diff options
Diffstat (limited to 'fs/btrfs/dev-replace.c')
| -rw-r--r-- | fs/btrfs/dev-replace.c | 856 |
1 files changed, 856 insertions, 0 deletions
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c new file mode 100644 index 000000000000..66dbc8dbddf7 --- /dev/null +++ b/fs/btrfs/dev-replace.c @@ -0,0 +1,856 @@ +/* + * Copyright (C) STRATO AG 2012. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ +#include <linux/sched.h> +#include <linux/bio.h> +#include <linux/slab.h> +#include <linux/buffer_head.h> +#include <linux/blkdev.h> +#include <linux/random.h> +#include <linux/iocontext.h> +#include <linux/capability.h> +#include <linux/kthread.h> +#include <linux/math64.h> +#include <asm/div64.h> +#include "compat.h" +#include "ctree.h" +#include "extent_map.h" +#include "disk-io.h" +#include "transaction.h" +#include "print-tree.h" +#include "volumes.h" +#include "async-thread.h" +#include "check-integrity.h" +#include "rcu-string.h" +#include "dev-replace.h" + +static u64 btrfs_get_seconds_since_1970(void); +static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, + int scrub_ret); +static void btrfs_dev_replace_update_device_in_mapping_tree( + struct btrfs_fs_info *fs_info, + struct btrfs_device *srcdev, + struct btrfs_device *tgtdev); +static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, + char *srcdev_name, + struct btrfs_device **device); +static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info); +static int btrfs_dev_replace_kthread(void *data); +static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info); + + +int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info) +{ + struct btrfs_key key; + struct btrfs_root *dev_root = fs_info->dev_root; + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + struct extent_buffer *eb; + int slot; + int ret = 0; + struct btrfs_path *path = NULL; + int item_size; + struct btrfs_dev_replace_item *ptr; + u64 src_devid; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + key.objectid = 0; + key.type = BTRFS_DEV_REPLACE_KEY; + key.offset = 0; + ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0); + if (ret) { +no_valid_dev_replace_entry_found: + ret = 0; + dev_replace->replace_state = + BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED; + dev_replace->cont_reading_from_srcdev_mode = + BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS; + dev_replace->replace_state = 0; + dev_replace->time_started = 0; + dev_replace->time_stopped = 0; + atomic64_set(&dev_replace->num_write_errors, 0); + atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); + dev_replace->cursor_left = 0; + dev_replace->committed_cursor_left = 0; + dev_replace->cursor_left_last_write_of_item = 0; + dev_replace->cursor_right = 0; + dev_replace->srcdev = NULL; + dev_replace->tgtdev = NULL; + dev_replace->is_valid = 0; + dev_replace->item_needs_writeback = 0; + goto out; + } + slot = path->slots[0]; + eb = path->nodes[0]; + item_size = btrfs_item_size_nr(eb, slot); + ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_replace_item); + + if (item_size != sizeof(struct btrfs_dev_replace_item)) { + pr_warn("btrfs: dev_replace entry found has unexpected size, ignore entry\n"); + goto no_valid_dev_replace_entry_found; + } + + src_devid = btrfs_dev_replace_src_devid(eb, ptr); + dev_replace->cont_reading_from_srcdev_mode = + btrfs_dev_replace_cont_reading_from_srcdev_mode(eb, ptr); + dev_replace->replace_state = btrfs_dev_replace_replace_state(eb, ptr); + dev_replace->time_started = btrfs_dev_replace_time_started(eb, ptr); + dev_replace->time_stopped = + btrfs_dev_replace_time_stopped(eb, ptr); + atomic64_set(&dev_replace->num_write_errors, + btrfs_dev_replace_num_write_errors(eb, ptr)); + atomic64_set(&dev_replace->num_uncorrectable_read_errors, + btrfs_dev_replace_num_uncorrectable_read_errors(eb, ptr)); + dev_replace->cursor_left = btrfs_dev_replace_cursor_left(eb, ptr); + dev_replace->committed_cursor_left = dev_replace->cursor_left; + dev_replace->cursor_left_last_write_of_item = dev_replace->cursor_left; + dev_replace->cursor_right = btrfs_dev_replace_cursor_right(eb, ptr); + dev_replace->is_valid = 1; + + dev_replace->item_needs_writeback = 0; + switch (dev_replace->replace_state) { + case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: + dev_replace->srcdev = NULL; + dev_replace->tgtdev = NULL; + break; + case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: + dev_replace->srcdev = btrfs_find_device(fs_info, src_devid, + NULL, NULL); + dev_replace->tgtdev = btrfs_find_device(fs_info, + BTRFS_DEV_REPLACE_DEVID, + NULL, NULL); + /* + * allow 'btrfs dev replace_cancel' if src/tgt device is + * missing + */ + if (!dev_replace->srcdev && + !btrfs_test_opt(dev_root, DEGRADED)) { + ret = -EIO; + pr_warn("btrfs: cannot mount because device replace operation is ongoing and\n" "srcdev (devid %llu) is missing, need to run 'btrfs dev scan'?