/* * 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 #include #include #include #include #include #include #include #include #include #include #include "compat.h" #include "ctree.h" #include "disk-io.h" #include "transaction.h" #include "btrfs_inode.h" #include "volumes.h" #include "print-tree.h" #include "async-thread.h" #include "locking.h" #include "tree-log.h" #include "free-space-cache.h" static struct extent_io_ops btree_extent_io_ops; static void end_workqueue_fn(struct btrfs_work *work); static void free_fs_root(struct btrfs_root *root); static atomic_t btrfs_bdi_num = ATOMIC_INIT(0); /* * end_io_wq structs are used to do processing in task context when an IO is * complete. This is used during reads to verify checksums, and it is used * by writes to insert metadata for new file extents after IO is complete. */ struct end_io_wq { struct bio *bio; bio_end_io_t *end_io; void *private; struct btrfs_fs_info *info; int error; int metadata; struct list_head list; struct btrfs_work work; }; /* * async submit bios are used to offload expensive checksumming * onto the worker threads. They checksum file and metadata bios * just before they are sent down the IO stack. */ struct async_submit_bio { struct inode *inode; struct bio *bio; struct list_head list; extent_submit_bio_hook_t *submit_bio_start; extent_submit_bio_hook_t *submit_bio_done; int rw; int mirror_num; unsigned long bio_flags; struct btrfs_work work; }; /* These are used to set the lockdep class on the extent buffer locks. * The class is set by the readpage_end_io_hook after the buffer has * passed csum validation but before the pages are unlocked. * * The lockdep class is also set by btrfs_init_new_buffer on freshly * allocated blocks. * * The class is based on the level in the tree block, which allows lockdep * to know that lower nodes nest inside the locks of higher nodes. * * We also add a check to make sure the highest level of the tree is * the same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this * code needs update as well. */ #ifdef CONFIG_DEBUG_LOCK_ALLOC # if BTRFS_MAX_LEVEL != 8 # error # endif static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1]; static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = { /* leaf */ "btrfs-extent-00", "btrfs-extent-01", "btrfs-extent-02", "btrfs-extent-03", "btrfs-extent-04", "btrfs-extent-05", "btrfs-extent-06", "btrfs-extent-07", /* highest possible level */ "btrfs-extent-08", }; #endif /* * extents on the btree inode are pretty simple, there's one extent * that covers the entire device */ static struct extent_map *btree_get_extent(struct inode *inode, struct page *page, size_t page_offset, u64 start, u64 len, int create) { struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; struct extent_map *em; int ret; read_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, start, len); if (em) { em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev; read_unlock(&em_tree->lock); goto out; } read_unlock(&em_tree->lock); em = alloc_extent_map(GFP_NOFS); if (!em) { em = ERR_PTR(-ENOMEM); goto out; } em->start = 0; em->len = (u64)-1; em->block_len = (u64)-1; em->block_start = 0; em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev; write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em); if (ret == -EEXIST) { u64 failed_start = em->start; u64 failed_len = em->len; free_extent_map(em); em = lookup_extent_mapping(em_tree, start, len); if (em) { ret = 0; } else { em = lookup_extent_mapping(em_tree, failed_start, failed_len); ret = -EIO; } } else if (ret) { free_extent_map(em); em = NULL; } write_unlock(&em_tree->lock); if (ret) em = ERR_PTR(ret); out: return em; } u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len) { return crc32c(seed, data, len); } void btrfs_csum_final(u32 crc, char *result) { *(__le32 *)result = ~cpu_to_le32(crc); } /* * compute the csum for a btree block, and either verify it or write it * into the csum field of the block. */ static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf, int verify) { u16 csum_size = btrfs_super_csum_size(&root->fs_info->super_copy); char *result = NULL; unsigned long len; unsigned long cur_len; unsigned long offset = BTRFS_CSUM_SIZE; char *map_token = NULL; char *kaddr; unsigned long map_start; unsigned long map_len; int err; u32 crc = ~(u32)0; unsigned long inline_result; len = buf->len - offset; while (len > 0) { err = map_private_extent_buffer(buf, offset, 32, &map_token, &kaddr, &map_start, &map_len, KM_USER0); if (err) return 1; cur_len = min(len, map_len - (offset - map_start)); crc = btrfs_csum_data(root, kaddr + offset - map_start, crc, cur_len); len -= cur_len; offset += cur_len; unmap_extent_buffer(buf, map_token, KM_USER0); } if (csum_size > sizeof(inline_result)) { result = kzalloc(csum_size * sizeof(char), GFP_NOFS); if (!result) return 1; } else { result = (char *)&inline_result; } btrfs_csum_final(crc, result); if (verify) { if (memcmp_extent_buffer(buf, result, 0, csum_size)) { u32 val; u32 found = 0; memcpy(&found, result, csum_size); read_extent_buffer(buf, &val, 0, csum_size); if (printk_ratelimit()) { printk(KERN_INFO "btrfs: %s checksum verify " "failed on %llu wanted %X found %X " "level %d\n", root->fs_info->sb->s_id, (unsigned long long)buf->start, val, found, btrfs_header_level(buf)); } if (result != (char *)&inline_result) kfree(result); return 1; } } else { write_extent_buffer(buf, result, 0, csum_size); } if (result != (char *)&inline_result) kfree(result); return 0; } /* * we can't consider a given block up to date unless the transid of the * block matches the transid in the parent node's pointer. This is how we * detect blocks that either didn't get written at all or got written * in the wrong place. */ static int verify_parent_transid(struct extent_io_tree *io_tree, struct extent_buffer *eb, u64 parent_transid) { int ret; if (!parent_transid || btrfs_header_generation(eb) == parent_transid) return 0; lock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS); if (extent_buffer_uptodate(io_tree, eb) && btrfs_header_generation(eb) == parent_transid) { ret = 0; goto out; } if (printk_ratelimit()) { printk("parent transid verify failed on %llu wanted %llu " "found %llu\n", (unsigned long long)eb->start, (unsigned long long)parent_transid, (unsigned long long)btrfs_header_generation(eb)); } ret = 1; clear_extent_buffer_uptodate(io_tree, eb); out: unlock_extent(io_tree, eb->start, eb->start + eb->len - 1, GFP_NOFS); return ret; } /* * helper to read a given tree block, doing retries as required when * the checksums don't match and we have alternate mirrors to try. */ static int btree_read_extent_buffer_pages(struct btrfs_root *root, struct extent_buffer *eb, u64 start, u64 parent_transid) { struct extent_io_tree *io_tree; int ret; int num_copies = 0; int mirror_num = 0; io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree; while (1) { ret = read_extent_buffer_pages(io_tree, eb, start, 1, btree_get_extent, mirror_num); if (!ret && !verify_parent_transid(io_tree, eb, parent_transid)) return ret; num_copies = btrfs_num_copies(&root->fs_info->mapping_tree, eb->start, eb->len); if (num_copies == 1) return ret; mirror_num++; if (mirror_num > num_copies) return ret; } return -EIO; } /* * checksum a dirty tree block before IO. This has extra checks to make sure * we only fill in the checksum field in the first page of a multi-page block */ static int csum_dirty_buffer(struct btrfs_root *root, struct page *page) { struct extent_io_tree *tree; u64 start = (u64)page->index << PAGE_CACHE_SHIFT; u64 found_start; int found_level; unsigned long len; struct extent_buffer *eb; int ret; tree = &BTRFS_I(page->mapping->host)->io_tree; if (page->private == EXTENT_PAGE_PRIVATE) goto out; if (!page->private) goto out; len = page->private >> 2; WARN_ON(len == 0); eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS); ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE, btrfs_header_generation(eb)); BUG_ON(ret); found_start = btrfs_header_bytenr(eb); if (found_start != start) { WARN_ON(1); goto err; } if (eb->first_page != page) { WARN_ON(1); goto err; } if (!PageUptodate(page)) { WARN_ON(1); goto err; } found_level = btrfs_header_level(eb); csum_tree_block(root, eb, 0); err: free_extent_buffer(eb); out: return 0; } static int check_tree_block_fsid(struct btrfs_root *root, struct extent_buffer *eb) { struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; u8 fsid[BTRFS_UUID_SIZE]; int ret = 1; read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb), BTRFS_FSID_SIZE); while (fs_devices) { if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) { ret = 0; break; } fs_devices = fs_devices->seed; } return ret; } #ifdef CONFIG_DEBUG_LOCK_ALLOC void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level) { lockdep_set_class_and_name(&eb->lock, &btrfs_eb_class[level], btrfs_eb_name[level]); } #endif static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end, struct extent_state *state) { struct extent_io_tree *tree; u64 found_start; int found_level; unsigned long len; struct extent_buffer *eb; struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; int ret = 0; tree = &BTRFS_I(page->mapping->host)->io_tree; if (page->private == EXTENT_PAGE_PRIVATE) goto out; if (!page->private) goto out; len = page->private >> 2; WARN_ON(len == 0); eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS); found_start = btrfs_header_bytenr(eb); if (found_start != start) { if (printk_ratelimit()) { printk(KERN_INFO "btrfs bad tree block start " "%llu %llu\n", (unsigned long long)found_start, (unsigned long long)eb->start); } ret = -EIO; goto err; } if (eb->first_page != page) { printk(KERN_INFO "btrfs bad first page %lu %lu\n", eb->first_page->index, page->index); WARN_ON(1); ret = -EIO; goto err; } if (check_tree_block_fsid(root, eb)) { if (printk_ratelimit()) { printk(KERN_INFO "btrfs bad fsid on block %llu\n", (unsigned long long)eb->start); } ret = -EIO; goto err; } found_level = btrfs_header_level(eb); btrfs_set_buffer_lockdep_class(eb, found_level); ret = csum_tree_block(root, eb, 1); if (ret) ret = -EIO; end = min_t(u64, eb->len, PAGE_CACHE_SIZE); end = eb->start + end - 1; err: free_extent_buffer(eb); out: return ret; } static void end_workqueue_bio(struct bio *bio, int err) { struct end_io_wq *end_io_wq = bio->bi_private; struct btrfs_fs_info *fs_info; fs_info = end_io_wq->info; end_io_wq->error = err; end_io_wq->work.func = end_workqueue_fn; end_io_wq->work.flags = 0; if (bio->bi_rw & (1 << BIO_RW)) { if (end_io_wq->metadata) btrfs_queue_worker(&fs_info->endio_meta_write_workers, &end_io_wq->work); else btrfs_queue_worker(&fs_info->endio_write_workers, &end_io_wq->work); } else { if (end_io_wq->metadata) btrfs_queue_worker(&fs_info->endio_meta_workers, &end_io_wq->work); else btrfs_queue_worker(&fs_info->endio_workers, &end_io_wq->work); } } int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio, int metadata) { struct end_io_wq *end_io_wq; end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS); if (!end_io_wq) return -ENOMEM; end_io_wq->private = bio->bi_private; end_io_wq->end_io = bio->bi_end_io; end_io_wq->info = info; end_io_wq->error = 0; end_io_wq->bio = bio; end_io_wq->metadata = metadata; bio->bi_private = end_io_wq; bio->bi_end_io = end_workqueue_bio; return 0; } unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info) { unsigned long limit = min_t(unsigned long, info->workers.max_workers, info->fs_devices->open_devices); return 256 * limit; } int btrfs_congested_async(struct btrfs_fs_info *info, int iodone) { return atomic_read(&info->nr_async_bios) > btrfs_async_submit_limit(info); } static void run_one_async_start(struct btrfs_work *work) { struct btrfs_fs_info *fs_info; struct async_submit_bio *async; async = container_of(work, struct async_submit_bio, work); fs_info = BTRFS_I(async->inode)->root->fs_info; async->submit_bio_start(async->inode, async->rw, async->bio, async->mirror_num, async->bio_flags); } static void run_one_async_done(struct btrfs_work *work) { struct btrfs_fs_info *fs_info; struct async_submit_bio *async; int limit; async = container_of(work, struct async_submit_bio, work); fs_info = BTRFS_I(async->inode)->root->fs_info; limit = btrfs_async_submit_limit(fs_info); limit = limit * 2 / 3; atomic_dec(&fs_info->nr_async_submits); if (atomic_read(&fs_info->nr_async_submits) < limit && waitqueue_active(&fs_info->async_submit_wait)) wake_up(&fs_info->async_submit_wait); async->submit_bio_done(async->inode, async->rw, async->bio, async->mirror_num, async->bio_flags); } static void run_one_async_free(struct btrfs_work *work) { struct async_submit_bio *async; async = container_of(work, struct async_submit_bio, work); kfree(async); } int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags, extent_submit_bio_hook_t *submit_bio_start, extent_submit_bio_hook_t *submit_bio_done) { struct async_submit_bio *async; async = kmalloc(sizeof(*async), GFP_NOFS); if (!async) return -ENOMEM; async->inode = inode; async->rw = rw; async->bio = bio; async->mirror_num = mirror_num; async->submit_bio_start = submit_bio_start; async->submit_bio_done = submit_bio_done; async->work.func = run_one_async_start; async->work.ordered_func = run_one_async_done; async->work.ordered_free = run_one_async_free; async->work.flags = 0; async->bio_flags = bio_flags; atomic_inc(&fs_info->nr_async_submits); if (rw & (1 << BIO_RW_SYNCIO)) btrfs_set_work_high_prio(&async->work); btrfs_queue_worker(&fs_info->workers, &async->work); while (atomic_read(&fs_info->async_submit_draining) && atomic_read(&fs_info->nr_async_submits)) { wait_event(fs_info->async_submit_wait, (atomic_read(&fs_info->nr_async_submits) == 0)); } return 0; } static int btree_csum_one_bio(struct bio *bio) { struct bio_vec *bvec = bio->bi_io_vec; int bio_index = 0; struct btrfs_root *root; WARN_ON(bio->bi_vcnt <= 0); while (bio_index < bio->bi_vcnt) { root = BTRFS_I(bvec->bv_page->mapping->host)->root; csum_dirty_buffer(root, bvec->bv_page); bio_index++; bvec++; } return 0; } static int __btree_submit_bio_start(struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags) { /* * when we're called for a write, we're already in the async * submission context. Just jump into btrfs_map_bio */ btree_csum_one_bio(bio); return 0; } static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags) { /* * when we're called for a write, we're already in the async * submission context. Just jump into btrfs_map_bio */ return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1); } static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags) { int ret; ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info, bio, 1); BUG_ON(ret); if (!(rw & (1 << BIO_RW))) { /* * called for a read, do the setup so that checksum validation * can happen in the async kernel threads */ return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 0); } /* * kthread helpers are used to submit writes so that checksumming * can happen in parallel across all CPUs */ return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info, inode, rw, bio, mirror_num, 0, __btree_submit_bio_start, __btree_submit_bio_done); } static int btree_writepage(struct page *page, struct writeback_control *wbc) { struct extent_io_tree *tree; struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; struct extent_buffer *eb; int was_dirty; tree = &BTRFS_I(page->mapping->host)->io_tree; if (!