xref: /titanic_44/usr/src/uts/common/fs/zfs/sys/dnode.h (revision 45405cce0657d01714b3d014a0facf3bdce45736)
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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
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 #include <sys/zrlock.h>
37 
38 #ifdef	__cplusplus
39 extern "C" {
40 #endif
41 
42 /*
43  * dnode_hold() flags.
44  */
45 #define	DNODE_MUST_BE_ALLOCATED	1
46 #define	DNODE_MUST_BE_FREE	2
47 
48 /*
49  * dnode_next_offset() flags.
50  */
51 #define	DNODE_FIND_HOLE		1
52 #define	DNODE_FIND_BACKWARDS	2
53 #define	DNODE_FIND_HAVELOCK	4
54 
55 /*
56  * Fixed constants.
57  */
58 #define	DNODE_SHIFT		9	/* 512 bytes */
59 #define	DN_MIN_INDBLKSHIFT	12	/* 4k */
60 #define	DN_MAX_INDBLKSHIFT	14	/* 16k */
61 #define	DNODE_BLOCK_SHIFT	14	/* 16k */
62 #define	DNODE_CORE_SIZE		64	/* 64 bytes for dnode sans blkptrs */
63 #define	DN_MAX_OBJECT_SHIFT	48	/* 256 trillion (zfs_fid_t limit) */
64 #define	DN_MAX_OFFSET_SHIFT	64	/* 2^64 bytes in a dnode */
65 
66 /*
67  * dnode id flags
68  *
69  * Note: a file will never ever have its
70  * ids moved from bonus->spill
71  * and only in a crypto environment would it be on spill
72  */
73 #define	DN_ID_CHKED_BONUS	0x1
74 #define	DN_ID_CHKED_SPILL	0x2
75 #define	DN_ID_OLD_EXIST		0x4
76 #define	DN_ID_NEW_EXIST		0x8
77 
78 /*
79  * Derived constants.
80  */
81 #define	DNODE_SIZE	(1 << DNODE_SHIFT)
82 #define	DN_MAX_NBLKPTR	((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
83 #define	DN_MAX_BONUSLEN	(DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT))
84 #define	DN_MAX_OBJECT	(1ULL << DN_MAX_OBJECT_SHIFT)
85 #define	DN_ZERO_BONUSLEN	(DN_MAX_BONUSLEN + 1)
86 #define	DN_KILL_SPILLBLK (1)
87 
88 #define	DNODES_PER_BLOCK_SHIFT	(DNODE_BLOCK_SHIFT - DNODE_SHIFT)
89 #define	DNODES_PER_BLOCK	(1ULL << DNODES_PER_BLOCK_SHIFT)
90 #define	DNODES_PER_LEVEL_SHIFT	(DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
91 #define	DNODES_PER_LEVEL	(1ULL << DNODES_PER_LEVEL_SHIFT)
92 
93 /* The +2 here is a cheesy way to round up */
94 #define	DN_MAX_LEVELS	(2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \
95 	(DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))
96 
97 #define	DN_BONUS(dnp)	((void*)((dnp)->dn_bonus + \
98 	(((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))
99 
100 #define	DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \
101 	(dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT)
102 
103 #define	EPB(blkshift, typeshift)	(1 << (blkshift - typeshift))
104 
105 struct dmu_buf_impl;
106 struct objset;
107 struct zio;
108 
109 enum dnode_dirtycontext {
110 	DN_UNDIRTIED,
111 	DN_DIRTY_OPEN,
112 	DN_DIRTY_SYNC
113 };
114 
115 /* Is dn_used in bytes?  if not, it's in multiples of SPA_MINBLOCKSIZE */
116 #define	DNODE_FLAG_USED_BYTES		(1<<0)
117 #define	DNODE_FLAG_USERUSED_ACCOUNTED	(1<<1)
118 
119 /* Does dnode have a SA spill blkptr in bonus? */
120 #define	DNODE_FLAG_SPILL_BLKPTR	(1<<2)
121 
122 typedef struct dnode_phys {
123 	uint8_t dn_type;		/* dmu_object_type_t */
124 	uint8_t dn_indblkshift;		/* ln2(indirect block size) */
125 	uint8_t dn_nlevels;		/* 1=dn_blkptr->data blocks */
126 	uint8_t dn_nblkptr;		/* length of dn_blkptr */
127 	uint8_t dn_bonustype;		/* type of data in bonus buffer */
128 	uint8_t	dn_checksum;		/* ZIO_CHECKSUM type */
129 	uint8_t	dn_compress;		/* ZIO_COMPRESS type */
130 	uint8_t dn_flags;		/* DNODE_FLAG_* */
131 	uint16_t dn_datablkszsec;	/* data block size in 512b sectors */
132 	uint16_t dn_bonuslen;		/* length of dn_bonus */
133 	uint8_t dn_pad2[4];
134 
135 	/* accounting is protected by dn_dirty_mtx */
136 	uint64_t dn_maxblkid;		/* largest allocated block ID */
137 	uint64_t dn_used;		/* bytes (or sectors) of disk space */
138 
139 	uint64_t dn_pad3[4];
140 
141 	blkptr_t dn_blkptr[1];
142 	uint8_t dn_bonus[DN_MAX_BONUSLEN - sizeof (blkptr_t)];
143 	blkptr_t dn_spill;
144 } dnode_phys_t;
145 
146 typedef struct dnode {
147 	/*
148 	 * Protects the structure of the dnode, including the number of levels
149 	 * of indirection (dn_nlevels), dn_maxblkid, and dn_next_*
150 	 */
151 	krwlock_t dn_struct_rwlock;
152 
153 	/* Our link on dn_objset->os_dnodes list; protected by os_lock.  */
154 	list_node_t dn_link;
155 
156 	/* immutable: */
157 	struct objset *dn_objset;
158 	uint64_t dn_object;
159 	struct dmu_buf_impl *dn_dbuf;
160 	struct dnode_handle *dn_handle;
161 	dnode_phys_t *dn_phys; /* pointer into dn->dn_dbuf->db.db_data */
162 
163 	/*
164 	 * Copies of stuff in dn_phys.  They're valid in the open
165 	 * context (eg. even before the dnode is first synced).
