| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Copyright (C) STRATO AG 2012. All rights reserved. |
| 4 | */ |
| 5 | |
| 6 | #include <linux/sched.h> |
| 7 | #include <linux/bio.h> |
| 8 | #include <linux/slab.h> |
| 9 | #include <linux/blkdev.h> |
| 10 | #include <linux/kthread.h> |
| 11 | #include <linux/math64.h> |
| 12 | #include "misc.h" |
| 13 | #include "ctree.h" |
| 14 | #include "extent_map.h" |
| 15 | #include "disk-io.h" |
| 16 | #include "transaction.h" |
| 17 | #include "print-tree.h" |
| 18 | #include "volumes.h" |
| 19 | #include "async-thread.h" |
| 20 | #include "check-integrity.h" |
| 21 | #include "rcu-string.h" |
| 22 | #include "dev-replace.h" |
| 23 | #include "sysfs.h" |
| 24 | |
| 25 | /* |
| 26 | * Device replace overview |
| 27 | * |
| 28 | * [Objective] |
| 29 | * To copy all extents (both new and on-disk) from source device to target |
| 30 | * device, while still keeping the filesystem read-write. |
| 31 | * |
| 32 | * [Method] |
| 33 | * There are two main methods involved: |
| 34 | * |
| 35 | * - Write duplication |
| 36 | * |
| 37 | * All new writes will be written to both target and source devices, so even |
| 38 | * if replace gets canceled, sources device still contans up-to-date data. |
| 39 | * |
| 40 | * Location: handle_ops_on_dev_replace() from __btrfs_map_block() |
| 41 | * Start: btrfs_dev_replace_start() |
| 42 | * End: btrfs_dev_replace_finishing() |
| 43 | * Content: Latest data/metadata |
| 44 | * |
| 45 | * - Copy existing extents |
| 46 | * |
| 47 | * This happens by re-using scrub facility, as scrub also iterates through |
| 48 | * existing extents from commit root. |
| 49 | * |
| 50 | * Location: scrub_write_block_to_dev_replace() from |
| 51 | * scrub_block_complete() |
| 52 | * Content: Data/meta from commit root. |
| 53 | * |
| 54 | * Due to the content difference, we need to avoid nocow write when dev-replace |
| 55 | * is happening. This is done by marking the block group read-only and waiting |
| 56 | * for NOCOW writes. |
| 57 | * |
| 58 | * After replace is done, the finishing part is done by swapping the target and |
| 59 | * source devices. |
| 60 | * |
| 61 | * Location: btrfs_dev_replace_update_device_in_mapping_tree() from |
| 62 | * btrfs_dev_replace_finishing() |
| 63 | */ |
| 64 | |
| 65 | static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, |
| 66 | int scrub_ret); |
| 67 | static void btrfs_dev_replace_update_device_in_mapping_tree( |
| 68 | struct btrfs_fs_info *fs_info, |
| 69 | struct btrfs_device *srcdev, |
| 70 | struct btrfs_device *tgtdev); |
| 71 | static int btrfs_dev_replace_kthread(void *data); |
| 72 | |
| 73 | int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) |
| 74 | { |
| 75 | struct btrfs_key key; |
| 76 | struct btrfs_root *dev_root = fs_info->dev_root; |
| 77 | struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; |
| 78 | struct extent_buffer *eb; |
| 79 | int slot; |
| 80 | int ret = 0; |
| 81 | struct btrfs_path *path = NULL; |
| 82 | int item_size; |
| 83 | struct btrfs_dev_replace_item *ptr; |
| 84 | u64 src_devid; |
| 85 | |
| 86 | path = btrfs_alloc_path(); |
| 87 | if (!path) { |
| 88 | ret = -ENOMEM; |
| 89 | goto out; |
| 90 | } |
| 91 | |
| 92 | key.objectid = 0; |
| 93 | key.type = BTRFS_DEV_REPLACE_KEY; |
| 94 | key.offset = 0; |
| 95 | ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); |
| 96 | if (ret) { |
| 97 | no_valid_dev_replace_entry_found: |
| 98 | ret = 0; |
| 99 | dev_replace->replace_state = |
| 100 | BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED; |
| 101 | dev_replace->cont_reading_from_srcdev_mode = |
| 102 | BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS; |
| 103 | dev_replace->time_started = 0; |
| 104 | dev_replace->time_stopped = 0; |
| 105 | atomic64_set(&dev_replace->num_write_errors, 0); |
| 106 | atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); |
| 107 | dev_replace->cursor_left = 0; |
| 108 | dev_replace->committed_cursor_left = 0; |
| 109 | dev_replace->cursor_left_last_write_of_item = 0; |
| 110 | dev_replace->cursor_right = 0; |
| 111 | dev_replace->srcdev = NULL; |
| 112 | dev_replace->tgtdev = NULL; |
| 113 | dev_replace->is_valid = 0; |
| 114 | dev_replace->item_needs_writeback = 0; |
| 115 | goto out; |
| 116 | } |
| 117 | slot = path->slots[0]; |
| 118 | eb = path->nodes[0]; |
| 119 | item_size = btrfs_item_size_nr(eb, slot); |
| 120 | ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item); |
| 121 | |
| 122 | if (item_size != sizeof(struct btrfs_dev_replace_item)) { |
| 123 | btrfs_warn(fs_info, |
| 124 | "dev_replace entry found has unexpected size, ignore entry"); |
| 125 | goto no_valid_dev_replace_entry_found; |
| 126 | } |
| 127 | |
| 128 | src_devid = btrfs_dev_replace_src_devid(eb, ptr); |
| 129 | dev_replace->cont_reading_from_srcdev_mode = |
| 130 | btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr); |
| 131 | dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr); |
| 132 | dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr); |
| 133 | dev_replace->time_stopped = |
| 134 | btrfs_dev_replace_time_stopped(eb, ptr); |
| 135 | atomic64_set(&dev_replace->num_write_errors, |
| 136 | btrfs_dev_replace_num_write_errors(eb, ptr)); |
| 137 | atomic64_set(&dev_replace->num_uncorrectable_read_errors, |
| 138 | btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr)); |
| 139 | dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr); |
| 140 | dev_replace->committed_cursor_left = dev_replace->cursor_left; |