(current->flags & PF_MEMALLOC)) { return extent_write_full_page(tree, page, btree_get_extent, wbc); } redirty_page_for_writepage(wbc, page); eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE); WARN_ON(!eb); was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags); if (!was_dirty) { spin_lock(&root->fs_info->delalloc_lock); root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE; spin_unlock(&root->fs_info->delalloc_lock); } free_extent_buffer(eb); unlock_page(page); return 0; } static int btree_writepages(struct address_space *mapping, struct writeback_control *wbc) { struct extent_io_tree *tree; tree = &BTRFS_I(mapping->host)->io_tree; if (wbc->sync_mode == WB_SYNC_NONE) { struct btrfs_root *root = BTRFS_I(mapping->host)->root; u64 num_dirty; unsigned long thresh = 32 * 1024 * 1024; if (wbc->for_kupdate) return 0; /* this is a bit racy, but that's ok */ num_dirty = root->fs_info->dirty_metadata_bytes; if (num_dirty < thresh) return 0; } return extent_writepages(tree, mapping, btree_get_extent, wbc); } static int btree_readpage(struct file *file, struct page *page) { struct extent_io_tree *tree; tree = &BTRFS_I(page->mapping->host)->io_tree; return extent_read_full_page(tree, page, btree_get_extent); } static int btree_releasepage(struct page *page, gfp_t gfp_flags) { struct extent_io_tree *tree; struct extent_map_tree *map; int ret; if (PageWriteback(page) || PageDirty(page)) return 0; tree = &BTRFS_I(page->mapping->host)->io_tree; map = &BTRFS_I(page->mapping->host)->extent_tree; ret = try_release_extent_state(map, tree, page, gfp_flags); if (!ret) return 0; ret = try_release_extent_buffer(tree, page); if (ret == 1) { ClearPagePrivate(page); set_page_private(page, 0); page_cache_release(page); } return ret; } static void btree_invalidatepage(struct page *page, unsigned long offset) { struct extent_io_tree *tree; tree = &BTRFS_I(page->mapping->host)->io_tree; extent_invalidatepage(tree, page, offset); btree_releasepage(page, GFP_NOFS); if (PagePrivate(page)) { printk(KERN_WARNING "btrfs warning page private not zero " "on page %llu\n", (unsigned long long)page_offset(page)); ClearPagePrivate(page); set_page_private(page, 0); page_cache_release(page); } } static const struct address_space_operations btree_aops = { .readpage = btree_readpage, .writepage = btree_writepage, .writepages = btree_writepages, .releasepage = btree_releasepage, .invalidatepage = btree_invalidatepage, .sync_page = block_sync_page, }; int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize, u64 parent_transid) { struct extent_buffer *buf = NULL; struct inode *btree_inode = root->fs_info->btree_inode; int ret = 0; buf = btrfs_find_create_tree_block(root, bytenr, blocksize); if (!buf) return 0; read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree, buf, 0, 0, btree_get_extent, 0); free_extent_buffer(buf); return ret; } struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize) { struct inode *btree_inode = root->fs_info->btree_inode; struct extent_buffer *eb; eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree, bytenr, blocksize, GFP_NOFS); return eb; } struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize) { struct inode *btree_inode = root->fs_info->btree_inode; struct extent_buffer *eb; eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree, bytenr, blocksize, NULL, GFP_NOFS); return eb; } int btrfs_write_tree_block(struct extent_buffer *buf) { return btrfs_fdatawrite_range(buf->first_page->mapping, buf->start, buf->start + buf->len - 1, WB_SYNC_ALL); } int btrfs_wait_tree_block_writeback(struct extent_buffer *buf) { return btrfs_wait_on_page_writeback_range(buf->first_page->mapping, buf->start >> PAGE_CACHE_SHIFT, (buf->start + buf->len - 1) >> PAGE_CACHE_SHIFT); } struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize, u64 parent_transid) { struct extent_buffer *buf = NULL; struct inode *btree_inode = root->fs_info->btree_inode; struct extent_io_tree *io_tree; int ret; io_tree = &BTRFS_I(btree_inode)->io_tree; buf = btrfs_find_create_tree_block(root, bytenr, blocksize); if (!buf) return NULL; ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid); if (ret == 0) set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags); return buf; } int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf) { struct inode *btree_inode = root->fs_info->btree_inode; if (btrfs_header_generation(buf) == root->fs_info->running_transaction->transid) { btrfs_assert_tree_locked(buf); if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) { spin_lock(&root->fs_info->delalloc_lock); if (root->fs_info->dirty_metadata_bytes >= buf->len) root->fs_info->dirty_metadata_bytes -= buf->len; else WARN_ON(1); spin_unlock(&root->fs_info->delalloc_lock); } /* ugh, clear_extent_buffer_dirty needs to lock the page */ btrfs_set_lock_blocking(buf); clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf); } return 0; } static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize, u32 stripesize, struct btrfs_root *root, struct btrfs_fs_info *fs_info, u64 objectid) { root->node = NULL; root->commit_root = NULL; root->sectorsize = sectorsize; root->nodesize = nodesize; root->leafsize = leafsize; root->stripesize = stripesize; root->ref_cows = 0; root->track_dirty = 0; root->fs_info = fs_info; root->objectid = objectid; root->last_trans = 0; root->highest_objectid = 0; root->name = NULL; root->in_sysfs = 0; root->inode_tree.rb_node = NULL; INIT_LIST_HEAD(&root->dirty_list); INIT_LIST_HEAD(&root->orphan_list); INIT_LIST_HEAD(&root->root_list); spin_lock_init(&root->node_lock); spin_lock_init(&root->list_lock); spin_lock_init(&root->inode_lock); mutex_init(&root->objectid_mutex); mutex_init(&root->log_mutex); init_waitqueue_head(&root->log_writer_wait); init_waitqueue_head(&root->log_commit_wait[0]); init_waitqueue_head(&root->log_commit_wait[1]); atomic_set(&root->log_commit[0], 0); atomic_set(&root->log_commit[1], 0); atomic_set(&root->log_writers, 0); root->log_batch = 0; root->log_transid = 0; extent_io_tree_init(&root->dirty_log_pages, fs_info->btree_inode->i_mapping, GFP_NOFS); memset(&root->root_key, 0, sizeof(root->root_key)); memset(&root->root_item, 0, sizeof(root->root_item)); memset(&root->defrag_progress, 0, sizeof(root->defrag_progress)); memset(&root->root_kobj, 0, sizeof(root->root_kobj)); root->defrag_trans_start = fs_info->generation; init_completion(&root->kobj_unregister); root->defrag_running = 0; root->defrag_level = 0; root->root_key.objectid = objectid; root->anon_super.s_root = NULL; root->anon_super.s_dev = 0; INIT_LIST_HEAD(&root->anon_super.s_list); INIT_LIST_HEAD(&root->anon_super.s_instances); init_rwsem(&root->anon_super.s_umount); return 0; } static int find_and_setup_root(struct btrfs_root *tree_root, struct btrfs_fs_info *fs_info, u64 objectid, struct btrfs_root *root) { int ret; u32 blocksize; u64 generation; __setup_root(tree_root->nodesize, tree_root->leafsize, tree_root->sectorsize, tree_root->stripesize, root, fs_info, objectid); ret = btrfs_find_last_root(tree_root, objectid, &root->root_item, &root->root_key); if (ret > 0) return -ENOENT; BUG_ON(ret); generation = btrfs_root_generation(&root->root_item); blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item)); root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item), blocksize, generation); BUG_ON(!root->node); root->commit_root = btrfs_root_node(root); return 0; } int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info) { struct extent_buffer *eb; struct btrfs_root *log_root_tree = fs_info->log_root_tree; u64 start = 0; u64 end = 0; int ret; if (!log_root_tree) return 0; while (1) { ret = find_first_extent_bit(&log_root_tree->dirty_log_pages, 0, &start, &end, EXTENT_DIRTY); if (ret) break; clear_extent_dirty(&log_root_tree->dirty_log_pages, start, end, GFP_NOFS); } eb = fs_info->log_root_tree->node; WARN_ON(btrfs_header_level(eb) != 0); WARN_ON(btrfs_header_nritems(eb) != 0); ret = btrfs_free_reserved_extent(fs_info->tree_root, eb->start, eb->len); BUG_ON(ret); free_extent_buffer(eb); kfree(fs_info->log_root_tree); fs_info->log_root_tree = NULL; return 0; } static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info) { struct btrfs_root *root; struct btrfs_root *tree_root = fs_info->tree_root; struct extent_buffer *leaf; root = kzalloc(sizeof(*root), GFP_NOFS); if (!root) return