GNU Linux-libre 4.9.308-gnu1
[releases.git] / fs / cifs / smb2file.c
1 /*
2  *   fs/cifs/smb2file.c
3  *
4  *   Copyright (C) International Business Machines  Corp., 2002, 2011
5  *   Author(s): Steve French (sfrench@us.ibm.com),
6  *              Pavel Shilovsky ((pshilovsky@samba.org) 2012
7  *
8  *   This library is free software; you can redistribute it and/or modify
9  *   it under the terms of the GNU Lesser General Public License as published
10  *   by the Free Software Foundation; either version 2.1 of the License, or
11  *   (at your option) any later version.
12  *
13  *   This library is distributed in the hope that it will be useful,
14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
16  *   the GNU Lesser General Public License for more details.
17  *
18  *   You should have received a copy of the GNU Lesser General Public License
19  *   along with this library; if not, write to the Free Software
20  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21  */
22 #include <linux/fs.h>
23 #include <linux/stat.h>
24 #include <linux/slab.h>
25 #include <linux/pagemap.h>
26 #include <asm/div64.h>
27 #include "cifsfs.h"
28 #include "cifspdu.h"
29 #include "cifsglob.h"
30 #include "cifsproto.h"
31 #include "cifs_debug.h"
32 #include "cifs_fs_sb.h"
33 #include "cifs_unicode.h"
34 #include "fscache.h"
35 #include "smb2proto.h"
36
37 int
38 smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms,
39                __u32 *oplock, FILE_ALL_INFO *buf)
40 {
41         int rc;
42         __le16 *smb2_path;
43         struct smb2_file_all_info *smb2_data = NULL;
44         __u8 smb2_oplock[17];
45         struct cifs_fid *fid = oparms->fid;
46         struct network_resiliency_req nr_ioctl_req;
47
48         smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb);
49         if (smb2_path == NULL) {
50                 rc = -ENOMEM;
51                 goto out;
52         }
53
54         smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
55                             GFP_KERNEL);
56         if (smb2_data == NULL) {
57                 rc = -ENOMEM;
58                 goto out;
59         }
60
61         oparms->desired_access |= FILE_READ_ATTRIBUTES;
62         *smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
63
64         if (oparms->tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LEASING)
65                 memcpy(smb2_oplock + 1, fid->lease_key, SMB2_LEASE_KEY_SIZE);
66
67         rc = SMB2_open(xid, oparms, smb2_path, smb2_oplock, smb2_data, NULL);
68         if (rc)
69                 goto out;
70
71
72         if (oparms->tcon->use_resilient) {
73                 nr_ioctl_req.Timeout = 0; /* use server default (120 seconds) */
74                 nr_ioctl_req.Reserved = 0;
75                 rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid,
76                         fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY, true,
77                         (char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
78                         NULL, NULL /* no return info */);
79                 if (rc == -EOPNOTSUPP) {
80                         cifs_dbg(VFS,
81                              "resiliency not supported by server, disabling\n");
82                         oparms->tcon->use_resilient = false;
83                 } else if (rc)
84                         cifs_dbg(FYI, "error %d setting resiliency\n", rc);
85
86                 rc = 0;
87         }
88
89         if (buf) {
90                 /* open response does not have IndexNumber field - get it */
91                 rc = SMB2_get_srv_num(xid, oparms->tcon, fid->persistent_fid,
92                                       fid->volatile_fid,
93                                       &smb2_data->IndexNumber);
94                 if (rc) {
95                         /* let get_inode_info disable server inode numbers */
96                         smb2_data->IndexNumber = 0;
97                         rc = 0;
98                 }
99                 move_smb2_info_to_cifs(buf, smb2_data);
100         }
101
102         *oplock = *smb2_oplock;
103 out:
104         kfree(smb2_data);
105         kfree(smb2_path);
106         return rc;
107 }
108
109 int
110 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
111                   const unsigned int xid)
112 {
113         int rc = 0, stored_rc;
114         unsigned int max_num, num = 0, max_buf;
115         struct smb2_lock_element *buf, *cur;
116         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
117         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
118         struct cifsLockInfo *li, *tmp;
119         __u64 length = 1 + flock->fl_end - flock->fl_start;
120         struct list_head tmp_llist;
121
122         INIT_LIST_HEAD(&tmp_llist);
123
124         /*
125          * Accessing maxBuf is racy with cifs_reconnect - need to store value
126          * and check it before using.
