Line data Source code
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 : #include "lib/util/memcache.h"
25 :
26 : /****************************************************************************
27 : Normalise for DOS usage.
28 : ****************************************************************************/
29 :
30 1435 : static void disk_norm(uint64_t *bsize, uint64_t *dfree, uint64_t *dsize)
31 : {
32 : /* check if the disk is beyond the max disk size */
33 1435 : uint64_t maxdisksize = lp_max_disk_size();
34 1435 : if (maxdisksize) {
35 : /* convert to blocks - and don't overflow */
36 0 : maxdisksize = ((maxdisksize*1024)/(*bsize))*1024;
37 0 : if (*dsize > maxdisksize) {
38 0 : *dsize = maxdisksize;
39 : }
40 0 : if (*dfree > maxdisksize) {
41 0 : *dfree = maxdisksize - 1;
42 : }
43 : /* the -1 should stop applications getting div by 0
44 : errors */
45 : }
46 1435 : }
47 :
48 :
49 :
50 : /****************************************************************************
51 : Return number of 1K blocks available on a path and total number.
52 : ****************************************************************************/
53 :
54 1435 : static uint64_t sys_disk_free(connection_struct *conn,
55 : struct smb_filename *fname,
56 : uint64_t *bsize,
57 : uint64_t *dfree,
58 : uint64_t *dsize)
59 : {
60 1193 : const struct loadparm_substitution *lp_sub =
61 242 : loadparm_s3_global_substitution();
62 : uint64_t dfree_retval;
63 1435 : uint64_t dfree_q = 0;
64 1435 : uint64_t bsize_q = 0;
65 1435 : uint64_t dsize_q = 0;
66 : const char *dfree_command;
67 : static bool dfree_broken = false;
68 1435 : char *path = fname->base_name;
69 :
70 1435 : (*dfree) = (*dsize) = 0;
71 1435 : (*bsize) = 512;
72 :
73 : /*
74 : * If external disk calculation specified, use it.
75 : */
76 :
77 1435 : dfree_command = lp_dfree_command(talloc_tos(), lp_sub, SNUM(conn));
78 1435 : if (dfree_command && *dfree_command) {
79 : const char *p;
80 10 : char **lines = NULL;
81 10 : char **argl = NULL;
82 :
83 10 : argl = talloc_zero_array(talloc_tos(),
84 : char *,
85 : 3);
86 10 : if (argl == NULL) {
87 0 : return (uint64_t)-1;
88 : }
89 :
90 10 : argl[0] = talloc_strdup(argl, dfree_command);
91 10 : if (argl[0] == NULL) {
92 0 : TALLOC_FREE(argl);
93 0 : return (uint64_t)-1;
94 : }
95 10 : argl[1] = path;
96 10 : argl[2] = NULL;
97 :
98 10 : DBG_NOTICE("Running command '%s %s'\n",
99 : dfree_command,
100 : path);
101 :
102 10 : lines = file_lines_ploadv(talloc_tos(), argl, NULL);
103 :
104 10 : TALLOC_FREE(argl);
105 :
106 10 : if (lines != NULL) {
107 10 : char *line = lines[0];
108 :
109 10 : DEBUG (3, ("Read input from dfree, \"%s\"\n", line));
110 :
111 10 : *dsize = STR_TO_SMB_BIG_UINT(line, &p);
112 30 : while (p && *p && isspace(*p))
113 10 : p++;
114 10 : if (p && *p)
115 10 : *dfree = STR_TO_SMB_BIG_UINT(p, &p);
116 30 : while (p && *p && isspace(*p))
117 10 : p++;
118 10 : if (p && *p)
119 10 : *bsize = STR_TO_SMB_BIG_UINT(p, NULL);
120 : else
121 0 : *bsize = 1024;
122 10 : TALLOC_FREE(lines);
123 10 : DEBUG (3, ("Parsed output of dfree, dsize=%u, dfree=%u, bsize=%u\n",
124 : (unsigned int)*dsize, (unsigned int)*dfree, (unsigned int)*bsize));
125 :
126 10 : if (!*dsize)
127 0 : *dsize = 2048;
128 10 : if (!*dfree)
129 0 : *dfree = 1024;
130 :
131 20 : goto dfree_done;
132 : }
133 0 : DBG_ERR("file_lines_load() failed for "
134 : "command '%s %s'. Error was : %s\n",
135 : dfree_command, path, strerror(errno));
136 : }
137 :
138 1425 : if (SMB_VFS_DISK_FREE(conn, fname, bsize, dfree, dsize) ==
139 : (uint64_t)-1) {
140 0 : DBG_ERR("VFS disk_free failed. Error was : %s\n",
141 : strerror(errno));
142 0 : return (uint64_t)-1;
143 : }
144 :
145 1425 : if (disk_quotas(conn, fname, &bsize_q, &dfree_q, &dsize_q)) {
146 36 : uint64_t min_bsize = MIN(*bsize, bsize_q);
147 :
148 36 : (*dfree) = (*dfree) * (*bsize) / min_bsize;
149 36 : (*dsize) = (*dsize) * (*bsize) / min_bsize;
150 36 : dfree_q = dfree_q * bsize_q / min_bsize;
151 36 : dsize_q = dsize_q * bsize_q / min_bsize;
152 :
153 36 : (*bsize) = min_bsize;
154 36 : (*dfree) = MIN(*dfree,dfree_q);
155 36 : (*dsize) = MIN(*dsize,dsize_q);
156 : }
157 :
158 : /* FIXME : Any reason for this assumption ? */
159 1425 : if (*bsize < 256) {
160 0 : DEBUG(5,("disk_free:Warning: bsize == %d < 256 . Changing to assumed correct bsize = 512\n",(int)*bsize));
161 0 : *bsize = 512;
162 : }
163 :
164 1425 : if ((*dsize)<1) {
165 0 : if (!dfree_broken) {
166 0 : DEBUG(0,("WARNING: dfree is broken on this system\n"));
167 0 : dfree_broken=true;
168 : }
169 0 : *dsize = 20*1024*1024/(*bsize);
170 0 : *dfree = MAX(1,*dfree);
171 : }
172 :
173 2618 : dfree_done:
174 1435 : disk_norm(bsize, dfree, dsize);
175 :
176 1435 : if ((*bsize) < 1024) {
177 1385 : dfree_retval = (*dfree)/(1024/(*bsize));
178 : } else {
179 50 : dfree_retval = ((*bsize)/1024)*(*dfree);
180 : }
181 :
182 1435 : return(dfree_retval);
183 : }
184 :
185 : /****************************************************************************
186 : Potentially returned cached dfree info.