ERR_PTR(-ENOMEM); __setup_root(tree_root->nodesize, tree_root->leafsize, tree_root->sectorsize, tree_root->stripesize, root, fs_info, BTRFS_TREE_LOG_OBJECTID); root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID; root->root_key.type = BTRFS_ROOT_ITEM_KEY; root->root_key.offset = BTRFS_TREE_LOG_OBJECTID; /* * log trees do not get reference counted because they go away * before a real commit is actually done. They do store pointers * to file data extents, and those reference counts still get * updated (along with back refs to the log tree). */ root->ref_cows = 0; leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0, BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0); if (IS_ERR(leaf)) { kfree(root); return ERR_CAST(leaf); } memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header)); btrfs_set_header_bytenr(leaf, leaf->start); btrfs_set_header_generation(leaf, trans->transid); btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV); btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID); root->node = leaf; write_extent_buffer(root->node, root->fs_info->fsid, (unsigned long)btrfs_header_fsid(root->node), BTRFS_FSID_SIZE); btrfs_mark_buffer_dirty(root->node); btrfs_tree_unlock(root->node); return root; } int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info) { struct btrfs_root *log_root; log_root = alloc_log_tree(trans, fs_info); if (IS_ERR(log_root)) return PTR_ERR(log_root); WARN_ON(fs_info->log_root_tree); fs_info->log_root_tree = log_root; return 0; } int btrfs_add_log_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_root *log_root; struct btrfs_inode_item *inode_item; log_root = alloc_log_tree(trans, root->fs_info); if (IS_ERR(log_root)) return PTR_ERR(log_root); log_root->last_trans = trans->transid; log_root->root_key.offset = root->root_key.objectid; inode_item = &log_root->root_item.inode; inode_item->generation = cpu_to_le64(1); inode_item->size = cpu_to_le64(3); inode_item->nlink = cpu_to_le32(1); inode_item->nbytes = cpu_to_le64(root->leafsize); inode_item->mode = cpu_to_le32(S_IFDIR | 0755); btrfs_set_root_node(&log_root->root_item, log_root->node); WARN_ON(root->log_root); root->log_root = log_root; root->log_transid = 0; return 0; } struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root, struct btrfs_key *location) { struct btrfs_root *root; struct btrfs_fs_info *fs_info = tree_root->fs_info; struct btrfs_path *path; struct extent_buffer *l; u64 generation; u32 blocksize; int ret = 0; root = kzalloc(sizeof(*root), GFP_NOFS); if (!root) return ERR_PTR(-ENOMEM); if (location->offset == (u64)-1) { ret = find_and_setup_root(tree_root, fs_info, location->objectid, root); if (ret) { kfree(root); return ERR_PTR(ret); } goto out; } __setup_root(tree_root->nodesize, tree_root->leafsize, tree_root->sectorsize, tree_root->stripesize, root, fs_info, location->objectid); path = btrfs_alloc_path(); BUG_ON(!path); ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0); if (ret == 0) { l = path->nodes[0]; read_extent_buffer(l, &root->root_item, btrfs_item_ptr_offset(l, path->slots[0]), sizeof(root->root_item)); memcpy(&root->root_key, location, sizeof(*location)); } btrfs_free_path(path); if (ret) { if (ret > 0) ret = -ENOENT; return ERR_PTR(ret); } generation = btrfs_root_generation(&root->root_item); blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item)); root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item), blocksize, generation); root->commit_root = btrfs_root_node(root); BUG_ON(!root->node); out: if (location->objectid != BTRFS_TREE_LOG_OBJECTID) root->ref_cows = 1; return root; } struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info, u64 root_objectid) { struct btrfs_root *root; if (root_objectid == BTRFS_ROOT_TREE_OBJECTID) return fs_info->tree_root; if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID) return fs_info->extent_root; root = radix_tree_lookup(&fs_info->fs_roots_radix, (unsigned long)root_objectid); return root; } struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info, struct btrfs_key *location) { struct btrfs_root *root; int ret; if (location->objectid == BTRFS_ROOT_TREE_OBJECTID) return fs_info->tree_root; if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID) return fs_info->extent_root; if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID) return fs_info->chunk_root; if (location->objectid == BTRFS_DEV_TREE_OBJECTID) return fs_info->dev_root; if (location->objectid == BTRFS_CSUM_TREE_OBJECTID) return fs_info->csum_root; again: spin_lock(&fs_info->fs_roots_radix_lock); root = radix_tree_lookup(&fs_info->fs_roots_radix, (unsigned long)location->objectid); spin_unlock(&fs_info->fs_roots_radix_lock); if (root) return root; ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid); if (ret == 0) ret = -ENOENT; if (ret < 0) return ERR_PTR(ret); root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location); if (IS_ERR(root)) return root; WARN_ON(btrfs_root_refs(&root->root_item) == 0); set_anon_super(&root->anon_super, NULL); ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM); if (ret) goto fail; spin_lock(&fs_info->fs_roots_radix_lock); ret = radix_tree_insert(&fs_info->fs_roots_radix, (unsigned long)root->root_key.objectid, root); if (ret == 0) root->in_radix = 1; spin_unlock(&fs_info->fs_roots_radix_lock); radix_tree_preload_end(); if (ret) { if (ret == -EEXIST) { free_fs_root(root); goto again; } goto fail; } ret = btrfs_find_dead_roots(fs_info->tree_root, root->root_key.objectid); WARN_ON(ret); if (!(fs_info->sb->s_flags & MS_RDONLY)) btrfs_orphan_cleanup(root); return root; fail: free_fs_root(root); return ERR_PTR(ret); } struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_key *location, const char *name, int namelen) { return btrfs_read_fs_root_no_name(fs_info, location); #if 0 struct btrfs_root *root; int ret; root = btrfs_read_fs_root_no_name(fs_info, location); if (!root) return NULL; if (root->in_sysfs) return root; ret = btrfs_set_root_name(root, name, namelen); if (ret) { free_extent_buffer(root->node); kfree(root); return ERR_PTR(ret); } ret = btrfs_sysfs_add_root(root); if (ret) { free_extent_buffer(root->node); kfree(root->name); kfree(root); return ERR_PTR(ret); } root->in_sysfs = 1; return root; #endif } static int btrfs_congested_fn(void *congested_data, int bdi_bits) { struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data; int ret = 0; struct btrfs_device *device; struct backing_dev_info *bdi; list_for_each_entry(device, &info->fs_devices->devices, dev_list) { if (!device->bdev) continue; bdi = blk_get_backing_dev_info(device->bdev); if (bdi && bdi_congested(bdi, bdi_bits)) { ret = 1; break; } } return ret; } /* * this unplugs every device on the box, and it is only used when page * is null */ static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page) { struct btrfs_device *device; struct btrfs_fs_info *info; info = (struct btrfs_fs_info *)bdi->unplug_io_data; list_for_each_entry(device, &info->fs_devices->devices, dev_list) { if (!device->bdev) continue; bdi = blk_get_backing_dev_info(device->bdev); if (bdi->unplug_io_fn) bdi->unplug_io_fn(bdi, page); } } static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) { struct inode *inode; struct extent_map_tree *em_tree; struct extent_map *em; struct address_space *mapping; u64 offset; /* the generic O_DIRECT read code does this */ if (1 || !page) { __unplug_io_fn(bdi, page); return; } /* * page->mapping may change at any time. Get a consistent copy * and use that for everything below */ smp_mb(); mapping = page->mapping; if (!mapping) return; inode = mapping->host; /* * don't do the expensive searching for a small number of * devices */ if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) { __unplug_io_fn(bdi, page); return; } offset = page_offset(page); em_tree = &BTRFS_I(inode)->extent_tree; read_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE); read_unlock(&em_tree->lock); if (!em) { __unplug_io_fn(bdi, page); return; } if (em->block_start >= EXTENT_MAP_LAST_BYTE) { free_extent_map(em); __unplug_io_fn(bdi, page); return; } offset = offset - em->start; btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree, em->block_start + offset, page); free_extent_map(em); } /* * If this fails, caller must call bdi_destroy() to get rid of the * bdi again. */ static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi) { int err; bdi->name = "btrfs"; bdi->capabilities = BDI_CAP_MAP_COPY; err = bdi_init(bdi); if (err) return err; err = bdi_register(bdi, NULL, "btrfs-%d", atomic_inc_return(&btrfs_bdi_num)); if (err) { bdi_destroy(bdi); return err; } bdi->ra_pages = default_backing_dev_info.ra_pages; bdi->unplug_io_fn = btrfs_unplug_io_fn; bdi->unplug_io_data = info; bdi->congested_fn = btrfs_congested_fn; bdi->congested_data = info; return 0; } static int bio_ready_for_csum(struct bio *bio) { u64 length = 0; u64 buf_len = 0; u64 start = 0; struct page *page; struct extent_io_tree *io_tree = NULL; struct btrfs_fs_info *info = NULL; struct bio_vec *bvec; int i; int ret; bio_for_each_segment(bvec, bio, i) { page = bvec->bv_page; if (page->private == EXTENT_PAGE_PRIVATE) { length += bvec->bv_len; continue; } if (!page->private) { length += bvec->bv_len; continue; } length = bvec->bv_len; buf_len = page->private >> 2; start = page_offset(page) + bvec->bv_offset; io_tree = &BTRFS_I(page->mapping->host)->io_tree; info = BTRFS_I(page->mapping->host)->root->fs_info; } /* are we fully contained in this bio? */ if (buf_len <= length) return 1; ret = extent_range_uptodate(io_tree, start + length, start + buf_len - 1); return ret; } /* * called by the kthread helper functions to finally call the bio end_io * functions. This is where read checksum verification actually happens */ static void end_workqueue_fn(struct btrfs_work *work) { struct bio *bio; struct end_io_wq *end_io_wq; struct btrfs_fs_info *fs_info; int error; end_io_wq = container_of(work, struct end_io_wq, work); bio = end_io_wq->bio; fs_info = end_io_wq->info; /* metadata bio reads are special because the whole tree block must * be checksummed at once. This makes sure the entire block is in * ram and up to date before trying to verify things. For * blocksize <= pagesize, it is basically a noop */ if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata && !bio_ready_for_csum(bio)) { btrfs_queue_worker(&fs_info->endio_meta_workers, &end_io_wq->work); return; } error = end_io_wq->error; bio->bi_private = end_io_wq->private; bio->bi_end_io = end_io_wq->end_io; kfree(end_io_wq); bio_endio(bio, error); } static int cleaner_kthread(void *arg) { struct btrfs_root *root = arg; do { smp_mb(); if (root->fs_info->closing) break; vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE); if (!(root->fs_info->sb->s_flags & MS_RDONLY) && mutex_trylock(&root->fs_info->cleaner_mutex)) { btrfs_clean_old_snapshots(root); mutex_unlock(&root->fs_info->cleaner_mutex); } if (freezing(current)) { refrigerator(); } else { smp_mb(); if (root->fs_info->closing) break; set_current_state(TASK_INTERRUPTIBLE); schedule(); __set_current_state(TASK_RUNNING); } } while (!kthread_should_stop()); return 0; } static int transaction_kthread(void *arg) { struct btrfs_root *root = arg; struct btrfs_trans_handle *trans; struct btrfs_transaction *cur; unsigned long now; unsigned long delay; int ret; do { smp_mb(); if (root->fs_info->closing) break; delay = HZ * 30; vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE); mutex_lock(&root->fs_info->transaction_kthread_mutex); mutex_lock(&root->fs_info->trans_mutex); cur = root->fs_info->running_transaction; if (!cur) { mutex_unlock(&root->fs_info->trans_mutex); goto sleep; } now = get_seconds(); if (now < cur->start_time || now - cur->start_time < 30) { mutex_unlock(&root->fs_info->trans_mutex); delay = HZ * 5; goto sleep; } mutex_unlock(&root->fs_info->trans_mutex); trans = btrfs_start_transaction(root, 1); ret = btrfs_commit_transaction(trans, root); sleep: wake_up_process(root->fs_info->cleaner_kthread); mutex_unlock(&root->fs_info->transaction_kthread_mutex); if (freezing(current)) { refrigerator(); } else { if (root->fs_info->closing) break; set_current_state(TASK_INTERRUPTIBLE); schedule_timeout(delay); __set_current_state(TASK_RUNNING); } } while (!kthread_should_stop()); return 0; } struct btrfs_root *open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices, char *options) { u32 sectorsize; u32 nodesize; u32 leafsize; u32 blocksize; u32 stripesize; u64 generation; u64 features; struct btrfs_key location; struct buffer_head *bh; struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info), GFP_NOFS); struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); struct btrfs_root *log_tree_root; int ret; int err = -EINVAL; struct btrfs_super_block *disk_super; if (!extent_root || !tree_root || !fs_info || !chunk_root || !dev_root || !csum_root) { err = -ENOMEM; goto fail; } ret = init_srcu_struct(&fs_info->subvol_srcu); if (ret) { err = ret; goto fail; } ret = setup_bdi(fs_info, &fs_info->bdi); if (ret) { err = ret; goto fail_srcu; } fs_info->btree_inode = new_inode(sb); if (!fs_info->btree_inode) { err = -ENOMEM; goto fail_bdi; } INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC); INIT_LIST_HEAD(&fs_info->trans_list); INIT_LIST_HEAD(&fs_info->dead_roots); INIT_LIST_HEAD(&fs_info->hashers); INIT_LIST_HEAD(&fs_info->delalloc_inodes); INIT_LIST_HEAD(&fs_info->ordered_operations); INIT_LIST_HEAD(&fs_info->caching_block_groups); spin_lock_init(&fs_info->delalloc_lock); spin_lock_init(&fs_info->new_trans_lock); spin_lock_init(&fs_info->ref_cache_lock); spin_lock_init(&fs_info->fs_roots_radix_lock); init_completion(&fs_info->kobj_unregister); fs_info->tree_root = tree_root; fs_info->extent_root = extent_root; fs_info->csum_root = csum_root; fs_info->chunk_root = chunk_root; fs_info->dev_root = dev_root; fs_info->fs_devices = fs_devices; INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots); INIT_LIST_HEAD(&fs_info->space_info); btrfs_mapping_init(&fs_info->mapping_tree); atomic_set(&fs_info->nr_async_submits, 0); atomic_set(&fs_info->async_delalloc_pages, 0); atomic_set(&fs_info->async_submit_draining, 0); atomic_set(&fs_info->nr_async_bios, 0); fs_info->sb = sb; fs_info->max_extent = (u64)-1; fs_info->max_inline = 8192 * 1024; fs_info->metadata_ratio = 0; fs_info->thread_pool_size = min_t(unsigned long, num_online_cpus() + 2, 8); INIT_LIST_HEAD(&fs_info->ordered_extents); spin_lock_init(&fs_info->ordered_extent_lock); sb->s_blocksize = 4096; sb->s_blocksize_bits = blksize_bits(4096); sb->s_bdi = &fs_info->bdi; fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID; fs_info->btree_inode->i_nlink = 1; /* * we set the i_size on the btree inode to the max possible int. * the real end of the address space is determined by all of * the devices in the system */ fs_info->btree_inode->i_size = OFFSET_MAX; fs_info->btree_inode->i_mapping->a_ops = &btree_aops; fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi; RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node); extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree, fs_info->btree_inode->i_mapping, GFP_NOFS); extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree, GFP_NOFS); BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops; BTRFS_I(fs_info->btree_inode)->root = tree_root; memset(&BTRFS_I(fs_info->btree_inode)->location, 0, sizeof(struct btrfs_key)); BTRFS_I(fs_info->btree_inode)->dummy_inode = 1; insert_inode_hash(fs_info->btree_inode); spin_lock_init(&fs_info->block_group_cache_lock); fs_info->block_group_cache_tree.rb_node = NULL; extent_io_tree_init(&fs_info->freed_extents[0], fs_info->btree_inode->i_mapping, GFP_NOFS); extent_io_tree_init(&fs_info->freed_extents[1], fs_info->btree_inode->i_mapping, GFP_NOFS); fs_info->pinned_extents = &fs_info->freed_extents[0]; fs_info->do_barriers = 1; mutex_init(&fs_info->trans_mutex); mutex_init(&fs_info->ordered_operations_mutex); mutex_init(&fs_info->tree_log_mutex); mutex_init(&fs_info->chunk_mutex); mutex_init(&fs_info->transaction_kthread_mutex); mutex_init(&fs_info->cleaner_mutex); mutex_init(&fs_info->volume_mutex); init_rwsem(&fs_info->extent_commit_sem); init_rwsem(&fs_info->subvol_sem); btrfs_init_free_cluster(&fs_info->meta_alloc_cluster); btrfs_init_free_cluster(&fs_info->data_alloc_cluster); init_waitqueue_head(&fs_info->transaction_throttle); init_waitqueue_head(&fs_info->transaction_wait); init_waitqueue_head(&fs_info->async_submit_wait); __setup_root(4096, 4096, 4096, 4096, tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID); bh = btrfs_read_dev_super(fs_devices->latest_bdev); if (!bh) goto fail_iput; memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy)); memcpy(&fs_info->super_for_commit, &fs_info->super_copy, sizeof(fs_info->super_for_commit)); brelse(bh); memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE); disk_super = &fs_info->super_copy; if (!btrfs_super_root(disk_super)) goto fail_iput; ret = btrfs_parse_options(tree_root, options); if (ret) { err = ret; goto fail_iput; } features = btrfs_super_incompat_flags(disk_super) & ~BTRFS_FEATURE_INCOMPAT_SUPP; if (features) { printk(KERN_ERR "BTRFS: couldn't mount because of " "unsupported optional features (%Lx).\n", (unsigned long long)features); err = -EINVAL; goto fail_iput; } features = btrfs_super_incompat_flags(disk_super); if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) { features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF; btrfs_set_super_incompat_flags(disk_super, features); } features = btrfs_super_compat_ro_flags(disk_super) & ~BTRFS_FEATURE_COMPAT_RO_SUPP; if (!(sb->s_flags & MS_RDONLY) && features) { printk(KERN_ERR "BTRFS: couldn't mount RDWR because of " "unsupported option features (%Lx).\n", (unsigned long long)features); err = -EINVAL; goto fail_iput; } printk("thread pool is %d\n", fs_info->thread_pool_size); /* * we need to start all the end_io workers up front because the * queue work function gets called at interrupt time, and so it * cannot dynamically grow. */ btrfs_init_workers(&fs_info->workers, "worker", fs_info->thread_pool_size); btrfs_init_workers(&fs_info->delalloc_workers, "delalloc", fs_info->thread_pool_size); btrfs_init_workers(&fs_info->submit_workers, "submit", min_t(u64, fs_devices->num_devices, fs_info->thread_pool_size)); /* a higher idle thresh on the submit workers makes it much more * likely that bios will be send down in a sane order to the * devices */ fs_info->submit_workers.idle_thresh = 64; fs_info->workers.idle_thresh = 16; fs_info->workers.ordered = 1; fs_info->delalloc_workers.idle_thresh = 2; fs_info->delalloc_workers.ordered = 1; btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1); btrfs_init_workers(&fs_info->endio_workers, "endio", fs_info->thread_pool_size); btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta", fs_info->thread_pool_size); btrfs_init_workers(&fs_info->endio_meta_write_workers, "endio-meta-write", fs_info->thread_pool_size); btrfs_init_workers(&fs_info->endio_write_workers, "endio-write", fs_info->thread_pool_size); /* * endios are largely parallel and should have a very * low idle thresh */ fs_info->endio_workers.idle_thresh = 4; fs_info->endio_meta_workers.idle_thresh = 4; fs_info->endio_write_workers.idle_thresh = 2; fs_info->endio_meta_write_workers.idle_thresh = 2; fs_info->endio_workers.atomic_worker_start = 1; fs_info->endio_meta_workers.atomic_worker_start = 1; fs_info->endio_write_workers.atomic_worker_start = 1; fs_info->endio_meta_write_workers.atomic_worker_start = 1; btrfs_start_workers(&fs_info->workers, 1); btrfs_start_workers(&fs_info->submit_workers, 1); btrfs_start_workers(&fs_info->delalloc_workers, 1); btrfs_start_workers(&fs_info->fixup_workers, 1); btrfs_start_workers(&fs_info->endio_workers, 1); btrfs_start_workers(&fs_info->endio_meta_workers, 1); btrfs_start_workers(&fs_info->endio_meta_write_workers, 1); btrfs_start_workers(&fs_info->endio_write_workers, 1); fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super); fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages, 4 * 1024 * 1024 / PAGE_CACHE_SIZE); nodesize = btrfs_super_nodesize(disk_super); leafsize = btrfs_super_leafsize(disk_super); sectorsize = btrfs_super_sectorsize(disk_super); stripesize = btrfs_super_stripesize(disk_super); tree_root->nodesize = nodesize; tree_root->leafsize = leafsize; tree_root->sectorsize = sectorsize; tree_root->stripesize = stripesize; sb->s_blocksize = sectorsize; sb->s_blocksize_bits = blksize_bits(sectorsize); if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC, sizeof(disk_super->magic))) { printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id); goto fail_sb_buffer; } mutex_lock(&fs_info->chunk_mutex); ret = btrfs_read_sys_array(tree_root); mutex_unlock(&fs_info->chunk_mutex); if (ret) { printk(KERN_WARNING "btrfs: failed to read the system " "array on %s\n", sb->s_id); goto fail_sb_buffer; } blocksize = btrfs_level_size(tree_root, btrfs_super_chunk_root_level(disk_super)); generation = btrfs_super_chunk_root_generation(disk_super); __setup_root(nodesize, leafsize, sectorsize, stripesize, chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID); chunk_root->node = read_tree_block(chunk_root, btrfs_super_chunk_root(disk_super), blocksize, generation); BUG_ON(!chunk_root->node); if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) { printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n", sb->s_id); goto fail_chunk_root; } btrfs_set_root_node(&chunk_root->root_item, chunk_root->node); chunk_root->commit_root = btrfs_root_node(chunk_root); read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid, (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node), BTRFS_UUID_SIZE); mutex_lock(&fs_info->chunk_mutex); ret = btrfs_read_chunk_tree(chunk_root); mutex_unlock(&fs_info->chunk_mutex); if (ret) { printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n", sb->s_id); goto fail_chunk_root; } btrfs_close_extra_devices(fs_devices); blocksize = btrfs_level_size(tree_root, btrfs_super_root_level(disk_super)); generation = btrfs_super_generation(disk_super); tree_root->node = read_tree_block(tree_root, btrfs_super_root(disk_super), blocksize, generation); if (!tree_root->node) goto fail_chunk_root; if (!test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) { printk(KERN_WARNING "btrfs: failed to read tree root on %s\n", sb->s_id); goto fail_tree_root; } btrfs_set_root_node(&tree_root->root_item, tree_root->node); tree_root->commit_root = btrfs_root_node(tree_root); ret = find_and_setup_root(tree_root, fs_info, BTRFS_EXTENT_TREE_OBJECTID, extent_root); if (ret) goto fail_tree_root; extent_root->track_dirty = 1; ret = find_and_setup_root(tree_root, fs_info, BTRFS_DEV_TREE_OBJECTID, dev_root); if (ret) goto fail_extent_root; dev_root->track_dirty = 1; ret = find_and_setup_root(tree_root, fs_info, BTRFS_CSUM_TREE_OBJECTID, csum_root); if (ret) goto fail_dev_root; csum_root->track_dirty = 1; btrfs_read_block_groups(extent_root); fs_info->generation = generation; fs_info->last_trans_committed = generation; fs_info->data_alloc_profile = (u64)-1; fs_info->metadata_alloc_profile = (u64)-1; fs_info->system_alloc_profile = fs_info->metadata_alloc_profile; fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root, "btrfs-cleaner"); if (IS_ERR(fs_info->cleaner_kthread)) goto fail_csum_root; fs_info->transaction_kthread = kthread_run(transaction_kthread, tree_root, "btrfs-transaction"); if (IS_ERR(fs_info->transaction_kthread)) goto fail_cleaner; if (!btrfs_test_opt(tree_root, SSD) && !btrfs_test_opt(tree_root, NOSSD) && !fs_info->fs_devices->rotating) { printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD " "mode\n"); btrfs_set_opt(fs_info->mount_opt, SSD); } if (btrfs_super_log_root(disk_super) != 0) { u64 bytenr = btrfs_super_log_root(disk_super); if (fs_devices->rw_devices == 0) { printk(KERN_WARNING "Btrfs log replay required " "on RO media\n"); err = -EIO; goto fail_trans_kthread; } blocksize = btrfs_level_size(tree_root, btrfs_super_log_root_level(disk_super)); log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); __setup_root(nodesize, leafsize, sectorsize, stripesize, log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID); log_tree_root->node = read_tree_block(tree_root, bytenr, blocksize, generation + 1); ret = btrfs_recover_log_trees(log_tree_root); BUG_ON(ret); if (sb->s_flags & MS_RDONLY) { ret = btrfs_commit_super(tree_root); BUG_ON(ret); } } ret = btrfs_find_orphan_roots(tree_root); BUG_ON(ret); if (!