2 * linux/include/linux/jbd2.h
4 * Written by Stephen C. Tweedie <sct@redhat.com>
6 * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved
8 * This file is part of the Linux kernel and is made available under
9 * the terms of the GNU General Public License, version 2, or at your
10 * option, any later version, incorporated herein by reference.
12 * Definitions for transaction data structures for the buffer cache
13 * filesystem journaling support.
19 /* Allow this file to be included directly into e2fsprogs */
21 #include "jfs_compat.h"
25 #include <linux/types.h>
26 #include <linux/buffer_head.h>
27 #include <linux/journal-head.h>
28 #include <linux/stddef.h>
29 #include <linux/mutex.h>
30 #include <linux/timer.h>
31 #include <linux/slab.h>
32 #include <linux/bit_spinlock.h>
33 #include <crypto/hash.h>
36 #define journal_oom_retry 1
39 * Define JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds
40 * certain classes of error which can occur due to failed IOs. Under
41 * normal use we want ext4 to continue after such errors, because
42 * hardware _can_ fail, but for debugging purposes when running tests on
43 * known-good hardware we may want to trap these errors.
45 #undef JBD2_PARANOID_IOFAIL
48 * The default maximum commit age, in seconds.
50 #define JBD2_DEFAULT_MAX_COMMIT_AGE 5
52 #ifdef CONFIG_JBD2_DEBUG
54 * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal
55 * consistency checks. By default we don't do this unless
56 * CONFIG_JBD2_DEBUG is on.
58 #define JBD2_EXPENSIVE_CHECKING
59 extern ushort jbd2_journal_enable_debug
;
60 void __jbd2_debug(int level
, const char *file
, const char *func
,
61 unsigned int line
, const char *fmt
, ...);
63 #define jbd_debug(n, fmt, a...) \
64 __jbd2_debug((n), __FILE__, __func__, __LINE__, (fmt), ##a)
66 #define jbd_debug(n, fmt, a...) /**/
69 extern void *jbd2_alloc(size_t size
, gfp_t flags
);
70 extern void jbd2_free(void *ptr
, size_t size
);
72 #define JBD2_MIN_JOURNAL_BLOCKS 1024
77 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process.
79 * All filesystem modifications made by the process go
80 * through this handle. Recursive operations (such as quota operations)
81 * are gathered into a single update.
83 * The buffer credits field is used to account for journaled buffers
84 * being modified by the running process. To ensure that there is
85 * enough log space for all outstanding operations, we need to limit the
86 * number of outstanding buffers possible at any time. When the
87 * operation completes, any buffer credits not used are credited back to
88 * the transaction, so that at all times we know how many buffers the
89 * outstanding updates on a transaction might possibly touch.
91 * This is an opaque datatype.
93 typedef struct jbd2_journal_handle handle_t
; /* Atomic operation type */
97 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem.
99 * journal_t is linked to from the fs superblock structure.
101 * We use the journal_t to keep track of all outstanding transaction
102 * activity on the filesystem, and to manage the state of the log
105 * This is an opaque datatype.
107 typedef struct journal_s journal_t
; /* Journal control structure */
111 * Internal structures used by the logging mechanism:
114 #define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
121 * Descriptor block types:
124 #define JBD2_DESCRIPTOR_BLOCK 1
125 #define JBD2_COMMIT_BLOCK 2
126 #define JBD2_SUPERBLOCK_V1 3
127 #define JBD2_SUPERBLOCK_V2 4
128 #define JBD2_REVOKE_BLOCK 5
131 * Standard header for all descriptor blocks:
133 typedef struct journal_header_s
143 #define JBD2_CRC32_CHKSUM 1
144 #define JBD2_MD5_CHKSUM 2
145 #define JBD2_SHA1_CHKSUM 3
146 #define JBD2_CRC32C_CHKSUM 4
148 #define JBD2_CRC32_CHKSUM_SIZE 4
150 #define JBD2_CHECKSUM_BYTES (32 / sizeof(u32))
152 * Commit block header for storing transactional checksums:
154 * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum*
155 * fields are used to store a checksum of the descriptor and data blocks.
157 * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum
158 * field is used to store crc32c(uuid+commit_block). Each journal metadata
159 * block gets its own checksum, and data block checksums are stored in
160 * journal_block_tag (in the descriptor). The other h_chksum* fields are
163 * If FEATURE_INCOMPAT_CSUM_V3 is set, the descriptor block uses
164 * journal_block_tag3_t to store a full 32-bit checksum. Everything else
167 * Checksum v1, v2, and v3 are mutually exclusive features.
169 struct commit_header
{
173 unsigned char h_chksum_type
;
174 unsigned char h_chksum_size
;
175 unsigned char h_padding
[2];
176 __be32 h_chksum
[JBD2_CHECKSUM_BYTES
];
178 __be32 h_commit_nsec
;
182 * The block tag: used to describe a single buffer in the journal.
183 * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this
184 * raw struct shouldn't be used for pointer math or sizeof() - use
185 * journal_tag_bytes(journal) instead to compute this.
187 typedef struct journal_block_tag3_s
189 __be32 t_blocknr
; /* The on-disk block number */
190 __be32 t_flags
; /* See below */
191 __be32 t_blocknr_high
; /* most-significant high 32bits. */
192 __be32 t_checksum
; /* crc32c(uuid+seq+block) */
193 } journal_block_tag3_t
;
195 typedef struct journal_block_tag_s
197 __be32 t_blocknr
; /* The on-disk block number */
198 __be16 t_checksum
; /* truncated crc32c(uuid+seq+block) */
199 __be16 t_flags
; /* See below */
200 __be32 t_blocknr_high
; /* most-significant high 32bits. */
201 } journal_block_tag_t
;
203 /* Tail of descriptor or revoke block, for checksumming */
204 struct jbd2_journal_block_tail
{
205 __be32 t_checksum
; /* crc32c(uuid+descr_block) */
209 * The revoke descriptor: used on disk to describe a series of blocks to
210 * be revoked from the log
212 typedef struct jbd2_journal_revoke_header_s
214 journal_header_t r_header
;
215 __be32 r_count
; /* Count of bytes used in the block */
216 } jbd2_journal_revoke_header_t
;
218 /* Definitions for the journal tag flags word: */
219 #define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */
220 #define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */
221 #define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */
222 #define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
226 * The journal superblock. All fields are in big-endian byte order.
