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Merge branch 'for-linus' of git://git.kernel.dk/linux-block
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Pull block fixes from Jens Axboe:
 "Five fixes for this series:

   - a fix from me to ensure that blk-mq drivers that terminate IO in
     their ->queue_rq() handler by returning QUEUE_ERROR don't stall
     with a scheduler enabled.

   - four nbd fixes from Josef and Ratna, fixing various problems that
     are critical enough to go in for this cycle. They have been well
     tested"

* 'for-linus' of git://git.kernel.dk/linux-block:
  nbd: replace kill_bdev() with __invalidate_device()
  nbd: set queue timeout properly
  nbd: set rq->errors to actual error code
  nbd: handle ERESTARTSYS properly
  blk-mq: include errors in did_work calculation
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Linus Torvalds committed Mar 29, 2017
2 parents 52b9c81 + abbbdf1 commit 806276b
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Showing 2 changed files with 107 additions and 36 deletions.
7 changes: 4 additions & 3 deletions block/blk-mq.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -969,7 +969,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list)
struct request *rq;
LIST_HEAD(driver_list);
struct list_head *dptr;
int queued, ret = BLK_MQ_RQ_QUEUE_OK;
int errors, queued, ret = BLK_MQ_RQ_QUEUE_OK;

/*
* Start off with dptr being NULL, so we start the first request
Expand All @@ -980,7 +980,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list)
/*
* Now process all the entries, sending them to the driver.
*/
queued = 0;
errors = queued = 0;
while (!list_empty(list)) {
struct blk_mq_queue_data bd;

Expand Down Expand Up @@ -1037,6 +1037,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list)
default:
pr_err("blk-mq: bad return on queue: %d\n", ret);
case BLK_MQ_RQ_QUEUE_ERROR:
errors++;
rq->errors = -EIO;
blk_mq_end_request(rq, rq->errors);
break;
Expand Down Expand Up @@ -1088,7 +1089,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list)
blk_mq_run_hw_queue(hctx, true);
}

return queued != 0;
return (queued + errors) != 0;
}

static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
Expand Down
136 changes: 103 additions & 33 deletions drivers/block/nbd.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -47,6 +47,8 @@ static DEFINE_MUTEX(nbd_index_mutex);
struct nbd_sock {
struct socket *sock;
struct mutex tx_lock;
struct request *pending;
int sent;
};

#define NBD_TIMEDOUT 0
Expand Down Expand Up @@ -124,7 +126,8 @@ static const char *nbdcmd_to_ascii(int cmd)

static int nbd_size_clear(struct nbd_device *nbd, struct block_device *bdev)
{
bd_set_size(bdev, 0);
if (bdev->bd_openers <= 1)
bd_set_size(bdev, 0);
set_capacity(nbd->disk, 0);
kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);

Expand Down Expand Up @@ -190,7 +193,7 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,

dev_err(nbd_to_dev(nbd), "Connection timed out, shutting down connection\n");
set_bit(NBD_TIMEDOUT, &nbd->runtime_flags);
req->errors++;
req->errors = -EIO;

mutex_lock(&nbd->config_lock);
sock_shutdown(nbd);
Expand All @@ -202,7 +205,7 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
* Send or receive packet.
*/
static int sock_xmit(struct nbd_device *nbd, int index, int send,
struct iov_iter *iter, int msg_flags)
struct iov_iter *iter, int msg_flags, int *sent)
{
struct socket *sock = nbd->socks[index]->sock;
int result;
Expand Down Expand Up @@ -237,6 +240,8 @@ static int sock_xmit(struct nbd_device *nbd, int index, int send,
result = -EPIPE; /* short read */
break;
}
if (sent)
*sent += result;
} while (msg_data_left(&msg));

tsk_restore_flags(current, pflags, PF_MEMALLOC);
Expand All @@ -248,6 +253,7 @@ static int sock_xmit(struct nbd_device *nbd, int index, int send,
static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
{
struct request *req = blk_mq_rq_from_pdu(cmd);
struct nbd_sock *nsock = nbd->socks[index];
int result;
struct nbd_request request = {.magic = htonl(NBD_REQUEST_MAGIC)};
struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)};
Expand All @@ -256,6 +262,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
struct bio *bio;
u32 type;
u32 tag = blk_mq_unique_tag(req);
int sent = nsock->sent, skip = 0;

iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request));

Expand Down Expand Up @@ -283,6 +290,17 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
return -EIO;
}

