source3/modules/vfs_dirsort.c

   1 /*
   2  * VFS module to provide a sorted directory list.
   3  *
   4  * Copyright (C) Andy Kelk (andy@mopoke.co.uk), 2009
   5  *
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "includes.h"
  22 #include "smbd/smbd.h"
  23 #include "system/filesys.h"
  24
  25 static int compare_dirent (const struct dirent *da, const struct dirent *db)
  26 {
  27         return strcasecmp_m(da->d_name, db->d_name);
  28 }
  29
  30 struct dirsort_privates {
  31         struct dirsort_privates *prev, *next;
  32         long pos;
  33         struct dirent *directory_list;
  34         unsigned int number_of_entries;
  35         struct timespec mtime;
  36         DIR *source_directory;
  37         files_struct *fsp; /* If open via FDOPENDIR. */
  38         struct smb_filename *smb_fname; /* If open via OPENDIR */
  39 };
  40
  41 static bool get_sorted_dir_mtime(vfs_handle_struct *handle,
  42                                 struct dirsort_privates *data,
  43                                 struct timespec *ret_mtime)
  44 {
  45         int ret;
  46         struct timespec mtime;
  47         NTSTATUS status;
  48
  49         if (data->fsp) {
  50                 status = vfs_stat_fsp(data->fsp);
  51                 if (!NT_STATUS_IS_OK(status)) {
  52                         return false;
  53                 }
  54                 mtime = data->fsp->fsp_name->st.st_ex_mtime;
  55         } else {
  56                 ret = SMB_VFS_STAT(handle->conn, data->smb_fname);
  57                 if (ret == -1) {
  58                         return false;
  59                 }
  60                 mtime = data->smb_fname->st.st_ex_mtime;
  61         }
  62
  63         *ret_mtime = mtime;
  64
  65         return true;
  66 }
  67
  68 static bool open_and_sort_dir(vfs_handle_struct *handle,
  69                                 struct dirsort_privates *data)
  70 {
  71         uint32_t total_count = 0;
  72         /* This should be enough for most use cases */
  73         uint32_t dirent_allocated = 64;
  74         struct dirent *dp;
  75
  76         data->number_of_entries = 0;
  77
  78         if (get_sorted_dir_mtime(handle, data, &data->mtime) == false) {
  79                 return false;
  80         }
  81
  82         dp = SMB_VFS_NEXT_READDIR(handle, data->source_directory, NULL);
  83         if (dp == NULL) {
  84                 return false;
  85         }
  86
  87         /* Set up an array and read the directory entries into it */
  88         TALLOC_FREE(data->directory_list); /* destroy previous cache if needed */
  89         data->directory_list = talloc_zero_array(data,
  90                                                  struct dirent,
  91                                                  dirent_allocated);
  92         if (data->directory_list == NULL) {
  93                 return false;
  94         }
  95
  96         do {
  97                 if (total_count >= dirent_allocated) {
  98                         struct dirent *dlist;
  99
 100                         /*
 101                          * Be memory friendly.
 102                          *
 103                          * We should not double the amount of memory. With a lot
 104                          * of files we reach easily 50MB, and doubling will
 105                          * get much bigger just for a few files more.
 106                          *
 107                          * For 200k files this means 50 memory reallocations.