228 typedef struct journal_superblock_s
231 journal_header_t s_header
;
234 /* Static information describing the journal */
235 __be32 s_blocksize
; /* journal device blocksize */
236 __be32 s_maxlen
; /* total blocks in journal file */
237 __be32 s_first
; /* first block of log information */
240 /* Dynamic information describing the current state of the log */
241 __be32 s_sequence
; /* first commit ID expected in log */
242 __be32 s_start
; /* blocknr of start of log */
245 /* Error value, as set by jbd2_journal_abort(). */
249 /* Remaining fields are only valid in a version-2 superblock */
250 __be32 s_feature_compat
; /* compatible feature set */
251 __be32 s_feature_incompat
; /* incompatible feature set */
252 __be32 s_feature_ro_compat
; /* readonly-compatible feature set */
254 __u8 s_uuid
[16]; /* 128-bit uuid for journal */
257 __be32 s_nr_users
; /* Nr of filesystems sharing log */
259 __be32 s_dynsuper
; /* Blocknr of dynamic superblock copy*/
262 __be32 s_max_transaction
; /* Limit of journal blocks per trans.*/
263 __be32 s_max_trans_data
; /* Limit of data blocks per trans. */
266 __u8 s_checksum_type
; /* checksum type */
269 __be32 s_checksum
; /* crc32c(superblock) */
272 __u8 s_users
[16*48]; /* ids of all fs'es sharing the log */
274 } journal_superblock_t
;
276 /* Use the jbd2_{has,set,clear}_feature_* helpers; these will be removed */
277 #define JBD2_HAS_COMPAT_FEATURE(j,mask) \
278 ((j)->j_format_version >= 2 && \
279 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
280 #define JBD2_HAS_RO_COMPAT_FEATURE(j,mask) \
281 ((j)->j_format_version >= 2 && \
282 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
283 #define JBD2_HAS_INCOMPAT_FEATURE(j,mask) \
284 ((j)->j_format_version >= 2 && \
285 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
287 #define JBD2_FEATURE_COMPAT_CHECKSUM 0x00000001
289 #define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001
290 #define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002
291 #define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004
292 #define JBD2_FEATURE_INCOMPAT_CSUM_V2 0x00000008
293 #define JBD2_FEATURE_INCOMPAT_CSUM_V3 0x00000010
295 /* See "journal feature predicate functions" below */
297 /* Features known to this kernel version: */
298 #define JBD2_KNOWN_COMPAT_FEATURES JBD2_FEATURE_COMPAT_CHECKSUM
299 #define JBD2_KNOWN_ROCOMPAT_FEATURES 0
300 #define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \
301 JBD2_FEATURE_INCOMPAT_64BIT | \
302 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT | \
303 JBD2_FEATURE_INCOMPAT_CSUM_V2 | \
304 JBD2_FEATURE_INCOMPAT_CSUM_V3)
308 #include <linux/fs.h>
309 #include <linux/sched.h>
311 enum jbd_state_bits
{
312 BH_JBD
/* Has an attached ext3 journal_head */
314 BH_JWrite
, /* Being written to log (@@@ DEBUGGING) */
315 BH_Freed
, /* Has been freed (truncated) */
316 BH_Revoked
, /* Has been revoked from the log */
317 BH_RevokeValid
, /* Revoked flag is valid */
318 BH_JBDDirty
, /* Is dirty but journaled */
319 BH_State
, /* Pins most journal_head state */
320 BH_JournalHead
, /* Pins bh->b_private and jh->b_bh */
321 BH_Shadow
, /* IO on shadow buffer is running */
322 BH_Verified
, /* Metadata block has been verified ok */
323 BH_JBDPrivateStart
, /* First bit available for private use by FS */
327 BUFFER_FNS(JWrite
, jwrite
)
328 BUFFER_FNS(JBDDirty
, jbddirty
)
329 TAS_BUFFER_FNS(JBDDirty
, jbddirty
)
330 BUFFER_FNS(Revoked
, revoked
)
331 TAS_BUFFER_FNS(Revoked
, revoked
)
332 BUFFER_FNS(RevokeValid
, revokevalid
)
333 TAS_BUFFER_FNS(RevokeValid
, revokevalid
)
334 BUFFER_FNS(Freed
, freed
)
335 BUFFER_FNS(Shadow
, shadow
)
336 BUFFER_FNS(Verified
, verified
)
338 static inline struct buffer_head
*jh2bh(struct journal_head
*jh
)
343 static inline struct journal_head
*bh2jh(struct buffer_head
*bh
)
345 return bh
->b_private
;
348 static inline void jbd_lock_bh_state(struct buffer_head
*bh
)
350 bit_spin_lock(BH_State
, &bh
->b_state
);
353 static inline int jbd_trylock_bh_state(struct buffer_head
*bh
)
355 return bit_spin_trylock(BH_State
, &bh
->b_state
);
358 static inline int jbd_is_locked_bh_state(struct buffer_head
*bh
)
360 return bit_spin_is_locked(BH_State
, &bh
->b_state
);
363 static inline void jbd_unlock_bh_state(struct buffer_head
*bh
)
365 bit_spin_unlock(BH_State
, &bh
->b_state
);
368 static inline void jbd_lock_bh_journal_head(struct buffer_head
*bh
)
370 bit_spin_lock(BH_JournalHead
, &bh
->b_state
);
373 static inline void jbd_unlock_bh_journal_head(struct buffer_head
*bh
)
375 bit_spin_unlock(BH_JournalHead
, &bh
->b_state
);
378 #define J_ASSERT(assert) BUG_ON(!(assert))
380 #define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
381 #define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
383 #if defined(JBD2_PARANOID_IOFAIL)
384 #define J_EXPECT(expr, why...) J_ASSERT(expr)
385 #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr)
386 #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr)
388 #define __journal_expect(expr, why...) \
393 "JBD2 unexpected failure: %s: %s;\n", \
395 printk(KERN_ERR why "\n"); \
399 #define J_EXPECT(expr, why...) __journal_expect(expr, ## why)
400 #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why)
401 #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why)
404 /* Flags in jbd_inode->i_flags */
405 #define __JI_COMMIT_RUNNING 0
406 /* Commit of the inode data in progress. We use this flag to protect us from
407 * concurrent deletion of inode. We cannot use reference to inode for this
408 * since we cannot afford doing last iput() on behalf of kjournald
410 #define JI_COMMIT_RUNNING (1 << __JI_COMMIT_RUNNING)
413 * struct jbd_inode is the structure linking inodes in ordered mode
414 * present in a transaction so that we can sync them during commit.
