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authorLinus Torvalds <torvalds@linux-foundation.org>2020-03-07 08:04:54 -0600
committerLinus Torvalds <torvalds@linux-foundation.org>2020-03-07 08:04:54 -0600
commitcbee7c8b4485fb876895b82ddba19ae4e2e2d102 (patch)
tree4f3fac5090b301f8561c6e3f3f356cc494fc5194 /drivers
parentfa883d6afb158c3c9bf33262272da3b6f0489742 (diff)
parent4ab50af63d2eb5da5c1571f8518948514f535782 (diff)
downloadlinux-cbee7c8b4485fb876895b82ddba19ae4e2e2d102.tar.bz2
Merge tag 'for-linus-5.6b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross: "Four fixes and a small cleanup patch: - two fixes by Dongli Zhang fixing races in the xenbus driver - two fixes by me fixing issues introduced in 5.6 - a small cleanup by Gustavo Silva replacing a zero-length array with a flexible-array" * tag 'for-linus-5.6b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/blkfront: fix ring info addressing xen/xenbus: fix locking xenbus: req->err should be updated before req->state xenbus: req->body should be updated before req->state xen: Replace zero-length array with flexible-array member
Diffstat (limited to 'drivers')
-rw-r--r--drivers/block/xen-blkfront.c80
-rw-r--r--drivers/xen/xen-pciback/pciback.h2
-rw-r--r--drivers/xen/xenbus/xenbus_comms.c4
-rw-r--r--drivers/xen/xenbus/xenbus_probe.c10
-rw-r--r--drivers/xen/xenbus/xenbus_probe_backend.c5
-rw-r--r--drivers/xen/xenbus/xenbus_xs.c9
6 files changed, 61 insertions, 49 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index e2ad6bba2281..9df516a56bb2 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -213,6 +213,7 @@ struct blkfront_info
struct blk_mq_tag_set tag_set;
struct blkfront_ring_info *rinfo;
unsigned int nr_rings;
+ unsigned int rinfo_size;
/* Save uncomplete reqs and bios for migration. */
struct list_head requests;
struct bio_list bio_list;
@@ -259,6 +260,18 @@ static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo);
static void blkfront_gather_backend_features(struct blkfront_info *info);
static int negotiate_mq(struct blkfront_info *info);
+#define for_each_rinfo(info, ptr, idx) \
+ for ((ptr) = (info)->rinfo, (idx) = 0; \
+ (idx) < (info)->nr_rings; \
+ (idx)++, (ptr) = (void *)(ptr) + (info)->rinfo_size)
+
+static inline struct blkfront_ring_info *
+get_rinfo(const struct blkfront_info *info, unsigned int i)
+{
+ BUG_ON(i >= info->nr_rings);
+ return (void *)info->rinfo + i * info->rinfo_size;
+}
+
static int get_id_from_freelist(struct blkfront_ring_info *rinfo)
{
unsigned long free = rinfo->shadow_free;
@@ -883,8 +896,7 @@ static blk_status_t blkif_queue_rq(struct blk_mq_hw_ctx *hctx,
struct blkfront_info *info = hctx->queue->queuedata;
struct blkfront_ring_info *rinfo = NULL;
- BUG_ON(info->nr_rings <= qid);
- rinfo = &info->rinfo[qid];
+ rinfo = get_rinfo(info, qid);
blk_mq_start_request(qd->rq);
spin_lock_irqsave(&rinfo->ring_lock, flags);
if (RING_FULL(&rinfo->ring))
@@ -1181,6 +1193,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
static void xlvbd_release_gendisk(struct blkfront_info *info)
{
unsigned int minor, nr_minors, i;
+ struct blkfront_ring_info *rinfo;
if (info->rq == NULL)
return;
@@ -1188,9 +1201,7 @@ static void xlvbd_release_gendisk(struct blkfront_info *info)
/* No more blkif_request(). */
blk_mq_stop_hw_queues(info->rq);
- for (i = 0; i < info->nr_rings; i++) {
- struct blkfront_ring_info *rinfo = &info->rinfo[i];
-
+ for_each_rinfo(info, rinfo, i) {
/* No more gnttab callback work. */
gnttab_cancel_free_callback(&rinfo->callback);
@@ -1339,6 +1350,7 @@ free_shadow:
static void blkif_free(struct blkfront_info *info, int suspend)
{
unsigned int i;
+ struct blkfront_ring_info *rinfo;
/* Prevent new requests being issued until we fix things up. */
info->connected = suspend ?
