xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/zil.h (revision fb2a9bae0030340ad72b9c26ba1ffee2ee3cafec)
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_ZIL_H
27 #define	_SYS_ZIL_H
28 
29 #include <sys/types.h>
30 #include <sys/spa.h>
31 #include <sys/zio.h>
32 #include <sys/dmu.h>
33 
34 #ifdef	__cplusplus
35 extern "C" {
36 #endif
37 
38 /*
39  * Intent log format:
40  *
41  * Each objset has its own intent log.  The log header (zil_header_t)
42  * for objset N's intent log is kept in the Nth object of the SPA's
43  * intent_log objset.  The log header points to a chain of log blocks,
44  * each of which contains log records (i.e., transactions) followed by
45  * a log block trailer (zil_trailer_t).  The format of a log record
46  * depends on the record (or transaction) type, but all records begin
47  * with a common structure that defines the type, length, and txg.
48  */
49 
50 /*
51  * Intent log header - this on disk structure holds fields to manage
52  * the log.  All fields are 64 bit to easily handle cross architectures.
53  */
54 typedef struct zil_header {
55 	uint64_t zh_claim_txg;	/* txg in which log blocks were claimed */
56 	uint64_t zh_replay_seq;	/* highest replayed sequence number */
57 	blkptr_t zh_log;	/* log chain */
58 	uint64_t zh_claim_blk_seq; /* highest claimed block sequence number */
59 	uint64_t zh_flags;	/* header flags */
60 	uint64_t zh_claim_lr_seq; /* highest claimed lr sequence number */
61 	uint64_t zh_pad[3];
62 } zil_header_t;
63 
64 /*
65  * zh_flags bit settings
66  */
67 #define	ZIL_REPLAY_NEEDED	0x1	/* replay needed - internal only */
68 #define	ZIL_CLAIM_LR_SEQ_VALID	0x2	/* zh_claim_lr_seq field is valid */
69 
70 /*
71  * Log block chaining.
72  *
73  * Log blocks are chained together. Originally they were chained at the
74  * end of the block. For performance reasons the chain was moved to the
75  * beginning of the block which allows writes for only the data being used.
76  * The older position is supported for backwards compatability.
77  *
78  * The zio_eck_t contains a zec_cksum which for the intent log is
79  * the sequence number of this log block. A seq of 0 is invalid.
80  * The zec_cksum is checked by the SPA against the sequence
81  * number passed in the blk_cksum field of the blkptr_t
82  */
83 typedef struct zil_chain {
84 	uint64_t zc_pad;
85 	blkptr_t zc_next_blk;	/* next block in chain */
86 	uint64_t zc_nused;	/* bytes in log block used */
87 	zio_eck_t zc_eck;	/* block trailer */
88 } zil_chain_t;
89 
90 #define	ZIL_MIN_BLKSZ	4096ULL
91 #define	ZIL_MAX_BLKSZ	SPA_MAXBLOCKSIZE
92 
93 /*
94  * The words of a log block checksum.
95  */
96 #define	ZIL_ZC_GUID_0	0
97 #define	ZIL_ZC_GUID_1	1
98 #define	ZIL_ZC_OBJSET	2
99 #define	ZIL_ZC_SEQ	3
100 
101 typedef enum zil_create {
102 	Z_FILE,
103 	Z_DIR,
104 	Z_XATTRDIR,
105 } zil_create_t;
106 
107 /*
108  * size of xvattr log section.
109  * its composed of lr_attr_t + xvattr bitmap + 2 64 bit timestamps
110  * for create time and a single 64 bit integer for all of the attributes,
111  * and 4 64 bit integers (32 bytes) for the scanstamp.
112  *
113  */
114 
115 #define	ZIL_XVAT_SIZE(mapsize) \
116 	sizeof (lr_attr_t) + (sizeof (uint32_t) * (mapsize - 1)) + \
117 	(sizeof (uint64_t) * 7)
118 
119 /*
120  * Size of ACL in log.  The ACE data is padded out to properly align
121  * on 8 byte boundary.
122  */
123 
124 #define	ZIL_ACE_LENGTH(x)	(roundup(x, sizeof (uint64_t)))
125 
126 /*
127  * Intent log transaction types and record structures
128  */
129 #define	TX_CREATE		1	/* Create file */
130 #define	TX_MKDIR		2	/* Make directory */
131 #define	TX_MKXATTR		3	/* Make XATTR directory */
132 #define	TX_SYMLINK		4	/* Create symbolic link to a file */
133 #define	TX_REMOVE		5	/* Remove file */
134 #define	TX_RMDIR		6	/* Remove directory */
135 #define	TX_LINK			7	/* Create hard link to a file */
136 #define	TX_RENAME		8	/* Rename a file */
137 #define	TX_WRITE		9	/* File write */
138 #define	TX_TRUNCATE		10	/* Truncate a file */
139 #define	TX_SETATTR		11	/* Set file attributes */
140 #define	TX_ACL_V0		12	/* Set old formatted ACL */
141 #define	TX_ACL			13	/* Set ACL */
142 #define	TX_CREATE_ACL		14	/* create with ACL */
143 #define	TX_CREATE_ATTR		15	/* create + attrs */
144 #define	TX_CREATE_ACL_ATTR 	16	/* create with ACL + attrs */
145 #define	TX_MKDIR_ACL		17	/* mkdir with ACL */
146 #define	TX_MKDIR_ATTR		18	/* mkdir with attr */
147 #define	TX_MKDIR_ACL_ATTR	19	/* mkdir with ACL + attrs */
148 #define	TX_WRITE2		20	/* dmu_sync EALREADY write */
149 #define	TX_MAX_TYPE		21	/* Max transaction type */
150 
151 /*
152  * The transactions for mkdir, symlink, remove, rmdir, link, and rename
153  * may have the following bit set, indicating the original request
154  * specified case-insensitive handling of names.
155  */
156 #define	TX_CI	((uint64_t)0x1 << 63) /* case-insensitive behavior requested */
157 
158 /*
159  * Transactions for write, truncate, setattr, acl_v0, and acl can be logged
160  * out of order.  For convenience in the code, all such records must have
161  * lr_foid at the same offset.
162  */
163 #define	TX_OOO(txtype)			\
164 	((txtype) == TX_WRITE ||	\
165 	(txtype) == TX_TRUNCATE ||	\
166 	(txtype) == TX_SETATTR ||	\
167 	(txtype) == TX_ACL_V0 ||	\
168 	(txtype) == TX_ACL ||		\
169 	(txtype) == TX_WRITE2)
170 
171 
172 /*
173  * Format of log records.
174  * The fields are carefully defined to allow them to be aligned
175  * and sized the same on sparc & intel architectures.
176  * Each log record has a common structure at the beginning.
177  *
178  * Note, lrc_seq holds two different sequence numbers. Whilst in memory
179  * it contains the transaction sequence number.  The log record on
180  * disk holds the sequence number of all log records which is used to
181  * ensure we don't replay the same record.  The two sequence numbers are
182  * different because the transactions can now be pushed out of order.
183  */
184 typedef struct {			/* common log record header */
185 	uint64_t	lrc_txtype;	/* intent log transaction type */
186 	uint64_t	lrc_reclen;	/* transaction record length */
187 	uint64_t	lrc_txg;	/* dmu transaction group number */
188 	uint64_t	lrc_seq;	/* see comment above */
189 } lr_t;
190 
191 /*
192  * Common start of all out-of-order record types (TX_OOO() above).
193  */
194 typedef struct {
195 	lr_t		lr_common;	/* common portion of log record */
196 	uint64_t	lr_foid;	/* object id */
197 } lr_ooo_t;
198 
199 /*
200  * Handle option extended vattr attributes.
201  *
202  * Whenever new attributes are added the version number
203  * will need to be updated as will code in
204  * zfs_log.c and zfs_replay.c
205  */
206 typedef struct {
207 	uint32_t	lr_attr_masksize; /* number of elements in array */
208 	uint32_t	lr_attr_bitmap; /* First entry of array */
209 	/* remainder of array and any additional fields */
210 } lr_attr_t;
211 
212 /*
213  * log record for creates without optional ACL.
214  * This log record does support optional xvattr_t attributes.
215  */
216 typedef struct {
217 	lr_t		lr_common;	/* common portion of log record */
218 	uint64_t	lr_doid;	/* object id of directory */
219 	uint64_t	lr_foid;	/* object id of created file object */
220 	uint64_t	lr_mode;	/* mode of object */
221 	uint64_t	lr_uid;		/* uid of object */
222 	uint64_t	lr_gid;		/* gid of object */
223 	uint64_t	lr_gen;		/* generation (txg of creation) */
224 	uint64_t	lr_crtime[2];	/* creation time */
225 	uint64_t	lr_rdev;	/* rdev of object to create */
226 	/* name of object to create follows this */
227 	/* for symlinks, link content follows name */
228 	/* for creates with xvattr data, the name follows the xvattr info */
229 } lr_create_t;
230 
231 /*
232  * FUID ACL record will be an array of ACEs from the original ACL.
233  * If this array includes ephemeral IDs, the record will also include
234  * an array of log-specific FUIDs to replace the ephemeral IDs.