417 /* Which transaction does this inode belong to? Either the running
418 * transaction or the committing one. [j_list_lock] */
419 transaction_t
*i_transaction
;
421 /* Pointer to the running transaction modifying inode's data in case
422 * there is already a committing transaction touching it. [j_list_lock] */
423 transaction_t
*i_next_transaction
;
425 /* List of inodes in the i_transaction [j_list_lock] */
426 struct list_head i_list
;
428 /* VFS inode this inode belongs to [constant during the lifetime
429 * of the structure] */
430 struct inode
*i_vfs_inode
;
432 /* Flags of inode [j_list_lock] */
433 unsigned long i_flags
;
436 struct jbd2_revoke_table_s
;
439 * struct handle_s - The handle_s type is the concrete type associated with
441 * @h_transaction: Which compound transaction is this update a part of?
442 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty.
443 * @h_ref: Reference count on this handle
444 * @h_err: Field for caller's use to track errors through large fs operations
445 * @h_sync: flag for sync-on-close
446 * @h_jdata: flag to force data journaling
447 * @h_aborted: flag indicating fatal error on handle
450 /* Docbook can't yet cope with the bit fields, but will leave the documentation
451 * in so it can be fixed later.
454 struct jbd2_journal_handle
457 /* Which compound transaction is this update a part of? */
458 transaction_t
*h_transaction
;
459 /* Which journal handle belongs to - used iff h_reserved set */
460 journal_t
*h_journal
;
463 /* Handle reserved for finishing the logical operation */
464 handle_t
*h_rsv_handle
;
466 /* Number of remaining buffers we are allowed to dirty: */
467 int h_buffer_credits
;
469 /* Reference count on this handle */
472 /* Field for caller's use to track errors through large fs */
476 /* Flags [no locking] */
477 unsigned int h_sync
: 1; /* sync-on-close */
478 unsigned int h_jdata
: 1; /* force data journaling */
479 unsigned int h_reserved
: 1; /* handle with reserved credits */
480 unsigned int h_aborted
: 1; /* fatal error on handle */
481 unsigned int h_type
: 8; /* for handle statistics */
482 unsigned int h_line_no
: 16; /* for handle statistics */
484 unsigned long h_start_jiffies
;
485 unsigned int h_requested_credits
;
487 #ifdef CONFIG_DEBUG_LOCK_ALLOC
488 struct lockdep_map h_lockdep_map
;
494 * Some stats for checkpoint phase
496 struct transaction_chp_stats_s
{
497 unsigned long cs_chp_time
;
498 __u32 cs_forced_to_close
;
503 /* The transaction_t type is the guts of the journaling mechanism. It
504 * tracks a compound transaction through its various states:
506 * RUNNING: accepting new updates
507 * LOCKED: Updates still running but we don't accept new ones
508 * RUNDOWN: Updates are tidying up but have finished requesting
509 * new buffers to modify (state not used for now)
510 * FLUSH: All updates complete, but we are still writing to disk
511 * COMMIT: All data on disk, writing commit record
512 * FINISHED: We still have to keep the transaction for checkpointing.
514 * The transaction keeps track of all of the buffers modified by a
515 * running transaction, and all of the buffers committed but not yet
516 * flushed to home for finished transactions.
523 * ->jbd_lock_bh_journal_head() (This is "innermost")
526 * ->jbd_lock_bh_state()
528 * jbd_lock_bh_state()
535 * ->j_list_lock (journal_unmap_buffer)
541 /* Pointer to the journal for this transaction. [no locking] */
542 journal_t
*t_journal
;
544 /* Sequence number for this transaction [no locking] */
548 * Transaction's current state
549 * [no locking - only kjournald2 alters this]
550 * [j_list_lock] guards transition of a transaction into T_FINISHED
551 * state and subsequent call of __jbd2_journal_drop_transaction()
552 * FIXME: needs barriers
553 * KLUDGE: [use j_state_lock]
567 * Where in the log does this transaction's commit start? [no locking]
569 unsigned long t_log_start
;
571 /* Number of buffers on the t_buffers list [j_list_lock] */
575 * Doubly-linked circular list of all buffers reserved but not yet
576 * modified by this transaction [j_list_lock]
578 struct journal_head
*t_reserved_list
;
581 * Doubly-linked circular list of all metadata buffers owned by this
582 * transaction [j_list_lock]
584 struct journal_head
*t_buffers
;
587 * Doubly-linked circular list of all forget buffers (superseded
588 * buffers which we can un-checkpoint once this transaction commits)
591 struct journal_head
*t_forget
;
594 * Doubly-linked circular list of all buffers still to be flushed before
595 * this transaction can be checkpointed. [j_list_lock]
597 struct journal_head
*t_checkpoint_list
;
600 * Doubly-linked circular list of all buffers submitted for IO while
601 * checkpointing. [j_list_lock]
603 struct journal_head
*t_checkpoint_io_list
;
606 * Doubly-linked circular list of metadata buffers being shadowed by log
607 * IO. The IO buffers on the iobuf list and the shadow buffers on this
608 * list match each other one for one at all times. [j_list_lock]
610 struct journal_head
*t_shadow_list
;
613 * List of inodes whose data we've modified in data=ordered mode.
616 struct list_head t_inode_list
;
619 * Protects info related to handles
621 spinlock_t t_handle_lock
;
624 * Longest time some handle had to wait for running transaction
626 unsigned long t_max_wait
;
629 * When transaction started
631 unsigned long t_start
;
634 * When commit was requested
636 unsigned long t_requested
;
639 * Checkpointing stats [j_checkpoint_sem]
641 struct transaction_chp_stats_s t_chp_stats
;
644 * Number of outstanding updates running on this transaction
650 * Number of buffers reserved for use by all handles in this transaction
651 * handle but not yet modified. [t_handle_lock]
653 atomic_t t_outstanding_credits
;
656 * Forward and backward links for the circular list of all transactions
657 * awaiting checkpoint. [j_list_lock]
659 transaction_t
*t_cpnext
, *t_cpprev
;
662 * When will the transaction expire (become due for commit), in jiffies?