| 141 | dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left; |
| 142 | dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr); |
| 143 | dev_replace->is_valid = 1; |
| 144 | |
| 145 | dev_replace->item_needs_writeback = 0; |
| 146 | switch (dev_replace->replace_state) { |
| 147 | case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: |
| 148 | case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: |
| 149 | case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: |
| 150 | dev_replace->srcdev = NULL; |
| 151 | dev_replace->tgtdev = NULL; |
| 152 | break; |
| 153 | case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: |
| 154 | case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: |
| 155 | dev_replace->srcdev = btrfs_find_device(fs_info->fs_devices, |
| 156 | src_devid, NULL, NULL, true); |
| 157 | dev_replace->tgtdev = btrfs_find_device(fs_info->fs_devices, |
| 158 | BTRFS_DEV_REPLACE_DEVID, |
| 159 | NULL, NULL, true); |
| 160 | /* |
| 161 | * allow 'btrfs dev replace_cancel' if src/tgt device is |
| 162 | * missing |
| 163 | */ |
| 164 | if (!dev_replace->srcdev && |
| 165 | !btrfs_test_opt(fs_info, DEGRADED)) { |
| 166 | ret = -EIO; |
| 167 | btrfs_warn(fs_info, |
| 168 | "cannot mount because device replace operation is ongoing and"); |
| 169 | btrfs_warn(fs_info, |
| 170 | "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?", |
| 171 | src_devid); |
| 172 | } |
| 173 | if (!dev_replace->tgtdev && |
| 174 | !btrfs_test_opt(fs_info, DEGRADED)) { |
| 175 | ret = -EIO; |
| 176 | btrfs_warn(fs_info, |
| 177 | "cannot mount because device replace operation is ongoing and"); |
| 178 | btrfs_warn(fs_info, |
| 179 | "tgtdev (devid %llu) is missing, need to run 'btrfs dev scan'?", |
| 180 | BTRFS_DEV_REPLACE_DEVID); |
| 181 | } |
| 182 | if (dev_replace->tgtdev) { |
| 183 | if (dev_replace->srcdev) { |
| 184 | dev_replace->tgtdev->total_bytes = |
| 185 | dev_replace->srcdev->total_bytes; |
| 186 | dev_replace->tgtdev->disk_total_bytes = |
| 187 | dev_replace->srcdev->disk_total_bytes; |
| 188 | dev_replace->tgtdev->commit_total_bytes = |
| 189 | dev_replace->srcdev->commit_total_bytes; |
| 190 | dev_replace->tgtdev->bytes_used = |
| 191 | dev_replace->srcdev->bytes_used; |
| 192 | dev_replace->tgtdev->commit_bytes_used = |
| 193 | dev_replace->srcdev->commit_bytes_used; |
| 194 | } |
| 195 | set_bit(BTRFS_DEV_STATE_REPLACE_TGT, |
| 196 | &dev_replace->tgtdev->dev_state); |
| 197 | |
| 198 | WARN_ON(fs_info->fs_devices->rw_devices == 0); |
| 199 | dev_replace->tgtdev->io_width = fs_info->sectorsize; |
| 200 | dev_replace->tgtdev->io_align = fs_info->sectorsize; |
| 201 | dev_replace->tgtdev->sector_size = fs_info->sectorsize; |
| 202 | dev_replace->tgtdev->fs_info = fs_info; |
| 203 | set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, |
| 204 | &dev_replace->tgtdev->dev_state); |
| 205 | } |
| 206 | break; |
| 207 | } |
| 208 | |
| 209 | out: |
| 210 | btrfs_free_path(path); |
| 211 | return ret; |
| 212 | } |
| 213 | |
| 214 | /* |
| 215 | * Initialize a new device for device replace target from a given source dev |
| 216 | * and path. |
| 217 | * |
| 218 | * Return 0 and new device in @device_out, otherwise return < 0 |
| 219 | */ |
| 220 | static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info, |
| 221 | const char *device_path, |
| 222 | struct btrfs_device *srcdev, |
| 223 | struct btrfs_device **device_out) |
| 224 | { |
| 225 | struct btrfs_device *device; |
| 226 | struct block_device *bdev; |
| 227 | struct list_head *devices; |
| 228 | struct rcu_string *name; |
| 229 | u64 devid = BTRFS_DEV_REPLACE_DEVID; |
| 230 | int ret = 0; |
| 231 | |
| 232 | *device_out = NULL; |
| 233 | if (fs_info->fs_devices->seeding) { |
| 234 | btrfs_err(fs_info, "the filesystem is a seed filesystem!"); |
| 235 | return -EINVAL; |
| 236 | } |
| 237 | |
| 238 | bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL, |
| 239 | fs_info->bdev_holder); |
| 240 | if (IS_ERR(bdev)) { |
| 241 | btrfs_err(fs_info, "target device %s is invalid!", device_path); |
| 242 | return PTR_ERR(bdev); |
| 243 | } |
| 244 | |
| 245 | sync_blockdev(bdev); |
| 246 | |
| 247 | devices = &fs_info->fs_devices->devices; |
| 248 | list_for_each_entry(device, devices, dev_list) { |
| 249 | if (device->bdev == bdev) { |
| 250 | btrfs_err(fs_info, |
| 251 | "target device is in the filesystem!"); |
| 252 | ret = -EEXIST; |
| 253 | goto error; |
| 254 | } |
| 255 | } |
| 256 | |
| 257 | |
| 258 | if (i_size_read(bdev->bd_inode) < |
| 259 | btrfs_device_get_total_bytes(srcdev)) { |
| 260 | btrfs_err(fs_info, |
| 261 | "target device is smaller than source device!"); |
| 262 | ret = -EINVAL; |
| 263 | goto error; |
| 264 | } |
| 265 | |
| 266 | |
| 267 | device = btrfs_alloc_device(NULL, &devid, NULL); |
| 268 | if (IS_ERR(device)) { |
| 269 | ret = PTR_ERR(device); |
| 270 | goto error; |
| 271 | } |
| 272 | |
| 273 | name = rcu_string_strdup(device_path, GFP_KERNEL); |
| 274 | if (!name) { |
| 275 | btrfs_free_device(device); |
| 276 | ret = -ENOMEM; |
| 277 | goto error; |
| 278 | } |
| 279 | rcu_assign_pointer(device->name, name); |
| 280 | |
| 281 | set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); |
| 282 | device->generation = 0; |
| 283 | device->io_width = fs_info->sectorsize; |
| 284 | device->io_align = fs_info->sectorsize; |
| 285 | device->sector_size = fs_info->sectorsize; |
| 286 | device->total_bytes = btrfs_device_get_total_bytes(srcdev); |
