* Boston, MA 021110-1307, USA.
*/
-#include <linux/module.h>
#include <linux/fs.h>
#include <linux/sched.h>
+#include <linux/writeback.h>
+#include <linux/pagemap.h>
+#include <linux/blkdev.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
+#include "locking.h"
+#include "ref-cache.h"
+#include "tree-log.h"
-static int total_trans = 0;
extern struct kmem_cache *btrfs_trans_handle_cachep;
extern struct kmem_cache *btrfs_transaction_cachep;
-static struct workqueue_struct *trans_wq;
-
#define BTRFS_ROOT_TRANS_TAG 0
-static void put_transaction(struct btrfs_transaction *transaction)
+static noinline void put_transaction(struct btrfs_transaction *transaction)
{
WARN_ON(transaction->use_count == 0);
transaction->use_count--;
if (transaction->use_count == 0) {
- WARN_ON(total_trans == 0);
- total_trans--;
list_del_init(&transaction->list);
memset(transaction, 0, sizeof(*transaction));
kmem_cache_free(btrfs_transaction_cachep, transaction);
}
}
-static int join_transaction(struct btrfs_root *root)
+/*
+ * either allocate a new transaction or hop into the existing one
+ */
+static noinline int join_transaction(struct btrfs_root *root)
{
struct btrfs_transaction *cur_trans;
cur_trans = root->fs_info->running_transaction;
if (!cur_trans) {
cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
GFP_NOFS);
- total_trans++;
BUG_ON(!cur_trans);
root->fs_info->generation++;
- root->fs_info->running_transaction = cur_trans;
- cur_trans->num_writers = 0;
+ root->fs_info->last_alloc = 0;
+ root->fs_info->last_data_alloc = 0;
+ cur_trans->num_writers = 1;
+ cur_trans->num_joined = 0;
cur_trans->transid = root->fs_info->generation;
init_waitqueue_head(&cur_trans->writer_wait);
init_waitqueue_head(&cur_trans->commit_wait);
cur_trans->in_commit = 0;
+ cur_trans->blocked = 0;
cur_trans->use_count = 1;
cur_trans->commit_done = 0;
cur_trans->start_time = get_seconds();
+ INIT_LIST_HEAD(&cur_trans->pending_snapshots);
list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
- init_bit_radix(&cur_trans->dirty_pages);
+ extent_io_tree_init(&cur_trans->dirty_pages,
+ root->fs_info->btree_inode->i_mapping,
+ GFP_NOFS);
+ spin_lock(&root->fs_info->new_trans_lock);
+ root->fs_info->running_transaction = cur_trans;
+ spin_unlock(&root->fs_info->new_trans_lock);
+ } else {
+ cur_trans->num_writers++;
+ cur_trans->num_joined++;
}
- cur_trans->num_writers++;
+
return 0;
}
-struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
- int num_blocks)
+/*
+ * this does all the record keeping required to make sure that a
+ * reference counted root is properly recorded in a given transaction.
+ * This is required to make sure the old root from before we joined the transaction
+ * is deleted when the transaction commits
+ */
+noinline int btrfs_record_root_in_trans(struct btrfs_root *root)
+{
+ struct btrfs_dirty_root *dirty;
+ u64 running_trans_id = root->fs_info->running_transaction->transid;
+ if (root->ref_cows && root->last_trans < running_trans_id) {
+ WARN_ON(root == root->fs_info->extent_root);
+ if (root->root_item.refs != 0) {
+ radix_tree_tag_set(&root->fs_info->fs_roots_radix,
+ (unsigned long)root->root_key.objectid,
+ BTRFS_ROOT_TRANS_TAG);
+
+ dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
+ BUG_ON(!dirty);
+ dirty->root = kmalloc(sizeof(*dirty->root), GFP_NOFS);
+ BUG_ON(!dirty->root);
+ dirty->latest_root = root;
+ INIT_LIST_HEAD(&dirty->list);
+
+ root->commit_root = btrfs_root_node(root);
+
+ memcpy(dirty->root, root, sizeof(*root));
+ spin_lock_init(&dirty->root->node_lock);
+ spin_lock_init(&dirty->root->list_lock);
+ mutex_init(&dirty->root->objectid_mutex);
+ mutex_init(&dirty->root->log_mutex);
+ INIT_LIST_HEAD(&dirty->root->dead_list);
+ dirty->root->node = root->commit_root;
+ dirty->root->commit_root = NULL;
+
+ spin_lock(&root->list_lock);
+ list_add(&dirty->root->dead_list, &root->dead_list);
+ spin_unlock(&root->list_lock);
+
+ root->dirty_root = dirty;
+ } else {
+ WARN_ON(1);
+ }
+ root->last_trans = running_trans_id;
+ }
+ return 0;
+}
+
+/* wait for commit against the current transaction to become unblocked
+ * when this is done, it is safe to start a new transaction, but the current
+ * transaction might not be fully on disk.
