Btrfs: Support reading/writing on disk free ino cache

[cascardo/linux.git] / fs / btrfs / transaction.c

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 3d73c8d..4d1dbcb 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -27,15 +27,14 @@
 #include "transaction.h"
 #include "locking.h"
 #include "tree-log.h"
+#include "inode-map.h"
 
 #define BTRFS_ROOT_TRANS_TAG 0
 
 static noinline void put_transaction(struct btrfs_transaction *transaction)
 {
-       WARN_ON(transaction->use_count == 0);
-       transaction->use_count--;
-       if (transaction->use_count == 0) {
-               list_del_init(&transaction->list);
+       WARN_ON(atomic_read(&transaction->use_count) == 0);
+       if (atomic_dec_and_test(&transaction->use_count)) {
                memset(transaction, 0, sizeof(*transaction));
                kmem_cache_free(btrfs_transaction_cachep, transaction);
        }
@@ -57,16 +56,17 @@ static noinline int join_transaction(struct btrfs_root *root)
        if (!cur_trans) {
                cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
                                             GFP_NOFS);
-               BUG_ON(!cur_trans);
+               if (!cur_trans)
+                       return -ENOMEM;
                root->fs_info->generation++;
-               cur_trans->num_writers = 1;
+               atomic_set(&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;
+               atomic_set(&cur_trans->use_count, 1);
                cur_trans->commit_done = 0;
                cur_trans->start_time = get_seconds();
 
@@ -87,7 +87,7 @@ static noinline int join_transaction(struct btrfs_root *root)
                root->fs_info->running_transaction = cur_trans;
                spin_unlock(&root->fs_info->new_trans_lock);
        } else {
-               cur_trans->num_writers++;
+               atomic_inc(&cur_trans->num_writers);
                cur_trans->num_joined++;
        }
 
@@ -144,7 +144,7 @@ static void wait_current_trans(struct btrfs_root *root)
        cur_trans = root->fs_info->running_transaction;
        if (cur_trans && cur_trans->blocked) {
                DEFINE_WAIT(wait);
-               cur_trans->use_count++;
+               atomic_inc(&cur_trans->use_count);
                while (1) {
                        prepare_to_wait(&root->fs_info->transaction_wait, &wait,
                                        TASK_UNINTERRUPTIBLE);
@@ -180,6 +180,7 @@ static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
 {
        struct btrfs_trans_handle *h;
        struct btrfs_transaction *cur_trans;
+       int retries = 0;
        int ret;
 
        if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
@@ -195,10 +196,15 @@ again:
                wait_current_trans(root);
 
        ret = join_transaction(root);
-       BUG_ON(ret);
+       if (ret < 0) {
+               kmem_cache_free(btrfs_trans_handle_cachep, h);
+               if (type != TRANS_JOIN_NOLOCK)
+                       mutex_unlock(&root->fs_info->trans_mutex);
+               return ERR_PTR(ret);
+       }
 
        cur_trans = root->fs_info->running_transaction;
-       cur_trans->use_count++;
+       atomic_inc(&cur_trans->use_count);
        if (type != TRANS_JOIN_NOLOCK)
                mutex_unlock(&root->fs_info->trans_mutex);
 
@@ -218,10 +224,18 @@ again:
 
        if (num_items > 0) {
                ret = btrfs_trans_reserve_metadata(h, root, num_items);
-               if (ret == -EAGAIN) {
+               if (ret == -EAGAIN && !retries) {
+                       retries++;
                        btrfs_commit_transaction(h, root);
                        goto again;
+               } else if (ret == -EAGAIN) {
+                       /*
+                        * We have already retried and got EAGAIN, so really we
+                        * don't have space, so set ret to -ENOSPC.
+                        */
+                       ret = -ENOSPC;
                }
+
                if (ret < 0) {
                        btrfs_end_transaction(h, root);
                        return ERR_PTR(ret);
@@ -321,7 +335,7 @@ int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid)
                        goto out_unlock;  /* nothing committing|committed */
        }
 
-       cur_trans->use_count++;
+       atomic_inc(&cur_trans->use_count);
        mutex_unlock(&root->fs_info->trans_mutex);
 
        wait_for_commit(root, cur_trans);
@@ -451,18 +465,14 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
                        wake_up_process(info->transaction_kthread);
        }
 
