[PATCH 0 of 7] blktap/pvops updates

[PATCH 0 of 7] blktap/pvops updates

[Daniel Stodden]

Hi.

A bunch of updates to the backend/blktap2 branch.

The main difference is that all queue runs are synchronous on behalf
of tapdisk system entries now. As a consequence we can drop a couple
locks, which is good, and the .unmap vma hook, which is better.

This removes pause/unpause from the kernel interface. I don't
anticipate it's going to be missed, because that code must have been
deadlocking on sysfs node removal for quite a while. Next toolstack
update will redo pause/unpause in userspace.

On the misc side, there is some cleanup and removal of bdev
passthrough mode. The idea was nice but it never got excercised a lot.

Cheers,
Daniel

[PATCH 1 of 7] blktap: Synchronous queue dispatch

[Daniel Stodden]

[-- Attachment #1: blktap-ring-sync.diff --]
[-- Type: text/x-patch, Size: 11979 bytes --]

blktap: Synchronous queue dispatch.

Move all queue runs into tapdisk context. Queue dispatch moved into
ring.poll. That's not nice, but keeps the toolstack fully
compatible. Won't make much of a difference because the original poll
code wasn't level-triggered either.

Obsoletes/removes:
 * run deferrals and wait_queue.o.
 * blktap.tap_sem.
 * vma.unmap.

Signed-off-by: Jake Wires <jake.wires@citrix.com>
Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com>

diff -r 16fc7d4e03d6 -r 989a51acce0a drivers/xen/blktap/Makefile
--- a/drivers/xen/blktap/Makefile	Wed Jun 02 19:45:24 2010 -0700
+++ b/drivers/xen/blktap/Makefile	Wed Jun 02 19:45:24 2010 -0700
@@ -1,3 +1,3 @@
 obj-$(CONFIG_XEN_BLKDEV_TAP) := blktap.o
 
-blktap-objs := control.o ring.o wait_queue.o device.o request.o sysfs.o
+blktap-objs := control.o ring.o device.o request.o sysfs.o
diff -r 16fc7d4e03d6 -r 989a51acce0a drivers/xen/blktap/blktap.h
--- a/drivers/xen/blktap/blktap.h	Wed Jun 02 19:45:24 2010 -0700
+++ b/drivers/xen/blktap/blktap.h	Wed Jun 02 19:45:24 2010 -0700
@@ -35,7 +35,6 @@
 #define BLKTAP_PAUSED                7
 #define BLKTAP_SHUTDOWN_REQUESTED    8
 #define BLKTAP_PASSTHROUGH           9
-#define BLKTAP_DEFERRED              10
 
 /* blktap IOCTLs: */
 #define BLKTAP2_IOCTL_KICK_FE        1
@@ -168,8 +167,6 @@
 
 	struct blktap_params           params;
 
-	struct rw_semaphore            tap_sem;
-
 	struct blktap_ring             ring;
 	struct blktap_device           device;
 
@@ -178,7 +175,6 @@
 	struct scatterlist             sg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
 
 	wait_queue_head_t              wq;
-	struct list_head               deferred_queue;
 
 	struct blktap_statistics       stats;
 };
@@ -222,6 +218,7 @@
 int blktap_device_destroy(struct blktap *);
 int blktap_device_pause(struct blktap *);
 int blktap_device_resume(struct blktap *);
+int blktap_device_run_queue(struct blktap *);
 void blktap_device_restart(struct blktap *);
 void blktap_device_finish_request(struct blktap *,
 				  struct blkif_response *,
@@ -232,9 +229,6 @@
 				     unsigned, unsigned);
 #endif
 
-void blktap_defer(struct blktap *);
-void blktap_run_deferred(void);
-
 int blktap_request_pool_init(void);
 void blktap_request_pool_free(void);
 int blktap_request_pool_grow(void);
diff -r 16fc7d4e03d6 -r 989a51acce0a drivers/xen/blktap/control.c
--- a/drivers/xen/blktap/control.c	Wed Jun 02 19:45:24 2010 -0700
+++ b/drivers/xen/blktap/control.c	Wed Jun 02 19:45:24 2010 -0700
@@ -20,7 +20,6 @@
 
 	memset(tap, 0, sizeof(*tap));
 	set_bit(BLKTAP_CONTROL, &tap->dev_inuse);
-	init_rwsem(&tap->tap_sem);
 	init_waitqueue_head(&tap->wq);
 	atomic_set(&tap->refcnt, 0);
 	sg_init_table(tap->sg, BLKIF_MAX_SEGMENTS_PER_REQUEST);
diff -r 16fc7d4e03d6 -r 989a51acce0a drivers/xen/blktap/device.c
--- a/drivers/xen/blktap/device.c	Wed Jun 02 19:45:24 2010 -0700
+++ b/drivers/xen/blktap/device.c	Wed Jun 02 19:45:24 2010 -0700
@@ -212,9 +212,6 @@
 	BUG_ON(ret);
 }
 
-/*
- * tap->tap_sem held on entry
- */
 static void
 blktap_device_fast_flush(struct blktap *tap, struct blktap_request *request)
 {
@@ -302,9 +299,6 @@
 			       request->nr_pages << PAGE_SHIFT, NULL);
 }
 
-/*
- * tap->tap_sem held on entry
- */
 static void
 blktap_unmap(struct blktap *tap, struct blktap_request *request)
 {
@@ -349,8 +343,6 @@
 	if (!test_bit(BLKTAP_DEVICE, &tap->dev_inuse))
 		return;
 
-	down_write(&tap->tap_sem);
-
 	dev = &tap->device;
 	for (usr_idx = 0; usr_idx < MAX_PENDING_REQS; usr_idx++) {
 		request = tap->pending_requests[usr_idx];
@@ -368,8 +360,6 @@
 		blktap_request_free(tap, request);
 	}
 
-	up_write(&tap->tap_sem);
-
 	spin_lock_irq(&dev->lock);
 
 	/* fail any future requests */
@@ -379,9 +369,6 @@
 	spin_unlock_irq(&dev->lock);
 }
 
-/*
- * tap->tap_sem held on entry
- */
 void
 blktap_device_finish_request(struct blktap *tap,
 			     struct blkif_response *res,
@@ -590,9 +577,6 @@
 	err = -1;
 	memset(&table, 0, sizeof(table));
 
-	if (!blktap_active(tap))
-		goto out;
-
 	ring    = &tap->ring;
 	usr_idx = request->usr_idx;
 	blkif_req.id = usr_idx;
@@ -774,24 +758,24 @@
 #endif
 
 /*
- * dev->lock held on entry
+ * called from tapdisk context
  */
-static void
+int
 blktap_device_run_queue(struct blktap *tap)
 {
-	int queued, err;
+	int err, rv;
 	struct request_queue *rq;
 	struct request *req;
 	struct blktap_ring *ring;
 	struct blktap_device *dev;
 	struct blktap_request *request;
 
