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authorLinus Torvalds <torvalds@linux-foundation.org>2019-05-31 10:53:34 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-31 10:53:34 -0700
commit8164c5719b864da3bcfee97ad8af8cfd7ee5ad8c (patch)
tree2259ef4e7a709c9edc2417adacf3da97c6075a47 /drivers/xen/xenbus
parent27a03b1a71b9adfa7f4ef3f61452fb3bc5b195b1 (diff)
parentd10e0cc113c9e1b64b5c6e3db37b5c839794f3df (diff)
Merge tag 'for-linus-5.2b-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross: "One minor cleanup patch and a fix for handling of live migration when running as Xen guest" * tag 'for-linus-5.2b-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xenbus: Avoid deadlock during suspend due to open transactions xen/pvcalls: Remove set but not used variable
Diffstat (limited to 'drivers/xen/xenbus')
-rw-r--r--drivers/xen/xenbus/xenbus.h3
-rw-r--r--drivers/xen/xenbus/xenbus_dev_frontend.c18
-rw-r--r--drivers/xen/xenbus/xenbus_xs.c7
3 files changed, 26 insertions, 2 deletions
diff --git a/drivers/xen/xenbus/xenbus.h b/drivers/xen/xenbus/xenbus.h
index 092981171df1..d75a2385b37c 100644
--- a/drivers/xen/xenbus/xenbus.h
+++ b/drivers/xen/xenbus/xenbus.h
@@ -83,6 +83,7 @@ struct xb_req_data {
int num_vecs;
int err;
enum xb_req_state state;
+ bool user_req;
void (*cb)(struct xb_req_data *);
void *par;
};
@@ -133,4 +134,6 @@ void xenbus_ring_ops_init(void);
int xenbus_dev_request_and_reply(struct xsd_sockmsg *msg, void *par);
void xenbus_dev_queue_reply(struct xb_req_data *req);
+extern unsigned int xb_dev_generation_id;
+
#endif
diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c
index faf452d0edf0..08adc590f631 100644
--- a/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -62,6 +62,8 @@
#include "xenbus.h"
+unsigned int xb_dev_generation_id;
+
/*
* An element of a list of outstanding transactions, for which we're
* still waiting a reply.
@@ -69,6 +71,7 @@
struct xenbus_transaction_holder {
struct list_head list;
struct xenbus_transaction handle;
+ unsigned int generation_id;
};
/*
@@ -441,6 +444,7 @@ static int xenbus_write_transaction(unsigned msg_type,
rc = -ENOMEM;
goto out;
}
+ trans->generation_id = xb_dev_generation_id;
list_add(&trans->list, &u->transactions);
} else if (msg->hdr.tx_id != 0 &&
!xenbus_get_transaction(u, msg->hdr.tx_id))
@@ -449,6 +453,20 @@ static int xenbus_write_transaction(unsigned msg_type,
!(msg->hdr.len == 2 &&
(!strcmp(msg->body, "T") || !strcmp(msg->body, "F"))))
return xenbus_command_reply(u, XS_ERROR, "EINVAL");
+ else if (msg_type == XS_TRANSACTION_END) {
+ trans = xenbus_get_transaction(u, msg->hdr.tx_id);
+ if (trans && trans->generation_id != xb_dev_generation_id) {
+ list_del(&trans->list);
+ kfree(trans);
+ if (!strcmp(msg->body, "T"))
+ return xenbus_command_reply(u, XS_ERROR,
+ "EAGAIN");
+ else
+ return xenbus_command_reply(u,
+ XS_TRANSACTION_END,
+ "OK");
+ }
+ }
rc = xenbus_dev_request_and_reply(&msg->hdr, u);
if (rc && trans) {
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index 49a3874ae6bb..ddc18da61834 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -105,6 +105,7 @@ static void xs_suspend_enter(void)
static void xs_suspend_exit(void)
{
+ xb_dev_generation_id++;
spin_lock(&xs_state_lock);
xs_suspend_active--;
spin_unlock(&xs_state_lock);
@@ -125,7 +126,7 @@ static uint32_t xs_request_enter(struct xb_req_data *req)
spin_lock(&xs_state_lock);
}
- if (req->type == XS_TRANSACTION_START)
+ if (req->type == XS_TRANSACTION_START && !req->user_req)
xs_state_users++;
xs_state_users++;
rq_id = xs_request_id++;
@@ -140,7 +141,7 @@ void xs_request_exit(struct xb_req_data *req)
spin_lock(&xs_state_lock);
xs_state_users--;
if ((req->type == XS_TRANSACTION_START && req->msg.type == XS_ERROR) ||
- (req->type == XS_TRANSACTION_END &&
+ (req->type == XS_TRANSACTION_END && !req->user_req &&
!WARN_ON_ONCE(req->msg.type == XS_ERROR &&
!strcmp(req->body, "ENOENT"))))
xs_state_users--;
@@ -286,6 +287,7 @@ int xenbus_dev_request_and_reply(struct xsd_sockmsg *msg, void *par)
req->num_vecs = 1;
req->cb = xenbus_dev_queue_reply;
req->par = par;
+ req->user_req = true;
xs_send(req, msg);
@@ -313,6 +315,7 @@ static void *xs_talkv(struct xenbus_transaction t,
req->vec = iovec;
req->num_vecs = num_vecs;
req->cb = xs_wake_up;
+ req->user_req = false;
msg.req_id = 0;
msg.tx_id = t.id;