#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;
#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 */
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
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
#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);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff