tmpfs_vfsops.c revision 222167
1170808Sdelphij/* $NetBSD: tmpfs_vfsops.c,v 1.10 2005/12/11 12:24:29 christos Exp $ */ 2170808Sdelphij 3182739Sdelphij/*- 4170808Sdelphij * Copyright (c) 2005 The NetBSD Foundation, Inc. 5170808Sdelphij * All rights reserved. 6170808Sdelphij * 7170808Sdelphij * This code is derived from software contributed to The NetBSD Foundation 8170808Sdelphij * by Julio M. Merino Vidal, developed as part of Google's Summer of Code 9170808Sdelphij * 2005 program. 10170808Sdelphij * 11170808Sdelphij * Redistribution and use in source and binary forms, with or without 12170808Sdelphij * modification, are permitted provided that the following conditions 13170808Sdelphij * are met: 14170808Sdelphij * 1. Redistributions of source code must retain the above copyright 15170808Sdelphij * notice, this list of conditions and the following disclaimer. 16170808Sdelphij * 2. Redistributions in binary form must reproduce the above copyright 17170808Sdelphij * notice, this list of conditions and the following disclaimer in the 18170808Sdelphij * documentation and/or other materials provided with the distribution. 19170808Sdelphij * 20170808Sdelphij * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21170808Sdelphij * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22170808Sdelphij * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23170808Sdelphij * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24170808Sdelphij * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25170808Sdelphij * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26170808Sdelphij * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27170808Sdelphij * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28170808Sdelphij * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29170808Sdelphij * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30170808Sdelphij * POSSIBILITY OF SUCH DAMAGE. 31170808Sdelphij */ 32170808Sdelphij 33170808Sdelphij/* 34170808Sdelphij * Efficient memory file system. 35170808Sdelphij * 36170808Sdelphij * tmpfs is a file system that uses NetBSD's virtual memory sub-system 37170808Sdelphij * (the well-known UVM) to store file data and metadata in an efficient 38170808Sdelphij * way. This means that it does not follow the structure of an on-disk 39170808Sdelphij * file system because it simply does not need to. Instead, it uses 40170808Sdelphij * memory-specific data structures and algorithms to automatically 41170808Sdelphij * allocate and release resources. 42170808Sdelphij */ 43170808Sdelphij#include <sys/cdefs.h> 44170808Sdelphij__FBSDID("$FreeBSD: head/sys/fs/tmpfs/tmpfs_vfsops.c 222167 2011-05-22 01:07:54Z rmacklem $"); 45170808Sdelphij 46170808Sdelphij#include <sys/param.h> 47171308Sdelphij#include <sys/limits.h> 48170808Sdelphij#include <sys/lock.h> 49170808Sdelphij#include <sys/mutex.h> 50170808Sdelphij#include <sys/kernel.h> 51170808Sdelphij#include <sys/stat.h> 52170808Sdelphij#include <sys/systm.h> 53170808Sdelphij#include <sys/sysctl.h> 