Re: [PATCH] squashfs: enable __GFP_FS in ->readpage to prevent hang in mem alloc

From: Michal Hocko
Date: Tue Dec 18 2018 - 06:32:35 EST

On Tue 18-12-18 14:06:11, Hou Tao wrote:
> In my understanding (correct me if I am wrong), there are three ways through which
> reclamation will invoked fs related code and may cause dead-lock:
> (1) write-back dirty pages. Not possible for squashfs.

only from kswapd context. So not relevant to OOM killer/

> (2) the reclamation of inodes & dentries. The current file is in-use, so it will be not
> reclaimed, and for other reclaimable inodes, squashfs_destroy_inode() will
> be invoked and it doesn't take any locks.

There are other inodes, not only those in use. Do you use any locks that
could be taken from an inode teardown?
Michal Hocko