| Message ID | 20240621100540.2976618-7-john.g.garry@oracle.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | forcealign for xfs | expand |
On Fri, Jun 21, 2024 at 10:05:33AM +0000, John Garry wrote: > From: Dave Chinner <dchinner@redhat.com> > > If args->minlen is not aligned to the constraints of forced > alignment, we may do minlen allocations that are not aligned when we > approach ENOSPC. Avoid this by always aligning args->minlen > appropriately. If alignment of minlen results in a value smaller > than the alignment constraint, fail the allocation immediately. > > Signed-off-by: Dave Chinner <dchinner@redhat.com> > Signed-off-by: John Garry <john.g.garry@oracle.com> Looks good! Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D > --- > fs/xfs/libxfs/xfs_bmap.c | 45 +++++++++++++++++++++++++++------------- > 1 file changed, 31 insertions(+), 14 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c > index 9131ba8113a6..c9cf138e13c4 100644 > --- a/fs/xfs/libxfs/xfs_bmap.c > +++ b/fs/xfs/libxfs/xfs_bmap.c > @@ -3278,33 +3278,48 @@ xfs_bmap_longest_free_extent( > return 0; > } > > -static xfs_extlen_t > +static int > xfs_bmap_select_minlen( > struct xfs_bmalloca *ap, > struct xfs_alloc_arg *args, > xfs_extlen_t blen) > { > - > /* Adjust best length for extent start alignment. */ > if (blen > args->alignment) > blen -= args->alignment; > > /* > * Since we used XFS_ALLOC_FLAG_TRYLOCK in _longest_free_extent(), it is > - * possible that there is enough contiguous free space for this request. > + * possible that there is enough contiguous free space for this request > + * even if best length is less that the minimum length we need. > + * > + * If the best length won't satisfy the maximum length we requested, > + * then use it as the minimum length so we get as large an allocation > + * as possible. > */ > if (blen < ap->minlen) > - return ap->minlen; > + blen = ap->minlen; > + else if (blen > args->maxlen) > + blen = args->maxlen; > > /* > - * If the best seen length is less than the request length, > - * use the best as the minimum, otherwise we've got the maxlen we > - * were asked for. > + * If we have alignment constraints, round the minlen down to match the > + * constraint so that alignment will be attempted. This may reduce the > + * allocation to smaller than was requested, so clamp the minimum to > + * ap->minlen to allow unaligned allocation to succeed. If we are forced > + * to align the allocation, return ENOSPC at this point because we don't > + * have enough contiguous free space to guarantee aligned allocation. > */ > - if (blen < args->maxlen) > - return blen; > - return args->maxlen; > - > + if (args->alignment > 1) { > + blen = rounddown(blen, args->alignment); > + if (blen < ap->minlen) { > + if (args->datatype & XFS_ALLOC_FORCEALIGN) > + return -ENOSPC; > + blen = ap->minlen; > + } > + } > + args->minlen = blen; > + return 0; > } > > static int > @@ -3340,8 +3355,7 @@ xfs_bmap_btalloc_select_lengths( > if (pag) > xfs_perag_rele(pag); > > - args->minlen = xfs_bmap_select_minlen(ap, args, blen); > - return error; > + return xfs_bmap_select_minlen(ap, args, blen); > } > > /* Update all inode and quota accounting for the allocation we just did. */ > @@ -3661,7 +3675,10 @@ xfs_bmap_btalloc_filestreams( > goto out_low_space; > } > > - args->minlen = xfs_bmap_select_minlen(ap, args, blen); > + error = xfs_bmap_select_minlen(ap, args, blen); > + if (error) > + goto out_low_space; > + > if (ap->aeof && ap->offset) > error = xfs_bmap_btalloc_at_eof(ap, args); > > -- > 2.31.1 > >
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index 9131ba8113a6..c9cf138e13c4 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -3278,33 +3278,48 @@ xfs_bmap_longest_free_extent( return 0; } -static xfs_extlen_t +static int xfs_bmap_select_minlen( struct xfs_bmalloca *ap, struct xfs_alloc_arg *args, xfs_extlen_t blen) { - /* Adjust best length for extent start alignment. */ if (blen > args->alignment) blen -= args->alignment; /* * Since we used XFS_ALLOC_FLAG_TRYLOCK in _longest_free_extent(), it is - * possible that there is enough contiguous free space for this request. + * possible that there is enough contiguous free space for this request + * even if best length is less that the minimum length we need. + * + * If the best length won't satisfy the maximum length we requested, + * then use it as the minimum length so we get as large an allocation + * as possible. */ if (blen < ap->minlen) - return ap->minlen; + blen = ap->minlen; + else if (blen > args->maxlen) + blen = args->maxlen; /* - * If the best seen length is less than the request length, - * use the best as the minimum, otherwise we've got the maxlen we - * were asked for. + * If we have alignment constraints, round the minlen down to match the + * constraint so that alignment will be attempted. This may reduce the + * allocation to smaller than was requested, so clamp the minimum to + * ap->minlen to allow unaligned allocation to succeed. If we are forced + * to align the allocation, return ENOSPC at this point because we don't + * have enough contiguous free space to guarantee aligned allocation. */ - if (blen < args->maxlen) - return blen; - return args->maxlen; - + if (args->alignment > 1) { + blen = rounddown(blen, args->alignment); + if (blen < ap->minlen) { + if (args->datatype & XFS_ALLOC_FORCEALIGN) + return -ENOSPC; + blen = ap->minlen; + } + } + args->minlen = blen; + return 0; } static int @@ -3340,8 +3355,7 @@ xfs_bmap_btalloc_select_lengths( if (pag) xfs_perag_rele(pag); - args->minlen = xfs_bmap_select_minlen(ap, args, blen); - return error; + return xfs_bmap_select_minlen(ap, args, blen); } /* Update all inode and quota accounting for the allocation we just did. */ @@ -3661,7 +3675,10 @@ xfs_bmap_btalloc_filestreams( goto out_low_space; } - args->minlen = xfs_bmap_select_minlen(ap, args, blen); + error = xfs_bmap_select_minlen(ap, args, blen); + if (error) + goto out_low_space; + if (ap->aeof && ap->offset) error = xfs_bmap_btalloc_at_eof(ap, args);