/* We did a partial send previously, and we at least sent the whole
* request struct, so just go and send the rest of the pages in the
* request.
*/
if (sent) {
if (sent >= sizeof(request)) {
skip = sent - sizeof(request);
goto send_pages;
}
iov_iter_advance(&from, sent);
}
request.type = htonl(type);
if (type != NBD_CMD_FLUSH) {
request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9);
Expand All @@ -294,15 +312,27 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
cmd, nbdcmd_to_ascii(type),
(unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req));
result = sock_xmit(nbd, index, 1, &from,
(type == NBD_CMD_WRITE) ? MSG_MORE : 0);
(type == NBD_CMD_WRITE) ? MSG_MORE : 0, &sent);
if (result <= 0) {
if (result == -ERESTARTSYS) {
/* If we havne't sent anything we can just return BUSY,
* however if we have sent something we need to make
* sure we only allow this req to be sent until we are
* completely done.
*/
if (sent) {
nsock->pending = req;
nsock->sent = sent;
}
return BLK_MQ_RQ_QUEUE_BUSY;
}
dev_err_ratelimited(disk_to_dev(nbd->disk),
"Send control failed (result %d)\n", result);
return -EIO;
}

send_pages:
if (type != NBD_CMD_WRITE)
return 0;
goto out;

bio = req->bio;
while (bio) {
Expand All @@ -318,8 +348,25 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
cmd, bvec.bv_len);
iov_iter_bvec(&from, ITER_BVEC | WRITE,
&bvec, 1, bvec.bv_len);
result = sock_xmit(nbd, index, 1, &from, flags);
if (skip) {
if (skip >= iov_iter_count(&from)) {
skip -= iov_iter_count(&from);
continue;
}
iov_iter_advance(&from, skip);
skip = 0;
}
result = sock_xmit(nbd, index, 1, &from, flags, &sent);
if (result <= 0) {
if (result == -ERESTARTSYS) {
/* We've already sent the header, we
* have no choice but to set pending and
* return BUSY.
*/
nsock->pending = req;
nsock->sent = sent;
return BLK_MQ_RQ_QUEUE_BUSY;
}
dev_err(disk_to_dev(nbd->disk),
"Send data failed (result %d)\n",
result);
Expand All @@ -336,6 +383,9 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
}
bio = next;
}
out:
nsock->pending = NULL;
nsock->sent = 0;
return 0;
}

Expand All @@ -353,7 +403,7 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)

reply.magic = 0;
iov_iter_kvec(&to, READ | ITER_KVEC, &iov, 1, sizeof(reply));
result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL);
result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
if (result <= 0) {
if (!test_bit(NBD_DISCONNECTED, &nbd->runtime_flags) &&
!test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags))
Expand Down Expand Up @@ -383,7 +433,7 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
if (ntohl(reply.error)) {
dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n",
ntohl(reply.error));
req->errors++;
req->errors = -EIO;
return cmd;
}

Expand All @@ -395,11 +445,11 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
rq_for_each_segment(bvec, req, iter) {
iov_iter_bvec(&to, ITER_BVEC | READ,
&bvec, 1, bvec.bv_len);
result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL);
result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
if (result <= 0) {
dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n",
result);
req->errors++;
req->errors = -EIO;
return cmd;
}
dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n",
Expand Down Expand Up @@ -469,7 +519,7 @@ static void nbd_clear_req(struct request *req, void *data, bool reserved)
if (!blk_mq_request_started(req))
return;
cmd = blk_mq_rq_to_pdu(req);
req->errors++;
req->errors = -EIO;
nbd_end_request(cmd);
}

Expand All @@ -482,22 +532,23 @@ static void nbd_clear_que(struct nbd_device *nbd)
}


static void nbd_handle_cmd(struct nbd_cmd *cmd, int index)
static int nbd_handle_cmd(struct nbd_cmd *cmd, int index)
{
struct request *req = blk_mq_rq_from_pdu(cmd);
struct nbd_device *nbd = cmd->nbd;
struct nbd_sock *nsock;
int ret;

if (index >= nbd->num_connections) {
dev_err_ratelimited(disk_to_dev(nbd->disk),
"Attempted send on invalid socket\n");
goto error_out;
return -EINVAL;
}

if (test_bit(NBD_DISCONNECTED, &nbd->runtime_flags)) {
dev_err_ratelimited(disk_to_dev(nbd->disk),
"Attempted send on closed socket\n");
goto error_out;
return -EINVAL;
}

