bsd/vfs/vfs_journal.c

2979 ;				adding an extent to the list, and the list already occupies
2981 ;				if unable to allocate more space, or 0 if the extent list was
3007 		printf("jnl: trim_realloc: unable to grow extent list!\n");
3018 	/* Copy the old extent list to the newly allocated list. */
3041  ; Function:		Search the given extent list to see if any of its extents
3042  ;				overlap the given extent.
3047  ;	length		- The number of bytes of the extent being searched for.
3061 	/* A binary search over the extent list. */
3091 ;				to add recently freed extents to its free extent cache, but
3100 ;	length		- The number of bytes of the extent being trimmed.
3108 	dk_extent_t *extent;
3136 	 * input extent.  We start by counting the number of extents that end
3137 	 * strictly before the input extent, then count the number of extents
3138 	 * that overlap or are contiguous with the input extent.
3140 	extent = tr->trim.extents;
3142 	while (insert_index < tr->trim.extent_count && extent->offset + extent->length < offset) {
3144 		++extent;
3147 	while (insert_index + replace_count < tr->trim.extent_count && extent->offset <= end) {
3149 		++extent;
3153 	 * If none of the existing extents can be combined with the input extent,
3175 		/* Store the new extent in the list. */
3186 	 * Update extent number insert_index to be the union of the input extent
3191 	extent = &tr->trim.extents[insert_index + replace_count - 1];
3192 	if (extent->offset + extent->length > end)
3193 		end = extent->offset + extent->length;
3198 	 * If we were replacing more than one existing extent, then shift any
3201 	 * We're going to leave extent #insert_index alone since it was just updated, above.
3203 	 * the list by (replace_count - 1) positions so that they overwrite extent #(insert_index + 1).
3231 ;				added to its free extent cache (if some portion of the newly
3237 ;	length		- The number of bytes of the extent being trimmed.
3244 	dk_extent_t *extent;
3252 	 * extent.  These extents will be modified if they overlap the input
3253 	 * extent.  Other extents between them will be deleted.
3255 	extent = trim->extents;
3257 	while (keep_before < trim->extent_count && extent->offset < offset) {
3259 		++extent;
3263 		/* See if previous extent extends beyond both ends of input extent. */
3265 		--extent;
3267 	while (keep_after < trim->extent_count && (extent->offset + extent->length) <= end) {
3269 		++extent;
3274 	 * start before the input extent, and extents (keep_after .. extent_count-1)
3275 	 * end after the input extent.  We'll need to keep, all of those extents,
3277 	 * that overlaps with the input extent.
3281 	 * Does the input extent start after and end before the same existing
3282 	 * extent?  If so, we have to "punch a hole" in that extent and convert
3295 		 * Make room for a new extent by shifting extents #keep_after and later
3296 		 * down by one extent.  When we're done, extents #keep_before and
3298 		 * the portion that overlaps the input extent.
3307 		 * Fall through.  We now have the case where the length of extent
3308 		 * #(keep_before - 1) needs to be updated, and the start of extent
3314 	 * May need to truncate the end of extent #(keep_before - 1) if it overlaps
3315 	 * the input extent.
3318 		extent = &trim->extents[keep_before - 1];
3319 		if (extent->offset + extent->length > offset) {
3320 			extent->length = offset - extent->offset;
3325 	 * May need to update the start of extent #(keep_after) if it overlaps the
3326 	 * input extent.
3329 		extent = &trim->extents[keep_after];
3330 		if (extent->offset < end) {
3331 			extent->length = extent->offset + extent->length - end;
3332 			extent->offset = end;
3337 	 * If there were whole extents that overlapped the input extent, get rid
3364  ;	length		- The number of bytes of the extent being trimmed.
3408 			 * There was an overlap, so avoid trimming the extent we
4031 	// free up the extent list.