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authorDan Williams <dan.j.williams@intel.com>2019-07-17 18:08:15 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-07-31 07:27:11 +0200
commit1a547d24ec8a488a7f2f4b85f1f1b82c015b7ac8 (patch)
treea0fd0940ef43ae2168ea13658d7768c768e0fd76 /drivers/nvdimm
parentb993a66d8ddc1c26da0d9aa3471789cc170b28ee (diff)
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libnvdimm/bus: Stop holding nvdimm_bus_list_mutex over __nd_ioctl()
commit b70d31d054ee3a6fc1034b9d7fc0ae1e481aa018 upstream. In preparation for fixing a deadlock between wait_for_bus_probe_idle() and the nvdimm_bus_list_mutex arrange for __nd_ioctl() without nvdimm_bus_list_mutex held. This also unifies the 'dimm' and 'bus' level ioctls into a common nd_ioctl() preamble implementation. Marked for -stable as it is a pre-requisite for a follow-on fix. Cc: <stable@vger.kernel.org> Fixes: bf9bccc14c05 ("libnvdimm: pmem label sets and namespace instantiation") Cc: Vishal Verma <vishal.l.verma@intel.com> Tested-by: Jane Chu <jane.chu@oracle.com> Link: https://lore.kernel.org/r/156341209518.292348.7183897251740665198.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/nvdimm')
-rw-r--r--drivers/nvdimm/bus.c96
-rw-r--r--drivers/nvdimm/nd-core.h3
2 files changed, 60 insertions, 39 deletions
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index a3132a9eb91c..ee39e2c1644a 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -86,7 +86,7 @@ static void nvdimm_bus_probe_end(struct nvdimm_bus *nvdimm_bus)
{
nvdimm_bus_lock(&nvdimm_bus->dev);
if (--nvdimm_bus->probe_active == 0)
- wake_up(&nvdimm_bus->probe_wait);
+ wake_up(&nvdimm_bus->wait);
nvdimm_bus_unlock(&nvdimm_bus->dev);
}
@@ -348,7 +348,7 @@ struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
return NULL;
INIT_LIST_HEAD(&nvdimm_bus->list);
INIT_LIST_HEAD(&nvdimm_bus->mapping_list);
- init_waitqueue_head(&nvdimm_bus->probe_wait);
+ init_waitqueue_head(&nvdimm_bus->wait);
nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
mutex_init(&nvdimm_bus->reconfig_mutex);
badrange_init(&nvdimm_bus->badrange);
@@ -418,6 +418,9 @@ static int nd_bus_remove(struct device *dev)
list_del_init(&nvdimm_bus->list);
mutex_unlock(&nvdimm_bus_list_mutex);
+ wait_event(nvdimm_bus->wait,
+ atomic_read(&nvdimm_bus->ioctl_active) == 0);
+
nd_synchronize();
device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
@@ -838,7 +841,7 @@ void wait_nvdimm_bus_probe_idle(struct device *dev)
if (nvdimm_bus->probe_active == 0)
break;
nvdimm_bus_unlock(&nvdimm_bus->dev);
- wait_event(nvdimm_bus->probe_wait,
+ wait_event(nvdimm_bus->wait,
nvdimm_bus->probe_active == 0);
nvdimm_bus_lock(&nvdimm_bus->dev);
} while (true);
@@ -1068,24 +1071,10 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
return rc;
}
-static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
-{
- long id = (long) file->private_data;
- int rc = -ENXIO, ro;
- struct nvdimm_bus *nvdimm_bus;
-
- ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);
- mutex_lock(&nvdimm_bus_list_mutex);
- list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
- if (nvdimm_bus->id == id) {
- rc = __nd_ioctl(nvdimm_bus, NULL, ro, cmd, arg);
- break;
- }
- }
- mutex_unlock(&nvdimm_bus_list_mutex);
-
- return rc;
-}
+enum nd_ioctl_mode {
+ BUS_IOCTL,
+ DIMM_IOCTL,
+};
static int match_dimm(struct device *dev, void *data)
{
@@ -1100,31 +1089,62 @@ static int match_dimm(struct device *dev, void *data)
return 0;
}
-static long nvdimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
+ enum nd_ioctl_mode mode)
+
{
- int rc = -ENXIO, ro;
- struct nvdimm_bus *nvdimm_bus;
+ struct nvdimm_bus *nvdimm_bus, *found = NULL;
+ long id = (long) file->private_data;
+ struct nvdimm *nvdimm = NULL;
+ int rc, ro;
ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);
mutex_lock(&nvdimm_bus_list_mutex);
list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
- struct device *dev = device_find_child(&nvdimm_bus->dev,
- file->private_data, match_dimm);
- struct nvdimm *nvdimm;
-
- if (!dev)
- continue;
+ if (mode == DIMM_IOCTL) {
+ struct device *dev;
+
+ dev = device_find_child(&nvdimm_bus->dev,
+ file->private_data, match_dimm);
+ if (!dev)
+ continue;
+ nvdimm = to_nvdimm(dev);
+ found = nvdimm_bus;
+ } else if (nvdimm_bus->id == id) {
+ found = nvdimm_bus;
+ }
- nvdimm = to_nvdimm(dev);
- rc = __nd_ioctl(nvdimm_bus, nvdimm, ro, cmd, arg);
- put_device(dev);
- break;
+ if (found) {
+ atomic_inc(&nvdimm_bus->ioctl_active);
+ break;
+ }
}
mutex_unlock(&nvdimm_bus_list_mutex);
+ if (!found)
+ return -ENXIO;
+
+ nvdimm_bus = found;
+ rc = __nd_ioctl(nvdimm_bus, nvdimm, ro, cmd, arg);
+
+ if (nvdimm)
+ put_device(&nvdimm->dev);
+ if (atomic_dec_and_test(&nvdimm_bus->ioctl_active))
+ wake_up(&nvdimm_bus->wait);
+
return rc;
}
+static long bus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ return nd_ioctl(file, cmd, arg, BUS_IOCTL);
+}
+
+static long dimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ return nd_ioctl(file, cmd, arg, DIMM_IOCTL);
+}
+
static int nd_open(struct inode *inode, struct file *file)
{
long minor = iminor(inode);
@@ -1136,16 +1156,16 @@ static int nd_open(struct inode *inode, struct file *file)
static const struct file_operations nvdimm_bus_fops = {
.owner = THIS_MODULE,
.open = nd_open,
- .unlocked_ioctl = nd_ioctl,
- .compat_ioctl = nd_ioctl,
+ .unlocked_ioctl = bus_ioctl,
+ .compat_ioctl = bus_ioctl,
.llseek = noop_llseek,
};
static const struct file_operations nvdimm_fops = {
.owner = THIS_MODULE,
.open = nd_open,
- .unlocked_ioctl = nvdimm_ioctl,
- .compat_ioctl = nvdimm_ioctl,
+ .unlocked_ioctl = dimm_ioctl,
+ .compat_ioctl = dimm_ioctl,
.llseek = noop_llseek,
};
diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h
index 5ff254dc9b14..adf62a6c0fe2 100644
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -25,10 +25,11 @@ extern int nvdimm_major;
struct nvdimm_bus {
struct nvdimm_bus_descriptor *nd_desc;
- wait_queue_head_t probe_wait;
+ wait_queue_head_t wait;
struct list_head list;
struct device dev;
int id, probe_active;
+ atomic_t ioctl_active;
struct list_head mapping_list;
struct mutex reconfig_mutex;
struct badrange badrange;