source3/modules/vfs_btrfs.c

   1 /*
   2  * Module to make use of awesome Btrfs features
   3  *
   4  * Copyright (C) David Disseldorp 2011-2013
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/ioctl.h>
  21 #include <linux/fs.h>
  22 #include <sys/ioctl.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include "system/filesys.h"
  26 #include "includes.h"
  27 #include "smbd/smbd.h"
  28 #include "librpc/gen_ndr/smbXsrv.h"
  29 #include "librpc/gen_ndr/ioctl.h"
  30 #include "lib/util/tevent_ntstatus.h"
  31
  32 static uint32_t btrfs_fs_capabilities(struct vfs_handle_struct *handle,
  33                                       enum timestamp_set_resolution *_ts_res)
  34 {
  35         uint32_t fs_capabilities;
  36         enum timestamp_set_resolution ts_res;
  37
  38         /* inherit default capabilities, expose compression support */
  39         fs_capabilities = SMB_VFS_NEXT_FS_CAPABILITIES(handle, &ts_res);
  40         fs_capabilities |= FILE_FILE_COMPRESSION;
  41         *_ts_res = ts_res;
  42
  43         return fs_capabilities;
  44 }
  45
  46 struct btrfs_ioctl_clone_range_args {
  47         int64_t src_fd;
  48         uint64_t src_offset;
  49         uint64_t src_length;
  50         uint64_t dest_offset;
  51 };
  52
  53 #define BTRFS_IOCTL_MAGIC 0x94
  54 #define BTRFS_IOC_CLONE_RANGE _IOW(BTRFS_IOCTL_MAGIC, 13, \
  55                                    struct btrfs_ioctl_clone_range_args)
  56
  57 struct btrfs_cc_state {
  58         struct vfs_handle_struct *handle;
  59         off_t copied;
  60         struct tevent_req *subreq;      /* non-null if passed to next VFS fn */
  61 };
  62 static void btrfs_copy_chunk_done(struct tevent_req *subreq);
  63
  64 static struct tevent_req *btrfs_copy_chunk_send(struct vfs_handle_struct *handle,
  65                                                 TALLOC_CTX *mem_ctx,
  66                                                 struct tevent_context *ev,
  67                                                 struct files_struct *src_fsp,
  68                                                 off_t src_off,
  69                                                 struct files_struct *dest_fsp,
  70                                                 off_t dest_off,
  71                                                 off_t num)
  72 {
  73         struct tevent_req *req;
  74         struct btrfs_cc_state *cc_state;
  75         struct btrfs_ioctl_clone_range_args cr_args;
  76         struct lock_struct src_lck;
  77         struct lock_struct dest_lck;
  78         int ret;
  79         NTSTATUS status;
  80
  81         req = tevent_req_create(mem_ctx, &cc_state, struct btrfs_cc_state);
  82         if (req == NULL) {
  83                 return NULL;
  84         }
  85         cc_state->handle = handle;
  86
  87         if (num == 0) {
  88                 /*
  89                  * With a @src_length of zero, BTRFS_IOC_CLONE_RANGE clones
  90                  * all data from @src_offset->EOF! This is certainly not what
  91                  * the caller expects, and not what vfs_default does.
  92                  */
  93                 cc_state->subreq = SMB_VFS_NEXT_COPY_CHUNK_SEND(handle,
  94                                                                 cc_state, ev,
  95                                                                 src_fsp,
  96                                                                 src_off,
  97                                                                 dest_fsp,
  98                                                                 dest_off, num);
  99                 if (tevent_req_nomem(cc_state->subreq, req)) {
 100                         return tevent_req_post(req, ev);
 101                 }
 102                 tevent_req_set_callback(cc_state->subreq,
 103                                         btrfs_copy_chunk_done,
 104                                         req);
 105                 return req;
 106         }
 107
 108         status = vfs_stat_fsp(src_fsp);
 109         if (tevent_req_nterror(req, status)) {
 110                 return tevent_req_post(req, ev);
 111         }
 112
 113         if (src_fsp->fsp_name->st.st_ex_size < src_off + num) {
 114                 /* [MS-SMB2] Handling a Server-Side Data Copy Request */
 115                 tevent_req_nterror(req, NT_STATUS_INVALID_VIEW_SIZE);
 116                 return tevent_req_post(req, ev);
 117         }
 118
 119         init_strict_lock_struct(src_fsp,
 120                                 src_fsp->op->global->open_persistent_id,
 121                                 src_off,
 122                                 num,
 123                                 READ_LOCK,
 124                                 &src_lck);
 125         init_strict_lock_struct(dest_fsp,
 126                                 dest_fsp->op->global->open_persistent_id,
 127                                 dest_off,
 128                                 num,
