ext4: Convert truncate_mutex to read write semaphore.
We are currently taking the truncate_mutex for every read. This would have
performance impact on large CPU configuration. Convert the lock to read write
semaphore and take read lock when we are trying to read the file.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index effd375..c730544 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -593,7 +593,7 @@
#ifdef CONFIG_EXT4DEV_FS_XATTR
init_rwsem(&ei->xattr_sem);
#endif
- mutex_init(&ei->truncate_mutex);
+ init_rwsem(&ei->i_data_sem);
inode_init_once(&ei->vfs_inode);
}