| 287 | device->disk_total_bytes = btrfs_device_get_disk_total_bytes(srcdev); |
| 288 | device->bytes_used = btrfs_device_get_bytes_used(srcdev); |
| 289 | device->commit_total_bytes = srcdev->commit_total_bytes; |
| 290 | device->commit_bytes_used = device->bytes_used; |
| 291 | device->fs_info = fs_info; |
| 292 | device->bdev = bdev; |
| 293 | set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); |
| 294 | set_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); |
| 295 | device->mode = FMODE_EXCL; |
| 296 | device->dev_stats_valid = 1; |
| 297 | set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE); |
| 298 | device->fs_devices = fs_info->fs_devices; |
| 299 | |
| 300 | mutex_lock(&fs_info->fs_devices->device_list_mutex); |
| 301 | list_add(&device->dev_list, &fs_info->fs_devices->devices); |
| 302 | fs_info->fs_devices->num_devices++; |
| 303 | fs_info->fs_devices->open_devices++; |
| 304 | mutex_unlock(&fs_info->fs_devices->device_list_mutex); |
| 305 | |
| 306 | *device_out = device; |
| 307 | return 0; |
| 308 | |
| 309 | error: |
| 310 | blkdev_put(bdev, FMODE_EXCL); |
| 311 | return ret; |
| 312 | } |
| 313 | |
| 314 | /* |
| 315 | * called from commit_transaction. Writes changed device replace state to |
| 316 | * disk. |
| 317 | */ |
| 318 | int btrfs_run_dev_replace(struct btrfs_trans_handle *trans) |
| 319 | { |
| 320 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 321 | int ret; |
| 322 | struct btrfs_root *dev_root = fs_info->dev_root; |
| 323 | struct btrfs_path *path; |
| 324 | struct btrfs_key key; |
| 325 | struct extent_buffer *eb; |
| 326 | struct btrfs_dev_replace_item *ptr; |
| 327 | struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; |
| 328 | |
| 329 | down_read(&dev_replace->rwsem); |
| 330 | if (!dev_replace->is_valid || |
| 331 | !dev_replace->item_needs_writeback) { |
| 332 | up_read(&dev_replace->rwsem); |
| 333 | return 0; |
| 334 | } |
| 335 | up_read(&dev_replace->rwsem); |
| 336 | |
| 337 | key.objectid = 0; |
| 338 | key.type = BTRFS_DEV_REPLACE_KEY; |
| 339 | key.offset = 0; |
| 340 | |
| 341 | path = btrfs_alloc_path(); |
| 342 | if (!path) { |
| 343 | ret = -ENOMEM; |
| 344 | goto out; |
| 345 | } |
| 346 | ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); |
| 347 | if (ret < 0) { |
| 348 | btrfs_warn(fs_info, |
| 349 | "error %d while searching for dev_replace item!", |
| 350 | ret); |
| 351 | goto out; |
| 352 | } |
| 353 | |
| 354 | if (ret == 0 && |
| 355 | btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { |
| 356 | /* |
| 357 | * need to delete old one and insert a new one. |
| 358 | * Since no attempt is made to recover any old state, if the |
| 359 | * dev_replace state is 'running', the data on the target |
| 360 | * drive is lost. |
| 361 | * It would be possible to recover the state: just make sure |
| 362 | * that the beginning of the item is never changed and always |
| 363 | * contains all the essential information. Then read this |
| 364 | * minimal set of information and use it as a base for the |
| 365 | * new state. |
| 366 | */ |
| 367 | ret = btrfs_del_item(trans, dev_root, path); |
| 368 | if (ret != 0) { |
| 369 | btrfs_warn(fs_info, |
| 370 | "delete too small dev_replace item failed %d!", |
| 371 | ret); |
| 372 | goto out; |
| 373 | } |
| 374 | ret = 1; |
| 375 | } |
| 376 | |
| 377 | if (ret == 1) { |
| 378 | /* need to insert a new item */ |
| 379 | btrfs_release_path(path); |
| 380 | ret = btrfs_insert_empty_item(trans, dev_root, path, |
| 381 | &key, sizeof(*ptr)); |
| 382 | if (ret < 0) { |
| 383 | btrfs_warn(fs_info, |
| 384 | "insert dev_replace item failed %d!", ret); |
| 385 | goto out; |
| 386 | } |
| 387 | } |
| 388 | |
| 389 | eb = path->nodes[0]; |
| 390 | ptr = btrfs_item_ptr(eb, path->slots[0], |
| 391 | struct btrfs_dev_replace_item); |
| 392 | |
| 393 | down_write(&dev_replace->rwsem); |
| 394 | if (dev_replace->srcdev) |
| 395 | btrfs_set_dev_replace_src_devid(eb, ptr, |
| 396 | dev_replace->srcdev->devid); |
| 397 | else |
| 398 | btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); |
| 399 | btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, |
| 400 | dev_replace->cont_reading_from_srcdev_mode); |
| 401 | btrfs_set_dev_replace_replace_state(eb, ptr, |
| 402 | dev_replace->replace_state); |
| 403 | btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); |
| 404 | btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); |
| 405 | btrfs_set_dev_replace_num_write_errors(eb, ptr, |
| 406 | atomic64_read(&dev_replace->num_write_errors)); |
| 407 | btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, |
| 408 | atomic64_read(&dev_replace->num_uncorrectable_read_errors)); |
| 409 | dev_replace->cursor_left_last_write_of_item = |
| 410 | dev_replace->cursor_left; |
| 411 | btrfs_set_dev_replace_cursor_left(eb, ptr, |
| 412 | dev_replace->cursor_left_last_write_of_item); |
| 413 | btrfs_set_dev_replace_cursor_right(eb, ptr, |
| 414 | dev_replace->cursor_right); |
| 415 | dev_replace->item_needs_writeback = 0; |
| 416 | up_write(&dev_replace->rwsem); |
| 417 | |
| 418 | btrfs_mark_buffer_dirty(eb); |
| 419 | |
| 420 | out: |
| 421 | btrfs_free_path(path); |
| 422 | |
| 423 | return ret; |
| 424 | } |
| 425 | |
| 426 | static char* btrfs_dev_name(struct btrfs_device *device) |
| 427 | { |
| 428 | if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) |
| 429 | return "<missing disk>"; |
| 430 | else |
| 431 | return rcu_str_deref(device->name); |
| 432 | } |
| 433 | |
