sys/vfs/devfs/devfs_vfsops.c

   1 /*
   2  * (MPSAFE)
   3  *
   4  * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
   5  *
   6  * This code is derived from software contributed to The DragonFly Project
   7  * by Alex Hornung <ahornung@gmail.com>
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  * 3. Neither the name of The DragonFly Project nor the names of its
  20  *    contributors may be used to endorse or promote products derived
  21  *    from this software without specific, prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  26  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  27  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  28  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  29  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  30  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  31  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  32  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  33  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/kernel.h>
  39 #include <sys/mount.h>
  40 #include <sys/namecache.h>
  41 #include <sys/vnode.h>
  42 #include <sys/jail.h>
  43 #include <sys/lock.h>
  44 #include <sys/devfs.h>
  45
  46 MALLOC_DECLARE(M_DEVFS);
  47
  48 extern struct vop_ops devfs_vnode_norm_vops;
  49 extern struct vop_ops devfs_vnode_dev_vops;
  50 extern struct lock      devfs_lock;
  51
  52 static int      devfs_vfs_mount (struct mount *mp, char *path, caddr_t data,
  53                                   struct ucred *cred);
  54 static int      devfs_vfs_statfs (struct mount *mp, struct statfs *sbp,
  55                                 struct ucred *cred);
  56 static int      devfs_vfs_unmount (struct mount *mp, int mntflags);
  57 int             devfs_vfs_root(struct mount *mp, struct vnode **vpp);
  58 static int      devfs_vfs_vget(struct mount *mp, struct vnode *dvp,
  59                                 ino_t ino, struct vnode **vpp);
  60 static int      devfs_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
  61                                 struct fid *fhp, struct vnode **vpp);
  62 static int      devfs_vfs_vptofh(struct vnode *vp, struct fid *fhp);
  63
  64
  65 /*
  66  * VFS Operations.
  67  *
  68  * mount system call
  69  */
  70 static int
  71 devfs_vfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
  72 {
  73         struct devfs_mount_info info;
  74         struct devfs_mnt_data *mnt;
  75         size_t size;
  76         int error;
  77
  78         devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_mount() called!\n");
  79
  80         if (mp->mnt_flag & MNT_UPDATE)
  81                 return (EOPNOTSUPP);
  82
  83         if (data == NULL) {
  84                 bzero(&info, sizeof(info));
  85         } else {
  86                 if ((error = copyin(data, &info, sizeof(info))) != 0)
  87                         return (error);
  88         }
  89
  90         mp->mnt_flag |= MNT_LOCAL;
  91         mp->mnt_kern_flag |= MNTK_NOSTKMNT | MNTK_ALL_MPSAFE;
  92         mp->mnt_data = NULL;
  93         vfs_getnewfsid(mp);
  94
  95         size = sizeof("devfs") - 1;
  96         bcopy("devfs", mp->mnt_stat.f_mntfromname, size);
  97         bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
  98         copyinstr(path, mp->mnt_stat.f_mntonname,
  99             sizeof(mp->mnt_stat.f_mntonname) -1, &size);
 100         devfs_vfs_statfs(mp, &mp->mnt_stat, cred);
 101
 102         /*
 103          * XXX: save other mount info passed from userland or so.
 104          */
 105         mnt = kmalloc(sizeof(*mnt), M_DEVFS, M_WAITOK | M_ZERO);
 106
 107         lockmgr(&devfs_lock, LK_EXCLUSIVE);
 108         mp->mnt_data = (qaddr_t)mnt;
 109
 110         if (info.flags & DEVFS_MNT_JAIL)
 111                 mnt->jailed = 1;
 112         else
 113                 mnt->jailed = jailed(cred);
 114
 115         mnt->leak_count = 0;
 116         mnt->file_count = 0;
 117         mnt->mp = mp;
 118         TAILQ_INIT(&mnt->orphan_list);
 119         mnt->root_node = devfs_allocp(Nroot, "", NULL, mp, NULL);
 120         KKASSERT(mnt->root_node);
 121         lockmgr(&devfs_lock, LK_RELEASE);
 122
 123         vfs_add_vnodeops(mp, &devfs_vnode_norm_vops, &mp->mnt_vn_norm_ops);
 124         vfs_add_vnodeops(mp, &devfs_vnode_dev_vops, &mp->mnt_vn_spec_ops);
 125
 126         devfs_debug(DEVFS_DEBUG_DEBUG, "calling devfs_mount_add\n");
 127         devfs_mount_add(mnt);
 128
 129         return (0);
 130 }
 131
 132 /*
 133  * unmount system call
 134  */
 135 static int
 136 devfs_vfs_unmount(struct mount *mp, int mntflags)
 137 {
 138         int error = 0;
 139         int flags = 0;
 140
 141         devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_unmount() called!\n");
 142
 143         if (mntflags & MNT_FORCE)
 144                 flags |= FORCECLOSE;
 145
 146         error = vflush(mp, 0, flags);
 147
 148         if (error)
 149                 return (error);
 150         lockmgr(&devfs_lock, LK_EXCLUSIVE);
 151         devfs_tracer_orphan_count(mp, 1);
 152         lockmgr(&devfs_lock, LK_RELEASE);
 153         devfs_mount_del(DEVFS_MNTDATA(mp));
 154         kfree(mp->mnt_data, M_DEVFS);
 155         mp->mnt_data = NULL;
 156
 157         return (0);
 158 }
 159
 160 /*
 161  * Sets *vpp to the root procfs vnode, referenced and exclusively locked
 162  */
 163 int
 164 devfs_vfs_root(struct mount *mp, struct vnode **vpp)
 165 {
 166         int ret;
 167
 168         devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_root() called!\n");
 169         lockmgr(&devfs_lock, LK_EXCLUSIVE);
 170         ret = devfs_allocv(vpp, DEVFS_MNTDATA(mp)->root_node);
 171         lockmgr(&devfs_lock, LK_RELEASE);
 172
 173         return ret;
 174 }
 175
 176 /*
 177  * Get file system statistics.
