src/patches/60043_xen-blkback-cdrom.patch1

   1 Subject: CDROM removable media-present attribute plus handling code
   2 From: plc@novell.com
   3 Patch-mainline: obsolete
   4 References: 159907
   5
   6 Index: head-2008-05-08/drivers/xen/blkback/Makefile
   7 ===================================================================
   8 --- head-2008-05-08.orig/drivers/xen/blkback/Makefile   2008-05-08 15:34:23.000000000 +0200
   9 +++ head-2008-05-08/drivers/xen/blkback/Makefile        2008-05-08 15:05:13.000000000 +0200
  10 @@ -1,3 +1,3 @@
  11  obj-$(CONFIG_XEN_BLKDEV_BACKEND) := blkbk.o
  12
  13 -blkbk-y        := blkback.o xenbus.o interface.o vbd.o
  14 +blkbk-y        := blkback.o xenbus.o interface.o vbd.o cdrom.o
  15 Index: head-2008-05-08/drivers/xen/blkback/cdrom.c
  16 ===================================================================
  17 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
  18 +++ head-2008-05-08/drivers/xen/blkback/cdrom.c 2008-05-13 15:34:40.000000000 +0200
  19 @@ -0,0 +1,162 @@
  20 +/******************************************************************************
  21 + * blkback/cdrom.c
  22 + *
  23 + * Routines for managing cdrom watch and media-present attribute of a
  24 + * cdrom type virtual block device (VBD).
  25 + *
  26 + * Copyright (c) 2003-2005, Keir Fraser & Steve Hand
  27 + * Copyright (c) 2007       Pat Campbell
  28 + *
  29 + * This program is free software; you can redistribute it and/or
  30 + * modify it under the terms of the GNU General Public License version 2
  31 + * as published by the Free Software Foundation; or, when distributed
  32 + * separately from the Linux kernel or incorporated into other
  33 + * software packages, subject to the following license:
  34 + *
  35 + * Permission is hereby granted, free of charge, to any person obtaining a copy
  36 + * of this source file (the "Software"), to deal in the Software without
  37 + * restriction, including without limitation the rights to use, copy, modify,
  38 + * merge, publish, distribute, sublicense, and/or sell copies of the Software,
  39 + * and to permit persons to whom the Software is furnished to do so, subject to
  40 + * the following conditions:
  41 + *
  42 + * The above copyright notice and this permission notice shall be included in
  43 + * all copies or substantial portions of the Software.
  44 + *
  45 + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  46 + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  47 + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  48 + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  49 + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  50 + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  51 + * IN THE SOFTWARE.
  52 + */
  53 +
  54 +#include "common.h"
  55 +
  56 +#undef DPRINTK
  57 +#define DPRINTK(_f, _a...)                     \
  58 +       printk("(%s() file=%s, line=%d) " _f "\n",      \
  59 +                __PRETTY_FUNCTION__, __FILE__ , __LINE__ , ##_a )
  60 +
  61 +
  62 +#define MEDIA_PRESENT "media-present"
  63 +
  64 +static void cdrom_media_changed(struct xenbus_watch *, const char **, unsigned int);
  65 +
  66 +/**
  67 + * Writes media-present=1 attribute for the given vbd device if not
  68 + * already there
  69 + */
  70 +static int cdrom_xenstore_write_media_present(struct backend_info *be)
  71 +{
  72 +       struct xenbus_device *dev = be->dev;
  73 +       struct xenbus_transaction xbt;
  74 +       int err;
  75 +       int media_present;
  76 +
  77 +       err = xenbus_scanf(XBT_NIL, dev->nodename, MEDIA_PRESENT, "%d",
  78 +                          &media_present);
  79 +       if (0 < err) {