+ */
+static void wait_current_trans(struct btrfs_root *root)
+{
+ struct btrfs_transaction *cur_trans;
+
+ cur_trans = root->fs_info->running_transaction;
+ if (cur_trans && cur_trans->blocked) {
+ DEFINE_WAIT(wait);
+ cur_trans->use_count++;
+ while(1) {
+ prepare_to_wait(&root->fs_info->transaction_wait, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (cur_trans->blocked) {
+ mutex_unlock(&root->fs_info->trans_mutex);
+ schedule();
+ mutex_lock(&root->fs_info->trans_mutex);
+ finish_wait(&root->fs_info->transaction_wait,
+ &wait);
+ } else {
+ finish_wait(&root->fs_info->transaction_wait,
+ &wait);
+ break;
+ }
+ }
+ put_transaction(cur_trans);
+ }
+}
+
+static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
+ int num_blocks, int wait)
{
struct btrfs_trans_handle *h =
kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
int ret;
- u64 running_trans_id;
mutex_lock(&root->fs_info->trans_mutex);
+ if (!root->fs_info->log_root_recovering &&
+ ((wait == 1 && !root->fs_info->open_ioctl_trans) || wait == 2))
+ wait_current_trans(root);
ret = join_transaction(root);
BUG_ON(ret);
- running_trans_id = root->fs_info->running_transaction->transid;
- if (root != root->fs_info->tree_root && root->last_trans <
- running_trans_id) {
- if (root->root_item.refs != 0) {
- radix_tree_tag_set(&root->fs_info->fs_roots_radix,
- (unsigned long)root->root_key.objectid,
- BTRFS_ROOT_TRANS_TAG);
- root->commit_root = root->node;
- get_bh(root->node);
- } else {
- WARN_ON(1);
- }
- }
- root->last_trans = running_trans_id;
- h->transid = running_trans_id;
+ btrfs_record_root_in_trans(root);
+ h->transid = root->fs_info->running_transaction->transid;
h->transaction = root->fs_info->running_transaction;
h->blocks_reserved = num_blocks;
h->blocks_used = 0;
- h->block_group = NULL;
+ h->block_group = 0;
+ h->alloc_exclude_nr = 0;
+ h->alloc_exclude_start = 0;
root->fs_info->running_transaction->use_count++;
mutex_unlock(&root->fs_info->trans_mutex);
return h;
}
-int btrfs_end_transaction(struct btrfs_trans_handle *trans,
- struct btrfs_root *root)
+struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
+ int num_blocks)
{
- struct btrfs_transaction *cur_trans;
+ return start_transaction(root, num_blocks, 1);
+}
+struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root,
+ int num_blocks)
+{
+ return start_transaction(root, num_blocks, 0);
+}
+struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r,
+ int num_blocks)
+{
+ return start_transaction(r, num_blocks, 2);
+}
+
+/* wait for a transaction commit to be fully complete */
+static noinline int wait_for_commit(struct btrfs_root *root,
+ struct btrfs_transaction *commit)
+{
+ DEFINE_WAIT(wait);
mutex_lock(&root->fs_info->trans_mutex);
- cur_trans = root->fs_info->running_transaction;
+ while(!commit->commit_done) {
+ prepare_to_wait(&commit->commit_wait, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (commit->commit_done)
+ break;
+ mutex_unlock(&root->fs_info->trans_mutex);
+ schedule();
+ mutex_lock(&root->fs_info->trans_mutex);
+ }
+ mutex_unlock(&root->fs_info->trans_mutex);
+ finish_wait(&commit->commit_wait, &wait);
+ return 0;
+}
+
+/*
+ * rate limit against the drop_snapshot code. This helps to slow down new operations
+ * if the drop_snapshot code isn't able to keep up.
+ */
+static void throttle_on_drops(struct btrfs_root *root)
+{
+ struct btrfs_fs_info *info = root->fs_info;
+ int harder_count = 0;
+
+harder:
+ if (atomic_read(&info->throttles)) {
+ DEFINE_WAIT(wait);
+ int thr;
+ thr = atomic_read(&info->throttle_gen);
+
+ do {
+ prepare_to_wait(&info->transaction_throttle,
+ &wait, TASK_UNINTERRUPTIBLE);
+ if (!atomic_read(&info->throttles)) {
+ finish_wait(&info->transaction_throttle, &wait);
+ break;
+ }
+ schedule();
+ finish_wait(&info->transaction_throttle, &wait);
+ } while (thr == atomic_read(&info->throttle_gen));
+ harder_count++;
+
+ if (root->fs_info->total_ref_cache_size > 1 * 1024 * 1024 &&
+ harder_count < 2)
+ goto harder;
+
+ if (root->fs_info->total_ref_cache_size > 5 * 1024 * 1024 &&
+ harder_count < 10)
+ goto harder;
+
+ if (root->fs_info->total_ref_cache_size > 10 * 1024 * 1024 &&
+ harder_count < 20)
+ goto harder;
+ }
+}
+
+void btrfs_throttle(struct btrfs_root *root)
