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XArray: Regularise xa_reserve

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The xa_reserve() function was a little unusual in that it attempted to
be callable for all kinds of locking scenarios.  Make it look like the
other APIs with __xa_reserve, xa_reserve_bh and xa_reserve_irq variants.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
This commit is contained in:
Matthew Wilcox
2018-10-30 09:45:55 -04:00
parent fe2b51145c
commit 4c0608f4a0
4 changed files with 105 additions and 12 deletions
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80
include/linux/xarray.h
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@@ -291,7 +291,6 @@ void *xa_load(struct xarray *, unsigned long index);
void *xa_store(struct xarray *, unsigned long index, void *entry, gfp_t);
void *xa_cmpxchg(struct xarray *, unsigned long index,
void *old, void *entry, gfp_t);
int xa_reserve(struct xarray *, unsigned long index, gfp_t);
void *xa_store_range(struct xarray *, unsigned long first, unsigned long last,
void *entry, gfp_t);
bool xa_get_mark(struct xarray *, unsigned long index, xa_mark_t);
@@ -455,6 +454,7 @@ void *__xa_store(struct xarray *, unsigned long index, void *entry, gfp_t);
void *__xa_cmpxchg(struct xarray *, unsigned long index, void *old,
void *entry, gfp_t);
int __xa_alloc(struct xarray *, u32 *id, u32 max, void *entry, gfp_t);
int __xa_reserve(struct xarray *, unsigned long index, gfp_t);
void __xa_set_mark(struct xarray *, unsigned long index, xa_mark_t);
void __xa_clear_mark(struct xarray *, unsigned long index, xa_mark_t);
@@ -621,6 +621,84 @@ static inline int xa_alloc_irq(struct xarray *xa, u32 *id, u32 max, void *entry,
return err;
}
/**
* xa_reserve() - Reserve this index in the XArray.
* @xa: XArray.
* @index: Index into array.
* @gfp: Memory allocation flags.
*
* Ensures there is somewhere to store an entry at @index in the array.
* If there is already something stored at @index, this function does
* nothing. If there was nothing there, the entry is marked as reserved.
* Loading from a reserved entry returns a %NULL pointer.
*
* If you do not use the entry that you have reserved, call xa_release()
* or xa_erase() to free any unnecessary memory.
*
* Context: Any context. Takes and releases the xa_lock.
* May sleep if the @gfp flags permit.
* Return: 0 if the reservation succeeded or -ENOMEM if it failed.
*/
static inline
int xa_reserve(struct xarray *xa, unsigned long index, gfp_t gfp)
{
int ret;
xa_lock(xa);
ret = __xa_reserve(xa, index, gfp);
xa_unlock(xa);
return ret;
}
/**
* xa_reserve_bh() - Reserve this index in the XArray.
* @xa: XArray.
* @index: Index into array.
* @gfp: Memory allocation flags.
*
* A softirq-disabling version of xa_reserve().
*
* Context: Any context. Takes and releases the xa_lock while
* disabling softirqs.
* Return: 0 if the reservation succeeded or -ENOMEM if it failed.
*/
static inline
int xa_reserve_bh(struct xarray *xa, unsigned long index, gfp_t gfp)
{
int ret;
xa_lock_bh(xa);
ret = __xa_reserve(xa, index, gfp);
xa_unlock_bh(xa);
return ret;
}
/**
* xa_reserve_irq() - Reserve this index in the XArray.
* @xa: XArray.
* @index: Index into array.
* @gfp: Memory allocation flags.
*
* An interrupt-disabling version of xa_reserve().
*
* Context: Process context. Takes and releases the xa_lock while
* disabling interrupts.
* Return: 0 if the reservation succeeded or -ENOMEM if it failed.
*/
static inline
int xa_reserve_irq(struct xarray *xa, unsigned long index, gfp_t gfp)
{
int ret;
xa_lock_irq(xa);
ret = __xa_reserve(xa, index, gfp);
xa_unlock_irq(xa);
return ret;
}
/* Everything below here is the Advanced API. Proceed with caution. */
/*