| /* |
| * linux/include/linux/jbd2.h |
| * |
| * Written by Stephen C. Tweedie <sct@redhat.com> |
| * |
| * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved |
| * |
| * This file is part of the Linux kernel and is made available under |
| * the terms of the GNU General Public License, version 2, or at your |
| * option, any later version, incorporated herein by reference. |
| * |
| * Definitions for transaction data structures for the buffer cache |
| * filesystem journaling support. |
| */ |
| |
| #ifndef _LINUX_JBD_H |
| #define _LINUX_JBD_H |
| |
| /* Allow this file to be included directly into e2fsprogs */ |
| #ifndef __KERNEL__ |
| #include "jfs_compat.h" |
| #define JBD2_DEBUG |
| #define jfs_debug jbd_debug |
| #else |
| |
| #include <linux/types.h> |
| #include <linux/buffer_head.h> |
| #include <linux/journal-head.h> |
| #include <linux/stddef.h> |
| #include <linux/bit_spinlock.h> |
| #include <linux/mutex.h> |
| #include <linux/timer.h> |
| |
| #include <asm/semaphore.h> |
| #endif |
| |
| #define journal_oom_retry 1 |
| |
| /* |
| * Define JBD_PARANIOD_IOFAIL to cause a kernel BUG() if ext3 finds |
| * certain classes of error which can occur due to failed IOs. Under |
| * normal use we want ext3 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 JBD_PARANOID_IOFAIL |
| |
| /* |
| * The default maximum commit age, in seconds. |
| */ |
| #define JBD_DEFAULT_MAX_COMMIT_AGE 5 |
| |
| #ifdef CONFIG_JBD2_DEBUG |
| /* |
| * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal |
| * consistency checks. By default we don't do this unless |
| * CONFIG_JBD2_DEBUG is on. |
| */ |
| #define JBD_EXPENSIVE_CHECKING |
| extern int jbd2_journal_enable_debug; |
| |
| #define jbd_debug(n, f, a...) \ |
| do { \ |
| if ((n) <= jbd2_journal_enable_debug) { \ |
| printk (KERN_DEBUG "(%s, %d): %s: ", \ |
| __FILE__, __LINE__, __FUNCTION__); \ |
| printk (f, ## a); \ |
| } \ |
| } while (0) |
| #else |
| #define jbd_debug(f, a...) /**/ |
| #endif |
| |
| extern void * __jbd2_kmalloc (const char *where, size_t size, gfp_t flags, int retry); |
| extern void * jbd2_slab_alloc(size_t size, gfp_t flags); |
| extern void jbd2_slab_free(void *ptr, size_t size); |
| |
| #define jbd_kmalloc(size, flags) \ |
| __jbd2_kmalloc(__FUNCTION__, (size), (flags), journal_oom_retry) |
| #define jbd_rep_kmalloc(size, flags) \ |
| __jbd2_kmalloc(__FUNCTION__, (size), (flags), 1) |
| |
| #define JBD2_MIN_JOURNAL_BLOCKS 1024 |
| |
| #ifdef __KERNEL__ |
| |
| /** |
| * 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. |
| **/ |
| typedef struct handle_s 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. |
| **/ |
| typedef struct 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! */ |
| |
| /* |
| * On-disk structures |
| */ |
| |
| /* |
| * Descriptor block types: |
| */ |
| |
| #define JBD2_DESCRIPTOR_BLOCK 1 |
| #define JBD2_COMMIT_BLOCK 2 |
| #define JBD2_SUPERBLOCK_V1 3 |
| #define JBD2_SUPERBLOCK_V2 4 |
| #define JBD2_REVOKE_BLOCK 5 |
| |
| /* |
| * Standard header for all descriptor blocks: |
| */ |
| typedef struct journal_header_s |
| { |
| __be32 h_magic; |
| __be32 h_blocktype; |
| __be32 h_sequence; |
| } journal_header_t; |
| |
| |
| /* |
| * 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. |
| */ |
| typedef struct journal_block_tag_s |
| { |
| __be32 t_blocknr; /* The on-disk block number */ |
| __be32 t_flags; /* See below */ |
| __be32 t_blocknr_high; /* most-significant high 32bits. */ |
| } journal_block_tag_t; |
| |
| #define JBD_TAG_SIZE32 (offsetof(journal_block_tag_t, t_blocknr_high)) |
| #define JBD_TAG_SIZE64 (sizeof(journal_block_tag_t)) |
| |
| /* |
| * The revoke descriptor: used on disk to describe a series of blocks to |
