source/modules/vfs_tsmsm.c

   1 /*
   2   Unix SMB/CIFS implementation.
   3   Samba VFS module for handling offline files
   4   with Tivoli Storage Manager Space Management
   5
   6   (c) Alexander Bokovoy, 2007, 2008
   7   (c) Andrew Tridgell, 2007, 2008
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21  */
  22 /*
  23   This VFS module accepts following options:
  24   tsmsm: hsm script = <path to hsm script> (default does nothing)
  25          hsm script should point to a shell script which accepts two arguments:
  26          <operation> <filepath>
  27          where <operation> is currently 'offline' to set offline status of the <filepath>
  28
  29   tsmsm: online ratio = ratio to check reported size against actual file size (0.5 by default)
  30   tsmsm: attribute name = name of DMAPI attribute that is present when a file is offline.
  31   Default is "IBMobj" (which is what GPFS uses)
  32
  33   The TSMSM VFS module tries to avoid calling expensive DMAPI calls with some heuristics
  34   based on the fact that number of blocks reported of a file multiplied by 512 will be
  35   bigger than 'online ratio' of actual size for online (non-migrated) files.
  36
  37   If checks fail, we call DMAPI and ask for specific attribute which present for
  38   offline (migrated) files. If this attribute presents, we consider file offline.
  39  */
  40
  41 #include "includes.h"
  42
  43 #ifndef USE_DMAPI
  44 #error "This module requires DMAPI support!"
  45 #endif
  46
  47 #ifdef HAVE_XFS_DMAPI_H
  48 #include <xfs/dmapi.h>
  49 #elif defined(HAVE_SYS_DMI_H)
  50 #include <sys/dmi.h>
  51 #elif defined(HAVE_SYS_JFSDMAPI_H)
  52 #include <sys/jfsdmapi.h>
  53 #elif defined(HAVE_SYS_DMAPI_H)
  54 #include <sys/dmapi.h>
  55 #elif defined(HAVE_DMAPI_H)
  56 #include <dmapi.h>
  57 #endif
  58
  59 #ifndef _ISOC99_SOURCE
  60 #define _ISOC99_SOURCE
  61 #endif
  62
  63 #include <math.h>
  64
  65 /* optimisation tunables - used to avoid the DMAPI slow path */
  66 #define FILE_IS_ONLINE_RATIO      0.5
  67
  68 /* default attribute name to look for */
  69 #define DM_ATTRIB_OBJECT "IBMObj"
  70
  71 struct tsmsm_struct {
  72         float online_ratio;
  73         char *hsmscript;
  74         const char *attrib_name;
  75         const char *attrib_value;
  76 };
  77
  78 static void tsmsm_free_data(void **pptr) {
  79         struct tsmsm_struct **tsmd = (struct tsmsm_struct **)pptr;
  80         if(!tsmd) return;
  81         TALLOC_FREE(*tsmd);
  82 }
  83
  84 /*
  85    called when a client connects to a share
  86 */
  87 static int tsmsm_connect(struct vfs_handle_struct *handle,
  88                          const char *service,
  89                          const char *user) {
  90         struct tsmsm_struct *tsmd = TALLOC_ZERO_P(handle, struct tsmsm_struct);
  91         const char *fres;
  92         const char *tsmname;
  93
  94         if (!tsmd) {
  95                 DEBUG(0,("tsmsm_connect: out of memory!\n"));
  96                 return -1;
  97         }
  98
  99         if (!dmapi_have_session()) {
 100                 DEBUG(0,("tsmsm_connect: no DMAPI session for Samba is available!\n"));
 101                 TALLOC_FREE(tsmd);
 102                 return -1;
 103         }
 104
 105         tsmname = (handle->param ? handle->param : "tsmsm");
 106
 107         /* Get 'hsm script' and 'dmapi attribute' parameters to tsmd context */
 108         tsmd->hsmscript = lp_parm_talloc_string(SNUM(handle->conn), tsmname,
 109                                                 "hsm script", NULL);
 110         talloc_steal(tsmd, tsmd->hsmscript);
 111
 112         tsmd->attrib_name = lp_parm_talloc_string(SNUM(handle->conn), tsmname,
 113                                                   "dmapi attribute", DM_ATTRIB_OBJECT);
 114         talloc_steal(tsmd, tsmd->attrib_name);
 115
 116         tsmd->attrib_value = lp_parm_talloc_string(SNUM(handle->conn), "tsmsm",
 117                                                    "dmapi value", NULL);
 118         talloc_steal(tsmd, tsmd->attrib_value);
 119
