diff options
Diffstat (limited to 'source3/smbd/dfree.c')
-rw-r--r-- | source3/smbd/dfree.c | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/source3/smbd/dfree.c b/source3/smbd/dfree.c new file mode 100644 index 0000000..236ca88 --- /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 accomodate 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); +} |