a004338372
Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Prashanth Sreenivasa <pks@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
dbuf_read() creates a zio_root() to track and wait for all the zio's
that may happen as part of this call. However, if the blkptr_t for
this buffer is NULL or a hole, we will not create any more zio's, so
this zio_root() is unnecessary. This is always the case when calling
dbuf_read() on a bonus buffer, because it has no blkptr (it's part of
the containing dnode). For workloads that read a lot of bonus buffers
(e.g. file creation and removal), creating and destroying these
unnecessary zio's can decrease performance by around 3%.
The fix is to only create/destroy the zio_root() in dbuf_read() if the
blkptr is not NULL and not a hole.
Porting Notes:
- The error handling for when dbuf_read_impl() fails which was
originally added in commit 5f6d0b6f5 has been preserved.
OpenZFS-issue: https://www.illumos.org/issues/8025
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/8ec5c7c
Closes #6048
3852 lines
108 KiB
C
3852 lines
108 KiB
C
/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License (the "License").
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* You may not use this file except in compliance with the License.
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*
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* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
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* or http://www.opensolaris.org/os/licensing.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
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* If applicable, add the following below this CDDL HEADER, with the
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* fields enclosed by brackets "[]" replaced with your own identifying
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* information: Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*/
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/*
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* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
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* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
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* Copyright (c) 2012, 2017 by Delphix. All rights reserved.
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* Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
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* Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
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*/
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#include <sys/zfs_context.h>
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#include <sys/arc.h>
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#include <sys/dmu.h>
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#include <sys/dmu_send.h>
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#include <sys/dmu_impl.h>
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#include <sys/dbuf.h>
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#include <sys/dmu_objset.h>
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#include <sys/dsl_dataset.h>
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#include <sys/dsl_dir.h>
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#include <sys/dmu_tx.h>
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#include <sys/spa.h>
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#include <sys/zio.h>
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#include <sys/dmu_zfetch.h>
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#include <sys/sa.h>
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#include <sys/sa_impl.h>
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#include <sys/zfeature.h>
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#include <sys/blkptr.h>
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#include <sys/range_tree.h>
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#include <sys/trace_dbuf.h>
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#include <sys/callb.h>
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#include <sys/abd.h>
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struct dbuf_hold_impl_data {
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/* Function arguments */
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dnode_t *dh_dn;
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uint8_t dh_level;
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uint64_t dh_blkid;
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boolean_t dh_fail_sparse;
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boolean_t dh_fail_uncached;
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void *dh_tag;
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dmu_buf_impl_t **dh_dbp;
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/* Local variables */
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dmu_buf_impl_t *dh_db;
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dmu_buf_impl_t *dh_parent;
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blkptr_t *dh_bp;
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int dh_err;
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dbuf_dirty_record_t *dh_dr;
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arc_buf_contents_t dh_type;
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int dh_depth;
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};
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static void __dbuf_hold_impl_init(struct dbuf_hold_impl_data *dh,
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dnode_t *dn, uint8_t level, uint64_t blkid, boolean_t fail_sparse,
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boolean_t fail_uncached,
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void *tag, dmu_buf_impl_t **dbp, int depth);
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static int __dbuf_hold_impl(struct dbuf_hold_impl_data *dh);
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uint_t zfs_dbuf_evict_key;
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static boolean_t dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
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static void dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx);
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extern inline void dmu_buf_init_user(dmu_buf_user_t *dbu,
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dmu_buf_evict_func_t *evict_func_sync,
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dmu_buf_evict_func_t *evict_func_async,
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dmu_buf_t **clear_on_evict_dbufp);
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/*
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* Global data structures and functions for the dbuf cache.
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*/
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static kmem_cache_t *dbuf_kmem_cache;
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static taskq_t *dbu_evict_taskq;
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static kthread_t *dbuf_cache_evict_thread;
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static kmutex_t dbuf_evict_lock;
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static kcondvar_t dbuf_evict_cv;
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static boolean_t dbuf_evict_thread_exit;
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/*
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* LRU cache of dbufs. The dbuf cache maintains a list of dbufs that
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* are not currently held but have been recently released. These dbufs
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* are not eligible for arc eviction until they are aged out of the cache.
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* Dbufs are added to the dbuf cache once the last hold is released. If a
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* dbuf is later accessed and still exists in the dbuf cache, then it will
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* be removed from the cache and later re-added to the head of the cache.
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* Dbufs that are aged out of the cache will be immediately destroyed and
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* become eligible for arc eviction.
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*/
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static multilist_t *dbuf_cache;
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static refcount_t dbuf_cache_size;
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unsigned long dbuf_cache_max_bytes = 100 * 1024 * 1024;
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/* Cap the size of the dbuf cache to log2 fraction of arc size. */
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int dbuf_cache_max_shift = 5;
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/*
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* The dbuf cache uses a three-stage eviction policy:
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* - A low water marker designates when the dbuf eviction thread
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* should stop evicting from the dbuf cache.
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* - When we reach the maximum size (aka mid water mark), we
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* signal the eviction thread to run.
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* - The high water mark indicates when the eviction thread
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* is unable to keep up with the incoming load and eviction must
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* happen in the context of the calling thread.
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*
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* The dbuf cache:
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* (max size)
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* low water mid water hi water
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* +----------------------------------------+----------+----------+
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* | | | |
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* | | | |
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* | | | |
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* | | | |
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* +----------------------------------------+----------+----------+
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* stop signal evict
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* evicting eviction directly
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* thread
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*
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* The high and low water marks indicate the operating range for the eviction
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* thread. The low water mark is, by default, 90% of the total size of the
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* cache and the high water mark is at 110% (both of these percentages can be
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* changed by setting dbuf_cache_lowater_pct and dbuf_cache_hiwater_pct,
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* respectively). The eviction thread will try to ensure that the cache remains
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* within this range by waking up every second and checking if the cache is
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* above the low water mark. The thread can also be woken up by callers adding
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* elements into the cache if the cache is larger than the mid water (i.e max
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* cache size). Once the eviction thread is woken up and eviction is required,
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* it will continue evicting buffers until it's able to reduce the cache size
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* to the low water mark. If the cache size continues to grow and hits the high
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* water mark, then callers adding elements to the cache will begin to evict
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* directly from the cache until the cache is no longer above the high water
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* mark.
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*/
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/*
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* The percentage above and below the maximum cache size.
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*/
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uint_t dbuf_cache_hiwater_pct = 10;
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uint_t dbuf_cache_lowater_pct = 10;
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/* ARGSUSED */
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static int
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dbuf_cons(void *vdb, void *unused, int kmflag)
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{
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dmu_buf_impl_t *db = vdb;
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bzero(db, sizeof (dmu_buf_impl_t));
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mutex_init(&db->db_mtx, NULL, MUTEX_DEFAULT, NULL);
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cv_init(&db->db_changed, NULL, CV_DEFAULT, NULL);
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multilist_link_init(&db->db_cache_link);
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refcount_create(&db->db_holds);
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multilist_link_init(&db->db_cache_link);
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return (0);
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}
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/* ARGSUSED */
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static void
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dbuf_dest(void *vdb, void *unused)
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{
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dmu_buf_impl_t *db = vdb;
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mutex_destroy(&db->db_mtx);
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cv_destroy(&db->db_changed);
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ASSERT(!multilist_link_active(&db->db_cache_link));
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refcount_destroy(&db->db_holds);
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}
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/*
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* dbuf hash table routines
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*/
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static dbuf_hash_table_t dbuf_hash_table;
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static uint64_t dbuf_hash_count;
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static uint64_t
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dbuf_hash(void *os, uint64_t obj, uint8_t lvl, uint64_t blkid)
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{
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uintptr_t osv = (uintptr_t)os;
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uint64_t crc = -1ULL;
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ASSERT(zfs_crc64_table[128] == ZFS_CRC64_POLY);
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crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (lvl)) & 0xFF];
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crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (osv >> 6)) & 0xFF];
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crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 0)) & 0xFF];
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crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (obj >> 8)) & 0xFF];
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crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (blkid >> 0)) & 0xFF];
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crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ (blkid >> 8)) & 0xFF];
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crc ^= (osv>>14) ^ (obj>>16) ^ (blkid>>16);
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return (crc);
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}
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#define DBUF_EQUAL(dbuf, os, obj, level, blkid) \
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((dbuf)->db.db_object == (obj) && \
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(dbuf)->db_objset == (os) && \
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(dbuf)->db_level == (level) && \
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(dbuf)->db_blkid == (blkid))
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dmu_buf_impl_t *
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dbuf_find(objset_t *os, uint64_t obj, uint8_t level, uint64_t blkid)
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{
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dbuf_hash_table_t *h = &dbuf_hash_table;
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uint64_t hv;
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uint64_t idx;
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dmu_buf_impl_t *db;
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hv = dbuf_hash(os, obj, level, blkid);
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idx = hv & h->hash_table_mask;
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mutex_enter(DBUF_HASH_MUTEX(h, idx));
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for (db = h->hash_table[idx]; db != NULL; db = db->db_hash_next) {
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if (DBUF_EQUAL(db, os, obj, level, blkid)) {
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mutex_enter(&db->db_mtx);
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if (db->db_state != DB_EVICTING) {
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mutex_exit(DBUF_HASH_MUTEX(h, idx));
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return (db);
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}
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mutex_exit(&db->db_mtx);
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}
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}
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mutex_exit(DBUF_HASH_MUTEX(h, idx));
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return (NULL);
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}
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static dmu_buf_impl_t *
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dbuf_find_bonus(objset_t *os, uint64_t object)
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{
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dnode_t *dn;
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dmu_buf_impl_t *db = NULL;
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if (dnode_hold(os, object, FTAG, &dn) == 0) {
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rw_enter(&dn->dn_struct_rwlock, RW_READER);
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if (dn->dn_bonus != NULL) {
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db = dn->dn_bonus;
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mutex_enter(&db->db_mtx);
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}
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rw_exit(&dn->dn_struct_rwlock);
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dnode_rele(dn, FTAG);
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}
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return (db);
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}
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/*
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* Insert an entry into the hash table. If there is already an element
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* equal to elem in the hash table, then the already existing element
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* will be returned and the new element will not be inserted.
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* Otherwise returns NULL.
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*/
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static dmu_buf_impl_t *
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dbuf_hash_insert(dmu_buf_impl_t *db)
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{
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dbuf_hash_table_t *h = &dbuf_hash_table;
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objset_t *os = db->db_objset;
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uint64_t obj = db->db.db_object;
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int level = db->db_level;
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uint64_t blkid, hv, idx;
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dmu_buf_impl_t *dbf;
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blkid = db->db_blkid;
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hv = dbuf_hash(os, obj, level, blkid);
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idx = hv & h->hash_table_mask;
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mutex_enter(DBUF_HASH_MUTEX(h, idx));
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for (dbf = h->hash_table[idx]; dbf != NULL; dbf = dbf->db_hash_next) {
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if (DBUF_EQUAL(dbf, os, obj, level, blkid)) {
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mutex_enter(&dbf->db_mtx);
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if (dbf->db_state != DB_EVICTING) {
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mutex_exit(DBUF_HASH_MUTEX(h, idx));
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return (dbf);
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}
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mutex_exit(&dbf->db_mtx);
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}
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}
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mutex_enter(&db->db_mtx);
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db->db_hash_next = h->hash_table[idx];
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h->hash_table[idx] = db;
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mutex_exit(DBUF_HASH_MUTEX(h, idx));
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atomic_inc_64(&dbuf_hash_count);
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return (NULL);
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}
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/*
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* Remove an entry from the hash table. It must be in the EVICTING state.
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*/
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static void
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dbuf_hash_remove(dmu_buf_impl_t *db)
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{
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dbuf_hash_table_t *h = &dbuf_hash_table;
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uint64_t hv, idx;
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dmu_buf_impl_t *dbf, **dbp;
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hv = dbuf_hash(db->db_objset, db->db.db_object,
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db->db_level, db->db_blkid);
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idx = hv & h->hash_table_mask;
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/*
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* We mustn't hold db_mtx to maintain lock ordering:
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* DBUF_HASH_MUTEX > db_mtx.
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*/
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ASSERT(refcount_is_zero(&db->db_holds));
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ASSERT(db->db_state == DB_EVICTING);
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ASSERT(!MUTEX_HELD(&db->db_mtx));
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mutex_enter(DBUF_HASH_MUTEX(h, idx));
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dbp = &h->hash_table[idx];
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while ((dbf = *dbp) != db) {
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dbp = &dbf->db_hash_next;
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ASSERT(dbf != NULL);
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}
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*dbp = db->db_hash_next;
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db->db_hash_next = NULL;
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mutex_exit(DBUF_HASH_MUTEX(h, idx));
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atomic_dec_64(&dbuf_hash_count);
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}
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typedef enum {
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DBVU_EVICTING,
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DBVU_NOT_EVICTING
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} dbvu_verify_type_t;
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static void
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dbuf_verify_user(dmu_buf_impl_t *db, dbvu_verify_type_t verify_type)
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{
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#ifdef ZFS_DEBUG
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int64_t holds;
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if (db->db_user == NULL)
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return;
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/* Only data blocks support the attachment of user data. */
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ASSERT(db->db_level == 0);
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/* Clients must resolve a dbuf before attaching user data. */
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ASSERT(db->db.db_data != NULL);
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ASSERT3U(db->db_state, ==, DB_CACHED);
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holds = refcount_count(&db->db_holds);
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if (verify_type == DBVU_EVICTING) {
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/*
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* Immediate eviction occurs when holds == dirtycnt.
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* For normal eviction buffers, holds is zero on
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* eviction, except when dbuf_fix_old_data() calls
|
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* dbuf_clear_data(). However, the hold count can grow
|
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* during eviction even though db_mtx is held (see
|
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* dmu_bonus_hold() for an example), so we can only
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* test the generic invariant that holds >= dirtycnt.
|
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*/
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ASSERT3U(holds, >=, db->db_dirtycnt);
|
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} else {
|
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if (db->db_user_immediate_evict == TRUE)
|
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ASSERT3U(holds, >=, db->db_dirtycnt);
|
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else
|
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ASSERT3U(holds, >, 0);
|
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}
|
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#endif
|
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}
|
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|
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static void
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dbuf_evict_user(dmu_buf_impl_t *db)
|
|
{
|
|
dmu_buf_user_t *dbu = db->db_user;
|
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boolean_t has_async;
|
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|
|
ASSERT(MUTEX_HELD(&db->db_mtx));
|
|
|
|
if (dbu == NULL)
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return;
|
|
|
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dbuf_verify_user(db, DBVU_EVICTING);
|
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db->db_user = NULL;
|
|
|
|
#ifdef ZFS_DEBUG
|
|
if (dbu->dbu_clear_on_evict_dbufp != NULL)
|
|
*dbu->dbu_clear_on_evict_dbufp = NULL;
|
|
#endif
|
|
|
|
/*
|
|
* There are two eviction callbacks - one that we call synchronously
|
|
* and one that we invoke via a taskq. The async one is useful for
|
|
* avoiding lock order reversals and limiting stack depth.
|
|
*
|
|
* Note that if we have a sync callback but no async callback,
|
|
* it's likely that the sync callback will free the structure
|
|
* containing the dbu. In that case we need to take care to not
|
|
* dereference dbu after calling the sync evict func.
|
|
*/
|
|
has_async = (dbu->dbu_evict_func_async != NULL);
|
|
|
|
if (dbu->dbu_evict_func_sync != NULL)
|
|
dbu->dbu_evict_func_sync(dbu);
|
|
|
|
if (has_async) {
|
|
taskq_dispatch_ent(dbu_evict_taskq, dbu->dbu_evict_func_async,
|
|
dbu, 0, &dbu->dbu_tqent);
|
|
}
|
|
}
|
|
|
|
boolean_t
|
|
dbuf_is_metadata(dmu_buf_impl_t *db)
|
|
{
|
|
/*
|
|
* Consider indirect blocks and spill blocks to be meta data.
|
|
*/
|
|
if (db->db_level > 0 || db->db_blkid == DMU_SPILL_BLKID) {
|
|
return (B_TRUE);
|
|
} else {
|
|
boolean_t is_metadata;
|
|
|
|
DB_DNODE_ENTER(db);
|
|
is_metadata = DMU_OT_IS_METADATA(DB_DNODE(db)->dn_type);
|
|
DB_DNODE_EXIT(db);
|
|
|
|
return (is_metadata);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* This function *must* return indices evenly distributed between all
|
|
* sublists of the multilist. This is needed due to how the dbuf eviction
|
|
* code is laid out; dbuf_evict_thread() assumes dbufs are evenly
|
|
* distributed between all sublists and uses this assumption when
|
|
* deciding which sublist to evict from and how much to evict from it.
|
|
*/
|
|
unsigned int
|
|
dbuf_cache_multilist_index_func(multilist_t *ml, void *obj)
|
|
{
|
|
dmu_buf_impl_t *db = obj;
|
|
|
|
/*
|
|
* The assumption here, is the hash value for a given
|
|
* dmu_buf_impl_t will remain constant throughout it's lifetime
|
|
* (i.e. it's objset, object, level and blkid fields don't change).
|
|
* Thus, we don't need to store the dbuf's sublist index
|
|
* on insertion, as this index can be recalculated on removal.
|
|
*
|
|
* Also, the low order bits of the hash value are thought to be
|
|
* distributed evenly. Otherwise, in the case that the multilist
|
|
* has a power of two number of sublists, each sublists' usage
|
|
* would not be evenly distributed.
|
|
*/
|
|
return (dbuf_hash(db->db_objset, db->db.db_object,
|
|
db->db_level, db->db_blkid) %
|
|
multilist_get_num_sublists(ml));
|
|
}
|
|
|
|
static inline boolean_t
|
|
dbuf_cache_above_hiwater(void)
|
|
{
|
|
uint64_t dbuf_cache_hiwater_bytes =
|
|
(dbuf_cache_max_bytes * dbuf_cache_hiwater_pct) / 100;
|
|
|
|
return (refcount_count(&dbuf_cache_size) >
|
|
dbuf_cache_max_bytes + dbuf_cache_hiwater_bytes);
|
|
}
|
|
|
|
static inline boolean_t
|
|
dbuf_cache_above_lowater(void)
|
|
{
|
|
uint64_t dbuf_cache_lowater_bytes =
|
|
(dbuf_cache_max_bytes * dbuf_cache_lowater_pct) / 100;
|
|
|
|
return (refcount_count(&dbuf_cache_size) >
|
|
dbuf_cache_max_bytes - dbuf_cache_lowater_bytes);
|
|
}
|
|
|
|
/*
|
|
* Evict the oldest eligible dbuf from the dbuf cache.
|
|
*/
|
|
static void
|
|
dbuf_evict_one(void)
|
|
{
|
|
int idx = multilist_get_random_index(dbuf_cache);
|
|
multilist_sublist_t *mls = multilist_sublist_lock(dbuf_cache, idx);
|
|
dmu_buf_impl_t *db;
|
|
ASSERT(!MUTEX_HELD(&dbuf_evict_lock));
|
|
|
|
/*
|
|
* Set the thread's tsd to indicate that it's processing evictions.
|
|
* Once a thread stops evicting from the dbuf cache it will
|
|
* reset its tsd to NULL.
|
|
*/
|
|
ASSERT3P(tsd_get(zfs_dbuf_evict_key), ==, NULL);
|
|
(void) tsd_set(zfs_dbuf_evict_key, (void *)B_TRUE);
|
|
|
|
db = multilist_sublist_tail(mls);
|
|
while (db != NULL && mutex_tryenter(&db->db_mtx) == 0) {
|
|
db = multilist_sublist_prev(mls, db);
|
|
}
|
|
|
|
DTRACE_PROBE2(dbuf__evict__one, dmu_buf_impl_t *, db,
|
|
multilist_sublist_t *, mls);
|
|
|
|
if (db != NULL) {
|
|
multilist_sublist_remove(mls, db);
|
|
multilist_sublist_unlock(mls);
|
|
(void) refcount_remove_many(&dbuf_cache_size,
|
|
db->db.db_size, db);
|
|
dbuf_destroy(db);
|
|
} else {
|
|
multilist_sublist_unlock(mls);
|
|
}
|
|
(void) tsd_set(zfs_dbuf_evict_key, NULL);
|
|
}
|
|
|
|
/*
|
|
* The dbuf evict thread is responsible for aging out dbufs from the
|
|
* cache. Once the cache has reached it's maximum size, dbufs are removed
|
|
* and destroyed. The eviction thread will continue running until the size
|
|
* of the dbuf cache is at or below the maximum size. Once the dbuf is aged
|
|
* out of the cache it is destroyed and becomes eligible for arc eviction.
