Merge master.kernel.org:/pub/scm/linux/kernel/git/mingo/mutex-2.6

13 files changed, 178 insertions, 18 deletions

diff --git a/include/linux/ext3_fs_i.h b/include/linux/ext3_fs_i.h
index 2914f7b07156..e71dd98dbcae 100644
--- a/include/linux/ext3_fs_i.h
+++ b/include/linux/ext3_fs_i.h
@@ -87,7 +87,7 @@ struct ext3_inode_info {
 #ifdef CONFIG_EXT3_FS_XATTR
         /*
          * Extended attributes can be read independently of the main file
-         * data. Taking i_sem even when reading would cause contention
+         * data. Taking i_mutex even when reading would cause contention
          * between readers of EAs and writers of regular file data, so
          * instead we synchronize on xattr_sem when reading or changing
          * EAs.
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4c82219b0fae..92ae3e2067b0 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -219,6 +219,7 @@ extern int dir_notify_enable;
 #include <linux/prio_tree.h>
 #include <linux/init.h>
 #include <linux/sched.h>
+#include <linux/mutex.h>
 
 #include <asm/atomic.h>
 #include <asm/semaphore.h>
@@ -484,7 +485,7 @@ struct inode {
         unsigned long           i_blocks;
         unsigned short          i_bytes;
         spinlock_t              i_lock; /* i_blocks, i_bytes, maybe i_size */
-        struct semaphore        i_sem;
+        struct mutex            i_mutex;
         struct rw_semaphore     i_alloc_sem;
         struct inode_operations *i_op;
         struct file_operations  *i_fop; /* former ->i_op->default_file_ops */
@@ -820,7 +821,7 @@ struct super_block {
         unsigned long           s_magic;
         struct dentry           *s_root;
         struct rw_semaphore     s_umount;
-        struct semaphore        s_lock;
+        struct mutex            s_lock;
         int                     s_count;
         int                     s_syncing;
         int                     s_need_sync_fs;
@@ -892,13 +893,13 @@ static inline int has_fs_excl(void)
 static inline void lock_super(struct super_block * sb)
 {
         get_fs_excl();
-        down(&sb->s_lock);
+        mutex_lock(&sb->s_lock);
 }
 
 static inline void unlock_super(struct super_block * sb)
 {
         put_fs_excl();
-        up(&sb->s_lock);
+        mutex_unlock(&sb->s_lock);
 }
 
 /*
@@ -1191,7 +1192,7 @@ int sync_inode(struct inode *inode, struct writeback_control *wbc);
  *    directory.  The name should be stored in the @name (with the
  *    understanding that it is already pointing to a a %NAME_MAX+1 sized
  *    buffer.   get_name() should return %0 on success, a negative error code
- *    or error.  @get_name will be called without @parent->i_sem held.
+ *    or error.  @get_name will be called without @parent->i_mutex held.
  *
  * get_parent:
  *    @get_parent should find the parent directory for the given @child which
@@ -1213,7 +1214,7 @@ int sync_inode(struct inode *inode, struct writeback_control *wbc);
  *    nfsd_find_fh_dentry() in either the @obj or @parent parameters.
  *
  * Locking rules:
- *    get_parent is called with child->d_inode->i_sem down
+ *    get_parent is called with child->d_inode->i_mutex down
  *    get_name is not (which is possibly inconsistent)
  */
 
diff --git a/include/linux/ide.h b/include/linux/ide.h
index ef8d0cbb832f..9a8c05dbe4f3 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -18,6 +18,7 @@
 #include <linux/bio.h>
 #include <linux/device.h>
 #include <linux/pci.h>
+#include <linux/completion.h>
 #include <asm/byteorder.h>
 #include <asm/system.h>
 #include <asm/io.h>
@@ -638,7 +639,7 @@ typedef struct ide_drive_s {
         int             crc_count;      /* crc counter to reduce drive speed */
         struct list_head list;
         struct device   gendev;
-        struct semaphore gendev_rel_sem;        /* to deal with device release() */
+        struct completion gendev_rel_comp;      /* to deal with device release() */
 } ide_drive_t;
 
