/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * linux/include/linux/jbd2.h * * Written by Stephen C. Tweedie <sct@redhat.com> * * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved * * Definitions for transaction data structures for the buffer cache * filesystem journaling support.
*/
#ifndef _LINUX_JBD2_H #define _LINUX_JBD2_H
/* Allow this file to be included directly into e2fsprogs */ #ifndef __KERNEL__ #include"jfs_compat.h" #define JBD2_DEBUG #else
/* * Define JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds * certain classes of error which can occur due to failed IOs. Under * normal use we want ext4 to continue after such errors, because * hardware _can_ fail, but for debugging purposes when running tests on * known-good hardware we may want to trap these errors.
*/ #undef JBD2_PARANOID_IOFAIL
/* * The default maximum commit age, in seconds.
*/ #define JBD2_DEFAULT_MAX_COMMIT_AGE 5
#ifdef CONFIG_JBD2_DEBUG /* * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal * consistency checks. By default we don't do this unless * CONFIG_JBD2_DEBUG is on.
*/ #define JBD2_EXPENSIVE_CHECKING void __jbd2_debug(int level, constchar *file, constchar *func, unsignedint line, constchar *fmt, ...);
/** * typedef handle_t - The handle_t type represents a single atomic update being performed by some process. * * All filesystem modifications made by the process go * through this handle. Recursive operations (such as quota operations) * are gathered into a single update. * * The buffer credits field is used to account for journaled buffers * being modified by the running process. To ensure that there is * enough log space for all outstanding operations, we need to limit the * number of outstanding buffers possible at any time. When the * operation completes, any buffer credits not used are credited back to * the transaction, so that at all times we know how many buffers the * outstanding updates on a transaction might possibly touch. * * This is an opaque datatype.
**/ typedefstruct jbd2_journal_handle handle_t; /* Atomic operation type */
/** * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem. * * journal_t is linked to from the fs superblock structure. * * We use the journal_t to keep track of all outstanding transaction * activity on the filesystem, and to manage the state of the log * writing process. * * This is an opaque datatype.
**/ typedefstruct journal_s journal_t; /* Journal control structure */ #endif
/* * Internal structures used by the logging mechanism:
*/
#define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
#define JBD2_CHECKSUM_BYTES (32 / sizeof(u32)) /* * Commit block header for storing transactional checksums: * * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum* * fields are used to store a checksum of the descriptor and data blocks. * * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum * field is used to store crc32c(uuid+commit_block). Each journal metadata * block gets its own checksum, and data block checksums are stored in * journal_block_tag (in the descriptor). The other h_chksum* fields are * not used. * * If FEATURE_INCOMPAT_CSUM_V3 is set, the descriptor block uses * journal_block_tag3_t to store a full 32-bit checksum. Everything else * is the same as v2. * * Checksum v1, v2, and v3 are mutually exclusive features.
*/ struct commit_header {
__be32 h_magic;
__be32 h_blocktype;
__be32 h_sequence; unsignedchar h_chksum_type; unsignedchar h_chksum_size; unsignedchar h_padding[2];
__be32 h_chksum[JBD2_CHECKSUM_BYTES];
__be64 h_commit_sec;
__be32 h_commit_nsec;
};
/* * The block tag: used to describe a single buffer in the journal. * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this * raw struct shouldn't be used for pointer math or sizeof() - use * journal_tag_bytes(journal) instead to compute this.
*/ typedefstruct journal_block_tag3_s
{
__be32 t_blocknr; /* The on-disk block number */
__be32 t_flags; /* See below */
__be32 t_blocknr_high; /* most-significant high 32bits. */
__be32 t_checksum; /* crc32c(uuid+seq+block) */
} journal_block_tag3_t;
typedefstruct journal_block_tag_s
{
__be32 t_blocknr; /* The on-disk block number */
__be16 t_checksum; /* truncated crc32c(uuid+seq+block) */
__be16 t_flags; /* See below */
__be32 t_blocknr_high; /* most-significant high 32bits. */
} journal_block_tag_t;
/* Tail of descriptor or revoke block, for checksumming */ struct jbd2_journal_block_tail {
__be32 t_checksum; /* crc32c(uuid+descr_block) */
};
/* * The revoke descriptor: used on disk to describe a series of blocks to * be revoked from the log
*/ typedefstruct jbd2_journal_revoke_header_s
{
journal_header_t r_header;
__be32 r_count; /* Count of bytes used in the block */
} jbd2_journal_revoke_header_t;
/* Definitions for the journal tag flags word: */ #define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */ #define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */ #define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */ #define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
/* * The journal superblock. All fields are in big-endian byte order.
