Re: [PATCH 2/5] xfs: implement live quotacheck inode scan

Darrick J. Wong
2024-01-09T01:23:47Z

On Fri, Jan 05, 2024 at 05:16:50PM -0800, Darrick J. Wong wrote:
> On Thu, Jan 04, 2024 at 09:29:16PM -0800, Christoph Hellwig wrote:
> > Looks good,
> >
> > but a few nitpick below:
> >
> > > +int
> > > +xchk_trans_alloc_empty(
> > > + struct xfs_scrub *sc)
> > > +{
> > > + return xfs_trans_alloc_empty(sc->mp, &sc->tp);
> > > +}
> >
> > Can this and the conversion of an existing not quota related caller
> > of xfs_trans_alloc_empty be split into a separate patch that also
> > documents why this pretty trivial helper is useful?
>
> Done.
>
> > > +#ifdef CONFIG_XFS_QUOTA
> > > +void xchk_qcheck_set_corrupt(struct xfs_scrub *sc, unsigned int dqtype,
> > > + xfs_dqid_t id);
> > > +#endif /* CONFIG_XFS_QUOTA */
> >
> > No need for the ifdef here.
>
> Fixed.

...and reverted because I forgot to remove the #ifdef around the
tracepoint in that function. I tried to fix that, and got a ton of
macro spew over ... something not being defined. In the end, I decided
that it was better not to waste memory on !CONFIG_XFS_QUOTA and not to
waste time on minor things like this.

(I spent all day rebasing to for-next again because I didn't realize
that Chandan had pulled in a bunch more of your cleanups.)

--D

> > > + /* Figure out the data / rt device block counts. */
> > > + xfs_ilock(ip, XFS_IOLOCK_SHARED);
> > > + if (isreg)
> > > + xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
> > > + if (XFS_IS_REALTIME_INODE(ip)) {
> > > + ilock_flags = xfs_ilock_data_map_shared(ip);
> > > + error = xfs_iread_extents(tp, ip, XFS_DATA_FORK);
> > > + if (error)
> > > + goto out_incomplete;
> > > + } else {
> > > + ilock_flags = XFS_ILOCK_SHARED;
> > > + xfs_ilock(ip, XFS_ILOCK_SHARED);
> > > + }
> >
> > The need to call xfs_iread_extents only for RT inodes here look good,
> > but I guess it is explained by the logic in xfs_inode_count_blocks.
> > Maybe add a comment?
>
> /*
> * Read in the data fork for rt files so that _count_blocks
> * can count the number of blocks allocated from the rt volume.
> * Inodes do not track that separately.
> */
>
> > > +/*
> > > + * Load an array element, but zero the buffer if there's no data because we
> > > + * haven't stored to that array element yet.
> > > + */
> > > +static inline int
> > > +xfarray_load_sparse(
> > > + struct xfarray *array,
> > > + uint64_t idx,
> > > + void *rec)
> > > +{
> > > + int error = xfarray_load(array, idx, rec);
> > > +
> > > + if (error == -ENODATA) {
> > > + memset(rec, 0, array->obj_size);
> > > + return 0;
> > > + }
> > > + return error;
> > > +}
> >
> > Please split this into a separate prep patch.
>
> Done.
>
> > > +/* Compute the number of data and realtime blocks used by a file. */
> > > +void
> > > +xfs_inode_count_blocks(
> > > + struct xfs_trans *tp,
> > > + struct xfs_inode *ip,
> > > + xfs_filblks_t *dblocks,
> > > + xfs_filblks_t *rblocks)
> > > +{
> > > + struct xfs_ifork *ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
> > > +
> > > + if (!XFS_IS_REALTIME_INODE(ip)) {
> > > + *dblocks = ip->i_nblocks;
> > > + *rblocks = 0;
> > > + return;
> > > + }
> > > +
> > > + *rblocks = 0;
> > > + xfs_bmap_count_leaves(ifp, rblocks);
> > > + *dblocks = ip->i_nblocks - *rblocks;
> > > +}
> >
> > Same for this one. The flow here also reads a little odd to me,
> > what speaks against:
> >
> > *rblocks = 0;
> > if (XFS_IS_REALTIME_INODE(ip))
> > xfs_bmap_count_leaves(&ip->i_df, rblocks);
> > *dblocks = ip->i_nblocks - *rblocks;
>
> Yeah, that is more tidy. Thanks for the suggestion, I'll incorporate
> that.
>
> --D
>