History log of /linux/drivers/dax/fsdev.c (Results 1 – 7 of 7)
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Revision tags: v7.1-rc2
# 0fc8f620 27-Apr-2026 Thomas Zimmermann <tzimmermann@suse.de>

Merge drm/drm-fixes into drm-misc-fixes

Getting fixes and updates from v7.1-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>


Revision tags: v7.1-rc1
# bb0bc49a 21-Apr-2026 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'libnvdimm-for-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull dax updates from Ira Weiny:
"The series adds DAX support required for the upcoming fuse/famfs file

Merge tag 'libnvdimm-for-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull dax updates from Ira Weiny:
"The series adds DAX support required for the upcoming fuse/famfs file
system.[1] The support here is required because famfs is backed by
devdax rather than pmem. This all lays the groundwork for using shared
memory as a file system"

Link: https://lore.kernel.org/all/0100019d43e5f632-f5862a3e-361c-4b54-a9a6-96c242a8f17a-000000@email.amazonses.com/ [1]

* tag 'libnvdimm-for-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
dax/fsdev: fix uninitialized kaddr in fsdev_dax_zero_page_range()
dax: export dax_dev_get()
dax: Add fs_dax_get() func to prepare dax for fs-dax usage
dax: Add dax_set_ops() for setting dax_operations at bind time
dax: Add dax_operations for use by fs-dax on fsdev dax
dax: Save the kva from memremap
dax: add fsdev.c driver for fs-dax on character dax
dax: Factor out dax_folio_reset_order() helper
dax: move dax_pgoff_to_phys from [drivers/dax/] device.c to bus.c

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Revision tags: v7.0
# 45df9111 12-Apr-2026 John Groves <John@Groves.net>

dax/fsdev: fix uninitialized kaddr in fsdev_dax_zero_page_range()

__fsdev_dax_direct_access() returns -EFAULT without setting *kaddr when
dax_pgoff_to_phys() returns -1 (pgoff out of range). The ret

dax/fsdev: fix uninitialized kaddr in fsdev_dax_zero_page_range()

__fsdev_dax_direct_access() returns -EFAULT without setting *kaddr when
dax_pgoff_to_phys() returns -1 (pgoff out of range). The return value
was ignored, leaving kaddr uninitialized before being passed to
fsdev_write_dax().

Check the return value and propagate the error.

Thanks to Dan Carpenter and the smatch project for reporting this.

Signed-off-by: John Groves <john@groves.net>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://patch.msgid.link/0100019d8262cda2-9714d31c-8fc1-4ca5-b32d-4df678240d14-000000@email.amazonses.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

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Revision tags: v7.0-rc7, v7.0-rc6
# 700ecbc1 27-Mar-2026 John Groves <John@Groves.net>

dax: Add dax_set_ops() for setting dax_operations at bind time

Add a new dax_set_ops() function that allows drivers to set the
dax_operations after the dax_device has been allocated. This is needed

dax: Add dax_set_ops() for setting dax_operations at bind time

Add a new dax_set_ops() function that allows drivers to set the
dax_operations after the dax_device has been allocated. This is needed
for fsdev_dax where the operations need to be set during probe and
cleared during unbind.

The fsdev driver uses devm_add_action_or_reset() for cleanup consistency,
avoiding the complexity of mixing devm-managed resources with manual
cleanup in a remove() callback. This ensures cleanup happens automatically
in the correct reverse order when the device is unbound.

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Signed-off-by: John Groves <john@groves.net>
Link: https://patch.msgid.link/0100019d311d65a0-b9c1419e-f3a0-4afd-b0bd-848f18ff5950-000000@email.amazonses.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

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# 099c81a1 27-Mar-2026 John Groves <John@Groves.net>

dax: Add dax_operations for use by fs-dax on fsdev dax

fsdev: Add dax_operations for use by famfs.

This replicates the functionality from drivers/nvdimm/pmem.c that
conventional fs-dax file systems

dax: Add dax_operations for use by fs-dax on fsdev dax

fsdev: Add dax_operations for use by famfs.

This replicates the functionality from drivers/nvdimm/pmem.c that
conventional fs-dax file systems (e.g. xfs) use to support dax
read/write/mmap to a daxdev - without which famfs can't sit atop a
daxdev.

- These methods are based on pmem_dax_ops from drivers/nvdimm/pmem.c
- fsdev_dax_direct_access() returns the hpa, pfn and kva. The kva was
newly stored as dev_dax->virt_addr by dev_dax_probe().
- The hpa/pfn are used for mmap (dax_iomap_fault()), and the kva is used
for read/write (dax_iomap_rw())
- fsdev_dax_recovery_write() and dev_dax_zero_page_range() have not been
tested yet. I'm looking for suggestions as to how to test those.
- dax-private.h: add dev_dax->cached_size, which fsdev needs to
remember. The dev_dax size cannot change while a driver is bound
(dev_dax_resize returns -EBUSY if dev->driver is set). Caching the size
at probe time allows fsdev's direct_access path can use it without
acquiring dax_dev_rwsem (which isn't exported anyway).

Signed-off-by: John Groves <john@groves.net>
Link: https://patch.msgid.link/0100019d311d415a-bd6af0fe-5445-484c-9d39-210b8170b686-000000@email.amazonses.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

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# 75945584 27-Mar-2026 John Groves <john@groves.net>

dax: Save the kva from memremap

Save the kva from memremap because we need it for iomap rw support.

Prior to famfs, there were no iomap users of /dev/dax - so the virtual
address from memremap was

dax: Save the kva from memremap

Save the kva from memremap because we need it for iomap rw support.

Prior to famfs, there were no iomap users of /dev/dax - so the virtual
address from memremap was not needed.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Signed-off-by: John Groves <john@groves.net>
Link: https://patch.msgid.link/0100019d311d1d08-dd372cb9-5934-43b8-bef8-089660d04a81-000000@email.amazonses.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

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# d5406bd4 27-Mar-2026 John Groves <john@groves.net>

dax: add fsdev.c driver for fs-dax on character dax

The new fsdev driver provides pages/folios initialized compatibly with
fsdax - normal rather than devdax-style refcounting, and starting out
with

dax: add fsdev.c driver for fs-dax on character dax

The new fsdev driver provides pages/folios initialized compatibly with
fsdax - normal rather than devdax-style refcounting, and starting out
with order-0 folios.

When fsdev binds to a daxdev, it is usually (always?) switching from the
devdax mode (device.c), which pre-initializes compound folios according
to its alignment. Fsdev uses fsdev_clear_folio_state() to switch the
folios into a fsdax-compatible state.

A side effect of this is that raw mmap doesn't (can't?) work on an fsdev
dax instance. Accordingly, The fsdev driver does not provide raw mmap -
devices must be put in 'devdax' mode (drivers/dax/device.c) to get raw
mmap capability.

In this commit is just the framework, which remaps pages/folios compatibly
with fsdax.

Enabling dax changes:

- bus.h: add DAXDRV_FSDEV_TYPE driver type
- bus.c: allow DAXDRV_FSDEV_TYPE drivers to bind to daxdevs
- dax.h: prototype inode_dax(), which fsdev needs

Suggested-by: Dan Williams <dan.j.williams@intel.com>
Suggested-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Signed-off-by: John Groves <john@groves.net>
Link: https://patch.msgid.link/0100019d311cf904-419e9526-bdaf-4daa-97f1-5060b31a5c9f-000000@email.amazonses.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

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