665 unsigned long t_expires
;
668 * When this transaction started, in nanoseconds [no locking]
670 ktime_t t_start_time
;
673 * How many handles used this transaction? [t_handle_lock]
675 atomic_t t_handle_count
;
678 * This transaction is being forced and some process is
679 * waiting for it to finish.
681 unsigned int t_synchronous_commit
:1;
683 /* Disk flush needs to be sent to fs partition [no locking] */
684 int t_need_data_flush
;
687 * For use by the filesystem to store fs-specific data
688 * structures associated with the transaction
690 struct list_head t_private_list
;
693 struct transaction_run_stats_s
{
694 unsigned long rs_wait
;
695 unsigned long rs_request_delay
;
696 unsigned long rs_running
;
697 unsigned long rs_locked
;
698 unsigned long rs_flushing
;
699 unsigned long rs_logging
;
701 __u32 rs_handle_count
;
703 __u32 rs_blocks_logged
;
706 struct transaction_stats_s
{
707 unsigned long ts_tid
;
708 unsigned long ts_requested
;
709 struct transaction_run_stats_s run
;
712 static inline unsigned long
713 jbd2_time_diff(unsigned long start
, unsigned long end
)
718 return end
+ (MAX_JIFFY_OFFSET
- start
);
721 #define JBD2_NR_BATCH 64
724 * struct journal_s - The journal_s type is the concrete type associated with
726 * @j_flags: General journaling state flags
727 * @j_errno: Is there an outstanding uncleared error on the journal (from a
729 * @j_sb_buffer: First part of superblock buffer
730 * @j_superblock: Second part of superblock buffer
731 * @j_format_version: Version of the superblock format
732 * @j_state_lock: Protect the various scalars in the journal
733 * @j_barrier_count: Number of processes waiting to create a barrier lock
734 * @j_barrier: The barrier lock itself
735 * @j_running_transaction: The current running transaction..
736 * @j_committing_transaction: the transaction we are pushing to disk
737 * @j_checkpoint_transactions: a linked circular list of all transactions
738 * waiting for checkpointing
739 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction
740 * to start committing, or for a barrier lock to be released
741 * @j_wait_done_commit: Wait queue for waiting for commit to complete
742 * @j_wait_commit: Wait queue to trigger commit
743 * @j_wait_updates: Wait queue to wait for updates to complete
744 * @j_wait_reserved: Wait queue to wait for reserved buffer credits to drop
745 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints
746 * @j_head: Journal head - identifies the first unused block in the journal
747 * @j_tail: Journal tail - identifies the oldest still-used block in the
749 * @j_free: Journal free - how many free blocks are there in the journal?
750 * @j_first: The block number of the first usable block
751 * @j_last: The block number one beyond the last usable block
752 * @j_dev: Device where we store the journal
753 * @j_blocksize: blocksize for the location where we store the journal.
754 * @j_blk_offset: starting block offset for into the device where we store the
756 * @j_fs_dev: Device which holds the client fs. For internal journal this will
758 * @j_reserved_credits: Number of buffers reserved from the running transaction
759 * @j_maxlen: Total maximum capacity of the journal region on disk.
760 * @j_list_lock: Protects the buffer lists and internal buffer state.
761 * @j_inode: Optional inode where we store the journal. If present, all journal
762 * block numbers are mapped into this inode via bmap().
763 * @j_tail_sequence: Sequence number of the oldest transaction in the log
764 * @j_transaction_sequence: Sequence number of the next transaction to grant
765 * @j_commit_sequence: Sequence number of the most recently committed
767 * @j_commit_request: Sequence number of the most recent transaction wanting
769 * @j_uuid: Uuid of client object.
770 * @j_task: Pointer to the current commit thread for this journal
771 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a
772 * single compound commit transaction
773 * @j_commit_interval: What is the maximum transaction lifetime before we begin
775 * @j_commit_timer: The timer used to wakeup the commit thread
776 * @j_revoke_lock: Protect the revoke table
777 * @j_revoke: The revoke table - maintains the list of revoked blocks in the
778 * current transaction.
779 * @j_revoke_table: alternate revoke tables for j_revoke
780 * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction
781 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the
782 * number that will fit in j_blocksize
783 * @j_last_sync_writer: most recent pid which did a synchronous write
784 * @j_history: Buffer storing the transactions statistics history
785 * @j_history_max: Maximum number of transactions in the statistics history
786 * @j_history_cur: Current number of transactions in the statistics history
787 * @j_history_lock: Protect the transactions statistics history
788 * @j_proc_entry: procfs entry for the jbd statistics directory
789 * @j_stats: Overall statistics
790 * @j_private: An opaque pointer to fs-private information.
795 /* General journaling state flags [j_state_lock] */
796 unsigned long j_flags
;
799 * Is there an outstanding uncleared error on the journal (from a prior
800 * abort)? [j_state_lock]
804 /* The superblock buffer */
805 struct buffer_head
*j_sb_buffer
;
806 journal_superblock_t
*j_superblock
;
808 /* Version of the superblock format */
809 int j_format_version
;
812 * Protect the various scalars in the journal
814 rwlock_t j_state_lock
;
817 * Number of processes waiting to create a barrier lock [j_state_lock]
821 /* The barrier lock itself */
822 struct mutex j_barrier
;
825 * Transactions: The current running transaction...