 129                                 WRITE_LOCK,
 130                                 &dest_lck);
 131
 132         if (!SMB_VFS_STRICT_LOCK(src_fsp->conn, src_fsp, &src_lck)) {
 133                 tevent_req_nterror(req, NT_STATUS_FILE_LOCK_CONFLICT);
 134                 return tevent_req_post(req, ev);
 135         }
 136         if (!SMB_VFS_STRICT_LOCK(dest_fsp->conn, dest_fsp, &dest_lck)) {
 137                 SMB_VFS_STRICT_UNLOCK(src_fsp->conn, src_fsp, &src_lck);
 138                 tevent_req_nterror(req, NT_STATUS_FILE_LOCK_CONFLICT);
 139                 return tevent_req_post(req, ev);
 140         }
 141
 142         ZERO_STRUCT(cr_args);
 143         cr_args.src_fd = src_fsp->fh->fd;
 144         cr_args.src_offset = (uint64_t)src_off;
 145         cr_args.dest_offset = (uint64_t)dest_off;
 146         cr_args.src_length = (uint64_t)num;
 147
 148         ret = ioctl(dest_fsp->fh->fd, BTRFS_IOC_CLONE_RANGE, &cr_args);
 149         SMB_VFS_STRICT_UNLOCK(dest_fsp->conn, dest_fsp, &dest_lck);
 150         SMB_VFS_STRICT_UNLOCK(src_fsp->conn, src_fsp, &src_lck);
 151         if (ret < 0) {
 152                 /*
 153                  * BTRFS_IOC_CLONE_RANGE only supports 'sectorsize' aligned
 154                  * cloning. Which is 4096 by default, therefore fall back to
 155                  * manual read/write on failure.
 156                  */
 157                 DEBUG(5, ("BTRFS_IOC_CLONE_RANGE failed: %s, length %llu, "
 158                           "src fd: %lld off: %llu, dest fd: %d off: %llu\n",
 159                           strerror(errno),
 160                           (unsigned long long)cr_args.src_length,
 161                           (long long)cr_args.src_fd,
 162                           (unsigned long long)cr_args.src_offset,
 163                           dest_fsp->fh->fd,
 164                           (unsigned long long)cr_args.dest_offset));
 165                 cc_state->subreq = SMB_VFS_NEXT_COPY_CHUNK_SEND(handle,
 166                                                                 cc_state, ev,
 167                                                                 src_fsp,
 168                                                                 src_off,
 169                                                                 dest_fsp,
 170                                                                 dest_off, num);
 171                 if (tevent_req_nomem(cc_state->subreq, req)) {
 172                         return tevent_req_post(req, ev);
 173                 }
 174                 /* wait for subreq completion */
 175                 tevent_req_set_callback(cc_state->subreq,
 176                                         btrfs_copy_chunk_done,
 177                                         req);
 178                 return req;
 179         }
 180
 181         DEBUG(5, ("BTRFS_IOC_CLONE_RANGE returned %d\n", ret));
 182         /* BTRFS_IOC_CLONE_RANGE is all or nothing */
 183         cc_state->copied = num;
 184         tevent_req_done(req);
 185         return tevent_req_post(req, ev);
 186 }
 187
 188 /* only used if the request is passed through to next VFS module */
 189 static void btrfs_copy_chunk_done(struct tevent_req *subreq)
 190 {
 191         struct tevent_req *req = tevent_req_callback_data(
 192                 subreq, struct tevent_req);
 193         struct btrfs_cc_state *cc_state = tevent_req_data(req,
 194                                                         struct btrfs_cc_state);
 195         NTSTATUS status;
 196
 197         status = SMB_VFS_NEXT_COPY_CHUNK_RECV(cc_state->handle,
 198                                               cc_state->subreq,
 199                                               &cc_state->copied);
 200         if (tevent_req_nterror(req, status)) {
 201                 return;
 202         }
 203         tevent_req_done(req);
 204 }
 205
 206 static NTSTATUS btrfs_copy_chunk_recv(struct vfs_handle_struct *handle,
 207                                       struct tevent_req *req,
 208                                       off_t *copied)
 209 {
 210         NTSTATUS status;
 211         struct btrfs_cc_state *cc_state = tevent_req_data(req,
 212                                                         struct btrfs_cc_state);
 213
 214         if (tevent_req_is_nterror(req, &status)) {
 215                 DEBUG(4, ("server side copy chunk failed: %s\n",
 216                           nt_errstr(status)));
 217                 tevent_req_received(req);
 218                 return status;
 219         }
 220
 221         DEBUG(10, ("server side copy chunk copied %llu\n",
 222                    (unsigned long long)cc_state->copied));
 223         *copied = cc_state->copied;
 224         tevent_req_received(req);
 225         return NT_STATUS_OK;
 226 }
 227
 228 /*
 229  * caller must pass a non-null fsp or smb_fname. If fsp is null, then
 230  * fall back to opening the corresponding file to issue the ioctl.