-	queued = 0;
 	ring   = &tap->ring;
 	dev    = &tap->device;
 	rq     = dev->gd->queue;
 
 	BTDBG("running queue for %d\n", tap->minor);
+	spin_lock_irq(&dev->lock);
 
 	while ((req = blk_peek_request(rq)) != NULL) {
 		if (!blk_fs_request(req)) {
@@ -816,7 +800,6 @@
 		wait:
 			/* Avoid pointless unplugs. */
 			blk_stop_queue(rq);
-			blktap_defer(tap);
 			break;
 		}
 
@@ -836,27 +819,26 @@
 		blk_start_request(req);
 
 		spin_unlock_irq(&dev->lock);
-		down_read(&tap->tap_sem);
 
 		err = blktap_device_process_request(tap, request, req);
-		if (!err)
-			queued++;
-		else {
+		if (err) {
 			blktap_device_end_dequeued_request(dev, req, -EIO);
 			blktap_request_free(tap, request);
 		}
 
-		up_read(&tap->tap_sem);
 		spin_lock_irq(&dev->lock);
 	}
 
-	if (queued)
-		blktap_ring_kick_user(tap);
+	spin_unlock_irq(&dev->lock);
+
+	rv = ring->ring.req_prod_pvt -
+		ring->ring.sring->req_prod;
+
+	RING_PUSH_REQUESTS(&ring->ring);
+
+	return rv;
 }
 
-/*
- * dev->lock held on entry
- */
 static void
 blktap_device_do_request(struct request_queue *rq)
 {
@@ -872,13 +854,7 @@
 	if (!blktap_active(tap))
 		goto fail;
 
-	if (test_bit(BLKTAP_PAUSED, &tap->dev_inuse) ||
-	    test_bit(BLKTAP_PAUSE_REQUESTED, &tap->dev_inuse)) {
-		blktap_defer(tap);
-		return;
-	}
-
-	blktap_device_run_queue(tap);
+	blktap_ring_kick_user(tap);
 	return;
 
 fail:
@@ -896,18 +872,6 @@
 	struct blktap_device *dev;
 
 	dev = &tap->device;
-
-	if (blktap_active(tap) && RING_FULL(&tap->ring.ring)) {
-		blktap_defer(tap);
-		return;
-	}
-
-	if (test_bit(BLKTAP_PAUSED, &tap->dev_inuse) ||
-	    test_bit(BLKTAP_PAUSE_REQUESTED, &tap->dev_inuse)) {
-		blktap_defer(tap);
-		return;
-	}
-
 	spin_lock_irq(&dev->lock);
 
 	/* Re-enable calldowns. */
diff -r 16fc7d4e03d6 -r 989a51acce0a drivers/xen/blktap/ring.c
--- a/drivers/xen/blktap/ring.c	Wed Jun 02 19:45:24 2010 -0700
+++ b/drivers/xen/blktap/ring.c	Wed Jun 02 19:45:24 2010 -0700
@@ -30,7 +30,7 @@
   */
 #define RING_PAGES 1
 
-static int
+static void
 blktap_read_ring(struct blktap *tap)
 {
 	/* This is called to read responses from the ring. */
@@ -40,13 +40,9 @@
 	struct blktap_ring *ring;
 	struct blktap_request *request;
 
-	down_read(&tap->tap_sem);
-
 	ring = &tap->ring;
-	if (!ring->vma) {
-		up_read(&tap->tap_sem);
-		return 0;
-	}
+	if (!ring->vma)
+		return;
 
 	/* for each outstanding message on the ring  */
 	rp = ring->ring.sring->rsp_prod;
@@ -54,7 +50,6 @@
 
 	for (rc = ring->ring.rsp_cons; rc != rp; rc++) {
 		memcpy(&res, RING_GET_RESPONSE(&ring->ring, rc), sizeof(res));
-		mb(); /* rsp_cons read by RING_FULL() in do_block_io_op(). */
 		++ring->ring.rsp_cons;
 
 		usr_idx = (int)res.id;
@@ -70,11 +65,9 @@
 		blktap_device_finish_request(tap, &res, request);
 	}
 
-	up_read(&tap->tap_sem);
 
-	blktap_run_deferred();
-
-	return 0;
+	blktap_device_restart(tap);
+	return;
 }
 
 static int blktap_ring_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
@@ -163,29 +156,14 @@
 }
 
 static void
-blktap_ring_vm_unmap(struct vm_area_struct *vma)
-{
-	struct blktap *tap = vma_to_blktap(vma);
-
-	down_write(&tap->tap_sem);
-	clear_bit(BLKTAP_RING_VMA, &tap->dev_inuse);
-	clear_bit(BLKTAP_PAUSED, &tap->dev_inuse);
-	clear_bit(BLKTAP_PAUSE_REQUESTED, &tap->dev_inuse);
-	up_write(&tap->tap_sem);
-}
-
-static void
 blktap_ring_vm_close(struct vm_area_struct *vma)
 {
 	struct blktap *tap = vma_to_blktap(vma);
 	struct blktap_ring *ring = &tap->ring;
 
-	blktap_ring_vm_unmap(vma);                 /* fail future requests */
 	blktap_device_fail_pending_requests(tap);  /* fail pending requests */
 	blktap_device_restart(tap);                /* fail deferred requests */
 
-	down_write(&tap->tap_sem);
-
 	zap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
 
 	kfree(ring->foreign_map.map);
@@ -198,16 +176,17 @@
 	BTINFO("unmapping ring %d\n", tap->minor);
 	ring->ring.sring = NULL;
 	ring->vma = NULL;
+	clear_bit(BLKTAP_RING_VMA, &tap->dev_inuse);
 
-	up_write(&tap->tap_sem);
+	clear_bit(BLKTAP_PAUSED, &tap->dev_inuse);
+	clear_bit(BLKTAP_PAUSE_REQUESTED, &tap->dev_inuse);
 
 	wake_up(&tap->wq);
 }
 
 static struct vm_operations_struct blktap_ring_vm_operations = {
 	.close    = blktap_ring_vm_close,
-	.unmap    = blktap_ring_vm_unmap,
-	.fault   = blktap_ring_fault,
+	.fault    = blktap_ring_fault,
 	.zap_pte  = blktap_ring_clear_pte,
 };
 
@@ -363,10 +342,8 @@
 {
 	struct blktap_ring *ring = &tap->ring;
 
-	down_read(&tap->tap_sem);
 	if (ring->ring.sring)
 		ring->ring.sring->pad[0] = msg;
-	up_read(&tap->tap_sem);
 }
 
 static int
@@ -381,12 +358,16 @@
 	switch(cmd) {
 	case BLKTAP2_IOCTL_KICK_FE:
 		/* There are fe messages to process. */
-		return blktap_read_ring(tap);
+		blktap_read_ring(tap);
+		return 0;
 
 	case BLKTAP2_IOCTL_CREATE_DEVICE:
 		if (!arg)
 			return -EINVAL;
 
+		if (!blktap_active(tap))
+			return -ENODEV;
+
 		if (copy_from_user(&params, (struct blktap_params __user *)arg,
 				   sizeof(params))) {
 			BTERR("failed to get params\n");
@@ -473,13 +454,26 @@
 {
 	struct blktap *tap = filp->private_data;
 	struct blktap_ring *ring = &tap->ring;
+	int work = 0;
+
+	down_read(&current->mm->mmap_sem);
+
+	if (!blktap_active(tap)) {
+		up_read(&current->mm->mmap_sem);
+		force_sig(SIGSEGV, current);
+		return 0;
+	}
 
 	poll_wait(filp, &ring->poll_wait, wait);
-	if (ring->ring.sring->pad[0] != 0 ||
-	    ring->ring.req_prod_pvt != ring->ring.sring->req_prod) {
-		RING_PUSH_REQUESTS(&ring->ring);
+
+	if (test_bit(BLKTAP_DEVICE, &tap->dev_inuse))
+		work = blktap_device_run_queue(tap);
+
+	up_read(&current->mm->mmap_sem);
+
+	if (work ||
+	    ring->ring.sring->pad[0])
 		return POLLIN | POLLRDNORM;
-	}
 
 	return 0;
 }
diff -r 16fc7d4e03d6 -r 989a51acce0a drivers/xen/blktap/sysfs.c
--- a/drivers/xen/blktap/sysfs.c	Wed Jun 02 19:45:24 2010 -0700
+++ b/drivers/xen/blktap/sysfs.c	Wed Jun 02 19:45:24 2010 -0700
@@ -265,8 +265,6 @@
 		       "device users: %d\n", tap->params.capacity,
 		       tap->params.sector_size, tap->device.users);
 
-	down_read(&tap->tap_sem);
-
 	tmp += sprintf(tmp, "pending requests: %d\n", tap->pending_cnt);
 	for (i = 0; i < MAX_PENDING_REQS; i++) {
 		struct blktap_request *req = tap->pending_requests[i];
@@ -282,7 +280,6 @@
 			       req->time.tv_usec);
 	}
 
-	up_read(&tap->tap_sem);
 	ret = (tmp - buf) + 1;
 
 out:
diff -r 16fc7d4e03d6 -r 989a51acce0a drivers/xen/blktap/wait_queue.c
--- a/drivers/xen/blktap/wait_queue.c	Wed Jun 02 19:45:24 2010 -0700
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,40 +0,0 @@
-#include <linux/list.h>
-#include <linux/spinlock.h>
-
-#include "blktap.h"
-
-static LIST_HEAD(deferred_work_queue);
-static DEFINE_SPINLOCK(deferred_work_lock);
-
-void
-blktap_run_deferred(void)
-{
-	LIST_HEAD(queue);
-	struct blktap *tap;
-	unsigned long flags;
-
-	spin_lock_irqsave(&deferred_work_lock, flags);
-	list_splice_init(&deferred_work_queue, &queue);
-	list_for_each_entry(tap, &queue, deferred_queue)
-		clear_bit(BLKTAP_DEFERRED, &tap->dev_inuse);
-	spin_unlock_irqrestore(&deferred_work_lock, flags);
-
-	while (!list_empty(&queue)) {
-		tap = list_entry(queue.next, struct blktap, deferred_queue);
-		list_del_init(&tap->deferred_queue);
-		blktap_device_restart(tap);
-	}
-}
-
-void
-blktap_defer(struct blktap *tap)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&deferred_work_lock, flags);
-	if (!test_bit(BLKTAP_DEFERRED, &tap->dev_inuse)) {
-		set_bit(BLKTAP_DEFERRED, &tap->dev_inuse);
-		list_add_tail(&tap->deferred_queue, &deferred_work_queue);
-	}
-	spin_unlock_irqrestore(&deferred_work_lock, flags);
-}

[-- Attachment #2: Type: text/plain, Size: 138 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

[PATCH 2 of 7] linux: Remove unmap hook from vm_operations struct

[Daniel Stodden]

[-- Attachment #1: blktap-kern-vma-unmap.diff --]
[-- Type: text/x-patch, Size: 1787 bytes --]

linux: Remove unmap hook from vm_operations struct.

Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com>

diff -r 989a51acce0a -r 68eb38b6b16b include/linux/mm.h
--- a/include/linux/mm.h	Wed Jun 02 19:45:24 2010 -0700
+++ b/include/linux/mm.h	Wed Jun 02 19:45:25 2010 -0700
@@ -206,10 +206,6 @@
 	 * original value of @ptep. */
 	pte_t (*zap_pte)(struct vm_area_struct *vma, 
 			 unsigned long addr, pte_t *ptep, int is_fullmm);
-
-	/* called before close() to indicate no more pages should be mapped */
-	void (*unmap)(struct vm_area_struct *area);
-
 #ifdef CONFIG_NUMA
 	/*
 	 * set_policy() op must add a reference to any non-NULL @new mempolicy
diff -r 989a51acce0a -r 68eb38b6b16b mm/mmap.c
--- a/mm/mmap.c	Wed Jun 02 19:45:24 2010 -0700
+++ b/mm/mmap.c	Wed Jun 02 19:45:25 2010 -0700
@@ -1799,12 +1799,6 @@
 	tlb_finish_mmu(tlb, start, end);
 }
 
-static inline void unmap_vma(struct vm_area_struct *vma)
-{
-	if (unlikely(vma->vm_ops && vma->vm_ops->unmap))
-		vma->vm_ops->unmap(vma);
-}
-
 /*
  * Create a list of vma's touched by the unmap, removing them from the mm's
  * vma list as we go..
@@ -1820,7 +1814,6 @@
 	insertion_point = (prev ? &prev->vm_next : &mm->mmap);
 	do {
 		rb_erase(&vma->vm_rb, &mm->mm_rb);
-		unmap_vma(vma);
 		mm->map_count--;
 		tail_vma = vma;
 		vma = vma->vm_next;
@@ -2103,7 +2096,7 @@
 void exit_mmap(struct mm_struct *mm)
 {
 	struct mmu_gather *tlb;
-	struct vm_area_struct *vma, *vma_tmp;
+	struct vm_area_struct *vma;
 	unsigned long nr_accounted = 0;
 	unsigned long end;
 
@@ -2125,9 +2118,6 @@
 	if (!vma)	/* Can happen if dup_mmap() received an OOM */
 		return;
 
-	for (vma_tmp = mm->mmap; vma_tmp; vma_tmp = vma_tmp->vm_next)
-		unmap_vma(vma_tmp);
-
 	lru_add_drain();
 	flush_cache_mm(mm);
 	tlb = tlb_gather_mmu(mm, 1);

[-- Attachment #2: Type: text/plain, Size: 138 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

[PATCH 3 of 7] blktap: Remove broken sysfs pause/resume API

[Daniel Stodden]

[-- Attachment #1: blktap-rm-sysfs-pause.diff --]
[-- Type: text/x-patch, Size: 10902 bytes --]

blktap: Remove broken sysfs pause/resume API.

