mirror of
https://github.com/torvalds/linux.git
synced 2024-11-22 04:02:20 +00:00
e5e5cae05b
Replace the pag pointers in the extent free, bmap, rmap and refcount intent structures with a pointer to the generic group to prepare for adding intents for realtime groups. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
85 lines
3.2 KiB
C
85 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Copyright (C) 2022-2023 Oracle. All Rights Reserved.
|
|
* Author: Darrick J. Wong <djwong@kernel.org>
|
|
*/
|
|
#ifndef XFS_DRAIN_H_
|
|
#define XFS_DRAIN_H_
|
|
|
|
struct xfs_group;
|
|
struct xfs_perag;
|
|
|
|
#ifdef CONFIG_XFS_DRAIN_INTENTS
|
|
/*
|
|
* Passive drain mechanism. This data structure tracks a count of some items
|
|
* and contains a waitqueue for callers who would like to wake up when the
|
|
* count hits zero.
|
|
*/
|
|
struct xfs_defer_drain {
|
|
/* Number of items pending in some part of the filesystem. */
|
|
atomic_t dr_count;
|
|
|
|
/* Queue to wait for dri_count to go to zero */
|
|
struct wait_queue_head dr_waiters;
|
|
};
|
|
|
|
void xfs_defer_drain_init(struct xfs_defer_drain *dr);
|
|
void xfs_defer_drain_free(struct xfs_defer_drain *dr);
|
|
|
|
void xfs_drain_wait_disable(void);
|
|
void xfs_drain_wait_enable(void);
|
|
|
|
/*
|
|
* Deferred Work Intent Drains
|
|
* ===========================
|
|
*
|
|
* When a writer thread executes a chain of log intent items, the AG header
|
|
* buffer locks will cycle during a transaction roll to get from one intent
|
|
* item to the next in a chain. Although scrub takes all AG header buffer
|
|
* locks, this isn't sufficient to guard against scrub checking an AG while
|
|
* that writer thread is in the middle of finishing a chain because there's no
|
|
* higher level locking primitive guarding allocation groups.
|
|
*
|
|
* When there's a collision, cross-referencing between data structures (e.g.
|
|
* rmapbt and refcountbt) yields false corruption events; if repair is running,
|
|
* this results in incorrect repairs, which is catastrophic.
|
|
*
|
|
* The solution is to the perag structure the count of active intents and make
|
|
* scrub wait until it has both AG header buffer locks and the intent counter
|
|
* reaches zero. It is therefore critical that deferred work threads hold the
|
|
* AGI or AGF buffers when decrementing the intent counter.
|
|
*
|
|
* Given a list of deferred work items, the deferred work manager will complete
|
|
* a work item and all the sub-items that the parent item creates before moving
|
|
* on to the next work item in the list. This is also true for all levels of
|
|
* sub-items. Writer threads are permitted to queue multiple work items
|
|
* targetting the same AG, so a deferred work item (such as a BUI) that creates
|
|
* sub-items (such as RUIs) must bump the intent counter and maintain it until
|
|
* the sub-items can themselves bump the intent counter.
|
|
*
|
|
* Therefore, the intent count tracks entire lifetimes of deferred work items.
|
|
* All functions that create work items must increment the intent counter as
|
|
* soon as the item is added to the transaction and cannot drop the counter
|
|
* until the item is finished or cancelled.
|
|
*/
|
|
struct xfs_group *xfs_group_intent_get(struct xfs_mount *mp,
|
|
xfs_fsblock_t fsbno, enum xfs_group_type type);
|
|
void xfs_group_intent_put(struct xfs_group *rtg);
|
|
|
|
int xfs_group_intent_drain(struct xfs_group *xg);
|
|
bool xfs_group_intent_busy(struct xfs_group *xg);
|
|
|
|
#else
|
|
struct xfs_defer_drain { /* empty */ };
|
|
|
|
#define xfs_defer_drain_free(dr) ((void)0)
|
|
#define xfs_defer_drain_init(dr) ((void)0)
|
|
|
|
#define xfs_group_intent_get(_mp, _fsbno, _type) \
|
|
xfs_group_get_by_fsb((_mp), (_fsbno), (_type))
|
|
#define xfs_group_intent_put(xg) xfs_group_put(xg)
|
|
|
|
#endif /* CONFIG_XFS_DRAIN_INTENTS */
|
|
|
|
#endif /* XFS_DRAIN_H_ */
|