| 434 | static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, |
| 435 | const char *tgtdev_name, u64 srcdevid, const char *srcdev_name, |
| 436 | int read_src) |
| 437 | { |
| 438 | struct btrfs_root *root = fs_info->dev_root; |
| 439 | struct btrfs_trans_handle *trans; |
| 440 | struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; |
| 441 | int ret; |
| 442 | struct btrfs_device *tgt_device = NULL; |
| 443 | struct btrfs_device *src_device = NULL; |
| 444 | |
| 445 | src_device = btrfs_find_device_by_devspec(fs_info, srcdevid, |
| 446 | srcdev_name); |
| 447 | if (IS_ERR(src_device)) |
| 448 | return PTR_ERR(src_device); |
| 449 | |
| 450 | if (btrfs_pinned_by_swapfile(fs_info, src_device)) { |
| 451 | btrfs_warn_in_rcu(fs_info, |
| 452 | "cannot replace device %s (devid %llu) due to active swapfile", |
| 453 | btrfs_dev_name(src_device), src_device->devid); |
| 454 | return -ETXTBSY; |
| 455 | } |
| 456 | |
| 457 | /* |
| 458 | * Here we commit the transaction to make sure commit_total_bytes |
| 459 | * of all the devices are updated. |
| 460 | */ |
| 461 | trans = btrfs_attach_transaction(root); |
| 462 | if (!IS_ERR(trans)) { |
| 463 | ret = btrfs_commit_transaction(trans); |
| 464 | if (ret) |
| 465 | return ret; |
| 466 | } else if (PTR_ERR(trans) != -ENOENT) { |
| 467 | return PTR_ERR(trans); |
| 468 | } |
| 469 | |
| 470 | ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name, |
| 471 | src_device, &tgt_device); |
| 472 | if (ret) |
| 473 | return ret; |
| 474 | |
| 475 | down_write(&dev_replace->rwsem); |
| 476 | switch (dev_replace->replace_state) { |
| 477 | case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: |
| 478 | case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: |
| 479 | case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: |
| 480 | break; |
| 481 | case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: |
| 482 | case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: |
| 483 | ASSERT(0); |
| 484 | ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; |
| 485 | up_write(&dev_replace->rwsem); |
| 486 | goto leave; |
| 487 | } |
| 488 | |
| 489 | dev_replace->cont_reading_from_srcdev_mode = read_src; |
| 490 | dev_replace->srcdev = src_device; |
| 491 | dev_replace->tgtdev = tgt_device; |
| 492 | |
| 493 | btrfs_info_in_rcu(fs_info, |
| 494 | "dev_replace from %s (devid %llu) to %s started", |
| 495 | btrfs_dev_name(src_device), |
| 496 | src_device->devid, |
| 497 | rcu_str_deref(tgt_device->name)); |
| 498 | |
| 499 | /* |
| 500 | * from now on, the writes to the srcdev are all duplicated to |
| 501 | * go to the tgtdev as well (refer to btrfs_map_block()). |
| 502 | */ |
| 503 | dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; |
| 504 | dev_replace->time_started = ktime_get_real_seconds(); |
| 505 | dev_replace->cursor_left = 0; |
| 506 | dev_replace->committed_cursor_left = 0; |
| 507 | dev_replace->cursor_left_last_write_of_item = 0; |
| 508 | dev_replace->cursor_right = 0; |
| 509 | dev_replace->is_valid = 1; |
| 510 | dev_replace->item_needs_writeback = 1; |
| 511 | atomic64_set(&dev_replace->num_write_errors, 0); |
| 512 | atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); |
| 513 | up_write(&dev_replace->rwsem); |
| 514 | |
| 515 | ret = btrfs_sysfs_add_devices_dir(tgt_device->fs_devices, tgt_device); |
| 516 | if (ret) |
| 517 | btrfs_err(fs_info, "kobj add dev failed %d", ret); |
| 518 | |
| 519 | btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); |
| 520 | |
| 521 | /* Commit dev_replace state and reserve 1 item for it. */ |
| 522 | trans = btrfs_start_transaction(root, 1); |
| 523 | if (IS_ERR(trans)) { |
| 524 | ret = PTR_ERR(trans); |
| 525 | down_write(&dev_replace->rwsem); |
| 526 | dev_replace->replace_state = |
| 527 | BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED; |
| 528 | dev_replace->srcdev = NULL; |
| 529 | dev_replace->tgtdev = NULL; |
| 530 | up_write(&dev_replace->rwsem); |
| 531 | goto leave; |
| 532 | } |
| 533 | |
| 534 | ret = btrfs_commit_transaction(trans); |
| 535 | WARN_ON(ret); |
| 536 | |
| 537 | /* the disk copy procedure reuses the scrub code */ |
| 538 | ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, |
| 539 | btrfs_device_get_total_bytes(src_device), |
| 540 | &dev_replace->scrub_progress, 0, 1); |
| 541 | |
| 542 | ret = btrfs_dev_replace_finishing(fs_info, ret); |
| 543 | if (ret == -EINPROGRESS) |
| 544 | ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS; |
| 545 | |
| 546 | return ret; |
| 547 | |
| 548 | leave: |
| 549 | btrfs_destroy_dev_replace_tgtdev(tgt_device); |
| 550 | return ret; |
| 551 | } |
| 552 | |
| 553 | int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info, |
| 554 | struct btrfs_ioctl_dev_replace_args *args) |
| 555 | { |
| 556 | int ret; |
| 557 | |
| 558 | switch (args->start.cont_reading_from_srcdev_mode) { |
| 559 | case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: |
| 560 | case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: |
| 561 | break; |
| 562 | default: |
| 563 | return -EINVAL; |
| 564 | } |
| 565 | |
| 566 | if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || |
| 567 | args->start.tgtdev_name[0] == '\0') |
| 568 | return -EINVAL; |
| 569 | |
| 570 | ret = btrfs_dev_replace_start(fs_info, args->start.tgtdev_name, |
| 571 | args->start.srcdevid, |
| 572 | args->start.srcdev_name, |
| 573 | args->start.cont_reading_from_srcdev_mode); |
| 574 | args->result = ret; |
| 575 | /* don't warn if EINPROGRESS, someone else might be running scrub */ |
