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
  24 /****************************************************************************
  25  Normalise for DOS usage.
  26 ****************************************************************************/
  27
  28 void disk_norm(uint64_t *bsize, uint64_t *dfree, uint64_t *dsize)
  29 {
  30         /* check if the disk is beyond the max disk size */
  31         uint64_t maxdisksize = lp_max_disk_size();
  32         if (maxdisksize) {
  33                 /* convert to blocks - and don't overflow */
  34                 maxdisksize = ((maxdisksize*1024)/(*bsize))*1024;
  35                 if (*dsize > maxdisksize) {
  36                         *dsize = maxdisksize;
  37                 }
  38                 if (*dfree > maxdisksize) {
  39                         *dfree = maxdisksize - 1;
  40                 }
  41                 /* the -1 should stop applications getting div by 0
  42                    errors */
  43         }
  44 }
  45
  46
  47
  48 /****************************************************************************
  49  Return number of 1K blocks available on a path and total number.
  50 ****************************************************************************/
  51
  52 uint64_t sys_disk_free(connection_struct *conn, const char *path,
  53                        uint64_t *bsize, uint64_t *dfree, uint64_t *dsize)
  54 {
  55         uint64_t dfree_retval;
  56         uint64_t dfree_q = 0;
  57         uint64_t bsize_q = 0;
  58         uint64_t dsize_q = 0;
  59         const char *dfree_command;
  60         static bool dfree_broken = false;
  61
  62         (*dfree) = (*dsize) = 0;
  63         (*bsize) = 512;
  64
  65         /*
  66          * If external disk calculation specified, use it.
  67          */
  68
  69         dfree_command = lp_dfree_command(talloc_tos(), SNUM(conn));
  70         if (dfree_command && *dfree_command) {
  71                 const char *p;
  72                 char **lines = NULL;
  73                 char *syscmd = NULL;
  74
  75                 syscmd = talloc_asprintf(talloc_tos(),
  76                                 "%s %s",
  77                                 dfree_command,
  78                                 path);
  79
  80                 if (!syscmd) {
  81                         return (uint64_t)-1;
  82                 }
  83
  84                 DEBUG (3, ("disk_free: Running command '%s'\n", syscmd));
  85
  86                 lines = file_lines_pload(syscmd, NULL);
  87                 if (lines != NULL) {
  88                         char *line = lines[0];
  89
  90                         DEBUG (3, ("Read input from dfree, \"%s\"\n", line));
  91
  92                         *dsize = STR_TO_SMB_BIG_UINT(line, &p);
  93                         while (p && *p && isspace(*p))
  94                                 p++;
  95                         if (p && *p)
  96                                 *dfree = STR_TO_SMB_BIG_UINT(p, &p);
  97                         while (p && *p && isspace(*p))
  98                                 p++;
  99                         if (p && *p)
 100                                 *bsize = STR_TO_SMB_BIG_UINT(p, NULL);
 101                         else
 102                                 *bsize = 1024;
 103                         TALLOC_FREE(lines);
 104                         DEBUG (3, ("Parsed output of dfree, dsize=%u, dfree=%u, bsize=%u\n",
 105                                 (unsigned int)*dsize, (unsigned int)*dfree, (unsigned int)*bsize));
 106
 107                         if (!*dsize)
 108                                 *dsize = 2048;
 109                         if (!*dfree)
 110                                 *dfree = 1024;
 111
 112                         goto dfree_done;
 113                 }
 114                 DEBUG (0, ("disk_free: file_lines_load() failed for "
 115                            "command '%s'. Error was : %s\n",
 116                            syscmd, strerror(errno) ));
 117         }
 118
 119         if (sys_fsusage(path, dfree, dsize) != 0) {
 120                 DEBUG (0, ("disk_free: sys_fsusage() failed. Error was : %s\n",
 121                         strerror(errno) ));
 122                 return (uint64_t)-1;
 123         }
 124
 125         if (disk_quotas(path, &bsize_q, &dfree_q, &dsize_q)) {
 126                 (*bsize) = bsize_q;
 127                 (*dfree) = MIN(*dfree,dfree_q);
 128                 (*dsize) = MIN(*dsize,dsize_q);
 129         }
 130
 131         /* FIXME : Any reason for this assumption ? */
 132         if (*bsize < 256) {
 133                 DEBUG(5,("disk_free:Warning: bsize == %d < 256 . Changing to assumed correct bsize = 512\n",(int)*bsize));
 134                 *bsize = 512;
 135         }
 136
 137         if ((*dsize)<1) {
 138                 if (!dfree_broken) {
 139                         DEBUG(0,("WARNING: dfree is broken on this system\n"));
 140                         dfree_broken=true;
 141                 }
 142                 *dsize = 20*1024*1024/(*bsize);
 143                 *dfree = MAX(1,*dfree);
 144         }
 145
 146 dfree_done:
 147         disk_norm(bsize, dfree, dsize);
 148
 149         if ((*bsize) < 1024) {
 150                 dfree_retval = (*dfree)/(1024/(*bsize));
 151         } else {
 152                 dfree_retval = ((*bsize)/1024)*(*dfree);
 153         }
 154
 155         return(dfree_retval);
 156 }
 157
 158 /****************************************************************************
 159  Potentially returned cached dfree info.
 160 ****************************************************************************/
 161
 162 uint64_t get_dfree_info(connection_struct *conn,
 163                         const char *path,
 164                         uint64_t *bsize,
 165                         uint64_t *dfree,
 166                         uint64_t *dsize)
 167 {
 168         int dfree_cache_time = lp_dfree_cache_time(SNUM(conn));
 169         struct dfree_cached_info *dfc = conn->dfree_info;
 170         uint64_t dfree_ret;
 171
 172         if (!dfree_cache_time) {
 173                 return SMB_VFS_DISK_FREE(conn, path, bsize, dfree, dsize);
 174         }
 175
 176         if (dfc && (conn->lastused - dfc->last_dfree_time < dfree_cache_time)) {
 177                 /* Return cached info. */
 178                 *bsize = dfc->bsize;
 179                 *dfree = dfc->dfree;
 180                 *dsize = dfc->dsize;
 181                 return dfc->dfree_ret;
 182         }
 183
 184         dfree_ret = SMB_VFS_DISK_FREE(conn, path, bsize, dfree, dsize);
 185
 186         if (dfree_ret == (uint64_t)-1) {
 187                 /* Don't cache bad data. */
 188                 return dfree_ret;
 189         }
 190
 191         /* No cached info or time to refresh. */
 192         if (!dfc) {
 193                 dfc = talloc(conn, struct dfree_cached_info);
 194                 if (!dfc) {
 195                         return dfree_ret;
 196                 }
 197                 conn->dfree_info = dfc;
 198         }
 199
 200         dfc->bsize = *bsize;
 201         dfc->dfree = *dfree;
 202         dfc->dsize = *dsize;
 203         dfc->dfree_ret = dfree_ret;
 204         dfc->last_dfree_time = conn->lastused;
 205
 206         return dfree_ret;
 207 }