xref: /openbmc/linux/include/linux/jbd2.h (revision dcfaf8b5)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * linux/include/linux/jbd2.h
4  *
5  * Written by Stephen C. Tweedie <sct@redhat.com>
6  *
7  * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved
8  *
9  * Definitions for transaction data structures for the buffer cache
10  * filesystem journaling support.
11  */
12 
13 #ifndef _LINUX_JBD2_H
14 #define _LINUX_JBD2_H
15 
16 /* Allow this file to be included directly into e2fsprogs */
17 #ifndef __KERNEL__
18 #include "jfs_compat.h"
19 #define JBD2_DEBUG
20 #else
21 
22 #include <linux/types.h>
23 #include <linux/buffer_head.h>
24 #include <linux/journal-head.h>
25 #include <linux/stddef.h>
26 #include <linux/mutex.h>
27 #include <linux/timer.h>
28 #include <linux/slab.h>
29 #include <linux/bit_spinlock.h>
30 #include <linux/blkdev.h>
31 #include <crypto/hash.h>
32 #endif
33 
34 #define journal_oom_retry 1
35 
36 /*
37  * Define JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds
38  * certain classes of error which can occur due to failed IOs.  Under
39  * normal use we want ext4 to continue after such errors, because
40  * hardware _can_ fail, but for debugging purposes when running tests on
41  * known-good hardware we may want to trap these errors.
42  */
43 #undef JBD2_PARANOID_IOFAIL
44 
45 /*
46  * The default maximum commit age, in seconds.
47  */
48 #define JBD2_DEFAULT_MAX_COMMIT_AGE 5
49 
50 #ifdef CONFIG_JBD2_DEBUG
51 /*
52  * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal
53  * consistency checks.  By default we don't do this unless
54  * CONFIG_JBD2_DEBUG is on.
55  */
56 #define JBD2_EXPENSIVE_CHECKING
57 void __jbd2_debug(int level, const char *file, const char *func,
58 		  unsigned int line, const char *fmt, ...);
59 
60 #define jbd2_debug(n, fmt, a...) \
61 	__jbd2_debug((n), __FILE__, __func__, __LINE__, (fmt), ##a)
62 #else
63 #define jbd2_debug(n, fmt, a...)  no_printk(fmt, ##a)
64 #endif
65 
66 extern void *jbd2_alloc(size_t size, gfp_t flags);
67 extern void jbd2_free(void *ptr, size_t size);
68 
69 #define JBD2_MIN_JOURNAL_BLOCKS 1024
70 #define JBD2_DEFAULT_FAST_COMMIT_BLOCKS 256
71 
72 #ifdef __KERNEL__
73 
74 /**
75  * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
76  *
77  * All filesystem modifications made by the process go
78  * through this handle.  Recursive operations (such as quota operations)
79  * are gathered into a single update.
80  *
81  * The buffer credits field is used to account for journaled buffers
82  * being modified by the running process.  To ensure that there is
83  * enough log space for all outstanding operations, we need to limit the
84  * number of outstanding buffers possible at any time.  When the
85  * operation completes, any buffer credits not used are credited back to
86  * the transaction, so that at all times we know how many buffers the
87  * outstanding updates on a transaction might possibly touch.
88  *
89  * This is an opaque datatype.
90  **/
91 typedef struct jbd2_journal_handle handle_t;	/* Atomic operation type */
92 
93 
94 /**
95  * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
96  *
97  * journal_t is linked to from the fs superblock structure.
98  *
99  * We use the journal_t to keep track of all outstanding transaction
100  * activity on the filesystem, and to manage the state of the log
101  * writing process.
102  *
103  * This is an opaque datatype.
104  **/
105 typedef struct journal_s	journal_t;	/* Journal control structure */
106 #endif
107 
108 /*
109  * Internal structures used by the logging mechanism:
110  */
111 
112 #define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
113 
114 /*
115  * On-disk structures
116  */
117 
118 /*
119  * Descriptor block types:
120  */
121 
122 #define JBD2_DESCRIPTOR_BLOCK	1
123 #define JBD2_COMMIT_BLOCK	2
124 #define JBD2_SUPERBLOCK_V1	3
125 #define JBD2_SUPERBLOCK_V2	4
126 #define JBD2_REVOKE_BLOCK	5
127 
128 /*
129  * Standard header for all descriptor blocks:
130  */
131 typedef struct journal_header_s
132 {
133 	__be32		h_magic;
134 	__be32		h_blocktype;
135 	__be32		h_sequence;
136 } journal_header_t;
137 
138 /*
139  * Checksum types.
140  */
141 #define JBD2_CRC32_CHKSUM   1
142 #define JBD2_MD5_CHKSUM     2
143 #define JBD2_SHA1_CHKSUM    3
144 #define JBD2_CRC32C_CHKSUM  4
145 
146 #define JBD2_CRC32_CHKSUM_SIZE 4
147 
148 #define JBD2_CHECKSUM_BYTES (32 / sizeof(u32))
149 /*
150  * Commit block header for storing transactional checksums:
151  *
152  * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum*
153  * fields are used to store a checksum of the descriptor and data blocks.
154  *
155  * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum
156  * field is used to store crc32c(uuid+commit_block).  Each journal metadata
157  * block gets its own checksum, and data block checksums are stored in
158  * journal_block_tag (in the descriptor).  The other h_chksum* fields are
159  * not used.
160  *
161  * If FEATURE_INCOMPAT_CSUM_V3 is set, the descriptor block uses
162  * journal_block_tag3_t to store a full 32-bit checksum.  Everything else
163  * is the same as v2.
164  *
165  * Checksum v1, v2, and v3 are mutually exclusive features.
166  */
167 struct commit_header {
168 	__be32		h_magic;
169 	__be32          h_blocktype;
170 	__be32          h_sequence;
171 	unsigned char   h_chksum_type;
172 	unsigned char   h_chksum_size;
173 	unsigned char 	h_padding[2];
174 	__be32 		h_chksum[JBD2_CHECKSUM_BYTES];
175 	__be64		h_commit_sec;
176 	__be32		h_commit_nsec;
177 };
178 
179 /*
180  * The block tag: used to describe a single buffer in the journal.
181  * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this
182  * raw struct shouldn't be used for pointer math or sizeof() - use
183  * journal_tag_bytes(journal) instead to compute this.
184  */
185 typedef struct journal_block_tag3_s
186 {
187 	__be32		t_blocknr;	/* The on-disk block number */
188 	__be32		t_flags;	/* See below */
189 	__be32		t_blocknr_high; /* most-significant high 32bits. */
190 	__be32		t_checksum;	/* crc32c(uuid+seq+block) */
191 } journal_block_tag3_t;
192 
193 typedef struct journal_block_tag_s
194 {
195 	__be32		t_blocknr;	/* The on-disk block number */
196 	__be16		t_checksum;	/* truncated crc32c(uuid+seq+block) */
197 	__be16		t_flags;	/* See below */
198 	__be32		t_blocknr_high; /* most-significant high 32bits. */
199 } journal_block_tag_t;
200 
201 /* Tail of descriptor or revoke block, for checksumming */
202 struct jbd2_journal_block_tail {
203 	__be32		t_checksum;	/* crc32c(uuid+descr_block) */
204 };
205 
206 /*
207  * The revoke descriptor: used on disk to describe a series of blocks to
208  * be revoked from the log
209  */
210 typedef struct jbd2_journal_revoke_header_s
211 {
212 	journal_header_t r_header;
213 	__be32		 r_count;	/* Count of bytes used in the block */
214 } jbd2_journal_revoke_header_t;
215 
216 /* Definitions for the journal tag flags word: */
217 #define JBD2_FLAG_ESCAPE		1	/* on-disk block is escaped */
218 #define JBD2_FLAG_SAME_UUID	2	/* block has same uuid as previous */
219 #define JBD2_FLAG_DELETED	4	/* block deleted by this transaction */
220 #define JBD2_FLAG_LAST_TAG	8	/* last tag in this descriptor block */
221 
222 
223 /*
224  * The journal superblock.  All fields are in big-endian byte order.
