lustre/obdecho/echo.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  linux/fs/ext2_obd/ext2_obd.c
   5  *
   6  * Copyright (C) 2001  Cluster File Systems, Inc.
   7  *
   8  * This code is issued under the GNU General Public License.
   9  * See the file COPYING in this distribution
  10  *
  11  * by Peter Braam <braam@clusterfs.com>
  12  */
  13
  14 #define EXPORT_SYMTAB
  15
  16 #include <linux/version.h>
  17 #include <linux/module.h>
  18 #include <linux/fs.h>
  19 #include <linux/stat.h>
  20 #include <linux/locks.h>
  21 #include <linux/ext2_fs.h>
  22 #include <linux/quotaops.h>
  23 #include <asm/unistd.h>
  24
  25 #define DEBUG_SUBSYSTEM S_ECHO
  26
  27 #include <linux/obd_support.h>
  28 #include <linux/obd_class.h>
  29 #include <linux/obd_echo.h>
  30
  31 extern struct obd_device obd_dev[MAX_OBD_DEVICES];
  32 static struct obdo OA;
  33 static obd_count GEN;
  34 static long echo_pages = 0;
  35
  36 static int echo_connect(struct obd_conn *conn)
  37 {
  38         int rc;
  39
  40         MOD_INC_USE_COUNT;
  41         rc = gen_connect(conn);
  42
  43         if (rc)
  44                 MOD_DEC_USE_COUNT;
  45
  46         return rc;
  47 }
  48
  49 static int echo_disconnect(struct obd_conn *conn)
  50 {
  51         int rc;
  52
  53         rc = gen_disconnect(conn);
  54         if (!rc)
  55                 MOD_DEC_USE_COUNT;
  56
  57         return rc;
  58 }
  59
  60 static int echo_getattr(struct obd_conn *conn, struct obdo *oa)
  61 {
  62         memcpy(oa, &OA, sizeof(*oa));
  63         oa->o_mode = ++GEN;
  64
  65         return 0;
  66 }
  67
  68 int echo_preprw(int cmd, struct obd_conn *conn, int objcount,
  69                 struct obd_ioobj *obj, int niocount, struct niobuf *nb,
  70                 struct niobuf *res)
  71 {
  72         struct niobuf *r = res;
  73         int rc = 0;
  74         int i;
  75
  76         ENTRY;
  77
  78         memset(res, 0, sizeof(*res) * niocount);
  79
  80         CDEBUG(D_PAGE, "%s %d obdos with %d IOs\n",
  81                cmd == OBD_BRW_READ ? "reading" : "writing", objcount, niocount);
  82
  83         for (i = 0; i < objcount; i++, obj++) {
  84                 int j;
  85
  86                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, nb++, r++) {
  87                         unsigned long address;
  88
  89                         address = get_zeroed_page(GFP_KERNEL);
  90                         if (!address) {
  91                                 CERROR("can't get new page %d/%d for id %Ld\n",
  92                                        j, obj->ioo_bufcnt,
  93                                        (unsigned long long)obj->ioo_id);
  94                                 rc = -ENOMEM;
  95                                 EXIT;
  96                                 goto preprw_cleanup;
  97                         }
  98                         echo_pages++;
  99
 100                         /*
 101                         if (cmd == OBD_BRW_READ) {
 102                                 __u64 *data = address;
 103
 104                                 data[0] = obj->ioo_id;
 105                                 data[1] = j;
 106                                 data[2] = nb->offset;
 107                                 data[3] = nb->len;
 108                         }
 109                         */
 110
 111                         r->addr = address;
 112                         r->offset = nb->offset;
 113                         r->page = virt_to_page(address);
 114                         r->len = nb->len;
 115                         // r->flags
 116                 }
 117         }
 118         CDEBUG(D_PAGE, "%ld pages allocated after prep\n", echo_pages);
 119
 120         EXIT;
 121         return 0;
 122
 123 preprw_cleanup:
 124         /* It is possible that we would rather handle errors by  allow
 125          * any already-set-up pages to complete, rather than tearing them
 126          * all down again.  I believe that this is what the in-kernel
 127          * prep/commit operations do.
 128          */
 129         CERROR("cleaning up %ld pages (%d obdos)\n", (long)(r - res), objcount);
 130         while (r-- > res) {
 131                 unsigned long addr = r->addr;
 132
 133                 free_pages(addr, 0);
 134                 echo_pages--;
 135         }
 136         memset(res, 0, sizeof(*res) * niocount);
 137
 138         return rc;
 139 }
 140
 141 int echo_commitrw(int cmd, struct obd_conn *conn, int objcount,
 142                   struct obd_ioobj *obj, int niocount, struct niobuf *res)
 143 {
 144         struct niobuf *r = res;
 145         int rc = 0;
 146         int i;
 147
 148         ENTRY;
 149
 150         CDEBUG(D_PAGE, "%s %d obdos with %d IOs\n",
 151                cmd == OBD_BRW_READ ? "reading" : "writing", objcount, niocount);
 152
 153         if (niocount && !r) {
 154                 CERROR("NULL res niobuf with niocount %d\n", niocount);
 155                 EXIT;
 156                 return -EINVAL;
 157         }
 158
 159         for (i = 0; i < objcount; i++, obj++) {
 160                 int j;
 161
 162                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, r++) {
 163                         struct page *page = r->page;
 164                         unsigned long addr = (unsigned long)page_address(page);
 165
 166                         if (!addr || !kern_addr_valid(addr)) {
 167                                 CERROR("bad page %p, id %Ld (%d), buf %d/%d\n",
 168                                        page, (unsigned long long)obj->ioo_id, i,
 169                                        j, obj->ioo_bufcnt);
 170                                 rc = -EFAULT;
 171                                 EXIT;
 172                                 goto commitrw_cleanup;
 173                         }
 174
 175                         free_pages(addr, 0);
 176                         echo_pages--;
 177                 }
 178         }
 179         CDEBUG(D_PAGE, "%ld pages remain after commit\n", echo_pages);
 180         EXIT;
 181         return 0;
 182
 183 commitrw_cleanup:
 184         CERROR("cleaning up %ld pages (%d obdos)\n",
 185                niocount - (long)(r - res) - 1, objcount);
 186         while (++r < res + niocount) {
 187                 struct page *page = r->page;
 188                 unsigned long addr = (unsigned long)page_address(page);
 189
 190                 free_pages(addr, 0);
 191                 echo_pages--;
 192         }
 193         return rc;
 194 }
 195
 196 struct obd_ops echo_obd_ops = {
 197         o_connect:     echo_connect,
 198         o_disconnect:  echo_disconnect,
 199         o_getattr:     echo_getattr,
 200         o_preprw:      echo_preprw,
 201         o_commitrw:    echo_commitrw,
 202 };
 203
 204
 205 static int __init obdecho_init(void)
 206 {
 207         printk(KERN_INFO "Echo OBD driver  v0.001, braam@clusterfs.com\n");
 208
 209         return obd_register_type(&echo_obd_ops, OBD_ECHO_DEVICENAME);
 210 }
 211
 212 static void __exit obdecho_exit(void)
 213 {
 214         CERROR("%ld prep/commitrw pages leaked\n", echo_pages);
 215         obd_unregister_type(OBD_ECHO_DEVICENAME);
 216 }
 217
 218 MODULE_AUTHOR("Peter J. Braam <braam@clusterfs.com>");
 219 MODULE_DESCRIPTION("Lustre Testing Echo OBD driver v1.0");
 220 MODULE_LICENSE("GPL");
 221
 222 module_init(obdecho_init);
 223 module_exit(obdecho_exit);