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-rw-r--r--source3/smbd/dfree.c296
1 files changed, 296 insertions, 0 deletions
diff --git a/source3/smbd/dfree.c b/source3/smbd/dfree.c
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index 0000000..89dc112
--- /dev/null
+++ b/source3/smbd/dfree.c
@@ -0,0 +1,296 @@
+/*
+ Unix SMB/CIFS implementation.
+ functions to calculate the free disk space
+ Copyright (C) Andrew Tridgell 1998
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "smbd/smbd.h"
+#include "smbd/globals.h"
+#include "lib/util_file.h"
+#include "lib/util/memcache.h"
+
+/****************************************************************************
+ Normalise for DOS usage.
+****************************************************************************/
+
+static void disk_norm(uint64_t *bsize, uint64_t *dfree, uint64_t *dsize)
+{
+ /* check if the disk is beyond the max disk size */
+ uint64_t maxdisksize = lp_max_disk_size();
+ if (maxdisksize) {
+ /* convert to blocks - and don't overflow */
+ maxdisksize = ((maxdisksize*1024)/(*bsize))*1024;
+ if (*dsize > maxdisksize) {
+ *dsize = maxdisksize;
+ }
+ if (*dfree > maxdisksize) {
+ *dfree = maxdisksize - 1;
+ }
+ /* the -1 should stop applications getting div by 0
+ errors */
+ }
+}
+
+
+
+/****************************************************************************
+ Return number of 1K blocks available on a path and total number.
+****************************************************************************/
+
+static uint64_t sys_disk_free(connection_struct *conn,
+ struct smb_filename *fname,
+ uint64_t *bsize,
+ uint64_t *dfree,
+ uint64_t *dsize)
+{
+ const struct loadparm_substitution *lp_sub =
+ loadparm_s3_global_substitution();
+ uint64_t dfree_retval;
+ uint64_t dfree_q = 0;
+ uint64_t bsize_q = 0;
+ uint64_t dsize_q = 0;
+ const char *dfree_command;
+ static bool dfree_broken = false;
+ char *path = fname->base_name;
+
+ (*dfree) = (*dsize) = 0;
+ (*bsize) = 512;
+
+ /*
+ * If external disk calculation specified, use it.
+ */
+
+ dfree_command = lp_dfree_command(talloc_tos(), lp_sub, SNUM(conn));
+ if (dfree_command && *dfree_command) {
+ const char *p;
+ char **lines = NULL;
+ char **argl = NULL;
+
+ argl = str_list_make_empty(talloc_tos());
+ str_list_add_printf(&argl, "%s", dfree_command);
+ str_list_add_printf(&argl, "%s", path);
+ if (argl == NULL) {
+ return (uint64_t)-1;
+ }
+
+ DBG_NOTICE("Running command '%s %s'\n",
+ dfree_command,
+ path);
+
+ lines = file_lines_ploadv(talloc_tos(), argl, NULL);
+
+ TALLOC_FREE(argl);
+
+ if (lines != NULL) {
+ char *line = lines[0];
+
+ DEBUG (3, ("Read input from dfree, \"%s\"\n", line));
+
+ *dsize = STR_TO_SMB_BIG_UINT(line, &p);
+ while (p && *p && isspace(*p))
+ p++;
+ if (p && *p)
+ *dfree = STR_TO_SMB_BIG_UINT(p, &p);
+ while (p && *p && isspace(*p))
+ p++;
+ if (p && *p)
+ *bsize = STR_TO_SMB_BIG_UINT(p, NULL);
+ else
+ *bsize = 1024;
+ TALLOC_FREE(lines);
+ DEBUG (3, ("Parsed output of dfree, dsize=%u, dfree=%u, bsize=%u\n",
+ (unsigned int)*dsize, (unsigned int)*dfree, (unsigned int)*bsize));
+
+ if (!*dsize)
+ *dsize = 2048;
+ if (!*dfree)
+ *dfree = 1024;
+
+ goto dfree_done;
+ }
+ DBG_ERR("file_lines_load() failed for "
+ "command '%s %s'. Error was : %s\n",
+ dfree_command, path, strerror(errno));
+ }
+
+ if (SMB_VFS_DISK_FREE(conn, fname, bsize, dfree, dsize) ==
+ (uint64_t)-1) {
+ DBG_ERR("VFS disk_free failed. Error was : %s\n",
+ strerror(errno));
+ return (uint64_t)-1;
+ }
+
+ if (disk_quotas(conn, fname, &bsize_q, &dfree_q, &dsize_q)) {
+ uint64_t min_bsize = MIN(*bsize, bsize_q);
+
+ (*dfree) = (*dfree) * (*bsize) / min_bsize;
+ (*dsize) = (*dsize) * (*bsize) / min_bsize;
+ dfree_q = dfree_q * bsize_q / min_bsize;
+ dsize_q = dsize_q * bsize_q / min_bsize;
+
+ (*bsize) = min_bsize;
+ (*dfree) = MIN(*dfree,dfree_q);
+ (*dsize) = MIN(*dsize,dsize_q);
+ }
+
+ /* FIXME : Any reason for this assumption ? */
+ if (*bsize < 256) {
+ DEBUG(5,("disk_free:Warning: bsize == %d < 256 . Changing to assumed correct bsize = 512\n",(int)*bsize));
+ *bsize = 512;
+ }
+
+ if ((*dsize)<1) {
+ if (!dfree_broken) {
+ DEBUG(0,("WARNING: dfree is broken on this system\n"));
+ dfree_broken=true;
+ }
+ *dsize = 20*1024*1024/(*bsize);
+ *dfree = MAX(1,*dfree);
+ }
+
+dfree_done:
+ disk_norm(bsize, dfree, dsize);
+
+ if ((*bsize) < 1024) {
+ dfree_retval = (*dfree)/(1024/(*bsize));
+ } else {
+ dfree_retval = ((*bsize)/1024)*(*dfree);
+ }
+
+ return(dfree_retval);
+}
+
+/****************************************************************************
+ Potentially returned cached dfree info.
