From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Christoph Hellwig To: viro@zeniv.linux.org.uk Cc: Avi Kivity , linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 5/7] aio: refactor read/write iocb setup Date: Sun, 15 Apr 2018 17:01:06 +0200 Message-Id: <20180415150108.1341-6-hch@lst.de> In-Reply-To: <20180415150108.1341-1-hch@lst.de> References: <20180415150108.1341-1-hch@lst.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: Don't reference the kiocb structure from the common aio code, and move any use of it into helper specific to the read/write path. This is in preparation for aio_poll support that wants to use the space for different fields. Signed-off-by: Christoph Hellwig Acked-by: Jeff Moyer Reviewed-by: Greg Kroah-Hartman Reviewed-by: Darrick J. Wong --- fs/aio.c | 159 +++++++++++++++++++++++++++++++------------------------ 1 file changed, 91 insertions(+), 68 deletions(-) diff --git a/fs/aio.c b/fs/aio.c index d7be32cdd1db..d4dd002712c8 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -170,7 +170,9 @@ struct kioctx { #define KIOCB_CANCELLED ((void *) (~0ULL)) struct aio_kiocb { - struct kiocb common; + union { + struct kiocb rw; + }; struct kioctx *ki_ctx; kiocb_cancel_fn *ki_cancel; @@ -549,7 +551,7 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events) void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel) { - struct aio_kiocb *req = container_of(iocb, struct aio_kiocb, common); + struct aio_kiocb *req = container_of(iocb, struct aio_kiocb, rw); struct kioctx *ctx = req->ki_ctx; unsigned long flags; @@ -581,7 +583,7 @@ static int kiocb_cancel(struct aio_kiocb *kiocb) cancel = cmpxchg(&kiocb->ki_cancel, old, KIOCB_CANCELLED); } while (cancel != old); - return cancel(&kiocb->common); + return cancel(&kiocb->rw); } /* @@ -1046,15 +1048,6 @@ static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx) return NULL; } -static void kiocb_free(struct aio_kiocb *req) -{ - if (req->common.ki_filp) - fput(req->common.ki_filp); - if (req->ki_eventfd != NULL) - eventfd_ctx_put(req->ki_eventfd); - kmem_cache_free(kiocb_cachep, req); -} - static struct kioctx *lookup_ioctx(unsigned long ctx_id) { struct aio_ring __user *ring = (void __user *)ctx_id; @@ -1085,27 +1078,14 @@ static struct kioctx *lookup_ioctx(unsigned long ctx_id) /* aio_complete * Called when the io request on the given iocb is complete. */ -static void aio_complete(struct kiocb *kiocb, long res, long res2) +static void aio_complete(struct aio_kiocb *iocb, long res, long res2) { - struct aio_kiocb *iocb = container_of(kiocb, struct aio_kiocb, common); struct kioctx *ctx = iocb->ki_ctx; struct aio_ring *ring; struct io_event *ev_page, *event; unsigned tail, pos, head; unsigned long flags; - if (kiocb->ki_flags & IOCB_WRITE) { - struct file *file = kiocb->ki_filp; - - /* - * Tell lockdep we inherited freeze protection from submission - * thread. - */ - if (S_ISREG(file_inode(file)->i_mode)) - __sb_writers_acquired(file_inode(file)->i_sb, SB_FREEZE_WRITE); - file_end_write(file); - } - if (!list_empty_careful(&iocb->ki_list)) { unsigned long flags; @@ -1167,11 +1147,12 @@ static void aio_complete(struct kiocb *kiocb, long res, long res2) * eventfd. The eventfd_signal() function is safe to be called * from IRQ context. */ - if (iocb->ki_eventfd != NULL) + if (iocb->ki_eventfd) { eventfd_signal(iocb->ki_eventfd, 1); + eventfd_ctx_put(iocb->ki_eventfd); + } - /* everything turned out well, dispose of the aiocb. */ - kiocb_free(iocb); + kmem_cache_free(kiocb_cachep, iocb); /* * We have to order our ring_info tail store above and test @@ -1434,6 +1415,45 @@ SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx) return -EINVAL; } +static void aio_complete_rw(struct kiocb *kiocb, long res, long res2) +{ + struct aio_kiocb *iocb = container_of(kiocb, struct aio_kiocb, rw); + + if (kiocb->ki_flags & IOCB_WRITE) { + struct inode *inode = file_inode(kiocb->ki_filp); + + /* + * Tell lockdep we inherited freeze protection from submission + * thread. + */ + if (S_ISREG(inode->i_mode)) + __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE); + file_end_write(kiocb->ki_filp); + } + + fput(kiocb->ki_filp); + aio_complete(iocb, res, res2); +} + +static int aio_prep_rw(struct kiocb *req, struct iocb *iocb) +{ + int ret; + + req->ki_filp = fget(iocb->aio_fildes); + if (unlikely(!req->ki_filp)) + return -EBADF; + req->ki_complete = aio_complete_rw; + req->ki_pos = iocb->aio_offset; + req->ki_flags = iocb_flags(req->ki_filp); + if (iocb->aio_flags & IOCB_FLAG_RESFD) + req->ki_flags |= IOCB_EVENTFD; + req->ki_hint = file_write_hint(req->ki_filp); + ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags); + if (unlikely(ret)) + fput(req->ki_filp); + return ret; +} + static int aio_setup_rw(int rw, struct iocb *iocb, struct iovec **iovec, bool vectored, bool compat, struct iov_iter *iter) { @@ -1453,7 +1473,7 @@ static int aio_setup_rw(int rw, struct iocb *iocb, struct iovec **iovec, return