Add fsync file operation method

Add a scoutfs_file_fsync() which synchronously commits the current
transaction and call it to fsync files and directories.  This fixes a
number of generic xfstests in the quick group which were failing because
fsync wasn't supported.

Signed-off-by: Zach Brown <zab@versity.com>
Reviewed-by: Mark Fasheh <mfasheh@versity.com>

kmod/src/dir.c

@@ -1013,6 +1013,7 @@ out:
 
 const struct file_operations scoutfs_dir_fops = {
 	.readdir	= scoutfs_readdir,
+	.fsync		= scoutfs_file_fsync,
 };
 
 const struct inode_operations scoutfs_dir_iops = {

kmod/src/filerw.c

@@ -671,4 +671,5 @@ const struct file_operations scoutfs_file_fops = {
 	.aio_read	= generic_file_aio_read,
 	.aio_write	= generic_file_aio_write,
 	.unlocked_ioctl	= scoutfs_ioctl,
+	.fsync		= scoutfs_file_fsync,
 };

kmod/src/trans.c

@@ -177,6 +177,12 @@ int scoutfs_sync_fs(struct super_block *sb, int wait)
 	return ret;
 }
 
+int scoutfs_file_fsync(struct file *file, loff_t start, loff_t end,
+		       int datasync)
+{
+	return scoutfs_sync_fs(file->f_inode->i_sb, 1);
+}
+
 int scoutfs_hold_trans(struct super_block *sb)
 {
 	struct scoutfs_sb_info *sbi = SCOUTFS_SB(sb);

kmod/src/trans.h

@@ -3,6 +3,8 @@
 
 void scoutfs_trans_write_func(struct work_struct *work);
 int scoutfs_sync_fs(struct super_block *sb, int wait);
+int scoutfs_file_fsync(struct file *file, loff_t start, loff_t end,
+		       int datasync);
 
 int scoutfs_hold_trans(struct super_block *sb);
 void scoutfs_release_trans(struct super_block *sb);