The patch titled Subject: gadget: remove only user of aio retry has been added to the -mm tree. Its filename is gadget-remove-only-user-of-aio-retry.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Zach Brown <zab@xxxxxxxxxx> Subject: gadget: remove only user of aio retry This removes the only in-tree user of aio retry. This will let us remove the retry code from the aio core. Removing retry is relatively easy as the USB gadget wasn't using it to retry IOs at all. It always fully submitted the IO in the context of the initial io_submit() call. It only used the AIO retry facility to get the submitter's mm context for copying the result of a read back to user space. This is easy to implement with use_mm() and a work struct, much like kvm does with async_pf_execute() for get_user_pages(). Signed-off-by: Zach Brown <zab@xxxxxxxxxx> Signed-off-by: Kent Overstreet <koverstreet@xxxxxxxxxx> Cc: Felipe Balbi <balbi@xxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Mark Fasheh <mfasheh@xxxxxxxx> Cc: Joel Becker <jlbec@xxxxxxxxxxxx> Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Asai Thambi S P <asamymuthupa@xxxxxxxxxx> Cc: Selvan Mani <smani@xxxxxxxxxx> Cc: Sam Bradshaw <sbradshaw@xxxxxxxxxx> Cc: Jeff Moyer <jmoyer@xxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Benjamin LaHaise <bcrl@xxxxxxxxx> Cc: Theodore Ts'o <tytso@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/usb/gadget/inode.c | 38 ++++++++++++++++++++++++++--------- 1 file changed, 29 insertions(+), 9 deletions(-) diff -puN drivers/usb/gadget/inode.c~gadget-remove-only-user-of-aio-retry drivers/usb/gadget/inode.c --- a/drivers/usb/gadget/inode.c~gadget-remove-only-user-of-aio-retry +++ a/drivers/usb/gadget/inode.c @@ -24,6 +24,7 @@ #include <linux/sched.h> #include <linux/slab.h> #include <linux/poll.h> +#include <linux/mmu_context.h> #include <linux/device.h> #include <linux/moduleparam.h> @@ -513,6 +514,9 @@ static long ep_ioctl(struct file *fd, un struct kiocb_priv { struct usb_request *req; struct ep_data *epdata; + struct kiocb *iocb; + struct mm_struct *mm; + struct work_struct work; void *buf; const struct iovec *iv; unsigned long nr_segs; @@ -540,15 +544,12 @@ static int ep_aio_cancel(struct kiocb *i return value; } -static ssize_t ep_aio_read_retry(struct kiocb *iocb) +static ssize_t ep_copy_to_user(struct kiocb_priv *priv) { - struct kiocb_priv *priv = iocb->private; ssize_t len, total; void *to_copy; int i; - /* we "retry" to get the right mm context for this: */ - /* copy stuff into user buffers */ total = priv->actual; len = 0; @@ -568,9 +569,26 @@ static ssize_t ep_aio_read_retry(struct if (total == 0) break; } + + return len; +} + +static void ep_user_copy_worker(struct work_struct *work) +{ + struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work); + struct mm_struct *mm = priv->mm; + struct kiocb *iocb = priv->iocb; + size_t ret; + + use_mm(mm); + ret = ep_copy_to_user(priv); + unuse_mm(mm); + + /* completing the iocb can drop the ctx and mm, don't touch mm after */ + aio_complete(iocb, ret, ret); + kfree(priv->buf); kfree(priv); - return len; } static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req) @@ -596,14 +614,14 @@ static void ep_aio_complete(struct usb_e aio_complete(iocb, req->actual ? req->actual : req->status, req->status); } else { - /* retry() won't report both; so we hide some faults */ + /* ep_copy_to_user() won't report both; we hide some faults */ if (unlikely(0 != req->status)) DBG(epdata->dev, "%s fault %d len %d\n", ep->name, req->status, req->actual); priv->buf = req->buf; priv->actual = req->actual; - kick_iocb(iocb); + schedule_work(&priv->work); } spin_unlock(&epdata->dev->lock); @@ -633,8 +651,10 @@ fail: return value; } iocb->private = priv; + priv->iocb = iocb; priv->iv = iv; priv->nr_segs = nr_segs; + INIT_WORK(&priv->work, ep_user_copy_worker); value = get_ready_ep(iocb->ki_filp->f_flags, epdata); if (unlikely(value < 0)) { @@ -646,6 +666,7 @@ fail: get_ep(epdata); priv->epdata = epdata; priv->actual = 0; + priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */ /* each kiocb is coupled to one usb_request, but we can't * allocate or submit those if the host disconnected. @@ -674,7 +695,7 @@ fail: kfree(priv); put_ep(epdata); } else - value = (iv ? -EIOCBRETRY : -EIOCBQUEUED); + value = -EIOCBQUEUED; return value; } @@ -692,7 +713,6 @@ ep_aio_read(struct kiocb *iocb, const st if (unlikely(!buf)) return -ENOMEM; - iocb->ki_retry = ep_aio_read_retry; return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs); } _ Patches currently in -mm which might be from zab@xxxxxxxxxx are mm-remove-old-aio-use_mm-comment.patch aio-remove-dead-code-from-aioh.patch gadget-remove-only-user-of-aio-retry.patch aio-remove-retry-based-aio.patch char-add-aio_readwrite-to-dev-nullzero.patch aio-kill-return-value-of-aio_complete.patch aio-add-kiocb_cancel.patch aio-move-private-stuff-out-of-aioh.patch aio-dprintk-pr_debug.patch aio-do-fget-after-aio_get_req.patch aio-make-aio_put_req-lockless.patch aio-refcounting-cleanup.patch wait-add-wait_event_hrtimeout.patch aio-make-aio_read_evt-more-efficient-convert-to-hrtimers.patch aio-use-flush_dcache_page.patch aio-use-cancellation-list-lazily.patch aio-change-reqs_active-to-include-unreaped-completions.patch aio-kill-batch-allocation.patch aio-kill-struct-aio_ring_info.patch aio-give-shared-kioctx-fields-their-own-cachelines.patch aio-reqs_active-reqs_available.patch aio-percpu-reqs_available.patch generic-dynamic-per-cpu-refcounting.patch aio-percpu-ioctx-refcount.patch aio-use-xchg-instead-of-completion_lock.patch aio-dont-include-aioh-in-schedh.patch aio-kill-ki_key.patch aio-kill-ki_retry.patch block-prep-work-for-batch-completion.patch block-aio-batch-completion-for-bios-kiocbs.patch virtio-blk-convert-to-batch-completion.patch mtip32xx-convert-to-batch-completion.patch aio-fix-kioctx-not-being-freed-after-cancellation-at-exit-time.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html