2 Unix SMB/CIFS implementation.
3 Files[] structure handling
4 Copyright (C) Andrew Tridgell 1998
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.
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.
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.
23 static int real_max_open_files;
25 #define VALID_FNUM(fnum) (((fnum) >= 0) && ((fnum) < real_max_open_files))
27 #define FILE_HANDLE_OFFSET 0x1000
29 static struct bitmap *file_bmap;
31 static files_struct *Files;
33 /* a fsp to use when chaining */
34 static files_struct *chain_fsp = NULL;
35 /* a fsp to use to save when breaking an oplock. */
36 static files_struct *oplock_save_chain_fsp = NULL;
38 static int files_used;
40 /****************************************************************************
41 Return a unique number identifying this fsp over the life of this pid.
42 ****************************************************************************/
44 static unsigned long get_gen_count(void)
46 static unsigned long file_gen_counter;
48 if ((++file_gen_counter) == 0)
49 return ++file_gen_counter;
50 return file_gen_counter;
53 /****************************************************************************
54 Find first available file slot.
55 ****************************************************************************/
57 files_struct *file_new(connection_struct *conn)
60 static int first_file;
61 files_struct *fsp, *next;
63 /* we want to give out file handles differently on each new
64 connection because of a common bug in MS clients where they try to
65 reuse a file descriptor from an earlier smb connection. This code
66 increases the chance that the errant client will get an error rather
67 than causing corruption */
68 if (first_file == 0) {
69 first_file = (sys_getpid() ^ (int)time(NULL)) % real_max_open_files;
72 i = bitmap_find(file_bmap, first_file);
75 * Before we give up, go through the open files
76 * and see if there are any files opened with a
77 * batch oplock. If so break the oplock and then
78 * re-use that entry (if it becomes closed).
79 * This may help as NT/95 clients tend to keep
80 * files batch oplocked for quite a long time
81 * after they have finished with them.
83 for (fsp=Files;fsp;fsp=next) {
85 if (attempt_close_oplocked_file(fsp)) {
86 return file_new(conn);
90 DEBUG(0,("ERROR! Out of file structures\n"));
91 unix_ERR_class = ERRSRV;
92 unix_ERR_code = ERRnofids;
96 fsp = (files_struct *)malloc(sizeof(*fsp));
98 unix_ERR_class = ERRSRV;
99 unix_ERR_code = ERRnofids;
106 fsp->file_id = get_gen_count();
107 GetTimeOfDay(&fsp->open_time);
109 first_file = (i+1) % real_max_open_files;
111 bitmap_set(file_bmap, i);
114 fsp->fnum = i + FILE_HANDLE_OFFSET;
115 string_set(&fsp->fsp_name,"");
117 DLIST_ADD(Files, fsp);
119 DEBUG(5,("allocated file structure %d, fnum = %d (%d used)\n",
120 i, fsp->fnum, files_used));
127 /****************************************************************************
128 Close all open files for a connection.
129 ****************************************************************************/
131 void file_close_conn(connection_struct *conn)
133 files_struct *fsp, *next;
135 for (fsp=Files;fsp;fsp=next) {
137 if (fsp->conn == conn) {
138 close_file(fsp,False);
143 /****************************************************************************
144 Initialise file structures.
145 ****************************************************************************/
147 #define MAX_OPEN_FUDGEFACTOR 10
151 int request_max_open_files = lp_max_open_files();
155 * Set the max_open files to be the requested
156 * max plus a fudgefactor to allow for the extra
157 * fd's we need such as log files etc...
159 real_lim = set_maxfiles(request_max_open_files + MAX_OPEN_FUDGEFACTOR);
161 real_max_open_files = real_lim - MAX_OPEN_FUDGEFACTOR;
163 if(real_max_open_files != request_max_open_files) {
164 DEBUG(1,("file_init: Information only: requested %d \
165 open files, %d are available.\n", request_max_open_files, real_max_open_files));
168 file_bmap = bitmap_allocate(real_max_open_files);
171 exit_server("out of memory in file_init");
175 * Ensure that pipe_handle_oppset is set correctly.
