Save one level of indention by returning error early.
Introduce some local variables to make the code easier to read a bit,
and do preparation for next patch.
Signed-off-by: Eryu Guan <guaneryu@xxxxxxxxx>
---
v2: split the cleanup code into a seperate patch to make the review easier
fs/direct-io.c | 69 ++++++++++++++++++++++++++++++----------------------------
1 file changed, 36 insertions(+), 33 deletions(-)
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 4720377..9d5aff9 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -607,52 +607,55 @@ static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,
int ret;
sector_t fs_startblk; /* Into file, in filesystem-sized blocks */
sector_t fs_endblk; /* Into file, in filesystem-sized blocks */
+ sector_t block_in_file = sdio->block_in_file;
unsigned long fs_count; /* Number of filesystem-sized blocks */
int create;
- unsigned int i_blkbits = sdio->blkbits + sdio->blkfactor;
+ unsigned int blkbits = sdio->blkbits;
+ unsigned int blkfactor = sdio->blkfactor;
+ unsigned int i_blkbits = blkbits + blkfactor;
+ struct inode *inode = dio->inode;
/*
* If there was a memory error and we've overwritten all the
* mapped blocks then we can now return that memory error
*/
ret = dio->page_errors;
- if (ret == 0) {
- BUG_ON(sdio->block_in_file >= sdio->final_block_in_request);
- fs_startblk = sdio->block_in_file >> sdio->blkfactor;
- fs_endblk = (sdio->final_block_in_request - 1) >>
- sdio->blkfactor;
- fs_count = fs_endblk - fs_startblk + 1;
+ if (ret)
+ return ret;
- map_bh->b_state = 0;
- map_bh->b_size = fs_count << i_blkbits;
+ BUG_ON(block_in_file >= sdio->final_block_in_request);
+ fs_startblk = block_in_file >> blkfactor;
+ fs_endblk = (sdio->final_block_in_request - 1) >> blkfactor;
+ fs_count = fs_endblk - fs_startblk + 1;
- /*
- * For writes inside i_size on a DIO_SKIP_HOLES filesystem we
- * forbid block creations: only overwrites are permitted.
- * We will return early to the caller once we see an
- * unmapped buffer head returned, and the caller will fall
- * back to buffered I/O.
- *
- * Otherwise the decision is left to the get_blocks method,
- * which may decide to handle it or also return an unmapped
- * buffer head.
- */
- create = dio->rw & WRITE;
- if (dio->flags & DIO_SKIP_HOLES) {
- if (sdio->block_in_file < (i_size_read(dio->inode) >>
- sdio->blkbits))
- create = 0;
- }
+ map_bh->b_state = 0;
+ map_bh->b_size = fs_count << i_blkbits;
+
+ /*
+ * For writes inside i_size on a DIO_SKIP_HOLES filesystem we
+ * forbid block creations: only overwrites are permitted.
+ * We will return early to the caller once we see an
+ * unmapped buffer head returned, and the caller will fall
+ * back to buffered I/O.
+ *
+ * Otherwise the decision is left to the get_blocks method,
+ * which may decide to handle it or also return an unmapped
+ * buffer head.
+ */
+ create = dio->rw & WRITE;
+ if (dio->flags & DIO_SKIP_HOLES) {
+ if (block_in_file < (i_size_read(inode) >> blkbits))
+ create = 0;
+ }
- ret = (*sdio->get_block)(dio->inode, fs_startblk,
- map_bh, create);
+ ret = (*sdio->get_block)(inode, fs_startblk, map_bh, create);
- /* Store for completion */
- dio->private = map_bh->b_private;
+ /* Store for completion */
+ dio->private = map_bh->b_private;
+
+ if (ret == 0 && buffer_defer_completion(map_bh))
+ ret = dio_set_defer_completion(dio);
- if (ret == 0 && buffer_defer_completion(map_bh))
- ret = dio_set_defer_completion(dio);
- }
return ret;
}
--
2.5.5
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