-       if (lock)
-               mutex_lock(&info->trans_mutex);
        WARN_ON(cur_trans != info->running_transaction);
-       WARN_ON(cur_trans->num_writers < 1);
-       cur_trans->num_writers--;
+       WARN_ON(atomic_read(&cur_trans->num_writers) < 1);
+       atomic_dec(&cur_trans->num_writers);
 
        smp_mb();
        if (waitqueue_active(&cur_trans->writer_wait))
                wake_up(&cur_trans->writer_wait);
        put_transaction(cur_trans);
-       if (lock)
-               mutex_unlock(&info->trans_mutex);
 
        if (current->journal_info == trans)
                current->journal_info = NULL;
@@ -751,8 +761,14 @@ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans,
                        btrfs_update_reloc_root(trans, root);
                        btrfs_orphan_commit_root(trans, root);
 
+                       btrfs_save_ino_cache(root, trans);
+
                        if (root->commit_root != root->node) {
+                               mutex_lock(&root->fs_commit_mutex);
                                switch_commit_root(root);
+                               btrfs_unpin_free_ino(root);
+                               mutex_unlock(&root->fs_commit_mutex);
+
                                btrfs_set_root_node(&root->root_item,
                                                    root->node);
                        }
@@ -921,7 +937,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
                goto fail;
        }
 
-       ret = btrfs_find_free_objectid(trans, tree_root, 0, &objectid);
+       ret = btrfs_find_free_objectid(tree_root, &objectid);
        if (ret) {
                pending->error = ret;
                goto fail;
@@ -958,7 +974,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
        BUG_ON(ret);
        ret = btrfs_insert_dir_item(trans, parent_root,
                                dentry->d_name.name, dentry->d_name.len,
-                               parent_inode->i_ino, &key,
+                               btrfs_ino(parent_inode), &key,
                                BTRFS_FT_DIR, index);
        BUG_ON(ret);
 
@@ -970,6 +986,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
        record_root_in_trans(trans, root);
        btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
        memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
+       btrfs_check_and_init_root_item(new_root_item);
 
        root_flags = btrfs_root_flags(new_root_item);
        if (pending->readonly)
@@ -999,7 +1016,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
         */
        ret = btrfs_add_root_ref(trans, tree_root, objectid,
                                 parent_root->root_key.objectid,
-                                parent_inode->i_ino, index,
+                                btrfs_ino(parent_inode), index,
                                 dentry->d_name.name, dentry->d_name.len);
        BUG_ON(ret);
        dput(parent);
@@ -1156,7 +1173,8 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
        struct btrfs_transaction *cur_trans;
 
        ac = kmalloc(sizeof(*ac), GFP_NOFS);
-       BUG_ON(!ac);
+       if (!ac)
+               return -ENOMEM;
 
        INIT_DELAYED_WORK(&ac->work, do_async_commit);
        ac->root = root;
@@ -1170,7 +1188,7 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
        /* take transaction reference */
        mutex_lock(&root->fs_info->trans_mutex);
        cur_trans = trans->transaction;
-       cur_trans->use_count++;
+       atomic_inc(&cur_trans->use_count);
        mutex_unlock(&root->fs_info->trans_mutex);
 
        btrfs_end_transaction(trans, root);
@@ -1229,7 +1247,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 
        mutex_lock(&root->fs_info->trans_mutex);
        if (cur_trans->in_commit) {
-               cur_trans->use_count++;
+               atomic_inc(&cur_trans->use_count);
                mutex_unlock(&root->fs_info->trans_mutex);
                btrfs_end_transaction(trans, root);
 
@@ -1251,7 +1269,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
                prev_trans = list_entry(cur_trans->list.prev,
                                        struct btrfs_transaction, list);
                if (!prev_trans->commit_done) {
-                       prev_trans->use_count++;
+                       atomic_inc(&prev_trans->use_count);
                        mutex_unlock(&root->fs_info->trans_mutex);
 
                        wait_for_commit(root, prev_trans);
@@ -1292,14 +1310,14 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
                                TASK_UNINTERRUPTIBLE);
 
                smp_mb();
-               if (cur_trans->num_writers > 1)
+               if (atomic_read(&cur_trans->num_writers) > 1)
                        schedule_timeout(MAX_SCHEDULE_TIMEOUT);
                else if (should_grow)
                        schedule_timeout(1);
 
                mutex_lock(&root->fs_info->trans_mutex);
                finish_wait(&cur_trans->writer_wait, &wait);
-       } while (cur_trans->num_writers > 1 ||
+       } while (atomic_read(&cur_trans->num_writers) > 1 ||
                 (should_grow && cur_trans->num_joined != joined));
 
        ret = create_pending_snapshots(trans, root->fs_info);
@@ -1386,9 +1404,12 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 
        wake_up(&cur_trans->commit_wait);
 
+       list_del_init(&cur_trans->list);
        put_transaction(cur_trans);
        put_transaction(cur_trans);
 
+       trace_btrfs_transaction_commit(root);
+
        mutex_unlock(&root->fs_info->trans_mutex);
 
        if (current->journal_info == trans)