import_iovec(rw, buf, len, UIO_FASTIOV, iovec, iter); } -static inline ssize_t aio_ret(struct kiocb *req, ssize_t ret) +static inline ssize_t aio_rw_ret(struct kiocb *req, ssize_t ret) { switch (ret) { case -EIOCBQUEUED: @@ -1469,7 +1489,7 @@ static inline ssize_t aio_ret(struct kiocb *req, ssize_t ret) ret = -EINTR; /*FALLTHRU*/ default: - aio_complete(req, ret, 0); + aio_complete_rw(req, ret, 0); return 0; } } @@ -1477,57 +1497,77 @@ static inline ssize_t aio_ret(struct kiocb *req, ssize_t ret) static ssize_t aio_read(struct kiocb *req, struct iocb *iocb, bool vectored, bool compat) { - struct file *file = req->ki_filp; struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; struct iov_iter iter; + struct file *file; ssize_t ret; + ret = aio_prep_rw(req, iocb); + if (ret) + return ret; + file = req->ki_filp; + + ret = -EBADF; if (unlikely(!(file->f_mode & FMODE_READ))) - return -EBADF; + goto out_fput; + ret = -EINVAL; if (unlikely(!file->f_op->read_iter)) - return -EINVAL; + goto out_fput; ret = aio_setup_rw(READ, iocb, &iovec, vectored, compat, &iter); if (ret) - return ret; + goto out_fput; ret = rw_verify_area(READ, file, &req->ki_pos, iov_iter_count(&iter)); if (!ret) - ret = aio_ret(req, call_read_iter(file, req, &iter)); + ret = aio_rw_ret(req, call_read_iter(file, req, &iter)); kfree(iovec); +out_fput: + if (unlikely(ret && ret != -EIOCBQUEUED)) + fput(file); return ret; } static ssize_t aio_write(struct kiocb *req, struct iocb *iocb, bool vectored, bool compat) { - struct file *file = req->ki_filp; struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; struct iov_iter iter; + struct file *file; ssize_t ret; + ret = aio_prep_rw(req, iocb); + if (ret) + return ret; + file = req->ki_filp; + + ret = -EBADF; if (unlikely(!(file->f_mode & FMODE_WRITE))) - return -EBADF; + goto out_fput; + ret = -EINVAL; if (unlikely(!file->f_op->write_iter)) - return -EINVAL; + goto out_fput; ret = aio_setup_rw(WRITE, iocb, &iovec, vectored, compat, &iter); if (ret) - return ret; + goto out_fput; ret = rw_verify_area(WRITE, file, &req->ki_pos, iov_iter_count(&iter)); if (!ret) { /* - * We release freeze protection in aio_complete(). Fool lockdep - * by telling it the lock got released so that it doesn't - * complain about held lock when we return to userspace. + * We release freeze protection in aio_complete_rw(). Fool + * lockdep by telling it the lock got released so that it + * doesn't complain about held lock when we return to userspace. */ if (S_ISREG(file_inode(file)->i_mode)) { __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true); __sb_writers_release(file_inode(file)->i_sb, SB_FREEZE_WRITE); } req->ki_flags |= IOCB_WRITE; - ret = aio_ret(req, call_write_iter(file, req, &iter)); + ret = aio_rw_ret(req, call_write_iter(file, req, &iter)); } kfree(iovec); +out_fput: + if (unlikely(ret && ret != -EIOCBQUEUED)) + fput(file); return ret; } @@ -1535,7 +1575,6 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, struct iocb *iocb, bool compat) { struct aio_kiocb *req; - struct file *file; ssize_t ret; /* enforce forwards compatibility on users */ @@ -1558,16 +1597,6 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, if (unlikely(!req)) return -EAGAIN; - req->common.ki_filp = file = fget(iocb->aio_fildes); - if (unlikely(!req->common.ki_filp)) { - ret = -EBADF; - goto out_put_req; - } - req->common.ki_pos = iocb->aio_offset; - req->common.ki_complete = aio_complete; - req->common.ki_flags = iocb_flags(req->common.ki_filp); - req->common.ki_hint = file_write_hint(file); - if (iocb->aio_flags & IOCB_FLAG_RESFD) { /* * If the IOCB_FLAG_RESFD flag of aio_flags is set, get an @@ -1581,14 +1610,6 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, req->ki_eventfd = NULL; goto out_put_req; } - - req->common.ki_flags |= IOCB_EVENTFD; - } - - ret = kiocb_set_rw_flags(&req->common, iocb->aio_rw_flags); - if (unlikely(ret)) { - pr_debug("EINVAL: aio_rw_flags\n"); - goto out_put_req; } ret = put_user(KIOCB_KEY, &user_iocb->aio_key); @@ -1602,16 +1623,16 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, switch (iocb->aio_lio_opcode) { case IOCB_CMD_PREAD: - ret = aio_read(&req->common, iocb, false, compat); + ret = aio_read(&req->rw, iocb, false, compat); break; case IOCB_CMD_PWRITE: - ret = aio_write(&req->common, iocb, false, compat); + ret = aio_write(&req->rw, iocb, false, compat); break; case IOCB_CMD_PREADV: - ret = aio_read(&req->common, iocb, true, compat); + ret = aio_read(&req->rw, iocb, true, compat); break; case IOCB_CMD_PWRITEV: - ret = aio_write(&req->common, iocb, true, compat); + ret = aio_write(&req->rw, iocb, true, compat); break; default: pr_debug("invalid aio operation %d\n", iocb->aio_lio_opcode); @@ -1625,7 +1646,9 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, out_put_req: put_reqs_available(ctx, 1); percpu_ref_put(&ctx->reqs); - kiocb_free(req); + if (req->ki_eventfd) + eventfd_ctx_put(req->ki_eventfd); + kmem_cache_free(kiocb_cachep, req); return ret; } -- 2.17.0