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authorJosef Bacik <josef@toxicpanda.com>2019-10-21 15:56:27 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-11-10 11:27:34 +0100
commit82b7c99ee1410a50b52283f4b80dca31fa7591b6 (patch)
tree0ef8d47606ed84cf2d699c8059c9416f46b2cc1b /drivers/block
parent80b42f4381c25021cf6d3ca73eb0540c265018b7 (diff)
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nbd: protect cmd->status with cmd->lock
[ Upstream commit de6346ecbc8f5591ebd6c44ac164e8b8671d71d7 ] We already do this for the most part, except in timeout and clear_req. For the timeout case we take the lock after we grab a ref on the config, but that isn't really necessary because we're safe to touch the cmd at this point, so just move the order around. For the clear_req cause this is initiated by the user, so again is safe. Reviewed-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/nbd.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index bd9aafe86c2f..da6a36d14f4c 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -349,17 +349,16 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
struct nbd_device *nbd = cmd->nbd;
struct nbd_config *config;
+ if (!mutex_trylock(&cmd->lock))
+ return BLK_EH_RESET_TIMER;
+
if (!refcount_inc_not_zero(&nbd->config_refs)) {
cmd->status = BLK_STS_TIMEOUT;
+ mutex_unlock(&cmd->lock);
goto done;
}
config = nbd->config;
- if (!mutex_trylock(&cmd->lock)) {
- nbd_config_put(nbd);
- return BLK_EH_RESET_TIMER;
- }
-
if (config->num_connections > 1) {
dev_err_ratelimited(nbd_to_dev(nbd),
"Connection timed out, retrying (%d/%d alive)\n",
@@ -745,7 +744,10 @@ static void nbd_clear_req(struct request *req, void *data, bool reserved)
{
struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
+ mutex_lock(&cmd->lock);
cmd->status = BLK_STS_IOERR;
+ mutex_unlock(&cmd->lock);
+
blk_mq_complete_request(req);
}