| * be revoked from the log |
| */ |
| typedef struct 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. |
| */ |
| typedef struct 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 */ |
| __u32 s_padding[44]; |
| |
| /* 0x0100 */ |
| __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ |
| /* 0x0400 */ |
| } journal_superblock_t; |
| |
| #define JBD2_HAS_COMPAT_FEATURE(j,mask) \ |
| ((j)->j_format_version >= 2 && \ |
| ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) |
| #define JBD2_HAS_RO_COMPAT_FEATURE(j,mask) \ |
| ((j)->j_format_version >= 2 && \ |
| ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) |
| #define JBD2_HAS_INCOMPAT_FEATURE(j,mask) \ |
| ((j)->j_format_version >= 2 && \ |
| ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) |
| |
| #define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001 |
| #define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002 |
| |
| /* Features known to this kernel version: */ |
| #define JBD2_KNOWN_COMPAT_FEATURES 0 |
| #define JBD2_KNOWN_ROCOMPAT_FEATURES 0 |
| #define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \ |
| JBD2_FEATURE_INCOMPAT_64BIT) |
| |
| #ifdef __KERNEL__ |
| |
| #include <linux/fs.h> |
| #include <linux/sched.h> |
| |
| #define JBD_ASSERTIONS |
| #ifdef JBD_ASSERTIONS |
| #define J_ASSERT(assert) \ |
| do { \ |
| if (!(assert)) { \ |
| printk (KERN_EMERG \ |
| "Assertion failure in %s() at %s:%d: \"%s\"\n", \ |
| __FUNCTION__, __FILE__, __LINE__, # assert); \ |
| BUG(); \ |
| } \ |
| } while (0) |
| |
| #if defined(CONFIG_BUFFER_DEBUG) |
| void buffer_assertion_failure(struct buffer_head *bh); |
| #define J_ASSERT_BH(bh, expr) \ |
| do { \ |
| if (!(expr)) \ |
| buffer_assertion_failure(bh); \ |
| J_ASSERT(expr); \ |
| } while (0) |
| #define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr) |
| #else |
| #define J_ASSERT_BH(bh, expr) J_ASSERT(expr) |
| #define J_ASSERT_JH(jh, expr) J_ASSERT(expr) |
| #endif |
| |
| #else |
| #define J_ASSERT(assert) do { } while (0) |
| #endif /* JBD_ASSERTIONS */ |
| |
| #if defined(JBD_PARANOID_IOFAIL) |
| #define J_EXPECT(expr, why...) J_ASSERT(expr) |
| #define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr) |
| #define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr) |
| #else |
| #define __journal_expect(expr, why...) \ |
| ({ \ |
| int val = (expr); \ |
| if (!val) { \ |
| printk(KERN_ERR \ |
| "EXT3-fs unexpected failure: %s;\n",# expr); \ |
| printk(KERN_ERR why "\n"); \ |
| } \ |
| val; \ |
| }) |
| #define J_EXPECT(expr, why...) __journal_expect(expr, ## why) |
| #define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why) |
| #define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why) |
| #endif |
| |
| 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_State, /* Pins most journal_head state */ |
| BH_JournalHead, /* Pins bh->b_private and jh->b_bh */ |
| BH_Unshadow, /* Dummy bit, for BJ_Shadow wakeup filtering */ |
| }; |
| |
| BUFFER_FNS(JBD, jbd) |
| BUFFER_FNS(JWrite, jwrite) |
| BUFFER_FNS(JBDDirty, jbddirty) |
| TAS_BUFFER_FNS(JBDDirty, jbddirty) |
| BUFFER_FNS(Revoked, revoked) |
| TAS_BUFFER_FNS(Revoked, revoked) |
| BUFFER_FNS(RevokeValid, revokevalid) |
| TAS_BUFFER_FNS(RevokeValid, revokevalid) |
| BUFFER_FNS(Freed, freed) |
| |
| static inline struct buffer_head *jh2bh(struct journal_head *jh) |
| { |
| return jh->b_bh; |
| } |
| |
| static inline struct journal_head *bh2jh(struct buffer_head *bh) |
| { |
| return bh->b_private; |
| } |
| |
| static inline void jbd_lock_bh_state(struct buffer_head *bh) |
| { |
| bit_spin_lock(BH_State, &bh->b_state); |
| } |
| |
| static inline int jbd_trylock_bh_state(struct buffer_head *bh) |
| { |