*/ typedefstruct journal_superblock_s
{ /* 0x0000 */
journal_header_t s_header;
/* 0x000C */ /* Static information describing the journal */
__be32 s_blocksize; /* journal device blocksize */
__be32 s_maxlen; /* total blocks in journal file */
__be32 s_first; /* first block of log information */
/* 0x0018 */ /* Dynamic information describing the current state of the log */
__be32 s_sequence; /* first commit ID expected in log */
__be32 s_start; /* blocknr of start of log */
/* 0x0020 */ /* Error value, as set by jbd2_journal_abort(). */
__be32 s_errno;
/* 0x0024 */ /* Remaining fields are only valid in a version-2 superblock */
__be32 s_feature_compat; /* compatible feature set */
__be32 s_feature_incompat; /* incompatible feature set */
__be32 s_feature_ro_compat; /* readonly-compatible feature set */ /* 0x0030 */
__u8 s_uuid[16]; /* 128-bit uuid for journal */
/* 0x0040 */
__be32 s_nr_users; /* Nr of filesystems sharing log */
__be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
/* 0x0048 */
__be32 s_max_transaction; /* Limit of journal blocks per trans.*/
__be32 s_max_trans_data; /* Limit of data blocks per trans. */
/* 0x0050 */
__u8 s_checksum_type; /* checksum type */
__u8 s_padding2[3]; /* 0x0054 */
__be32 s_num_fc_blks; /* Number of fast commit blocks */
__be32 s_head; /* blocknr of head of log, only uptodate
* while the filesystem is clean */ /* 0x005C */
__u32 s_padding[40];
__be32 s_checksum; /* crc32c(superblock) */
/* 0x0100 */
__u8 s_users[16*48]; /* ids of all fs'es sharing the log */ /* 0x0400 */
} journal_superblock_t;
/* See "journal feature predicate functions" below */
/* Features known to this kernel version: */ #define JBD2_KNOWN_COMPAT_FEATURES JBD2_FEATURE_COMPAT_CHECKSUM #define JBD2_KNOWN_ROCOMPAT_FEATURES 0 #define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \
JBD2_FEATURE_INCOMPAT_64BIT | \
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT | \
JBD2_FEATURE_INCOMPAT_CSUM_V2 | \
JBD2_FEATURE_INCOMPAT_CSUM_V3 | \
JBD2_FEATURE_INCOMPAT_FAST_COMMIT)
#ifdef __KERNEL__
#include <linux/fs.h> #include <linux/sched.h>
enum jbd_state_bits {
BH_JBD /* Has an attached ext3 journal_head */
= BH_PrivateStart,
BH_JWrite, /* Being written to log (@@@ DEBUGGING) */
BH_Freed, /* Has been freed (truncated) */
BH_Revoked, /* Has been revoked from the log */
BH_RevokeValid, /* Revoked flag is valid */
BH_JBDDirty, /* Is dirty but journaled */
BH_JournalHead, /* Pins bh->b_private and jh->b_bh */
BH_Shadow, /* IO on shadow buffer is running */
BH_Verified, /* Metadata block has been verified ok */
BH_JBDPrivateStart, /* First bit available for private use by FS */
};
/* * Commit of the inode data in progress. We use this flag to protect us from * concurrent deletion of inode. We cannot use reference to inode for this * since we cannot afford doing last iput() on behalf of kjournald
*/ #define JI_COMMIT_RUNNING (1 << __JI_COMMIT_RUNNING) /* Write allocated dirty buffers in this inode before commit */ #define JI_WRITE_DATA (1 << __JI_WRITE_DATA) /* Wait for outstanding data writes for this inode before commit */ #define JI_WAIT_DATA (1 << __JI_WAIT_DATA)
/** * struct jbd2_inode - The jbd_inode type is the structure linking inodes in * ordered mode present in a transaction so that we can sync them during commit.
