diff options
Diffstat (limited to 'fs/btrfs/disk-io.c')
| -rw-r--r-- | fs/btrfs/disk-io.c | 3693 |
1 files changed, 3693 insertions, 0 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c new file mode 100644 index 00000000..a7ffc88a --- /dev/null +++ b/fs/btrfs/disk-io.c @@ -0,0 +1,3693 @@ +/* + * 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/fs.h> +#include <linux/blkdev.h> +#include <linux/scatterlist.h> +#include <linux/swap.h> +#include <linux/radix-tree.h> +#include <linux/writeback.h> +#include <linux/buffer_head.h> +#include <linux/workqueue.h> +#include <linux/kthread.h> +#include <linux/freezer.h> +#include <linux/crc32c.h> +#include <linux/slab.h> +#include <linux/migrate.h> +#include <linux/ratelimit.h> +#include <asm/unaligned.h> +#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" +#include "inode-map.h" +#include "check-integrity.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 int btrfs_check_super_valid(struct btrfs_fs_info *fs_info, + int read_only); +static void btrfs_destroy_ordered_operations(struct btrfs_root *root); +static void btrfs_destroy_ordered_extents(struct btrfs_root *root); +static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans, + struct btrfs_root *root); +static void btrfs_destroy_pending_snapshots(struct btrfs_transaction *t); +static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root); +static int btrfs_destroy_marked_extents(struct btrfs_root *root, + struct extent_io_tree *dirty_pages, + int mark); +static int btrfs_destroy_pinned_extent(struct btrfs_root *root, + struct extent_io_tree *pinned_extents); + +/* + * 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; + /* + * bio_offset is optional, can be used if the pages in the bio + * can't tell us where in the file the bio should go + */ + u64 bio_offset; + struct btrfs_work work; + int error; +}; + +/* + * Lockdep class keys for extent_buffer->lock's in this root. For a given + * eb, the lockdep key is determined by the btrfs_root it belongs to and + * the level the eb occupies in the tree. + * + * Different roots are used for different purposes and may nest inside each + * other and they require separate keysets. As lockdep keys should be + * static, assign keysets according to the purpose of the root as indicated + * by btrfs_root->objectid. This ensures that all special purpose roots + * have separate keysets. + * + * Lock-nesting across peer nodes is always done with the immediate parent + * node locked thus preventing deadlock. As lockdep doesn't know this, use + * subclass to avoid triggering lockdep warning in such cases. + * + * The key is set by the readpage_end_io_hook after the buffer has passed + * csum validation but before the pages are unlocked. It is also set by + * btrfs_init_new_buffer on freshly allocated blocks. + * + * 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 btrfs_lockdep_keyset { + u64 id; /* root objectid */ + const char *name_stem; /* lock name stem */ + char names[BTRFS_MAX_LEVEL + 1][20]; + struct lock_class_key keys[BTRFS_MAX_LEVEL + 1]; +} btrfs_lockdep_keysets[] = { + { .id = BTRFS_ROOT_TREE_OBJECTID, .name_stem = "root" }, + { .id = BTRFS_EXTENT_TREE_OBJECTID, .name_stem = "extent" }, + { .id = BTRFS_CHUNK_TREE_OBJECTID, .name_stem = "chunk" }, + { .id = BTRFS_DEV_TREE_OBJECTID, .name_stem = "dev" }, + { .id = BTRFS_FS_TREE_OBJECTID, .name_stem = "fs" }, + { .id = BTRFS_CSUM_TREE_OBJECTID, .name_stem = "csum" }, + { .id = BTRFS_ORPHAN_OBJECTID, .name_stem = "orphan" }, + { .id = BTRFS_TREE_LOG_OBJECTID, .name_stem = "log" }, + { .id = BTRFS_TREE_RELOC_OBJECTID, .name_stem = "treloc" }, + { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc" }, + { .id = 0, .name_stem = "tree" }, +}; + +void __init btrfs_init_lockdep(void) +{ + int i, j; + + /* initialize lockdep class names */ + for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) { + struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i]; + + for (j = 0; j < ARRAY_SIZE(ks->names); j++) + snprintf(ks->names[j], sizeof(ks->names[j]), + "btrfs-%s-%02d", ks->name_stem, j); + } +} + +void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb, + int level) +{ + struct btrfs_lockdep_keyset *ks; + + BUG_ON(level >= ARRAY_SIZE(ks->keys)); + + /* find the matching keyset, id 0 is the default entry */ + for (ks = btrfs_lockdep_keysets; ks->id; ks++) + if (ks->id == objectid) + break; + + lockdep_set_class_and_name(&eb->lock, + &ks->keys[level], ks->names[level]); +} + +#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 pg_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(); + 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) +{ + put_unaligned_le32(~crc, result); +} + +/* + * 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 *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, + &kaddr, &map_start, &map_len); + 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; + } + 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); + printk_ratelimited(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 atomic) +{ + struct extent_state *cached_state = NULL; + int ret; + + if (!parent_transid || btrfs_header_generation(eb) == parent_transid) + return 0; + + if (atomic) + return -EAGAIN; + + lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1, + 0, &cached_state); + if (extent_buffer_uptodate(eb) && + btrfs_header_generation(eb) == parent_transid) { + ret = 0; + goto out; + } + printk_ratelimited("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(eb); +out: + unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1, + &cached_state, 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 failed = 0; + int ret; + int num_copies = 0; + int mirror_num = 0; + int failed_mirror = 0; + + clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags); + io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree; + while (1) { + ret = read_extent_buffer_pages(io_tree, eb, start, + WAIT_COMPLETE, + btree_get_extent, mirror_num); + if (!ret && !verify_parent_transid(io_tree, eb, + parent_transid, 0)) + break; + + /* + * This buffer's crc is fine, but its contents are corrupted, so + * there is no reason to read the other copies, they won't be + * any less wrong. + */ + if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags)) + break; + + num_copies = btrfs_num_copies(&root->fs_info->mapping_tree, + eb->start, eb->len); + if (num_copies == 1) + break; + + if (!failed_mirror) { + failed = 1; + failed_mirror = eb->read_mirror; + } + + mirror_num++; + if (mirror_num == failed_mirror) + mirror_num++; + + if (mirror_num > num_copies) + break; + } + + if (failed && !ret) + repair_eb_io_failure(root, eb, failed_mirror); + + return ret; +} + +/* + * 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; + struct extent_buffer *eb; + + tree = &BTRFS_I(page->mapping->host)->io_tree; + + eb = (struct extent_buffer *)page->private; + if (page != eb->pages[0]) + return 0; + found_start = btrfs_header_bytenr(eb); + if (found_start != start) { + WARN_ON(1); + return 0; + } + if (eb->pages[0] != page) { + WARN_ON(1); + return 0; + } + if (!PageUptodate(page)) { + WARN_ON(1); + return 0; + } + csum_tree_block(root, eb, 0); + 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; +} + +#define CORRUPT(reason, eb, root, slot) \ + printk(KERN_CRIT "btrfs: corrupt leaf, %s: block=%llu," \ + "root=%llu, slot=%d\n", reason, \ + (unsigned long long)btrfs_header_bytenr(eb), \ + (unsigned long long)root->objectid, slot) + +static noinline int check_leaf(struct btrfs_root *root, + struct extent_buffer *leaf) +{ + struct btrfs_key key; + struct btrfs_key leaf_key; + u32 nritems = btrfs_header_nritems(leaf); + int slot; + + if (nritems == 0) + return 0; + + /* Check the 0 item */ + if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) != + BTRFS_LEAF_DATA_SIZE(root)) { + CORRUPT("invalid item offset size pair", leaf, root, 0); + return -EIO; + } + + /* + * Check to make sure each items keys are in the correct order and their + * offsets make sense. We only have to loop through nritems-1 because + * we check the current slot against the next slot, which verifies the + * next slot's offset+size makes sense and that the current's slot + * offset is correct. + */ + for (slot = 0; slot < nritems - 1; slot++) { + btrfs_item_key_to_cpu(leaf, &leaf_key, slot); + btrfs_item_key_to_cpu(leaf, &key, slot + 1); + + /* Make sure the keys are in the right order */ + if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) { + CORRUPT("bad key order", leaf, root, slot); + return -EIO; + } + + /* + * Make sure the offset and ends are right, remember that the + * item data starts at the end of the leaf and grows towards the + * front. + */ + if (btrfs_item_offset_nr(leaf, slot) != + btrfs_item_end_nr(leaf, slot + 1)) { + CORRUPT("slot offset bad", leaf, root, slot); + return -EIO; + } + + /* + * Check to make sure that we don't point outside of the leaf, + * just incase all the items are consistent to eachother, but + * all point outside of the leaf. + */ + if (btrfs_item_end_nr(leaf, slot) > + BTRFS_LEAF_DATA_SIZE(root)) { + CORRUPT("slot end outside of leaf", leaf, root, slot); + return -EIO; + } + } + + return 0; +} + +struct extent_buffer *find_eb_for_page(struct extent_io_tree *tree, + struct page *page, int max_walk) +{ + struct extent_buffer *eb; + u64 start = page_offset(page); + u64 target = start; + u64 min_start; + + if (start < max_walk) + min_start = 0; + else + min_start = start - max_walk; + + while (start >= min_start) { + eb = find_extent_buffer(tree, start, 0); + if (eb) { + /* + * we found an extent buffer and it contains our page + * horray! + */ + if (eb->start <= target && + eb->start + eb->len > target) + return eb; + + /* we found an extent buffer that wasn't for us */ + free_extent_buffer(eb); + return NULL; + } + if (start == 0) + break; + start -= PAGE_CACHE_SIZE; + } + return NULL; +} + +static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end, + struct extent_state *state, int mirror) +{ + struct extent_io_tree *tree; + u64 found_start; + int found_level; + struct extent_buffer *eb; + struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; + int ret = 0; + int reads_done; + + if (!page->private) + goto out; + + tree = &BTRFS_I(page->mapping->host)->io_tree; + eb = (struct extent_buffer *)page->private; + + /* the pending IO might have been the only thing that kept this buffer + * in memory. Make sure we have a ref for all this other checks + */ + extent_buffer_get(eb); + + reads_done = atomic_dec_and_test(&eb->io_pages); + if (!reads_done) + goto err; + + eb->read_mirror = mirror; + if (test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) { + ret = -EIO; + goto err; + } + + found_start = btrfs_header_bytenr(eb); + if (found_start != eb->start) { + printk_ratelimited(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 (check_tree_block_fsid(root, eb)) { + printk_ratelimited(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(btrfs_header_owner(eb), + eb, found_level); + + ret = csum_tree_block(root, eb, 1); + if (ret) { + ret = -EIO; + goto err; + } + + /* + * If this is a leaf block and it is corrupt, set the corrupt bit so + * that we don't try and read the other copies of this block, just + * return -EIO. + */ + if (found_level == 0 && check_leaf(root, eb)) { + set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags); + ret = -EIO; + } + + if (!ret) + set_extent_buffer_uptodate(eb); +err: + if (test_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) { + clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags); + btree_readahead_hook(root, eb, eb->start, ret); + } + + if (ret) + clear_extent_buffer_uptodate(eb); + free_extent_buffer(eb); +out: + return ret; +} + +static int btree_io_failed_hook(struct page *page, int failed_mirror) +{ + struct extent_buffer *eb; + struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; + + eb = (struct extent_buffer *)page->private; + set_bit(EXTENT_BUFFER_IOERR, &eb->bflags); + eb->read_mirror = failed_mirror; + if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) + btree_readahead_hook(root, eb, eb->start, -EIO); + return -EIO; /* we fixed nothing */ +} + +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 & REQ_WRITE) { + if (end_io_wq->metadata == 1) + btrfs_queue_worker(&fs_info->endio_meta_write_workers, + &end_io_wq->work); + else if (end_io_wq->metadata == 2) + btrfs_queue_worker(&fs_info->endio_freespace_worker, + &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); + } +} + +/* + * For the metadata arg you want + * + * 0 - if data + * 1 - if normal metadta + * 2 - if writing to the free space cache area + */ +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; +} + +static void run_one_async_start(struct btrfs_work *work) +{ + struct async_submit_bio *async; + int ret; + + async = container_of(work, struct async_submit_bio, work); + ret = async->submit_bio_start(async->inode, async->rw, async->bio, + async->mirror_num, async->bio_flags, + async->bio_offset); + if (ret) + async->error = ret; +} + +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); + + /* If an error occured we just want to clean up the bio and move on */ + if (async->error) { + bio_endio(async->bio, async->error); + return; + } + + async->submit_bio_done(async->inode, async->rw, async->bio, + async->mirror_num, async->bio_flags, + async->bio_offset); +} + +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, + u64 bio_offset, + 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; + async->bio_offset = bio_offset; + + async->error = 0; + + atomic_inc(&fs_info->nr_async_submits); + + if (rw & REQ_SYNC) + 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; + int ret = 0; + + WARN_ON(bio->bi_vcnt <= 0); + while (bio_index < bio->bi_vcnt) { + root = BTRFS_I(bvec->bv_page->mapping->host)->root; + ret = csum_dirty_buffer(root, bvec->bv_page); + if (ret) + break; + bio_index++; + bvec++; + } + return ret; +} + +static int __btree_submit_bio_start(struct inode *inode, int rw, + struct bio *bio, int mirror_num, + unsigned long bio_flags, + u64 bio_offset) +{ + /* + * when we're called for a write, we're already in the async + * submission context. Just jump into btrfs_map_bio + */ + return btree_csum_one_bio(bio); +} + +static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio, + int mirror_num, unsigned long bio_flags, + u64 bio_offset) +{ + /* + * 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, + u64 bio_offset) +{ + int ret; + + if (!(rw & REQ_WRITE)) { + + /* + * called for a read, do the setup so that checksum validation + * can happen in the async kernel threads + */ + ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info, + bio, 1); + if (ret) + return ret; + 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, + bio_offset, + __btree_submit_bio_start, + __btree_submit_bio_done); +} + +#ifdef CONFIG_MIGRATION +static int btree_migratepage(struct address_space *mapping, + struct page *newpage, struct page *page, + enum migrate_mode mode) +{ + /* + * we can't safely write a btree page from here, + * we haven't done the locking hook + */ + if (PageDirty(page)) + return -EAGAIN; + /* + * Buffers may be managed in a filesystem specific way. + * We must have no buffers or drop them. + */ + if (page_has_private(page) && + !try_to_release_page(page, GFP_KERNEL)) + return -EAGAIN; + return migrate_page(mapping, newpage, page, mode); +} +#endif + + +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 btree_write_cache_pages(mapping, 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, 0); +} + +static int btree_releasepage(struct page *page, gfp_t gfp_flags) +{ + if (PageWriteback(page) || PageDirty(page)) + return 0; + /* + * We need to mask out eg. __GFP_HIGHMEM and __GFP_DMA32 as we're doing + * slab allocation from alloc_extent_state down the callchain where + * it'd hit a BUG_ON as those flags are not allowed. + */ + gfp_flags &= ~GFP_SLAB_BUG_MASK; + + return try_release_extent_buffer(page, gfp_flags); +} + +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 int btree_set_page_dirty(struct page *page) +{ + struct extent_buffer *eb; + + BUG_ON(!PagePrivate(page)); + eb = (struct extent_buffer *)page->private; + BUG_ON(!eb); + BUG_ON(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); + BUG_ON(!atomic_read(&eb->refs)); + btrfs_assert_tree_locked(eb); + return __set_page_dirty_nobuffers(page); +} + +static const struct address_space_operations btree_aops = { + .readpage = btree_readpage, + .writepages = btree_writepages, + .releasepage = btree_releasepage, + .invalidatepage = btree_invalidatepage, +#ifdef CONFIG_MIGRATION + .migratepage = btree_migratepage, +#endif + .set_page_dirty = btree_set_page_dirty, +}; + +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, WAIT_NONE, btree_get_extent, 0); + free_extent_buffer(buf); + return ret; +} + +int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize, + int mirror_num, struct extent_buffer **eb) +{ + struct extent_buffer *buf = NULL; + struct inode *btree_inode = root->fs_info->btree_inode; + struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree; + int ret; + + buf = btrfs_find_create_tree_block(root, bytenr, blocksize); + if (!buf) + return 0; + + set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags); + + ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK, + btree_get_extent, mirror_num); + if (ret) { + free_extent_buffer(buf); + return ret; + } + + if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) { + free_extent_buffer(buf); + return -EIO; + } else if (extent_buffer_uptodate(buf)) { + *eb = buf; + } else { + free_extent_buffer(buf); + } + return 0; +} + +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); + 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); + return eb; +} + + +int btrfs_write_tree_block(struct extent_buffer *buf) +{ + return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start, + buf->start + buf->len - 1); +} + +int btrfs_wait_tree_block_writeback(struct extent_buffer *buf) +{ + return filemap_fdatawait_range(buf->pages[0]->mapping, + buf->start, buf->start + buf->len - 1); +} + +struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr, + u32 blocksize, u64 parent_transid) +{ + struct extent_buffer *buf = NULL; + int ret; + + buf = btrfs_find_create_tree_block(root, bytenr, blocksize); + if (!buf) + return NULL; + + ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid); + return buf; + +} + +void clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, + struct extent_buffer *buf) +{ + 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 { + spin_unlock(&root->fs_info->delalloc_lock); + btrfs_panic(root->fs_info, -EOVERFLOW, + "Can't clear %lu bytes from " + " dirty_mdatadata_bytes (%lu)", + buf->len, + root->fs_info->dirty_metadata_bytes); + } + 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(buf); + } +} + +static void __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->in_radix = 0; + root->orphan_item_inserted = 0; + root->orphan_cleanup_state = 0; + + root->objectid = objectid; + root->last_trans = 0; + root->highest_objectid = 0; + root->name = NULL; + root->inode_tree = RB_ROOT; + INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC); + root->block_rsv = NULL; + root->orphan_block_rsv = NULL; + + INIT_LIST_HEAD(&root->dirty_list); + INIT_LIST_HEAD(&root->orphan_list); + INIT_LIST_HEAD(&root->root_list); + spin_lock_init(&root->orphan_lock); + spin_lock_init(&root->inode_lock); + spin_lock_init(&root->accounting_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; + root->last_log_commit = 0; + extent_io_tree_init(&root->dirty_log_pages, + fs_info->btree_inode->i_mapping); + + 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->root_key.objectid = objectid; + root->anon_dev = 0; +} + +static int __must_check 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; + else if (ret < 0) + return ret; + + generation = btrfs_root_generation(&root->root_item); + blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item)); + root->commit_root = NULL; + root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item), + blocksize, generation); + if (!root->node || !btrfs_buffer_uptodate(root->node, generation, 0)) { + free_extent_buffer(root->node); + root->node = NULL; + return -EIO; + } + root->commit_root = btrfs_root_node(root); + return 0; +} + +static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *root = kzalloc(sizeof(*root), GFP_NOFS); + if (root) + root->fs_info = fs_info; + return root; +} + +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 = btrfs_alloc_root(fs_info); + 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, 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; + root->last_log_commit = 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 = btrfs_alloc_root(fs_info); + 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(); + if (!path) { + kfree(root); + return ERR_PTR(-ENOMEM); + } + 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) { + kfree(root); + 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); /* -ENOMEM */ +out: + if (location->objectid != BTRFS_TREE_LOG_OBJECTID) { + root->ref_cows = 1; + btrfs_check_and_init_root_item(&root->root_item); + } + + 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; + + root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location); + if (IS_ERR(root)) + return root; + + root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS); + root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned), + GFP_NOFS); + if (!root->free_ino_pinned || !root->free_ino_ctl) { + ret = -ENOMEM; + goto fail; + } + + btrfs_init_free_ino_ctl(root); + mutex_init(&root->fs_commit_mutex); + spin_lock_init(&root->cache_lock); + init_waitqueue_head(&root->cache_wait); + + ret = get_anon_bdev(&root->anon_dev); + if (ret) + goto fail; + + if (btrfs_root_refs(&root->root_item) == 0) { + ret = -ENOENT; + goto fail; + } + + ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid); + if (ret < 0) + goto fail; + if (ret == 0) + root->orphan_item_inserted = 1; + + 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); + return root; +fail: + free_fs_root(root); + return ERR_PTR(ret); +} + +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; + + rcu_read_lock(); + list_for_each_entry_rcu(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; + } + } + rcu_read_unlock(); + return ret; +} + +/* + * 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->capabilities = BDI_CAP_MAP_COPY; + err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY); + if (err) + return err; + + bdi->ra_pages = default_backing_dev_info.ra_pages; + bdi->congested_fn = btrfs_congested_fn; + bdi->congested_data = info; + return 0; +} + +/* + * 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; + + 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 { + 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_run_delayed_iputs(root); + btrfs_clean_old_snapshots(root); + mutex_unlock(&root->fs_info->cleaner_mutex); + btrfs_run_defrag_inodes(root->fs_info); + } + + if (!try_to_freeze()) { + set_current_state(TASK_INTERRUPTIBLE); + if (!kthread_should_stop()) + 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; + u64 transid; + unsigned long now; + unsigned long delay; + bool cannot_commit; + + do { + cannot_commit = false; + delay = HZ * 30; + vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE); + mutex_lock(&root->fs_info->transaction_kthread_mutex); + + spin_lock(&root->fs_info->trans_lock); + cur = root->fs_info->running_transaction; + if (!cur) { + spin_unlock(&root->fs_info->trans_lock); + goto sleep; + } + + now = get_seconds(); + if (!cur->blocked && + (now < cur->start_time || now - cur->start_time < 30)) { + spin_unlock(&root->fs_info->trans_lock); + delay = HZ * 5; + goto sleep; + } + transid = cur->transid; + spin_unlock(&root->fs_info->trans_lock); + + /* If the file system is aborted, this will always fail. */ + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + cannot_commit = true; + goto sleep; + } + if (transid == trans->transid) { + btrfs_commit_transaction(trans, root); + } else { + btrfs_end_transaction(trans, root); + } +sleep: + wake_up_process(root->fs_info->cleaner_kthread); + mutex_unlock(&root->fs_info->transaction_kthread_mutex); + + if (!try_to_freeze()) { + set_current_state(TASK_INTERRUPTIBLE); + if (!kthread_should_stop() && + (!btrfs_transaction_blocked(root->fs_info) || + cannot_commit)) + schedule_timeout(delay); + __set_current_state(TASK_RUNNING); + } + } while (!kthread_should_stop()); + return 0; +} + +/* + * this will find the highest generation in the array of + * root backups. The index of the highest array is returned, + * or -1 if we can't find anything. + * + * We check to make sure the array is valid by comparing the + * generation of the latest root in the array with the generation + * in the super block. If they don't match we pitch it. + */ +static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen) +{ + u64 cur; + int newest_index = -1; + struct btrfs_root_backup *root_backup; + int i; + + for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) { + root_backup = info->super_copy->super_roots + i; + cur = btrfs_backup_tree_root_gen(root_backup); + if (cur == newest_gen) + newest_index = i; + } + + /* check to see if we actually wrapped around */ + if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) { + root_backup = info->super_copy->super_roots; + cur = btrfs_backup_tree_root_gen(root_backup); + if (cur == newest_gen) + newest_index = 0; + } + return newest_index; +} + + +/* + * find the oldest backup so we know where to store new entries + * in the backup array. This will set the backup_root_index + * field in the fs_info struct + */ +static void find_oldest_super_backup(struct btrfs_fs_info *info, + u64 newest_gen) +{ + int newest_index = -1; + + newest_index = find_newest_super_backup(info, newest_gen); + /* if there was garbage in there, just move along */ + if (newest_index == -1) { + info->backup_root_index = 0; + } else { + info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS; + } +} + +/* + * copy all the root pointers into the super backup array. + * this will bump the backup pointer by one when it is + * done + */ +static void backup_super_roots(struct btrfs_fs_info *info) +{ + int next_backup; + struct btrfs_root_backup *root_backup; + int last_backup; + + next_backup = info->backup_root_index; + last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) % + BTRFS_NUM_BACKUP_ROOTS; + + /* + * just overwrite the last backup if we're at the same generation + * this happens only at umount + */ + root_backup = info->super_for_commit->super_roots + last_backup; + if (btrfs_backup_tree_root_gen(root_backup) == + btrfs_header_generation(info->tree_root->node)) + next_backup = last_backup; + + root_backup = info->super_for_commit->super_roots + next_backup; + + /* + * make sure all of our padding and empty slots get zero filled + * regardless of which ones we use today + */ + memset(root_backup, 0, sizeof(*root_backup)); + + info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS; + + btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start); + btrfs_set_backup_tree_root_gen(root_backup, + btrfs_header_generation(info->tree_root->node)); + + btrfs_set_backup_tree_root_level(root_backup, + btrfs_header_level(info->tree_root->node)); + + btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start); + btrfs_set_backup_chunk_root_gen(root_backup, + btrfs_header_generation(info->chunk_root->node)); + btrfs_set_backup_chunk_root_level(root_backup, + btrfs_header_level(info->chunk_root->node)); + + btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start); + btrfs_set_backup_extent_root_gen(root_backup, + btrfs_header_generation(info->extent_root->node)); + btrfs_set_backup_extent_root_level(root_backup, + btrfs_header_level(info->extent_root->node)); + + /* + * we might commit during log recovery, which happens before we set + * the fs_root. Make sure it is valid before we fill it in. + */ + if (info->fs_root && info->fs_root->node) { + btrfs_set_backup_fs_root(root_backup, + info->fs_root->node->start); + btrfs_set_backup_fs_root_gen(root_backup, + btrfs_header_generation(info->fs_root->node)); + btrfs_set_backup_fs_root_level(root_backup, + btrfs_header_level(info->fs_root->node)); + } + + btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start); + btrfs_set_backup_dev_root_gen(root_backup, + btrfs_header_generation(info->dev_root->node)); + btrfs_set_backup_dev_root_level(root_backup, + btrfs_header_level(info->dev_root->node)); + + btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start); + btrfs_set_backup_csum_root_gen(root_backup, + btrfs_header_generation(info->csum_root->node)); + btrfs_set_backup_csum_root_level(root_backup, + btrfs_header_level(info->csum_root->node)); + + btrfs_set_backup_total_bytes(root_backup, + btrfs_super_total_bytes(info->super_copy)); + btrfs_set_backup_bytes_used(root_backup, + btrfs_super_bytes_used(info->super_copy)); + btrfs_set_backup_num_devices(root_backup, + btrfs_super_num_devices(info->super_copy)); + + /* + * if we don't copy this out to the super_copy, it won't get remembered + * for the next commit + */ + memcpy(&info->super_copy->super_roots, + &info->super_for_commit->super_roots, + sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS); +} + +/* + * this copies info out of the root backup array and back into + * the in-memory super block. It is meant to help iterate through + * the array, so you send it the number of backups you've already + * tried and the last backup index you used. + * + * this returns -1 when it has tried all the backups + */ +static noinline int next_root_backup(struct btrfs_fs_info *info, + struct btrfs_super_block *super, + int *num_backups_tried, int *backup_index) +{ + struct btrfs_root_backup *root_backup; + int newest = *backup_index; + + if (*num_backups_tried == 0) { + u64 gen = btrfs_super_generation(super); + + newest = find_newest_super_backup(info, gen); + if (newest == -1) + return -1; + + *backup_index = newest; + *num_backups_tried = 1; + } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) { + /* we've tried all the backups, all done */ + return -1; + } else { + /* jump to the next oldest backup */ + newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) % + BTRFS_NUM_BACKUP_ROOTS; + *backup_index = newest; + *num_backups_tried += 1; + } + root_backup = super->super_roots + newest; + + btrfs_set_super_generation(super, + btrfs_backup_tree_root_gen(root_backup)); + btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup)); + btrfs_set_super_root_level(super, + btrfs_backup_tree_root_level(root_backup)); + btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup)); + + /* + * fixme: the total bytes and num_devices need to match or we should + * need a fsck + */ + btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup)); + btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup)); + return 0; +} + +/* helper to cleanup tree roots */ +static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root) +{ + free_extent_buffer(info->tree_root->node); + free_extent_buffer(info->tree_root->commit_root); + free_extent_buffer(info->dev_root->node); + free_extent_buffer(info->dev_root->commit_root); + free_extent_buffer(info->extent_root->node); + free_extent_buffer(info->extent_root->commit_root); + free_extent_buffer(info->csum_root->node); + free_extent_buffer(info->csum_root->commit_root); + + info->tree_root->node = NULL; + info->tree_root->commit_root = NULL; + info->dev_root->node = NULL; + info->dev_root->commit_root = NULL; + info->extent_root->node = NULL; + info->extent_root->commit_root = NULL; + info->csum_root->node = NULL; + info->csum_root->commit_root = NULL; + + if (chunk_root) { + free_extent_buffer(info->chunk_root->node); + free_extent_buffer(info->chunk_root->commit_root); + info->chunk_root->node = NULL; + info->chunk_root->commit_root = NULL; + } +} + + +int 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_super_block *disk_super; + struct btrfs_fs_info *fs_info = btrfs_sb(sb); + struct btrfs_root *tree_root; + struct btrfs_root *extent_root; + struct btrfs_root *csum_root; + struct btrfs_root *chunk_root; + struct btrfs_root *dev_root; + struct btrfs_root *log_tree_root; + int ret; + int err = -EINVAL; + int num_backups_tried = 0; + int backup_index = 0; + + tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info); + extent_root = fs_info->extent_root = btrfs_alloc_root(fs_info); + csum_root = fs_info->csum_root = btrfs_alloc_root(fs_info); + chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info); + dev_root = fs_info->dev_root = btrfs_alloc_root(fs_info); + + if (!tree_root || !extent_root || !csum_root || + !chunk_root || !dev_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; + } + + mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS); + + 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->delayed_iputs); + 