diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/ChangeLog | 4 | ||||
| -rw-r--r-- | include/linux/jfs.h | 650 | ||||
| -rw-r--r-- | include/linux/jfs_compat.h | 56 | ||||
| -rw-r--r-- | include/linux/list.h | 108 |
4 files changed, 818 insertions, 0 deletions
diff --git a/include/linux/ChangeLog b/include/linux/ChangeLog index 0067f461..d9c81a1f 100644 --- a/include/linux/ChangeLog +++ b/include/linux/ChangeLog @@ -1,3 +1,7 @@ +2000-12-09 <tytso@snap.thunk.org> + + * jfs.h, jfs_compat.h, list.h: New files added to support ext3. + 2000-10-24 <tytso@valinux.com> * ext2_fs.h (EXT2_JOURNAL_INO): Add definition for diff --git a/include/linux/jfs.h b/include/linux/jfs.h new file mode 100644 index 00000000..fffd8df0 --- /dev/null +++ b/include/linux/jfs.h @@ -0,0 +1,650 @@ +/* + * linux/include/linux/jfs.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_JFS_H +#define _LINUX_JFS_H + +/* Allow this file to be included directly into e2fsprogs */ +#ifndef __KERNEL__ +#include "jfs_compat.h" +#endif + +/* + * Debug code enabled by default for kernel builds + */ +#ifdef __KERNEL__ +#define JFS_DEBUG +#else +#define JFS_DEBUG +#endif + +extern int journal_enable_debug; + +#ifdef JFS_DEBUG +#define jfs_debug(n, f, a...) \ + do { \ + if ((n) <= journal_enable_debug) { \ + printk (KERN_DEBUG "JFS DEBUG: (%s, %d): %s: ", \ + __FILE__, __LINE__, __FUNCTION__); \ + printk (f, a); \ + } \ + } while (0) +#else +#define jfs_debug(f, a...) /**/ +#endif + +#define JFS_MIN_JOURNAL_BLOCKS 1024 + +/* + * Internal structures used by the logging mechanism: + */ + +#define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */ + + +/* + * On-disk structures + */ + +/* + * Descriptor block types: + */ + +#define JFS_DESCRIPTOR_BLOCK 1 +#define JFS_COMMIT_BLOCK 2 +#define JFS_SUPERBLOCK_V1 3 +#define JFS_SUPERBLOCK_V2 4 +#define JFS_REVOKE_BLOCK 5 + +/* + * Standard header for all descriptor blocks: + */ +typedef struct journal_header_s +{ + __u32 h_magic; + __u32 h_blocktype; + __u32 h_sequence; +} journal_header_t; + + +/* + * The block tag: used to describe a single buffer in the journal + */ +typedef struct journal_block_tag_s +{ + __u32 t_blocknr; /* The on-disk block number */ + __u32 t_flags; /* See below */ +} journal_block_tag_t; + +/* + * The revoke descriptor: used on disk to describe a series of blocks to + * be revoked from the log + */ +typedef struct journal_revoke_header_s +{ + journal_header_t r_header; + int r_count; /* Count of bytes used in the block */ +} journal_revoke_header_t; + + +/* Definitions for the journal tag flags word: */ +#define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */ +#define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */ +#define JFS_FLAG_DELETED 4 /* block deleted by this transaction */ +#define JFS_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 */ + __u32 s_blocksize; /* journal device blocksize */ + __u32 s_maxlen; /* total blocks in journal file */ + __u32 s_first; /* first block of log information */ + +/* 0x0018 */ + /* Dynamic information describing the current state of the log */ + __u32 s_sequence; /* first commit ID expected in log */ + __u32 s_start; /* blocknr of start of log */ + +/* 0x0020 */ + /* Error value, as set by journal_abort(). */ + __s32 s_errno; + +/* 0x0024 */ + /* Remaining fields are only valid in a version-2 superblock */ + __u32 s_feature_compat; /* compatible feature set */ + __u32 s_feature_incompat; /* incompatible feature set */ + __u32 s_feature_ro_compat; /* readonly-compatible feature set */ +/* 0x0030 */ + __u8 s_uuid[16]; /* 128-bit uuid for journal */ + +/* 0x0040 */ + __u32 s_nr_users; /* Nr of filesystems sharing log */ + + __u32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ + +/* 0x0048 */ + __u32 s_max_transaction; /* Limit of journal blocks per trans.