*/ struct jbd2_inode { /** * @i_transaction: * * Which transaction does this inode belong to? Either the running * transaction or the committing one. [j_list_lock]
*/
transaction_t *i_transaction;
/** * @i_next_transaction: * * Pointer to the running transaction modifying inode's data in case * there is already a committing transaction touching it. [j_list_lock]
*/
transaction_t *i_next_transaction;
/** * @i_list: List of inodes in the i_transaction [j_list_lock]
*/ struct list_head i_list;
/** * @i_vfs_inode: * * VFS inode this inode belongs to [constant for lifetime of structure]
*/ struct inode *i_vfs_inode;
/** * @i_flags: Flags of inode [j_list_lock]
*/ unsignedlong i_flags;
/** * @i_dirty_start: * * Offset in bytes where the dirty range for this inode starts. * [j_list_lock]
*/
loff_t i_dirty_start;
/** * @i_dirty_end: * * Inclusive offset in bytes where the dirty range for this inode * ends. [j_list_lock]
*/
loff_t i_dirty_end;
};
struct jbd2_revoke_table_s;
/** * struct jbd2_journal_handle - The jbd2_journal_handle type is the concrete * type associated with handle_t. * @h_transaction: Which compound transaction is this update a part of? * @h_journal: Which journal handle belongs to - used iff h_reserved set. * @h_rsv_handle: Handle reserved for finishing the logical operation. * @h_total_credits: Number of remaining buffers we are allowed to add to * journal. These are dirty buffers and revoke descriptor blocks. * @h_revoke_credits: Number of remaining revoke records available for handle * @h_ref: Reference count on this handle. * @h_err: Field for caller's use to track errors through large fs operations. * @h_sync: Flag for sync-on-close. * @h_reserved: Flag for handle for reserved credits. * @h_aborted: Flag indicating fatal error on handle. * @h_type: For handle statistics. * @h_line_no: For handle statistics. * @h_start_jiffies: Handle Start time. * @h_requested_credits: Holds @h_total_credits after handle is started. * @h_revoke_credits_requested: Holds @h_revoke_credits after handle is started. * @saved_alloc_context: Saved context while transaction is open.
**/
/* Docbook can't yet cope with the bit fields, but will leave the documentation * in so it can be fixed later.
*/
struct jbd2_journal_handle
{ union {
transaction_t *h_transaction; /* Which journal handle belongs to - used iff h_reserved set */
journal_t *h_journal;
};
handle_t *h_rsv_handle; int h_total_credits; int h_revoke_credits; int h_revoke_credits_requested; int h_ref; int h_err;
/* * Some stats for checkpoint phase
*/ struct transaction_chp_stats_s { unsignedlong cs_chp_time;
__u32 cs_forced_to_close;
__u32 cs_written;
__u32 cs_dropped;
};
/* The transaction_t type is the guts of the journaling mechanism. It * tracks a compound transaction through its various states: * * RUNNING: accepting new updates * LOCKED: Updates still running but we don't accept new ones * RUNDOWN: Updates are tidying up but have finished requesting * new buffers to modify (state not used for now) * FLUSH: All updates complete, but we are still writing to disk * COMMIT: All data on disk, writing commit record * FINISHED: We still have to keep the transaction for checkpointing. * * The transaction keeps track of all of the buffers modified by a * running transaction, and all of the buffers committed but not yet * flushed to home for finished transactions. * (Locking Documentation improved by LockDoc)
*/
struct transaction_s
{ /* Pointer to the journal for this transaction. [no locking] */
journal_t *t_journal;
/* Sequence number for this transaction [no locking] */
tid_t t_tid;