 231  */
 232 static NTSTATUS btrfs_get_compression(struct vfs_handle_struct *handle,
 233                                       TALLOC_CTX *mem_ctx,
 234                                       struct files_struct *fsp,
 235                                       struct smb_filename *smb_fname,
 236                                       uint16_t *_compression_fmt)
 237 {
 238         int ret;
 239         long flags = 0;
 240         int fd;
 241         bool opened = false;
 242         NTSTATUS status;
 243
 244         if ((fsp != NULL) && (fsp->fh->fd != -1)) {
 245                 fd = fsp->fh->fd;
 246         } else if (smb_fname != NULL) {
 247                 if (S_ISDIR(smb_fname->st.st_ex_mode)) {
 248                         DIR *dir = opendir(smb_fname->base_name);
 249                         if (dir == NULL) {
 250                                 return NT_STATUS_UNSUCCESSFUL;
 251                         }
 252                         fd = dirfd(dir);
 253                 } else {
 254                         fd = open(smb_fname->base_name, O_RDONLY);
 255                 }
 256                 if (fd < 0) {
 257                         return NT_STATUS_UNSUCCESSFUL;
 258                 }
 259                 opened = true;
 260         } else {
 261                 return NT_STATUS_INVALID_PARAMETER;
 262         }
 263
 264         ret = ioctl(fd, FS_IOC_GETFLAGS, &flags);
 265         if (ret < 0) {
 266                 DEBUG(1, ("FS_IOC_GETFLAGS failed: %s, fd %lld\n",
 267                           strerror(errno), (long long)fd));
 268                 status = map_nt_error_from_unix(errno);
 269                 goto err_close;
 270         }
 271         if (flags & FS_COMPR_FL) {
 272                 *_compression_fmt = COMPRESSION_FORMAT_LZNT1;
 273         } else {
 274                 *_compression_fmt = COMPRESSION_FORMAT_NONE;
 275         }
 276         status = NT_STATUS_OK;
 277 err_close:
 278         if (opened) {
 279                 close(fd);
 280         }
 281
 282         return status;
 283 }
 284
 285 static NTSTATUS btrfs_set_compression(struct vfs_handle_struct *handle,
 286                                       TALLOC_CTX *mem_ctx,
 287                                       struct files_struct *fsp,
 288                                       uint16_t compression_fmt)
 289 {
 290         int ret;
 291         long flags = 0;
 292         int fd;
 293         NTSTATUS status;
 294
 295         if ((fsp == NULL) || (fsp->fh->fd == -1)) {
 296                 status = NT_STATUS_INVALID_PARAMETER;
 297                 goto err_out;
 298         }
 299         fd = fsp->fh->fd;
 300
 301         ret = ioctl(fd, FS_IOC_GETFLAGS, &flags);
 302         if (ret < 0) {
 303                 DEBUG(1, ("FS_IOC_GETFLAGS failed: %s, fd %d\n",
 304                           strerror(errno), fd));
 305                 status = map_nt_error_from_unix(errno);
 306                 goto err_out;
 307         }
 308
 309         if (compression_fmt == COMPRESSION_FORMAT_NONE) {
 310                 DEBUG(5, ("setting compression\n"));
 311                 flags &= (~FS_COMPR_FL);
 312         } else if ((compression_fmt == COMPRESSION_FORMAT_DEFAULT)
 313                 || (compression_fmt == COMPRESSION_FORMAT_LZNT1)) {
 314                 DEBUG(5, ("clearing compression\n"));
 315                 flags |= FS_COMPR_FL;
 316         } else {
 317                 DEBUG(1, ("invalid compression format 0x%x\n",
 318                           (int)compression_fmt));
 319                 status = NT_STATUS_INVALID_PARAMETER;
 320                 goto err_out;
 321         }
 322
 323         ret = ioctl(fd, FS_IOC_SETFLAGS, &flags);
 324         if (ret < 0) {
 325                 DEBUG(1, ("FS_IOC_SETFLAGS failed: %s, fd %d\n",
 326                           strerror(errno), fd));
 327                 status = map_nt_error_from_unix(errno);
 328                 goto err_out;
 329         }
 330         status = NT_STATUS_OK;
 331 err_out:
 332         return status;
 333 }
 334
 335
 336 static struct vfs_fn_pointers btrfs_fns = {
 337         .fs_capabilities_fn = btrfs_fs_capabilities,
 338         .copy_chunk_send_fn = btrfs_copy_chunk_send,
 339         .copy_chunk_recv_fn = btrfs_copy_chunk_recv,
 340         .get_compression_fn = btrfs_get_compression,
 341         .set_compression_fn = btrfs_set_compression,
 342 };
 343
 344 NTSTATUS vfs_btrfs_init(void);
 345 NTSTATUS vfs_btrfs_init(void)
 346 {
 347         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION,
 348                                 "btrfs", &btrfs_fns);
 349 }