linux/fs/cifs/smb2file.c
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   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
  37void
  38smb2_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
  39{
  40        oplock &= 0xFF;
  41        if (oplock == SMB2_OPLOCK_LEVEL_NOCHANGE)
  42                return;
  43        if (oplock == SMB2_OPLOCK_LEVEL_EXCLUSIVE ||
  44            oplock == SMB2_OPLOCK_LEVEL_BATCH) {
  45                cinode->clientCanCacheAll = true;
  46                cinode->clientCanCacheRead = true;
  47                cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
  48                         &cinode->vfs_inode);
  49        } else if (oplock == SMB2_OPLOCK_LEVEL_II) {
  50                cinode->clientCanCacheAll = false;
  51                cinode->clientCanCacheRead = true;
  52                cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
  53                         &cinode->vfs_inode);
  54        } else {
  55                cinode->clientCanCacheAll = false;
  56                cinode->clientCanCacheRead = false;
  57        }
  58}
  59
  60int
  61smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms,
  62               __u32 *oplock, FILE_ALL_INFO *buf)
  63{
  64        int rc;
  65        __le16 *smb2_path;
  66        struct smb2_file_all_info *smb2_data = NULL;
  67        __u8 smb2_oplock[17];
  68        struct cifs_fid *fid = oparms->fid;
  69
  70        smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb);
  71        if (smb2_path == NULL) {
  72                rc = -ENOMEM;
  73                goto out;
  74        }
  75
  76        smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + MAX_NAME * 2,
  77                            GFP_KERNEL);
  78        if (smb2_data == NULL) {
  79                rc = -ENOMEM;
  80                goto out;
  81        }
  82
  83        oparms->desired_access |= FILE_READ_ATTRIBUTES;
  84        *smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
  85
  86        if (oparms->tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LEASING)
  87                memcpy(smb2_oplock + 1, fid->lease_key, SMB2_LEASE_KEY_SIZE);
  88
  89        rc = SMB2_open(xid, oparms, smb2_path, smb2_oplock, smb2_data);
  90        if (rc)
  91                goto out;
  92
  93        if (buf) {
  94                /* open response does not have IndexNumber field - get it */
  95                rc = SMB2_get_srv_num(xid, oparms->tcon, fid->persistent_fid,
  96                                      fid->volatile_fid,
  97                                      &smb2_data->IndexNumber);
  98                if (rc) {
  99                        /* let get_inode_info disable server inode numbers */
 100                        smb2_data->IndexNumber = 0;
 101                        rc = 0;
 102                }
 103                move_smb2_info_to_cifs(buf, smb2_data);
 104        }
 105
 106        *oplock = *smb2_oplock;
 107out:
 108        kfree(smb2_data);
 109        kfree(smb2_path);
 110        return rc;
 111}
 112
 113int
 114smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
 115                  const unsigned int xid)
 116{
 117        int rc = 0, stored_rc;
 118        unsigned int max_num, num = 0, max_buf;
 119        struct smb2_lock_element *buf, *cur;
 120        struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 121        struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 122        struct cifsLockInfo *li, *tmp;
 123        __u64 length = 1 + flock->fl_end - flock->fl_start;
 124        struct list_head tmp_llist;
 125
 126        INIT_LIST_HEAD(&tmp_llist);
 127
 128        /*
 129         * Accessing maxBuf is racy with cifs_reconnect - need to store value
 130         * and check it for zero before using.
 131         */
 132        max_buf = tcon->ses->server->maxBuf;
 133        if (!max_buf)
 134                return -EINVAL;
 135
 136        max_num = max_buf / sizeof(struct smb2_lock_element);
 137        buf = kzalloc(max_num * sizeof(struct smb2_lock_element), GFP_KERNEL);
 138        if (!buf)
 139                return -ENOMEM;
 140
 141        cur = buf;
 142
 143        down_write(&cinode->lock_sem);
 144        list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
 145                if (flock->fl_start > li->offset ||
 146                    (flock->fl_start + length) <
 147                    (li->offset + li->length))
 148                        continue;
 149                if (current->tgid != li->pid)
 150                        continue;
 151                if (cinode->can_cache_brlcks) {
 152                        /*
 153                         * We can cache brlock requests - simply remove a lock
 154                         * from the file's list.
