diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/direct-io.c | 271 |
1 files changed, 132 insertions, 139 deletions
diff --git a/fs/direct-io.c b/fs/direct-io.c index 6d42582..d740ab6 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1043,136 +1043,10 @@ out: return ret; } -static inline ssize_t -direct_io_worker(int rw, struct kiocb *iocb, struct inode *inode, - const struct iovec *iov, loff_t offset, unsigned long nr_segs, - unsigned blkbits, get_block_t get_block, dio_iodone_t end_io, - dio_submit_t submit_io, struct dio *dio, struct dio_submit *sdio) +static inline int drop_refcount(struct dio *dio) { - unsigned long user_addr; + int ret2; unsigned long flags; - int seg; - ssize_t ret = 0; - ssize_t ret2; - size_t bytes; - struct buffer_head map_bh = { 0, }; - - dio->inode = inode; - dio->rw = rw; - sdio->blkbits = blkbits; - sdio->blkfactor = inode->i_blkbits - blkbits; - sdio->block_in_file = offset >> blkbits; - - sdio->get_block = get_block; - dio->end_io = end_io; - sdio->submit_io = submit_io; - sdio->final_block_in_bio = -1; - sdio->next_block_for_io = -1; - - dio->iocb = iocb; - dio->i_size = i_size_read(inode); - - spin_lock_init(&dio->bio_lock); - dio->refcount = 1; - - /* - * In case of non-aligned buffers, we may need 2 more - * pages since we need to zero out first and last block. - */ - if (unlikely(sdio->blkfactor)) - sdio->pages_in_io = 2; - - for (seg = 0; seg < nr_segs; seg++) { - user_addr = (unsigned long)iov[seg].iov_base; - sdio->pages_in_io += - ((user_addr+iov[seg].iov_len +PAGE_SIZE-1)/PAGE_SIZE - - user_addr/PAGE_SIZE); - } - - for (seg = 0; seg < nr_segs; seg++) { - user_addr = (unsigned long)iov[seg].iov_base; - sdio->size += bytes = iov[seg].iov_len; - - /* Index into the first page of the first block */ - sdio->first_block_in_page = (user_addr & ~PAGE_MASK) >> blkbits; - sdio->final_block_in_request = sdio->block_in_file + - (bytes >> blkbits); - /* Page fetching state */ - sdio->head = 0; - sdio->tail = 0; - sdio->curr_page = 0; - - sdio->total_pages = 0; - if (user_addr & (PAGE_SIZE-1)) { - sdio->total_pages++; - bytes -= PAGE_SIZE - (user_addr & (PAGE_SIZE - 1)); - } - sdio->total_pages += (bytes + PAGE_SIZE - 1) / PAGE_SIZE; - sdio->curr_user_address = user_addr; - - ret = do_direct_IO(dio, sdio, &map_bh); - - dio->result += iov[seg].iov_len - - ((sdio->final_block_in_request - sdio->block_in_file) << - blkbits); - - if (ret) { - dio_cleanup(dio, sdio); - break; - } - } /* end iovec loop */ - - if (ret == -ENOTBLK) { - /* - * The remaining part of the request will be - * be handled by buffered I/O when we return - */ - ret = 0; - } - /* - * There may be some unwritten disk at the end of a part-written - * fs-block-sized block. Go zero that now. - */ - dio_zero_block(dio, sdio, 1, &map_bh); - - if (sdio->cur_page) { - ret2 = dio_send_cur_page(dio, sdio, &map_bh); - if (ret == 0) - ret = ret2; - page_cache_release(sdio->cur_page); - sdio->cur_page = NULL; - } - if (sdio->bio) - dio_bio_submit(dio, sdio); - - /* - * 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); - - /* - * All block lookups have been performed. For READ requests - * we can let i_mutex go now that its achieved its purpose - * of protecting us from looking up uninitialized blocks. - */ - if (rw == READ && (dio->flags & DIO_LOCKING)) - mutex_unlock(&dio->inode->i_mutex); - - /* - * The only time we want to leave bios in flight is when a successful - * partial aio read or full aio write have been setup. In that case - * bio completion will call aio_complete. The only time it's safe to - * call aio_complete is when we return -EIOCBQUEUED, so we key on that. - * This had *better* be the only place that raises -EIOCBQUEUED. - */ - BUG_ON(ret == -EIOCBQUEUED); - if (dio->is_async && ret == 0 && dio->result && - ((rw & READ) || (dio->result == sdio->size))) - ret = -EIOCBQUEUED; - - if (ret != -EIOCBQUEUED) - dio_await_completion(dio); /* * Sync will always be dropping the final ref and completing the @@ -1188,14 +1062,7 @@ direct_io_worker(int rw, struct kiocb *iocb, struct inode *inode, spin_lock_irqsave(&dio->bio_lock, flags); ret2 = --dio->refcount; spin_unlock_irqrestore(&dio->bio_lock, flags); - - if (ret2 == 0) { - ret = dio_complete(dio, offset, ret, false); - kmem_cache_free(dio_cache, dio); - } else - BUG_ON(ret != -EIOCBQUEUED); - - return ret; + return ret2; } /* @@ -1239,6 +1106,9 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, loff_t end = offset; struct dio *dio; struct dio_submit sdio = { 0, }; + unsigned long user_addr; + size_t bytes; + struct buffer_head map_bh = { 0, }; if (rw & WRITE) rw = WRITE_ODIRECT; @@ -1316,9 +1186,132 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, dio->is_async = !is_sync_kiocb(iocb) && !