mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 02:30:34 +02:00
a5b696ee6e
We can't be holding btree_trans_lock while copying to user space, which might incur a page fault. To fix this, convert it to a seqmutex so we can unlock/relock. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
48 lines
869 B
C
48 lines
869 B
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _BCACHEFS_SEQMUTEX_H
|
|
#define _BCACHEFS_SEQMUTEX_H
|
|
|
|
#include <linux/mutex.h>
|
|
|
|
struct seqmutex {
|
|
struct mutex lock;
|
|
u32 seq;
|
|
};
|
|
|
|
#define seqmutex_init(_lock) mutex_init(&(_lock)->lock)
|
|
|
|
static inline bool seqmutex_trylock(struct seqmutex *lock)
|
|
{
|
|
return mutex_trylock(&lock->lock);
|
|
}
|
|
|
|
static inline void seqmutex_lock(struct seqmutex *lock)
|
|
{
|
|
mutex_lock(&lock->lock);
|
|
}
|
|
|
|
static inline void seqmutex_unlock(struct seqmutex *lock)
|
|
{
|
|
lock->seq++;
|
|
mutex_unlock(&lock->lock);
|
|
}
|
|
|
|
static inline u32 seqmutex_seq(struct seqmutex *lock)
|
|
{
|
|
return lock->seq;
|
|
}
|
|
|
|
static inline bool seqmutex_relock(struct seqmutex *lock, u32 seq)
|
|
{
|
|
if (lock->seq != seq || !mutex_trylock(&lock->lock))
|
|
return false;
|
|
|
|
if (lock->seq != seq) {
|
|
mutex_unlock(&lock->lock);
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
#endif /* _BCACHEFS_SEQMUTEX_H */
|