| 576 | if (ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS || |
| 577 | ret == BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR) |
| 578 | return 0; |
| 579 | |
| 580 | return ret; |
| 581 | } |
| 582 | |
| 583 | /* |
| 584 | * blocked until all in-flight bios operations are finished. |
| 585 | */ |
| 586 | static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) |
| 587 | { |
| 588 | set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); |
| 589 | wait_event(fs_info->dev_replace.replace_wait, !percpu_counter_sum( |
| 590 | &fs_info->dev_replace.bio_counter)); |
| 591 | } |
| 592 | |
| 593 | /* |
| 594 | * we have removed target device, it is safe to allow new bios request. |
| 595 | */ |
| 596 | static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) |
| 597 | { |
| 598 | clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); |
| 599 | wake_up(&fs_info->dev_replace.replace_wait); |
| 600 | } |
| 601 | |
| 602 | /* |
| 603 | * When finishing the device replace, before swapping the source device with the |
| 604 | * target device we must update the chunk allocation state in the target device, |
| 605 | * as it is empty because replace works by directly copying the chunks and not |
| 606 | * through the normal chunk allocation path. |
| 607 | */ |
| 608 | static int btrfs_set_target_alloc_state(struct btrfs_device *srcdev, |
| 609 | struct btrfs_device *tgtdev) |
| 610 | { |
| 611 | struct extent_state *cached_state = NULL; |
| 612 | u64 start = 0; |
| 613 | u64 found_start; |
| 614 | u64 found_end; |
| 615 | int ret = 0; |
| 616 | |
| 617 | lockdep_assert_held(&srcdev->fs_info->chunk_mutex); |
| 618 | |
| 619 | while (!find_first_extent_bit(&srcdev->alloc_state, start, |
| 620 | &found_start, &found_end, |
| 621 | CHUNK_ALLOCATED, &cached_state)) { |
| 622 | ret = set_extent_bits(&tgtdev->alloc_state, found_start, |
| 623 | found_end, CHUNK_ALLOCATED); |
| 624 | if (ret) |
| 625 | break; |
| 626 | start = found_end + 1; |
| 627 | } |
| 628 | |
| 629 | free_extent_state(cached_state); |
| 630 | return ret; |
| 631 | } |
| 632 | |
| 633 | static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, |
| 634 | int scrub_ret) |
| 635 | { |
| 636 | struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; |
| 637 | struct btrfs_device *tgt_device; |
| 638 | struct btrfs_device *src_device; |
| 639 | struct btrfs_root *root = fs_info->tree_root; |
| 640 | u8 uuid_tmp[BTRFS_UUID_SIZE]; |
| 641 | struct btrfs_trans_handle *trans; |
| 642 | int ret = 0; |
| 643 | |
| 644 | /* don't allow cancel or unmount to disturb the finishing procedure */ |
| 645 | mutex_lock(&dev_replace->lock_finishing_cancel_unmount); |
| 646 | |
| 647 | down_read(&dev_replace->rwsem); |
| 648 | /* was the operation canceled, or is it finished? */ |
| 649 | if (dev_replace->replace_state != |
| 650 | BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { |
| 651 | up_read(&dev_replace->rwsem); |
| 652 | mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); |
| 653 | return 0; |
| 654 | } |
| 655 | |
| 656 | tgt_device = dev_replace->tgtdev; |
| 657 | src_device = dev_replace->srcdev; |
| 658 | up_read(&dev_replace->rwsem); |
| 659 | |
| 660 | /* |
| 661 | * flush all outstanding I/O and inode extent mappings before the |
| 662 | * copy operation is declared as being finished |
| 663 | */ |
| 664 | ret = btrfs_start_delalloc_roots(fs_info, U64_MAX); |
| 665 | if (ret) { |
| 666 | mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); |
| 667 | return ret; |
| 668 | } |
| 669 | btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); |
| 670 | |
| 671 | /* |
| 672 | * We have to use this loop approach because at this point src_device |
| 673 | * has to be available for transaction commit to complete, yet new |
| 674 | * chunks shouldn't be allocated on the device. |
| 675 | */ |
| 676 | while (1) { |
| 677 | trans = btrfs_start_transaction(root, 0); |
| 678 | if (IS_ERR(trans)) { |
| 679 | mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); |
| 680 | return PTR_ERR(trans); |
| 681 | } |
| 682 | ret = btrfs_commit_transaction(trans); |
| 683 | WARN_ON(ret); |
| 684 | |
| 685 | /* Prevent write_all_supers() during the finishing procedure */ |
| 686 | mutex_lock(&fs_info->fs_devices->device_list_mutex); |
| 687 | /* Prevent new chunks being allocated on the source device */ |
| 688 | mutex_lock(&fs_info->chunk_mutex); |
| 689 | |
| 690 | if (!list_empty(&src_device->post_commit_list)) { |
| 691 | mutex_unlock(&fs_info->fs_devices->device_list_mutex); |
| 692 | mutex_unlock(&fs_info->chunk_mutex); |
| 693 | } else { |
| 694 | break; |
| 695 | } |
| 696 | } |
| 697 | |
| 698 | down_write(&dev_replace->rwsem); |
| 699 | dev_replace->replace_state = |
| 700 | scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED |
| 701 | : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; |
| 702 | dev_replace->tgtdev = NULL; |
| 703 | dev_replace->srcdev = NULL; |
| 704 | dev_replace->time_stopped = ktime_get_real_seconds(); |
| 705 | dev_replace->item_needs_writeback = 1; |
| 706 | |
| 707 | /* |
| 708 | * Update allocation state in the new device and replace the old device |
| 709 | * with the new one in the mapping tree. |
| 710 | */ |
| 711 | if (!scrub_ret) { |
| 712 | scrub_ret = btrfs_set_target_alloc_state(src_device, tgt_device); |
| 713 | if (scrub_ret) |
| 714 | goto error; |
| 715 | btrfs_dev_replace_update_device_in_mapping_tree(fs_info, |
| 716 | src_device, |