|
|
*/
|
|
static void
|
|
dbuf_evict_thread(void)
|
|
{
|
|
callb_cpr_t cpr;
|
|
|
|
CALLB_CPR_INIT(&cpr, &dbuf_evict_lock, callb_generic_cpr, FTAG);
|
|
|
|
mutex_enter(&dbuf_evict_lock);
|
|
while (!dbuf_evict_thread_exit) {
|
|
while (!dbuf_cache_above_lowater() && !dbuf_evict_thread_exit) {
|
|
CALLB_CPR_SAFE_BEGIN(&cpr);
|
|
(void) cv_timedwait_sig_hires(&dbuf_evict_cv,
|
|
&dbuf_evict_lock, SEC2NSEC(1), MSEC2NSEC(1), 0);
|
|
CALLB_CPR_SAFE_END(&cpr, &dbuf_evict_lock);
|
|
}
|
|
mutex_exit(&dbuf_evict_lock);
|
|
|
|
/*
|
|
* Keep evicting as long as we're above the low water mark
|
|
* for the cache. We do this without holding the locks to
|
|
* minimize lock contention.
|
|
*/
|
|
while (dbuf_cache_above_lowater() && !dbuf_evict_thread_exit) {
|
|
dbuf_evict_one();
|
|
}
|
|
|
|
mutex_enter(&dbuf_evict_lock);
|
|
}
|
|
|
|
dbuf_evict_thread_exit = B_FALSE;
|
|
cv_broadcast(&dbuf_evict_cv);
|
|
CALLB_CPR_EXIT(&cpr); /* drops dbuf_evict_lock */
|
|
thread_exit();
|
|
}
|
|
|
|
/*
|
|
* Wake up the dbuf eviction thread if the dbuf cache is at its max size.
|
|
* If the dbuf cache is at its high water mark, then evict a dbuf from the
|
|
* dbuf cache using the callers context.
|
|
*/
|
|
static void
|
|
dbuf_evict_notify(void)
|
|
{
|
|
|
|
/*
|
|
* We use thread specific data to track when a thread has
|
|
* started processing evictions. This allows us to avoid deeply
|
|
* nested stacks that would have a call flow similar to this:
|
|
*
|
|
* dbuf_rele()-->dbuf_rele_and_unlock()-->dbuf_evict_notify()
|
|
* ^ |
|
|
* | |
|
|
* +-----dbuf_destroy()<--dbuf_evict_one()<--------+
|
|
*
|
|
* The dbuf_eviction_thread will always have its tsd set until
|
|
* that thread exits. All other threads will only set their tsd
|
|
* if they are participating in the eviction process. This only
|
|
* happens if the eviction thread is unable to process evictions
|
|
* fast enough. To keep the dbuf cache size in check, other threads
|
|
* can evict from the dbuf cache directly. Those threads will set
|
|
* their tsd values so that we ensure that they only evict one dbuf
|
|
* from the dbuf cache.
|
|
*/
|
|
if (tsd_get(zfs_dbuf_evict_key) != NULL)
|
|
return;
|
|
|
|
if (refcount_count(&dbuf_cache_size) > dbuf_cache_max_bytes) {
|
|
boolean_t evict_now = B_FALSE;
|
|
|
|
mutex_enter(&dbuf_evict_lock);
|
|
if (refcount_count(&dbuf_cache_size) > dbuf_cache_max_bytes) {
|
|
evict_now = dbuf_cache_above_hiwater();
|
|
cv_signal(&dbuf_evict_cv);
|
|
}
|
|
mutex_exit(&dbuf_evict_lock);
|
|
|
|
if (evict_now) {
|
|
dbuf_evict_one();
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
|
|
void
|
|
dbuf_init(void)
|
|
{
|
|
uint64_t hsize = 1ULL << 16;
|
|
dbuf_hash_table_t *h = &dbuf_hash_table;
|
|
int i;
|
|
|
|
/*
|
|
* The hash table is big enough to fill all of physical memory
|
|
* with an average block size of zfs_arc_average_blocksize (default 8K).
|
|
* By default, the table will take up
|
|
* totalmem * sizeof(void*) / 8K (1MB per GB with 8-byte pointers).
|
|
*/
|
|
while (hsize * zfs_arc_average_blocksize < physmem * PAGESIZE)
|
|
hsize <<= 1;
|
|
|
|
retry:
|
|
h->hash_table_mask = hsize - 1;
|
|
#if defined(_KERNEL) && defined(HAVE_SPL)
|
|
/*
|
|
* Large allocations which do not require contiguous pages
|
|
* should be using vmem_alloc() in the linux kernel
|
|
*/
|
|
h->hash_table = vmem_zalloc(hsize * sizeof (void *), KM_SLEEP);
|
|
#else
|
|
h->hash_table = kmem_zalloc(hsize * sizeof (void *), KM_NOSLEEP);
|
|
#endif
|
|
if (h->hash_table == NULL) {
|
|
/* XXX - we should really return an error instead of assert */
|
|
ASSERT(hsize > (1ULL << 10));
|
|
hsize >>= 1;
|
|
goto retry;
|
|
}
|
|
|
|
dbuf_kmem_cache = kmem_cache_create("dmu_buf_impl_t",
|
|
sizeof (dmu_buf_impl_t),
|
|
0, dbuf_cons, dbuf_dest, NULL, NULL, NULL, 0);
|
|
|
|
for (i = 0; i < DBUF_MUTEXES; i++)
|
|
mutex_init(&h->hash_mutexes[i], NULL, MUTEX_DEFAULT, NULL);
|
|
|
|
dbuf_stats_init(h);
|
|
|
|
/*
|
|
* Setup the parameters for the dbuf cache. We cap the size of the
|
|
* dbuf cache to 1/32nd (default) of the size of the ARC.
|
|
*/
|
|
dbuf_cache_max_bytes = MIN(dbuf_cache_max_bytes,
|
|
arc_max_bytes() >> dbuf_cache_max_shift);
|
|
|
|
/*
|
|
* All entries are queued via taskq_dispatch_ent(), so min/maxalloc
|
|
* configuration is not required.
|
|
*/
|
|
dbu_evict_taskq = taskq_create("dbu_evict", 1, defclsyspri, 0, 0, 0);
|
|
|
|
dbuf_cache = multilist_create(sizeof (dmu_buf_impl_t),
|
|
offsetof(dmu_buf_impl_t, db_cache_link),
|
|
dbuf_cache_multilist_index_func);
|
|
refcount_create(&dbuf_cache_size);
|
|
|
|
tsd_create(&zfs_dbuf_evict_key, NULL);
|
|
dbuf_evict_thread_exit = B_FALSE;
|
|
mutex_init(&dbuf_evict_lock, NULL, MUTEX_DEFAULT, NULL);
|
|
cv_init(&dbuf_evict_cv, NULL, CV_DEFAULT, NULL);
|
|
dbuf_cache_evict_thread = thread_create(NULL, 0, dbuf_evict_thread,
|
|
NULL, 0, &p0, TS_RUN, minclsyspri);
|
|
}
|
|
|
|
void
|
|
dbuf_fini(void)
|
|
{
|
|
dbuf_hash_table_t *h = &dbuf_hash_table;
|
|
int i;
|
|
|
|
dbuf_stats_destroy();
|
|
|
|
for (i = 0; i < DBUF_MUTEXES; i++)
|
|
mutex_destroy(&h->hash_mutexes[i]);
|
|
#if defined(_KERNEL) && defined(HAVE_SPL)
|
|
/*
|
|
* Large allocations which do not require contiguous pages
|
|
* should be using vmem_free() in the linux kernel
|
|
*/
|
|
vmem_free(h->hash_table, (h->hash_table_mask + 1) * sizeof (void *));
|
|
#else
|
|
kmem_free(h->hash_table, (h->hash_table_mask + 1) * sizeof (void *));
|
|
#endif
|
|
kmem_cache_destroy(dbuf_kmem_cache);
|
|
taskq_destroy(dbu_evict_taskq);
|
|
|
|
mutex_enter(&dbuf_evict_lock);
|
|
dbuf_evict_thread_exit = B_TRUE;
|
|
while (dbuf_evict_thread_exit) {
|
|
cv_signal(&dbuf_evict_cv);
|
|
cv_wait(&dbuf_evict_cv, &dbuf_evict_lock);
|
|
}
|
|
mutex_exit(&dbuf_evict_lock);
|
|
tsd_destroy(&zfs_dbuf_evict_key);
|
|
|
|
mutex_destroy(&dbuf_evict_lock);
|
|
cv_destroy(&dbuf_evict_cv);
|
|
|
|
refcount_destroy(&dbuf_cache_size);
|
|
multilist_destroy(dbuf_cache);
|
|
}
|
|
|
|
/*
|
|
* Other stuff.
|
|
*/
|
|
|
|
#ifdef ZFS_DEBUG
|
|
static void
|
|
dbuf_verify(dmu_buf_impl_t *db)
|
|
{
|
|
dnode_t *dn;
|
|
dbuf_dirty_record_t *dr;
|
|
|
|
ASSERT(MUTEX_HELD(&db->db_mtx));
|
|
|
|
if (!(zfs_flags & ZFS_DEBUG_DBUF_VERIFY))
|
|
return;
|
|
|
|
ASSERT(db->db_objset != NULL);
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
if (dn == NULL) {
|
|
ASSERT(db->db_parent == NULL);
|
|
ASSERT(db->db_blkptr == NULL);
|
|
} else {
|
|
ASSERT3U(db->db.db_object, ==, dn->dn_object);
|
|
ASSERT3P(db->db_objset, ==, dn->dn_objset);
|
|
ASSERT3U(db->db_level, <, dn->dn_nlevels);
|
|
ASSERT(db->db_blkid == DMU_BONUS_BLKID ||
|
|
db->db_blkid == DMU_SPILL_BLKID ||
|
|
!avl_is_empty(&dn->dn_dbufs));
|
|
}
|
|
if (db->db_blkid == DMU_BONUS_BLKID) {
|
|
ASSERT(dn != NULL);
|
|
ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
|
|
ASSERT3U(db->db.db_offset, ==, DMU_BONUS_BLKID);
|
|
} else if (db->db_blkid == DMU_SPILL_BLKID) {
|
|
ASSERT(dn != NULL);
|
|
ASSERT0(db->db.db_offset);
|
|
} else {
|
|
ASSERT3U(db->db.db_offset, ==, db->db_blkid * db->db.db_size);
|
|
}
|
|
|
|
for (dr = db->db_data_pending; dr != NULL; dr = dr->dr_next)
|
|
ASSERT(dr->dr_dbuf == db);
|
|
|
|
for (dr = db->db_last_dirty; dr != NULL; dr = dr->dr_next)
|
|
ASSERT(dr->dr_dbuf == db);
|
|
|
|
/*
|
|
* We can't assert that db_size matches dn_datablksz because it
|
|
* can be momentarily different when another thread is doing
|
|
* dnode_set_blksz().
|
|
*/
|
|
if (db->db_level == 0 && db->db.db_object == DMU_META_DNODE_OBJECT) {
|
|
dr = db->db_data_pending;
|
|
/*
|
|
* It should only be modified in syncing context, so
|
|
* make sure we only have one copy of the data.
|
|
*/
|
|
ASSERT(dr == NULL || dr->dt.dl.dr_data == db->db_buf);
|
|
}
|
|
|
|
/* verify db->db_blkptr */
|
|
if (db->db_blkptr) {
|
|
if (db->db_parent == dn->dn_dbuf) {
|
|
/* db is pointed to by the dnode */
|
|
/* ASSERT3U(db->db_blkid, <, dn->dn_nblkptr); */
|
|
if (DMU_OBJECT_IS_SPECIAL(db->db.db_object))
|
|
ASSERT(db->db_parent == NULL);
|
|
else
|
|
ASSERT(db->db_parent != NULL);
|
|
if (db->db_blkid != DMU_SPILL_BLKID)
|
|
ASSERT3P(db->db_blkptr, ==,
|
|
&dn->dn_phys->dn_blkptr[db->db_blkid]);
|
|
} else {
|
|
/* db is pointed to by an indirect block */
|
|
ASSERTV(int epb = db->db_parent->db.db_size >>
|
|
SPA_BLKPTRSHIFT);
|
|
ASSERT3U(db->db_parent->db_level, ==, db->db_level+1);
|
|
ASSERT3U(db->db_parent->db.db_object, ==,
|
|
db->db.db_object);
|
|
/*
|
|
* dnode_grow_indblksz() can make this fail if we don't
|
|
* have the struct_rwlock. XXX indblksz no longer
|
|
* grows. safe to do this now?
|
|
*/
|
|
if (RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
|
|
ASSERT3P(db->db_blkptr, ==,
|
|
((blkptr_t *)db->db_parent->db.db_data +
|
|
db->db_blkid % epb));
|
|
}
|
|
}
|
|
}
|
|
if ((db->db_blkptr == NULL || BP_IS_HOLE(db->db_blkptr)) &&
|
|
(db->db_buf == NULL || db->db_buf->b_data) &&
|
|
db->db.db_data && db->db_blkid != DMU_BONUS_BLKID &&
|
|
db->db_state != DB_FILL && !dn->dn_free_txg) {
|
|
/*
|
|
* If the blkptr isn't set but they have nonzero data,
|
|
* it had better be dirty, otherwise we'll lose that
|
|
* data when we evict this buffer.
|
|
*
|
|
* There is an exception to this rule for indirect blocks; in
|
|
* this case, if the indirect block is a hole, we fill in a few
|
|
* fields on each of the child blocks (importantly, birth time)
|
|
* to prevent hole birth times from being lost when you
|
|
* partially fill in a hole.
|
|
*/
|
|
if (db->db_dirtycnt == 0) {
|
|
if (db->db_level == 0) {
|
|
uint64_t *buf = db->db.db_data;
|
|
int i;
|
|
|
|
for (i = 0; i < db->db.db_size >> 3; i++) {
|
|
ASSERT(buf[i] == 0);
|
|
}
|
|
} else {
|
|
int i;
|
|
blkptr_t *bps = db->db.db_data;
|
|
ASSERT3U(1 << DB_DNODE(db)->dn_indblkshift, ==,
|
|
db->db.db_size);
|
|
/*
|
|
* We want to verify that all the blkptrs in the
|
|
* indirect block are holes, but we may have
|
|
* automatically set up a few fields for them.
|
|
* We iterate through each blkptr and verify
|
|
* they only have those fields set.
|
|
*/
|
|
for (i = 0;
|
|
i < db->db.db_size / sizeof (blkptr_t);
|
|
i++) {
|
|
blkptr_t *bp = &bps[i];
|
|
ASSERT(ZIO_CHECKSUM_IS_ZERO(
|
|
&bp->blk_cksum));
|
|
ASSERT(
|
|
DVA_IS_EMPTY(&bp->blk_dva[0]) &&
|
|
DVA_IS_EMPTY(&bp->blk_dva[1]) &&
|
|
DVA_IS_EMPTY(&bp->blk_dva[2]));
|
|
ASSERT0(bp->blk_fill);
|
|
ASSERT0(bp->blk_pad[0]);
|
|
ASSERT0(bp->blk_pad[1]);
|
|
ASSERT(!BP_IS_EMBEDDED(bp));
|
|
ASSERT(BP_IS_HOLE(bp));
|
|
ASSERT0(bp->blk_phys_birth);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
DB_DNODE_EXIT(db);
|
|
}
|
|
#endif
|
|
|
|
static void
|
|
dbuf_clear_data(dmu_buf_impl_t *db)
|
|
{
|
|
ASSERT(MUTEX_HELD(&db->db_mtx));
|
|
dbuf_evict_user(db);
|
|
ASSERT3P(db->db_buf, ==, NULL);
|
|
db->db.db_data = NULL;
|
|
if (db->db_state != DB_NOFILL)
|
|
db->db_state = DB_UNCACHED;
|
|
}
|
|
|
|
static void
|
|
dbuf_set_data(dmu_buf_impl_t *db, arc_buf_t *buf)
|
|
{
|
|
ASSERT(MUTEX_HELD(&db->db_mtx));
|
|
ASSERT(buf != NULL);
|
|
|
|
db->db_buf = buf;
|
|
ASSERT(buf->b_data != NULL);
|
|
db->db.db_data = buf->b_data;
|
|
}
|
|
|
|
/*
|
|
* Loan out an arc_buf for read. Return the loaned arc_buf.
|
|
*/
|
|
arc_buf_t *
|
|
dbuf_loan_arcbuf(dmu_buf_impl_t *db)
|
|
{
|
|
arc_buf_t *abuf;
|
|
|
|
ASSERT(db->db_blkid != DMU_BONUS_BLKID);
|
|
mutex_enter(&db->db_mtx);
|
|
if (arc_released(db->db_buf) || refcount_count(&db->db_holds) > 1) {
|
|
int blksz = db->db.db_size;
|
|
spa_t *spa = db->db_objset->os_spa;
|
|
|
|
mutex_exit(&db->db_mtx);
|
|
abuf = arc_loan_buf(spa, B_FALSE, blksz);
|
|
bcopy(db->db.db_data, abuf->b_data, blksz);
|
|
} else {
|
|
abuf = db->db_buf;
|
|
arc_loan_inuse_buf(abuf, db);
|
|
db->db_buf = NULL;
|
|
dbuf_clear_data(db);
|
|
mutex_exit(&db->db_mtx);
|
|
}
|
|
return (abuf);
|
|
}
|
|
|
|
/*
|
|
* Calculate which level n block references the data at the level 0 offset
|
|
* provided.
|
|
*/
|
|
uint64_t
|
|
dbuf_whichblock(const dnode_t *dn, const int64_t level, const uint64_t offset)
|
|
{
|
|
if (dn->dn_datablkshift != 0 && dn->dn_indblkshift != 0) {
|
|
/*
|
|
* The level n blkid is equal to the level 0 blkid divided by
|
|
* the number of level 0s in a level n block.
|
|
*
|
|
* The level 0 blkid is offset >> datablkshift =
|
|
* offset / 2^datablkshift.
|
|
*
|
|
* The number of level 0s in a level n is the number of block
|
|
* pointers in an indirect block, raised to the power of level.
|
|
* This is 2^(indblkshift - SPA_BLKPTRSHIFT)^level =
|
|
* 2^(level*(indblkshift - SPA_BLKPTRSHIFT)).
|
|
*
|
|
* Thus, the level n blkid is: offset /
|
|
* ((2^datablkshift)*(2^(level*(indblkshift - SPA_BLKPTRSHIFT)))
|
|
* = offset / 2^(datablkshift + level *
|
|
* (indblkshift - SPA_BLKPTRSHIFT))
|
|
* = offset >> (datablkshift + level *
|
|
* (indblkshift - SPA_BLKPTRSHIFT))
|
|
*/
|
|
|
|
const unsigned exp = dn->dn_datablkshift +
|
|
level * (dn->dn_indblkshift - SPA_BLKPTRSHIFT);
|
|
|
|
if (exp >= 8 * sizeof (offset)) {
|
|
/* This only happens on the highest indirection level */
|
|
ASSERT3U(level, ==, dn->dn_nlevels - 1);
|
|
return (0);
|
|
}
|
|
|
|
ASSERT3U(exp, <, 8 * sizeof (offset));
|
|
|
|
return (offset >> exp);
|
|
} else {
|
|
ASSERT3U(offset, <, dn->dn_datablksz);
|
|
return (0);
|
|
}
|
|
}
|
|
|
|
static void
|
|
dbuf_read_done(zio_t *zio, arc_buf_t *buf, void *vdb)
|
|
{
|
|
dmu_buf_impl_t *db = vdb;
|
|
|
|
mutex_enter(&db->db_mtx);
|
|
ASSERT3U(db->db_state, ==, DB_READ);
|
|
/*
|
|
* All reads are synchronous, so we must have a hold on the dbuf
|
|
*/
|
|
ASSERT(refcount_count(&db->db_holds) > 0);
|
|
ASSERT(db->db_buf == NULL);
|
|
ASSERT(db->db.db_data == NULL);
|
|
if (db->db_level == 0 && db->db_freed_in_flight) {
|
|
/* we were freed in flight; disregard any error */
|
|
arc_release(buf, db);
|
|
bzero(buf->b_data, db->db.db_size);
|
|
arc_buf_freeze(buf);
|
|
db->db_freed_in_flight = FALSE;
|
|
dbuf_set_data(db, buf);
|
|
db->db_state = DB_CACHED;
|
|
} else if (zio == NULL || zio->io_error == 0) {
|
|
dbuf_set_data(db, buf);
|
|
db->db_state = DB_CACHED;
|
|
} else {
|
|
ASSERT(db->db_blkid != DMU_BONUS_BLKID);
|
|
ASSERT3P(db->db_buf, ==, NULL);
|
|
arc_buf_destroy(buf, db);
|
|
db->db_state = DB_UNCACHED;
|
|
}
|
|
cv_broadcast(&db->db_changed);
|
|
dbuf_rele_and_unlock(db, NULL);
|
|
}
|
|
|
|
static int
|
|
dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
|
|
{
|
|
dnode_t *dn;
|
|
zbookmark_phys_t zb;
|
|
uint32_t aflags = ARC_FLAG_NOWAIT;
|
|
int err;
|
|
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
ASSERT(!refcount_is_zero(&db->db_holds));
|
|
/* We need the struct_rwlock to prevent db_blkptr from changing. */
|
|
ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
|
|
ASSERT(MUTEX_HELD(&db->db_mtx));
|
|
ASSERT(db->db_state == DB_UNCACHED);
|
|
ASSERT(db->db_buf == NULL);
|
|
|
|
if (db->db_blkid == DMU_BONUS_BLKID) {
|
|
/*
|
|
* The bonus length stored in the dnode may be less than
|
|
* the maximum available space in the bonus buffer.
|
|
*/
|
|
int bonuslen = MIN(dn->dn_bonuslen, dn->dn_phys->dn_bonuslen);
|
|
int max_bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots);
|
|
|
|
ASSERT3U(bonuslen, <=, db->db.db_size);
|
|
db->db.db_data = kmem_alloc(max_bonuslen, KM_SLEEP);
|
|
arc_space_consume(max_bonuslen, ARC_SPACE_BONUS);
|
|
if (bonuslen < max_bonuslen)
|
|
bzero(db->db.db_data, max_bonuslen);
|
|
if (bonuslen)
|
|
bcopy(DN_BONUS(dn->dn_phys), db->db.db_data, bonuslen);
|
|
DB_DNODE_EXIT(db);
|
|
db->db_state = DB_CACHED;
|
|
mutex_exit(&db->db_mtx);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Recheck BP_IS_HOLE() after dnode_block_freed() in case dnode_sync()
|
|
* processes the delete record and clears the bp while we are waiting
|
|
* for the dn_mtx (resulting in a "no" from block_freed).
|
|
*/
|
|
if (db->db_blkptr == NULL || BP_IS_HOLE(db->db_blkptr) ||
|
|
(db->db_level == 0 && (dnode_block_freed(dn, db->db_blkid) ||
|
|
BP_IS_HOLE(db->db_blkptr)))) {
|
|
arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
|
|
|
|
dbuf_set_data(db, arc_alloc_buf(db->db_objset->os_spa, db, type,
|
|
db->db.db_size));
|
|
bzero(db->db.db_data, db->db.db_size);
|
|
|
|
if (db->db_blkptr != NULL && db->db_level > 0 &&
|
|
BP_IS_HOLE(db->db_blkptr) &&
|
|
db->db_blkptr->blk_birth != 0) {
|
|
blkptr_t *bps = db->db.db_data;
|
|
int i;
|
|
for (i = 0; i < ((1 <<
|
|
DB_DNODE(db)->dn_indblkshift) / sizeof (blkptr_t));
|
|
i++) {
|
|
blkptr_t *bp = &bps[i];
|
|
ASSERT3U(BP_GET_LSIZE(db->db_blkptr), ==,
|
|
1 << dn->dn_indblkshift);
|
|
BP_SET_LSIZE(bp,
|
|
BP_GET_LEVEL(db->db_blkptr) == 1 ?
|
|
dn->dn_datablksz :
|
|
BP_GET_LSIZE(db->db_blkptr));
|
|
BP_SET_TYPE(bp, BP_GET_TYPE(db->db_blkptr));
|
|
BP_SET_LEVEL(bp,
|
|
BP_GET_LEVEL(db->db_blkptr) - 1);
|
|
BP_SET_BIRTH(bp, db->db_blkptr->blk_birth, 0);
|
|
}
|
|
}
|
|
DB_DNODE_EXIT(db);
|
|
db->db_state = DB_CACHED;
|
|
mutex_exit(&db->db_mtx);
|
|
return (0);
|
|
}
|
|
|
|
DB_DNODE_EXIT(db);
|
|
|
|
db->db_state = DB_READ;
|
|
mutex_exit(&db->db_mtx);
|
|
|
|
if (DBUF_IS_L2CACHEABLE(db))
|
|
aflags |= ARC_FLAG_L2CACHE;
|
|
|
|
SET_BOOKMARK(&zb, db->db_objset->os_dsl_dataset ?
|
|
db->db_objset->os_dsl_dataset->ds_object : DMU_META_OBJSET,
|
|
db->db.db_object, db->db_level, db->db_blkid);
|
|
|
|
dbuf_add_ref(db, NULL);
|
|
|
|
err = arc_read(zio, db->db_objset->os_spa, db->db_blkptr,
|
|
dbuf_read_done, db, ZIO_PRIORITY_SYNC_READ,
|
|
(flags & DB_RF_CANFAIL) ? ZIO_FLAG_CANFAIL : ZIO_FLAG_MUSTSUCCEED,
|
|
&aflags, &zb);
|
|
|
|
return (err);
|
|
}
|
|
|
|
/*
|
|
* This is our just-in-time copy function. It makes a copy of buffers that
|
|
* have been modified in a previous transaction group before we access them in
|
|
* the current active group.
|
|
*
|
|
* This function is used in three places: when we are dirtying a buffer for the
|
|
* first time in a txg, when we are freeing a range in a dnode that includes
|
|
* this buffer, and when we are accessing a buffer which was received compressed
|
|
* and later referenced in a WRITE_BYREF record.
|
|
*
|
|
* Note that when we are called from dbuf_free_range() we do not put a hold on
|
|
* the buffer, we just traverse the active dbuf list for the dnode.
|
|
*/
|
|
static void
|
|
dbuf_fix_old_data(dmu_buf_impl_t *db, uint64_t txg)
|
|
{
|
|
dbuf_dirty_record_t *dr = db->db_last_dirty;
|
|
|
|
ASSERT(MUTEX_HELD(&db->db_mtx));
|
|
ASSERT(db->db.db_data != NULL);
|
|
ASSERT(db->db_level == 0);
|
|
ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT);
|
|
|
|
if (dr == NULL ||
|
|
(dr->dt.dl.dr_data !=
|
|
((db->db_blkid == DMU_BONUS_BLKID) ? db->db.db_data : db->db_buf)))
|
|
return;
|
|
|
|
/*
|
|
* If the last dirty record for this dbuf has not yet synced
|
|
* and its referencing the dbuf data, either:
|
|
* reset the reference to point to a new copy,
|
|
* or (if there a no active holders)
|
|
* just null out the current db_data pointer.
|
|
*/
|
|
ASSERT(dr->dr_txg >= txg - 2);
|
|
if (db->db_blkid == DMU_BONUS_BLKID) {
|
|
dnode_t *dn = DB_DNODE(db);
|
|
int bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots);
|
|
dr->dt.dl.dr_data = kmem_alloc(bonuslen, KM_SLEEP);
|
|
arc_space_consume(bonuslen, ARC_SPACE_BONUS);
|
|
bcopy(db->db.db_data, dr->dt.dl.dr_data, bonuslen);
|
|
} else if (refcount_count(&db->db_holds) > db->db_dirtycnt) {
|
|
int size = arc_buf_size(db->db_buf);
|
|
arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
|
|
spa_t *spa = db->db_objset->os_spa;
|
|
enum zio_compress compress_type =
|
|
arc_get_compression(db->db_buf);
|
|
|
|
if (compress_type == ZIO_COMPRESS_OFF) {
|
|
dr->dt.dl.dr_data = arc_alloc_buf(spa, db, type, size);
|
|
} else {
|
|
ASSERT3U(type, ==, ARC_BUFC_DATA);
|
|
dr->dt.dl.dr_data = arc_alloc_compressed_buf(spa, db,
|
|
size, arc_buf_lsize(db->db_buf), compress_type);
|
|
}
|
|
bcopy(db->db.db_data, dr->dt.dl.dr_data->b_data, size);
|
|
} else {
|
|
db->db_buf = NULL;
|
|
dbuf_clear_data(db);
|
|
}
|
|
}
|
|
|
|
int
|
|
dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
|
|
{
|
|
int err = 0;
|
|
boolean_t prefetch;
|
|
dnode_t *dn;
|
|
|
|
/*
|
|
* We don't have to hold the mutex to check db_state because it
|
|
* can't be freed while we have a hold on the buffer.
|
|
*/
|
|
ASSERT(!refcount_is_zero(&db->db_holds));
|
|
|
|
if (db->db_state == DB_NOFILL)
|
|
return (SET_ERROR(EIO));
|
|
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
if ((flags & DB_RF_HAVESTRUCT) == 0)
|
|
rw_enter(&dn->dn_struct_rwlock, RW_READER);
|
|
|
|
prefetch = db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
|
|
(flags & DB_RF_NOPREFETCH) == 0 && dn != NULL &&
|
|
DBUF_IS_CACHEABLE(db);
|
|
|
|
mutex_enter(&db->db_mtx);
|
|
if (db->db_state == DB_CACHED) {
|
|
/*
|
|
* If the arc buf is compressed, we need to decompress it to
|
|
* read the data. This could happen during the "zfs receive" of
|
|
* a stream which is compressed and deduplicated.
|
|
*/
|
|
if (db->db_buf != NULL &&
|
|
arc_get_compression(db->db_buf) != ZIO_COMPRESS_OFF) {
|
|
dbuf_fix_old_data(db,
|
|
spa_syncing_txg(dmu_objset_spa(db->db_objset)));
|
|
err = arc_decompress(db->db_buf);
|
|
dbuf_set_data(db, db->db_buf);
|
|
}
|
|
mutex_exit(&db->db_mtx);
|
|
if (prefetch)
|
|
dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE);
|
|
if ((flags & DB_RF_HAVESTRUCT) == 0)
|
|
rw_exit(&dn->dn_struct_rwlock);
|
|
DB_DNODE_EXIT(db);
|
|
} else if (db->db_state == DB_UNCACHED) {
|
|
spa_t *spa = dn->dn_objset->os_spa;
|
|
boolean_t need_wait = B_FALSE;
|
|
|
|
if (zio == NULL &&
|
|
db->db_blkptr != NULL && !BP_IS_HOLE(db->db_blkptr)) {
|
|
zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
|
|
need_wait = B_TRUE;
|
|
}
|
|
err = dbuf_read_impl(db, zio, flags);
|
|
|
|
/* dbuf_read_impl has dropped db_mtx for us */
|
|
|
|
if (!err && prefetch)
|
|
dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE);
|
|
|
|
if ((flags & DB_RF_HAVESTRUCT) == 0)
|
|
rw_exit(&dn->dn_struct_rwlock);
|
|
DB_DNODE_EXIT(db);
|
|
|
|
if (!err && need_wait)
|
|
err = zio_wait(zio);
|
|
} else {
|
|
/*
|
|
* Another reader came in while the dbuf was in flight
|
|
* between UNCACHED and CACHED. Either a writer will finish
|
|
* writing the buffer (sending the dbuf to CACHED) or the
|
|
* first reader's request will reach the read_done callback
|
|
* and send the dbuf to CACHED. Otherwise, a failure
|
|
* occurred and the dbuf went to UNCACHED.
|
|
*/
|
|
mutex_exit(&db->db_mtx);
|
|
if (prefetch)
|
|
dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE);
|
|
if ((flags & DB_RF_HAVESTRUCT) == 0)
|
|
rw_exit(&dn->dn_struct_rwlock);
|
|
DB_DNODE_EXIT(db);
|
|
|
|
/* Skip the wait per the caller's request. */
|
|
mutex_enter(&db->db_mtx);
|
|
if ((flags & DB_RF_NEVERWAIT) == 0) {
|
|
while (db->db_state == DB_READ ||
|
|
db->db_state == DB_FILL) {
|
|
ASSERT(db->db_state == DB_READ ||
|
|
(flags & DB_RF_HAVESTRUCT) == 0);
|
|
DTRACE_PROBE2(blocked__read, dmu_buf_impl_t *,
|
|
db, zio_t *, zio);
|
|
cv_wait(&db->db_changed, &db->db_mtx);
|
|
}
|
|
if (db->db_state == DB_UNCACHED)
|
|
err = SET_ERROR(EIO);
|
|
}
|
|
mutex_exit(&db->db_mtx);
|
|
}
|
|
|
|
return (err);
|
|
}
|
|
|
|
static void
|
|
dbuf_noread(dmu_buf_impl_t *db)
|
|
{
|
|
ASSERT(!refcount_is_zero(&db->db_holds));
|
|
ASSERT(db->db_blkid != DMU_BONUS_BLKID);
|
|
mutex_enter(&db->db_mtx);
|
|
while (db->db_state == DB_READ || db->db_state == DB_FILL)
|
|
cv_wait(&db->db_changed, &db->db_mtx);
|
|
if (db->db_state == DB_UNCACHED) {
|
|
arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
|
|
spa_t *spa = db->db_objset->os_spa;
|
|
|
|
ASSERT(db->db_buf == NULL);
|
|
ASSERT(db->db.db_data == NULL);
|
|
dbuf_set_data(db, arc_alloc_buf(spa, db, type, db->db.db_size));
|
|
db->db_state = DB_FILL;
|
|
} else if (db->db_state == DB_NOFILL) {
|
|
dbuf_clear_data(db);
|
|
} else {
|
|
ASSERT3U(db->db_state, ==, DB_CACHED);
|
|
}
|
|
mutex_exit(&db->db_mtx);
|
|
}
|
|
|
|
void
|
|
dbuf_unoverride(dbuf_dirty_record_t *dr)
|
|
{
|
|
dmu_buf_impl_t *db = dr->dr_dbuf;
|
|
blkptr_t *bp = &dr->dt.dl.dr_overridden_by;
|
|
uint64_t txg = dr->dr_txg;
|
|
|
|
ASSERT(MUTEX_HELD(&db->db_mtx));
|
|
ASSERT(dr->dt.dl.dr_override_state != DR_IN_DMU_SYNC);
|
|
ASSERT(db->db_level == 0);
|
|
|
|
if (db->db_blkid == DMU_BONUS_BLKID ||
|
|
dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN)
|
|
return;
|
|
|
|
ASSERT(db->db_data_pending != dr);
|
|
|
|
/* free this block */
|
|
if (!BP_IS_HOLE(bp) && !dr->dt.dl.dr_nopwrite)
|
|
zio_free(db->db_objset->os_spa, txg, bp);
|
|
|
|
dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
|
|
dr->dt.dl.dr_nopwrite = B_FALSE;
|
|
|
|
/*
|
|
* Release the already-written buffer, so we leave it in
|
|
* a consistent dirty state. Note that all callers are
|
|
* modifying the buffer, so they will immediately do
|
|
* another (redundant) arc_release(). Therefore, leave
|
|
* the buf thawed to save the effort of freezing &
|
|
* immediately re-thawing it.
|
|
*/
|
|
arc_release(dr->dt.dl.dr_data, db);
|
|
}
|
|
|
|
/*
|
|
* Evict (if its unreferenced) or clear (if its referenced) any level-0
|
|
* data blocks in the free range, so that any future readers will find
|
|
* empty blocks.
|
|
*/
|
|
void
|
|
dbuf_free_range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid,
|
|
dmu_tx_t *tx)
|
|
{
|
|
dmu_buf_impl_t *db_search;
|
|
dmu_buf_impl_t *db, *db_next;
|
|
uint64_t txg = tx->tx_txg;
|
|
avl_index_t where;
|
|
|
|
if (end_blkid > dn->dn_maxblkid &&
|
|
!(start_blkid == DMU_SPILL_BLKID || end_blkid == DMU_SPILL_BLKID))
|
|
end_blkid = dn->dn_maxblkid;
|
|
dprintf_dnode(dn, "start=%llu end=%llu\n", start_blkid, end_blkid);
|
|
|
|
db_search = kmem_alloc(sizeof (dmu_buf_impl_t), KM_SLEEP);
|
|
db_search->db_level = 0;
|
|
db_search->db_blkid = start_blkid;
|
|
db_search->db_state = DB_SEARCH;
|
|
|
|
mutex_enter(&dn->dn_dbufs_mtx);
|
|
db = avl_find(&dn->dn_dbufs, db_search, &where);
|
|
ASSERT3P(db, ==, NULL);
|
|
|
|
db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
|
|
|
|
for (; db != NULL; db = db_next) {
|
|
db_next = AVL_NEXT(&dn->dn_dbufs, db);
|
|
ASSERT(db->db_blkid != DMU_BONUS_BLKID);
|
|
|
|
if (db->db_level != 0 || db->db_blkid > end_blkid) {
|
|
break;
|
|
}
|
|
ASSERT3U(db->db_blkid, >=, start_blkid);
|
|
|
|
/* found a level 0 buffer in the range */
|
|
mutex_enter(&db->db_mtx);
|
|
if (dbuf_undirty(db, tx)) {
|
|
/* mutex has been dropped and dbuf destroyed */
|
|
continue;
|
|
}
|
|
|
|
if (db->db_state == DB_UNCACHED ||
|
|
db->db_state == DB_NOFILL ||
|
|
db->db_state == DB_EVICTING) {
|
|
ASSERT(db->db.db_data == NULL);
|
|
mutex_exit(&db->db_mtx);
|
|
continue;
|
|
}
|
|
if (db->db_state == DB_READ || db->db_state == DB_FILL) {
|
|
/* will be handled in dbuf_read_done or dbuf_rele */
|
|
db->db_freed_in_flight = TRUE;
|
|
mutex_exit(&db->db_mtx);
|
|
continue;
|
|
}
|
|
if (refcount_count(&db->db_holds) == 0) {
|
|
ASSERT(db->db_buf);
|
|
dbuf_destroy(db);
|
|
continue;
|
|
}
|
|
/* The dbuf is referenced */
|
|
|
|
if (db->db_last_dirty != NULL) {
|
|
dbuf_dirty_record_t *dr = db->db_last_dirty;
|
|
|
|
if (dr->dr_txg == txg) {
|
|
/*
|
|
* This buffer is "in-use", re-adjust the file
|
|
* size to reflect that this buffer may
|
|
* contain new data when we sync.
|
|
*/
|
|
if (db->db_blkid != DMU_SPILL_BLKID &&
|
|
db->db_blkid > dn->dn_maxblkid)
|
|
dn->dn_maxblkid = db->db_blkid;
|
|
dbuf_unoverride(dr);
|
|
} else {
|
|
/*
|
|
* This dbuf is not dirty in the open context.
|
|
* Either uncache it (if its not referenced in
|
|
* the open context) or reset its contents to
|
|
* empty.
|
|
*/
|
|
dbuf_fix_old_data(db, txg);
|
|
}
|
|
}
|
|
/* clear the contents if its cached */
|
|
if (db->db_state == DB_CACHED) {
|
|
ASSERT(db->db.db_data != NULL);
|
|
arc_release(db->db_buf, db);
|
|
bzero(db->db.db_data, db->db.db_size);
|
|
arc_buf_freeze(db->db_buf);
|
|
}
|
|
|
|
mutex_exit(&db->db_mtx);
|
|
}
|
|
|
|
kmem_free(db_search, sizeof (dmu_buf_impl_t));
|
|
mutex_exit(&dn->dn_dbufs_mtx);
|
|
}
|
|
|
|
void
|
|
dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx)
|
|
{
|
|
arc_buf_t *buf, *obuf;
|
|
int osize = db->db.db_size;
|
|
arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
|
|
dnode_t *dn;
|
|
|
|
ASSERT(db->db_blkid != DMU_BONUS_BLKID);
|
|
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
|
|
/* XXX does *this* func really need the lock? */
|
|
ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
|
|
|
|
/*
|
|
* This call to dmu_buf_will_dirty() with the dn_struct_rwlock held
|
|
* is OK, because there can be no other references to the db
|
|
* when we are changing its size, so no concurrent DB_FILL can
|
|
* be happening.
|
|
*/
|
|
/*
|
|
* XXX we should be doing a dbuf_read, checking the return
|
|
* value and returning that up to our callers
|
|
*/
|
|
dmu_buf_will_dirty(&db->db, tx);
|
|
|
|
/* create the data buffer for the new block */
|
|
buf = arc_alloc_buf(dn->dn_objset->os_spa, db, type, size);
|
|
|
|
/* copy old block data to the new block */
|
|
obuf = db->db_buf;
|
|
bcopy(obuf->b_data, buf->b_data, MIN(osize, size));
|
|
/* zero the remainder */
|
|
if (size > osize)
|
|
bzero((uint8_t *)buf->b_data + osize, size - osize);
|
|
|
|
mutex_enter(&db->db_mtx);
|
|
dbuf_set_data(db, buf);
|
|
arc_buf_destroy(obuf, db);
|
|
db->db.db_size = size;
|
|
|
|
if (db->db_level == 0) {
|
|
ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg);
|
|
db->db_last_dirty->dt.dl.dr_data = buf;
|
|
}
|
|
mutex_exit(&db->db_mtx);
|
|
|
|
dmu_objset_willuse_space(dn->dn_objset, size - osize, tx);
|
|
DB_DNODE_EXIT(db);
|
|
}
|
|
|
|
void
|
|
dbuf_release_bp(dmu_buf_impl_t *db)
|
|
{
|
|
ASSERTV(objset_t *os = db->db_objset);
|
|
|
|
ASSERT(dsl_pool_sync_context(dmu_objset_pool(os)));
|
|
ASSERT(arc_released(os->os_phys_buf) ||
|
|
list_link_active(&os->os_dsl_dataset->ds_synced_link));
|
|
ASSERT(db->db_parent == NULL || arc_released(db->db_parent->db_buf));
|
|
|
|
(void) arc_release(db->db_buf, db);
|
|
}
|
|
|
|
/*
|
|
* We already have a dirty record for this TXG, and we are being
|
|
* dirtied again.