*/ + __u32 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 JFS_HAS_COMPAT_FEATURE(j,mask) \ + ((j)->j_format_version >= 2 && \ + ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) +#define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \ + ((j)->j_format_version >= 2 && \ + ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) +#define JFS_HAS_INCOMPAT_FEATURE(j,mask) \ + ((j)->j_format_version >= 2 && \ + ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) + +#define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001 + +/* Features known to this kernel version: */ +#define JFS_KNOWN_COMPAT_FEATURES 0 +#define JFS_KNOWN_ROCOMPAT_FEATURES 0 +#define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE + +#ifdef __KERNEL__ + +#include <linux/fs.h> + + +#define J_ASSERT(assert) \ + do { if (!(assert)) { \ + printk (KERN_EMERG \ + "Assertion failure in %s() at %s line %d: " \ + "\"%s\"\n", \ + __FUNCTION__, __FILE__, __LINE__, # assert); \ + * ((char *) 0) = 0; \ + } } while (0) + + +struct jfs_revoke_table_s; + +/* 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. */ + +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; + + /* Flags */ + unsigned int h_sync : 1; /* sync-on-close */ + unsigned int h_jdata : 1; /* force data journaling */ +}; + + +/* 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. + */ + +struct transaction_s +{ + /* Pointer to the journal for this transaction. */ + journal_t * t_journal; + + /* Sequence number for this transaction */ + tid_t t_tid; + + /* Transaction's current state */ + 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? */ + unsigned long t_log_start; + + /* Doubly-linked circular list of all inodes owned by this + transaction */ + struct inode * t_ilist; + + /* Number of buffers on the t_buffers list */ + int t_nr_buffers; + + /* Doubly-linked circular list of all buffers reserved but not + yet modified by this transaction */ + struct buffer_head * t_reserved_list; + + /* Doubly-linked circular list of all metadata buffers owned by this + transaction */ + struct buffer_head * t_buffers; + + /* Doubly-linked circular list of all data buffers still to be + flushed before this transaction can be committed */ + struct buffer_head * t_datalist; + + /* Doubly-linked circular list of all forget buffers (superceded + buffers which we can un-checkpoint once this transaction + commits) */ + struct buffer_head * t_forget; + + /* Doubly-linked circular list of all buffers still to be + flushed before this transaction can be checkpointed */ + struct buffer_head * t_checkpoint_list; + + /* Doubly-linked circular list of temporary buffers currently + undergoing IO in the log */ + struct buffer_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. */ + struct buffer_head * t_shadow_list; + + /* Doubly-linked circular list of control buffers being written + to the log. */ + struct buffer_head * t_log_list; + + /* Number of outstanding updates running on this transaction */ + int t_updates; + + /* Number of buffers reserved for use by all handles in this + * transaction handle but not yet modified. */ + int t_outstanding_credits; + + /* Wait queue to wait for updates to complete */ + struct wait_queue * t_wait; + + /* Forward and backward links for the circular list of all + * transactions awaiting checkpoint */ + transaction_t *t_cpnext, *t_cpprev; + + /* When will the transaction expire (become due for commit), in + * jiffies ? */ + unsigned long t_expires; +}; + + +/* The journal_t maintains all of the journaling state information for a + * single filesystem. It 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. */ + +struct journal_s +{ + /* General journaling state flags */ + unsigned long j_flags; + + /* Is there an outstanding uncleared error on the journal (from + * a prior abort)? */ + 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; + + /* Transactions: The current running transaction... */ + transaction_t * j_running_transaction; + + /* ... the transaction we are pushing to disk ... */ + transaction_t * j_committing_transaction; + + /* ... and a linked circular list of all transactions waiting + * for checkpointing. */ + transaction_t * j_checkpoint_transactions; + + /* Wait queue for locking of the journal structure. */ + struct wait_queue * j_wait_lock; + + /* Wait queue for waiting for a locked transaction to