Safe to remove. This never worked on kernels > 2.6.18 anyway, because
the original pause/resume attribute flipping would deadlock. Newer
toolstacks should use tap-ctl calls instead.

Signed-off-by: Jake Wires <jake.wires@citrix.com>
Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com>

diff -r 68eb38b6b16b -r 69301010e4cf drivers/xen/blktap/blktap.h
--- a/drivers/xen/blktap/blktap.h	Wed Jun 02 19:45:25 2010 -0700
+++ b/drivers/xen/blktap/blktap.h	Wed Jun 02 19:45:25 2010 -0700
@@ -31,8 +31,6 @@
 #define BLKTAP_RING_FD               2
 #define BLKTAP_RING_VMA              3
 #define BLKTAP_DEVICE                4
-#define BLKTAP_PAUSE_REQUESTED       6
-#define BLKTAP_PAUSED                7
 #define BLKTAP_SHUTDOWN_REQUESTED    8
 #define BLKTAP_PASSTHROUGH           9
 
@@ -41,15 +39,9 @@
 #define BLKTAP2_IOCTL_ALLOC_TAP	     200
 #define BLKTAP2_IOCTL_FREE_TAP       201
 #define BLKTAP2_IOCTL_CREATE_DEVICE  202
-#define BLKTAP2_IOCTL_SET_PARAMS     203
-#define BLKTAP2_IOCTL_PAUSE          204
-#define BLKTAP2_IOCTL_REOPEN         205
-#define BLKTAP2_IOCTL_RESUME         206
 
 #define BLKTAP2_MAX_MESSAGE_LEN      256
 
-#define BLKTAP2_RING_MESSAGE_PAUSE   1
-#define BLKTAP2_RING_MESSAGE_RESUME  2
 #define BLKTAP2_RING_MESSAGE_CLOSE   3
 
 #define BLKTAP_REQUEST_FREE          0
@@ -120,8 +112,6 @@
 	unsigned long                  ring_vstart;
 	unsigned long                  user_vstart;
 
-	int                            response;
-
 	wait_queue_head_t              poll_wait;
 
 	dev_t                          devno;
@@ -203,8 +193,6 @@
 int blktap_ring_free(void);
 int blktap_ring_create(struct blktap *);
 int blktap_ring_destroy(struct blktap *);
-int blktap_ring_pause(struct blktap *);
-int blktap_ring_resume(struct blktap *);
 void blktap_ring_kick_user(struct blktap *);
 
 int blktap_sysfs_init(void);
@@ -216,8 +204,6 @@
 void blktap_device_free(void);
 int blktap_device_create(struct blktap *);
 int blktap_device_destroy(struct blktap *);
-int blktap_device_pause(struct blktap *);
-int blktap_device_resume(struct blktap *);
 int blktap_device_run_queue(struct blktap *);
 void blktap_device_restart(struct blktap *);
 void blktap_device_finish_request(struct blktap *,
diff -r 68eb38b6b16b -r 69301010e4cf drivers/xen/blktap/device.c
--- a/drivers/xen/blktap/device.c	Wed Jun 02 19:45:25 2010 -0700
+++ b/drivers/xen/blktap/device.c	Wed Jun 02 19:45:25 2010 -0700
@@ -923,52 +923,6 @@
 }
 
 int
-blktap_device_resume(struct blktap *tap)
-{
-	int err;
-
-	if (!test_bit(BLKTAP_DEVICE, &tap->dev_inuse) || !blktap_active(tap))
-		return -ENODEV;
-
-	if (!test_bit(BLKTAP_PAUSED, &tap->dev_inuse))
-		return 0;
-
-	err = blktap_ring_resume(tap);
-	if (err)
-		return err;
-
-	/* device size may have changed */
-	blktap_device_configure(tap);
-
-	BTDBG("restarting device\n");
-	blktap_device_restart(tap);
-
-	return 0;
-}
-
-int
-blktap_device_pause(struct blktap *tap)
-{
-	unsigned long flags;
-	struct blktap_device *dev = &tap->device;
-
-	if (!test_bit(BLKTAP_DEVICE, &tap->dev_inuse) || !blktap_active(tap))
-		return -ENODEV;
-
-	if (test_bit(BLKTAP_PAUSED, &tap->dev_inuse))
-		return 0;
-
-	spin_lock_irqsave(&dev->lock, flags);
-
-	blk_stop_queue(dev->gd->queue);
-	set_bit(BLKTAP_PAUSE_REQUESTED, &tap->dev_inuse);
-
-	spin_unlock_irqrestore(&dev->lock, flags);
-
-	return blktap_ring_pause(tap);
-}
-
-int
 blktap_device_destroy(struct blktap *tap)
 {
 	struct blktap_device *dev = &tap->device;
diff -r 68eb38b6b16b -r 69301010e4cf drivers/xen/blktap/request.c
--- a/drivers/xen/blktap/request.c	Wed Jun 02 19:45:25 2010 -0700
+++ b/drivers/xen/blktap/request.c	Wed Jun 02 19:45:25 2010 -0700
@@ -238,12 +238,10 @@
 	list_add(&request->free_list, &pool.free_list);
 	atomic_dec(&handle->bucket->reqs_in_use);
 	free = atomic_dec_and_test(&pool.reqs_in_use);
+	tap->pending_cnt--;
 
 	spin_unlock_irqrestore(&pool.lock, flags);
 
-	if (--tap->pending_cnt == 0)
-		wake_up_interruptible(&tap->wq);
-
 	if (free)
 		wake_up(&pool.wait_queue);
 }
diff -r 68eb38b6b16b -r 69301010e4cf drivers/xen/blktap/ring.c
--- a/drivers/xen/blktap/ring.c	Wed Jun 02 19:45:25 2010 -0700
+++ b/drivers/xen/blktap/ring.c	Wed Jun 02 19:45:25 2010 -0700
@@ -178,9 +178,6 @@
 	ring->vma = NULL;
 	clear_bit(BLKTAP_RING_VMA, &tap->dev_inuse);
 
-	clear_bit(BLKTAP_PAUSED, &tap->dev_inuse);
-	clear_bit(BLKTAP_PAUSE_REQUESTED, &tap->dev_inuse);
-
 	wake_up(&tap->wq);
 }
 
