io_uring: Add register support for non-4k PAGE_SIZE

Now allocated rsrc table uses PAGE_SIZE as the size of 2nd-level, and
accessing this table relies on each level index from fixed TABLE_SHIFT
(12 - 3) in 4k page case. In order to correctly work in non-4k page,
define TABLE_SHIFT as non-fixed (PAGE_SHIFT - shift of data) for
2nd-level table entry number.
Signed-off-by: wangyangbo <wangyangbo@uniontech.com>
Link: https://lore.kernel.org/r/20210819055657.27327-1-wangyangbo@uniontech.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -92,12 +92,12 @@
 #define IORING_MAX_CQ_ENTRIES	(2 * IORING_MAX_ENTRIES)
 #define IORING_SQPOLL_CAP_ENTRIES_VALUE 8
 
-/* 512 entries per page on 64-bit archs, 64 pages max */
+/* only define max */
 #define IORING_MAX_FIXED_FILES	(1U << 15)
 #define IORING_MAX_RESTRICTIONS	(IORING_RESTRICTION_LAST + \
 				 IORING_REGISTER_LAST + IORING_OP_LAST)
 
-#define IO_RSRC_TAG_TABLE_SHIFT	9
+#define IO_RSRC_TAG_TABLE_SHIFT	(PAGE_SHIFT - 3)
 #define IO_RSRC_TAG_TABLE_MAX	(1U << IO_RSRC_TAG_TABLE_SHIFT)
 #define IO_RSRC_TAG_TABLE_MASK	(IO_RSRC_TAG_TABLE_MAX - 1)