@@ -1347,8 +1359,8 @@ static void blkif_free(struct blkfront_info *info, int suspend)
if (info->rq)
blk_mq_stop_hw_queues(info->rq);
- for (i = 0; i < info->nr_rings; i++)
- blkif_free_ring(&info->rinfo[i]);
+ for_each_rinfo(info, rinfo, i)
+ blkif_free_ring(rinfo);
kvfree(info->rinfo);
info->rinfo = NULL;
@@ -1775,6 +1787,7 @@ static int talk_to_blkback(struct xenbus_device *dev,
int err;
unsigned int i, max_page_order;
unsigned int ring_page_order;
+ struct blkfront_ring_info *rinfo;
if (!info)
return -ENODEV;
@@ -1788,9 +1801,7 @@ static int talk_to_blkback(struct xenbus_device *dev,
if (err)
goto destroy_blkring;
- for (i = 0; i < info->nr_rings; i++) {
- struct blkfront_ring_info *rinfo = &info->rinfo[i];
-
+ for_each_rinfo(info, rinfo, i) {
/* Create shared ring, alloc event channel. */
err = setup_blkring(dev, rinfo);
if (err)
@@ -1815,7 +1826,7 @@ again:
/* We already got the number of queues/rings in _probe */
if (info->nr_rings == 1) {
- err = write_per_ring_nodes(xbt, &info->rinfo[0], dev->nodename);
+ err = write_per_ring_nodes(xbt, info->rinfo, dev->nodename);
if (err)
goto destroy_blkring;
} else {
@@ -1837,10 +1848,10 @@ again:
goto abort_transaction;
}
- for (i = 0; i < info->nr_rings; i++) {
+ for_each_rinfo(info, rinfo, i) {
memset(path, 0, pathsize);
snprintf(path, pathsize, "%s/queue-%u", dev->nodename, i);
- err = write_per_ring_nodes(xbt, &info->rinfo[i], path);
+ err = write_per_ring_nodes(xbt, rinfo, path);
if (err) {
kfree(path);
goto destroy_blkring;
@@ -1868,9 +1879,8 @@ again:
goto destroy_blkring;
}
- for (i = 0; i < info->nr_rings; i++) {
+ for_each_rinfo(info, rinfo, i) {
unsigned int j;
- struct blkfront_ring_info *rinfo = &info->rinfo[i];
for (j = 0; j < BLK_RING_SIZE(info); j++)
rinfo->shadow[j].req.u.rw.id = j + 1;
@@ -1900,6 +1910,7 @@ static int negotiate_mq(struct blkfront_info *info)
{
unsigned int backend_max_queues;
unsigned int i;
+ struct blkfront_ring_info *rinfo;
BUG_ON(info->nr_rings);
@@ -1911,20 +1922,16 @@ static int negotiate_mq(struct blkfront_info *info)
if (!info->nr_rings)
info->nr_rings = 1;
- info->rinfo = kvcalloc(info->nr_rings,
- struct_size(info->rinfo, shadow,
- BLK_RING_SIZE(info)),
- GFP_KERNEL);
+ info->rinfo_size = struct_size(info->rinfo, shadow,
+ BLK_RING_SIZE(info));
+ info->rinfo = kvcalloc(info->nr_rings, info->rinfo_size, GFP_KERNEL);
if (!info->rinfo) {
xenbus_dev_fatal(info->xbdev, -ENOMEM, "allocating ring_info structure");
info->nr_rings = 0;
return -ENOMEM;
}
- for (i = 0; i < info->nr_rings; i++) {
- struct blkfront_ring_info *rinfo;
-
- rinfo = &info->rinfo[i];
+ for_each_rinfo(info, rinfo, i) {
INIT_LIST_HEAD(&rinfo->indirect_pages);
INIT_LIST_HEAD(&rinfo->grants);
rinfo->dev_info = info;
@@ -2017,6 +2024,7 @@ static int blkif_recover(struct blkfront_info *info)
int rc;
struct bio *bio;
unsigned int segs;
+ struct blkfront_ring_info *rinfo;
blkfront_gather_backend_features(info);
/* Reset limits changed by blk_mq_update_nr_hw_queues(). */
@@ -2024,9 +2032,7 @@ static int blkif_recover(struct blkfront_info *info)
segs = info->max_indirect_segments ? : BLKIF_MAX_SEGMENTS_PER_REQUEST;
blk_queue_max_segments(info->rq, segs / GRANTS_PER_PSEG);
