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author | Josef Bacik <josef@redhat.com> | 2010-06-21 18:48:16 (GMT) |
---|---|---|
committer | Josef Bacik <josef@redhat.com> | 2010-10-28 19:59:09 (GMT) |
commit | 0af3d00bad38d3bb9912a60928ad0669f17bdb76 (patch) | |
tree | abbf4c773138a33dcde483ac60f016c4b5e55dcc /fs/btrfs/transaction.c | |
parent | f6f94e2ab1b33f0082ac22d71f66385a60d8157f (diff) | |
download | linux-fsl-qoriq-0af3d00bad38d3bb9912a60928ad0669f17bdb76.tar.xz |
Btrfs: create special free space cache inode
In order to save free space cache, we need an inode to hold the data, and we
need a special item to point at the right inode for the right block group. So
first, create a special item that will point to the right inode, and the number
of extent entries we will have and the number of bitmaps we will have. We
truncate and pre-allocate space everytime to make sure it's uptodate.
This feature will be turned on as soon as you mount with -o space_cache, however
it is safe to boot into old kernels, they will just generate the cache the old
fashion way. When you boot back into a newer kernel we will notice that we
modified and not the cache and automatically discard the cache.
Signed-off-by: Josef Bacik <josef@redhat.com>
Diffstat (limited to 'fs/btrfs/transaction.c')
-rw-r--r-- | fs/btrfs/transaction.c | 43 |
1 files changed, 32 insertions, 11 deletions
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 66e4c66..e7144c4 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -163,6 +163,7 @@ enum btrfs_trans_type { TRANS_START, TRANS_JOIN, TRANS_USERSPACE, + TRANS_JOIN_NOLOCK, }; static int may_wait_transaction(struct btrfs_root *root, int type) @@ -186,7 +187,8 @@ again: if (!h) return ERR_PTR(-ENOMEM); - mutex_lock(&root->fs_info->trans_mutex); + if (type != TRANS_JOIN_NOLOCK) + mutex_lock(&root->fs_info->trans_mutex); if (may_wait_transaction(root, type)) wait_current_trans(root); @@ -195,7 +197,8 @@ again: cur_trans = root->fs_info->running_transaction; cur_trans->use_count++; - mutex_unlock(&root->fs_info->trans_mutex); + if (type != TRANS_JOIN_NOLOCK) + mutex_unlock(&root->fs_info->trans_mutex); h->transid = cur_trans->transid; h->transaction = cur_trans; @@ -224,9 +227,11 @@ again: } } - mutex_lock(&root->fs_info->trans_mutex); + if (type != TRANS_JOIN_NOLOCK) + mutex_lock(&root->fs_info->trans_mutex); record_root_in_trans(h, root); - mutex_unlock(&root->fs_info->trans_mutex); + if (type != TRANS_JOIN_NOLOCK) + mutex_unlock(&root->fs_info->trans_mutex); if (!current->journal_info && type != TRANS_USERSPACE) current->journal_info = h; @@ -244,6 +249,12 @@ struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root, return start_transaction(root, 0, TRANS_JOIN); } +struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root, + int num_blocks) +{ + return start_transaction(root, 0, TRANS_JOIN_NOLOCK); +} + struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r, int num_blocks) { @@ -348,7 +359,7 @@ int btrfs_should_end_transaction(struct btrfs_trans_handle *trans, } static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, - struct btrfs_root *root, int throttle) + struct btrfs_root *root, int throttle, int lock) { struct btrfs_transaction *cur_trans = trans->transaction; struct btrfs_fs_info *info = root->fs_info; @@ -376,18 +387,19 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, btrfs_trans_release_metadata(trans, root); - if (!root->fs_info->open_ioctl_trans && + if (lock && !root->fs_info->open_ioctl_trans && should_end_transaction(trans, root)) trans->transaction->blocked = 1; - if (cur_trans->blocked && !cur_trans->in_commit) { + if (lock && cur_trans->blocked && !cur_trans->in_commit) { if (throttle) return btrfs_commit_transaction(trans, root); else wake_up_process(info->transaction_kthread); } - mutex_lock(&info->trans_mutex); + 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--; @@ -395,7 +407,8 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, if (waitqueue_active(&cur_trans->writer_wait)) wake_up(&cur_trans->writer_wait); put_transaction(cur_trans); - mutex_unlock(&info->trans_mutex); + if (lock) + mutex_unlock(&info->trans_mutex); if (current->journal_info == trans) current->journal_info = NULL; @@ -411,13 +424,19 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, int btrfs_end_transaction(struct btrfs_trans_handle *trans, struct btrfs_root *root) { - return __btrfs_end_transaction(trans, root, 0); + return __btrfs_end_transaction(trans, root, 0, 1); } int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans, struct btrfs_root *root) { - return __btrfs_end_transaction(trans, root, 1); + return __btrfs_end_transaction(trans, root, 1, 1); +} + +int btrfs_end_transaction_nolock(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + return __btrfs_end_transaction(trans, root, 0, 0); } /* @@ -966,6 +985,8 @@ static void update_super_roots(struct btrfs_root *root) super->root = root_item->bytenr; super->generation = root_item->generation; super->root_level = root_item->level; + if (super->cache_generation != 0 || btrfs_test_opt(root, SPACE_CACHE)) + super->cache_generation = root_item->generation; } int btrfs_transaction_in_commit(struct btrfs_fs_info *info) |