* [PATCH v2 1/2] nbd: Fix might_sleep warning on xmit timeout
2016-05-03 16:38 [PATCH v2 0/2] nbd: fix might_sleep warning and checkpatch fixes Pranay Kr. Srivastava
@ 2016-05-03 16:38 ` Pranay Kr. Srivastava
2016-05-03 16:38 ` [PATCH v2 2/2] nbd: Fix checkpatch errors Pranay Kr. Srivastava
1 sibling, 0 replies; 5+ messages in thread
From: Pranay Kr. Srivastava @ 2016-05-03 16:38 UTC (permalink / raw)
To: mpa, nbd-general, linux-kernel, gregkh; +Cc: Pranay Kr. Srivastava
This patch fixes the warning generated when a timeout occurs
on the request and socket is closed from a non-sleep context
by
1. Moving the socket closing on a timeout to nbd_thread_send
2. Make sock lock to be a mutex instead of a spin lock, since
nbd_xmit_timeout doesn't need to hold it anymore.
Signed-off-by: Pranay Kr. Srivastava <pranjas@gmail.com>
---
drivers/block/nbd.c | 65 ++++++++++++++++++++++++++++++++---------------------
1 file changed, 39 insertions(+), 26 deletions(-)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 31e73a7..c79bcd7 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -57,12 +57,12 @@ struct nbd_device {
int blksize;
loff_t bytesize;
int xmit_timeout;
- bool timedout;
+ atomic_t timedout;
bool disconnect; /* a disconnect has been requested by user */
struct timer_list timeout_timer;
/* protects initialization and shutdown of the socket */
- spinlock_t sock_lock;
+ struct mutex sock_lock;
struct task_struct *task_recv;
struct task_struct *task_send;
@@ -172,10 +172,9 @@ static void nbd_end_request(struct nbd_device *nbd, struct request *req)
*/
static void sock_shutdown(struct nbd_device *nbd)
{
- spin_lock_irq(&nbd->sock_lock);
-
+ mutex_lock(&nbd->sock_lock);
if (!nbd->sock) {
- spin_unlock_irq(&nbd->sock_lock);
+ mutex_unlock(&nbd->sock_lock);
return;
}
@@ -183,27 +182,19 @@ static void sock_shutdown(struct nbd_device *nbd)
kernel_sock_shutdown(nbd->sock, SHUT_RDWR);
sockfd_put(nbd->sock);
nbd->sock = NULL;
- spin_unlock_irq(&nbd->sock_lock);
-
+ mutex_unlock(&nbd->sock_lock);
del_timer(&nbd->timeout_timer);
}
static void nbd_xmit_timeout(unsigned long arg)
{
struct nbd_device *nbd = (struct nbd_device *)arg;
- unsigned long flags;
if (list_empty(&nbd->queue_head))
return;
- spin_lock_irqsave(&nbd->sock_lock, flags);
-
- nbd->timedout = true;
-
- if (nbd->sock)
- kernel_sock_shutdown(nbd->sock, SHUT_RDWR);
-
- spin_unlock_irqrestore(&nbd->sock_lock, flags);
+ atomic_inc(&nbd->timedout);
+ wake_up(&nbd->waiting_wq);
dev_err(nbd_to_dev(nbd), "Connection timed out, shutting down connection\n");
}
@@ -579,7 +570,27 @@ static int nbd_thread_send(void *data)
/* wait for something to do */
wait_event_interruptible(nbd->waiting_wq,
kthread_should_stop() ||
- !list_empty(&nbd->waiting_queue));
+ !list_empty(&nbd->waiting_queue) ||
+ atomic_read(&nbd->timedout));
+
+ if (atomic_read(&nbd->timedout)) {
+ mutex_lock(&nbd->sock_lock);
+ if (nbd->sock) {
+ struct request sreq;
+
+ blk_rq_init(NULL, &sreq);
+ sreq.cmd_type = REQ_TYPE_DRV_PRIV;
+ mutex_lock(&nbd->tx_lock);
+ nbd->disconnect = true;