225  */
226 typedef struct journal_superblock_s
227 {
228 /* 0x0000 */
229 	journal_header_t s_header;
230 
231 /* 0x000C */
232 	/* Static information describing the journal */
233 	__be32	s_blocksize;		/* journal device blocksize */
234 	__be32	s_maxlen;		/* total blocks in journal file */
235 	__be32	s_first;		/* first block of log information */
236 
237 /* 0x0018 */
238 	/* Dynamic information describing the current state of the log */
239 	__be32	s_sequence;		/* first commit ID expected in log */
240 	__be32	s_start;		/* blocknr of start of log */
241 
242 /* 0x0020 */
243 	/* Error value, as set by jbd2_journal_abort(). */
244 	__be32	s_errno;
245 
246 /* 0x0024 */
247 	/* Remaining fields are only valid in a version-2 superblock */
248 	__be32	s_feature_compat;	/* compatible feature set */
249 	__be32	s_feature_incompat;	/* incompatible feature set */
250 	__be32	s_feature_ro_compat;	/* readonly-compatible feature set */
251 /* 0x0030 */
252 	__u8	s_uuid[16];		/* 128-bit uuid for journal */
253 
254 /* 0x0040 */
255 	__be32	s_nr_users;		/* Nr of filesystems sharing log */
256 
257 	__be32	s_dynsuper;		/* Blocknr of dynamic superblock copy*/
258 
259 /* 0x0048 */
260 	__be32	s_max_transaction;	/* Limit of journal blocks per trans.*/
261 	__be32	s_max_trans_data;	/* Limit of data blocks per trans. */
262 
263 /* 0x0050 */
264 	__u8	s_checksum_type;	/* checksum type */
265 	__u8	s_padding2[3];
266 /* 0x0054 */
267 	__be32	s_num_fc_blks;		/* Number of fast commit blocks */
268 	__be32	s_head;			/* blocknr of head of log, only uptodate
269 					 * while the filesystem is clean */
270 /* 0x005C */
271 	__u32	s_padding[40];
272 	__be32	s_checksum;		/* crc32c(superblock) */
273 
274 /* 0x0100 */
275 	__u8	s_users[16*48];		/* ids of all fs'es sharing the log */
276 /* 0x0400 */
277 } journal_superblock_t;
278 
279 #define JBD2_FEATURE_COMPAT_CHECKSUM		0x00000001
280 
281 #define JBD2_FEATURE_INCOMPAT_REVOKE		0x00000001
282 #define JBD2_FEATURE_INCOMPAT_64BIT		0x00000002
283 #define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT	0x00000004
284 #define JBD2_FEATURE_INCOMPAT_CSUM_V2		0x00000008
285 #define JBD2_FEATURE_INCOMPAT_CSUM_V3		0x00000010
286 #define JBD2_FEATURE_INCOMPAT_FAST_COMMIT	0x00000020
287 
288 /* See "journal feature predicate functions" below */
289 
290 /* Features known to this kernel version: */
291 #define JBD2_KNOWN_COMPAT_FEATURES	JBD2_FEATURE_COMPAT_CHECKSUM
292 #define JBD2_KNOWN_ROCOMPAT_FEATURES	0
293 #define JBD2_KNOWN_INCOMPAT_FEATURES	(JBD2_FEATURE_INCOMPAT_REVOKE | \
294 					JBD2_FEATURE_INCOMPAT_64BIT | \
295 					JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT | \
296 					JBD2_FEATURE_INCOMPAT_CSUM_V2 | \
297 					JBD2_FEATURE_INCOMPAT_CSUM_V3 | \
298 					JBD2_FEATURE_INCOMPAT_FAST_COMMIT)
299 
300 #ifdef __KERNEL__
301 
302 #include <linux/fs.h>
303 #include <linux/sched.h>
304 
305 enum jbd_state_bits {
306 	BH_JBD			/* Has an attached ext3 journal_head */
307 	  = BH_PrivateStart,
308 	BH_JWrite,		/* Being written to log (@@@ DEBUGGING) */
309 	BH_Freed,		/* Has been freed (truncated) */
310 	BH_Revoked,		/* Has been revoked from the log */
311 	BH_RevokeValid,		/* Revoked flag is valid */
312 	BH_JBDDirty,		/* Is dirty but journaled */
313 	BH_JournalHead,		/* Pins bh->b_private and jh->b_bh */
314 	BH_Shadow,		/* IO on shadow buffer is running */
315 	BH_Verified,		/* Metadata block has been verified ok */
316 	BH_JBDPrivateStart,	/* First bit available for private use by FS */
317 };
318 
BUFFER_FNS(JBD,jbd)319 BUFFER_FNS(JBD, jbd)
320 BUFFER_FNS(JWrite, jwrite)
321 BUFFER_FNS(JBDDirty, jbddirty)
322 TAS_BUFFER_FNS(JBDDirty, jbddirty)
323 BUFFER_FNS(Revoked, revoked)
324 TAS_BUFFER_FNS(Revoked, revoked)
325 BUFFER_FNS(RevokeValid, revokevalid)
326 TAS_BUFFER_FNS(RevokeValid, revokevalid)
327 BUFFER_FNS(Freed, freed)
328 BUFFER_FNS(Shadow, shadow)
329 BUFFER_FNS(Verified, verified)
330 
331 static inline struct buffer_head *jh2bh(struct journal_head *jh)
332 {
333 	return jh->b_bh;
334 }
335 
bh2jh(struct buffer_head * bh)336 static inline struct journal_head *bh2jh(struct buffer_head *bh)
337 {
338 	return bh->b_private;
339 }
340 
jbd_lock_bh_journal_head(struct buffer_head * bh)341 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
342 {
343 	bit_spin_lock(BH_JournalHead, &bh->b_state);
344 }
345 
jbd_unlock_bh_journal_head(struct buffer_head * bh)346 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
347 {
348 	bit_spin_unlock(BH_JournalHead, &bh->b_state);
349 }
350 
351 #define J_ASSERT(assert)	BUG_ON(!(assert))
352 
353 #define J_ASSERT_BH(bh, expr)	J_ASSERT(expr)
354 #define J_ASSERT_JH(jh, expr)	J_ASSERT(expr)
355 
356 #if defined(JBD2_PARANOID_IOFAIL)
357 #define J_EXPECT(expr, why...)		J_ASSERT(expr)
358 #define J_EXPECT_BH(bh, expr, why...)	J_ASSERT_BH(bh, expr)
359 #define J_EXPECT_JH(jh, expr, why...)	J_ASSERT_JH(jh, expr)
360 #else
361 #define __journal_expect(expr, why...)					     \
362 	({								     \
363 		int val = (expr);					     \
364 		if (!val) {						     \
365 			printk(KERN_ERR					     \
366 			       "JBD2 unexpected failure: %s: %s;\n",	     \
367 			       __func__, #expr);			     \
368 			printk(KERN_ERR why "\n");			     \
369 		}							     \
370 		val;							     \
371 	})
372 #define J_EXPECT(expr, why...)		__journal_expect(expr, ## why)
373 #define J_EXPECT_BH(bh, expr, why...)	__journal_expect(expr, ## why)
374 #define J_EXPECT_JH(jh, expr, why...)	__journal_expect(expr, ## why)
375 #endif
376 
377 /* Flags in jbd_inode->i_flags */
378 #define __JI_COMMIT_RUNNING 0
379 #define __JI_WRITE_DATA 1
380 #define __JI_WAIT_DATA 2
381 
382 /*
383  * Commit of the inode data in progress. We use this flag to protect us from
384  * concurrent deletion of inode. We cannot use reference to inode for this
385  * since we cannot afford doing last iput() on behalf of kjournald
386  */
387 #define JI_COMMIT_RUNNING (1 << __JI_COMMIT_RUNNING)
388 /* Write allocated dirty buffers in this inode before commit */
389 #define JI_WRITE_DATA (1 << __JI_WRITE_DATA)
390 /* Wait for outstanding data writes for this inode before commit */
391 #define JI_WAIT_DATA (1 << __JI_WAIT_DATA)
392 
393 /**
394  * struct jbd2_inode - The jbd_inode type is the structure linking inodes in
395  * ordered mode present in a transaction so that we can sync them during commit.
396  */
397 struct jbd2_inode {
398 	/**
399 	 * @i_transaction:
400 	 *
401 	 * Which transaction does this inode belong to? Either the running
402 	 * transaction or the committing one. [j_list_lock]
403 	 */
404 	transaction_t *i_transaction;
405 
406 	/**
407 	 * @i_next_transaction:
408 	 *
409 	 * Pointer to the running transaction modifying inode's data in case
410 	 * there is already a committing transaction touching it. [j_list_lock]
411 	 */
412 	transaction_t *i_next_transaction;
413 
414 	/**
415 	 * @i_list: List of inodes in the i_transaction [j_list_lock]
416 	 */
417 	struct list_head i_list;
418 
419 	/**
420 	 * @i_vfs_inode:
421 	 *
422 	 * VFS inode this inode belongs to [constant for lifetime of structure]
423 	 */
424 	struct inode *i_vfs_inode;
425 
426 	/**
427 	 * @i_flags: Flags of inode [j_list_lock]
428 	 */
429 	unsigned long i_flags;
430 
431 	/**
432 	 * @i_dirty_start:
433 	 *
434 	 * Offset in bytes where the dirty range for this inode starts.
435 	 * [j_list_lock]
436 	 */
437 	loff_t i_dirty_start;
438 
439 	/**
440 	 * @i_dirty_end:
441 	 *
442 	 * Inclusive offset in bytes where the dirty range for this inode
443 	 * ends. [j_list_lock]
444 	 */
445 	loff_t i_dirty_end;
446 };
447 
448 struct jbd2_revoke_table_s;
449 
450 /**
451  * struct jbd2_journal_handle - The jbd2_journal_handle type is the concrete
452  *     type associated with handle_t.