| return bit_spin_trylock(BH_State, &bh->b_state); |
| } |
| |
| static inline int jbd_is_locked_bh_state(struct buffer_head *bh) |
| { |
| return bit_spin_is_locked(BH_State, &bh->b_state); |
| } |
| |
| static inline void jbd_unlock_bh_state(struct buffer_head *bh) |
| { |
| bit_spin_unlock(BH_State, &bh->b_state); |
| } |
| |
| static inline void jbd_lock_bh_journal_head(struct buffer_head *bh) |
| { |
| bit_spin_lock(BH_JournalHead, &bh->b_state); |
| } |
| |
| static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh) |
| { |
| bit_spin_unlock(BH_JournalHead, &bh->b_state); |
| } |
| |
| struct jbd2_revoke_table_s; |
| |
| /** |
| * struct handle_s - The handle_s type is the concrete type associated with |
| * handle_t. |
| * @h_transaction: Which compound transaction is this update a part of? |
| * @h_buffer_credits: Number of remaining buffers we are allowed to dirty. |
| * @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_jdata: flag to force data journaling |
| * @h_aborted: flag indicating fatal error on handle |
| **/ |
| |
| /* Docbook can't yet cope with the bit fields, but will leave the documentation |
| * in so it can be fixed later. |
| */ |
| |
| struct handle_s |
| { |
| /* Which compound transaction is this update a part of? */ |
| transaction_t *h_transaction; |
| |
| /* Number of remaining buffers we are allowed to dirty: */ |
| int h_buffer_credits; |
| |
| /* Reference count on this handle */ |
| int h_ref; |
| |
| /* Field for caller's use to track errors through large fs */ |
| /* operations */ |
| int h_err; |
| |
| /* Flags [no locking] */ |
| unsigned int h_sync: 1; /* sync-on-close */ |
| unsigned int h_jdata: 1; /* force data journaling */ |
| unsigned int h_aborted: 1; /* fatal error on handle */ |
| }; |
| |
| |
| /* 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. |
| */ |
| |
| /* |
| * Lock ranking: |
| * |
| * j_list_lock |
| * ->jbd_lock_bh_journal_head() (This is "innermost") |
| * |
| * j_state_lock |
| * ->jbd_lock_bh_state() |
| * |
| * jbd_lock_bh_state() |
| * ->j_list_lock |
| * |
| * j_state_lock |
| * ->t_handle_lock |
| * |
| * j_state_lock |
| * ->j_list_lock (journal_unmap_buffer) |
| * |
| */ |
| |
| 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] |
| * FIXME: needs barriers |
| * KLUDGE: [use j_state_lock] |
| */ |
| enum { |
| T_RUNNING, |
| T_LOCKED, |
| T_RUNDOWN, |
| T_FLUSH, |
| T_COMMIT, |
| T_FINISHED |
| } t_state; |
| |
| /* |
| * Where in the log does this transaction's commit start? [no locking] |
| */ |
| unsigned long t_log_start; |
| |
| /* Number of buffers on the t_buffers list [j_list_lock] */ |
| int t_nr_buffers; |
| |
| /* |
| * Doubly-linked circular list of all buffers reserved but not yet |
| * modified by this transaction [j_list_lock] |
| */ |
| struct journal_head *t_reserved_list; |
| |
| /* |
| * Doubly-linked circular list of all buffers under writeout during |
| * commit [j_list_lock] |
| */ |
| struct journal_head *t_locked_list; |
| |
| /* |
| * Doubly-linked circular list of all metadata buffers owned by this |
| * transaction [j_list_lock] |
| */ |
| struct journal_head *t_buffers; |
| |
| /* |
| * Doubly-linked circular list of all data buffers still to be |
| * flushed before this transaction can be committed [j_list_lock] |
| */ |
| struct journal_head *t_sync_datalist; |
| |
| /* |
| * 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 all buffers submitted for IO while |
| * checkpointing. [j_list_lock] |
| */ |
| struct journal_head *t_checkpoint_io_list; |
| |
| /* |
| * Doubly-linked circular list of temporary buffers currently undergoing |
| * IO in the log [j_list_lock] |
| */ |
| struct journal_head *t_iobuf_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] |
| */ |
| struct journal_head *t_shadow_list; |
| |
| /* |
| * Doubly-linked circular list of control buffers being written to the |
| * log. [j_list_lock] |
| */ |
| struct journal_head *t_log_list; |
| |
| /* |
| * Protects info related to handles |
| */ |
| spinlock_t t_handle_lock; |
| |
| /* |
| * Number of outstanding updates running on this transaction |
| * [t_handle_lock] |
| */ |
| int t_updates; |
| |
| /* |
| * Number of buffers reserved for use by all handles in this transaction |
| * handle but not yet modified. [t_handle_lock] |
| */ |
| int t_outstanding_credits; |
| |
| /* |
| * 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] |
| */ |
| unsigned long t_expires; |
| |
| /* |
| * How many handles used this transaction? [t_handle_lock] |
| */ |
| int t_handle_count; |
| |
| }; |
| |
| /** |
| * struct journal_s - The journal_s type is the concrete type associated with |
| * journal_t. |
| * @j_flags: General journaling state flags |
| * @j_errno: Is there an outstanding uncleared error on the journal (from a |
| * prior abort)? |
| * @j_sb_buffer: First part of superblock buffer |
| * @j_superblock: Second part of superblock buffer |
| * @j_format_version: Version of the superblock format |
| * @j_state_lock: Protect the various scalars in the journal |
| * @j_barrier_count: Number of processes waiting to create a barrier lock |
| * @j_barrier: The barrier lock itself |
| * @j_running_transaction: The current running transaction.. |
| * @j_committing_transaction: the transaction we are pushing to disk |
| * @j_checkpoint_transactions: a linked circular list of all transactions |
| * waiting for checkpointing |
| * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction |
| * to start committing, or for a barrier lock to be released |
| * @j_wait_logspace: Wait queue for waiting for checkpointing to complete |
| * @j_wait_done_commit: Wait queue for waiting for commit to complete |
| * @j_wait_checkpoint: Wait queue to trigger checkpointing |
| * @j_wait_commit: Wait queue to trigger commit |
| * @j_wait_updates: Wait queue to wait for updates to complete |
| * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints |
| * @j_head: Journal head - identifies the first unused block in the journal |
| * @j_tail: Journal tail - identifies the oldest still-used block in the |
| * journal. |
| * @j_free: Journal free - how many free blocks are there in the journal? |
| * @j_first: The block number of the first usable block |
| * @j_last: The block number one beyond the last usable block |
| * @j_dev: Device where we store the journal |
| * @j_blocksize: blocksize for the location where we store the journal. |
| * @j_blk_offset: starting block offset for into the device where we store the |
| * journal |
| * @j_fs_dev: Device which holds the client fs. For internal journal this will |
| * be equal to j_dev |
| * @j_maxlen: Total maximum capacity of the journal region on disk. |
| * @j_list_lock: Protects the buffer lists and internal buffer state. |
| * @j_inode: Optional inode where we store the journal. If present, all journal |
| * block numbers are mapped into this inode via bmap(). |
| * @j_tail_sequence: Sequence number of the oldest transaction in the log |
| * @j_transaction_sequence: Sequence number of the next transaction to grant |
| * @j_commit_sequence: Sequence number of the most recently committed |
| * transaction |
| * @j_commit_request: Sequence number of the most recent transaction wanting |
| * commit |
| * @j_uuid: Uuid of client object. |
| * @j_task: Pointer to the current commit thread for this journal |
| * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a |