/* * Transaction's current state * [no locking - only kjournald2 alters this] * [j_list_lock] guards transition of a transaction into T_FINISHED * state and subsequent call of __jbd2_journal_drop_transaction() * FIXME: needs barriers * KLUDGE: [use j_state_lock]
*/ enum {
T_RUNNING,
T_LOCKED,
T_SWITCH,
T_FLUSH,
T_COMMIT,
T_COMMIT_DFLUSH,
T_COMMIT_JFLUSH,
T_COMMIT_CALLBACK,
T_FINISHED
} t_state;
/* * Where in the log does this transaction's commit start? [no locking]
*/ unsignedlong t_log_start;
/* * Number of buffers on the t_buffers list [j_list_lock, no locks * needed for jbd2 thread]
*/ int t_nr_buffers;
/* * Doubly-linked circular list of all buffers reserved but not yet * modified by this transaction [j_list_lock, no locks needed fo * jbd2 thread]
*/ struct journal_head *t_reserved_list;
/* * Doubly-linked circular list of all metadata buffers owned by this * transaction [j_list_lock, no locks needed for jbd2 thread]
*/ struct journal_head *t_buffers;
/* * Doubly-linked circular list of all forget buffers (superseded * buffers which we can un-checkpoint once this transaction commits) * [j_list_lock]
*/ struct journal_head *t_forget;
/* * Doubly-linked circular list of all buffers still to be flushed before * this transaction can be checkpointed. [j_list_lock]
*/ struct journal_head *t_checkpoint_list;
/* * Doubly-linked circular list of metadata buffers being * shadowed by log IO. The IO buffers on the iobuf list and * the shadow buffers on this list match each other one for * one at all times. [j_list_lock, no locks needed for jbd2 * thread]
*/ struct journal_head *t_shadow_list;
/* * List of inodes associated with the transaction; e.g., ext4 uses * this to track inodes in data=ordered and data=journal mode that * need special handling on transaction commit; also used by ocfs2. * [j_list_lock]
*/ struct list_head t_inode_list;
/* * Longest time some handle had to wait for running transaction
*/ unsignedlong t_max_wait;
/* * When transaction started
*/ unsignedlong t_start;
/* * When commit was requested [j_state_lock]
*/ unsignedlong t_requested;
/* * Number of outstanding updates running on this transaction * [none]
*/
atomic_t t_updates;
/* * Number of blocks reserved for this transaction in the journal. * This is including all credits reserved when starting transaction * handles as well as all journal descriptor blocks needed for this * transaction. [none]
*/
atomic_t t_outstanding_credits;
/* * Number of revoke records for this transaction added by already * stopped handles. [none]
*/
atomic_t t_outstanding_revokes;
/* * How many handles used this transaction? [none]
*/
atomic_t t_handle_count;
/* * Forward and backward links for the circular list of all transactions * awaiting checkpoint. [j_list_lock]
*/
transaction_t *t_cpnext, *t_cpprev;
/* * When will the transaction expire (become due for commit), in jiffies? * [no locking]
*/ unsignedlong t_expires;
/* * When this transaction started, in nanoseconds [no locking]
*/
ktime_t t_start_time;
/* * This transaction is being forced and some process is * waiting for it to finish.
*/ unsignedint t_synchronous_commit:1;
/* Disk flush needs to be sent to fs partition [no locking] */ int t_need_data_flush;
};
/** * struct journal_s - The journal_s type is the concrete type associated with * journal_t.
*/ struct journal_s
{ /** * @j_flags: General journaling state flags [j_state_lock, * no lock for quick racy checks]
*/ unsignedlong j_flags;
/** * @j_errno: * * Is there an outstanding uncleared error on the journal (from a prior * abort)? [j_state_lock]
*/ int j_errno;
/** * @j_sb_buffer: The first part of the superblock buffer.
*/ struct buffer_head *j_sb_buffer;
/** * @j_superblock: The second part of the superblock buffer.
*/
journal_superblock_t *j_superblock;
/** * @j_state_lock: Protect the various scalars in the journal.