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->trans_lock); + spin_lock_init(&fs_info->ref_cache_lock); + spin_lock_init(&fs_info->fs_roots_radix_lock); + spin_lock_init(&fs_info->delayed_iput_lock); + spin_lock_init(&fs_info->defrag_inodes_lock); + spin_lock_init(&fs_info->free_chunk_lock); + mutex_init(&fs_info->reloc_mutex); + + init_completion(&fs_info->kobj_unregister); + INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots); + INIT_LIST_HEAD(&fs_info->space_info); + btrfs_mapping_init(&fs_info->mapping_tree); + btrfs_init_block_rsv(&fs_info->global_block_rsv); + btrfs_init_block_rsv(&fs_info->delalloc_block_rsv); + btrfs_init_block_rsv(&fs_info->trans_block_rsv); + btrfs_init_block_rsv(&fs_info->chunk_block_rsv); + btrfs_init_block_rsv(&fs_info->empty_block_rsv); + btrfs_init_block_rsv(&fs_info->delayed_block_rsv); + 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); + atomic_set(&fs_info->defrag_running, 0); + fs_info->sb = sb; + fs_info->max_inline = 8192 * 1024; + fs_info->metadata_ratio = 0; + fs_info->defrag_inodes = RB_ROOT; + fs_info->trans_no_join = 0; + fs_info->free_chunk_space = 0; + + /* readahead state */ + INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT); + spin_lock_init(&fs_info->reada_lock); + + 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); + fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root), + GFP_NOFS); + if (!fs_info->delayed_root) { + err = -ENOMEM; + goto fail_iput; + } + btrfs_init_delayed_root(fs_info->delayed_root); + + mutex_init(&fs_info->scrub_lock); + atomic_set(&fs_info->scrubs_running, 0); + atomic_set(&fs_info->scrub_pause_req, 0); + atomic_set(&fs_info->scrubs_paused, 0); + atomic_set(&fs_info->scrub_cancel_req, 0); + init_waitqueue_head(&fs_info->scrub_pause_wait); + init_rwsem(&fs_info->scrub_super_lock); + fs_info->scrub_workers_refcnt = 0; +#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY + fs_info->check_integrity_print_mask = 0; +#endif + + spin_lock_init(&fs_info->balance_lock); + mutex_init(&fs_info->balance_mutex); + atomic_set(&fs_info->balance_running, 0); + atomic_set(&fs_info->balance_pause_req, 0); + atomic_set(&fs_info->balance_cancel_req, 0); + fs_info->balance_ctl = NULL; + init_waitqueue_head(&fs_info->balance_wait_q); + + 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; + set_nlink(fs_info->btree_inode, 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); + BTRFS_I(fs_info->btree_inode)->io_tree.track_uptodate = 0; + extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree); + + 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_ROOT; + + extent_io_tree_init(&fs_info->freed_extents[0], + fs_info->btree_inode->i_mapping); + extent_io_tree_init(&fs_info->freed_extents[1], + fs_info->btree_inode->i_mapping); + fs_info->pinned_extents = &fs_info->freed_extents[0]; + fs_info->do_barriers = 1; + + + 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->cleanup_work_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->transaction_blocked_wait); + init_waitqueue_head(&fs_info->async_submit_wait); + + __setup_root(4096, 4096, 4096, 4096, tree_root, + fs_info, BTRFS_ROOT_TREE_OBJECTID); + + invalidate_bdev(fs_devices->latest_bdev); + bh = btrfs_read_dev_super(fs_devices->latest_bdev); + if (!bh) { + err = -EINVAL; + goto fail_alloc; + } + + 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_alloc; + + /* check FS state, whether FS is broken. */ + fs_info->fs_state |= btrfs_super_flags(disk_super); + + ret = btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY); + if (ret) { + printk(KERN_ERR "btrfs: superblock contains fatal errors\n"); + err = ret; + goto fail_alloc; + } + + /* + * run through our array of backup supers and setup + * our ring pointer to the oldest one + */ + generation = btrfs_super_generation(disk_super); + find_oldest_super_backup(fs_info, generation); + + /* + * In the long term, we'll store the compression type in the super + * block, and it'll be used for per file compression control. + */ + fs_info->compress_type = BTRFS_COMPRESS_ZLIB; + + ret = btrfs_parse_options(tree_root, options); + if (ret) { + err = ret; + goto fail_alloc; + } + + 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_alloc; + } + + if (btrfs_super_leafsize(disk_super) != + btrfs_super_nodesize(disk_super)) { + printk(KERN_ERR "BTRFS: couldn't mount because metadata " + "blocksizes don't match. node %d leaf %d\n", + btrfs_super_nodesize(disk_super), + btrfs_super_leafsize(disk_super)); + err = -EINVAL; + goto fail_alloc; + } + if (btrfs_super_leafsize(disk_super) > BTRFS_MAX_METADATA_BLOCKSIZE) { + printk(KERN_ERR "BTRFS: couldn't mount because metadata " + "blocksize (%d) was too large\n", + btrfs_super_leafsize(disk_super)); + err = -EINVAL; + goto fail_alloc; + } + + features = btrfs_super_incompat_flags(disk_super); + features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF; + if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO) + features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO; + + /* + * flag our filesystem as having big metadata blocks if + * they are bigger than the page size + */ + if (btrfs_super_leafsize(disk_super) > PAGE_CACHE_SIZE) { + if (!(features & BTRFS_FEATURE_INCOMPAT_BIG_METADATA)) + printk(KERN_INFO "btrfs flagging fs with big metadata feature\n"); + features |= BTRFS_FEATURE_INCOMPAT_BIG_METADATA; + } + + nodesize = btrfs_super_nodesize(disk_super); + leafsize = btrfs_super_leafsize(disk_super); + sectorsize = btrfs_super_sectorsize(disk_super); + stripesize = btrfs_super_stripesize(disk_super); + + /* + * mixed block groups end up with duplicate but slightly offset + * extent buffers for the same range. It leads to corruptions + */ + if ((features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) && + (sectorsize != leafsize)) { + printk(KERN_WARNING "btrfs: unequal leaf/node/sector sizes " + "are not allowed for mixed block groups on %s\n", + sb->s_id); + goto fail_alloc; + } + + 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_alloc; + } + + btrfs_init_workers(&fs_info->generic_worker, + "genwork", 1, NULL); + + btrfs_init_workers(&fs_info->workers, "worker", + fs_info->thread_pool_size, + &fs_info->generic_worker); + + btrfs_init_workers(&fs_info->delalloc_workers, "delalloc", + fs_info->thread_pool_size, + &fs_info->generic_worker); + + btrfs_init_workers(&fs_info->submit_workers, "submit", + min_t(u64, fs_devices->num_devices, + fs_info->thread_pool_size), + &fs_info->generic_worker); + + btrfs_init_workers(&fs_info->caching_workers, "cache", + 2, &fs_info->generic_worker); + + /* 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, + &fs_info->generic_worker); + btrfs_init_workers(&fs_info->endio_workers, "endio", + fs_info->thread_pool_size, + &fs_info->generic_worker); + btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta", + fs_info->thread_pool_size, + &fs_info->generic_worker); + btrfs_init_workers(&fs_info->endio_meta_write_workers, + "endio-meta-write", fs_info->thread_pool_size, + &fs_info->generic_worker); + btrfs_init_workers(&fs_info->endio_write_workers, "endio-write", + fs_info->thread_pool_size, + &fs_info->generic_worker); + btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write", + 1, &fs_info->generic_worker); + btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta", + fs_info->thread_pool_size, + &fs_info->generic_worker); + btrfs_init_workers(&fs_info->readahead_workers, "readahead", + fs_info->thread_pool_size, + &fs_info->generic_worker); + + /* + * 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->readahead_workers.idle_thresh = 2; + + /* + * btrfs_start_workers can really only fail because of ENOMEM so just + * return -ENOMEM if any of these fail. + */ + ret = btrfs_start_workers(&fs_info->workers); + ret |= btrfs_start_workers(&fs_info->generic_worker); + ret |= btrfs_start_workers(&fs_info->submit_workers); + ret |= btrfs_start_workers(&fs_info->delalloc_workers); + ret |= btrfs_start_workers(&fs_info->fixup_workers); + ret |= btrfs_start_workers(&fs_info->endio_workers); + ret |= btrfs_start_workers(&fs_info->endio_meta_workers); + ret |= btrfs_start_workers(&fs_info->endio_meta_write_workers); + ret |= btrfs_start_workers(&fs_info->endio_write_workers); + ret |= btrfs_start_workers(&fs_info->endio_freespace_worker); + ret |= btrfs_start_workers(&fs_info->delayed_workers); + ret |= btrfs_start_workers(&fs_info->caching_workers); + ret |= btrfs_start_workers(&fs_info->readahead_workers); + if (ret) { + ret = -ENOMEM; + goto fail_sb_buffer; + } + + 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); + + 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; + } + + if (sectorsize != PAGE_SIZE) { + printk(KERN_WARNING "btrfs: Incompatible sector size(%lu) " + "found on %s\n", (unsigned long)sectorsize, 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); /* -ENOMEM */ + 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_tree_roots; + } + 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); + + ret = btrfs_read_chunk_tree(chunk_root); + if (ret) { + printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n", + sb->s_id); + goto fail_tree_roots; + } + + btrfs_close_extra_devices(fs_devices); + + if (!fs_devices->latest_bdev) { + printk(KERN_CRIT "btrfs: failed to read devices on %s\n", + sb->s_id); + goto fail_tree_roots; + } + +retry_root_backup: + 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 || + !