826 * [j_state_lock] [caller holding open handle]
828 transaction_t
*j_running_transaction
;
831 * the transaction we are pushing to disk
832 * [j_state_lock] [caller holding open handle]
834 transaction_t
*j_committing_transaction
;
837 * ... and a linked circular list of all transactions waiting for
838 * checkpointing. [j_list_lock]
840 transaction_t
*j_checkpoint_transactions
;
843 * Wait queue for waiting for a locked transaction to start committing,
844 * or for a barrier lock to be released
846 wait_queue_head_t j_wait_transaction_locked
;
848 /* Wait queue for waiting for commit to complete */
849 wait_queue_head_t j_wait_done_commit
;
851 /* Wait queue to trigger commit */
852 wait_queue_head_t j_wait_commit
;
854 /* Wait queue to wait for updates to complete */
855 wait_queue_head_t j_wait_updates
;
857 /* Wait queue to wait for reserved buffer credits to drop */
858 wait_queue_head_t j_wait_reserved
;
860 /* Semaphore for locking against concurrent checkpoints */
861 struct mutex j_checkpoint_mutex
;
864 * List of buffer heads used by the checkpoint routine. This
865 * was moved from jbd2_log_do_checkpoint() to reduce stack
866 * usage. Access to this array is controlled by the
867 * j_checkpoint_mutex. [j_checkpoint_mutex]
869 struct buffer_head
*j_chkpt_bhs
[JBD2_NR_BATCH
];
872 * Journal head: identifies the first unused block in the journal.
875 unsigned long j_head
;
878 * Journal tail: identifies the oldest still-used block in the journal.
881 unsigned long j_tail
;
884 * Journal free: how many free blocks are there in the journal?
887 unsigned long j_free
;
890 * Journal start and end: the block numbers of the first usable block
891 * and one beyond the last usable block in the journal. [j_state_lock]
893 unsigned long j_first
;
894 unsigned long j_last
;
897 * Device, blocksize and starting block offset for the location where we
900 struct block_device
*j_dev
;
902 unsigned long long j_blk_offset
;
903 char j_devname
[BDEVNAME_SIZE
+24];
906 * Device which holds the client fs. For internal journal this will be
909 struct block_device
*j_fs_dev
;
911 /* Total maximum capacity of the journal region on disk. */
912 unsigned int j_maxlen
;
914 /* Number of buffers reserved from the running transaction */
915 atomic_t j_reserved_credits
;
918 * Protects the buffer lists and internal buffer state.
920 spinlock_t j_list_lock
;
922 /* Optional inode where we store the journal. If present, all */
923 /* journal block numbers are mapped into this inode via */
925 struct inode
*j_inode
;
928 * Sequence number of the oldest transaction in the log [j_state_lock]
930 tid_t j_tail_sequence
;
933 * Sequence number of the next transaction to grant [j_state_lock]
935 tid_t j_transaction_sequence
;
938 * Sequence number of the most recently committed transaction
941 tid_t j_commit_sequence
;
944 * Sequence number of the most recent transaction wanting commit
947 tid_t j_commit_request
;
950 * Journal uuid: identifies the object (filesystem, LVM volume etc)
951 * backed by this journal. This will eventually be replaced by an array
952 * of uuids, allowing us to index multiple devices within a single
953 * journal and to perform atomic updates across them.
957 /* Pointer to the current commit thread for this journal */
958 struct task_struct
*j_task
;
961 * Maximum number of metadata buffers to allow in a single compound
964 int j_max_transaction_buffers
;
967 * What is the maximum transaction lifetime before we begin a commit?
969 unsigned long j_commit_interval
;
971 /* The timer used to wakeup the commit thread: */
972 struct timer_list j_commit_timer
;
975 * The revoke table: maintains the list of revoked blocks in the
976 * current transaction. [j_revoke_lock]
978 spinlock_t j_revoke_lock
;
979 struct jbd2_revoke_table_s
*j_revoke
;
980 struct jbd2_revoke_table_s
*j_revoke_table
[2];
983 * array of bhs for jbd2_journal_commit_transaction
985 struct buffer_head
**j_wbuf
;
989 * this is the pid of hte last person to run a synchronous operation
990 * through the journal
992 pid_t j_last_sync_writer
;
995 * the average amount of time in nanoseconds it takes to commit a
996 * transaction to disk. [j_state_lock]
998 u64 j_average_commit_time
;
1001 * minimum and maximum times that we should wait for
1002 * additional filesystem operations to get batched into a
1003 * synchronous handle in microseconds
1005 u32 j_min_batch_time
;
1006 u32 j_max_batch_time
;
1008 /* This function is called when a transaction is closed */
1009 void (*j_commit_callback
)(journal_t
*,
1013 * Journal statistics
1015 spinlock_t j_history_lock
;
1016 struct proc_dir_entry
*j_proc_entry
;
1017 struct transaction_stats_s j_stats
;
1019 /* Failed journal commit ID */
1020 unsigned int j_failed_commit
;
1023 * An opaque pointer to fs-private information. ext3 puts its
1024 * superblock pointer here
1028 /* Reference to checksum algorithm driver via cryptoapi */
1029 struct crypto_shash
*j_chksum_driver
;
1031 /* Precomputed journal UUID checksum for seeding other checksums */
1035 /* journal feature predicate functions */
1036 #define JBD2_FEATURE_COMPAT_FUNCS(name, flagname) \
1037 static inline bool jbd2_has_feature_##name(journal_t *j) \
1039 return ((j)->j_format_version >= 2 && \
1040 ((j)->j_superblock->s_feature_compat & \
1041 cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname)) != 0); \
1043 static inline void jbd2_set_feature_##name(journal_t *j) \
1045 (j)->j_superblock->s_feature_compat |= \
1046 cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \
1048 static inline void jbd2_clear_feature_##name(journal_t *j) \
1050 (j)->j_superblock->s_feature_compat &= \
1051 ~cpu_to_be32(JBD2_FEATURE_COMPAT_##flagname); \
1054 #define JBD2_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
1055 static inline bool jbd2_has_feature_##name(journal_t *j) \
