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 void
  38 smb2_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                 cinode->clientCanCacheAll = true;
  45                 cinode->clientCanCacheRead = true;
  46                 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
  47                          &cinode->vfs_inode);
  48         } else if (oplock == SMB2_OPLOCK_LEVEL_II) {
  49                 cinode->clientCanCacheAll = false;
  50                 cinode->clientCanCacheRead = true;
  51                 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
  52                          &cinode->vfs_inode);
  53         } else {
  54                 cinode->clientCanCacheAll = false;
  55                 cinode->clientCanCacheRead = false;
  56         }
  57 }
  58
  59 int
  60 smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms,
  61                __u32 *oplock, FILE_ALL_INFO *buf)
  62 {
  63         int rc;
  64         __le16 *smb2_path;
  65         struct smb2_file_all_info *smb2_data = NULL;
  66         __u8 smb2_oplock[17];
  67         struct cifs_fid *fid = oparms->fid;
  68
  69         smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb);
  70         if (smb2_path == NULL) {
  71                 rc = -ENOMEM;
  72                 goto out;
  73         }
  74
  75         smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + MAX_NAME * 2,
  76                             GFP_KERNEL);
  77         if (smb2_data == NULL) {
  78                 rc = -ENOMEM;
  79                 goto out;
  80         }
  81
  82         oparms->desired_access |= FILE_READ_ATTRIBUTES;
  83         *smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
  84
  85         if (oparms->tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LEASING)
  86                 memcpy(smb2_oplock + 1, fid->lease_key, SMB2_LEASE_KEY_SIZE);
  87
  88         rc = SMB2_open(xid, oparms, smb2_path, smb2_oplock, smb2_data);
  89         if (rc)
  90                 goto out;
  91
  92         if (buf) {
  93                 /* open response does not have IndexNumber field - get it */
  94                 rc = SMB2_get_srv_num(xid, oparms->tcon, fid->persistent_fid,
  95                                       fid->volatile_fid,
  96                                       &smb2_data->IndexNumber);
  97                 if (rc) {
  98                         /* let get_inode_info disable server inode numbers */
  99                         smb2_data->IndexNumber = 0;
 100                         rc = 0;
 101                 }
 102                 move_smb2_info_to_cifs(buf, smb2_data);
 103         }
 104
 105         *oplock = *smb2_oplock;
 106 out:
 107         kfree(smb2_data);
 108         kfree(smb2_path);
 109         return rc;
 110 }
 111
 112 int
 113 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
 114                   const unsigned int xid)
 115 {
 116         int rc = 0, stored_rc;
 117         unsigned int max_num, num = 0, max_buf;
 118         struct smb2_lock_element *buf, *cur;
 119         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 120         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 121         struct cifsLockInfo *li, *tmp;
 122         __u64 length = 1 + flock->fl_end - flock->fl_start;
 123         struct list_head tmp_llist;
 124
 125         INIT_LIST_HEAD(&tmp_llist);
 126
 127         /*
 128          * Accessing maxBuf is racy with cifs_reconnect - need to store value
 129          * and check it for zero before using.
 130          */
 131         max_buf = tcon->ses->server->maxBuf;
 132         if (!max_buf)
 133                 return -EINVAL;
 134
 135         max_num = max_buf / sizeof(struct smb2_lock_element);
 136         buf = kzalloc(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(cfile->dentry->d_inode);
 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) {
 267                 free_xid(xid);
 268                 return -EINVAL;
 269         }
 270
 271         max_num = max_buf / sizeof(struct smb2_lock_element);
 272         buf = kzalloc(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 }