127          */
128         max_buf = tcon->ses->server->maxBuf;
129         if (max_buf < sizeof(struct smb2_lock_element))
130                 return -EINVAL;
131
132         BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
133         max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
134         max_num = max_buf / sizeof(struct smb2_lock_element);
135         buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
136         if (!buf)
137                 return -ENOMEM;
138
139         cur = buf;
140
141         cifs_down_write(&cinode->lock_sem);
142         list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
143                 if (flock->fl_start > li->offset ||
144                     (flock->fl_start + length) <
145                     (li->offset + li->length))
146                         continue;
147                 if (current->tgid != li->pid)
148                         continue;
149                 if (cinode->can_cache_brlcks) {
150                         /*
151                          * We can cache brlock requests - simply remove a lock
152                          * from the file's list.
153                          */
154                         list_del(&li->llist);
155                         cifs_del_lock_waiters(li);
156                         kfree(li);
157                         continue;
158                 }
159                 cur->Length = cpu_to_le64(li->length);
160                 cur->Offset = cpu_to_le64(li->offset);
161                 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
162                 /*
163                  * We need to save a lock here to let us add it again to the
164                  * file's list if the unlock range request fails on the server.
165                  */
166                 list_move(&li->llist, &tmp_llist);
167                 if (++num == max_num) {
168                         stored_rc = smb2_lockv(xid, tcon,
169                                                cfile->fid.persistent_fid,
170                                                cfile->fid.volatile_fid,
171                                                current->tgid, num, buf);
172                         if (stored_rc) {
173                                 /*
174                                  * We failed on the unlock range request - add
175                                  * all locks from the tmp list to the head of
176                                  * the file's list.
177                                  */
178                                 cifs_move_llist(&tmp_llist,
179                                                 &cfile->llist->locks);
180                                 rc = stored_rc;
181                         } else
182                                 /*
183                                  * The unlock range request succeed - free the
184                                  * tmp list.
185                                  */
186                                 cifs_free_llist(&tmp_llist);
187                         cur = buf;
188                         num = 0;
189                 } else
190                         cur++;
191         }
192         if (num) {
193                 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
194                                        cfile->fid.volatile_fid, current->tgid,
195                                        num, buf);
196                 if (stored_rc) {
197                         cifs_move_llist(&tmp_llist, &cfile->llist->locks);
198                         rc = stored_rc;
199                 } else
200                         cifs_free_llist(&tmp_llist);
201         }
202         up_write(&cinode->lock_sem);
203
204         kfree(buf);
205         return rc;
206 }
207
208 static int
209 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
210                        struct smb2_lock_element *buf, unsigned int max_num)
211 {
212         int rc = 0, stored_rc;
213         struct cifsFileInfo *cfile = fdlocks->cfile;
214         struct cifsLockInfo *li;
215         unsigned int num = 0;
216         struct smb2_lock_element *cur = buf;
217         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
218
219         list_for_each_entry(li, &fdlocks->locks, llist) {
220                 cur->Length = cpu_to_le64(li->length);
221                 cur->Offset = cpu_to_le64(li->offset);
222                 cur->Flags = cpu_to_le32(li->type |
223                                                 SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
224                 if (++num == max_num) {
225                         stored_rc = smb2_lockv(xid, tcon,
226                                                cfile->fid.persistent_fid,
227                                                cfile->fid.volatile_fid,
228                                                current->tgid, num, buf);
229                         if (stored_rc)
230                                 rc = stored_rc;
231                         cur = buf;
232                         num = 0;
233                 } else
234                         cur++;
235         }
236         if (num) {
237                 stored_rc = smb2_lockv(xid, tcon,
238                                        cfile->fid.persistent_fid,
239                                        cfile->fid.volatile_fid,
240                                        current->tgid, num, buf);
241                 if (stored_rc)
242                         rc = stored_rc;
243         }
244
245         return rc;
246 }
247
248 int
249 smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
250 {
251         int rc = 0, stored_rc;
252         unsigned int xid;
253         unsigned int max_num, max_buf;
254         struct smb2_lock_element *buf;
255         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
256         struct cifs_fid_locks *fdlocks;
257
258         xid = get_xid();
259
260         /*
261          * Accessing maxBuf is racy with cifs_reconnect - need to store value
262          * and check it for zero before using.
263          */
264         max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
265         if (max_buf < sizeof(struct smb2_lock_element)) {
266                 free_xid(xid);
267                 return -EINVAL;
268         }
269
270         BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
271         max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
272         max_num = max_buf / sizeof(struct smb2_lock_element);
273         buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
274         if (!buf) {
275                 free_xid(xid);
276                 return -ENOMEM;
277         }
278
279         list_for_each_entry(fdlocks, &cinode->llist, llist) {
280                 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
281                 if (stored_rc)
282                         rc = stored_rc;
283         }
284
285         kfree(buf);
286         free_xid(xid);
287         return rc;
288 }