source3/smbd/dfree.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    functions to calculate the free disk space
   4    Copyright (C) Andrew Tridgell 1998
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "smbd/smbd.h"
  22 #include "smbd/globals.h"
  23 #include "lib/util_file.h"
  24
  25 /****************************************************************************
  26  Normalise for DOS usage.
  27 ****************************************************************************/
  28
  29 static void disk_norm(uint64_t *bsize, uint64_t *dfree, uint64_t *dsize)
  30 {
  31         /* check if the disk is beyond the max disk size */
  32         uint64_t maxdisksize = lp_max_disk_size();
  33         if (maxdisksize) {
  34                 /* convert to blocks - and don't overflow */
  35                 maxdisksize = ((maxdisksize*1024)/(*bsize))*1024;
  36                 if (*dsize > maxdisksize) {
  37                         *dsize = maxdisksize;
  38                 }
  39                 if (*dfree > maxdisksize) {
  40                         *dfree = maxdisksize - 1;
  41                 }
  42                 /* the -1 should stop applications getting div by 0
  43                    errors */
  44         }
  45 }
  46
  47
  48
  49 /****************************************************************************
  50  Return number of 1K blocks available on a path and total number.
  51 ****************************************************************************/
  52
  53 uint64_t sys_disk_free(connection_struct *conn, struct smb_filename *fname,
  54                        uint64_t *bsize, uint64_t *dfree, uint64_t *dsize)
  55 {
  56         uint64_t dfree_retval;
  57         uint64_t dfree_q = 0;
  58         uint64_t bsize_q = 0;
  59         uint64_t dsize_q = 0;
  60         const char *dfree_command;
  61         static bool dfree_broken = false;
  62         const char *path = fname->base_name;
  63
  64         (*dfree) = (*dsize) = 0;
  65         (*bsize) = 512;
  66
  67         /*
  68          * If external disk calculation specified, use it.
  69          */
  70
  71         dfree_command = lp_dfree_command(talloc_tos(), SNUM(conn));
  72         if (dfree_command && *dfree_command) {
  73                 const char *p;
  74                 char **lines = NULL;
  75                 char *syscmd = NULL;
  76
  77                 syscmd = talloc_asprintf(talloc_tos(),
  78                                 "%s %s",
  79                                 dfree_command,
  80                                 path);
  81
  82                 if (!syscmd) {
  83                         return (uint64_t)-1;
  84                 }
  85
  86                 DEBUG (3, ("disk_free: Running command '%s'\n", syscmd));
  87
  88                 lines = file_lines_pload(talloc_tos(), syscmd, NULL);
  89                 if (lines != NULL) {
  90                         char *line = lines[0];
  91
  92                         DEBUG (3, ("Read input from dfree, \"%s\"\n", line));
  93
  94                         *dsize = STR_TO_SMB_BIG_UINT(line, &p);
  95                         while (p && *p && isspace(*p))
  96                                 p++;
  97                         if (p && *p)
  98                                 *dfree = STR_TO_SMB_BIG_UINT(p, &p);
  99                         while (p && *p && isspace(*p))
 100                                 p++;
 101                         if (p && *p)
 102                                 *bsize = STR_TO_SMB_BIG_UINT(p, NULL);
 103                         else
 104                                 *bsize = 1024;
 105                         TALLOC_FREE(lines);
 106                         DEBUG (3, ("Parsed output of dfree, dsize=%u, dfree=%u, bsize=%u\n",
 107                                 (unsigned int)*dsize, (unsigned int)*dfree, (unsigned int)*bsize));
 108
 109                         if (!*dsize)
 110                                 *dsize = 2048;
