dax: drop rcu patch not applicable to 4.8

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

2 files changed, 0 insertions, 135 deletions

diff --git a/queue/device-dax-switch-to-srcu-fix-rcu_read_lock-vs-pte-a.patch b/queue/device-dax-switch-to-srcu-fix-rcu_read_lock-vs-pte-a.patch
deleted file mode 100644
index 4dd7516..0000000
--- a/queue/device-dax-switch-to-srcu-fix-rcu_read_lock-vs-pte-a.patch
+++ /dev/null
@@ -1,134 +0,0 @@
-From 956a4cd2c957acf638ff29951aabaa9d8e92bbc2 Mon Sep 17 00:00:00 2001
-From: Dan Williams <dan.j.williams@intel.com>
-Date: Fri, 7 Apr 2017 16:42:08 -0700
-Subject: [PATCH] device-dax: switch to srcu, fix rcu_read_lock() vs pte
- allocation
-
-commit 956a4cd2c957acf638ff29951aabaa9d8e92bbc2 upstream.
-
-The following warning triggers with a new unit test that stresses the
-device-dax interface.
-
- ===============================
- [ ERR: suspicious RCU usage.  ]
- 4.11.0-rc4+ #1049 Tainted: G           O
- -------------------------------
- ./include/linux/rcupdate.h:521 Illegal context switch in RCU read-side critical section!
-
- other info that might help us debug this:
-
- rcu_scheduler_active = 2, debug_locks = 0
- 2 locks held by fio/9070:
-  #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff8d0739d7>] __do_page_fault+0x167/0x4f0
-  #1:  (rcu_read_lock){......}, at: [<ffffffffc03fbd02>] dax_dev_huge_fault+0x32/0x620 [dax]
-
- Call Trace:
-  dump_stack+0x86/0xc3
-  lockdep_rcu_suspicious+0xd7/0x110
-  ___might_sleep+0xac/0x250
-  __might_sleep+0x4a/0x80
-  __alloc_pages_nodemask+0x23a/0x360
-  alloc_pages_current+0xa1/0x1f0
-  pte_alloc_one+0x17/0x80
-  __pte_alloc+0x1e/0x120
-  __get_locked_pte+0x1bf/0x1d0
-  insert_pfn.isra.70+0x3a/0x100
-  ? lookup_memtype+0xa6/0xd0
-  vm_insert_mixed+0x64/0x90
-  dax_dev_huge_fault+0x520/0x620 [dax]
-  ? dax_dev_huge_fault+0x32/0x620 [dax]
-  dax_dev_fault+0x10/0x20 [dax]
-  __do_fault+0x1e/0x140
-  __handle_mm_fault+0x9af/0x10d0
-  handle_mm_fault+0x16d/0x370
-  ? handle_mm_fault+0x47/0x370
-  __do_page_fault+0x28c/0x4f0
-  trace_do_page_fault+0x58/0x2a0
-  do_async_page_fault+0x1a/0xa0
-  async_page_fault+0x28/0x30
-
-Inserting a page table entry may trigger an allocation while we are
-holding a read lock to keep the device instance alive for the duration
-of the fault. Use srcu for this keep-alive protection.
-
-Fixes: dee410792419 ("/dev/dax, core: file operations and dax-mmap")
-Cc: <stable@vger.kernel.org>
-Signed-off-by: Dan Williams <dan.j.williams@intel.com>
-
-diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig
-index 3e2ab3b14eea..9e95bf94eb13 100644
---- a/drivers/dax/Kconfig
-+++ b/drivers/dax/Kconfig
-@@ -2,6 +2,7 @@ menuconfig DEV_DAX
- 	tristate "DAX: direct access to differentiated memory"
- 	default m if NVDIMM_DAX
- 	depends on TRANSPARENT_HUGEPAGE
-+	select SRCU
- 	help
- 	  Support raw access to differentiated (persistence, bandwidth,
- 	  latency...) memory via an mmap(2) capable character
-diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c
-index 80c6db279ae1..806f180c80d8 100644
---- a/drivers/dax/dax.c
-+++ b/drivers/dax/dax.c
-@@ -25,6 +25,7 @@
- #include "dax.h"
- 
- static dev_t dax_devt;
-+DEFINE_STATIC_SRCU(dax_srcu);
- static struct class *dax_class;
- static DEFINE_IDA(dax_minor_ida);
- static int nr_dax = CONFIG_NR_DEV_DAX;
-@@ -60,7 +61,7 @@ struct dax_region {
-  * @region - parent region
-  * @dev - device backing the character device
-  * @cdev - core chardev data
-- * @alive - !alive + rcu grace period == no new mappings can be established
-+ * @alive - !alive + srcu grace period == no new mappings can be established
-  * @id - child id in the region
-  * @num_resources - number of physical address extents in this device
-  * @res - array of physical address ranges
-@@ -569,7 +570,7 @@ static int __dax_dev_pud_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
- static int dax_dev_huge_fault(struct vm_fault *vmf,
- 		enum page_entry_size pe_size)
- {
--	int rc;
-+	int rc, id;
- 	struct file *filp = vmf->vma->vm_file;
- 	struct dax_dev *dax_dev = filp->private_data;
- 
-@@ -578,7 +579,7 @@ static int dax_dev_huge_fault(struct vm_fault *vmf,
- 			? "write" : "read",
- 			vmf->vma->vm_start, vmf->vma->vm_end);
- 
--	rcu_read_lock();
-+	id = srcu_read_lock(&dax_srcu);
- 	switch (pe_size) {
- 	case PE_SIZE_PTE:
- 		rc = __dax_dev_pte_fault(dax_dev, vmf);
-@@ -592,7 +593,7 @@ static int dax_dev_huge_fault(struct vm_fault *vmf,
- 	default:
- 		return VM_FAULT_FALLBACK;
- 	}
--	rcu_read_unlock();
-+	srcu_read_unlock(&dax_srcu, id);
- 
- 	return rc;
- }
-@@ -713,11 +714,11 @@ static void unregister_dax_dev(void *dev)
- 	 * Note, rcu is not protecting the liveness of dax_dev, rcu is
- 	 * ensuring that any fault handlers that might have seen
- 	 * dax_dev->alive == true, have completed.  Any fault handlers
--	 * that start after synchronize_rcu() has started will abort
-+	 * that start after synchronize_srcu() has started will abort
- 	 * upon seeing dax_dev->alive == false.
- 	 */
- 	dax_dev->alive = false;
--	synchronize_rcu();
-+	synchronize_srcu(&dax_srcu);
- 	unmap_mapping_range(dax_dev->inode->i_mapping, 0, 0, 1);
- 	cdev_del(cdev);
- 	device_unregister(dev);
--- 
-2.12.0
-
diff --git a/queue/series b/queue/series
index 4e5ccc1..b07a53e 100644
--- a/queue/series
+++ b/queue/series
@@ -12,7 +12,6 @@ mac80211-reject-ToDS-broadcast-data-frames.patch
 ubi-upd-Always-flush-after-prepared-for-an-update.patch
 powerpc-kprobe-Fix-oops-when-kprobed-on-stdu-instruc.patch
 x86-mce-AMD-Give-a-name-to-MCA-bank-3-when-accessed-.patch
-device-dax-switch-to-srcu-fix-rcu_read_lock-vs-pte-a.patch
 Revert-mmc-sdhci-msm-Enable-few-quirks.patch
 ping-implement-proper-locking.patch
 sparc64-kern_addr_valid-regression.patch