1 files changed, 0 insertions, 655 deletions

diff --git a/sys/contrib/opensolaris/uts/common/fs/zfs/dmu_zfetch.c b/sys/contrib/opensolaris/uts/common/fs/zfs/dmu_zfetch.c
deleted file mode 100644
index 78d625c..0000000
--- a/sys/contrib/opensolaris/uts/common/fs/zfs/dmu_zfetch.c
+++ /dev/null
@@ -1,655 +0,0 @@
-/*
- * CDDL HEADER START
- *
- * The contents of this file are subject to the terms of the
- * Common Development and Distribution License (the "License").
- * You may not use this file except in compliance with the License.
- *
- * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
- * or http://www.opensolaris.org/os/licensing.
- * See the License for the specific language governing permissions
- * and limitations under the License.
- *
- * When distributing Covered Code, include this CDDL HEADER in each
- * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
- * If applicable, add the following below this CDDL HEADER, with the
- * fields enclosed by brackets "[]" replaced with your own identifying
- * information: Portions Copyright [yyyy] [name of copyright owner]
- *
- * CDDL HEADER END
- */
-/*
- * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
- * Use is subject to license terms.
- */
-
-#pragma ident	"%Z%%M%	%I%	%E% SMI"
-
-#include <sys/zfs_context.h>
-#include <sys/dnode.h>
-#include <sys/dmu_objset.h>
-#include <sys/dmu_zfetch.h>
-#include <sys/dmu.h>
-#include <sys/dbuf.h>
-
-/*
- * I'm against tune-ables, but these should probably exist as tweakable globals
- * until we can get this working the way we want it to.
- */
-
-int zfs_prefetch_disable = 0;
-SYSCTL_DECL(_vfs_zfs);
-TUNABLE_INT("vfs.zfs.prefetch_disable", &zfs_prefetch_disable);
-SYSCTL_INT(_vfs_zfs, OID_AUTO, prefetch_disable, CTLFLAG_RDTUN,
-    &zfs_prefetch_disable, 0, "Disable prefetch");
-
-/* max # of streams per zfetch */
-uint32_t	zfetch_max_streams = 8;
-/* min time before stream reclaim */
-uint32_t	zfetch_min_sec_reap = 2;
-/* max number of blocks to fetch at a time */
-uint32_t	zfetch_block_cap = 256;
-/* number of bytes in a array_read at which we stop prefetching (1Mb) */
-uint64_t	zfetch_array_rd_sz = 1024 * 1024;
-
-/* forward decls for static routines */
-static int		dmu_zfetch_colinear(zfetch_t *, zstream_t *);
-static void		dmu_zfetch_dofetch(zfetch_t *, zstream_t *);
-static uint64_t		dmu_zfetch_fetch(dnode_t *, uint64_t, uint64_t);
-static uint64_t		dmu_zfetch_fetchsz(dnode_t *, uint64_t, uint64_t);
-static int		dmu_zfetch_find(zfetch_t *, zstream_t *, int);
-static int		dmu_zfetch_stream_insert(zfetch_t *, zstream_t *);
-static zstream_t	*dmu_zfetch_stream_reclaim(zfetch_t *);
-static void		dmu_zfetch_stream_remove(zfetch_t *, zstream_t *);
-static int		dmu_zfetch_streams_equal(zstream_t *, zstream_t *);
-
-/*
- * Given a zfetch structure and a zstream structure, determine whether the
- * blocks to be read are part of a co-linear pair of existing prefetch
- * streams.  If a set is found, coalesce the streams, removing one, and
- * configure the prefetch so it looks for a strided access pattern.
- *
- * In other words: if we find two sequential access streams that are
- * the same length and distance N appart, and this read is N from the
- * last stream, then we are probably in a strided access pattern.  So
- * combine the two sequential streams into a single strided stream.
- *
- * If no co-linear streams are found, return NULL.
