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
   7   (c) Andrew Tridgell, 2007
   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> (/bin/true by default, i.e. 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
  31   The TSMSM VFS module tries to avoid calling expensive DMAPI calls with some heuristics
  32   based on the fact that number of blocks reported of a file multiplied by 512 will be
  33   bigger than 'online ratio' of actual size for online (non-migrated) files.
  34
  35   If checks fail, we call DMAPI and ask for specific IBM attribute which present for
  36   offline (migrated) files. If this attribute presents, we consider file offline.
  37  */
  38
  39 #include "includes.h"
  40
  41 #ifndef USE_DMAPI
  42 #error "This module requires DMAPI support!"
  43 #endif
  44
  45 #ifdef HAVE_XFS_DMAPI_H
  46 #include <xfs/dmapi.h>
  47 #elif defined(HAVE_SYS_DMI_H)
  48 #include <sys/dmi.h>
  49 #elif defined(HAVE_SYS_JFSDMAPI_H)
  50 #include <sys/jfsdmapi.h>
  51 #elif defined(HAVE_SYS_DMAPI_H)
  52 #include <sys/dmapi.h>
  53 #elif defined(HAVE_DMAPI_H)
  54 #include <dmapi.h>
  55 #endif
  56
  57 #ifndef _ISOC99_SOURCE
  58 #define _ISOC99_SOURCE
  59 #endif
  60
  61 #include <math.h>
  62
  63 /* optimisation tunables - used to avoid the DMAPI slow path */
  64 #define FILE_IS_ONLINE_RATIO      0.5
  65 #define DM_ATTRIB_OBJECT "IBMObj"
  66 #define DM_ATTRIB_MIGRATED "IBMMig"
  67
  68 struct tsmsm_struct {
  69         dm_sessid_t sid;
  70         float online_ratio;
  71         char *hsmscript;
  72 };
  73
  74 #define TSM_STRINGIFY(a) #a
  75 #define TSM_TOSTRING(a) TSM_STRINGIFY(a)
  76
  77 static void tsmsm_free_data(void **pptr) {
  78         struct tsmsm_struct **tsmd = (struct tsmsm_struct **)pptr;
  79         if(!tsmd) return;
  80         TALLOC_FREE(*tsmd);
  81 }
  82
  83 static int tsmsm_connect(struct vfs_handle_struct *handle,
  84                          const char *service,
  85                          const char *user) {
  86         struct tsmsm_struct *tsmd = TALLOC_ZERO_P(handle, struct tsmsm_struct);
  87         const char *hsmscript, *tsmname;
  88         const char *fres;
  89
  90         if (!tsmd) {
  91                 DEBUG(0,("tsmsm_connect: out of memory!\n"));
  92                 return -1;
  93         }
  94
  95         tsmd->sid = *(dm_sessid_t*) dmapi_get_current_session();
  96
  97         if (tsmd->sid == DM_NO_SESSION) {
  98                 DEBUG(0,("tsmsm_connect: no DMAPI session for Samba is available!\n"));
  99                 TALLOC_FREE(tsmd);
 100                 return -1;
 101         }
 102
 103         tsmname = (handle->param ? handle->param : "tsmsm");
 104         hsmscript = lp_parm_const_string(SNUM(handle->conn), tsmname,
 105                                          "hsm script", NULL);
 106         if (hsmscript) {
 107                 tsmd->hsmscript = talloc_strdup(tsmd, hsmscript);
 108                 if(!tsmd->hsmscript) {
 109                         DEBUG(1, ("tsmsm_connect: can't allocate memory for hsm script path"));
 110                         TALLOC_FREE(tsmd);
 111                         return -1;
 112                 }
 113         } else {
 114                 DEBUG(1, ("tsmsm_connect: can't call hsm script because it "
 115                           "is not set to anything in the smb.conf\n"
 116                           "Use %s: 'hsm script = path' to set it\n",
 117                           tsmname));
 118                 TALLOC_FREE(tsmd);
 119                 return -1;
 120         }
 121
 122         fres = lp_parm_const_string(SNUM(handle->conn), tsmname,
 123                                     "online ratio", TSM_TOSTRING(FILE_IS_ONLINE_RATIO));
 124         tsmd->online_ratio = strtof(fres, NULL);
 125         if((tsmd->online_ratio == (float)0) || ((errno == ERANGE) &&
 126                                                 ((tsmd->online_ratio == HUGE_VALF) ||
 127                                                  (tsmd->online_ratio == HUGE_VALL)))) {