+{
+ mutex_lock(&root->fs_info->trans_mutex);
+ if (!root->fs_info->open_ioctl_trans)
+ wait_current_trans(root);
+ mutex_unlock(&root->fs_info->trans_mutex);
+
+ throttle_on_drops(root);
+}
+
+static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, int throttle)
+{
+ struct btrfs_transaction *cur_trans;
+ struct btrfs_fs_info *info = root->fs_info;
+
+ mutex_lock(&info->trans_mutex);
+ cur_trans = info->running_transaction;
+ WARN_ON(cur_trans != trans->transaction);
WARN_ON(cur_trans->num_writers < 1);
+ cur_trans->num_writers--;
+
if (waitqueue_active(&cur_trans->writer_wait))
wake_up(&cur_trans->writer_wait);
- cur_trans->num_writers--;
put_transaction(cur_trans);
- mutex_unlock(&root->fs_info->trans_mutex);
+ mutex_unlock(&info->trans_mutex);
memset(trans, 0, sizeof(*trans));
kmem_cache_free(btrfs_trans_handle_cachep, trans);
+
+ if (throttle)
+ throttle_on_drops(root);
+
return 0;
}
+int btrfs_end_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ return __btrfs_end_transaction(trans, root, 0);
+}
-int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
- struct btrfs_root *root)
+int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ return __btrfs_end_transaction(trans, root, 1);
+}
+
+/*
+ * when btree blocks are allocated, they have some corresponding bits set for
+ * them in one of two extent_io trees. This is used to make sure all of
+ * those extents are on disk for transaction or log commit
+ */
+int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
+ struct extent_io_tree *dirty_pages)
{
- unsigned long gang[16];
int ret;
- int i;
- int err;
+ int err = 0;
int werr = 0;
struct page *page;
- struct radix_tree_root *dirty_pages;
struct inode *btree_inode = root->fs_info->btree_inode;
+ u64 start = 0;
+ u64 end;
+ unsigned long index;
- if (!trans || !trans->transaction) {
- return filemap_write_and_wait(btree_inode->i_mapping);
- }
- dirty_pages = &trans->transaction->dirty_pages;
while(1) {
- ret = find_first_radix_bit(dirty_pages, gang,
- 0, ARRAY_SIZE(gang));
- if (!ret)
+ ret = find_first_extent_bit(dirty_pages, start, &start, &end,
+ EXTENT_DIRTY);
+ if (ret)
break;
- for (i = 0; i < ret; i++) {
- /* FIXME EIO */
- clear_radix_bit(dirty_pages, gang[i]);
- page = find_lock_page(btree_inode->i_mapping,
- gang[i]);
+ while(start <= end) {
+ cond_resched();
+
+ index = start >> PAGE_CACHE_SHIFT;
+ start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
+ page = find_get_page(btree_inode->i_mapping, index);
if (!page)
continue;
+
+ btree_lock_page_hook(page);
+ if (!page->mapping) {
+ unlock_page(page);
+ page_cache_release(page);
+ continue;
+ }
+
+ if (PageWriteback(page)) {
+ if (PageDirty(page))
+ wait_on_page_writeback(page);
+ else {
+ unlock_page(page);
+ page_cache_release(page);
+ continue;
+ }
+ }
err = write_one_page(page, 0);
if (err)
werr = err;
page_cache_release(page);
}
}
- err = filemap_fdatawait(btree_inode->i_mapping);
+ while(1) {
+ ret = find_first_extent_bit(dirty_pages, 0, &start, &end,
+ EXTENT_DIRTY);
+ if (ret)
+ break;
+
+ clear_extent_dirty(dirty_pages, start, end, 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;
+ if (PageDirty(page)) {
+ btree_lock_page_hook(page);
+ wait_on_page_writeback(page);
+ err = write_one_page(page, 0);
+ if (err)
+ werr = err;
+ }
+ wait_on_page_writeback(page);
+ page_cache_release(page);
+ cond_resched();
+ }
+ }
if (err)
werr = err;
return werr;
}
-int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
- struct btrfs_root *root)
+int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ if (!trans || !trans->transaction) {
+ struct inode *btree_inode;
+ btree_inode = root->fs_info->btree_inode;
+ return filemap_write_and_wait(btree_inode->i_mapping);
+ }
+ return btrfs_write_and_wait_marked_extents(root,
+ &trans->transaction->dirty_pages);
+}
+
+/*
+ * this is used to update the root pointer in the tree of tree roots.
+ *
+ * But, in the case of the extent allocation tree, updating the root
+ * pointer may allocate blocks which may change the root of the extent
+ * allocation tree.
+ *
+ * So, this loops and repeats and makes sure the cowonly root didn't
+ * change while the root pointer was being updated in the metadata.
