linux-ext4 - Re: Question about ext4_free_blocks() Behavior for Per-File Data Journaling Mode

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Date:	Tue, 08 Dec 2015 07:02:20 +0000 (GMT)
From:	Daeho Jeong <daeho.jeong@...sung.com>
To:	"tytso@....edu" <tytso@....edu>, jack@...e.cz
Cc:	Daeho Jeong <daeho.jeong@...sung.com>,
	"linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org>
Subject: Re: Question about ext4_free_blocks() Behavior for Per-File Data
 Journaling Mode

> Hi. I have a question about ext4_free_blocks() behavior for per-file data journaling
> mode. AFAIUI, in ext4_free_blocks(), it doesn't invoke ext4_forget() function for
> data blocks of a per-file data journaling enabled file, because all the data blocks
> of the file are not linked to the block device's address space of the file, but the
> address space of the inode of the file, so any data blocks of the file cannot be
> found by sb_find_get_block() function. It seems a bug, but I am not sure.
> Is this a problem?

I just answer my own question. It was a silly question, because all the data buffers
of per-file data journalled file are forgotten by jbd2_journal_invalidatepage() in advance
of invoking ext4_free_blocks().

Anyway, the revoke operation to the data blocks is still missing in ext4_free_blocks().
I will fix this problem. :-)