From: Dan Williams <dan.j.williams@intel.com> To: linux-nvdimm@lists.01.org Cc: peterz@infradead.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH v2 5/7] libnvdimm/bus: Stop holding nvdimm_bus_list_mutex over __nd_ioctl() Date: Wed, 17 Jul 2019 18:08:15 -0700 [thread overview] Message-ID: <156341209518.292348.7183897251740665198.stgit@dwillia2-desk3.amr.corp.intel.com> (raw) In-Reply-To: <156341206785.292348.1660822720191643298.stgit@dwillia2-desk3.amr.corp.intel.com> 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> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- drivers/nvdimm/bus.c | 96 ++++++++++++++++++++++++++++------------------ drivers/nvdimm/nd-core.h | 3 + 2 files changed, 60 insertions(+), 39 deletions(-) diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c index a3180c28fb2b..a38572bf486b 100644 --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -73,7 +73,7 @@ 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); } @@ -341,7 +341,7 @@ 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); if (nvdimm_bus->id < 0) { kfree(nvdimm_bus); @@ -426,6 +426,9 @@ 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); @@ -885,7 +888,7 @@ 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); @@ -1130,24 +1133,10 @@ 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) { @@ -1162,31 +1151,62 @@ 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); @@ -1198,16 +1218,16 @@ 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 391e88de3a29..6cd470547106 100644 --- a/drivers/nvdimm/nd-core.h +++ b/drivers/nvdimm/nd-core.h @@ -17,10 +17,11 @@ extern struct workqueue_struct *nvdimm_wq; 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; _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm
WARNING: multiple messages have this Message-ID (diff)
From: Dan Williams <dan.j.williams@intel.com> To: linux-nvdimm@lists.01.org Cc: stable@vger.kernel.org, Vishal Verma <vishal.l.verma@intel.com>, Jane Chu <jane.chu@oracle.com>, peterz@infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 5/7] libnvdimm/bus: Stop holding nvdimm_bus_list_mutex over __nd_ioctl() Date: Wed, 17 Jul 2019 18:08:15 -0700 [thread overview] Message-ID: <156341209518.292348.7183897251740665198.stgit@dwillia2-desk3.amr.corp.intel.com> (raw) In-Reply-To: <156341206785.292348.1660822720191643298.stgit@dwillia2-desk3.amr.corp.intel.com> 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> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- drivers/nvdimm/bus.c | 96 ++++++++++++++++++++++++++++------------------ drivers/nvdimm/nd-core.h | 3 + 2 files changed, 60 insertions(+), 39 deletions(-) diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c index a3180c28fb2b..a38572bf486b 100644 --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -73,7 +73,7 @@ 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); } @@ -341,7 +341,7 @@ 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); if (nvdimm_bus->id < 0) { kfree(nvdimm_bus); @@ -426,6 +426,9 @@ 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); @@ -885,7 +888,7 @@ 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); @@ -1130,24 +1133,10 @@ 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) { @@ -1162,31 +1151,62 @@ 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); @@ -1198,16 +1218,16 @@ 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 391e88de3a29..6cd470547106 100644 --- a/drivers/nvdimm/nd-core.h +++ b/drivers/nvdimm/nd-core.h @@ -17,10 +17,11 @@ extern struct workqueue_struct *nvdimm_wq; 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;
next prev parent reply other threads:[~2019-07-18 1:25 UTC|newest] Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-07-18 1:07 [PATCH v2 0/7] libnvdimm: Fix async operations and locking Dan Williams 2019-07-18 1:07 ` Dan Williams 2019-07-18 1:07 ` [PATCH v2 1/7] drivers/base: Introduce kill_device() Dan Williams 2019-07-18 1:07 ` Dan Williams 2019-07-18 2:29 ` Greg Kroah-Hartman 2019-07-18 2:29 ` Greg Kroah-Hartman [not found] ` <156341207332.292348.14959761496009347574.stgit-p8uTFz9XbKj2zm6wflaqv1nYeNYlB/vhral2JQCrhuEAvxtiuMwx3w@public.gmane.org> 2019-07-19 0:45 ` Sasha Levin 2019-07-18 1:07 ` [PATCH v2 2/7] libnvdimm/bus: Prevent duplicate device_unregister() calls Dan Williams 2019-07-18 1:07 ` Dan Williams 2019-07-18 1:08 ` [PATCH v2 3/7] libnvdimm/region: Register badblocks before namespaces Dan Williams 2019-07-18 1:08 ` Dan Williams 2019-07-18 18:16 ` Verma, Vishal L 2019-07-18 18:16 ` Verma, Vishal L 2019-07-18 1:08 ` [PATCH v2 4/7] libnvdimm/bus: Prepare the nd_ioctl() path to be re-entrant Dan Williams 2019-07-18 1:08 ` Dan Williams 2019-07-18 18:21 ` Verma, Vishal L 2019-07-18 18:21 ` Verma, Vishal L 2019-07-18 1:08 ` Dan Williams [this message] 2019-07-18 1:08 ` [PATCH v2 5/7] libnvdimm/bus: Stop holding nvdimm_bus_list_mutex over __nd_ioctl() Dan Williams 2019-07-18 1:08 ` [PATCH v2 6/7] libnvdimm/bus: Fix wait_nvdimm_bus_probe_idle() ABBA deadlock Dan Williams 2019-07-18 1:08 ` Dan Williams 2019-07-18 2:04 ` Sasha Levin 2019-07-18 2:04 ` Sasha Levin 2019-07-18 6:39 ` Dan Williams 2019-07-18 6:39 ` Dan Williams 2019-07-18 1:08 ` [PATCH v2 7/7] driver-core, libnvdimm: Let device subsystems add local lockdep coverage Dan Williams 2019-07-18 1:08 ` Dan Williams 2019-07-18 2:28 ` Greg Kroah-Hartman 2019-07-18 2:28 ` Greg Kroah-Hartman 2019-07-18 16:09 ` Ira Weiny 2019-07-18 16:09 ` Ira Weiny
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