+ */
+static int update_cowonly_root(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
{
int ret;
- u64 old_extent_block;
- struct btrfs_fs_info *fs_info = root->fs_info;
- struct btrfs_root *tree_root = fs_info->tree_root;
- struct btrfs_root *extent_root = fs_info->extent_root;
+ u64 old_root_bytenr;
+ struct btrfs_root *tree_root = root->fs_info->tree_root;
+
+ btrfs_extent_post_op(trans, root);
+ btrfs_write_dirty_block_groups(trans, root);
+ btrfs_extent_post_op(trans, root);
- btrfs_write_dirty_block_groups(trans, extent_root);
while(1) {
- old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
- if (old_extent_block == bh_blocknr(extent_root->node))
+ old_root_bytenr = btrfs_root_bytenr(&root->root_item);
+ if (old_root_bytenr == root->node->start)
break;
- btrfs_set_root_blocknr(&extent_root->root_item,
- bh_blocknr(extent_root->node));
+ btrfs_set_root_bytenr(&root->root_item,
+ root->node->start);
+ btrfs_set_root_level(&root->root_item,
+ btrfs_header_level(root->node));
+ btrfs_set_root_generation(&root->root_item, trans->transid);
+
+ btrfs_extent_post_op(trans, root);
+
ret = btrfs_update_root(trans, tree_root,
- &extent_root->root_key,
- &extent_root->root_item);
+ &root->root_key,
+ &root->root_item);
BUG_ON(ret);
- btrfs_write_dirty_block_groups(trans, extent_root);
+ btrfs_write_dirty_block_groups(trans, root);
+ btrfs_extent_post_op(trans, root);
}
return 0;
}
-static int wait_for_commit(struct btrfs_root *root,
- struct btrfs_transaction *commit)
+/*
+ * update all the cowonly tree roots on disk
+ */
+int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
{
- DEFINE_WAIT(wait);
- while(!commit->commit_done) {
- prepare_to_wait(&commit->commit_wait, &wait,
- TASK_UNINTERRUPTIBLE);
- if (commit->commit_done)
- break;
- mutex_unlock(&root->fs_info->trans_mutex);
- schedule();
- mutex_lock(&root->fs_info->trans_mutex);
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct list_head *next;
+ struct extent_buffer *eb;
+
+ btrfs_extent_post_op(trans, fs_info->tree_root);
+
+ eb = btrfs_lock_root_node(fs_info->tree_root);
+ btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb, 0);
+ btrfs_tree_unlock(eb);
+ free_extent_buffer(eb);
+
+ btrfs_extent_post_op(trans, fs_info->tree_root);
+
+ while(!list_empty(&fs_info->dirty_cowonly_roots)) {
+ next = fs_info->dirty_cowonly_roots.next;
+ list_del_init(next);
+ root = list_entry(next, struct btrfs_root, dirty_list);
+
+ update_cowonly_root(trans, root);
}
- finish_wait(&commit->commit_wait, &wait);
return 0;
}
-struct dirty_root {
- struct list_head list;
- struct btrfs_key snap_key;
- struct buffer_head *commit_root;
- struct btrfs_root *root;
- int free_on_drop;
-};
-
-int btrfs_add_dead_root(struct btrfs_root *root, struct list_head *dead_list)
+/*
+ * dead roots are old snapshots that need to be deleted. This allocates
+ * a dirty root struct and adds it into the list of dead roots that need to
+ * be deleted
+ */
+int btrfs_add_dead_root(struct btrfs_root *root, struct btrfs_root *latest)
{
- struct dirty_root *dirty;
+ struct btrfs_dirty_root *dirty;
dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
if (!dirty)
return -ENOMEM;
- memcpy(&dirty->snap_key, &root->root_key, sizeof(root->root_key));
- dirty->commit_root = root->node;
dirty->root = root;
- dirty->free_on_drop = 1;
- list_add(&dirty->list, dead_list);
+ dirty->latest_root = latest;
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ list_add(&dirty->list, &latest->fs_info->dead_roots);
+ mutex_unlock(&root->fs_info->trans_mutex);
return 0;
}
-static int add_dirty_roots(struct btrfs_trans_handle *trans,
- struct radix_tree_root *radix,
- struct list_head *list)
+/*
+ * at transaction commit time we need to schedule the old roots for
+ * deletion via btrfs_drop_snapshot. This runs through all the
+ * reference counted roots that were modified in the current
+ * transaction and puts them into the drop list
+ */
+static noinline int add_dirty_roots(struct btrfs_trans_handle *trans,
+ struct radix_tree_root *radix,
+ struct list_head *list)
{
- struct dirty_root *dirty;
+ struct btrfs_dirty_root *dirty;
struct btrfs_root *gang[8];
struct btrfs_root *root;
- struct btrfs_root_item tmp_item;
int i;
int ret;
int err = 0;
radix_tree_tag_clear(radix,
(unsigned long)root->root_key.objectid,
BTRFS_ROOT_TRANS_TAG);
+
+ BUG_ON(!root->ref_tree);
+ dirty = root->dirty_root;
+
+ btrfs_free_log(trans, root);
+ btrfs_free_reloc_root(trans, root);
+
if (root->commit_root == root->node) {
- WARN_ON(bh_blocknr(root->node) !=
- btrfs_root_blocknr(&root->root_item));
- brelse(root->commit_root);
+ WARN_ON(root->node->start !=
+ btrfs_root_bytenr(&root->root_item));
+
+ free_extent_buffer(root->commit_root);
root->commit_root = NULL;
+ root->dirty_root = NULL;
+
+ spin_lock(&root->list_lock);
+ list_del_init(&dirty->root->dead_list);
+ spin_unlock(&root->list_lock);
+
+ kfree(dirty->root);
+ kfree(dirty);
+
+ /* make sure to update the root on disk
+ * so we get any updates to the block used
+ * counts
+ */
+ err = btrfs_update_root(trans,
+ root->fs_info->tree_root,
+ &root->root_key,
+ &root->root_item);
continue;
}
- dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
- BUG_ON(!dirty);
- memcpy(&dirty->snap_key, &root->root_key,
- sizeof(root->root_key));
- dirty->commit_root = root->commit_root;
- root->commit_root = NULL;
- dirty->root = root;
- dirty->free_on_drop = 0;
- memcpy(&tmp_item, &root->root_item, sizeof(tmp_item));
+ memset(&root->root_item.drop_progress, 0,
+ sizeof(struct btrfs_disk_key));
+ root->root_item.drop_level = 0;
+ root->commit_root = NULL;
+ root->dirty_root = NULL;
root->root_key.offset = root->fs_info->generation;
- btrfs_set_root_blocknr(&root->root_item,
- bh_blocknr(root->node));
+ btrfs_set_root_bytenr(&root->root_item,
+ root->node->start);
+ btrfs_set_root_level(&root->root_item,
+ btrfs_header_level(root->node));
+ btrfs_set_root_generation(&root->root_item,
+ root->root_key.offset);
+
err = btrfs_insert_root(trans, root->fs_info->tree_root,
&root->root_key,
&root->root_item);
if (err)
break;
- refs = btrfs_root_refs(&tmp_item);
- btrfs_set_root_refs(&tmp_item, refs - 1);
+ refs = btrfs_root_refs(&dirty->root->root_item);
+ btrfs_set_root_refs(&dirty->root->root_item, refs - 1);
err = btrfs_update_root(trans, root->fs_info->tree_root,
- &dirty->snap_key,
- &tmp_item);
+ &dirty->root->root_key,
+ &dirty->root->root_item);
BUG_ON(err);
- if (refs == 1)
+ if (refs == 1) {
list_add(&dirty->list, list);
- else
+ } else {
+ WARN_ON(1);
+ free_extent_buffer(dirty->root->node);
+ kfree(dirty->root);
kfree(dirty);
+ }
}
}
return err;
}
-static int drop_dirty_roots(struct btrfs_root *tree_root,
- struct list_head *list)
+/*
+ * defrag a given btree. If cacheonly == 1, this won't read from the disk,
+ * otherwise every leaf in the btree is read and defragged.