- for (r_index = 0; r_index < info->nr_rings; r_index++) {
- struct blkfront_ring_info *rinfo = &info->rinfo[r_index];
-
+ for_each_rinfo(info, rinfo, r_index) {
rc = blkfront_setup_indirect(rinfo);
if (rc)
return rc;
@@ -2036,10 +2042,7 @@ static int blkif_recover(struct blkfront_info *info)
/* Now safe for us to use the shared ring */
info->connected = BLKIF_STATE_CONNECTED;
- for (r_index = 0; r_index < info->nr_rings; r_index++) {
- struct blkfront_ring_info *rinfo;
-
- rinfo = &info->rinfo[r_index];
+ for_each_rinfo(info, rinfo, r_index) {
/* Kick any other new requests queued since we resumed */
kick_pending_request_queues(rinfo);
}
@@ -2072,13 +2075,13 @@ static int blkfront_resume(struct xenbus_device *dev)
struct blkfront_info *info = dev_get_drvdata(&dev->dev);
int err = 0;
unsigned int i, j;
+ struct blkfront_ring_info *rinfo;
dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename);
bio_list_init(&info->bio_list);
INIT_LIST_HEAD(&info->requests);
- for (i = 0; i < info->nr_rings; i++) {
- struct blkfront_ring_info *rinfo = &info->rinfo[i];
+ for_each_rinfo(info, rinfo, i) {
struct bio_list merge_bio;
struct blk_shadow *shadow = rinfo->shadow;
@@ -2337,6 +2340,7 @@ static void blkfront_connect(struct blkfront_info *info)
unsigned int binfo;
char *envp[] = { "RESIZE=1", NULL };
int err, i;
+ struct blkfront_ring_info *rinfo;
switch (info->connected) {
case BLKIF_STATE_CONNECTED:
@@ -2394,8 +2398,8 @@ static void blkfront_connect(struct blkfront_info *info)
"physical-sector-size",
sector_size);
blkfront_gather_backend_features(info);
- for (i = 0; i < info->nr_rings; i++) {
- err = blkfront_setup_indirect(&info->rinfo[i]);
+ for_each_rinfo(info, rinfo, i) {
+ err = blkfront_setup_indirect(rinfo);
if (err) {
xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s",
info->xbdev->otherend);
@@ -2416,8 +2420,8 @@ static void blkfront_connect(struct blkfront_info *info)
/* Kick pending requests. */
info->connected = BLKIF_STATE_CONNECTED;
- for (i = 0; i < info->nr_rings; i++)
- kick_pending_request_queues(&info->rinfo[i]);
+ for_each_rinfo(info, rinfo, i)
+ kick_pending_request_queues(rinfo);
device_add_disk(&info->xbdev->dev, info->gd, NULL);
@@ -2652,9 +2656,9 @@ static void purge_persistent_grants(struct blkfront_info *info)
{
unsigned int i;
unsigned long flags;
+ struct blkfront_ring_info *rinfo;
- for (i = 0; i < info->nr_rings; i++) {
- struct blkfront_ring_info *rinfo = &info->rinfo[i];
+ for_each_rinfo(info, rinfo, i) {
struct grant *gnt_list_entry, *tmp;
spin_lock_irqsave(&rinfo->ring_lock, flags);
diff --git a/drivers/xen/xen-pciback/pciback.h b/drivers/xen/xen-pciback/pciback.h
index ce1077e32466..7c95516a860f 100644
--- a/drivers/xen/xen-pciback/pciback.h
+++ b/drivers/xen/xen-pciback/pciback.h
@@ -52,7 +52,7 @@ struct xen_pcibk_dev_data {
unsigned int ack_intr:1; /* .. and ACK-ing */
unsigned long handled;
unsigned int irq; /* Saved in case device transitions to MSI/MSI-X */
- char irq_name[0]; /* xen-pcibk[000:04:00.0] */
+ char irq_name[]; /* xen-pcibk[000:04:00.0] */
};
/* Used by XenBus and xen_pcibk_ops.c */
diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c
index d239fc3c5e3d..eb5151fc8efa 100644
