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maple_tree: simplify mas_is_span_wr() 

Make the code for detecting spanning writes more concise.

Link: https://lkml.kernel.org/r/20230524031247.65949-5-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Peng Zhang 2023-05-24 11:12:41 +08:00 committed by Andrew Morton
parent 14c4b5ab6a
commit bc147f0f70
1 changed files with 14 additions and 26 deletions
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40
lib/maple_tree.c
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@ -3728,43 +3728,31 @@ static inline void mas_store_root(struct ma_state *mas, void *entry)
*/
static bool mas_is_span_wr(struct ma_wr_state *wr_mas)
{
unsigned long max;
unsigned long max = wr_mas->r_max;
unsigned long last = wr_mas->mas->last;
unsigned long piv = wr_mas->r_max;
enum maple_type type = wr_mas->type;
void *entry = wr_mas->entry;
/* Contained in this pivot */
if (piv > last)
/* Contained in this pivot, fast path */
if (last < max)
return false;
max = wr_mas->mas->max;
if (unlikely(ma_is_leaf(type))) {
/* Fits in the node, but may span slots. */
if (ma_is_leaf(type)) {
max = wr_mas->mas->max;
if (last < max)
return false;
/* Writes to the end of the node but not null. */
if ((last == max) && entry)
return false;
/*
* Writing ULONG_MAX is not a spanning write regardless of the
* value being written as long as the range fits in the node.
*/
if ((last == ULONG_MAX) && (last == max))
return false;
} else if (piv == last) {
if (entry)
return false;
/* Detect spanning store wr walk */
if (last == ULONG_MAX)
return false;
}
trace_ma_write(__func__, wr_mas->mas, piv, entry);
if (last == max) {
/*
* The last entry of leaf node cannot be NULL unless it is the
* rightmost node (writing ULONG_MAX), otherwise it spans slots.
*/
if (entry || last == ULONG_MAX)
return false;
}
trace_ma_write(__func__, wr_mas->mas, wr_mas->r_max, entry);
return true;
}