453  * @h_transaction: Which compound transaction is this update a part of?
454  * @h_journal: Which journal handle belongs to - used iff h_reserved set.
455  * @h_rsv_handle: Handle reserved for finishing the logical operation.
456  * @h_total_credits: Number of remaining buffers we are allowed to add to
457  *	journal. These are dirty buffers and revoke descriptor blocks.
458  * @h_revoke_credits: Number of remaining revoke records available for handle
459  * @h_ref: Reference count on this handle.
460  * @h_err: Field for caller's use to track errors through large fs operations.
461  * @h_sync: Flag for sync-on-close.
462  * @h_jdata: Flag to force data journaling.
463  * @h_reserved: Flag for handle for reserved credits.
464  * @h_aborted: Flag indicating fatal error on handle.
465  * @h_type: For handle statistics.
466  * @h_line_no: For handle statistics.
467  * @h_start_jiffies: Handle Start time.
468  * @h_requested_credits: Holds @h_total_credits after handle is started.
469  * @h_revoke_credits_requested: Holds @h_revoke_credits after handle is started.
470  * @saved_alloc_context: Saved context while transaction is open.
471  **/
472 
473 /* Docbook can't yet cope with the bit fields, but will leave the documentation
474  * in so it can be fixed later.
475  */
476 
477 struct jbd2_journal_handle
478 {
479 	union {
480 		transaction_t	*h_transaction;
481 		/* Which journal handle belongs to - used iff h_reserved set */
482 		journal_t	*h_journal;
483 	};
484 
485 	handle_t		*h_rsv_handle;
486 	int			h_total_credits;
487 	int			h_revoke_credits;
488 	int			h_revoke_credits_requested;
489 	int			h_ref;
490 	int			h_err;
491 
492 	/* Flags [no locking] */
493 	unsigned int	h_sync:		1;
494 	unsigned int	h_jdata:	1;
495 	unsigned int	h_reserved:	1;
496 	unsigned int	h_aborted:	1;
497 	unsigned int	h_type:		8;
498 	unsigned int	h_line_no:	16;
499 
500 	unsigned long		h_start_jiffies;
501 	unsigned int		h_requested_credits;
502 
503 	unsigned int		saved_alloc_context;
504 };
505 
506 
507 /*
508  * Some stats for checkpoint phase
509  */
510 struct transaction_chp_stats_s {
511 	unsigned long		cs_chp_time;
512 	__u32			cs_forced_to_close;
513 	__u32			cs_written;
514 	__u32			cs_dropped;
515 };
516 
517 /* The transaction_t type is the guts of the journaling mechanism.  It
518  * tracks a compound transaction through its various states:
519  *
520  * RUNNING:	accepting new updates
521  * LOCKED:	Updates still running but we don't accept new ones
522  * RUNDOWN:	Updates are tidying up but have finished requesting
523  *		new buffers to modify (state not used for now)
524  * FLUSH:       All updates complete, but we are still writing to disk
525  * COMMIT:      All data on disk, writing commit record
526  * FINISHED:	We still have to keep the transaction for checkpointing.
527  *
528  * The transaction keeps track of all of the buffers modified by a
529  * running transaction, and all of the buffers committed but not yet
530  * flushed to home for finished transactions.
531  * (Locking Documentation improved by LockDoc)
532  */
533 
534 /*
535  * Lock ranking:
536  *
537  *    j_list_lock
538  *      ->jbd_lock_bh_journal_head()	(This is "innermost")
539  *
540  *    j_state_lock
541  *    ->b_state_lock
542  *
543  *    b_state_lock
544  *    ->j_list_lock
545  *
546  *    j_state_lock
547  *    ->j_list_lock			(journal_unmap_buffer)
548  *
549  */
550 
551 struct transaction_s
552 {
553 	/* Pointer to the journal for this transaction. [no locking] */
554 	journal_t		*t_journal;
555 
556 	/* Sequence number for this transaction [no locking] */
557 	tid_t			t_tid;
558 
559 	/*
560 	 * Transaction's current state
561 	 * [no locking - only kjournald2 alters this]
562 	 * [j_list_lock] guards transition of a transaction into T_FINISHED
563 	 * state and subsequent call of __jbd2_journal_drop_transaction()
564 	 * FIXME: needs barriers
565 	 * KLUDGE: [use j_state_lock]
566 	 */
567 	enum {
568 		T_RUNNING,
569 		T_LOCKED,
570 		T_SWITCH,
571 		T_FLUSH,
572 		T_COMMIT,
573 		T_COMMIT_DFLUSH,
574 		T_COMMIT_JFLUSH,
575 		T_COMMIT_CALLBACK,
576 		T_FINISHED
577 	}			t_state;
578 
579 	/*
580 	 * Where in the log does this transaction's commit start? [no locking]
581 	 */
582 	unsigned long		t_log_start;
583 
584 	/*
585 	 * Number of buffers on the t_buffers list [j_list_lock, no locks
586 	 * needed for jbd2 thread]
587 	 */
588 	int			t_nr_buffers;
589 
590 	/*
591 	 * Doubly-linked circular list of all buffers reserved but not yet
592 	 * modified by this transaction [j_list_lock, no locks needed fo
593 	 * jbd2 thread]
594 	 */
595 	struct journal_head	*t_reserved_list;
596 
597 	/*
598 	 * Doubly-linked circular list of all metadata buffers owned by this
599 	 * transaction [j_list_lock, no locks needed for jbd2 thread]
600 	 */
601 	struct journal_head	*t_buffers;
602 
603 	/*
604 	 * Doubly-linked circular list of all forget buffers (superseded
605 	 * buffers which we can un-checkpoint once this transaction commits)
606 	 * [j_list_lock]
607 	 */
608 	struct journal_head	*t_forget;
609 
610 	/*
611 	 * Doubly-linked circular list of all buffers still to be flushed before
612 	 * this transaction can be checkpointed. [j_list_lock]
613 	 */
614 	struct journal_head	*t_checkpoint_list;
615 
616 	/*
617 	 * Doubly-linked circular list of metadata buffers being
618 	 * shadowed by log IO.  The IO buffers on the iobuf list and
619 	 * the shadow buffers on this list match each other one for
620 	 * one at all times. [j_list_lock, no locks needed for jbd2
621 	 * thread]
622 	 */
623 	struct journal_head	*t_shadow_list;
624 
625 	/*
626 	 * List of inodes associated with the transaction; e.g., ext4 uses
627 	 * this to track inodes in data=ordered and data=journal mode that
628 	 * need special handling on transaction commit; also used by ocfs2.
629 	 * [j_list_lock]
630 	 */
631 	struct list_head	t_inode_list;
632 
633 	/*
634 	 * Longest time some handle had to wait for running transaction
635 	 */
636 	unsigned long		t_max_wait;
637 
638 	/*
639 	 * When transaction started
640 	 */
641 	unsigned long		t_start;
642 
643 	/*
644 	 * When commit was requested [j_state_lock]
645 	 */
646 	unsigned long		t_requested;
647 
648 	/*
649 	 * Checkpointing stats [j_list_lock]
650 	 */
651 	struct transaction_chp_stats_s t_chp_stats;
652 
653 	/*
654 	 * Number of outstanding updates running on this transaction
655 	 * [none]
656 	 */
657 	atomic_t		t_updates;
658 
659 	/*
660 	 * Number of blocks reserved for this transaction in the journal.
661 	 * This is including all credits reserved when starting transaction
662 	 * handles as well as all journal descriptor blocks needed for this
663 	 * transaction. [none]
664 	 */
665 	atomic_t		t_outstanding_credits;
666 
667 	/*
668 	 * Number of revoke records for this transaction added by already
669 	 * stopped handles. [none]
670 	 */
671 	atomic_t		t_outstanding_revokes;
672 
673 	/*
674 	 * How many handles used this transaction? [none]
675 	 */
676 	atomic_t		t_handle_count;
677 
678 	/*
679 	 * Forward and backward links for the circular list of all transactions
680 	 * awaiting checkpoint. [j_list_lock]
681 	 */
682 	transaction_t		*t_cpnext, *t_cpprev;
683 
684 	/*
685 	 * When will the transaction expire (become due for commit), in jiffies?
686 	 * [no locking]
687 	 */
688 	unsigned long		t_expires;
689 
690 	/*
691 	 * When this transaction started, in nanoseconds [no locking]
692 	 */
693 	ktime_t			t_start_time;
694 
695 	/*
696 	 * This transaction is being forced and some process is
697 	 * waiting for it to finish.
