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