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_EXCLUSIVE) {
  42                 cinode->clientCanCacheAll = true;
  43                 cinode->clientCanCacheRead = true;
  44                 cFYI(1, "Exclusive Oplock granted on inode %p",
  45                      &cinode->vfs_inode);
  46         } else if (oplock == SMB2_OPLOCK_LEVEL_II) {
  47                 cinode->clientCanCacheAll = false;
  48                 cinode->clientCanCacheRead = true;
  49                 cFYI(1, "Level II Oplock granted on inode %p",
  50                     &cinode->vfs_inode);
  51         } else {
  52                 cinode->clientCanCacheAll = false;
  53                 cinode->clientCanCacheRead = false;
  54         }
  55 }
  56
  57 int
  58 smb2_open_file(const unsigned int xid, struct cifs_tcon *tcon, const char *path,
  59                int disposition, int desired_access, int create_options,
  60                struct cifs_fid *fid, __u32 *oplock, FILE_ALL_INFO *buf,
  61                struct cifs_sb_info *cifs_sb)
  62 {
  63         int rc;
  64         __le16 *smb2_path;
  65         struct smb2_file_all_info *smb2_data = NULL;
  66
  67         smb2_path = cifs_convert_path_to_utf16(path, cifs_sb);
  68         if (smb2_path == NULL) {
  69                 rc = -ENOMEM;
  70                 goto out;
  71         }
  72
  73         smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + MAX_NAME * 2,
  74                             GFP_KERNEL);
  75         if (smb2_data == NULL) {
  76                 rc = -ENOMEM;
  77                 goto out;
  78         }
  79
  80         desired_access |= FILE_READ_ATTRIBUTES;
  81         *oplock = SMB2_OPLOCK_LEVEL_EXCLUSIVE;
  82
  83         rc = SMB2_open(xid, tcon, smb2_path, &fid->persistent_fid,
  84                        &fid->volatile_fid, desired_access, disposition,
  85                        0, 0, (__u8 *)oplock, smb2_data);
  86         if (rc)
  87                 goto out;
  88
  89         if (buf) {
  90                 /* open response does not have IndexNumber field - get it */
  91                 rc = SMB2_get_srv_num(xid, 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 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(cfile->dentry->d_inode);
 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 for zero before using.
 126          */
 127         max_buf = tcon->ses->server->maxBuf;
 128         if (!max_buf)
 129                 return -EINVAL;
 130
 131         max_num = max_buf / sizeof(struct smb2_lock_element);
 132         buf = kzalloc(max_num * sizeof(struct smb2_lock_element), GFP_KERNEL);
 133         if (!buf)
 134                 return -ENOMEM;
 135
 136         cur = buf;
 137
 138         down_write(&cinode->lock_sem);
 139         list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
 140                 if (flock->fl_start > li->offset ||
 141                     (flock->fl_start + length) <
 142                     (li->offset + li->length))
 143                         continue;
 144                 if (current->tgid != li->pid)
 145                         continue;
 146                 if (cinode->can_cache_brlcks) {
 147                         /*
 148                          * We can cache brlock requests - simply remove a lock
 149                          * from the file's list.
 150                          */
 151                         list_del(&li->llist);
 152                         cifs_del_lock_waiters(li);
 153                         kfree(li);
 154                         continue;
 155                 }
 156                 cur->Length = cpu_to_le64(li->length);
 157                 cur->Offset = cpu_to_le64(li->offset);
 158                 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
 159                 /*
 160                  * We need to save a lock here to let us add it again to the
 161                  * file's list if the unlock range request fails on the server.
 162                  */
 163                 list_move(&li->llist, &tmp_llist);
 164                 if (++num == max_num) {
 165                         stored_rc = smb2_lockv(xid, tcon,
 166                                                cfile->fid.persistent_fid,
 167                                                cfile->fid.volatile_fid,
 168                                                current->tgid, num, buf);
 169                         if (stored_rc) {
 170                                 /*
 171                                  * We failed on the unlock range request - add
 172                                  * all locks from the tmp list to the head of
 173                                  * the file's list.