@@ -381,70 +378,6 @@
 
 		tap->params = params;
 		return blktap_device_create(tap);
-
-	case BLKTAP2_IOCTL_SET_PARAMS:
-		if (!arg)
-			return -EINVAL;
-
-		if (!test_bit(BLKTAP_PAUSED, &tap->dev_inuse))
-			return -EINVAL;
-
-		if (copy_from_user(&params, (struct blktap_params __user *)arg,
-				   sizeof(params))) {
-			BTERR("failed to get params\n");
-			return -EFAULT;
-		}
-
-		if (blktap_validate_params(tap, &params)) {
-			BTERR("invalid params\n");
-			return -EINVAL;
-		}
-
-		tap->params = params;
-		return 0;
-
-	case BLKTAP2_IOCTL_PAUSE:
-		if (!test_bit(BLKTAP_PAUSE_REQUESTED, &tap->dev_inuse))
-			return -EINVAL;
-
-		set_bit(BLKTAP_PAUSED, &tap->dev_inuse);
-		clear_bit(BLKTAP_PAUSE_REQUESTED, &tap->dev_inuse);
-
-		blktap_ring_set_message(tap, 0);
-		wake_up_interruptible(&tap->wq);
-
-		return 0;
-
-
-	case BLKTAP2_IOCTL_REOPEN:
-		if (!test_bit(BLKTAP_PAUSED, &tap->dev_inuse))
-			return -EINVAL;
-
-		if (!arg)
-			return -EINVAL;
-
-		if (copy_to_user((char __user *)arg,
-				 tap->params.name,
-				 strlen(tap->params.name) + 1))
-			return -EFAULT;
-
-		blktap_ring_set_message(tap, 0);
-		wake_up_interruptible(&tap->wq);
-
-		return 0;
-
-	case BLKTAP2_IOCTL_RESUME:
-		if (!test_bit(BLKTAP_PAUSED, &tap->dev_inuse))
-			return -EINVAL;
-
-		tap->ring.response = (int)arg;
-		if (!tap->ring.response)
-			clear_bit(BLKTAP_PAUSED, &tap->dev_inuse);
-
-		blktap_ring_set_message(tap, 0);
-		wake_up_interruptible(&tap->wq);
-
-		return 0;
 	}
 
 	return -ENOIOCTLCMD;
@@ -494,66 +427,6 @@
 }
 
 int
-blktap_ring_resume(struct blktap *tap)
-{
-	int err;
-	struct blktap_ring *ring = &tap->ring;
-
-	if (!blktap_active(tap))
-		return -ENODEV;
-
-	if (!test_bit(BLKTAP_PAUSED, &tap->dev_inuse))
-		return -EINVAL;
-
-	/* set shared flag for resume */
-	ring->response = 0;
-
-	blktap_ring_set_message(tap, BLKTAP2_RING_MESSAGE_RESUME);
-	blktap_ring_kick_user(tap);
-
-	wait_event_interruptible(tap->wq, ring->response ||
-				 !test_bit(BLKTAP_PAUSED, &tap->dev_inuse));
-
-	err = ring->response;
-	ring->response = 0;
-
-	BTDBG("err: %d\n", err);
-
-	if (err)
-		return err;
-
-	if (test_bit(BLKTAP_PAUSED, &tap->dev_inuse))
-		return -EAGAIN;
-
-	return 0;
-}
-
-int
-blktap_ring_pause(struct blktap *tap)
-{
-	if (!blktap_active(tap))
-		return -ENODEV;
-
-	if (!test_bit(BLKTAP_PAUSE_REQUESTED, &tap->dev_inuse))
-		return -EINVAL;
-
-	BTDBG("draining queue\n");
-	wait_event_interruptible(tap->wq, !tap->pending_cnt);
-	if (tap->pending_cnt)
-		return -EAGAIN;
-
-	blktap_ring_set_message(tap, BLKTAP2_RING_MESSAGE_PAUSE);
-	blktap_ring_kick_user(tap);
-
-	BTDBG("waiting for tapdisk response\n");
-	wait_event_interruptible(tap->wq, test_bit(BLKTAP_PAUSED, &tap->dev_inuse));
-	if (!test_bit(BLKTAP_PAUSED, &tap->dev_inuse))
-		return -EAGAIN;
-
-	return 0;
-}
-
-int
 blktap_ring_destroy(struct blktap *tap)
 {
 	if (!test_bit(BLKTAP_RING_FD, &tap->dev_inuse) &&
diff -r 68eb38b6b16b -r 69301010e4cf drivers/xen/blktap/sysfs.c
--- a/drivers/xen/blktap/sysfs.c	Wed Jun 02 19:45:25 2010 -0700
+++ b/drivers/xen/blktap/sysfs.c	Wed Jun 02 19:45:25 2010 -0700
@@ -38,12 +38,6 @@
 }
 
 #define CLASS_DEVICE_ATTR(a,b,c,d) DEVICE_ATTR(a,b,c,d)
-
-static ssize_t blktap_sysfs_pause_device(struct device *, struct device_attribute *, const char *, size_t);
-CLASS_DEVICE_ATTR(pause, S_IWUSR, NULL, blktap_sysfs_pause_device);
-static ssize_t blktap_sysfs_resume_device(struct device *, struct device_attribute *, const char *, size_t);
-CLASS_DEVICE_ATTR(resume, S_IWUSR, NULL, blktap_sysfs_resume_device);
-
 static ssize_t
 blktap_sysfs_set_name(struct device *dev, struct device_attribute *attr, const char *buf, size_t size)
 {
@@ -57,12 +51,6 @@
 		err = -ENODEV;
 		goto out;
 	}
-
-	if (!test_bit(BLKTAP_PAUSED, &tap->dev_inuse)) {
-		err = -EPERM;
-		goto out;
-	}
-
 	if (size > BLKTAP2_MAX_MESSAGE_LEN) {
 		err = -ENAMETOOLONG;
 		goto out;
@@ -123,81 +111,6 @@
 }
 CLASS_DEVICE_ATTR(remove, S_IWUSR, NULL, blktap_sysfs_remove_device);
 