--- a/drivers/xen/xenbus/xenbus_comms.c
+++ b/drivers/xen/xenbus/xenbus_comms.c
@@ -313,6 +313,8 @@ static int process_msg(void)
req->msg.type = state.msg.type;
req->msg.len = state.msg.len;
req->body = state.body;
+ /* write body, then update state */
+ virt_wmb();
req->state = xb_req_state_got_reply;
req->cb(req);
} else
@@ -395,6 +397,8 @@ static int process_writes(void)
if (state.req->state == xb_req_state_aborted)
kfree(state.req);
else {
+ /* write err, then update state */
+ virt_wmb();
state.req->state = xb_req_state_got_reply;
wake_up(&state.req->wq);
}
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 66975da4f3b6..8c4d05b687b7 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -239,9 +239,9 @@ int xenbus_dev_probe(struct device *_dev)
goto fail;
}
- spin_lock(&dev->reclaim_lock);
+ down(&dev->reclaim_sem);
err = drv->probe(dev, id);
- spin_unlock(&dev->reclaim_lock);
+ up(&dev->reclaim_sem);
if (err)
goto fail_put;
@@ -271,9 +271,9 @@ int xenbus_dev_remove(struct device *_dev)
free_otherend_watch(dev);
if (drv->remove) {
- spin_lock(&dev->reclaim_lock);
+ down(&dev->reclaim_sem);
drv->remove(dev);
- spin_unlock(&dev->reclaim_lock);
+ up(&dev->reclaim_sem);
}
module_put(drv->driver.owner);
@@ -473,7 +473,7 @@ int xenbus_probe_node(struct xen_bus_type *bus,
goto fail;
dev_set_name(&xendev->dev, "%s", devname);
- spin_lock_init(&xendev->reclaim_lock);
+ sema_init(&xendev->reclaim_sem, 1);
/* Register with generic device framework. */
err = device_register(&xendev->dev);
diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c
index 791f6fe01e91..9b2fbe69bccc 100644
--- a/drivers/xen/xenbus/xenbus_probe_backend.c
+++ b/drivers/xen/xenbus/xenbus_probe_backend.c
@@ -45,6 +45,7 @@
#include <linux/mm.h>
#include <linux/notifier.h>
#include <linux/export.h>
+#include <linux/semaphore.h>
#include <asm/page.h>
#include <asm/pgtable.h>
@@ -257,10 +258,10 @@ static int backend_reclaim_memory(struct device *dev, void *data)
drv = to_xenbus_driver(dev->driver);
if (drv && drv->reclaim_memory) {
xdev = to_xenbus_device(dev);
- if (!spin_trylock(&xdev->reclaim_lock))
+ if (down_trylock(&xdev->reclaim_sem))
return 0;
drv->reclaim_memory(xdev);
- spin_unlock(&xdev->reclaim_lock);
+ up(&xdev->reclaim_sem);
}
return 0;
}
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index ddc18da61834..3a06eb699f33 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -191,8 +191,11 @@ static bool xenbus_ok(void)
static bool test_reply(struct xb_req_data *req)
{
- if (req->state == xb_req_state_got_reply || !xenbus_ok())
+ if (req->state == xb_req_state_got_reply || !xenbus_ok()) {
+ /* read req->state before all other fields */
+ virt_rmb();
return true;
+ }
/* Make sure to reread req->state each time. */
barrier();
@@ -202,7 +205,7 @@ static bool test_reply(struct xb_req_data *req)
static void *read_reply(struct xb_req_data *req)
{
- while (req->state != xb_req_state_got_reply) {
+ do {
wait_event(req->wq, test_reply(req));
if (!xenbus_ok())
@@ -216,7 +219,7 @@ static void *read_reply(struct xb_req_data *req)
if (req->err)
return ERR_PTR(req->err);
- }
+ } while (req->state != xb_req_state_got_reply);
return req->body;
}