start + committing */ + struct wait_queue * j_wait_transaction_locked; + + /* Wait queue for waiting for checkpointing to complete */ + struct wait_queue * j_wait_logspace; + + /* Wait queue for waiting for commit to complete */ + struct wait_queue * j_wait_done_commit; + + /* Wait queue to trigger checkpointing */ + struct wait_queue * j_wait_checkpoint; + + /* Wait queue to trigger commit */ + struct wait_queue * j_wait_commit; + + /* Semaphore for locking against concurrent checkpoints */ + struct semaphore j_checkpoint_sem; + + /* Journal running state: */ + /* The lock flag is *NEVER* touched from interrupts. */ + unsigned int j_locked : 1; + + /* Journal head: identifies the first unused block in the journal. */ + unsigned long j_head; + + /* Journal tail: identifies the oldest still-used block in the + * journal. */ + unsigned long j_tail; + + /* Journal free: how many free blocks are there in the journal? */ + 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. */ + unsigned long j_first, j_last; + + /* Device, blocksize and starting block offset for the location + * where we store the journal. */ + kdev_t j_dev; + int j_blocksize; + unsigned int j_blk_offset; + + /* Total maximum capacity of the journal region on disk. */ + unsigned int j_maxlen; + + /* 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 */ + tid_t j_tail_sequence; + /* Sequence number of the next transaction to grant */ + tid_t j_transaction_sequence; + /* Sequence number of the most recently committed transaction */ + tid_t j_commit_sequence; + /* Sequence number of the most recent transaction wanting commit */ + 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; + int j_commit_timer_active; + + /* The revoke table: maintains the list of revoked blocks in the + current transaction. */ + struct jfs_revoke_table_s *j_revoke; +}; + +/* + * Journal flag definitions + */ +#define JFS_UNMOUNT 1 /* Journal thread is being destroyed */ +#define JFS_SYNC 2 /* Perform synchronous transaction commits */ +#define JFS_ABORT 4 /* Journaling has been aborted for errors. */ +#define JFS_ACK_ERR 8 /* The errno in the sb has been acked */ + +/* + * Journaling internal variables/parameters + */ + +extern int journal_flush_nr_buffers; + + +/* + * Function declarations for the journaling transaction and buffer + * management + */ + +/* Filing buffers */ +extern void journal_unfile_buffer(struct buffer_head *); +extern void journal_refile_buffer(struct buffer_head *); +extern void journal_file_buffer(struct buffer_head *, transaction_t *, int); +extern void journal_clean_data_list(transaction_t *transaction); + +/* Log buffer allocation */ +extern struct buffer_head * journal_get_descriptor_buffer(journal_t *); +extern unsigned long journal_next_log_block(journal_t *); + +/* Commit management */ +extern void journal_commit_transaction(journal_t *); + +/* Checkpoint list management */ +extern void journal_remove_checkpoint(struct buffer_head *); +extern void journal_insert_checkpoint(struct buffer_head *, transaction_t *); + +/* Buffer IO */ +extern int +journal_write_metadata_buffer(transaction_t *transaction, + struct buffer_head *bh_in, + struct buffer_head **bh_out, + int blocknr); + +/* Create and destroy transactions */ +extern transaction_t * get_transaction (journal_t *); +extern void put_transaction (transaction_t *); + +/* Notify state transitions (called by the log writer thread): */ +extern int set_transaction_state (transaction_t *, int); + + +/* Transaction locking */ +extern void __wait_on_journal (journal_t *); + +/* Journal locking. In 2.2, we assume that the kernel lock is already + * held. */ +static inline void lock_journal (journal_t * journal) +{ +#ifdef __SMP__ + J_ASSERT(current->lock_depth >= 0); +#endif + if (journal->j_locked) + __wait_on_journal(journal); + journal->j_locked = 1; +} + +static inline int try_lock_journal (journal_t * journal) +{ + if (journal->j_locked) + return 1; + journal->j_locked = 1; + return 0; +} + +static inline void unlock_journal (journal_t * journal) +{ + J_ASSERT (journal->j_locked); + journal->j_locked = 0; + wake_up(&journal->j_wait_lock); +} + +/* This function is gross, but unfortunately we need it as long as + * existing filesystems want to guard against races by testing + * bh->b_count. @@@ Remove this? We no longer abuse b_count so badly! + */ + +static inline int journal_is_buffer_shared(struct buffer_head *bh) +{ + int count = bh->b_count; + J_ASSERT (count >= 1); + return (count > 1); +} + +/* The journaling code user interface: + * + * Create and destroy handles + * Register buffer modifications against the current transaction. + */ + +extern handle_t *journal_start (journal_t *, int nblocks); +extern int journal_restart (handle_t *, int nblocks); +extern int journal_extend (handle_t *, int nblocks); +extern int journal_get_write_access (handle_t *, struct buffer_head *); +extern int journal_get_create_access (handle_t *, struct buffer_head *); +extern int journal_get_undo_access (handle_t *, struct buffer_head *); +extern int journal_dirty_data (handle_t *, struct buffer_head *); +extern int journal_dirty_metadata (handle_t *, struct buffer_head *); +extern void journal_release_buffer (handle_t *, struct buffer_head *); +extern void journal_forget (handle_t *, struct buffer_head *); +extern void journal_sync_buffer (struct buffer_head *); +extern int journal_stop (handle_t *); +extern int journal_flush (journal_t *); + +extern journal_t * journal_init_dev (kdev_t, int start, int len, int bsize); +extern journal_t * journal_init_inode (struct inode *); +extern int journal_update_format (journal_t *); +extern int journal_check_used_features + (journal_t *, unsigned long, unsigned long, unsigned long); +extern int journal_check_available_features + (journal_t *, unsigned long, unsigned long, unsigned long); +extern int journal_set_features + (journal_t *, unsigned long, unsigned long, unsigned long); +extern int journal_create (journal_t *); +extern int journal_load (journal_t *); +extern void journal_release (journal_t *); +extern int journal_recover (journal_t *); +extern void journal_update_superblock (journal_t *, int); +extern void __journal_abort (journal_t *); +extern void journal_abort (journal_t *, int); +extern int journal_errno (journal_t *); +extern void journal_ack_err (journal_t *); +extern int journal_clear_err (journal_t *); + +/* Primary revoke support */ +#define JOURNAL_REVOKE_DEFAULT_HASH 256 +extern int journal_init_revoke(journal_t *, int); +extern void journal_destroy_revoke(journal_t *); +extern int journal_revoke (handle_t *, unsigned long, struct buffer_head *); +extern void journal_cancel_revoke(handle_t *, struct buffer_head *); +extern void journal_write_revoke_records(journal_t *, transaction_t *); + +/* Recovery revoke support */ +extern int journal_set_revoke(journal_t *, unsigned long, tid_t); +extern int journal_test_revoke(journal_t *, unsigned long, tid_t); +extern void journal_clear_revoke(journal_t *); + + +/* The log thread user interface: + * + * Request space in the current transaction, and force transaction commit + * transitions on demand. + */ + +extern int log_space_left (journal_t *); /* Called with journal locked */ +extern void log_start_commit (journal_t *, transaction_t *); +extern void log_wait_commit (journal_t *, tid_t); +extern int log_do_checkpoint (journal_t *, int); + +extern void log_wait_for_space(journal_t *, int nblocks); +extern void journal_drop_transaction(journal_t *, transaction_t *); +extern int cleanup_journal_tail(journal_t *); + + +/* Debugging code only: */ + +#define jfs_ENOSYS() \ +do { \ + printk (KERN_ERR "JFS unimplemented function " __FUNCTION__); \ + current->state = TASK_UNINTERRUPTIBLE; \ + schedule(); \ +} while (1) + +/* + * is_journal_abort + * + * Simple test wrapper function to test the JFS_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_abort(journal_t *journal) +{ + return journal->j_flags & JFS_ABORT; +} + +#endif /* __KERNEL__ */ + +/* Comparison functions for transaction IDs: perform comparisons using + * modulo arithmetic so that they work over sequence number wraps. */ + +static inline int