-static ssize_t
-blktap_sysfs_pause_device(struct device *dev,
-			  struct device_attribute *attr,
-			  const char *buf, size_t size)
-{
-	int err;
-	struct blktap *tap = (struct blktap *)dev_get_drvdata(dev);
-
-	blktap_sysfs_enter(tap);
-
-	BTDBG("pausing %u:%u: dev_inuse: %lu\n",
-	      MAJOR(tap->ring.devno), MINOR(tap->ring.devno), tap->dev_inuse);
-
-	if (!tap->ring.dev ||
-	    test_bit(BLKTAP_SHUTDOWN_REQUESTED, &tap->dev_inuse)) {
-		err = -ENODEV;
-		goto out;
-	}
-
-	if (test_bit(BLKTAP_PAUSE_REQUESTED, &tap->dev_inuse)) {
-		err = -EBUSY;
-		goto out;
-	}
-
-	if (test_bit(BLKTAP_PAUSED, &tap->dev_inuse)) {
-		err = 0;
-		goto out;
-	}
-
-	err = blktap_device_pause(tap);
-	if (!err) {
-		device_remove_file(dev, &dev_attr_pause);
-		err = device_create_file(dev, &dev_attr_resume);
-	}
-
-out:
-	blktap_sysfs_exit(tap);
-
-	return (err ? err : size);
-}
-
-static ssize_t
-blktap_sysfs_resume_device(struct device *dev,
-			   struct device_attribute *attr,
-			   const char *buf, size_t size)
-{
-	int err;
-	struct blktap *tap = (struct blktap *)dev_get_drvdata(dev);
-
-	blktap_sysfs_enter(tap);
-
-	if (!tap->ring.dev ||
-	    test_bit(BLKTAP_SHUTDOWN_REQUESTED, &tap->dev_inuse)) {
-		err = -ENODEV;
-		goto out;
-	}
-
-	if (!test_bit(BLKTAP_PAUSED, &tap->dev_inuse)) {
-		err = -EINVAL;
-		goto out;
-	}
-
-	err = blktap_device_resume(tap);
-	if (!err) {
-		device_remove_file(dev, &dev_attr_resume);
-		err = device_create_file(dev, &dev_attr_pause);
-	}
-
-out:
-	blktap_sysfs_exit(tap);
-
-	BTDBG("returning %zd\n", (err ? err : size));
-	return (err ? err : size);
-}
-
 #ifdef ENABLE_PASSTHROUGH
 static ssize_t
 blktap_sysfs_enable_passthrough(struct device *dev,
@@ -316,26 +229,18 @@
 	printk(KERN_CRIT "%s: adding attributes for dev %p\n", __func__, dev);
 	err = device_create_file(dev, &dev_attr_name);
 	if (err)
-		goto out;
+		goto fail;
 	err = device_create_file(dev, &dev_attr_remove);
 	if (err)
-		goto out_unregister_name;
-	err = device_create_file(dev, &dev_attr_pause);
-	if (err)
-		goto out_unregister_remove;
+		goto fail;
 	err = device_create_file(dev, &dev_attr_debug);
 	if (err)
-		goto out_unregister_pause;
+		goto fail;
 
 	return 0;
 
-out_unregister_pause:
-	device_remove_file(dev, &dev_attr_pause);
-out_unregister_remove:
-	device_remove_file(dev, &dev_attr_remove);
-out_unregister_name:
-	device_remove_file(dev, &dev_attr_name);
-out:
+fail:
+	device_unregister(dev);
 	return err;
 }
 

[-- Attachment #2: Type: text/plain, Size: 138 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

[PATCH 4 of 7] blktap: Make the device destruction path synchronous

[Daniel Stodden]

[-- Attachment #1: blktap-device-destroy-sync.diff --]
[-- Type: text/x-patch, Size: 5491 bytes --]

blktap: Make the device destruction path synchronous.

diff -r 69301010e4cf -r 6a74cabb7220 drivers/xen/blktap/control.c
--- a/drivers/xen/blktap/control.c	Wed Jun 02 19:45:25 2010 -0700
+++ b/drivers/xen/blktap/control.c	Wed Jun 02 19:45:25 2010 -0700
@@ -163,46 +163,29 @@
 blktap_control_destroy_device(struct blktap *tap)
 {
 	int err;
-	unsigned long inuse;
 
 	if (!tap)
 		return 0;
 
 	set_bit(BLKTAP_SHUTDOWN_REQUESTED, &tap->dev_inuse);
 
-	for (;;) {
-		inuse = tap->dev_inuse;
-		err   = blktap_device_destroy(tap);
-		if (err)
-			goto wait;
+	err = blktap_device_destroy(tap);
+	if (err)
+		return err;
 
-		inuse = tap->dev_inuse;
-		err   = blktap_ring_destroy(tap);
-		if (err)
-			goto wait;
+	err = blktap_sysfs_destroy(tap);
+	if (err)
+		return err;
 
-		inuse = tap->dev_inuse;
-		err   = blktap_sysfs_destroy(tap);
-		if (err)
-			goto wait;
-
-		break;
-
-	wait:
-		BTDBG("inuse: 0x%lx, dev_inuse: 0x%lx\n",
-		      inuse, tap->dev_inuse);
-		if (wait_event_interruptible(tap->wq, tap->dev_inuse != inuse))
-			break;
-	}
+	err = blktap_ring_destroy(tap);
+	if (err)
+		return err;
 
 	clear_bit(BLKTAP_SHUTDOWN_REQUESTED, &tap->dev_inuse);
+	clear_bit(BLKTAP_CONTROL, &tap->dev_inuse);
+	wake_up(&tap->wq);
 
-	if (tap->dev_inuse == (1UL << BLKTAP_CONTROL)) {
-		err = 0;
-		clear_bit(BLKTAP_CONTROL, &tap->dev_inuse);
-	}
-
-	return err;
+	return 0;
 }
 
 static int __init
diff -r 69301010e4cf -r 6a74cabb7220 drivers/xen/blktap/device.c
--- a/drivers/xen/blktap/device.c	Wed Jun 02 19:45:25 2010 -0700
+++ b/drivers/xen/blktap/device.c	Wed Jun 02 19:45:25 2010 -0700
@@ -65,7 +65,7 @@
 
 	dev->users--;
 	if (test_bit(BLKTAP_SHUTDOWN_REQUESTED, &tap->dev_inuse))
-		blktap_device_destroy(tap);
+		blktap_control_destroy_device(tap);
 
 	return 0;
 }
@@ -306,7 +306,6 @@
 	unsigned long kvaddr;
 
 	usr_idx = request->usr_idx;
-	down_write(&tap->ring.vma->vm_mm->mmap_sem);
 
 	for (i = 0; i < request->nr_pages; i++) {
 		kvaddr = request_to_kaddr(request, i);
@@ -324,13 +323,17 @@
 		}
 	}
 
-	blktap_device_fast_flush(tap, request);
-	up_write(&tap->ring.vma->vm_mm->mmap_sem);
+	if (blktap_active(tap)) {
+		down_write(&tap->ring.vma->vm_mm->mmap_sem);
+		blktap_device_fast_flush(tap, request);
+		up_write(&tap->ring.vma->vm_mm->mmap_sem);
+	}
 }
 
 /*
  * called if the tapdisk process dies unexpectedly.
  * fail and release any pending requests and disable queue.
+ * may be called from non-tapdisk context.
  */
 void
 blktap_device_fail_pending_requests(struct blktap *tap)
@@ -933,8 +936,11 @@
 
 	BTINFO("destroy device %d users %d\n", tap->minor, dev->users);
 
-	if (dev->users)
+	if (dev->users) {
+		blktap_device_fail_pending_requests(tap);
+		blktap_device_restart(tap);
 		return -EBUSY;
+	}
 
 	spin_lock_irq(&dev->lock);
 	/* No more blktap_device_do_request(). */
@@ -952,8 +958,6 @@
 	blk_cleanup_queue(gd->queue);
 	put_disk(gd);
 
-	wake_up(&tap->wq);
-
 	return 0;
 }
 
diff -r 69301010e4cf -r 6a74cabb7220 drivers/xen/blktap/ring.c
--- a/drivers/xen/blktap/ring.c	Wed Jun 02 19:45:25 2010 -0700
+++ b/drivers/xen/blktap/ring.c	Wed Jun 02 19:45:25 2010 -0700
@@ -161,24 +161,12 @@
 	struct blktap *tap = vma_to_blktap(vma);
 	struct blktap_ring *ring = &tap->ring;
 