 178  */
 179 static int
 180 devfs_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
 181 {
 182         devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_stat() called!\n");
 183         sbp->f_bsize = DEV_BSIZE;
 184         sbp->f_iosize = DEV_BSIZE;
 185         sbp->f_blocks = 2;      /* avoid divide by zero in some df's */
 186         sbp->f_bfree = 0;
 187         sbp->f_bavail = 0;
 188         sbp->f_files = (DEVFS_MNTDATA(mp))?(DEVFS_MNTDATA(mp)->file_count):0;
 189         sbp->f_ffree = 0;
 190
 191         if (sbp != &mp->mnt_stat) {
 192                 sbp->f_type = mp->mnt_vfc->vfc_typenum;
 193                 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
 194                 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
 195         }
 196
 197         return (0);
 198 }
 199
 200 static int
 201 devfs_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
 202                  struct fid *fhp, struct vnode **vpp)
 203 {
 204         struct vnode            *vp;
 205         struct devfs_fid        *dfhp;
 206
 207         dfhp = (struct devfs_fid *)fhp;
 208
 209         if (dfhp->fid_gen != boottime.tv_sec)
 210                 return EINVAL;
 211
 212         vp = devfs_inode_to_vnode(mp, dfhp->fid_ino);
 213
 214         if (vp == NULL)
 215                 return ENOENT;
 216
 217         *vpp = vp;
 218         return 0;
 219 }
 220
 221 /*
 222  * Vnode pointer to File handle
 223  */
 224 static int
 225 devfs_vfs_vptofh(struct vnode *vp, struct fid *fhp)
 226 {
 227         struct devfs_node       *node;
 228         struct devfs_fid        *dfhp;
 229
 230         if ((node = DEVFS_NODE(vp)) != NULL) {
 231                 dfhp = (struct devfs_fid *)fhp;
 232                 dfhp->fid_len = sizeof(struct devfs_fid);
 233                 dfhp->fid_ino = node->d_dir.d_ino;
 234                 dfhp->fid_gen = boottime.tv_sec;
 235         } else {
 236                 return ENOENT;
 237         }
 238
 239         return (0);
 240 }
 241
 242 static int
 243 devfs_vfs_vget(struct mount *mp, struct vnode *dvp,
 244                ino_t ino, struct vnode **vpp)
 245 {
 246         struct vnode *vp;
 247         vp = devfs_inode_to_vnode(mp, ino);
 248
 249         if (vp == NULL)
 250                 return ENOENT;
 251
 252         *vpp = vp;
 253         return 0;
 254 }
 255
 256 static void
 257 devfs_vfs_ncpgen_set(struct mount *mp, struct namecache *ncp)
 258 {
 259         ncp->nc_namecache_gen = mp->mnt_namecache_gen;
 260 }
 261
 262 static int
 263 devfs_vfs_ncpgen_test(struct mount *mp, struct namecache *ncp)
 264 {
 265         return (ncp->nc_namecache_gen != mp->mnt_namecache_gen);
 266 }
 267
 268 static struct vfsops devfs_vfsops = {
 269         .vfs_mount      = devfs_vfs_mount,
 270         .vfs_unmount    = devfs_vfs_unmount,
 271         .vfs_root       = devfs_vfs_root,
 272         .vfs_statfs     = devfs_vfs_statfs,
 273         .vfs_vget       = devfs_vfs_vget,
 274         .vfs_vptofh     = devfs_vfs_vptofh,
 275         .vfs_fhtovp     = devfs_vfs_fhtovp,
 276         .vfs_ncpgen_set = devfs_vfs_ncpgen_set,
 277         .vfs_ncpgen_test        = devfs_vfs_ncpgen_test
 278 };
 279
 280 VFS_SET(devfs_vfsops, devfs, VFCF_SYNTHETIC | VFCF_MPSAFE);
 281 MODULE_VERSION(devfs, 1);