fs/cifs/smb2file.c

   1 // SPDX-License-Identifier: LGPL-2.1
   2 /*
   3  *   fs/cifs/smb2file.c
   4  *
   5  *   Copyright (C) International Business Machines  Corp., 2002, 2011
   6  *   Author(s): Steve French (sfrench@us.ibm.com),
   7  *              Pavel Shilovsky ((pshilovsky@samba.org) 2012
   8  *
   9  */
  10 #include <linux/fs.h>
  11 #include <linux/stat.h>
  12 #include <linux/slab.h>
  13 #include <linux/pagemap.h>
  14 #include <asm/div64.h>
  15 #include "cifsfs.h"
  16 #include "cifspdu.h"
  17 #include "cifsglob.h"
  18 #include "cifsproto.h"
  19 #include "cifs_debug.h"
  20 #include "cifs_fs_sb.h"
  21 #include "cifs_unicode.h"
  22 #include "fscache.h"
  23 #include "smb2proto.h"
  24
  25 int
  26 smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms,
  27                __u32 *oplock, FILE_ALL_INFO *buf)
  28 {
  29         int rc;
  30         __le16 *smb2_path;
  31         struct smb2_file_all_info *smb2_data = NULL;
  32         __u8 smb2_oplock;
  33         struct cifs_fid *fid = oparms->fid;
  34         struct network_resiliency_req nr_ioctl_req;
  35
  36         smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb);
  37         if (smb2_path == NULL) {
  38                 rc = -ENOMEM;
  39                 goto out;
  40         }
  41
  42         smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
  43                             GFP_KERNEL);
  44         if (smb2_data == NULL) {
  45                 rc = -ENOMEM;
  46                 goto out;
  47         }
  48
  49         oparms->desired_access |= FILE_READ_ATTRIBUTES;
  50         smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
  51
  52         rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL,
  53                        NULL, NULL);
  54         if (rc)
  55                 goto out;
  56
  57
  58         if (oparms->tcon->use_resilient) {
  59                 /* default timeout is 0, servers pick default (120 seconds) */
  60                 nr_ioctl_req.Timeout =
  61                         cpu_to_le32(oparms->tcon->handle_timeout);
  62                 nr_ioctl_req.Reserved = 0;
  63                 rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid,
  64                         fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY,
  65                         true /* is_fsctl */,
  66                         (char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
  67                         CIFSMaxBufSize, NULL, NULL /* no return info */);
  68                 if (rc == -EOPNOTSUPP) {
  69                         cifs_dbg(VFS,
  70                              "resiliency not supported by server, disabling\n");
  71                         oparms->tcon->use_resilient = false;
  72                 } else if (rc)
  73                         cifs_dbg(FYI, "error %d setting resiliency\n", rc);
  74
  75                 rc = 0;
  76         }
  77
  78         if (buf) {
  79                 /* if open response does not have IndexNumber field - get it */
  80                 if (smb2_data->IndexNumber == 0) {
  81                         rc = SMB2_get_srv_num(xid, oparms->tcon,
  82                                       fid->persistent_fid,
  83                                       fid->volatile_fid,
  84                                       &smb2_data->IndexNumber);
  85                         if (rc) {
  86                                 /*
  87                                  * let get_inode_info disable server inode
  88                                  * numbers
  89                                  */
  90                                 smb2_data->IndexNumber = 0;
  91                                 rc = 0;
  92                         }
  93                 }
  94                 move_smb2_info_to_cifs(buf, smb2_data);
  95         }
  96
  97         *oplock = smb2_oplock;
  98 out:
  99         kfree(smb2_data);
 100         kfree(smb2_path);
 101         return rc;
 102 }
 103
 104 int
 105 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
 106                   const unsigned int xid)
 107 {
 108         int rc = 0, stored_rc;
 109         unsigned int max_num, num = 0, max_buf;
 110         struct smb2_lock_element *buf, *cur;
 111         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 112         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 113         struct cifsLockInfo *li, *tmp;
 114         __u64 length = 1 + flock->fl_end - flock->fl_start;
 115         struct list_head tmp_llist;
 116
 117         INIT_LIST_HEAD(&tmp_llist);
 118
 119         /*
 120          * Accessing maxBuf is racy with cifs_reconnect - need to store value
 121          * and check it before using.
 122          */
 123         max_buf = tcon->ses->server->maxBuf;
 124         if (max_buf < sizeof(struct smb2_lock_element))
 125                 return -EINVAL;
 126
 127         BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
 128         max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 129         max_num = max_buf / sizeof(struct smb2_lock_element);
 130         buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
 131         if (!buf)
 132                 return -ENOMEM;
 133
 134         cur = buf;
 135
 136         cifs_down_write(&cinode->lock_sem);
 137         list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
 138                 if (flock->fl_start > li->offset ||
 139                     (flock->fl_start + length) <
 140                     (li->offset + li->length))
 141                         continue;
 142                 if (current->tgid != li->pid)
 143                         /*
 144                          * flock and OFD lock are associated with an open
 145                          * file description, not the process.
 146                          */
 147                         if (!(flock->fl_flags & (FL_FLOCK | FL_OFDLCK)))
 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 }