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-rw-r--r--fs/btrfs/extent-tree.c3
-rw-r--r--fs/btrfs/inode.c18
-rw-r--r--fs/btrfs/transaction.c62
-rw-r--r--fs/btrfs/transaction.h5
4 files changed, 80 insertions, 8 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 3b8b6c21270..a421c32c6cf 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3797,7 +3797,8 @@ int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
break;
if (wret < 0)
ret = wret;
- if (trans->transaction->in_commit) {
+ if (trans->transaction->in_commit ||
+ trans->transaction->delayed_refs.flushing) {
ret = -EAGAIN;
break;
}
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7d4f948bc22..13a17477c4f 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1502,6 +1502,7 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
struct btrfs_trans_handle *trans;
struct btrfs_ordered_extent *ordered_extent;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_path *path;
int compressed = 0;
int ret;
@@ -1509,6 +1510,23 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
if (!ret)
return 0;
+ /*
+ * before we join the transaction, try to do some of our IO.
+ * This will limit the amount of IO that we have to do with
+ * the transaction running. We're unlikely to need to do any
+ * IO if the file extents are new, the disk_i_size checks
+ * covers the most common case.
+ */
+ if (start < BTRFS_I(inode)->disk_i_size) {
+ path = btrfs_alloc_path();
+ if (path) {
+ ret = btrfs_lookup_file_extent(NULL, root, path,
+ inode->i_ino,
+ start, 0);
+ btrfs_free_path(path);
+ }
+ }
+
trans = btrfs_join_transaction(root, 1);
ordered_extent = btrfs_lookup_ordered_extent(inode, start);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 903edab3659..01c9620bb00 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -192,6 +192,7 @@ static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
h->alloc_exclude_nr = 0;
h->alloc_exclude_start = 0;
h->delayed_ref_updates = 0;
+
root->fs_info->running_transaction->use_count++;
mutex_unlock(&root->fs_info->trans_mutex);
return h;
@@ -281,7 +282,6 @@ void btrfs_throttle(struct btrfs_root *root)
if (!root->fs_info->open_ioctl_trans)
wait_current_trans(root);
mutex_unlock(&root->fs_info->trans_mutex);
-
throttle_on_drops(root);
}
@@ -298,6 +298,13 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
if (cur &&
trans->transaction->delayed_refs.num_heads_ready > 64) {
trans->delayed_ref_updates = 0;
+
+ /*
+ * do a full flush if the transaction is trying
+ * to close
+ */
+ if (trans->transaction->delayed_refs.flushing)
+ cur = 0;
btrfs_run_delayed_refs(trans, root, cur);
} else {
break;
@@ -666,6 +673,31 @@ int btrfs_defrag_root(struct btrfs_root *root, int cacheonly)
}
/*
+ * when dropping snapshots, we generate a ton of delayed refs, and it makes
+ * sense not to join the transaction while it is trying to flush the current
+ * queue of delayed refs out.
+ *
+ * This is used by the drop snapshot code only
+ */
+static noinline int wait_transaction_pre_flush(struct btrfs_fs_info *info)
+{
+ DEFINE_WAIT(wait);
+
+ mutex_lock(&info->trans_mutex);
+ while (info->running_transaction &&
+ info->running_transaction->delayed_refs.flushing) {
+ prepare_to_wait(&info->transaction_wait, &wait,
+ TASK_UNINTERRUPTIBLE);
+ mutex_unlock(&info->trans_mutex);
+ schedule();
+ mutex_lock(&info->trans_mutex);
+ finish_wait(&info->transaction_wait, &wait);
+ }
+ mutex_unlock(&info->trans_mutex);
+ return 0;
+}
+
+/*
* Given a list of roots that need to be deleted, call btrfs_drop_snapshot on
* all of them
*/
@@ -692,7 +724,22 @@ static noinline int drop_dirty_roots(struct btrfs_root *tree_root,
atomic_inc(&root->fs_info->throttles);
while (1) {
+ /*
+ * we don't want to jump in and create a bunch of
+ * delayed refs if the transaction is starting to close
+ */
+ wait_transaction_pre_flush(tree_root->fs_info);
trans = btrfs_start_transaction(tree_root, 1);
+
+ /*
+ * we've joined a transaction, make sure it isn't
+ * closing right now
+ */
+ if (trans->transaction->delayed_refs.flushing) {
+ btrfs_end_transaction(trans, tree_root);
+ continue;
+ }
+
mutex_lock(&root->fs_info->drop_mutex);
ret = btrfs_drop_snapshot(trans, dirty->root);
if (ret != -EAGAIN)
@@ -932,20 +979,20 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
ret = btrfs_run_delayed_refs(trans, root, 0);
BUG_ON(ret);
+ cur_trans = trans->transaction;
/*
* set the flushing flag so procs in this transaction have to
* start sending their work down.
*/
- trans->transaction->delayed_refs.flushing = 1;
+ cur_trans->delayed_refs.flushing = 1;
ret = btrfs_run_delayed_refs(trans, root, 0);
BUG_ON(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++;
+ INIT_LIST_HEAD(&dirty_fs_roots);
+ if (cur_trans->in_commit) {
+ cur_trans->use_count++;
mutex_unlock(&root->fs_info->trans_mutex);
btrfs_end_transaction(trans, root);
@@ -968,7 +1015,6 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
trans->transaction->in_commit = 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);
@@ -1081,6 +1127,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
btrfs_copy_pinned(root, pinned_copy);
trans->transaction->blocked = 0;
+
wake_up(&root->fs_info->transaction_throttle);
wake_up(&root->fs_info->transaction_wait);
@@ -1107,6 +1154,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
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);
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 94876709217..94f5bde2b58 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -23,7 +23,12 @@
struct btrfs_transaction {
u64 transid;
+ /*
+ * total writers in this transaction, it must be zero before the
+ * transaction can end
+ */
unsigned long num_writers;
+
unsigned long num_joined;
int in_commit;
int use_count;
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-17 14:37:41 +0000