xref: /titanic_52/usr/src/uts/common/fs/zfs/sys/dnode.h (revision af3025fd013117424096c94bd9e116ecc538cc6b)
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 2007 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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 #include <sys/zfs_context.h>
32 #include <sys/avl.h>
33 #include <sys/spa.h>
34 #include <sys/txg.h>
35 #include <sys/zio.h>
36 #include <sys/refcount.h>
37 #include <sys/dmu_zfetch.h>
38 
39 #ifdef	__cplusplus
40 extern "C" {
41 #endif
42 
43 /*
44  * Flags.
45  */
46 #define	DNODE_MUST_BE_ALLOCATED	1
47 #define	DNODE_MUST_BE_FREE	2
48 
49 /*
50  * Fixed constants.
51  */
52 #define	DNODE_SHIFT		9	/* 512 bytes */
53 #define	DN_MIN_INDBLKSHIFT	10	/* 1k */
54 #define	DN_MAX_INDBLKSHIFT	14	/* 16k */
55 #define	DNODE_BLOCK_SHIFT	14	/* 16k */
56 #define	DNODE_CORE_SIZE		64	/* 64 bytes for dnode sans blkptrs */
57 #define	DN_MAX_OBJECT_SHIFT	48	/* 256 trillion (zfs_fid_t limit) */
58 #define	DN_MAX_OFFSET_SHIFT	64	/* 2^64 bytes in a dnode */
59 
60 /*
61  * Derived constants.
62  */
63 #define	DNODE_SIZE	(1 << DNODE_SHIFT)
64 #define	DN_MAX_NBLKPTR	((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
65 #define	DN_MAX_BONUSLEN	(DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT))
66 #define	DN_MAX_OBJECT	(1ULL << DN_MAX_OBJECT_SHIFT)
67 
68 #define	DNODES_PER_BLOCK_SHIFT	(DNODE_BLOCK_SHIFT - DNODE_SHIFT)
69 #define	DNODES_PER_BLOCK	(1ULL << DNODES_PER_BLOCK_SHIFT)
70 #define	DNODES_PER_LEVEL_SHIFT	(DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
71 
72 /* The +2 here is a cheesy way to round up */
73 #define	DN_MAX_LEVELS	(2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \
74 	(DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))
75 
76 #define	DN_BONUS(dnp)	((void*)((dnp)->dn_bonus + \
77 	(((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))
78 
79 #define	DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \
80 	(dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT)
81 
82 #define	EPB(blkshift, typeshift)	(1 << (blkshift - typeshift))
83 
84 struct dmu_buf_impl;
85 struct objset_impl;
86 struct zio;
87 
88 enum dnode_dirtycontext {
89 	DN_UNDIRTIED,
90 	DN_DIRTY_OPEN,
91 	DN_DIRTY_SYNC
92 };
93 
94 /* Is dn_used in bytes?  if not, it's in multiples of SPA_MINBLOCKSIZE */
95 #define	DNODE_FLAG_USED_BYTES	(1<<0)
96 
97 typedef struct dnode_phys {
98 	uint8_t dn_type;		/* dmu_object_type_t */
99 	uint8_t dn_indblkshift;		/* ln2(indirect block size) */
100 	uint8_t dn_nlevels;		/* 1=dn_blkptr->data blocks */
101 	uint8_t dn_nblkptr;		/* length of dn_blkptr */
102 	uint8_t dn_bonustype;		/* type of data in bonus buffer */
103 	uint8_t	dn_checksum;		/* ZIO_CHECKSUM type */
104 	uint8_t	dn_compress;		/* ZIO_COMPRESS type */
105 	uint8_t dn_flags;		/* DNODE_FLAG_* */
106 	uint16_t dn_datablkszsec;	/* data block size in 512b sectors */
107 	uint16_t dn_bonuslen;		/* length of dn_bonus */
108 	uint8_t dn_pad2[4];
109 
110 	/* accounting is protected by dn_dirty_mtx */
111 	uint64_t dn_maxblkid;		/* largest allocated block ID */
112 	uint64_t dn_used;		/* bytes (or sectors) of disk space */
113 
114 	uint64_t dn_pad3[4];
115 
116 	blkptr_t dn_blkptr[1];
117 	uint8_t dn_bonus[DN_MAX_BONUSLEN];
118 } dnode_phys_t;
119 
120 typedef struct dnode {
121 	/*
122 	 * dn_struct_rwlock protects the structure of the dnode,
123 	 * including the number of levels of indirection (dn_nlevels),
124 	 * dn_maxblkid, and dn_next_*
125 	 */
126 	krwlock_t dn_struct_rwlock;
127 
128 	/*
129 	 * Our link on dataset's dd_dnodes list.
130 	 * Protected by dd_accounting_mtx.
131 	 */
132 	list_node_t dn_link;
133 
134 	/* immutable: */
135 	struct objset_impl *dn_objset;
136 	uint64_t dn_object;
137 	struct dmu_buf_impl *dn_dbuf;
138 	dnode_phys_t *dn_phys; /* pointer into dn->dn_dbuf->db.db_data */
139 
140 	/*
141 	 * Copies of stuff in dn_phys.  They're valid in the open
142 	 * context (eg. even before the dnode is first synced).
143 	 * Where necessary, these are protected by dn_struct_rwlock.