 #define to_ide_device(dev)container_of(dev, ide_drive_t, gendev)
@@ -794,7 +795,7 @@ typedef struct hwif_s {
         unsigned        sg_mapped  : 1; /* sg_table and sg_nents are ready */
 
         struct device   gendev;
-        struct semaphore gendev_rel_sem; /* To deal with device release() */
+        struct completion gendev_rel_comp; /* To deal with device release() */
 
         void            *hwif_data;     /* extra hwif data */
 
diff --git a/include/linux/jffs2_fs_i.h b/include/linux/jffs2_fs_i.h
index ef85ab56302b..ad565bf9dcc1 100644
--- a/include/linux/jffs2_fs_i.h
+++ b/include/linux/jffs2_fs_i.h
@@ -8,11 +8,11 @@
 #include <asm/semaphore.h>
 
 struct jffs2_inode_info {
-        /* We need an internal semaphore similar to inode->i_sem.
+        /* We need an internal mutex similar to inode->i_mutex.
            Unfortunately, we can't used the existing one, because
            either the GC would deadlock, or we'd have to release it
            before letting GC proceed. Or we'd have to put ugliness
-           into the GC code so it didn't attempt to obtain the i_sem
+           into the GC code so it didn't attempt to obtain the i_mutex
            for the inode(s) which are already locked */
         struct semaphore sem;
 
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index ca7ff8fdd090..d0e6ca3b00ef 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -286,6 +286,15 @@ extern void dump_stack(void);
         1; \
 })
 
+/*
+ * Check at compile time that 'function' is a certain type, or is a pointer
+ * to that type (needs to use typedef for the function type.)
+ */
+#define typecheck_fn(type,function) \
+({      typeof(type) __tmp = function; \
+        (void)__tmp; \
+})
+
 #endif /* __KERNEL__ */
 
 #define SI_LOAD_SHIFT   16
diff --git a/include/linux/loop.h b/include/linux/loop.h
index 40f63c9879d2..f96506782ebe 100644
--- a/include/linux/loop.h
+++ b/include/linux/loop.h
@@ -58,9 +58,9 @@ struct loop_device {
         struct bio              *lo_bio;
         struct bio              *lo_biotail;
         int                     lo_state;
-        struct semaphore        lo_sem;
+        struct completion       lo_done;
+        struct completion       lo_bh_done;
         struct semaphore        lo_ctl_mutex;
-        struct semaphore        lo_bh_mutex;
         int                     lo_pending;
 
         request_queue_t         *lo_queue;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index df80e63903b5..3f1fafc0245e 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -13,6 +13,7 @@
 #include <linux/rbtree.h>
 #include <linux/prio_tree.h>
 #include <linux/fs.h>
+#include <linux/mutex.h>
 
 struct mempolicy;
 struct anon_vma;
@@ -1024,6 +1025,9 @@ static inline void vm_stat_account(struct mm_struct *mm,
 static inline void
 kernel_map_pages(struct page *page, int numpages, int enable)
 {
+        if (!PageHighMem(page) && !enable)
+                mutex_debug_check_no_locks_freed(page_address(page),
+                                                 page_address(page + numpages));
 }
 #endif
 
