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authorDaniel Vetter <daniel.vetter@ffwll.ch>2013-05-21 09:52:16 +0200
committerDaniel Vetter <daniel.vetter@ffwll.ch>2013-05-21 09:52:16 +0200
commite1b73cba13a0cc68dd4f746eced15bd6bb24cda4 (patch)
treeb1c9e10730724024a700031ad56c20419dabb500 /include/linux/device-mapper.h
parent98304ad186296dc1e655399e28d5973c21db6a73 (diff)
parentc7788792a5e7b0d5d7f96d0766b4cb6112d47d75 (diff)
Merge tag 'v3.10-rc2' into drm-intel-next-queued
Backmerge Linux 3.10-rc2 since the various (rather trivial) conflicts grew a bit out of hand. intel_dp.c has the only real functional conflict since the logic changed while dev_priv->edp.bpp was moved around. Also squash in a whitespace fixup from Ben Widawsky for i915_gem_gtt.c, git seems to do something pretty strange in there (which I don't fully understand tbh). Conflicts: drivers/gpu/drm/i915/i915_reg.h drivers/gpu/drm/i915/intel_dp.c Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'include/linux/device-mapper.h')
-rw-r--r--include/linux/device-mapper.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 1e483fa7afb4..3cd32478f2fd 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);