|
|
*/
|
|
static void
|
|
dbuf_redirty(dbuf_dirty_record_t *dr)
|
|
{
|
|
dmu_buf_impl_t *db = dr->dr_dbuf;
|
|
|
|
ASSERT(MUTEX_HELD(&db->db_mtx));
|
|
|
|
if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID) {
|
|
/*
|
|
* If this buffer has already been written out,
|
|
* we now need to reset its state.
|
|
*/
|
|
dbuf_unoverride(dr);
|
|
if (db->db.db_object != DMU_META_DNODE_OBJECT &&
|
|
db->db_state != DB_NOFILL) {
|
|
/* Already released on initial dirty, so just thaw. */
|
|
ASSERT(arc_released(db->db_buf));
|
|
arc_buf_thaw(db->db_buf);
|
|
}
|
|
}
|
|
}
|
|
|
|
dbuf_dirty_record_t *
|
|
dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
|
|
{
|
|
dnode_t *dn;
|
|
objset_t *os;
|
|
dbuf_dirty_record_t **drp, *dr;
|
|
int drop_struct_lock = FALSE;
|
|
int txgoff = tx->tx_txg & TXG_MASK;
|
|
|
|
ASSERT(tx->tx_txg != 0);
|
|
ASSERT(!refcount_is_zero(&db->db_holds));
|
|
DMU_TX_DIRTY_BUF(tx, db);
|
|
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
/*
|
|
* Shouldn't dirty a regular buffer in syncing context. Private
|
|
* objects may be dirtied in syncing context, but only if they
|
|
* were already pre-dirtied in open context.
|
|
*/
|
|
#ifdef DEBUG
|
|
if (dn->dn_objset->os_dsl_dataset != NULL) {
|
|
rrw_enter(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock,
|
|
RW_READER, FTAG);
|
|
}
|
|
ASSERT(!dmu_tx_is_syncing(tx) ||
|
|
BP_IS_HOLE(dn->dn_objset->os_rootbp) ||
|
|
DMU_OBJECT_IS_SPECIAL(dn->dn_object) ||
|
|
dn->dn_objset->os_dsl_dataset == NULL);
|
|
if (dn->dn_objset->os_dsl_dataset != NULL)
|
|
rrw_exit(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock, FTAG);
|
|
#endif
|
|
/*
|
|
* We make this assert for private objects as well, but after we
|
|
* check if we're already dirty. They are allowed to re-dirty
|
|
* in syncing context.
|
|
*/
|
|
ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT ||
|
|
dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx ==
|
|
(dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN));
|
|
|
|
mutex_enter(&db->db_mtx);
|
|
/*
|
|
* XXX make this true for indirects too? The problem is that
|
|
* transactions created with dmu_tx_create_assigned() from
|
|
* syncing context don't bother holding ahead.
|
|
*/
|
|
ASSERT(db->db_level != 0 ||
|
|
db->db_state == DB_CACHED || db->db_state == DB_FILL ||
|
|
db->db_state == DB_NOFILL);
|
|
|
|
mutex_enter(&dn->dn_mtx);
|
|
/*
|
|
* Don't set dirtyctx to SYNC if we're just modifying this as we
|
|
* initialize the objset.
|
|
*/
|
|
if (dn->dn_dirtyctx == DN_UNDIRTIED) {
|
|
if (dn->dn_objset->os_dsl_dataset != NULL) {
|
|
rrw_enter(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock,
|
|
RW_READER, FTAG);
|
|
}
|
|
if (!BP_IS_HOLE(dn->dn_objset->os_rootbp)) {
|
|
dn->dn_dirtyctx = (dmu_tx_is_syncing(tx) ?
|
|
DN_DIRTY_SYNC : DN_DIRTY_OPEN);
|
|
ASSERT(dn->dn_dirtyctx_firstset == NULL);
|
|
dn->dn_dirtyctx_firstset = kmem_alloc(1, KM_SLEEP);
|
|
}
|
|
if (dn->dn_objset->os_dsl_dataset != NULL) {
|
|
rrw_exit(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock,
|
|
FTAG);
|
|
}
|
|
}
|
|
mutex_exit(&dn->dn_mtx);
|
|
|
|
if (db->db_blkid == DMU_SPILL_BLKID)
|
|
dn->dn_have_spill = B_TRUE;
|
|
|
|
/*
|
|
* If this buffer is already dirty, we're done.
|
|
*/
|
|
drp = &db->db_last_dirty;
|
|
ASSERT(*drp == NULL || (*drp)->dr_txg <= tx->tx_txg ||
|
|
db->db.db_object == DMU_META_DNODE_OBJECT);
|
|
while ((dr = *drp) != NULL && dr->dr_txg > tx->tx_txg)
|
|
drp = &dr->dr_next;
|
|
if (dr && dr->dr_txg == tx->tx_txg) {
|
|
DB_DNODE_EXIT(db);
|
|
|
|
dbuf_redirty(dr);
|
|
mutex_exit(&db->db_mtx);
|
|
return (dr);
|
|
}
|
|
|
|
/*
|
|
* Only valid if not already dirty.
|
|
*/
|
|
ASSERT(dn->dn_object == 0 ||
|
|
dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx ==
|
|
(dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN));
|
|
|
|
ASSERT3U(dn->dn_nlevels, >, db->db_level);
|
|
ASSERT((dn->dn_phys->dn_nlevels == 0 && db->db_level == 0) ||
|
|
dn->dn_phys->dn_nlevels > db->db_level ||
|
|
dn->dn_next_nlevels[txgoff] > db->db_level ||
|
|
dn->dn_next_nlevels[(tx->tx_txg-1) & TXG_MASK] > db->db_level ||
|
|
dn->dn_next_nlevels[(tx->tx_txg-2) & TXG_MASK] > db->db_level);
|
|
|
|
/*
|
|
* We should only be dirtying in syncing context if it's the
|
|
* mos or we're initializing the os or it's a special object.
|
|
* However, we are allowed to dirty in syncing context provided
|
|
* we already dirtied it in open context. Hence we must make
|
|
* this assertion only if we're not already dirty.
|
|
*/
|
|
os = dn->dn_objset;
|
|
VERIFY3U(tx->tx_txg, <=, spa_final_dirty_txg(os->os_spa));
|
|
#ifdef DEBUG
|
|
if (dn->dn_objset->os_dsl_dataset != NULL)
|
|
rrw_enter(&os->os_dsl_dataset->ds_bp_rwlock, RW_READER, FTAG);
|
|
ASSERT(!dmu_tx_is_syncing(tx) || DMU_OBJECT_IS_SPECIAL(dn->dn_object) ||
|
|
os->os_dsl_dataset == NULL || BP_IS_HOLE(os->os_rootbp));
|
|
if (dn->dn_objset->os_dsl_dataset != NULL)
|
|
rrw_exit(&os->os_dsl_dataset->ds_bp_rwlock, FTAG);
|
|
#endif
|
|
ASSERT(db->db.db_size != 0);
|
|
|
|
dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size);
|
|
|
|
if (db->db_blkid != DMU_BONUS_BLKID) {
|
|
dmu_objset_willuse_space(os, db->db.db_size, tx);
|
|
}
|
|
|
|
/*
|
|
* If this buffer is dirty in an old transaction group we need
|
|
* to make a copy of it so that the changes we make in this
|
|
* transaction group won't leak out when we sync the older txg.
|
|
*/
|
|
dr = kmem_zalloc(sizeof (dbuf_dirty_record_t), KM_SLEEP);
|
|
list_link_init(&dr->dr_dirty_node);
|
|
if (db->db_level == 0) {
|
|
void *data_old = db->db_buf;
|
|
|
|
if (db->db_state != DB_NOFILL) {
|
|
if (db->db_blkid == DMU_BONUS_BLKID) {
|
|
dbuf_fix_old_data(db, tx->tx_txg);
|
|
data_old = db->db.db_data;
|
|
} else if (db->db.db_object != DMU_META_DNODE_OBJECT) {
|
|
/*
|
|
* Release the data buffer from the cache so
|
|
* that we can modify it without impacting
|
|
* possible other users of this cached data
|
|
* block. Note that indirect blocks and
|
|
* private objects are not released until the
|
|
* syncing state (since they are only modified
|
|
* then).
|
|
*/
|
|
arc_release(db->db_buf, db);
|
|
dbuf_fix_old_data(db, tx->tx_txg);
|
|
data_old = db->db_buf;
|
|
}
|
|
ASSERT(data_old != NULL);
|
|
}
|
|
dr->dt.dl.dr_data = data_old;
|
|
} else {
|
|
mutex_init(&dr->dt.di.dr_mtx, NULL, MUTEX_NOLOCKDEP, NULL);
|
|
list_create(&dr->dt.di.dr_children,
|
|
sizeof (dbuf_dirty_record_t),
|
|
offsetof(dbuf_dirty_record_t, dr_dirty_node));
|
|
}
|
|
if (db->db_blkid != DMU_BONUS_BLKID && os->os_dsl_dataset != NULL)
|
|
dr->dr_accounted = db->db.db_size;
|
|
dr->dr_dbuf = db;
|
|
dr->dr_txg = tx->tx_txg;
|
|
dr->dr_next = *drp;
|
|
*drp = dr;
|
|
|
|
/*
|
|
* We could have been freed_in_flight between the dbuf_noread
|
|
* and dbuf_dirty. We win, as though the dbuf_noread() had
|
|
* happened after the free.
|
|
*/
|
|
if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
|
|
db->db_blkid != DMU_SPILL_BLKID) {
|
|
mutex_enter(&dn->dn_mtx);
|
|
if (dn->dn_free_ranges[txgoff] != NULL) {
|
|
range_tree_clear(dn->dn_free_ranges[txgoff],
|
|
db->db_blkid, 1);
|
|
}
|
|
mutex_exit(&dn->dn_mtx);
|
|
db->db_freed_in_flight = FALSE;
|
|
}
|
|
|
|
/*
|
|
* This buffer is now part of this txg
|
|
*/
|
|
dbuf_add_ref(db, (void *)(uintptr_t)tx->tx_txg);
|
|
db->db_dirtycnt += 1;
|
|
ASSERT3U(db->db_dirtycnt, <=, 3);
|
|
|
|
mutex_exit(&db->db_mtx);
|
|
|
|
if (db->db_blkid == DMU_BONUS_BLKID ||
|
|
db->db_blkid == DMU_SPILL_BLKID) {
|
|
mutex_enter(&dn->dn_mtx);
|
|
ASSERT(!list_link_active(&dr->dr_dirty_node));
|
|
list_insert_tail(&dn->dn_dirty_records[txgoff], dr);
|
|
mutex_exit(&dn->dn_mtx);
|
|
dnode_setdirty(dn, tx);
|
|
DB_DNODE_EXIT(db);
|
|
return (dr);
|
|
}
|
|
|
|
/*
|
|
* The dn_struct_rwlock prevents db_blkptr from changing
|
|
* due to a write from syncing context completing
|
|
* while we are running, so we want to acquire it before
|
|
* looking at db_blkptr.
|
|
*/
|
|
if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
|
|
rw_enter(&dn->dn_struct_rwlock, RW_READER);
|
|
drop_struct_lock = TRUE;
|
|
}
|
|
|
|
/*
|
|
* If we are overwriting a dedup BP, then unless it is snapshotted,
|
|
* when we get to syncing context we will need to decrement its
|
|
* refcount in the DDT. Prefetch the relevant DDT block so that
|
|
* syncing context won't have to wait for the i/o.
|
|
*/
|
|
ddt_prefetch(os->os_spa, db->db_blkptr);
|
|
|
|
if (db->db_level == 0) {
|
|
dnode_new_blkid(dn, db->db_blkid, tx, drop_struct_lock);
|
|
ASSERT(dn->dn_maxblkid >= db->db_blkid);
|
|
}
|
|
|
|
if (db->db_level+1 < dn->dn_nlevels) {
|
|
dmu_buf_impl_t *parent = db->db_parent;
|
|
dbuf_dirty_record_t *di;
|
|
int parent_held = FALSE;
|
|
|
|
if (db->db_parent == NULL || db->db_parent == dn->dn_dbuf) {
|
|
int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
|
|
|
|
parent = dbuf_hold_level(dn, db->db_level+1,
|
|
db->db_blkid >> epbs, FTAG);
|
|
ASSERT(parent != NULL);
|
|
parent_held = TRUE;
|
|
}
|
|
if (drop_struct_lock)
|
|
rw_exit(&dn->dn_struct_rwlock);
|
|
ASSERT3U(db->db_level+1, ==, parent->db_level);
|
|
di = dbuf_dirty(parent, tx);
|
|
if (parent_held)
|
|
dbuf_rele(parent, FTAG);
|
|
|
|
mutex_enter(&db->db_mtx);
|
|
/*
|
|
* Since we've dropped the mutex, it's possible that
|
|
* dbuf_undirty() might have changed this out from under us.
|
|
*/
|
|
if (db->db_last_dirty == dr ||
|
|
dn->dn_object == DMU_META_DNODE_OBJECT) {
|
|
mutex_enter(&di->dt.di.dr_mtx);
|
|
ASSERT3U(di->dr_txg, ==, tx->tx_txg);
|
|
ASSERT(!list_link_active(&dr->dr_dirty_node));
|
|
list_insert_tail(&di->dt.di.dr_children, dr);
|
|
mutex_exit(&di->dt.di.dr_mtx);
|
|
dr->dr_parent = di;
|
|
}
|
|
mutex_exit(&db->db_mtx);
|
|
} else {
|
|
ASSERT(db->db_level+1 == dn->dn_nlevels);
|
|
ASSERT(db->db_blkid < dn->dn_nblkptr);
|
|
ASSERT(db->db_parent == NULL || db->db_parent == dn->dn_dbuf);
|
|
mutex_enter(&dn->dn_mtx);
|
|
ASSERT(!list_link_active(&dr->dr_dirty_node));
|
|
list_insert_tail(&dn->dn_dirty_records[txgoff], dr);
|
|
mutex_exit(&dn->dn_mtx);
|
|
if (drop_struct_lock)
|
|
rw_exit(&dn->dn_struct_rwlock);
|
|
}
|
|
|
|
dnode_setdirty(dn, tx);
|
|
DB_DNODE_EXIT(db);
|
|
return (dr);
|
|
}
|
|
|
|
/*
|
|
* Undirty a buffer in the transaction group referenced by the given
|
|
* transaction. Return whether this evicted the dbuf.
|
|
*/
|
|
static boolean_t
|
|
dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
|
|
{
|
|
dnode_t *dn;
|
|
uint64_t txg = tx->tx_txg;
|
|
dbuf_dirty_record_t *dr, **drp;
|
|
|
|
ASSERT(txg != 0);
|
|
|
|
/*
|
|
* Due to our use of dn_nlevels below, this can only be called
|
|
* in open context, unless we are operating on the MOS.
|
|
* From syncing context, dn_nlevels may be different from the
|
|
* dn_nlevels used when dbuf was dirtied.
|
|
*/
|
|
ASSERT(db->db_objset ==
|
|
dmu_objset_pool(db->db_objset)->dp_meta_objset ||
|
|
txg != spa_syncing_txg(dmu_objset_spa(db->db_objset)));
|
|
ASSERT(db->db_blkid != DMU_BONUS_BLKID);
|
|
ASSERT0(db->db_level);
|
|
ASSERT(MUTEX_HELD(&db->db_mtx));
|
|
|
|
/*
|
|
* If this buffer is not dirty, we're done.
|
|
*/
|
|
for (drp = &db->db_last_dirty; (dr = *drp) != NULL; drp = &dr->dr_next)
|
|
if (dr->dr_txg <= txg)
|
|
break;
|
|
if (dr == NULL || dr->dr_txg < txg)
|
|
return (B_FALSE);
|
|
ASSERT(dr->dr_txg == txg);
|
|
ASSERT(dr->dr_dbuf == db);
|
|
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
|
|
dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size);
|
|
|
|
ASSERT(db->db.db_size != 0);
|
|
|
|
dsl_pool_undirty_space(dmu_objset_pool(dn->dn_objset),
|
|
dr->dr_accounted, txg);
|
|
|
|
*drp = dr->dr_next;
|
|
|
|
/*
|
|
* Note that there are three places in dbuf_dirty()
|
|
* where this dirty record may be put on a list.
|
|
* Make sure to do a list_remove corresponding to
|
|
* every one of those list_insert calls.
|
|
*/
|
|
if (dr->dr_parent) {
|
|
mutex_enter(&dr->dr_parent->dt.di.dr_mtx);
|
|
list_remove(&dr->dr_parent->dt.di.dr_children, dr);
|
|
mutex_exit(&dr->dr_parent->dt.di.dr_mtx);
|
|
} else if (db->db_blkid == DMU_SPILL_BLKID ||
|
|
db->db_level + 1 == dn->dn_nlevels) {
|
|
ASSERT(db->db_blkptr == NULL || db->db_parent == dn->dn_dbuf);
|
|
mutex_enter(&dn->dn_mtx);
|
|
list_remove(&dn->dn_dirty_records[txg & TXG_MASK], dr);
|
|
mutex_exit(&dn->dn_mtx);
|
|
}
|
|
DB_DNODE_EXIT(db);
|
|
|
|
if (db->db_state != DB_NOFILL) {
|
|
dbuf_unoverride(dr);
|
|
|
|
ASSERT(db->db_buf != NULL);
|
|
ASSERT(dr->dt.dl.dr_data != NULL);
|
|
if (dr->dt.dl.dr_data != db->db_buf)
|
|
arc_buf_destroy(dr->dt.dl.dr_data, db);
|
|
}
|
|
|
|
kmem_free(dr, sizeof (dbuf_dirty_record_t));
|
|
|
|
ASSERT(db->db_dirtycnt > 0);
|
|
db->db_dirtycnt -= 1;
|
|
|
|
if (refcount_remove(&db->db_holds, (void *)(uintptr_t)txg) == 0) {
|
|
ASSERT(db->db_state == DB_NOFILL || arc_released(db->db_buf));
|
|
dbuf_destroy(db);
|
|
return (B_TRUE);
|
|
}
|
|
|
|
return (B_FALSE);
|
|
}
|
|
|
|
void
|
|
dmu_buf_will_dirty(dmu_buf_t *db_fake, dmu_tx_t *tx)
|
|
{
|
|
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
|
|
int rf = DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH;
|
|
dbuf_dirty_record_t *dr;
|
|
|
|
ASSERT(tx->tx_txg != 0);
|
|
ASSERT(!refcount_is_zero(&db->db_holds));
|
|
|
|
/*
|
|
* Quick check for dirtyness. For already dirty blocks, this
|
|
* reduces runtime of this function by >90%, and overall performance
|
|
* by 50% for some workloads (e.g. file deletion with indirect blocks
|
|
* cached).
|
|
*/
|
|
mutex_enter(&db->db_mtx);
|
|
|
|
for (dr = db->db_last_dirty;
|
|
dr != NULL && dr->dr_txg >= tx->tx_txg; dr = dr->dr_next) {
|
|
/*
|
|
* It's possible that it is already dirty but not cached,
|
|
* because there are some calls to dbuf_dirty() that don't
|
|
* go through dmu_buf_will_dirty().
