/* * Copyright (C) 2007 Oracle. 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/buffer_head.h> #include <linux/blkdev.h> #include <linux/random.h> #include <linux/iocontext.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" struct map_lookup { u64 type; int io_align; int io_width; int stripe_len; int sector_size; int num_stripes; int sub_stripes; struct btrfs_bio_stripe stripes[]; }; static int init_first_rw_device(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_device *device); static int btrfs_relocate_sys_chunks(struct btrfs_root *root); #define map_lookup_size(n) (sizeof(struct map_lookup) + \ (sizeof(struct btrfs_bio_stripe) * (n))) static DEFINE_MUTEX(uuid_mutex); static LIST_HEAD(fs_uuids); void btrfs_lock_volumes(void) { mutex_lock(&uuid_mutex); } void btrfs_unlock_volumes(void) { mutex_unlock(&uuid_mutex); } static void lock_chunks(struct btrfs_root *root) { mutex_lock(&root->fs_info->chunk_mutex); } static void unlock_chunks(struct btrfs_root *root) { mutex_unlock(&root->fs_info->chunk_mutex); } static void free_fs_devices(struct btrfs_fs_devices *fs_devices) { struct btrfs_device *device; WARN_ON(fs_devices->opened); while (!list_empty(&fs_devices->devices)) { device = list_entry(fs_devices->devices.next, struct btrfs_device, dev_list); list_del(&device->dev_list); kfree(device->name); kfree(device); } kfree(fs_devices); } int btrfs_cleanup_fs_uuids(void) { struct btrfs_fs_devices *fs_devices; while (!list_empty(&fs_uuids)) { fs_devices = list_entry(fs_uuids.next, struct btrfs_fs_devices, list); list_del(&fs_devices->list); free_fs_devices(fs_devices); } return 0; } static noinline struct btrfs_device *__find_device(struct list_head *head, u64 devid, u8 *uuid) { struct btrfs_device *dev; list_for_each_entry(dev, head, dev_list) { if (dev->devid == devid && (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) { return dev; } } return NULL; } static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid) { struct btrfs_fs_devices *fs_devices; list_for_each_entry(fs_devices, &fs_uuids, list) { if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0) return fs_devices; } return NULL; } static void requeue_list(struct btrfs_pending_bios *pending_bios, struct bio *head, struct bio *tail) { struct bio *old_head; old_head = pending_bios->head; pending_bios->head = head; if (pending_bios->tail) tail->bi_next = old_head; else pending_bios->tail = tail; } /* * we try to collect pending bios for a device so we don't get a large * number of procs sending bios down to the same device. This greatly * improves the schedulers ability to collect and merge the bios. * * But, it also turns into a long list of bios to process and that is sure * to eventually make the worker thread block. The solution here is to * make some progress and then put this work struct back at the end of * the list if the block device is congested. This way, multiple devices * can make progress from a single worker thread. */ static noinline int run_scheduled_bios(struct btrfs_device *device) { struct bio *pending; struct backing_dev_info *bdi; struct btrfs_fs_info *fs_info; struct btrfs_pending_bios *pending_bios; struct bio *tail; struct bio *cur; int again = 0; unsigned long num_run; unsigned long num_sync_run; unsigned long limit; unsigned long last_waited = 0; bdi = blk_get_backing_dev_info(device->bdev); fs_info = device->dev_root->fs_info; limit = btrfs_async_submit_limit(fs_info); limit = limit * 2 / 3; /* we want to make sure that every time we switch from the sync * list to the normal list, we unplug */ num_sync_run = 0; loop: spin_lock(&device->io_lock); num_run = 0; loop_lock: /* take all the bios off the list at once and process them * later on (without the lock held). But, remember the * tail and other pointers so the bios can be properly reinserted * into the list if we hit congestion */ if (device->pending_sync_bios.head) pending_bios = &device->pending_sync_bios; else pending_bios = &device->pending_bios; pending = pending_bios->head; tail = pending_bios->tail; WARN_ON(pending && !tail); /* * if pending was null this time around, no bios need processing * at all and we can stop. Otherwise it'll loop back up again * and do an additional check so no bios are missed. * * device->running_pending is used to synchronize with the * schedule_bio code. */ if (device->pending_sync_bios.head == NULL && device->pending_bios.head == NULL) { again = 0; device->running_pending = 0; } else { again = 1; device->running_pending = 1; } pending_bios->head = NULL; pending_bios->tail = NULL; spin_unlock(&device->io_lock); /* * if we're doing the regular priority list, make sure we unplug * for any high prio bios we've sent down */ if (pending_bios == &device->pending_bios && num_sync_run > 0) { num_sync_run = 0; blk_run_backing_dev(bdi, NULL); } while (pending) { rmb(); if (pending_bios != &device->pending_sync_bios && device->pending_sync_bios.head && num_run > 16) { cond_resched(); spin_lock(&device->io_lock); requeue_list(pending_bios, pending, tail); goto loop_lock; } cur = pending; pending = pending->bi_next; cur->bi_next = NULL; atomic_dec(&fs_info->nr_async_bios); if (atomic_read(&fs_info->nr_async_bios) < limit && waitqueue_active(&fs_info->async_submit_wait)) wake_up(&fs_info->async_submit_wait); BUG_ON(atomic_read(&cur->bi_cnt) == 0); submit_bio(cur->bi_rw, cur); num_run++; if (bio_sync(cur)) num_sync_run++; if (need_resched()) { if (num_sync_run) { blk_run_backing_dev(bdi, NULL); num_sync_run = 0; } cond_resched(); } /* * we made progress, there is more work to do and the bdi * is now congested. Back off and let other work structs * run instead */ if (pending && bdi_write_congested(bdi) && num_run > 16 && fs_info->fs_devices->open_devices > 1) { struct io_context *ioc; ioc = current->io_context; /* * the main goal here is that we don't want to * block if we're going to be able to submit * more requests without blocking. * * This code does two great things, it pokes into * the elevator code from a filesystem _and_ * it makes assumptions about how batching works. */ if (ioc && ioc->nr_batch_requests > 0 && time_before(jiffies, ioc->last_waited + HZ/50UL) && (last_waited == 0 || ioc->last_waited == last_waited)) { /* * we want to go through our batch of * requests and stop. So, we copy out * the ioc->last_waited time and test * against it before looping */ last_waited = ioc->last_waited; if (need_resched()) { if (num_sync_run) { blk_run_backing_dev(bdi, NULL); num_sync_run = 0; } cond_resched(); } continue; } spin_lock(&device->io_lock); requeue_list(pending_bios, pending, tail); device->running_pending = 1; spin_unlock(&device->io_lock); btrfs_requeue_work(&device->work); goto done; } } if (num_sync_run) { num_sync_run = 0; blk_run_backing_dev(bdi, NULL); } cond_resched(); if (again) goto loop; spin_lock(&device->io_lock); if (device->pending_bios.head || device->pending_sync_bios.head) goto loop_lock; spin_unlock(&device->io_lock); /* * IO has already been through a long path to get here. Checksumming, * async helper threads, perhaps compression. We've done a pretty * good job of collecting a batch of IO and should just unplug * the device right away. * * This will help anyone who is waiting on the IO, they might have * already unplugged, but managed to do so before the bio they * cared about found its way down here. */ blk_run_backing_dev(bdi, NULL); done: return 0; } static void pending_bios_fn(struct btrfs_work *work) { struct btrfs_device *device; device = container_of(work, struct btrfs_device, work); run_scheduled_bios(device); } static noinline int device_list_add(const char *path, struct btrfs_super_block *disk_super, u64 devid, struct btrfs_fs_devices **fs_devices_ret) { struct btrfs_device *device; struct btrfs_fs_devices *fs_devices; u64 found_transid = btrfs_super_generation(disk_super); fs_devices = find_fsid(disk_super->fsid); if (!fs_devices) { fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS); if (!fs_devices) return -ENOMEM; INIT_LIST_HEAD(&fs_devices->devices); INIT_LIST_HEAD(&fs_devices->alloc_list); list_add(&fs_devices->list, &fs_uuids); memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE); fs_devices->latest_devid = devid; fs_devices->latest_trans = found_transid; device = NULL; } else { device = __find_device(&fs_devices->devices, devid, disk_super->dev_item.uuid); } if (!device) { if (fs_devices->opened) return -EBUSY; device = kzalloc(sizeof(*device), GFP_NOFS); if (!device) { /* we can safely leave the fs_devices entry around */ return -ENOMEM; } device->devid = devid; device->work.func = pending_bios_fn; memcpy(device->uuid, disk_super->dev_item.uuid, BTRFS_UUID_SIZE); device->barriers = 1; spin_lock_init(&device->io_lock); device->name = kstrdup(path, GFP_NOFS); if (!device->name) { kfree(device); return -ENOMEM; } INIT_LIST_HEAD(&device->dev_alloc_list); list_add(&device->dev_list, &fs_devices->devices); device->fs_devices = fs_devices; fs_devices->num_devices++; } if (found_transid > fs_devices->latest_trans) { fs_devices->latest_devid = devid; fs_devices->latest_trans = found_transid; } *fs_devices_ret = fs_devices; return 0; } static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig) { struct btrfs_fs_devices *fs_devices; struct btrfs_device *device; struct btrfs_device *orig_dev; fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS); if (!fs_devices) return ERR_PTR(-ENOMEM); INIT_LIST_HEAD(&fs_devices->devices); INIT_LIST_HEAD(&fs_devices->alloc_list); INIT_LIST_HEAD(&fs_devices->list); fs_devices->latest_devid = orig->latest_devid; fs_devices->latest_trans = orig->latest_trans; memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid)); list_for_each_entry(orig_dev, &orig->devices, dev_list) { device = kzalloc(sizeof(*device), GFP_NOFS); if (!device) goto error; device->name = kstrdup(orig_dev->name, GFP_NOFS); if (!device->name) goto error; device->devid = orig_dev->devid; device->work.func = pending_bios_fn; memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid)); device->barriers = 1; spin_lock_init(&device->io_lock); INIT_LIST_HEAD(&device->dev_list); INIT_LIST_HEAD(&device->dev_alloc_list); list_add(&device->dev_list, &fs_devices->devices); device->fs_devices = fs_devices; fs_devices->num_devices++; } return fs_devices; error: free_fs_devices(fs_devices); return ERR_PTR(-ENOMEM); } int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices) { struct btrfs_device *device, *next; mutex_lock(&uuid_mutex); again: list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) { if (device->in_fs_metadata) continue; if (device->bdev) { close_bdev_exclusive(device->bdev, device->mode); device->bdev = NULL; fs_devices->open_devices--; } if (device->writeable) { list_del_init(&device->dev_alloc_list); device->writeable = 0; fs_devices->rw_devices--; } list_del_init(&device->dev_list); fs_devices->num_devices--; kfree(device->name); kfree(device); } if (fs_devices->seed) { fs_devices = fs_devices->seed; goto again; } mutex_unlock(&uuid_mutex); return 0; } static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices) { struct btrfs_device *device; if (--fs_devices->opened > 0) return 0; list_for_each_entry(device, &fs_devices->devices, dev_list) { if (device->bdev) { close_bdev_exclusive(device->bdev, device->mode); fs_devices->open_devices--; } if (device->writeable) { list_del_init(&device->dev_alloc_list); fs_devices->rw_devices--; } device->bdev = NULL; device->writeable = 0; device->in_fs_metadata = 0; } WARN_ON(fs_devices->open_devices); WARN_ON(fs_devices->rw_devices); fs_devices->opened = 0; fs_devices->seeding = 0; return 0; } int btrfs_close_devices(struct btrfs_fs_devices *fs_devices) { struct btrfs_fs_devices *seed_devices = NULL; int ret; mutex_lock(&uuid_mutex); ret = __btrfs_close_devices(fs_devices); if (!fs_devices->opened) { seed_devices = fs_devices->seed; fs_devices->seed = NULL; } mutex_unlock(&uuid_mutex); while (seed_devices) { fs_devices = seed_devices; seed_devices = fs_devices->seed; __btrfs_close_devices(fs_devices); free_fs_devices(fs_devices); } return ret; } static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices, fmode_t flags, void *holder) { struct block_device *bdev; struct list_head *head = &fs_devices->devices; struct btrfs_device *device; struct block_device *latest_bdev = NULL; struct buffer_head *bh; struct btrfs_super_block *disk_super; u64 latest_devid = 0; u64 latest_transid = 0; u64 devid; int seeding = 1; int ret = 0; list_for_each_entry(device, head, dev_list) { if (device->bdev) continue; if (!device->name) continue; bdev = open_bdev_exclusive(device->name, flags, holder); if (IS_ERR(bdev)) { printk(KERN_INFO "open %s failed\n", device->name); goto error; } set_blocksize(bdev, 4096); bh = btrfs_read_dev_super(bdev); if (!bh) goto error_close; disk_super = (struct btrfs_super_block *)bh->b_data; devid = le64_to_cpu(disk_super->dev_item.devid); if (devid != device->devid) goto error_brelse; if (memcmp(device->uuid, disk_super->dev_item.uuid, BTRFS_UUID_SIZE)) goto error_brelse; device->generation = btrfs_super_generation(disk_super); if (!latest_transid || device->generation > latest_transid) { latest_devid = devid; latest_transid = device->generation; latest_bdev = bdev; } if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) { device->writeable = 0; } else { device->writeable = !bdev_read_only(bdev); seeding = 0; } device->bdev = bdev; device->in_fs_metadata = 0; device->mode = flags; fs_devices->open_devices++; if (device->writeable) { fs_devices->rw_devices++; list_add(&device->dev_alloc_list, &fs_devices->alloc_list); } continue; error_brelse: brelse(bh); error_close: close_bdev_exclusive(bdev, FMODE_READ); error: continue; } if (fs_devices->open_devices == 0) { ret = -EIO; goto out; } fs_devices->seeding = seeding; fs_devices->opened = 1; fs_devices->latest_bdev = latest_bdev; fs_devices->latest_devid = latest_devid; fs_devices->latest_trans = latest_transid; fs_devices->total_rw_bytes = 0; out: return ret; } int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, fmode_t flags, void *holder) { int ret; mutex_lock(&uuid_mutex); if (fs_devices->opened) { fs_devices->opened++; ret = 0; } else { ret = __btrfs_open_devices(fs_devices, flags, holder); } mutex_unlock(&uuid_mutex); return ret; } int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder, struct btrfs_fs_devices **fs_devices_ret) { struct btrfs_super_block *disk_super; struct block_device *bdev; struct buffer_head *bh; int ret; u64 devid; u64 transid; mutex_lock(&uuid_mutex); bdev = open_bdev_exclusive(path, flags, holder); if (IS_ERR(bdev)) { ret = PTR_ERR(bdev); goto error; } ret = set_blocksize(bdev, 4096); if (ret) goto error_close; bh = btrfs_read_dev_super(bdev); if (!bh) { ret = -EIO; goto error_close; } disk_super = (struct btrfs_super_block *)bh->b_data; devid = le64_to_cpu(disk_super->dev_item.devid); transid = btrfs_super_generation(disk_super); if (disk_super->label[0]) printk(KERN_INFO "device label %s ", disk_super->label); else { /* FIXME, make a readl uuid parser */ printk(KERN_INFO "device fsid %llx-%llx ", *(unsigned long long *)disk_super->fsid, *(unsigned long long *)(disk_super->fsid + 8)); } printk(KERN_CONT "devid %llu transid %llu %s\n", (unsigned long long)devid, (unsigned long long)transid, path); ret = device_list_add(path, disk_super, devid, fs_devices_ret); brelse(bh); error_close: close_bdev_exclusive(bdev, flags); error: mutex_unlock(&uuid_mutex); return ret; } /* * this uses a pretty simple search, the expectation is that it is * called very infrequently and that a given device has a small number * of extents */ static noinline int find_free_dev_extent(struct btrfs_trans_handle *trans, struct btrfs_device *device, u64 num_bytes, u64 *start) { struct btrfs_key key; struct btrfs_root *root = device->dev_root; struct btrfs_dev_extent *dev_extent = NULL; struct btrfs_path *path; u64 hole_size = 0; u64 last_byte = 0; u64 search_start = 0; u64 search_end = device->total_bytes; int ret; int slot = 0; int start_found; struct extent_buffer *l; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = 2; start_found = 0; /* FIXME use last free of some kind */ /* we don't want to overwrite the superblock on the drive, * so we make sure to start at an offset of at least 1MB */ search_start = max((u64)1024 * 1024, search_start); if (root->fs_info->alloc_start + num_bytes <= device->total_bytes) search_start = max(root->fs_info->alloc_start, search_start); key.objectid = device->devid; key.offset = search_start; key.type = BTRFS_DEV_EXTENT_KEY; ret = btrfs_search_slot(trans, root, &key, path, 0, 0); if (ret < 0) goto error; ret = btrfs_previous_item(root, path, 0, key.type); if (ret < 0) goto error; l = path->nodes[0]; btrfs_item_key_to_cpu(l, &key, path->slots[0]); while (1) { l = path->nodes[0]; slot = path->slots[0]; if (slot >= btrfs_header_nritems(l)) { ret = btrfs_next_leaf(root, path); if (ret == 0) continue; if (ret < 0) goto error; no_more_items: if (!start_found) { if (search_start >= search_end) { ret = -ENOSPC; goto error; } *start = search_start; start_found = 1; goto check_pending; } *start = last_byte > search_start ? last_byte : search_start; if (search_end <= *start) { ret = -ENOSPC; goto error; } goto check_pending; } btrfs_item_key_to_cpu(l, &key, slot); if (key.objectid < device->devid) goto next; if (key.objectid > device->devid) goto no_more_items; if (key.offset >= search_start && key.offset > last_byte && start_found) { if (last_byte < search_start) last_byte = search_start; hole_size = key.offset - last_byte; if (key.offset > last_byte && hole_size >= num_bytes) { *start = last_byte; goto check_pending; } } if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) goto next; start_found = 1; dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent); next: path->slots[0]++; cond_resched(); } check_pending: /* we have to make sure we didn't find an extent that has already * been allocated by the map tree or the original allocation */ BUG_ON(*start < search_start); if (*start + num_bytes > search_end) { ret = -ENOSPC; goto error; } /* check for pending inserts here */ ret = 0; error: btrfs_free_path(path); return ret; } static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans, struct btrfs_device *device, u64 start) { int ret; struct btrfs_path *path; struct btrfs_root *root = device->dev_root; struct btrfs_key key; struct btrfs_key found_key; struct extent_buffer *leaf = NULL; struct btrfs_dev_extent *extent = NULL; path = btrfs_alloc_path(); if (!path) return -ENOMEM; key.objectid = device->devid; key.offset = start; key.type = BTRFS_DEV_EXTENT_KEY; ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret > 0) { ret = btrfs_previous_item(root, path, key.objectid, BTRFS_DEV_EXTENT_KEY); BUG_ON(ret); leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); extent = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_extent); BUG_ON(found_key.offset > start || found_key.offset + btrfs_dev_extent_length(leaf, extent) < start); ret = 0; } else if (ret == 0) { leaf = path->nodes[0]; extent = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_extent); } BUG_ON(ret); if (device->bytes_used > 0) device->bytes_used -= btrfs_dev_extent_length(leaf, extent); ret = btrfs_del_item(trans, root, path); BUG_ON(ret); btrfs_free_path(path); return ret; } int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans, struct btrfs_device *device, u64 chunk_tree, u64 chunk_objectid, u64 chunk_offset, u64 start, u64 num_bytes) { int ret; struct btrfs_path *path; struct btrfs_root *root = device->dev_root; struct btrfs_dev_extent *extent; struct extent_buffer *leaf; struct btrfs_key key; WARN_ON(!device->in_fs_metadata); path = btrfs_alloc_path(); if (!path) return -ENOMEM; key.objectid = device->devid; key.offset = start; key.type = BTRFS_DEV_EXTENT_KEY; ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*extent)); BUG_ON(ret); leaf = path->nodes[0]; extent = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_extent); btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree); btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid); btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset); write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid, (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent), BTRFS_UUID_SIZE); btrfs_set_dev_extent_length(leaf, extent, num_bytes); btrfs_mark_buffer_dirty(leaf); btrfs_free_path(path); return ret; } static noinline int find_next_chunk(struct btrfs_root *root, u64 objectid, u64 *offset) { struct btrfs_path *path; int ret; struct btrfs_key key; struct btrfs_chunk *chunk; struct btrfs_key found_key; path = btrfs_alloc_path(); BUG_ON(!path); key.objectid = objectid; key.offset = (u64)-1; key.type = BTRFS_CHUNK_ITEM_KEY; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto error; BUG_ON(ret == 0); ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY); if (ret) { *offset = 0; } else { btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); if (found_key.objectid != objectid) *offset = 0; else { chunk = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_chunk); *offset = found_key.offset + btrfs_chunk_length(path->nodes[0], chunk); } } ret = 0; error: btrfs_free_path(path); return ret; } static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid) { int ret; struct btrfs_key key; struct btrfs_key found_key; struct btrfs_path *path; root = root->fs_info->chunk_root; path = btrfs_alloc_path(); if (!path) return -ENOMEM; key.objectid = BTRFS_DEV_ITEMS_OBJECTID; key.type = BTRFS_DEV_ITEM_KEY; key.offset = (u64)-1; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto error; BUG_ON(ret == 0); ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID, BTRFS_DEV_ITEM_KEY); if (ret) { *objectid = 1; } else { btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); *objectid = found_key.offset + 1; } ret = 0; error: btrfs_free_path(path); return ret; } /* * the device information is stored in the chunk root * the btrfs_device struct should be fully filled in */ int btrfs_add_device(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_device *device) { int ret; struct btrfs_path *path; struct btrfs_dev_item *dev_item; struct extent_buffer *leaf; struct btrfs_key key; unsigned long ptr; root = root->fs_info->chunk_root; path = btrfs_alloc_path(); if (!path) return -ENOMEM; key.objectid = BTRFS_DEV_ITEMS_OBJECTID; key.type = BTRFS_DEV_ITEM_KEY; key.offset = device->devid; ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*dev_item)); if (ret) goto out; leaf = path->nodes[0]; dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item); btrfs_set_device_id(leaf, dev_item, device->devid); btrfs_set_device_generation(leaf, dev_item, 0); btrfs_set_device_type(leaf, dev_item, device->type); btrfs_set_device_io_align(leaf, dev_item, device->io_align); btrfs_set_device_io_width(leaf, dev_item, device->io_width); btrfs_set_device_sector_size(leaf, dev_item, device->sector_size); btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes); btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used); btrfs_set_device_group(leaf, dev_item, 0); btrfs_set_device_seek_speed(leaf, dev_item, 0); btrfs_set_device_bandwidth(leaf, dev_item, 0); btrfs_set_device_start_offset(leaf, dev_item, 0); ptr = (unsigned long)btrfs_device_uuid(dev_item); write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE); ptr = (unsigned long)btrfs_device_fsid(dev_item); write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE); btrfs_mark_buffer_dirty(leaf); ret = 0; out: btrfs_free_path(path); return ret; } static int btrfs_rm_dev_item(struct btrfs_root *root, struct btrfs_device *device) { int ret; struct btrfs_path *path; struct btrfs_key key; struct btrfs_trans_handle *trans; root = root->fs_info->chunk_root; path = btrfs_alloc_path(); if (!path) return -ENOMEM; trans = btrfs_start_transaction(root, 1); key.objectid = BTRFS_DEV_ITEMS_OBJECTID; key.type = BTRFS_DEV_ITEM_KEY; key.offset = device->devid; lock_chunks(root); ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret < 0) goto out; if (ret > 0) { ret = -ENOENT; goto out; } ret = btrfs_del_item(trans, root, path); if (ret) goto out; out: btrfs_free_path(path); unlock_chunks(root); btrfs_commit_transaction(trans, root); return ret; } int btrfs_rm_device(struct btrfs_root *root, char *device_path) { struct btrfs_device *device; struct btrfs_device *next_device; struct block_device *bdev; struct buffer_head *bh = NULL; struct btrfs_super_block *disk_super; u64 all_avail; u64 devid; u64 num_devices; u8 *dev_uuid; int ret = 0; mutex_lock(&uuid_mutex); mutex_lock(&root->fs_info->volume_mutex); all_avail = root->fs_info->avail_data_alloc_bits | root->fs_info->avail_system_alloc_bits | root->fs_info->avail_metadata_alloc_bits; if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && root->fs_info->fs_devices->rw_devices <= 4) { printk(KERN_ERR "btrfs: unable to go below four devices " "on raid10\n"); ret = -EINVAL; goto out; } if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && root->fs_info->fs_devices->rw_devices <= 2) { printk(KERN_ERR "btrfs: unable to go below two " "devices on raid1\n"); ret = -EINVAL; goto out; } if (strcmp(device_path, "missing") == 0) { struct list_head *devices; struct btrfs_device *tmp; device = NULL; devices = &root->fs_info->fs_devices->devices; list_for_each_entry(tmp, devices, dev_list) { if (tmp->in_fs_metadata && !tmp->bdev) { device = tmp; break; } } bdev = NULL; bh = NULL; disk_super = NULL; if (!device) { printk(KERN_ERR "btrfs: no missing devices found to " "remove\n"); goto out; } } else { bdev = open_bdev_exclusive(device_path, FMODE_READ, root->fs_info->bdev_holder); if (IS_ERR(bdev)) { ret = PTR_ERR(bdev); goto out; } set_blocksize(bdev, 4096); bh = btrfs_read_dev_super(bdev); if (!bh) { ret = -EIO; goto error_close; } disk_super = (struct btrfs_super_block *)bh->b_data; devid = le64_to_cpu(disk_super->dev_item.devid); dev_uuid = disk_super->dev_item.uuid; device = btrfs_find_device(root, devid, dev_uuid, disk_super->fsid); if (!device) { ret = -ENOENT; goto error_brelse; } } if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) { printk(KERN_ERR "btrfs: unable to remove the only writeable " "device\n"); ret = -EINVAL; goto error_brelse; } if (device->writeable) { list_del_init(&device->dev_alloc_list); root->fs_info->fs_devices->rw_devices--; } ret = btrfs_shrink_device(device, 0); if (ret) goto error_brelse; ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device); if (ret) goto error_brelse; device->in_fs_metadata = 0; list_del_init(&device->dev_list); device->fs_devices->num_devices--; next_device = list_entry(root->fs_info->fs_devices->devices.next, struct btrfs_device, dev_list); if (device->bdev == root->fs_info->sb->s_bdev) root->fs_info->sb->s_bdev = next_device->bdev; if (device->bdev == root->fs_info->fs_devices->latest_bdev) root->fs_info->fs_devices->latest_bdev = next_device->bdev; if (device->bdev) { close_bdev_exclusive(device->bdev, device->mode); device->bdev = NULL; device->fs_devices->open_devices--; } num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1; btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices); if (device->fs_devices->open_devices == 0) { struct btrfs_fs_devices *fs_devices; fs_devices = root->fs_info->fs_devices; while (fs_devices) { if (fs_devices->seed == device->fs_devices) break; fs_devices = fs_devices->seed; } fs_devices->seed = device->fs_devices->seed; device->fs_devices->seed = NULL; __btrfs_close_devices(device->fs_devices); free_fs_devices(device->fs_devices); } /* * at this point, the device is zero sized. We want to * remove it from the devices list and zero out the old super */ if (device->writeable) { /* make sure this device isn't detected as part of * the FS anymore */ memset(&disk_super->magic, 0, sizeof(disk_super->magic)); set_buffer_dirty(bh); sync_dirty_buffer(bh); } kfree(device->name); kfree(device); ret = 0; error_brelse: brelse(bh); error_close: if (bdev) close_bdev_exclusive(bdev, FMODE_READ); out: mutex_unlock(&root->fs_info->volume_mutex); mutex_unlock(&uuid_mutex); return ret; } /* * does all the dirty work required for changing file system's UUID. */ static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; struct btrfs_fs_devices *old_devices; struct btrfs_fs_devices *seed_devices; struct btrfs_super_block *disk_super = &root->fs_info->super_copy; struct btrfs_device *device; u64 super_flags; BUG_ON(!mutex_is_locked(&uuid_mutex)); if (!fs_devices->seeding) return -EINVAL; seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS); if (!seed_devices) return -ENOMEM; old_devices = clone_fs_devices(fs_devices); if (IS_ERR(old_devices)) { kfree(seed_devices); return PTR_ERR(old_devices); } list_add(&old_devices->list, &fs_uuids); memcpy(seed_devices, fs_devices, sizeof(*seed_devices)); seed_devices->opened = 1; INIT_LIST_HEAD(&seed_devices->devices); INIT_LIST_HEAD(&seed_devices->alloc_list); list_splice_init(&fs_devices->devices, &seed_devices->devices); list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list); list_for_each_entry(device, &seed_devices->devices, dev_list) { device->fs_devices = seed_devices; } fs_devices->seeding = 0; fs_devices->num_devices = 0; fs_devices->open_devices = 0; fs_devices->seed = seed_devices; generate_random_uuid(fs_devices->fsid); memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE); memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE); super_flags = btrfs_super_flags(disk_super) & ~BTRFS_SUPER_FLAG_SEEDING; btrfs_set_super_flags(disk_super, super_flags); return 0; } /* * strore the expected generation for seed devices in device items. */ static int btrfs_finish_sprout(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_dev_item *dev_item; struct btrfs_device *device; struct btrfs_key key; u8 fs_uuid[BTRFS_UUID_SIZE]; u8 dev_uuid[BTRFS_UUID_SIZE]; u64 devid; int ret; path = btrfs_alloc_path(); if (!path) return -ENOMEM; root = root->fs_info->chunk_root; key.objectid = BTRFS_DEV_ITEMS_OBJECTID; key.offset = 0; key.type = BTRFS_DEV_ITEM_KEY; while (1) { ret = btrfs_search_slot(trans, root, &key, path, 0, 1); if (ret < 0) goto error; leaf = path->nodes[0]; next_slot: if (path->slots[0] >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret > 0) break; if (ret < 0) goto error; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); btrfs_release_path(root, path); continue; } btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID || key.type != BTRFS_DEV_ITEM_KEY) break; dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item); devid = btrfs_device_id(leaf, dev_item); read_extent_buffer(leaf, dev_uuid, (unsigned long)btrfs_device_uuid(dev_item), BTRFS_UUID_SIZE); read_extent_buffer(leaf, fs_uuid, (unsigned long)btrfs_device_fsid(dev_item), BTRFS_UUID_SIZE); device = btrfs_find_device(root, devid, dev_uuid, fs_uuid); BUG_ON(!device); if (device->fs_devices->seeding) { btrfs_set_device_generation(leaf, dev_item, device->generation); btrfs_mark_buffer_dirty(leaf); } path->slots[0]++; goto next_slot; } ret = 0; error: btrfs_free_path(path); return ret; } int btrfs_init_new_device(struct btrfs_root *root, char *device_path) { struct btrfs_trans_handle *trans; struct btrfs_device *device; struct block_device *bdev; struct list_head *devices; struct super_block *sb = root->fs_info->sb; u64 total_bytes; int seeding_dev = 0; int ret = 0; if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding) return -EINVAL; bdev = open_bdev_exclusive(device_path, 0, root->fs_info->bdev_holder); if (!bdev) return -EIO; if (root->fs_info->fs_devices->seeding) { seeding_dev = 1; down_write(&sb->s_umount); mutex_lock(&uuid_mutex); } filemap_write_and_wait(bdev->bd_inode->i_mapping); mutex_lock(&root->fs_info->volume_mutex); devices = &root->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) { /* we can safely leave the fs_devices entry around */ ret = -ENOMEM; goto error; } device->name = kstrdup(device_path, GFP_NOFS); if (!device->name) { kfree(device); ret = -ENOMEM; goto error; } ret = find_next_devid(root, &device->devid); if (ret) { kfree(device); goto error; } trans = btrfs_start_transaction(root, 1); lock_chunks(root); device->barriers = 1; device->writeable = 1; device->work.func = pending_bios_fn; generate_random_uuid(device->uuid); spin_lock_init(&device->io_lock); device->generation = trans->transid; 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->dev_root = root->fs_info->dev_root; device->bdev = bdev; device->in_fs_metadata = 1; device->mode = 0; set_blocksize(device->bdev, 4096); if (seeding_dev) { sb->s_flags &= ~MS_RDONLY; ret = btrfs_prepare_sprout(trans, root); BUG_ON(ret); } device->fs_devices = root->fs_info->fs_devices; list_add(&device->dev_list, &root->fs_info->fs_devices->devices); list_add(&device->dev_alloc_list, &root->fs_info->fs_devices->alloc_list); root->fs_info->fs_devices->num_devices++; root->fs_info->fs_devices->open_devices++; root->fs_info->fs_devices->rw_devices++; root->fs_info->fs_devices->total_rw_bytes += device->total_bytes; total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy); btrfs_set_super_total_bytes(&root->fs_info->super_copy, total_bytes + device->total_bytes); total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy); btrfs_set_super_num_devices(&root->fs_info->super_copy, total_bytes + 1); if (seeding_dev) { ret = init_first_rw_device(trans, root, device); BUG_ON(ret); ret = btrfs_finish_sprout(trans, root); BUG_ON(ret); } else { ret = btrfs_add_device(trans, root, device); } /* * we've got more storage, clear any full flags on the space * infos */ btrfs_clear_space_info_full(root->fs_info); unlock_chunks(root); btrfs_commit_transaction(trans, root); if (seeding_dev) { mutex_unlock(&uuid_mutex); up_write(&sb->s_umount); ret = btrfs_relocate_sys_chunks(root); BUG_ON(ret); } out: mutex_unlock(&root->fs_info->volume_mutex); return ret; error: close_bdev_exclusive(bdev, 0); if (seeding_dev) { mutex_unlock(&uuid_mutex); up_write(&sb->s_umount); } goto out; } static noinline int btrfs_update_device(struct btrfs_trans_handle *trans, struct btrfs_device *device) { int ret; struct btrfs_path *path; struct btrfs_root *root; struct btrfs_dev_item *dev_item; struct extent_buffer *leaf; struct btrfs_key key; root = device->dev_root->fs_info->chunk_root; path = btrfs_alloc_path(); if (!path) return -ENOMEM; key.objectid = BTRFS_DEV_ITEMS_OBJECTID; key.type = BTRFS_DEV_ITEM_KEY; key.offset = device->devid; ret = btrfs_search_slot(trans, root, &key, path, 0, 1); if (ret < 0) goto out; if (ret > 0) { ret = -ENOENT; goto out; } leaf = path->nodes[0]; dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item); btrfs_set_device_id(leaf, dev_item, device->devid); btrfs_set_device_type(leaf, dev_item, device->type); btrfs_set_device_io_align(leaf, dev_item, device->io_align); btrfs_set_device_io_width(leaf, dev_item, device->io_width); btrfs_set_device_sector_size(leaf, dev_item, device->sector_size); btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes); btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used); btrfs_mark_buffer_dirty(leaf); out: btrfs_free_path(path); return ret; } static int __btrfs_grow_device(struct btrfs_trans_handle *trans, struct btrfs_device *device, u64 new_size) { struct btrfs_super_block *super_copy = &device->dev_root->fs_info->super_copy; u64 old_total = btrfs_super_total_bytes(super_copy); u64 diff = new_size - device->total_bytes; if (!device->writeable) return -EACCES; if (new_size <= device->total_bytes) return -EINVAL; btrfs_set_super_total_bytes(super_copy, old_total + diff); device->fs_devices->total_rw_bytes += diff; device->total_bytes = new_size; btrfs_clear_space_info_full(device->dev_root->fs_info); return btrfs_update_device(trans, device); } int btrfs_grow_device(struct btrfs_trans_handle *trans, struct btrfs_device *device, u64 new_size) { int ret; lock_chunks(device->dev_root); ret = __btrfs_grow_device(trans, device, new_size); unlock_chunks(device->dev_root); return ret; } static int btrfs_free_chunk(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 chunk_tree, u64 chunk_objectid, u64 chunk_offset) { int ret; struct btrfs_path *path; struct btrfs_key key; root = root->fs_info->chunk_root; path = btrfs_alloc_path(); if (!path) return -ENOMEM; key.objectid = chunk_objectid; key.offset = chunk_offset; key.type = BTRFS_CHUNK_ITEM_KEY; ret = btrfs_search_slot(trans, root, &key, path, -1, 1); BUG_ON(ret); ret = btrfs_del_item(trans, root, path); BUG_ON(ret); btrfs_free_path(path); return 0; } static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64 chunk_offset) { struct btrfs_super_block *super_copy = &root->fs_info->super_copy; struct btrfs_disk_key *disk_key; struct btrfs_chunk *chunk; u8 *ptr; int ret = 0; u32 num_stripes; u32 array_size; u32 len = 0; u32 cur; struct btrfs_key key; array_size = btrfs_super_sys_array_size(super_copy); ptr = super_copy->sys_chunk_array; cur = 0; while (cur < array_size) { disk_key = (struct btrfs_disk_key *)ptr; btrfs_disk_key_to_cpu(&key, disk_key); len = sizeof(*disk_key); if (key.type == BTRFS_CHUNK_ITEM_KEY) { chunk = (struct btrfs_chunk *)(ptr + len); num_stripes = btrfs_stack_chunk_num_stripes(chunk); len += btrfs_chunk_item_size(num_stripes); } else { ret = -EIO; break; } if (key.objectid == chunk_objectid && key.offset == chunk_offset) { memmove(ptr, ptr + len, array_size - (cur + len)); array_size -= len; btrfs_set_super_sys_array_size(super_copy, array_size); } else { ptr += len; cur += len; } } return ret; } static int btrfs_relocate_chunk(struct btrfs_root *root, u64 chunk_tree, u64 chunk_objectid, u64 chunk_offset) { struct extent_map_tree *em_tree; struct btrfs_root *extent_root; struct btrfs_trans_handle *trans; struct extent_map *em; struct map_lookup *map; int ret; int i; printk(KERN_INFO "btrfs relocating chunk %llu\n", (unsigned long long)chunk_offset); root = root->fs_info->chunk_root; extent_root = root->fs_info->extent_root; em_tree = &root->fs_info->mapping_tree.map_tree; /* step one, relocate all the extents inside this chunk */ ret = btrfs_relocate_block_group(extent_root, chunk_offset); BUG_ON(ret); trans = btrfs_start_transaction(root, 1); BUG_ON(!trans); lock_chunks(root); /* * step two, delete the device extents and the * chunk tree entries */ spin_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, chunk_offset, 1); spin_unlock(&em_tree->lock); BUG_ON(em->start > chunk_offset || em->start + em->len < chunk_offset); map = (struct map_lookup *)em->bdev; for (i = 0; i < map->num_stripes; i++) { ret = btrfs_free_dev_extent(trans, map->stripes[i].dev, map->stripes[i].physical); BUG_ON(ret); if (map->stripes[i].dev) { ret = btrfs_update_device(trans, map->stripes[i].dev); BUG_ON(ret); } } ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid, chunk_offset); BUG_ON(ret); if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) { ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset); BUG_ON(ret); } ret = btrfs_remove_block_group(trans, extent_root, chunk_offset); BUG_ON(ret); spin_lock(&em_tree->lock); remove_extent_mapping(em_tree, em); spin_unlock(&em_tree->lock); kfree(map); em->bdev = NULL; /* once for the tree */ free_extent_map(em); /* once for us */ free_extent_map(em); unlock_chunks(root); btrfs_end_transaction(trans, root); return 0; } static int btrfs_relocate_sys_chunks(struct btrfs_root *root) { struct btrfs_root *chunk_root = root->fs_info->chunk_root; struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_chunk *chunk; struct btrfs_key key; struct btrfs_key found_key; u64 chunk_tree = chunk_root->root_key.objectid; u64 chunk_type; int ret; path = btrfs_alloc_path(); if (!path) return -ENOMEM; key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; key.offset = (u64)-1; key.type = BTRFS_CHUNK_ITEM_KEY; while (1) { ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0); if (ret < 0) goto error; BUG_ON(ret == 0); ret = btrfs_previous_item(chunk_root, path, key.objectid, key.type); if (ret < 0) goto error; if (ret > 0) break; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); chunk = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_chunk); chunk_type = btrfs_chunk_type(leaf, chunk); btrfs_release_path(chunk_root, path); if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) { ret = btrfs_relocate_chunk(chunk_root, chunk_tree, found_key.objectid, found_key.offset); BUG_ON(ret); } if (found_key.offset == 0) break; key.offset = found_key.offset - 1; } ret = 0; error: btrfs_free_path(path); return ret; } static u64 div_factor(u64 num, int factor) { if (factor == 10) return num; num *= factor; do_div(num, 10); return num; } int btrfs_balance(struct btrfs_root *dev_root) { int ret; struct list_head *devices = &dev_root->fs_info->fs_devices->devices; struct btrfs_device *device; u64 old_size; u64 size_to_free; struct btrfs_path *path; struct btrfs_key key; struct btrfs_chunk *chunk; struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root; struct btrfs_trans_handle *trans; struct btrfs_key found_key; if (dev_root->fs_info->sb->s_flags & MS_RDONLY) return -EROFS; mutex_lock(&dev_root->fs_info->volume_mutex); dev_root = dev_root->fs_info->dev_root; /* step one make some room on all the devices */ list_for_each_entry(device, devices, dev_list) { old_size = device->total_bytes; size_to_free = div_factor(old_size, 1); size_to_free = min(size_to_free, (u64)1 * 1024 * 1024); if (!device->writeable || device->total_bytes - device->bytes_used > size_to_free) continue; ret = btrfs_shrink_device(device, old_size - size_to_free); BUG_ON(ret); trans = btrfs_start_transaction(dev_root, 1); BUG_ON(!trans); ret = btrfs_grow_device(trans, device, old_size); BUG_ON(ret); btrfs_end_transaction(trans, dev_root); } /* step two, relocate all the chunks */ path = btrfs_alloc_path(); BUG_ON(!path); key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; key.offset = (u64)-1; key.type = BTRFS_CHUNK_ITEM_KEY; while (1) { ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0); if (ret < 0) goto error; /* * this shouldn't happen, it means the last relocate * failed */ if (ret == 0) break; ret = btrfs_previous_item(chunk_root, path, 0, BTRFS_CHUNK_ITEM_KEY); if (ret) break; btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); if (found_key.objectid != key.objectid) break; chunk = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_chunk); key.offset = found_key.offset; /* chunk zero is special */ if (key.offset == 0) break; btrfs_release_path(chunk_root, path); ret = btrfs_relocate_chunk(chunk_root, chunk_root->root_key.objectid, found_key.objectid, found_key.offset); BUG_ON(ret); } ret = 0; error: btrfs_free_path(path); mutex_unlock(&dev_root->fs_info->volume_mutex); return ret; } /* * shrinking a device means finding all of the device extents past * the new size, and then following the back refs to the chunks. * The chunk relocation code actually frees the device extent */ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size) { struct btrfs_trans_handle *trans; struct btrfs_root *root = device->dev_root; struct btrfs_dev_extent *dev_extent = NULL; struct btrfs_path *path; u64 length; u64 chunk_tree; u64 chunk_objectid; u64 chunk_offset; int ret; int slot; struct extent_buffer *l; struct btrfs_key key; struct btrfs_super_block *super_copy = &root->fs_info->super_copy; u64 old_total = btrfs_super_total_bytes(super_copy); u64 diff = device->total_bytes - new_size; if (new_size >= device->total_bytes) return -EINVAL; path = btrfs_alloc_path(); if (!path) return -ENOMEM; trans = btrfs_start_transaction(root, 1); if (!trans) { ret = -ENOMEM; goto done; } path->reada = 2; lock_chunks(root); device->total_bytes = new_size; if (device->writeable) device->fs_devices->total_rw_bytes -= diff; ret = btrfs_update_device(trans, device); if (ret) { unlock_chunks(root); btrfs_end_transaction(trans, root); goto done; } WARN_ON(diff > old_total); btrfs_set_super_total_bytes(super_copy, old_total - diff); unlock_chunks(root); btrfs_end_transaction(trans, root); key.objectid = device->devid; key.offset = (u64)-1; key.type = BTRFS_DEV_EXTENT_KEY; while (1) { ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto done; ret = btrfs_previous_item(root, path, 0, key.type); if (ret < 0) goto done; if (ret) { ret = 0; goto done; } l = path->nodes[0]; slot = path->slots[0]; btrfs_item_key_to_cpu(l, &key, path->slots[0]); if (key.objectid != device->devid) goto done; dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); length = btrfs_dev_extent_length(l, dev_extent); if (key.offset + length <= new_size) goto done; chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent); chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent); chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); btrfs_release_path(root, path); ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid, chunk_offset); if (ret) goto done; } done: btrfs_free_path(path); return ret; } static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_key *key, struct btrfs_chunk *chunk, int item_size) { struct btrfs_super_block *super_copy = &root->fs_info->super_copy; struct btrfs_disk_key disk_key; u32 array_size; u8 *ptr; array_size = btrfs_super_sys_array_size(super_copy); if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) return -EFBIG; ptr = super_copy->sys_chunk_array + array_size; btrfs_cpu_key_to_disk(&disk_key, key); memcpy(ptr, &disk_key, sizeof(disk_key)); ptr += sizeof(disk_key); memcpy(ptr, chunk, item_size); item_size += sizeof(disk_key); btrfs_set_super_sys_array_size(super_copy, array_size + item_size); return 0; } static noinline u64 chunk_bytes_by_type(u64 type, u64 calc_size, int num_stripes, int sub_stripes) { if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP)) return calc_size; else if (type & BTRFS_BLOCK_GROUP_RAID10) return calc_size * (num_stripes / sub_stripes); else return calc_size * num_stripes; } static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, struct map_lookup **map_ret, u64 *num_bytes, u64 *stripe_size, u64 start, u64 type) { struct btrfs_fs_info *info = extent_root->fs_info; struct btrfs_device *device = NULL; struct btrfs_fs_devices *fs_devices = info->fs_devices; struct list_head *cur; struct map_lookup *map = NULL; struct extent_map_tree *em_tree; struct extent_map *em; struct list_head private_devs; int min_stripe_size = 1 * 1024 * 1024; u64 calc_size = 1024 * 1024 * 1024; u64 max_chunk_size = calc_size; u64 min_free; u64 avail; u64 max_avail = 0; u64 dev_offset; int num_stripes = 1; int min_stripes = 1; int sub_stripes = 0; int looped = 0; int ret; int index; int stripe_len = 64 * 1024; if ((type & BTRFS_BLOCK_GROUP_RAID1) && (type & BTRFS_BLOCK_GROUP_DUP)) { WARN_ON(1); type &= ~BTRFS_BLOCK_GROUP_DUP; } if (list_empty(&fs_devices->alloc_list)) return -ENOSPC; if (type & (BTRFS_BLOCK_GROUP_RAID0)) { num_stripes = fs_devices->rw_devices; min_stripes = 2; } if (type & (BTRFS_BLOCK_GROUP_DUP)) { num_stripes = 2; min_stripes = 2; } if (type & (BTRFS_BLOCK_GROUP_RAID1)) { num_stripes = min_t(u64, 2, fs_devices->rw_devices); if (num_stripes < 2) return -ENOSPC; min_stripes = 2; } if (type & (BTRFS_BLOCK_GROUP_RAID10)) { num_stripes = fs_devices->rw_devices; if (num_stripes < 4) return -ENOSPC; num_stripes &= ~(u32)1; sub_stripes = 2; min_stripes = 4; } if (type & BTRFS_BLOCK_GROUP_DATA) { max_chunk_size = 10 * calc_size; min_stripe_size = 64 * 1024 * 1024; } else if (type & BTRFS_BLOCK_GROUP_METADATA) { max_chunk_size = 4 * calc_size; min_stripe_size = 32 * 1024 * 1024; } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) { calc_size = 8 * 1024 * 1024; max_chunk_size = calc_size * 2; min_stripe_size = 1 * 1024 * 1024; } /* we don't want a chunk larger than 10% of writeable space */ max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1), max_chunk_size); again: if (!map || map->num_stripes != num_stripes) { kfree(map); map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS); if (!map) return -ENOMEM; map->num_stripes = num_stripes; } if (calc_size * num_stripes > max_chunk_size) { calc_size = max_chunk_size; do_div(calc_size, num_stripes); do_div(calc_size, stripe_len); calc_size *= stripe_len; } /* we don't want tiny stripes */ calc_size = max_t(u64, min_stripe_size, calc_size); do_div(calc_size, stripe_len); calc_size *= stripe_len; cur = fs_devices->alloc_list.next; index = 0; if (type & BTRFS_BLOCK_GROUP_DUP) min_free = calc_size * 2; else min_free = calc_size; /* * we add 1MB because we never use the first 1MB of the device, unless * we've looped, then we are likely allocating the maximum amount of * space left already */ if (!looped) min_free += 1024 * 1024; INIT_LIST_HEAD(&private_devs); while (index < num_stripes) { device = list_entry(cur, struct btrfs_device, dev_alloc_list); BUG_ON(!device->writeable); if (device->total_bytes > device->bytes_used) avail = device->total_bytes - device->bytes_used; else avail = 0; cur = cur->next; if (device->in_fs_metadata && avail >= min_free) { ret = find_free_dev_extent(trans, device, min_free, &dev_offset); if (ret == 0) { list_move_tail(&device->dev_alloc_list, &private_devs); map->stripes[index].dev = device; map->stripes[index].physical = dev_offset; index++; if (type & BTRFS_BLOCK_GROUP_DUP) { map->stripes[index].dev = device; map->stripes[index].physical = dev_offset + calc_size; index++; } } } else if (device->in_fs_metadata && avail > max_avail) max_avail = avail; if (cur == &fs_devices->alloc_list) break; } list_splice(&private_devs, &fs_devices->alloc_list); if (index < num_stripes) { if (index >= min_stripes) { num_stripes = index; if (type & (BTRFS_BLOCK_GROUP_RAID10)) { num_stripes /= sub_stripes; num_stripes *= sub_stripes; } looped = 1; goto again; } if (!looped && max_avail > 0) { looped = 1; calc_size = max_avail; goto again; } kfree(map); return -ENOSPC; } map->sector_size = extent_root->sectorsize; map->stripe_len = stripe_len; map->io_align = stripe_len; map->io_width = stripe_len; map->type = type; map->num_stripes = num_stripes; map->sub_stripes = sub_stripes; *map_ret = map; *stripe_size = calc_size; *num_bytes = chunk_bytes_by_type(type, calc_size, num_stripes, sub_stripes); em = alloc_extent_map(GFP_NOFS); if (!em) { kfree(map); return -ENOMEM; } em->bdev = (struct block_device *)map; em->start = start; em->len = *num_bytes; em->block_start = 0; em->block_len = em->len; em_tree = &extent_root->fs_info->mapping_tree.map_tree; spin_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em); spin_unlock(&em_tree->lock); BUG_ON(ret); free_extent_map(em); ret = btrfs_make_block_group(trans, extent_root, 0, type, BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, *num_bytes); BUG_ON(ret); index = 0; while (index < map->num_stripes) { device = map->stripes[index].dev; dev_offset = map->stripes[index].physical; ret = btrfs_alloc_dev_extent(trans, device, info->chunk_root->root_key.objectid, BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, dev_offset, calc_size); BUG_ON(ret); index++; } return 0; } static int __finish_chunk_alloc(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, struct map_lookup *map, u64 chunk_offset, u64 chunk_size, u64 stripe_size) { u64 dev_offset; struct btrfs_key key; struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root; struct btrfs_device *device; struct btrfs_chunk *chunk; struct btrfs_stripe *stripe; size_t item_size = btrfs_chunk_item_size(map->num_stripes); int index = 0; int ret; chunk = kzalloc(item_size, GFP_NOFS); if (!chunk) return -ENOMEM; index = 0; while (index < map->num_stripes) { device = map->stripes[index].dev; device->bytes_used += stripe_size; ret = btrfs_update_device(trans, device); BUG_ON(ret); index++; } index = 0; stripe = &chunk->stripe; while (index < map->num_stripes) { device = map->stripes[index].dev; dev_offset = map->stripes[index].physical; btrfs_set_stack_stripe_devid(stripe, device->devid); btrfs_set_stack_stripe_offset(stripe, dev_offset); memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE); stripe++; index++; } btrfs_set_stack_chunk_length(chunk, chunk_size); btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid); btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len); btrfs_set_stack_chunk_type(chunk, map->type); btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes); btrfs_set_stack_chunk_io_align(chunk, map->stripe_len); btrfs_set_stack_chunk_io_width(chunk, map->stripe_len); btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize); btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes); key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; key.type = BTRFS_CHUNK_ITEM_KEY; key.offset = chunk_offset; ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size); BUG_ON(ret); if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) { ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk, item_size); BUG_ON(ret); } kfree(chunk); return 0; } /* * Chunk allocation falls into two parts. The first part does works * that make the new allocated chunk useable, but not do any operation * that modifies the chunk tree. The second part does the works that * require modifying the chunk tree. This division is important for the * bootstrap process of adding storage to a seed btrfs. */ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, u64 type) { u64 chunk_offset; u64 chunk_size; u64 stripe_size; struct map_lookup *map; struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root; int ret; ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset); if (ret) return ret; ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size, &stripe_size, chunk_offset, type); if (ret) return ret; ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset, chunk_size, stripe_size); BUG_ON(ret); return 0; } static noinline int init_first_rw_device(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_device *device) { u64 chunk_offset; u64 sys_chunk_offset; u64 chunk_size; u64 sys_chunk_size; u64 stripe_size; u64 sys_stripe_size; u64 alloc_profile; struct map_lookup *map; struct map_lookup *sys_map; struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_root *extent_root = fs_info->extent_root; int ret; ret = find_next_chunk(fs_info->chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset); BUG_ON(ret); alloc_profile = BTRFS_BLOCK_GROUP_METADATA | (fs_info->metadata_alloc_profile & fs_info->avail_metadata_alloc_bits); alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile); ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size, &stripe_size, chunk_offset, alloc_profile); BUG_ON(ret); sys_chunk_offset = chunk_offset + chunk_size; alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM | (fs_info->system_alloc_profile & fs_info->avail_system_alloc_bits); alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile); ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map, &sys_chunk_size, &sys_stripe_size, sys_chunk_offset, alloc_profile); BUG_ON(ret); ret = btrfs_add_device(trans, fs_info->chunk_root, device); BUG_ON(ret); /* * Modifying chunk tree needs allocating new blocks from both * system block group and metadata block group. So we only can * do operations require modifying the chunk tree after both * block groups were created. */ ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset, chunk_size, stripe_size); BUG_ON(ret); ret = __finish_chunk_alloc(trans, extent_root, sys_map, sys_chunk_offset, sys_chunk_size, sys_stripe_size); BUG_ON(ret); return 0; } int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset) { struct extent_map *em; struct map_lookup *map; struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree; int readonly = 0; int i; spin_lock(&map_tree->map_tree.lock); em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1); spin_unlock(&map_tree->map_tree.lock); if (!em) return 1; map = (struct map_lookup *)em->bdev; for (i = 0; i < map->num_stripes; i++) { if (!map->stripes[i].dev->writeable) { readonly = 1; break; } } free_extent_map(em); return readonly; } void btrfs_mapping_init(struct btrfs_mapping_tree *tree) { extent_map_tree_init(&tree->map_tree, GFP_NOFS); } void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree) { struct extent_map *em; while (1) { spin_lock(&tree->map_tree.lock); em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1); if (em) remove_extent_mapping(&tree->map_tree, em); spin_unlock(&tree->map_tree.lock); if (!em) break; kfree(em->bdev); /* once for us */ free_extent_map(em); /* once for the tree */ free_extent_map(em); } } int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len) { struct extent_map *em; struct map_lookup *map; struct extent_map_tree *em_tree = &map_tree->map_tree; int ret; spin_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, logical, len); spin_unlock(&em_tree->lock); BUG_ON(!em); BUG_ON(em->start > logical || em->start + em->len < logical); map = (struct map_lookup *)em->bdev; if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1)) ret = map->num_stripes; else if (map->type & BTRFS_BLOCK_GROUP_RAID10) ret = map->sub_stripes; else ret = 1; free_extent_map(em); return ret; } static int find_live_mirror(struct map_lookup *map, int first, int num, int optimal) { int i; if (map->stripes[optimal].dev->bdev) return optimal; for (i = first; i < first + num; i++) { if (map->stripes[i].dev->bdev) return i; } /* we couldn't find one that doesn't fail. Just return something * and the io error handling code will clean up eventually */ return optimal; } static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, u64 logical, u64 *length, struct btrfs_multi_bio **multi_ret, int mirror_num, struct page *unplug_page) { struct extent_map *em; struct map_lookup *map; struct extent_map_tree *em_tree = &map_tree->map_tree; u64 offset; u64 stripe_offset; u64 stripe_nr; int stripes_allocated = 8; int stripes_required = 1; int stripe_index; int i; int num_stripes; int max_errors = 0; struct btrfs_multi_bio *multi = NULL; if (multi_ret && !