1057 return ((j)->j_format_version >= 2 && \
1058 ((j)->j_superblock->s_feature_ro_compat & \
1059 cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname)) != 0); \
1061 static inline void jbd2_set_feature_##name(journal_t *j) \
1063 (j)->j_superblock->s_feature_ro_compat |= \
1064 cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \
1066 static inline void jbd2_clear_feature_##name(journal_t *j) \
1068 (j)->j_superblock->s_feature_ro_compat &= \
1069 ~cpu_to_be32(JBD2_FEATURE_RO_COMPAT_##flagname); \
1072 #define JBD2_FEATURE_INCOMPAT_FUNCS(name, flagname) \
1073 static inline bool jbd2_has_feature_##name(journal_t *j) \
1075 return ((j)->j_format_version >= 2 && \
1076 ((j)->j_superblock->s_feature_incompat & \
1077 cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname)) != 0); \
1079 static inline void jbd2_set_feature_##name(journal_t *j) \
1081 (j)->j_superblock->s_feature_incompat |= \
1082 cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \
1084 static inline void jbd2_clear_feature_##name(journal_t *j) \
1086 (j)->j_superblock->s_feature_incompat &= \
1087 ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_##flagname); \
1090 JBD2_FEATURE_COMPAT_FUNCS(checksum
, CHECKSUM
)
1092 JBD2_FEATURE_INCOMPAT_FUNCS(revoke
, REVOKE
)
1093 JBD2_FEATURE_INCOMPAT_FUNCS(64bit
, 64BIT
)
1094 JBD2_FEATURE_INCOMPAT_FUNCS(async_commit
, ASYNC_COMMIT
)
1095 JBD2_FEATURE_INCOMPAT_FUNCS(csum2
, CSUM_V2
)
1096 JBD2_FEATURE_INCOMPAT_FUNCS(csum3
, CSUM_V3
)
1099 * Journal flag definitions
1101 #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */
1102 #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */
1103 #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */
1104 #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */
1105 #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */
1106 #define JBD2_BARRIER 0x020 /* Use IDE barriers */
1107 #define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file
1108 * data write error in ordered
1110 #define JBD2_REC_ERR 0x080 /* The errno in the sb has been recorded */
1113 * Function declarations for the journaling transaction and buffer
1117 /* Filing buffers */
1118 extern void jbd2_journal_unfile_buffer(journal_t
*, struct journal_head
*);
1119 extern void __jbd2_journal_refile_buffer(struct journal_head
*);
1120 extern void jbd2_journal_refile_buffer(journal_t
*, struct journal_head
*);
1121 extern void __jbd2_journal_file_buffer(struct journal_head
*, transaction_t
*, int);
1122 extern void __journal_free_buffer(struct journal_head
*bh
);
1123 extern void jbd2_journal_file_buffer(struct journal_head
*, transaction_t
*, int);
1124 extern void __journal_clean_data_list(transaction_t
*transaction
);
1125 static inline void jbd2_file_log_bh(struct list_head
*head
, struct buffer_head
*bh
)
1127 list_add_tail(&bh
->b_assoc_buffers
, head
);
1129 static inline void jbd2_unfile_log_bh(struct buffer_head
*bh
)
1131 list_del_init(&bh
->b_assoc_buffers
);
1134 /* Log buffer allocation */
1135 struct buffer_head
*jbd2_journal_get_descriptor_buffer(transaction_t
*, int);
1136 void jbd2_descriptor_block_csum_set(journal_t
*, struct buffer_head
*);
1137 int jbd2_journal_next_log_block(journal_t
*, unsigned long long *);
1138 int jbd2_journal_get_log_tail(journal_t
*journal
, tid_t
*tid
,
1139 unsigned long *block
);
1140 int __jbd2_update_log_tail(journal_t
*journal
, tid_t tid
, unsigned long block
);
1141 void jbd2_update_log_tail(journal_t
*journal
, tid_t tid
, unsigned long block
);
1143 /* Commit management */
1144 extern void jbd2_journal_commit_transaction(journal_t
*);
1146 /* Checkpoint list management */
1147 void __jbd2_journal_clean_checkpoint_list(journal_t
*journal
, bool destroy
);
1148 int __jbd2_journal_remove_checkpoint(struct journal_head
*);
1149 void jbd2_journal_destroy_checkpoint(journal_t
*journal
);
1150 void __jbd2_journal_insert_checkpoint(struct journal_head
*, transaction_t
*);
1157 struct jbd2_buffer_trigger_type
{
1159 * Fired a the moment data to write to the journal are known to be
1160 * stable - so either at the moment b_frozen_data is created or just
1161 * before a buffer is written to the journal. mapped_data is a mapped
1162 * buffer that is the frozen data for commit.
1164 void (*t_frozen
)(struct jbd2_buffer_trigger_type
*type
,
1165 struct buffer_head
*bh
, void *mapped_data
,
1169 * Fired during journal abort for dirty buffers that will not be
1172 void (*t_abort
)(struct jbd2_buffer_trigger_type
*type
,
1173 struct buffer_head
*bh
);
1176 extern void jbd2_buffer_frozen_trigger(struct journal_head
*jh
,
1178 struct jbd2_buffer_trigger_type
*triggers
);
1179 extern void jbd2_buffer_abort_trigger(struct journal_head
*jh
,
1180 struct jbd2_buffer_trigger_type
*triggers
);
1183 extern int jbd2_journal_write_metadata_buffer(transaction_t
*transaction
,
1184 struct journal_head
*jh_in
,
1185 struct buffer_head
**bh_out
,
1188 /* Transaction locking */
1189 extern void __wait_on_journal (journal_t
*);
1191 /* Transaction cache support */
1192 extern void jbd2_journal_destroy_transaction_cache(void);
1193 extern int jbd2_journal_init_transaction_cache(void);
1194 extern void jbd2_journal_free_transaction(transaction_t
*);
1199 * We need to lock the journal during transaction state changes so that nobody
1200 * ever tries to take a handle on the running transaction while we are in the
1201 * middle of moving it to the commit phase. j_state_lock does this.
1203 * Note that the locking is completely interrupt unsafe. We never touch
1204 * journal structures from interrupts.
1207 static inline handle_t
*journal_current_handle(void)
1209 return current
->journal_info
;
1212 /* The journaling code user interface:
1214 * Create and destroy handles
1215 * Register buffer modifications against the current transaction.