+ nbd_send_req(nbd, &sreq);
+ mutex_unlock(&nbd->tx_lock);
+ dev_err(disk_to_dev(nbd->disk),
+ "Device Timeout occured.Shutting down"
+ " socket.");
+ }
+ mutex_unlock(&nbd->sock_lock);
+ sock_shutdown(nbd);
+ }
/* extract request */
if (list_empty(&nbd->waiting_queue))
@@ -592,7 +603,11 @@ static int nbd_thread_send(void *data)
spin_unlock_irq(&nbd->queue_lock);
/* handle request */
- nbd_handle_req(nbd, req);
+ if (atomic_read(&nbd->timedout)) {
+ req->errors++;
+ nbd_end_request(nbd, req);
+ } else
+ nbd_handle_req(nbd, req);
}
nbd->task_send = NULL;
@@ -647,7 +662,7 @@ static int nbd_set_socket(struct nbd_device *nbd, struct socket *sock)
{
int ret = 0;
- spin_lock_irq(&nbd->sock_lock);
+ mutex_lock(&nbd->sock_lock);
if (nbd->sock) {
ret = -EBUSY;
@@ -657,7 +672,7 @@ static int nbd_set_socket(struct nbd_device *nbd, struct socket *sock)
nbd->sock = sock;
out:
- spin_unlock_irq(&nbd->sock_lock);
+ mutex_unlock(&nbd->sock_lock);
return ret;
}
@@ -666,7 +681,7 @@ out:
static void nbd_reset(struct nbd_device *nbd)
{
nbd->disconnect = false;
- nbd->timedout = false;
+ atomic_set(&nbd->timedout, 0);
nbd->blksize = 1024;
nbd->bytesize = 0;
set_capacity(nbd->disk, 0);
@@ -803,17 +818,15 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
error = nbd_thread_recv(nbd, bdev);
nbd_dev_dbg_close(nbd);
kthread_stop(thread);
-
- mutex_lock(&nbd->tx_lock);
-
sock_shutdown(nbd);
+ mutex_lock(&nbd->tx_lock);
nbd_clear_que(nbd);
kill_bdev(bdev);
nbd_bdev_reset(bdev);
if (nbd->disconnect) /* user requested, ignore socket errors */
error = 0;
- if (nbd->timedout)
+ if (atomic_read(&nbd->timedout))
error = -ETIMEDOUT;
nbd_reset(nbd);
@@ -1075,7 +1088,7 @@ static int __init nbd_init(void)
nbd_dev[i].magic = NBD_MAGIC;
INIT_LIST_HEAD(&nbd_dev[i].waiting_queue);
spin_lock_init(&nbd_dev[i].queue_lock);
- spin_lock_init(&nbd_dev[i].sock_lock);
+ mutex_init(&nbd_dev[i].sock_lock);
INIT_LIST_HEAD(&nbd_dev[i].queue_head);
mutex_init(&nbd_dev[i].tx_lock);
init_timer(&nbd_dev[i].timeout_timer);
--
2.6.2
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v2 2/2] nbd: Fix checkpatch errors.
2016-05-03 16:38 [PATCH v2 0/2] nbd: fix might_sleep warning and checkpatch fixes Pranay Kr. Srivastava
2016-05-03 16:38 ` [PATCH v2 1/2] nbd: Fix might_sleep warning on xmit timeout Pranay Kr. Srivastava
@ 2016-05-03 16:38 ` Pranay Kr. Srivastava
2016-05-03 18:16 ` Greg KH
2016-06-02 1:03 ` Pavel Machek
1 sibling, 2 replies; 5+ messages in thread
From: Pranay Kr. Srivastava @ 2016-05-03 16:38 UTC (permalink / raw)
To: mpa, nbd-general, linux-kernel, gregkh; +Cc: Pranay Kr. Srivastava
Signed-off-by: Pranay Kr. Srivastava <pranjas@gmail.com>
---
drivers/block/nbd.c | 33 ++++++++++++++++++---------------
1 file changed, 18 insertions(+), 15 deletions(-)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index c79bcd7..9ab3a27 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -3,7 +3,7 @@
*
* Note that you can not swap over this thing, yet. Seems to work but
* deadlocks sometimes - you can not swap over TCP in general.
