wrappers for ->i_mutex access

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/mm/shmem.c b/mm/shmem.c
index fa2ceb2..38c5e72 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1902,7 +1902,7 @@
 	if (whence != SEEK_DATA && whence != SEEK_HOLE)
 		return generic_file_llseek_size(file, offset, whence,
 					MAX_LFS_FILESIZE, i_size_read(inode));
-	mutex_lock(&inode->i_mutex);
+	inode_lock(inode);
 	/* We're holding i_mutex so we can access i_size directly */
 
 	if (offset < 0)
@@ -1926,7 +1926,7 @@
 
 	if (offset >= 0)
 		offset = vfs_setpos(file, offset, MAX_LFS_FILESIZE);
-	mutex_unlock(&inode->i_mutex);
+	inode_unlock(inode);
 	return offset;
 }
 
@@ -2091,7 +2091,7 @@
 	if (seals & ~(unsigned int)F_ALL_SEALS)
 		return -EINVAL;
 
-	mutex_lock(&inode->i_mutex);
+	inode_lock(inode);
 
 	if (info->seals & F_SEAL_SEAL) {
 		error = -EPERM;
@@ -2114,7 +2114,7 @@
 	error = 0;
 
 unlock:
-	mutex_unlock(&inode->i_mutex);
+	inode_unlock(inode);
 	return error;
 }
 EXPORT_SYMBOL_GPL(shmem_add_seals);
@@ -2164,7 +2164,7 @@
 	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
 		return -EOPNOTSUPP;
 
-	mutex_lock(&inode->i_mutex);
+	inode_lock(inode);
 
 	if (mode & FALLOC_FL_PUNCH_HOLE) {
 		struct address_space *mapping = file->f_mapping;
@@ -2277,7 +2277,7 @@
 	inode->i_private = NULL;
 	spin_unlock(&inode->i_lock);
 out:
-	mutex_unlock(&inode->i_mutex);
+	inode_unlock(inode);
 	return error;
 }