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;
  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                         true /* is_fsctl */,
  78                         (char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
  79                         CIFSMaxBufSize, NULL, NULL /* no return info */);
  80                 if (rc == -EOPNOTSUPP) {
  81                         cifs_dbg(VFS,
  82                              "resiliency not supported by server, disabling\n");
  83                         oparms->tcon->use_resilient = false;
  84                 } else if (rc)
  85                         cifs_dbg(FYI, "error %d setting resiliency\n", rc);
  86
  87                 rc = 0;
  88         }
  89
  90         if (buf) {
  91                 /* if open response does not have IndexNumber field - get it */
  92                 if (smb2_data->IndexNumber == 0) {
  93                         rc = SMB2_get_srv_num(xid, oparms->tcon,
  94                                       fid->persistent_fid,
  95                                       fid->volatile_fid,
  96                                       &smb2_data->IndexNumber);
  97                         if (rc) {
  98                                 /*
  99                                  * let get_inode_info disable server inode
 100                                  * numbers
 101                                  */
 102                                 smb2_data->IndexNumber = 0;
 103                                 rc = 0;
 104                         }
 105                 }
 106                 move_smb2_info_to_cifs(buf, smb2_data);
 107         }
 108
 109         *oplock = smb2_oplock;
 110 out:
 111         kfree(smb2_data);
 112         kfree(smb2_path);
 113         return rc;
 114 }
 115
 116 int
 117 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
 118                   const unsigned int xid)
 119 {
 120         int rc = 0, stored_rc;
 121         unsigned int max_num, num = 0, max_buf;
 122         struct smb2_lock_element *buf, *cur;
 123         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 124         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 125         struct cifsLockInfo *li, *tmp;
 126         __u64 length = 1 + flock->fl_end - flock->fl_start;
 127         struct list_head tmp_llist;
 128
 129         INIT_LIST_HEAD(&tmp_llist);
 130
 131         /*
 132          * Accessing maxBuf is racy with cifs_reconnect - need to store value
 133          * and check it before using.
 134          */
 135         max_buf = tcon->ses->server->maxBuf;
 136         if (max_buf < sizeof(struct smb2_lock_element))
 137                 return -EINVAL;
 138
 139         BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
 140         max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 141         max_num = max_buf / sizeof(struct smb2_lock_element);
 142         buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
 143         if (!buf)
 144                 return -ENOMEM;
 145
 146         cur = buf;
 147
 148         cifs_down_write(&cinode->lock_sem);
 149         list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
 150                 if (flock->fl_start > li->offset ||
 151                     (flock->fl_start + length) <
 152                     (li->offset + li->length))
 153                         continue;
 154                 if (current->tgid != li->pid)
 155                         /*
 156                          * flock and OFD lock are associated with an open
 157                          * file description, not the process.
 158                          */
 159                         if (!(flock->fl_flags & (FL_FLOCK | FL_OFDLCK)))
 160                                 continue;
 161                 if (cinode->can_cache_brlcks) {
 162                         /*
 163                          * We can cache brlock requests - simply remove a lock
 164                          * from the file's list.
 165                          */
 166                         list_del(&li->llist);
 167                         cifs_del_lock_waiters(li);
 168                         kfree(li);
 169                         continue;
 170                 }
 171                 cur->Length = cpu_to_le64(li->length);
 172                 cur->Offset = cpu_to_le64(li->offset);
 173                 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
 174                 /*
 175                  * We need to save a lock here to let us add it again to the
 176                  * file's list if the unlock range request fails on the server.
 177                  */
 178                 list_move(&li->llist, &tmp_llist);
 179                 if (++num == max_num) {
 180                         stored_rc = smb2_lockv(xid, tcon,
 181                                                cfile->fid.persistent_fid,
 182                                                cfile->fid.volatile_fid,
 183                                                current->tgid, num, buf);
 184                         if (stored_rc) {
 185                                 /*
 186                                  * We failed on the unlock range request - add
 187                                  * all locks from the tmp list to the head of
 188                                  * the file's list.
 189                                  */
 190                                 cifs_move_llist(&tmp_llist,
 191                                                 &cfile->llist->locks);
 192                                 rc = stored_rc;
 193                         } else
 194                                 /*
 195                                  * The unlock range request succeed - free the
 196                                  * tmp list.
 197                                  */
 198                                 cifs_free_llist(&tmp_llist);
 199                         cur = buf;
 200                         num = 0;
 201                 } else
 202                         cur++;
 203         }
 204         if (num) {
 205                 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
 206                                        cfile->fid.volatile_fid, current->tgid,
 207                                        num, buf);
 208                 if (stored_rc) {
 209                         cifs_move_llist(&tmp_llist, &cfile->llist->locks);
 210                         rc = stored_rc;
 211                 } else
 212                         cifs_free_llist(&tmp_llist);
 213         }
 214         up_write(&cinode->lock_sem);
 215
 216         kfree(buf);
 217         return rc;
 218 }
 219
 220 static int
 221 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
 222                        struct smb2_lock_element *buf, unsigned int max_num)
 223 {
 224         int rc = 0, stored_rc;
 225         struct cifsFileInfo *cfile = fdlocks->cfile;
 226         struct cifsLockInfo *li;
 227         unsigned int num = 0;
 228         struct smb2_lock_element *cur = buf;
 229         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 230
 231         list_for_each_entry(li, &fdlocks->locks, llist) {
 232                 cur->Length = cpu_to_le64(li->length);
 233                 cur->Offset = cpu_to_le64(li->offset);
 234                 cur->Flags = cpu_to_le32(li->type |
 235                                                 SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
 236                 if (++num == max_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                         cur = buf;
 244                         num = 0;
 245                 } else
 246                         cur++;
 247         }
 248         if (num) {
 249                 stored_rc = smb2_lockv(xid, tcon,
 250                                        cfile->fid.persistent_fid,
 251                                        cfile->fid.volatile_fid,
 252                                        current->tgid, num, buf);
 253                 if (stored_rc)
 254                         rc = stored_rc;
 255         }
 256
 257         return rc;
 258 }
 259
 260 int
 261 smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
 262 {
 263         int rc = 0, stored_rc;
 264         unsigned int xid;
 265         unsigned int max_num, max_buf;
 266         struct smb2_lock_element *buf;
 267         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 268         struct cifs_fid_locks *fdlocks;
 269
 270         xid = get_xid();
 271
 272         /*
 273          * Accessing maxBuf is racy with cifs_reconnect - need to store value
 274          * and check it for zero before using.
 275          */
 276         max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
 277         if (max_buf < sizeof(struct smb2_lock_element)) {
 278                 free_xid(xid);
 279                 return -EINVAL;
 280         }
 281
 282         BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
 283         max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 284         max_num = max_buf / sizeof(struct smb2_lock_element);
 285         buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
 286         if (!buf) {
 287                 free_xid(xid);
 288                 return -ENOMEM;
 289         }
 290
 291         list_for_each_entry(fdlocks, &cinode->llist, llist) {
 292                 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
 293                 if (stored_rc)
 294                         rc = stored_rc;
 295         }
 296
 297         kfree(buf);
 298         free_xid(xid);
 299         return rc;
 300 }