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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
smb2_open_file(const unsigned int xid,struct cifs_open_parms * oparms,__u32 * oplock,FILE_ALL_INFO * buf)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;
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 	rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL,
65 		       NULL, NULL);
66 	if (rc)
67 		goto out;
68 
69 
70 	if (oparms->tcon->use_resilient) {
71 		/* default timeout is 0, servers pick default (120 seconds) */
72 		nr_ioctl_req.Timeout =
73 			cpu_to_le32(oparms->tcon->handle_timeout);
74 		nr_ioctl_req.Reserved = 0;
75 		rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid,
76 			fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY,
77 			(char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
78 			CIFSMaxBufSize, 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 		/* if open response does not have IndexNumber field - get it */
91 		if (smb2_data->IndexNumber == 0) {
92 			rc = SMB2_get_srv_num(xid, oparms->tcon,
93 				      fid->persistent_fid,
94 				      fid->volatile_fid,
95 				      &smb2_data->IndexNumber);
96 			if (rc) {
97 				/*
98 				 * let get_inode_info disable server inode
99 				 * numbers
100 				 */
101 				smb2_data->IndexNumber = 0;
102 				rc = 0;
103 			}
104 		}
105 		move_smb2_info_to_cifs(buf, smb2_data);
106 	}
107 
108 	*oplock = smb2_oplock;
109 out:
110 	kfree(smb2_data);
111 	kfree(smb2_path);
112 	return rc;
113 }
114 
115 int
smb2_unlock_range(struct cifsFileInfo * cfile,struct file_lock * flock,const unsigned int xid)116 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
117 		  const unsigned int xid)
118 {
119 	int rc = 0, stored_rc;
120 	unsigned int max_num, num = 0, max_buf;
121 	struct smb2_lock_element *buf, *cur;
122 	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
123 	struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
124 	struct cifsLockInfo *li, *tmp;
125 	__u64 length = 1 + flock->fl_end - flock->fl_start;
126 	struct list_head tmp_llist;
127 
128 	INIT_LIST_HEAD(&tmp_llist);
129 
130 	/*
131 	 * Accessing maxBuf is racy with cifs_reconnect - need to store value
132 	 * and check it before using.
133 	 */
134 	max_buf = tcon->ses->server->maxBuf;
135 	if (max_buf < sizeof(struct smb2_lock_element))
136 		return -EINVAL;
137 
138 	BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
139 	max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
140 	max_num = max_buf / sizeof(struct smb2_lock_element);
141 	buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
142 	if (!buf)
143 		return -ENOMEM;
144 
145 	cur = buf;
146 
147 	cifs_down_write(&cinode->lock_sem);
148 	list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
149 		if (flock->fl_start > li->offset ||
150 		    (flock->fl_start + length) <
151 		    (li->offset + li->length))
152 			continue;
153 		if (current->tgid != li->pid)
154 			/*
155 			 * flock and OFD lock are associated with an open
156 			 * file description, not the process.
157 			 */
158 			if (!(flock->fl_flags & (FL_FLOCK | FL_OFDLCK)))
159 				continue;
160 		if (cinode->can_cache_brlcks) {
161 			/*
162 			 * We can cache brlock requests - simply remove a lock
163 			 * from the file's list.
164 			 */
165 			list_del(&li->llist);
166 			cifs_del_lock_waiters(li);
167 			kfree(li);
168 			continue;
169 		}
170 		cur->Length = cpu_to_le64(li->length);
171 		cur->Offset = cpu_to_le64(li->offset);
172 		cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
173 		/*
174 		 * We need to save a lock here to let us add it again to the
175 		 * file's list if the unlock range request fails on the server.