| * single compound commit transaction |
| * @j_commit_interval: What is the maximum transaction lifetime before we begin |
| * a commit? |
| * @j_commit_timer: The timer used to wakeup the commit thread |
| * @j_revoke_lock: Protect the revoke table |
| * @j_revoke: The revoke table - maintains the list of revoked blocks in the |
| * current transaction. |
| * @j_revoke_table: alternate revoke tables for j_revoke |
| * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction |
| * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the |
| * number that will fit in j_blocksize |
| * @j_last_sync_writer: most recent pid which did a synchronous write |
| * @j_private: An opaque pointer to fs-private information. |
| */ |
| |
| struct journal_s |
| { |
| /* General journaling state flags [j_state_lock] */ |
| unsigned long j_flags; |
| |
| /* |
| * Is there an outstanding uncleared error on the journal (from a prior |
| * abort)? [j_state_lock] |
| */ |
| int j_errno; |
| |
| /* The superblock buffer */ |
| struct buffer_head *j_sb_buffer; |
| journal_superblock_t *j_superblock; |
| |
| /* Version of the superblock format */ |
| int j_format_version; |
| |
| /* |
| * Protect the various scalars in the journal |
| */ |
| spinlock_t j_state_lock; |
| |
| /* |
| * Number of processes waiting to create a barrier lock [j_state_lock] |
| */ |
| int j_barrier_count; |
| |
| /* The barrier lock itself */ |
| struct mutex j_barrier; |
| |
| /* |
| * Transactions: The current running transaction... |
| * [j_state_lock] [caller holding open handle] |
| */ |
| transaction_t *j_running_transaction; |
| |
| /* |
| * the transaction we are pushing to disk |
| * [j_state_lock] [caller holding open handle] |
| */ |
| transaction_t *j_committing_transaction; |
| |
| /* |
| * ... and a linked circular list of all transactions waiting for |
| * checkpointing. [j_list_lock] |
| */ |
| transaction_t *j_checkpoint_transactions; |
| |
| /* |
| * 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; |
| |
| /* Wait queue for waiting for checkpointing to complete */ |
| wait_queue_head_t j_wait_logspace; |
| |
| /* Wait queue for waiting for commit to complete */ |
| wait_queue_head_t j_wait_done_commit; |
| |
| /* Wait queue to trigger checkpointing */ |
| wait_queue_head_t j_wait_checkpoint; |
| |
| /* Wait queue to trigger commit */ |
| wait_queue_head_t j_wait_commit; |
| |
| /* Wait queue to wait for updates to complete */ |
| wait_queue_head_t j_wait_updates; |
| |
| /* Semaphore for locking against concurrent checkpoints */ |
| struct mutex j_checkpoint_mutex; |
| |
| /* |
| * Journal head: identifies the first unused block in the journal. |
| * [j_state_lock] |
| */ |
| unsigned long j_head; |
| |
| /* |
| * Journal tail: identifies the oldest still-used block in the journal. |
| * [j_state_lock] |
| */ |
| unsigned long j_tail; |
| |
| /* |
| * Journal free: how many free blocks are there in the journal? |
| * [j_state_lock] |
| */ |
| unsigned long j_free; |
| |
| /* |
| * Journal start and end: the block numbers of the first usable block |
| * and one beyond the last usable block in the journal. [j_state_lock] |
| */ |
| unsigned long j_first; |
| unsigned long j_last; |
| |
| /* |
| * Device, blocksize and starting block offset for the location where we |
| * store the journal. |
| */ |
| struct block_device *j_dev; |
| int j_blocksize; |
| unsigned long long j_blk_offset; |
| |
| /* |
| * Device which holds the client fs. For internal journal this will be |
| * equal to j_dev. |
| */ |
| struct block_device *j_fs_dev; |
| |
| /* Total maximum capacity of the journal region on disk. */ |
| unsigned int j_maxlen; |
| |
| /* |
| * Protects the buffer lists and internal buffer state. |
| */ |
| spinlock_t j_list_lock; |
| |
| /* Optional inode where we store the journal. If present, all */ |
| /* journal block numbers are mapped into this inode via */ |
| /* bmap(). */ |
| struct inode *j_inode; |
| |
| /* |
| * Sequence number of the oldest transaction in the log [j_state_lock] |
| */ |
| tid_t j_tail_sequence; |
| |
| /* |
| * Sequence number of the next transaction to grant [j_state_lock] |
| */ |
| tid_t j_transaction_sequence; |
| |
| /* |
| * Sequence number of the most recently committed transaction |
| * [j_state_lock]. |
| */ |
| tid_t j_commit_sequence; |
| |
| /* |
| * Sequence number of the most recent transaction wanting commit |
| * [j_state_lock] |
| */ |
| tid_t j_commit_request; |
| |
| /* |
| * 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]; |
| |
| /* Pointer to the current commit thread for this journal */ |
| struct task_struct *j_task; |
| |
| /* |
| * Maximum number of metadata buffers to allow in a single compound |
| * commit transaction |
| */ |
| int j_max_transaction_buffers; |
| |
| /* |
| * What is the maximum transaction lifetime before we begin a commit? |
| */ |
| unsigned long j_commit_interval; |
| |
| /* The timer used to wakeup the commit thread: */ |
| struct timer_list j_commit_timer; |
| |
| /* |
| * The revoke table: maintains the list of revoked blocks in the |
| * current transaction. [j_revoke_lock] |
| */ |
| spinlock_t j_revoke_lock; |
| struct jbd2_revoke_table_s *j_revoke; |
| struct jbd2_revoke_table_s *j_revoke_table[2]; |
| |
| /* |
| * array of bhs for jbd2_journal_commit_transaction |
| */ |
| struct buffer_head **j_wbuf; |
| int j_wbufsize; |
| |
| pid_t j_last_sync_writer; |
| |
| /* |
| * An opaque pointer to fs-private information. ext3 puts its |
| * superblock pointer here |
| */ |
| void *j_private; |
| }; |
| |
| /* |
| * 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 */ |
| |
| /* |
| * Function declarations for the journaling transaction and buffer |
| * management |
| */ |
| |
| /* Filing buffers */ |
| extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *); |
| extern void __jbd2_journal_unfile_buffer(struct journal_head *); |
| extern void __jbd2_journal_refile_buffer(struct journal_head *); |
| extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *); |
| extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); |
| extern void __journal_free_buffer(struct journal_head *bh); |
| extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); |
| extern void __journal_clean_data_list(transaction_t *transaction); |
| |
| /* Log buffer allocation */ |
| extern struct journal_head * jbd2_journal_get_descriptor_buffer(journal_t *); |
| int jbd2_journal_next_log_block(journal_t *, unsigned long long *); |
| |
| /* Commit management */ |
| extern void jbd2_journal_commit_transaction(journal_t *); |
| |
| /* Checkpoint list management */ |
| int __jbd2_journal_clean_checkpoint_list(journal_t *journal); |
| int __jbd2_journal_remove_checkpoint(struct journal_head *); |
| void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *); |
| |
| /* Buffer IO */ |
| extern int |
| jbd2_journal_write_metadata_buffer(transaction_t *transaction, |
| struct journal_head *jh_in, |
| struct journal_head **jh_out, |
| unsigned long long blocknr); |
| |
| /* Transaction locking */ |
| extern void __wait_on_journal (journal_t *); |
| |
| /* |
| * 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. |
| */ |
| |
| static inline handle_t *journal_current_handle(void) |
| { |
| return current->journal_info; |
| } |
| |
| /* The journaling code user interface: |
| * |
| * Create and destroy handles |
