diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2017-04-11 09:49:49 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2017-04-12 21:59:14 -0700 |
| commit | 7b6be8444e0f0dd675b54d059793423d3c9b4c03 (patch) | |
| tree | b2782a46dda7b03fac23216f873b1a6bf1df58cb /include/linux/dax.h | |
| parent | 5f0694b300b9fb8409272c550418c22e0e57314a (diff) | |
dax: refactor dax-fs into a generic provider of 'struct dax_device' instances
We want dax capable drivers to be able to publish a set of dax
operations [1]. However, we do not want to further abuse block_devices
to advertise these operations. Instead we will attach these operations
to a dax device and add a lookup mechanism to go from block device path
to a dax device. A dax capable driver like pmem or brd is responsible
for registering a dax device, alongside a block device, and then a dax
capable filesystem is responsible for retrieving the dax device by path
name if it wants to call dax_operations.
For now, we refactor the dax pseudo-fs to be a generic facility, rather
than an implementation detail, of the device-dax use case. Where a "dax
device" is just an inode + dax infrastructure, and "Device DAX" is a
mapping service layered on top of that base 'struct dax_device'.
"Filesystem DAX" is then a mapping service that layers a filesystem on
top of that same base device. Filesystem DAX is associated with a
block_device for now, but perhaps directly to a dax device in the
future, or for new pmem-only filesystems.
[1]: https://lkml.org/lkml/2017/1/19/880
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'include/linux/dax.h')
| -rw-r--r-- | include/linux/dax.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/dax.h b/include/linux/dax.h index d8a3dc042e1c..5b62f5d19aea 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -8,6 +8,9 @@ struct iomap_ops; +int dax_read_lock(void); +void dax_read_unlock(int id); + /* * We use lowest available bit in exceptional entry for locking, one bit for * the entry size (PMD) and two more to tell us if the entry is a huge zero |