- */
-static int
-dmu_zfetch_colinear(zfetch_t *zf, zstream_t *zh)
-{
-	zstream_t	*z_walk;
-	zstream_t	*z_comp;
-
-	if (! rw_tryenter(&zf->zf_rwlock, RW_WRITER))
-		return (0);
-
-	if (zh == NULL) {
-		rw_exit(&zf->zf_rwlock);
-		return (0);
-	}
-
-	for (z_walk = list_head(&zf->zf_stream); z_walk;
-	    z_walk = list_next(&zf->zf_stream, z_walk)) {
-		for (z_comp = list_next(&zf->zf_stream, z_walk); z_comp;
-		    z_comp = list_next(&zf->zf_stream, z_comp)) {
-			int64_t		diff;
-
-			if (z_walk->zst_len != z_walk->zst_stride ||
-			    z_comp->zst_len != z_comp->zst_stride) {
-				continue;
-			}
-
-			diff = z_comp->zst_offset - z_walk->zst_offset;
-			if (z_comp->zst_offset + diff == zh->zst_offset) {
-				z_walk->zst_offset = zh->zst_offset;
-				z_walk->zst_direction = diff < 0 ? -1 : 1;
-				z_walk->zst_stride =
-				    diff * z_walk->zst_direction;
-				z_walk->zst_ph_offset =
-				    zh->zst_offset + z_walk->zst_stride;
-				dmu_zfetch_stream_remove(zf, z_comp);
-				mutex_destroy(&z_comp->zst_lock);
-				kmem_free(z_comp, sizeof (zstream_t));
-
-				dmu_zfetch_dofetch(zf, z_walk);
-
-				rw_exit(&zf->zf_rwlock);
-				return (1);
-			}
-
-			diff = z_walk->zst_offset - z_comp->zst_offset;
-			if (z_walk->zst_offset + diff == zh->zst_offset) {
-				z_walk->zst_offset = zh->zst_offset;
-				z_walk->zst_direction = diff < 0 ? -1 : 1;
-				z_walk->zst_stride =
-				    diff * z_walk->zst_direction;
-				z_walk->zst_ph_offset =
-				    zh->zst_offset + z_walk->zst_stride;
-				dmu_zfetch_stream_remove(zf, z_comp);
-				mutex_destroy(&z_comp->zst_lock);
-				kmem_free(z_comp, sizeof (zstream_t));
-
-				dmu_zfetch_dofetch(zf, z_walk);
-
-				rw_exit(&zf->zf_rwlock);
-				return (1);
-			}
-		}
-	}
-
-	rw_exit(&zf->zf_rwlock);
-	return (0);
-}
-
-/*
- * Given a zstream_t, determine the bounds of the prefetch.  Then call the
- * routine that actually prefetches the individual blocks.
- */
-static void
-dmu_zfetch_dofetch(zfetch_t *zf, zstream_t *zs)
-{
-	uint64_t	prefetch_tail;
-	uint64_t	prefetch_limit;
-	uint64_t	prefetch_ofst;
-	uint64_t	prefetch_len;
-	uint64_t	blocks_fetched;
-
-	zs->zst_stride = MAX((int64_t)zs->zst_stride, zs->zst_len);
-	zs->zst_cap = MIN(zfetch_block_cap, 2 * zs->zst_cap);
-
-	prefetch_tail = MAX((int64_t)zs->zst_ph_offset,
-	    (int64_t)(zs->zst_offset + zs->zst_stride));
-	/*
-	 * XXX: use a faster division method?
-	 */
-	prefetch_limit = zs->zst_offset + zs->zst_len +
-	    (zs->zst_cap * zs->zst_stride) / zs->zst_len;
-
-	while (prefetch_tail < prefetch_limit) {
-		prefetch_ofst = zs->zst_offset + zs->zst_direction *
-		    (prefetch_tail - zs->zst_offset);
-
-		prefetch_len = zs->zst_len;
-
-		/*
-		 * Don't prefetch beyond the end of the file, if working
-		 * backwards.