| * Register buffer modifications against the current transaction. |
| */ |
| |
| extern handle_t *jbd2_journal_start(journal_t *, int nblocks); |
| extern int jbd2_journal_restart (handle_t *, int nblocks); |
| extern int jbd2_journal_extend (handle_t *, int nblocks); |
| extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *); |
| extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *); |
| extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *); |
| extern int jbd2_journal_dirty_data (handle_t *, struct buffer_head *); |
| extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *); |
| extern void jbd2_journal_release_buffer (handle_t *, struct buffer_head *); |
| extern int jbd2_journal_forget (handle_t *, struct buffer_head *); |
| extern void journal_sync_buffer (struct buffer_head *); |
| extern void jbd2_journal_invalidatepage(journal_t *, |
| struct page *, unsigned long); |
| extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); |
| extern int jbd2_journal_stop(handle_t *); |
| extern int jbd2_journal_flush (journal_t *); |
| extern void jbd2_journal_lock_updates (journal_t *); |
| extern void jbd2_journal_unlock_updates (journal_t *); |
| |
| extern journal_t * jbd2_journal_init_dev(struct block_device *bdev, |
| struct block_device *fs_dev, |
| unsigned long long start, int len, int bsize); |
| extern journal_t * jbd2_journal_init_inode (struct inode *); |
| extern int jbd2_journal_update_format (journal_t *); |
| extern int jbd2_journal_check_used_features |
| (journal_t *, unsigned long, unsigned long, unsigned long); |
| extern int jbd2_journal_check_available_features |
| (journal_t *, unsigned long, unsigned long, unsigned long); |
| extern int jbd2_journal_set_features |
| (journal_t *, unsigned long, unsigned long, unsigned long); |
| extern int jbd2_journal_create (journal_t *); |
| extern int jbd2_journal_load (journal_t *journal); |
| extern void jbd2_journal_destroy (journal_t *); |
| extern int jbd2_journal_recover (journal_t *journal); |
| extern int jbd2_journal_wipe (journal_t *, int); |
| extern int jbd2_journal_skip_recovery (journal_t *); |
| extern void jbd2_journal_update_superblock (journal_t *, int); |
| extern void __jbd2_journal_abort_hard (journal_t *); |
| extern void jbd2_journal_abort (journal_t *, int); |
| extern int jbd2_journal_errno (journal_t *); |
| extern void jbd2_journal_ack_err (journal_t *); |
| extern int jbd2_journal_clear_err (journal_t *); |
| extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *); |
| extern int jbd2_journal_force_commit(journal_t *); |
| |
| /* |
| * journal_head management |
| */ |
| struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh); |
| struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh); |
| void jbd2_journal_remove_journal_head(struct buffer_head *bh); |
| void jbd2_journal_put_journal_head(struct journal_head *jh); |
| |
| /* |
| * handle management |
| */ |
| extern struct kmem_cache *jbd2_handle_cache; |
| |
| static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags) |
| { |
| return kmem_cache_alloc(jbd2_handle_cache, gfp_flags); |
| } |
| |
| static inline void jbd_free_handle(handle_t *handle) |
| { |
| kmem_cache_free(jbd2_handle_cache, handle); |
| } |
| |
| /* Primary revoke support */ |
| #define JOURNAL_REVOKE_DEFAULT_HASH 256 |
| extern int jbd2_journal_init_revoke(journal_t *, int); |
| extern void jbd2_journal_destroy_revoke_caches(void); |
| extern int jbd2_journal_init_revoke_caches(void); |
| |
| extern void jbd2_journal_destroy_revoke(journal_t *); |
| extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *); |
| extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *); |
| extern void jbd2_journal_write_revoke_records(journal_t *, transaction_t *); |