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 recovery_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 recovery_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 recovery_tree_root; + dev_root->track_dirty = 1; + + ret = find_and_setup_root(tree_root, fs_info, + BTRFS_CSUM_TREE_OBJECTID, csum_root); + if (ret) + goto recovery_tree_root; + + csum_root->track_dirty = 1; + + fs_info->generation = generation; + fs_info->last_trans_committed = generation; + + ret = btrfs_init_space_info(fs_info); + if (ret) { + printk(KERN_ERR "Failed to initial space info: %d\n", ret); + goto fail_block_groups; + } + + ret = btrfs_read_block_groups(extent_root); + if (ret) { + printk(KERN_ERR "Failed to read block groups: %d\n", ret); + goto fail_block_groups; + } + + fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root, + "btrfs-cleaner"); + if (IS_ERR(fs_info->cleaner_kthread)) + goto fail_block_groups; + + 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); + } + +#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY + if (btrfs_test_opt(tree_root, CHECK_INTEGRITY)) { + ret = btrfsic_mount(tree_root, fs_devices, + btrfs_test_opt(tree_root, + CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ? + 1 : 0, + fs_info->check_integrity_print_mask); + if (ret) + printk(KERN_WARNING "btrfs: failed to initialize" + " integrity check module %s\n", sb->s_id); + } +#endif + + /* do not make disk changes in broken FS */ + if (btrfs_super_log_root(disk_super) != 0 && + !(fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)) { + 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 = btrfs_alloc_root(fs_info); + if (!log_tree_root) { + err = -ENOMEM; + goto fail_trans_kthread; + } + + __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); + /* returns with log_tree_root freed on success */ + ret = btrfs_recover_log_trees(log_tree_root); + if (ret) { + btrfs_error(tree_root->fs_info, ret, + "Failed to recover log tree"); + free_extent_buffer(log_tree_root->node); + kfree(log_tree_root); + goto fail_trans_kthread; + } + + if (sb->s_flags & MS_RDONLY) { + ret = btrfs_commit_super(tree_root); + if (ret) + goto fail_trans_kthread; + } + } + + ret = btrfs_find_orphan_roots(tree_root); + if (ret) + goto fail_trans_kthread; + + if (!(sb->s_flags & MS_RDONLY)) { + ret = btrfs_cleanup_fs_roots(fs_info); + if (ret) { + } + + ret = btrfs_recover_relocation(tree_root); + if (ret < 0) { + printk(KERN_WARNING + "btrfs: failed to recover relocation\n"); + err = -EINVAL; + goto fail_trans_kthread; + } + } + + 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; + if (IS_ERR(fs_info->fs_root)) { + err = PTR_ERR(fs_info->fs_root); + goto fail_trans_kthread; + } + + if (!(sb->s_flags & MS_RDONLY)) { + down_read(&fs_info->cleanup_work_sem); + err = btrfs_orphan_cleanup(fs_info->fs_root); + if (!err) + err = btrfs_orphan_cleanup(fs_info->tree_root); + up_read(&fs_info->cleanup_work_sem); + + if (!err) + err = btrfs_recover_balance(fs_info->tree_root); + + if (err) { + close_ctree(tree_root); + return err; + } + } + + return 0; + +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_block_groups: + btrfs_free_block_groups(fs_info); + +fail_tree_roots: + free_root_pointers(fs_info, 1); + +fail_sb_buffer: + btrfs_stop_workers(&fs_info->generic_worker); + btrfs_stop_workers(&fs_info->readahead_workers); + 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->endio_freespace_worker); + btrfs_stop_workers(&fs_info->submit_workers); + btrfs_stop_workers(&fs_info->delayed_workers); + btrfs_stop_workers(&fs_info->caching_workers); +fail_alloc: +fail_iput: + btrfs_mapping_tree_free(&fs_info->mapping_tree); + + invalidate_inode_pages2(fs_info->btree_inode->i_mapping); + iput(fs_info->btree_inode); +fail_bdi: + bdi_destroy(&fs_info->bdi); +fail_srcu: + cleanup_srcu_struct(&fs_info->subvol_srcu); +fail: + btrfs_close_devices(fs_info->fs_devices); + return err; + +recovery_tree_root: + if (!btrfs_test_opt(tree_root, RECOVERY)) + goto fail_tree_roots; + + free_root_pointers(fs_info, 0); + + /* don't use the log in recovery mode, it won't be valid */ + btrfs_set_super_log_root(disk_super, 0); + + /* we can't trust the free space cache either */ + btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE); + + ret = next_root_backup(fs_info, fs_info->super_copy, + &num_backups_tried, &backup_index); + if (ret == -1) + goto fail_block_groups; + goto retry_root_backup; +} + +static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate) +{ + char b[BDEVNAME_SIZE]; + + if (uptodate) { + set_buffer_uptodate(bh); + } else { + printk_ratelimited(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; + + if (max_mirrors == 0) + max_mirrors = BTRFS_SUPER_MIRROR_MAX; + + 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; + } + + /* + * we fua the first super. The others we allow + * to go down lazy. + */ + ret = btrfsic_submit_bh(WRITE_FUA, bh); + if (ret) + errors++; + } + return errors < i ? 0 : -1; +} + +/* + * endio for the write_dev_flush, this will wake anyone waiting + * for the barrier when it is done + */ +static void btrfs_end_empty_barrier(struct bio *bio, int err) +{ + if (err) { + if (err == -EOPNOTSUPP) + set_bit(BIO_EOPNOTSUPP, &bio->bi_flags); + clear_bit(BIO_UPTODATE, &bio->bi_flags); + } + if (bio->bi_private) + complete(bio->bi_private); + bio_put(bio); +} + +/* + * trigger flushes for one the devices. If you pass wait == 0, the flushes are + * sent down. With wait == 1, it waits for the previous flush. + * + * any device where the flush fails with eopnotsupp are flagged as not-barrier + * capable + */ +static int write_dev_flush(struct btrfs_device *device, int wait) +{ + struct bio *bio; + int ret = 0; + + if (device->nobarriers) + return 0; + + if (wait) { + bio = device->flush_bio; + if (!bio) + return 0; + + wait_for_completion(&device->flush_wait); + + if (bio_flagged(bio, BIO_EOPNOTSUPP)) { + printk("btrfs: disabling barriers on dev %s\n", + device->name); + device->nobarriers = 1; + } + if (!bio_flagged(bio, BIO_UPTODATE)) { + ret = -EIO; + } + + /* drop the reference from the wait == 0 run */ + bio_put(bio); + device->flush_bio = NULL; + + return ret; + } + + /* + * one reference for us, and we leave it for the + * caller + */ + device->flush_bio = NULL;; + bio = bio_alloc(GFP_NOFS, 0); + if (!bio) + return -ENOMEM; + + bio->bi_end_io = btrfs_end_empty_barrier; + bio->bi_bdev = device->bdev; + init_completion(&device->flush_wait); + bio->bi_private = &device->flush_wait; + device->flush_bio = bio; + + bio_get(bio); + btrfsic_submit_bio(WRITE_FLUSH, bio); + + return 0; +} + +/* + * send an empty flush down to each device in parallel, + * then wait for them + */ +static int barrier_all_devices(struct btrfs_fs_info *info) +{ + struct list_head *head; + struct btrfs_device *dev; + int errors = 0; + int ret; + + /* send down all the barriers */ + head = &info->fs_devices->devices; + list_for_each_entry_rcu(dev, head, dev_list) { + if (!dev->bdev) { + errors++; + continue; + } + if (!dev->in_fs_metadata || !dev->writeable) + continue; + + ret = write_dev_flush(dev, 0); + if (ret) + errors++; + } + + /* wait for all the barriers */ + list_for_each_entry_rcu(dev, head, dev_list) { + if (!dev->bdev) { + errors++; + continue; + } + if (!dev->in_fs_metadata || !dev->writeable) + continue; + + ret = write_dev_flush(dev, 1); + if (ret) + errors++; + } + if (errors) + return -EIO; + return 0; +} + +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); + backup_super_roots(root->fs_info); + + 