[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>

8 files changed, 33 insertions, 33 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index 478f4c74cc31..5fca2737c971 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -61,7 +61,7 @@ generic_file_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
  *      ->swap_lock             (exclusive_swap_page, others)
  *        ->mapping->tree_lock
  *
- *  ->i_sem
+ *  ->i_mutex
  *    ->i_mmap_lock             (truncate->unmap_mapping_range)
  *
  *  ->mmap_sem
@@ -73,9 +73,9 @@ generic_file_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
  *    ->lock_page               (access_process_vm)
  *
  *  ->mmap_sem
- *    ->i_sem                   (msync)
+ *    ->i_mutex                 (msync)
  *
- *  ->i_sem
+ *  ->i_mutex
  *    ->i_alloc_sem             (various)
  *
  *  ->inode_lock
@@ -276,7 +276,7 @@ static int wait_on_page_writeback_range(struct address_space *mapping,
  * integrity" operation.  It waits upon in-flight writeout before starting and
  * waiting upon new writeout.  If there was an IO error, return it.
  *
- * We need to re-take i_sem during the generic_osync_inode list walk because
+ * We need to re-take i_mutex during the generic_osync_inode list walk because
  * it is otherwise livelockable.
  */
 int sync_page_range(struct inode *inode, struct address_space *mapping,
@@ -290,9 +290,9 @@ int sync_page_range(struct inode *inode, struct address_space *mapping,
                 return 0;
         ret = filemap_fdatawrite_range(mapping, pos, pos + count - 1);
         if (ret == 0) {
-                down(&inode->i_sem);
+                mutex_lock(&inode->i_mutex);
                 ret = generic_osync_inode(inode, mapping, OSYNC_METADATA);
-                up(&inode->i_sem);
+                mutex_unlock(&inode->i_mutex);
         }
         if (ret == 0)
                 ret = wait_on_page_writeback_range(mapping, start, end);
@@ -301,7 +301,7 @@ int sync_page_range(struct inode *inode, struct address_space *mapping,
 EXPORT_SYMBOL(sync_page_range);
 
 /*
- * Note: Holding i_sem across sync_page_range_nolock is not a good idea
+ * Note: Holding i_mutex across sync_page_range_nolock is not a good idea
  * as it forces O_SYNC writers to different parts of the same file
  * to be serialised right until io completion.
  */
@@ -1892,7 +1892,7 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
         /*
          * Sync the fs metadata but not the minor inode changes and
          * of course not the data as we did direct DMA for the IO.
-         * i_sem is held, which protects generic_osync_inode() from
+         * i_mutex is held, which protects generic_osync_inode() from
          * livelocking.
          */
         if (written >= 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
@@ -2195,10 +2195,10 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const char __user *buf,
 
         BUG_ON(iocb->ki_pos != pos);
 
-        down(&inode->i_sem);
+        mutex_lock(&inode->i_mutex);
         ret = __generic_file_aio_write_nolock(iocb, &local_iov, 1,
                                                 &iocb->ki_pos);
-        up(&inode->i_sem);
+        mutex_unlock(&inode->i_mutex);
 
         if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
                 ssize_t err;
@@ -2220,9 +2220,9 @@ ssize_t generic_file_write(struct file *file, const char __user *buf,
         struct iovec local_iov = { .iov_base = (void __user *)buf,
                                         .iov_len = count };
 
-        down(&inode->i_sem);
+        mutex_lock(&inode->i_mutex);
         ret = __generic_file_write_nolock(file, &local_iov, 1, ppos);
-        up(&inode->i_sem);
+        mutex_unlock(&inode->i_mutex);
 
         if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
                 ssize_t err;
@@ -2256,9 +2256,9 @@ ssize_t generic_file_writev(struct file *file, const struct iovec *iov,
         struct inode *inode = mapping->host;
         ssize_t ret;
 
-        down(&inode->i_sem);
+        mutex_lock(&inode->i_mutex);
         ret = __generic_file_write_nolock(file, iov, nr_segs, ppos);
-        up(&inode->i_sem);
+        mutex_unlock(&inode->i_mutex);
 
         if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
                 int err;
@@ -2272,7 +2272,7 @@ ssize_t generic_file_writev(struct file *file, const struct iovec *iov,
 EXPORT_SYMBOL(generic_file_writev);
 
 /*
- * Called under i_sem for writes to S_ISREG files.   Returns -EIO if something
+ * Called under i_mutex for writes to S_ISREG files.   Returns -EIO if something
  * went wrong during pagecache shootdown.
  */
 static ssize_t
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index 9cf687e4a29a..e2b34e95913e 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -338,7 +338,7 @@ __xip_file_write(struct file *filp, const char __user *buf,
         *ppos = pos;
         /*
          * No need to use i_size_read() here, the i_size
-         * cannot change under us because we hold i_sem.
+         * cannot change under us because we hold i_mutex.
          */
         if (pos > inode->i_size) {
                 i_size_write(inode, pos);
@@ -358,7 +358,7 @@ xip_file_write(struct file *filp, const char __user *buf, size_t len,
         loff_t pos;
         ssize_t ret;
 
