diff options
Diffstat (limited to 'fs/iomap/direct-io.c')
-rw-r--r-- | fs/iomap/direct-io.c | 88 |
1 files changed, 59 insertions, 29 deletions
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 4ecd255e0511..b4dc51063d36 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -31,6 +31,7 @@ struct iomap_dio { atomic_t ref; unsigned flags; int error; + size_t done_before; bool wait_for_completion; union { @@ -38,8 +39,7 @@ struct iomap_dio { struct { struct iov_iter *iter; struct task_struct *waiter; - struct request_queue *last_queue; - blk_qc_t cookie; + struct bio *poll_bio; } submit; /* used for aio completion: */ @@ -49,29 +49,20 @@ struct iomap_dio { }; }; -int iomap_dio_iopoll(struct kiocb *kiocb, bool spin) -{ - struct request_queue *q = READ_ONCE(kiocb->private); - - if (!q) - return 0; - return blk_poll(q, READ_ONCE(kiocb->ki_cookie), spin); -} -EXPORT_SYMBOL_GPL(iomap_dio_iopoll); - static void iomap_dio_submit_bio(const struct iomap_iter *iter, struct iomap_dio *dio, struct bio *bio, loff_t pos) { atomic_inc(&dio->ref); - if (dio->iocb->ki_flags & IOCB_HIPRI) + if (dio->iocb->ki_flags & IOCB_HIPRI) { bio_set_polled(bio, dio->iocb); + dio->submit.poll_bio = bio; + } - dio->submit.last_queue = bdev_get_queue(iter->iomap.bdev); if (dio->dops && dio->dops->submit_io) - dio->submit.cookie = dio->dops->submit_io(iter, bio, pos); + dio->dops->submit_io(iter, bio, pos); else - dio->submit.cookie = submit_bio(bio); + submit_bio(bio); } ssize_t iomap_dio_complete(struct iomap_dio *dio) @@ -124,6 +115,9 @@ ssize_t iomap_dio_complete(struct iomap_dio *dio) if (ret > 0 && (dio->flags & IOMAP_DIO_NEED_SYNC)) ret = generic_write_sync(iocb, ret); + if (ret > 0) + ret += dio->done_before; + kfree(dio); return ret; @@ -135,7 +129,7 @@ static void iomap_dio_complete_work(struct work_struct *work) struct iomap_dio *dio = container_of(work, struct iomap_dio, aio.work); struct kiocb *iocb = dio->iocb; - iocb->ki_complete(iocb, iomap_dio_complete(dio), 0); + iocb->ki_complete(iocb, iomap_dio_complete(dio)); } /* @@ -164,9 +158,11 @@ static void iomap_dio_bio_end_io(struct bio *bio) } else if (dio->flags & IOMAP_DIO_WRITE) { struct inode *inode = file_inode(dio->iocb->ki_filp); + WRITE_ONCE(dio->iocb->private, NULL); INIT_WORK(&dio->aio.work, iomap_dio_complete_work); queue_work(inode->i_sb->s_dio_done_wq, &dio->aio.work); } else { + WRITE_ONCE(dio->iocb->private, NULL); iomap_dio_complete_work(&dio->aio.work); } } @@ -282,6 +278,13 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter, if (!iov_iter_count(dio->submit.iter)) goto out; + /* + * We can only poll for single bio I/Os. + */ + if (need_zeroout || + ((dio->flags & IOMAP_DIO_WRITE) && pos >= i_size_read(inode))) + dio->iocb->ki_flags &= ~IOCB_HIPRI; + if (need_zeroout) { /* zero out from the start of the block to the write offset */ pad = pos & (fs_block_size - 1); @@ -339,6 +342,11 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter, nr_pages = bio_iov_vecs_to_alloc(dio->submit.iter, BIO_MAX_VECS); + /* + * We can only poll for single bio I/Os. + */ + if (nr_pages) + dio->iocb->ki_flags &= ~IOCB_HIPRI; iomap_dio_submit_bio(iter, dio, bio, pos); pos += n; } while (nr_pages); @@ -371,6 +379,8 @@ static loff_t iomap_dio_hole_iter(const struct iomap_iter *iter, loff_t length = iov_iter_zero(iomap_length(iter), dio->submit.iter); dio->size += length; + if (!length) + return -EFAULT; return length; } @@ -402,6 +412,8 @@ static loff_t iomap_dio_inline_iter(const struct iomap_iter *iomi, copied = copy_to_iter(inline_data, length, iter); } dio->size += copied; + if (!copied) + return -EFAULT; return copied; } @@ -446,13 +458,21 @@ static loff_t iomap_dio_iter(const struct iomap_iter *iter, * may be pure data writes. In that case, we still need to do a full data sync * completion. * + * When page faults are disabled and @dio_flags includes IOMAP_DIO_PARTIAL, + * __iomap_dio_rw can return a partial result if it encounters a non-resident + * page in @iter after preparing a transfer. In that case, the non-resident + * pages can be faulted in and the request resumed with @done_before set to the + * number of bytes previously transferred. The request will then complete with + * the correct total number of bytes transferred; this is essential for + * completing partial requests asynchronously. + * * Returns -ENOTBLK In case of a page invalidation invalidation failure for * writes. The callers needs to fall back to buffered I/O in this case. */ struct iomap_dio * __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops, const struct iomap_dio_ops *dops, - unsigned int dio_flags) + unsigned int dio_flags, size_t done_before) { struct address_space *mapping = iocb->ki_filp->f_mapping; struct inode *inode = file_inode(iocb->ki_filp); @@ -482,11 +502,11 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, dio->dops = dops; dio->error = 0; dio->flags = 0; + dio->done_before = done_before; dio->submit.iter = iter; dio->submit.waiter = current; - dio->submit.cookie = BLK_QC_T_NONE; - dio->submit.last_queue = NULL; + dio->submit.poll_bio = NULL; if (iov_iter_rw(iter) == READ) { if (iomi.pos >= dio->i_size) @@ -565,8 +585,15 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, inode_dio_begin(inode); blk_start_plug(&plug); - while ((ret = iomap_iter(&iomi, ops)) > 0) + while ((ret = iomap_iter(&iomi, ops)) > 0) { iomi.processed = iomap_dio_iter(&iomi, dio); + + /* + * We can only poll for single bio I/Os. + */ + iocb->ki_flags &= ~IOCB_HIPRI; + } + blk_finish_plug(&plug); /* @@ -577,6 +604,12 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, if (iov_iter_rw(iter) == READ && iomi.pos >= dio->i_size) iov_iter_revert(iter, iomi.pos - dio->i_size); + if (ret == -EFAULT && dio->size && (dio_flags & IOMAP_DIO_PARTIAL)) { + if (!(iocb->ki_flags & IOCB_NOWAIT)) + wait_for_completion = true; + ret = 0; + } + /* magic error code to fall back to buffered I/O */ if (ret == -ENOTBLK) { wait_for_completion = true; @@ -592,8 +625,7 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, if (dio->flags & IOMAP_DIO_WRITE_FUA) dio->flags &= ~IOMAP_DIO_NEED_SYNC; - WRITE_ONCE(iocb->ki_cookie, dio->submit.cookie); - WRITE_ONCE(iocb->private, dio->submit.last_queue); + WRITE_ONCE(iocb->private, dio->submit.poll_bio); /* * We are about to drop our additional submission reference, which @@ -620,10 +652,8 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, if (!READ_ONCE(dio->submit.waiter)) break; - if (!(iocb->ki_flags & IOCB_HIPRI) || - !dio->submit.last_queue || - !blk_poll(dio->submit.last_queue, - dio->submit.cookie, true)) + if (!dio->submit.poll_bio || + !bio_poll(dio->submit.poll_bio, NULL, 0)) blk_io_schedule(); } __set_current_state(TASK_RUNNING); @@ -642,11 +672,11 @@ EXPORT_SYMBOL_GPL(__iomap_dio_rw); ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops, const struct iomap_dio_ops *dops, - unsigned int dio_flags) + unsigned int dio_flags, size_t done_before) { struct iomap_dio *dio; - dio = __iomap_dio_rw(iocb, iter, ops, dops, dio_flags); + dio = __iomap_dio_rw(iocb, iter, ops, dops, dio_flags, done_before); if (IS_ERR_OR_NULL(dio)) return PTR_ERR_OR_ZERO(dio); return iomap_dio_complete(dio); |