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[17];
  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         if (oparms->tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LEASING)
  65                 memcpy(smb2_oplock + 1, fid->lease_key, SMB2_LEASE_KEY_SIZE);
  66
  67         rc = SMB2_open(xid, oparms, smb2_path, smb2_oplock, smb2_data, NULL);
  68         if (rc)
  69                 goto out;
  70
  71
  72         if (oparms->tcon->use_resilient) {
  73                 nr_ioctl_req.Timeout = 0; /* use server default (120 seconds) */
  74                 nr_ioctl_req.Reserved = 0;
  75                 rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid,
  76                         fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY, true,
  77                         (char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
  78                         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                 /* open response does not have IndexNumber field - get it */
  91                 rc = SMB2_get_srv_num(xid, oparms->tcon, fid->persistent_fid,
  92                                       fid->volatile_fid,
  93                                       &smb2_data->IndexNumber);
  94                 if (rc) {
  95                         /* let get_inode_info disable server inode numbers */
  96                         smb2_data->IndexNumber = 0;
  97                         rc = 0;
  98                 }
  99                 move_smb2_info_to_cifs(buf, smb2_data);
 100         }
 101
 102         *oplock = *smb2_oplock;
 103 out:
 104         kfree(smb2_data);
 105         kfree(smb2_path);
 106         return rc;
 107 }
 108
 109 int
 110 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
 111                   const unsigned int xid)
 112 {
 113         int rc = 0, stored_rc;
 114         unsigned int max_num, num = 0, max_buf;
 115         struct smb2_lock_element *buf, *cur;
 116         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 117         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 118         struct cifsLockInfo *li, *tmp;
 119         __u64 length = 1 + flock->fl_end - flock->fl_start;
 120         struct list_head tmp_llist;
 121
 122         INIT_LIST_HEAD(&tmp_llist);
 123
 124         /*
 125          * Accessing maxBuf is racy with cifs_reconnect - need to store value
 126          * and check it before using.
 127          */
 128         max_buf = tcon->ses->server->maxBuf;
 129         if (max_buf < sizeof(struct smb2_lock_element))
 130                 return -EINVAL;
 131
 132         BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
 133         max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 134         max_num = max_buf / sizeof(struct smb2_lock_element);
 135         buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
 136         if (!buf)
 137                 return -ENOMEM;
 138
 139         cur = buf;
 140
 141         cifs_down_write(&cinode->lock_sem);
 142         list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
 143                 if (flock->fl_start > li->offset ||
 144                     (flock->fl_start + length) <
 145                     (li->offset + li->length))
 146                         continue;
 147                 if (current->tgid != li->pid)
 148                         continue;
 149                 if (cinode->can_cache_brlcks) {
 150                         /*
 151                          * We can cache brlock requests - simply remove a lock
 152                          * from the file's list.
 153                          */
 154                         list_del(&li->llist);
 155                         cifs_del_lock_waiters(li);
 156                         kfree(li);
 157                         continue;
 158                 }
 159                 cur->Length = cpu_to_le64(li->length);
 160                 cur->Offset = cpu_to_le64(li->offset);
 161                 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
 162                 /*
 163                  * We need to save a lock here to let us add it again to the
 164                  * file's list if the unlock range request fails on the server.
 165                  */
 166                 list_move(&li->llist, &tmp_llist);
 167                 if (++num == max_num) {
 168                         stored_rc = smb2_lockv(xid, tcon,
 169                                                cfile->fid.persistent_fid,
 170                                                cfile->fid.volatile_fid,
 171                                                current->tgid, num, buf);
 172                         if (stored_rc) {
 173                                 /*
 174                                  * We failed on the unlock range request - add
 175                                  * all locks from the tmp list to the head of
 176                                  * the file's list.
 177                                  */
 178                                 cifs_move_llist(&tmp_llist,
 179                                                 &cfile->llist->locks);
 180                                 rc = stored_rc;
 181                         } else
 182                                 /*
 183                                  * The unlock range request succeed - free the
 184                                  * tmp list.
 185                                  */
 186                                 cifs_free_llist(&tmp_llist);
 187                         cur = buf;
 188                         num = 0;
 189                 } else
 190                         cur++;
 191         }
 192         if (num) {
 193                 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
 194                                        cfile->fid.volatile_fid, current->tgid,
 195                                        num, buf);
 196                 if (stored_rc) {
 197                         cifs_move_llist(&tmp_llist, &cfile->llist->locks);
 198                         rc = stored_rc;
 199                 } else
 200                         cifs_free_llist(&tmp_llist);
 201         }
 202         up_write(&cinode->lock_sem);
 203
 204         kfree(buf);
 205         return rc;
 206 }
 207
 208 static int
 209 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
 210                        struct smb2_lock_element *buf, unsigned int max_num)
 211 {
 212         int rc = 0, stored_rc;
 213         struct cifsFileInfo *cfile = fdlocks->cfile;
 214         struct cifsLockInfo *li;
 215         unsigned int num = 0;
 216         struct smb2_lock_element *cur = buf;
 217         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 218
 219         list_for_each_entry(li, &fdlocks->locks, llist) {
 220                 cur->Length = cpu_to_le64(li->length);
 221                 cur->Offset = cpu_to_le64(li->offset);
 222                 cur->Flags = cpu_to_le32(li->type |
 223                                                 SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
 224                 if (++num == max_num) {
 225                         stored_rc = smb2_lockv(xid, tcon,
 226                                                cfile->fid.persistent_fid,
 227                                                cfile->fid.volatile_fid,
 228                                                current->tgid, num, buf);
 229                         if (stored_rc)
 230                                 rc = stored_rc;
 231                         cur = buf;
 232                         num = 0;
 233                 } else
 234                         cur++;
 235         }
 236         if (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         }
 244
 245         return rc;
 246 }
 247
 248 int
 249 smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
 250 {
 251         int rc = 0, stored_rc;
 252         unsigned int xid;
 253         unsigned int max_num, max_buf;
 254         struct smb2_lock_element *buf;
 255         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 256         struct cifs_fid_locks *fdlocks;
 257
 258         xid = get_xid();
 259
 260         /*
 261          * Accessing maxBuf is racy with cifs_reconnect - need to store value
 262          * and check it for zero before using.
 263          */
 264         max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
 265         if (max_buf < sizeof(struct smb2_lock_element)) {
 266                 free_xid(xid);
 267                 return -EINVAL;
 268         }
 269
 270         BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
 271         max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 272         max_num = max_buf / sizeof(struct smb2_lock_element);
 273         buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
 274         if (!buf) {
 275                 free_xid(xid);
 276                 return -ENOMEM;
 277         }
 278
 279         list_for_each_entry(fdlocks, &cinode->llist, llist) {
 280                 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
 281                 if (stored_rc)
 282                         rc = stored_rc;
 283         }
 284
 285         kfree(buf);
 286         free_xid(xid);
 287         return rc;
 288 }