+
+ Depending on the file system layout and file system features, the free space
+ information can be different for different sub directories underneath a SMB
+ share. Store the cache information in memcache using the query path as the
+ key to accommodate this.
+****************************************************************************/
+
+struct dfree_cached_info {
+ time_t last_dfree_time;
+ uint64_t dfree_ret;
+ uint64_t bsize;
+ uint64_t dfree;
+ uint64_t dsize;
+};
+
+uint64_t get_dfree_info(connection_struct *conn, struct smb_filename *fname,
+ uint64_t *bsize, uint64_t *dfree, uint64_t *dsize)
+{
+ int dfree_cache_time = lp_dfree_cache_time(SNUM(conn));
+ struct dfree_cached_info *dfc = NULL;
+ struct dfree_cached_info dfc_new = { 0 };
+ uint64_t dfree_ret;
+ char tmpbuf[PATH_MAX];
+ char *full_path = NULL;
+ char *to_free = NULL;
+ char *key_path = NULL;
+ size_t len;
+ DATA_BLOB key, value;
+ bool found;
+
+ if (!dfree_cache_time) {
+ return sys_disk_free(conn, fname, bsize, dfree, dsize);
+ }
+
+ len = full_path_tos(conn->connectpath,
+ fname->base_name,
+ tmpbuf,
+ sizeof(tmpbuf),
+ &full_path,
+ &to_free);
+ if (len == -1) {
+ errno = ENOMEM;
+ return -1;
+ }
+
+ if (VALID_STAT(fname->st) && S_ISREG(fname->st.st_ex_mode)) {
+ /*
+ * In case of a file use the parent directory to reduce number
+ * of cache entries.
+ */
+ bool ok;
+
+ ok = parent_dirname(talloc_tos(),
+ full_path,
+ &key_path,
+ NULL);
+ TALLOC_FREE(to_free); /* We're done with full_path */
+
+ if (!ok) {
+ errno = ENOMEM;
+ return -1;
+ }
+
+ /*
+ * key_path is always a talloced object.
+ */
+ to_free = key_path;
+ } else {
+ /*
+ * key_path might not be a talloced object; rely on
+ * to_free set from full_path_tos.
+ */
+ key_path = full_path;
+ }
+
+ key = data_blob_const(key_path, strlen(key_path));
+ found = memcache_lookup(smbd_memcache(),
+ DFREE_CACHE,
+ key,
+ &value);
+ dfc = found ? (struct dfree_cached_info *)value.data : NULL;
+
+ if (dfc && (conn->lastused - dfc->last_dfree_time < dfree_cache_time)) {
+ DBG_DEBUG("Returning dfree cache entry for %s\n", key_path);
+ *bsize = dfc->bsize;
+ *dfree = dfc->dfree;
+ *dsize = dfc->dsize;
+ dfree_ret = dfc->dfree_ret;
+ goto out;
+ }
+
+ dfree_ret = sys_disk_free(conn, fname, bsize, dfree, dsize);
+
+ if (dfree_ret == (uint64_t)-1) {
+ /* Don't cache bad data. */
+ goto out;
+ }
+
+ DBG_DEBUG("Creating dfree cache entry for %s\n", key_path);
+ dfc_new.bsize = *bsize;
+ dfc_new.dfree = *dfree;
+ dfc_new.dsize = *dsize;
+ dfc_new.dfree_ret = dfree_ret;
+ dfc_new.last_dfree_time = conn->lastused;
+ memcache_add(smbd_memcache(),
+ DFREE_CACHE,
+ key,
+ data_blob_const(&dfc_new, sizeof(dfc_new)));
+
+out:
+ TALLOC_FREE(to_free);
+ return dfree_ret;
+}
+
+void flush_dfree_cache(void)
+{
+ memcache_flush(smbd_memcache(), DFREE_CACHE);
+}