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                 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
 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 before using.
 126          */
 127         max_buf = tcon->ses->server->maxBuf;
 128         if (max_buf < sizeof(struct smb2_lock_element))
 129                 return -EINVAL;
 130
 131         BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
 132         max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 133         max_num = max_buf / sizeof(struct smb2_lock_element);
 134         buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
 135         if (!buf)
 136                 return -ENOMEM;
 137
 138         cur = buf;
 139
 140         down_write(&cinode->lock_sem);
 141         list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
 142                 if (flock->fl_start > li->offset ||
 143                     (flock->fl_start + length) <
 144                     (li->offset + li->length))
 145                         continue;
 146                 if (current->tgid != li->pid)
 147                         continue;
 148                 if (cinode->can_cache_brlcks) {
 149                         /*
 150                          * We can cache brlock requests - simply remove a lock
 151                          * from the file's list.
 152                          */
 153                         list_del(&li->llist);
 154                         cifs_del_lock_waiters(li);
 155                         kfree(li);
 156                         continue;
 157                 }
 158                 cur->Length = cpu_to_le64(li->length);
 159                 cur->Offset = cpu_to_le64(li->offset);
 160                 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
 161                 /*
 162                  * We need to save a lock here to let us add it again to the
 163                  * file's list if the unlock range request fails on the server.
 164                  */
 165                 list_move(&li->llist, &tmp_llist);
 166                 if (++num == max_num) {
 167                         stored_rc = smb2_lockv(xid, tcon,
 168                                                cfile->fid.persistent_fid,
 169                                                cfile->fid.volatile_fid,
 170                                                current->tgid, num, buf);
 171                         if (stored_rc) {
 172                                 /*
 173                                  * We failed on the unlock range request - add
 174                                  * all locks from the tmp list to the head of
 175                                  * the file's list.
 176                                  */
 177                                 cifs_move_llist(&tmp_llist,
 178                                                 &cfile->llist->locks);
 179                                 rc = stored_rc;
 180                         } else
 181                                 /*
 182                                  * The unlock range request succeed - free the
 183                                  * tmp list.
 184                                  */
 185                                 cifs_free_llist(&tmp_llist);
 186                         cur = buf;
 187                         num = 0;
 188                 } else
 189                         cur++;
 190         }
 191         if (num) {
 192                 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
 193                                        cfile->fid.volatile_fid, current->tgid,
 194                                        num, buf);
 195                 if (stored_rc) {
 196                         cifs_move_llist(&tmp_llist, &cfile->llist->locks);
 197                         rc = stored_rc;
 198                 } else
 199                         cifs_free_llist(&tmp_llist);
 200         }
 201         up_write(&cinode->lock_sem);
 202
 203         kfree(buf);
 204         return rc;
 205 }
 206
 207 static int
 208 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
 209                        struct smb2_lock_element *buf, unsigned int max_num)
 210 {
 211         int rc = 0, stored_rc;
 212         struct cifsFileInfo *cfile = fdlocks->cfile;
 213         struct cifsLockInfo *li;
 214         unsigned int num = 0;
 215         struct smb2_lock_element *cur = buf;
 216         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 217
 218         list_for_each_entry(li, &fdlocks->locks, llist) {
 219                 cur->Length = cpu_to_le64(li->length);
 220                 cur->Offset = cpu_to_le64(li->offset);
 221                 cur->Flags = cpu_to_le32(li->type |
 222                                                 SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
 223                 if (++num == max_num) {
 224                         stored_rc = smb2_lockv(xid, tcon,
 225                                                cfile->fid.persistent_fid,
 226                                                cfile->fid.volatile_fid,
 227                                                current->tgid, num, buf);
 228                         if (stored_rc)
 229                                 rc = stored_rc;
 230                         cur = buf;
 231                         num = 0;
 232                 } else
 233                         cur++;
 234         }
 235         if (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         }
 243
 244         return rc;
 245 }
 246
 247 int
 248 smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
 249 {
 250         int rc = 0, stored_rc;
 251         unsigned int xid;
 252         unsigned int max_num, max_buf;
 253         struct smb2_lock_element *buf;
 254         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 255         struct cifs_fid_locks *fdlocks;
 256
 257         xid = get_xid();
 258
 259         /*
 260          * Accessing maxBuf is racy with cifs_reconnect - need to store value
 261          * and check it for zero before using.
 262          */
 263         max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
 264         if (max_buf < sizeof(struct smb2_lock_element)) {
 265                 free_xid(xid);
 266                 return -EINVAL;
 267         }
 268
 269         BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
 270         max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 271         max_num = max_buf / sizeof(struct smb2_lock_element);
 272         buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
 273         if (!buf) {
 274                 free_xid(xid);
 275                 return -ENOMEM;
 276         }
 277
 278         list_for_each_entry(fdlocks, &cinode->llist, llist) {
 279                 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
 280                 if (stored_rc)
 281                         rc = stored_rc;
 282         }
 283
 284         kfree(buf);
 285         free_xid(xid);
 286         return rc;
 287 }