698 	 */
699 	unsigned int t_synchronous_commit:1;
700 
701 	/* Disk flush needs to be sent to fs partition [no locking] */
702 	int			t_need_data_flush;
703 
704 	/*
705 	 * For use by the filesystem to store fs-specific data
706 	 * structures associated with the transaction
707 	 */
708 	struct list_head	t_private_list;
709 };
710 
711 struct transaction_run_stats_s {
712 	unsigned long		rs_wait;
713 	unsigned long		rs_request_delay;
714 	unsigned long		rs_running;
715 	unsigned long		rs_locked;
716 	unsigned long		rs_flushing;
717 	unsigned long		rs_logging;
718 
719 	__u32			rs_handle_count;
720 	__u32			rs_blocks;
721 	__u32			rs_blocks_logged;
722 };
723 
724 struct transaction_stats_s {
725 	unsigned long		ts_tid;
726 	unsigned long		ts_requested;
727 	struct transaction_run_stats_s run;
728 };
729 
730 static inline unsigned long
jbd2_time_diff(unsigned long start,unsigned long end)731 jbd2_time_diff(unsigned long start, unsigned long end)
732 {
733 	if (end >= start)
734 		return end - start;
735 
736 	return end + (MAX_JIFFY_OFFSET - start);
737 }
738 
739 #define JBD2_NR_BATCH	64
740 
741 enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY};
742 
743 #define JBD2_FC_REPLAY_STOP	0
744 #define JBD2_FC_REPLAY_CONTINUE	1
745 
746 /**
747  * struct journal_s - The journal_s type is the concrete type associated with
748  *     journal_t.
749  */
750 struct journal_s
751 {
752 	/**
753 	 * @j_flags: General journaling state flags [j_state_lock,
754 	 * no lock for quick racy checks]
755 	 */
756 	unsigned long		j_flags;
757 
758 	/**
759 	 * @j_atomic_flags: Atomic journaling state flags.
760 	 */
761 	unsigned long		j_atomic_flags;
762 
763 	/**
764 	 * @j_errno:
765 	 *
766 	 * Is there an outstanding uncleared error on the journal (from a prior
767 	 * abort)? [j_state_lock]
768 	 */
769 	int			j_errno;
770 
771 	/**
772 	 * @j_abort_mutex: Lock the whole aborting procedure.
773 	 */
774 	struct mutex		j_abort_mutex;
775 
776 	/**
777 	 * @j_sb_buffer: The first part of the superblock buffer.
778 	 */
779 	struct buffer_head	*j_sb_buffer;
780 
781 	/**
782 	 * @j_superblock: The second part of the superblock buffer.
783 	 */
784 	journal_superblock_t	*j_superblock;
785 
786 	/**
787 	 * @j_state_lock: Protect the various scalars in the journal.
788 	 */
789 	rwlock_t		j_state_lock;
790 
791 	/**
792 	 * @j_barrier_count:
793 	 *
794 	 * Number of processes waiting to create a barrier lock [j_state_lock,
795 	 * no lock for quick racy checks]
796 	 */
797 	int			j_barrier_count;
798 
799 	/**
800 	 * @j_barrier: The barrier lock itself.
801 	 */
802 	struct mutex		j_barrier;
803 
804 	/**
805 	 * @j_running_transaction:
806 	 *
807 	 * Transactions: The current running transaction...
808 	 * [j_state_lock, no lock for quick racy checks] [caller holding
809 	 * open handle]
810 	 */
811 	transaction_t		*j_running_transaction;
812 
813 	/**
814 	 * @j_committing_transaction:
815 	 *
816 	 * the transaction we are pushing to disk
817 	 * [j_state_lock] [caller holding open handle]
818 	 */
819 	transaction_t		*j_committing_transaction;
820 
821 	/**
822 	 * @j_checkpoint_transactions:
823 	 *
824 	 * ... and a linked circular list of all transactions waiting for
825 	 * checkpointing. [j_list_lock]
826 	 */
827 	transaction_t		*j_checkpoint_transactions;
828 
829 	/**
830 	 * @j_wait_transaction_locked:
831 	 *
832 	 * Wait queue for waiting for a locked transaction to start committing,
833 	 * or for a barrier lock to be released.
834 	 */
835 	wait_queue_head_t	j_wait_transaction_locked;
836 
837 	/**
838 	 * @j_wait_done_commit: Wait queue for waiting for commit to complete.
839 	 */
840 	wait_queue_head_t	j_wait_done_commit;
841 
842 	/**
843 	 * @j_wait_commit: Wait queue to trigger commit.
844 	 */
845 	wait_queue_head_t	j_wait_commit;
846 
847 	/**
848 	 * @j_wait_updates: Wait queue to wait for updates to complete.
849 	 */
850 	wait_queue_head_t	j_wait_updates;
851 
852 	/**
853 	 * @j_wait_reserved:
854 	 *
855 	 * Wait queue to wait for reserved buffer credits to drop.
856 	 */
857 	wait_queue_head_t	j_wait_reserved;
858 
859 	/**
860 	 * @j_fc_wait:
861 	 *
862 	 * Wait queue to wait for completion of async fast commits.
863 	 */
864 	wait_queue_head_t	j_fc_wait;
865 
866 	/**
867 	 * @j_checkpoint_mutex:
868 	 *
869 	 * Semaphore for locking against concurrent checkpoints.
870 	 */
871 	struct mutex		j_checkpoint_mutex;
872 
873 	/**
874 	 * @j_chkpt_bhs:
875 	 *
876 	 * List of buffer heads used by the checkpoint routine.  This
877 	 * was moved from jbd2_log_do_checkpoint() to reduce stack
878 	 * usage.  Access to this array is controlled by the
879 	 * @j_checkpoint_mutex.  [j_checkpoint_mutex]
880 	 */
881 	struct buffer_head	*j_chkpt_bhs[JBD2_NR_BATCH];
882 
883 	/**
884 	 * @j_shrinker:
885 	 *
886 	 * Journal head shrinker, reclaim buffer's journal head which
887 	 * has been written back.
888 	 */
889 	struct shrinker		j_shrinker;
890 
891 	/**
892 	 * @j_checkpoint_jh_count:
893 	 *
894 	 * Number of journal buffers on the checkpoint list. [j_list_lock]
895 	 */
896 	struct percpu_counter	j_checkpoint_jh_count;
897 
898 	/**
899 	 * @j_shrink_transaction:
900 	 *
901 	 * Record next transaction will shrink on the checkpoint list.
902 	 * [j_list_lock]
903 	 */
904 	transaction_t		*j_shrink_transaction;
905 
906 	/**
907 	 * @j_head:
908 	 *
909 	 * Journal head: identifies the first unused block in the journal.
910 	 * [j_state_lock]
911 	 */
912 	unsigned long		j_head;
913 
914 	/**
915 	 * @j_tail:
916 	 *
917 	 * Journal tail: identifies the oldest still-used block in the journal.
918 	 * [j_state_lock]
919 	 */
920 	unsigned long		j_tail;
921 
922 	/**
923 	 * @j_free:
924 	 *
925 	 * Journal free: how many free blocks are there in the journal?
926 	 * [j_state_lock]
927 	 */
928 	unsigned long		j_free;
929 
930 	/**
931 	 * @j_first:
932 	 *
933 	 * The block number of the first usable block in the journal
934 	 * [j_state_lock].
935 	 */
936 	unsigned long		j_first;
937 
938 	/**
939 	 * @j_last:
940 	 *
941 	 * The block number one beyond the last usable block in the journal
942 	 * [j_state_lock].
943 	 */
944 	unsigned long		j_last;
945 
946 	/**
947 	 * @j_fc_first:
948 	 *
949 	 * The block number of the first fast commit block in the journal
950 	 * [j_state_lock].
951 	 */
952 	unsigned long		j_fc_first;
953 
954 	/**
955 	 * @j_fc_off:
956 	 *
957 	 * Number of fast commit blocks currently allocated. Accessed only
958 	 * during fast commit. Currently only process can do fast commit, so
959 	 * this field is not protected by any lock.
960 	 */
961 	unsigned long		j_fc_off;
962 
963 	/**
964 	 * @j_fc_last:
965 	 *
966 	 * The block number one beyond the last fast commit block in the journal
967 	 * [j_state_lock].
968 	 */
969 	unsigned long		j_fc_last;
970 
971 	/**
972 	 * @j_dev: Device where we store the journal.
973 	 */
974 	struct block_device	*j_dev;
975 
976 	/**
977 	 * @j_blocksize: Block size for the location where we store the journal.
978 	 */
979 	int			j_blocksize;
980 
981 	/**
982 	 * @j_blk_offset:
983 	 *
984 	 * Starting block offset into the device where we store the journal.
985 	 */
986 	unsigned long long	j_blk_offset;
987 
988 	/**
989 	 * @j_devname: Journal device name.
990 	 */
991 	char			j_devname[BDEVNAME_SIZE+24];
992 
993 	/**
994 	 * @j_fs_dev:
995 	 *
996 	 * Device which holds the client fs.  For internal journal this will be
997 	 * equal to j_dev.