235  * Only one copy of each unique domain will be present, so the log-specific
236  * FUIDs will use an index into a compressed domain table.  On replay this
237  * information will be used to construct real FUIDs (and bypass idmap,
238  * since it may not be available).
239  */
240 
241 /*
242  * Log record for creates with optional ACL
243  * This log record is also used for recording any FUID
244  * information needed for replaying the create.  If the
245  * file doesn't have any actual ACEs then the lr_aclcnt
246  * would be zero.
247  */
248 typedef struct {
249 	lr_create_t	lr_create;	/* common create portion */
250 	uint64_t	lr_aclcnt;	/* number of ACEs in ACL */
251 	uint64_t	lr_domcnt;	/* number of unique domains */
252 	uint64_t	lr_fuidcnt;	/* number of real fuids */
253 	uint64_t	lr_acl_bytes;	/* number of bytes in ACL */
254 	uint64_t	lr_acl_flags;	/* ACL flags */
255 	/* lr_acl_bytes number of variable sized ace's follows */
256 	/* if create is also setting xvattr's, then acl data follows xvattr */
257 	/* if ACE FUIDs are needed then they will follow the xvattr_t */
258 	/* Following the FUIDs will be the domain table information. */
259 	/* The FUIDs for the owner and group will be in the lr_create */
260 	/* portion of the record. */
261 	/* name follows ACL data */
262 } lr_acl_create_t;
263 
264 typedef struct {
265 	lr_t		lr_common;	/* common portion of log record */
266 	uint64_t	lr_doid;	/* obj id of directory */
267 	/* name of object to remove follows this */
268 } lr_remove_t;
269 
270 typedef struct {
271 	lr_t		lr_common;	/* common portion of log record */
272 	uint64_t	lr_doid;	/* obj id of directory */
273 	uint64_t	lr_link_obj;	/* obj id of link */
274 	/* name of object to link follows this */
275 } lr_link_t;
276 
277 typedef struct {
278 	lr_t		lr_common;	/* common portion of log record */
279 	uint64_t	lr_sdoid;	/* obj id of source directory */
280 	uint64_t	lr_tdoid;	/* obj id of target directory */
281 	/* 2 strings: names of source and destination follow this */
282 } lr_rename_t;
283 
284 typedef struct {
285 	lr_t		lr_common;	/* common portion of log record */
286 	uint64_t	lr_foid;	/* file object to write */
287 	uint64_t	lr_offset;	/* offset to write to */
288 	uint64_t	lr_length;	/* user data length to write */
289 	uint64_t	lr_blkoff;	/* no longer used */
290 	blkptr_t	lr_blkptr;	/* spa block pointer for replay */
291 	/* write data will follow for small writes */
292 } lr_write_t;
293 
294 typedef struct {
295 	lr_t		lr_common;	/* common portion of log record */
296 	uint64_t	lr_foid;	/* object id of file to truncate */
297 	uint64_t	lr_offset;	/* offset to truncate from */
298 	uint64_t	lr_length;	/* length to truncate */
299 } lr_truncate_t;
300 
301 typedef struct {
302 	lr_t		lr_common;	/* common portion of log record */
303 	uint64_t	lr_foid;	/* file object to change attributes */
304 	uint64_t	lr_mask;	/* mask of attributes to set */
305 	uint64_t	lr_mode;	/* mode to set */
306 	uint64_t	lr_uid;		/* uid to set */
307 	uint64_t	lr_gid;		/* gid to set */
308 	uint64_t	lr_size;	/* size to set */
309 	uint64_t	lr_atime[2];	/* access time */
310 	uint64_t	lr_mtime[2];	/* modification time */
311 	/* optional attribute lr_attr_t may be here */
312 } lr_setattr_t;
313 
314 typedef struct {
315 	lr_t		lr_common;	/* common portion of log record */
316 	uint64_t	lr_foid;	/* obj id of file */
317 	uint64_t	lr_aclcnt;	/* number of acl entries */
318 	/* lr_aclcnt number of ace_t entries follow this */
319 } lr_acl_v0_t;
320 
321 typedef struct {
322 	lr_t		lr_common;	/* common portion of log record */
323 	uint64_t	lr_foid;	/* obj id of file */
324 	uint64_t	lr_aclcnt;	/* number of ACEs in ACL */
325 	uint64_t	lr_domcnt;	/* number of unique domains */
326 	uint64_t	lr_fuidcnt;	/* number of real fuids */
327 	uint64_t	lr_acl_bytes;	/* number of bytes in ACL */
328 	uint64_t	lr_acl_flags;	/* ACL flags */
329 	/* lr_acl_bytes number of variable sized ace's follows */
330 } lr_acl_t;
331 
332 /*
333  * ZIL structure definitions, interface function prototype and globals.