 120         /* retrieve 'online ratio'. In case of error default to FILE_IS_ONLINE_RATIO */
 121         fres = lp_parm_const_string(SNUM(handle->conn), tsmname,
 122                                     "online ratio", NULL);
 123         if (fres == NULL) {
 124                 tsmd->online_ratio = FILE_IS_ONLINE_RATIO;
 125         } else {
 126                 tsmd->online_ratio = strtof(fres, NULL);
 127                 if (tsmd->online_ratio > 1.0 ||
 128                     tsmd->online_ratio <= 0.0) {
 129                         DEBUG(1, ("tsmsm_connect: invalid online ration %f - using %f.\n",
 130                                   tsmd->online_ratio, (float)FILE_IS_ONLINE_RATIO));
 131                 }
 132         }
 133
 134         /* Store the private data. */
 135         SMB_VFS_HANDLE_SET_DATA(handle, tsmd, tsmsm_free_data,
 136                                 struct tsmsm_struct, return -1);
 137         return SMB_VFS_NEXT_CONNECT(handle, service, user);
 138 }
 139
 140 static bool tsmsm_is_offline(struct vfs_handle_struct *handle,
 141                             const char *path,
 142                             SMB_STRUCT_STAT *stbuf) {
 143         struct tsmsm_struct *tsmd = (struct tsmsm_struct *) handle->data;
 144         const dm_sessid_t *dmsession_id;
 145         void *dmhandle = NULL;
 146         size_t dmhandle_len = 0;
 147         size_t rlen;
 148         dm_attrname_t dmname;
 149         int ret, lerrno;
 150         bool offline;
 151         char *buf = NULL;
 152         size_t buflen;
 153
 154         /* if the file has more than FILE_IS_ONLINE_RATIO of blocks available,
 155            then assume it is not offline (it may not be 100%, as it could be sparse) */
 156         if (512 * (off_t)stbuf->st_blocks >= stbuf->st_size * tsmd->online_ratio) {
 157                 DEBUG(10,("%s not offline: st_blocks=%ld st_size=%ld "
 158                           "online_ratio=%.2f\n", path, (long)stbuf->st_blocks,
 159                           (long)stbuf->st_size, tsmd->online_ratio));
 160                 return false;
 161         }
 162
 163         dmsession_id = dmapi_get_current_session();
 164         if (dmsession_id == NULL) {
 165                 DEBUG(2, ("tsmsm_is_offline: no DMAPI session available? "
 166                           "Assume file is online.\n"));
 167                 return false;
 168         }
 169
 170         /* using POSIX capabilities does not work here. It's a slow path, so
 171          * become_root() is just as good anyway (tridge)
 172          */
 173
 174         /* Also, AIX has DMAPI but no POSIX capablities support. In this case,
 175          * we need to be root to do DMAPI manipulations.
 176          */
 177         become_root();
 178
 179         /* go the slow DMAPI route */
 180         if (dm_path_to_handle((char*)path, &dmhandle, &dmhandle_len) != 0) {
 181                 DEBUG(2,("dm_path_to_handle failed - assuming offline (%s) - %s\n",
 182                          path, strerror(errno)));
 183                 offline = true;
 184                 goto done;
 185         }
 186
 187         memset(&dmname, 0, sizeof(dmname));
 188         strlcpy((char *)&dmname.an_chars[0], tsmd->attrib_name, sizeof(dmname.an_chars));
 189
 190         if (tsmd->attrib_value != NULL) {
 191                 buflen = strlen(tsmd->attrib_value);
 192         } else {
 193                 buflen = 1;
 194         }
 195         buf = talloc_zero_size(tsmd, buflen);
 196         if (buf == NULL) {
 197                 DEBUG(0,("out of memory in tsmsm_is_offline -- assuming online (%s)\n", path));
 198                 errno = ENOMEM;
 199                 offline = false;
 200                 goto done;
 201         }
 202
 203         do {
 204                 lerrno = 0;
 205
 206                 ret = dm_get_dmattr(*dmsession_id, dmhandle, dmhandle_len,
 207                                     DM_NO_TOKEN, &dmname, buflen, buf, &rlen);
 208                 if (ret == -1 && errno == EINVAL) {
 209                         DEBUG(0, ("Stale DMAPI session, re-creating it.\n"));
