io_uring: defer alloc_hint update to io_file_bitmap_set()

io_file_bitmap_get() returns a free bitmap slot, but if it isn't used later, such as io_queue_rsrc_removal() returns error, in this case, we should not update alloc_hint at all, which still should be considered as a valid candidate for next io_file_bitmap_get() calls. To fix this issue, only update alloc_hint in io_file_bitmap_set(). Signed-off-by: Xiaoguang Wang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]>
amarioguy · May 31, 2022 · 4278a0d · 4278a0d
1 parent 8c71fe7
commit 4278a0d
Showing 1 changed file with 3 additions and 8 deletions.
diff --git a/fs/io_uring.c b/fs/io_uring.c
@@ -5419,15 +5419,11 @@ static int io_file_bitmap_get(struct io_ring_ctx *ctx)
 	unsigned long nr = ctx->nr_user_files;
 	int ret;
 
-	if (table->alloc_hint >= nr)
-		table->alloc_hint = 0;
-
 	do {
 		ret = find_next_zero_bit(table->bitmap, nr, table->alloc_hint);
-		if (ret != nr) {
-			table->alloc_hint = ret + 1;
+		if (ret != nr)
 			return ret;
-		}
+
 		if (!table->alloc_hint)
 			break;
 
@@ -9682,8 +9678,7 @@ static inline void io_file_bitmap_set(struct io_file_table *table, int bit)
 {
 	WARN_ON_ONCE(test_bit(bit, table->bitmap));
 	__set_bit(bit, table->bitmap);
-	if (bit == table->alloc_hint)
-		table->alloc_hint++;
+	table->alloc_hint = bit + 1;
 }
 
 static inline void io_file_bitmap_clear(struct io_file_table *table, int bit)