xref: /titanic_50/usr/src/uts/common/fs/zfs/sys/dnode.h (revision 42cc51e07cdbcad3b9aca8d9d991fc09b251feb7)
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  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
25  */
26 
27 #ifndef	_SYS_DNODE_H
28 #define	_SYS_DNODE_H
29 
30 #include <sys/zfs_context.h>
31 #include <sys/avl.h>
32 #include <sys/spa.h>
33 #include <sys/txg.h>
34 #include <sys/zio.h>
35 #include <sys/refcount.h>
36 #include <sys/dmu_zfetch.h>
37 #include <sys/zrlock.h>
38 
39 #ifdef	__cplusplus
40 extern "C" {
41 #endif
42 
43 /*
44  * dnode_hold() flags.
45  */
46 #define	DNODE_MUST_BE_ALLOCATED	1
47 #define	DNODE_MUST_BE_FREE	2
48 
49 /*
50  * dnode_next_offset() flags.
51  */
52 #define	DNODE_FIND_HOLE		1
53 #define	DNODE_FIND_BACKWARDS	2
54 #define	DNODE_FIND_HAVELOCK	4
55 
56 /*
57  * Fixed constants.
58  */
59 #define	DNODE_SHIFT		9	/* 512 bytes */
60 #define	DN_MIN_INDBLKSHIFT	12	/* 4k */
61 #define	DN_MAX_INDBLKSHIFT	14	/* 16k */
62 #define	DNODE_BLOCK_SHIFT	14	/* 16k */
63 #define	DNODE_CORE_SIZE		64	/* 64 bytes for dnode sans blkptrs */
64 #define	DN_MAX_OBJECT_SHIFT	48	/* 256 trillion (zfs_fid_t limit) */
65 #define	DN_MAX_OFFSET_SHIFT	64	/* 2^64 bytes in a dnode */
66 
67 /*
68  * dnode id flags
69  *
70  * Note: a file will never ever have its
71  * ids moved from bonus->spill
72  * and only in a crypto environment would it be on spill
73  */
74 #define	DN_ID_CHKED_BONUS	0x1
75 #define	DN_ID_CHKED_SPILL	0x2
76 #define	DN_ID_OLD_EXIST		0x4
77 #define	DN_ID_NEW_EXIST		0x8
78 
79 /*
80  * Derived constants.
81  */
82 #define	DNODE_SIZE	(1 << DNODE_SHIFT)
83 #define	DN_MAX_NBLKPTR	((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
84 #define	DN_MAX_BONUSLEN	(DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT))
85 #define	DN_MAX_OBJECT	(1ULL << DN_MAX_OBJECT_SHIFT)
86 #define	DN_ZERO_BONUSLEN	(DN_MAX_BONUSLEN + 1)
87 #define	DN_KILL_SPILLBLK (1)
88 
89 #define	DNODES_PER_BLOCK_SHIFT	(DNODE_BLOCK_SHIFT - DNODE_SHIFT)
90 #define	DNODES_PER_BLOCK	(1ULL << DNODES_PER_BLOCK_SHIFT)
91 #define	DNODES_PER_LEVEL_SHIFT	(DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
92 #define	DNODES_PER_LEVEL	(1ULL << DNODES_PER_LEVEL_SHIFT)
93 
94 /* The +2 here is a cheesy way to round up */
95 #define	DN_MAX_LEVELS	(2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \
96 	(DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))
97 
98 #define	DN_BONUS(dnp)	((void*)((dnp)->dn_bonus + \
99 	(((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))
100 
101 #define	DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \
102 	(dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT)
103 
104 #define	EPB(blkshift, typeshift)	(1 << (blkshift - typeshift))
105 
106 struct dmu_buf_impl;
107 struct objset;
108 struct zio;
109 
110 enum dnode_dirtycontext {
111 	DN_UNDIRTIED,
112 	DN_DIRTY_OPEN,
113 	DN_DIRTY_SYNC
114 };
115 
116 /* Is dn_used in bytes?  if not, it's in multiples of SPA_MINBLOCKSIZE */
117 #define	DNODE_FLAG_USED_BYTES		(1<<0)
118 #define	DNODE_FLAG_USERUSED_ACCOUNTED	(1<<1)
119 
120 /* Does dnode have a SA spill blkptr in bonus? */
121 #define	DNODE_FLAG_SPILL_BLKPTR	(1<<2)
122 
123 typedef struct dnode_phys {
124 	uint8_t dn_type;		/* dmu_object_type_t */
125 	uint8_t dn_indblkshift;		/* ln2(indirect block size) */
126 	uint8_t dn_nlevels;		/* 1=dn_blkptr->data blocks */
127 	uint8_t dn_nblkptr;		/* length of dn_blkptr */
128 	uint8_t dn_bonustype;		/* type of data in bonus buffer */
129 	uint8_t	dn_checksum;		/* ZIO_CHECKSUM type */
130 	uint8_t	dn_compress;		/* ZIO_COMPRESS type */
131 	uint8_t dn_flags;		/* DNODE_FLAG_* */
132 	uint16_t dn_datablkszsec;	/* data block size in 512b sectors */