| 717 | tgt_device); |
| 718 | } else { |
| 719 | if (scrub_ret != -ECANCELED) |
| 720 | btrfs_err_in_rcu(fs_info, |
| 721 | "btrfs_scrub_dev(%s, %llu, %s) failed %d", |
| 722 | btrfs_dev_name(src_device), |
| 723 | src_device->devid, |
| 724 | rcu_str_deref(tgt_device->name), scrub_ret); |
| 725 | error: |
| 726 | up_write(&dev_replace->rwsem); |
| 727 | mutex_unlock(&fs_info->chunk_mutex); |
| 728 | mutex_unlock(&fs_info->fs_devices->device_list_mutex); |
| 729 | btrfs_rm_dev_replace_blocked(fs_info); |
| 730 | if (tgt_device) |
| 731 | btrfs_destroy_dev_replace_tgtdev(tgt_device); |
| 732 | btrfs_rm_dev_replace_unblocked(fs_info); |
| 733 | mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); |
| 734 | |
| 735 | return scrub_ret; |
| 736 | } |
| 737 | |
| 738 | btrfs_info_in_rcu(fs_info, |
| 739 | "dev_replace from %s (devid %llu) to %s finished", |
| 740 | btrfs_dev_name(src_device), |
| 741 | src_device->devid, |
| 742 | rcu_str_deref(tgt_device->name)); |
| 743 | clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state); |
| 744 | tgt_device->devid = src_device->devid; |
| 745 | src_device->devid = BTRFS_DEV_REPLACE_DEVID; |
| 746 | memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); |
| 747 | memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); |
| 748 | memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); |
| 749 | btrfs_device_set_total_bytes(tgt_device, src_device->total_bytes); |
| 750 | btrfs_device_set_disk_total_bytes(tgt_device, |
| 751 | src_device->disk_total_bytes); |
| 752 | btrfs_device_set_bytes_used(tgt_device, src_device->bytes_used); |
| 753 | tgt_device->commit_bytes_used = src_device->bytes_used; |
| 754 | |
| 755 | btrfs_assign_next_active_device(src_device, tgt_device); |
| 756 | |
| 757 | list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); |
| 758 | fs_info->fs_devices->rw_devices++; |
| 759 | |
| 760 | up_write(&dev_replace->rwsem); |
| 761 | btrfs_rm_dev_replace_blocked(fs_info); |
| 762 | |
| 763 | btrfs_rm_dev_replace_remove_srcdev(src_device); |
| 764 | |
| 765 | btrfs_rm_dev_replace_unblocked(fs_info); |
| 766 | |
| 767 | /* |
| 768 | * Increment dev_stats_ccnt so that btrfs_run_dev_stats() will |
| 769 | * update on-disk dev stats value during commit transaction |
| 770 | */ |
| 771 | atomic_inc(&tgt_device->dev_stats_ccnt); |
| 772 | |
| 773 | /* |
| 774 | * this is again a consistent state where no dev_replace procedure |
| 775 | * is running, the target device is part of the filesystem, the |
| 776 | * source device is not part of the filesystem anymore and its 1st |
| 777 | * superblock is scratched out so that it is no longer marked to |
| 778 | * belong to this filesystem. |
| 779 | */ |
| 780 | mutex_unlock(&fs_info->chunk_mutex); |
| 781 | mutex_unlock(&fs_info->fs_devices->device_list_mutex); |
| 782 | |
| 783 | /* replace the sysfs entry */ |
| 784 | btrfs_sysfs_remove_devices_dir(fs_info->fs_devices, src_device); |
| 785 | btrfs_sysfs_update_devid(tgt_device); |
| 786 | if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &src_device->dev_state)) |
| 787 | btrfs_scratch_superblocks(fs_info, src_device->bdev, |
| 788 | src_device->name->str); |
| 789 | |
| 790 | /* write back the superblocks */ |
| 791 | trans = btrfs_start_transaction(root, 0); |
| 792 | if (!IS_ERR(trans)) |
| 793 | btrfs_commit_transaction(trans); |
| 794 | |
| 795 | mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); |
| 796 | |
| 797 | btrfs_rm_dev_replace_free_srcdev(src_device); |
| 798 | |
| 799 | return 0; |
| 800 | } |
| 801 | |
| 802 | static void btrfs_dev_replace_update_device_in_mapping_tree( |
| 803 | struct btrfs_fs_info *fs_info, |
| 804 | struct btrfs_device *srcdev, |
| 805 | struct btrfs_device *tgtdev) |
| 806 | { |
| 807 | struct extent_map_tree *em_tree = &fs_info->mapping_tree; |
| 808 | struct extent_map *em; |
| 809 | struct map_lookup *map; |
| 810 | u64 start = 0; |
| 811 | int i; |
| 812 | |
| 813 | write_lock(&em_tree->lock); |
| 814 | do { |
| 815 | em = lookup_extent_mapping(em_tree, start, (u64)-1); |
| 816 | if (!em) |
| 817 | break; |
| 818 | map = em->map_lookup; |
| 819 | for (i = 0; i < map->num_stripes; i++) |
| 820 | if (srcdev == map->stripes[i].dev) |
| 821 | map->stripes[i].dev = tgtdev; |
| 822 | start = em->start + em->len; |
| 823 | free_extent_map(em); |
| 824 | } while (start); |
| 825 | write_unlock(&em_tree->lock); |
| 826 | } |
| 827 | |
| 828 | /* |
| 829 | * Read progress of device replace status according to the state and last |
| 830 | * stored position. The value format is the same as for |
| 831 | * btrfs_dev_replace::progress_1000 |
| 832 | */ |
| 833 | static u64 btrfs_dev_replace_progress(struct btrfs_fs_info *fs_info) |
| 834 | { |
| 835 | struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; |
| 836 | u64 ret = 0; |
| 837 | |
| 838 | switch (dev_replace->replace_state) { |
| 839 | case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: |
| 840 | case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: |
| 841 | ret = 0; |
| 842 | break; |
| 843 | case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: |
| 844 | ret = 1000; |
| 845 | break; |
| 846 | case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: |
| 847 | case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: |
| 848 | ret = div64_u64(dev_replace->cursor_left, |
| 849 | div_u64(btrfs_device_get_total_bytes( |
| 850 | dev_replace->srcdev), 1000)); |
| 851 | break; |
| 852 | } |
| 853 | |
| 854 | return ret; |