54170808Sdelphij 55170808Sdelphij#include <vm/vm.h> 56170808Sdelphij#include <vm/vm_object.h> 57170808Sdelphij#include <vm/vm_param.h> 58170808Sdelphij 59170808Sdelphij#include <fs/tmpfs/tmpfs.h> 60170808Sdelphij 61170808Sdelphij/* 62171070Sdelphij * Default permission for root node 63170808Sdelphij */ 64170808Sdelphij#define TMPFS_DEFAULT_ROOT_MODE (S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) 65170808Sdelphij 66170808SdelphijMALLOC_DEFINE(M_TMPFSMNT, "tmpfs mount", "tmpfs mount structures"); 67171087SdelphijMALLOC_DEFINE(M_TMPFSNAME, "tmpfs name", "tmpfs file names"); 68170808Sdelphij 69170808Sdelphij/* --------------------------------------------------------------------- */ 70170808Sdelphij 71191990Sattiliostatic int tmpfs_mount(struct mount *); 72191990Sattiliostatic int tmpfs_unmount(struct mount *, int); 73191990Sattiliostatic int tmpfs_root(struct mount *, int flags, struct vnode **); 74222167Srmacklemstatic int tmpfs_fhtovp(struct mount *, struct fid *, int, 75222167Srmacklem struct vnode **); 76191990Sattiliostatic int tmpfs_statfs(struct mount *, struct statfs *); 77170808Sdelphij 78170808Sdelphij/* --------------------------------------------------------------------- */ 79170808Sdelphij 80170808Sdelphijstatic const char *tmpfs_opts[] = { 81203164Sjh "from", "size", "maxfilesize", "inodes", "uid", "gid", "mode", "export", 82170808Sdelphij NULL 83170808Sdelphij}; 84170808Sdelphij 85170808Sdelphij/* --------------------------------------------------------------------- */ 86170808Sdelphij 87171029Sdelphijstatic int 88171029Sdelphijtmpfs_node_ctor(void *mem, int size, void *arg, int flags) 89171029Sdelphij{ 90171029Sdelphij struct tmpfs_node *node = (struct tmpfs_node *)mem; 91171070Sdelphij 92171362Sdelphij node->tn_gen++; 93171029Sdelphij node->tn_size = 0; 94171029Sdelphij node->tn_status = 0; 95171029Sdelphij node->tn_flags = 0; 96171029Sdelphij node->tn_links = 0; 97171029Sdelphij node->tn_vnode = NULL; 98171029Sdelphij node->tn_vpstate = 0; 99170808Sdelphij 100171029Sdelphij return (0); 101171029Sdelphij} 102171029Sdelphij 103171029Sdelphijstatic void 104171029Sdelphijtmpfs_node_dtor(void *mem, int size, void *arg) 105171029Sdelphij{ 106171029Sdelphij struct tmpfs_node *node = (struct tmpfs_node *)mem; 107171029Sdelphij node->tn_type = VNON; 108171029Sdelphij} 109171029Sdelphij 110171070Sdelphijstatic int 111171029Sdelphijtmpfs_node_init(void *mem, int size, int flags) 112171029Sdelphij{ 113171029Sdelphij struct tmpfs_node *node = (struct tmpfs_node *)mem; 114171029Sdelphij node->tn_id = 0; 115171029Sdelphij 116171029Sdelphij mtx_init(&node->tn_interlock, "tmpfs node interlock", NULL, MTX_DEF); 117171362Sdelphij node->tn_gen = arc4random(); 118171070Sdelphij 119171029Sdelphij return (0); 120171029Sdelphij} 121171029Sdelphij 122171029Sdelphijstatic void 123171029Sdelphijtmpfs_node_fini(void *mem, int size) 124171029Sdelphij{ 125171029Sdelphij struct tmpfs_node *node = (struct tmpfs_node *)mem; 126171070Sdelphij 127171029Sdelphij mtx_destroy(&node->tn_interlock); 