*/
rwlock_t j_state_lock;
/** * @j_barrier_count: * * Number of processes waiting to create a barrier lock [j_state_lock, * no lock for quick racy checks]
*/ int j_barrier_count;
/** * @j_running_transaction: * * Transactions: The current running transaction... * [j_state_lock, no lock for quick racy checks] [caller holding * open handle]
*/
transaction_t *j_running_transaction;
/** * @j_committing_transaction: * * the transaction we are pushing to disk * [j_state_lock] [caller holding open handle]
*/
transaction_t *j_committing_transaction;
/** * @j_checkpoint_transactions: * * ... and a linked circular list of all transactions waiting for * checkpointing. [j_list_lock]
*/
transaction_t *j_checkpoint_transactions;
/** * @j_wait_transaction_locked: * * Wait queue for waiting for a locked transaction to start committing, * or for a barrier lock to be released.
*/
wait_queue_head_t j_wait_transaction_locked;
/** * @j_wait_done_commit: Wait queue for waiting for commit to complete.
*/
wait_queue_head_t j_wait_done_commit;
/** * @j_wait_updates: Wait queue to wait for updates to complete.
*/
wait_queue_head_t j_wait_updates;
/** * @j_wait_reserved: * * Wait queue to wait for reserved buffer credits to drop.
*/
wait_queue_head_t j_wait_reserved;
/** * @j_fc_wait: * * Wait queue to wait for completion of async fast commits.
*/
wait_queue_head_t j_fc_wait;
/** * @j_checkpoint_mutex: * * Semaphore for locking against concurrent checkpoints.
*/ struct mutex j_checkpoint_mutex;
/** * @j_chkpt_bhs: * * List of buffer heads used by the checkpoint routine. This * was moved from jbd2_log_do_checkpoint() to reduce stack * usage. Access to this array is controlled by the * @j_checkpoint_mutex. [j_checkpoint_mutex]
*/ struct buffer_head *j_chkpt_bhs[JBD2_NR_BATCH];
/** * @j_shrinker: * * Journal head shrinker, reclaim buffer's journal head which * has been written back.
*/ struct shrinker *j_shrinker;
/** * @j_checkpoint_jh_count: * * Number of journal buffers on the checkpoint list. [j_list_lock]
*/ struct percpu_counter j_checkpoint_jh_count;
/** * @j_shrink_transaction: * * Record next transaction will shrink on the checkpoint list. * [j_list_lock]
*/
transaction_t *j_shrink_transaction;
/** * @j_head: * * Journal head: identifies the first unused block in the journal. * [j_state_lock]
*/ unsignedlong j_head;
/** * @j_tail: * * Journal tail: identifies the oldest still-used block in the journal. * [j_state_lock]
*/ unsignedlong j_tail;
/** * @j_free: * * Journal free: how many free blocks are there in the journal? * [j_state_lock]
*/ unsignedlong j_free;
/** * @j_first: * * The block number of the first usable block in the journal * [j_state_lock].
*/ unsignedlong j_first;
/** * @j_last: * * The block number one beyond the last usable block in the journal * [j_state_lock].
*/ unsignedlong j_last;
/** * @j_fc_first: * * The block number of the first fast commit block in the journal * [j_state_lock].
*/ unsignedlong j_fc_first;
/** * @j_fc_off: * * Number of fast commit blocks currently allocated. Accessed only * during fast commit. Currently only process can do fast commit, so * this field is not protected by any lock.
*/ unsignedlong j_fc_off;
/** * @j_fc_last: * * The block number one beyond the last fast commit block in the journal * [j_state_lock].
*/ unsignedlong j_fc_last;
/** * @j_dev: Device where we store the journal.
*/ struct block_device *j_dev;
/** * @j_blocksize: Block size for the location where we store the journal.
*/ int j_blocksize;
/** * @j_blk_offset: * * Starting block offset into the device where we store the journal.
*/ unsignedlonglong j_blk_offset;
/** * @j_fs_dev: * * Device which holds the client fs. For internal journal this will be * equal to j_dev.
*/ struct block_device *j_fs_dev;
/** * @j_fs_dev_wb_err: * * Records the errseq of the client fs's backing block device.