 155                         */
 156                        list_del(&li->llist);
 157                        cifs_del_lock_waiters(li);
 158                        kfree(li);
 159                        continue;
 160                }
 161                cur->Length = cpu_to_le64(li->length);
 162                cur->Offset = cpu_to_le64(li->offset);
 163                cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
 164                /*
 165                 * We need to save a lock here to let us add it again to the
 166                 * file's list if the unlock range request fails on the server.
 167                 */
 168                list_move(&li->llist, &tmp_llist);
 169                if (++num == max_num) {
 170                        stored_rc = smb2_lockv(xid, tcon,
 171                                               cfile->fid.persistent_fid,
 172                                               cfile->fid.volatile_fid,
 173                                               current->tgid, num, buf);
 174                        if (stored_rc) {
 175                                /*
 176                                 * We failed on the unlock range request - add
 177                                 * all locks from the tmp list to the head of
 178                                 * the file's list.
 179                                 */
 180                                cifs_move_llist(&tmp_llist,
 181                                                &cfile->llist->locks);
 182                                rc = stored_rc;
 183                        } else
 184                                /*
 185                                 * The unlock range request succeed - free the
 186                                 * tmp list.
 187                                 */
 188                                cifs_free_llist(&tmp_llist);
 189                        cur = buf;
 190                        num = 0;
 191                } else
 192                        cur++;
 193        }
 194        if (num) {
 195                stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
 196                                       cfile->fid.volatile_fid, current->tgid,
 197                                       num, buf);
 198                if (stored_rc) {
 199                        cifs_move_llist(&tmp_llist, &cfile->llist->locks);
 200                        rc = stored_rc;
 201                } else
 202                        cifs_free_llist(&tmp_llist);
 203        }
 204        up_write(&cinode->lock_sem);
 205
 206        kfree(buf);
 207        return rc;
 208}
 209
 210static int
 211smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
 212                       struct smb2_lock_element *buf, unsigned int max_num)
 213{
 214        int rc = 0, stored_rc;
 215        struct cifsFileInfo *cfile = fdlocks->cfile;
 216        struct cifsLockInfo *li;
 217        unsigned int num = 0;
 218        struct smb2_lock_element *cur = buf;
 219        struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 220
 221        list_for_each_entry(li, &fdlocks->locks, llist) {
 222                cur->Length = cpu_to_le64(li->length);
 223                cur->Offset = cpu_to_le64(li->offset);
 224                cur->Flags = cpu_to_le32(li->type |
 225                                                SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
 226                if (++num == max_num) {
 227                        stored_rc = smb2_lockv(xid, tcon,
 228                                               cfile->fid.persistent_fid,
 229                                               cfile->fid.volatile_fid,
 230                                               current->tgid, num, buf);
 231                        if (stored_rc)
 232                                rc = stored_rc;
 233                        cur = buf;
 234                        num = 0;
 235                } else
 236                        cur++;
 237        }
 238        if (num) {
 239                stored_rc = smb2_lockv(xid, tcon,
 240                                       cfile->fid.persistent_fid,
 241                                       cfile->fid.volatile_fid,
 242                                       current->tgid, num, buf);
 243                if (stored_rc)
 244                        rc = stored_rc;
 245        }
 246
 247        return rc;
 248}
 249
 250int
 251smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
 252{
 253        int rc = 0, stored_rc;
 254        unsigned int xid;
 255        unsigned int max_num, max_buf;
 256        struct smb2_lock_element *buf;
 257        struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 258        struct cifs_fid_locks *fdlocks;
 259
 260        xid = get_xid();
 261
 262        /*
 263         * Accessing maxBuf is racy with cifs_reconnect - need to store value
 264         * and check it for zero before using.
 265         */
 266        max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
 267        if (!max_buf) {
 268                free_xid(xid);
 269                return -EINVAL;
 270        }
 271
 272        max_num = max_buf / sizeof(struct smb2_lock_element);
 273        buf = kzalloc(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}
 289
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