133 	uint16_t dn_bonuslen;		/* length of dn_bonus */
134 	uint8_t dn_pad2[4];
135 
136 	/* accounting is protected by dn_dirty_mtx */
137 	uint64_t dn_maxblkid;		/* largest allocated block ID */
138 	uint64_t dn_used;		/* bytes (or sectors) of disk space */
139 
140 	uint64_t dn_pad3[4];
141 
142 	blkptr_t dn_blkptr[1];
143 	uint8_t dn_bonus[DN_MAX_BONUSLEN - sizeof (blkptr_t)];
144 	blkptr_t dn_spill;
145 } dnode_phys_t;
146 
147 typedef struct dnode {
148 	/*
149 	 * Protects the structure of the dnode, including the number of levels
150 	 * of indirection (dn_nlevels), dn_maxblkid, and dn_next_*
151 	 */
152 	krwlock_t dn_struct_rwlock;
153 
154 	/* Our link on dn_objset->os_dnodes list; protected by os_lock.  */
155 	list_node_t dn_link;
156 
157 	/* immutable: */
158 	struct objset *dn_objset;
159 	uint64_t dn_object;
160 	struct dmu_buf_impl *dn_dbuf;
161 	struct dnode_handle *dn_handle;
162 	dnode_phys_t *dn_phys; /* pointer into dn->dn_dbuf->db.db_data */
163 
164 	/*
165 	 * Copies of stuff in dn_phys.  They're valid in the open
166 	 * context (eg. even before the dnode is first synced).
167 	 * Where necessary, these are protected by dn_struct_rwlock.
168 	 */
169 	dmu_object_type_t dn_type;	/* object type */
170 	uint16_t dn_bonuslen;		/* bonus length */
171 	uint8_t dn_bonustype;		/* bonus type */
172 	uint8_t dn_nblkptr;		/* number of blkptrs (immutable) */
173 	uint8_t dn_checksum;		/* ZIO_CHECKSUM type */
174 	uint8_t dn_compress;		/* ZIO_COMPRESS type */
175 	uint8_t dn_nlevels;
176 	uint8_t dn_indblkshift;
177 	uint8_t dn_datablkshift;	/* zero if blksz not power of 2! */
178 	uint8_t dn_moved;		/* Has this dnode been moved? */
179 	uint16_t dn_datablkszsec;	/* in 512b sectors */
180 	uint32_t dn_datablksz;		/* in bytes */
181 	uint64_t dn_maxblkid;
182 	uint8_t dn_next_type[TXG_SIZE];
183 	uint8_t dn_next_nblkptr[TXG_SIZE];
184 	uint8_t dn_next_nlevels[TXG_SIZE];
185 	uint8_t dn_next_indblkshift[TXG_SIZE];
186 	uint8_t dn_next_bonustype[TXG_SIZE];
187 	uint8_t dn_rm_spillblk[TXG_SIZE];	/* for removing spill blk */
188 	uint16_t dn_next_bonuslen[TXG_SIZE];
189 	uint32_t dn_next_blksz[TXG_SIZE];	/* next block size in bytes */
190 
191 	/* protected by dn_dbufs_mtx; declared here to fill 32-bit hole */
192 	uint32_t dn_dbufs_count;	/* count of dn_dbufs */
193 	/* There are no level-0 blocks of this blkid or higher in dn_dbufs */
194 	uint64_t dn_unlisted_l0_blkid;
195 
196 	/* protected by os_lock: */
197 	list_node_t dn_dirty_link[TXG_SIZE];	/* next on dataset's dirty */
198 
199 	/* protected by dn_mtx: */
200 	kmutex_t dn_mtx;
201 	list_t dn_dirty_records[TXG_SIZE];
202 	struct range_tree *dn_free_ranges[TXG_SIZE];
203 	uint64_t dn_allocated_txg;
204 	uint64_t dn_free_txg;
205 	uint64_t dn_assigned_txg;
206 	kcondvar_t dn_notxholds;
207 	enum dnode_dirtycontext dn_dirtyctx;
208 	uint8_t *dn_dirtyctx_firstset;		/* dbg: contents meaningless */
209 
210 	/* protected by own devices */
211 	refcount_t dn_tx_holds;
212 	refcount_t dn_holds;
213 
214 	kmutex_t dn_dbufs_mtx;
215 	/*
216 	 * Descendent dbufs, ordered by dbuf_compare. Note that dn_dbufs
217 	 * can contain multiple dbufs of the same (level, blkid) when a
218 	 * dbuf is marked DB_EVICTING without being removed from
219 	 * dn_dbufs. To maintain the avl invariant that there cannot be
220 	 * duplicate entries, we order the dbufs by an arbitrary value -
221 	 * their address in memory. This means that dn_dbufs cannot be used to
222 	 * directly look up a dbuf. Instead, callers must use avl_walk, have
223 	 * a reference to the dbuf, or look up a non-existant node with
224 	 * db_state = DB_SEARCH (see dbuf_free_range for an example).