(sb->s_flags & MS_RDONLY)) { ret = btrfs_recover_relocation(tree_root); BUG_ON(ret); } location.objectid = BTRFS_FS_TREE_OBJECTID; location.type = BTRFS_ROOT_ITEM_KEY; location.offset = (u64)-1; fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location); if (!fs_info->fs_root) goto fail_trans_kthread; return tree_root; fail_trans_kthread: kthread_stop(fs_info->transaction_kthread); fail_cleaner: kthread_stop(fs_info->cleaner_kthread); /* * make sure we're done with the btree inode before we stop our * kthreads */ filemap_write_and_wait(fs_info->btree_inode->i_mapping); invalidate_inode_pages2(fs_info->btree_inode->i_mapping); fail_csum_root: free_extent_buffer(csum_root->node); free_extent_buffer(csum_root->commit_root); fail_dev_root: free_extent_buffer(dev_root->node); free_extent_buffer(dev_root->commit_root); fail_extent_root: free_extent_buffer(extent_root->node); free_extent_buffer(extent_root->commit_root); fail_tree_root: free_extent_buffer(tree_root->node); free_extent_buffer(tree_root->commit_root); fail_chunk_root: free_extent_buffer(chunk_root->node); free_extent_buffer(chunk_root->commit_root); fail_sb_buffer: btrfs_stop_workers(&fs_info->fixup_workers); btrfs_stop_workers(&fs_info->delalloc_workers); btrfs_stop_workers(&fs_info->workers); btrfs_stop_workers(&fs_info->endio_workers); btrfs_stop_workers(&fs_info->endio_meta_workers); btrfs_stop_workers(&fs_info->endio_meta_write_workers); btrfs_stop_workers(&fs_info->endio_write_workers); btrfs_stop_workers(&fs_info->submit_workers); fail_iput: invalidate_inode_pages2(fs_info->btree_inode->i_mapping); iput(fs_info->btree_inode); btrfs_close_devices(fs_info->fs_devices); btrfs_mapping_tree_free(&fs_info->mapping_tree); fail_bdi: bdi_destroy(&fs_info->bdi); fail_srcu: cleanup_srcu_struct(&fs_info->subvol_srcu); fail: kfree(extent_root); kfree(tree_root); kfree(fs_info); kfree(chunk_root); kfree(dev_root); kfree(csum_root); return ERR_PTR(err); } static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate) { char b[BDEVNAME_SIZE]; if (uptodate) { set_buffer_uptodate(bh); } else { if (!buffer_eopnotsupp(bh) && printk_ratelimit()) { printk(KERN_WARNING "lost page write due to " "I/O error on %s\n", bdevname(bh->b_bdev, b)); } /* note, we dont' set_buffer_write_io_error because we have * our own ways of dealing with the IO errors */ clear_buffer_uptodate(bh); } unlock_buffer(bh); put_bh(bh); } struct buffer_head *btrfs_read_dev_super(struct block_device *bdev) { struct buffer_head *bh; struct buffer_head *latest = NULL; struct btrfs_super_block *super; int i; u64 transid = 0; u64 bytenr; /* we would like to check all the supers, but that would make * a btrfs mount succeed after a mkfs from a different FS. * So, we need to add a special mount option to scan for * later supers, using BTRFS_SUPER_MIRROR_MAX instead */ for (i = 0; i < 1; i++) { bytenr = btrfs_sb_offset(i); if (bytenr + 4096 >= i_size_read(bdev->bd_inode)) break; bh = __bread(bdev, bytenr / 4096, 4096); if (!bh) continue; super = (struct btrfs_super_block *)bh->b_data; if (btrfs_super_bytenr(super) != bytenr || strncmp((char *)(&super->magic), BTRFS_MAGIC, sizeof(super->magic))) { brelse(bh); continue; } if (!latest || btrfs_super_generation(super) > transid) { brelse(latest); latest = bh; transid = btrfs_super_generation(super); } else { brelse(bh); } } return latest; } /* * this should be called twice, once with wait == 0 and * once with wait == 1. When wait == 0 is done, all the buffer heads * we write are pinned. * * They are released when wait == 1 is done. * max_mirrors must be the same for both runs, and it indicates how * many supers on this one device should be written. * * max_mirrors == 0 means to write them all. */ static int write_dev_supers(struct btrfs_device *device, struct btrfs_super_block *sb, int do_barriers, int wait, int max_mirrors) { struct buffer_head *bh; int i; int ret; int errors = 0; u32 crc; u64 bytenr; int last_barrier = 0; if (max_mirrors == 0) max_mirrors = BTRFS_SUPER_MIRROR_MAX; /* make sure only the last submit_bh does a barrier */ if (do_barriers) { for (i = 0; i < max_mirrors; i++) { bytenr = btrfs_sb_offset(i); if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes) break; last_barrier = i; } } for (i = 0; i < max_mirrors; i++) { bytenr = btrfs_sb_offset(i); if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes) break; if (wait) { bh = __find_get_block(device->bdev, bytenr / 4096, BTRFS_SUPER_INFO_SIZE); BUG_ON(!bh); wait_on_buffer(bh); if (!buffer_uptodate(bh)) errors++; /* drop our reference */ brelse(bh); /* drop the reference from the wait == 0 run */ brelse(bh); continue; } else { btrfs_set_super_bytenr(sb, bytenr); crc = ~(u32)0; crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE); btrfs_csum_final(crc, sb->csum); /* * one reference for us, and we leave it for the * caller */ bh = __getblk(device->bdev, bytenr / 4096, BTRFS_SUPER_INFO_SIZE); memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE); /* one reference for submit_bh */ get_bh(bh); set_buffer_uptodate(bh); lock_buffer(bh); bh->b_end_io = btrfs_end_buffer_write_sync; } if (i == last_barrier && do_barriers && device->barriers) { ret = submit_bh(WRITE_BARRIER, bh); if (ret == -EOPNOTSUPP) { printk("btrfs: disabling barriers on dev %s\n", device->name); set_buffer_uptodate(bh); device->barriers = 0; /* one reference for submit_bh */ get_bh(bh); lock_buffer(bh); ret = submit_bh(WRITE_SYNC, bh); } } else { ret = submit_bh(WRITE_SYNC, bh); } if (ret) errors++; } return errors < i ? 0 : -1; } int write_all_supers(struct btrfs_root *root, int max_mirrors) { struct list_head *head; struct btrfs_device *dev; struct btrfs_super_block *sb; struct btrfs_dev_item *dev_item; int ret; int do_barriers; int max_errors; int total_errors = 0; u64 flags; max_errors = btrfs_super_num_devices(&root->fs_info->super_copy) - 1; do_barriers = !btrfs_test_opt(root, NOBARRIER); sb = &root->fs_info->super_for_commit; dev_item = &sb->dev_item; mutex_lock(&root->fs_info->fs_devices->device_list_mutex); head = &root->fs_info->fs_devices->devices; list_for_each_entry(dev, head, dev_list) { if (!dev->bdev) { total_errors++; continue; } if (!dev->in_fs_metadata || !dev->writeable) continue; btrfs_set_stack_device_generation(dev_item, 0); btrfs_set_stack_device_type(dev_item, dev->type); btrfs_set_stack_device_id(dev_item, dev->devid); btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes); btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used); btrfs_set_stack_device_io_align(dev_item, dev->io_align); btrfs_set_stack_device_io_width(dev_item, dev->io_width); btrfs_set_stack_device_sector_size(dev_item, dev->sector_size); memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE); memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE); flags = btrfs_super_flags(sb); btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN); ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors); if (ret) total_errors++; } if (total_errors > max_errors) { printk(KERN_ERR "btrfs: %d errors while writing supers\n", total_errors); BUG(); } total_errors = 0; list_for_each_entry(dev, head, dev_list) { if (!dev->bdev) continue; if (!dev->in_fs_metadata || !dev->writeable) continue; ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors); if (ret) total_errors++; } mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); if (total_errors > max_errors) { printk(KERN_ERR "btrfs: %d errors while writing supers\n", total_errors); BUG(); } return 0; } int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root *root, int max_mirrors) { int ret; ret = write_all_supers(root, max_mirrors); return ret; } int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root) { spin_lock(&fs_info->fs_roots_radix_lock); radix_tree_delete(&fs_info->fs_roots_radix, (unsigned long)root->root_key.objectid); spin_unlock(&fs_info->fs_roots_radix_lock); if (btrfs_root_refs(&root->root_item) == 0) synchronize_srcu(&fs_info->subvol_srcu); free_fs_root(root); return 0; } static void free_fs_root(struct btrfs_root *root) { WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree)); if (root->anon_super.s_dev) { down_write(&root->anon_super.s_umount); kill_anon_super(&root->anon_super); } free_extent_buffer(root->node); free_extent_buffer(root->commit_root); kfree(root->name); kfree(root); } static int del_fs_roots(struct btrfs_fs_info *fs_info) { int ret; struct btrfs_root *gang[8]; int i; while (!list_empty(&fs_info->dead_roots)) { gang[0] = list_entry(fs_info->dead_roots.next, struct btrfs_root, root_list); list_del(&gang[0]->root_list); if (gang[0]->in_radix) { btrfs_free_fs_root(fs_info, gang[0]); } else { free_extent_buffer(gang[0]->node); free_extent_buffer(gang[0]->commit_root); kfree(gang[0]); } } while (1) { ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix, (void **)gang, 0, ARRAY_SIZE(gang)); if (!ret) break; for (i = 0; i < ret; i++) btrfs_free_fs_root(fs_info, gang[i]); } return 0; } int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info) { u64 root_objectid = 0; struct btrfs_root *gang[8]; int i; int ret; while (1) { ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix, (void **)gang, root_objectid, ARRAY_SIZE(gang)); if (!ret) break; root_objectid = gang[ret - 1]->root_key.objectid + 1; for (i = 0; i < ret; i++) { root_objectid = gang[i]->root_key.objectid; btrfs_orphan_cleanup(gang[i]); } root_objectid++; } return 0; } int btrfs_commit_super(struct btrfs_root *root) { struct btrfs_trans_handle *trans; int ret; mutex_lock(&root->fs_info->cleaner_mutex); btrfs_clean_old_snapshots(root); mutex_unlock(&root->fs_info->cleaner_mutex); trans = btrfs_start_transaction(root, 1); ret = btrfs_commit_transaction(trans, root); BUG_ON(ret); /* run commit again to drop the original snapshot */ trans = btrfs_start_transaction(root, 1); btrfs_commit_transaction(trans, root); ret = btrfs_write_and_wait_transaction(NULL, root); BUG_ON(ret); ret = write_ctree_super(NULL, root, 0); return ret; } int close_ctree(struct btrfs_root *root) { struct btrfs_fs_info *fs_info = root->fs_info; int ret; fs_info->closing = 1; smp_mb(); kthread_stop(root->fs_info->transaction_kthread); kthread_stop(root->fs_info->cleaner_kthread); if (!(fs_info->sb->s_flags & MS_RDONLY)) { ret = btrfs_commit_super(root); if (ret) printk(KERN_ERR "btrfs: commit super ret %d\n", ret); } fs_info->closing = 2; smp_mb(); if (fs_info->delalloc_bytes) { printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n", (unsigned long long)fs_info->delalloc_bytes); } if (fs_info->total_ref_cache_size) { printk(KERN_INFO "btrfs: at umount reference cache size %llu\n", (unsigned long long)fs_info->total_ref_cache_size); } free_extent_buffer(fs_info->extent_root->node); free_extent_buffer(fs_info->extent_root->commit_root); free_extent_buffer(fs_info->tree_root->node); free_extent_buffer(fs_info->tree_root->commit_root); free_extent_buffer(root->fs_info->chunk_root->node); free_extent_buffer(root->fs_info->chunk_root->commit_root); free_extent_buffer(root->fs_info->dev_root->node); free_extent_buffer(root->fs_info->dev_root->commit_root); free_extent_buffer(root->fs_info->csum_root->node); free_extent_buffer(root->fs_info->csum_root->commit_root); btrfs_free_block_groups(root->fs_info); del_fs_roots(fs_info); iput(fs_info->btree_inode); btrfs_stop_workers(&fs_info->fixup_workers); btrfs_stop_workers(&fs_info->delalloc_workers); btrfs_stop_workers(&fs_info->workers); btrfs_stop_workers(&fs_info->endio_workers); btrfs_stop_workers(&fs_info->endio_meta_workers); btrfs_stop_workers(&fs_info->endio_meta_write_workers); btrfs_stop_workers(&fs_info->endio_write_workers); btrfs_stop_workers(&fs_info->submit_workers); btrfs_close_devices(fs_info->fs_devices); btrfs_mapping_tree_free(&fs_info->mapping_tree); bdi_destroy(&fs_info->bdi); cleanup_srcu_struct(&fs_info->subvol_srcu); kfree(fs_info->extent_root); kfree(fs_info->tree_root); kfree(fs_info->chunk_root); kfree(fs_info->dev_root); kfree(fs_info->csum_root); return 0; } int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid) { int ret; struct inode *btree_inode = buf->first_page->mapping->host; ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf); if (!ret) return ret; ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf, parent_transid); return !ret; } int btrfs_set_buffer_uptodate(struct extent_buffer *buf) { struct inode *btree_inode = buf->first_page->mapping->host; return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf); } void btrfs_mark_buffer_dirty(struct extent_buffer *buf) { struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root; u64 transid = btrfs_header_generation(buf); struct inode *btree_inode = root->fs_info->btree_inode; int was_dirty; btrfs_assert_tree_locked(buf); if (transid != root->fs_info->generation) { printk(KERN_CRIT "btrfs transid mismatch buffer %llu, " "found %llu running %llu\n", (unsigned long long)buf->start, (unsigned long long)transid, (unsigned long long)root->fs_info->generation); WARN_ON(1); } was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf); if (!was_dirty) { spin_lock(&root->fs_info->delalloc_lock); root->fs_info->dirty_metadata_bytes += buf->len; spin_unlock(&root->fs_info->delalloc_lock); } } void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr) { /* * looks as though older kernels can get into trouble with * this code, they end up stuck in balance_dirty_pages forever */ u64 num_dirty; unsigned long thresh = 32 * 1024 * 1024; if (current->flags & PF_MEMALLOC) return; num_dirty = root->fs_info->dirty_metadata_bytes; if (num_dirty > thresh) { balance_dirty_pages_ratelimited_nr( root->fs_info->btree_inode->i_mapping, 1); } return; } int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid) { struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root; int ret; ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid); if (ret == 0) set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags); return ret; } int btree_lock_page_hook(struct page *page) { struct inode *inode = page->mapping->host; struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct extent_buffer *eb; unsigned long len; u64 bytenr = page_offset(page); if (page->private == EXTENT_PAGE_PRIVATE) goto out; len = page->private >> 2; eb = find_extent_buffer(io_tree, bytenr, len, GFP_NOFS); if (!eb) goto out; btrfs_tree_lock(eb); btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN); if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) { spin_lock(&root->fs_info->delalloc_lock); if (root->fs_info->dirty_metadata_bytes >= eb->len) root->fs_info->dirty_metadata_bytes -= eb->len; else WARN_ON(1); spin_unlock(&root->fs_info->delalloc_lock); } btrfs_tree_unlock(eb); free_extent_buffer(eb); out: lock_page(page); return 0; } static struct extent_io_ops btree_extent_io_ops = { .write_cache_pages_lock_hook = btree_lock_page_hook, .readpage_end_io_hook = btree_readpage_end_io_hook, .submit_bio_hook = btree_submit_bio_hook, /* note we're sharing with inode.c for the merge bio hook */ .merge_bio_hook = btrfs_merge_bio_hook, };