Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 133 insertions, 0 deletions

diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
new file mode 100644
index 000000000..290508894
--- /dev/null
+++ b/fs/btrfs/disk-io.h
@@ -0,0 +1,133 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ */
+
+#ifndef BTRFS_DISK_IO_H
+#define BTRFS_DISK_IO_H
+
+#include <linux/sizes.h>
+#include <linux/compiler_types.h>
+#include "ctree.h"
+#include "bio.h"
+#include "ordered-data.h"
+
+struct block_device;
+struct super_block;
+struct extent_buffer;
+struct btrfs_eb_prealloc;
+struct btrfs_device;
+struct btrfs_fs_devices;
+struct btrfs_fs_info;
+struct btrfs_super_block;
+struct btrfs_trans_handle;
+struct btrfs_tree_parent_check;
+struct btrfs_transaction;
+
+#define BTRFS_SUPER_MIRROR_MAX	 3
+#define BTRFS_SUPER_MIRROR_SHIFT 12
+
+/*
+ * Fixed blocksize for all devices, applies to specific ways of reading
+ * metadata like superblock. Must meet the set_blocksize requirements.
+ *
+ * Do not change.
+ */
+#define BTRFS_BDEV_BLOCKSIZE	(4096)
+
+static inline u64 btrfs_sb_offset(int mirror)
+{
+	u64 start = SZ_16K;
+	if (mirror)
+		return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
+	return BTRFS_SUPER_INFO_OFFSET;
+}
+
+void btrfs_check_leaked_roots(const struct btrfs_fs_info *fs_info);
+void btrfs_init_fs_info(struct btrfs_fs_info *fs_info);
+struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
+				      struct btrfs_tree_parent_check *check);
+struct extent_buffer *btrfs_find_create_tree_block(
+						struct btrfs_fs_info *fs_info,
+						struct btrfs_eb_prealloc *pa,
+						u64 bytenr, u64 owner_root,
+						int level);
+int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info);
+int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
+			   const struct btrfs_super_block *disk_sb);
+int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices);
+void __cold close_ctree(struct btrfs_fs_info *fs_info);
+int btrfs_validate_super(const struct btrfs_fs_info *fs_info,
+			 const struct btrfs_super_block *sb, int mirror_num);
+int btrfs_check_features(struct btrfs_fs_info *fs_info, bool is_rw_mount);
+int write_all_supers(struct btrfs_trans_handle *trans);
+int btrfs_commit_super(struct btrfs_fs_info *fs_info);
+struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
+					const struct btrfs_key *key);
+int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
+			 struct btrfs_root *root);
+void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
+
+struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
+				     u64 objectid, bool check_ref);
+struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
+					 u64 objectid, dev_t *anon_dev);
+struct btrfs_root *btrfs_get_fs_root_commit_root(struct btrfs_fs_info *fs_info,
+						 struct btrfs_path *path,
+						 u64 objectid);
+int btrfs_global_root_insert(struct btrfs_root *root);
+void btrfs_global_root_delete(struct btrfs_root *root);
+struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
+				     const struct btrfs_key *key);
+struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr);
+struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info, u64 bytenr);
+
+void btrfs_free_fs_info(struct btrfs_fs_info *fs_info);
+void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
+void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
+void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
+				 struct btrfs_root *root);
+int btrfs_validate_extent_buffer(struct extent_buffer *eb,
+				 const struct btrfs_tree_parent_check *check);
+#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info);
+#endif
+
+/*
+ * This function is used to grab the root, and avoid it is freed when we
+ * access it. But it doesn't ensure that the tree is not dropped.
+ */
+static inline struct btrfs_root *btrfs_grab_root(struct btrfs_root *root)
+{
+	if (!root)
+		return NULL;
+	if (refcount_inc_not_zero(&root->refs))
+		return root;
+	return NULL;
+}
+
+void btrfs_put_root(struct btrfs_root *root);
+void btrfs_mark_buffer_dirty(struct btrfs_trans_handle *trans,
+			     struct extent_buffer *buf);
+int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
+			  const struct btrfs_tree_parent_check *check);
+int btrfs_read_extent_buffer(struct extent_buffer *buf,
+			     const struct btrfs_tree_parent_check *check);
+
+int btree_csum_one_bio(struct btrfs_bio *bbio);
+int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
+			      struct btrfs_root *root);
+int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
+			     struct btrfs_fs_info *fs_info);
+int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
+		       struct btrfs_root *root);
+void btrfs_cleanup_dirty_bgs(struct btrfs_transaction *trans,
+			     struct btrfs_fs_info *fs_info);
+void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans);
+struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
+				     u64 objectid);
+int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
+int btrfs_get_free_objectid(struct btrfs_root *root, u64 *objectid);
+int btrfs_init_root_free_objectid(struct btrfs_root *root);
+
+#endif