From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 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 --- drivers/md/persistent-data/dm-btree.h | 216 ++++++++++++++++++++++++++++++++++ 1 file changed, 216 insertions(+) create mode 100644 drivers/md/persistent-data/dm-btree.h (limited to 'drivers/md/persistent-data/dm-btree.h') diff --git a/drivers/md/persistent-data/dm-btree.h b/drivers/md/persistent-data/dm-btree.h new file mode 100644 index 000000000..1b92acd78 --- /dev/null +++ b/drivers/md/persistent-data/dm-btree.h @@ -0,0 +1,216 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2011 Red Hat, Inc. + * + * This file is released under the GPL. + */ +#ifndef _LINUX_DM_BTREE_H +#define _LINUX_DM_BTREE_H + +#include "dm-block-manager.h" + +struct dm_transaction_manager; + +/*----------------------------------------------------------------*/ + +/* + * Annotations used to check on-disk metadata is handled as little-endian. + */ +#ifdef __CHECKER__ +# define __dm_written_to_disk(x) __releases(x) +# define __dm_reads_from_disk(x) __acquires(x) +# define __dm_bless_for_disk(x) __acquire(x) +# define __dm_unbless_for_disk(x) __release(x) +#else +# define __dm_written_to_disk(x) +# define __dm_reads_from_disk(x) +# define __dm_bless_for_disk(x) +# define __dm_unbless_for_disk(x) +#endif + +/*----------------------------------------------------------------*/ + +/* + * Manipulates hierarchical B+ trees with 64-bit keys and arbitrary-sized + * values. + */ + +/* + * Information about the values stored within the btree. + */ +struct dm_btree_value_type { + void *context; + + /* + * The size in bytes of each value. + */ + uint32_t size; + + /* + * Any of these methods can be safely set to NULL if you do not + * need the corresponding feature. + */ + + /* + * The btree is making a duplicate of a run of values, for instance + * because previously-shared btree nodes have now diverged. + * @value argument is the new copy that the copy function may modify. + * (Probably it just wants to increment a reference count + * somewhere.) This method is _not_ called for insertion of a new + * value: It is assumed the ref count is already 1. + */ + void (*inc)(void *context, const void *value, unsigned int count); + + /* + * These values are being deleted. The btree takes care of freeing + * the memory pointed to by @value. Often the del function just + * needs to decrement a reference counts somewhere. + */ + void (*dec)(void *context, const void *value, unsigned int count); + + /* + * A test for equality between two values. When a value is + * overwritten with a new one, the old one has the dec method + * called _unless_ the new and old value are deemed equal. + */ + int (*equal)(void *context, const void *value1, const void *value2); +}; + +/* + * The shape and contents of a btree. + */ +struct dm_btree_info { + struct dm_transaction_manager *tm; + + /* + * Number of nested btrees. (Not the depth of a single tree.) + */ + unsigned int levels; + struct dm_btree_value_type value_type; +}; + +/* + * Set up an empty tree. O(1). + */ +int dm_btree_empty(struct dm_btree_info *info, dm_block_t *root); + +/* + * Delete a tree. O(n) - this is the slow one! It can also block, so + * please don't call it on an IO path. + */ +int dm_btree_del(struct dm_btree_info *info, dm_block_t root); + +/* + * All the lookup functions return -ENODATA if the key cannot be found. + */ + +/* + * Tries to find a key that matches exactly. O(ln(n)) + */ +int dm_btree_lookup(struct dm_btree_info *info, dm_block_t root, + uint64_t *keys, void *value_le); + +/* + * Tries to find the first key where the bottom level key is >= to that + * given. Useful for skipping empty sections of the btree. + */ +int dm_btree_lookup_next(struct dm_btree_info *info, dm_block_t root, + uint64_t *keys, uint64_t *rkey, void *value_le); + +/* + * Insertion (or overwrite an existing value). O(ln(n)) + */ +int dm_btree_insert(struct dm_btree_info *info, dm_block_t root, + uint64_t *keys, void *value, dm_block_t *new_root) + __dm_written_to_disk(value); + +/* + * A variant of insert that indicates whether it actually inserted or just + * overwrote. Useful if you're keeping track of the number of entries in a + * tree. + */ +int dm_btree_insert_notify(struct dm_btree_info *info, dm_block_t root, + uint64_t *keys, void *value, dm_block_t *new_root, + int *inserted) + __dm_written_to_disk(value); + +/* + * Remove a key if present. This doesn't remove empty sub trees. Normally + * subtrees represent a separate entity, like a snapshot map, so this is + * correct behaviour. O(ln(n)). + */ +int dm_btree_remove(struct dm_btree_info *info, dm_block_t root, + uint64_t *keys, dm_block_t *new_root); + +/* + * Removes a _contiguous_ run of values starting from 'keys' and not + * reaching keys2 (where keys2 is keys with the final key replaced with + * 'end_key'). 'end_key' is the one-past-the-end value. 'keys' may be + * altered. + */ +int dm_btree_remove_leaves(struct dm_btree_info *info, dm_block_t root, + uint64_t *keys, uint64_t end_key, + dm_block_t *new_root, unsigned int *nr_removed); + +/* + * Returns < 0 on failure. Otherwise the number of key entries that have + * been filled out. Remember trees can have zero entries, and as such have + * no lowest key. + */ +int dm_btree_find_lowest_key(struct dm_btree_info *info, dm_block_t root, + uint64_t *result_keys); + +/* + * Returns < 0 on failure. Otherwise the number of key entries that have + * been filled out. Remember trees can have zero entries, and as such have + * no highest key. + */ +int dm_btree_find_highest_key(struct dm_btree_info *info, dm_block_t root, + uint64_t *result_keys); + +/* + * Iterate through the a btree, calling fn() on each entry. + * It only works for single level trees and is internally recursive, so + * monitor stack usage carefully. + */ +int dm_btree_walk(struct dm_btree_info *info, dm_block_t root, + int (*fn)(void *context, uint64_t *keys, void *leaf), + void *context); + + +/*----------------------------------------------------------------*/ + +/* + * Cursor API. This does not follow the rolling lock convention. Since we + * know the order that values are required we can issue prefetches to speed + * up iteration. Use on a single level btree only. + */ +#define DM_BTREE_CURSOR_MAX_DEPTH 16 + +struct cursor_node { + struct dm_block *b; + unsigned int index; +}; + +struct dm_btree_cursor { + struct dm_btree_info *info; + dm_block_t root; + + bool prefetch_leaves; + unsigned int depth; + struct cursor_node nodes[DM_BTREE_CURSOR_MAX_DEPTH]; +}; + +/* + * Creates a fresh cursor. If prefetch_leaves is set then it is assumed + * the btree contains block indexes that will be prefetched. The cursor is + * quite large, so you probably don't want to put it on the stack. + */ +int dm_btree_cursor_begin(struct dm_btree_info *info, dm_block_t root, + bool prefetch_leaves, struct dm_btree_cursor *c); +void dm_btree_cursor_end(struct dm_btree_cursor *c); +int dm_btree_cursor_next(struct dm_btree_cursor *c); +int dm_btree_cursor_skip(struct dm_btree_cursor *c, uint32_t count); +int dm_btree_cursor_get_value(struct dm_btree_cursor *c, uint64_t *key, void *value_le); + +#endif /* _LINUX_DM_BTREE_H */ -- cgit v1.3.1