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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-10-02 12:17:24 -0700 |
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| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-10-02 12:17:24 -0700 |
| commit | 3f1fe48a36b0b6722dc3fd421d93512bac138e9a (patch) | |
| tree | b767d7f6e26bc64334d3f14f8422d187239dc45d /drivers/md/persistent-data/dm-array.h | |
| download | linux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.tar.gz linux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.zip | |
Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linuxgrafted
Pull io_uring fixes from Jens Axboe:
- Fix a task_work add use-after-free with SQPOLL.
The sqpoll thread could pop and complete the last request while
io_req_normal_work_add() was still looking at them after the mpscq
push.
Use the same approach as DEFER_TASKRUN to protect from that, holding
an RCU read lock across the add, and have exit wait for an RCU grace
period for SQPOLL rings as well.
- CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the
big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED
rings
- Mark the source filter table as COW when cloning bpf filters, so
registering another filter on the source doesn't modify the shared
table in place
- Initialize the task context before running the BPF loop
- Requeue zcrx multishot receives stopped by a local resource
- End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit)
* tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
io_uring: fix task_work add use-after-free with SQPOLL
io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full
io_uring/zcrx: requeue multishot receives stopped by a local resource
io_uring: initialize task context before running the BPF loop
io_uring: zero big_cqe for aux CQEs on CQE32 rings
io_uring: fix free entry check for 32b CQEs on CQE32 rings
io_uring: only post the dummy skip CQE on CQE_MIXED rings
io_uring/bpf_filter: mark source as COW when cloning filters
Diffstat (limited to 'drivers/md/persistent-data/dm-array.h')
| -rw-r--r-- | drivers/md/persistent-data/dm-array.h | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/md/persistent-data/dm-array.h b/drivers/md/persistent-data/dm-array.h new file mode 100644 index 000000000..91d616542 --- /dev/null +++ b/drivers/md/persistent-data/dm-array.h @@ -0,0 +1,220 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2012 Red Hat, Inc. + * + * This file is released under the GPL. + */ +#ifndef _LINUX_DM_ARRAY_H +#define _LINUX_DM_ARRAY_H + +#include "dm-btree.h" + +/*----------------------------------------------------------------*/ + +/* + * The dm-array is a persistent version of an array. It packs the data + * more efficiently than a btree which will result in less disk space use, + * and a performance boost. The element get and set operations are still + * O(ln(n)), but with a much smaller constant. + * + * The value type structure is reused from the btree type to support proper + * reference counting of values. + * + * The arrays implicitly know their length, and bounds are checked for + * lookups and updated. It doesn't store this in an accessible place + * because it would waste a whole metadata block. Make sure you store the + * size along with the array root in your encompassing data. + * + * Array entries are indexed via an unsigned integer starting from zero. + * Arrays are not sparse; if you resize an array to have 'n' entries then + * 'n - 1' will be the last valid index. + * + * Typical use: + * + * a) initialise a dm_array_info structure. This describes the array + * values and ties it into a specific transaction manager. It holds no + * instance data; the same info can be used for many similar arrays if + * you wish. + * + * b) Get yourself a root. The root is the index of a block of data on the + * disk that holds a particular instance of an array. You may have a + * pre existing root in your metadata that you wish to use, or you may + * want to create a brand new, empty array with dm_array_empty(). + * + * Like the other data structures in this library, dm_array objects are + * immutable between transactions. Update functions will return you the + * root for a _new_ array. If you've incremented the old root, via + * dm_tm_inc(), before calling the update function you may continue to use + * it in parallel with the new root. + * + * c) resize an array with dm_array_resize(). + * + * d) Get a value from the array with dm_array_get_value(). + * + * e) Set a value in the array with dm_array_set_value(). + * + * f) Walk an array of values in index order with dm_array_walk(). More + * efficient than making many calls to dm_array_get_value(). + * + * g) Destroy the array with dm_array_del(). This tells the transaction + * manager that you're no longer using this data structure so it can + * recycle it's blocks. (dm_array_dec() would be a better name for it, + * but del is in keeping with dm_btree_del()). + */ + +/* + * Describes an array. Don't initialise this structure yourself, use the + * init function below. + */ +struct dm_array_info { + struct dm_transaction_manager *tm; + struct dm_btree_value_type value_type; + struct dm_btree_info btree_info; +}; + +/* + * Sets up a dm_array_info structure. You don't need to do anything with + * this structure when you finish using it. + * + * info - the structure being filled in. + * tm - the transaction manager that should supervise this structure. + * vt - describes the leaf values. + */ +void dm_array_info_init(struct dm_array_info *info, + struct dm_transaction_manager *tm, + struct dm_btree_value_type *vt); + +/* + * Create an empty, zero length array. + * + * info - describes the array + * root - on success this will be filled out with the root block + */ +int dm_array_empty(struct dm_array_info *info, dm_block_t *root); + +/* + * Resizes the array. + * + * info - describes the array + * root - the root block of the array on disk + * old_size - the caller is responsible for remembering the size of + * the array + * new_size - can be bigger or smaller than old_size + * value - if we're growing the array the new entries will have this value + * new_root - on success, points to the new root block + * + * If growing the inc function for 'value' will be called the appropriate + * number of times. So if the caller is holding a reference they may want + * to drop it. + */ +int dm_array_resize(struct dm_array_info *info, dm_block_t root, + uint32_t old_size, uint32_t new_size, + const void *value, dm_block_t *new_root) + __dm_written_to_disk(value); + +/* + * Creates a new array populated with values provided by a callback + * function. This is more efficient than creating an empty array, + * resizing, and then setting values since that process incurs a lot of + * copying. + * + * Assumes 32bit values for now since it's only used by the cache hint + * array. + * + * info - describes the array + * root - the root block of the array on disk + * size - the number of entries in the array + * fn - the callback + * context - passed to the callback + */ +typedef int (*value_fn)(uint32_t index, void *value_le, void *context); +int dm_array_new(struct dm_array_info *info, dm_block_t *root, + uint32_t size, value_fn fn, void *context); + +/* + * Frees a whole array. The value_type's decrement operation will be called + * for all values in the array + */ +int dm_array_del(struct dm_array_info *info, dm_block_t root); + +/* + * Lookup a value in the array + * + * info - describes the array + * root - root block of the array + * index - array index + * value - the value to be read. Will be in on-disk format of course. + * + * -ENODATA will be returned if the index is out of bounds. + */ +int dm_array_get_value(struct dm_array_info *info, dm_block_t root, + uint32_t index, void *value); + +/* + * Set an entry in the array. + * + * info - describes the array + * root - root block of the array + * index - array index + * value - value to be written to disk. Make sure you confirm the value is + * in on-disk format with__dm_bless_for_disk() before calling. + * new_root - the new root block + * + * The old value being overwritten will be decremented, the new value + * incremented. + * + * -ENODATA will be returned if the index is out of bounds. + */ +int dm_array_set_value(struct dm_array_info *info, dm_block_t root, + uint32_t index, const void *value, dm_block_t *new_root) + __dm_written_to_disk(value); + +/* + * Walk through all the entries in an array. + * + * info - describes the array + * root - root block of the array + * fn - called back for every element + * context - passed to the callback + */ +int dm_array_walk(struct dm_array_info *info, dm_block_t root, + int (*fn)(void *context, uint64_t key, void *leaf), + void *context); + +/*----------------------------------------------------------------*/ + +/* + * Cursor api. + * + * This lets you iterate through all the entries in an array efficiently + * (it will preload metadata). + * + * I'm using a cursor, rather than a walk function with a callback because + * the cache target needs to iterate both the mapping and hint arrays in + * unison. + */ +struct dm_array_cursor { + struct dm_array_info *info; + struct dm_btree_cursor cursor; + + struct dm_block *block; + struct array_block *ab; + unsigned int index; +}; + +int dm_array_cursor_begin(struct dm_array_info *info, + dm_block_t root, struct dm_array_cursor *c); +void dm_array_cursor_end(struct dm_array_cursor *c); + +uint32_t dm_array_cursor_index(struct dm_array_cursor *c); +int dm_array_cursor_next(struct dm_array_cursor *c); +int dm_array_cursor_skip(struct dm_array_cursor *c, uint32_t count); + +/* + * value_le is only valid while the cursor points at the current value. + */ +void dm_array_cursor_get_value(struct dm_array_cursor *c, void **value_le); + +/*----------------------------------------------------------------*/ + +#endif /* _LINUX_DM_ARRAY_H */ |