128171029Sdelphij} 129171029Sdelphij 130170808Sdelphijstatic int 131191990Sattiliotmpfs_mount(struct mount *mp) 132170808Sdelphij{ 133170808Sdelphij struct tmpfs_mount *tmp; 134170808Sdelphij struct tmpfs_node *root; 135203164Sjh size_t pages; 136202708Sjh uint32_t nodes; 137170808Sdelphij int error; 138171308Sdelphij /* Size counters. */ 139202708Sjh u_int nodes_max; 140203164Sjh u_quad_t size_max, maxfilesize; 141170808Sdelphij 142171308Sdelphij /* Root node attributes. */ 143202187Sjh uid_t root_uid; 144202187Sjh gid_t root_gid; 145202187Sjh mode_t root_mode; 146171308Sdelphij 147202187Sjh struct vattr va; 148171308Sdelphij 149170808Sdelphij if (vfs_filteropt(mp->mnt_optnew, tmpfs_opts)) 150170808Sdelphij return (EINVAL); 151170808Sdelphij 152170808Sdelphij if (mp->mnt_flag & MNT_UPDATE) { 153170808Sdelphij /* XXX: There is no support yet to update file system 154170808Sdelphij * settings. Should be added. */ 155170808Sdelphij 156170808Sdelphij return EOPNOTSUPP; 157170808Sdelphij } 158170808Sdelphij 159172441Sdelphij printf("WARNING: TMPFS is considered to be a highly experimental " 160173724Sdelphij "feature in FreeBSD.\n"); 161172441Sdelphij 162175202Sattilio vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY); 163182371Sattilio error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred); 164175294Sattilio VOP_UNLOCK(mp->mnt_vnodecovered, 0); 165171308Sdelphij if (error) 166171308Sdelphij return (error); 167170808Sdelphij 168171308Sdelphij if (mp->mnt_cred->cr_ruid != 0 || 169171308Sdelphij vfs_scanopt(mp->mnt_optnew, "gid", "%d", &root_gid) != 1) 170171308Sdelphij root_gid = va.va_gid; 171171308Sdelphij if (mp->mnt_cred->cr_ruid != 0 || 172171308Sdelphij vfs_scanopt(mp->mnt_optnew, "uid", "%d", &root_uid) != 1) 173171308Sdelphij root_uid = va.va_uid; 174171308Sdelphij if (mp->mnt_cred->cr_ruid != 0 || 175173570Sdelphij vfs_scanopt(mp->mnt_optnew, "mode", "%ho", &root_mode) != 1) 176171308Sdelphij root_mode = va.va_mode; 177202708Sjh if (vfs_scanopt(mp->mnt_optnew, "inodes", "%u", &nodes_max) != 1) 178171308Sdelphij nodes_max = 0; 179173724Sdelphij if (vfs_scanopt(mp->mnt_optnew, "size", "%qu", &size_max) != 1) 180171308Sdelphij size_max = 0; 181203164Sjh if (vfs_scanopt(mp->mnt_optnew, "maxfilesize", "%qu", 182203164Sjh &maxfilesize) != 1) 183203164Sjh maxfilesize = 0; 184170808Sdelphij 185170808Sdelphij /* Do not allow mounts if we do not have enough memory to preserve 186170808Sdelphij * the minimum reserved pages. */ 187203164Sjh if (tmpfs_mem_info() < TMPFS_PAGES_RESERVED) 188170808Sdelphij return ENOSPC; 189170808Sdelphij 190170808Sdelphij /* Get the maximum number of memory pages this file system is 191170808Sdelphij * allowed to use, based on the maximum size the user passed in 192170808Sdelphij * the mount structure. A value of zero is treated as if the 193170808Sdelphij * maximum available space was requested. */ 194202187Sjh if (size_max < PAGE_SIZE || size_max > SIZE_MAX - PAGE_SIZE) 195170808Sdelphij pages = SIZE_MAX; 196170808Sdelphij