\n", + (unsigned long long)src_devid); + } + if (!dev_replace->tgtdev && + !btrfs_test_opt(dev_root, DEGRADED)) { + ret = -EIO; + pr_warn("btrfs: cannot mount because device replace operation is ongoing and\n" "tgtdev (devid %llu) is missing, need to run btrfs dev scan?\n", + (unsigned long long)BTRFS_DEV_REPLACE_DEVID); + } + if (dev_replace->tgtdev) { + if (dev_replace->srcdev) { + dev_replace->tgtdev->total_bytes = + dev_replace->srcdev->total_bytes; + dev_replace->tgtdev->disk_total_bytes = + dev_replace->srcdev->disk_total_bytes; + dev_replace->tgtdev->bytes_used = + dev_replace->srcdev->bytes_used; + } + dev_replace->tgtdev->is_tgtdev_for_dev_replace = 1; + btrfs_init_dev_replace_tgtdev_for_resume(fs_info, + dev_replace->tgtdev); + } + break; + } + +out: + if (path) + btrfs_free_path(path); + return ret; +} + +/* + * called from commit_transaction. Writes changed device replace state to + * disk. + */ +int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info) +{ + int ret; + struct btrfs_root *dev_root = fs_info->dev_root; + struct btrfs_path *path; + struct btrfs_key key; + struct extent_buffer *eb; + struct btrfs_dev_replace_item *ptr; + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + + btrfs_dev_replace_lock(dev_replace); + if (!dev_replace->is_valid || + !dev_replace->item_needs_writeback) { + btrfs_dev_replace_unlock(dev_replace); + return 0; + } + btrfs_dev_replace_unlock(dev_replace); + + key.objectid = 0; + key.type = BTRFS_DEV_REPLACE_KEY; + key.offset = 0; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); + if (ret < 0) { + pr_warn("btrfs: error %d while searching for dev_replace item!\n", + ret); + goto out; + } + + if (ret == 0 && + btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { + /* + * need to delete old one and insert a new one. + * Since no attempt is made to recover any old state, if the + * dev_replace state is 'running', the data on the target + * drive is lost. + * It would be possible to recover the state: just make sure + * that the beginning of the item is never changed and always + * contains all the essential information. Then read this + * minimal set of information and use it as a base for the + * new state. + */ + ret = btrfs_del_item(trans, dev_root, path); + if (ret != 0) { + pr_warn("btrfs: delete too small dev_replace item failed %d!\n", + ret); + goto out; + } + ret = 1; + } + + if (ret == 1) { + /* need to insert a new item */ + btrfs_release_path(path); + ret = btrfs_insert_empty_item(trans, dev_root, path, + &key, sizeof(*ptr)); + if (ret < 0) { + pr_warn("btrfs: insert dev_replace item failed %d!\n", + ret); + goto out; + } + } + + eb = path->nodes[0]; + ptr = btrfs_item_ptr(eb, path->slots[0], + struct btrfs_dev_replace_item); + + btrfs_dev_replace_lock(dev_replace); + if (dev_replace->srcdev) + btrfs_set_dev_replace_src_devid(eb, ptr, + dev_replace->srcdev->devid); + else + btrfs_set_dev_replace_src_devid(eb, ptr, (u64)-1); + btrfs_set_dev_replace_cont_reading_from_srcdev_mode(eb, ptr, + dev_replace->cont_reading_from_srcdev_mode); + btrfs_set_dev_replace_replace_state(eb, ptr, + dev_replace->replace_state); + btrfs_set_dev_replace_time_started(eb, ptr, dev_replace->time_started); + btrfs_set_dev_replace_time_stopped(eb, ptr, dev_replace->time_stopped); + btrfs_set_dev_replace_num_write_errors(eb, ptr, + atomic64_read(&dev_replace->num_write_errors)); + btrfs_set_dev_replace_num_uncorrectable_read_errors(eb, ptr, + atomic64_read(&dev_replace->num_uncorrectable_read_errors)); + dev_replace->cursor_left_last_write_of_item = + dev_replace->cursor_left; + btrfs_set_dev_replace_cursor_left(eb, ptr, + dev_replace->cursor_left_last_write_of_item); + btrfs_set_dev_replace_cursor_right(eb, ptr, + dev_replace->cursor_right); + dev_replace->item_needs_writeback = 0; + btrfs_dev_replace_unlock(dev_replace); + + btrfs_mark_buffer_dirty(eb); + +out: + btrfs_free_path(path); + + return ret; +} + +void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info) +{ + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + + dev_replace->committed_cursor_left = + dev_replace->cursor_left_last_write_of_item; +} + +static u64 btrfs_get_seconds_since_1970(void) +{ + struct timespec t = CURRENT_TIME_SEC; + + return t.tv_sec; +} + +int btrfs_dev_replace_start(struct btrfs_root *root, + struct btrfs_ioctl_dev_replace_args *args) +{ + struct btrfs_trans_handle *trans; + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + int ret; + struct btrfs_device *tgt_device = NULL; + struct btrfs_device *src_device = NULL; + + switch (args->start.cont_reading_from_srcdev_mode) { + case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS: + case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: + break; + default: + return -EINVAL; + } + + if ((args->start.srcdevid == 0 && args->start.srcdev_name[0] == '\0') || + args->start.tgtdev_name[0] == '\0') + return -EINVAL; + + mutex_lock(&fs_info->volume_mutex); + ret = btrfs_init_dev_replace_tgtdev(root, args->start.tgtdev_name, + &tgt_device); + if (ret) { + pr_err("btrfs: target device %s is invalid!\n", + args->start.tgtdev_name); + mutex_unlock(&fs_info->volume_mutex); + return -EINVAL; + } + + ret = btrfs_dev_replace_find_srcdev(root, args->start.srcdevid, + args->start.srcdev_name, + &src_device); + mutex_unlock(&fs_info->volume_mutex); + if (ret) { + ret = -EINVAL; + goto leave_no_lock; + } + + if (tgt_device->total_bytes < src_device->total_bytes) { + pr_err("btrfs: target device is smaller than source device!\n"); + ret = -EINVAL; + goto leave_no_lock; + } + + btrfs_dev_replace_lock(dev_replace); + switch (dev_replace->replace_state) { + case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: + break; + case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: + args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; + goto leave; + } + + dev_replace->cont_reading_from_srcdev_mode = + args->start.cont_reading_from_srcdev_mode; + WARN_ON(!src_device); + dev_replace->srcdev = src_device; + WARN_ON(!tgt_device); + dev_replace->tgtdev = tgt_device; + + printk_in_rcu(KERN_INFO + "btrfs: dev_replace from %s (devid %llu) to %s) started\n", + src_device->missing ? "<missing disk>" : + rcu_str_deref(src_device->name), + src_device->devid, + rcu_str_deref(tgt_device->name)); + + tgt_device->total_bytes = src_device->total_bytes; + tgt_device->disk_total_bytes = src_device->disk_total_bytes; + tgt_device->bytes_used = src_device->bytes_used; + + /* + * from now on, the writes to the srcdev are all duplicated to + * go to the tgtdev as well (refer to btrfs_map_block()). + */ + dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; + dev_replace->time_started = btrfs_get_seconds_since_1970(); + dev_replace->cursor_left = 0; + dev_replace->committed_cursor_left = 0; + dev_replace->cursor_left_last_write_of_item = 0; + dev_replace->cursor_right = 0; + dev_replace->is_valid = 1; + dev_replace->item_needs_writeback = 1; + args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; + btrfs_dev_replace_unlock(dev_replace); + + btrfs_wait_ordered_extents(root, 0); + + /* force writing the updated state information to disk */ + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + btrfs_dev_replace_lock(dev_replace); + goto leave; + } + + ret = btrfs_commit_transaction(trans, root); + WARN_ON(ret); + + /* the disk copy procedure reuses the scrub code */ + ret = btrfs_scrub_dev(fs_info, src_device->devid, 0, + src_device->total_bytes, + &dev_replace->scrub_progress, 0, 1); + + ret = btrfs_dev_replace_finishing(root->fs_info, ret); + WARN_ON(ret); + + return 0; + +leave: + dev_replace->srcdev = NULL; + dev_replace->tgtdev = NULL; + btrfs_dev_replace_unlock(dev_replace); +leave_no_lock: + if (tgt_device) + btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); + return ret; +} + +static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, + int scrub_ret) +{ + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + struct btrfs_device *tgt_device; + struct btrfs_device *src_device; + struct btrfs_root *root = fs_info->tree_root; + u8 uuid_tmp[BTRFS_UUID_SIZE]; + struct btrfs_trans_handle *trans; + int ret = 0; + + /* don't allow cancel or unmount to disturb the finishing