diff --git a/include/linux/mutex-debug.h b/include/linux/mutex-debug.h
new file mode 100644
index 000000000000..0ccd8f983b50
--- /dev/null
+++ b/include/linux/mutex-debug.h
@@ -0,0 +1,21 @@
+#ifndef __LINUX_MUTEX_DEBUG_H
+#define __LINUX_MUTEX_DEBUG_H
+
+/*
+ * Mutexes - debugging helpers:
+ */
+
+#define __DEBUG_MUTEX_INITIALIZER(lockname) \
+        , .held_list = LIST_HEAD_INIT(lockname.held_list), \
+          .name = #lockname , .magic = &lockname
+
+#define mutex_init(sem)         __mutex_init(sem, __FUNCTION__)
+
+extern void FASTCALL(mutex_destroy(struct mutex *lock));
+
+extern void mutex_debug_show_all_locks(void);
+extern void mutex_debug_show_held_locks(struct task_struct *filter);
+extern void mutex_debug_check_no_locks_held(struct task_struct *task);
+extern void mutex_debug_check_no_locks_freed(const void *from, const void *to);
+
+#endif
diff --git a/include/linux/mutex.h b/include/linux/mutex.h
new file mode 100644
index 000000000000..9bce0fee68d4
--- /dev/null
+++ b/include/linux/mutex.h
@@ -0,0 +1,119 @@
+/*
+ * Mutexes: blocking mutual exclusion locks
+ *
+ * started by Ingo Molnar:
+ *
+ *  Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *
+ * This file contains the main data structure and API definitions.
+ */
+#ifndef __LINUX_MUTEX_H
+#define __LINUX_MUTEX_H
+
+#include <linux/list.h>
+#include <linux/spinlock_types.h>
+
+#include <asm/atomic.h>
+
+/*
+ * Simple, straightforward mutexes with strict semantics:
+ *
+ * - only one task can hold the mutex at a time
+ * - only the owner can unlock the mutex
+ * - multiple unlocks are not permitted
+ * - recursive locking is not permitted
+ * - a mutex object must be initialized via the API
+ * - a mutex object must not be initialized via memset or copying
+ * - task may not exit with mutex held
+ * - memory areas where held locks reside must not be freed
+ * - held mutexes must not be reinitialized
+ * - mutexes may not be used in irq contexts
+ *
+ * These semantics are fully enforced when DEBUG_MUTEXES is
+ * enabled. Furthermore, besides enforcing the above rules, the mutex
+ * debugging code also implements a number of additional features
+ * that make lock debugging easier and faster:
+ *
+ * - uses symbolic names of mutexes, whenever they are printed in debug output
+ * - point-of-acquire tracking, symbolic lookup of function names
+ * - list of all locks held in the system, printout of them
+ * - owner tracking
+ * - detects self-recursing locks and prints out all relevant info
+ * - detects multi-task circular deadlocks and prints out all affected
+ *   locks and tasks (and only those tasks)
+ */
+struct mutex {
+        /* 1: unlocked, 0: locked, negative: locked, possible waiters */
+        atomic_t                count;
+        spinlock_t              wait_lock;
+        struct list_head        wait_list;
+#ifdef CONFIG_DEBUG_MUTEXES
+        struct thread_info      *owner;
+        struct list_head        held_list;
+        unsigned long           acquire_ip;
+        const char              *name;
+        void                    *magic;
+#endif
+};
+
+/*
+ * This is the control structure for tasks blocked on mutex,
+ * which resides on the blocked task's kernel stack:
+ */
+struct mutex_waiter {
+        struct list_head        list;
+        struct task_struct      *task;
+#ifdef CONFIG_DEBUG_MUTEXES
+        struct mutex            *lock;
+        void                    *magic;
+#endif
+};
+
+#ifdef CONFIG_DEBUG_MUTEXES
+# include <linux/mutex-debug.h>
+#else
+# define __DEBUG_MUTEX_INITIALIZER(lockname)
+# define mutex_init(mutex)                      __mutex_init(mutex, NULL)
+# define mutex_destroy(mutex)                           do { } while (0)
+# define mutex_debug_show_all_locks()                   do { } while (0)
+# define mutex_debug_show_held_locks(p)                 do { } while (0)
+# define mutex_debug_check_no_locks_held(task)          do { } while (0)
+# define mutex_debug_check_no_locks_freed(from, to)     do { } while (0)
+#endif
+
+#define __MUTEX_INITIALIZER(lockname) \
+                { .count = ATOMIC_INIT(1) \
+                , .wait_lock = SPIN_LOCK_UNLOCKED \
+                , .wait_list = LIST_HEAD_INIT(lockname.wait_list) \
+                __DEBUG_MUTEX_INITIALIZER(lockname) }
+
+#define DEFINE_MUTEX(mutexname) \
+        struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
+
+extern void fastcall __mutex_init(struct mutex *lock, const char *name);
+
+/***
+ * mutex_is_locked - is the mutex locked
+ * @lock: the mutex to be queried
+ *
+ * Returns 1 if the mutex is locked, 0 if unlocked.
+ */
+static inline int fastcall mutex_is_locked(struct mutex *lock)
+{
+        return atomic_read(&lock->count) != 1;
+}
+
+/*
+ * See kernel/mutex.c for detailed documentation of these APIs.
+ * Also see Documentation/mutex-design.txt.
+ */
+extern void fastcall mutex_lock(struct mutex *lock);
+extern int fastcall mutex_lock_interruptible(struct mutex *lock);
+/*
+ * NOTE: mutex_trylock() follows the spin_trylock() convention,
+ *       not the down_trylock() convention!
+ */
+extern int fastcall mutex_trylock(struct mutex *lock);
+extern void fastcall mutex_unlock(struct mutex *lock);
+
+#endif
diff --git a/include/linux/nfsd/nfsfh.h b/include/linux/nfsd/nfsfh.h
index bb842ea41033..0798b7781a6e 100644
--- a/include/linux/nfsd/nfsfh.h
+++ b/include/linux/nfsd/nfsfh.h
@@ -294,7 +294,7 @@ fill_post_wcc(struct svc_fh *fhp)
 /*
  * Lock a file handle/inode
  * NOTE: both fh_lock and fh_unlock are done "by hand" in
- * vfs.c:nfsd_rename as it needs to grab 2 i_sem's at once
+ * vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
  * so, any changes here should be reflected there.
  */
 static inline void
@@ -317,7 +317,7 @@ fh_lock(struct svc_fh *fhp)
         }
 
