dnode.h revision 288549
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
40extern "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
106struct dmu_buf_impl;
107struct objset;
108struct zio;
109
110enum 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
123typedef 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
147typedef 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 */
252typedef 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
258typedef 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
264typedef struct free_range {
265	avl_node_t fr_node;
266	uint64_t fr_blkid;
267	uint64_t fr_nblks;
268} free_range_t;
269
270void dnode_special_open(struct objset *dd, dnode_phys_t *dnp,
271    uint64_t object, dnode_handle_t *dnh);
272void dnode_special_close(dnode_handle_t *dnh);
273
274void dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx);
275void dnode_setbonus_type(dnode_t *dn, dmu_object_type_t, dmu_tx_t *tx);
276void dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx);
277
278int dnode_hold(struct objset *dd, uint64_t object,
279    void *ref, dnode_t **dnp);
280int dnode_hold_impl(struct objset *dd, uint64_t object, int flag,
281    void *ref, dnode_t **dnp);
282boolean_t dnode_add_ref(dnode_t *dn, void *ref);
283void dnode_rele(dnode_t *dn, void *ref);
284void dnode_rele_and_unlock(dnode_t *dn, void *tag);
285void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx);
286void dnode_sync(dnode_t *dn, dmu_tx_t *tx);
287void 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);
289void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
290    dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
291void dnode_free(dnode_t *dn, dmu_tx_t *tx);
292void dnode_byteswap(dnode_phys_t *dnp);
293void dnode_buf_byteswap(void *buf, size_t size);
294void dnode_verify(dnode_t *dn);
295int dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx);
296void dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx);
297void dnode_diduse_space(dnode_t *dn, int64_t space);
298void dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx);
299void dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t);
300uint64_t dnode_block_freed(dnode_t *dn, uint64_t blkid);
301void dnode_init(void);
302void dnode_fini(void);
303int dnode_next_offset(dnode_t *dn, int flags, uint64_t *off,
304    int minlvl, uint64_t blkfill, uint64_t txg);
305void dnode_evict_dbufs(dnode_t *dn);
306void 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