forked from Minki/linux
direct-io: merge direct_io_walker into __blockdev_direct_IO
This doesn't change anything for the compiler, but hch thought it would make the code clearer. I moved the reference counting into its own little inline. Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Andi Kleen
root
parent
ba253fbf6d
commit
847cc6371b
271
fs/direct-io.c
271
fs/direct-io.c
@ -1043,136 +1043,10 @@ out:
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return ret;
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}
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static inline ssize_t
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direct_io_worker(int rw, struct kiocb *iocb, struct inode *inode,
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const struct iovec *iov, loff_t offset, unsigned long nr_segs,
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unsigned blkbits, get_block_t get_block, dio_iodone_t end_io,
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dio_submit_t submit_io, struct dio *dio, struct dio_submit *sdio)
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static inline int drop_refcount(struct dio *dio)
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{
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unsigned long user_addr;
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int ret2;
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unsigned long flags;
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int seg;
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ssize_t ret = 0;
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ssize_t ret2;
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size_t bytes;
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struct buffer_head map_bh = { 0, };
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dio->inode = inode;
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dio->rw = rw;
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sdio->blkbits = blkbits;
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sdio->blkfactor = inode->i_blkbits - blkbits;
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sdio->block_in_file = offset >> blkbits;
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sdio->get_block = get_block;
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dio->end_io = end_io;
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sdio->submit_io = submit_io;
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sdio->final_block_in_bio = -1;
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sdio->next_block_for_io = -1;
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dio->iocb = iocb;
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dio->i_size = i_size_read(inode);
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spin_lock_init(&dio->bio_lock);
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dio->refcount = 1;
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/*
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* In case of non-aligned buffers, we may need 2 more
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* pages since we need to zero out first and last block.
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*/
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if (unlikely(sdio->blkfactor))
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sdio->pages_in_io = 2;
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for (seg = 0; seg < nr_segs; seg++) {
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user_addr = (unsigned long)iov[seg].iov_base;
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sdio->pages_in_io +=
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((user_addr+iov[seg].iov_len +PAGE_SIZE-1)/PAGE_SIZE
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- user_addr/PAGE_SIZE);
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}
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for (seg = 0; seg < nr_segs; seg++) {
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user_addr = (unsigned long)iov[seg].iov_base;
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sdio->size += bytes = iov[seg].iov_len;
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/* Index into the first page of the first block */
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sdio->first_block_in_page = (user_addr & ~PAGE_MASK) >> blkbits;
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sdio->final_block_in_request = sdio->block_in_file +
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(bytes >> blkbits);
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/* Page fetching state */
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sdio->head = 0;
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sdio->tail = 0;
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sdio->curr_page = 0;
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sdio->total_pages = 0;
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if (user_addr & (PAGE_SIZE-1)) {
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sdio->total_pages++;
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bytes -= PAGE_SIZE - (user_addr & (PAGE_SIZE - 1));
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}
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sdio->total_pages += (bytes + PAGE_SIZE - 1) / PAGE_SIZE;
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sdio->curr_user_address = user_addr;
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ret = do_direct_IO(dio, sdio, &map_bh);
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dio->result += iov[seg].iov_len -
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((sdio->final_block_in_request - sdio->block_in_file) <<
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blkbits);
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if (ret) {
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dio_cleanup(dio, sdio);
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break;
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}
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} /* end iovec loop */
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if (ret == -ENOTBLK) {
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/*
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* The remaining part of the request will be
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* be handled by buffered I/O when we return
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*/
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ret = 0;
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}
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/*
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* There may be some unwritten disk at the end of a part-written
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* fs-block-sized block. Go zero that now.
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*/
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dio_zero_block(dio, sdio, 1, &map_bh);
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if (sdio->cur_page) {
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ret2 = dio_send_cur_page(dio, sdio, &map_bh);
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if (ret == 0)
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ret = ret2;
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page_cache_release(sdio->cur_page);
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sdio->cur_page = NULL;
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}
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if (sdio->bio)
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dio_bio_submit(dio, sdio);
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/*
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* It is possible that, we return short IO due to end of file.
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* In that case, we need to release all the pages we got hold on.
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*/
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dio_cleanup(dio, sdio);
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/*
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* All block lookups have been performed. For READ requests
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* we can let i_mutex go now that its achieved its purpose
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* of protecting us from looking up uninitialized blocks.
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*/
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if (rw == READ && (dio->flags & DIO_LOCKING))
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mutex_unlock(&dio->inode->i_mutex);
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/*
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* The only time we want to leave bios in flight is when a successful
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* partial aio read or full aio write have been setup. In that case
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* bio completion will call aio_complete. The only time it's safe to
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* call aio_complete is when we return -EIOCBQUEUED, so we key on that.
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* This had *better* be the only place that raises -EIOCBQUEUED.