procedure */ + mutex_lock(&dev_replace->lock_finishing_cancel_unmount); + + btrfs_dev_replace_lock(dev_replace); + /* was the operation canceled, or is it finished? */ + if (dev_replace->replace_state != + BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { + btrfs_dev_replace_unlock(dev_replace); + mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); + return 0; + } + + tgt_device = dev_replace->tgtdev; + src_device = dev_replace->srcdev; + btrfs_dev_replace_unlock(dev_replace); + + /* replace old device with new one in mapping tree */ + if (!scrub_ret) + btrfs_dev_replace_update_device_in_mapping_tree(fs_info, + src_device, + tgt_device); + + /* + * flush all outstanding I/O and inode extent mappings before the + * copy operation is declared as being finished + */ + btrfs_start_delalloc_inodes(root, 0); + btrfs_wait_ordered_extents(root, 0); + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); + return PTR_ERR(trans); + } + ret = btrfs_commit_transaction(trans, root); + WARN_ON(ret); + + /* keep away write_all_supers() during the finishing procedure */ + mutex_lock(&root->fs_info->fs_devices->device_list_mutex); + btrfs_dev_replace_lock(dev_replace); + dev_replace->replace_state = + scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED + : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; + dev_replace->tgtdev = NULL; + dev_replace->srcdev = NULL; + dev_replace->time_stopped = btrfs_get_seconds_since_1970(); + dev_replace->item_needs_writeback = 1; + + if (scrub_ret) { + printk_in_rcu(KERN_ERR + "btrfs: btrfs_scrub_dev(%s, %llu, %s) failed %d\n", + src_device->missing ? "<missing disk>" : + rcu_str_deref(src_device->name), + src_device->devid, + rcu_str_deref(tgt_device->name), scrub_ret); + btrfs_dev_replace_unlock(dev_replace); + mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); + if (tgt_device) + btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); + mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); + + return 0; + } + + printk_in_rcu(KERN_INFO + "btrfs: dev_replace from %s (devid %llu) to %s) finished\n", + src_device->missing ? "<missing disk>" : + rcu_str_deref(src_device->name), + src_device->devid, + rcu_str_deref(tgt_device->name)); + tgt_device->is_tgtdev_for_dev_replace = 0; + tgt_device->devid = src_device->devid; + src_device->devid = BTRFS_DEV_REPLACE_DEVID; + tgt_device->bytes_used = src_device->bytes_used; + memcpy(uuid_tmp, tgt_device->uuid, sizeof(uuid_tmp)); + memcpy(tgt_device->uuid, src_device->uuid, sizeof(tgt_device->uuid)); + memcpy(src_device->uuid, uuid_tmp, sizeof(src_device->uuid)); + tgt_device->total_bytes = src_device->total_bytes; + tgt_device->disk_total_bytes = src_device->disk_total_bytes; + tgt_device->bytes_used = src_device->bytes_used; + if (fs_info->sb->s_bdev == src_device->bdev) + fs_info->sb->s_bdev = tgt_device->bdev; + if (fs_info->fs_devices->latest_bdev == src_device->bdev) + fs_info->fs_devices->latest_bdev = tgt_device->bdev; + list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); + + btrfs_rm_dev_replace_srcdev(fs_info, src_device); + if (src_device->bdev) { + /* zero out the old super */ + btrfs_scratch_superblock(src_device); + } + /* + * this is again a consistent state where no dev_replace procedure + * is running, the target device is part of the filesystem, the + * source device is not part of the filesystem anymore and its 1st + * superblock is scratched out so that it is no longer marked to + * belong to this filesystem. + */ + btrfs_dev_replace_unlock(dev_replace); + mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); + + /* write back the superblocks */ + trans = btrfs_start_transaction(root, 0); + if (!IS_ERR(trans)) + btrfs_commit_transaction(trans, root); + + mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); + + return 0; +} + +static void btrfs_dev_replace_update_device_in_mapping_tree( + struct btrfs_fs_info *fs_info, + struct btrfs_device *srcdev, + struct btrfs_device *tgtdev) +{ + struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree; + struct extent_map *em; + struct map_lookup *map; + u64 start = 0; + int i; + + write_lock(&em_tree->lock); + do { + em = lookup_extent_mapping(em_tree, start, (u64)-1); + if (!em) + break; + map = (struct map_lookup *)em->bdev; + for (i = 0; i < map->num_stripes; i++) + if (srcdev == map->stripes[i].dev) + map->stripes[i].dev = tgtdev; + start = em->start + em->len; + free_extent_map(em); + } while (start); + write_unlock(&em_tree->lock); +} + +static int btrfs_dev_replace_find_srcdev(struct btrfs_root *root, u64 srcdevid, + char *srcdev_name, + struct btrfs_device **device) +{ + int ret; + + if (srcdevid) { + ret = 0; + *device = btrfs_find_device(root->fs_info, srcdevid, NULL, + NULL); + if (!