mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-04-14 09:57:39 +02:00
3fb84dfb97
commit66314e9a57upstream. I received a report from the release engineering side of the house that xfs_scrub without the -n flag (aka fix it mode) would try to fix a broken filesystem even on a kernel that doesn't have online repair built into it: # xfs_scrub -dTvn /mnt/test EXPERIMENTAL xfs_scrub program in use! Use at your own risk! Phase 1: Find filesystem geometry. /mnt/test: using 1 threads to scrub. Phase 1: Memory used: 132k/0k (108k/25k), time: 0.00/ 0.00/ 0.00s <snip> Phase 4: Repair filesystem. <snip> Info: /mnt/test/some/victimdir directory entries: Attempting repair. (repair.c line 351) Corruption: /mnt/test/some/victimdir directory entries: Repair unsuccessful; offline repair required. (repair.c line 204) Source: https://blogs.oracle.com/linux/post/xfs-online-filesystem-repair It is strange that xfs_scrub doesn't refuse to run, because the kernel is supposed to return EOPNOTSUPP if we actually needed to run a repair, and xfs_io's repair subcommand will perror that. And yet: # xfs_io -x -c 'repair probe' /mnt/test # The first problem is commitdcb660f922(4.15) which should have had xchk_probe set the CORRUPT OFLAG so that any of the repair machinery will get called at all. It turns out that some refactoring that happened in the 6.6-6.8 era broke the operation of this corner case. What we *really* want to happen is that all the predicates that would steer xfs_scrub_metadata() towards calling xrep_attempt() should function the same way that they do when repair is compiled in; and then xrep_attempt gets to return the fatal EOPNOTSUPP error code that causes the probe to fail. Instead, commit8336a64eb7(6.6) started the failwhale swimming by hoisting OFLAG checking logic into a helper whose non-repair stub always returns false, causing scrub to return "repair not needed" when in fact the repair is not supported. Prior to that commit, the oflag checking that was open-coded in scrub.c worked correctly. Similarly, in commit4bdfd7d157(6.8) we hoisted the IFLAG_REPAIR and ALREADY_FIXED logic into a helper whose non-repair stub always returns false, so we never enter the if test body that would have called xrep_attempt, let alone fail to decode the OFLAGs correctly. The final insult (yes, we're doing The Naked Gun now) is commit48a72f6086(6.8) in which we hoisted the "are we going to try a repair?" predicate into yet another function with a non-repair stub always returns false. Fix xchk_probe to trigger xrep_probe if repair is enabled, or return EOPNOTSUPP directly if it is not. For all the other scrub types, we need to fix the header predicates so that the ->repair functions (which are all xrep_notsupported) get called to return EOPNOTSUPP. Commit 48a72 is tagged here because the scrub code prior to LTS 6.12 are incomplete and not worth patching. Reported-by: David Flynn <david.flynn@oracle.com> Cc: <stable@vger.kernel.org> # v6.8 Fixes:8336a64eb7("xfs: don't complain about unfixed metadata when repairs were injected") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>