|
|
*/
|
|
if (dr->dr_txg == tx->tx_txg && db->db_state == DB_CACHED) {
|
|
/* This dbuf is already dirty and cached. */
|
|
dbuf_redirty(dr);
|
|
mutex_exit(&db->db_mtx);
|
|
return;
|
|
}
|
|
}
|
|
mutex_exit(&db->db_mtx);
|
|
|
|
DB_DNODE_ENTER(db);
|
|
if (RW_WRITE_HELD(&DB_DNODE(db)->dn_struct_rwlock))
|
|
rf |= DB_RF_HAVESTRUCT;
|
|
DB_DNODE_EXIT(db);
|
|
(void) dbuf_read(db, NULL, rf);
|
|
(void) dbuf_dirty(db, tx);
|
|
}
|
|
|
|
void
|
|
dmu_buf_will_not_fill(dmu_buf_t *db_fake, dmu_tx_t *tx)
|
|
{
|
|
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
|
|
|
|
db->db_state = DB_NOFILL;
|
|
|
|
dmu_buf_will_fill(db_fake, tx);
|
|
}
|
|
|
|
void
|
|
dmu_buf_will_fill(dmu_buf_t *db_fake, dmu_tx_t *tx)
|
|
{
|
|
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
|
|
|
|
ASSERT(db->db_blkid != DMU_BONUS_BLKID);
|
|
ASSERT(tx->tx_txg != 0);
|
|
ASSERT(db->db_level == 0);
|
|
ASSERT(!refcount_is_zero(&db->db_holds));
|
|
|
|
ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT ||
|
|
dmu_tx_private_ok(tx));
|
|
|
|
dbuf_noread(db);
|
|
(void) dbuf_dirty(db, tx);
|
|
}
|
|
|
|
#pragma weak dmu_buf_fill_done = dbuf_fill_done
|
|
/* ARGSUSED */
|
|
void
|
|
dbuf_fill_done(dmu_buf_impl_t *db, dmu_tx_t *tx)
|
|
{
|
|
mutex_enter(&db->db_mtx);
|
|
DBUF_VERIFY(db);
|
|
|
|
if (db->db_state == DB_FILL) {
|
|
if (db->db_level == 0 && db->db_freed_in_flight) {
|
|
ASSERT(db->db_blkid != DMU_BONUS_BLKID);
|
|
/* we were freed while filling */
|
|
/* XXX dbuf_undirty? */
|
|
bzero(db->db.db_data, db->db.db_size);
|
|
db->db_freed_in_flight = FALSE;
|
|
}
|
|
db->db_state = DB_CACHED;
|
|
cv_broadcast(&db->db_changed);
|
|
}
|
|
mutex_exit(&db->db_mtx);
|
|
}
|
|
|
|
void
|
|
dmu_buf_write_embedded(dmu_buf_t *dbuf, void *data,
|
|
bp_embedded_type_t etype, enum zio_compress comp,
|
|
int uncompressed_size, int compressed_size, int byteorder,
|
|
dmu_tx_t *tx)
|
|
{
|
|
dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf;
|
|
struct dirty_leaf *dl;
|
|
dmu_object_type_t type;
|
|
|
|
if (etype == BP_EMBEDDED_TYPE_DATA) {
|
|
ASSERT(spa_feature_is_active(dmu_objset_spa(db->db_objset),
|
|
SPA_FEATURE_EMBEDDED_DATA));
|
|
}
|
|
|
|
DB_DNODE_ENTER(db);
|
|
type = DB_DNODE(db)->dn_type;
|
|
DB_DNODE_EXIT(db);
|
|
|
|
ASSERT0(db->db_level);
|
|
ASSERT(db->db_blkid != DMU_BONUS_BLKID);
|
|
|
|
dmu_buf_will_not_fill(dbuf, tx);
|
|
|
|
ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg);
|
|
dl = &db->db_last_dirty->dt.dl;
|
|
encode_embedded_bp_compressed(&dl->dr_overridden_by,
|
|
data, comp, uncompressed_size, compressed_size);
|
|
BPE_SET_ETYPE(&dl->dr_overridden_by, etype);
|
|
BP_SET_TYPE(&dl->dr_overridden_by, type);
|
|
BP_SET_LEVEL(&dl->dr_overridden_by, 0);
|
|
BP_SET_BYTEORDER(&dl->dr_overridden_by, byteorder);
|
|
|
|
dl->dr_override_state = DR_OVERRIDDEN;
|
|
dl->dr_overridden_by.blk_birth = db->db_last_dirty->dr_txg;
|
|
}
|
|
|
|
/*
|
|
* Directly assign a provided arc buf to a given dbuf if it's not referenced
|
|
* by anybody except our caller. Otherwise copy arcbuf's contents to dbuf.
|
|
*/
|
|
void
|
|
dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx)
|
|
{
|
|
ASSERT(!refcount_is_zero(&db->db_holds));
|
|
ASSERT(db->db_blkid != DMU_BONUS_BLKID);
|
|
ASSERT(db->db_level == 0);
|
|
ASSERT3U(dbuf_is_metadata(db), ==, arc_is_metadata(buf));
|
|
ASSERT(buf != NULL);
|
|
ASSERT(arc_buf_lsize(buf) == db->db.db_size);
|
|
ASSERT(tx->tx_txg != 0);
|
|
|
|
arc_return_buf(buf, db);
|
|
ASSERT(arc_released(buf));
|
|
|
|
mutex_enter(&db->db_mtx);
|
|
|
|
while (db->db_state == DB_READ || db->db_state == DB_FILL)
|
|
cv_wait(&db->db_changed, &db->db_mtx);
|
|
|
|
ASSERT(db->db_state == DB_CACHED || db->db_state == DB_UNCACHED);
|
|
|
|
if (db->db_state == DB_CACHED &&
|
|
refcount_count(&db->db_holds) - 1 > db->db_dirtycnt) {
|
|
mutex_exit(&db->db_mtx);
|
|
(void) dbuf_dirty(db, tx);
|
|
bcopy(buf->b_data, db->db.db_data, db->db.db_size);
|
|
arc_buf_destroy(buf, db);
|
|
xuio_stat_wbuf_copied();
|
|
return;
|
|
}
|
|
|
|
xuio_stat_wbuf_nocopy();
|
|
if (db->db_state == DB_CACHED) {
|
|
dbuf_dirty_record_t *dr = db->db_last_dirty;
|
|
|
|
ASSERT(db->db_buf != NULL);
|
|
if (dr != NULL && dr->dr_txg == tx->tx_txg) {
|
|
ASSERT(dr->dt.dl.dr_data == db->db_buf);
|
|
if (!arc_released(db->db_buf)) {
|
|
ASSERT(dr->dt.dl.dr_override_state ==
|
|
DR_OVERRIDDEN);
|
|
arc_release(db->db_buf, db);
|
|
}
|
|
dr->dt.dl.dr_data = buf;
|
|
arc_buf_destroy(db->db_buf, db);
|
|
} else if (dr == NULL || dr->dt.dl.dr_data != db->db_buf) {
|
|
arc_release(db->db_buf, db);
|
|
arc_buf_destroy(db->db_buf, db);
|
|
}
|
|
db->db_buf = NULL;
|
|
}
|
|
ASSERT(db->db_buf == NULL);
|
|
dbuf_set_data(db, buf);
|
|
db->db_state = DB_FILL;
|
|
mutex_exit(&db->db_mtx);
|
|
(void) dbuf_dirty(db, tx);
|
|
dmu_buf_fill_done(&db->db, tx);
|
|
}
|
|
|
|
void
|
|
dbuf_destroy(dmu_buf_impl_t *db)
|
|
{
|
|
dnode_t *dn;
|
|
dmu_buf_impl_t *parent = db->db_parent;
|
|
dmu_buf_impl_t *dndb;
|
|
|
|
ASSERT(MUTEX_HELD(&db->db_mtx));
|
|
ASSERT(refcount_is_zero(&db->db_holds));
|
|
|
|
if (db->db_buf != NULL) {
|
|
arc_buf_destroy(db->db_buf, db);
|
|
db->db_buf = NULL;
|
|
}
|
|
|
|
if (db->db_blkid == DMU_BONUS_BLKID) {
|
|
int slots = DB_DNODE(db)->dn_num_slots;
|
|
int bonuslen = DN_SLOTS_TO_BONUSLEN(slots);
|
|
ASSERT(db->db.db_data != NULL);
|
|
kmem_free(db->db.db_data, bonuslen);
|
|
arc_space_return(bonuslen, ARC_SPACE_BONUS);
|
|
db->db_state = DB_UNCACHED;
|
|
}
|
|
|
|
dbuf_clear_data(db);
|
|
|
|
if (multilist_link_active(&db->db_cache_link)) {
|
|
multilist_remove(dbuf_cache, db);
|
|
(void) refcount_remove_many(&dbuf_cache_size,
|
|
db->db.db_size, db);
|
|
}
|
|
|
|
ASSERT(db->db_state == DB_UNCACHED || db->db_state == DB_NOFILL);
|
|
ASSERT(db->db_data_pending == NULL);
|
|
|
|
db->db_state = DB_EVICTING;
|
|
db->db_blkptr = NULL;
|
|
|
|
/*
|
|
* Now that db_state is DB_EVICTING, nobody else can find this via
|
|
* the hash table. We can now drop db_mtx, which allows us to
|
|
* acquire the dn_dbufs_mtx.
|
|
*/
|
|
mutex_exit(&db->db_mtx);
|
|
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
dndb = dn->dn_dbuf;
|
|
if (db->db_blkid != DMU_BONUS_BLKID) {
|
|
boolean_t needlock = !MUTEX_HELD(&dn->dn_dbufs_mtx);
|
|
if (needlock)
|
|
mutex_enter(&dn->dn_dbufs_mtx);
|
|
avl_remove(&dn->dn_dbufs, db);
|
|
atomic_dec_32(&dn->dn_dbufs_count);
|
|
membar_producer();
|
|
DB_DNODE_EXIT(db);
|
|
if (needlock)
|
|
mutex_exit(&dn->dn_dbufs_mtx);
|
|
/*
|
|
* Decrementing the dbuf count means that the hold corresponding
|
|
* to the removed dbuf is no longer discounted in dnode_move(),
|
|
* so the dnode cannot be moved until after we release the hold.
|
|
* The membar_producer() ensures visibility of the decremented
|
|
* value in dnode_move(), since DB_DNODE_EXIT doesn't actually
|
|
* release any lock.
|
|
*/
|
|
dnode_rele(dn, db);
|
|
db->db_dnode_handle = NULL;
|
|
|
|
dbuf_hash_remove(db);
|
|
} else {
|
|
DB_DNODE_EXIT(db);
|
|
}
|
|
|
|
ASSERT(refcount_is_zero(&db->db_holds));
|
|
|
|
db->db_parent = NULL;
|
|
|
|
ASSERT(db->db_buf == NULL);
|
|
ASSERT(db->db.db_data == NULL);
|
|
ASSERT(db->db_hash_next == NULL);
|
|
ASSERT(db->db_blkptr == NULL);
|
|
ASSERT(db->db_data_pending == NULL);
|
|
ASSERT(!multilist_link_active(&db->db_cache_link));
|
|
|
|
kmem_cache_free(dbuf_kmem_cache, db);
|
|
arc_space_return(sizeof (dmu_buf_impl_t), ARC_SPACE_DBUF);
|
|
|
|
/*
|
|
* If this dbuf is referenced from an indirect dbuf,
|
|
* decrement the ref count on the indirect dbuf.
|
|
*/
|
|
if (parent && parent != dndb)
|
|
dbuf_rele(parent, db);
|
|
}
|
|
|
|
/*
|
|
* Note: While bpp will always be updated if the function returns success,
|
|
* parentp will not be updated if the dnode does not have dn_dbuf filled in;
|
|
* this happens when the dnode is the meta-dnode, or a userused or groupused
|
|
* object.
|
|
*/
|
|
__attribute__((always_inline))
|
|
static inline int
|
|
dbuf_findbp(dnode_t *dn, int level, uint64_t blkid, int fail_sparse,
|
|
dmu_buf_impl_t **parentp, blkptr_t **bpp, struct dbuf_hold_impl_data *dh)
|
|
{
|
|
int nlevels, epbs;
|
|
|
|
*parentp = NULL;
|
|
*bpp = NULL;
|
|
|
|
ASSERT(blkid != DMU_BONUS_BLKID);
|
|
|
|
if (blkid == DMU_SPILL_BLKID) {
|
|
mutex_enter(&dn->dn_mtx);
|
|
if (dn->dn_have_spill &&
|
|
(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR))
|
|
*bpp = DN_SPILL_BLKPTR(dn->dn_phys);
|
|
else
|
|
*bpp = NULL;
|
|
dbuf_add_ref(dn->dn_dbuf, NULL);
|
|
*parentp = dn->dn_dbuf;
|
|
mutex_exit(&dn->dn_mtx);
|
|
return (0);
|
|
}
|
|
|
|
nlevels =
|
|
(dn->dn_phys->dn_nlevels == 0) ? 1 : dn->dn_phys->dn_nlevels;
|
|
epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
|
|
|
|
ASSERT3U(level * epbs, <, 64);
|
|
ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
|
|
/*
|
|
* This assertion shouldn't trip as long as the max indirect block size
|
|
* is less than 1M. The reason for this is that up to that point,
|
|
* the number of levels required to address an entire object with blocks
|
|
* of size SPA_MINBLOCKSIZE satisfies nlevels * epbs + 1 <= 64. In
|
|
* other words, if N * epbs + 1 > 64, then if (N-1) * epbs + 1 > 55
|
|
* (i.e. we can address the entire object), objects will all use at most
|
|
* N-1 levels and the assertion won't overflow. However, once epbs is
|
|
* 13, 4 * 13 + 1 = 53, but 5 * 13 + 1 = 66. Then, 4 levels will not be
|
|
* enough to address an entire object, so objects will have 5 levels,
|
|
* but then this assertion will overflow.
|
|
*
|
|
* All this is to say that if we ever increase DN_MAX_INDBLKSHIFT, we
|
|
* need to redo this logic to handle overflows.
|
|
*/
|
|
ASSERT(level >= nlevels ||
|
|
((nlevels - level - 1) * epbs) +
|
|
highbit64(dn->dn_phys->dn_nblkptr) <= 64);
|
|
if (level >= nlevels ||
|
|
blkid >= ((uint64_t)dn->dn_phys->dn_nblkptr <<
|
|
((nlevels - level - 1) * epbs)) ||
|
|
(fail_sparse &&
|
|
blkid > (dn->dn_phys->dn_maxblkid >> (level * epbs)))) {
|
|
/* the buffer has no parent yet */
|
|
return (SET_ERROR(ENOENT));
|
|
} else if (level < nlevels-1) {
|
|
/* this block is referenced from an indirect block */
|
|
int err;
|
|
if (dh == NULL) {
|
|
err = dbuf_hold_impl(dn, level+1,
|
|
blkid >> epbs, fail_sparse, FALSE, NULL, parentp);
|
|
} else {
|
|
__dbuf_hold_impl_init(dh + 1, dn, dh->dh_level + 1,
|
|
blkid >> epbs, fail_sparse, FALSE, NULL,
|
|
parentp, dh->dh_depth + 1);
|
|
err = __dbuf_hold_impl(dh + 1);
|
|
}
|
|
if (err)
|
|
return (err);
|
|
err = dbuf_read(*parentp, NULL,
|
|
(DB_RF_HAVESTRUCT | DB_RF_NOPREFETCH | DB_RF_CANFAIL));
|
|
if (err) {
|
|
dbuf_rele(*parentp, NULL);
|
|
*parentp = NULL;
|
|
return (err);
|
|
}
|
|
*bpp = ((blkptr_t *)(*parentp)->db.db_data) +
|
|
(blkid & ((1ULL << epbs) - 1));
|
|
if (blkid > (dn->dn_phys->dn_maxblkid >> (level * epbs)))
|
|
ASSERT(BP_IS_HOLE(*bpp));
|
|
return (0);
|
|
} else {
|
|
/* the block is referenced from the dnode */
|
|
ASSERT3U(level, ==, nlevels-1);
|
|
ASSERT(dn->dn_phys->dn_nblkptr == 0 ||
|
|
blkid < dn->dn_phys->dn_nblkptr);
|
|
if (dn->dn_dbuf) {
|
|
dbuf_add_ref(dn->dn_dbuf, NULL);
|
|
*parentp = dn->dn_dbuf;
|
|
}
|
|
*bpp = &dn->dn_phys->dn_blkptr[blkid];
|
|
return (0);
|
|
}
|
|
}
|
|
|
|
static dmu_buf_impl_t *
|
|
dbuf_create(dnode_t *dn, uint8_t level, uint64_t blkid,
|
|
dmu_buf_impl_t *parent, blkptr_t *blkptr)
|
|
{
|
|
objset_t *os = dn->dn_objset;
|
|
dmu_buf_impl_t *db, *odb;
|
|
|
|
ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
|
|
ASSERT(dn->dn_type != DMU_OT_NONE);
|
|
|
|
db = kmem_cache_alloc(dbuf_kmem_cache, KM_SLEEP);
|
|
|
|
db->db_objset = os;
|
|
db->db.db_object = dn->dn_object;
|
|
db->db_level = level;
|
|
db->db_blkid = blkid;
|
|
db->db_last_dirty = NULL;
|
|
db->db_dirtycnt = 0;
|
|
db->db_dnode_handle = dn->dn_handle;
|
|
db->db_parent = parent;
|
|
db->db_blkptr = blkptr;
|
|
|
|
db->db_user = NULL;
|
|
db->db_user_immediate_evict = FALSE;
|
|
db->db_freed_in_flight = FALSE;
|
|
db->db_pending_evict = FALSE;
|
|
|
|
if (blkid == DMU_BONUS_BLKID) {
|
|
ASSERT3P(parent, ==, dn->dn_dbuf);
|
|
db->db.db_size = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) -
|
|
(dn->dn_nblkptr-1) * sizeof (blkptr_t);
|
|
ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
|
|
db->db.db_offset = DMU_BONUS_BLKID;
|
|
db->db_state = DB_UNCACHED;
|
|
/* the bonus dbuf is not placed in the hash table */
|
|
arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_DBUF);
|
|
return (db);
|
|
} else if (blkid == DMU_SPILL_BLKID) {
|
|
db->db.db_size = (blkptr != NULL) ?
|
|
BP_GET_LSIZE(blkptr) : SPA_MINBLOCKSIZE;
|
|
db->db.db_offset = 0;
|
|
} else {
|
|
int blocksize =
|
|
db->db_level ? 1 << dn->dn_indblkshift : dn->dn_datablksz;
|
|
db->db.db_size = blocksize;
|
|
db->db.db_offset = db->db_blkid * blocksize;
|
|
}
|
|
|
|
/*
|
|
* Hold the dn_dbufs_mtx while we get the new dbuf
|
|
* in the hash table *and* added to the dbufs list.
|
|
* This prevents a possible deadlock with someone
|
|
* trying to look up this dbuf before its added to the
|
|
* dn_dbufs list.
|
|
*/
|
|
mutex_enter(&dn->dn_dbufs_mtx);
|
|
db->db_state = DB_EVICTING;
|
|
if ((odb = dbuf_hash_insert(db)) != NULL) {
|
|
/* someone else inserted it first */
|
|
kmem_cache_free(dbuf_kmem_cache, db);
|
|
mutex_exit(&dn->dn_dbufs_mtx);
|
|
return (odb);
|
|
}
|
|
avl_add(&dn->dn_dbufs, db);
|
|
|
|
db->db_state = DB_UNCACHED;
|
|
mutex_exit(&dn->dn_dbufs_mtx);
|
|
arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_DBUF);
|
|
|
|
if (parent && parent != dn->dn_dbuf)
|
|
dbuf_add_ref(parent, db);
|
|
|
|
ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT ||
|
|
refcount_count(&dn->dn_holds) > 0);
|
|
(void) refcount_add(&dn->dn_holds, db);
|
|
atomic_inc_32(&dn->dn_dbufs_count);
|
|
|
|
dprintf_dbuf(db, "db=%p\n", db);
|
|
|
|
return (db);
|
|
}
|
|
|
|
typedef struct dbuf_prefetch_arg {
|
|
spa_t *dpa_spa; /* The spa to issue the prefetch in. */
|
|
zbookmark_phys_t dpa_zb; /* The target block to prefetch. */
|
|
int dpa_epbs; /* Entries (blkptr_t's) Per Block Shift. */
|
|
int dpa_curlevel; /* The current level that we're reading */
|
|
dnode_t *dpa_dnode; /* The dnode associated with the prefetch */
|
|
zio_priority_t dpa_prio; /* The priority I/Os should be issued at. */
|
|
zio_t *dpa_zio; /* The parent zio_t for all prefetches. */
|
|
arc_flags_t dpa_aflags; /* Flags to pass to the final prefetch. */
|
|
} dbuf_prefetch_arg_t;
|
|
|
|
/*
|
|
* Actually issue the prefetch read for the block given.
|
|
*/
|
|
static void
|
|
dbuf_issue_final_prefetch(dbuf_prefetch_arg_t *dpa, blkptr_t *bp)
|
|
{
|
|
arc_flags_t aflags;
|
|
if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp))
|
|
return;
|
|
|
|
aflags = dpa->dpa_aflags | ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH;
|
|
|
|
ASSERT3U(dpa->dpa_curlevel, ==, BP_GET_LEVEL(bp));
|
|
ASSERT3U(dpa->dpa_curlevel, ==, dpa->dpa_zb.zb_level);
|
|
ASSERT(dpa->dpa_zio != NULL);
|
|
(void) arc_read(dpa->dpa_zio, dpa->dpa_spa, bp, NULL, NULL,
|
|
dpa->dpa_prio, ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
|
|
&aflags, &dpa->dpa_zb);
|
|
}
|
|
|
|
/*
|
|
* Called when an indirect block above our prefetch target is read in. This
|
|
* will either read in the next indirect block down the tree or issue the actual
|
|
* prefetch if the next block down is our target.
|
|
*/
|
|
static void
|
|
dbuf_prefetch_indirect_done(zio_t *zio, arc_buf_t *abuf, void *private)
|
|
{
|
|
dbuf_prefetch_arg_t *dpa = private;
|
|
uint64_t nextblkid;
|
|
blkptr_t *bp;
|
|
|
|
ASSERT3S(dpa->dpa_zb.zb_level, <, dpa->dpa_curlevel);
|
|
ASSERT3S(dpa->dpa_curlevel, >, 0);
|
|
|
|
/*
|
|
* The dpa_dnode is only valid if we are called with a NULL
|
|
* zio. This indicates that the arc_read() returned without
|
|
* first calling zio_read() to issue a physical read. Once
|
|
* a physical read is made the dpa_dnode must be invalidated
|
|
* as the locks guarding it may have been dropped. If the
|
|
* dpa_dnode is still valid, then we want to add it to the dbuf
|
|
* cache. To do so, we must hold the dbuf associated with the block
|
|
* we just prefetched, read its contents so that we associate it
|
|
* with an arc_buf_t, and then release it.
