[PATCH] mutex subsystem, semaphore to mutex: VFS, ->i_sem

This patch converts the inode semaphore to a mutex. I have tested it on
XFS and compiled as much as one can consider on an ia64. Anyway your
luck with it might be different.

Modified-by: Ingo Molnar <mingo@elte.hu>

(finished the conversion)

Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

6 files changed, 12 insertions, 11 deletions

diff --git a/include/linux/ext3_fs_i.h b/include/linux/ext3_fs_i.h
index 2914f7b0715..e71dd98dbca 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 4c82219b0fa..01654b218e4 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 */
@@ -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/jffs2_fs_i.h b/include/linux/jffs2_fs_i.h
index ef85ab56302..ad565bf9dcc 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/nfsd/nfsfh.h b/include/linux/nfsd/nfsfh.h
index bb842ea4103..0798b7781a6 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 1767073df26..b12e59c7575 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 001ab82df05..e276c5ba2bb 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,