XArray: Add xa_cmpxchg_irq and xa_cmpxchg_bh

These convenience wrappers match the other _irq and _bh wrappers we
already have.  It turns out I'd already open-coded xa_cmpxchg_irq()
in the shmem code, so convert that.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
This commit is contained in:
Matthew Wilcox
2018-11-26 16:08:43 -05:00
parent eff3860bbf
commit 55f3f7eab7
3 changed files with 59 additions and 4 deletions

View File

@@ -553,6 +553,60 @@ static inline void *xa_cmpxchg(struct xarray *xa, unsigned long index,
return curr;
}
/**
* xa_cmpxchg_bh() - Conditionally replace an entry in the XArray.
* @xa: XArray.
* @index: Index into array.
* @old: Old value to test against.
* @entry: New value to place in array.
* @gfp: Memory allocation flags.
*
* This function is like calling xa_cmpxchg() except it disables softirqs
* while holding the array lock.
*
* Context: Any context. Takes and releases the xa_lock while
* disabling softirqs. May sleep if the @gfp flags permit.
* Return: The old value at this index or xa_err() if an error happened.
*/
static inline void *xa_cmpxchg_bh(struct xarray *xa, unsigned long index,
void *old, void *entry, gfp_t gfp)
{
void *curr;
xa_lock_bh(xa);
curr = __xa_cmpxchg(xa, index, old, entry, gfp);
xa_unlock_bh(xa);
return curr;
}
/**
* xa_cmpxchg_irq() - Conditionally replace an entry in the XArray.
* @xa: XArray.
* @index: Index into array.
* @old: Old value to test against.
* @entry: New value to place in array.
* @gfp: Memory allocation flags.
*
* This function is like calling xa_cmpxchg() except it disables interrupts
* while holding the array lock.
*
* Context: Process context. Takes and releases the xa_lock while
* disabling interrupts. May sleep if the @gfp flags permit.
* Return: The old value at this index or xa_err() if an error happened.
*/
static inline void *xa_cmpxchg_irq(struct xarray *xa, unsigned long index,
void *old, void *entry, gfp_t gfp)
{
void *curr;
xa_lock_irq(xa);
curr = __xa_cmpxchg(xa, index, old, entry, gfp);
xa_unlock_irq(xa);
return curr;
}
/**
* xa_insert() - Store this entry in the XArray unless another entry is
* already present.