998 	 */
999 	struct block_device	*j_fs_dev;
1000 
1001 	/**
1002 	 * @j_total_len: Total maximum capacity of the journal region on disk.
1003 	 */
1004 	unsigned int		j_total_len;
1005 
1006 	/**
1007 	 * @j_reserved_credits:
1008 	 *
1009 	 * Number of buffers reserved from the running transaction.
1010 	 */
1011 	atomic_t		j_reserved_credits;
1012 
1013 	/**
1014 	 * @j_list_lock: Protects the buffer lists and internal buffer state.
1015 	 */
1016 	spinlock_t		j_list_lock;
1017 
1018 	/**
1019 	 * @j_inode:
1020 	 *
1021 	 * Optional inode where we store the journal.  If present, all
1022 	 * journal block numbers are mapped into this inode via bmap().
1023 	 */
1024 	struct inode		*j_inode;
1025 
1026 	/**
1027 	 * @j_tail_sequence:
1028 	 *
1029 	 * Sequence number of the oldest transaction in the log [j_state_lock]
1030 	 */
1031 	tid_t			j_tail_sequence;
1032 
1033 	/**
1034 	 * @j_transaction_sequence:
1035 	 *
1036 	 * Sequence number of the next transaction to grant [j_state_lock]
1037 	 */
1038 	tid_t			j_transaction_sequence;
1039 
1040 	/**
1041 	 * @j_commit_sequence:
1042 	 *
1043 	 * Sequence number of the most recently committed transaction
1044 	 * [j_state_lock, no lock for quick racy checks]
1045 	 */
1046 	tid_t			j_commit_sequence;
1047 
1048 	/**
1049 	 * @j_commit_request:
1050 	 *
1051 	 * Sequence number of the most recent transaction wanting commit
1052 	 * [j_state_lock, no lock for quick racy checks]
1053 	 */
1054 	tid_t			j_commit_request;
1055 
1056 	/**
1057 	 * @j_uuid:
1058 	 *
1059 	 * Journal uuid: identifies the object (filesystem, LVM volume etc)
1060 	 * backed by this journal.  This will eventually be replaced by an array
1061 	 * of uuids, allowing us to index multiple devices within a single
1062 	 * journal and to perform atomic updates across them.
1063 	 */
1064 	__u8			j_uuid[16];
1065 
1066 	/**
1067 	 * @j_task: Pointer to the current commit thread for this journal.
1068 	 */
1069 	struct task_struct	*j_task;
1070 
1071 	/**
1072 	 * @j_max_transaction_buffers:
1073 	 *
1074 	 * Maximum number of metadata buffers to allow in a single compound
1075 	 * commit transaction.
1076 	 */
1077 	int			j_max_transaction_buffers;
1078 
1079 	/**
1080 	 * @j_revoke_records_per_block:
1081 	 *
1082 	 * Number of revoke records that fit in one descriptor block.
1083 	 */
1084 	int			j_revoke_records_per_block;
1085 
1086 	/**
1087 	 * @j_transaction_overhead_buffers:
1088 	 *
1089 	 * Number of blocks each transaction needs for its own bookkeeping
1090 	 */
1091 	int			j_transaction_overhead_buffers;
1092 
1093 	/**
1094 	 * @j_commit_interval:
1095 	 *
1096 	 * What is the maximum transaction lifetime before we begin a commit?
1097 	 */
1098 	unsigned long		j_commit_interval;
1099 
1100 	/**
1101 	 * @j_commit_timer: The timer used to wakeup the commit thread.
1102 	 */
1103 	struct timer_list	j_commit_timer;
1104 
1105 	/**
1106 	 * @j_revoke_lock: Protect the revoke table.
1107 	 */
1108 	spinlock_t		j_revoke_lock;
1109 
1110 	/**
1111 	 * @j_revoke:
1112 	 *
1113 	 * The revoke table - maintains the list of revoked blocks in the
1114 	 * current transaction.
1115 	 */
1116 	struct jbd2_revoke_table_s *j_revoke;
1117 
1118 	/**
1119 	 * @j_revoke_table: Alternate revoke tables for j_revoke.
1120 	 */
1121 	struct jbd2_revoke_table_s *j_revoke_table[2];
1122 
1123 	/**
1124 	 * @j_wbuf: Array of bhs for jbd2_journal_commit_transaction.
1125 	 */
1126 	struct buffer_head	**j_wbuf;
1127 
1128 	/**
1129 	 * @j_fc_wbuf: Array of fast commit bhs for fast commit. Accessed only
1130 	 * during a fast commit. Currently only process can do fast commit, so
1131 	 * this field is not protected by any lock.
1132 	 */
1133 	struct buffer_head	**j_fc_wbuf;
1134 
1135 	/**
1136 	 * @j_wbufsize:
1137 	 *
1138 	 * Size of @j_wbuf array.
1139 	 */
1140 	int			j_wbufsize;
1141 
1142 	/**
1143 	 * @j_fc_wbufsize:
1144 	 *
1145 	 * Size of @j_fc_wbuf array.
1146 	 */
1147 	int			j_fc_wbufsize;
1148 
1149 	/**
1150 	 * @j_last_sync_writer:
1151 	 *
1152 	 * The pid of the last person to run a synchronous operation
1153 	 * through the journal.
1154 	 */
1155 	pid_t			j_last_sync_writer;
1156 
1157 	/**
1158 	 * @j_average_commit_time:
1159 	 *
1160 	 * The average amount of time in nanoseconds it takes to commit a
1161 	 * transaction to disk. [j_state_lock]
1162 	 */
1163 	u64			j_average_commit_time;
1164 
1165 	/**
1166 	 * @j_min_batch_time:
1167 	 *
1168 	 * Minimum time that we should wait for additional filesystem operations
1169 	 * to get batched into a synchronous handle in microseconds.
1170 	 */
1171 	u32			j_min_batch_time;
1172 
1173 	/**
1174 	 * @j_max_batch_time:
1175 	 *
1176 	 * Maximum time that we should wait for additional filesystem operations
1177 	 * to get batched into a synchronous handle in microseconds.
1178 	 */
1179 	u32			j_max_batch_time;
1180 
1181 	/**
1182 	 * @j_commit_callback:
1183 	 *
1184 	 * This function is called when a transaction is closed.
1185 	 */
1186 	void			(*j_commit_callback)(journal_t *,
1187 						     transaction_t *);
1188 
1189 	/**
1190 	 * @j_submit_inode_data_buffers:
1191 	 *
1192 	 * This function is called for all inodes associated with the
1193 	 * committing transaction marked with JI_WRITE_DATA flag
1194 	 * before we start to write out the transaction to the journal.
1195 	 */
1196 	int			(*j_submit_inode_data_buffers)
1197 					(struct jbd2_inode *);
1198 
1199 	/**
1200 	 * @j_finish_inode_data_buffers:
1201 	 *
1202 	 * This function is called for all inodes associated with the
1203 	 * committing transaction marked with JI_WAIT_DATA flag
1204 	 * after we have written the transaction to the journal
1205 	 * but before we write out the commit block.
1206 	 */
1207 	int			(*j_finish_inode_data_buffers)
1208 					(struct jbd2_inode *);
1209 
1210 	/*
1211 	 * Journal statistics
1212 	 */
1213 
1214 	/**
1215 	 * @j_history_lock: Protect the transactions statistics history.
1216 	 */
1217 	spinlock_t		j_history_lock;
1218 
1219 	/**
1220 	 * @j_proc_entry: procfs entry for the jbd statistics directory.
1221 	 */
1222 	struct proc_dir_entry	*j_proc_entry;
1223 
1224 	/**
1225 	 * @j_stats: Overall statistics.
1226 	 */
1227 	struct transaction_stats_s j_stats;
1228 
1229 	/**
1230 	 * @j_failed_commit: Failed journal commit ID.
1231 	 */
1232 	unsigned int		j_failed_commit;
1233 
1234 	/**
1235 	 * @j_private:
1236 	 *
1237 	 * An opaque pointer to fs-private information.  ext3 puts its
1238 	 * superblock pointer here.
1239 	 */
1240 	void *j_private;
1241 
1242 	/**
1243 	 * @j_chksum_driver:
1244 	 *
1245 	 * Reference to checksum algorithm driver via cryptoapi.
1246 	 */
1247 	struct crypto_shash *j_chksum_driver;
1248 
1249 	/**
1250 	 * @j_csum_seed:
1251 	 *
1252 	 * Precomputed journal UUID checksum for seeding other checksums.
1253 	 */
1254 	__u32 j_csum_seed;
1255 
1256 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1257 	/**
1258 	 * @j_trans_commit_map:
1259 	 *
1260 	 * Lockdep entity to track transaction commit dependencies. Handles
1261 	 * hold this "lock" for read, when we wait for commit, we acquire the
1262 	 * "lock" for writing. This matches the properties of jbd2 journalling
1263 	 * where the running transaction has to wait for all handles to be
1264 	 * dropped to commit that transaction and also acquiring a handle may
1265 	 * require transaction commit to finish.
