On Mon 09-09-24 11:19:00, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@xxxxxxxx> > > XFS no longer builds on kernels with MMU disabled: > > arm-linux-gnueabi-ld: fs/xfs/xfs_file.o: in function `xfs_write_fault.constprop.0': > xfs_file.c:(.text.xfs_write_fault.constprop.0+0xc): undefined reference to `filemap_fsnotify_fault' > > It's rather unlikely that anyone is using this combination, > so just add a Kconfig dependency. > > Fixes: 436df5326f57 ("xfs: add pre-content fsnotify hook for write faults") > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> Thanks! I've noticed the error from 0-day over the weekend as well. At this point I'd rather handle this in a similar way as e.g. filemap_fault() is handled in NOMMU case. I agree users of XFS (or bcachefs for that matter) with !CONFIG_MMU are unlikely but fsnotify_filemap_fault() can grow more users over time and providing the stub is easy enough. I'll push out fixed version of the patch. Honza > --- > fs/xfs/Kconfig | 1 + > lib/Kconfig.debug | 1 + > 2 files changed, 2 insertions(+) > > diff --git a/fs/xfs/Kconfig b/fs/xfs/Kconfig > index fffd6fffdce0..1834932a512d 100644 > --- a/fs/xfs/Kconfig > +++ b/fs/xfs/Kconfig > @@ -2,6 +2,7 @@ > config XFS_FS > tristate "XFS filesystem support" > depends on BLOCK > + depends on MMU > select EXPORTFS > select LIBCRC32C > select FS_IOMAP > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 7c0546480078..8906e2cd1ed5 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -2862,6 +2862,7 @@ config TEST_KMOD > depends on NETDEVICES && NET_CORE && INET # for TUN > depends on BLOCK > depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS > + depends on MMU # for XFS_FS > select TEST_LKM > select XFS_FS > select TUN > -- > 2.39.2 > -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR