Multi ABD Type

Adding the mutli abd type, which allows for linear and scatter abd's to be chained together into a single abd. Signed-off-by: Brian <batkinson.lanl.gov> Authored-by: Mark Maybee <[email protected]>
openzfs · Feb 28, 2020 · dfd871f · dfd871f
1 parent abef699
commit dfd871f
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Showing 4 changed files with 451 additions and 113 deletions.
diff --git a/include/sys/abd.h b/include/sys/abd.h
@@ -36,12 +36,15 @@ extern "C" {
 #endif
 
 typedef enum abd_flags {
-	ABD_FLAG_LINEAR	= 1 << 0,	/* is buffer linear (or scattered)? */
-	ABD_FLAG_OWNER	= 1 << 1,	/* does it own its data buffers? */
-	ABD_FLAG_META	= 1 << 2,	/* does this represent FS metadata? */
-	ABD_FLAG_MULTI_ZONE  = 1 << 3,	/* pages split over memory zones */
-	ABD_FLAG_MULTI_CHUNK = 1 << 4,	/* pages split over multiple chunks */
-	ABD_FLAG_LINEAR_PAGE = 1 << 5,	/* linear but allocd from page */
+	ABD_FLAG_LINEAR		= 1 << 0, /* is buffer linear (or scattered)? */
+	ABD_FLAG_OWNER		= 1 << 1, /* does it own its data buffers? */
+	ABD_FLAG_META		= 1 << 2, /* does this represent FS metadata? */
+	ABD_FLAG_MULTI_ZONE  	= 1 << 3, /* pages split over memory zones */
+	ABD_FLAG_MULTI_CHUNK 	= 1 << 4, /* pages split over multiple chunks */
+	ABD_FLAG_LINEAR_PAGE 	= 1 << 5, /* linear but allocd from page */
+	ABD_FLAG_MULTI_LIST	= 1 << 6, /* mult ABDs chained together */
+	ABD_FLAG_GAP		= 1 << 7, /* ABD for read gap */
+	ABD_FLAG_ZEROS		= 1 << 8, /* ABD for zero-filled buffer */
 } abd_flags_t;
 
 typedef struct abd {
@@ -64,6 +67,9 @@ typedef struct abd {
 			void		*abd_buf;
 			struct scatterlist *abd_sgl; /* for LINEAR_PAGE */
 		} abd_linear;
+		struct abd_multi {
+			list_t abd_chain;
+		} abd_multi;
 	} abd_u;
 } abd_t;
 
@@ -91,11 +97,14 @@ abd_is_linear_page(abd_t *abd)
 
 abd_t *abd_alloc(size_t, boolean_t);
 abd_t *abd_alloc_linear(size_t, boolean_t);
+abd_t *abd_alloc_multi(void);
 abd_t *abd_alloc_for_io(size_t, boolean_t);
 abd_t *abd_alloc_sametype(abd_t *, size_t);
+void abd_add_child(abd_t *, abd_t *, boolean_t);
 void abd_free(abd_t *);
 abd_t *abd_get_offset(abd_t *, size_t);
 abd_t *abd_get_offset_size(abd_t *, size_t, size_t);
+abd_t *abd_get_zeros(size_t);
 abd_t *abd_get_from_buf(void *, size_t);
 void abd_put(abd_t *);
 
@@ -126,8 +135,7 @@ int abd_cmp_buf_off(abd_t *, const void *, size_t, size_t);
 void abd_zero_off(abd_t *, size_t, size_t);
 
 #if defined(_KERNEL)
-unsigned int abd_scatter_bio_map_off(struct bio *, abd_t *, unsigned int,
-		size_t);
+unsigned int abd_bio_map_off(struct bio *, abd_t *, unsigned int, size_t);
 unsigned long abd_nr_pages_off(abd_t *, unsigned int, size_t);
 #endif