LXR linux/fs/cifs/smb2file.c

   1// SPDX-License-Identifier: LGPL-2.1
   2/*
   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 */
   9#include <linux/fs.h>
  10#include <linux/stat.h>
  11#include <linux/slab.h>
  12#include <linux/pagemap.h>
  13#include <asm/div64.h>
  14#include "cifsfs.h"
  15#include "cifspdu.h"
  16#include "cifsglob.h"
  17#include "cifsproto.h"
  18#include "cifs_debug.h"
  19#include "cifs_fs_sb.h"
  20#include "cifs_unicode.h"
  21#include "fscache.h"
  22#include "smb2proto.h"
  23
  24int
  25smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms,
  26               __u32 *oplock, FILE_ALL_INFO *buf)
  27{
  28        int rc;
  29        __le16 *smb2_path;
  30        struct smb2_file_all_info *smb2_data = NULL;
  31        __u8 smb2_oplock;
  32        struct cifs_fid *fid = oparms->fid;
  33        struct network_resiliency_req nr_ioctl_req;
  34
  35        smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb);
  36        if (smb2_path == NULL) {
  37                rc = -ENOMEM;
  38                goto out;
  39        }
  40
  41        smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
  42                            GFP_KERNEL);
  43        if (smb2_data == NULL) {
  44                rc = -ENOMEM;
  45                goto out;
  46        }
  47
  48        oparms->desired_access |= FILE_READ_ATTRIBUTES;
  49        smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
  50
  51        rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL,
  52                       NULL, NULL);
  53        if (rc)
  54                goto out;
  55
  56
  57        if (oparms->tcon->use_resilient) {
  58                /* default timeout is 0, servers pick default (120 seconds) */
  59                nr_ioctl_req.Timeout =
  60                        cpu_to_le32(oparms->tcon->handle_timeout);
  61                nr_ioctl_req.Reserved = 0;
  62                rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid,
  63                        fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY,
  64                        true /* is_fsctl */,
  65                        (char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
  66                        CIFSMaxBufSize, NULL, NULL /* no return info */);
  67                if (rc == -EOPNOTSUPP) {
  68                        cifs_dbg(VFS,
  69                             "resiliency not supported by server, disabling\n");
  70                        oparms->tcon->use_resilient = false;
  71                } else if (rc)
  72                        cifs_dbg(FYI, "error %d setting resiliency\n", rc);
  73
  74                rc = 0;
  75        }
  76
  77        if (buf) {
  78                /* if open response does not have IndexNumber field - get it */
  79                if (smb2_data->IndexNumber == 0) {
  80                        rc = SMB2_get_srv_num(xid, oparms->tcon,
  81                                      fid->persistent_fid,
  82                                      fid->volatile_fid,
  83                                      &smb2_data->IndexNumber);
  84                        if (rc) {
  85                                /*
  86                                 * let get_inode_info disable server inode
  87                                 * numbers
  88                                 */
  89                                smb2_data->IndexNumber = 0;
  90                                rc = 0;
  91                        }
  92                }
  93                move_smb2_info_to_cifs(buf, smb2_data);
  94        }
  95
  96        *oplock = smb2_oplock;
  97out:
  98        kfree(smb2_data);
  99        kfree(smb2_path);
 100        return rc;
 101}
 102
 103int
 104smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
 105                  const unsigned int xid)
 106{
 107        int rc = 0, stored_rc;
 108        unsigned int max_num, num = 0, max_buf;
 109        struct smb2_lock_element *buf, *cur;
 110        struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 111        struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 112        struct cifsLockInfo *li, *tmp;
 113        __u64 length = 1 + flock->fl_end - flock->fl_start;
 114        struct list_head tmp_llist;
 115
 116        INIT_LIST_HEAD(&tmp_llist);
 117
 118        /*
 119         * Accessing maxBuf is racy with cifs_reconnect - need to store value
 120         * and check it before using.
 121         */
 122        max_buf = tcon->ses->server->maxBuf;
 123        if (max_buf < sizeof(struct smb2_lock_element))
 124                return -EINVAL;
 125
 126        BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
 127        max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 128        max_num = max_buf / sizeof(struct smb2_lock_element);
 129        buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
 130        if (!buf)
 131                return -ENOMEM;
 132
 133        cur = buf;
 134
 135        cifs_down_write(&cinode->lock_sem);
 136        list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
 137                if (flock->fl_start > li->offset ||
 138                    (flock->fl_start + length) <
 139                    (li->offset + li->length))
 140                        continue;
 141                if (current->tgid != li->pid)
 142                        /*
 143                         * flock and OFD lock are associated with an open
 144                         * file description, not the process.
