diff options
Diffstat (limited to 'include/linux/reiserfs_fs.h')
| -rw-r--r-- | include/linux/reiserfs_fs.h | 132 |
1 files changed, 110 insertions, 22 deletions
diff --git a/include/linux/reiserfs_fs.h b/include/linux/reiserfs_fs.h index dd31e7bae35c..1ba3cf6edfbb 100644 --- a/include/linux/reiserfs_fs.h +++ b/include/linux/reiserfs_fs.h @@ -52,11 +52,89 @@ #define REISERFS_IOC32_GETVERSION FS_IOC32_GETVERSION #define REISERFS_IOC32_SETVERSION FS_IOC32_SETVERSION -/* Locking primitives */ -/* Right now we are still falling back to (un)lock_kernel, but eventually that - would evolve into real per-fs locks */ -#define reiserfs_write_lock( sb ) lock_kernel() -#define reiserfs_write_unlock( sb ) unlock_kernel() +/* + * Locking primitives. The write lock is a per superblock + * special mutex that has properties close to the Big Kernel Lock + * which was used in the previous locking scheme. + */ +void reiserfs_write_lock(struct super_block *s); +void reiserfs_write_unlock(struct super_block *s); +int reiserfs_write_lock_once(struct super_block *s); +void reiserfs_write_unlock_once(struct super_block *s, int lock_depth); + +#ifdef CONFIG_REISERFS_CHECK +void reiserfs_lock_check_recursive(struct super_block *s); +#else +static inline void reiserfs_lock_check_recursive(struct super_block *s) { } +#endif + +/* + * Several mutexes depend on the write lock. + * However sometimes we want to relax the write lock while we hold + * these mutexes, according to the release/reacquire on schedule() + * properties of the Bkl that were used. + * Reiserfs performances and locking were based on this scheme. + * Now that the write lock is a mutex and not the bkl anymore, doing so + * may result in a deadlock: + * + * A acquire write_lock + * A acquire j_commit_mutex + * A release write_lock and wait for something + * B acquire write_lock + * B can't acquire j_commit_mutex and sleep + * A can't acquire write lock anymore + * deadlock + * + * What we do here is avoiding such deadlock by playing the same game + * than the Bkl: if we can't acquire a mutex that depends on the write lock, + * we release the write lock, wait a bit and then retry. + * + * The mutexes concerned by this hack are: + * - The commit mutex of a journal list + * - The flush mutex + * - The journal lock + * - The inode mutex + */ +static inline void reiserfs_mutex_lock_safe(struct mutex *m, + struct super_block *s) +{ + reiserfs_lock_check_recursive(s); + reiserfs_write_unlock(s); + mutex_lock(m); + reiserfs_write_lock(s); +} + +static inline void +reiserfs_mutex_lock_nested_safe(struct mutex *m, unsigned int subclass, + struct super_block *s) +{ + reiserfs_lock_check_recursive(s); + reiserfs_write_unlock(s); + mutex_lock_nested(m, subclass); + reiserfs_write_lock(s); +} + +static inline void +reiserfs_down_read_safe(struct rw_semaphore *sem, struct super_block *s) +{ + reiserfs_lock_check_recursive(s); + reiserfs_write_unlock(s); + down_read(sem); + reiserfs_write_lock(s); +} + +/* + * When we schedule, we usually want to also release the write lock, + * according to the previous bkl based locking scheme of reiserfs. + */ +static inline void reiserfs_cond_resched(struct super_block *s) +{ + if (need_resched()) { + reiserfs_write_unlock(s); + schedule(); + reiserfs_write_lock(s); + } +} struct fid; @@ -1329,7 +1407,11 @@ static inline loff_t max_reiserfs_offset(struct inode *inode) #define get_generation(s) atomic_read (&fs_generation(s)) #define FILESYSTEM_CHANGED_TB(tb) (get_generation((tb)->tb_sb) != (tb)->fs_gen) #define __fs_changed(gen,s) (gen != get_generation (s)) -#define fs_changed(gen,s) ({cond_resched(); __fs_changed(gen, s);}) +#define fs_changed(gen,s) \ +({ \ + reiserfs_cond_resched(s); \ + __fs_changed(gen, s); \ +}) /***************************************************************************/ /* FIXATE NODES */ @@ -1995,25 +2077,12 @@ void set_de_name_and_namelen(struct reiserfs_dir_entry *de); int search_by_entry_key(struct super_block *sb, const struct cpu_key *key, struct treepath *path, struct reiserfs_dir_entry *de); struct dentry *reiserfs_get_parent(struct dentry *); -/* procfs.c */ - -#if defined( CONFIG_PROC_FS ) && defined( CONFIG_REISERFS_PROC_INFO ) -#define REISERFS_PROC_INFO -#else -#undef REISERFS_PROC_INFO -#endif +#ifdef CONFIG_REISERFS_PROC_INFO int reiserfs_proc_info_init(struct super_block *sb); int reiserfs_proc_info_done(struct super_block *sb); -struct proc_dir_entry *reiserfs_proc_register_global(char *name, - read_proc_t * func); -void reiserfs_proc_unregister_global(const char *name); int reiserfs_proc_info_global_init(void); int reiserfs_proc_info_global_done(void); -int reiserfs_global_version_in_proc(char *buffer, char **start, off_t offset, - int count, int *eof, void *data); - -#if defined( REISERFS_PROC_INFO ) #define PROC_EXP( e ) e @@ -2028,6 +2097,26 @@ int reiserfs_global_version_in_proc(char *buffer, char **start, off_t offset, PROC_INFO_ADD( sb, free_at[ ( level ) ], B_FREE_SPACE( bh ) ); \ PROC_INFO_ADD( sb, items_at[ ( level ) ], B_NR_ITEMS( bh ) ) #else +static inline int reiserfs_proc_info_init(struct super_block *sb) +{ + return 0; +} + +static inline int reiserfs_proc_info_done(struct super_block *sb) +{ + return 0; +} + +static inline int reiserfs_proc_info_global_init(void) +{ + return 0; +} + +static inline int reiserfs_proc_info_global_done(void) +{ + return 0; +} + #define PROC_EXP( e ) #define VOID_V ( ( void ) 0 ) #define PROC_INFO_MAX( sb, field, value ) VOID_V @@ -2258,8 +2347,7 @@ __u32 r5_hash(const signed char *msg, int len); #define SPARE_SPACE 500 /* prototypes from ioctl.c */ -int reiserfs_ioctl(struct inode *inode, struct file *filp, - unsigned int cmd, unsigned long arg); +long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg); long reiserfs_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg); int reiserfs_unpack(struct inode *inode, struct file *filp); |