334  */
335 
336 /*
337  * Writes are handled in three different ways:
338  *
339  * WR_INDIRECT:
340  *    In this mode, if we need to commit the write later, then the block
341  *    is immediately written into the file system (using dmu_sync),
342  *    and a pointer to the block is put into the log record.
343  *    When the txg commits the block is linked in.
344  *    This saves additionally writing the data into the log record.
345  *    There are a few requirements for this to occur:
346  *	- write is greater than zfs/zvol_immediate_write_sz
347  *	- not using slogs (as slogs are assumed to always be faster
348  *	  than writing into the main pool)
349  *	- the write occupies only one block
350  * WR_COPIED:
351  *    If we know we'll immediately be committing the
352  *    transaction (FSYNC or FDSYNC), the we allocate a larger
353  *    log record here for the data and copy the data in.
354  * WR_NEED_COPY:
355  *    Otherwise we don't allocate a buffer, and *if* we need to
356  *    flush the write later then a buffer is allocated and
357  *    we retrieve the data using the dmu.
358  */
359 typedef enum {
360 	WR_INDIRECT,	/* indirect - a large write (dmu_sync() data */
361 			/* and put blkptr in log, rather than actual data) */
362 	WR_COPIED,	/* immediate - data is copied into lr_write_t */
363 	WR_NEED_COPY,	/* immediate - data needs to be copied if pushed */
364 	WR_NUM_STATES	/* number of states */
365 } itx_wr_state_t;
366 
367 typedef struct itx {
368 	list_node_t	itx_node;	/* linkage on zl_itx_list */
369 	void		*itx_private;	/* type-specific opaque data */
370 	itx_wr_state_t	itx_wr_state;	/* write state */
371 	uint8_t		itx_sync;	/* synchronous transaction */
372 	uint64_t	itx_sod;	/* record size on disk */
373 	lr_t		itx_lr;		/* common part of log record */
374 	/* followed by type-specific part of lr_xx_t and its immediate data */
375 } itx_t;
376 
377 typedef int zil_parse_blk_func_t(zilog_t *zilog, blkptr_t *bp, void *arg,
378     uint64_t txg);
379 typedef int zil_parse_lr_func_t(zilog_t *zilog, lr_t *lr, void *arg,
380     uint64_t txg);
381 typedef int zil_replay_func_t();
382 typedef int zil_get_data_t(void *arg, lr_write_t *lr, char *dbuf, zio_t *zio);
383 
384 extern int zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func,
385     zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg);
386 
387 extern void	zil_init(void);
388 extern void	zil_fini(void);
389 
390 extern zilog_t	*zil_alloc(objset_t *os, zil_header_t *zh_phys);
391 extern void	zil_free(zilog_t *zilog);
392 
393 extern zilog_t	*zil_open(objset_t *os, zil_get_data_t *get_data);
394 extern void	zil_close(zilog_t *zilog);
395 
396 extern void	zil_replay(objset_t *os, void *arg,
397     zil_replay_func_t *replay_func[TX_MAX_TYPE]);
398 extern boolean_t zil_replaying(zilog_t *zilog, dmu_tx_t *tx);
399 extern void	zil_destroy(zilog_t *zilog, boolean_t keep_first);
400 extern void	zil_rollback_destroy(zilog_t *zilog, dmu_tx_t *tx);
401 
402 extern itx_t	*zil_itx_create(uint64_t txtype, size_t lrsize);
403 extern void	zil_itx_destroy(itx_t *itx);
404 extern uint64_t zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx);
405 
406 extern void	zil_commit(zilog_t *zilog, uint64_t seq, uint64_t oid);
407 
408 extern int	zil_vdev_offline(const char *osname, void *txarg);
409 extern int	zil_claim(const char *osname, void *txarg);
410 extern int	zil_check_log_chain(const char *osname, void *txarg);
411 extern void	zil_sync(zilog_t *zilog, dmu_tx_t *tx);
412 extern void	zil_clean(zilog_t *zilog);
413 
414 extern int	zil_suspend(zilog_t *zilog);
415 extern void	zil_resume(zilog_t *zilog);
416 
417 extern void	zil_add_block(zilog_t *zilog, const blkptr_t *bp);
418 extern int	zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp);
419 
420 extern void	zil_set_logbias(zilog_t *zilog, uint64_t slogval);
421 
422 extern int zil_disable;
423 
424 #ifdef	__cplusplus
425 }
426 #endif
427 
428 #endif	/* _SYS_ZIL_H */
429