176 		 */
177 		list_move(&li->llist, &tmp_llist);
178 		if (++num == max_num) {
179 			stored_rc = smb2_lockv(xid, tcon,
180 					       cfile->fid.persistent_fid,
181 					       cfile->fid.volatile_fid,
182 					       current->tgid, num, buf);
183 			if (stored_rc) {
184 				/*
185 				 * We failed on the unlock range request - add
186 				 * all locks from the tmp list to the head of
187 				 * the file's list.
188 				 */
189 				cifs_move_llist(&tmp_llist,
190 						&cfile->llist->locks);
191 				rc = stored_rc;
192 			} else
193 				/*
194 				 * The unlock range request succeed - free the
195 				 * tmp list.
196 				 */
197 				cifs_free_llist(&tmp_llist);
198 			cur = buf;
199 			num = 0;
200 		} else
201 			cur++;
202 	}
203 	if (num) {
204 		stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
205 				       cfile->fid.volatile_fid, current->tgid,
206 				       num, buf);
207 		if (stored_rc) {
208 			cifs_move_llist(&tmp_llist, &cfile->llist->locks);
209 			rc = stored_rc;
210 		} else
211 			cifs_free_llist(&tmp_llist);
212 	}
213 	up_write(&cinode->lock_sem);
214 
215 	kfree(buf);
216 	return rc;
217 }
218 
219 static int
smb2_push_mand_fdlocks(struct cifs_fid_locks * fdlocks,const unsigned int xid,struct smb2_lock_element * buf,unsigned int max_num)220 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
221 		       struct smb2_lock_element *buf, unsigned int max_num)
222 {
223 	int rc = 0, stored_rc;
224 	struct cifsFileInfo *cfile = fdlocks->cfile;
225 	struct cifsLockInfo *li;
226 	unsigned int num = 0;
227 	struct smb2_lock_element *cur = buf;
228 	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
229 
230 	list_for_each_entry(li, &fdlocks->locks, llist) {
231 		cur->Length = cpu_to_le64(li->length);
232 		cur->Offset = cpu_to_le64(li->offset);
233 		cur->Flags = cpu_to_le32(li->type |
234 						SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
235 		if (++num == max_num) {
236 			stored_rc = smb2_lockv(xid, tcon,
237 					       cfile->fid.persistent_fid,
238 					       cfile->fid.volatile_fid,
239 					       current->tgid, num, buf);
240 			if (stored_rc)
241 				rc = stored_rc;
242 			cur = buf;
243 			num = 0;
244 		} else
245 			cur++;
246 	}
247 	if (num) {
248 		stored_rc = smb2_lockv(xid, tcon,
249 				       cfile->fid.persistent_fid,
250 				       cfile->fid.volatile_fid,
251 				       current->tgid, num, buf);
252 		if (stored_rc)
253 			rc = stored_rc;
254 	}
255 
256 	return rc;
257 }
258 
259 int
smb2_push_mandatory_locks(struct cifsFileInfo * cfile)260 smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
261 {
262 	int rc = 0, stored_rc;
263 	unsigned int xid;
264 	unsigned int max_num, max_buf;
265 	struct smb2_lock_element *buf;
266 	struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
267 	struct cifs_fid_locks *fdlocks;
268 
269 	xid = get_xid();
270 
271 	/*
272 	 * Accessing maxBuf is racy with cifs_reconnect - need to store value
273 	 * and check it for zero before using.
274 	 */
275 	max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
276 	if (max_buf < sizeof(struct smb2_lock_element)) {
277 		free_xid(xid);
278 		return -EINVAL;
279 	}
280 
281 	BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
282 	max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
283 	max_num = max_buf / sizeof(struct smb2_lock_element);
284 	buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
285 	if (!buf) {
286 		free_xid(xid);
287 		return -ENOMEM;
288 	}
289 
290 	list_for_each_entry(fdlocks, &cinode->llist, llist) {
291 		stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
292 		if (stored_rc)
293 			rc = stored_rc;
294 	}
295 
296 	kfree(buf);
297 	free_xid(xid);
298 	return rc;
299 }
300