1266 	 */
1267 	struct lockdep_map	j_trans_commit_map;
1268 #endif
1269 
1270 	/**
1271 	 * @j_fc_cleanup_callback:
1272 	 *
1273 	 * Clean-up after fast commit or full commit. JBD2 calls this function
1274 	 * after every commit operation.
1275 	 */
1276 	void (*j_fc_cleanup_callback)(struct journal_s *journal, int full, tid_t tid);
1277 
1278 	/**
1279 	 * @j_fc_replay_callback:
1280 	 *
1281 	 * File-system specific function that performs replay of a fast
1282 	 * commit. JBD2 calls this function for each fast commit block found in
1283 	 * the journal. This function should return JBD2_FC_REPLAY_CONTINUE
1284 	 * to indicate that the block was processed correctly and more fast
1285 	 * commit replay should continue. Return value of JBD2_FC_REPLAY_STOP
1286 	 * indicates the end of replay (no more blocks remaining). A negative
1287 	 * return value indicates error.
1288 	 */
1289 	int (*j_fc_replay_callback)(struct journal_s *journal,
1290 				    struct buffer_head *bh,
1291 				    enum passtype pass, int off,
1292 				    tid_t expected_commit_id);
1293 
1294 	/**
1295 	 * @j_bmap:
1296 	 *
1297 	 * Bmap function that should be used instead of the generic
1298 	 * VFS bmap function.
1299 	 */
1300 	int (*j_bmap)(struct journal_s *journal, sector_t *block);
1301 };
1302 
1303 #define jbd2_might_wait_for_commit(j) \
1304 	do { \
1305 		rwsem_acquire(&j->j_trans_commit_map, 0, 0, _THIS_IP_); \
1306 		rwsem_release(&j->j_trans_commit_map, _THIS_IP_); \
1307 	} while (0)
1308 
1309 /*
1310  * We can support any known requested features iff the
1311  * superblock is not in version 1.  Otherwise we fail to support any
1312  * extended sb features.
1313  */
jbd2_format_support_feature(journal_t * j)1314 static inline bool jbd2_format_support_feature(journal_t *j)
1315 {
1316 	return j->j_superblock->s_header.h_blocktype !=
1317 					cpu_to_be32(JBD2_SUPERBLOCK_V1);
1318 }
1319 
1320 /* journal feature predicate functions */
1321 #define JBD2_FEATURE_COMPAT_FUNCS(name, flagname) \
1322 static inline bool jbd2_has_feature_##name(journal_t *j) \
1323 { \
1324 	return (jbd2_format_support_feature(j) && \
1325 		((j)->j_superblock->s_feature_compat & \
1326 		 cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname)) != 0); \
1327 } \
1328 static inline void jbd2_set_feature_##name(journal_t *j) \
1329 { \
1330 	(j)->j_superblock->s_feature_compat |= \
1331 		cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \
1332 } \
1333 static inline void jbd2_clear_feature_##name(journal_t *j) \
1334 { \
1335 	(j)->j_superblock->s_feature_compat &= \
1336 		~cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \
1337 }
1338 
1339 #define JBD2_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
1340 static inline bool jbd2_has_feature_##name(journal_t *j) \
1341 { \
1342 	return (jbd2_format_support_feature(j) && \
1343 		((j)->j_superblock->s_feature_ro_compat & \
1344 		 cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname)) != 0); \
1345 } \
1346 static inline void jbd2_set_feature_##name(journal_t *j) \
1347 { \
1348 	(j)->j_superblock->s_feature_ro_compat |= \
1349 		cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \
1350 } \
1351 static inline void jbd2_clear_feature_##name(journal_t *j) \
1352 { \
1353 	(j)->j_superblock->s_feature_ro_compat &= \
1354 		~cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \
1355 }
1356 
1357 #define JBD2_FEATURE_INCOMPAT_FUNCS(name, flagname) \
1358 static inline bool jbd2_has_feature_##name(journal_t *j) \
1359 { \
1360 	return (jbd2_format_support_feature(j) && \
1361 		((j)->j_superblock->s_feature_incompat & \
1362 		 cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname)) != 0); \
1363 } \
1364 static inline void jbd2_set_feature_##name(journal_t *j) \
1365 { \
1366 	(j)->j_superblock->s_feature_incompat |= \
1367 		cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \
1368 } \
1369 static inline void jbd2_clear_feature_##name(journal_t *j) \
1370 { \
1371 	(j)->j_superblock->s_feature_incompat &= \
1372 		~cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \
1373 }
1374 
1375 JBD2_FEATURE_COMPAT_FUNCS(checksum,		CHECKSUM)
1376 
1377 JBD2_FEATURE_INCOMPAT_FUNCS(revoke,		REVOKE)
1378 JBD2_FEATURE_INCOMPAT_FUNCS(64bit,		64BIT)
1379 JBD2_FEATURE_INCOMPAT_FUNCS(async_commit,	ASYNC_COMMIT)
1380 JBD2_FEATURE_INCOMPAT_FUNCS(csum2,		CSUM_V2)
1381 JBD2_FEATURE_INCOMPAT_FUNCS(csum3,		CSUM_V3)
1382 JBD2_FEATURE_INCOMPAT_FUNCS(fast_commit,	FAST_COMMIT)
1383 
1384 /* Journal high priority write IO operation flags */
1385 #define JBD2_JOURNAL_REQ_FLAGS		(REQ_META | REQ_SYNC | REQ_IDLE)
1386 
1387 /*
1388  * Journal flag definitions
1389  */
1390 #define JBD2_UNMOUNT	0x001	/* Journal thread is being destroyed */
1391 #define JBD2_ABORT	0x002	/* Journaling has been aborted for errors. */
1392 #define JBD2_ACK_ERR	0x004	/* The errno in the sb has been acked */
1393 #define JBD2_FLUSHED	0x008	/* The journal superblock has been flushed */
1394 #define JBD2_LOADED	0x010	/* The journal superblock has been loaded */
1395 #define JBD2_BARRIER	0x020	/* Use IDE barriers */
1396 #define JBD2_ABORT_ON_SYNCDATA_ERR	0x040	/* Abort the journal on file
1397 						 * data write error in ordered
1398 						 * mode */
1399 #define JBD2_CYCLE_RECORD		0x080	/* Journal cycled record log on
1400 						 * clean and empty filesystem
1401 						 * logging area */
1402 #define JBD2_FAST_COMMIT_ONGOING	0x100	/* Fast commit is ongoing */
1403 #define JBD2_FULL_COMMIT_ONGOING	0x200	/* Full commit is ongoing */
1404 #define JBD2_JOURNAL_FLUSH_DISCARD	0x0001
1405 #define JBD2_JOURNAL_FLUSH_ZEROOUT	0x0002
1406 #define JBD2_JOURNAL_FLUSH_VALID	(JBD2_JOURNAL_FLUSH_DISCARD | \
1407 					JBD2_JOURNAL_FLUSH_ZEROOUT)
1408 
1409 /*
1410  * Journal atomic flag definitions
1411  */
1412 #define JBD2_CHECKPOINT_IO_ERROR	0x001	/* Detect io error while writing
1413 						 * buffer back to disk */
1414 
1415 /*
1416  * Function declarations for the journaling transaction and buffer
1417  * management
1418  */
1419 
1420 /* Filing buffers */
1421 extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *);
1422 extern bool __jbd2_journal_refile_buffer(struct journal_head *);
1423 extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *);
1424 extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
1425 extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int);
jbd2_file_log_bh(struct list_head * head,struct buffer_head * bh)1426 static inline void jbd2_file_log_bh(struct list_head *head, struct buffer_head *bh)
1427 {
1428 	list_add_tail(&bh->b_assoc_buffers, head);
1429 }
jbd2_unfile_log_bh(struct buffer_head * bh)1430 static inline void jbd2_unfile_log_bh(struct buffer_head *bh)
1431 {
1432 	list_del_init(&bh->b_assoc_buffers);
1433 }
1434 
1435 /* Log buffer allocation */
1436 struct buffer_head *jbd2_journal_get_descriptor_buffer(transaction_t *, int);
1437 void jbd2_descriptor_block_csum_set(journal_t *, struct buffer_head *);
1438 int jbd2_journal_next_log_block(journal_t *, unsigned long long *);
1439 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
1440 			      unsigned long *block);
1441 int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
1442 void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block);
1443 
1444 /* Commit management */
1445 extern void jbd2_journal_commit_transaction(journal_t *);
1446 
1447 /* Checkpoint list management */
1448 void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy);
1449 unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, unsigned long *nr_to_scan);
1450 int __jbd2_journal_remove_checkpoint(struct journal_head *);
1451 int jbd2_journal_try_remove_checkpoint(struct journal_head *jh);
1452 void jbd2_journal_destroy_checkpoint(journal_t *journal);
1453 void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *);
1454 
1455 
1456 /*
1457  * Triggers
1458  */
1459 
1460 struct jbd2_buffer_trigger_type {
1461 	/*
1462 	 * Fired a the moment data to write to the journal are known to be
1463 	 * stable - so either at the moment b_frozen_data is created or just
1464 	 * before a buffer is written to the journal.  mapped_data is a mapped
1465 	 * buffer that is the frozen data for commit.