|
|
*/
|
|
if (zio != NULL) {
|
|
ASSERT3S(BP_GET_LEVEL(zio->io_bp), ==, dpa->dpa_curlevel);
|
|
if (zio->io_flags & ZIO_FLAG_RAW) {
|
|
ASSERT3U(BP_GET_PSIZE(zio->io_bp), ==, zio->io_size);
|
|
} else {
|
|
ASSERT3U(BP_GET_LSIZE(zio->io_bp), ==, zio->io_size);
|
|
}
|
|
ASSERT3P(zio->io_spa, ==, dpa->dpa_spa);
|
|
|
|
dpa->dpa_dnode = NULL;
|
|
} else if (dpa->dpa_dnode != NULL) {
|
|
uint64_t curblkid = dpa->dpa_zb.zb_blkid >>
|
|
(dpa->dpa_epbs * (dpa->dpa_curlevel -
|
|
dpa->dpa_zb.zb_level));
|
|
dmu_buf_impl_t *db = dbuf_hold_level(dpa->dpa_dnode,
|
|
dpa->dpa_curlevel, curblkid, FTAG);
|
|
(void) dbuf_read(db, NULL,
|
|
DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH | DB_RF_HAVESTRUCT);
|
|
dbuf_rele(db, FTAG);
|
|
}
|
|
|
|
dpa->dpa_curlevel--;
|
|
|
|
nextblkid = dpa->dpa_zb.zb_blkid >>
|
|
(dpa->dpa_epbs * (dpa->dpa_curlevel - dpa->dpa_zb.zb_level));
|
|
bp = ((blkptr_t *)abuf->b_data) +
|
|
P2PHASE(nextblkid, 1ULL << dpa->dpa_epbs);
|
|
if (BP_IS_HOLE(bp) || (zio != NULL && zio->io_error != 0)) {
|
|
kmem_free(dpa, sizeof (*dpa));
|
|
} else if (dpa->dpa_curlevel == dpa->dpa_zb.zb_level) {
|
|
ASSERT3U(nextblkid, ==, dpa->dpa_zb.zb_blkid);
|
|
dbuf_issue_final_prefetch(dpa, bp);
|
|
kmem_free(dpa, sizeof (*dpa));
|
|
} else {
|
|
arc_flags_t iter_aflags = ARC_FLAG_NOWAIT;
|
|
zbookmark_phys_t zb;
|
|
|
|
ASSERT3U(dpa->dpa_curlevel, ==, BP_GET_LEVEL(bp));
|
|
|
|
SET_BOOKMARK(&zb, dpa->dpa_zb.zb_objset,
|
|
dpa->dpa_zb.zb_object, dpa->dpa_curlevel, nextblkid);
|
|
|
|
(void) arc_read(dpa->dpa_zio, dpa->dpa_spa,
|
|
bp, dbuf_prefetch_indirect_done, dpa, dpa->dpa_prio,
|
|
ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
|
|
&iter_aflags, &zb);
|
|
}
|
|
|
|
arc_buf_destroy(abuf, private);
|
|
}
|
|
|
|
/*
|
|
* Issue prefetch reads for the given block on the given level. If the indirect
|
|
* blocks above that block are not in memory, we will read them in
|
|
* asynchronously. As a result, this call never blocks waiting for a read to
|
|
* complete.
|
|
*/
|
|
void
|
|
dbuf_prefetch(dnode_t *dn, int64_t level, uint64_t blkid, zio_priority_t prio,
|
|
arc_flags_t aflags)
|
|
{
|
|
blkptr_t bp;
|
|
int epbs, nlevels, curlevel;
|
|
uint64_t curblkid;
|
|
dmu_buf_impl_t *db;
|
|
zio_t *pio;
|
|
dbuf_prefetch_arg_t *dpa;
|
|
dsl_dataset_t *ds;
|
|
|
|
ASSERT(blkid != DMU_BONUS_BLKID);
|
|
ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
|
|
|
|
if (blkid > dn->dn_maxblkid)
|
|
return;
|
|
|
|
if (dnode_block_freed(dn, blkid))
|
|
return;
|
|
|
|
/*
|
|
* This dnode hasn't been written to disk yet, so there's nothing to
|
|
* prefetch.
|
|
*/
|
|
nlevels = dn->dn_phys->dn_nlevels;
|
|
if (level >= nlevels || dn->dn_phys->dn_nblkptr == 0)
|
|
return;
|
|
|
|
epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
|
|
if (dn->dn_phys->dn_maxblkid < blkid << (epbs * level))
|
|
return;
|
|
|
|
db = dbuf_find(dn->dn_objset, dn->dn_object,
|
|
level, blkid);
|
|
if (db != NULL) {
|
|
mutex_exit(&db->db_mtx);
|
|
/*
|
|
* This dbuf already exists. It is either CACHED, or
|
|
* (we assume) about to be read or filled.
|
|
*/
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Find the closest ancestor (indirect block) of the target block
|
|
* that is present in the cache. In this indirect block, we will
|
|
* find the bp that is at curlevel, curblkid.
|
|
*/
|
|
curlevel = level;
|
|
curblkid = blkid;
|
|
while (curlevel < nlevels - 1) {
|
|
int parent_level = curlevel + 1;
|
|
uint64_t parent_blkid = curblkid >> epbs;
|
|
dmu_buf_impl_t *db;
|
|
|
|
if (dbuf_hold_impl(dn, parent_level, parent_blkid,
|
|
FALSE, TRUE, FTAG, &db) == 0) {
|
|
blkptr_t *bpp = db->db_buf->b_data;
|
|
bp = bpp[P2PHASE(curblkid, 1 << epbs)];
|
|
dbuf_rele(db, FTAG);
|
|
break;
|
|
}
|
|
|
|
curlevel = parent_level;
|
|
curblkid = parent_blkid;
|
|
}
|
|
|
|
if (curlevel == nlevels - 1) {
|
|
/* No cached indirect blocks found. */
|
|
ASSERT3U(curblkid, <, dn->dn_phys->dn_nblkptr);
|
|
bp = dn->dn_phys->dn_blkptr[curblkid];
|
|
}
|
|
if (BP_IS_HOLE(&bp))
|
|
return;
|
|
|
|
ASSERT3U(curlevel, ==, BP_GET_LEVEL(&bp));
|
|
|
|
pio = zio_root(dmu_objset_spa(dn->dn_objset), NULL, NULL,
|
|
ZIO_FLAG_CANFAIL);
|
|
|
|
dpa = kmem_zalloc(sizeof (*dpa), KM_SLEEP);
|
|
ds = dn->dn_objset->os_dsl_dataset;
|
|
SET_BOOKMARK(&dpa->dpa_zb, ds != NULL ? ds->ds_object : DMU_META_OBJSET,
|
|
dn->dn_object, level, blkid);
|
|
dpa->dpa_curlevel = curlevel;
|
|
dpa->dpa_prio = prio;
|
|
dpa->dpa_aflags = aflags;
|
|
dpa->dpa_spa = dn->dn_objset->os_spa;
|
|
dpa->dpa_dnode = dn;
|
|
dpa->dpa_epbs = epbs;
|
|
dpa->dpa_zio = pio;
|
|
|
|
/*
|
|
* If we have the indirect just above us, no need to do the asynchronous
|
|
* prefetch chain; we'll just run the last step ourselves. If we're at
|
|
* a higher level, though, we want to issue the prefetches for all the
|
|
* indirect blocks asynchronously, so we can go on with whatever we were
|
|
* doing.
|
|
*/
|
|
if (curlevel == level) {
|
|
ASSERT3U(curblkid, ==, blkid);
|
|
dbuf_issue_final_prefetch(dpa, &bp);
|
|
kmem_free(dpa, sizeof (*dpa));
|
|
} else {
|
|
arc_flags_t iter_aflags = ARC_FLAG_NOWAIT;
|
|
zbookmark_phys_t zb;
|
|
|
|
SET_BOOKMARK(&zb, ds != NULL ? ds->ds_object : DMU_META_OBJSET,
|
|
dn->dn_object, curlevel, curblkid);
|
|
(void) arc_read(dpa->dpa_zio, dpa->dpa_spa,
|
|
&bp, dbuf_prefetch_indirect_done, dpa, prio,
|
|
ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
|
|
&iter_aflags, &zb);
|
|
}
|
|
/*
|
|
* We use pio here instead of dpa_zio since it's possible that
|
|
* dpa may have already been freed.
|
|
*/
|
|
zio_nowait(pio);
|
|
}
|
|
|
|
#define DBUF_HOLD_IMPL_MAX_DEPTH 20
|
|
|
|
/*
|
|
* Returns with db_holds incremented, and db_mtx not held.
|
|
* Note: dn_struct_rwlock must be held.
|
|
*/
|
|
static int
|
|
__dbuf_hold_impl(struct dbuf_hold_impl_data *dh)
|
|
{
|
|
ASSERT3S(dh->dh_depth, <, DBUF_HOLD_IMPL_MAX_DEPTH);
|
|
dh->dh_parent = NULL;
|
|
|
|
ASSERT(dh->dh_blkid != DMU_BONUS_BLKID);
|
|
ASSERT(RW_LOCK_HELD(&dh->dh_dn->dn_struct_rwlock));
|
|
ASSERT3U(dh->dh_dn->dn_nlevels, >, dh->dh_level);
|
|
|
|
*(dh->dh_dbp) = NULL;
|
|
|
|
/* dbuf_find() returns with db_mtx held */
|
|
dh->dh_db = dbuf_find(dh->dh_dn->dn_objset, dh->dh_dn->dn_object,
|
|
dh->dh_level, dh->dh_blkid);
|
|
|
|
if (dh->dh_db == NULL) {
|
|
dh->dh_bp = NULL;
|
|
|
|
if (dh->dh_fail_uncached)
|
|
return (SET_ERROR(ENOENT));
|
|
|
|
ASSERT3P(dh->dh_parent, ==, NULL);
|
|
dh->dh_err = dbuf_findbp(dh->dh_dn, dh->dh_level, dh->dh_blkid,
|
|
dh->dh_fail_sparse, &dh->dh_parent, &dh->dh_bp, dh);
|
|
if (dh->dh_fail_sparse) {
|
|
if (dh->dh_err == 0 &&
|
|
dh->dh_bp && BP_IS_HOLE(dh->dh_bp))
|
|
dh->dh_err = SET_ERROR(ENOENT);
|
|
if (dh->dh_err) {
|
|
if (dh->dh_parent)
|
|
dbuf_rele(dh->dh_parent, NULL);
|
|
return (dh->dh_err);
|
|
}
|
|
}
|
|
if (dh->dh_err && dh->dh_err != ENOENT)
|
|
return (dh->dh_err);
|
|
dh->dh_db = dbuf_create(dh->dh_dn, dh->dh_level, dh->dh_blkid,
|
|
dh->dh_parent, dh->dh_bp);
|
|
}
|
|
|
|
if (dh->dh_fail_uncached && dh->dh_db->db_state != DB_CACHED) {
|
|
mutex_exit(&dh->dh_db->db_mtx);
|
|
return (SET_ERROR(ENOENT));
|
|
}
|
|
|
|
if (dh->dh_db->db_buf != NULL)
|
|
ASSERT3P(dh->dh_db->db.db_data, ==, dh->dh_db->db_buf->b_data);
|
|
|
|
ASSERT(dh->dh_db->db_buf == NULL || arc_referenced(dh->dh_db->db_buf));
|
|
|
|
/*
|
|
* If this buffer is currently syncing out, and we are are
|
|
* still referencing it from db_data, we need to make a copy
|
|
* of it in case we decide we want to dirty it again in this txg.
|
|
*/
|
|
if (dh->dh_db->db_level == 0 &&
|
|
dh->dh_db->db_blkid != DMU_BONUS_BLKID &&
|
|
dh->dh_dn->dn_object != DMU_META_DNODE_OBJECT &&
|
|
dh->dh_db->db_state == DB_CACHED && dh->dh_db->db_data_pending) {
|
|
dh->dh_dr = dh->dh_db->db_data_pending;
|
|
|
|
if (dh->dh_dr->dt.dl.dr_data == dh->dh_db->db_buf) {
|
|
dh->dh_type = DBUF_GET_BUFC_TYPE(dh->dh_db);
|
|
|
|
dbuf_set_data(dh->dh_db,
|
|
arc_alloc_buf(dh->dh_dn->dn_objset->os_spa,
|
|
dh->dh_db, dh->dh_type, dh->dh_db->db.db_size));
|
|
bcopy(dh->dh_dr->dt.dl.dr_data->b_data,
|
|
dh->dh_db->db.db_data, dh->dh_db->db.db_size);
|
|
}
|
|
}
|
|
|
|
if (multilist_link_active(&dh->dh_db->db_cache_link)) {
|
|
ASSERT(refcount_is_zero(&dh->dh_db->db_holds));
|
|
multilist_remove(dbuf_cache, dh->dh_db);
|
|
(void) refcount_remove_many(&dbuf_cache_size,
|
|
dh->dh_db->db.db_size, dh->dh_db);
|
|
}
|
|
(void) refcount_add(&dh->dh_db->db_holds, dh->dh_tag);
|
|
DBUF_VERIFY(dh->dh_db);
|
|
mutex_exit(&dh->dh_db->db_mtx);
|
|
|
|
/* NOTE: we can't rele the parent until after we drop the db_mtx */
|
|
if (dh->dh_parent)
|
|
dbuf_rele(dh->dh_parent, NULL);
|
|
|
|
ASSERT3P(DB_DNODE(dh->dh_db), ==, dh->dh_dn);
|
|
ASSERT3U(dh->dh_db->db_blkid, ==, dh->dh_blkid);
|
|
ASSERT3U(dh->dh_db->db_level, ==, dh->dh_level);
|
|
*(dh->dh_dbp) = dh->dh_db;
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* The following code preserves the recursive function dbuf_hold_impl()
|
|
* but moves the local variables AND function arguments to the heap to
|
|
* minimize the stack frame size. Enough space is initially allocated
|
|
* on the stack for 20 levels of recursion.
|
|
*/
|
|
int
|
|
dbuf_hold_impl(dnode_t *dn, uint8_t level, uint64_t blkid,
|
|
boolean_t fail_sparse, boolean_t fail_uncached,
|
|
void *tag, dmu_buf_impl_t **dbp)
|
|
{
|
|
struct dbuf_hold_impl_data *dh;
|
|
int error;
|
|
|
|
dh = kmem_alloc(sizeof (struct dbuf_hold_impl_data) *
|
|
DBUF_HOLD_IMPL_MAX_DEPTH, KM_SLEEP);
|
|
__dbuf_hold_impl_init(dh, dn, level, blkid, fail_sparse,
|
|
fail_uncached, tag, dbp, 0);
|
|
|
|
error = __dbuf_hold_impl(dh);
|
|
|
|
kmem_free(dh, sizeof (struct dbuf_hold_impl_data) *
|
|
DBUF_HOLD_IMPL_MAX_DEPTH);
|
|
|
|
return (error);
|
|
}
|
|
|
|
static void
|
|
__dbuf_hold_impl_init(struct dbuf_hold_impl_data *dh,
|
|
dnode_t *dn, uint8_t level, uint64_t blkid,
|
|
boolean_t fail_sparse, boolean_t fail_uncached,
|
|
void *tag, dmu_buf_impl_t **dbp, int depth)
|
|
{
|
|
dh->dh_dn = dn;
|
|
dh->dh_level = level;
|
|
dh->dh_blkid = blkid;
|
|
|
|
dh->dh_fail_sparse = fail_sparse;
|
|
dh->dh_fail_uncached = fail_uncached;
|
|
|
|
dh->dh_tag = tag;
|
|
dh->dh_dbp = dbp;
|
|
|
|
dh->dh_db = NULL;
|
|
dh->dh_parent = NULL;
|
|
dh->dh_bp = NULL;
|
|
dh->dh_err = 0;
|
|
dh->dh_dr = NULL;
|
|
dh->dh_type = 0;
|
|
|
|
dh->dh_depth = depth;
|
|
}
|
|
|
|
dmu_buf_impl_t *
|
|
dbuf_hold(dnode_t *dn, uint64_t blkid, void *tag)
|
|
{
|
|
return (dbuf_hold_level(dn, 0, blkid, tag));
|
|
}
|
|
|
|
dmu_buf_impl_t *
|
|
dbuf_hold_level(dnode_t *dn, int level, uint64_t blkid, void *tag)
|
|
{
|
|
dmu_buf_impl_t *db;
|
|
int err = dbuf_hold_impl(dn, level, blkid, FALSE, FALSE, tag, &db);
|
|
return (err ? NULL : db);
|
|
}
|
|
|
|
void
|
|
dbuf_create_bonus(dnode_t *dn)
|
|
{
|
|
ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
|
|
|
|
ASSERT(dn->dn_bonus == NULL);
|
|
dn->dn_bonus = dbuf_create(dn, 0, DMU_BONUS_BLKID, dn->dn_dbuf, NULL);
|
|
}
|
|
|
|
int
|
|
dbuf_spill_set_blksz(dmu_buf_t *db_fake, uint64_t blksz, dmu_tx_t *tx)
|
|
{
|
|
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
|
|
dnode_t *dn;
|
|
|
|
if (db->db_blkid != DMU_SPILL_BLKID)
|
|
return (SET_ERROR(ENOTSUP));
|
|
if (blksz == 0)
|
|
blksz = SPA_MINBLOCKSIZE;
|
|
ASSERT3U(blksz, <=, spa_maxblocksize(dmu_objset_spa(db->db_objset)));
|
|
blksz = P2ROUNDUP(blksz, SPA_MINBLOCKSIZE);
|
|
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
|
|
dbuf_new_size(db, blksz, tx);
|
|
rw_exit(&dn->dn_struct_rwlock);
|
|
DB_DNODE_EXIT(db);
|
|
|
|
return (0);
|
|
}
|
|
|
|
void
|
|
dbuf_rm_spill(dnode_t *dn, dmu_tx_t *tx)
|
|
{
|
|
dbuf_free_range(dn, DMU_SPILL_BLKID, DMU_SPILL_BLKID, tx);
|
|
}
|
|
|
|
#pragma weak dmu_buf_add_ref = dbuf_add_ref
|
|
void
|
|
dbuf_add_ref(dmu_buf_impl_t *db, void *tag)
|
|
{
|
|
int64_t holds = refcount_add(&db->db_holds, tag);
|
|
VERIFY3S(holds, >, 1);
|
|
}
|
|
|
|
#pragma weak dmu_buf_try_add_ref = dbuf_try_add_ref
|
|
boolean_t
|
|
dbuf_try_add_ref(dmu_buf_t *db_fake, objset_t *os, uint64_t obj, uint64_t blkid,
|
|
void *tag)
|
|
{
|
|
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
|
|
dmu_buf_impl_t *found_db;
|
|
boolean_t result = B_FALSE;
|
|
|
|
if (blkid == DMU_BONUS_BLKID)
|
|
found_db = dbuf_find_bonus(os, obj);
|
|
else
|
|
found_db = dbuf_find(os, obj, 0, blkid);
|
|
|
|
if (found_db != NULL) {
|
|
if (db == found_db && dbuf_refcount(db) > db->db_dirtycnt) {
|
|
(void) refcount_add(&db->db_holds, tag);
|
|
result = B_TRUE;
|
|
}
|
|
mutex_exit(&found_db->db_mtx);
|
|
}
|
|
return (result);
|
|
}
|
|
|
|
/*
|
|
* If you call dbuf_rele() you had better not be referencing the dnode handle
|
|
* unless you have some other direct or indirect hold on the dnode. (An indirect
|
|
* hold is a hold on one of the dnode's dbufs, including the bonus buffer.)
|
|
* Without that, the dbuf_rele() could lead to a dnode_rele() followed by the
|
|
* dnode's parent dbuf evicting its dnode handles.
|
|
*/
|
|
void
|
|
dbuf_rele(dmu_buf_impl_t *db, void *tag)
|
|
{
|
|
mutex_enter(&db->db_mtx);
|
|
dbuf_rele_and_unlock(db, tag);
|
|
}
|
|
|
|
void
|
|
dmu_buf_rele(dmu_buf_t *db, void *tag)
|
|
{
|
|
dbuf_rele((dmu_buf_impl_t *)db, tag);
|
|
}
|
|
|
|
/*
|
|
* dbuf_rele() for an already-locked dbuf. This is necessary to allow
|
|
* db_dirtycnt and db_holds to be updated atomically.
|
|
*/
|
|
void
|
|
dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag)
|
|
{
|
|
int64_t holds;
|
|
|
|
ASSERT(MUTEX_HELD(&db->db_mtx));
|
|
DBUF_VERIFY(db);
|
|
|
|
/*
|
|
* Remove the reference to the dbuf before removing its hold on the
|
|
* dnode so we can guarantee in dnode_move() that a referenced bonus
|
|
* buffer has a corresponding dnode hold.