 210                         lerrno = EINVAL;
 211                         if (dmapi_new_session()) {
 212                                 dmsession_id = dmapi_get_current_session();
 213                         } else {
 214                                 DEBUG(0,
 215                                       ("Unable to re-create DMAPI session, assuming offline (%s) - %s\n",
 216                                        path, strerror(errno)));
 217                                 offline = true;
 218                                 dm_handle_free(dmhandle, dmhandle_len);
 219                                 goto done;
 220                         }
 221                 }
 222         } while (ret == -1 && lerrno == EINVAL);
 223
 224         /* check if we need a specific attribute value */
 225         if (tsmd->attrib_value != NULL) {
 226                 offline = (ret == 0 && rlen == buflen &&
 227                             memcmp(buf, tsmd->attrib_value, buflen) == 0);
 228         } else {
 229                 /* its offline if the specified DMAPI attribute exists */
 230                 offline = (ret == 0 || (ret == -1 && errno == E2BIG));
 231         }
 232
 233         DEBUG(10,("dm_get_dmattr %s ret=%d (%s)\n", path, ret, strerror(errno)));
 234
 235         ret = 0;
 236
 237         dm_handle_free(dmhandle, dmhandle_len);
 238
 239 done:
 240         talloc_free(buf);
 241         unbecome_root();
 242         return offline;
 243 }
 244
 245
 246 static bool tsmsm_aio_force(struct vfs_handle_struct *handle, struct files_struct *fsp)
 247 {
 248         SMB_STRUCT_STAT sbuf;
 249         struct tsmsm_struct *tsmd = (struct tsmsm_struct *) handle->data;
 250         /* see if the file might be offline. This is called before each IO
 251            to ensure we use AIO if the file is offline. We don't do the full dmapi
 252            call as that would be too slow, instead we err on the side of using AIO
 253            if the file might be offline
 254         */
 255         if(SMB_VFS_FSTAT(fsp, &sbuf) == 0) {
 256                 DEBUG(10,("tsmsm_aio_force st_blocks=%ld st_size=%ld "
 257                           "online_ratio=%.2f\n", (long)sbuf.st_blocks,
 258                           (long)sbuf.st_size, tsmd->online_ratio));
 259                 return !(512 * (off_t)sbuf.st_blocks >= sbuf.st_size * tsmd->online_ratio);
 260         }
 261         return false;
 262 }
 263
 264 static ssize_t tsmsm_aio_return(struct vfs_handle_struct *handle, struct files_struct *fsp,
 265                                 SMB_STRUCT_AIOCB *aiocb)
 266 {
 267         ssize_t result;
 268
 269         result = SMB_VFS_NEXT_AIO_RETURN(handle, fsp, aiocb);
 270         if(result >= 0) {
 271                 notify_fname(handle->conn, NOTIFY_ACTION_MODIFIED,
 272                              FILE_NOTIFY_CHANGE_ATTRIBUTES,
 273                              fsp->fsp_name);
 274         }
 275
 276         return result;
 277 }
 278
 279 static ssize_t tsmsm_sendfile(vfs_handle_struct *handle, int tofd, files_struct *fsp, const DATA_BLOB *hdr,
 280                               SMB_OFF_T offset, size_t n)
 281 {
 282         bool file_offline = tsmsm_aio_force(handle, fsp);
 283
 284         if (file_offline) {
 285                 DEBUG(10,("tsmsm_sendfile on offline file - rejecting\n"));
 286                 errno = ENOSYS;
 287                 return -1;
 288         }
 289
 290         return SMB_VFS_NEXT_SENDFILE(handle, tofd, fsp, hdr, offset, n);
 291 }
 292
 293 /* We do overload pread to allow notification when file becomes online after offline status */
 294 /* We don't intercept SMB_VFS_READ here because all file I/O now goes through SMB_VFS_PREAD instead */
 295 static ssize_t tsmsm_pread(struct vfs_handle_struct *handle, struct files_struct *fsp,
 296                            void *data, size_t n, SMB_OFF_T offset) {
 297         ssize_t result;
 298         bool notify_online = tsmsm_aio_force(handle, fsp);
 299
 300         result = SMB_VFS_NEXT_PREAD(handle, fsp, data, n, offset);