187 :
188 : Depending on the file system layout and file system features, the free space
189 : information can be different for different sub directories underneath a SMB
190 : share. Store the cache information in memcache using the query path as the
191 : key to accomodate this.
192 : ****************************************************************************/
193 :
194 : struct dfree_cached_info {
195 : time_t last_dfree_time;
196 : uint64_t dfree_ret;
197 : uint64_t bsize;
198 : uint64_t dfree;
199 : uint64_t dsize;
200 : };
201 :
202 1435 : uint64_t get_dfree_info(connection_struct *conn, struct smb_filename *fname,
203 : uint64_t *bsize, uint64_t *dfree, uint64_t *dsize)
204 : {
205 1435 : int dfree_cache_time = lp_dfree_cache_time(SNUM(conn));
206 1435 : struct dfree_cached_info *dfc = NULL;
207 1435 : struct dfree_cached_info dfc_new = { 0 };
208 : uint64_t dfree_ret;
209 : char tmpbuf[PATH_MAX];
210 1435 : char *full_path = NULL;
211 1435 : char *to_free = NULL;
212 1435 : char *key_path = NULL;
213 : size_t len;
214 : DATA_BLOB key, value;
215 : bool found;
216 :
217 1435 : if (!dfree_cache_time) {
218 1431 : return sys_disk_free(conn, fname, bsize, dfree, dsize);
219 : }
220 :
221 4 : len = full_path_tos(conn->connectpath,
222 4 : fname->base_name,
223 : tmpbuf,
224 : sizeof(tmpbuf),
225 : &full_path,
226 : &to_free);
227 4 : if (len == -1) {
228 0 : errno = ENOMEM;
229 0 : return -1;
230 : }
231 :
232 4 : if (VALID_STAT(fname->st) && S_ISREG(fname->st.st_ex_mode)) {
233 : /*
234 : * In case of a file use the parent directory to reduce number
235 : * of cache entries.
236 : */
237 : bool ok;
238 :
239 0 : ok = parent_dirname(talloc_tos(),
240 : full_path,
241 : &key_path,
242 : NULL);
243 0 : TALLOC_FREE(to_free); /* We're done with full_path */
244 :
245 0 : if (!ok) {
246 0 : errno = ENOMEM;
247 0 : return -1;
248 : }
249 :
250 : /*
251 : * key_path is always a talloced object.
252 : */
253 0 : to_free = key_path;
254 : } else {
255 : /*
256 : * key_path might not be a talloced object; rely on
257 : * to_free set from full_path_tos.
258 : */
259 4 : key_path = full_path;
260 : }
261 :
262 4 : key = data_blob_const(key_path, strlen(key_path));
263 4 : found = memcache_lookup(smbd_memcache(),
264 : DFREE_CACHE,
265 : key,
266 : &value);
267 4 : dfc = found ? (struct dfree_cached_info *)value.data : NULL;
268 :
269 4 : if (dfc && (conn->lastused - dfc->last_dfree_time < dfree_cache_time)) {
270 0 : DBG_DEBUG("Returning dfree cache entry for %s\n", key_path);
271 0 : *bsize = dfc->bsize;
272 0 : *dfree = dfc->dfree;
273 0 : *dsize = dfc->dsize;
274 0 : dfree_ret = dfc->dfree_ret;
275 0 : goto out;
276 : }
277 :
278 4 : dfree_ret = sys_disk_free(conn, fname, bsize, dfree, dsize);
279 :
280 4 : if (dfree_ret == (uint64_t)-1) {
281 : /* Don't cache bad data. */
282 0 : goto out;
283 : }
284 :
285 4 : DBG_DEBUG("Creating dfree cache entry for %s\n", key_path);
286 4 : dfc_new.bsize = *bsize;
287 4 : dfc_new.dfree = *dfree;
288 4 : dfc_new.dsize = *dsize;
289 4 : dfc_new.dfree_ret = dfree_ret;
290 4 : dfc_new.last_dfree_time = conn->lastused;
291 4 : memcache_add(smbd_memcache(),
292 : DFREE_CACHE,
293 : key,
294 : data_blob_const(&dfc_new, sizeof(dfc_new)));
295 :
296 4 : out:
297 4 : TALLOC_FREE(to_free);
298 4 : return dfree_ret;
299 : }
300 :
301 1184 : void flush_dfree_cache(void)
302 : {
303 1184 : memcache_flush(smbd_memcache(), DFREE_CACHE);
304 1184 : }
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