|
|
*/
|
|
holds = refcount_remove(&db->db_holds, tag);
|
|
ASSERT(holds >= 0);
|
|
|
|
/*
|
|
* We can't freeze indirects if there is a possibility that they
|
|
* may be modified in the current syncing context.
|
|
*/
|
|
if (db->db_buf != NULL &&
|
|
holds == (db->db_level == 0 ? db->db_dirtycnt : 0)) {
|
|
arc_buf_freeze(db->db_buf);
|
|
}
|
|
|
|
if (holds == db->db_dirtycnt &&
|
|
db->db_level == 0 && db->db_user_immediate_evict)
|
|
dbuf_evict_user(db);
|
|
|
|
if (holds == 0) {
|
|
if (db->db_blkid == DMU_BONUS_BLKID) {
|
|
dnode_t *dn;
|
|
boolean_t evict_dbuf = db->db_pending_evict;
|
|
|
|
/*
|
|
* If the dnode moves here, we cannot cross this
|
|
* barrier until the move completes.
|
|
*/
|
|
DB_DNODE_ENTER(db);
|
|
|
|
dn = DB_DNODE(db);
|
|
atomic_dec_32(&dn->dn_dbufs_count);
|
|
|
|
/*
|
|
* Decrementing the dbuf count means that the bonus
|
|
* buffer's dnode hold is no longer discounted in
|
|
* dnode_move(). The dnode cannot move until after
|
|
* the dnode_rele() below.
|
|
*/
|
|
DB_DNODE_EXIT(db);
|
|
|
|
/*
|
|
* Do not reference db after its lock is dropped.
|
|
* Another thread may evict it.
|
|
*/
|
|
mutex_exit(&db->db_mtx);
|
|
|
|
if (evict_dbuf)
|
|
dnode_evict_bonus(dn);
|
|
|
|
dnode_rele(dn, db);
|
|
} else if (db->db_buf == NULL) {
|
|
/*
|
|
* This is a special case: we never associated this
|
|
* dbuf with any data allocated from the ARC.
|
|
*/
|
|
ASSERT(db->db_state == DB_UNCACHED ||
|
|
db->db_state == DB_NOFILL);
|
|
dbuf_destroy(db);
|
|
} else if (arc_released(db->db_buf)) {
|
|
/*
|
|
* This dbuf has anonymous data associated with it.
|
|
*/
|
|
dbuf_destroy(db);
|
|
} else {
|
|
boolean_t do_arc_evict = B_FALSE;
|
|
blkptr_t bp;
|
|
spa_t *spa = dmu_objset_spa(db->db_objset);
|
|
|
|
if (!DBUF_IS_CACHEABLE(db) &&
|
|
db->db_blkptr != NULL &&
|
|
!BP_IS_HOLE(db->db_blkptr) &&
|
|
!BP_IS_EMBEDDED(db->db_blkptr)) {
|
|
do_arc_evict = B_TRUE;
|
|
bp = *db->db_blkptr;
|
|
}
|
|
|
|
if (!DBUF_IS_CACHEABLE(db) ||
|
|
db->db_pending_evict) {
|
|
dbuf_destroy(db);
|
|
} else if (!multilist_link_active(&db->db_cache_link)) {
|
|
multilist_insert(dbuf_cache, db);
|
|
(void) refcount_add_many(&dbuf_cache_size,
|
|
db->db.db_size, db);
|
|
mutex_exit(&db->db_mtx);
|
|
|
|
dbuf_evict_notify();
|
|
}
|
|
|
|
if (do_arc_evict)
|
|
arc_freed(spa, &bp);
|
|
}
|
|
} else {
|
|
mutex_exit(&db->db_mtx);
|
|
}
|
|
|
|
}
|
|
|
|
#pragma weak dmu_buf_refcount = dbuf_refcount
|
|
uint64_t
|
|
dbuf_refcount(dmu_buf_impl_t *db)
|
|
{
|
|
return (refcount_count(&db->db_holds));
|
|
}
|
|
|
|
void *
|
|
dmu_buf_replace_user(dmu_buf_t *db_fake, dmu_buf_user_t *old_user,
|
|
dmu_buf_user_t *new_user)
|
|
{
|
|
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
|
|
|
|
mutex_enter(&db->db_mtx);
|
|
dbuf_verify_user(db, DBVU_NOT_EVICTING);
|
|
if (db->db_user == old_user)
|
|
db->db_user = new_user;
|
|
else
|
|
old_user = db->db_user;
|
|
dbuf_verify_user(db, DBVU_NOT_EVICTING);
|
|
mutex_exit(&db->db_mtx);
|
|
|
|
return (old_user);
|
|
}
|
|
|
|
void *
|
|
dmu_buf_set_user(dmu_buf_t *db_fake, dmu_buf_user_t *user)
|
|
{
|
|
return (dmu_buf_replace_user(db_fake, NULL, user));
|
|
}
|
|
|
|
void *
|
|
dmu_buf_set_user_ie(dmu_buf_t *db_fake, dmu_buf_user_t *user)
|
|
{
|
|
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
|
|
|
|
db->db_user_immediate_evict = TRUE;
|
|
return (dmu_buf_set_user(db_fake, user));
|
|
}
|
|
|
|
void *
|
|
dmu_buf_remove_user(dmu_buf_t *db_fake, dmu_buf_user_t *user)
|
|
{
|
|
return (dmu_buf_replace_user(db_fake, user, NULL));
|
|
}
|
|
|
|
void *
|
|
dmu_buf_get_user(dmu_buf_t *db_fake)
|
|
{
|
|
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
|
|
|
|
dbuf_verify_user(db, DBVU_NOT_EVICTING);
|
|
return (db->db_user);
|
|
}
|
|
|
|
void
|
|
dmu_buf_user_evict_wait()
|
|
{
|
|
taskq_wait(dbu_evict_taskq);
|
|
}
|
|
|
|
blkptr_t *
|
|
dmu_buf_get_blkptr(dmu_buf_t *db)
|
|
{
|
|
dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
|
|
return (dbi->db_blkptr);
|
|
}
|
|
|
|
objset_t *
|
|
dmu_buf_get_objset(dmu_buf_t *db)
|
|
{
|
|
dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
|
|
return (dbi->db_objset);
|
|
}
|
|
|
|
dnode_t *
|
|
dmu_buf_dnode_enter(dmu_buf_t *db)
|
|
{
|
|
dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
|
|
DB_DNODE_ENTER(dbi);
|
|
return (DB_DNODE(dbi));
|
|
}
|
|
|
|
void
|
|
dmu_buf_dnode_exit(dmu_buf_t *db)
|
|
{
|
|
dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
|
|
DB_DNODE_EXIT(dbi);
|
|
}
|
|
|
|
static void
|
|
dbuf_check_blkptr(dnode_t *dn, dmu_buf_impl_t *db)
|
|
{
|
|
/* ASSERT(dmu_tx_is_syncing(tx) */
|
|
ASSERT(MUTEX_HELD(&db->db_mtx));
|
|
|
|
if (db->db_blkptr != NULL)
|
|
return;
|
|
|
|
if (db->db_blkid == DMU_SPILL_BLKID) {
|
|
db->db_blkptr = DN_SPILL_BLKPTR(dn->dn_phys);
|
|
BP_ZERO(db->db_blkptr);
|
|
return;
|
|
}
|
|
if (db->db_level == dn->dn_phys->dn_nlevels-1) {
|
|
/*
|
|
* This buffer was allocated at a time when there was
|
|
* no available blkptrs from the dnode, or it was
|
|
* inappropriate to hook it in (i.e., nlevels mis-match).
|
|
*/
|
|
ASSERT(db->db_blkid < dn->dn_phys->dn_nblkptr);
|
|
ASSERT(db->db_parent == NULL);
|
|
db->db_parent = dn->dn_dbuf;
|
|
db->db_blkptr = &dn->dn_phys->dn_blkptr[db->db_blkid];
|
|
DBUF_VERIFY(db);
|
|
} else {
|
|
dmu_buf_impl_t *parent = db->db_parent;
|
|
int epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
|
|
|
|
ASSERT(dn->dn_phys->dn_nlevels > 1);
|
|
if (parent == NULL) {
|
|
mutex_exit(&db->db_mtx);
|
|
rw_enter(&dn->dn_struct_rwlock, RW_READER);
|
|
parent = dbuf_hold_level(dn, db->db_level + 1,
|
|
db->db_blkid >> epbs, db);
|
|
rw_exit(&dn->dn_struct_rwlock);
|
|
mutex_enter(&db->db_mtx);
|
|
db->db_parent = parent;
|
|
}
|
|
db->db_blkptr = (blkptr_t *)parent->db.db_data +
|
|
(db->db_blkid & ((1ULL << epbs) - 1));
|
|
DBUF_VERIFY(db);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* dbuf_sync_indirect() is called recursively from dbuf_sync_list() so it
|
|
* is critical the we not allow the compiler to inline this function in to
|
|
* dbuf_sync_list() thereby drastically bloating the stack usage.
|
|
*/
|
|
noinline static void
|
|
dbuf_sync_indirect(dbuf_dirty_record_t *dr, dmu_tx_t *tx)
|
|
{
|
|
dmu_buf_impl_t *db = dr->dr_dbuf;
|
|
dnode_t *dn;
|
|
zio_t *zio;
|
|
|
|
ASSERT(dmu_tx_is_syncing(tx));
|
|
|
|
dprintf_dbuf_bp(db, db->db_blkptr, "blkptr=%p", db->db_blkptr);
|
|
|
|
mutex_enter(&db->db_mtx);
|
|
|
|
ASSERT(db->db_level > 0);
|
|
DBUF_VERIFY(db);
|
|
|
|
/* Read the block if it hasn't been read yet. */
|
|
if (db->db_buf == NULL) {
|
|
mutex_exit(&db->db_mtx);
|
|
(void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED);
|
|
mutex_enter(&db->db_mtx);
|
|
}
|
|
ASSERT3U(db->db_state, ==, DB_CACHED);
|
|
ASSERT(db->db_buf != NULL);
|
|
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
/* Indirect block size must match what the dnode thinks it is. */
|
|
ASSERT3U(db->db.db_size, ==, 1<<dn->dn_phys->dn_indblkshift);
|
|
dbuf_check_blkptr(dn, db);
|
|
DB_DNODE_EXIT(db);
|
|
|
|
/* Provide the pending dirty record to child dbufs */
|
|
db->db_data_pending = dr;
|
|
|
|
mutex_exit(&db->db_mtx);
|
|
dbuf_write(dr, db->db_buf, tx);
|
|
|
|
zio = dr->dr_zio;
|
|
mutex_enter(&dr->dt.di.dr_mtx);
|
|
dbuf_sync_list(&dr->dt.di.dr_children, db->db_level - 1, tx);
|
|
ASSERT(list_head(&dr->dt.di.dr_children) == NULL);
|
|
mutex_exit(&dr->dt.di.dr_mtx);
|
|
zio_nowait(zio);
|
|
}
|
|
|
|
/*
|
|
* dbuf_sync_leaf() is called recursively from dbuf_sync_list() so it is
|
|
* critical the we not allow the compiler to inline this function in to
|
|
* dbuf_sync_list() thereby drastically bloating the stack usage.
|
|
*/
|
|
noinline static void
|
|
dbuf_sync_leaf(dbuf_dirty_record_t *dr, dmu_tx_t *tx)
|
|
{
|
|
arc_buf_t **datap = &dr->dt.dl.dr_data;
|
|
dmu_buf_impl_t *db = dr->dr_dbuf;
|
|
dnode_t *dn;
|
|
objset_t *os;
|
|
uint64_t txg = tx->tx_txg;
|
|
|
|
ASSERT(dmu_tx_is_syncing(tx));
|
|
|
|
dprintf_dbuf_bp(db, db->db_blkptr, "blkptr=%p", db->db_blkptr);
|
|
|
|
mutex_enter(&db->db_mtx);
|
|
/*
|
|
* To be synced, we must be dirtied. But we
|
|
* might have been freed after the dirty.
|
|
*/
|
|
if (db->db_state == DB_UNCACHED) {
|
|
/* This buffer has been freed since it was dirtied */
|
|
ASSERT(db->db.db_data == NULL);
|
|
} else if (db->db_state == DB_FILL) {
|
|
/* This buffer was freed and is now being re-filled */
|
|
ASSERT(db->db.db_data != dr->dt.dl.dr_data);
|
|
} else {
|
|
ASSERT(db->db_state == DB_CACHED || db->db_state == DB_NOFILL);
|
|
}
|
|
DBUF_VERIFY(db);
|
|
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
|
|
if (db->db_blkid == DMU_SPILL_BLKID) {
|
|
mutex_enter(&dn->dn_mtx);
|
|
if (!(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) {
|
|
/*
|
|
* In the previous transaction group, the bonus buffer
|
|
* was entirely used to store the attributes for the
|
|
* dnode which overrode the dn_spill field. However,
|
|
* when adding more attributes to the file a spill
|
|
* block was required to hold the extra attributes.
|
|
*
|
|
* Make sure to clear the garbage left in the dn_spill
|
|
* field from the previous attributes in the bonus
|
|
* buffer. Otherwise, after writing out the spill
|
|
* block to the new allocated dva, it will free
|
|
* the old block pointed to by the invalid dn_spill.
|
|
*/
|
|
db->db_blkptr = NULL;
|
|
}
|
|
dn->dn_phys->dn_flags |= DNODE_FLAG_SPILL_BLKPTR;
|
|
mutex_exit(&dn->dn_mtx);
|
|
}
|
|
|
|
/*
|
|
* If this is a bonus buffer, simply copy the bonus data into the
|
|
* dnode. It will be written out when the dnode is synced (and it
|
|
* will be synced, since it must have been dirty for dbuf_sync to
|
|
* be called).
|
|
*/
|
|
if (db->db_blkid == DMU_BONUS_BLKID) {
|
|
dbuf_dirty_record_t **drp;
|
|
|
|
ASSERT(*datap != NULL);
|
|
ASSERT0(db->db_level);
|
|
ASSERT3U(dn->dn_phys->dn_bonuslen, <=,
|
|
DN_SLOTS_TO_BONUSLEN(dn->dn_phys->dn_extra_slots + 1));
|
|
bcopy(*datap, DN_BONUS(dn->dn_phys), dn->dn_phys->dn_bonuslen);
|
|
DB_DNODE_EXIT(db);
|
|
|
|
if (*datap != db->db.db_data) {
|
|
int slots = DB_DNODE(db)->dn_num_slots;
|
|
int bonuslen = DN_SLOTS_TO_BONUSLEN(slots);
|
|
kmem_free(*datap, bonuslen);
|
|
arc_space_return(bonuslen, ARC_SPACE_BONUS);
|
|
}
|
|
db->db_data_pending = NULL;
|
|
drp = &db->db_last_dirty;
|
|
while (*drp != dr)
|
|
drp = &(*drp)->dr_next;
|
|
ASSERT(dr->dr_next == NULL);
|
|
ASSERT(dr->dr_dbuf == db);
|
|
*drp = dr->dr_next;
|
|
if (dr->dr_dbuf->db_level != 0) {
|
|
mutex_destroy(&dr->dt.di.dr_mtx);
|
|
list_destroy(&dr->dt.di.dr_children);
|
|
}
|
|
kmem_free(dr, sizeof (dbuf_dirty_record_t));
|
|
ASSERT(db->db_dirtycnt > 0);
|
|
db->db_dirtycnt -= 1;
|
|
dbuf_rele_and_unlock(db, (void *)(uintptr_t)txg);
|
|
return;
|
|
}
|
|
|
|
os = dn->dn_objset;
|
|
|
|
/*
|
|
* This function may have dropped the db_mtx lock allowing a dmu_sync
|
|
* operation to sneak in. As a result, we need to ensure that we
|
|
* don't check the dr_override_state until we have returned from
|
|
* dbuf_check_blkptr.
|
|
*/
|
|
dbuf_check_blkptr(dn, db);
|
|
|
|
/*
|
|
* If this buffer is in the middle of an immediate write,
|
|
* wait for the synchronous IO to complete.
|
|
*/
|
|
while (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC) {
|
|
ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
|
|
cv_wait(&db->db_changed, &db->db_mtx);
|
|
ASSERT(dr->dt.dl.dr_override_state != DR_NOT_OVERRIDDEN);
|
|
}
|
|
|
|
if (db->db_state != DB_NOFILL &&
|
|
dn->dn_object != DMU_META_DNODE_OBJECT &&
|
|
refcount_count(&db->db_holds) > 1 &&
|
|
dr->dt.dl.dr_override_state != DR_OVERRIDDEN &&
|
|
*datap == db->db_buf) {
|
|
/*
|
|
* If this buffer is currently "in use" (i.e., there
|
|
* are active holds and db_data still references it),
|
|
* then make a copy before we start the write so that
|
|
* any modifications from the open txg will not leak
|
|
* into this write.
|
|
*
|
|
* NOTE: this copy does not need to be made for
|
|
* objects only modified in the syncing context (e.g.
|
|
* DNONE_DNODE blocks).
|
|
*/
|
|
int psize = arc_buf_size(*datap);
|
|
arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
|
|
enum zio_compress compress_type = arc_get_compression(*datap);
|
|
|
|
if (compress_type == ZIO_COMPRESS_OFF) {
|
|
*datap = arc_alloc_buf(os->os_spa, db, type, psize);
|
|
} else {
|
|
int lsize = arc_buf_lsize(*datap);
|
|
ASSERT3U(type, ==, ARC_BUFC_DATA);
|
|
*datap = arc_alloc_compressed_buf(os->os_spa, db,
|
|
psize, lsize, compress_type);
|
|
}
|
|
bcopy(db->db.db_data, (*datap)->b_data, psize);
|
|
}
|
|
db->db_data_pending = dr;
|
|
|
|
mutex_exit(&db->db_mtx);
|
|
|
|
dbuf_write(dr, *datap, tx);
|
|
|
|
ASSERT(!list_link_active(&dr->dr_dirty_node));
|
|
if (dn->dn_object == DMU_META_DNODE_OBJECT) {
|
|
list_insert_tail(&dn->dn_dirty_records[txg&TXG_MASK], dr);
|
|
DB_DNODE_EXIT(db);
|
|
} else {
|
|
/*
|
|
* Although zio_nowait() does not "wait for an IO", it does
|
|
* initiate the IO. If this is an empty write it seems plausible
|
|
* that the IO could actually be completed before the nowait
|
|
* returns. We need to DB_DNODE_EXIT() first in case
|
|
* zio_nowait() invalidates the dbuf.
|
|
*/
|
|
DB_DNODE_EXIT(db);
|
|
zio_nowait(dr->dr_zio);
|
|
}
|
|
}
|
|
|
|
void
|
|
dbuf_sync_list(list_t *list, int level, dmu_tx_t *tx)
|
|
{
|
|
dbuf_dirty_record_t *dr;
|
|
|
|
while ((dr = list_head(list))) {
|
|
if (dr->dr_zio != NULL) {
|
|
/*
|
|
* If we find an already initialized zio then we
|
|
* are processing the meta-dnode, and we have finished.
|
|
* The dbufs for all dnodes are put back on the list
|
|
* during processing, so that we can zio_wait()
|
|
* these IOs after initiating all child IOs.