177 set_pipe_handle_offset(real_max_open_files);
180 /****************************************************************************
181 Close files open by a specified vuid.
182 ****************************************************************************/
184 void file_close_user(int vuid)
186 files_struct *fsp, *next;
188 for (fsp=Files;fsp;fsp=next) {
190 if (fsp->vuid == vuid) {
191 close_file(fsp,False);
196 /****************************************************************************
197 Find a fsp given a file descriptor.
198 ****************************************************************************/
200 files_struct *file_find_fd(int fd)
205 for (fsp=Files;fsp;fsp=fsp->next,count++) {
208 DLIST_PROMOTE(Files, fsp);
217 /****************************************************************************
218 Find a fsp given a device, inode and file_id.
219 ****************************************************************************/
221 files_struct *file_find_dif(SMB_DEV_T dev, SMB_INO_T inode, unsigned long file_id)
226 for (fsp=Files;fsp;fsp=fsp->next,count++) {
229 fsp->inode == inode &&
230 fsp->file_id == file_id ) {
232 DLIST_PROMOTE(Files, fsp);
241 /****************************************************************************
242 Check if an fsp still exists.
243 ****************************************************************************/
245 files_struct *file_find_fsp(files_struct *orig_fsp)
249 for (fsp=Files;fsp;fsp=fsp->next) {
257 /****************************************************************************
258 Find the first fsp given a device and inode.
259 ****************************************************************************/
261 files_struct *file_find_di_first(SMB_DEV_T dev, SMB_INO_T inode)
265 for (fsp=Files;fsp;fsp=fsp->next) {
266 if ( fsp->fd != -1 &&
268 fsp->inode == inode )
275 /****************************************************************************
276 Find the next fsp having the same device and inode.
277 ****************************************************************************/
279 files_struct *file_find_di_next(files_struct *start_fsp)
283 for (fsp = start_fsp->next;fsp;fsp=fsp->next) {
284 if ( fsp->fd != -1 &&
285 fsp->dev == start_fsp->dev &&
286 fsp->inode == start_fsp->inode )
293 /****************************************************************************
294 Find a fsp that is open for printing.
295 ****************************************************************************/
297 files_struct *file_find_print(void)
301 for (fsp=Files;fsp;fsp=fsp->next) {
302 if (fsp->print_file) return fsp;
308 /****************************************************************************
309 Sync open files on a connection.
310 ****************************************************************************/
312 void file_sync_all(connection_struct *conn)
314 files_struct *fsp, *next;
316 for (fsp=Files;fsp;fsp=next) {
318 if ((conn == fsp->conn) && (fsp->fd != -1)) {
324 /****************************************************************************
326 ****************************************************************************/
328 void file_free(files_struct *fsp)
330 DLIST_REMOVE(Files, fsp);
332 string_free(&fsp->fsp_name);
334 bitmap_clear(file_bmap, fsp->fnum - FILE_HANDLE_OFFSET);
337 DEBUG(5,("freed files structure %d (%d used)\n",
338 fsp->fnum, files_used));
340 /* this is paranoia, just in case someone tries to reuse the
344 if (fsp == chain_fsp) chain_fsp = NULL;
349 /****************************************************************************
350 Get a fsp from a packet given the offset of a 16 bit fnum.
351 ****************************************************************************/
353 files_struct *file_fsp(char *buf, int where)
361 fnum = SVAL(buf, where);
363 for (fsp=Files;fsp;fsp=fsp->next, count++) {
364 if (fsp->fnum == fnum) {
367 DLIST_PROMOTE(Files, fsp);
375 /****************************************************************************
376 Reset the chained fsp - done at the start of a packet reply.
377 ****************************************************************************/
379 void file_chain_reset(void)
384 /****************************************************************************
385 Save the chained fsp - done when about to do an oplock break.
386 ****************************************************************************/
388 void file_chain_save(void)
390 oplock_save_chain_fsp = chain_fsp;
393 /****************************************************************************
394 Restore the chained fsp - done after an oplock break.
395 ****************************************************************************/
397 void file_chain_restore(void)
399 chain_fsp = oplock_save_chain_fsp;