225 	 */
226 	avl_tree_t dn_dbufs;
227 
228 	/* protected by dn_struct_rwlock */
229 	struct dmu_buf_impl *dn_bonus;	/* bonus buffer dbuf */
230 
231 	boolean_t dn_have_spill;	/* have spill or are spilling */
232 
233 	/* parent IO for current sync write */
234 	zio_t *dn_zio;
235 
236 	/* used in syncing context */
237 	uint64_t dn_oldused;	/* old phys used bytes */
238 	uint64_t dn_oldflags;	/* old phys dn_flags */
239 	uint64_t dn_olduid, dn_oldgid;
240 	uint64_t dn_newuid, dn_newgid;
241 	int dn_id_flags;
242 
243 	/* holds prefetch structure */
244 	struct zfetch	dn_zfetch;
245 } dnode_t;
246 
247 /*
248  * Adds a level of indirection between the dbuf and the dnode to avoid
249  * iterating descendent dbufs in dnode_move(). Handles are not allocated
250  * individually, but as an array of child dnodes in dnode_hold_impl().
251  */
252 typedef struct dnode_handle {
253 	/* Protects dnh_dnode from modification by dnode_move(). */
254 	zrlock_t dnh_zrlock;
255 	dnode_t *dnh_dnode;
256 } dnode_handle_t;
257 
258 typedef struct dnode_children {
259 	dmu_buf_user_t dnc_dbu;		/* User evict data */
260 	size_t dnc_count;		/* number of children */
261 	dnode_handle_t dnc_children[];	/* sized dynamically */
262 } dnode_children_t;
263 
264 typedef struct free_range {
265 	avl_node_t fr_node;
266 	uint64_t fr_blkid;
267 	uint64_t fr_nblks;
268 } free_range_t;
269 
270 void dnode_special_open(struct objset *dd, dnode_phys_t *dnp,
271     uint64_t object, dnode_handle_t *dnh);
272 void dnode_special_close(dnode_handle_t *dnh);
273 
274 void dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx);
275 void dnode_setbonus_type(dnode_t *dn, dmu_object_type_t, dmu_tx_t *tx);
276 void dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx);
277 
278 int dnode_hold(struct objset *dd, uint64_t object,
279     void *ref, dnode_t **dnp);
280 int dnode_hold_impl(struct objset *dd, uint64_t object, int flag,
281     void *ref, dnode_t **dnp);
282 boolean_t dnode_add_ref(dnode_t *dn, void *ref);
283 void dnode_rele(dnode_t *dn, void *ref);
284 void dnode_rele_and_unlock(dnode_t *dn, void *tag);
285 void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx);
286 void dnode_sync(dnode_t *dn, dmu_tx_t *tx);
287 void dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
288     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
289 void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
290     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
291 void dnode_free(dnode_t *dn, dmu_tx_t *tx);
292 void dnode_byteswap(dnode_phys_t *dnp);
293 void dnode_buf_byteswap(void *buf, size_t size);
294 void dnode_verify(dnode_t *dn);
295 int dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx);
296 void dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx);
297 void dnode_diduse_space(dnode_t *dn, int64_t space);
298 void dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx);
299 void dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t);
300 uint64_t dnode_block_freed(dnode_t *dn, uint64_t blkid);
301 void dnode_init(void);
302 void dnode_fini(void);
303 int dnode_next_offset(dnode_t *dn, int flags, uint64_t *off,
304     int minlvl, uint64_t blkfill, uint64_t txg);
305 void dnode_evict_dbufs(dnode_t *dn);
306 void dnode_evict_bonus(dnode_t *dn);
307 
308 #ifdef ZFS_DEBUG
309 
310 /*
311  * There should be a ## between the string literal and fmt, to make it
312  * clear that we're joining two strings together, but that piece of shit
313  * gcc doesn't support that preprocessor token.
314  */
315 #define	dprintf_dnode(dn, fmt, ...) do { \
316 	if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
317 	char __db_buf[32]; \
318 	uint64_t __db_obj = (dn)->dn_object; \
319 	if (__db_obj == DMU_META_DNODE_OBJECT) \
320 		(void) strcpy(__db_buf, "mdn"); \
321 	else \
322 		(void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \
323 		    (u_longlong_t)__db_obj);\
324 	dprintf_ds((dn)->dn_objset->os_dsl_dataset, "obj=%s " fmt, \
325 	    __db_buf, __VA_ARGS__); \
326 	} \
327 _NOTE(CONSTCOND) } while (0)
328 
329 #define	DNODE_VERIFY(dn)		dnode_verify(dn)
330 #define	FREE_VERIFY(db, start, end, tx)	free_verify(db, start, end, tx)
331 
332 #else
333 
334 #define	dprintf_dnode(db, fmt, ...)
335 #define	DNODE_VERIFY(dn)
336 #define	FREE_VERIFY(db, start, end, tx)
337 
338 #endif
339 
340 #ifdef	__cplusplus
341 }
342 #endif
343 
344 #endif	/* _SYS_DNODE_H */
345