-		 */
-		if ((zs->zst_direction == ZFETCH_BACKWARD) &&
-		    (prefetch_ofst > prefetch_tail)) {
-			prefetch_len += prefetch_ofst;
-			prefetch_ofst = 0;
-		}
-
-		/* don't prefetch more than we're supposed to */
-		if (prefetch_len > zs->zst_len)
-			break;
-
-		blocks_fetched = dmu_zfetch_fetch(zf->zf_dnode,
-		    prefetch_ofst, zs->zst_len);
-
-		prefetch_tail += zs->zst_stride;
-		/* stop if we've run out of stuff to prefetch */
-		if (blocks_fetched < zs->zst_len)
-			break;
-	}
-	zs->zst_ph_offset = prefetch_tail;
-	zs->zst_last = lbolt;
-}
-
-/*
- * This takes a pointer to a zfetch structure and a dnode.  It performs the
- * necessary setup for the zfetch structure, grokking data from the
- * associated dnode.
- */
-void
-dmu_zfetch_init(zfetch_t *zf, dnode_t *dno)
-{
-	if (zf == NULL) {
-		return;
-	}
-
-	zf->zf_dnode = dno;
-	zf->zf_stream_cnt = 0;
-	zf->zf_alloc_fail = 0;
-
-	list_create(&zf->zf_stream, sizeof (zstream_t),
-	    offsetof(zstream_t, zst_node));
-
-	rw_init(&zf->zf_rwlock, NULL, RW_DEFAULT, NULL);
-}
-
-/*
- * This function computes the actual size, in blocks, that can be prefetched,
- * and fetches it.
- */
-static uint64_t
-dmu_zfetch_fetch(dnode_t *dn, uint64_t blkid, uint64_t nblks)
-{
-	uint64_t	fetchsz;
-	uint64_t	i;
-
-	fetchsz = dmu_zfetch_fetchsz(dn, blkid, nblks);
-
-	for (i = 0; i < fetchsz; i++) {
-		dbuf_prefetch(dn, blkid + i);
-	}
-
-	return (fetchsz);
-}
-
-/*
- * this function returns the number of blocks that would be prefetched, based
- * upon the supplied dnode, blockid, and nblks.  This is used so that we can
- * update streams in place, and then prefetch with their old value after the
- * fact.  This way, we can delay the prefetch, but subsequent accesses to the
- * stream won't result in the same data being prefetched multiple times.
- */
-static uint64_t
-dmu_zfetch_fetchsz(dnode_t *dn, uint64_t blkid, uint64_t nblks)
-{
-	uint64_t	fetchsz;
-
-	if (blkid > dn->dn_maxblkid) {
-		return (0);
-	}
-
-	/* compute fetch size */
-	if (blkid + nblks + 1 > dn->dn_maxblkid) {
-		fetchsz = (dn->dn_maxblkid - blkid) + 1;
-		ASSERT(blkid + fetchsz - 1 <= dn->dn_maxblkid);
-	} else {
-		fetchsz = nblks;
-	}
-
-
-	return (fetchsz);
-}
-
-/*
- * given a zfetch and a zsearch structure, see if there is an associated zstream
- * for this block read.  If so, it starts a prefetch for the stream it
- * located and returns true, otherwise it returns false
- */
-static int
-dmu_zfetch_find(zfetch_t *zf, zstream_t *zh, int prefetched)
-{
-	zstream_t	*zs;
-	int64_t		diff;
-	int		reset = !prefetched;
-	int		rc = 0;
-
-	if (zh == NULL)
-		return (0);
-
-	/*
-	 * XXX: This locking strategy is a bit coarse; however, it's impact has
-	 * yet to be tested.  If this turns out to be an issue, it can be
-	 * modified in a number of different ways.
-	 */
-
-	rw_enter(&zf->zf_rwlock, RW_READER);
-top:
-
-	for (zs = list_head(&zf->zf_stream); zs;
-	    zs = list_next(&zf->zf_stream, zs)) {
-
-		/*
-		 * XXX - should this be an assert?
-		 */
-		if (zs->zst_len == 0) {
-			/* bogus stream */
-			continue;
-		}
-
-		/*
-		 * We hit this case when we are in a strided prefetch stream:
-		 * we will read "len" blocks before "striding".
-		 */
-		if (zh->zst_offset >= zs->zst_offset &&
-		    zh->zst_offset < zs->zst_offset + zs->zst_len) {
-			/* already fetched */
-			rc = 1;
-			goto out;
-		}
-
-		/*
-		 * This is the forward sequential read case: we increment
-		 * len by one each time we hit here, so we will enter this
-		 * case on every read.
-		 */
-		if (zh->zst_offset == zs->zst_offset + zs->zst_len) {
-
-			reset = !prefetched && zs->zst_len > 1;
-
-			mutex_enter(&zs->zst_lock);
-
-			if (zh->zst_offset != zs->zst_offset + zs->zst_len) {
-				mutex_exit(&zs->zst_lock);
-				goto top;
-			}
-			zs->zst_len += zh->zst_len;
-			diff = zs->zst_len - zfetch_block_cap;
-			if (diff > 0) {
-				zs->zst_offset += diff;
-				zs->zst_len = zs->zst_len > diff ?
-				    zs->zst_len - diff : 0;
-			}
-			zs->zst_direction = ZFETCH_FORWARD;
-
-			break;
-
-		/*
-		 * Same as above, but reading backwards through the file.
-		 */
-		} else if (zh->zst_offset == zs->zst_offset - zh->zst_len) {
-			/* backwards sequential access */
-
-			reset = !prefetched && zs->zst_len > 1;
-
-			mutex_enter(&zs->zst_lock);
-
-			if (zh->zst_offset != zs->zst_offset - zh->zst_len) {
-				mutex_exit(&zs->zst_lock);
-				goto top;
-			}
-
-			zs->zst_offset = zs->zst_offset > zh->zst_len ?
-			    zs->zst_offset - zh->zst_len : 0;
-			zs->zst_ph_offset = zs->zst_ph_offset > zh->zst_len ?
-			    zs->zst_ph_offset - zh->zst_len : 0;
-			zs->zst_len += zh->zst_len;
-
-			diff = zs->zst_len - zfetch_block_cap;
-			if (diff > 0) {
-				zs->zst_ph_offset = zs->zst_ph_offset > diff ?
-				    zs->zst_ph_offset - diff : 0;
-				zs->zst_len = zs->zst_len > diff ?
-				    zs->zst_len - diff : zs->zst_len;
-			}
-			zs->zst_direction = ZFETCH_BACKWARD;
-
-			break;
-
-		} else if ((zh->zst_offset - zs->zst_offset - zs->zst_stride <
-		    zs->zst_len) && (zs->zst_len != zs->zst_stride)) {
-			/* strided forward access */
-
-			mutex_enter(&zs->zst_lock);
-
-			if ((zh->zst_offset - zs->zst_offset - zs->zst_stride >=
-			    zs->zst_len) || (zs->zst_len == zs->zst_stride)) {
-				mutex_exit(&zs->zst_lock);
-				goto top;
-			}
-
-			zs->zst_offset += zs->zst_stride;
-			zs->zst_direction = ZFETCH_FORWARD;
-
-			break;
-
-		} else if ((zh->zst_offset - zs->zst_offset + zs->zst_stride <
-		    zs->zst_len) && (zs->zst_len != zs->zst_stride)) {
-			/* strided reverse access */
-
-			mutex_enter(&zs->zst_lock);
-
-			if ((zh->zst_offset - zs->zst_offset + zs->zst_stride >=
-			    zs->zst_len) || (zs->zst_len == zs->zst_stride)) {
-				mutex_exit(&zs->zst_lock);
-				goto top;
-			}
-
-			zs->zst_offset = zs->zst_offset > zs->zst_stride ?
-			    zs->zst_offset - zs->zst_stride : 0;
-			zs->zst_ph_offset = (zs->zst_ph_offset >
-			    (2 * zs->zst_stride)) ?
-			    (zs->zst_ph_offset - (2 * zs->zst_stride)) : 0;
-			zs->zst_direction = ZFETCH_BACKWARD;
-
-			break;
-		}
-	}
-
-	if (zs) {
-		if (reset) {
-			zstream_t *remove = zs;
-
-			rc = 0;
-			mutex_exit(&zs->zst_lock);
-			rw_exit(&zf->zf_rwlock);
-			rw_enter(&zf->zf_rwlock, RW_WRITER);
-			/*
-			 * Relocate the stream, in case someone removes
-			 * it while we were acquiring the WRITER lock.
-			 */
-			for (zs = list_head(&zf->zf_stream); zs;
-			    zs = list_next(&zf->zf_stream, zs)) {
-				if (zs == remove) {
-					dmu_zfetch_stream_remove(zf, zs);
-					mutex_destroy(&zs->zst_lock);
-					kmem_free(zs, sizeof (zstream_t));
-					break;
-				}
-			}
-		} else {
-			rc = 1;
-			dmu_zfetch_dofetch(zf, zs);
-			mutex_exit(&zs->zst_lock);
-		}
-	}
-out:
-	rw_exit(&zf->zf_rwlock);
-	return (rc);
-}
-
-/*
- * Clean-up state associated with a zfetch structure.  This frees allocated
- * structure members, empties the zf_stream tree, and generally makes things
- * nice.  This doesn't free the zfetch_t itself, that's left to the caller.
- */
-void
-dmu_zfetch_rele(zfetch_t *zf)
-{
-	zstream_t	*zs;
-	zstream_t	*zs_next;
-
-	ASSERT(!RW_LOCK_HELD(&zf->zf_rwlock));
-
-	for (zs = list_head(&zf->zf_stream); zs; zs = zs_next) {
-		zs_next = list_next(&zf->zf_stream, zs);
-
-		list_remove(&zf->zf_stream, zs);
-		mutex_destroy(&zs->zst_lock);
-		kmem_free(zs, sizeof (zstream_t));
-	}
-	list_destroy(&zf->zf_stream);
-	rw_destroy(&zf->zf_rwlock);
-
-	zf->zf_dnode = NULL;
-}
-
-/*
- * Given a zfetch and zstream structure, insert the zstream structure into the
- * AVL tree contained within the zfetch structure.  Peform the appropriate
- * book-keeping.  It is possible that another thread has inserted a stream which
- * matches one that we are about to insert, so we must be sure to check for this
- * case.  If one is found, return failure, and let the caller cleanup the
- * duplicates.
- */
-static int
-dmu_zfetch_stream_insert(zfetch_t *zf, zstream_t *zs)
-{
-	zstream_t	*zs_walk;
-	zstream_t	*zs_next;
-
-	ASSERT(RW_WRITE_HELD(&zf->zf_rwlock));
-
-	for (zs_walk = list_head(&zf->zf_stream); zs_walk; zs_walk = zs_next) {
-		zs_next = list_next(&zf->zf_stream, zs_walk);
-
-		if (dmu_zfetch_streams_equal(zs_walk, zs)) {
-		    return (0);
-		}
-	}
-
-	list_insert_head(&zf->zf_stream, zs);
-	zf->zf_stream_cnt++;
-
-	return (1);
-}
-
-
-/*
- * Walk the list of zstreams in the given zfetch, find an old one (by time), and
- * reclaim it for use by the caller.
- */
-static zstream_t *
-dmu_zfetch_stream_reclaim(zfetch_t *zf)
-{
-	zstream_t	*zs;
-
-	if (! rw_tryenter(&zf->zf_rwlock, RW_WRITER))
-		return (0);
-
-	for (zs = list_head(&zf->zf_stream); zs;
-	    zs = list_next(&zf->zf_stream, zs)) {
-
-		if (((lbolt - zs->zst_last) / hz) > zfetch_min_sec_reap)
-			break;
-	}
-
-	if (zs) {
-		dmu_zfetch_stream_remove(zf, zs);
-		mutex_destroy(&zs->zst_lock);
-		bzero(zs, sizeof (zstream_t));
-	} else {
-		zf->zf_alloc_fail++;
-	}
-	rw_exit(&zf->zf_rwlock);
-
-	return (zs);
-}
-
-/*
- * Given a zfetch and zstream structure, remove the zstream structure from its
- * container in the zfetch structure.  Perform the appropriate book-keeping.
- */
-static void
-dmu_zfetch_stream_remove(zfetch_t *zf, zstream_t *zs)
-{
-	ASSERT(RW_WRITE_HELD(&zf->zf_rwlock));
-
-	list_remove(&zf->zf_stream, zs);
-	zf->zf_stream_cnt--;
-}
-
-static int
-dmu_zfetch_streams_equal(zstream_t *zs1, zstream_t *zs2)
-{
-	if (zs1->zst_offset != zs2->zst_offset)
-		return (0);
-
-	if (zs1->zst_len != zs2->zst_len)
-		return (0);
-
-	if (zs1->zst_stride != zs2->zst_stride)
-		return (0);
-
-	if (zs1->zst_ph_offset != zs2->zst_ph_offset)
-		return (0);
-
-	if (zs1->zst_cap != zs2->zst_cap)
-		return (0);
-
-	if (zs1->zst_direction != zs2->zst_direction)
-		return (0);
-
-	return (1);
-}
-
-/*
- * This is the prefetch entry point.  It calls all of the other dmu_zfetch
- * routines to create, delete, find, or operate upon prefetch streams.
- */
-void
-dmu_zfetch(zfetch_t *zf, uint64_t offset, uint64_t size, int prefetched)
-{
-	zstream_t	zst;
-	zstream_t	*newstream;
-	int		fetched;
-	int		inserted;
-	unsigned int	blkshft;
-	uint64_t	blksz;
-
-	if (zfs_prefetch_disable)
-		return;
-
-	/* files that aren't ln2 blocksz are only one block -- nothing to do */
-	if (!zf->zf_dnode->dn_datablkshift)
-		return;
-
-	/* convert offset and size, into blockid and nblocks */
-	blkshft = zf->zf_dnode->dn_datablkshift;
-	blksz = (1 << blkshft);
-
-	bzero(&zst, sizeof (zstream_t));
-	zst.zst_offset = offset >> blkshft;
-	zst.zst_len = (P2ROUNDUP(offset + size, blksz) -
-	    P2ALIGN(offset, blksz)) >> blkshft;
-
-	fetched = dmu_zfetch_find(zf, &zst, prefetched);
-	if (!fetched) {
-		fetched = dmu_zfetch_colinear(zf, &zst);
-	}
-
-	if (!fetched) {
-		newstream = dmu_zfetch_stream_reclaim(zf);
-
-		/*
-		 * we still couldn't find a stream, drop the lock, and allocate
-		 * one if possible.  Otherwise, give up and go home.
-		 */
-		if (newstream == NULL) {
-			uint64_t	maxblocks;
-			uint32_t	max_streams;
-			uint32_t	cur_streams;
-
-			cur_streams = zf->zf_stream_cnt;
-			maxblocks = zf->zf_dnode->dn_maxblkid;
-
-			max_streams = MIN(zfetch_max_streams,
-			    (maxblocks / zfetch_block_cap));
-			if (max_streams == 0) {
-				max_streams++;
-			}
-
-			if (cur_streams >= max_streams) {
-				return;
-			}
-
-			newstream = kmem_zalloc(sizeof (zstream_t), KM_SLEEP);
-		}
-
-		newstream->zst_offset = zst.zst_offset;
-		newstream->zst_len = zst.zst_len;
-		newstream->zst_stride = zst.zst_len;
-		newstream->zst_ph_offset = zst.zst_len + zst.zst_offset;
-		newstream->zst_cap = zst.zst_len;
-		newstream->zst_direction = ZFETCH_FORWARD;
-		newstream->zst_last = lbolt;
-
-		mutex_init(&newstream->zst_lock, NULL, MUTEX_DEFAULT, NULL);
-
-		rw_enter(&zf->zf_rwlock, RW_WRITER);
-		inserted = dmu_zfetch_stream_insert(zf, newstream);
-		rw_exit(&zf->zf_rwlock);
-
-		if (!inserted) {
-			mutex_destroy(&newstream->zst_lock);
-			kmem_free(newstream, sizeof (zstream_t));
-		}
-	}
-}