diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-10 09:02:50 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-10 09:02:50 -0700 |
commit | ec6671589a07d9b27ff5832138ff435b3a3c9b09 (patch) | |
tree | 4866cfd09e45a492b5b96380818fb5d1e3a4fac0 /include/linux | |
parent | f755407dd19072b7d20719bc5454caed9ab41cc1 (diff) | |
parent | 2f14f4b51ed34fe2b704af8df178f5cd8c81f65e (diff) |
Merge tag 'dm-3.10-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm
Pull device-mapper updates from Alasdair Kergon:
"Allow devices that hold metadata for the device-mapper thin
provisioning target to be extended easily; allow WRITE SAME on
multipath devices; an assortment of little fixes and clean-ups."
* tag 'dm-3.10-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm: (21 commits)
dm cache: set config value
dm cache: move config fns
dm thin: generate event when metadata threshold passed
dm persistent metadata: add space map threshold callback
dm persistent data: add threshold callback to space map
dm thin: detect metadata device resizing
dm persistent data: support space map resizing
dm thin: open dev read only when possible
dm thin: refactor data dev resize
dm cache: replace memcpy with struct assignment
dm cache: fix typos in comments
dm cache policy: fix description of lookup fn
dm: document iterate_devices
dm persistent data: fix error message typos
dm cache: tune migration throttling
dm mpath: enable WRITE SAME support
dm table: fix write same support
dm bufio: avoid a possible __vmalloc deadlock
dm snapshot: fix error return code in snapshot_ctr
dm cache: fix error return code in cache_create
...
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/device-mapper.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 1e483fa7afb..3cd32478f2f 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -79,11 +79,26 @@ typedef int (*dm_ioctl_fn) (struct dm_target *ti, unsigned int cmd, typedef int (*dm_merge_fn) (struct dm_target *ti, struct bvec_merge_data *bvm, struct bio_vec *biovec, int max_size); +/* + * These iteration functions are typically used to check (and combine) + * properties of underlying devices. + * E.g. Does at least one underlying device support flush? + * Does any underlying device not support WRITE_SAME? + * + * The callout function is called once for each contiguous section of + * an underlying device. State can be maintained in *data. + * Return non-zero to stop iterating through any further devices. + */ typedef int (*iterate_devices_callout_fn) (struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data); +/* + * This function must iterate through each section of device used by the + * target until it encounters a non-zero return code, which it then returns. + * Returns zero if no callout returned non-zero. + */ typedef int (*dm_iterate_devices_fn) (struct dm_target *ti, iterate_devices_callout_fn fn, void *data); |