1218 extern handle_t
*jbd2_journal_start(journal_t
*, int nblocks
);
1219 extern handle_t
*jbd2__journal_start(journal_t
*, int blocks
, int rsv_blocks
,
1220 gfp_t gfp_mask
, unsigned int type
,
1221 unsigned int line_no
);
1222 extern int jbd2_journal_restart(handle_t
*, int nblocks
);
1223 extern int jbd2__journal_restart(handle_t
*, int nblocks
, gfp_t gfp_mask
);
1224 extern int jbd2_journal_start_reserved(handle_t
*handle
,
1225 unsigned int type
, unsigned int line_no
);
1226 extern void jbd2_journal_free_reserved(handle_t
*handle
);
1227 extern int jbd2_journal_extend (handle_t
*, int nblocks
);
1228 extern int jbd2_journal_get_write_access(handle_t
*, struct buffer_head
*);
1229 extern int jbd2_journal_get_create_access (handle_t
*, struct buffer_head
*);
1230 extern int jbd2_journal_get_undo_access(handle_t
*, struct buffer_head
*);
1231 void jbd2_journal_set_triggers(struct buffer_head
*,
1232 struct jbd2_buffer_trigger_type
*type
);
1233 extern int jbd2_journal_dirty_metadata (handle_t
*, struct buffer_head
*);
1234 extern int jbd2_journal_forget (handle_t
*, struct buffer_head
*);
1235 extern void journal_sync_buffer (struct buffer_head
*);
1236 extern int jbd2_journal_invalidatepage(journal_t
*,
1237 struct page
*, unsigned int, unsigned int);
1238 extern int jbd2_journal_try_to_free_buffers(journal_t
*, struct page
*, gfp_t
);
1239 extern int jbd2_journal_stop(handle_t
*);
1240 extern int jbd2_journal_flush (journal_t
*);
1241 extern void jbd2_journal_lock_updates (journal_t
*);
1242 extern void jbd2_journal_unlock_updates (journal_t
*);
1244 extern journal_t
* jbd2_journal_init_dev(struct block_device
*bdev
,
1245 struct block_device
*fs_dev
,
1246 unsigned long long start
, int len
, int bsize
);
1247 extern journal_t
* jbd2_journal_init_inode (struct inode
*);
1248 extern int jbd2_journal_update_format (journal_t
*);
1249 extern int jbd2_journal_check_used_features
1250 (journal_t
*, unsigned long, unsigned long, unsigned long);
1251 extern int jbd2_journal_check_available_features
1252 (journal_t
*, unsigned long, unsigned long, unsigned long);
1253 extern int jbd2_journal_set_features
1254 (journal_t
*, unsigned long, unsigned long, unsigned long);
1255 extern void jbd2_journal_clear_features
1256 (journal_t
*, unsigned long, unsigned long, unsigned long);
1257 extern int jbd2_journal_load (journal_t
*journal
);
1258 extern int jbd2_journal_destroy (journal_t
*);
1259 extern int jbd2_journal_recover (journal_t
*journal
);
1260 extern int jbd2_journal_wipe (journal_t
*, int);
1261 extern int jbd2_journal_skip_recovery (journal_t
*);
1262 extern void jbd2_journal_update_sb_errno(journal_t
*);
1263 extern int jbd2_journal_update_sb_log_tail (journal_t
*, tid_t
,
1264 unsigned long, int);
1265 extern void __jbd2_journal_abort_hard (journal_t
*);
1266 extern void jbd2_journal_abort (journal_t
*, int);
1267 extern int jbd2_journal_errno (journal_t
*);
1268 extern void jbd2_journal_ack_err (journal_t
*);
1269 extern int jbd2_journal_clear_err (journal_t
*);
1270 extern int jbd2_journal_bmap(journal_t
*, unsigned long, unsigned long long *);
1271 extern int jbd2_journal_force_commit(journal_t
*);
1272 extern int jbd2_journal_force_commit_nested(journal_t
*);
1273 extern int jbd2_journal_file_inode(handle_t
*handle
, struct jbd2_inode
*inode
);
1274 extern int jbd2_journal_begin_ordered_truncate(journal_t
*journal
,
1275 struct jbd2_inode
*inode
, loff_t new_size
);
1276 extern void jbd2_journal_init_jbd_inode(struct jbd2_inode
*jinode
, struct inode
*inode
);
1277 extern void jbd2_journal_release_jbd_inode(journal_t
*journal
, struct jbd2_inode
*jinode
);
1280 * journal_head management
1282 struct journal_head
*jbd2_journal_add_journal_head(struct buffer_head
*bh
);
1283 struct journal_head
*jbd2_journal_grab_journal_head(struct buffer_head
*bh
);
1284 void jbd2_journal_put_journal_head(struct journal_head
*jh
);
1289 extern struct kmem_cache
*jbd2_handle_cache
;
1291 static inline handle_t
*jbd2_alloc_handle(gfp_t gfp_flags
)
1293 return kmem_cache_zalloc(jbd2_handle_cache
, gfp_flags
);
1296 static inline void jbd2_free_handle(handle_t
*handle
)
1298 kmem_cache_free(jbd2_handle_cache
, handle
);
1302 * jbd2_inode management (optional, for those file systems that want to use
1303 * dynamically allocated jbd2_inode structures)
1305 extern struct kmem_cache
*jbd2_inode_cache
;
1307 static inline struct jbd2_inode
*jbd2_alloc_inode(gfp_t gfp_flags
)
1309 return kmem_cache_alloc(jbd2_inode_cache
, gfp_flags
);
1312 static inline void jbd2_free_inode(struct jbd2_inode
*jinode
)
1314 kmem_cache_free(jbd2_inode_cache
, jinode
);
1317 /* Primary revoke support */
1318 #define JOURNAL_REVOKE_DEFAULT_HASH 256
1319 extern int jbd2_journal_init_revoke(journal_t
*, int);
1320 extern void jbd2_journal_destroy_revoke_caches(void);
1321 extern int jbd2_journal_init_revoke_caches(void);
1323 extern void jbd2_journal_destroy_revoke(journal_t
*);
1324 extern int jbd2_journal_revoke (handle_t
*, unsigned long long, struct buffer_head
*);
1325 extern int jbd2_journal_cancel_revoke(handle_t
*, struct journal_head
*);
1326 extern void jbd2_journal_write_revoke_records(transaction_t
*transaction
,
1327 struct list_head
*log_bufs
);
1329 /* Recovery revoke support */
1330 extern int jbd2_journal_set_revoke(journal_t
*, unsigned long long, tid_t
);
1331 extern int jbd2_journal_test_revoke(journal_t
*, unsigned long long, tid_t
);
1332 extern void jbd2_journal_clear_revoke(journal_t
*);
1333 extern void jbd2_journal_switch_revoke_table(journal_t
*journal
);
1334 extern void jbd2_clear_buffer_revoked_flags(journal_t
*journal
);
1337 * The log thread user interface:
1339 * Request space in the current transaction, and force transaction commit
1340 * transitions on demand.