*device) + ret = -ENOENT; + } else { + ret = btrfs_find_device_missing_or_by_path(root, srcdev_name, + device); + } + return ret; +} + +void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, + struct btrfs_ioctl_dev_replace_args *args) +{ + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + + btrfs_dev_replace_lock(dev_replace); + /* even if !dev_replace_is_valid, the values are good enough for + * the replace_status ioctl */ + args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; + args->status.replace_state = dev_replace->replace_state; + args->status.time_started = dev_replace->time_started; + args->status.time_stopped = dev_replace->time_stopped; + args->status.num_write_errors = + atomic64_read(&dev_replace->num_write_errors); + args->status.num_uncorrectable_read_errors = + atomic64_read(&dev_replace->num_uncorrectable_read_errors); + switch (dev_replace->replace_state) { + case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: + args->status.progress_1000 = 0; + break; + case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: + args->status.progress_1000 = 1000; + break; + case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: + args->status.progress_1000 = div64_u64(dev_replace->cursor_left, + div64_u64(dev_replace->srcdev->total_bytes, 1000)); + break; + } + btrfs_dev_replace_unlock(dev_replace); +} + +int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, + struct btrfs_ioctl_dev_replace_args *args) +{ + args->result = __btrfs_dev_replace_cancel(fs_info); + return 0; +} + +static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) +{ + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + struct btrfs_device *tgt_device = NULL; + struct btrfs_trans_handle *trans; + struct btrfs_root *root = fs_info->tree_root; + u64 result; + int ret; + + mutex_lock(&dev_replace->lock_finishing_cancel_unmount); + btrfs_dev_replace_lock(dev_replace); + switch (dev_replace->replace_state) { + case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: + result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; + btrfs_dev_replace_unlock(dev_replace); + goto leave; + case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: + result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; + tgt_device = dev_replace->tgtdev; + dev_replace->tgtdev = NULL; + dev_replace->srcdev = NULL; + break; + } + dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; + dev_replace->time_stopped = btrfs_get_seconds_since_1970(); + dev_replace->item_needs_writeback = 1; + btrfs_dev_replace_unlock(dev_replace); + btrfs_scrub_cancel(fs_info); + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); + return PTR_ERR(trans); + } + ret = btrfs_commit_transaction(trans, root); + WARN_ON(ret); + if (tgt_device) + btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); + +leave: + mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); + return result; +} + +void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) +{ + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + + mutex_lock(&dev_replace->lock_finishing_cancel_unmount); + btrfs_dev_replace_lock(dev_replace); + switch (dev_replace->replace_state) { + case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: + break; + case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: + dev_replace->replace_state = + BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED; + dev_replace->time_stopped = btrfs_get_seconds_since_1970(); + dev_replace->item_needs_writeback = 1; + pr_info("btrfs: suspending dev_replace for unmount\n"); + break; + } + + btrfs_dev_replace_unlock(dev_replace); + mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); +} + +/* resume dev_replace procedure that was interrupted by unmount */ +int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) +{ + struct task_struct *task; + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + + btrfs_dev_replace_lock(dev_replace); + switch (dev_replace->replace_state) { + case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: + btrfs_dev_replace_unlock(dev_replace); + return 0; + case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: + break; + case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: + dev_replace->replace_state = + BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED; + break; + } + if (!dev_replace->tgtdev || !dev_replace->tgtdev->bdev) { + pr_info("btrfs: cannot continue dev_replace, tgtdev is missing\n" + "btrfs: you may cancel the operation after 'mount -o degraded'\n"); + btrfs_dev_replace_unlock(dev_replace); + return 0; + } + btrfs_dev_replace_unlock(dev_replace); + + WARN_ON(atomic_xchg( + &fs_info->mutually_exclusive_operation_running, 1)); + task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl"); + return PTR_RET(task); +} + +static int btrfs_dev_replace_kthread(void *data) +{ + struct btrfs_fs_info *fs_info = data; + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + struct btrfs_ioctl_dev_replace_args *status_args; + u64 progress; + + status_args = kzalloc(sizeof(*status_args), GFP_NOFS); + if (status_args) { + btrfs_dev_replace_status(fs_info, status_args); + progress = status_args->status.progress_1000; + kfree(status_args); + do_div(progress, 10); + printk_in_rcu(KERN_INFO + "btrfs: continuing dev_replace from %s (devid %llu) to %s @%u%%\n", + dev_replace->srcdev->missing ? "<missing disk>" : + rcu_str_deref(dev_replace->srcdev->name), + dev_replace->srcdev->devid, + dev_replace->tgtdev ? + rcu_str_deref(dev_replace->tgtdev->name) : + "<missing target disk>", + (unsigned int)progress); + } + btrfs_dev_replace_continue_on_mount(fs_info); + atomic_set(&fs_info->mutually_exclusive_operation_running, 0); + + return 0; +} + +static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info) +{ + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + int ret; + + ret = btrfs_scrub_dev(fs_info, dev_replace->srcdev->devid, + dev_replace->committed_cursor_left, + dev_replace->srcdev->total_bytes, + &dev_replace->scrub_progress, 0, 1); + ret = btrfs_dev_replace_finishing(fs_info, ret); + WARN_ON(ret); + return 0; +} + +int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) +{ + if (!dev_replace->is_valid) + return 0; + + switch (dev_replace->replace_state) { + case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: + return 0; + case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: + case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: + /* + * return true even if tgtdev is missing (this is + * something that can happen if the dev_replace + * procedure is suspended by an umount and then + * the tgtdev is missing (or "btrfs dev scan") was + * not called and the the filesystem is remounted + * in degraded state. This does not stop the + * dev_replace procedure. It needs to be canceled + * manually if the cancelation is wanted. + */ + break; + } + return 1; +} + +void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace) +{ + /* the beginning is just an optimization for the typical case */ + if (atomic_read(&dev_replace->nesting_level) == 0) { +acquire_lock: + /* this is not a nested case where the same thread + * is trying to acqurire the same lock twice */ + mutex_lock(&dev_replace->lock); + mutex_lock(&dev_replace->lock_management_lock); + dev_replace->lock_owner = current->pid; + atomic_inc(&dev_replace->nesting_level); + mutex_unlock(&dev_replace->lock_management_lock); + return; + } + + mutex_lock(&dev_replace->lock_management_lock); + if (atomic_read(&dev_replace->nesting_level) > 0 && + dev_replace->lock_owner == current->pid) { + WARN_ON(!mutex_is_locked(&dev_replace->lock)); + atomic_inc(&dev_replace->nesting_level); + mutex_unlock(&dev_replace->lock_management_lock); + return; + } + + mutex_unlock(&dev_replace->lock_management_lock); + goto acquire_lock; +} + +void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace) +{ + WARN_ON(!mutex_is_locked(&dev_replace->lock)); + mutex_lock(&dev_replace->lock_management_lock); + WARN_ON(atomic_read(&dev_replace->nesting_level) < 1); + WARN_ON(dev_replace->lock_owner != current->pid); + atomic_dec(&dev_replace->nesting_level); + if (atomic_read(&dev_replace->nesting_level) == 0) { + dev_replace->lock_owner = 0; + mutex_unlock(&dev_replace->lock_management_lock); + mutex_unlock(&dev_replace->lock); + } else { + mutex_unlock(&dev_replace->lock_management_lock); + } +} |