 108                          */
 109                         dirent_allocated += 4096;
 110
 111                         dlist = talloc_realloc(data,
 112                                                data->directory_list,
 113                                                struct dirent,
 114                                                dirent_allocated);
 115                         if (dlist == NULL) {
 116                                 break;
 117                         }
 118                         data->directory_list = dlist;
 119                 }
 120                 data->directory_list[total_count] = *dp;
 121
 122                 total_count++;
 123                 dp = SMB_VFS_NEXT_READDIR(handle, data->source_directory, NULL);
 124         } while (dp != NULL);
 125
 126         data->number_of_entries = total_count;
 127
 128         /* Sort the directory entries by name */
 129         TYPESAFE_QSORT(data->directory_list, data->number_of_entries, compare_dirent);
 130         return true;
 131 }
 132
 133 static DIR *dirsort_opendir(vfs_handle_struct *handle,
 134                                 const struct smb_filename *smb_fname,
 135                                 const char *mask,
 136                                 uint32_t attr)
 137 {
 138         struct dirsort_privates *list_head = NULL;
 139         struct dirsort_privates *data = NULL;
 140
 141         if (SMB_VFS_HANDLE_TEST_DATA(handle)) {
 142                 /* Find the list head of all open directories. */
 143                 SMB_VFS_HANDLE_GET_DATA(handle, list_head, struct dirsort_privates,
 144                                 return NULL);
 145         }
 146
 147         /* set up our private data about this directory */
 148         data = talloc_zero(handle->conn, struct dirsort_privates);
 149         if (!data) {
 150                 return NULL;
 151         }
 152
 153         data->smb_fname = cp_smb_filename(data, smb_fname);
 154         if (data->smb_fname == NULL) {
 155                 TALLOC_FREE(data);
 156                 return NULL;
 157         }
 158
 159         if (ISDOT(data->smb_fname->base_name)) {
 160                 struct smb_filename *cwd_fname = vfs_GetWd(data, handle->conn);
 161                 if (cwd_fname == NULL) {
 162                         TALLOC_FREE(data);
 163                         return NULL;
 164                 }
 165                 TALLOC_FREE(data->smb_fname->base_name);
 166                 data->smb_fname->base_name = talloc_move(data->smb_fname,
 167                                                 &cwd_fname->base_name);
 168                 TALLOC_FREE(cwd_fname);
 169         }
 170
 171         /* Open the underlying directory and count the number of entries */
 172         data->source_directory = SMB_VFS_NEXT_OPENDIR(handle, smb_fname, mask,
 173                                                       attr);
 174
 175         if (data->source_directory == NULL) {
 176                 TALLOC_FREE(data);
 177                 return NULL;
 178         }
 179
 180         if (!open_and_sort_dir(handle, data)) {
 181                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 182                 TALLOC_FREE(data);
 183                 return NULL;
 184         }
 185
 186         /* Add to the private list of all open directories. */
 187         DLIST_ADD(list_head, data);
 188         SMB_VFS_HANDLE_SET_DATA(handle, list_head, NULL,
 189                                 struct dirsort_privates, return NULL);
 190
 191         return data->source_directory;
 192 }
 193
 194 static DIR *dirsort_fdopendir(vfs_handle_struct *handle,
 195                                         files_struct *fsp,
 196                                         const char *mask,
 197                                         uint32_t attr)
 198 {
 199         struct dirsort_privates *list_head = NULL;
 200         struct dirsort_privates *data = NULL;
 201
 202         if (SMB_VFS_HANDLE_TEST_DATA(handle)) {
 203                 /* Find the list head of all open directories. */
 204                 SMB_VFS_HANDLE_GET_DATA(handle, list_head, struct dirsort_privates,
 205                                 return NULL);
 206         }
 207
 208         /* set up our private data about this directory */
 209         data = talloc_zero(handle->conn, struct dirsort_privates);
 210         if (!data) {
 211                 return NULL;
 212         }
 213
 214         data->fsp = fsp;
 215
 216         /* Open the underlying directory and count the number of entries */
 217         data->source_directory = SMB_VFS_NEXT_FDOPENDIR(handle, fsp, mask,
 218                                                       attr);
 219
 220         if (data->source_directory == NULL) {
 221                 TALLOC_FREE(data);
 222                 return NULL;
 223         }
 224
 225         if (!open_and_sort_dir(handle, data)) {
 226                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 227                 TALLOC_FREE(data);
 228                 /* fd is now closed. */
 229                 fsp->fh->fd = -1;
 230                 return NULL;
 231         }
 232
 233         /* Add to the private list of all open directories. */
 234         DLIST_ADD(list_head, data);
 235         SMB_VFS_HANDLE_SET_DATA(handle, list_head, NULL,
 236                                 struct dirsort_privates, return NULL);
 237
 238         return data->source_directory;
 239 }
 240
 241 static struct dirent *dirsort_readdir(vfs_handle_struct *handle,
 242                                           DIR *dirp,
 243                                           SMB_STRUCT_STAT *sbuf)
 244 {
 245         struct dirsort_privates *data = NULL;