 128                 DEBUG(1, ("tsmsm_connect: error while getting online ratio from smb.conf."
 129                           "Default to %s.\n", TSM_TOSTRING(FILE_IS_ONLINE_RATIO)));
 130                 tsmd->online_ratio = FILE_IS_ONLINE_RATIO;
 131         }
 132
 133         /* Store the private data. */
 134         SMB_VFS_HANDLE_SET_DATA(handle, tsmd, tsmsm_free_data,
 135                                 struct tsmsm_struct, return -1);
 136         return SMB_VFS_NEXT_CONNECT(handle, service, user);
 137 }
 138
 139 static bool tsmsm_is_offline(struct vfs_handle_struct *handle,
 140                             const char *path,
 141                             SMB_STRUCT_STAT *stbuf) {
 142         struct tsmsm_struct *tsmd = (struct tsmsm_struct *) handle->data;
 143         void *dmhandle = NULL;
 144         size_t dmhandle_len = 0;
 145         size_t rlen;
 146         dm_attrname_t dmname;
 147         int ret;
 148         bool offline;
 149
 150         /* if the file has more than FILE_IS_ONLINE_RATIO of blocks available,
 151            then assume it is not offline (it may not be 100%, as it could be sparse) */
 152         if (512 * (off_t)stbuf->st_blocks >= stbuf->st_size * tsmd->online_ratio) {
 153                 DEBUG(10,("%s not offline: st_blocks=%ld st_size=%ld online_ratio=%.2f\n",
 154                           path, stbuf->st_blocks, stbuf->st_size, tsmd->online_ratio));
 155                 return false;
 156         }
 157
 158         /* using POSIX capabilities does not work here. It's a slow path, so
 159          * become_root() is just as good anyway (tridge)
 160          */
 161
 162         /* Also, AIX has DMAPI but no POSIX capablities support. In this case,
 163          * we need to be root to do DMAPI manipulations.
 164          */
 165         become_root();
 166
 167         /* go the slow DMAPI route */
 168         if (dm_path_to_handle((char*)path, &dmhandle, &dmhandle_len) != 0) {
 169                 DEBUG(2,("dm_path_to_handle failed - assuming offline (%s) - %s\n",
 170                          path, strerror(errno)));
 171                 offline = true;
 172                 goto done;
 173         }
 174
 175         memset(&dmname, 0, sizeof(dmname));
 176         strlcpy((char *)&dmname.an_chars[0], DM_ATTRIB_OBJECT, sizeof(dmname.an_chars));
 177
 178         ret = dm_get_dmattr(tsmd->sid, dmhandle, dmhandle_len,
 179                             DM_NO_TOKEN, &dmname, 0, NULL, &rlen);
 180
 181         /* its offline if the IBMObj attribute exists */
 182         offline = (ret == 0 || (ret == -1 && errno == E2BIG));
 183
 184         DEBUG(10,("dm_get_dmattr %s ret=%d (%s)\n", path, ret, strerror(errno)));
 185
 186         ret = 0;
 187
 188         dm_handle_free(dmhandle, dmhandle_len);
 189
 190 done:
 191         unbecome_root();
 192         return offline;
 193 }
 194
 195
 196 static bool tsmsm_aio_force(struct vfs_handle_struct *handle, struct files_struct *fsp)
 197 {
 198         SMB_STRUCT_STAT sbuf;
 199         struct tsmsm_struct *tsmd = (struct tsmsm_struct *) handle->data;
 200         /* see if the file might be offline. This is called before each IO
 201            to ensure we use AIO if the file is offline. We don't do the full dmapi
 202            call as that would be too slow, instead we err on the side of using AIO
 203            if the file might be offline
 204         */
 205         if(SMB_VFS_FSTAT(fsp, &sbuf) == 0) {
 206                 DEBUG(10,("tsmsm_aio_force st_blocks=%ld st_size=%ld online_ratio=%.2f\n",
 207                           sbuf.st_blocks, sbuf.st_size, tsmd->online_ratio));
 208                 return !(512 * (off_t)sbuf.st_blocks >= sbuf.st_size * tsmd->online_ratio);
 209         }
 210         return false;
 211 }
 212
 213 static ssize_t tsmsm_aio_return(struct vfs_handle_struct *handle, struct files_struct *fsp,
 214                                 SMB_STRUCT_AIOCB *aiocb)
 215 {
 216         ssize_t result;
 217
 218         result = SMB_VFS_NEXT_AIO_RETURN(handle, fsp, aiocb);
 219         if(result >= 0) {
 220                 notify_fname(handle->conn, NOTIFY_ACTION_MODIFIED,
 221                              FILE_NOTIFY_CHANGE_ATTRIBUTES,
 222                              fsp->fsp_name);
 223         }
 224
 225         return result;
 226 }
 227
 228 static ssize_t tsmsm_sendfile(vfs_handle_struct *handle, int tofd, files_struct *fsp, const DATA_BLOB *hdr,
 229                               SMB_OFF_T offset, size_t n)
 230 {