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*/
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BUG_ON(ret == -EIOCBQUEUED);
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if (dio->is_async && ret == 0 && dio->result &&
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((rw & READ) || (dio->result == sdio->size)))
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ret = -EIOCBQUEUED;
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if (ret != -EIOCBQUEUED)
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dio_await_completion(dio);
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/*
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* Sync will always be dropping the final ref and completing the
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@ -1188,14 +1062,7 @@ direct_io_worker(int rw, struct kiocb *iocb, struct inode *inode,
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spin_lock_irqsave(&dio->bio_lock, flags);
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ret2 = --dio->refcount;
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spin_unlock_irqrestore(&dio->bio_lock, flags);
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if (ret2 == 0) {
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ret = dio_complete(dio, offset, ret, false);
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kmem_cache_free(dio_cache, dio);
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} else
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BUG_ON(ret != -EIOCBQUEUED);
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return ret;
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return ret2;
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}
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/*
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@ -1239,6 +1106,9 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
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loff_t end = offset;
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struct dio *dio;
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struct dio_submit sdio = { 0, };
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unsigned long user_addr;
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size_t bytes;
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struct buffer_head map_bh = { 0, };
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if (rw & WRITE)
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rw = WRITE_ODIRECT;
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@ -1316,9 +1186,132 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
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dio->is_async = !is_sync_kiocb(iocb) && !((rw & WRITE) &&
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(end > i_size_read(inode)));
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retval = direct_io_worker(rw, iocb, inode, iov, offset,
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nr_segs, blkbits, get_block, end_io,
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submit_io, dio, &sdio);
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retval = 0;
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dio->inode = inode;
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dio->rw = rw;
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sdio.blkbits = blkbits;
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sdio.blkfactor = inode->i_blkbits - blkbits;
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sdio.block_in_file = offset >> blkbits;
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sdio.get_block = get_block;
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dio->end_io = end_io;
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sdio.submit_io = submit_io;
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sdio.final_block_in_bio = -1;
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sdio.next_block_for_io = -1;
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dio->iocb = iocb;
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dio->i_size = i_size_read(inode);
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spin_lock_init(&dio->bio_lock);
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dio->refcount = 1;
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/*
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* In case of non-aligned buffers, we may need 2 more
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* pages since we need to zero out first and last block.
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*/
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if (unlikely(sdio.blkfactor))
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sdio.pages_in_io = 2;
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for (seg = 0; seg < nr_segs; seg++) {
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user_addr = (unsigned long)iov[seg].iov_base;
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sdio.pages_in_io +=
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((user_addr + iov[seg].iov_len + PAGE_SIZE-1) /
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PAGE_SIZE - user_addr / PAGE_SIZE);
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}
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for (seg = 0; seg < nr_segs; seg++) {
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user_addr = (unsigned long)iov[seg].iov_base;
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sdio.size += bytes = iov[seg].iov_len;
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/* Index into the first page of the first block */
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sdio.first_block_in_page = (user_addr & ~PAGE_MASK) >> blkbits;
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sdio.final_block_in_request = sdio.block_in_file +
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(bytes >> blkbits);
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/* Page fetching state */
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sdio.head = 0;
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sdio.tail = 0;
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sdio.curr_page = 0;
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sdio.total_pages = 0;
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if (user_addr & (PAGE_SIZE-1)) {
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sdio.total_pages++;
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bytes -= PAGE_SIZE - (user_addr & (PAGE_SIZE - 1));
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}
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sdio.total_pages += (bytes + PAGE_SIZE - 1) / PAGE_SIZE;
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sdio.curr_user_address = user_addr;
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retval = do_direct_IO(dio, &sdio, &map_bh);
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dio->result += iov[seg].iov_len -
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((sdio.final_block_in_request - sdio.block_in_file) <<
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blkbits);
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if (retval) {
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dio_cleanup(dio, &sdio);
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break;
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}
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} /* end iovec loop */
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if (retval == -ENOTBLK) {
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/*
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* The remaining part of the request will be
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* be handled by buffered I/O when we return
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*/
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retval = 0;
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}
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/*
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* There may be some unwritten disk at the end of a part-written
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* fs-block-sized block. Go zero that now.
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*/
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dio_zero_block(dio, &sdio, 1, &map_bh);
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if (sdio.cur_page) {
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ssize_t ret2;
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ret2 = dio_send_cur_page(dio, &sdio, &map_bh);
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if (retval == 0)
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retval = ret2;
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page_cache_release(sdio.cur_page);
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sdio.cur_page = NULL;
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}
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if (sdio.bio)
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dio_bio_submit(dio, &sdio);
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/*
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* It is possible that, we return short IO due to end of file.
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* In that case, we need to release all the pages we got hold on.
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*/
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dio_cleanup(dio, &sdio);
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/*
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* All block lookups have been performed. For READ requests
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* we can let i_mutex go now that its achieved its purpose
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* of protecting us from looking up uninitialized blocks.
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*/
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if (rw == READ && (dio->flags & DIO_LOCKING))
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mutex_unlock(&dio->inode->i_mutex);
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/*
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* The only time we want to leave bios in flight is when a successful
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* partial aio read or full aio write have been setup. In that case
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* bio completion will call aio_complete. The only time it's safe to
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* call aio_complete is when we return -EIOCBQUEUED, so we key on that.
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* This had *better* be the only place that raises -EIOCBQUEUED.
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*/
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BUG_ON(retval == -EIOCBQUEUED);
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if (dio->is_async && retval == 0 && dio->result &&
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((rw & READ) || (dio->result == sdio.size)))
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retval = -EIOCBQUEUED;
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if (retval != -EIOCBQUEUED)
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dio_await_completion(dio);
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if (drop_refcount(dio) == 0) {
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retval = dio_complete(dio, offset, retval, false);
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kmem_cache_free(dio_cache, dio);
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} else
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BUG_ON(retval != -EIOCBQUEUED);
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out:
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return retval;
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