req->errors = 0;
Expand All @@ -508,29 +559,30 @@ static void nbd_handle_cmd(struct nbd_cmd *cmd, int index)
mutex_unlock(&nsock->tx_lock);
dev_err_ratelimited(disk_to_dev(nbd->disk),
"Attempted send on closed socket\n");
goto error_out;
return -EINVAL;
}

if (nbd_send_cmd(nbd, cmd, index) != 0) {
dev_err_ratelimited(disk_to_dev(nbd->disk),
"Request send failed\n");
req->errors++;
nbd_end_request(cmd);
/* Handle the case that we have a pending request that was partially
* transmitted that _has_ to be serviced first. We need to call requeue
* here so that it gets put _after_ the request that is already on the
* dispatch list.
*/
if (unlikely(nsock->pending && nsock->pending != req)) {
blk_mq_requeue_request(req, true);
ret = 0;
goto out;
}

ret = nbd_send_cmd(nbd, cmd, index);
out:
mutex_unlock(&nsock->tx_lock);

return;

error_out:
req->errors++;
nbd_end_request(cmd);
return ret;
}

static int nbd_queue_rq(struct blk_mq_hw_ctx *hctx,
const struct blk_mq_queue_data *bd)
{
struct nbd_cmd *cmd = blk_mq_rq_to_pdu(bd->rq);
int ret;

/*
* Since we look at the bio's to send the request over the network we
Expand All @@ -543,10 +595,20 @@ static int nbd_queue_rq(struct blk_mq_hw_ctx *hctx,
*/
init_completion(&cmd->send_complete);
blk_mq_start_request(bd->rq);
nbd_handle_cmd(cmd, hctx->queue_num);

/* We can be called directly from the user space process, which means we
* could possibly have signals pending so our sendmsg will fail. In
* this case we need to return that we are busy, otherwise error out as
* appropriate.
*/
ret = nbd_handle_cmd(cmd, hctx->queue_num);
if (ret < 0)
ret = BLK_MQ_RQ_QUEUE_ERROR;
if (!ret)
ret = BLK_MQ_RQ_QUEUE_OK;
complete(&cmd->send_complete);

return BLK_MQ_RQ_QUEUE_OK;
return ret;
}

static int nbd_add_socket(struct nbd_device *nbd, struct block_device *bdev,
Expand Down Expand Up @@ -581,6 +643,8 @@ static int nbd_add_socket(struct nbd_device *nbd, struct block_device *bdev,

mutex_init(&nsock->tx_lock);
nsock->sock = sock;
nsock->pending = NULL;
nsock->sent = 0;
socks[nbd->num_connections++] = nsock;

if (max_part)
Expand All @@ -602,6 +666,8 @@ static void nbd_reset(struct nbd_device *nbd)

static void nbd_bdev_reset(struct block_device *bdev)
{
if (bdev->bd_openers > 1)
return;
set_device_ro(bdev, false);
bdev->bd_inode->i_size = 0;
if (max_part > 0) {
Expand Down Expand Up @@ -634,7 +700,7 @@ static void send_disconnects(struct nbd_device *nbd)

for (i = 0; i < nbd->num_connections; i++) {
iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request));
ret = sock_xmit(nbd, i, 1, &from, 0);
ret = sock_xmit(nbd, i, 1, &from, 0, NULL);
if (ret <= 0)
dev_err(disk_to_dev(nbd->disk),
"Send disconnect failed %d\n", ret);
Expand Down Expand Up @@ -665,7 +731,8 @@ static int nbd_clear_sock(struct nbd_device *nbd, struct block_device *bdev)
{
sock_shutdown(nbd);
nbd_clear_que(nbd);
kill_bdev(bdev);

__invalidate_device(bdev, true);
nbd_bdev_reset(bdev);
/*
* We want to give the run thread a chance to wait for everybody
Expand Down Expand Up @@ -781,7 +848,10 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
nbd_size_set(nbd, bdev, nbd->blksize, arg);
return 0;
case NBD_SET_TIMEOUT:
nbd->tag_set.timeout = arg * HZ;
if (arg) {
nbd->tag_set.timeout = arg * HZ;
blk_queue_rq_timeout(nbd->disk->queue, arg * HZ);
}
return 0;

case NBD_SET_FLAGS:
Expand Down

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