1466 	 */
1467 	void (*t_frozen)(struct jbd2_buffer_trigger_type *type,
1468 			 struct buffer_head *bh, void *mapped_data,
1469 			 size_t size);
1470 
1471 	/*
1472 	 * Fired during journal abort for dirty buffers that will not be
1473 	 * committed.
1474 	 */
1475 	void (*t_abort)(struct jbd2_buffer_trigger_type *type,
1476 			struct buffer_head *bh);
1477 };
1478 
1479 extern void jbd2_buffer_frozen_trigger(struct journal_head *jh,
1480 				       void *mapped_data,
1481 				       struct jbd2_buffer_trigger_type *triggers);
1482 extern void jbd2_buffer_abort_trigger(struct journal_head *jh,
1483 				      struct jbd2_buffer_trigger_type *triggers);
1484 
1485 /* Buffer IO */
1486 extern int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
1487 					      struct journal_head *jh_in,
1488 					      struct buffer_head **bh_out,
1489 					      sector_t blocknr);
1490 
1491 /* Transaction cache support */
1492 extern void jbd2_journal_destroy_transaction_cache(void);
1493 extern int __init jbd2_journal_init_transaction_cache(void);
1494 extern void jbd2_journal_free_transaction(transaction_t *);
1495 
1496 /*
1497  * Journal locking.
1498  *
1499  * We need to lock the journal during transaction state changes so that nobody
1500  * ever tries to take a handle on the running transaction while we are in the
1501  * middle of moving it to the commit phase.  j_state_lock does this.
1502  *
1503  * Note that the locking is completely interrupt unsafe.  We never touch
1504  * journal structures from interrupts.
1505  */
1506 
journal_current_handle(void)1507 static inline handle_t *journal_current_handle(void)
1508 {
1509 	return current->journal_info;
1510 }
1511 
1512 /* The journaling code user interface:
1513  *
1514  * Create and destroy handles
1515  * Register buffer modifications against the current transaction.
1516  */
1517 
1518 extern handle_t *jbd2_journal_start(journal_t *, int nblocks);
1519 extern handle_t *jbd2__journal_start(journal_t *, int blocks, int rsv_blocks,
1520 				     int revoke_records, gfp_t gfp_mask,
1521 				     unsigned int type, unsigned int line_no);
1522 extern int	 jbd2_journal_restart(handle_t *, int nblocks);
1523 extern int	 jbd2__journal_restart(handle_t *, int nblocks,
1524 				       int revoke_records, gfp_t gfp_mask);
1525 extern int	 jbd2_journal_start_reserved(handle_t *handle,
1526 				unsigned int type, unsigned int line_no);
1527 extern void	 jbd2_journal_free_reserved(handle_t *handle);
1528 extern int	 jbd2_journal_extend(handle_t *handle, int nblocks,
1529 				     int revoke_records);
1530 extern int	 jbd2_journal_get_write_access(handle_t *, struct buffer_head *);
1531 extern int	 jbd2_journal_get_create_access (handle_t *, struct buffer_head *);
1532 extern int	 jbd2_journal_get_undo_access(handle_t *, struct buffer_head *);
1533 void		 jbd2_journal_set_triggers(struct buffer_head *,
1534 					   struct jbd2_buffer_trigger_type *type);
1535 extern int	 jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *);
1536 extern int	 jbd2_journal_forget (handle_t *, struct buffer_head *);
1537 int jbd2_journal_invalidate_folio(journal_t *, struct folio *,
1538 					size_t offset, size_t length);
1539 bool jbd2_journal_try_to_free_buffers(journal_t *journal, struct folio *folio);
1540 extern int	 jbd2_journal_stop(handle_t *);
1541 extern int	 jbd2_journal_flush(journal_t *journal, unsigned int flags);
1542 extern void	 jbd2_journal_lock_updates (journal_t *);
1543 extern void	 jbd2_journal_unlock_updates (journal_t *);
1544 
1545 void jbd2_journal_wait_updates(journal_t *);
1546 
1547 extern journal_t * jbd2_journal_init_dev(struct block_device *bdev,
1548 				struct block_device *fs_dev,
1549 				unsigned long long start, int len, int bsize);
1550 extern journal_t * jbd2_journal_init_inode (struct inode *);
1551 extern int	   jbd2_journal_update_format (journal_t *);
1552 extern int	   jbd2_journal_check_used_features
1553 		   (journal_t *, unsigned long, unsigned long, unsigned long);
1554 extern int	   jbd2_journal_check_available_features
1555 		   (journal_t *, unsigned long, unsigned long, unsigned long);
1556 extern int	   jbd2_journal_set_features
1557 		   (journal_t *, unsigned long, unsigned long, unsigned long);
1558 extern void	   jbd2_journal_clear_features
1559 		   (journal_t *, unsigned long, unsigned long, unsigned long);
1560 extern int	   jbd2_journal_load       (journal_t *journal);
1561 extern int	   jbd2_journal_destroy    (journal_t *);
1562 extern int	   jbd2_journal_recover    (journal_t *journal);
1563 extern int	   jbd2_journal_wipe       (journal_t *, int);
1564 extern int	   jbd2_journal_skip_recovery	(journal_t *);
1565 extern void	   jbd2_journal_update_sb_errno(journal_t *);
1566 extern int	   jbd2_journal_update_sb_log_tail	(journal_t *, tid_t,
1567 				unsigned long, blk_opf_t);
1568 extern void	   jbd2_journal_abort      (journal_t *, int);
1569 extern int	   jbd2_journal_errno      (journal_t *);
1570 extern void	   jbd2_journal_ack_err    (journal_t *);
1571 extern int	   jbd2_journal_clear_err  (journal_t *);
1572 extern int	   jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *);
1573 extern int	   jbd2_journal_force_commit(journal_t *);
1574 extern int	   jbd2_journal_force_commit_nested(journal_t *);
1575 extern int	   jbd2_journal_inode_ranged_write(handle_t *handle,
1576 			struct jbd2_inode *inode, loff_t start_byte,
1577 			loff_t length);
1578 extern int	   jbd2_journal_inode_ranged_wait(handle_t *handle,
1579 			struct jbd2_inode *inode, loff_t start_byte,
1580 			loff_t length);
1581 extern int	   jbd2_journal_finish_inode_data_buffers(
1582 			struct jbd2_inode *jinode);
1583 extern int	   jbd2_journal_begin_ordered_truncate(journal_t *journal,
1584 				struct jbd2_inode *inode, loff_t new_size);
1585 extern void	   jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode);
1586 extern void	   jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode);
1587 
1588 /*
1589  * journal_head management
1590  */
1591 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh);
1592 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh);
1593 void jbd2_journal_put_journal_head(struct journal_head *jh);
1594 
1595 /*
1596  * handle management
1597  */
1598 extern struct kmem_cache *jbd2_handle_cache;
1599 
jbd2_alloc_handle(gfp_t gfp_flags)1600 static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags)
1601 {
1602 	return kmem_cache_zalloc(jbd2_handle_cache, gfp_flags);
1603 }
1604 
jbd2_free_handle(handle_t * handle)1605 static inline void jbd2_free_handle(handle_t *handle)
1606 {
1607 	kmem_cache_free(jbd2_handle_cache, handle);
1608 }
1609 
1610 /*
1611  * jbd2_inode management (optional, for those file systems that want to use
1612  * dynamically allocated jbd2_inode structures)
1613  */
1614 extern struct kmem_cache *jbd2_inode_cache;
1615 
jbd2_alloc_inode(gfp_t gfp_flags)1616 static inline struct jbd2_inode *jbd2_alloc_inode(gfp_t gfp_flags)
1617 {
1618 	return kmem_cache_alloc(jbd2_inode_cache, gfp_flags);
1619 }
1620 
jbd2_free_inode(struct jbd2_inode * jinode)1621 static inline void jbd2_free_inode(struct jbd2_inode *jinode)
1622 {
1623 	kmem_cache_free(jbd2_inode_cache, jinode);
1624 }
1625 
1626 /* Primary revoke support */
1627 #define JOURNAL_REVOKE_DEFAULT_HASH 256
1628 extern int	   jbd2_journal_init_revoke(journal_t *, int);
1629 extern void	   jbd2_journal_destroy_revoke_record_cache(void);
1630 extern void	   jbd2_journal_destroy_revoke_table_cache(void);
1631 extern int __init jbd2_journal_init_revoke_record_cache(void);
1632 extern int __init jbd2_journal_init_revoke_table_cache(void);
1633 
1634 extern void	   jbd2_journal_destroy_revoke(journal_t *);
1635 extern int	   jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *);
1636 extern int	   jbd2_journal_cancel_revoke(handle_t *, struct journal_head *);
1637 extern void	   jbd2_journal_write_revoke_records(transaction_t *transaction,
1638 						     struct list_head *log_bufs);
1639 
1640 /* Recovery revoke support */
1641 extern int	jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t);
1642 extern int	jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t);
1643 extern void	jbd2_journal_clear_revoke(journal_t *);
1644 extern void	jbd2_journal_switch_revoke_table(journal_t *journal);
1645 extern void	jbd2_clear_buffer_revoked_flags(journal_t *journal);
1646 
1647 /*
1648  * The log thread user interface:
1649  *
1650  * Request space in the current transaction, and force transaction commit
1651  * transitions on demand.