+ */
+int btrfs_defrag_root(struct btrfs_root *root, int cacheonly)
+{
+ struct btrfs_fs_info *info = root->fs_info;
+ int ret;
+ struct btrfs_trans_handle *trans;
+ unsigned long nr;
+
+ smp_mb();
+ if (root->defrag_running)
+ return 0;
+ trans = btrfs_start_transaction(root, 1);
+ while (1) {
+ root->defrag_running = 1;
+ ret = btrfs_defrag_leaves(trans, root, cacheonly);
+ nr = trans->blocks_used;
+ btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(info->tree_root, nr);
+ cond_resched();
+
+ trans = btrfs_start_transaction(root, 1);
+ if (root->fs_info->closing || ret != -EAGAIN)
+ break;
+ }
+ root->defrag_running = 0;
+ smp_mb();
+ btrfs_end_transaction(trans, root);
+ return 0;
+}
+
+/*
+ * Given a list of roots that need to be deleted, call btrfs_drop_snapshot on
+ * all of them
+ */
+static noinline int drop_dirty_roots(struct btrfs_root *tree_root,
+ struct list_head *list)
{
- struct dirty_root *dirty;
+ struct btrfs_dirty_root *dirty;
struct btrfs_trans_handle *trans;
+ unsigned long nr;
+ u64 num_bytes;
+ u64 bytes_used;
+ u64 max_useless;
int ret = 0;
+ int err;
+
while(!list_empty(list)) {
- mutex_lock(&tree_root->fs_info->fs_mutex);
- dirty = list_entry(list->next, struct dirty_root, list);
+ struct btrfs_root *root;
+
+ dirty = list_entry(list->prev, struct btrfs_dirty_root, list);
list_del_init(&dirty->list);
- trans = btrfs_start_transaction(tree_root, 1);
-printk("deleting root %Lu %u %Lu\n", dirty->snap_key.objectid, dirty->snap_key.flags, dirty->snap_key.offset);
- ret = btrfs_drop_snapshot(trans, dirty->root,
- dirty->commit_root);
+ num_bytes = btrfs_root_used(&dirty->root->root_item);
+ root = dirty->latest_root;
+ atomic_inc(&root->fs_info->throttles);
+
+ while(1) {
+ trans = btrfs_start_transaction(tree_root, 1);
+ mutex_lock(&root->fs_info->drop_mutex);
+ ret = btrfs_drop_snapshot(trans, dirty->root);
+ if (ret != -EAGAIN) {
+ break;
+ }
+ mutex_unlock(&root->fs_info->drop_mutex);
+
+ err = btrfs_update_root(trans,
+ tree_root,
+ &dirty->root->root_key,
+ &dirty->root->root_item);
+ if (err)
+ ret = err;
+ nr = trans->blocks_used;
+ ret = btrfs_end_transaction(trans, tree_root);
+ BUG_ON(ret);
+
+ btrfs_btree_balance_dirty(tree_root, nr);
+ cond_resched();
+ }
BUG_ON(ret);
- ret = btrfs_del_root(trans, tree_root, &dirty->snap_key);
- if (ret)
+ atomic_dec(&root->fs_info->throttles);
+ wake_up(&root->fs_info->transaction_throttle);
+
+ num_bytes -= btrfs_root_used(&dirty->root->root_item);
+ bytes_used = btrfs_root_used(&root->root_item);
+ if (num_bytes) {
+ btrfs_record_root_in_trans(root);
+ btrfs_set_root_used(&root->root_item,
+ bytes_used - num_bytes);
+ }
+
+ ret = btrfs_del_root(trans, tree_root, &dirty->root->root_key);
+ if (ret) {
+ BUG();
break;
+ }
+ mutex_unlock(&root->fs_info->drop_mutex);
+
+ spin_lock(&root->list_lock);
+ list_del_init(&dirty->root->dead_list);
+ if (!list_empty(&root->dead_list)) {
+ struct btrfs_root *oldest;
+ oldest = list_entry(root->dead_list.prev,
+ struct btrfs_root, dead_list);
+ max_useless = oldest->root_key.offset - 1;
+ } else {
+ max_useless = root->root_key.offset - 1;
+ }
+ spin_unlock(&root->list_lock);
+
+ nr = trans->blocks_used;
ret = btrfs_end_transaction(trans, tree_root);
BUG_ON(ret);
- if (dirty->free_on_drop)
- kfree(dirty->root);
+ ret = btrfs_remove_leaf_refs(root, max_useless, 0);
+ BUG_ON(ret);
+
+ free_extent_buffer(dirty->root->node);
+ kfree(dirty->root);
kfree(dirty);
- mutex_unlock(&tree_root->fs_info->fs_mutex);
- btrfs_btree_balance_dirty(tree_root);
+
+ btrfs_btree_balance_dirty(tree_root, nr);
+ cond_resched();
+ }
+ return ret;
+}
+
+/*
+ * new snapshots need to be created at a very specific time in the
+ * transaction commit. This does the actual creation
+ */
+static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info,
+ struct btrfs_pending_snapshot *pending)
+{
+ struct btrfs_key key;
+ struct btrfs_root_item *new_root_item;
+ struct btrfs_root *tree_root = fs_info->tree_root;
+ struct btrfs_root *root = pending->root;
+ struct extent_buffer *tmp;
+ struct extent_buffer *old;
+ int ret;
+ u64 objectid;
+