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; + + if (do_barriers) + barrier_all_devices(root->fs_info); + + list_for_each_entry_rcu(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); + + /* This shouldn't happen. FUA is masked off if unsupported */ + BUG(); + } + + total_errors = 0; + list_for_each_entry_rcu(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) { + btrfs_error(root->fs_info, -EIO, + "%d errors while writing supers", total_errors); + return -EIO; + } + 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; +} + +/* Kill all outstanding I/O */ +void btrfs_abort_devices(struct btrfs_root *root) +{ + struct list_head *head; + struct btrfs_device *dev; + mutex_lock(&root->fs_info->fs_devices->device_list_mutex); + head = &root->fs_info->fs_devices->devices; + list_for_each_entry_rcu(dev, head, dev_list) { + blk_abort_queue(dev->bdev->bd_disk->queue); + } + mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); +} + +void 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); + + __btrfs_remove_free_space_cache(root->free_ino_pinned); + __btrfs_remove_free_space_cache(root->free_ino_ctl); + free_fs_root(root); +} + +static void free_fs_root(struct btrfs_root *root) +{ + iput(root->cache_inode); + WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree)); + if (root->anon_dev) + free_anon_bdev(root->anon_dev); + free_extent_buffer(root->node); + free_extent_buffer(root->commit_root); + kfree(root->free_ino_ctl); + kfree(root->free_ino_pinned); + kfree(root->name); + kfree(root); +} + +static void 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]); + } +} + +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++) { + int err; + + root_objectid = gang[i]->root_key.objectid; + err = btrfs_orphan_cleanup(gang[i]); + if (err) + return err; + } + 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_run_delayed_iputs(root); + btrfs_clean_old_snapshots(root); + mutex_unlock(&root->fs_info->cleaner_mutex); + + /* wait until ongoing cleanup work done */ + down_write(&root->fs_info->cleanup_work_sem); + up_write(&root->fs_info->cleanup_work_sem); + + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) + return PTR_ERR(trans); + ret = btrfs_commit_transaction(trans, root); + if (ret) + return ret; + /* run commit again to drop the original snapshot */ + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) + return PTR_ERR(trans); + ret = btrfs_commit_transaction(trans, root); + if (ret) + return ret; + ret = btrfs_write_and_wait_transaction(NULL, root); + if (ret) { + btrfs_error(root->fs_info, ret, + "Failed to sync btree inode to disk."); + return 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(); + + /* pause restriper - we want to resume on mount */ + btrfs_pause_balance(root->fs_info); + + btrfs_scrub_cancel(root); + + /* wait for any defraggers to finish */ + wait_event(fs_info->transaction_wait, + (atomic_read(&fs_info->defrag_running) == 0)); + + /* clear out the rbtree of defraggable inodes */ + btrfs_run_defrag_inodes(fs_info); + + /* + * Here come 2 situations when btrfs is broken to flip readonly: + * + * 1. when btrfs flips readonly somewhere else before + * btrfs_commit_super, sb->s_flags has MS_RDONLY flag, + * and btrfs will skip to write sb directly to keep + * ERROR state on disk. + * + * 2. when btrfs flips readonly just in btrfs_commit_super, + * and in such case, btrfs cannot write sb via btrfs_commit_super, + * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag, + * btrfs will cleanup all FS resources first and write sb then. + */ + 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); + } + + if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) { + ret = btrfs_error_commit_super(root); + if (ret) + printk(KERN_ERR "btrfs: commit super ret %d\n", ret); + } + + btrfs_put_block_group_cache(fs_info); + + kthread_stop(fs_info->transaction_kthread); + kthread_stop(fs_info->cleaner_kthread); + + 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(fs_info->chunk_root->node); + free_extent_buffer(fs_info->chunk_root->commit_root); + free_extent_buffer(fs_info->dev_root->node); + free_extent_buffer(fs_info->dev_root->commit_root); + free_extent_buffer(fs_info->csum_root->node); + free_extent_buffer(fs_info->csum_root->commit_root); + + btrfs_free_block_groups(fs_info); + + del_fs_roots(fs_info); + + iput(fs_info->btree_inode); + + btrfs_stop_workers(&fs_info->generic_worker); + 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->endio_freespace_worker); + btrfs_stop_workers(&fs_info->submit_workers); + btrfs_stop_workers(&fs_info->delayed_workers); + btrfs_stop_workers(&fs_info->caching_workers); + btrfs_stop_workers(&fs_info->readahead_workers); + +#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY + if (btrfs_test_opt(root, CHECK_INTEGRITY)) + btrfsic_unmount(root, fs_info->fs_devices); +#endif + + 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); + + return 0; +} + +int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid, + int atomic) +{ + int ret; + struct inode *btree_inode = buf->pages[0]->mapping->host; + + ret = extent_buffer_uptodate(buf); + if (!ret) + return ret; + + ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf, + parent_transid, atomic); + if (ret == -EAGAIN) + return ret; + return !ret; +} + +int btrfs_set_buffer_uptodate(struct extent_buffer *buf) +{ + return set_extent_buffer_uptodate(buf); +} + +void btrfs_mark_buffer_dirty(struct extent_buffer *buf) +{ + struct btrfs_root *root = BTRFS_I(buf->pages[0]->mapping->host)->root; + u64 transid = btrfs_header_generation(buf); + 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(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; + + btrfs_balance_delayed_items(root); + + 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; +} + +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->pages[0]->mapping->host)->root; + return btree_read_extent_buffer_pages(root, buf, 0, parent_transid); +} + +static int btree_lock_page_hook(struct page *page, void *data, + void (*flush_fn)(void *)) +{ + struct inode *inode = page->mapping->host; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_buffer *eb; + + /* + * We culled this eb but the page is still hanging out on the mapping, + * carry on. + */ + if (!PagePrivate(page)) + goto out; + + eb = (struct extent_buffer *)page->private; + if (!eb) { + WARN_ON(1); + goto out; + } + if (page != eb->pages[0]) + goto out; + + if (!btrfs_try_tree_write_lock(eb)) { + flush_fn(data); + 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); +out: + if (!trylock_page(page)) { + flush_fn(data); + lock_page(page); + } + return 0; +} + +static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info, + int read_only) +{ + if (btrfs_super_csum_type(fs_info->super_copy) >= ARRAY_SIZE(btrfs_csum_sizes)) { + printk(KERN_ERR "btrfs: unsupported checksum algorithm\n"); + return -EINVAL; + } + + if (read_only) + return 0; + + if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) { + printk(KERN_WARNING "warning: mount fs with errors, " + "running btrfsck is recommended\n"); + } + + return 0; +} + +int btrfs_error_commit_super(struct btrfs_root *root) +{ + int ret; + + mutex_lock(&root->fs_info->cleaner_mutex); + btrfs_run_delayed_iputs(root); + mutex_unlock(&root->fs_info->cleaner_mutex); + + down_write(&root->fs_info->cleanup_work_sem); + up_write(&root->fs_info->cleanup_work_sem); + + /* cleanup FS via transaction */ + btrfs_cleanup_transaction(root); + + ret = write_ctree_super(NULL, root, 0); + + return ret; +} + +static void btrfs_destroy_ordered_operations(struct btrfs_root *root) +{ + struct btrfs_inode *btrfs_inode; + struct list_head splice; + + INIT_LIST_HEAD(&splice); + + mutex_lock(&root->fs_info->ordered_operations_mutex); + spin_lock(&root->fs_info->ordered_extent_lock); + + list_splice_init(&root->fs_info->ordered_operations, &splice); + while (!list_empty(&splice)) { + btrfs_inode = list_entry(splice.next, struct btrfs_inode, + ordered_operations); + + list_del_init(&btrfs_inode->ordered_operations); + + btrfs_invalidate_inodes(btrfs_inode->root); + } + + spin_unlock(&root->fs_info->ordered_extent_lock); + mutex_unlock(&root->fs_info->ordered_operations_mutex); +} + +static void btrfs_destroy_ordered_extents(struct btrfs_root *root) +{ + struct list_head splice; + struct btrfs_ordered_extent *ordered; + struct inode *inode; + + INIT_LIST_HEAD(&splice); + + spin_lock(&root->fs_info->ordered_extent_lock); + + list_splice_init(&root->fs_info->ordered_extents, &splice); + while (!list_empty(&splice)) { + ordered = list_entry(splice.next, struct btrfs_ordered_extent, + root_extent_list); + + list_del_init(&ordered->root_extent_list); + atomic_inc(&ordered->refs); + + /* the inode may be getting freed (in sys_unlink path). */ + inode = igrab(ordered->inode); + + spin_unlock(&root->fs_info->ordered_extent_lock); + if (inode) + iput(inode); + + atomic_set(&ordered->refs, 1); + btrfs_put_ordered_extent(ordered); + + spin_lock(&root->fs_info->ordered_extent_lock); + } + + spin_unlock(&root->fs_info->ordered_extent_lock); +} + +int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans, + struct btrfs_root *root) +{ + struct rb_node *node; + struct btrfs_delayed_ref_root *delayed_refs; + struct btrfs_delayed_ref_node *ref; + int ret = 0; + + delayed_refs = &trans->delayed_refs; + +again: + spin_lock(&delayed_refs->lock); + if (delayed_refs->num_entries == 0) { + spin_unlock(&delayed_refs->lock); + printk(KERN_INFO "delayed_refs has NO entry\n"); + return ret; + } + + node = rb_first(&delayed_refs->root); + while (node) { + ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node); + node = rb_next(node); + + ref->in_tree = 0; + rb_erase(&ref->rb_node, &delayed_refs->root); + delayed_refs->num_entries--; + + atomic_set(&ref->refs, 1); + if (btrfs_delayed_ref_is_head(ref)) { + struct btrfs_delayed_ref_head *head; + + head = btrfs_delayed_node_to_head(ref); + spin_unlock(&delayed_refs->lock); + mutex_lock(&head->mutex); + kfree(head->extent_op); + delayed_refs->num_heads--; + if (list_empty(&head->cluster)) + delayed_refs->num_heads_ready--; + list_del_init(&head->cluster); + mutex_unlock(&head->mutex); + btrfs_put_delayed_ref(ref); + goto again; + } + spin_unlock(&delayed_refs->lock); + btrfs_put_delayed_ref(ref); + + cond_resched(); + spin_lock(&delayed_refs->lock); + } + + spin_unlock(&delayed_refs->lock); + + return ret; +} + +static void btrfs_destroy_pending_snapshots(struct btrfs_transaction *t) +{ + struct btrfs_pending_snapshot *snapshot; + struct list_head splice; + + INIT_LIST_HEAD(&splice); + + list_splice_init(&t->pending_snapshots, &splice); + + while (!list_empty(&splice)) { + snapshot = list_entry(splice.next, + struct btrfs_pending_snapshot, + list); + + list_del_init(&snapshot->list); + + kfree(snapshot); + } +} + +static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root) +{ + struct btrfs_inode *btrfs_inode; + struct list_head splice; + + INIT_LIST_HEAD(&splice); + + spin_lock(&root->fs_info->delalloc_lock); + list_splice_init(&root->fs_info->delalloc_inodes, &splice); + + while (!list_empty(&splice)) { + btrfs_inode = list_entry(splice.next, struct btrfs_inode, + delalloc_inodes); + + list_del_init(&btrfs_inode->delalloc_inodes); + + btrfs_invalidate_inodes(btrfs_inode->root); + } + + spin_unlock(&root->fs_info->delalloc_lock); +} + +static int btrfs_destroy_marked_extents(struct btrfs_root *root, + struct extent_io_tree *dirty_pages, + int mark) +{ + int ret; + struct page *page; + struct inode *btree_inode = root->fs_info->btree_inode; + struct extent_buffer *eb; + u64 start = 0; + u64 end; + u64 offset; + unsigned long index; + + while (1) { + ret = find_first_extent_bit(dirty_pages, start, &start, &end, + mark); + if (ret) + break; + + clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS); + while (start <= end) { + index = start >> PAGE_CACHE_SHIFT; + start = (u64)(index + 1) << PAGE_CACHE_SHIFT; + page = find_get_page(btree_inode->i_mapping, index); + if (!page) + continue; + offset = page_offset(page); + + spin_lock(&dirty_pages->buffer_lock); + eb = radix_tree_lookup( + &(&BTRFS_I(page->mapping->host)->io_tree)->buffer, + offset >> PAGE_CACHE_SHIFT); + spin_unlock(&dirty_pages->buffer_lock); + if (eb) { + ret = test_and_clear_bit(EXTENT_BUFFER_DIRTY, + &eb->bflags); + atomic_set(&eb->refs, 1); + } + if (PageWriteback(page)) + end_page_writeback(page); + + lock_page(page); + if (PageDirty(page)) { + clear_page_dirty_for_io(page); + spin_lock_irq(&page->mapping->tree_lock); + radix_tree_tag_clear(&page->mapping->page_tree, + page_index(page), + PAGECACHE_TAG_DIRTY); + spin_unlock_irq(&page->mapping->tree_lock); + } + + page->mapping->a_ops->invalidatepage(page, 0); + unlock_page(page); + } + } + + return ret; +} + +static int btrfs_destroy_pinned_extent(struct btrfs_root *root, + struct extent_io_tree *pinned_extents) +{ + struct extent_io_tree *unpin; + u64 start; + u64 end; + int ret; + + unpin = pinned_extents; + while (1) { + ret = find_first_extent_bit(unpin, 0, &start, &end, + EXTENT_DIRTY); + if (ret) + break; + + /* opt_discard */ + if (btrfs_test_opt(root, DISCARD)) + ret = btrfs_error_discard_extent(root, start, + end + 1 - start, + NULL); + + clear_extent_dirty(unpin, start, end, GFP_NOFS); + btrfs_error_unpin_extent_range(root, start, end); + cond_resched(); + } + + return 0; +} + +void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans, + struct btrfs_root *root) +{ + btrfs_destroy_delayed_refs(cur_trans, root); + btrfs_block_rsv_release(root, &root->fs_info->trans_block_rsv, + cur_trans->dirty_pages.dirty_bytes); + + /* FIXME: cleanup wait for commit */ + cur_trans->in_commit = 1; + cur_trans->blocked = 1; + if (waitqueue_active(&root->fs_info->transaction_blocked_wait)) + wake_up(&root->fs_info->transaction_blocked_wait); + + cur_trans->blocked = 0; + if (waitqueue_active(&root->fs_info->transaction_wait)) + wake_up(&root->fs_info->transaction_wait); + + cur_trans->commit_done = 1; + if (waitqueue_active(&cur_trans->commit_wait)) + wake_up(&cur_trans->commit_wait); + + btrfs_destroy_pending_snapshots(cur_trans); + + btrfs_destroy_marked_extents(root, &cur_trans->dirty_pages, + EXTENT_DIRTY); + + /* + memset(cur_trans, 0, sizeof(*cur_trans)); + kmem_cache_free(btrfs_transaction_cachep, cur_trans); + */ +} + +int btrfs_cleanup_transaction(struct btrfs_root *root) +{ + struct btrfs_transaction *t; + LIST_HEAD(list); + + mutex_lock(&root->fs_info->transaction_kthread_mutex); + + spin_lock(&root->fs_info->trans_lock); + list_splice_init(&root->fs_info->trans_list, &list); + root->fs_info->trans_no_join = 1; + spin_unlock(&root->fs_info->trans_lock); + + while (!list_empty(&list)) { + t = list_entry(list.next, struct btrfs_transaction, list); + if (!t) + break; + + btrfs_destroy_ordered_operations(root); + + btrfs_destroy_ordered_extents(root); + + btrfs_destroy_delayed_refs(t, root); + + btrfs_block_rsv_release(root, + &root->fs_info->trans_block_rsv, + t->dirty_pages.dirty_bytes); + + /* FIXME: cleanup wait for commit */ + t->in_commit = 1; + t->blocked = 1; + if (waitqueue_active(&root->fs_info->transaction_blocked_wait)) + wake_up(&root->fs_info->transaction_blocked_wait); + + t->blocked = 0; + if (waitqueue_active(&root->fs_info->transaction_wait)) + wake_up(&root->fs_info->transaction_wait); + + t->commit_done = 1; + if (waitqueue_active(&t->commit_wait)) + wake_up(&t->commit_wait); + + btrfs_destroy_pending_snapshots(t); + + btrfs_destroy_delalloc_inodes(root); + + spin_lock(&root->fs_info->trans_lock); + root->fs_info->running_transaction = NULL; + spin_unlock(&root->fs_info->trans_lock); + + btrfs_destroy_marked_extents(root, &t->dirty_pages, + EXTENT_DIRTY); + + btrfs_destroy_pinned_extent(root, + root->fs_info->pinned_extents); + + atomic_set(&t->use_count, 0); + list_del_init(&t->list); + memset(t, 0, sizeof(*t)); + kmem_cache_free(btrfs_transaction_cachep, t); + } + + spin_lock(&root->fs_info->trans_lock); + root->fs_info->trans_no_join = 0; + spin_unlock(&root->fs_info->trans_lock); + mutex_unlock(&root->fs_info->transaction_kthread_mutex); + + return 0; +} + +static int btree_writepage_io_failed_hook(struct bio *bio, struct page *page, + u64 start, u64 end, + struct extent_state *state) +{ + struct super_block *sb = page->mapping->host->i_sb; + struct btrfs_fs_info *fs_info = btrfs_sb(sb); + btrfs_error(fs_info, -EIO, + "Error occured while writing out btree at %llu", start); + return -EIO; +} + +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, + .readpage_io_failed_hook = btree_io_failed_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, + .writepage_io_failed_hook = btree_writepage_io_failed_hook, +}; |