         inode = dentry->d_inode;
-        down(&inode->i_sem);
+        mutex_lock(&inode->i_mutex);
         fill_pre_wcc(fhp);
         fhp->fh_locked = 1;
 }
@@ -333,7 +333,7 @@ fh_unlock(struct svc_fh *fhp)
 
         if (fhp->fh_locked) {
                 fill_post_wcc(fhp);
-                up(&fhp->fh_dentry->d_inode->i_sem);
+                mutex_unlock(&fhp->fh_dentry->d_inode->i_mutex);
                 fhp->fh_locked = 0;
         }
 }
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index 1767073df26f..b12e59c75752 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -37,7 +37,7 @@ struct pipe_inode_info {
    memory allocation, whereas PIPE_BUF makes atomicity guarantees.  */
 #define PIPE_SIZE               PAGE_SIZE
 
-#define PIPE_SEM(inode)         (&(inode).i_sem)
+#define PIPE_MUTEX(inode)       (&(inode).i_mutex)
 #define PIPE_WAIT(inode)        (&(inode).i_pipe->wait)
 #define PIPE_READERS(inode)     ((inode).i_pipe->readers)
 #define PIPE_WRITERS(inode)     ((inode).i_pipe->writers)
diff --git a/include/linux/reiserfs_fs.h b/include/linux/reiserfs_fs.h
index 001ab82df051..e276c5ba2bb7 100644
--- a/include/linux/reiserfs_fs.h
+++ b/include/linux/reiserfs_fs.h
@@ -1857,7 +1857,7 @@ void padd_item(char *item, int total_length, int length);
 #define GET_BLOCK_CREATE 1      /* add anything you need to find block */
 #define GET_BLOCK_NO_HOLE 2     /* return -ENOENT for file holes */
 #define GET_BLOCK_READ_DIRECT 4 /* read the tail if indirect item not found */
-#define GET_BLOCK_NO_ISEM     8 /* i_sem is not held, don't preallocate */
+#define GET_BLOCK_NO_IMUX     8 /* i_mutex is not held, don't preallocate */
 #define GET_BLOCK_NO_DANGLE   16        /* don't leave any transactions running */
 
 int restart_transaction(struct reiserfs_transaction_handle *th,
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 78eb92ae4d94..85b53f87c703 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -817,6 +817,11 @@ struct task_struct {
 /* Protection of proc_dentry: nesting proc_lock, dcache_lock, write_lock_irq(&tasklist_lock); */
         spinlock_t proc_lock;
 
+#ifdef CONFIG_DEBUG_MUTEXES
+        /* mutex deadlock detection */
+        struct mutex_waiter *blocked_on;
+#endif
+
 /* journalling filesystem info */
         void *journal_info;