 111                         if (!*dfree)
 112                                 *dfree = 1024;
 113
 114                         goto dfree_done;
 115                 }
 116                 DEBUG (0, ("disk_free: file_lines_load() failed for "
 117                            "command '%s'. Error was : %s\n",
 118                            syscmd, strerror(errno) ));
 119         }
 120
 121         if (SMB_VFS_DISK_FREE(conn, fname, bsize, dfree, dsize) ==
 122             (uint64_t)-1) {
 123                 DBG_ERR("VFS disk_free failed. Error was : %s\n",
 124                         strerror(errno));
 125                 return (uint64_t)-1;
 126         }
 127
 128         if (disk_quotas(conn, fname, &bsize_q, &dfree_q, &dsize_q)) {
 129                 uint64_t min_bsize = MIN(*bsize, bsize_q);
 130
 131                 (*dfree) = (*dfree) * (*bsize) / min_bsize;
 132                 (*dsize) = (*dsize) * (*bsize) / min_bsize;
 133                 dfree_q = dfree_q * bsize_q / min_bsize;
 134                 dsize_q = dsize_q * bsize_q / min_bsize;
 135
 136                 (*bsize) = min_bsize;
 137                 (*dfree) = MIN(*dfree,dfree_q);
 138                 (*dsize) = MIN(*dsize,dsize_q);
 139         }
 140
 141         /* FIXME : Any reason for this assumption ? */
 142         if (*bsize < 256) {
 143                 DEBUG(5,("disk_free:Warning: bsize == %d < 256 . Changing to assumed correct bsize = 512\n",(int)*bsize));
 144                 *bsize = 512;
 145         }
 146
 147         if ((*dsize)<1) {
 148                 if (!dfree_broken) {
 149                         DEBUG(0,("WARNING: dfree is broken on this system\n"));
 150                         dfree_broken=true;
 151                 }
 152                 *dsize = 20*1024*1024/(*bsize);
 153                 *dfree = MAX(1,*dfree);
 154         }
 155
 156 dfree_done:
 157         disk_norm(bsize, dfree, dsize);
 158
 159         if ((*bsize) < 1024) {
 160                 dfree_retval = (*dfree)/(1024/(*bsize));
 161         } else {
 162                 dfree_retval = ((*bsize)/1024)*(*dfree);
 163         }
 164
 165         return(dfree_retval);
 166 }
 167
 168 /****************************************************************************
 169  Potentially returned cached dfree info.
 170 ****************************************************************************/
 171
 172 uint64_t get_dfree_info(connection_struct *conn, struct smb_filename *fname,
 173                         uint64_t *bsize, uint64_t *dfree, uint64_t *dsize)
 174 {
 175         int dfree_cache_time = lp_dfree_cache_time(SNUM(conn));
 176         struct dfree_cached_info *dfc = conn->dfree_info;
 177         uint64_t dfree_ret;
 178
 179         if (!dfree_cache_time) {
 180                 return sys_disk_free(conn, fname, bsize, dfree, dsize);
 181         }
 182
 183         if (dfc && (conn->lastused - dfc->last_dfree_time < dfree_cache_time)) {
 184                 /* Return cached info. */
 185                 *bsize = dfc->bsize;
 186                 *dfree = dfc->dfree;
 187                 *dsize = dfc->dsize;
 188                 return dfc->dfree_ret;
 189         }
 190
 191         dfree_ret = sys_disk_free(conn, fname, bsize, dfree, dsize);
 192
 193         if (dfree_ret == (uint64_t)-1) {
 194                 /* Don't cache bad data. */
 195                 return dfree_ret;
 196         }
 197
 198         /* No cached info or time to refresh. */
 199         if (!dfc) {
 200                 dfc = talloc(conn, struct dfree_cached_info);
 201                 if (!dfc) {
 202                         return dfree_ret;
 203                 }
 204                 conn->dfree_info = dfc;
 205         }
 206
 207         dfc->bsize = *bsize;
 208         dfc->dfree = *dfree;
 209         dfc->dsize = *dsize;
 210         dfc->dfree_ret = dfree_ret;
 211         dfc->last_dfree_time = conn->lastused;
 212
 213         return dfree_ret;
 214 }