*/
errseq_t j_fs_dev_wb_err;
/** * @j_total_len: Total maximum capacity of the journal region on disk.
*/ unsignedint j_total_len;
/** * @j_reserved_credits: * * Number of buffers reserved from the running transaction.
*/
atomic_t j_reserved_credits;
/** * @j_list_lock: Protects the buffer lists and internal buffer state.
*/
spinlock_t j_list_lock;
/** * @j_inode: * * Optional inode where we store the journal. If present, all * journal block numbers are mapped into this inode via bmap().
*/ struct inode *j_inode;
/** * @j_tail_sequence: * * Sequence number of the oldest transaction in the log [j_state_lock]
*/
tid_t j_tail_sequence;
/** * @j_transaction_sequence: * * Sequence number of the next transaction to grant [j_state_lock]
*/
tid_t j_transaction_sequence;
/** * @j_commit_sequence: * * Sequence number of the most recently committed transaction * [j_state_lock, no lock for quick racy checks]
*/
tid_t j_commit_sequence;
/** * @j_commit_request: * * Sequence number of the most recent transaction wanting commit * [j_state_lock, no lock for quick racy checks]
*/
tid_t j_commit_request;
/** * @j_uuid: * * Journal uuid: identifies the object (filesystem, LVM volume etc) * backed by this journal. This will eventually be replaced by an array * of uuids, allowing us to index multiple devices within a single * journal and to perform atomic updates across them.
*/
__u8 j_uuid[16];
/** * @j_task: Pointer to the current commit thread for this journal.
*/ struct task_struct *j_task;
/** * @j_max_transaction_buffers: * * Maximum number of metadata buffers to allow in a single compound * commit transaction.
*/ int j_max_transaction_buffers;
/** * @j_revoke_records_per_block: * * Number of revoke records that fit in one descriptor block.
*/ int j_revoke_records_per_block;
/** * @j_transaction_overhead_buffers: * * Number of blocks each transaction needs for its own bookkeeping
*/ int j_transaction_overhead_buffers;
/** * @j_commit_interval: * * What is the maximum transaction lifetime before we begin a commit?
*/ unsignedlong j_commit_interval;
/** * @j_commit_timer: The timer used to wakeup the commit thread.
*/ struct timer_list j_commit_timer;
/** * @j_revoke_lock: Protect the revoke table.
*/
spinlock_t j_revoke_lock;
/** * @j_revoke: * * The revoke table - maintains the list of revoked blocks in the * current transaction.
*/ struct jbd2_revoke_table_s *j_revoke;
/** * @j_wbuf: Array of bhs for jbd2_journal_commit_transaction.
*/ struct buffer_head **j_wbuf;
/** * @j_fc_wbuf: Array of fast commit bhs for fast commit. Accessed only * during a fast commit. Currently only process can do fast commit, so * this field is not protected by any lock.
*/ struct buffer_head **j_fc_wbuf;
/** * @j_wbufsize: * * Size of @j_wbuf array.
*/ int j_wbufsize;
/** * @j_fc_wbufsize: * * Size of @j_fc_wbuf array.
*/ int j_fc_wbufsize;
/** * @j_last_sync_writer: * * The pid of the last person to run a synchronous operation * through the journal.
*/
pid_t j_last_sync_writer;
/** * @j_average_commit_time: * * The average amount of time in nanoseconds it takes to commit a * transaction to disk. [j_state_lock]
*/
u64 j_average_commit_time;
/** * @j_min_batch_time: * * Minimum time that we should wait for additional filesystem operations * to get batched into a synchronous handle in microseconds.
*/
u32 j_min_batch_time;
/** * @j_max_batch_time: * * Maximum time that we should wait for additional filesystem operations * to get batched into a synchronous handle in microseconds.
*/
u32 j_max_batch_time;
/** * @j_commit_callback: * * This function is called when a transaction is closed.
*/ void (*j_commit_callback)(journal_t *,
transaction_t *);
/** * @j_submit_inode_data_buffers: * * This function is called for all inodes associated with the * committing transaction marked with JI_WRITE_DATA flag * before we start to write out the transaction to the journal.
