From eed4e51fb60c3863c134a5e9f6006b29805ead97 Mon Sep 17 00:00:00 2001 From: Badari Pulavarty Date: Sat, 30 Sep 2006 23:28:49 -0700 Subject: [PATCH] Add vector AIO support This work is initially done by Zach Brown to add support for vectored aio. These are the core changes for AIO to support IOCB_CMD_PREADV/IOCB_CMD_PWRITEV. [akpm@osdl.org: huge build fix] Signed-off-by: Zach Brown Signed-off-by: Christoph Hellwig Signed-off-by: Badari Pulavarty Acked-by: Benjamin LaHaise Acked-by: James Morris Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/aio.c | 171 +++++++++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 117 insertions(+), 54 deletions(-) (limited to 'fs/aio.c') diff --git a/fs/aio.c b/fs/aio.c index 27ff56540c7..2e0d1505ee3 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -415,6 +415,7 @@ static struct kiocb fastcall *__aio_get_req(struct kioctx *ctx) req->ki_retry = NULL; req->ki_dtor = NULL; req->private = NULL; + req->ki_iovec = NULL; INIT_LIST_HEAD(&req->ki_run_list); /* Check if the completion queue has enough free space to @@ -460,6 +461,8 @@ static inline void really_put_req(struct kioctx *ctx, struct kiocb *req) if (req->ki_dtor) req->ki_dtor(req); + if (req->ki_iovec != &req->ki_inline_vec) + kfree(req->ki_iovec); kmem_cache_free(kiocb_cachep, req); ctx->reqs_active--; @@ -1301,69 +1304,63 @@ asmlinkage long sys_io_destroy(aio_context_t ctx) return -EINVAL; } -/* - * aio_p{read,write} are the default ki_retry methods for - * IO_CMD_P{READ,WRITE}. They maintains kiocb retry state around potentially - * multiple calls to f_op->aio_read(). They loop around partial progress - * instead of returning -EIOCBRETRY because they don't have the means to call - * kick_iocb(). - */ -static ssize_t aio_pread(struct kiocb *iocb) +static void aio_advance_iovec(struct kiocb *iocb, ssize_t ret) { - struct file *file = iocb->ki_filp; - struct address_space *mapping = file->f_mapping; - struct inode *inode = mapping->host; - ssize_t ret = 0; - - do { - iocb->ki_inline_vec.iov_base = iocb->ki_buf; - iocb->ki_inline_vec.iov_len = iocb->ki_left; - - ret = file->f_op->aio_read(iocb, &iocb->ki_inline_vec, - 1, iocb->ki_pos); - /* - * Can't just depend on iocb->ki_left to determine - * whether we are done. This may have been a short read. - */ - if (ret > 0) { - iocb->ki_buf += ret; - iocb->ki_left -= ret; + struct iovec *iov = &iocb->ki_iovec[iocb->ki_cur_seg]; + + BUG_ON(ret <= 0); + + while (iocb->ki_cur_seg < iocb->ki_nr_segs && ret > 0) { + ssize_t this = min((ssize_t)iov->iov_len, ret); + iov->iov_base += this; + iov->iov_len -= this; + iocb->ki_left -= this; + ret -= this; + if (iov->iov_len == 0) { + iocb->ki_cur_seg++; + iov++; } + } - /* - * For pipes and sockets we return once we have some data; for - * regular files we retry till we complete the entire read or - * find that we can't read any more data (e.g short reads). - */ - } while (ret > 0 && iocb->ki_left > 0 && - !S_ISFIFO(inode->i_mode) && !S_ISSOCK(inode->i_mode)); - - /* This means we must have transferred all that we could */ - /* No need to retry anymore */ - if ((ret == 0) || (iocb->ki_left == 0)) - ret = iocb->ki_nbytes - iocb->ki_left; - - return ret; + /* the caller should not have done more io than what fit in + * the remaining iovecs */ + BUG_ON(ret > 0 && iocb->ki_left == 0); } -/* see aio_pread() */ -static ssize_t aio_pwrite(struct kiocb *iocb) +static ssize_t aio_rw_vect_retry(struct kiocb *iocb) { struct file *file = iocb->ki_filp; + struct address_space *mapping = file->f_mapping; + struct inode *inode = mapping->host; + ssize_t (*rw_op)(struct kiocb *, const struct iovec *, + unsigned long, loff_t); ssize_t ret = 0; + unsigned short opcode; + + if ((iocb->ki_opcode == IOCB_CMD_PREADV) || + (iocb->ki_opcode == IOCB_CMD_PREAD)) { + rw_op = file->f_op->aio_read; + opcode = IOCB_CMD_PREADV; + } else { + rw_op = file->f_op->aio_write; + opcode = IOCB_CMD_PWRITEV; + } do { - iocb->ki_inline_vec.iov_base = iocb->ki_buf; - iocb->ki_inline_vec.iov_len = iocb->ki_left; - - ret = file->f_op->aio_write(iocb, &iocb->ki_inline_vec, - 1, iocb->ki_pos); - if (ret > 0) { - iocb->ki_buf += ret; - iocb->ki_left -= ret; - } - } while (ret > 0 && iocb->ki_left > 0); + ret = rw_op(iocb, &iocb->ki_iovec[iocb->ki_cur_seg], + iocb->ki_nr_segs - iocb->ki_cur_seg, + iocb->ki_pos); + if (ret > 0) + aio_advance_iovec(iocb, ret); + + /* retry all partial writes. retry partial reads as long as its a + * regular file. */ + } while (ret > 0 && iocb->ki_left > 0 && + (opcode == IOCB_CMD_PWRITEV || + (!S_ISFIFO(inode->i_mode) && !S_ISSOCK(inode->i_mode)))); + /* This means we must have transferred all that we could */ + /* No need to retry anymore */ if ((ret == 0) || (iocb->ki_left == 0)) ret = iocb->ki_nbytes - iocb->ki_left; @@ -1390,6 +1387,38 @@ static ssize_t aio_fsync(struct kiocb *iocb) return ret; } +static ssize_t aio_setup_vectored_rw(int type, struct kiocb *kiocb) +{ + ssize_t ret; + + ret = rw_copy_check_uvector(type, (struct iovec __user *)kiocb->ki_buf, + kiocb->ki_nbytes, 1, + &kiocb->ki_inline_vec, &kiocb->ki_iovec); + if (ret < 0) + goto out; + + kiocb->ki_nr_segs = kiocb->ki_nbytes; + kiocb->ki_cur_seg = 0; + /* ki_nbytes/left now reflect bytes instead of segs */ + kiocb->ki_nbytes = ret; + kiocb->ki_left = ret; + + ret = 0; +out: + return ret; +} + +static ssize_t aio_setup_single_vector(struct kiocb *kiocb) +{ + kiocb->ki_iovec = &kiocb->ki_inline_vec; + kiocb->ki_iovec->iov_base = kiocb->ki_buf; + kiocb->ki_iovec->iov_len = kiocb->ki_left; + kiocb->ki_nr_segs = 1; + kiocb->ki_cur_seg = 0; + kiocb->ki_nbytes = kiocb->ki_left; + return 0; +} + /* * aio_setup_iocb: * Performs the initial checks and aio retry method @@ -1412,9 +1441,12 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb) ret = security_file_permission(file, MAY_READ); if (unlikely(ret)) break; + ret = aio_setup_single_vector(kiocb); + if (ret) + break; ret = -EINVAL; if (file->f_op->aio_read) - kiocb->ki_retry = aio_pread; + kiocb->ki_retry = aio_rw_vect_retry; break; case IOCB_CMD_PWRITE: ret = -EBADF; @@ -1427,9 +1459,40 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb) ret = security_file_permission(file, MAY_WRITE); if (unlikely(ret)) break; + ret = aio_setup_single_vector(kiocb); + if (ret) + break; + ret = -EINVAL; + if (file->f_op->aio_write) + kiocb->ki_retry = aio_rw_vect_retry; + break; + case IOCB_CMD_PREADV: + ret = -EBADF; + if (unlikely(!(file->f_mode & FMODE_READ))) + break; + ret = security_file_permission(file, MAY_READ); + if (unlikely(ret)) + break; + ret = aio_setup_vectored_rw(READ, kiocb); + if (ret) + break; + ret = -EINVAL; + if (file->f_op->aio_read) + kiocb->ki_retry = aio_rw_vect_retry; + break; + case IOCB_CMD_PWRITEV: + ret = -EBADF; + if (unlikely(!(file->f_mode & FMODE_WRITE))) + break; + ret = security_file_permission(file, MAY_WRITE); + if (unlikely(ret)) + break; + ret = aio_setup_vectored_rw(WRITE, kiocb); + if (ret) + break; ret = -EINVAL; if (file->f_op->aio_write) - kiocb->ki_retry = aio_pwrite; + kiocb->ki_retry = aio_rw_vect_retry; break; case IOCB_CMD_FDSYNC: ret = -EINVAL; -- cgit v1.2.3