- *
+ *
* Copyright 1997-2000, 2008 Pavel Machek <pavel@ucw.cz>
* Parts copyright 2001 Steven Whitehouse <steve@chygwyn.com>
*
@@ -35,14 +35,14 @@
#include <linux/types.h>
#include <linux/debugfs.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
#include <asm/types.h>
#include <linux/nbd.h>
struct nbd_device {
u32 flags;
- struct socket * sock; /* If == NULL, device is not ready, yet */
+ struct socket *sock; /* If == NULL, device is not ready, yet */
int magic;
spinlock_t queue_lock;
@@ -257,6 +257,7 @@ static inline int sock_send_bvec(struct nbd_device *nbd, struct bio_vec *bvec,
{
int result;
void *kaddr = kmap(bvec->bv_page);
+
result = sock_xmit(nbd, 1, kaddr + bvec->bv_offset,
bvec->bv_len, flags);
kunmap(bvec->bv_page);
@@ -354,6 +355,7 @@ static inline int sock_recv_bvec(struct nbd_device *nbd, struct bio_vec *bvec)
{
int result;
void *kaddr = kmap(bvec->bv_page);
+
result = sock_xmit(nbd, 0, kaddr + bvec->bv_offset, bvec->bv_len,
MSG_WAITALL);
kunmap(bvec->bv_page);
@@ -585,8 +587,7 @@ static int nbd_thread_send(void *data)
nbd_send_req(nbd, &sreq);
mutex_unlock(&nbd->tx_lock);
dev_err(disk_to_dev(nbd->disk),
- "Device Timeout occured.Shutting down"
- " socket.");
+ "Device Timeout occured.Shutting down socket.");
}
mutex_unlock(&nbd->sock_lock);
sock_shutdown(nbd);
@@ -616,8 +617,8 @@ static int nbd_thread_send(void *data)
}
/*
- * We always wait for result of write, for now. It would be nice to make it optional
- * in future
+ * We always wait for result of write, for now. It would be nice to make it
+ * optional in future
* if ((rq_data_dir(req) == WRITE) && (nbd->flags & NBD_WRITE_NOCHK))
* { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); }
*/
@@ -626,7 +627,7 @@ static void nbd_request_handler(struct request_queue *q)
__releases(q->queue_lock) __acquires(q->queue_lock)
{
struct request *req;
-
+
while ((req = blk_fetch_request(q)) != NULL) {
struct nbd_device *nbd;
@@ -744,7 +745,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
nbd_send_req(nbd, &sreq);
return 0;
}
-
+
case NBD_CLEAR_SOCK:
sock_shutdown(nbd);
nbd_clear_que(nbd);
@@ -869,8 +870,7 @@ static int nbd_ioctl(struct block_device *bdev, fmode_t mode,
return error;
}
-static const struct block_device_operations nbd_fops =
-{
+static const struct block_device_operations nbd_fops = {
.owner = THIS_MODULE,
.ioctl = nbd_ioctl,
.compat_ioctl = nbd_ioctl,
@@ -1005,7 +1005,7 @@ static void nbd_dbg_close(void)
#endif
/*
- * And here should be modules and kernel interface
+ * And here should be modules and kernel interface
* (Just smiley confuses emacs :-)
*/
@@ -1018,7 +1018,7 @@ static int __init nbd_init(void)
BUILD_BUG_ON(sizeof(struct nbd_request) != 28);
if (max_part < 0) {
- printk(KERN_ERR "nbd: max_part must be >= 0\n");
+ pr_err("nbd: max_part must be >= 0\n");
return -EINVAL;
}
@@ -1049,6 +1049,7 @@ static int __init nbd_init(void)
for (i = 0; i < nbds_max; i++) {
struct gendisk *disk = alloc_disk(1 << part_shift);
+
if (!disk)
goto out;
nbd_dev[i].disk = disk;
@@ -1079,12 +1080,13 @@ static int __init nbd_init(void)
goto out;
}
- printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR);
+ pr_info("nbd: registered device at major %d\n", NBD_MAJOR);
nbd_dbg_init();
for (i = 0; i < nbds_max; i++) {
struct gendisk *disk = nbd_dev[i].disk;
+
nbd_dev[i].magic = NBD_MAGIC;
INIT_LIST_HEAD(&nbd_dev[i].waiting_queue);
spin_lock_init(&nbd_dev[i].queue_lock);
@@ -1123,6 +1125,7 @@ static void __exit nbd_cleanup(void)
for (i = 0; i < nbds_max; i++) {
struct gendisk *disk = nbd_dev[i].disk;
+
nbd_dev[i].magic = 0;
if (disk) {
del_gendisk(disk);
@@ -1132,7 +1135,7 @@ static void __exit nbd_cleanup(void)
}
unregister_blkdev(NBD_MAJOR, "nbd");
kfree(nbd_dev);
- printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR);
+ pr_info("nbd: unregistered device at major %d\n", NBD_MAJOR);
}
module_init(nbd_init);
--
2.6.2
^ permalink raw reply related [flat|nested] 5+ messages in thread