+ new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
+ if (!new_root_item) {
+ ret = -ENOMEM;
+ goto fail;
}
+ ret = btrfs_find_free_objectid(trans, tree_root, 0, &objectid);
+ if (ret)
+ goto fail;
+
+ btrfs_record_root_in_trans(root);
+ btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
+ memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
+
+ key.objectid = objectid;
+ key.offset = trans->transid;
+ btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+
+ old = btrfs_lock_root_node(root);
+ btrfs_cow_block(trans, root, old, NULL, 0, &old, 0);
+
+ btrfs_copy_root(trans, root, old, &tmp, objectid);
+ btrfs_tree_unlock(old);
+ free_extent_buffer(old);
+
+ btrfs_set_root_bytenr(new_root_item, tmp->start);
+ btrfs_set_root_level(new_root_item, btrfs_header_level(tmp));
+ btrfs_set_root_generation(new_root_item, trans->transid);
+ ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
+ new_root_item);
+ btrfs_tree_unlock(tmp);
+ free_extent_buffer(tmp);
+ if (ret)
+ goto fail;
+
+ key.offset = (u64)-1;
+ memcpy(&pending->root_key, &key, sizeof(key));
+fail:
+ kfree(new_root_item);
+ return ret;
+}
+
+static noinline int finish_pending_snapshot(struct btrfs_fs_info *fs_info,
+ struct btrfs_pending_snapshot *pending)
+{
+ int ret;
+ int namelen;
+ u64 index = 0;
+ struct btrfs_trans_handle *trans;
+ struct inode *parent_inode;
+ struct inode *inode;
+ struct btrfs_root *parent_root;
+
+ parent_inode = pending->dentry->d_parent->d_inode;
+ parent_root = BTRFS_I(parent_inode)->root;
+ trans = btrfs_start_transaction(parent_root, 1);
+
+ /*
+ * insert the directory item
+ */
+ namelen = strlen(pending->name);
+ ret = btrfs_set_inode_index(parent_inode, &index);
+ ret = btrfs_insert_dir_item(trans, parent_root,
+ pending->name, namelen,
+ parent_inode->i_ino,
+ &pending->root_key, BTRFS_FT_DIR, index);
+
+ if (ret)
+ goto fail;
+
+ /* add the backref first */
+ ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root,
+ pending->root_key.objectid,
+ BTRFS_ROOT_BACKREF_KEY,
+ parent_root->root_key.objectid,
+ parent_inode->i_ino, index, pending->name,
+ namelen);
+
+ BUG_ON(ret);
+
+ /* now add the forward ref */
+ ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root,
+ parent_root->root_key.objectid,
+ BTRFS_ROOT_REF_KEY,
+ pending->root_key.objectid,
+ parent_inode->i_ino, index, pending->name,
+ namelen);
+
+ inode = btrfs_lookup_dentry(parent_inode, pending->dentry);
+ d_instantiate(pending->dentry, inode);
+fail:
+ btrfs_end_transaction(trans, fs_info->fs_root);
return ret;
}
+/*
+ * create all the snapshots we've scheduled for creation
+ */
+static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_pending_snapshot *pending;
+ struct list_head *head = &trans->transaction->pending_snapshots;
+ struct list_head *cur;
+ int ret;
+
+ list_for_each(cur, head) {
+ pending = list_entry(cur, struct btrfs_pending_snapshot, list);
+ ret = create_pending_snapshot(trans, fs_info, pending);
+ BUG_ON(ret);
+ }
+ return 0;
+}
+
+static noinline int finish_pending_snapshots(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_pending_snapshot *pending;
+ struct list_head *head = &trans->transaction->pending_snapshots;
+ int ret;
+
+ while(!list_empty(head)) {
+ pending = list_entry(head->next,
+ struct btrfs_pending_snapshot, list);
+ ret = finish_pending_snapshot(fs_info, pending);
+ BUG_ON(ret);
+ list_del(&pending->list);
+ kfree(pending->name);
+ kfree(pending);
+ }
+ return 0;
+}
+
int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
- int ret = 0;
+ unsigned long joined = 0;
+ unsigned long timeout = 1;
struct btrfs_transaction *cur_trans;
struct btrfs_transaction *prev_trans = NULL;
+ struct btrfs_root *chunk_root = root->fs_info->chunk_root;
struct list_head dirty_fs_roots;
+ struct extent_io_tree *pinned_copy;
DEFINE_WAIT(wait);
+ int ret;
INIT_LIST_HEAD(&dirty_fs_roots);
-
mutex_lock(&root->fs_info->trans_mutex);
if (trans->transaction->in_commit) {
cur_trans = trans->transaction;
trans->transaction->use_count++;
+ mutex_unlock(&root->fs_info->trans_mutex);
btrfs_end_transaction(trans, root);
+