166 	 * Where necessary, these are protected by dn_struct_rwlock.
167 	 */
168 	dmu_object_type_t dn_type;	/* object type */
169 	uint16_t dn_bonuslen;		/* bonus length */
170 	uint8_t dn_bonustype;		/* bonus type */
171 	uint8_t dn_nblkptr;		/* number of blkptrs (immutable) */
172 	uint8_t dn_checksum;		/* ZIO_CHECKSUM type */
173 	uint8_t dn_compress;		/* ZIO_COMPRESS type */
174 	uint8_t dn_nlevels;
175 	uint8_t dn_indblkshift;
176 	uint8_t dn_datablkshift;	/* zero if blksz not power of 2! */
177 	uint8_t dn_moved;		/* Has this dnode been moved? */
178 	uint16_t dn_datablkszsec;	/* in 512b sectors */
179 	uint32_t dn_datablksz;		/* in bytes */
180 	uint64_t dn_maxblkid;
181 	uint8_t dn_next_type[TXG_SIZE];
182 	uint8_t dn_next_nblkptr[TXG_SIZE];
183 	uint8_t dn_next_nlevels[TXG_SIZE];
184 	uint8_t dn_next_indblkshift[TXG_SIZE];
185 	uint8_t dn_next_bonustype[TXG_SIZE];
186 	uint8_t dn_rm_spillblk[TXG_SIZE];	/* for removing spill blk */
187 	uint16_t dn_next_bonuslen[TXG_SIZE];
188 	uint32_t dn_next_blksz[TXG_SIZE];	/* next block size in bytes */
189 
190 	/* protected by dn_dbufs_mtx; declared here to fill 32-bit hole */
191 	uint32_t dn_dbufs_count;	/* count of dn_dbufs */
192 	/* There are no level-0 blocks of this blkid or higher in dn_dbufs */
193 	uint64_t dn_unlisted_l0_blkid;
194 
195 	/* protected by os_lock: */
196 	list_node_t dn_dirty_link[TXG_SIZE];	/* next on dataset's dirty */
197 
198 	/* protected by dn_mtx: */
199 	kmutex_t dn_mtx;
200 	list_t dn_dirty_records[TXG_SIZE];
201 	struct range_tree *dn_free_ranges[TXG_SIZE];
202 	uint64_t dn_allocated_txg;
203 	uint64_t dn_free_txg;
204 	uint64_t dn_assigned_txg;
205 	kcondvar_t dn_notxholds;
206 	enum dnode_dirtycontext dn_dirtyctx;
207 	uint8_t *dn_dirtyctx_firstset;		/* dbg: contents meaningless */
208 
209 	/* protected by own devices */
210 	refcount_t dn_tx_holds;
211 	refcount_t dn_holds;
212 
213 	kmutex_t dn_dbufs_mtx;
214 	/*
215 	 * Descendent dbufs, ordered by dbuf_compare. Note that dn_dbufs
216 	 * can contain multiple dbufs of the same (level, blkid) when a
217 	 * dbuf is marked DB_EVICTING without being removed from
218 	 * dn_dbufs. To maintain the avl invariant that there cannot be
219 	 * duplicate entries, we order the dbufs by an arbitrary value -
220 	 * their address in memory. This means that dn_dbufs cannot be used to
221 	 * directly look up a dbuf. Instead, callers must use avl_walk, have
222 	 * a reference to the dbuf, or look up a non-existant node with
223 	 * db_state = DB_SEARCH (see dbuf_free_range for an example).