else 197171308Sdelphij pages = howmany(size_max, PAGE_SIZE); 198170808Sdelphij MPASS(pages > 0); 199170808Sdelphij 200202708Sjh if (nodes_max <= 3) { 201202708Sjh if (pages > UINT32_MAX - 3) 202202708Sjh nodes = UINT32_MAX; 203202708Sjh else 204202708Sjh nodes = pages + 3; 205202708Sjh } else 206171308Sdelphij nodes = nodes_max; 207170808Sdelphij MPASS(nodes >= 3); 208170808Sdelphij 209170808Sdelphij /* Allocate the tmpfs mount structure and fill it. */ 210170808Sdelphij tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount), 211170808Sdelphij M_TMPFSMNT, M_WAITOK | M_ZERO); 212171070Sdelphij 213170808Sdelphij mtx_init(&tmp->allnode_lock, "tmpfs allnode lock", NULL, MTX_DEF); 214170808Sdelphij tmp->tm_nodes_max = nodes; 215170808Sdelphij tmp->tm_nodes_inuse = 0; 216203164Sjh tmp->tm_maxfilesize = maxfilesize > 0 ? maxfilesize : UINT64_MAX; 217170808Sdelphij LIST_INIT(&tmp->tm_nodes_used); 218171070Sdelphij 219170808Sdelphij tmp->tm_pages_max = pages; 220170808Sdelphij tmp->tm_pages_used = 0; 221171362Sdelphij tmp->tm_ino_unr = new_unrhdr(2, INT_MAX, &tmp->allnode_lock); 222173724Sdelphij tmp->tm_dirent_pool = uma_zcreate("TMPFS dirent", 223173724Sdelphij sizeof(struct tmpfs_dirent), 224173724Sdelphij NULL, NULL, NULL, NULL, 225173724Sdelphij UMA_ALIGN_PTR, 0); 226173724Sdelphij tmp->tm_node_pool = uma_zcreate("TMPFS node", 227173724Sdelphij sizeof(struct tmpfs_node), 228173724Sdelphij tmpfs_node_ctor, tmpfs_node_dtor, 229173724Sdelphij tmpfs_node_init, tmpfs_node_fini, 230173724Sdelphij UMA_ALIGN_PTR, 0); 231170808Sdelphij 232170808Sdelphij /* Allocate the root node. */ 233171308Sdelphij error = tmpfs_alloc_node(tmp, VDIR, root_uid, 234171308Sdelphij root_gid, root_mode & ALLPERMS, NULL, NULL, 235191990Sattilio VNOVAL, &root); 236170808Sdelphij 237170808Sdelphij if (error != 0 || root == NULL) { 238171029Sdelphij uma_zdestroy(tmp->tm_node_pool); 239171029Sdelphij uma_zdestroy(tmp->tm_dirent_pool); 240171362Sdelphij delete_unrhdr(tmp->tm_ino_unr); 241170808Sdelphij free(tmp, M_TMPFSMNT); 242170808Sdelphij return error; 243170808Sdelphij } 244171362Sdelphij KASSERT(root->tn_id == 2, ("tmpfs root with invalid ino: %d", root->tn_id)); 245170808Sdelphij tmp->tm_root = root; 246170808Sdelphij 247170808Sdelphij MNT_ILOCK(mp); 248170808Sdelphij mp->mnt_flag |= MNT_LOCAL; 249170808Sdelphij mp->mnt_kern_flag |= MNTK_MPSAFE; 250170808Sdelphij MNT_IUNLOCK(mp); 251171070Sdelphij 252170808Sdelphij mp->mnt_data = tmp; 253170808Sdelphij mp->mnt_stat.f_namemax = MAXNAMLEN; 254170808Sdelphij vfs_getnewfsid(mp); 255170808Sdelphij vfs_mountedfrom(mp, "tmpfs"); 256170808Sdelphij 257170808Sdelphij return 0; 258170808Sdelphij} 259170808Sdelphij 260170808Sdelphij/* --------------------------------------------------------------------- */ 261170808Sdelphij 262170808Sdelphij/* ARGSUSED2 */ 263170808Sdelphijstatic int 264191990Sattiliotmpfs_unmount(struct mount *mp, int mntflags) 265170808Sdelphij{ 266170808Sdelphij int error; 267170808Sdelphij int flags = 0; 268170808Sdelphij struct