| 855 | } |
| 856 | |
| 857 | void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, |
| 858 | struct btrfs_ioctl_dev_replace_args *args) |
| 859 | { |
| 860 | struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; |
| 861 | |
| 862 | down_read(&dev_replace->rwsem); |
| 863 | /* even if !dev_replace_is_valid, the values are good enough for |
| 864 | * the replace_status ioctl */ |
| 865 | args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; |
| 866 | args->status.replace_state = dev_replace->replace_state; |
| 867 | args->status.time_started = dev_replace->time_started; |
| 868 | args->status.time_stopped = dev_replace->time_stopped; |
| 869 | args->status.num_write_errors = |
| 870 | atomic64_read(&dev_replace->num_write_errors); |
| 871 | args->status.num_uncorrectable_read_errors = |
| 872 | atomic64_read(&dev_replace->num_uncorrectable_read_errors); |
| 873 | args->status.progress_1000 = btrfs_dev_replace_progress(fs_info); |
| 874 | up_read(&dev_replace->rwsem); |
| 875 | } |
| 876 | |
| 877 | int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) |
| 878 | { |
| 879 | struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; |
| 880 | struct btrfs_device *tgt_device = NULL; |
| 881 | struct btrfs_device *src_device = NULL; |
| 882 | struct btrfs_trans_handle *trans; |
| 883 | struct btrfs_root *root = fs_info->tree_root; |
| 884 | int result; |
| 885 | int ret; |
| 886 | |
| 887 | if (sb_rdonly(fs_info->sb)) |
| 888 | return -EROFS; |
| 889 | |
| 890 | mutex_lock(&dev_replace->lock_finishing_cancel_unmount); |
| 891 | down_write(&dev_replace->rwsem); |
| 892 | switch (dev_replace->replace_state) { |
| 893 | case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: |
| 894 | case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: |
| 895 | case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: |
| 896 | result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; |
| 897 | up_write(&dev_replace->rwsem); |
| 898 | break; |
| 899 | case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: |
| 900 | tgt_device = dev_replace->tgtdev; |
| 901 | src_device = dev_replace->srcdev; |
| 902 | up_write(&dev_replace->rwsem); |
| 903 | ret = btrfs_scrub_cancel(fs_info); |
| 904 | if (ret < 0) { |
| 905 | result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; |
| 906 | } else { |
| 907 | result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; |
| 908 | /* |
| 909 | * btrfs_dev_replace_finishing() will handle the |
| 910 | * cleanup part |
| 911 | */ |
| 912 | btrfs_info_in_rcu(fs_info, |
| 913 | "dev_replace from %s (devid %llu) to %s canceled", |
| 914 | btrfs_dev_name(src_device), src_device->devid, |
| 915 | btrfs_dev_name(tgt_device)); |
| 916 | } |
| 917 | break; |
| 918 | case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: |
| 919 | /* |
| 920 | * Scrub doing the replace isn't running so we need to do the |
| 921 | * cleanup step of btrfs_dev_replace_finishing() here |
| 922 | */ |
| 923 | result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; |
| 924 | tgt_device = dev_replace->tgtdev; |
| 925 | src_device = dev_replace->srcdev; |
| 926 | dev_replace->tgtdev = NULL; |
| 927 | dev_replace->srcdev = NULL; |
| 928 | dev_replace->replace_state = |
| 929 | BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; |
| 930 | dev_replace->time_stopped = ktime_get_real_seconds(); |
| 931 | dev_replace->item_needs_writeback = 1; |
| 932 | |
| 933 | up_write(&dev_replace->rwsem); |
| 934 | |
| 935 | /* Scrub for replace must not be running in suspended state */ |
| 936 | ret = btrfs_scrub_cancel(fs_info); |
| 937 | ASSERT(ret != -ENOTCONN); |
| 938 | |
| 939 | trans = btrfs_start_transaction(root, 0); |
| 940 | if (IS_ERR(trans)) { |
| 941 | mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); |
| 942 | return PTR_ERR(trans); |
| 943 | } |
| 944 | ret = btrfs_commit_transaction(trans); |
| 945 | WARN_ON(ret); |
| 946 | |
| 947 | btrfs_info_in_rcu(fs_info, |
| 948 | "suspended dev_replace from %s (devid %llu) to %s canceled", |
| 949 | btrfs_dev_name(src_device), src_device->devid, |
| 950 | btrfs_dev_name(tgt_device)); |
| 951 | |
| 952 | if (tgt_device) |
| 953 | btrfs_destroy_dev_replace_tgtdev(tgt_device); |
| 954 | break; |
| 955 | default: |
| 956 | up_write(&dev_replace->rwsem); |
| 957 | result = -EINVAL; |
| 958 | } |
| 959 | |
| 960 | mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); |
| 961 | return result; |
| 962 | } |
| 963 | |
| 964 | void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) |
| 965 | { |
| 966 | struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; |
| 967 | |
| 968 | mutex_lock(&dev_replace->lock_finishing_cancel_unmount); |
| 969 | down_write(&dev_replace->rwsem); |
| 970 | |
| 971 | switch (dev_replace->replace_state) { |
| 972 | case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: |
| 973 | case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: |
| 974 | case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: |
| 975 | case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: |
| 976 | break; |
| 977 | case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: |
| 978 | dev_replace->replace_state = |
| 979 | BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; |
| 980 | dev_replace->time_stopped = ktime_get_real_seconds(); |
| 981 | dev_replace->item_needs_writeback = 1; |
| 982 | btrfs_info(fs_info, "suspending dev_replace for unmount"); |
| 983 | break; |
| 984 | } |
| 985 | |