1343 int jbd2_log_start_commit(journal_t
*journal
, tid_t tid
);
1344 int __jbd2_log_start_commit(journal_t
*journal
, tid_t tid
);
1345 int jbd2_journal_start_commit(journal_t
*journal
, tid_t
*tid
);
1346 int jbd2_log_wait_commit(journal_t
*journal
, tid_t tid
);
1347 int jbd2_complete_transaction(journal_t
*journal
, tid_t tid
);
1348 int jbd2_log_do_checkpoint(journal_t
*journal
);
1349 int jbd2_trans_will_send_data_barrier(journal_t
*journal
, tid_t tid
);
1351 void __jbd2_log_wait_for_space(journal_t
*journal
);
1352 extern void __jbd2_journal_drop_transaction(journal_t
*, transaction_t
*);
1353 extern int jbd2_cleanup_journal_tail(journal_t
*);
1358 * Simple test wrapper function to test the JBD2_ABORT state flag. This
1359 * bit, when set, indicates that we have had a fatal error somewhere,
1360 * either inside the journaling layer or indicated to us by the client
1361 * (eg. ext3), and that we and should not commit any further
1365 static inline int is_journal_aborted(journal_t
*journal
)
1367 return journal
->j_flags
& JBD2_ABORT
;
1370 static inline int is_handle_aborted(handle_t
*handle
)
1372 if (handle
->h_aborted
|| !handle
->h_transaction
)
1374 return is_journal_aborted(handle
->h_transaction
->t_journal
);
1377 static inline void jbd2_journal_abort_handle(handle_t
*handle
)
1379 handle
->h_aborted
= 1;
1382 #endif /* __KERNEL__ */
1384 /* Comparison functions for transaction IDs: perform comparisons using
1385 * modulo arithmetic so that they work over sequence number wraps. */
1387 static inline int tid_gt(tid_t x
, tid_t y
)
1389 int difference
= (x
- y
);
1390 return (difference
> 0);
1393 static inline int tid_geq(tid_t x
, tid_t y
)
1395 int difference
= (x
- y
);
1396 return (difference
>= 0);
1399 extern int jbd2_journal_blocks_per_page(struct inode
*inode
);
1400 extern size_t journal_tag_bytes(journal_t
*journal
);
1402 static inline bool jbd2_journal_has_csum_v2or3_feature(journal_t
*j
)
1404 return jbd2_has_feature_csum2(j
) || jbd2_has_feature_csum3(j
);
1407 static inline int jbd2_journal_has_csum_v2or3(journal_t
*journal
)
1409 WARN_ON_ONCE(jbd2_journal_has_csum_v2or3_feature(journal
) &&
1410 journal
->j_chksum_driver
== NULL
);
1412 return journal
->j_chksum_driver
!= NULL
;
1416 * We reserve t_outstanding_credits >> JBD2_CONTROL_BLOCKS_SHIFT for
1417 * transaction control blocks.
1419 #define JBD2_CONTROL_BLOCKS_SHIFT 5
1422 * Return the minimum number of blocks which must be free in the journal
1423 * before a new transaction may be started. Must be called under j_state_lock.
1425 static inline int jbd2_space_needed(journal_t
*journal
)
1427 int nblocks
= journal
->j_max_transaction_buffers
;
1428 return nblocks
+ (nblocks
>> JBD2_CONTROL_BLOCKS_SHIFT
);
1432 * Return number of free blocks in the log. Must be called under j_state_lock.
1434 static inline unsigned long jbd2_log_space_left(journal_t
*journal
)
1436 /* Allow for rounding errors */
1437 unsigned long free
= journal
->j_free
- 32;
1439 if (journal
->j_committing_transaction
) {
1440 unsigned long committing
= atomic_read(&journal
->
1441 j_committing_transaction
->t_outstanding_credits
);
1443 /* Transaction + control blocks */
1444 free
-= committing
+ (committing
>> JBD2_CONTROL_BLOCKS_SHIFT
);
1450 * Definitions which augment the buffer_head layer
1453 /* journaling buffer types */
1454 #define BJ_None 0 /* Not journaled */
1455 #define BJ_Metadata 1 /* Normal journaled metadata */
1456 #define BJ_Forget 2 /* Buffer superseded by this transaction */
1457 #define BJ_Shadow 3 /* Buffer contents being shadowed to the log */
1458 #define BJ_Reserved 4 /* Buffer is reserved for access by journal */
1461 extern int jbd_blocks_per_page(struct inode
*inode
);
1463 /* JBD uses a CRC32 checksum */
1464 #define JBD_MAX_CHECKSUM_SIZE 4
1466 static inline u32
jbd2_chksum(journal_t
*journal
, u32 crc
,
1467 const void *address
, unsigned int length
)
1470 struct shash_desc shash
;
1471 char ctx
[JBD_MAX_CHECKSUM_SIZE
];
1475 BUG_ON(crypto_shash_descsize(journal
->j_chksum_driver
) >
1476 JBD_MAX_CHECKSUM_SIZE
);
1478 desc
.shash
.tfm
= journal
->j_chksum_driver
;
1479 desc
.shash
.flags
= 0;
1480 *(u32
*)desc
.ctx
= crc
;
1482 err
= crypto_shash_update(&desc
.shash
, address
, length
);
1485 return *(u32
*)desc
.ctx
;
1488 /* Return most recent uncommitted transaction */
1489 static inline tid_t
jbd2_get_latest_transaction(journal_t
*journal
)
1493 read_lock(&journal
->j_state_lock
);
1494 tid
= journal
->j_commit_request
;
1495 if (journal
->j_running_transaction
)
1496 tid
= journal
->j_running_transaction
->t_tid
;
1497 read_unlock(&journal
->j_state_lock
);
1503 #define buffer_trace_init(bh) do {} while (0)
1504 #define print_buffer_fields(bh) do {} while (0)
1505 #define print_buffer_trace(bh) do {} while (0)
1506 #define BUFFER_TRACE(bh, info) do {} while (0)
1507 #define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
1508 #define JBUFFER_TRACE(jh, info) do {} while (0)
1510 #endif /* __KERNEL__ */
1512 #define EFSBADCRC EBADMSG /* Bad CRC detected */
1513 #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
1515 #endif /* _LINUX_JBD2_H */