tmpfs_mount *tmp; 269170808Sdelphij struct tmpfs_node *node; 270170808Sdelphij 271170808Sdelphij /* Handle forced unmounts. */ 272170808Sdelphij if (mntflags & MNT_FORCE) 273170808Sdelphij flags |= FORCECLOSE; 274170808Sdelphij 275170808Sdelphij /* Finalize all pending I/O. */ 276191990Sattilio error = vflush(mp, 0, flags, curthread); 277170808Sdelphij if (error != 0) 278170808Sdelphij return error; 279170808Sdelphij 280170808Sdelphij tmp = VFS_TO_TMPFS(mp); 281171070Sdelphij 282170808Sdelphij /* Free all associated data. The loop iterates over the linked list 283170808Sdelphij * we have containing all used nodes. For each of them that is 284170808Sdelphij * a directory, we free all its directory entries. Note that after 285170808Sdelphij * freeing a node, it will automatically go to the available list, 286170808Sdelphij * so we will later have to iterate over it to release its items. */ 287170808Sdelphij node = LIST_FIRST(&tmp->tm_nodes_used); 288170808Sdelphij while (node != NULL) { 289170808Sdelphij struct tmpfs_node *next; 290170808Sdelphij 291170808Sdelphij if (node->tn_type == VDIR) { 292170808Sdelphij struct tmpfs_dirent *de; 293170808Sdelphij 294170808Sdelphij de = TAILQ_FIRST(&node->tn_dir.tn_dirhead); 295170808Sdelphij while (de != NULL) { 296170808Sdelphij struct tmpfs_dirent *nde; 297170808Sdelphij 298170808Sdelphij nde = TAILQ_NEXT(de, td_entries); 299170808Sdelphij tmpfs_free_dirent(tmp, de, FALSE); 300170808Sdelphij de = nde; 301170808Sdelphij node->tn_size -= sizeof(struct tmpfs_dirent); 302170808Sdelphij } 303170808Sdelphij } 304170808Sdelphij 305170808Sdelphij next = LIST_NEXT(node, tn_entries); 306170808Sdelphij tmpfs_free_node(tmp, node); 307170808Sdelphij node = next; 308170808Sdelphij } 309170808Sdelphij 310171029Sdelphij uma_zdestroy(tmp->tm_dirent_pool); 311171029Sdelphij uma_zdestroy(tmp->tm_node_pool); 312171362Sdelphij delete_unrhdr(tmp->tm_ino_unr); 313170808Sdelphij 314170808Sdelphij mtx_destroy(&tmp->allnode_lock); 315170808Sdelphij MPASS(tmp->tm_pages_used == 0); 316171308Sdelphij MPASS(tmp->tm_nodes_inuse == 0); 317170808Sdelphij 318170808Sdelphij /* Throw away the tmpfs_mount structure. */ 319170808Sdelphij free(mp->mnt_data, M_TMPFSMNT); 320170808Sdelphij mp->mnt_data = NULL; 321171070Sdelphij 322170808Sdelphij MNT_ILOCK(mp); 323170808Sdelphij mp->mnt_flag &= ~MNT_LOCAL; 324170808Sdelphij MNT_IUNLOCK(mp); 325170808Sdelphij return 0; 326170808Sdelphij} 327170808Sdelphij 328170808Sdelphij/* --------------------------------------------------------------------- */ 329170808Sdelphij 330170808Sdelphijstatic int 331191990Sattiliotmpfs_root(struct mount *mp, int flags, struct vnode **vpp) 332170808Sdelphij{ 333170808Sdelphij int error; 334191990Sattilio error = tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, flags, vpp); 335170808Sdelphij 336170808Sdelphij if (!error) 337171029Sdelphij (*vpp)->v_vflag |= VV_ROOT; 338170808Sdelphij 339170808Sdelphij return error; 340170808Sdelphij} 341170808Sdelphij 