1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#ifndef	_SYS_DNODE_H
27#define	_SYS_DNODE_H
28
29#include <sys/zfs_context.h>
30#include <sys/avl.h>
31#include <sys/spa.h>
32#include <sys/txg.h>
33#include <sys/zio.h>
34#include <sys/refcount.h>
35#include <sys/dmu_zfetch.h>
36
37#ifdef	__cplusplus
38extern "C" {
39#endif
40
41/*
42 * dnode_hold() flags.
43 */
44#define	DNODE_MUST_BE_ALLOCATED	1
45#define	DNODE_MUST_BE_FREE	2
46
47/*
48 * dnode_next_offset() flags.
49 */
50#define	DNODE_FIND_HOLE		1
51#define	DNODE_FIND_BACKWARDS	2
52#define	DNODE_FIND_HAVELOCK	4
53
54/*
55 * Fixed constants.
56 */
57#define	DNODE_SHIFT		9	/* 512 bytes */
58#define	DN_MIN_INDBLKSHIFT	10	/* 1k */
59#define	DN_MAX_INDBLKSHIFT	14	/* 16k */
60#define	DNODE_BLOCK_SHIFT	14	/* 16k */
61#define	DNODE_CORE_SIZE		64	/* 64 bytes for dnode sans blkptrs */
62#define	DN_MAX_OBJECT_SHIFT	48	/* 256 trillion (zfs_fid_t limit) */
63#define	DN_MAX_OFFSET_SHIFT	64	/* 2^64 bytes in a dnode */
64
65/*
66 * Derived constants.
67 */
68#define	DNODE_SIZE	(1 << DNODE_SHIFT)
69#define	DN_MAX_NBLKPTR	((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
70#define	DN_MAX_BONUSLEN	(DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT))
71#define	DN_MAX_OBJECT	(1ULL << DN_MAX_OBJECT_SHIFT)
72#define	DN_ZERO_BONUSLEN	(DN_MAX_BONUSLEN + 1)
73
74#define	DNODES_PER_BLOCK_SHIFT	(DNODE_BLOCK_SHIFT - DNODE_SHIFT)
75#define	DNODES_PER_BLOCK	(1ULL << DNODES_PER_BLOCK_SHIFT)
76#define	DNODES_PER_LEVEL_SHIFT	(DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
77#define	DNODES_PER_LEVEL	(1ULL << DNODES_PER_LEVEL_SHIFT)
78
79/* The +2 here is a cheesy way to round up */
80#define	DN_MAX_LEVELS	(2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \
81	(DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))
82
83#define	DN_BONUS(dnp)	((void*)((dnp)->dn_bonus + \
84	(((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))
85
86#define	DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \
87	(dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT)
88
89#define	EPB(blkshift, typeshift)	(1 << (blkshift - typeshift))
90
91struct dmu_buf_impl;
92struct objset;
93struct zio;
94
95enum dnode_dirtycontext {
96	DN_UNDIRTIED,
97	DN_DIRTY_OPEN,
98	DN_DIRTY_SYNC
99};
100
101/* Is dn_used in bytes?  if not, it's in multiples of SPA_MINBLOCKSIZE */
102#define	DNODE_FLAG_USED_BYTES		(1<<0)
103#define	DNODE_FLAG_USERUSED_ACCOUNTED	(1<<1)
104
105typedef struct dnode_phys {
106	uint8_t dn_type;		/* dmu_object_type_t */
107	uint8_t dn_indblkshift;		/* ln2(indirect block size) */
108	uint8_t dn_nlevels;		/* 1=dn_blkptr->data blocks */
109	uint8_t dn_nblkptr;		/* length of dn_blkptr */
110	uint8_t dn_bonustype;		/* type of data in bonus buffer */
111	uint8_t	dn_checksum;		/* ZIO_CHECKSUM type */
112	uint8_t	dn_compress;		/* ZIO_COMPRESS type */
113	uint8_t dn_flags;		/* DNODE_FLAG_* */
114	uint16_t dn_datablkszsec;	/* data block size in 512b sectors */
115	uint16_t dn_bonuslen;		/* length of dn_bonus */
116	uint8_t dn_pad2[4];
117
118	/* accounting is protected by dn_dirty_mtx */
119	uint64_t dn_maxblkid;		/* largest allocated block ID */
120	uint64_t dn_used;		/* bytes (or sectors) of disk space */
121
122	uint64_t dn_pad3[4];
123
124	blkptr_t dn_blkptr[1];
125	uint8_t dn_bonus[DN_MAX_BONUSLEN];
126} dnode_phys_t;
127
128typedef struct dnode {
129	/*
130	 * dn_struct_rwlock protects the structure of the dnode,
131	 * including the number of levels of indirection (dn_nlevels),
132	 * dn_maxblkid, and dn_next_*
133	 */
134	krwlock_t dn_struct_rwlock;
135
136	/* Our link on dn_objset->os_dnodes list; protected by os_lock.  */
137	list_node_t dn_link;
138
139	/* immutable: */
140	struct objset *dn_objset;
141	uint64_t dn_object;
142	struct dmu_buf_impl *dn_dbuf;
143	dnode_phys_t *dn_phys; /* pointer into dn->dn_dbuf->db.db_data */
144
145	/*
146	 * Copies of stuff in dn_phys.  They're valid in the open
147	 * context (eg. even before the dnode is first synced).
148	 * Where necessary, these are protected by dn_struct_rwlock.
149	 */
150	dmu_object_type_t dn_type;	/* object type */
151	uint16_t dn_bonuslen;		/* bonus length */
152	uint8_t dn_bonustype;		/* bonus type */
153	uint8_t dn_nblkptr;		/* number of blkptrs (immutable) */
154	uint8_t dn_checksum;		/* ZIO_CHECKSUM type */
155	uint8_t dn_compress;		/* ZIO_COMPRESS type */
156	uint8_t dn_nlevels;
157	uint8_t dn_indblkshift;
158	uint8_t dn_datablkshift;	/* zero if blksz not power of 2! */
159	uint16_t dn_datablkszsec;	/* in 512b sectors */
160	uint32_t dn_datablksz;		/* in bytes */
161	uint64_t dn_maxblkid;
162	uint8_t dn_next_nblkptr[TXG_SIZE];
163	uint8_t dn_next_nlevels[TXG_SIZE];
164	uint8_t dn_next_indblkshift[TXG_SIZE];
165	uint16_t dn_next_bonuslen[TXG_SIZE];
166	uint32_t dn_next_blksz[TXG_SIZE];	/* next block size in bytes */
167
168	/* protected by os_lock: */
169	list_node_t dn_dirty_link[TXG_SIZE];	/* next on dataset's dirty */
170
171	/* protected by dn_mtx: */
172	kmutex_t dn_mtx;
173	list_t dn_dirty_records[TXG_SIZE];
174	avl_tree_t dn_ranges[TXG_SIZE];
175	uint64_t dn_allocated_txg;
176	uint64_t dn_free_txg;
177	uint64_t dn_assigned_txg;
178	kcondvar_t dn_notxholds;
179	enum dnode_dirtycontext dn_dirtyctx;
180	uint8_t *dn_dirtyctx_firstset;		/* dbg: contents meaningless */
181
182	/* protected by own devices */
183	refcount_t dn_tx_holds;
184	refcount_t dn_holds;
185
186	kmutex_t dn_dbufs_mtx;
187	list_t dn_dbufs;		/* linked list of descendent dbuf_t's */
188	struct dmu_buf_impl *dn_bonus;	/* bonus buffer dbuf */
189
190	/* parent IO for current sync write */
191	zio_t *dn_zio;
192
193	/* used in syncing context */
194	dnode_phys_t *dn_oldphys;
195
196	/* holds prefetch structure */
197	struct zfetch	dn_zfetch;
198} dnode_t;
199
200typedef struct free_range {
201	avl_node_t fr_node;
202	uint64_t fr_blkid;
203	uint64_t fr_nblks;
204} free_range_t;
205
206dnode_t *dnode_special_open(struct objset *dd, dnode_phys_t *dnp,
207    uint64_t object);
208void dnode_special_close(dnode_t *dn);
209
210void dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx);
211int dnode_hold(struct objset *dd, uint64_t object,
212    void *ref, dnode_t **dnp);
213int dnode_hold_impl(struct objset *dd, uint64_t object, int flag,
214    void *ref, dnode_t **dnp);
215boolean_t dnode_add_ref(dnode_t *dn, void *ref);
216void dnode_rele(dnode_t *dn, void *ref);
217void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx);
218void dnode_sync(dnode_t *dn, dmu_tx_t *tx);
219void dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
220    dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
221void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
222    dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
223void dnode_free(dnode_t *dn, dmu_tx_t *tx);
224void dnode_byteswap(dnode_phys_t *dnp);
225void dnode_buf_byteswap(void *buf, size_t size);
226void dnode_verify(dnode_t *dn);
227int dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx);
228uint64_t dnode_current_max_length(dnode_t *dn);
229void dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx);
230void dnode_clear_range(dnode_t *dn, uint64_t blkid,
231    uint64_t nblks, dmu_tx_t *tx);
232void dnode_diduse_space(dnode_t *dn, int64_t space);
233void dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx);
234void dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t);
235uint64_t dnode_block_freed(dnode_t *dn, uint64_t blkid);
236void dnode_init(void);
237void dnode_fini(void);
238int dnode_next_offset(dnode_t *dn, int flags, uint64_t *off,
239    int minlvl, uint64_t blkfill, uint64_t txg);
240void dnode_evict_dbufs(dnode_t *dn);
241
242#ifdef ZFS_DEBUG
243
244/*
245 * There should be a ## between the string literal and fmt, to make it
246 * clear that we're joining two strings together, but that piece of shit
247 * gcc doesn't support that preprocessor token.
248 */
249#define	dprintf_dnode(dn, fmt, ...) do { \
250	if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
251	char __db_buf[32]; \
252	uint64_t __db_obj = (dn)->dn_object; \
253	if (__db_obj == DMU_META_DNODE_OBJECT) \
254		(void) strcpy(__db_buf, "mdn"); \
255	else \
256		(void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \
257		    (u_longlong_t)__db_obj);\
258	dprintf_ds((dn)->dn_objset->os_dsl_dataset, "obj=%s " fmt, \
259	    __db_buf, __VA_ARGS__); \
260	} \
261_NOTE(CONSTCOND) } while (0)
262
263#define	DNODE_VERIFY(dn)		dnode_verify(dn)
264#define	FREE_VERIFY(db, start, end, tx)	free_verify(db, start, end, tx)
265
266#else
267
268#define	dprintf_dnode(db, fmt, ...)
269#define	DNODE_VERIFY(dn)
270#define	FREE_VERIFY(db, start, end, tx)
271
272#endif
273
274#ifdef	__cplusplus
275}
276#endif
277
278#endif	/* _SYS_DNODE_H */
279