-        down(&inode->i_sem);
+        mutex_lock(&inode->i_mutex);
 
         if (!access_ok(VERIFY_READ, buf, len)) {
                 ret=-EFAULT;
@@ -390,7 +390,7 @@ xip_file_write(struct file *filp, const char __user *buf, size_t len,
  out_backing:
         current->backing_dev_info = NULL;
  out_up:
-        up(&inode->i_sem);
+        mutex_unlock(&inode->i_mutex);
         return ret;
 }
 EXPORT_SYMBOL_GPL(xip_file_write);
diff --git a/mm/memory.c b/mm/memory.c
index 3944fec38012..7a11ddd5060f 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1784,13 +1784,13 @@ int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end)
         if (!inode->i_op || !inode->i_op->truncate_range)
                 return -ENOSYS;
 
-        down(&inode->i_sem);
+        mutex_lock(&inode->i_mutex);
         down_write(&inode->i_alloc_sem);
         unmap_mapping_range(mapping, offset, (end - offset), 1);
         truncate_inode_pages_range(mapping, offset, end);
         inode->i_op->truncate_range(inode, offset, end);
         up_write(&inode->i_alloc_sem);
-        up(&inode->i_sem);
+        mutex_unlock(&inode->i_mutex);
 
         return 0;
 }
diff --git a/mm/msync.c b/mm/msync.c
index 1b5b6f662dcf..3563a56e1a51 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -137,7 +137,7 @@ static int msync_interval(struct vm_area_struct *vma,
                         ret = filemap_fdatawrite(mapping);
                         if (file->f_op && file->f_op->fsync) {
                                 /*
-                                 * We don't take i_sem here because mmap_sem
+                                 * We don't take i_mutex here because mmap_sem
                                  * is already held.
                                  */
                                 err = file->f_op->fsync(file,file->f_dentry,1);
diff --git a/mm/rmap.c b/mm/rmap.c
index 66ec43053a4d..dfbb89f99a15 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -20,13 +20,13 @@
 /*
  * Lock ordering in mm:
  *
- * inode->i_sem (while writing or truncating, not reading or faulting)
+ * inode->i_mutex       (while writing or truncating, not reading or faulting)
  *   inode->i_alloc_sem
  *
  * When a page fault occurs in writing from user to file, down_read
- * of mmap_sem nests within i_sem; in sys_msync, i_sem nests within
- * down_read of mmap_sem; i_sem and down_write of mmap_sem are never
- * taken together; in truncation, i_sem is taken outermost.
+ * of mmap_sem nests within i_mutex; in sys_msync, i_mutex nests within
+ * down_read of mmap_sem; i_mutex and down_write of mmap_sem are never
+ * taken together; in truncation, i_mutex is taken outermost.
  *
  * mm->mmap_sem
  *   page->flags PG_locked (lock_page)
diff --git a/mm/shmem.c b/mm/shmem.c
index a1f2f02af724..343b3c0937e5 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1370,7 +1370,7 @@ shmem_file_write(struct file *file, const char __user *buf, size_t count, loff_t
         if (!access_ok(VERIFY_READ, buf, count))
                 return -EFAULT;
 
-        down(&inode->i_sem);
+        mutex_lock(&inode->i_mutex);
 
         pos = *ppos;
         written = 0;
@@ -1455,7 +1455,7 @@ shmem_file_write(struct file *file, const char __user *buf, size_t count, loff_t
         if (written)
                 err = written;
 out:
-        up(&inode->i_sem);
+        mutex_unlock(&inode->i_mutex);
         return err;
 }
 
@@ -1491,7 +1491,7 @@ static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_
 
                 /*
                  * We must evaluate after, since reads (unlike writes)
-                 * are called without i_sem protection against truncate
+                 * are called without i_mutex protection against truncate
                  */
                 nr = PAGE_CACHE_SIZE;
                 i_size = i_size_read(inode);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 80f948a2028b..6544565a7c0f 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1187,9 +1187,9 @@ asmlinkage long sys_swapoff(const char __user * specialfile)
                 set_blocksize(bdev, p->old_block_size);
                 bd_release(bdev);
         } else {
-                down(&inode->i_sem);
+                mutex_lock(&inode->i_mutex);
                 inode->i_flags &= ~S_SWAPFILE;
-                up(&inode->i_sem);
+                mutex_unlock(&inode->i_mutex);
         }
         filp_close(swap_file, NULL);
         err = 0;
@@ -1406,7 +1406,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
                 p->bdev = bdev;
         } else if (S_ISREG(inode->i_mode)) {
                 p->bdev = inode->i_sb->s_bdev;
-                down(&inode->i_sem);
+                mutex_lock(&inode->i_mutex);
                 did_down = 1;
                 if (IS_SWAPFILE(inode)) {
                         error = -EBUSY;
@@ -1596,7 +1596,7 @@ out:
         if (did_down) {
                 if (!error)
                         inode->i_flags |= S_SWAPFILE;
-                up(&inode->i_sem);
+                mutex_unlock(&inode->i_mutex);
         }
         return error;
 }
diff --git a/mm/truncate.c b/mm/truncate.c
index b1a463d0fe71..6cb3fff25f67 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -196,7 +196,7 @@ EXPORT_SYMBOL(truncate_inode_pages_range);
  * @mapping: mapping to truncate
  * @lstart: offset from which to truncate
  *
- * Called under (and serialised by) inode->i_sem.
+ * Called under (and serialised by) inode->i_mutex.
  */
 void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
 {