 246         struct timespec current_mtime;
 247
 248         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 249                                 return NULL);
 250
 251         while(data && (data->source_directory != dirp)) {
 252                 data = data->next;
 253         }
 254         if (data == NULL) {
 255                 return NULL;
 256         }
 257
 258         if (get_sorted_dir_mtime(handle, data, &current_mtime) == false) {
 259                 return NULL;
 260         }
 261
 262         /* throw away cache and re-read the directory if we've changed */
 263         if (timespec_compare(&current_mtime, &data->mtime)) {
 264                 SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
 265                 open_and_sort_dir(handle, data);
 266         }
 267
 268         if (data->pos >= data->number_of_entries) {
 269                 return NULL;
 270         }
 271
 272         return &data->directory_list[data->pos++];
 273 }
 274
 275 static void dirsort_seekdir(vfs_handle_struct *handle, DIR *dirp,
 276                             long offset)
 277 {
 278         struct timespec current_mtime;
 279         struct dirsort_privates *data = NULL;
 280
 281         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 282
 283         /* Find the entry holding dirp. */
 284         while(data && (data->source_directory != dirp)) {
 285                 data = data->next;
 286         }
 287         if (data == NULL) {
 288                 return;
 289         }
 290         if (offset >= data->number_of_entries) {
 291                 return;
 292         }
 293         data->pos = offset;
 294
 295         if (get_sorted_dir_mtime(handle, data, &current_mtime) == false) {
 296                 return;
 297         }
 298
 299         if (timespec_compare(&current_mtime, &data->mtime)) {
 300                 /* Directory changed. We must re-read the
 301                    cache and search for the name that was
 302                    previously stored at the offset being
 303                    requested, otherwise after the re-sort
 304                    we will point to the wrong entry. The
 305                    OS/2 incremental delete code relies on
 306                    this. */
 307                 unsigned int i;
 308                 char *wanted_name = talloc_strdup(handle->conn,
 309                                         data->directory_list[offset].d_name);
 310                 if (wanted_name == NULL) {
 311                         return;
 312                 }
 313                 SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
 314                 open_and_sort_dir(handle, data);
 315                 /* Now search for where we were. */
 316                 data->pos = 0;
 317                 for (i = 0; i < data->number_of_entries; i++) {
 318                         if(strcmp(wanted_name, data->directory_list[i].d_name) == 0) {
 319                                 data->pos = i;
 320                                 break;
 321                         }
 322                 }
 323                 TALLOC_FREE(wanted_name);
 324         }
 325 }
 326
 327 static long dirsort_telldir(vfs_handle_struct *handle, DIR *dirp)
 328 {
 329         struct dirsort_privates *data = NULL;
 330         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 331                                 return -1);
 332
 333         /* Find the entry holding dirp. */
 334         while(data && (data->source_directory != dirp)) {
 335                 data = data->next;
 336         }
 337         if (data == NULL) {
 338                 return -1;
 339         }
 340         return data->pos;
 341 }
 342
 343 static void dirsort_rewinddir(vfs_handle_struct *handle, DIR *dirp)
 344 {
 345         struct dirsort_privates *data = NULL;
 346         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 347
 348         /* Find the entry holding dirp. */
 349         while(data && (data->source_directory != dirp)) {
 350                 data = data->next;
 351         }
 352         if (data == NULL) {
 353                 return;
 354         }
 355         data->pos = 0;
 356 }
 357
 358 static int dirsort_closedir(vfs_handle_struct *handle, DIR *dirp)
 359 {
 360         struct dirsort_privates *list_head = NULL;
 361         struct dirsort_privates *data = NULL;
 362         int ret;
 363
 364         SMB_VFS_HANDLE_GET_DATA(handle, list_head, struct dirsort_privates, return -1);
 365         /* Find the entry holding dirp. */
 366         for(data = list_head; data && (data->source_directory != dirp); data = data->next) {
 367                 ;
 368         }
 369         if (data == NULL) {
 370                 return -1;
 371         }
 372         /* Remove from the list and re-store the list head. */
 373         DLIST_REMOVE(list_head, data);
 374         SMB_VFS_HANDLE_SET_DATA(handle, list_head, NULL,
 375                                 struct dirsort_privates, return -1);
 376
 377         ret = SMB_VFS_NEXT_CLOSEDIR(handle, dirp);
 378         TALLOC_FREE(data);
 379         return ret;
 380 }
 381
 382 static struct vfs_fn_pointers vfs_dirsort_fns = {
 383         .opendir_fn = dirsort_opendir,
 384         .fdopendir_fn = dirsort_fdopendir,
 385         .readdir_fn = dirsort_readdir,
 386         .seekdir_fn = dirsort_seekdir,
 387         .telldir_fn = dirsort_telldir,
 388         .rewind_dir_fn = dirsort_rewinddir,
 389         .closedir_fn = dirsort_closedir,
 390 };
 391
 392 static_decl_vfs;
 393 NTSTATUS vfs_dirsort_init(TALLOC_CTX *ctx)
 394 {
 395         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "dirsort",
 396                                 &vfs_dirsort_fns);
 397 }