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