ret = wait_for_commit(root, cur_trans);
BUG_ON(ret);
+
+ mutex_lock(&root->fs_info->trans_mutex);
put_transaction(cur_trans);
mutex_unlock(&root->fs_info->trans_mutex);
+
return 0;
}
- cur_trans = trans->transaction;
+
+ pinned_copy = kmalloc(sizeof(*pinned_copy), GFP_NOFS);
+ if (!pinned_copy)
+ return -ENOMEM;
+
+ extent_io_tree_init(pinned_copy,
+ root->fs_info->btree_inode->i_mapping, GFP_NOFS);
+
trans->transaction->in_commit = 1;
- while (trans->transaction->num_writers > 1) {
+ trans->transaction->blocked = 1;
+ cur_trans = trans->transaction;
+ if (cur_trans->list.prev != &root->fs_info->trans_list) {
+ prev_trans = list_entry(cur_trans->list.prev,
+ struct btrfs_transaction, list);
+ if (!prev_trans->commit_done) {
+ prev_trans->use_count++;
+ mutex_unlock(&root->fs_info->trans_mutex);
+
+ wait_for_commit(root, prev_trans);
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ put_transaction(prev_trans);
+ }
+ }
+
+ do {
+ int snap_pending = 0;
+ joined = cur_trans->num_joined;
+ if (!list_empty(&trans->transaction->pending_snapshots))
+ snap_pending = 1;
+
WARN_ON(cur_trans != trans->transaction);
- prepare_to_wait(&trans->transaction->writer_wait, &wait,
+ prepare_to_wait(&cur_trans->writer_wait, &wait,
TASK_UNINTERRUPTIBLE);
- if (trans->transaction->num_writers <= 1)
- break;
+
+ if (cur_trans->num_writers > 1)
+ timeout = MAX_SCHEDULE_TIMEOUT;
+ else
+ timeout = 1;
+
mutex_unlock(&root->fs_info->trans_mutex);
- schedule();
+
+ if (snap_pending) {
+ ret = btrfs_wait_ordered_extents(root, 1);
+ BUG_ON(ret);
+ }
+
+ schedule_timeout(timeout);
+
mutex_lock(&root->fs_info->trans_mutex);
- finish_wait(&trans->transaction->writer_wait, &wait);
- }
- finish_wait(&trans->transaction->writer_wait, &wait);
+ finish_wait(&cur_trans->writer_wait, &wait);
+ } while (cur_trans->num_writers > 1 ||
+ (cur_trans->num_joined != joined));
+
+ ret = create_pending_snapshots(trans, root->fs_info);
+ BUG_ON(ret);
+
WARN_ON(cur_trans != trans->transaction);
+
+ /* btrfs_commit_tree_roots is responsible for getting the
+ * various roots consistent with each other. Every pointer
+ * in the tree of tree roots has to point to the most up to date
+ * root for every subvolume and other tree. So, we have to keep
+ * the tree logging code from jumping in and changing any
+ * of the trees.
+ *
+ * At this point in the commit, there can't be any tree-log
+ * writers, but a little lower down we drop the trans mutex
+ * and let new people in. By holding the tree_log_mutex
+ * from now until after the super is written, we avoid races
+ * with the tree-log code.
+ */
+ mutex_lock(&root->fs_info->tree_log_mutex);
+ /*
+ * keep tree reloc code from adding new reloc trees
+ */
+ mutex_lock(&root->fs_info->tree_reloc_mutex);
+
+
ret = add_dirty_roots(trans, &root->fs_info->fs_roots_radix,
&dirty_fs_roots);
BUG_ON(ret);
+ /* add_dirty_roots gets rid of all the tree log roots, it is now
+ * safe to free the root of tree log roots
+ */
+ btrfs_free_log_root_tree(trans, root->fs_info);
+
ret = btrfs_commit_tree_roots(trans, root);
BUG_ON(ret);
cur_trans = root->fs_info->running_transaction;
+ spin_lock(&root->fs_info->new_trans_lock);
root->fs_info->running_transaction = NULL;
- if (cur_trans->list.prev != &root->fs_info->trans_list) {
- prev_trans = list_entry(cur_trans->list.prev,
- struct btrfs_transaction, list);
- if (prev_trans->commit_done)
- prev_trans = NULL;
- else
- prev_trans->use_count++;
+ spin_unlock(&root->fs_info->new_trans_lock);
+ btrfs_set_super_generation(&root->fs_info->super_copy,
+ cur_trans->transid);
+ btrfs_set_super_root(&root->fs_info->super_copy,
+ root->fs_info->tree_root->node->start);
+ btrfs_set_super_root_level(&root->fs_info->super_copy,
+ btrfs_header_level(root->fs_info->tree_root->node));
+
+ btrfs_set_super_chunk_root(&root->fs_info->super_copy,
+ chunk_root->node->start);
+ btrfs_set_super_chunk_root_level(&root->fs_info->super_copy,
+ btrfs_header_level(chunk_root->node));
+ btrfs_set_super_chunk_root_generation(&root->fs_info->super_copy,
+ btrfs_header_generation(chunk_root->node));
+
+ if (!root->fs_info->log_root_recovering) {