1652  */
1653 
1654 int jbd2_log_start_commit(journal_t *journal, tid_t tid);
1655 int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
1656 int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
1657 int jbd2_transaction_committed(journal_t *journal, tid_t tid);
1658 int jbd2_complete_transaction(journal_t *journal, tid_t tid);
1659 int jbd2_log_do_checkpoint(journal_t *journal);
1660 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
1661 
1662 void __jbd2_log_wait_for_space(journal_t *journal);
1663 extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *);
1664 extern int jbd2_cleanup_journal_tail(journal_t *);
1665 
1666 /* Fast commit related APIs */
1667 int jbd2_fc_begin_commit(journal_t *journal, tid_t tid);
1668 int jbd2_fc_end_commit(journal_t *journal);
1669 int jbd2_fc_end_commit_fallback(journal_t *journal);
1670 int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out);
1671 int jbd2_submit_inode_data(journal_t *journal, struct jbd2_inode *jinode);
1672 int jbd2_wait_inode_data(journal_t *journal, struct jbd2_inode *jinode);
1673 int jbd2_fc_wait_bufs(journal_t *journal, int num_blks);
1674 int jbd2_fc_release_bufs(journal_t *journal);
1675 
1676 /*
1677  * is_journal_abort
1678  *
1679  * Simple test wrapper function to test the JBD2_ABORT state flag.  This
1680  * bit, when set, indicates that we have had a fatal error somewhere,
1681  * either inside the journaling layer or indicated to us by the client
1682  * (eg. ext3), and that we and should not commit any further
1683  * transactions.
1684  */
1685 
is_journal_aborted(journal_t * journal)1686 static inline int is_journal_aborted(journal_t *journal)
1687 {
1688 	return journal->j_flags & JBD2_ABORT;
1689 }
1690 
is_handle_aborted(handle_t * handle)1691 static inline int is_handle_aborted(handle_t *handle)
1692 {
1693 	if (handle->h_aborted || !handle->h_transaction)
1694 		return 1;
1695 	return is_journal_aborted(handle->h_transaction->t_journal);
1696 }
1697 
jbd2_journal_abort_handle(handle_t * handle)1698 static inline void jbd2_journal_abort_handle(handle_t *handle)
1699 {
1700 	handle->h_aborted = 1;
1701 }
1702 
1703 #endif /* __KERNEL__   */
1704 
1705 /* Comparison functions for transaction IDs: perform comparisons using
1706  * modulo arithmetic so that they work over sequence number wraps. */
1707 
tid_gt(tid_t x,tid_t y)1708 static inline int tid_gt(tid_t x, tid_t y)
1709 {
1710 	int difference = (x - y);
1711 	return (difference > 0);
1712 }
1713 
tid_geq(tid_t x,tid_t y)1714 static inline int tid_geq(tid_t x, tid_t y)
1715 {
1716 	int difference = (x - y);
1717 	return (difference >= 0);
1718 }
1719 
1720 extern int jbd2_journal_blocks_per_page(struct inode *inode);
1721 extern size_t journal_tag_bytes(journal_t *journal);
1722 
jbd2_journal_has_csum_v2or3_feature(journal_t * j)1723 static inline bool jbd2_journal_has_csum_v2or3_feature(journal_t *j)
1724 {
1725 	return jbd2_has_feature_csum2(j) || jbd2_has_feature_csum3(j);
1726 }
1727 
jbd2_journal_has_csum_v2or3(journal_t * journal)1728 static inline int jbd2_journal_has_csum_v2or3(journal_t *journal)
1729 {
1730 	WARN_ON_ONCE(jbd2_journal_has_csum_v2or3_feature(journal) &&
1731 		     journal->j_chksum_driver == NULL);
1732 
1733 	return journal->j_chksum_driver != NULL;
1734 }
1735 
jbd2_journal_get_num_fc_blks(journal_superblock_t * jsb)1736 static inline int jbd2_journal_get_num_fc_blks(journal_superblock_t *jsb)
1737 {
1738 	int num_fc_blocks = be32_to_cpu(jsb->s_num_fc_blks);
1739 
1740 	return num_fc_blocks ? num_fc_blocks : JBD2_DEFAULT_FAST_COMMIT_BLOCKS;
1741 }
1742 
1743 /*
1744  * Return number of free blocks in the log. Must be called under j_state_lock.
1745  */
jbd2_log_space_left(journal_t * journal)1746 static inline unsigned long jbd2_log_space_left(journal_t *journal)
1747 {
1748 	/* Allow for rounding errors */
1749 	long free = journal->j_free - 32;
1750 
1751 	if (journal->j_committing_transaction) {
1752 		free -= atomic_read(&journal->
1753                         j_committing_transaction->t_outstanding_credits);
1754 	}
1755 	return max_t(long, free, 0);
1756 }
1757 
1758 /*
1759  * Definitions which augment the buffer_head layer
1760  */
1761 
1762 /* journaling buffer types */
1763 #define BJ_None		0	/* Not journaled */
1764 #define BJ_Metadata	1	/* Normal journaled metadata */
1765 #define BJ_Forget	2	/* Buffer superseded by this transaction */
1766 #define BJ_Shadow	3	/* Buffer contents being shadowed to the log */
1767 #define BJ_Reserved	4	/* Buffer is reserved for access by journal */
1768 #define BJ_Types	5
1769 
1770 /* JBD uses a CRC32 checksum */
1771 #define JBD_MAX_CHECKSUM_SIZE 4
1772 
jbd2_chksum(journal_t * journal,u32 crc,const void * address,unsigned int length)1773 static inline u32 jbd2_chksum(journal_t *journal, u32 crc,
1774 			      const void *address, unsigned int length)
1775 {
1776 	struct {
1777 		struct shash_desc shash;
1778 		char ctx[JBD_MAX_CHECKSUM_SIZE];
1779 	} desc;
1780 	int err;
1781 
1782 	BUG_ON(crypto_shash_descsize(journal->j_chksum_driver) >
1783 		JBD_MAX_CHECKSUM_SIZE);
1784 
1785 	desc.shash.tfm = journal->j_chksum_driver;
1786 	*(u32 *)desc.ctx = crc;
1787 
1788 	err = crypto_shash_update(&desc.shash, address, length);
1789 	BUG_ON(err);
1790 
1791 	return *(u32 *)desc.ctx;
1792 }
1793 
1794 /* Return most recent uncommitted transaction */
jbd2_get_latest_transaction(journal_t * journal)1795 static inline tid_t  jbd2_get_latest_transaction(journal_t *journal)
1796 {
1797 	tid_t tid;
1798 
1799 	read_lock(&journal->j_state_lock);
1800 	tid = journal->j_commit_request;
1801 	if (journal->j_running_transaction)
1802 		tid = journal->j_running_transaction->t_tid;
1803 	read_unlock(&journal->j_state_lock);
1804 	return tid;
1805 }
1806 
jbd2_handle_buffer_credits(handle_t * handle)1807 static inline int jbd2_handle_buffer_credits(handle_t *handle)
1808 {
1809 	journal_t *journal;
1810 
1811 	if (!handle->h_reserved)
1812 		journal = handle->h_transaction->t_journal;
1813 	else
1814 		journal = handle->h_journal;
1815 
1816 	return handle->h_total_credits -
1817 		DIV_ROUND_UP(handle->h_revoke_credits_requested,
1818 			     journal->j_revoke_records_per_block);
1819 }
1820 
1821 #ifdef __KERNEL__
1822 
1823 #define buffer_trace_init(bh)	do {} while (0)
1824 #define print_buffer_fields(bh)	do {} while (0)
1825 #define print_buffer_trace(bh)	do {} while (0)
1826 #define BUFFER_TRACE(bh, info)	do {} while (0)
1827 #define BUFFER_TRACE2(bh, bh2, info)	do {} while (0)
1828 #define JBUFFER_TRACE(jh, info)	do {} while (0)
1829 
1830 #endif	/* __KERNEL__ */
1831 
1832 #define EFSBADCRC	EBADMSG		/* Bad CRC detected */
1833 #define EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
1834 
1835 #endif	/* _LINUX_JBD2_H */
1836