 231         bool file_online = tsmsm_aio_force(handle, fsp);
 232
 233         if(!file_online)
 234             return ENOSYS;
 235
 236         return SMB_VFS_NEXT_SENDFILE(handle, tofd, fsp, hdr, offset, n);
 237 }
 238
 239 /* We do overload pread to allow notification when file becomes online after offline status */
 240 /* We don't intercept SMB_VFS_READ here because all file I/O now goes through SMB_VFS_PREAD instead */
 241 static ssize_t tsmsm_pread(struct vfs_handle_struct *handle, struct files_struct *fsp,
 242                            void *data, size_t n, SMB_OFF_T offset) {
 243         ssize_t result;
 244         bool notify_online = tsmsm_aio_force(handle, fsp);
 245
 246         result = SMB_VFS_NEXT_PREAD(handle, fsp, data, n, offset);
 247         if((result != -1) && notify_online) {
 248             /* We can't actually force AIO at this point (came here not from reply_read_and_X)
 249                what we can do is to send notification that file became online
 250             */
 251                 notify_fname(handle->conn, NOTIFY_ACTION_MODIFIED,
 252                              FILE_NOTIFY_CHANGE_ATTRIBUTES,
 253                              fsp->fsp_name);
 254         }
 255
 256         return result;
 257 }
 258
 259 static ssize_t tsmsm_pwrite(struct vfs_handle_struct *handle, struct files_struct *fsp,
 260                            void *data, size_t n, SMB_OFF_T offset) {
 261         ssize_t result;
 262         bool notify_online = tsmsm_aio_force(handle, fsp);
 263
 264         result = SMB_VFS_NEXT_PWRITE(handle, fsp, data, n, offset);
 265         if((result != -1) && notify_online) {
 266             /* We can't actually force AIO at this point (came here not from reply_read_and_X)
 267                what we can do is to send notification that file became online
 268             */
 269                 notify_fname(handle->conn, NOTIFY_ACTION_MODIFIED,
 270                              FILE_NOTIFY_CHANGE_ATTRIBUTES,
 271                              fsp->fsp_name);
 272         }
 273
 274         return result;
 275 }
 276
 277 static int tsmsm_set_offline(struct vfs_handle_struct *handle,
 278                              const char *path) {
 279         struct tsmsm_struct *tsmd = (struct tsmsm_struct *) handle->data;
 280         int result = 0;
 281         char *command;
 282
 283         /* Now, call the script */
 284         command = talloc_asprintf(tsmd, "%s offline \"%s\"", tsmd->hsmscript, path);
 285         if(!command) {
 286                 DEBUG(1, ("tsmsm_set_offline: can't allocate memory to run hsm script"));
 287                 return -1;
 288         }
 289         DEBUG(10, ("tsmsm_set_offline: Running [%s]\n", command));
 290         if((result = smbrun(command, NULL)) != 0) {
 291                 DEBUG(1,("tsmsm_set_offline: Running [%s] returned %d\n", command, result));
 292         }
 293         TALLOC_FREE(command);
 294         return result;
 295 }
 296
 297 static bool tsmsm_is_remotestorage(struct vfs_handle_struct *handle, const char *path) {
 298         return True;
 299 }
 300
 301 static vfs_op_tuple vfs_tsmsm_ops[] = {
 302
 303         /* Disk operations */
 304
 305         {SMB_VFS_OP(tsmsm_connect),     SMB_VFS_OP_CONNECT,
 306          SMB_VFS_LAYER_TRANSPARENT},
 307         {SMB_VFS_OP(tsmsm_aio_force),   SMB_VFS_OP_AIO_FORCE,
 308          SMB_VFS_LAYER_TRANSPARENT},
 309         {SMB_VFS_OP(tsmsm_aio_return),  SMB_VFS_OP_AIO_RETURN,
 310          SMB_VFS_LAYER_TRANSPARENT},
 311         {SMB_VFS_OP(tsmsm_pread),       SMB_VFS_OP_PREAD,
 312          SMB_VFS_LAYER_TRANSPARENT},
 313         {SMB_VFS_OP(tsmsm_pwrite),      SMB_VFS_OP_PWRITE,
 314          SMB_VFS_LAYER_TRANSPARENT},
 315         {SMB_VFS_OP(tsmsm_sendfile),    SMB_VFS_OP_SENDFILE,
 316          SMB_VFS_LAYER_TRANSPARENT},
 317         {SMB_VFS_OP(tsmsm_is_offline),SMB_VFS_OP_IS_OFFLINE,
 318          SMB_VFS_LAYER_OPAQUE},
 319         {SMB_VFS_OP(tsmsm_set_offline),SMB_VFS_OP_SET_OFFLINE,
 320          SMB_VFS_LAYER_OPAQUE},
 321         {SMB_VFS_OP(tsmsm_is_remotestorage),SMB_VFS_OP_IS_REMOTESTORAGE,
 322          SMB_VFS_LAYER_OPAQUE},
 323
 324         /* Finish VFS operations definition */
 325
 326         {SMB_VFS_OP(NULL),              SMB_VFS_OP_NOOP,
 327          SMB_VFS_LAYER_NOOP}
 328 };
 329
 330 NTSTATUS vfs_tsmsm_init(void);
 331 NTSTATUS vfs_tsmsm_init(void)
 332 {
 333         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION,
 334                                 "tsmsm", vfs_tsmsm_ops);
 335 }