On Tue, Jan 07, 2025 at 04:32:06PM -0800, Darrick J. Wong wrote: > On Tue, Jan 07, 2025 at 09:11:23PM +0800, Long Li wrote: > > On Mon, Jan 06, 2025 at 11:52:20AM -0800, Darrick J. Wong wrote: > > > On Tue, Dec 31, 2024 at 10:34:22AM +0800, Long Li wrote: > > > > When mounting an xfs disk that incompat with metadir and has no realtime > > > > subvolume, if CONFIG_XFS_RT is not enabled in the kernel, the mount will > > > > fail. During superblock log recovery, since mp->m_sb.sb_rgcount is greater > > > > than 0, updating the last rtag in-core is required, however, without > > > > CONFIG_XFS_RT enabled, xfs_update_last_rtgroup_size() always returns > > > > -EOPNOTSUPP, leading to mount failure. > > > > > > Didn't we fix the xfs_update_last_rtgroup_size stub to return 0? > > > > > > --D > > > > Indeed, when CONFIG_XFS_RT is not enabled, xfs_update_last_rtgroup_size() should > > return 0, as returning an error is meaningless. > > > > 1) For kernels without CONFIG_XFS_RT, mounting an image with realtime subvolume will > > fail at xfs_rtmount_init(). > > > > 2) For kernels without CONFIG_XFS_RT, mounting an image without realtime subvolume > > should succeed. > > > > However, in the current scenario, should sb_rgcount be initialized to 0 ? it will > > consistent with metadir feature is enabled. The xfs-documentation [1] describes > > sb_rgcount as follows: > > > > "Count of realtime groups in the filesystem, if the XFS_SB_FEAT_RO_INCOMPAT_METADIR > > feature is enabled. If no realtime subvolume exists, this value will be zero." > > > > [1] https://git.kernel.org/pub/scm/fs/xfs/xfs-documentation.git/tree/design/XFS_Filesystem_Structure/superblock.asciidoc > > Ah, I see your point finally -- if there's no realtime section, then > there's no need to allocate any incore rtgroups, nor is there any point > to set sb_rgcount==1. > > That said, I think the correct tags here are: > Cc: <stable@xxxxxxxxxxxxxxx> # v6.13-rc1 > Fixes: 96768e91511bfc ("xfs: define the format of rt groups") > > because 96768e91511bfc is the commit that actually added "to->sb_rgcount > = 1;". > Ok, thanks for point out that, In fact, xfs_grow_last_rtg() needs to be modified together, otherwise the growfs may be problematic. Therefore, I will release a new version. Long Li