(rw & (1 << BIO_RW))) stripes_allocated = 1; again: if (multi_ret) { multi = kzalloc(btrfs_multi_bio_size(stripes_allocated), GFP_NOFS); if (!multi) return -ENOMEM; atomic_set(&multi->error, 0); } spin_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, logical, *length); spin_unlock(&em_tree->lock); if (!em && unplug_page) return 0; if (!em) { printk(KERN_CRIT "unable to find logical %llu len %llu\n", (unsigned long long)logical, (unsigned long long)*length); BUG(); } BUG_ON(em->start > logical || em->start + em->len < logical); map = (struct map_lookup *)em->bdev; offset = logical - em->start; if (mirror_num > map->num_stripes) mirror_num = 0; /* if our multi bio struct is too small, back off and try again */ if (rw & (1 << BIO_RW)) { if (map->type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP)) { stripes_required = map->num_stripes; max_errors = 1; } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { stripes_required = map->sub_stripes; max_errors = 1; } } if (multi_ret && (rw & (1 << BIO_RW)) && stripes_allocated < stripes_required) { stripes_allocated = map->num_stripes; free_extent_map(em); kfree(multi); goto again; } stripe_nr = offset; /* * stripe_nr counts the total number of stripes we have to stride * to get to this block */ do_div(stripe_nr, map->stripe_len); stripe_offset = stripe_nr * map->stripe_len; BUG_ON(offset < stripe_offset); /* stripe_offset is the offset of this block in its stripe*/ stripe_offset = offset - stripe_offset; if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10 | BTRFS_BLOCK_GROUP_DUP)) { /* we limit the length of each bio to what fits in a stripe */ *length = min_t(u64, em->len - offset, map->stripe_len - stripe_offset); } else { *length = em->len - offset; } if (!multi_ret && !unplug_page) goto out; num_stripes = 1; stripe_index = 0; if (map->type & BTRFS_BLOCK_GROUP_RAID1) { if (unplug_page || (rw & (1 << BIO_RW))) num_stripes = map->num_stripes; else if (mirror_num) stripe_index = mirror_num - 1; else { stripe_index = find_live_mirror(map, 0, map->num_stripes, current->pid % map->num_stripes); } } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { if (rw & (1 << BIO_RW)) num_stripes = map->num_stripes; else if (mirror_num) stripe_index = mirror_num - 1; } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { int factor = map->num_stripes / map->sub_stripes; stripe_index = do_div(stripe_nr, factor); stripe_index *= map->sub_stripes; if (unplug_page || (rw & (1 << BIO_RW))) num_stripes = map->sub_stripes; else if (mirror_num) stripe_index += mirror_num - 1; else { stripe_index = find_live_mirror(map, stripe_index, map->sub_stripes, stripe_index + current->pid % map->sub_stripes); } } else { /* * after this do_div call, stripe_nr is the number of stripes * on this device we have to walk to find the data, and * stripe_index is the number of our device in the stripe array */ stripe_index = do_div(stripe_nr, map->num_stripes); } BUG_ON(stripe_index >= map->num_stripes); for (i = 0; i < num_stripes; i++) { if (unplug_page) { struct btrfs_device *device; struct backing_dev_info *bdi; device = map->stripes[stripe_index].dev; if (device->bdev) { bdi = blk_get_backing_dev_info(device->bdev); if (bdi->unplug_io_fn) bdi->unplug_io_fn(bdi, unplug_page); } } else { multi->stripes[i].physical = map->stripes[stripe_index].physical + stripe_offset + stripe_nr * map->stripe_len; multi->stripes[i].dev = map->stripes[stripe_index].dev; } stripe_index++; } if (multi_ret) { *multi_ret = multi; multi->num_stripes = num_stripes; multi->max_errors = max_errors; } out: free_extent_map(em); return 0; } int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, u64 logical, u64 *length, struct btrfs_multi_bio **multi_ret, int mirror_num) { return __btrfs_map_block(map_tree, rw, logical, length, multi_ret, mirror_num, NULL); } int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree, u64 chunk_start, u64 physical, u64 devid, u64 **logical, int *naddrs, int *stripe_len) { struct extent_map_tree *em_tree = &map_tree->map_tree; struct extent_map *em; struct map_lookup *map; u64 *buf; u64 bytenr; u64 length; u64 stripe_nr; int i, j, nr = 0; spin_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, chunk_start, 1); spin_unlock(&em_tree->lock); BUG_ON(!em || em->start != chunk_start); map = (struct map_lookup *)em->bdev; length = em->len; if (map->type & BTRFS_BLOCK_GROUP_RAID10) do_div(length, map->num_stripes / map->sub_stripes); else if (map->type & BTRFS_BLOCK_GROUP_RAID0) do_div(length, map->num_stripes); buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS); BUG_ON(!buf); for (i = 0; i < map->num_stripes; i++) { if (devid && map->stripes[i].dev->devid != devid) continue; if (map->stripes[i].physical > physical || map->stripes[i].physical + length <= physical) continue; stripe_nr = physical - map->stripes[i].physical; do_div(stripe_nr, map->stripe_len); if (map->type & BTRFS_BLOCK_GROUP_RAID10) { stripe_nr = stripe_nr * map->num_stripes + i; do_div(stripe_nr, map->sub_stripes); } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) { stripe_nr = stripe_nr * map->num_stripes + i; } bytenr = chunk_start + stripe_nr * map->stripe_len; WARN_ON(nr >= map->num_stripes); for (j = 0; j < nr; j++) { if (buf[j] == bytenr) break; } if (j == nr) { WARN_ON(nr >= map->num_stripes); buf[nr++] = bytenr; } } for (i = 0; i > nr; i++) { struct btrfs_multi_bio *multi; struct btrfs_bio_stripe *stripe; int ret; length = 1; ret = btrfs_map_block(map_tree, WRITE, buf[i], &length, &multi, 0); BUG_ON(ret); stripe = multi->stripes; for (j = 0; j < multi->num_stripes; j++) { if (stripe->physical >= physical && physical < stripe->physical + length) break; } BUG_ON(j >= multi->num_stripes); kfree(multi); } *logical = buf; *naddrs = nr; *stripe_len = map->stripe_len; free_extent_map(em); return 0; } int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree, u64 logical, struct page *page) { u64 length = PAGE_CACHE_SIZE; return __btrfs_map_block(map_tree, READ, logical, &length, NULL, 0, page); } static void end_bio_multi_stripe(struct bio *bio, int err) { struct btrfs_multi_bio *multi = bio->bi_private; int is_orig_bio = 0; if (err) atomic_inc(&multi->error); if (bio == multi->orig_bio) is_orig_bio = 1; if (atomic_dec_and_test(&multi->stripes_pending)) { if (!is_orig_bio) { bio_put(bio); bio = multi->orig_bio; } bio->bi_private = multi->private; bio->bi_end_io = multi->end_io; /* only send an error to the higher layers if it is * beyond the tolerance of the multi-bio */ if (atomic_read(&multi->error) > multi->max_errors) { err = -EIO; } else if (err) { /* * this bio is actually up to date, we didn't * go over the max number of errors */ set_bit(BIO_UPTODATE, &bio->bi_flags); err = 0; } kfree(multi); bio_endio(bio, err); } else if (!is_orig_bio) { bio_put(bio); } } struct async_sched { struct bio *bio; int rw; struct btrfs_fs_info *info; struct btrfs_work work; }; /* * see run_scheduled_bios for a description of why bios are collected for * async submit. * * This will add one bio to the pending list for a device and make sure * the work struct is scheduled. */ static noinline int schedule_bio(struct btrfs_root *root, struct btrfs_device *device, int rw, struct bio *bio) { int should_queue = 1; struct btrfs_pending_bios *pending_bios; /* don't bother with additional async steps for reads, right now */ if (!(rw & (1 << BIO_RW))) { bio_get(bio); submit_bio(rw, bio); bio_put(bio); return 0; } /* * nr_async_bios allows us to reliably return congestion to the * higher layers. Otherwise, the async bio makes it appear we have * made progress against dirty pages when we've really just put it * on a queue for later */ atomic_inc(&root->fs_info->nr_async_bios); WARN_ON(bio->bi_next); bio->bi_next = NULL; bio->bi_rw |= rw; spin_lock(&device->io_lock); if (bio_sync(bio)) pending_bios = &device->pending_sync_bios; else pending_bios = &device->pending_bios; if (pending_bios->tail) pending_bios->tail->bi_next = bio; pending_bios->tail = bio; if (!pending_bios->head) pending_bios->head = bio; if (device->running_pending) should_queue = 0; spin_unlock(&device->io_lock); if (should_queue) btrfs_queue_worker(&root->fs_info->submit_workers, &device->work); return 0; } int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio, int mirror_num, int async_submit) { struct btrfs_mapping_tree *map_tree; struct btrfs_device *dev; struct bio *first_bio = bio; u64 logical = (u64)bio->bi_sector << 9; u64 length = 0; u64 map_length; struct btrfs_multi_bio *multi = NULL; int ret; int dev_nr = 0; int total_devs = 1; length = bio->bi_size; map_tree = &root->fs_info->mapping_tree; map_length = length; ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi, mirror_num); BUG_ON(ret); total_devs = multi->num_stripes; if (map_length < length) { printk(KERN_CRIT "mapping failed logical %llu bio len %llu " "len %llu\n", (unsigned long long)logical, (unsigned long long)length, (unsigned long long)map_length); BUG(); } multi->end_io = first_bio->bi_end_io; multi->private = first_bio->bi_private; multi->orig_bio = first_bio; atomic_set(&multi->stripes_pending, multi->num_stripes); while (dev_nr < total_devs) { if (total_devs > 1) { if (dev_nr < total_devs - 1) { bio = bio_clone(first_bio, GFP_NOFS); BUG_ON(!bio); } else { bio = first_bio; } bio->bi_private = multi; bio->bi_end_io = end_bio_multi_stripe; } bio->bi_sector = multi->stripes[dev_nr].physical >> 9; dev = multi->stripes[dev_nr].dev; BUG_ON(rw == WRITE && !dev->writeable); if (dev && dev->bdev) { bio->bi_bdev = dev->bdev; if (async_submit) schedule_bio(root, dev, rw, bio); else submit_bio(rw, bio); } else { bio->bi_bdev = root->fs_info->fs_devices->latest_bdev; bio->bi_sector = logical >> 9; bio_endio(bio, -EIO); } dev_nr++; } if (total_devs == 1) kfree(multi); return 0; } struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid, u8 *uuid, u8 *fsid) { struct btrfs_device *device; struct btrfs_fs_devices *cur_devices; cur_devices = root->fs_info->fs_devices; while (cur_devices) { if (!fsid || !