Each bio is always submitted to block device one by one, so it isn't necessary to increase the bio refcount by one each time with holding dio->bio_lock.
Signed-off-by: Ming Lei <[email protected]> --- fs/direct-io.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/fs/direct-io.c b/fs/direct-io.c index 6fb00e3..57b8e73 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -79,6 +79,8 @@ struct dio_submit { get_block_t *get_block; /* block mapping function */ dio_submit_t *submit_io; /* IO submition function */ + long submitted_bio; + loff_t logical_offset_in_bio; /* current first logical block in bio */ sector_t final_block_in_bio; /* current final block in bio + 1 */ sector_t next_block_for_io; /* next block to be put under IO, @@ -121,7 +123,7 @@ struct dio { int is_async; /* is IO async ? */ bool defer_completion; /* defer AIO completion to workqueue? */ int io_error; /* IO error in completion path */ - unsigned long refcount; /* direct_io_worker() and bios */ + long refcount; /* direct_io_worker() and bios */ struct bio *bio_list; /* singly linked via bi_private */ struct task_struct *waiter; /* waiting task (NULL if none) */ @@ -383,14 +385,9 @@ dio_bio_alloc(struct dio *dio, struct dio_submit *sdio, static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio) { struct bio *bio = sdio->bio; - unsigned long flags; bio->bi_private = dio; - spin_lock_irqsave(&dio->bio_lock, flags); - dio->refcount++; - spin_unlock_irqrestore(&dio->bio_lock, flags); - if (dio->is_async && dio->rw == READ) bio_set_pages_dirty(bio); @@ -403,15 +400,26 @@ static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio) sdio->bio = NULL; sdio->boundary = 0; sdio->logical_offset_in_bio = 0; + sdio->submitted_bio++; } /* * Release any resources in case of a failure */ -static inline void dio_cleanup(struct dio *dio, struct dio_submit *sdio) +static inline void dio_cleanup(struct dio *dio, struct dio_submit *sdio, + bool commit_refcount) { + unsigned long flags; + while (sdio->head < sdio->tail) page_cache_release(dio->pages[sdio->head++]); + + if (!commit_refcount) + return; + + spin_lock_irqsave(&dio->bio_lock, flags); + dio->refcount += (sdio->submitted_bio + 1); + spin_unlock_irqrestore(&dio->bio_lock, flags); } /* @@ -1215,7 +1223,6 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, dio->i_size = i_size_read(inode); spin_lock_init(&dio->bio_lock); - dio->refcount = 1; sdio.iter = iter; sdio.final_block_in_request = @@ -1234,7 +1241,7 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, retval = do_direct_IO(dio, &sdio, &map_bh); if (retval) - dio_cleanup(dio, &sdio); + dio_cleanup(dio, &sdio, false); if (retval == -ENOTBLK) { /* @@ -1267,7 +1274,7 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, * It is possible that, we return short IO due to end of file. * In that case, we need to release all the pages we got hold on. */ - dio_cleanup(dio, &sdio); + dio_cleanup(dio, &sdio, true); /* * All block lookups have been performed. For READ requests -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