-	blktap_device_fail_pending_requests(tap);  /* fail pending requests */
-	blktap_device_restart(tap);                /* fail deferred requests */
+	BTINFO("unmapping ring %d\n", tap->minor);
+	zap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
+	clear_bit(BLKTAP_RING_VMA, &tap->dev_inuse);
+	ring->vma = NULL;
 
-	zap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
-
-	kfree(ring->foreign_map.map);
-	ring->foreign_map.map = NULL;
-
-	/* Free the ring page. */
-	ClearPageReserved(virt_to_page(ring->ring.sring));
-	free_page((unsigned long)ring->ring.sring);
-
-	BTINFO("unmapping ring %d\n", tap->minor);
-	ring->ring.sring = NULL;
-	ring->vma = NULL;
-	clear_bit(BLKTAP_RING_VMA, &tap->dev_inuse);
-
-	wake_up(&tap->wq);
+	blktap_control_destroy_device(tap);
 }
 
 static struct vm_operations_struct blktap_ring_vm_operations = {
@@ -206,6 +194,9 @@
 	if (!test_bit(BLKTAP_CONTROL, &tap->dev_inuse))
 		return -ENODEV;
 
+	if (test_bit(BLKTAP_SHUTDOWN_REQUESTED, &tap->dev_inuse))
+		return -EBUSY;
+
 	/* Only one process can access ring at a time */
 	if (test_and_set_bit(BLKTAP_RING_FD, &tap->dev_inuse))
 		return -EBUSY;
@@ -224,7 +215,9 @@
 	BTINFO("freeing device %d\n", tap->minor);
 	clear_bit(BLKTAP_RING_FD, &tap->dev_inuse);
 	filp->private_data = NULL;
-	wake_up(&tap->wq);	
+
+	blktap_control_destroy_device(tap);
+
 	return 0;
 }
 
diff -r 69301010e4cf -r 6a74cabb7220 drivers/xen/blktap/sysfs.c
--- a/drivers/xen/blktap/sysfs.c	Wed Jun 02 19:45:25 2010 -0700
+++ b/drivers/xen/blktap/sysfs.c	Wed Jun 02 19:45:25 2010 -0700
@@ -96,7 +96,6 @@
 			   struct device_attribute *attr,
 			   const char *buf, size_t size)
 {
-	int err;
 	struct blktap *tap = (struct blktap *)dev_get_drvdata(dev);
 
 	if (!tap->ring.dev)
@@ -105,9 +104,13 @@
 	if (test_and_set_bit(BLKTAP_SHUTDOWN_REQUESTED, &tap->dev_inuse))
 		return -EBUSY;
 
-	err = blktap_control_destroy_device(tap);
+	BTDBG("sending tapdisk close message\n");
+	tap->ring.ring.sring->pad[0] = BLKTAP2_RING_MESSAGE_CLOSE;
+	blktap_ring_kick_user(tap);
+	wait_event_interruptible(tap->wq,
+				 !test_bit(BLKTAP_CONTROL, &tap->dev_inuse));
 
-	return (err ? : size);
+	return 0;
 }
 CLASS_DEVICE_ATTR(remove, S_IWUSR, NULL, blktap_sysfs_remove_device);
 

[-- Attachment #2: Type: text/plain, Size: 138 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

[PATCH 5 of 7] blktap: Remove obsolete kernel version dependencies

[Daniel Stodden]

[-- Attachment #1: blktap-rm-versionisms.diff --]
[-- Type: text/x-patch, Size: 1467 bytes --]

blktap: Remove obsolete kernel version dependencies.

Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com>

diff -r 6a74cabb7220 -r 699e1fad7561 drivers/xen/blktap/device.c
--- a/drivers/xen/blktap/device.c	Wed Jun 02 19:45:25 2010 -0700
+++ b/drivers/xen/blktap/device.c	Wed Jun 02 19:45:25 2010 -0700
@@ -97,26 +97,6 @@
 		      command, (long)argument, inode->i_rdev);
 
 	switch (command) {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,16)
-	case HDIO_GETGEO: {
-		struct hd_geometry geo;
-		int ret;
-
-                if (!argument)
-                        return -EINVAL;
-
-		geo.start = get_start_sect(bd);
-		ret = blktap_device_getgeo(bd, &geo);
-		if (ret)
-			return ret;
-
-		if (copy_to_user((struct hd_geometry __user *)argument, &geo,
-				 sizeof(geo)))
-                        return -EFAULT;
-
-                return 0;
-	}
-#endif
 	case CDROMMULTISESSION:
 		BTDBG("FIXME: support multisession CDs later\n");
 		for (i = 0; i < sizeof(struct cdrom_multisession); i++)
@@ -149,9 +129,7 @@
 	.open      = blktap_device_open,
 	.release   = blktap_device_release,
 	.ioctl     = blktap_device_ioctl,
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
 	.getgeo    = blktap_device_getgeo
-#endif
 };
 
 static int
@@ -1005,11 +983,7 @@
 	if (!rq)
 		goto error;
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,10)
 	elevator_init(rq, "noop");
-#else
-	elevator_init(rq, &elevator_noop);
-#endif
 
 	gd->queue     = rq;
 	rq->queuedata = dev;

[-- Attachment #2: Type: text/plain, Size: 138 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

[PATCH 6 of 7] blktap: Update tap state when failing ring mmap

[Daniel Stodden]

[-- Attachment #1: blktap-ring-fail-mem.diff --]
[-- Type: text/x-patch, Size: 491 bytes --]

blktap: Update tap state when failing ring mmap.

Signed-off-by: Jake Wires <jake.wires@citrix.com>
Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com>

diff -r 699e1fad7561 -r 152ee0de9646 drivers/xen/blktap/ring.c
--- a/drivers/xen/blktap/ring.c	Wed Jun 02 19:45:25 2010 -0700
+++ b/drivers/xen/blktap/ring.c	Wed Jun 02 19:45:25 2010 -0700
@@ -324,6 +324,8 @@
 	free_page((unsigned long)sring);
 	kfree(map);
 
+	clear_bit(BLKTAP_RING_VMA, &tap->dev_inuse);
+
 	return -ENOMEM;
 }
 

[-- Attachment #2: Type: text/plain, Size: 138 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

[PATCH 7 of 7] blktap: Remove passthrough mode

[Daniel Stodden]

[-- Attachment #1: blktap-rm-passthrough.diff --]
[-- Type: text/x-patch, Size: 4524 bytes --]

blktap: Remove passthrough mode.