342170808Sdelphij/* --------------------------------------------------------------------- */ 343170808Sdelphij 344170808Sdelphijstatic int 345222167Srmacklemtmpfs_fhtovp(struct mount *mp, struct fid *fhp, int flags, 346222167Srmacklem struct vnode **vpp) 347170808Sdelphij{ 348170808Sdelphij boolean_t found; 349170808Sdelphij struct tmpfs_fid *tfhp; 350170808Sdelphij struct tmpfs_mount *tmp; 351170808Sdelphij struct tmpfs_node *node; 352170808Sdelphij 353170808Sdelphij tmp = VFS_TO_TMPFS(mp); 354170808Sdelphij 355170808Sdelphij tfhp = (struct tmpfs_fid *)fhp; 356170808Sdelphij if (tfhp->tf_len != sizeof(struct tmpfs_fid)) 357170808Sdelphij return EINVAL; 358170808Sdelphij 359170808Sdelphij if (tfhp->tf_id >= tmp->tm_nodes_max) 360170808Sdelphij return EINVAL; 361170808Sdelphij 362170808Sdelphij found = FALSE; 363170808Sdelphij 364170808Sdelphij TMPFS_LOCK(tmp); 365170808Sdelphij LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) { 366170808Sdelphij if (node->tn_id == tfhp->tf_id && 367170808Sdelphij node->tn_gen == tfhp->tf_gen) { 368170808Sdelphij found = TRUE; 369170808Sdelphij break; 370170808Sdelphij } 371170808Sdelphij } 372170808Sdelphij TMPFS_UNLOCK(tmp); 373170808Sdelphij 374171799Sdelphij if (found) 375191990Sattilio return (tmpfs_alloc_vp(mp, node, LK_EXCLUSIVE, vpp)); 376171799Sdelphij 377171799Sdelphij return (EINVAL); 378170808Sdelphij} 379170808Sdelphij 380170808Sdelphij/* --------------------------------------------------------------------- */ 381170808Sdelphij 382170808Sdelphij/* ARGSUSED2 */ 383170808Sdelphijstatic int 384191990Sattiliotmpfs_statfs(struct mount *mp, struct statfs *sbp) 385170808Sdelphij{ 386170808Sdelphij fsfilcnt_t freenodes; 387170808Sdelphij struct tmpfs_mount *tmp; 388170808Sdelphij 389170808Sdelphij tmp = VFS_TO_TMPFS(mp); 390170808Sdelphij 391171070Sdelphij sbp->f_iosize = PAGE_SIZE; 392170808Sdelphij sbp->f_bsize = PAGE_SIZE; 393170808Sdelphij 394170808Sdelphij sbp->f_blocks = TMPFS_PAGES_MAX(tmp); 395170808Sdelphij sbp->f_bavail = sbp->f_bfree = TMPFS_PAGES_AVAIL(tmp); 396170808Sdelphij 397170808Sdelphij freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_inuse, 398170808Sdelphij TMPFS_PAGES_AVAIL(tmp) * PAGE_SIZE / sizeof(struct tmpfs_node)); 399170808Sdelphij 400170808Sdelphij sbp->f_files = freenodes + tmp->tm_nodes_inuse; 401170808Sdelphij sbp->f_ffree = freenodes; 402170808Sdelphij /* sbp->f_owner = tmp->tn_uid; */ 403170808Sdelphij 404170808Sdelphij return 0; 405170808Sdelphij} 406170808Sdelphij 407170808Sdelphij/* --------------------------------------------------------------------- */ 408170808Sdelphij 409170808Sdelphij/* 410170808Sdelphij * tmpfs vfs operations. 411170808Sdelphij */ 412170808Sdelphij 413170808Sdelphijstruct vfsops tmpfs_vfsops = { 414170808Sdelphij .vfs_mount = tmpfs_mount, 415170808Sdelphij .vfs_unmount = tmpfs_unmount, 416170808Sdelphij .vfs_root = tmpfs_root, 417170808Sdelphij .vfs_statfs = tmpfs_statfs, 418170808Sdelphij .vfs_fhtovp = tmpfs_fhtovp, 419170808Sdelphij}; 420170808SdelphijVFS_SET(tmpfs_vfsops, tmpfs, 0); 421