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| author | Vishal Verma <vishal.l.verma@intel.com> | 2016-05-27 12:43:45 -0600 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2016-06-17 16:23:23 -0700 |
| commit | 0aefa05420c0e81eec2496b28a1b5d6e7783cb23 (patch) | |
| tree | 6119ee49bd3c9d6bdfae2bffb890b891b312c203 /Documentation/nvdimm | |
| parent | f02716db951c5e01acf48df9fe815007674fecff (diff) | |
| download | linux-rt-0aefa05420c0e81eec2496b28a1b5d6e7783cb23.tar.gz | |
libnvdimm, btt: update the usage section in Documentation
Section 5 about BTT's in kernel usage was quite obsolete,
replace it with a simple 'Usage' section that describes how
to set up a BTT namespace using the 'ndctl' utility.
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'Documentation/nvdimm')
| -rw-r--r-- | Documentation/nvdimm/btt.txt | 28 |
1 files changed, 9 insertions, 19 deletions
diff --git a/Documentation/nvdimm/btt.txt b/Documentation/nvdimm/btt.txt index b91443f577dc..e293fb664924 100644 --- a/Documentation/nvdimm/btt.txt +++ b/Documentation/nvdimm/btt.txt @@ -256,28 +256,18 @@ If any of these error conditions are encountered, the arena is put into a read only state using a flag in the info block. -5. In-kernel usage -================== +5. Usage +======== -Any block driver that supports byte granularity IO to the storage may register -with the BTT. It will have to provide the rw_bytes interface in its -block_device_operations struct: +The BTT can be set up on any disk (namespace) exposed by the libnvdimm subsystem +(pmem, or blk mode). The easiest way to set up such a namespace is using the +'ndctl' utility [1]: - int (*rw_bytes)(struct gendisk *, void *, size_t, off_t, int rw); +For example, the ndctl command line to setup a btt with a 4k sector size is: -It may register with the BTT after it adds its own gendisk, using btt_init: + ndctl create-namespace -f -e namespace0.0 -m sector -l 4k - struct btt *btt_init(struct gendisk *disk, unsigned long long rawsize, - u32 lbasize, u8 uuid[], int maxlane); +See ndctl create-namespace --help for more options. -note that maxlane is the maximum amount of concurrency the driver wishes to -allow the BTT to use. - -The BTT 'disk' appears as a stacked block device that grabs the underlying block -device in the O_EXCL mode. - -When the driver wishes to remove the backing disk, it should similarly call -btt_fini using the same struct btt* handle that was provided to it by btt_init. - - void btt_fini(struct btt *btt); +[1]: https://github.com/pmem/ndctl |