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Date:   Wed, 9 Mar 2022 11:14:26 +0100
From:   Jan Kara <jack@suse.cz>
To:     Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Cc:     linux-ext4@vger.kernel.org, riteshh@linux.ibm.com, jack@suse.cz,
        tytso@mit.edu
Subject: Re: [PATCH v2 2/5] ext4: for committing inode, make
 ext4_fc_track_inode wait
Message-ID: <20220309101426.qumxztpd4weqzrcs@quack3.lan>
References: <20220308163319.1183625-1-harshads@google.com>
 <20220308163319.1183625-3-harshads@google.com>
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On Tue 08-03-22 08:33:16, Harshad Shirwadkar wrote:
> From: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
> 
> If the inode that's being requested to track using ext4_fc_track_inode
> is being committed, then wait until the inode finishes the commit.
> 
> Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>

One comment below...

> --- a/fs/ext4/ext4_jbd2.c
> +++ b/fs/ext4/ext4_jbd2.c
> @@ -106,6 +106,18 @@ handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
>  				   GFP_NOFS, type, line);
>  }
>  
> +handle_t *__ext4_journal_start(struct inode *inode, unsigned int line,
> +				  int type, int blocks, int rsv_blocks,
> +				  int revoke_creds)
> +{
> +	handle_t *handle = __ext4_journal_start_sb(inode->i_sb, line,
> +						   type, blocks, rsv_blocks,
> +						   revoke_creds);
> +	if (ext4_handle_valid(handle) && !IS_ERR(handle))
> +		ext4_fc_track_inode(handle, inode);
> +	return handle;
> +}
> +

Please fix fs/ext4/inline.c rather than papering over the problem like
this. Because it is just a landmine waiting to explode in some strange
cornercase when someone does not call ext4_journal_start() but other handle
starting function.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR