From 20d60f6364474a978ab2a2146fb4c2bd9b6bbe3f Mon Sep 17 00:00:00 2001 From: Maciej Grochowski Date: Tue, 14 Apr 2020 00:17:03 -0400 Subject: include/linux/dmaengine: Typos fixes in API documentation Signed-off-by: Maciej Grochowski Link: https://lore.kernel.org/r/20200414041703.6661-1-maciek.grochowski@gmail.com Signed-off-by: Vinod Koul --- include/linux/dmaengine.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 21065c04c4ac..31e58ec9f741 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -83,9 +83,9 @@ enum dma_transfer_direction { /** * Interleaved Transfer Request * ---------------------------- - * A chunk is collection of contiguous bytes to be transfered. + * A chunk is collection of contiguous bytes to be transferred. * The gap(in bytes) between two chunks is called inter-chunk-gap(ICG). - * ICGs may or maynot change between chunks. + * ICGs may or may not change between chunks. * A FRAME is the smallest series of contiguous {chunk,icg} pairs, * that when repeated an integral number of times, specifies the transfer. * A transfer template is specification of a Frame, the number of times @@ -1069,7 +1069,7 @@ static inline int dmaengine_terminate_all(struct dma_chan *chan) * dmaengine_synchronize() needs to be called before it is safe to free * any memory that is accessed by previously submitted descriptors or before * freeing any resources accessed from within the completion callback of any - * perviously submitted descriptors. + * previously submitted descriptors. * * This function can be called from atomic context as well as from within a * complete callback of a descriptor submitted on the same channel. @@ -1091,7 +1091,7 @@ static inline int dmaengine_terminate_async(struct dma_chan *chan) * * Synchronizes to the DMA channel termination to the current context. When this * function returns it is guaranteed that all transfers for previously issued - * descriptors have stopped and and it is safe to free the memory assoicated + * descriptors have stopped and it is safe to free the memory associated * with them. Furthermore it is guaranteed that all complete callback functions * for a previously submitted descriptor have finished running and it is safe to * free resources accessed from within the complete callbacks. -- cgit From 0821009445a8261ac4d32a6df4b83938e007c765 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Mon, 13 Apr 2020 10:40:12 -0700 Subject: dmaengine: fix channel index enumeration When the channel register code was changed to allow hotplug operations, dynamic indexing wasn't taken into account. When channels are randomly plugged and unplugged out of order, the serial indexing breaks. Convert channel indexing to using IDA tracking in order to allow dynamic assignment. The previous code does not cause any regression bug for existing channel allocation besides idxd driver since the hotplug usage case is only used by idxd at this point. With this change, the chan->idr_ref is also not needed any longer. We can have a device with no channels registered due to hot plug. The channel device release code no longer should attempt to free the dma device id on the last channel release. Fixes: e81274cd6b52 ("dmaengine: add support to dynamic register/unregister of channels") Reported-by: Yixin Zhang Signed-off-by: Dave Jiang Tested-by: Yixin Zhang Link: https://lore.kernel.org/r/158679961260.7674.8485924270472851852.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Vinod Koul --- drivers/dma/dmaengine.c | 60 ++++++++++++++++++++--------------------------- include/linux/dmaengine.h | 4 ++-- 2 files changed, 28 insertions(+), 36 deletions(-) (limited to 'include/linux') diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 4830ba658ce1..d31076d9ef25 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -232,10 +232,6 @@ static void chan_dev_release(struct device *dev) struct dma_chan_dev *chan_dev; chan_dev = container_of(dev, typeof(*chan_dev), device); - if (atomic_dec_and_test(chan_dev->idr_ref)) { - ida_free(&dma_ida, chan_dev->dev_id); - kfree(chan_dev->idr_ref); - } kfree(chan_dev); } @@ -1043,27 +1039,9 @@ static int get_dma_id(struct dma_device *device) } static int __dma_async_device_channel_register(struct dma_device *device, - struct dma_chan *chan, - int chan_id) + struct dma_chan *chan) { int rc = 0; - int chancnt = device->chancnt; - atomic_t *idr_ref; - struct dma_chan *tchan; - - tchan = list_first_entry_or_null(&device->channels, - struct dma_chan, device_node); - if (!tchan) - return -ENODEV; - - if (tchan->dev) { - idr_ref = tchan->dev->idr_ref; - } else { - idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL); - if (!idr_ref) - return -ENOMEM; - atomic_set(idr_ref, 0); - } chan->local = alloc_percpu(typeof(*chan->local)); if (!chan->local) @@ -1079,29 +1057,36 @@ static int __dma_async_device_channel_register(struct dma_device *device, * When the chan_id is a negative value, we are dynamically adding * the channel. Otherwise we are static enumerating. */ - chan->chan_id = chan_id < 0 ? chancnt : chan_id; + mutex_lock(&device->chan_mutex); + chan->chan_id = ida_alloc(&device->chan_ida, GFP_KERNEL); + mutex_unlock(&device->chan_mutex); + if (chan->chan_id < 0) { + pr_err("%s: unable to alloc ida for chan: %d\n", + __func__, chan->chan_id); + goto err_out; + } + chan->dev->device.class = &dma_devclass; chan->dev->device.parent = device->dev; chan->dev->chan = chan; - chan->dev->idr_ref = idr_ref; chan->dev->dev_id = device->dev_id; - atomic_inc(idr_ref); dev_set_name(&chan->dev->device, "dma%dchan%d", device->dev_id, chan->chan_id); - rc = device_register(&chan->dev->device); if (rc) - goto err_out; + goto err_out_ida; chan->client_count = 0; - device->chancnt = chan->chan_id + 1; + device->chancnt++; return 0; + err_out_ida: + mutex_lock(&device->chan_mutex); + ida_free(&device->chan_ida, chan->chan_id); + mutex_unlock(&device->chan_mutex); err_out: free_percpu(chan->local); kfree(chan->dev); - if (atomic_dec_return(idr_ref) == 0) - kfree(idr_ref); return rc; } @@ -1110,7 +1095,7 @@ int dma_async_device_channel_register(struct dma_device *device, { int rc; - rc = __dma_async_device_channel_register(device, chan, -1); + rc = __dma_async_device_channel_register(device, chan); if (rc < 0) return rc; @@ -1130,6 +1115,9 @@ static void __dma_async_device_channel_unregister(struct dma_device *device, device->chancnt--; chan->dev->chan = NULL; mutex_unlock(&dma_list_mutex); + mutex_lock(&device->chan_mutex); + ida_free(&device->chan_ida, chan->chan_id); + mutex_unlock(&device->chan_mutex); device_unregister(&chan->dev->device); free_percpu(chan->local); } @@ -1152,7 +1140,7 @@ EXPORT_SYMBOL_GPL(dma_async_device_channel_unregister); */ int dma_async_device_register(struct dma_device *device) { - int rc, i = 0; + int rc; struct dma_chan* chan; if (!device) @@ -1257,9 +1245,12 @@ int dma_async_device_register(struct dma_device *device) if (rc != 0) return rc; + mutex_init(&device->chan_mutex); + ida_init(&device->chan_ida); + /* represent channels in sysfs. Probably want devs too */ list_for_each_entry(chan, &device->channels, device_node) { - rc = __dma_async_device_channel_register(device, chan, i++); + rc = __dma_async_device_channel_register(device, chan); if (rc < 0) goto err_out; } @@ -1334,6 +1325,7 @@ void dma_async_device_unregister(struct dma_device *device) */ dma_cap_set(DMA_PRIVATE, device->cap_mask); dma_channel_rebalance(); + ida_free(&dma_ida, device->dev_id); dma_device_put(device); mutex_unlock(&dma_list_mutex); } diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 31e58ec9f741..e1c03339918f 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -341,13 +341,11 @@ struct dma_chan { * @chan: driver channel device * @device: sysfs device * @dev_id: parent dma_device dev_id - * @idr_ref: reference count to gate release of dma_device dev_id */ struct dma_chan_dev { struct dma_chan *chan; struct device device; int dev_id; - atomic_t *idr_ref; }; /** @@ -835,6 +833,8 @@ struct dma_device { int dev_id; struct device *dev; struct module *owner; + struct ida chan_ida; + struct mutex chan_mutex; /* to protect chan_ida */ u32 src_addr_widths; u32 dst_addr_widths; -- cgit From 7c4310ff56422ea43418305d22bbc5fe19150ec4 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Fri, 3 Apr 2020 14:33:41 +1100 Subject: SUNRPC: defer slow parts of rpc_free_client() to a workqueue. The rpciod workqueue is on the write-out path for freeing dirty memory, so it is important that it never block waiting for memory to be allocated - this can lead to a deadlock. rpc_execute() - which is often called by an rpciod work item - calls rcp_task_release_client() which can lead to rpc_free_client(). rpc_free_client() makes two calls which could potentially block wating for memory allocation. rpc_clnt_debugfs_unregister() calls into debugfs and will block while any of the debugfs files are being accessed. In particular it can block while any of the 'open' methods are being called and all of these use malloc for one thing or another. So this can deadlock if the memory allocation waits for NFS to complete some writes via rpciod. rpc_clnt_remove_pipedir() can take the inode_lock() and while it isn't obvious that memory allocations can happen while the lock it held, it is safer to assume they might and to not let rpciod call rpc_clnt_remove_pipedir(). So this patch moves these two calls (together with the final kfree() and rpciod_down()) into a work-item to be run from the system work-queue. rpciod can continue its important work, and the final stages of the free can happen whenever they happen. I have seen this deadlock on a 4.12 based kernel where debugfs used synchronize_srcu() when removing objects. synchronize_srcu() requires a workqueue and there were no free workther threads and none could be allocated. While debugsfs no longer uses SRCU, I believe the deadlock is still possible. Signed-off-by: NeilBrown Signed-off-by: Trond Myklebust --- include/linux/sunrpc/clnt.h | 8 +++++++- net/sunrpc/clnt.c | 21 +++++++++++++++++---- 2 files changed, 24 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index ca7e108248e2..7bd124e06b36 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -71,7 +71,13 @@ struct rpc_clnt { #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) struct dentry *cl_debugfs; /* debugfs directory */ #endif - struct rpc_xprt_iter cl_xpi; + /* cl_work is only needed after cl_xpi is no longer used, + * and that are of similar size + */ + union { + struct rpc_xprt_iter cl_xpi; + struct work_struct cl_work; + }; const struct cred *cl_cred; }; diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 05404bb05607..8350d3a2e9a7 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -880,6 +880,20 @@ EXPORT_SYMBOL_GPL(rpc_shutdown_client); /* * Free an RPC client */ +static void rpc_free_client_work(struct work_struct *work) +{ + struct rpc_clnt *clnt = container_of(work, struct rpc_clnt, cl_work); + + /* These might block on processes that might allocate memory, + * so they cannot be called in rpciod, so they are handled separately + * here. + */ + rpc_clnt_debugfs_unregister(clnt); + rpc_clnt_remove_pipedir(clnt); + + kfree(clnt); + rpciod_down(); +} static struct rpc_clnt * rpc_free_client(struct rpc_clnt *clnt) { @@ -890,17 +904,16 @@ rpc_free_client(struct rpc_clnt *clnt) rcu_dereference(clnt->cl_xprt)->servername); if (clnt->cl_parent != clnt) parent = clnt->cl_parent; - rpc_clnt_debugfs_unregister(clnt); - rpc_clnt_remove_pipedir(clnt); rpc_unregister_client(clnt); rpc_free_iostats(clnt->cl_metrics); clnt->cl_metrics = NULL; xprt_put(rcu_dereference_raw(clnt->cl_xprt)); xprt_iter_destroy(&clnt->cl_xpi); - rpciod_down(); put_cred(clnt->cl_cred); rpc_free_clid(clnt); - kfree(clnt); + + INIT_WORK(&clnt->cl_work, rpc_free_client_work); + schedule_work(&clnt->cl_work); return parent; } -- cgit From dff58530c4ca8ce7ee5a74db431c6e35362cf682 Mon Sep 17 00:00:00 2001 From: Olga Kornievskaia Date: Fri, 24 Apr 2020 17:45:50 -0400 Subject: NFSv4.1: fix handling of backchannel binding in BIND_CONN_TO_SESSION Currently, if the client sends BIND_CONN_TO_SESSION with NFS4_CDFC4_FORE_OR_BOTH but only gets NFS4_CDFS4_FORE back it ignores that it wasn't able to enable a backchannel. To make sure, the client sends BIND_CONN_TO_SESSION as the first operation on the connections (ie., no other session compounds haven't been sent before), and if the client's request to bind the backchannel is not satisfied, then reset the connection and retry. Cc: stable@vger.kernel.org Signed-off-by: Olga Kornievskaia Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 8 ++++++++ include/linux/nfs_xdr.h | 2 ++ include/linux/sunrpc/clnt.h | 5 +++++ 3 files changed, 15 insertions(+) (limited to 'include/linux') diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 1c710a7834c2..a0c1e653a935 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -7891,6 +7891,7 @@ static void nfs4_bind_one_conn_to_session_done(struct rpc_task *task, void *calldata) { struct nfs41_bind_conn_to_session_args *args = task->tk_msg.rpc_argp; + struct nfs41_bind_conn_to_session_res *res = task->tk_msg.rpc_resp; struct nfs_client *clp = args->client; switch (task->tk_status) { @@ -7899,6 +7900,12 @@ nfs4_bind_one_conn_to_session_done(struct rpc_task *task, void *calldata) nfs4_schedule_session_recovery(clp->cl_session, task->tk_status); } + if (args->dir == NFS4_CDFC4_FORE_OR_BOTH && + res->dir != NFS4_CDFS4_BOTH) { + rpc_task_close_connection(task); + if (args->retries++ < MAX_BIND_CONN_TO_SESSION_RETRIES) + rpc_restart_call(task); + } } static const struct rpc_call_ops nfs4_bind_one_conn_to_session_ops = { @@ -7921,6 +7928,7 @@ int nfs4_proc_bind_one_conn_to_session(struct rpc_clnt *clnt, struct nfs41_bind_conn_to_session_args args = { .client = clp, .dir = NFS4_CDFC4_FORE_OR_BOTH, + .retries = 0, }; struct nfs41_bind_conn_to_session_res res; struct rpc_message msg = { diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h index 440230488025..e5f3e7d8d3d5 100644 --- a/include/linux/nfs_xdr.h +++ b/include/linux/nfs_xdr.h @@ -1317,11 +1317,13 @@ struct nfs41_impl_id { struct nfstime4 date; }; +#define MAX_BIND_CONN_TO_SESSION_RETRIES 3 struct nfs41_bind_conn_to_session_args { struct nfs_client *client; struct nfs4_sessionid sessionid; u32 dir; bool use_conn_in_rdma_mode; + int retries; }; struct nfs41_bind_conn_to_session_res { diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index 7bd124e06b36..02e7a5863d28 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -242,4 +242,9 @@ static inline int rpc_reply_expected(struct rpc_task *task) (task->tk_msg.rpc_proc->p_decode != NULL); } +static inline void rpc_task_close_connection(struct rpc_task *task) +{ + if (task->tk_xprt) + xprt_force_disconnect(task->tk_xprt); +} #endif /* _LINUX_SUNRPC_CLNT_H */ -- cgit From 6f49c2515e2258f08f2b905c9772dbf729610415 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Tue, 7 Apr 2020 21:20:34 -0700 Subject: dma-buf: fix documentation build warnings Fix documentation warnings in dma-buf.[hc]: ../drivers/dma-buf/dma-buf.c:678: warning: Function parameter or member 'importer_ops' not described in 'dma_buf_dynamic_attach' ../drivers/dma-buf/dma-buf.c:678: warning: Function parameter or member 'importer_priv' not described in 'dma_buf_dynamic_attach' ../include/linux/dma-buf.h:339: warning: Incorrect use of kernel-doc format: * @move_notify Signed-off-by: Randy Dunlap Cc: Sumit Semwal Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Signed-off-by: Sumit Semwal Link: https://patchwork.freedesktop.org/patch/msgid/7bcbe6fe-0b4b-87da-d003-b68a26eb4cf0@infradead.org --- drivers/dma-buf/dma-buf.c | 4 ++-- include/linux/dma-buf.h | 3 +-- 2 files changed, 3 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index de155d41d274..07df88f2e305 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -656,8 +656,8 @@ EXPORT_SYMBOL_GPL(dma_buf_put); * calls attach() of dma_buf_ops to allow device-specific attach functionality * @dmabuf: [in] buffer to attach device to. * @dev: [in] device to be attached. - * @importer_ops [in] importer operations for the attachment - * @importer_priv [in] importer private pointer for the attachment + * @importer_ops: [in] importer operations for the attachment + * @importer_priv: [in] importer private pointer for the attachment * * Returns struct dma_buf_attachment pointer for this attachment. Attachments * must be cleaned up by calling dma_buf_detach(). diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 1ade486fc2bb..57bcef6f988a 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -329,13 +329,12 @@ struct dma_buf { /** * struct dma_buf_attach_ops - importer operations for an attachment - * @move_notify: [optional] notification that the DMA-buf is moving * * Attachment operations implemented by the importer. */ struct dma_buf_attach_ops { /** - * @move_notify + * @move_notify: [optional] notification that the DMA-buf is moving * * If this callback is provided the framework can avoid pinning the * backing store while mappings exists. -- cgit