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 2 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, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22
  23 /****************************************************************************
  24  Normalise for DOS usage.
  25 ****************************************************************************/
  26
  27 static void disk_norm(BOOL small_query, SMB_BIG_UINT *bsize,SMB_BIG_UINT *dfree,SMB_BIG_UINT *dsize)
  28 {
  29         /* check if the disk is beyond the max disk size */
  30         SMB_BIG_UINT maxdisksize = lp_maxdisksize();
  31         if (maxdisksize) {
  32                 /* convert to blocks - and don't overflow */
  33                 maxdisksize = ((maxdisksize*1024)/(*bsize))*1024;
  34                 if (*dsize > maxdisksize) *dsize = maxdisksize;
  35                 if (*dfree > maxdisksize) *dfree = maxdisksize-1;
  36                 /* the -1 should stop applications getting div by 0
  37                    errors */
  38         }
  39
  40         if(small_query) {
  41                 while (*dfree > WORDMAX || *dsize > WORDMAX || *bsize < 512) {
  42                         *dfree /= 2;
  43                         *dsize /= 2;
  44                         *bsize *= 2;
  45                         /*
  46                          * Force max to fit in 16 bit fields.
  47                          */
  48                         if (*bsize > (WORDMAX*512)) {
  49                                 *bsize = (WORDMAX*512);
  50                                 if (*dsize > WORDMAX)
  51                                         *dsize = WORDMAX;
  52                                 if (*dfree >  WORDMAX)
  53                                         *dfree = WORDMAX;
  54                                 break;
  55                         }
  56                 }
  57         }
  58 }
  59
  60
  61
  62 /****************************************************************************
  63  Return number of 1K blocks available on a path and total number.
  64 ****************************************************************************/
  65
  66 SMB_BIG_UINT sys_disk_free(connection_struct *conn, const char *path, BOOL small_query,
  67                               SMB_BIG_UINT *bsize,SMB_BIG_UINT *dfree,SMB_BIG_UINT *dsize)
  68 {
  69         SMB_BIG_UINT dfree_retval;
  70         SMB_BIG_UINT dfree_q = 0;
  71         SMB_BIG_UINT bsize_q = 0;
  72         SMB_BIG_UINT dsize_q = 0;
  73         const char *dfree_command;
  74
  75         (*dfree) = (*dsize) = 0;
  76         (*bsize) = 512;
  77
  78         /*
  79          * If external disk calculation specified, use it.
  80          */
  81
  82         dfree_command = lp_dfree_command(SNUM(conn));
  83         if (dfree_command && *dfree_command) {
  84                 const char *p;
  85                 char **lines;
  86                 pstring syscmd;
  87
  88                 slprintf(syscmd, sizeof(syscmd)-1, "%s %s", dfree_command, path);
  89                 DEBUG (3, ("disk_free: Running command %s\n", syscmd));
  90
  91                 lines = file_lines_pload(syscmd, NULL);
  92                 if (lines) {
  93                         char *line = lines[0];
  94
  95                         DEBUG (3, ("Read input from dfree, \"%s\"\n", line));
  96
  97                         *dsize = STR_TO_SMB_BIG_UINT(line, &p);
  98                         while (p && *p && isspace(*p))
  99                                 p++;
 100                         if (p && *p)
 101                                 *dfree = STR_TO_SMB_BIG_UINT(p, &p);
 102                         while (p && *p && isspace(*p))
 103                                 p++;
 104                         if (p && *p)
 105                                 *bsize = STR_TO_SMB_BIG_UINT(p, NULL);
 106                         else
 107                                 *bsize = 1024;
 108                         file_lines_free(lines);
 109                         DEBUG (3, ("Parsed output of dfree, dsize=%u, dfree=%u, bsize=%u\n",
 110                                 (unsigned int)*dsize, (unsigned int)*dfree, (unsigned int)*bsize));
 111
 112                         if (!*dsize)
 113                                 *dsize = 2048;
 114                         if (!*dfree)
 115                                 *dfree = 1024;
 116                 } else {
 117                         DEBUG (0, ("disk_free: sys_popen() failed for command %s. Error was : %s\n",
 118                                 syscmd, strerror(errno) ));
 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 (SMB_BIG_UINT)-1;
 123                         }
 124                 }
 125         } else {
 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
 133         if (disk_quotas(path, &bsize_q, &dfree_q, &dsize_q)) {
 134                 (*bsize) = bsize_q;
 135                 (*dfree) = MIN(*dfree,dfree_q);
 136                 (*dsize) = MIN(*dsize,dsize_q);
 137         }
 138
 139         /* FIXME : Any reason for this assumption ? */
 140         if (*bsize < 256) {
 141                 DEBUG(5,("disk_free:Warning: bsize == %d < 256 . Changing to assumed correct bsize = 512\n",(int)*bsize));
 142                 *bsize = 512;
 143         }
 144
 145         if ((*dsize)<1) {
 146                 static int done;
 147                 if (!done) {
 148                         DEBUG(0,("WARNING: dfree is broken on this system\n"));
 149                         done=1;
 150                 }
 151                 *dsize = 20*1024*1024/(*bsize);
 152                 *dfree = MAX(1,*dfree);
 153         }
 154
 155         disk_norm(small_query,bsize,dfree,dsize);
 156
 157         if ((*bsize) < 1024) {
 158                 dfree_retval = (*dfree)/(1024/(*bsize));
 159         } else {
 160                 dfree_retval = ((*bsize)/1024)*(*dfree);
 161         }
 162
 163         return(dfree_retval);
 164 }
 165
 166 /****************************************************************************
 167  Potentially returned cached dfree info.
 168 ****************************************************************************/
 169
 170 SMB_BIG_UINT get_dfree_info(connection_struct *conn,
 171                         const char *path,
 172                         BOOL small_query,
 173                         SMB_BIG_UINT *bsize,
 174                         SMB_BIG_UINT *dfree,
 175                         SMB_BIG_UINT *dsize)
 176 {
 177         int dfree_cache_time = lp_dfree_cache_time(SNUM(conn));
 178         struct dfree_cached_info *dfc = conn->dfree_info;
 179         SMB_BIG_UINT dfree_ret;
 180
 181         if (!dfree_cache_time) {
 182                 return SMB_VFS_DISK_FREE(conn,path,small_query,bsize,dfree,dsize);
 183         }
 184
 185         if (dfc && (conn->lastused - dfc->last_dfree_time < dfree_cache_time)) {
 186                 /* Return cached info. */
 187                 *bsize = dfc->bsize;
 188                 *dfree = dfc->dfree;
 189                 *dsize = dfc->dsize;
 190                 return dfc->dfree_ret;
 191         }
 192
 193         dfree_ret = SMB_VFS_DISK_FREE(conn,path,small_query,bsize,dfree,dsize);
 194
 195         if (dfree_ret == (SMB_BIG_UINT)-1) {
 196                 /* Don't cache bad data. */
 197                 return dfree_ret;
 198         }
 199
 200         /* No cached info or time to refresh. */
 201         if (!dfc) {
 202                 dfc = TALLOC_P(conn->mem_ctx, struct dfree_cached_info);
 203                 if (!dfc) {
 204                         return dfree_ret;
 205                 }
 206                 conn->dfree_info = dfc;
 207         }
 208
 209         dfc->bsize = *bsize;
 210         dfc->dfree = *dfree;
 211         dfc->dsize = *dsize;
 212         dfc->dfree_ret = dfree_ret;
 213         dfc->last_dfree_time = conn->lastused;
 214
 215         return dfree_ret;
 216 }