  80 +               DPRINTK("already written err%d", err);
  81 +               return(0);
  82 +       }
  83 +       media_present = 1;
  84 +
  85 +again:
  86 +       err = xenbus_transaction_start(&xbt);
  87 +       if (err) {
  88 +               xenbus_dev_fatal(dev, err, "starting transaction");
  89 +               return(-1);
  90 +       }
  91 +
  92 +       err = xenbus_printf(xbt, dev->nodename, MEDIA_PRESENT, "%d", media_present );
  93 +       if (err) {
  94 +               xenbus_dev_fatal(dev, err, "writing %s/%s",
  95 +                        dev->nodename, MEDIA_PRESENT);
  96 +               goto abort;
  97 +       }
  98 +       err = xenbus_transaction_end(xbt, 0);
  99 +       if (err == -EAGAIN)
 100 +               goto again;
 101 +       if (err)
 102 +               xenbus_dev_fatal(dev, err, "ending transaction");
 103 +       return 0;
 104 + abort:
 105 +       xenbus_transaction_end(xbt, 1);
 106 +       return -1;
 107 +}
 108 +
 109 +/**
 110 + *
 111 + */
 112 +static int cdrom_is_type(struct backend_info *be)
 113 +{
 114 +       DPRINTK("type:%x", be->blkif->vbd.type );
 115 +       return (be->blkif->vbd.type & VDISK_CDROM)
 116 +              && (be->blkif->vbd.type & GENHD_FL_REMOVABLE);
 117 +}
 118 +
 119 +/**
 120 + *
 121 + */
 122 +void cdrom_add_media_watch(struct backend_info *be)
 123 +{
 124 +       struct xenbus_device *dev = be->dev;
 125 +       int err;
 126 +
 127 +       DPRINTK("nodename:%s", dev->nodename);
 128 +       if (cdrom_is_type(be)) {
 129 +               DPRINTK("is a cdrom");
 130 +               if ( cdrom_xenstore_write_media_present(be) == 0 ) {
 131 +                       DPRINTK( "xenstore wrote OK");
 132 +                       err = xenbus_watch_path2(dev, dev->nodename, MEDIA_PRESENT,
 133 +                                                &be->backend_cdrom_watch,
 134 +                                                cdrom_media_changed);
 135 +                       if (err)
 136 +                               DPRINTK( "media_present watch add failed" );
 137 +               }
 138 +       }
 139 +}
 140 +
 141 +/**
 142 + * Callback received when the "media_present" xenstore node is changed
 143 + */
 144 +static void cdrom_media_changed(struct xenbus_watch *watch,
 145 +                               const char **vec, unsigned int len)
 146 +{
 147 +       int err;
 148 +       unsigned media_present;
 149 +       struct backend_info *be
 150 +               = container_of(watch, struct backend_info, backend_cdrom_watch);
 151 +       struct xenbus_device *dev = be->dev;
 152 +
 153 +       if (!cdrom_is_type(be)) {
 154 +               DPRINTK("callback not for a cdrom" );
 155 +               return;
 156 +       }
 157 +
 158 +       err = xenbus_scanf(XBT_NIL, dev->nodename, MEDIA_PRESENT, "%d",
 159 +                          &media_present);
 160 +       if (err == 0 || err == -ENOENT) {
 161 +               DPRINTK("xenbus_read of cdrom media_present node error:%d",err);
 162 +               return;
 163 +       }
 164 +
 165 +       if (media_present == 0)
 166 +               vbd_free(&be->blkif->vbd);
 167 +       else {
 168 +               char *p = strrchr(dev->otherend, '/') + 1;
 169 +               long handle = simple_strtoul(p, NULL, 0);
 170 +
 171 +               if (!be->blkif->vbd.bdev) {
 172 +                       err = vbd_create(be->blkif, handle, be->major, be->minor,
 173 +                                        !strchr(be->mode, 'w'), 1);
 174 +                       if (err) {
 175 +                               be->major = be->minor = 0;
 176 +                               xenbus_dev_fatal(dev, err, "creating vbd structure");