| |
| /* Recovery revoke support */ |
| extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t); |
| extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t); |
| extern void jbd2_journal_clear_revoke(journal_t *); |
| extern void jbd2_journal_switch_revoke_table(journal_t *journal); |
| |
| /* |
| * The log thread user interface: |
| * |
| * Request space in the current transaction, and force transaction commit |
| * transitions on demand. |
| */ |
| |
| int __jbd2_log_space_left(journal_t *); /* Called with journal locked */ |
| int jbd2_log_start_commit(journal_t *journal, tid_t tid); |
| int __jbd2_log_start_commit(journal_t *journal, tid_t tid); |
| int jbd2_journal_start_commit(journal_t *journal, tid_t *tid); |
| int jbd2_journal_force_commit_nested(journal_t *journal); |
| int jbd2_log_wait_commit(journal_t *journal, tid_t tid); |
| int jbd2_log_do_checkpoint(journal_t *journal); |
| |
| void __jbd2_log_wait_for_space(journal_t *journal); |
| extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *); |
| extern int jbd2_cleanup_journal_tail(journal_t *); |
| |
| /* Debugging code only: */ |
| |
| #define jbd_ENOSYS() \ |
| do { \ |
| printk (KERN_ERR "JBD unimplemented function %s\n", __FUNCTION__); \ |
| current->state = TASK_UNINTERRUPTIBLE; \ |
| schedule(); \ |
| } while (1) |
| |
| /* |
| * 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. |
| */ |
| |
| static inline int is_journal_aborted(journal_t *journal) |
| { |
| return journal->j_flags & JBD2_ABORT; |
| } |
| |
| static inline int is_handle_aborted(handle_t *handle) |
| { |
| if (handle->h_aborted) |
| return 1; |
| return is_journal_aborted(handle->h_transaction->t_journal); |
| } |
| |
| static inline void jbd2_journal_abort_handle(handle_t *handle) |
| { |
| handle->h_aborted = 1; |
| } |
| |
| #endif /* __KERNEL__ */ |
| |
| /* Comparison functions for transaction IDs: perform comparisons using |
| * modulo arithmetic so that they work over sequence number wraps. */ |
| |
| static inline int tid_gt(tid_t x, tid_t y) |
| { |
| int difference = (x - y); |
| return (difference > 0); |
| } |
| |
| static inline int tid_geq(tid_t x, tid_t y) |
| { |
| int difference = (x - y); |
| return (difference >= 0); |
| } |
| |
| extern int jbd2_journal_blocks_per_page(struct inode *inode); |
| extern size_t journal_tag_bytes(journal_t *journal); |
| |
| /* |
| * Return the minimum number of blocks which must be free in the journal |
| * before a new transaction may be started. Must be called under j_state_lock. |
| */ |
| static inline int jbd_space_needed(journal_t *journal) |
| { |
| int nblocks = journal->j_max_transaction_buffers; |
| if (journal->j_committing_transaction) |
| nblocks += journal->j_committing_transaction-> |
| t_outstanding_credits; |
| return nblocks; |
| } |
| |
| /* |
| * Definitions which augment the buffer_head layer |
| */ |
| |
| /* journaling buffer types */ |
| #define BJ_None 0 /* Not journaled */ |
| #define BJ_SyncData 1 /* Normal data: flush before commit */ |
| #define BJ_Metadata 2 /* Normal journaled metadata */ |
| #define BJ_Forget 3 /* Buffer superseded by this transaction */ |
| #define BJ_IO 4 /* Buffer is for temporary IO use */ |
| #define BJ_Shadow 5 /* Buffer contents being shadowed to the log */ |
| #define BJ_LogCtl 6 /* Buffer contains log descriptors */ |
| #define BJ_Reserved 7 /* Buffer is reserved for access by journal */ |
| #define BJ_Locked 8 /* Locked for I/O during commit */ |
| #define BJ_Types 9 |
| |
| extern int jbd_blocks_per_page(struct inode *inode); |
| |
| #ifdef __KERNEL__ |
| |
| #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__ */ |
| |
| #endif /* _LINUX_JBD_H */ |