On Thu, Dec 13, 2018 at 03:29:54PM -0600, Eric Sandeen wrote: > > > On 12/12/18 7:24 PM, Darrick J. Wong wrote: > > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > > > Don't ever skip the realtime bitmap / summary inode initialization if > > there's a realtime device attached, because we'd rather fail the mount > > if iget declines to retrieve a NULL inode pointer. Right now, if > > someone sets rbmino to NULLFSINO on a rt-capable filesystem, mounts it, > > and writes a file to the rt device, we'll blow up. > > > > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > --- > > fs/xfs/xfs_rtalloc.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c > > index aefd63d46397..18ad31ded0bf 100644 > > --- a/fs/xfs/xfs_rtalloc.c > > +++ b/fs/xfs/xfs_rtalloc.c > > @@ -1206,7 +1206,8 @@ xfs_rtmount_inodes( > > xfs_sb_t *sbp; > > > > sbp = &mp->m_sb; > > - if (sbp->sb_rbmino == NULLFSINO) > > + if (!xfs_sb_version_hasrealtime(&mp->m_sb) && > > + sbp->sb_rbmino == NULLFSINO) > > return 0; > > error = xfs_iget(mp, NULL, sbp->sb_rbmino, 0, 0, &mp->m_rbmip); > > if (error) > > > > Seems fine as far as it goes, but now we have this weird situation where for > a filesystem without the realtime feature, we'll just skip this part and > mount if sb_rbmino is NULL, but if sb_rsumino is NULL, we'll fail the iget > and fail the mount. > > So while there's noting really wrong with the fix, it seems like it could all > be made a bit more consistent while you're here. (classic move by me!) ;) Hmm. Well if there /aren't supposed/ to be any XFSes out there with garbage/null realtime bitmap / summary inodes, then I'm happy to get rid of the "if (sbp->sb_rbmino == NULLFSINO) return 0;" logic. The current logic is sorta weird, but I don't know if that was a deliberate design decision or just a logic bug that needs to go away. Though now that I see that we can indeed add a realtime section to a filesystem that didn't previously have one, I guess I should go look at the rtrmapbt growfs code a little more closely. --D > -Eric