 174                                  */
 175                                 cifs_move_llist(&tmp_llist,
 176                                                 &cfile->llist->locks);
 177                                 rc = stored_rc;
 178                         } else
 179                                 /*
 180                                  * The unlock range request succeed - free the
 181                                  * tmp list.
 182                                  */
 183                                 cifs_free_llist(&tmp_llist);
 184                         cur = buf;
 185                         num = 0;
 186                 } else
 187                         cur++;
 188         }
 189         if (num) {
 190                 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
 191                                        cfile->fid.volatile_fid, current->tgid,
 192                                        num, buf);
 193                 if (stored_rc) {
 194                         cifs_move_llist(&tmp_llist, &cfile->llist->locks);
 195                         rc = stored_rc;
 196                 } else
 197                         cifs_free_llist(&tmp_llist);
 198         }
 199         up_write(&cinode->lock_sem);
 200
 201         kfree(buf);
 202         return rc;
 203 }
 204
 205 static int
 206 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
 207                        struct smb2_lock_element *buf, unsigned int max_num)
 208 {
 209         int rc = 0, stored_rc;
 210         struct cifsFileInfo *cfile = fdlocks->cfile;
 211         struct cifsLockInfo *li;
 212         unsigned int num = 0;
 213         struct smb2_lock_element *cur = buf;
 214         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 215
 216         list_for_each_entry(li, &fdlocks->locks, llist) {
 217                 cur->Length = cpu_to_le64(li->length);
 218                 cur->Offset = cpu_to_le64(li->offset);
 219                 cur->Flags = cpu_to_le32(li->type |
 220                                                 SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
 221                 if (++num == max_num) {
 222                         stored_rc = smb2_lockv(xid, tcon,
 223                                                cfile->fid.persistent_fid,
 224                                                cfile->fid.volatile_fid,
 225                                                current->tgid, num, buf);
 226                         if (stored_rc)
 227                                 rc = stored_rc;
 228                         cur = buf;
 229                         num = 0;
 230                 } else
 231                         cur++;
 232         }
 233         if (num) {
 234                 stored_rc = smb2_lockv(xid, tcon,
 235                                        cfile->fid.persistent_fid,
 236                                        cfile->fid.volatile_fid,
 237                                        current->tgid, num, buf);
 238                 if (stored_rc)
 239                         rc = stored_rc;
 240         }
 241
 242         return rc;
 243 }
 244
 245 int
 246 smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
 247 {
 248         int rc = 0, stored_rc;
 249         unsigned int xid;
 250         unsigned int max_num, max_buf;
 251         struct smb2_lock_element *buf;
 252         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
 253         struct cifs_fid_locks *fdlocks;
 254
 255         xid = get_xid();
 256         /* we are going to update can_cache_brlcks here - need a write access */
 257         down_write(&cinode->lock_sem);
 258         if (!cinode->can_cache_brlcks) {
 259                 up_write(&cinode->lock_sem);
 260                 free_xid(xid);
 261                 return rc;
 262         }
 263
 264         /*
 265          * Accessing maxBuf is racy with cifs_reconnect - need to store value
 266          * and check it for zero before using.
 267          */
 268         max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
 269         if (!max_buf) {
 270                 up_write(&cinode->lock_sem);
 271                 free_xid(xid);
 272                 return -EINVAL;
 273         }
 274
 275         max_num = max_buf / sizeof(struct smb2_lock_element);
 276         buf = kzalloc(max_num * sizeof(struct smb2_lock_element), GFP_KERNEL);
 277         if (!buf) {
 278                 up_write(&cinode->lock_sem);
 279                 free_xid(xid);
 280                 return -ENOMEM;
 281         }
 282
 283         list_for_each_entry(fdlocks, &cinode->llist, llist) {
 284                 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
 285                 if (stored_rc)
 286                         rc = stored_rc;
 287         }
 288
 289         cinode->can_cache_brlcks = false;
 290         kfree(buf);
 291
 292         up_write(&cinode->lock_sem);
 293         free_xid(xid);
 294         return rc;
 295 }