+ btrfs_set_super_log_root(&root->fs_info->super_copy, 0);
+ btrfs_set_super_log_root_level(&root->fs_info->super_copy, 0);
}
+
+ memcpy(&root->fs_info->super_for_commit, &root->fs_info->super_copy,
+ sizeof(root->fs_info->super_copy));
+
+ btrfs_copy_pinned(root, pinned_copy);
+
+ trans->transaction->blocked = 0;
+ wake_up(&root->fs_info->transaction_throttle);
+ wake_up(&root->fs_info->transaction_wait);
+
mutex_unlock(&root->fs_info->trans_mutex);
- mutex_unlock(&root->fs_info->fs_mutex);
ret = btrfs_write_and_wait_transaction(trans, root);
- if (prev_trans) {
- mutex_lock(&root->fs_info->trans_mutex);
- wait_for_commit(root, prev_trans);
- put_transaction(prev_trans);
- mutex_unlock(&root->fs_info->trans_mutex);
- }
- btrfs_set_super_generation(root->fs_info->disk_super,
- cur_trans->transid);
BUG_ON(ret);
- write_ctree_super(trans, root);
+ write_ctree_super(trans, root, 0);
+
+ /*
+ * the super is written, we can safely allow the tree-loggers
+ * to go about their business
+ */
+ mutex_unlock(&root->fs_info->tree_log_mutex);
+
+ btrfs_finish_extent_commit(trans, root, pinned_copy);
+ kfree(pinned_copy);
+
+ btrfs_drop_dead_reloc_roots(root);
+ mutex_unlock(&root->fs_info->tree_reloc_mutex);
+
+ /* do the directory inserts of any pending snapshot creations */
+ finish_pending_snapshots(trans, root->fs_info);
- mutex_lock(&root->fs_info->fs_mutex);
- btrfs_finish_extent_commit(trans, root);
mutex_lock(&root->fs_info->trans_mutex);
+
cur_trans->commit_done = 1;
+ root->fs_info->last_trans_committed = cur_trans->transid;
wake_up(&cur_trans->commit_wait);
+
put_transaction(cur_trans);
put_transaction(cur_trans);
+
+ list_splice_init(&dirty_fs_roots, &root->fs_info->dead_roots);
if (root->fs_info->closing)
list_splice_init(&root->fs_info->dead_roots, &dirty_fs_roots);
- else
- list_splice_init(&dirty_fs_roots, &root->fs_info->dead_roots);
+
mutex_unlock(&root->fs_info->trans_mutex);
+
kmem_cache_free(btrfs_trans_handle_cachep, trans);
if (root->fs_info->closing) {
- mutex_unlock(&root->fs_info->fs_mutex);
drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
- mutex_lock(&root->fs_info->fs_mutex);
}
return ret;
}
-void btrfs_transaction_cleaner(struct work_struct *work)
+/*
+ * interface function to delete all the snapshots we have scheduled for deletion
+ */
+int btrfs_clean_old_snapshots(struct btrfs_root *root)
{
- struct btrfs_fs_info *fs_info = container_of(work,
- struct btrfs_fs_info,
- trans_work.work);
-
- struct btrfs_root *root = fs_info->tree_root;
- struct btrfs_transaction *cur;
- struct btrfs_trans_handle *trans;
struct list_head dirty_roots;
- unsigned long now;
- unsigned long delay = HZ * 30;
- int ret;
-
INIT_LIST_HEAD(&dirty_roots);
- mutex_lock(&root->fs_info->fs_mutex);
- mutex_lock(&root->fs_info->trans_mutex);
- cur = root->fs_info->running_transaction;
- if (!cur) {
- mutex_unlock(&root->fs_info->trans_mutex);
- goto out;
- }
- now = get_seconds();
- if (now < cur->start_time || now - cur->start_time < 30) {
- mutex_unlock(&root->fs_info->trans_mutex);
- delay = HZ * 5;
- goto out;
- }
- mutex_unlock(&root->fs_info->trans_mutex);
- trans = btrfs_start_transaction(root, 1);
- ret = btrfs_commit_transaction(trans, root);
-out:
- mutex_unlock(&root->fs_info->fs_mutex);
-
+again:
mutex_lock(&root->fs_info->trans_mutex);
list_splice_init(&root->fs_info->dead_roots, &dirty_roots);
mutex_unlock(&root->fs_info->trans_mutex);
if (!list_empty(&dirty_roots)) {
drop_dirty_roots(root, &dirty_roots);
+ goto again;
}
- btrfs_transaction_queue_work(root, delay);
-}
-
-void btrfs_transaction_queue_work(struct btrfs_root *root, int delay)
-{
- queue_delayed_work(trans_wq, &root->fs_info->trans_work, delay);
-}
-
-void btrfs_transaction_flush_work(struct btrfs_root *root)
-{
- cancel_rearming_delayed_workqueue(trans_wq, &root->fs_info->trans_work);
- flush_workqueue(trans_wq);
-}
-
-void __init btrfs_init_transaction_sys(void)
-{
- trans_wq = create_workqueue("btrfs");
-}
-
-void __exit btrfs_exit_transaction_sys(void)
-{
- destroy_workqueue(trans_wq);
+ return 0;
}
-
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff