From: Stefan Behrens Date: Mon, 5 Nov 2012 16:33:06 +0000 (+0100) Subject: Btrfs: add new sources for device replace code X-Git-Tag: MMI-PSA29.97-13-9~15079^2~68 X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e93c89c1aaaaaec3487c4c18dd02360371790722;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git Btrfs: add new sources for device replace code This adds a new file to the sources together with the header file and the changes to ioctl.h and ctree.h that are required by the new C source file. Additionally, 4 new functions are added to volume.c that deal with device creation and destruction. Signed-off-by: Stefan Behrens Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile index d7fcdba141a2..7df3e0f0ee51 100644 --- a/fs/btrfs/Makefile +++ b/fs/btrfs/Makefile @@ -8,7 +8,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \ extent_io.o volumes.o async-thread.o ioctl.o locking.o orphan.o \ export.o tree-log.o free-space-cache.o zlib.o lzo.o \ compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \ - reada.o backref.o ulist.o qgroup.o send.o + reada.o backref.o ulist.o qgroup.o send.o dev-replace.o btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index ded7caa0d304..45e7f752b64a 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -142,6 +142,8 @@ struct btrfs_ordered_sum; #define BTRFS_EMPTY_SUBVOL_DIR_OBJECTID 2 +#define BTRFS_DEV_REPLACE_DEVID 0 + /* * the max metadata block size. This limit is somewhat artificial, * but the memmove costs go through the roof for larger blocks. 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#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 ? "" : + 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 ? "" : + 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 ? "" : + 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 ? "" : + rcu_str_deref(dev_replace->srcdev->name), + dev_replace->srcdev->devid, + dev_replace->tgtdev ? + rcu_str_deref(dev_replace->tgtdev->name) : + "", + (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); + } +} diff --git a/fs/btrfs/dev-replace.h b/fs/btrfs/dev-replace.h index 1fb5c89037ee..20035cbbf021 100644 --- a/fs/btrfs/dev-replace.h +++ b/fs/btrfs/dev-replace.h @@ -19,6 +19,24 @@ #if !defined(__BTRFS_DEV_REPLACE__) #define __BTRFS_DEV_REPLACE__ +struct btrfs_ioctl_dev_replace_args; + +int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info); +int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info); +void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info); +int btrfs_dev_replace_start(struct btrfs_root *root, + struct btrfs_ioctl_dev_replace_args *args); +void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, + struct btrfs_ioctl_dev_replace_args *args); +int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, + struct btrfs_ioctl_dev_replace_args *args); +void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info); +int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info); +int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace); +void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace); +void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace); + static inline void btrfs_dev_replace_stats_inc(atomic64_t *stat_value) { atomic64_inc(stat_value); diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index 731e2875ab93..62006ba02719 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -123,6 +123,48 @@ struct btrfs_ioctl_scrub_args { __u64 unused[(1024-32-sizeof(struct btrfs_scrub_progress))/8]; }; +#define BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS 0 +#define BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID 1 +struct btrfs_ioctl_dev_replace_start_params { + __u64 srcdevid; /* in, if 0, use srcdev_name instead */ + __u8 srcdev_name[BTRFS_PATH_NAME_MAX + 1]; /* in */ + __u8 tgtdev_name[BTRFS_PATH_NAME_MAX + 1]; /* in */ + __u64 cont_reading_from_srcdev_mode; /* in, see #define + * above */ +}; + +#define BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED 0 +#define BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED 1 +#define BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED 2 +#define BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED 3 +#define BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED 4 +struct btrfs_ioctl_dev_replace_status_params { + __u64 replace_state; /* out, see #define above */ + __u64 progress_1000; /* out, 0 <= x <= 1000 */ + __u64 time_started; /* out, seconds since 1-Jan-1970 */ + __u64 time_stopped; /* out, seconds since 1-Jan-1970 */ + __u64 num_write_errors; /* out */ + __u64 num_uncorrectable_read_errors; /* out */ +}; + +#define BTRFS_IOCTL_DEV_REPLACE_CMD_START 0 +#define BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS 1 +#define BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL 2 +#define BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR 0 +#define BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED 1 +#define BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED 2 +struct btrfs_ioctl_dev_replace_args { + __u64 cmd; /* in */ + __u64 result; /* out */ + + union { + struct btrfs_ioctl_dev_replace_start_params start; + struct btrfs_ioctl_dev_replace_status_params status; + }; /* in/out */ + + __u64 spare[64]; +}; + #define BTRFS_DEVICE_PATH_NAME_MAX 1024 struct btrfs_ioctl_dev_info_args { __u64 devid; /* in/out */ @@ -453,4 +495,7 @@ struct btrfs_ioctl_send_args { struct btrfs_ioctl_qgroup_limit_args) #define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \ struct btrfs_ioctl_get_dev_stats) +#define BTRFS_IOC_DEV_REPLACE _IOWR(BTRFS_IOCTL_MAGIC, 53, \ + struct btrfs_ioctl_dev_replace_args) + #endif diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 415862885b67..5777e6a9aab1 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1537,6 +1537,53 @@ error_undo: goto error_brelse; } +void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info, + struct btrfs_device *srcdev) +{ + WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex)); + list_del_rcu(&srcdev->dev_list); + list_del_rcu(&srcdev->dev_alloc_list); + fs_info->fs_devices->num_devices--; + if (srcdev->missing) { + fs_info->fs_devices->missing_devices--; + fs_info->fs_devices->rw_devices++; + } + if (srcdev->can_discard) + fs_info->fs_devices->num_can_discard--; + if (srcdev->bdev) + fs_info->fs_devices->open_devices--; + + call_rcu(&srcdev->rcu, free_device); +} + +void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info, + struct btrfs_device *tgtdev) +{ + struct btrfs_device *next_device; + + WARN_ON(!tgtdev); + mutex_lock(&fs_info->fs_devices->device_list_mutex); + if (tgtdev->bdev) { + btrfs_scratch_superblock(tgtdev); + fs_info->fs_devices->open_devices--; + } + fs_info->fs_devices->num_devices--; + if (tgtdev->can_discard) + fs_info->fs_devices->num_can_discard++; + + next_device = list_entry(fs_info->fs_devices->devices.next, + struct btrfs_device, dev_list); + if (tgtdev->bdev == fs_info->sb->s_bdev) + fs_info->sb->s_bdev = next_device->bdev; + if (tgtdev->bdev == fs_info->fs_devices->latest_bdev) + fs_info->fs_devices->latest_bdev = next_device->bdev; + list_del_rcu(&tgtdev->dev_list); + + call_rcu(&tgtdev->rcu, free_device); + + mutex_unlock(&fs_info->fs_devices->device_list_mutex); +} + int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path, struct btrfs_device **device) { @@ -1931,6 +1978,98 @@ error: return ret; } +int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path, + struct btrfs_device **device_out) +{ + struct request_queue *q; + struct btrfs_device *device; + struct block_device *bdev; + struct btrfs_fs_info *fs_info = root->fs_info; + struct list_head *devices; + struct rcu_string *name; + int ret = 0; + + *device_out = NULL; + if (fs_info->fs_devices->seeding) + return -EINVAL; + + bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL, + fs_info->bdev_holder); + if (IS_ERR(bdev)) + return PTR_ERR(bdev); + + filemap_write_and_wait(bdev->bd_inode->i_mapping); + + devices = &fs_info->fs_devices->devices; + list_for_each_entry(device, devices, dev_list) { + if (device->bdev == bdev) { + ret = -EEXIST; + goto error; + } + } + + device = kzalloc(sizeof(*device), GFP_NOFS); + if (!device) { + ret = -ENOMEM; + goto error; + } + + name = rcu_string_strdup(device_path, GFP_NOFS); + if (!name) { + kfree(device); + ret = -ENOMEM; + goto error; + } + rcu_assign_pointer(device->name, name); + + q = bdev_get_queue(bdev); + if (blk_queue_discard(q)) + device->can_discard = 1; + mutex_lock(&root->fs_info->fs_devices->device_list_mutex); + device->writeable = 1; + device->work.func = pending_bios_fn; + generate_random_uuid(device->uuid); + device->devid = BTRFS_DEV_REPLACE_DEVID; + spin_lock_init(&device->io_lock); + device->generation = 0; + device->io_width = root->sectorsize; + device->io_align = root->sectorsize; + device->sector_size = root->sectorsize; + device->total_bytes = i_size_read(bdev->bd_inode); + device->disk_total_bytes = device->total_bytes; + device->dev_root = fs_info->dev_root; + device->bdev = bdev; + device->in_fs_metadata = 1; + device->is_tgtdev_for_dev_replace = 1; + device->mode = FMODE_EXCL; + set_blocksize(device->bdev, 4096); + device->fs_devices = fs_info->fs_devices; + list_add(&device->dev_list, &fs_info->fs_devices->devices); + fs_info->fs_devices->num_devices++; + fs_info->fs_devices->open_devices++; + if (device->can_discard) + fs_info->fs_devices->num_can_discard++; + mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); + + *device_out = device; + return ret; + +error: + blkdev_put(bdev, FMODE_EXCL); + return ret; +} + +void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info, + struct btrfs_device *tgtdev) +{ + WARN_ON(fs_info->fs_devices->rw_devices == 0); + tgtdev->io_width = fs_info->dev_root->sectorsize; + tgtdev->io_align = fs_info->dev_root->sectorsize; + tgtdev->sector_size = fs_info->dev_root->sectorsize; + tgtdev->dev_root = fs_info->dev_root; + tgtdev->in_fs_metadata = 1; +} + static noinline int btrfs_update_device(struct btrfs_trans_handle *trans, struct btrfs_device *device) { diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 8fd5a4d8acc8..58d79375deaf 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -286,6 +286,8 @@ struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid, u8 *uuid, u8 *fsid); int btrfs_shrink_device(struct btrfs_device *device, u64 new_size); int btrfs_init_new_device(struct btrfs_root *root, char *path); +int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path, + struct btrfs_device **device_out); int btrfs_balance(struct btrfs_balance_control *bctl, struct btrfs_ioctl_balance_args *bargs); int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info); @@ -302,6 +304,12 @@ int btrfs_get_dev_stats(struct btrfs_root *root, int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info); int btrfs_run_dev_stats(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info); +void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info, + struct btrfs_device *srcdev); +void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info, + struct btrfs_device *tgtdev); +void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info, + struct btrfs_device *tgtdev); int btrfs_scratch_superblock(struct btrfs_device *device); static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,