fs/zfs/arc.c

131  * also in the arc_buf_hdr_t's private physical data block pointer (b_pabd).
134  * ability to store the physical data (b_pabd) associated with the DVA of the
135  * arc_buf_hdr_t. Since the b_pabd is a copy of the on-disk physical block,
138  * compressed ARC functionality is disabled, the b_pabd will point to an
177  *   | b_pabd    +-+           |b_next     +---->+-----------+
194  * existing uncompressed arc_buf_t, decompresses the hdr's b_pabd buffer into a
195  * new data buffer, or shares the hdr's b_pabd buffer, depending on whether the
219  *                |  b_pabd   +-+           |---------|     |b_next   +-->NULL
233  * Writing to the ARC requires that the ARC first discard the hdr's b_pabd
238  * a newly allocated b_pabd. Writes are always done into buffers which have
244  * When the L2ARC is in use, it will also take advantage of the b_pabd. The
245  * L2ARC will always write the contents of b_pabd to the L2ARC. This means
603 	 * Number of compressed bytes stored in the arc_buf_hdr_t's b_pabd.
609 	 * Uncompressed size of the data stored in b_pabd. If compressed
1088 	abd_t			*b_pabd;
1840 	    buf->b_hdr->b_l1hdr.b_pabd != NULL &&
1841 	    abd_is_linear(buf->b_hdr->b_l1hdr.b_pabd) &&
1842 	    buf->b_data == abd_to_buf(buf->b_hdr->b_l1hdr.b_pabd));
2287 			abd_copy_to_buf(buf->b_data, hdr->b_l1hdr.b_pabd,
2339 			    hdr->b_l1hdr.b_pabd, buf->b_data,
2376  * Return the size of the block, b_pabd, that is stored in the arc_buf_hdr_t.
2408 		ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL);
2415 	if (hdr->b_l1hdr.b_pabd != NULL) {
2443 		ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL);
2450 	if (hdr->b_l1hdr.b_pabd != NULL) {
2547 		update_old = (bufcnt > 0 || hdr->b_l1hdr.b_pabd != NULL);
2617 			ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL);
2646 			if (hdr->b_l1hdr.b_pabd != NULL) {
2659 			ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL);
2699 			ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL);
2786  * with the hdr's b_pabd.
2863 	 * sharing it's b_pabd with the arc_buf_t. Otherwise, we allocate a new
2875 	    abd_is_linear(hdr->b_l1hdr.b_pabd);
2879 		buf->b_data = abd_to_buf(hdr->b_l1hdr.b_pabd);
3010 	l2arc_free_abd_on_write(hdr->b_l1hdr.b_pabd, size, type);
3024 	ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL);
3033 	hdr->b_l1hdr.b_pabd = abd_get_from_buf(buf->b_data, arc_buf_size(buf));
3034 	abd_take_ownership_of_buf(hdr->b_l1hdr.b_pabd,
3055 	ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL);
3064 	abd_release_ownership_of_buf(hdr->b_l1hdr.b_pabd);
3065 	abd_put(hdr->b_l1hdr.b_pabd);
3066 	hdr->b_l1hdr.b_pabd = NULL;
3163 		 * hdr, then reassign the hdr's b_pabd to share it with the new
3178 			ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL);
3223 	ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL);
3224 	hdr->b_l1hdr.b_pabd = arc_get_data_abd(hdr, arc_hdr_size(hdr), hdr, do_adapt);
3226 	ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL);
3236 	ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL);
3248 		arc_free_data_abd(hdr, hdr->b_l1hdr.b_pabd,
3251 	hdr->b_l1hdr.b_pabd = NULL;
3329 		ASSERT3P(nhdr->b_l1hdr.b_pabd, ==, NULL);
3347 		 * l2arc device. Otherwise, the b_l1hdr.b_pabd field
3351 		VERIFY3P(hdr->b_l1hdr.b_pabd, ==, NULL);
3447 		ASSERT(!abd_is_linear(hdr->b_l1hdr.b_pabd));
3529 		if (hdr->b_l1hdr.b_pabd != NULL) {
3600 		 * (i.e. its b_pabd field) during it's write phase.
3615 		ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL);
5368 		ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL);
5476 	if (hdr != NULL && HDR_HAS_L1HDR(hdr) && hdr->b_l1hdr.b_pabd != NULL) {
5623 			ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL);
5644 		ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL);
5759 					abd = hdr->b_l1hdr.b_pabd;
5821 		rzio = zio_read(pio, spa, bp, hdr->b_l1hdr.b_pabd, size,
6010 			 * Now we need to recreate the hdr's b_pabd. Since we
6012 			 * we can't then we allocate a new b_pabd and copy the
6019 				abd_copy_from_buf(hdr->b_l1hdr.b_pabd,
6036 		ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL);
6057 		 * Allocate a new hdr. The new hdr will contain a b_pabd
6137 		if (hdr->b_l1hdr.b_pabd != NULL) {
6145 	ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL);
6184 		 * Ideally, we would always copy the io_abd into b_pabd, but the
6193 			abd_copy(hdr->b_l1hdr.b_pabd, zio->io_abd, psize);
6197 			abd_copy_from_buf(hdr->b_l1hdr.b_pabd, buf->b_data,
6356 	 * The hdr's b_pabd is now stale, free it now. A new data block
6359 	if (hdr->b_l1hdr.b_pabd != NULL) {
6375 	ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL);
7444 			abd_copy(hdr->b_l1hdr.b_pabd, cb->l2rcb_abd,
7461 		zio->io_abd = zio->io_orig_abd = hdr->b_l1hdr.b_pabd;
7469 	ASSERT3P(zio->io_abd, ==, hdr->b_l1hdr.b_pabd);
7502 			    hdr->b_l1hdr.b_pabd, zio->io_size, arc_read_done,
7767 			ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL);
7826 				to_write = hdr->b_l1hdr.b_pabd;
7830 				abd_copy(to_write, hdr->b_l1hdr.b_pabd, psize);