*/ int (*j_submit_inode_data_buffers)
(struct jbd2_inode *);
/** * @j_finish_inode_data_buffers: * * This function is called for all inodes associated with the * committing transaction marked with JI_WAIT_DATA flag * after we have written the transaction to the journal * but before we write out the commit block.
*/ int (*j_finish_inode_data_buffers)
(struct jbd2_inode *);
/* * Journal statistics
*/
/** * @j_history_lock: Protect the transactions statistics history.
*/
spinlock_t j_history_lock;
/** * @j_proc_entry: procfs entry for the jbd statistics directory.
*/ struct proc_dir_entry *j_proc_entry;
/** * @j_private: * * An opaque pointer to fs-private information. ext3 puts its * superblock pointer here.
*/ void *j_private;
/** * @j_csum_seed: * * Precomputed journal UUID checksum for seeding other checksums.
*/
__u32 j_csum_seed;
#ifdef CONFIG_DEBUG_LOCK_ALLOC /** * @j_trans_commit_map: * * Lockdep entity to track transaction commit dependencies. Handles * hold this "lock" for read, when we wait for commit, we acquire the * "lock" for writing. This matches the properties of jbd2 journalling * where the running transaction has to wait for all handles to be * dropped to commit that transaction and also acquiring a handle may * require transaction commit to finish.
*/ struct lockdep_map j_trans_commit_map; #endif
/** * @j_fc_cleanup_callback: * * Clean-up after fast commit or full commit. JBD2 calls this function * after every commit operation.
*/ void (*j_fc_cleanup_callback)(struct journal_s *journal, int full, tid_t tid);
/** * @j_fc_replay_callback: * * File-system specific function that performs replay of a fast * commit. JBD2 calls this function for each fast commit block found in * the journal. This function should return JBD2_FC_REPLAY_CONTINUE * to indicate that the block was processed correctly and more fast * commit replay should continue. Return value of JBD2_FC_REPLAY_STOP * indicates the end of replay (no more blocks remaining). A negative * return value indicates error.
*/ int (*j_fc_replay_callback)(struct journal_s *journal, struct buffer_head *bh, enum passtype pass, int off,
tid_t expected_commit_id);
/** * @j_bmap: * * Bmap function that should be used instead of the generic * VFS bmap function.
*/ int (*j_bmap)(struct journal_s *journal, sector_t *block);
};
#define jbd2_might_wait_for_commit(j) \ do { \
rwsem_acquire(&j->j_trans_commit_map, 0, 0, _THIS_IP_); \
rwsem_release(&j->j_trans_commit_map, _THIS_IP_); \
} while (0)
/* * We can support any known requested features iff the * superblock is not in version 1. Otherwise we fail to support any * extended sb features.
*/ staticinlinebool jbd2_format_support_feature(journal_t *j)
{ return j->j_superblock->s_header.h_blocktype !=
cpu_to_be32(JBD2_SUPERBLOCK_V1);
}
/* * Journal flag definitions
*/ #define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */ #define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */ #define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */ #define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */ #define JBD2_LOADED 0x010 /* The journal superblock has been loaded */ #define JBD2_BARRIER 0x020 /* Use IDE barriers */ #define JBD2_CYCLE_RECORD 0x080 /* Journal cycled record log on * clean and empty filesystem
* logging area */ #define JBD2_FAST_COMMIT_ONGOING 0x100 /* Fast commit is ongoing */ #define JBD2_FULL_COMMIT_ONGOING 0x200 /* Full commit is ongoing */ #define JBD2_JOURNAL_FLUSH_DISCARD 0x0001 #define JBD2_JOURNAL_FLUSH_ZEROOUT 0x0002 #define JBD2_JOURNAL_FLUSH_VALID (JBD2_JOURNAL_FLUSH_DISCARD | \
JBD2_JOURNAL_FLUSH_ZEROOUT)
/* * Function declarations for the journaling transaction and buffer * management
*/
struct jbd2_buffer_trigger_type { /* * Fired a the moment data to write to the journal are known to be * stable - so either at the moment b_frozen_data is created or just * before a buffer is written to the journal. mapped_data is a mapped * buffer that is the frozen data for commit.