|
|
*/
|
|
ASSERT3U(dr->dr_dbuf->db.db_object, ==,
|
|
DMU_META_DNODE_OBJECT);
|
|
break;
|
|
}
|
|
if (dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
|
|
dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) {
|
|
VERIFY3U(dr->dr_dbuf->db_level, ==, level);
|
|
}
|
|
list_remove(list, dr);
|
|
if (dr->dr_dbuf->db_level > 0)
|
|
dbuf_sync_indirect(dr, tx);
|
|
else
|
|
dbuf_sync_leaf(dr, tx);
|
|
}
|
|
}
|
|
|
|
/* ARGSUSED */
|
|
static void
|
|
dbuf_write_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
|
|
{
|
|
dmu_buf_impl_t *db = vdb;
|
|
dnode_t *dn;
|
|
blkptr_t *bp = zio->io_bp;
|
|
blkptr_t *bp_orig = &zio->io_bp_orig;
|
|
spa_t *spa = zio->io_spa;
|
|
int64_t delta;
|
|
uint64_t fill = 0;
|
|
int i;
|
|
|
|
ASSERT3P(db->db_blkptr, !=, NULL);
|
|
ASSERT3P(&db->db_data_pending->dr_bp_copy, ==, bp);
|
|
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
delta = bp_get_dsize_sync(spa, bp) - bp_get_dsize_sync(spa, bp_orig);
|
|
dnode_diduse_space(dn, delta - zio->io_prev_space_delta);
|
|
zio->io_prev_space_delta = delta;
|
|
|
|
if (bp->blk_birth != 0) {
|
|
ASSERT((db->db_blkid != DMU_SPILL_BLKID &&
|
|
BP_GET_TYPE(bp) == dn->dn_type) ||
|
|
(db->db_blkid == DMU_SPILL_BLKID &&
|
|
BP_GET_TYPE(bp) == dn->dn_bonustype) ||
|
|
BP_IS_EMBEDDED(bp));
|
|
ASSERT(BP_GET_LEVEL(bp) == db->db_level);
|
|
}
|
|
|
|
mutex_enter(&db->db_mtx);
|
|
|
|
#ifdef ZFS_DEBUG
|
|
if (db->db_blkid == DMU_SPILL_BLKID) {
|
|
ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR);
|
|
ASSERT(!(BP_IS_HOLE(bp)) &&
|
|
db->db_blkptr == DN_SPILL_BLKPTR(dn->dn_phys));
|
|
}
|
|
#endif
|
|
|
|
if (db->db_level == 0) {
|
|
mutex_enter(&dn->dn_mtx);
|
|
if (db->db_blkid > dn->dn_phys->dn_maxblkid &&
|
|
db->db_blkid != DMU_SPILL_BLKID)
|
|
dn->dn_phys->dn_maxblkid = db->db_blkid;
|
|
mutex_exit(&dn->dn_mtx);
|
|
|
|
if (dn->dn_type == DMU_OT_DNODE) {
|
|
i = 0;
|
|
while (i < db->db.db_size) {
|
|
dnode_phys_t *dnp = db->db.db_data + i;
|
|
|
|
i += DNODE_MIN_SIZE;
|
|
if (dnp->dn_type != DMU_OT_NONE) {
|
|
fill++;
|
|
i += dnp->dn_extra_slots *
|
|
DNODE_MIN_SIZE;
|
|
}
|
|
}
|
|
} else {
|
|
if (BP_IS_HOLE(bp)) {
|
|
fill = 0;
|
|
} else {
|
|
fill = 1;
|
|
}
|
|
}
|
|
} else {
|
|
blkptr_t *ibp = db->db.db_data;
|
|
ASSERT3U(db->db.db_size, ==, 1<<dn->dn_phys->dn_indblkshift);
|
|
for (i = db->db.db_size >> SPA_BLKPTRSHIFT; i > 0; i--, ibp++) {
|
|
if (BP_IS_HOLE(ibp))
|
|
continue;
|
|
fill += BP_GET_FILL(ibp);
|
|
}
|
|
}
|
|
DB_DNODE_EXIT(db);
|
|
|
|
if (!BP_IS_EMBEDDED(bp))
|
|
bp->blk_fill = fill;
|
|
|
|
mutex_exit(&db->db_mtx);
|
|
|
|
rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
|
|
*db->db_blkptr = *bp;
|
|
rw_exit(&dn->dn_struct_rwlock);
|
|
}
|
|
|
|
/* ARGSUSED */
|
|
/*
|
|
* This function gets called just prior to running through the compression
|
|
* stage of the zio pipeline. If we're an indirect block comprised of only
|
|
* holes, then we want this indirect to be compressed away to a hole. In
|
|
* order to do that we must zero out any information about the holes that
|
|
* this indirect points to prior to before we try to compress it.
|
|
*/
|
|
static void
|
|
dbuf_write_children_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
|
|
{
|
|
dmu_buf_impl_t *db = vdb;
|
|
dnode_t *dn;
|
|
blkptr_t *bp;
|
|
unsigned int epbs, i;
|
|
|
|
ASSERT3U(db->db_level, >, 0);
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
|
|
ASSERT3U(epbs, <, 31);
|
|
|
|
/* Determine if all our children are holes */
|
|
for (i = 0, bp = db->db.db_data; i < 1ULL << epbs; i++, bp++) {
|
|
if (!BP_IS_HOLE(bp))
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If all the children are holes, then zero them all out so that
|
|
* we may get compressed away.
|
|
*/
|
|
if (i == 1ULL << epbs) {
|
|
/*
|
|
* We only found holes. Grab the rwlock to prevent
|
|
* anybody from reading the blocks we're about to
|
|
* zero out.
|
|
*/
|
|
rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
|
|
bzero(db->db.db_data, db->db.db_size);
|
|
rw_exit(&dn->dn_struct_rwlock);
|
|
}
|
|
DB_DNODE_EXIT(db);
|
|
}
|
|
|
|
/*
|
|
* The SPA will call this callback several times for each zio - once
|
|
* for every physical child i/o (zio->io_phys_children times). This
|
|
* allows the DMU to monitor the progress of each logical i/o. For example,
|
|
* there may be 2 copies of an indirect block, or many fragments of a RAID-Z
|
|
* block. There may be a long delay before all copies/fragments are completed,
|
|
* so this callback allows us to retire dirty space gradually, as the physical
|
|
* i/os complete.
|
|
*/
|
|
/* ARGSUSED */
|
|
static void
|
|
dbuf_write_physdone(zio_t *zio, arc_buf_t *buf, void *arg)
|
|
{
|
|
dmu_buf_impl_t *db = arg;
|
|
objset_t *os = db->db_objset;
|
|
dsl_pool_t *dp = dmu_objset_pool(os);
|
|
dbuf_dirty_record_t *dr;
|
|
int delta = 0;
|
|
|
|
dr = db->db_data_pending;
|
|
ASSERT3U(dr->dr_txg, ==, zio->io_txg);
|
|
|
|
/*
|
|
* The callback will be called io_phys_children times. Retire one
|
|
* portion of our dirty space each time we are called. Any rounding
|
|
* error will be cleaned up by dsl_pool_sync()'s call to
|
|
* dsl_pool_undirty_space().
|
|
*/
|
|
delta = dr->dr_accounted / zio->io_phys_children;
|
|
dsl_pool_undirty_space(dp, delta, zio->io_txg);
|
|
}
|
|
|
|
/* ARGSUSED */
|
|
static void
|
|
dbuf_write_done(zio_t *zio, arc_buf_t *buf, void *vdb)
|
|
{
|
|
dmu_buf_impl_t *db = vdb;
|
|
blkptr_t *bp_orig = &zio->io_bp_orig;
|
|
blkptr_t *bp = db->db_blkptr;
|
|
objset_t *os = db->db_objset;
|
|
dmu_tx_t *tx = os->os_synctx;
|
|
dbuf_dirty_record_t **drp, *dr;
|
|
|
|
ASSERT0(zio->io_error);
|
|
ASSERT(db->db_blkptr == bp);
|
|
|
|
/*
|
|
* For nopwrites and rewrites we ensure that the bp matches our
|
|
* original and bypass all the accounting.
|
|
*/
|
|
if (zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE)) {
|
|
ASSERT(BP_EQUAL(bp, bp_orig));
|
|
} else {
|
|
dsl_dataset_t *ds = os->os_dsl_dataset;
|
|
(void) dsl_dataset_block_kill(ds, bp_orig, tx, B_TRUE);
|
|
dsl_dataset_block_born(ds, bp, tx);
|
|
}
|
|
|
|
mutex_enter(&db->db_mtx);
|
|
|
|
DBUF_VERIFY(db);
|
|
|
|
drp = &db->db_last_dirty;
|
|
while ((dr = *drp) != db->db_data_pending)
|
|
drp = &dr->dr_next;
|
|
ASSERT(!list_link_active(&dr->dr_dirty_node));
|
|
ASSERT(dr->dr_dbuf == db);
|
|
ASSERT(dr->dr_next == NULL);
|
|
*drp = dr->dr_next;
|
|
|
|
#ifdef ZFS_DEBUG
|
|
if (db->db_blkid == DMU_SPILL_BLKID) {
|
|
dnode_t *dn;
|
|
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR);
|
|
ASSERT(!(BP_IS_HOLE(db->db_blkptr)) &&
|
|
db->db_blkptr == DN_SPILL_BLKPTR(dn->dn_phys));
|
|
DB_DNODE_EXIT(db);
|
|
}
|
|
#endif
|
|
|
|
if (db->db_level == 0) {
|
|
ASSERT(db->db_blkid != DMU_BONUS_BLKID);
|
|
ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
|
|
if (db->db_state != DB_NOFILL) {
|
|
if (dr->dt.dl.dr_data != db->db_buf)
|
|
arc_buf_destroy(dr->dt.dl.dr_data, db);
|
|
}
|
|
} else {
|
|
dnode_t *dn;
|
|
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
ASSERT(list_head(&dr->dt.di.dr_children) == NULL);
|
|
ASSERT3U(db->db.db_size, ==, 1 << dn->dn_phys->dn_indblkshift);
|
|
if (!BP_IS_HOLE(db->db_blkptr)) {
|
|
ASSERTV(int epbs = dn->dn_phys->dn_indblkshift -
|
|
SPA_BLKPTRSHIFT);
|
|
ASSERT3U(db->db_blkid, <=,
|
|
dn->dn_phys->dn_maxblkid >> (db->db_level * epbs));
|
|
ASSERT3U(BP_GET_LSIZE(db->db_blkptr), ==,
|
|
db->db.db_size);
|
|
}
|
|
DB_DNODE_EXIT(db);
|
|
mutex_destroy(&dr->dt.di.dr_mtx);
|
|
list_destroy(&dr->dt.di.dr_children);
|
|
}
|
|
kmem_free(dr, sizeof (dbuf_dirty_record_t));
|
|
|
|
cv_broadcast(&db->db_changed);
|
|
ASSERT(db->db_dirtycnt > 0);
|
|
db->db_dirtycnt -= 1;
|
|
db->db_data_pending = NULL;
|
|
dbuf_rele_and_unlock(db, (void *)(uintptr_t)tx->tx_txg);
|
|
}
|
|
|
|
static void
|
|
dbuf_write_nofill_ready(zio_t *zio)
|
|
{
|
|
dbuf_write_ready(zio, NULL, zio->io_private);
|
|
}
|
|
|
|
static void
|
|
dbuf_write_nofill_done(zio_t *zio)
|
|
{
|
|
dbuf_write_done(zio, NULL, zio->io_private);
|
|
}
|
|
|
|
static void
|
|
dbuf_write_override_ready(zio_t *zio)
|
|
{
|
|
dbuf_dirty_record_t *dr = zio->io_private;
|
|
dmu_buf_impl_t *db = dr->dr_dbuf;
|
|
|
|
dbuf_write_ready(zio, NULL, db);
|
|
}
|
|
|
|
static void
|
|
dbuf_write_override_done(zio_t *zio)
|
|
{
|
|
dbuf_dirty_record_t *dr = zio->io_private;
|
|
dmu_buf_impl_t *db = dr->dr_dbuf;
|
|
blkptr_t *obp = &dr->dt.dl.dr_overridden_by;
|
|
|
|
mutex_enter(&db->db_mtx);
|
|
if (!BP_EQUAL(zio->io_bp, obp)) {
|
|
if (!BP_IS_HOLE(obp))
|
|
dsl_free(spa_get_dsl(zio->io_spa), zio->io_txg, obp);
|
|
arc_release(dr->dt.dl.dr_data, db);
|
|
}
|
|
mutex_exit(&db->db_mtx);
|
|
|
|
dbuf_write_done(zio, NULL, db);
|
|
|
|
if (zio->io_abd != NULL)
|
|
abd_put(zio->io_abd);
|
|
}
|
|
|
|
/* Issue I/O to commit a dirty buffer to disk. */
|
|
static void
|
|
dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx)
|
|
{
|
|
dmu_buf_impl_t *db = dr->dr_dbuf;
|
|
dnode_t *dn;
|
|
objset_t *os;
|
|
dmu_buf_impl_t *parent = db->db_parent;
|
|
uint64_t txg = tx->tx_txg;
|
|
zbookmark_phys_t zb;
|
|
zio_prop_t zp;
|
|
zio_t *zio;
|
|
int wp_flag = 0;
|
|
|
|
ASSERT(dmu_tx_is_syncing(tx));
|
|
|
|
DB_DNODE_ENTER(db);
|
|
dn = DB_DNODE(db);
|
|
os = dn->dn_objset;
|
|
|
|
if (db->db_state != DB_NOFILL) {
|
|
if (db->db_level > 0 || dn->dn_type == DMU_OT_DNODE) {
|
|
/*
|
|
* Private object buffers are released here rather
|
|
* than in dbuf_dirty() since they are only modified
|
|
* in the syncing context and we don't want the
|
|
* overhead of making multiple copies of the data.
|
|
*/
|
|
if (BP_IS_HOLE(db->db_blkptr)) {
|
|
arc_buf_thaw(data);
|
|
} else {
|
|
dbuf_release_bp(db);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (parent != dn->dn_dbuf) {
|
|
/* Our parent is an indirect block. */
|
|
/* We have a dirty parent that has been scheduled for write. */
|
|
ASSERT(parent && parent->db_data_pending);
|
|
/* Our parent's buffer is one level closer to the dnode. */
|
|
ASSERT(db->db_level == parent->db_level-1);
|
|
/*
|
|
* We're about to modify our parent's db_data by modifying
|
|
* our block pointer, so the parent must be released.
|
|
*/
|
|
ASSERT(arc_released(parent->db_buf));
|
|
zio = parent->db_data_pending->dr_zio;
|
|
} else {
|
|
/* Our parent is the dnode itself. */
|
|
ASSERT((db->db_level == dn->dn_phys->dn_nlevels-1 &&
|
|
db->db_blkid != DMU_SPILL_BLKID) ||
|
|
(db->db_blkid == DMU_SPILL_BLKID && db->db_level == 0));
|
|
if (db->db_blkid != DMU_SPILL_BLKID)
|
|
ASSERT3P(db->db_blkptr, ==,
|
|
&dn->dn_phys->dn_blkptr[db->db_blkid]);
|
|
zio = dn->dn_zio;
|
|
}
|
|
|
|
ASSERT(db->db_level == 0 || data == db->db_buf);
|
|
ASSERT3U(db->db_blkptr->blk_birth, <=, txg);
|
|
ASSERT(zio);
|
|
|
|
SET_BOOKMARK(&zb, os->os_dsl_dataset ?
|
|
os->os_dsl_dataset->ds_object : DMU_META_OBJSET,
|
|
db->db.db_object, db->db_level, db->db_blkid);
|
|
|
|
if (db->db_blkid == DMU_SPILL_BLKID)
|
|
wp_flag = WP_SPILL;
|
|
wp_flag |= (db->db_state == DB_NOFILL) ? WP_NOFILL : 0;
|
|
|
|
dmu_write_policy(os, dn, db->db_level, wp_flag,
|
|
(data != NULL && arc_get_compression(data) != ZIO_COMPRESS_OFF) ?
|
|
arc_get_compression(data) : ZIO_COMPRESS_INHERIT, &zp);
|
|
DB_DNODE_EXIT(db);
|
|
|
|
/*
|
|
* We copy the blkptr now (rather than when we instantiate the dirty
|
|
* record), because its value can change between open context and
|
|
* syncing context. We do not need to hold dn_struct_rwlock to read
|
|
* db_blkptr because we are in syncing context.
|
|
*/
|
|
dr->dr_bp_copy = *db->db_blkptr;
|
|
|
|
if (db->db_level == 0 &&
|
|
dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
|
|
/*
|
|
* The BP for this block has been provided by open context
|
|
* (by dmu_sync() or dmu_buf_write_embedded()).
|
|
*/
|
|
abd_t *contents = (data != NULL) ?
|
|
abd_get_from_buf(data->b_data, arc_buf_size(data)) : NULL;
|
|
|
|
dr->dr_zio = zio_write(zio, os->os_spa, txg,
|
|
&dr->dr_bp_copy, contents, db->db.db_size, db->db.db_size,
|
|
&zp, dbuf_write_override_ready, NULL, NULL,
|
|
dbuf_write_override_done,
|
|
dr, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb);
|
|
mutex_enter(&db->db_mtx);
|
|
dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
|
|
zio_write_override(dr->dr_zio, &dr->dt.dl.dr_overridden_by,
|
|
dr->dt.dl.dr_copies, dr->dt.dl.dr_nopwrite);
|
|
mutex_exit(&db->db_mtx);
|
|
} else if (db->db_state == DB_NOFILL) {
|
|
ASSERT(zp.zp_checksum == ZIO_CHECKSUM_OFF ||
|
|
zp.zp_checksum == ZIO_CHECKSUM_NOPARITY);
|
|
dr->dr_zio = zio_write(zio, os->os_spa, txg,
|
|
&dr->dr_bp_copy, NULL, db->db.db_size, db->db.db_size, &zp,
|
|
dbuf_write_nofill_ready, NULL, NULL,
|
|
dbuf_write_nofill_done, db,
|
|
ZIO_PRIORITY_ASYNC_WRITE,
|
|
ZIO_FLAG_MUSTSUCCEED | ZIO_FLAG_NODATA, &zb);
|
|
} else {
|
|
arc_done_func_t *children_ready_cb = NULL;
|
|
ASSERT(arc_released(data));
|
|
|
|
/*
|
|
* For indirect blocks, we want to setup the children
|
|
* ready callback so that we can properly handle an indirect
|
|
* block that only contains holes.
|
|
*/
|
|
if (db->db_level != 0)
|
|
children_ready_cb = dbuf_write_children_ready;
|
|
|
|
dr->dr_zio = arc_write(zio, os->os_spa, txg,
|
|
&dr->dr_bp_copy, data, DBUF_IS_L2CACHEABLE(db),
|
|
&zp, dbuf_write_ready,
|
|
children_ready_cb, dbuf_write_physdone,
|
|
dbuf_write_done, db, ZIO_PRIORITY_ASYNC_WRITE,
|
|
ZIO_FLAG_MUSTSUCCEED, &zb);
|
|
}
|
|
}
|
|
|
|
#if defined(_KERNEL) && defined(HAVE_SPL)
|
|
EXPORT_SYMBOL(dbuf_find);
|
|
EXPORT_SYMBOL(dbuf_is_metadata);
|
|
EXPORT_SYMBOL(dbuf_destroy);
|
|
EXPORT_SYMBOL(dbuf_loan_arcbuf);
|
|
EXPORT_SYMBOL(dbuf_whichblock);
|
|
EXPORT_SYMBOL(dbuf_read);
|
|
EXPORT_SYMBOL(dbuf_unoverride);
|
|
EXPORT_SYMBOL(dbuf_free_range);
|
|
EXPORT_SYMBOL(dbuf_new_size);
|
|
EXPORT_SYMBOL(dbuf_release_bp);
|
|
EXPORT_SYMBOL(dbuf_dirty);
|
|
EXPORT_SYMBOL(dmu_buf_will_dirty);
|
|
EXPORT_SYMBOL(dmu_buf_will_not_fill);
|
|
EXPORT_SYMBOL(dmu_buf_will_fill);
|
|
EXPORT_SYMBOL(dmu_buf_fill_done);
|
|
EXPORT_SYMBOL(dmu_buf_rele);
|
|
EXPORT_SYMBOL(dbuf_assign_arcbuf);
|
|
EXPORT_SYMBOL(dbuf_prefetch);
|
|
EXPORT_SYMBOL(dbuf_hold_impl);
|
|
EXPORT_SYMBOL(dbuf_hold);
|
|
EXPORT_SYMBOL(dbuf_hold_level);
|
|
EXPORT_SYMBOL(dbuf_create_bonus);
|
|
EXPORT_SYMBOL(dbuf_spill_set_blksz);
|
|
EXPORT_SYMBOL(dbuf_rm_spill);
|
|
EXPORT_SYMBOL(dbuf_add_ref);
|
|
EXPORT_SYMBOL(dbuf_rele);
|
|
EXPORT_SYMBOL(dbuf_rele_and_unlock);
|
|
EXPORT_SYMBOL(dbuf_refcount);
|
|
EXPORT_SYMBOL(dbuf_sync_list);
|
|
EXPORT_SYMBOL(dmu_buf_set_user);
|
|
EXPORT_SYMBOL(dmu_buf_set_user_ie);
|
|
EXPORT_SYMBOL(dmu_buf_get_user);
|
|
EXPORT_SYMBOL(dmu_buf_get_blkptr);
|
|
|
|
/* BEGIN CSTYLED */
|
|
module_param(dbuf_cache_max_bytes, ulong, 0644);
|
|
MODULE_PARM_DESC(dbuf_cache_max_bytes,
|
|
"Maximum size in bytes of the dbuf cache.");
|
|
|
|
module_param(dbuf_cache_hiwater_pct, uint, 0644);
|
|
MODULE_PARM_DESC(dbuf_cache_hiwater_pct,
|
|
"Percentage over dbuf_cache_max_bytes when dbufs must be evicted "
|
|
"directly.");
|
|
|
|
module_param(dbuf_cache_lowater_pct, uint, 0644);
|
|
MODULE_PARM_DESC(dbuf_cache_lowater_pct,
|
|
"Percentage below dbuf_cache_max_bytes when the evict thread stops "
|
|
"evicting dbufs.");
|
|
|
|
module_param(dbuf_cache_max_shift, int, 0644);
|
|
MODULE_PARM_DESC(dbuf_cache_max_shift,
|
|
"Cap the size of the dbuf cache to a log2 fraction of arc size.");
|
|
/* END CSTYLED */
|
|
#endif
|