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) { device = __find_device(&cur_devices->devices, devid, uuid); if (device) return device; } cur_devices = cur_devices->seed; } return NULL; } static struct btrfs_device *add_missing_dev(struct btrfs_root *root, u64 devid, u8 *dev_uuid) { struct btrfs_device *device; struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; device = kzalloc(sizeof(*device), GFP_NOFS); if (!device) return NULL; list_add(&device->dev_list, &fs_devices->devices); device->barriers = 1; device->dev_root = root->fs_info->dev_root; device->devid = devid; device->work.func = pending_bios_fn; device->fs_devices = fs_devices; fs_devices->num_devices++; spin_lock_init(&device->io_lock); INIT_LIST_HEAD(&device->dev_alloc_list); memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE); return device; } static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key, struct extent_buffer *leaf, struct btrfs_chunk *chunk) { struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree; struct map_lookup *map; struct extent_map *em; u64 logical; u64 length; u64 devid; u8 uuid[BTRFS_UUID_SIZE]; int num_stripes; int ret; int i; logical = key->offset; length = btrfs_chunk_length(leaf, chunk); spin_lock(&map_tree->map_tree.lock); em = lookup_extent_mapping(&map_tree->map_tree, logical, 1); spin_unlock(&map_tree->map_tree.lock); /* already mapped? */ if (em && em->start <= logical && em->start + em->len > logical) { free_extent_map(em); return 0; } else if (em) { free_extent_map(em); } em = alloc_extent_map(GFP_NOFS); if (!em) return -ENOMEM; num_stripes = btrfs_chunk_num_stripes(leaf, chunk); map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS); if (!map) { free_extent_map(em); return -ENOMEM; } em->bdev = (struct block_device *)map; em->start = logical; em->len = length; em->block_start = 0; em->block_len = em->len; map->num_stripes = num_stripes; map->io_width = btrfs_chunk_io_width(leaf, chunk); map->io_align = btrfs_chunk_io_align(leaf, chunk); map->sector_size = btrfs_chunk_sector_size(leaf, chunk); map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk); map->type = btrfs_chunk_type(leaf, chunk); map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk); for (i = 0; i < num_stripes; i++) { map->stripes[i].physical = btrfs_stripe_offset_nr(leaf, chunk, i); devid = btrfs_stripe_devid_nr(leaf, chunk, i); read_extent_buffer(leaf, uuid, (unsigned long) btrfs_stripe_dev_uuid_nr(chunk, i), BTRFS_UUID_SIZE); map->stripes[i].dev = btrfs_find_device(root, devid, uuid, NULL); if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) { kfree(map); free_extent_map(em); return -EIO; } if (!map->stripes[i].dev) { map->stripes[i].dev = add_missing_dev(root, devid, uuid); if (!map->stripes[i].dev) { kfree(map); free_extent_map(em); return -EIO; } } map->stripes[i].dev->in_fs_metadata = 1; } spin_lock(&map_tree->map_tree.lock); ret = add_extent_mapping(&map_tree->map_tree, em); spin_unlock(&map_tree->map_tree.lock); BUG_ON(ret); free_extent_map(em); return 0; } static int fill_device_from_item(struct extent_buffer *leaf, struct btrfs_dev_item *dev_item, struct btrfs_device *device) { unsigned long ptr; device->devid = btrfs_device_id(leaf, dev_item); device->total_bytes = btrfs_device_total_bytes(leaf, dev_item); device->bytes_used = btrfs_device_bytes_used(leaf, dev_item); device->type = btrfs_device_type(leaf, dev_item); device->io_align = btrfs_device_io_align(leaf, dev_item); device->io_width = btrfs_device_io_width(leaf, dev_item); device->sector_size = btrfs_device_sector_size(leaf, dev_item); ptr = (unsigned long)btrfs_device_uuid(dev_item); read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE); return 0; } static int open_seed_devices(struct btrfs_root *root, u8 *fsid) { struct btrfs_fs_devices *fs_devices; int ret; mutex_lock(&uuid_mutex); fs_devices = root->fs_info->fs_devices->seed; while (fs_devices) { if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) { ret = 0; goto out; } fs_devices = fs_devices->seed; } fs_devices = find_fsid(fsid); if (!fs_devices) { ret = -ENOENT; goto out; } fs_devices = clone_fs_devices(fs_devices); if (IS_ERR(fs_devices)) { ret = PTR_ERR(fs_devices); goto out; } ret = __btrfs_open_devices(fs_devices, FMODE_READ, root->fs_info->bdev_holder); if (ret) goto out; if (!fs_devices->seeding) { __btrfs_close_devices(fs_devices); free_fs_devices(fs_devices); ret = -EINVAL; goto out; } fs_devices->seed = root->fs_info->fs_devices->seed; root->fs_info->fs_devices->seed = fs_devices; out: mutex_unlock(&uuid_mutex); return ret; } static int read_one_dev(struct btrfs_root *root, struct extent_buffer *leaf, struct btrfs_dev_item *dev_item) { struct btrfs_device *device; u64 devid; int ret; u8 fs_uuid[BTRFS_UUID_SIZE]; u8 dev_uuid[BTRFS_UUID_SIZE]; devid = btrfs_device_id(leaf, dev_item); read_extent_buffer(leaf, dev_uuid, (unsigned long)btrfs_device_uuid(dev_item), BTRFS_UUID_SIZE); read_extent_buffer(leaf, fs_uuid, (unsigned long)btrfs_device_fsid(dev_item), BTRFS_UUID_SIZE); if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) { ret = open_seed_devices(root, fs_uuid); if (ret && !btrfs_test_opt(root, DEGRADED)) return ret; } device = btrfs_find_device(root, devid, dev_uuid, fs_uuid); if (!device || !device->bdev) { if (!btrfs_test_opt(root, DEGRADED)) return -EIO; if (!device) { printk(KERN_WARNING "warning devid %llu missing\n", (unsigned long long)devid); device = add_missing_dev(root, devid, dev_uuid); if (!device) return -ENOMEM; } } if (device->fs_devices != root->fs_info->fs_devices) { BUG_ON(device->writeable); if (device->generation != btrfs_device_generation(leaf, dev_item)) return -EINVAL; } fill_device_from_item(leaf, dev_item, device); device->dev_root = root->fs_info->dev_root; device->in_fs_metadata = 1; if (device->writeable) device->fs_devices->total_rw_bytes += device->total_bytes; ret = 0; return ret; } int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf) { struct btrfs_dev_item *dev_item; dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block, dev_item); return read_one_dev(root, buf, dev_item); } int btrfs_read_sys_array(struct btrfs_root *root) { struct btrfs_super_block *super_copy = &root->fs_info->super_copy; struct extent_buffer *sb; struct btrfs_disk_key *disk_key; struct btrfs_chunk *chunk; u8 *ptr; unsigned long sb_ptr; int ret = 0; u32 num_stripes; u32 array_size; u32 len = 0; u32 cur; struct btrfs_key key; sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET, BTRFS_SUPER_INFO_SIZE); if (!sb) return -ENOMEM; btrfs_set_buffer_uptodate(sb); btrfs_set_buffer_lockdep_class(sb, 0); write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE); array_size = btrfs_super_sys_array_size(super_copy); ptr = super_copy->sys_chunk_array; sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array); cur = 0; while (cur < array_size) { disk_key = (struct btrfs_disk_key *)ptr; btrfs_disk_key_to_cpu(&key, disk_key); len = sizeof(*disk_key); ptr += len; sb_ptr += len; cur += len; if (key.type == BTRFS_CHUNK_ITEM_KEY) { chunk = (struct btrfs_chunk *)sb_ptr; ret = read_one_chunk(root, &key, sb, chunk); if (ret) break; num_stripes = btrfs_chunk_num_stripes(sb, chunk); len = btrfs_chunk_item_size(num_stripes); } else { ret = -EIO; break; } ptr += len; sb_ptr += len; cur += len; } free_extent_buffer(sb); return ret; } int btrfs_read_chunk_tree(struct btrfs_root *root) { struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_key key; struct btrfs_key found_key; int ret; int slot; root = root->fs_info->chunk_root; path = btrfs_alloc_path(); if (!path) return -ENOMEM; /* first we search for all of the device items, and then we * read in all of the chunk items. This way we can create chunk * mappings that reference all of the devices that are afound */ key.objectid = BTRFS_DEV_ITEMS_OBJECTID; key.offset = 0; key.type = 0; again: ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); while (1) { leaf = path->nodes[0]; slot = path->slots[0]; if (slot >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret == 0) continue; if (ret < 0) goto error; break; } btrfs_item_key_to_cpu(leaf, &found_key, slot); if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) { if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID) break; if (found_key.type == BTRFS_DEV_ITEM_KEY) { struct btrfs_dev_item *dev_item; dev_item = btrfs_item_ptr(leaf, slot, struct btrfs_dev_item); ret = read_one_dev(root, leaf, dev_item); if (ret) goto error; } } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) { struct btrfs_chunk *chunk; chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk); ret = read_one_chunk(root, &found_key, leaf, chunk); if (ret) goto error; } path->slots[0]++; } if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) { key.objectid = 0; btrfs_release_path(root, path); goto again; } ret = 0; error: btrfs_free_path(path); return ret; }