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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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18
lib/xarray.c
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@@ -1488,7 +1488,7 @@ void *__xa_cmpxchg(struct xarray *xa, unsigned long index,
EXPORT_SYMBOL(__xa_cmpxchg);
/**
* xa_reserve() - Reserve this index in the XArray.
* __xa_reserve() - Reserve this index in the XArray.
* @xa: XArray.
* @index: Index into array.
* @gfp: Memory allocation flags.
@@ -1496,33 +1496,29 @@ EXPORT_SYMBOL(__xa_cmpxchg);
* 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.
* Loads from @index will continue to see a %NULL pointer until a
* subsequent store to @index.
* 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: Process context. Takes and releases the xa_lock, IRQ or BH safe
* if specified in XArray flags. May sleep if the @gfp flags permit.
* Context: Any context. Expects the xa_lock to be held on entry. May
* release the lock, sleep and reacquire the lock if the @gfp flags permit.
* Return: 0 if the reservation succeeded or -ENOMEM if it failed.
*/
int xa_reserve(struct xarray *xa, unsigned long index, gfp_t gfp)
int __xa_reserve(struct xarray *xa, unsigned long index, gfp_t gfp)
{
XA_STATE(xas, xa, index);
unsigned int lock_type = xa_lock_type(xa);
void *curr;
do {
xas_lock_type(&xas, lock_type);
curr = xas_load(&xas);
if (!curr)
xas_store(&xas, XA_ZERO_ENTRY);
xas_unlock_type(&xas, lock_type);
} while (xas_nomem(&xas, gfp));
} while (__xas_nomem(&xas, gfp));
return xas_error(&xas);
}
EXPORT_SYMBOL(xa_reserve);
EXPORT_SYMBOL(__xa_reserve);
#ifdef CONFIG_XARRAY_MULTI
static void xas_set_range(struct xa_state *xas, unsigned long first,