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 static void disk_norm(bool small_query, 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_maxdisksize();
  32         if (maxdisksize) {
  33                 /* convert to blocks - and don't overflow */
  34                 maxdisksize = ((maxdisksize*1024)/(*bsize))*1024;
  35                 if (*dsize > maxdisksize) *dsize = maxdisksize;
  36                 if (*dfree > maxdisksize) *dfree = maxdisksize-1;
  37                 /* the -1 should stop applications getting div by 0
  38                    errors */
  39         }
  40
  41         if(small_query) {
  42                 while (*dfree > WORDMAX || *dsize > WORDMAX || *bsize < 512) {
  43                         *dfree /= 2;
  44                         *dsize /= 2;
  45                         *bsize *= 2;
  46                         /*
  47                          * Force max to fit in 16 bit fields.
  48                          */
  49                         if (*bsize > (WORDMAX*512)) {
  50                                 *bsize = (WORDMAX*512);
  51                                 if (*dsize > WORDMAX)
  52                                         *dsize = WORDMAX;
  53                                 if (*dfree >  WORDMAX)
  54                                         *dfree = WORDMAX;
  55                                 break;
  56                         }
  57                 }
  58         }
  59 }
  60
  61
  62
  63 /****************************************************************************
  64  Return number of 1K blocks available on a path and total number.
  65 ****************************************************************************/
  66
  67 uint64_t sys_disk_free(connection_struct *conn, const char *path, bool small_query,
  68                               uint64_t *bsize,uint64_t *dfree,uint64_t *dsize)
  69 {
  70         uint64_t dfree_retval;
  71         uint64_t dfree_q = 0;
  72         uint64_t bsize_q = 0;
  73         uint64_t dsize_q = 0;
  74         const char *dfree_command;
  75
  76         (*dfree) = (*dsize) = 0;
  77         (*bsize) = 512;
  78
  79         /*
  80          * If external disk calculation specified, use it.
  81          */
  82
  83         dfree_command = lp_dfree_command(SNUM(conn));
  84         if (dfree_command && *dfree_command) {
  85                 const char *p;
  86                 char **lines = NULL;
  87                 char *syscmd = NULL;
  88
  89                 syscmd = talloc_asprintf(talloc_tos(),
  90                                 "%s %s",
  91                                 dfree_command,
  92                                 path);
  93
  94                 if (!syscmd) {
  95                         return (uint64_t)-1;
  96                 }
  97
  98                 DEBUG (3, ("disk_free: Running command %s\n", syscmd));
  99
 100                 lines = file_lines_pload(syscmd, NULL);
 101                 if (lines) {
 102                         char *line = lines[0];
 103
 104                         DEBUG (3, ("Read input from dfree, \"%s\"\n", line));
 105
 106                         *dsize = STR_TO_SMB_BIG_UINT(line, &p);
 107                         while (p && *p && isspace(*p))
 108                                 p++;
 109                         if (p && *p)
 110                                 *dfree = STR_TO_SMB_BIG_UINT(p, &p);
 111                         while (p && *p && isspace(*p))
 112                                 p++;
 113                         if (p && *p)
 114                                 *bsize = STR_TO_SMB_BIG_UINT(p, NULL);
 115                         else
 116                                 *bsize = 1024;
 117                         TALLOC_FREE(lines);
 118                         DEBUG (3, ("Parsed output of dfree, dsize=%u, dfree=%u, bsize=%u\n",
 119                                 (unsigned int)*dsize, (unsigned int)*dfree, (unsigned int)*bsize));
 120
 121                         if (!*dsize)
 122                                 *dsize = 2048;
 123                         if (!*dfree)
 124                                 *dfree = 1024;
 125                 } else {
 126                         DEBUG (0, ("disk_free: sys_popen() failed for command %s. Error was : %s\n",
 127                                 syscmd, strerror(errno) ));
 128                         if (sys_fsusage(path, dfree, dsize) != 0) {
 129                                 DEBUG (0, ("disk_free: sys_fsusage() failed. Error was : %s\n",
 130                                         strerror(errno) ));
 131                                 return (uint64_t)-1;
 132                         }
 133                 }
 134         } else {
 135                 if (sys_fsusage(path, dfree, dsize) != 0) {
 136                         DEBUG (0, ("disk_free: sys_fsusage() failed. Error was : %s\n",
 137                                 strerror(errno) ));
 138                         return (uint64_t)-1;
 139                 }
 140         }
 141
 142         if (disk_quotas(path, &bsize_q, &dfree_q, &dsize_q)) {
 143                 (*bsize) = bsize_q;
 144                 (*dfree) = MIN(*dfree,dfree_q);
 145                 (*dsize) = MIN(*dsize,dsize_q);
 146         }
 147
 148         /* FIXME : Any reason for this assumption ? */
 149         if (*bsize < 256) {
 150                 DEBUG(5,("disk_free:Warning: bsize == %d < 256 . Changing to assumed correct bsize = 512\n",(int)*bsize));
 151                 *bsize = 512;
 152         }
 153
 154         if ((*dsize)<1) {
 155                 if (!dfree_broken) {
 156                         DEBUG(0,("WARNING: dfree is broken on this system\n"));
 157                         dfree_broken=true;
 158                 }
 159                 *dsize = 20*1024*1024/(*bsize);
 160                 *dfree = MAX(1,*dfree);
 161         }
 162
 163         disk_norm(small_query,bsize,dfree,dsize);
 164
 165         if ((*bsize) < 1024) {
 166                 dfree_retval = (*dfree)/(1024/(*bsize));
 167         } else {
 168                 dfree_retval = ((*bsize)/1024)*(*dfree);
 169         }
 170
 171         return(dfree_retval);
 172 }
 173
 174 /****************************************************************************
 175  Potentially returned cached dfree info.
 176 ****************************************************************************/
 177
 178 uint64_t get_dfree_info(connection_struct *conn,
 179                         const char *path,
 180                         bool small_query,
 181                         uint64_t *bsize,
 182                         uint64_t *dfree,
 183                         uint64_t *dsize)
 184 {
 185         int dfree_cache_time = lp_dfree_cache_time(SNUM(conn));
 186         struct dfree_cached_info *dfc = conn->dfree_info;
 187         uint64_t dfree_ret;
 188
 189         if (!dfree_cache_time) {
 190                 return SMB_VFS_DISK_FREE(conn,path,small_query,bsize,dfree,dsize);
 191         }
 192
 193         if (dfc && (conn->lastused - dfc->last_dfree_time < dfree_cache_time)) {
 194                 /* Return cached info. */
 195                 *bsize = dfc->bsize;
 196                 *dfree = dfc->dfree;
 197                 *dsize = dfc->dsize;
 198                 return dfc->dfree_ret;
 199         }
 200
 201         dfree_ret = SMB_VFS_DISK_FREE(conn,path,small_query,bsize,dfree,dsize);
 202
 203         if (dfree_ret == (uint64_t)-1) {
 204                 /* Don't cache bad data. */
 205                 return dfree_ret;
 206         }
 207
 208         /* No cached info or time to refresh. */
 209         if (!dfc) {
 210                 dfc = talloc(conn, struct dfree_cached_info);
 211                 if (!dfc) {
 212                         return dfree_ret;
 213                 }
 214                 conn->dfree_info = dfc;
 215         }
 216
 217         dfc->bsize = *bsize;
 218         dfc->dfree = *dfree;
 219         dfc->dsize = *dsize;
 220         dfc->dfree_ret = dfree_ret;
 221         dfc->last_dfree_time = conn->lastused;
 222
 223         return dfree_ret;
 224 }