search for: subtract_offset

...de <stdint.h> #include <string.h> +#include <assert.h> #include <nbdkit-filter.h> @@ -132,6 +133,47 @@ offset_zero (struct nbdkit_next_ops *next_ops, void *nxdata, return next_ops->zero (nxdata, count, offs + offset, flags, err); } +/* Extents. */ +static int +subtract_offset (uint64_t offs, uint64_t length, uint32_t type, + void *vp) +{ + struct nbdkit_extents_map *extents_map = vp; + + assert (offs >= offset); + offs -= offset; + return nbdkit_extent_add (extents_map, offs, length, type); +} + +static int +offset_extents (struct nbdkit_next_ops...

I think the extents map is just too complicated and is unnecessarily so. How about instead we define the plugin interface to be: int can_extents (void *handle); // as before int extents (void *handle, uint32_t count, uint64_t offset, uint32_t flags, struct nbdkit_extents_list *list); and have the extents_list be a simple list. The first extent you add must start at offset.

...ap2 == NULL) + return -1; + if (next_ops->extents (nxdata, count, offs + offset, + flags, map2, err) == -1) { + nbdkit_extents_free (map2); + return -1; + } + + /* Transform offsets in map2, return result in extents_map. */ + if (nbdkit_extents_foreach (map2, subtract_offset, extents_map, + NBDKIT_EXTENTS_FOREACH_FLAG_RANGE, + offset, range) == -1) { + nbdkit_extents_free (map2); + return -1; + } + nbdkit_extents_free (map2); because the plugin was calling: + if (nbdkit_extent_add (extents_map, offs...

...(next_ops->extents (nxdata, count, offs + offset, > + flags, map2, err) == -1) { > + nbdkit_extents_free (map2); > + return -1; > + } > + > + /* Transform offsets in map2, return result in extents_map. */ > + if (nbdkit_extents_foreach (map2, subtract_offset, extents_map, > + NBDKIT_EXTENTS_FOREACH_FLAG_RANGE, > + offset, range) == -1) { > + nbdkit_extents_free (map2); > + return -1; > + } > + nbdkit_extents_free (map2); > > because the plugin was calling: >...

I want to post this but mainly for discussion and early review. It's not safe for these patches to all go upstream yet (because not all filters have been checked/adjusted), but if any patches were to go upstream then probably 1 & 2 only are safe. File, VDDK, memory and data plugins all work, although I have only done minimal testing on them. The current tests, such as they are, all