source/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
  22 /****************************************************************************
  23  Normalise for DOS usage.
  24 ****************************************************************************/
  25
  26 static void disk_norm(bool small_query, SMB_BIG_UINT *bsize,SMB_BIG_UINT *dfree,SMB_BIG_UINT *dsize)
  27 {
  28         /* check if the disk is beyond the max disk size */
  29         SMB_BIG_UINT maxdisksize = lp_maxdisksize();
  30         if (maxdisksize) {
  31                 /* convert to blocks - and don't overflow */
  32                 maxdisksize = ((maxdisksize*1024)/(*bsize))*1024;
  33                 if (*dsize > maxdisksize) *dsize = maxdisksize;
  34                 if (*dfree > maxdisksize) *dfree = maxdisksize-1;
  35                 /* the -1 should stop applications getting div by 0
  36                    errors */
  37         }
  38
  39         if(small_query) {
  40                 while (*dfree > WORDMAX || *dsize > WORDMAX || *bsize < 512) {
  41                         *dfree /= 2;
  42                         *dsize /= 2;
  43                         *bsize *= 2;
  44                         /*
  45                          * Force max to fit in 16 bit fields.
  46                          */
  47                         if (*bsize > (WORDMAX*512)) {
  48                                 *bsize = (WORDMAX*512);
  49                                 if (*dsize > WORDMAX)
  50                                         *dsize = WORDMAX;
  51                                 if (*dfree >  WORDMAX)
  52                                         *dfree = WORDMAX;
  53                                 break;
  54                         }
  55                 }
  56         }
  57 }
  58
  59
  60
  61 /****************************************************************************
  62  Return number of 1K blocks available on a path and total number.
  63 ****************************************************************************/
  64
  65 SMB_BIG_UINT sys_disk_free(connection_struct *conn, const char *path, bool small_query,
  66                               SMB_BIG_UINT *bsize,SMB_BIG_UINT *dfree,SMB_BIG_UINT *dsize)
  67 {
  68         SMB_BIG_UINT dfree_retval;
  69         SMB_BIG_UINT dfree_q = 0;
  70         SMB_BIG_UINT bsize_q = 0;
  71         SMB_BIG_UINT dsize_q = 0;
  72         const char *dfree_command;
  73
  74         (*dfree) = (*dsize) = 0;
  75         (*bsize) = 512;
  76
  77         /*
  78          * If external disk calculation specified, use it.
  79          */
  80
  81         dfree_command = lp_dfree_command(SNUM(conn));
  82         if (dfree_command && *dfree_command) {
  83                 const char *p;
  84                 char **lines = NULL;
  85                 char *syscmd = NULL;
  86
  87                 syscmd = talloc_asprintf(talloc_tos(),
  88                                 "%s %s",
  89                                 dfree_command,
  90                                 path);
  91
  92                 if (!syscmd) {
  93                         return (SMB_BIG_UINT)-1;
  94                 }
  95
  96                 DEBUG (3, ("disk_free: Running command %s\n", syscmd));
  97
  98                 lines = file_lines_pload(syscmd, NULL);
  99                 if (lines) {
 100                         char *line = lines[0];
 101
 102                         DEBUG (3, ("Read input from dfree, \"%s\"\n", line));
 103
 104                         *dsize = STR_TO_SMB_BIG_UINT(line, &p);
 105                         while (p && *p && isspace(*p))
 106                                 p++;
 107                         if (p && *p)
 108                                 *dfree = STR_TO_SMB_BIG_UINT(p, &p);
 109                         while (p && *p && isspace(*p))
 110                                 p++;
 111                         if (p && *p)
 112                                 *bsize = STR_TO_SMB_BIG_UINT(p, NULL);
 113                         else
 114                                 *bsize = 1024;
 115                         file_lines_free(lines);
 116                         DEBUG (3, ("Parsed output of dfree, dsize=%u, dfree=%u, bsize=%u\n",
 117                                 (unsigned int)*dsize, (unsigned int)*dfree, (unsigned int)*bsize));