 145                         */
 146                        if (!(flock->fl_flags & (FL_FLOCK | FL_OFDLCK)))
 147                                continue;
 148                if (cinode->can_cache_brlcks) {
 149                        /*
 150                         * We can cache brlock requests - simply remove a lock
 151                         * from the file's list.
 152                         */
 153                        list_del(&li->llist);
 154                        cifs_del_lock_waiters(li);
 155                        kfree(li);
 156                        continue;
 157                }
 158                cur->Length = cpu_to_le64(li->length);
 159                cur->Offset = cpu_to_le64(li->offset);
 160                cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
 161                /*
 162                 * We need to save a lock here to let us add it again to the
 163                 * file's list if the unlock range request fails on the server.
 164                 */
 165                list_move(&li->llist, &tmp_llist);
 166                if (++num == max_num) {
 167                        stored_rc = smb2_lockv(xid, tcon,
 168                                               cfile->fid.persistent_fid,
 169                                               cfile->fid.volatile_fid,
 170                                               current->tgid, num, buf);
 171                        if (stored_rc) {
 172                                /*
 173                                 * We failed on the unlock range request - add
 174                                 * all locks from the tmp list to the head of
 175                                 * the file's list.
 176                                 */
 177                                cifs_move_llist(&tmp_llist,
 178                                                &cfile->llist->locks);
 179                                rc = stored_rc;
 180                        } else
 181                                /*
 182                                 * The unlock range request succeed - free the
 183                                 * tmp list.
 184                                 */
 185                                cifs_free_llist(&tmp_llist);
 186                        cur = buf;
 187                        num = 0;
 188                } else
 189                        cur++;
 190        }
 191        if (num) {
 192                stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
 193                                       cfile->fid.volatile_fid, current->tgid,
 194                                       num, buf);
 195                if (stored_rc) {
 196                        cifs_move_llist(&tmp_llist, &cfile->llist->locks);
 197                        rc = stored_rc;
 198                } else
 199                        cifs_free_llist(&tmp_llist);
 200        }
 201        up_write(&cinode->lock_sem);
 202
 203        kfree(buf);
 204        return rc;
 205}
 206
 207static int
 208smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
 209                       struct smb2_lock_element *buf, unsigned int max_num)
 210{
 211        int rc = 0, stored_rc;
 212        struct cifsFileInfo *cfile = fdlocks->cfile;
 213        struct cifsLockInfo *li;
 214        unsigned int num = 0;
 215        struct smb2_lock_element *cur = buf;
 216        struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 217
 218        list_for_each_entry(li, &fdlocks->locks, llist) {
 219                cur->Length = cpu_to_le64(li->length);
 220                cur->Offset = cpu_to_le64(li->offset);
 221                cur->Flags = cpu_to_le32(li->type |
 222                                                SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
 223                if (++num == max_num) {
 224                        stored_rc = smb2_lockv(xid, tcon,
 225                                               cfile->fid.persistent_fid,
 226                                               cfile->fid.volatile_fid,
 227                                               current->tgid, num, buf);
 228                        if (stored_rc)
 229                                rc = stored_rc;
 230                        cur = buf;
 231                        num = 0;
 232                } else
 233                        cur++;
 234        }
 235        if (num) {
 236                stored_rc = smb2_lockv(xid, tcon,
 237                                       cfile->fid.persistent_fid,
 238                                       cfile->fid.volatile_fid,
 239                                       current->tgid, num, buf);
 240                if (stored_rc)
 241                        rc = stored_rc;
 242        }
 243
 244        return rc;
 245}
 246
 247int
 248smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
 249{
 250        int rc = 0, stored_rc;
 251        unsigned int xid;
 252        unsigned int max_num, max_buf;
 253        struct smb2_lock_element *buf;
 254        struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 255        struct cifs_fid_locks *fdlocks;
 256
 257        xid = get_xid();
 258
 259        /*
 260         * Accessing maxBuf is racy with cifs_reconnect - need to store value
 261         * and check it for zero before using.
 262         */
 263        max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
 264        if (max_buf < sizeof(struct smb2_lock_element)) {
 265                free_xid(xid);
 266                return -EINVAL;
 267        }
 268
 269        BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
 270        max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 271        max_num = max_buf / sizeof(struct smb2_lock_element);
 272        buf = kcalloc(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}
 288