((rw & WRITE) && (end > i_size_read(inode))); - retval = direct_io_worker(rw, iocb, inode, iov, offset, - nr_segs, blkbits, get_block, end_io, - submit_io, dio, &sdio); + retval = 0; + + dio->inode = inode; + dio->rw = rw; + sdio.blkbits = blkbits; + sdio.blkfactor = inode->i_blkbits - blkbits; + sdio.block_in_file = offset >> blkbits; + + sdio.get_block = get_block; + dio->end_io = end_io; + sdio.submit_io = submit_io; + sdio.final_block_in_bio = -1; + sdio.next_block_for_io = -1; + + dio->iocb = iocb; + dio->i_size = i_size_read(inode); + + spin_lock_init(&dio->bio_lock); + dio->refcount = 1; + + /* + * In case of non-aligned buffers, we may need 2 more + * pages since we need to zero out first and last block. + */ + if (unlikely(sdio.blkfactor)) + sdio.pages_in_io = 2; + + for (seg = 0; seg < nr_segs; seg++) { + user_addr = (unsigned long)iov[seg].iov_base; + sdio.pages_in_io += + ((user_addr + iov[seg].iov_len + PAGE_SIZE-1) / + PAGE_SIZE - user_addr / PAGE_SIZE); + } + + for (seg = 0; seg < nr_segs; seg++) { + user_addr = (unsigned long)iov[seg].iov_base; + sdio.size += bytes = iov[seg].iov_len; + + /* Index into the first page of the first block */ + sdio.first_block_in_page = (user_addr & ~PAGE_MASK) >> blkbits; + sdio.final_block_in_request = sdio.block_in_file + + (bytes >> blkbits); + /* Page fetching state */ + sdio.head = 0; + sdio.tail = 0; + sdio.curr_page = 0; + + sdio.total_pages = 0; + if (user_addr & (PAGE_SIZE-1)) { + sdio.total_pages++; + bytes -= PAGE_SIZE - (user_addr & (PAGE_SIZE - 1)); + } + sdio.total_pages += (bytes + PAGE_SIZE - 1) / PAGE_SIZE; + sdio.curr_user_address = user_addr; + + retval = do_direct_IO(dio, &sdio, &map_bh); + + dio->result += iov[seg].iov_len - + ((sdio.final_block_in_request - sdio.block_in_file) << + blkbits); + + if (retval) { + dio_cleanup(dio, &sdio); + break; + } + } /* end iovec loop */ + + if (retval == -ENOTBLK) { + /* + * The remaining part of the request will be + * be handled by buffered I/O when we return + */ + retval = 0; + } + /* + * There may be some unwritten disk at the end of a part-written + * fs-block-sized block. Go zero that now. + */ + dio_zero_block(dio, &sdio, 1, &map_bh); + + if (sdio.cur_page) { + ssize_t ret2; + + ret2 = dio_send_cur_page(dio, &sdio, &map_bh); + if (retval == 0) + retval = ret2; + page_cache_release(sdio.cur_page); + sdio.cur_page = NULL; + } + if (sdio.bio) + dio_bio_submit(dio, &sdio); + + /* + * 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); + + /* + * All block lookups have been performed. For READ requests + * we can let i_mutex go now that its achieved its purpose + * of protecting us from looking up uninitialized blocks. + */ + if (rw == READ && (dio->flags & DIO_LOCKING)) + mutex_unlock(&dio->inode->i_mutex); + + /* + * The only time we want to leave bios in flight is when a successful + * partial aio read or full aio write have been setup. In that case + * bio completion will call aio_complete. The only time it's safe to + * call aio_complete is when we return -EIOCBQUEUED, so we key on that. + * This had *better* be the only place that raises -EIOCBQUEUED. + */ + BUG_ON(retval == -EIOCBQUEUED); + if (dio->is_async && retval == 0 && dio->result && + ((rw & READ) || (dio->result == sdio.size))) + retval = -EIOCBQUEUED; + + if (retval != -EIOCBQUEUED) + dio_await_completion(dio); + + if (drop_refcount(dio) == 0) { + retval = dio_complete(dio, offset, retval, false); + kmem_cache_free(dio_cache, dio); + } else + BUG_ON(retval != -EIOCBQUEUED); out: return retval; |