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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /fs/btrfs/locking.h | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'fs/btrfs/locking.h')
| -rw-r--r-- | fs/btrfs/locking.h | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h new file mode 100644 index 000000000..a4673e7d9 --- /dev/null +++ b/fs/btrfs/locking.h @@ -0,0 +1,251 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2008 Oracle. All rights reserved. + */ + +#ifndef BTRFS_LOCKING_H +#define BTRFS_LOCKING_H + +#include <linux/atomic.h> +#include <linux/wait.h> +#include <linux/lockdep.h> +#include <linux/percpu_counter.h> +#include "extent_io.h" + +struct extent_buffer; +struct btrfs_path; +struct btrfs_root; + +#define BTRFS_WRITE_LOCK 1 +#define BTRFS_READ_LOCK 2 + +/* + * We are limited in number of subclasses by MAX_LOCKDEP_SUBCLASSES, which at + * the time of this patch is 8, which is how many we use. Keep this in mind if + * you decide you want to add another subclass. + */ +enum btrfs_lock_nesting { + BTRFS_NESTING_NORMAL, + + /* + * When we COW a block we are holding the lock on the original block, + * and since our lockdep maps are rootid+level, this confuses lockdep + * when we lock the newly allocated COW'd block. Handle this by having + * a subclass for COW'ed blocks so that lockdep doesn't complain. + */ + BTRFS_NESTING_COW, + + /* + * Oftentimes we need to lock adjacent nodes on the same level while + * still holding the lock on the original node we searched to, such as + * for searching forward or for split/balance. + * + * Because of this we need to indicate to lockdep that this is + * acceptable by having a different subclass for each of these + * operations. + */ + BTRFS_NESTING_LEFT, + BTRFS_NESTING_RIGHT, + + /* + * When splitting we will be holding a lock on the left/right node when + * we need to cow that node, thus we need a new set of subclasses for + * these two operations. + */ + BTRFS_NESTING_LEFT_COW, + BTRFS_NESTING_RIGHT_COW, + + /* + * When splitting we may push nodes to the left or right, but still use + * the subsequent nodes in our path, keeping our locks on those adjacent + * blocks. Thus when we go to allocate a new split block we've already + * used up all of our available subclasses, so this subclass exists to + * handle this case where we need to allocate a new split block. + */ + BTRFS_NESTING_SPLIT, + + /* + * When promoting a new block to a root we need to have a special + * subclass so we don't confuse lockdep, as it will appear that we are + * locking a higher level node before a lower level one. Copying also + * has this problem as it appears we're locking the same block again + * when we make a snapshot of an existing root. + */ + BTRFS_NESTING_NEW_ROOT, + + /* + * We are limited to MAX_LOCKDEP_SUBCLASSES number of subclasses, so + * add this in here and add a static_assert to keep us from going over + * the limit. As of this writing we're limited to 8, and we're + * definitely using 8, hence this check to keep us from messing up in + * the future. + */ + BTRFS_NESTING_MAX, +}; + +enum btrfs_lockdep_trans_states { + BTRFS_LOCKDEP_TRANS_COMMIT_PREP, + BTRFS_LOCKDEP_TRANS_UNBLOCKED, + BTRFS_LOCKDEP_TRANS_SUPER_COMMITTED, + BTRFS_LOCKDEP_TRANS_COMPLETED, +}; + +/* + * Lockdep annotation for wait events. + * + * @owner: The struct where the lockdep map is defined + * @lock: The lockdep map corresponding to a wait event + * + * This macro is used to annotate a wait event. In this case a thread acquires + * the lockdep map as writer (exclusive lock) because it has to block until all + * the threads that hold the lock as readers signal the condition for the wait + * event and release their locks. + */ +#define btrfs_might_wait_for_event(owner, lock) \ + do { \ + rwsem_acquire(&owner->lock##_map, 0, 0, _THIS_IP_); \ + rwsem_release(&owner->lock##_map, _THIS_IP_); \ + } while (0) + +/* + * Protection for the resource/condition of a wait event. + * + * @owner: The struct where the lockdep map is defined + * @lock: The lockdep map corresponding to a wait event + * + * Many threads can modify the condition for the wait event at the same time + * and signal the threads that block on the wait event. The threads that modify + * the condition and do the signaling acquire the lock as readers (shared + * lock). + */ +#define btrfs_lockdep_acquire(owner, lock) \ + rwsem_acquire_read(&owner->lock##_map, 0, 0, _THIS_IP_) + +/* + * Used after signaling the condition for a wait event to release the lockdep + * map held by a reader thread. + */ +#define btrfs_lockdep_release(owner, lock) \ + rwsem_release(&owner->lock##_map, _THIS_IP_) + +/* + * Used to account for the fact that when doing io_uring encoded I/O, we can + * return to userspace with the inode lock still held. + */ +#define btrfs_lockdep_inode_acquire(owner, lock) \ + rwsem_acquire_read(&owner->vfs_inode.lock.dep_map, 0, 0, _THIS_IP_) + +#define btrfs_lockdep_inode_release(owner, lock) \ + rwsem_release(&owner->vfs_inode.lock.dep_map, _THIS_IP_) + +/* + * Macros for the transaction states wait events, similar to the generic wait + * event macros. + */ +#define btrfs_might_wait_for_state(owner, i) \ + do { \ + rwsem_acquire(&owner->btrfs_state_change_map[i], 0, 0, _THIS_IP_); \ + rwsem_release(&owner->btrfs_state_change_map[i], _THIS_IP_); \ + } while (0) + +#define btrfs_trans_state_lockdep_acquire(owner, i) \ + rwsem_acquire_read(&owner->btrfs_state_change_map[i], 0, 0, _THIS_IP_) + +#define btrfs_trans_state_lockdep_release(owner, i) \ + rwsem_release(&owner->btrfs_state_change_map[i], _THIS_IP_) + +/* Initialization of the lockdep map */ +#define btrfs_lockdep_init_map(owner, lock) \ + do { \ + static struct lock_class_key lock##_key; \ + lockdep_init_map(&owner->lock##_map, #lock, &lock##_key, 0); \ + } while (0) + +/* Initialization of the transaction states lockdep maps. */ +#define btrfs_state_lockdep_init_map(owner, lock, state) \ + do { \ + static struct lock_class_key lock##_key; \ + lockdep_init_map(&owner->btrfs_state_change_map[state], #lock, \ + &lock##_key, 0); \ + } while (0) + +static_assert(BTRFS_NESTING_MAX <= MAX_LOCKDEP_SUBCLASSES, + "too many lock subclasses defined"); + +void btrfs_tree_lock_nested(struct extent_buffer *eb, enum btrfs_lock_nesting nest); + +static inline void btrfs_tree_lock(struct extent_buffer *eb) +{ + btrfs_tree_lock_nested(eb, BTRFS_NESTING_NORMAL); +} + +void btrfs_tree_unlock(struct extent_buffer *eb); + +void btrfs_tree_read_lock_nested(struct extent_buffer *eb, enum btrfs_lock_nesting nest); + +static inline void btrfs_tree_read_lock(struct extent_buffer *eb) +{ + btrfs_tree_read_lock_nested(eb, BTRFS_NESTING_NORMAL); +} + +void btrfs_tree_read_unlock(struct extent_buffer *eb); +bool btrfs_try_tree_read_lock(struct extent_buffer *eb); +struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root); +struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root); +struct extent_buffer *btrfs_try_read_lock_root_node(struct btrfs_root *root); + +#ifdef CONFIG_BTRFS_DEBUG +static inline void btrfs_assert_tree_write_locked(struct extent_buffer *eb) +{ + lockdep_assert_held_write(&eb->lock); +} +static inline void btrfs_assert_tree_read_locked(struct extent_buffer *eb) +{ + lockdep_assert_held_read(&eb->lock); +} +#else +static inline void btrfs_assert_tree_write_locked(struct extent_buffer *eb) { } +static inline void btrfs_assert_tree_read_locked(struct extent_buffer *eb) { } +#endif + +void btrfs_unlock_up_safe(struct btrfs_path *path, int level); + +static inline void btrfs_tree_unlock_rw(struct extent_buffer *eb, int rw) +{ + if (rw == BTRFS_WRITE_LOCK) + btrfs_tree_unlock(eb); + else if (rw == BTRFS_READ_LOCK) + btrfs_tree_read_unlock(eb); + else + BUG(); +} + +struct btrfs_drew_lock { + atomic_t readers; + atomic_t writers; + wait_queue_head_t pending_writers; + wait_queue_head_t pending_readers; +}; + +void btrfs_drew_lock_init(struct btrfs_drew_lock *lock); +void btrfs_drew_write_lock(struct btrfs_drew_lock *lock); +bool btrfs_drew_try_write_lock(struct btrfs_drew_lock *lock); +void btrfs_drew_write_unlock(struct btrfs_drew_lock *lock); +void btrfs_drew_read_lock(struct btrfs_drew_lock *lock); +void btrfs_drew_read_unlock(struct btrfs_drew_lock *lock); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb, int level); +void btrfs_maybe_reset_lockdep_class(struct btrfs_root *root, struct extent_buffer *eb); +#else +static inline void btrfs_set_buffer_lockdep_class(u64 objectid, + struct extent_buffer *eb, int level) +{ +} +static inline void btrfs_maybe_reset_lockdep_class(struct btrfs_root *root, + struct extent_buffer *eb) +{ +} +#endif + +#endif |
