Messages in this thread | | | From | Miklos Szeredi <> | Date | Mon, 18 Jul 2022 10:18:18 +0200 | Subject | Re: [PATCH] fuse: writeback_cache consistency enhancement (writeback_cache_v2) |
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On Mon, 18 Jul 2022 at 08:01, Jiachen Zhang <zhangjiachen.jaycee@bytedance.com> wrote: > > On Fri, Jul 15, 2022 at 6:07 PM Miklos Szeredi <miklos@szeredi.hu> wrote: > > > > On Fri, 24 Jun 2022 at 07:58, Jiachen Zhang > > <zhangjiachen.jaycee@bytedance.com> wrote:
> > > + if (fc->writeback_cache_v2 && S_ISREG(inode->i_mode)) { > > > + inode_lock(inode); > > > > I don't think this can work. fuse_change_attributes() might be > > called from within inlode locked context. E.g. > > > > lookup_slow -> __lookup_slow -> d_revalidate -> fuse_dentry_revalidate > > -> fuse_change_attributes > > > > Yes, this is a problem that should be fixed. As we can not check the > inode lock state from the inode->i_rwsem structure, I think we can > pass the inode lock state along the FUSE function call-path to > fuse_change_attributes(), and only when we can certainly know whether > the inode is locked or unlocked then we continue the > writeback_cache_v2 logics. What do you think?
Not liking it very much.
Better create a new lock for this purpose that we do always know the state of.
Thanks, Miklos
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