f2fs: reduce stack memory cost by using bitfield in struct f2fs_io_info

This patch tries to use bitfield in struct f2fs_io_info to improve
memory usage.

struct f2fs_io_info {
...
	unsigned int need_lock:8;	/* indicate we need to lock cp_rwsem */
	unsigned int version:8;		/* version of the node */
	unsigned int submitted:1;	/* indicate IO submission */
	unsigned int in_list:1;		/* indicate fio is in io_list */
	unsigned int is_por:1;		/* indicate IO is from recovery or not */
	unsigned int retry:1;		/* need to reallocate block address */
	unsigned int encrypted:1;	/* indicate file is encrypted */
	unsigned int post_read:1;	/* require post read */
...
};

After this patch, size of struct f2fs_io_info reduces from 136 to 120.

[Nathan: fix a compile warning (single-bit-bitfield-constant-conversion)]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index fbd1d25fecc2..19a1fee88a36 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1586,7 +1586,7 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
 		.op_flags = wbc_to_write_flags(wbc),
 		.page = page,
 		.encrypted_page = NULL,
-		.submitted = false,
+		.submitted = 0,
 		.io_type = io_type,
 		.io_wbc = wbc,
 	};