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>>>> /var/tmp/portage/sys-kernel/gentoo-kernel-6.5.9/work/linux-6.5/fs/btrfs/scrub.c:2040:21: note: ‘found_logical’ was declared here >>>>   2040 |                 u64 found_logical; >>>>        |                     ^~~~~~~~~~~~~ >>>> ``` >>> Good find! found_logical is passed by reference to >>> queue_scrub_stripe(..) (inlined) >>> where it is used without ever being set: >>> ... >>>     /* Either >0 as no more extents or <0 for error. */ >>>     if (ret) >>>         return ret; >>>     if (found_logical_ret) >>>         *found_logical_ret = stripe->logical; >>>     sctx->cur_stripe++; >>> ... >>> Something is missing here, and somehow I don't think it's just the >>> top-level >>> initialisation of found_logical. >> >> This looks like a false alert for me. >> >> @found_logical is intentionally uninitialized to catch any >> uninitialized usage by compiler. >> > > I feel like this sort of thing is going to be inevitable with -Wmaybe-uninitialized. Indeed, it can be tricky for compilers to handle. But it's not that frequent, thus the btrfs community is mostly fine to handle those reports manually. > >> It would be set by queue_scrub_stripe() when there is any stripe found. >> >> If there is no stripe found, queue_scrub_stripe() would return >0, >> then we know there is no more extent and break the loop. >> If there is any error, we error out too, thus no problem with that. >> >> So to me this looks like a false alert. >> >> Mind to share the compiler and its version? >> > > Sure, GCC 14.0.0 20231022 (experimental). Sorry, I'd meant to include > that in the original post.. Wow, the first time I can not catch up on the toolchain version... And considering it's still experimental, I'd say if we got another report on this particular call site, we may consider add a fix for it, by simply initializing @found_logical to zero. Thanks, Qu > >> Thanks, >> Qu >>> -h >