*/ void (*t_frozen)(struct jbd2_buffer_trigger_type *type, struct buffer_head *bh, void *mapped_data,
size_t size);
/* * Fired during journal abort for dirty buffers that will not be * committed.
*/ void (*t_abort)(struct jbd2_buffer_trigger_type *type, struct buffer_head *bh);
};
/* * Journal locking. * * We need to lock the journal during transaction state changes so that nobody * ever tries to take a handle on the running transaction while we are in the * middle of moving it to the commit phase. j_state_lock does this. * * Note that the locking is completely interrupt unsafe. We never touch * journal structures from interrupts.
*/
/* * This specialized allocator has to be a macro for its allocations to be * accounted separately (to have a separate alloc_tag). The typecast is * intentional to enforce typesafety.
*/ #define jbd2_alloc_handle(_gfp_flags) \
((handle_t *)kmem_cache_zalloc(jbd2_handle_cache, _gfp_flags))
/* * jbd2_inode management (optional, for those file systems that want to use * dynamically allocated jbd2_inode structures)
*/ externstruct kmem_cache *jbd2_inode_cache;
/* * This specialized allocator has to be a macro for its allocations to be * accounted separately (to have a separate alloc_tag). The typecast is * intentional to enforce typesafety.
*/ #define jbd2_alloc_inode(_gfp_flags) \
((struct jbd2_inode *)kmem_cache_alloc(jbd2_inode_cache, _gfp_flags))
/* * The log thread user interface: * * Request space in the current transaction, and force transaction commit * transitions on demand.
*/
int jbd2_log_start_commit(journal_t *journal, tid_t tid); int jbd2_journal_start_commit(journal_t *journal, tid_t *tid); int jbd2_log_wait_commit(journal_t *journal, tid_t tid); int jbd2_transaction_committed(journal_t *journal, tid_t tid); int jbd2_complete_transaction(journal_t *journal, tid_t tid); int jbd2_log_do_checkpoint(journal_t *journal); int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
/* Fast commit related APIs */ int jbd2_fc_begin_commit(journal_t *journal, tid_t tid); int jbd2_fc_end_commit(journal_t *journal); int jbd2_fc_end_commit_fallback(journal_t *journal); int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out); int jbd2_submit_inode_data(journal_t *journal, struct jbd2_inode *jinode); int jbd2_wait_inode_data(journal_t *journal, struct jbd2_inode *jinode); int jbd2_fc_wait_bufs(journal_t *journal, int num_blks); void jbd2_fc_release_bufs(journal_t *journal);
/* * is_journal_abort * * Simple test wrapper function to test the JBD2_ABORT state flag. This * bit, when set, indicates that we have had a fatal error somewhere, * either inside the journaling layer or indicated to us by the client * (eg. ext3), and that we and should not commit any further * transactions.
*/
/* * Save the original wb_err value of client fs's bdev mapping which * could be used to detect the client fs's metadata async write error.
*/
errseq_check_and_advance(&mapping->wb_err, &journal->j_fs_dev_wb_err);
}
/* * Return number of free blocks in the log. Must be called under j_state_lock.
*/ staticinlineunsignedlong jbd2_log_space_left(journal_t *journal)
{ /* Allow for rounding errors */ long free = journal->j_free - 32;
read_lock(&journal->j_state_lock);
tid = journal->j_commit_request; if (journal->j_running_transaction)
tid = journal->j_running_transaction->t_tid;
read_unlock(&journal->j_state_lock); return tid;
}
#define buffer_trace_init(bh) do {} while (0) #define print_buffer_fields(bh) do {} while (0) #define print_buffer_trace(bh) do {} while (0) #define BUFFER_TRACE(bh, info) do {} while (0) #define BUFFER_TRACE2(bh, bh2, info) do {} while (0) #define JBUFFER_TRACE(jh, info) do {} while (0)
#endif/* __KERNEL__ */
#define EFSBADCRC EBADMSG /* Bad CRC detected */ #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
#endif/* _LINUX_JBD2_H */
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