Signed-off-by: Jake Wires <jake.wires@citrix.com>
Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com>

diff -r 152ee0de9646 -r cc3749a5f7e9 drivers/xen/blktap/blktap.h
--- a/drivers/xen/blktap/blktap.h	Wed Jun 02 19:45:25 2010 -0700
+++ b/drivers/xen/blktap/blktap.h	Wed Jun 02 19:45:25 2010 -0700
@@ -9,8 +9,6 @@
 #include <xen/blkif.h>
 #include <xen/grant_table.h>
 
-//#define ENABLE_PASSTHROUGH
-
 extern int blktap_debug_level;
 
 #define BTPRINTK(level, tag, force, _f, _a...)				\
diff -r 152ee0de9646 -r cc3749a5f7e9 drivers/xen/blktap/device.c
--- a/drivers/xen/blktap/device.c	Wed Jun 02 19:45:25 2010 -0700
+++ b/drivers/xen/blktap/device.c	Wed Jun 02 19:45:25 2010 -0700
@@ -646,98 +646,6 @@
 	return err;
 }
 
-#ifdef ENABLE_PASSTHROUGH
-#define rq_for_each_bio_safe(_bio, _tmp, _req)				\
-	if ((_req)->bio)						\
-		for (_bio = (_req)->bio;				\
-		     _bio && ((_tmp = _bio->bi_next) || 1);		\
-		     _bio = _tmp)
-
-static void
-blktap_device_forward_request(struct blktap *tap, struct request *req)
-{
-	struct bio *bio, *tmp;
-	struct blktap_device *dev;
-
-	dev = &tap->device;
-
-	rq_for_each_bio_safe(bio, tmp, req) {
-		bio->bi_bdev = dev->bdev;
-		submit_bio(bio->bi_rw, bio);
-	}
-}
-
-static void
-blktap_device_close_bdev(struct blktap *tap)
-{
-	struct blktap_device *dev;
-
-	dev = &tap->device;
-
-	if (dev->bdev)
-		blkdev_put(dev->bdev);
-
-	dev->bdev = NULL;
-	clear_bit(BLKTAP_PASSTHROUGH, &tap->dev_inuse);
-}
-
-static int
-blktap_device_open_bdev(struct blktap *tap, u32 pdev)
-{
-	struct block_device *bdev;
-	struct blktap_device *dev;
-
-	dev = &tap->device;
-
-	bdev = open_by_devnum(pdev, FMODE_WRITE);
-	if (IS_ERR(bdev)) {
-		BTERR("opening device %x:%x failed: %ld\n",
-		      MAJOR(pdev), MINOR(pdev), PTR_ERR(bdev));
-		return PTR_ERR(bdev);
-	}
-
-	if (!bdev->bd_disk) {
-		BTERR("device %x:%x doesn't exist\n",
-		      MAJOR(pdev), MINOR(pdev));
-		blkdev_put(dev->bdev);
-		return -ENOENT;
-	}
-
-	dev->bdev = bdev;
-	set_bit(BLKTAP_PASSTHROUGH, &tap->dev_inuse);
-
-	/* TODO: readjust queue parameters */
-
-	BTINFO("set device %d to passthrough on %x:%x\n",
-	       tap->minor, MAJOR(pdev), MINOR(pdev));
-
-	return 0;
-}
-
-int
-blktap_device_enable_passthrough(struct blktap *tap,
-				 unsigned major, unsigned minor)
-{
-	u32 pdev;
-	struct blktap_device *dev;
-
-	dev  = &tap->device;
-	pdev = MKDEV(major, minor);
-
-	if (!test_bit(BLKTAP_PAUSED, &tap->dev_inuse))
-		return -EINVAL;
-
-	if (dev->bdev) {
-		if (pdev)
-			return -EINVAL;
-		blktap_device_close_bdev(tap);
-		return 0;
-	}
-
-	return blktap_device_open_bdev(tap, pdev);
-}
-#endif
-
 /*
  * called from tapdisk context
  */
@@ -769,14 +677,6 @@
 			continue;
 		}
 
-#ifdef ENABLE_PASSTHROUGH
-		if (test_bit(BLKTAP_PASSTHROUGH, &tap->dev_inuse)) {
-			blkdev_dequeue_request(req);
-			blktap_device_forward_request(tap, req);
-			continue;
-		}
-#endif
-
 		if (RING_FULL(&ring->ring)) {
 		wait:
 			/* Avoid pointless unplugs. */
@@ -927,11 +827,6 @@
 	dev->gd = NULL;
 	spin_unlock_irq(&dev->lock);
 
-#ifdef ENABLE_PASSTHROUGH
-	if (dev->bdev)
-		blktap_device_close_bdev(tap);
-#endif
-
 	del_gendisk(gd);
 	blk_cleanup_queue(gd->queue);
 	put_disk(gd);
diff -r 152ee0de9646 -r cc3749a5f7e9 drivers/xen/blktap/sysfs.c
--- a/drivers/xen/blktap/sysfs.c	Wed Jun 02 19:45:25 2010 -0700
+++ b/drivers/xen/blktap/sysfs.c	Wed Jun 02 19:45:25 2010 -0700
@@ -114,50 +114,6 @@
 }
 CLASS_DEVICE_ATTR(remove, S_IWUSR, NULL, blktap_sysfs_remove_device);
 
-#ifdef ENABLE_PASSTHROUGH
-static ssize_t
-blktap_sysfs_enable_passthrough(struct device *dev,
-				const char *buf, size_t size)
-{
-	int err;
-	unsigned major, minor;
-	struct blktap *tap = (struct blktap *)dev_get_drvdata(dev);
-
-	BTINFO("passthrough request enabled\n");
-
-	blktap_sysfs_enter(tap);
-
-	if (!tap->ring.dev ||
-	    test_bit(BLKTAP_SHUTDOWN_REQUESTED, &tap->dev_inuse)) {
-		err = -ENODEV;
-		goto out;
-	}
-
-	if (!test_bit(BLKTAP_PAUSED, &tap->dev_inuse)) {
-		err = -EINVAL;
-		goto out;
-	}
-
-	if (test_bit(BLKTAP_PASSTHROUGH, &tap->dev_inuse)) {
-		err = -EINVAL;
-		goto out;
-	}
-
-	err = sscanf(buf, "%x:%x", &major, &minor);
-	if (err != 2) {
-		err = -EINVAL;
-		goto out;
-	}
-
-	err = blktap_device_enable_passthrough(tap, major, minor);
-
-out:
-	blktap_sysfs_exit(tap);
-	BTDBG("returning %d\n", (err ? err : size));
-	return (err ? err : size);
-}
-#endif
-
 static ssize_t
 blktap_sysfs_debug_device(struct device *dev, struct device_attribute *attr, char *buf)
 {

[-- Attachment #2: Type: text/plain, Size: 138 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

Re: [PATCH 4 of 7] blktap: Make the device destruction path synchronous

[Daniel Stodden]

On Wed, 2010-06-02 at 23:12 -0400, Daniel Stodden wrote:

Signed-off-by: Jake Wires <jake.wires@citrix.com>
Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com>