abd: remove ABD_FLAG_ZEROS

Nothing ever checks it.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Alexander Motin <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Rob Norris <[email protected]>
Closes #16253

Author: robn

include/sys/abd.h

@@ -44,8 +44,7 @@ typedef enum abd_flags {
 	ABD_FLAG_LINEAR_PAGE 	= 1 << 5, /* linear but allocd from page */
 	ABD_FLAG_GANG		= 1 << 6, /* mult ABDs chained together */
 	ABD_FLAG_GANG_FREE	= 1 << 7, /* gang ABD is responsible for mem */
-	ABD_FLAG_ZEROS		= 1 << 8, /* ABD for zero-filled buffer */
-	ABD_FLAG_ALLOCD		= 1 << 9, /* we allocated the abd_t */
+	ABD_FLAG_ALLOCD		= 1 << 8, /* we allocated the abd_t */
 } abd_flags_t;
 
 typedef struct abd {

module/os/freebsd/zfs/abd_os.c

@@ -250,7 +250,7 @@ abd_alloc_zero_scatter(void)
 
 	n = abd_chunkcnt_for_bytes(SPA_MAXBLOCKSIZE);
 	abd_zero_scatter = abd_alloc_struct(SPA_MAXBLOCKSIZE);
-	abd_zero_scatter->abd_flags |= ABD_FLAG_OWNER | ABD_FLAG_ZEROS;
+	abd_zero_scatter->abd_flags |= ABD_FLAG_OWNER;
 	abd_zero_scatter->abd_size = SPA_MAXBLOCKSIZE;
 
 	ABD_SCATTER(abd_zero_scatter).abd_offset = 0;

module/os/linux/zfs/abd_os.c

@@ -509,7 +509,7 @@ abd_alloc_zero_scatter(void)
 	ABD_SCATTER(abd_zero_scatter).abd_sgl = table.sgl;
 	ABD_SCATTER(abd_zero_scatter).abd_nents = nr_pages;
 	abd_zero_scatter->abd_size = SPA_MAXBLOCKSIZE;
-	abd_zero_scatter->abd_flags |= ABD_FLAG_MULTI_CHUNK | ABD_FLAG_ZEROS;
+	abd_zero_scatter->abd_flags |= ABD_FLAG_MULTI_CHUNK;
 
 	abd_for_each_sg(abd_zero_scatter, sg, nr_pages, i) {
 		sg_set_page(sg, abd_zero_page, PAGESIZE, 0);

module/zfs/abd.c

@@ -113,7 +113,7 @@ abd_verify(abd_t *abd)
 	ASSERT3U(abd->abd_flags, ==, abd->abd_flags & (ABD_FLAG_LINEAR |
 	    ABD_FLAG_OWNER | ABD_FLAG_META | ABD_FLAG_MULTI_ZONE |
 	    ABD_FLAG_MULTI_CHUNK | ABD_FLAG_LINEAR_PAGE | ABD_FLAG_GANG |
-	    ABD_FLAG_GANG_FREE | ABD_FLAG_ZEROS | ABD_FLAG_ALLOCD));
+	    ABD_FLAG_GANG_FREE | ABD_FLAG_ALLOCD));
 	IMPLY(abd->abd_parent != NULL, !(abd->abd_flags & ABD_FLAG_OWNER));
 	IMPLY(abd->abd_flags & ABD_FLAG_META, abd->abd_flags & ABD_FLAG_OWNER);
 	if (abd_is_linear(abd)) {