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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc.
* All rights reserved. Use is subject to license terms.
*/
#ifndef _SYS_FS_TMP_H
#define _SYS_FS_TMP_H
#pragma ident "%Z%%M% %I% %E% SMI"
#ifdef __cplusplus
extern "C" {
#endif
/*
* tmpfs per-mount data structure.
*
* All fields are protected by tm_contents.
* File renames on a particular file system are protected tm_renamelck.
*/
struct tmount {
struct vfs *tm_vfsp; /* filesystem's vfs struct */
struct tmpnode *tm_rootnode; /* root tmpnode */
char *tm_mntpath; /* name of tmpfs mount point */
ulong_t tm_anonmax; /* file system max anon reservation */
pgcnt_t tm_anonmem; /* pages of reserved anon memory */
dev_t tm_dev; /* unique dev # of mounted `device' */
uint_t tm_gen; /* pseudo generation number for files */
kmutex_t tm_contents; /* lock for tmount structure */
kmutex_t tm_renamelck; /* rename lock for this mount */
};
/*
* File system independent to tmpfs conversion macros
*/
#define VFSTOTM(vfsp) ((struct tmount *)(vfsp)->vfs_data)
#define VTOTM(vp) ((struct tmount *)(vp)->v_vfsp->vfs_data)
#define VTOTN(vp) ((struct tmpnode *)(vp)->v_data)
#define TNTOV(tp) ((tp)->tn_vnode)
#define tmpnode_hold(tp) VN_HOLD(TNTOV(tp))
#define tmpnode_rele(tp) VN_RELE(TNTOV(tp))
/*
* enums
*/
enum de_op { DE_CREATE, DE_MKDIR, DE_LINK, DE_RENAME }; /* direnter ops */
enum dr_op { DR_REMOVE, DR_RMDIR, DR_RENAME }; /* dirremove ops */
/*
* tmpfs_minfree is the amount (in pages) of anonymous memory that tmpfs
* leaves free for the rest of the system. In antiquity, this number could be
* relevant on a system-wide basis, as physical DRAM was routinely exhausted;
* however, in more modern times, the relative growth of DRAM with respect to
* application footprint means that this number is only likely to become
* factor in a virtualized OS environment (e.g., a zone) -- and even then only
* when DRAM and swap have both been capped low to allow for maximum tenancy.
* TMPMINFREE -- the value from which tmpfs_minfree is derived -- should
* therefore be configured to a value that is roughly the smallest practical
* value for memory + swap minus the largest reasonable size for tmpfs in such
* a configuration. As of this writing, the smallest practical memory + swap
* configuration is 128MB, and it seems reasonable to allow tmpfs to consume
* no more than seven-eighths of this, yielding a TMPMINFREE of 16MB. Care
* should be exercised in changing this: tuning this value too high will
* result in spurious ENOSPC errors in tmpfs in small zones (a problem that
* can induce cascading failure surprisingly often); tuning this value too low
* will result in tmpfs consumption alone to alone induce application-level
* memory allocation failure.
*/
#define TMPMINFREE 16 * 1024 * 1024 /* 16 Megabytes */
extern size_t tmpfs_minfree; /* Anonymous memory in pages */
/*
* tmpfs can allocate only a certain percentage of kernel memory,
* which is used for tmpnodes, directories, file names, etc.
* This is statically set as TMPMAXFRACKMEM of physical memory.
* The actual number of allocatable bytes can be patched in tmpfs_maxkmem.
*/
#define TMPMAXFRACKMEM 25 /* 1/25 of physical memory */
extern size_t tmp_kmemspace;
extern size_t tmpfs_maxkmem; /* Allocatable kernel memory in bytes */
extern void tmpnode_init(struct tmount *, struct tmpnode *,
struct vattr *, struct cred *);
extern int tmpnode_trunc(struct tmount *, struct tmpnode *, ulong_t);
extern void tmpnode_growmap(struct tmpnode *, ulong_t);
extern int tdirlookup(struct tmpnode *, char *, struct tmpnode **,
struct cred *);
extern int tdirdelete(struct tmpnode *, struct tmpnode *, char *,
enum dr_op, struct cred *);
extern void tdirinit(struct tmpnode *, struct tmpnode *);
extern void tdirtrunc(struct tmpnode *);
extern void *tmp_memalloc(size_t, int);
extern void tmp_memfree(void *, size_t);
extern int tmp_resv(struct tmount *, struct tmpnode *, size_t, int);
extern int tmp_taccess(void *, int, struct cred *);
extern int tmp_sticky_remove_access(struct tmpnode *, struct tmpnode *,
struct cred *);
extern int tmp_convnum(char *, pgcnt_t *);
extern int tdirenter(struct tmount *, struct tmpnode *, char *,
enum de_op, struct tmpnode *, struct tmpnode *, struct vattr *,
struct tmpnode **, struct cred *, caller_context_t *);
#define TMP_MUSTHAVE 0x01
#ifdef __cplusplus
}
#endif
#endif /* _SYS_FS_TMP_H */
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