tid_ge(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); +} + + +#endif /* _LINUX_JFS_H */ diff --git a/include/linux/jfs_compat.h b/include/linux/jfs_compat.h new file mode 100644 index 00000000..8d87753b --- /dev/null +++ b/include/linux/jfs_compat.h @@ -0,0 +1,56 @@ + +#ifndef _JFS_COMPAT_H +#define _JFS_COMPAT_H + +#include <linux/list.h> +#include <errno.h> + +#define printk printf +#define KERN_ERR "" +#define KERN_DEBUG "" + +#define READ 0 +#define WRITE 1 + +#define cpu_to_be32(n) htonl(n) +#define be32_to_cpu(n) ntohl(n) + +typedef int tid_t; +typedef struct journal_s journal_t; + +struct buffer_head; +struct inode; + +struct journal_s +{ + unsigned long j_flags; + int j_errno; + struct buffer_head * j_sb_buffer; + struct journal_superblock_s *j_superblock; + int j_format_version; + unsigned long j_head; + unsigned long j_tail; + unsigned long j_free; + unsigned long j_first, j_last; + kdev_t j_dev; + int j_blocksize; + unsigned int j_blk_offset; + unsigned int j_maxlen; + struct inode * j_inode; + tid_t j_tail_sequence; + tid_t j_transaction_sequence; + __u8 j_uuid[16]; + struct jfs_revoke_table_s *j_revoke; +}; + +#define J_ASSERT(assert) \ + do { if (!(assert)) { \ + printf ("Assertion failure in %s() at %s line %d: " \ + "\"%s\"\n", \ + __FUNCTION__, __FILE__, __LINE__, # assert); \ + fatal_error(e2fsck_global_ctx, 0); \ + } } while (0) + +#define is_journal_abort(x) 0 + +#endif /* _JFS_COMPAT_H */ diff --git a/include/linux/list.h b/include/linux/list.h new file mode 100644 index 00000000..0e26f1fb --- /dev/null +++ b/include/linux/list.h @@ -0,0 +1,108 @@ +#ifndef _LINUX_LIST_H +#define _LINUX_LIST_H + +/* + * Simple doubly linked list implementation. + * + * Some of the internal functions ("__xxx") are useful when + * manipulating whole lists rather than single entries, as + * sometimes we already know the next/prev entries and we can + * generate better code by using them directly rather than + * using the generic single-entry routines. + */ + +struct list_head { + struct list_head *next, *prev; +}; + +#define LIST_HEAD_INIT(name) { &(name), &(name) } + +#define LIST_HEAD(name) \ + struct list_head name = { &name, &name } + +#define INIT_LIST_HEAD(ptr) do { \ + (ptr)->next = (ptr); (ptr)->prev = (ptr); \ +} while (0) + +/* + * Insert a new entry between two known consecutive entries. + * + * This is only for internal list manipulation where we know + * the prev/next entries already! + */ +static __inline__ void __list_add(struct list_head * new, + struct list_head * prev, + struct list_head * next) +{ + next->prev = new; + new->next = next; + new->prev = prev; + prev->next = new; +} + +/* + * Insert a new entry after the specified head.. + */ +static __inline__ void list_add(struct list_head *new, struct list_head *head) +{ + __list_add(new, head, head->next); +} + +/* + * Insert a new entry at the tail + */ +static __inline__ void list_add_tail(struct list_head *new, struct list_head *head) +{ + __list_add(new, head->prev, head); +} + +/* + * Delete a list entry by making the prev/next entries + * point to each other. + * + * This is only for internal list manipulation where we know + * the prev/next entries already! + */ +static __inline__ void __list_del(struct list_head * prev, + struct list_head * next) +{ + next->prev = prev; + prev->next = next; +} + +static __inline__ void list_del(struct list_head *entry) +{ + __list_del(entry->prev, entry->next); +} + +static __inline__ int list_empty(struct list_head *head) +{ + return head->next == head; +} + +/* + * Splice in "list" into "head" + */ +static __inline__ void list_splice(struct list_head *list, struct list_head *head) +{ + struct list_head *first = list->next; + + if (first != list) { + struct list_head *last = list->prev; + struct list_head *at = head->next; + + first->prev = head; + head->next = first; + + last->next = at; + at->prev = last; + } +} + +#define list_entry(ptr, type, member) \ + ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member))) + +#define list_for_each(pos, head) \ + for (pos = (head)->next; pos != (head); pos = pos->next) + +#endif |