 118
 119                         if (!*dsize)
 120                                 *dsize = 2048;
 121                         if (!*dfree)
 122                                 *dfree = 1024;
 123                 } else {
 124                         DEBUG (0, ("disk_free: sys_popen() failed for command %s. Error was : %s\n",
 125                                 syscmd, strerror(errno) ));
 126                         if (sys_fsusage(path, dfree, dsize) != 0) {
 127                                 DEBUG (0, ("disk_free: sys_fsusage() failed. Error was : %s\n",
 128                                         strerror(errno) ));
 129                                 return (SMB_BIG_UINT)-1;
 130                         }
 131                 }
 132         } else {
 133                 if (sys_fsusage(path, dfree, dsize) != 0) {
 134                         DEBUG (0, ("disk_free: sys_fsusage() failed. Error was : %s\n",
 135                                 strerror(errno) ));
 136                         return (SMB_BIG_UINT)-1;
 137                 }
 138         }
 139
 140         if (disk_quotas(path, &bsize_q, &dfree_q, &dsize_q)) {
 141                 (*bsize) = bsize_q;
 142                 (*dfree) = MIN(*dfree,dfree_q);
 143                 (*dsize) = MIN(*dsize,dsize_q);
 144         }
 145
 146         /* FIXME : Any reason for this assumption ? */
 147         if (*bsize < 256) {
 148                 DEBUG(5,("disk_free:Warning: bsize == %d < 256 . Changing to assumed correct bsize = 512\n",(int)*bsize));
 149                 *bsize = 512;
 150         }
 151
 152         if ((*dsize)<1) {
 153                 static bool done = false;
 154                 if (!done) {
 155                         DEBUG(0,("WARNING: dfree is broken on this system\n"));
 156                         done=true;
 157                 }
 158                 *dsize = 20*1024*1024/(*bsize);
 159                 *dfree = MAX(1,*dfree);
 160         }
 161
 162         disk_norm(small_query,bsize,dfree,dsize);
 163
 164         if ((*bsize) < 1024) {
 165                 dfree_retval = (*dfree)/(1024/(*bsize));
 166         } else {
 167                 dfree_retval = ((*bsize)/1024)*(*dfree);
 168         }
 169
 170         return(dfree_retval);
 171 }
 172
 173 /****************************************************************************
 174  Potentially returned cached dfree info.
 175 ****************************************************************************/
 176
 177 SMB_BIG_UINT get_dfree_info(connection_struct *conn,
 178                         const char *path,
 179                         bool small_query,
 180                         SMB_BIG_UINT *bsize,
 181                         SMB_BIG_UINT *dfree,
 182                         SMB_BIG_UINT *dsize)
 183 {
 184         int dfree_cache_time = lp_dfree_cache_time(SNUM(conn));
 185         struct dfree_cached_info *dfc = conn->dfree_info;
 186         SMB_BIG_UINT dfree_ret;
 187
 188         if (!dfree_cache_time) {
 189                 return SMB_VFS_DISK_FREE(conn,path,small_query,bsize,dfree,dsize);
 190         }
 191
 192         if (dfc && (conn->lastused - dfc->last_dfree_time < dfree_cache_time)) {
 193                 /* Return cached info. */
 194                 *bsize = dfc->bsize;
 195                 *dfree = dfc->dfree;
 196                 *dsize = dfc->dsize;
 197                 return dfc->dfree_ret;
 198         }
 199
 200         dfree_ret = SMB_VFS_DISK_FREE(conn,path,small_query,bsize,dfree,dsize);
 201
 202         if (dfree_ret == (SMB_BIG_UINT)-1) {
 203                 /* Don't cache bad data. */
 204                 return dfree_ret;
 205         }
 206
 207         /* No cached info or time to refresh. */
 208         if (!dfc) {
 209                 dfc = TALLOC_P(conn->mem_ctx, struct dfree_cached_info);
 210                 if (!dfc) {
 211                         return dfree_ret;
 212                 }
 213                 conn->dfree_info = dfc;
 214         }
 215
 216         dfc->bsize = *bsize;
 217         dfc->dfree = *dfree;
 218         dfc->dsize = *dsize;
 219         dfc->dfree_ret = dfree_ret;
 220         dfc->last_dfree_time = conn->lastused;
 221
 222         return dfree_ret;
 223 }