| 986 | up_write(&dev_replace->rwsem); |
| 987 | mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); |
| 988 | } |
| 989 | |
| 990 | /* resume dev_replace procedure that was interrupted by unmount */ |
| 991 | int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) |
| 992 | { |
| 993 | struct task_struct *task; |
| 994 | struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; |
| 995 | |
| 996 | down_write(&dev_replace->rwsem); |
| 997 | |
| 998 | switch (dev_replace->replace_state) { |
| 999 | case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: |
| 1000 | case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: |
| 1001 | case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: |
| 1002 | up_write(&dev_replace->rwsem); |
| 1003 | return 0; |
| 1004 | case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: |
| 1005 | break; |
| 1006 | case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: |
| 1007 | dev_replace->replace_state = |
| 1008 | BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; |
| 1009 | break; |
| 1010 | } |
| 1011 | if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { |
| 1012 | btrfs_info(fs_info, |
| 1013 | "cannot continue dev_replace, tgtdev is missing"); |
| 1014 | btrfs_info(fs_info, |
| 1015 | "you may cancel the operation after 'mount -o degraded'"); |
| 1016 | dev_replace->replace_state = |
| 1017 | BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; |
| 1018 | up_write(&dev_replace->rwsem); |
| 1019 | return 0; |
| 1020 | } |
| 1021 | up_write(&dev_replace->rwsem); |
| 1022 | |
| 1023 | /* |
| 1024 | * This could collide with a paused balance, but the exclusive op logic |
| 1025 | * should never allow both to start and pause. We don't want to allow |
| 1026 | * dev-replace to start anyway. |
| 1027 | */ |
| 1028 | if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REPLACE)) { |
| 1029 | down_write(&dev_replace->rwsem); |
| 1030 | dev_replace->replace_state = |
| 1031 | BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; |
| 1032 | up_write(&dev_replace->rwsem); |
| 1033 | btrfs_info(fs_info, |
| 1034 | "cannot resume dev-replace, other exclusive operation running"); |
| 1035 | return 0; |
| 1036 | } |
| 1037 | |
| 1038 | task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); |
| 1039 | return PTR_ERR_OR_ZERO(task); |
| 1040 | } |
| 1041 | |
| 1042 | static int btrfs_dev_replace_kthread(void *data) |
| 1043 | { |
| 1044 | struct btrfs_fs_info *fs_info = data; |
| 1045 | struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; |
| 1046 | u64 progress; |
| 1047 | int ret; |
| 1048 | |
| 1049 | progress = btrfs_dev_replace_progress(fs_info); |
| 1050 | progress = div_u64(progress, 10); |
| 1051 | btrfs_info_in_rcu(fs_info, |
| 1052 | "continuing dev_replace from %s (devid %llu) to target %s @%u%%", |
| 1053 | btrfs_dev_name(dev_replace->srcdev), |
| 1054 | dev_replace->srcdev->devid, |
| 1055 | btrfs_dev_name(dev_replace->tgtdev), |
| 1056 | (unsigned int)progress); |
| 1057 | |
| 1058 | ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, |
| 1059 | dev_replace->committed_cursor_left, |
| 1060 | btrfs_device_get_total_bytes(dev_replace->srcdev), |
| 1061 | &dev_replace->scrub_progress, 0, 1); |
| 1062 | ret = btrfs_dev_replace_finishing(fs_info, ret); |
| 1063 | WARN_ON(ret && ret != -ECANCELED); |
| 1064 | |
| 1065 | btrfs_exclop_finish(fs_info); |
| 1066 | return 0; |
| 1067 | } |
| 1068 | |
| 1069 | int __pure btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) |
| 1070 | { |
| 1071 | if (!dev_replace->is_valid) |
| 1072 | return 0; |
| 1073 | |
| 1074 | switch (dev_replace->replace_state) { |
| 1075 | case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: |
| 1076 | case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: |
| 1077 | case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: |
| 1078 | return 0; |
| 1079 | case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: |
| 1080 | case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: |
| 1081 | /* |
| 1082 | * return true even if tgtdev is missing (this is |
| 1083 | * something that can happen if the dev_replace |
| 1084 | * procedure is suspended by an umount and then |
| 1085 | * the tgtdev is missing (or "btrfs dev scan") was |
| 1086 | * not called and the filesystem is remounted |
| 1087 | * in degraded state. This does not stop the |
| 1088 | * dev_replace procedure. It needs to be canceled |
| 1089 | * manually if the cancellation is wanted. |
| 1090 | */ |
| 1091 | break; |
| 1092 | } |
| 1093 | return 1; |
| 1094 | } |
| 1095 | |
| 1096 | void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) |
| 1097 | { |
| 1098 | percpu_counter_inc(&fs_info->dev_replace.bio_counter); |
| 1099 | } |
| 1100 | |
| 1101 | void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) |
| 1102 | { |
| 1103 | percpu_counter_sub(&fs_info->dev_replace.bio_counter, amount); |
| 1104 | cond_wake_up_nomb(&fs_info->dev_replace.replace_wait); |
| 1105 | } |
| 1106 | |
| 1107 | void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) |
| 1108 | { |
| 1109 | while (1) { |
| 1110 | percpu_counter_inc(&fs_info->dev_replace.bio_counter); |
| 1111 | if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, |
| 1112 | &fs_info->fs_state))) |
| 1113 | break; |
| 1114 | |
| 1115 | btrfs_bio_counter_dec(fs_info); |
| 1116 | wait_event(fs_info->dev_replace.replace_wait, |
| 1117 | !test_bit(BTRFS_FS_STATE_DEV_REPLACING, |
| 1118 | &fs_info->fs_state)); |
| 1119 | } |
| 1120 | } |