linux-ext4 - Re: [PATCH v5 0/4] hide ->i

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Message-ID: <73885a08-f255-4638-8a53-f136537f4b4c@gmail.com>
Date: Fri, 19 Sep 2025 23:31:22 -0500
From: Russell Haley <yumpusamongus@...il.com>
To: Mateusz Guzik <mjguzik@...il.com>, brauner@...nel.org
Cc: viro@...iv.linux.org.uk, jack@...e.cz, linux-kernel@...r.kernel.org,
 linux-fsdevel@...r.kernel.org, josef@...icpanda.com, kernel-team@...com,
 amir73il@...il.com, linux-btrfs@...r.kernel.org, linux-ext4@...r.kernel.org,
 linux-xfs@...r.kernel.org, ceph-devel@...r.kernel.org,
 linux-unionfs@...r.kernel.org
Subject: Re: [PATCH v5 0/4] hide ->i_state behind accessors

On 9/19/25 10:49 AM, Mateusz Guzik wrote:
> This is generated against:
> https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git/commit/?h=vfs-6.18.inode.refcount.preliminaries
> 
> First commit message quoted verbatim with rationable + API:
> 
> [quote]
> Open-coded accesses prevent asserting they are done correctly. One
> obvious aspect is locking, but significantly more can checked. For
> example it can be detected when the code is clearing flags which are
> already missing, or is setting flags when it is illegal (e.g., I_FREEING
> when ->i_count > 0).
> 
> Given the late stage of the release cycle this patchset only aims to
> hide access, it does not provide any of the checks.
> 
> Consumers can be trivially converted. Suppose flags I_A and I_B are to
> be handled, then:
> 
> state = inode->i_state  	=> state = inode_state_read(inode)
> inode->i_state |= (I_A | I_B) 	=> inode_state_add(inode, I_A | I_B)
> inode->i_state &= ~(I_A | I_B) 	=> inode_state_del(inode, I_A | I_B)
> inode->i_state = I_A | I_B	=> inode_state_set(inode, I_A | I_B)
> [/quote]

Drive-by bikeshedding: s/set/replace/g

"replace" removes ambiguity with the concept of setting a bit ( |= ). An
alternative would be "set_only".