144 	 */
145 	dmu_object_type_t dn_type;	/* object type */
146 	uint16_t dn_bonuslen;		/* bonus length */
147 	uint8_t dn_bonustype;		/* bonus type */
148 	uint8_t dn_nblkptr;		/* number of blkptrs (immutable) */
149 	uint8_t dn_checksum;		/* ZIO_CHECKSUM type */
150 	uint8_t dn_compress;		/* ZIO_COMPRESS type */
151 	uint8_t dn_nlevels;
152 	uint8_t dn_indblkshift;
153 	uint8_t dn_datablkshift;	/* zero if blksz not power of 2! */
154 	uint16_t dn_datablkszsec;	/* in 512b sectors */
155 	uint32_t dn_datablksz;		/* in bytes */
156 	uint64_t dn_maxblkid;
157 	uint8_t dn_next_nlevels[TXG_SIZE];
158 	uint8_t dn_next_indblkshift[TXG_SIZE];
159 	uint32_t dn_next_blksz[TXG_SIZE];	/* next block size in bytes */
160 
161 	/* protected by os_lock: */
162 	list_node_t dn_dirty_link[TXG_SIZE];	/* next on dataset's dirty */
163 
164 	/* protected by dn_mtx: */
165 	kmutex_t dn_mtx;
166 	list_t dn_dirty_records[TXG_SIZE];
167 	avl_tree_t dn_ranges[TXG_SIZE];
168 	uint64_t dn_allocated_txg;
169 	uint64_t dn_free_txg;
170 	uint64_t dn_assigned_txg;
171 	kcondvar_t dn_notxholds;
172 	enum dnode_dirtycontext dn_dirtyctx;
173 	uint8_t *dn_dirtyctx_firstset;		/* dbg: contents meaningless */
174 
175 	/* protected by own devices */
176 	refcount_t dn_tx_holds;
177 	refcount_t dn_holds;
178 
179 	kmutex_t dn_dbufs_mtx;
180 	list_t dn_dbufs;		/* linked list of descendent dbuf_t's */
181 	struct dmu_buf_impl *dn_bonus;	/* bonus buffer dbuf */
182 
183 	/* parent IO for current sync write */
184 	zio_t *dn_zio;
185 
186 	/* holds prefetch structure */
187 	struct zfetch	dn_zfetch;
188 } dnode_t;
189 
190 typedef struct free_range {
191 	avl_node_t fr_node;
192 	uint64_t fr_blkid;
193 	uint64_t fr_nblks;
194 } free_range_t;
195 
196 dnode_t *dnode_special_open(struct objset_impl *dd, dnode_phys_t *dnp,
197     uint64_t object);
198 void dnode_special_close(dnode_t *dn);
199 
200 int dnode_hold(struct objset_impl *dd, uint64_t object,
201     void *ref, dnode_t **dnp);
202 int dnode_hold_impl(struct objset_impl *dd, uint64_t object, int flag,
203     void *ref, dnode_t **dnp);
204 void dnode_add_ref(dnode_t *dn, void *ref);
205 void dnode_rele(dnode_t *dn, void *ref);
206 void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx);
207 void dnode_sync(dnode_t *dn, dmu_tx_t *tx);
208 void dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
209     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
210 void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
211     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
212 void dnode_free(dnode_t *dn, dmu_tx_t *tx);
213 void dnode_byteswap(dnode_phys_t *dnp);
214 void dnode_buf_byteswap(void *buf, size_t size);
215 void dnode_verify(dnode_t *dn);
216 int dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx);
217 uint64_t dnode_current_max_length(dnode_t *dn);
218 void dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx);
219 void dnode_clear_range(dnode_t *dn, uint64_t blkid,
220     uint64_t nblks, dmu_tx_t *tx);
221 void dnode_diduse_space(dnode_t *dn, int64_t space);
222 void dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx);
223 void dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx);
224 uint64_t dnode_block_freed(dnode_t *dn, uint64_t blkid);
225 void dnode_init(void);
226 void dnode_fini(void);
227 int dnode_next_offset(dnode_t *dn, boolean_t hole, uint64_t *off, int minlvl,
228     uint64_t blkfill, uint64_t txg);
229 int dnode_evict_dbufs(dnode_t *dn, boolean_t try);
230 
231 #ifdef ZFS_DEBUG
232 
233 /*
234  * There should be a ## between the string literal and fmt, to make it
235  * clear that we're joining two strings together, but that piece of shit
236  * gcc doesn't support that preprocessor token.
237  */
238 #define	dprintf_dnode(dn, fmt, ...) do { \
239 	if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
240 	char __db_buf[32]; \
241 	uint64_t __db_obj = (dn)->dn_object; \
242 	if (__db_obj == DMU_META_DNODE_OBJECT) \
243 		(void) strcpy(__db_buf, "mdn"); \
244 	else \
245 		(void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \
246 		    (u_longlong_t)__db_obj);\
247 	dprintf_ds((dn)->dn_objset->os_dsl_dataset, "obj=%s " fmt, \
248 	    __db_buf, __VA_ARGS__); \
249 	} \
250 _NOTE(CONSTCOND) } while (0)
251 
252 #define	DNODE_VERIFY(dn)		dnode_verify(dn)
253 #define	FREE_VERIFY(db, start, end, tx)	free_verify(db, start, end, tx)
254 
255 #else
256 
257 #define	dprintf_dnode(db, fmt, ...)
258 #define	DNODE_VERIFY(dn)
259 #define	FREE_VERIFY(db, start, end, tx)
260 
261 #endif
262 
263 #ifdef	__cplusplus
264 }
265 #endif
266 
267 #endif	/* _SYS_DNODE_H */
268