usr/src/uts/common/fs/ctfs/ctfs_sym.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #pragma ident   "%Z%%M% %I%     %E% SMI"
  27
  28 #include <sys/types.h>
  29 #include <sys/param.h>
  30 #include <sys/time.h>
  31 #include <sys/cred.h>
  32 #include <sys/vfs.h>
  33 #include <sys/vfs_opreg.h>
  34 #include <sys/gfs.h>
  35 #include <sys/vnode.h>
  36 #include <sys/systm.h>
  37 #include <sys/errno.h>
  38 #include <sys/sysmacros.h>
  39 #include <fs/fs_subr.h>
  40 #include <sys/contract.h>
  41 #include <sys/contract_impl.h>
  42 #include <sys/ctfs.h>
  43 #include <sys/ctfs_impl.h>
  44 #include <sys/file.h>
  45 #include <sys/cmn_err.h>
  46
  47 /*
  48  * CTFS routines for the /system/contract/all/<ctid> vnode.
  49  */
  50
  51 /*
  52  * ctfs_create_symnode
  53  *
  54  * Creates and returns a symnode for the specified contract.
  55  */
  56 vnode_t *
  57 ctfs_create_symnode(vnode_t *pvp, contract_t *ct)
  58 {
  59         ctfs_symnode_t *symnode;
  60         vnode_t *vp;
  61         size_t len;
  62
  63         vp = gfs_file_create(sizeof (ctfs_symnode_t), pvp, ctfs_ops_sym);
  64         vp->v_type = VLNK;
  65         symnode = vp->v_data;
  66
  67         symnode->ctfs_sn_contract = ct;
  68         symnode->ctfs_sn_size = len = snprintf(NULL, 0, "../%s/%ld",
  69             ct->ct_type->ct_type_name, (long)ct->ct_id) + 1;
  70         symnode->ctfs_sn_string = kmem_alloc(len, KM_SLEEP);
  71         VERIFY(snprintf(symnode->ctfs_sn_string, len, "../%s/%ld",
  72             ct->ct_type->ct_type_name, (long)ct->ct_id) < len);
  73
  74         contract_hold(ct);
  75
  76         return (vp);
  77 }
  78
  79 /*
  80  * ctfs_sym_getattr - VOP_GETATTR entry point
  81  */
  82 /* ARGSUSED */
  83 static int
  84 ctfs_sym_getattr(
  85         vnode_t *vp,
  86         vattr_t *vap,
  87         int flags,
  88         cred_t *cr,
  89         caller_context_t *ct)
  90 {
  91         ctfs_symnode_t *symnode = vp->v_data;
  92
  93         vap->va_type = VLNK;
  94         vap->va_mode = 0444;
  95         vap->va_nlink = 1;
  96         vap->va_size = symnode->ctfs_sn_size - 1;
  97         vap->va_mtime = vap->va_atime = vap->va_ctime =
  98             symnode->ctfs_sn_contract->ct_ctime;
  99         ctfs_common_getattr(vp, vap);
 100
 101         return (0);
 102 }
 103
 104 /*
 105  * ctfs_sym_readlink - VOP_READLINK entry point
 106  *
 107  * Since we built the symlink string in ctfs_create_symnode, this is
 108  * just a uiomove.
 109  */
 110 /* ARGSUSED */
 111 int
 112 ctfs_sym_readlink(vnode_t *vp, uio_t *uiop, cred_t *cr, caller_context_t *ct)
 113 {
 114         ctfs_symnode_t *symnode = vp->v_data;
 115
 116         return (uiomove(symnode->ctfs_sn_string, symnode->ctfs_sn_size - 1,
 117             UIO_READ, uiop));
 118 }
 119
 120 /*
 121  * ctfs_sym_inactive - VOP_INACTIVE entry point
 122  */
 123 /* ARGSUSED */
 124 static void
 125 ctfs_sym_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
 126 {
 127         ctfs_symnode_t *symnode;
 128
 129         if ((symnode = gfs_file_inactive(vp)) != NULL) {
 130                 contract_rele(symnode->ctfs_sn_contract);
 131                 kmem_free(symnode->ctfs_sn_string, symnode->ctfs_sn_size);
 132                 kmem_free(symnode, sizeof (ctfs_symnode_t));
 133         }
 134 }
 135
 136 const fs_operation_def_t ctfs_tops_sym[] = {
 137         { VOPNAME_OPEN,         { .vop_open = ctfs_open } },
 138         { VOPNAME_CLOSE,        { .vop_close = ctfs_close } },
 139         { VOPNAME_IOCTL,        { .error = fs_inval } },
 140         { VOPNAME_GETATTR,      { .vop_getattr = ctfs_sym_getattr } },
 141         { VOPNAME_READLINK,     { .vop_readlink = ctfs_sym_readlink } },
 142         { VOPNAME_ACCESS,       { .vop_access = ctfs_access_readonly } },
 143         { VOPNAME_READDIR,      { .error = fs_notdir } },
 144         { VOPNAME_LOOKUP,       { .error = fs_notdir } },
 145         { VOPNAME_INACTIVE,     { .vop_inactive = ctfs_sym_inactive } },
 146         { NULL, NULL }
 147 };