMLEN 255
/* Validate maximum td_namelen length. */
CTASSERT(TMPFS_MAXNAMLEN < UINT16_MAX);
/*
* Reserved values for the virtual entries (the first must be 0) and EOF.
* The start/end of the incremental range, see tmpfs_dir_getseq().
*/
#define TMPFS_DIRSEQ_DOT 0
#define TMPFS_DIRSEQ_DOTDOT 1
#define TMPFS_DIRSEQ_EOF 2
#define TMPFS_DIRSEQ_START 3 /* inclusive */
#define TMPFS_DIRSEQ_END (1U << 30) /* exclusive */
/* Mark to indicate that the number is not set. */
#define TMPFS_DIRSEQ_NONE (1U << 31)
/* Flags: time update requests. */
#define TMPFS_UPDATE_ATIME 0x01
#define TMPFS_UPDATE_MTIME 0x02
#define TMPFS_UPDATE_CTIME 0x04
/*
* Bits indicating whiteout use for the directory.
* We abuse tmpfs_node_t::tn_gen for that.
*/
#define TMPFS_WHITEOUT_BIT (1U << 31)
#define TMPFS_NODE_GEN_MASK (TMPFS_WHITEOUT_BIT - 1)
#define TMPFS_NODE_GEN(node) \
((node)->tn_gen & TMPFS_NODE_GEN_MASK)
/* White-out inode indicator. */
#define TMPFS_NODE_WHITEOUT ((tmpfs_node_t *)-1)
/*
* Bit indicating this node must be reclaimed when holdcount reaches zero.
* Ored into tmpfs_node_t::tn_holdcount.
*/
#define TMPFS_NODE_RECLAIMED (1U << 30)
/*
* Internal representation of a tmpfs mount point.
*/
typedef struct tmpfs_mount {
/* Limit and number of bytes in use by the file system. */
uint64_t tm_mem_limit;
uint64_t tm_bytes_used;
kmutex_t tm_acc_lock;
/* Pointer to the root inode. */
tmpfs_node_t * tm_root;
/* Maximum number of possible nodes for this file system. */
unsigned int tm_nodes_max;
/* Number of nodes currently allocated. */
unsigned int tm_nodes_cnt;
/* List of inodes and the lock protecting it. */
kmutex_t tm_lock;
struct tmpfs_node_list tm_nodes;
} tmpfs_mount_t;
/*
* This structure maps a file identifier to a tmpfs node. Used by the
* NFS code.
*/
typedef struct tmpfs_fid {
uint16_t tf_len;
uint16_t tf_pad;
uint32_t tf_gen;
ino_t tf_id;
} tmpfs_fid_t;
/*
* Prototypes for tmpfs_subr.c.
*/
void tmpfs_free_node(tmpfs_mount_t *, tmpfs_node_t *);
int tmpfs_construct_node(vnode_t *, vnode_t **, struct vattr *,
struct componentname *, char *);
int tmpfs_alloc_dirent(tmpfs_mount_t *, const char *, uint16_t,
tmpfs_dirent_t **);
void tmpfs_free_dirent(tmpfs_mount_t *, tmpfs_dirent_t *);
void tmpfs_dir_attach(tmpfs_node_t *, tmpfs_dirent_t *, tmpfs_node_t *);
void tmpfs_dir_detach(tmpfs_node_t *, tmpfs_dirent_t *);
tmpfs_dirent_t *tmpfs_dir_lookup(tmpfs_node_t *, struct componentname *);
tmpfs_dirent_t *tmpfs_dir_cached(tmpfs_node_t *);
uint32_t tmpfs_dir_getseq(tmpfs_node_t *, tmpfs_dirent_t *);
tmpfs_dirent_t *tmpfs_dir_lookupbyseq(tmpfs_node_t *, off_t);
int tmpfs_dir_getdents(tmpfs_node_t *, struct uio *, off_t *);
int tmpfs_reg_resize(vnode_t *, off_t);
int tmpfs_chflags(vnode_t *, int, kauth_cred_t, lwp_t *);
int tmpfs_chmod(vnode_t *, mode_t, kauth_cred_t, lwp_t *);
int tmpfs_chown(vnode_t *, uid_t, gid_t, kauth_cred_t, lwp_t *);
int tmpfs_chsize(vnode_t *, u_quad_t, kauth_cred_t, lwp_t *);
int tmpfs_chtimes(vnode_t *, const struct timespec *,
const struct timespec *, const struct timespec *, int,
kauth_cred_t, lwp_t *);
void tmpfs_update(vnode_t *, unsigned);
void tmpfs_update_locked(vnode_t *, unsigned);
void tmpfs_update_lazily(vnode_t *, unsigned);
/*
* Prototypes for tmpfs_mem.c.
*/
void tmpfs_mntmem_init(tmpfs_mount_t *, uint64_t);
void tmpfs_mntmem_destroy(tmpfs_mount_t *);
int tmpfs_mntmem_set(tmpfs_mount_t *, uint64_t);
size_t tmpfs_mem_info(bool);
uint64_t tmpfs_bytes_max(tmpfs_mount_t *);
size_t tmpfs_pages_avail(tmpfs_mount_t *);
bool tmpfs_mem_incr(tmpfs_mount_t *, size_t);
void tmpfs_mem_decr(tmpfs_mount_t *, size_t);
tmpfs_dirent_t *tmpfs_dirent_get(tmpfs_mount_t *);
void tmpfs_dirent_put(tmpfs_mount_t *, tmpfs_dirent_t *);
tmpfs_node_t * tmpfs_node_get(tmpfs_mount_t *);
void tmpfs_node_put(tmpfs_mount_t *, tmpfs_node_t *);
char * tmpfs_strname_alloc(tmpfs_mount_t *, size_t);
void tmpfs_strname_free(tmpfs_mount_t *, char *, size_t);
bool tmpfs_strname_neqlen(struct componentname *, struct componentname *);
/*
* Ensures that the node pointed by 'node' is a directory and that its
* contents are consistent with respect to directories.
*/
#define TMPFS_VALIDATE_DIR(node) \
KASSERT((node)->tn_vnode == NULL || VOP_ISLOCKED((node)->tn_vnode)); \
KASSERT((node)->tn_type == VDIR); \
KASSERT((node)->tn_size % sizeof(tmpfs_dirent_t) == 0);
/*
* Routines to convert VFS structures to tmpfs internal ones.
*/
static __inline tmpfs_mount_t *
VFS_TO_TMPFS(struct mount *mp)
{
tmpfs_mount_t *tmp = mp->mnt_data;
KASSERT(tmp != NULL);
return tmp;
}
static __inline tmpfs_node_t *
VP_TO_TMPFS_DIR(vnode_t *vp)
{
tmpfs_node_t *node = vp->v_data;
KASSERT(node != NULL);
TMPFS_VALIDATE_DIR(node);
return node;
}
#endif /* defined(_KERNEL) */
static __inline tmpfs_node_t *
VP_TO_TMPFS_NODE(vnode_t *vp)
{
tmpfs_node_t *node = vp->v_data;
#ifdef KASSERT
KASSERT(node != NULL);
#endif
return node;
}
#endif /* _FS_TMPFS_TMPFS_H_ */
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