224 	 */
225 	avl_tree_t dn_dbufs;
226 
227 	/* protected by dn_struct_rwlock */
228 	struct dmu_buf_impl *dn_bonus;	/* bonus buffer dbuf */
229 
230 	boolean_t dn_have_spill;	/* have spill or are spilling */
231 
232 	/* parent IO for current sync write */
233 	zio_t *dn_zio;
234 
235 	/* used in syncing context */
236 	uint64_t dn_oldused;	/* old phys used bytes */
237 	uint64_t dn_oldflags;	/* old phys dn_flags */
238 	uint64_t dn_olduid, dn_oldgid;
239 	uint64_t dn_newuid, dn_newgid;
240 	int dn_id_flags;
241 
242 	/* holds prefetch structure */
243 	struct zfetch	dn_zfetch;
244 } dnode_t;
245 
246 /*
247  * Adds a level of indirection between the dbuf and the dnode to avoid
248  * iterating descendent dbufs in dnode_move(). Handles are not allocated
249  * individually, but as an array of child dnodes in dnode_hold_impl().
250  */
251 typedef struct dnode_handle {
252 	/* Protects dnh_dnode from modification by dnode_move(). */
253 	zrlock_t dnh_zrlock;
254 	dnode_t *dnh_dnode;
255 } dnode_handle_t;
256 
257 typedef struct dnode_children {
258 	size_t dnc_count;		/* number of children */
259 	dnode_handle_t dnc_children[];	/* sized dynamically */
260 } dnode_children_t;
261 
262 typedef struct free_range {
263 	avl_node_t fr_node;
264 	uint64_t fr_blkid;
265 	uint64_t fr_nblks;
266 } free_range_t;
267 
268 dnode_t *dnode_special_open(struct objset *dd, dnode_phys_t *dnp,
269     uint64_t object, dnode_handle_t *dnh);
270 void dnode_special_close(dnode_handle_t *dnh);
271 
272 void dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx);
273 void dnode_setbonus_type(dnode_t *dn, dmu_object_type_t, dmu_tx_t *tx);
274 void dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx);
275 
276 int dnode_hold(struct objset *dd, uint64_t object,
277     void *ref, dnode_t **dnp);
278 int dnode_hold_impl(struct objset *dd, uint64_t object, int flag,
279     void *ref, dnode_t **dnp);
280 boolean_t dnode_add_ref(dnode_t *dn, void *ref);
281 void dnode_rele(dnode_t *dn, void *ref);
282 void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx);
283 void dnode_sync(dnode_t *dn, dmu_tx_t *tx);
284 void dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
285     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
286 void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
287     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
288 void dnode_free(dnode_t *dn, dmu_tx_t *tx);
289 void dnode_byteswap(dnode_phys_t *dnp);
290 void dnode_buf_byteswap(void *buf, size_t size);
291 void dnode_verify(dnode_t *dn);
292 int dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx);
293 void dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx);
294 void dnode_diduse_space(dnode_t *dn, int64_t space);
295 void dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx);
296 void dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t);
297 uint64_t dnode_block_freed(dnode_t *dn, uint64_t blkid);
298 void dnode_init(void);
299 void dnode_fini(void);
300 int dnode_next_offset(dnode_t *dn, int flags, uint64_t *off,
301     int minlvl, uint64_t blkfill, uint64_t txg);
302 void dnode_evict_dbufs(dnode_t *dn);
303 
304 #ifdef ZFS_DEBUG
305 
306 /*
307  * There should be a ## between the string literal and fmt, to make it
308  * clear that we're joining two strings together, but that piece of shit
309  * gcc doesn't support that preprocessor token.
310  */
311 #define	dprintf_dnode(dn, fmt, ...) do { \
312 	if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
313 	char __db_buf[32]; \
314 	uint64_t __db_obj = (dn)->dn_object; \
315 	if (__db_obj == DMU_META_DNODE_OBJECT) \
316 		(void) strcpy(__db_buf, "mdn"); \
317 	else \
318 		(void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \
319 		    (u_longlong_t)__db_obj);\
320 	dprintf_ds((dn)->dn_objset->os_dsl_dataset, "obj=%s " fmt, \
321 	    __db_buf, __VA_ARGS__); \
322 	} \
323 _NOTE(CONSTCOND) } while (0)
324 
325 #define	DNODE_VERIFY(dn)		dnode_verify(dn)
326 #define	FREE_VERIFY(db, start, end, tx)	free_verify(db, start, end, tx)
327 
328 #else
329 
330 #define	dprintf_dnode(db, fmt, ...)
331 #define	DNODE_VERIFY(dn)
332 #define	FREE_VERIFY(db, start, end, tx)
333 
334 #endif
335 
336 #ifdef	__cplusplus
337 }
338 #endif
339 
340 #endif	/* _SYS_DNODE_H */
341