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);
66 	if (rc)
67 		goto out;
68 
69 
70 	 if (oparms->tcon->use_resilient) {
71 		nr_ioctl_req.Timeout = 0; /* use server default (120 seconds) */
72 		nr_ioctl_req.Reserved = 0;
73 		rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid,
74 			fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY,
75 			true /* is_fsctl */,
76 			(char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
77 			NULL, NULL /* no return info */);
78 		if (rc == -EOPNOTSUPP) {
79 			cifs_dbg(VFS,
80 			     "resiliency not supported by server, disabling\n");
81 			oparms->tcon->use_resilient = false;
82 		} else if (rc)
83 			cifs_dbg(FYI, "error %d setting resiliency\n", rc);
84 
85 		rc = 0;
86 	}
87 
88 	if (buf) {
89 		/* open response does not have IndexNumber field - get it */
90 		rc = SMB2_get_srv_num(xid, oparms->tcon, fid->persistent_fid,
91 				      fid->volatile_fid,
92 				      &smb2_data->IndexNumber);
93 		if (rc) {
94 			/* let get_inode_info disable server inode numbers */
95 			smb2_data->IndexNumber = 0;
96 			rc = 0;
97 		}
98 		move_smb2_info_to_cifs(buf, smb2_data);
99 	}
100 
101 	*oplock = smb2_oplock;
102 out:
103 	kfree(smb2_data);
104 	kfree(smb2_path);
105 	return rc;
106 }
107 
108 int
smb2_unlock_range(struct cifsFileInfo * cfile,struct file_lock * flock,const unsigned int xid)109 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
110 		  const unsigned int xid)
111 {
112 	int rc = 0, stored_rc;
113 	unsigned int max_num, num = 0, max_buf;
114 	struct smb2_lock_element *buf, *cur;
115 	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
116 	struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
117 	struct cifsLockInfo *li, *tmp;
118 	__u64 length = 1 + flock->fl_end - flock->fl_start;
119 	struct list_head tmp_llist;
120 
121 	INIT_LIST_HEAD(&tmp_llist);
122 
123 	/*
124 	 * Accessing maxBuf is racy with cifs_reconnect - need to store value
125 	 * and check it for zero before using.
126 	 */
127 	max_buf = tcon->ses->server->maxBuf;
128 	if (!max_buf)
129 		return -EINVAL;
130 
131 	max_num = max_buf / sizeof(struct smb2_lock_element);
132 	buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
133 	if (!buf)
134 		return -ENOMEM;
135 
136 	cur = buf;
137 
138 	down_write(&cinode->lock_sem);
139 	list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
140 		if (flock->fl_start > li->offset ||
141 		    (flock->fl_start + length) <
142 		    (li->offset + li->length))
143 			continue;
144 		if (current->tgid != li->pid)
145 			continue;
146 		if (cinode->can_cache_brlcks) {
147 			/*
148 			 * We can cache brlock requests - simply remove a lock
149 			 * from the file's list.
150 			 */
151 			list_del(&li->llist);
152 			cifs_del_lock_waiters(li);
153 			kfree(li);
154 			continue;
155 		}
156 		cur->Length = cpu_to_le64(li->length);
157 		cur->Offset = cpu_to_le64(li->offset);
158 		cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
159 		/*
160 		 * We need to save a lock here to let us add it again to the
161 		 * file's list if the unlock range request fails on the server.
162 		 */
163 		list_move(&li->llist, &tmp_llist);
164 		if (++num == max_num) {
165 			stored_rc = smb2_lockv(xid, tcon,
166 					       cfile->fid.persistent_fid,
167 					       cfile->fid.volatile_fid,
168 					       current->tgid, num, buf);
169 			if (stored_rc) {
170 				/*
171 				 * We failed on the unlock range request - add
172 				 * all locks from the tmp list to the head of
173 				 * the file's list.
174 				 */
175 				cifs_move_llist(&tmp_llist,
176 						&cfile->llist->locks);
177 				rc = stored_rc;
178 			} else
179 				/*
180 				 * The unlock range request succeed - free the
181 				 * tmp list.
182 				 */
183 				cifs_free_llist(&tmp_llist);
184 			cur = buf;
185 			num = 0;
186 		} else
187 			cur++;
188 	}
189 	if (num) {
190 		stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
191 				       cfile->fid.volatile_fid, current->tgid,
192 				       num, buf);
193 		if (stored_rc) {
194 			cifs_move_llist(&tmp_llist, &cfile->llist->locks);
195 			rc = stored_rc;
196 		} else
197 			cifs_free_llist(&tmp_llist);
198 	}
199 	up_write(&cinode->lock_sem);
200 
201 	kfree(buf);
202 	return rc;
203 }
204 
205 static int
smb2_push_mand_fdlocks(struct cifs_fid_locks * fdlocks,const unsigned int xid,struct smb2_lock_element * buf,unsigned int max_num)206 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
207 		       struct smb2_lock_element *buf, unsigned int max_num)
208 {
209 	int rc = 0, stored_rc;
210 	struct cifsFileInfo *cfile = fdlocks->cfile;
211 	struct cifsLockInfo *li;
212 	unsigned int num = 0;
213 	struct smb2_lock_element *cur = buf;
214 	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
215 
216 	list_for_each_entry(li, &fdlocks->locks, llist) {
217 		cur->Length = cpu_to_le64(li->length);
218 		cur->Offset = cpu_to_le64(li->offset);
219 		cur->Flags = cpu_to_le32(li->type |
220 						SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
221 		if (++num == max_num) {
222 			stored_rc = smb2_lockv(xid, tcon,
223 					       cfile->fid.persistent_fid,
224 					       cfile->fid.volatile_fid,
225 					       current->tgid, num, buf);
226 			if (stored_rc)
227 				rc = stored_rc;
228 			cur = buf;
229 			num = 0;
230 		} else
231 			cur++;
232 	}
233 	if (num) {
234 		stored_rc = smb2_lockv(xid, tcon,
235 				       cfile->fid.persistent_fid,
236 				       cfile->fid.volatile_fid,
237 				       current->tgid, num, buf);
238 		if (stored_rc)
239 			rc = stored_rc;
240 	}
241 
242 	return rc;
243 }
244 
245 int
smb2_push_mandatory_locks(struct cifsFileInfo * cfile)246 smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
247 {
248 	int rc = 0, stored_rc;
249 	unsigned int xid;
250 	unsigned int max_num, max_buf;
251 	struct smb2_lock_element *buf;
252 	struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
253 	struct cifs_fid_locks *fdlocks;
254 
255 	xid = get_xid();
256 
257 	/*
258 	 * Accessing maxBuf is racy with cifs_reconnect - need to store value
259 	 * and check it for zero before using.
260 	 */
261 	max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
262 	if (max_buf < sizeof(struct smb2_lock_element)) {
263 		free_xid(xid);
264 		return -EINVAL;
265 	}
266 
267 	max_num = max_buf / sizeof(struct smb2_lock_element);
268 	buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
269 	if (!buf) {
270 		free_xid(xid);
271 		return -ENOMEM;
272 	}
273 
274 	list_for_each_entry(fdlocks, &cinode->llist, llist) {
275 		stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
276 		if (stored_rc)
277 			rc = stored_rc;
278 	}
279 
280 	kfree(buf);
281 	free_xid(xid);
282 	return rc;
283 }
284