It seems that dead code removing is a hot topic :-)
I think that the following commit has introduced a little bit of such code:
commit 5d7b4d438c4a51eccc95e77a83a437b4d48380eb
Author: Matthew Ahrens <[email protected]>
Date: Thu Jun 5 13:19:08 2014 -0800
4757 ZFS embedded-data block pointers ("zero block compression")
4913 zfs release should not be subject to space checks
Reviewed by: [many]
In the following snippet psize == lsize condition is taken care of in the first
if-block, so that condition can never be true within the else-block. BTW, not
sure why psize < lsize assertion was removed.
@@ -1045,9 +1079,38 @@ zio_write_bp_init(zio_t *zio)
if (psize == 0 || psize == lsize) {
compress = ZIO_COMPRESS_OFF;
zio_buf_free(cbuf, lsize);
+ } else if (!zp->zp_dedup && psize <= BPE_PAYLOAD_SIZE &&
+ zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) &&
+ spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) {
+ encode_embedded_bp_compressed(bp,
+ cbuf, compress, lsize, psize);
+ BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA);
+ BP_SET_TYPE(bp, zio->io_prop.zp_type);
+ BP_SET_LEVEL(bp, zio->io_prop.zp_level);
+ zio_buf_free(cbuf, lsize);
+ bp->blk_birth = zio->io_txg;
+ zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
+ ASSERT(spa_feature_is_active(spa,
+ SPA_FEATURE_EMBEDDED_DATA));
+ return (ZIO_PIPELINE_CONTINUE);
} else {
- ASSERT(psize < lsize);
- zio_push_transform(zio, cbuf, psize, lsize, NULL);
+ /*
+ * Round up compressed size to MINBLOCKSIZE and
+ * zero the tail.
+ */
+ size_t rounded =
+ P2ROUNDUP(psize, (size_t)SPA_MINBLOCKSIZE);
+ if (rounded > psize) {
+ bzero((char *)cbuf + psize, rounded - psize);
+ psize = rounded;
+ }
+ if (psize == lsize) {
+ compress = ZIO_COMPRESS_OFF;
+ zio_buf_free(cbuf, lsize);
+ } else {
+ zio_push_transform(zio, cbuf,
+ psize, lsize, NULL);
+ }
}
}
--
Andriy Gapon_______________________________________________
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