 177 +                               return;
 178 +                       }
 179 +               }
 180 +       }
 181 +}
 182 Index: head-2008-05-08/drivers/xen/blkback/common.h
 183 ===================================================================
 184 --- head-2008-05-08.orig/drivers/xen/blkback/common.h   2008-05-08 15:34:23.000000000 +0200
 185 +++ head-2008-05-08/drivers/xen/blkback/common.h        2008-05-13 15:35:13.000000000 +0200
 186 @@ -96,6 +96,17 @@ typedef struct blkif_st {
 187         grant_ref_t    shmem_ref;
 188  } blkif_t;
 189
 190 +struct backend_info
 191 +{
 192 +       struct xenbus_device *dev;
 193 +       blkif_t *blkif;
 194 +       struct xenbus_watch backend_watch;
 195 +       struct xenbus_watch backend_cdrom_watch;
 196 +       unsigned major;
 197 +       unsigned minor;
 198 +       char *mode;
 199 +};
 200 +
 201  blkif_t *blkif_alloc(domid_t domid);
 202  void blkif_disconnect(blkif_t *blkif);
 203  void blkif_free(blkif_t *blkif);
 204 @@ -136,4 +147,7 @@ int blkif_schedule(void *arg);
 205  int blkback_barrier(struct xenbus_transaction xbt,
 206                     struct backend_info *be, int state);
 207
 208 +/* cdrom media change */
 209 +void cdrom_add_media_watch(struct backend_info *be);
 210 +
 211  #endif /* __BLKIF__BACKEND__COMMON_H__ */
 212 Index: head-2008-05-08/drivers/xen/blkback/vbd.c
 213 ===================================================================
 214 --- head-2008-05-08.orig/drivers/xen/blkback/vbd.c      2008-05-08 15:34:23.000000000 +0200
 215 +++ head-2008-05-08/drivers/xen/blkback/vbd.c   2008-05-08 15:05:13.000000000 +0200
 216 @@ -106,6 +106,9 @@ int vbd_translate(struct phys_req *req,
 217         if ((operation != READ) && vbd->readonly)
 218                 goto out;
 219
 220 +       if (vbd->bdev == NULL)
 221 +               goto out;
 222 +
 223         if (unlikely((req->sector_number + req->nr_sects) > vbd_sz(vbd)))
 224                 goto out;
 225
 226 Index: head-2008-05-08/drivers/xen/blkback/xenbus.c
 227 ===================================================================
 228 --- head-2008-05-08.orig/drivers/xen/blkback/xenbus.c   2008-05-08 15:34:23.000000000 +0200
 229 +++ head-2008-05-08/drivers/xen/blkback/xenbus.c        2008-05-08 15:05:13.000000000 +0200
 230 @@ -28,16 +28,6 @@
 231         pr_debug("blkback/xenbus (%s:%d) " fmt ".\n",   \
 232                  __FUNCTION__, __LINE__, ##args)
 233
 234 -struct backend_info
 235 -{
 236 -       struct xenbus_device *dev;
 237 -       blkif_t *blkif;
 238 -       struct xenbus_watch backend_watch;
 239 -       unsigned major;
 240 -       unsigned minor;
 241 -       char *mode;
 242 -};
 243 -
 244  static void connect(struct backend_info *);
 245  static int connect_ring(struct backend_info *);
 246  static void backend_changed(struct xenbus_watch *, const char **,
 247 @@ -183,6 +173,12 @@ static int blkback_remove(struct xenbus_
 248                 be->backend_watch.node = NULL;
 249         }
 250
 251 +       if (be->backend_cdrom_watch.node) {
 252 +               unregister_xenbus_watch(&be->backend_cdrom_watch);
 253 +               kfree(be->backend_cdrom_watch.node);
 254 +               be->backend_cdrom_watch.node = NULL;
 255 +       }
 256 +
 257         if (be->blkif) {
 258                 blkif_disconnect(be->blkif);
 259                 vbd_free(&be->blkif->vbd);
 260 @@ -339,6 +335,9 @@ static void backend_changed(struct xenbu
 261
 262                 /* We're potentially connected now */
 263                 update_blkif_status(be->blkif);
 264 +
 265 +               /* Add watch for cdrom media status if necessay */
 266 +               cdrom_add_media_watch(be);
 267         }
 268  }
 269