The patch titled
Subject: libnvdimm/pmem: support pmem block devices without dax
has been added to the -mm mm-unstable branch. Its filename is
libnvdimm-pmem-support-pmem-block-devices-without-dax.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/libnvdimm-pmem-support-pmem-block-devices-without-dax.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Dan Williams <dan.j.williams@xxxxxxxxx>
Subject: libnvdimm/pmem: support pmem block devices without dax
Date: Fri, 14 Oct 2022 16:58:26 -0700
In preparation for CONFIG_DAX growing a CONFIG_MMU dependency add support
for pmem to skip dax-device registration in the CONFIG_DAX=n case.
alloc_dax() returns NULL in the CONFIG_DAX=n case, ERR_PTR() in the
failure case, and a dax-device in the success case.
dax_remove_host(), kill_dax() and put_dax() are safe to call if
setup_dax() returns 0 because it suceeded, or 0 because CONFIG_DAX=n.
Link: https://lkml.kernel.org/r/166579190607.2236710.1230996282258115812.stgit@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Ben Skeggs <bskeggs@xxxxxxxxxx>
Cc: "Christian König" <christian.koenig@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: "Darrick J. Wong" <djwong@xxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: Jerome Glisse <jglisse@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Karol Herbst <kherbst@xxxxxxxxxx>
Cc: kernel test robot <lkp@xxxxxxxxx>
Cc: Lyude Paul <lyude@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: "Pan, Xinhui" <Xinhui.Pan@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/nvdimm/Kconfig | 2 -
drivers/nvdimm/pmem.c | 47 ++++++++++++++++++++++++---------------
2 files changed, 31 insertions(+), 18 deletions(-)
--- a/drivers/nvdimm/Kconfig~libnvdimm-pmem-support-pmem-block-devices-without-dax
+++ a/drivers/nvdimm/Kconfig
@@ -19,7 +19,7 @@ if LIBNVDIMM
config BLK_DEV_PMEM
tristate "PMEM: Persistent memory block device support"
default LIBNVDIMM
- select DAX
+ select DAX if MMU
select ND_BTT if BTT
select ND_PFN if NVDIMM_PFN
help
--- a/drivers/nvdimm/pmem.c~libnvdimm-pmem-support-pmem-block-devices-without-dax
+++ a/drivers/nvdimm/pmem.c
@@ -468,6 +468,32 @@ static const struct dev_pagemap_ops fsda
.memory_failure = pmem_pagemap_memory_failure,
};
+static int setup_dax(struct pmem_device *pmem, struct gendisk *disk,
+ struct nd_region *nd_region)
+{
+ struct dax_device *dax_dev;
+ int rc;
+
+ dax_dev = alloc_dax(pmem, &pmem_dax_ops);
+ if (IS_ERR(dax_dev))
+ return PTR_ERR(dax_dev);
+ if (!dax_dev)
+ return 0;
+ set_dax_nocache(dax_dev);
+ set_dax_nomc(dax_dev);
+ if (is_nvdimm_sync(nd_region))
+ set_dax_synchronous(dax_dev);
+ rc = dax_add_host(dax_dev, disk);
+ if (rc) {
+ kill_dax(dax_dev);
+ put_dax(dax_dev);
+ return rc;
+ }
+ dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
+ pmem->dax_dev = dax_dev;
+ return 0;
+}
+
static int pmem_attach_disk(struct device *dev,
struct nd_namespace_common *ndns)
{
@@ -477,7 +503,6 @@ static int pmem_attach_disk(struct devic
struct resource *res = &nsio->res;
struct range bb_range;
struct nd_pfn *nd_pfn = NULL;
- struct dax_device *dax_dev;
struct nd_pfn_sb *pfn_sb;
struct pmem_device *pmem;
struct request_queue *q;
@@ -578,24 +603,13 @@ static int pmem_attach_disk(struct devic
nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_range);
disk->bb = &pmem->bb;
- dax_dev = alloc_dax(pmem, &pmem_dax_ops);
- if (IS_ERR(dax_dev)) {
- rc = PTR_ERR(dax_dev);
- goto out;
- }
- set_dax_nocache(dax_dev);
- set_dax_nomc(dax_dev);
- if (is_nvdimm_sync(nd_region))
- set_dax_synchronous(dax_dev);
- rc = dax_add_host(dax_dev, disk);
+ rc = setup_dax(pmem, disk, nd_region);
if (rc)
- goto out_cleanup_dax;
- dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
- pmem->dax_dev = dax_dev;
+ goto out;
rc = device_add_disk(dev, disk, pmem_attribute_groups);
if (rc)
- goto out_remove_host;
+ goto out_dax;
if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
return -ENOMEM;
@@ -607,9 +621,8 @@ static int pmem_attach_disk(struct devic
dev_warn(dev, "'badblocks' notification disabled\n");
return 0;
-out_remove_host:
+out_dax:
dax_remove_host(pmem->disk);
-out_cleanup_dax:
kill_dax(pmem->dax_dev);
put_dax(pmem->dax_dev);
out:
_
Patches currently in -mm which might be from dan.j.williams@xxxxxxxxx are
fsdax-wait-on-page-not-page-_refcount.patch
fsdax-use-dax_page_idle-to-document-dax-busy-page-checking.patch
fsdax-include-unmapped-inodes-for-page-idle-detection.patch
fsdax-introduce-dax_zap_mappings.patch
fsdax-wait-for-pinned-pages-during-truncate_inode_pages_final.patch
fsdax-validate-dax-layouts-broken-before-truncate.patch
fsdax-hold-dax-lock-over-mapping-insertion.patch
fsdax-update-dax_insert_entry-calling-convention-to-return-an-error.patch
fsdax-rework-for_each_mapped_pfn-to-dax_for_each_folio.patch
fsdax-introduce-pgmap_request_folios.patch
fsdax-rework-dax_insert_entry-calling-convention.patch
fsdax-cleanup-dax_associate_entry.patch
devdax-minor-warning-fixups.patch
devdax-fix-sparse-lock-imbalance-warning.patch
libnvdimm-pmem-support-pmem-block-devices-without-dax.patch
devdax-move-address_space-helpers-to-the-dax-core.patch
devdax-sparse-fixes-for-xarray-locking.patch
devdax-sparse-fixes-for-vmfault_t-dax-entry-conversions.patch
devdax-sparse-fixes-for-vm_fault_t-in-tracepoints.patch
devdax-add-pud-support-to-the-dax-mapping-infrastructure.patch
devdax-use-dax_insert_entry-dax_delete_mapping_entry.patch
mm-memremap_pages-replace-zone_device_page_init-with-pgmap_request_folios.patch
mm-memremap_pages-initialize-all-zone_device-pages-to-start-at-refcount-0.patch
mm-meremap_pages-delete-put_devmap_managed_page_refs.patch
mm-gup-drop-dax-pgmap-accounting.patch
