diff options
| author | Trond Myklebust <trond.myklebust@primarydata.com> | 2016-03-16 16:24:36 -0400 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2016-03-16 16:25:09 -0400 |
| commit | 1425075e7272faaa3629a1e2df679c0ba4cf55d3 (patch) | |
| tree | 6d79a735f8a02d6dc9e27b915f6244fe1ab6b7ff /sound/core/pcm_native.c | |
| parent | 849dc3244c916545790bfb9055625a3719061c92 (diff) | |
| parent | 2fa8f88d8892507ecff0126fbc67906740491d31 (diff) | |
Merge tag 'nfs-rdma-4.6-1' of git://git.linux-nfs.org/projects/anna/nfs-rdma
NFS: NFSoRDMA Client Side Changes
These patches include several bugfixes and cleanups for the NFSoRDMA client.
This includes bugfixes for NFS v4.1, proper RDMA_ERROR handling, and fixes
from the recent workqueue swicchover. These patches also switch xprtrdma to
use the new CQ API
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* tag 'nfs-rdma-4.6-1' of git://git.linux-nfs.org/projects/anna/nfs-rdma: (787 commits)
xprtrdma: Use new CQ API for RPC-over-RDMA client send CQs
xprtrdma: Use an anonymous union in struct rpcrdma_mw
xprtrdma: Use new CQ API for RPC-over-RDMA client receive CQs
xprtrdma: Serialize credit accounting again
xprtrdma: Properly handle RDMA_ERROR replies
rpcrdma: Add RPCRDMA_HDRLEN_ERR
xprtrdma: Do not wait if ib_post_send() fails
xprtrdma: Segment head and tail XDR buffers on page boundaries
xprtrdma: Clean up dprintk format string containing a newline
xprtrdma: Clean up physical_op_map()
xprtrdma: Clean up unused RPCRDMA_INLINE_PAD_THRESH macro
Diffstat (limited to 'sound/core/pcm_native.c')
| -rw-r--r-- | sound/core/pcm_native.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index fadd3eb8e8bb..9106d8e2300e 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -74,6 +74,18 @@ static int snd_pcm_open(struct file *file, struct snd_pcm *pcm, int stream); static DEFINE_RWLOCK(snd_pcm_link_rwlock); static DECLARE_RWSEM(snd_pcm_link_rwsem); +/* Writer in rwsem may block readers even during its waiting in queue, + * and this may lead to a deadlock when the code path takes read sem + * twice (e.g. one in snd_pcm_action_nonatomic() and another in + * snd_pcm_stream_lock()). As a (suboptimal) workaround, let writer to + * spin until it gets the lock. + */ +static inline void down_write_nonblock(struct rw_semaphore *lock) +{ + while (!down_write_trylock(lock)) + cond_resched(); +} + /** * snd_pcm_stream_lock - Lock the PCM stream * @substream: PCM substream @@ -1813,7 +1825,7 @@ static int snd_pcm_link(struct snd_pcm_substream *substream, int fd) res = -ENOMEM; goto _nolock; } - down_write(&snd_pcm_link_rwsem); + down_write_nonblock(&snd_pcm_link_rwsem); write_lock_irq(&snd_pcm_link_rwlock); if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN || substream->runtime->status->state != substream1->runtime->status->state || @@ -1860,7 +1872,7 @@ static int snd_pcm_unlink(struct snd_pcm_substream *substream) struct snd_pcm_substream *s; int res = 0; - down_write(&snd_pcm_link_rwsem); + down_write_nonblock(&snd_pcm_link_rwsem); write_lock_irq(&snd_pcm_link_rwlock); if (!snd_pcm_stream_linked(substream)) { res = -EALREADY; |