 301         if((result != -1) && notify_online) {
 302             /* We can't actually force AIO at this point (came here not from reply_read_and_X)
 303                what we can do is to send notification that file became online
 304             */
 305                 notify_fname(handle->conn, NOTIFY_ACTION_MODIFIED,
 306                              FILE_NOTIFY_CHANGE_ATTRIBUTES,
 307                              fsp->fsp_name);
 308         }
 309
 310         return result;
 311 }
 312
 313 static ssize_t tsmsm_pwrite(struct vfs_handle_struct *handle, struct files_struct *fsp,
 314                            void *data, size_t n, SMB_OFF_T offset) {
 315         ssize_t result;
 316         bool notify_online = tsmsm_aio_force(handle, fsp);
 317
 318         result = SMB_VFS_NEXT_PWRITE(handle, fsp, data, n, offset);
 319         if((result != -1) && notify_online) {
 320             /* We can't actually force AIO at this point (came here not from reply_read_and_X)
 321                what we can do is to send notification that file became online
 322             */
 323                 notify_fname(handle->conn, NOTIFY_ACTION_MODIFIED,
 324                              FILE_NOTIFY_CHANGE_ATTRIBUTES,
 325                              fsp->fsp_name);
 326         }
 327
 328         return result;
 329 }
 330
 331 static int tsmsm_set_offline(struct vfs_handle_struct *handle,
 332                              const char *path) {
 333         struct tsmsm_struct *tsmd = (struct tsmsm_struct *) handle->data;
 334         int result = 0;
 335         char *command;
 336
 337         if (tsmd->hsmscript == NULL) {
 338                 /* no script enabled */
 339                 DEBUG(1, ("tsmsm_set_offline: No 'tsmsm:hsm script' configured\n"));
 340                 return 0;
 341         }
 342
 343         /* Now, call the script */
 344         command = talloc_asprintf(tsmd, "%s offline \"%s\"", tsmd->hsmscript, path);
 345         if(!command) {
 346                 DEBUG(1, ("tsmsm_set_offline: can't allocate memory to run hsm script"));
 347                 return -1;
 348         }
 349         DEBUG(10, ("tsmsm_set_offline: Running [%s]\n", command));
 350         if((result = smbrun(command, NULL)) != 0) {
 351                 DEBUG(1,("tsmsm_set_offline: Running [%s] returned %d\n", command, result));
 352         }
 353         TALLOC_FREE(command);
 354         return result;
 355 }
 356
 357 static uint32_t tsmsm_fs_capabilities(struct vfs_handle_struct *handle)
 358 {
 359         return SMB_VFS_NEXT_FS_CAPABILITIES(handle) | FILE_SUPPORTS_REMOTE_STORAGE | FILE_SUPPORTS_REPARSE_POINTS;
 360 }
 361
 362 static vfs_op_tuple vfs_tsmsm_ops[] = {
 363
 364         /* Disk operations */
 365
 366         {SMB_VFS_OP(tsmsm_connect),     SMB_VFS_OP_CONNECT,
 367          SMB_VFS_LAYER_TRANSPARENT},
 368         {SMB_VFS_OP(tsmsm_fs_capabilities),     SMB_VFS_OP_FS_CAPABILITIES,
 369          SMB_VFS_LAYER_TRANSPARENT},
 370         {SMB_VFS_OP(tsmsm_aio_force),   SMB_VFS_OP_AIO_FORCE,
 371          SMB_VFS_LAYER_TRANSPARENT},
 372         {SMB_VFS_OP(tsmsm_aio_return),  SMB_VFS_OP_AIO_RETURN,
 373          SMB_VFS_LAYER_TRANSPARENT},
 374         {SMB_VFS_OP(tsmsm_pread),       SMB_VFS_OP_PREAD,
 375          SMB_VFS_LAYER_TRANSPARENT},
 376         {SMB_VFS_OP(tsmsm_pwrite),      SMB_VFS_OP_PWRITE,
 377          SMB_VFS_LAYER_TRANSPARENT},
 378         {SMB_VFS_OP(tsmsm_sendfile),    SMB_VFS_OP_SENDFILE,
 379          SMB_VFS_LAYER_TRANSPARENT},
 380         {SMB_VFS_OP(tsmsm_is_offline),  SMB_VFS_OP_IS_OFFLINE,
 381          SMB_VFS_LAYER_OPAQUE},
 382         {SMB_VFS_OP(tsmsm_set_offline), SMB_VFS_OP_SET_OFFLINE,
 383          SMB_VFS_LAYER_OPAQUE},
 384
 385         /* Finish VFS operations definition */
 386
 387         {SMB_VFS_OP(NULL),              SMB_VFS_OP_NOOP,
 388          SMB_VFS_LAYER_NOOP}
 389 };
 390
 391 NTSTATUS vfs_tsmsm_init(void);
 392 NTSTATUS vfs_tsmsm_init(void)
 393 {
 394         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION,
 395                                 "tsmsm", vfs_tsmsm_ops);
 396 }