From: Darrick J. Wong Date: Tue, 15 Apr 2025 00:33:45 +0000 (-0700) Subject: xfs: fix fsmap for internal zoned devices X-Git-Tag: v6.15-rc3~40^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c6f1401b1d5fb3b83bd16ba8a0f89a8b1c805993;p=thirdparty%2Flinux.git xfs: fix fsmap for internal zoned devices Filesystems with an internal zoned rt section use xfs_rtblock_t values that are relative to the start of the data device. When fsmap reports on internal rt sections, it reports the space used by the data section as "OWN_FS". Unfortunately, the logic for resuming a query isn't quite right, so xfs/273 fails because it stress-tests GETFSMAP with a single-record buffer. If we enter the "report fake space as OWN_FS" block with a nonzero key[0].fmr_length, we should add that to key[0].fmr_physical and recheck if we still need to emit the fake record. We should /not/ just return 0 from the whole function because that prevents all rmap record iteration. If we don't enter that block, the resumption is still wrong. keys[*].fmr_physical is a reflection of what we copied out to userspace on a previous query, which means that it already accounts for rgstart. It is not correct to add rtstart_daddr when computing start_rtb or end_rtb, so stop that. While we're at it, add a xfs_has_zoned to make it clear that this is a zoned filesystem thing. Fixes: e50ec7fac81aa2 ("xfs: enable fsmap reporting for internal RT devices") Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Carlos Maiolino --- diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c index a4bc1642fe561..414b27a864588 100644 --- a/fs/xfs/xfs_fsmap.c +++ b/fs/xfs/xfs_fsmap.c @@ -876,6 +876,7 @@ xfs_getfsmap_rtdev_rmapbt( const struct xfs_fsmap *keys, struct xfs_getfsmap_info *info) { + struct xfs_fsmap key0 = *keys; /* struct copy */ struct xfs_mount *mp = tp->t_mountp; struct xfs_rtgroup *rtg = NULL; struct xfs_btree_cur *bt_cur = NULL; @@ -887,32 +888,46 @@ xfs_getfsmap_rtdev_rmapbt( int error = 0; eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rtstart + mp->m_sb.sb_rblocks); - if (keys[0].fmr_physical >= eofs) + if (key0.fmr_physical >= eofs) return 0; + /* + * On zoned filesystems with an internal rt volume, the volume comes + * immediately after the end of the data volume. However, the + * xfs_rtblock_t address space is relative to the start of the data + * device, which means that the first @rtstart fsblocks do not actually + * point anywhere. If a fsmap query comes in with the low key starting + * below @rtstart, report it as "owned by filesystem". + */ rtstart_daddr = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rtstart); - if (keys[0].fmr_physical < rtstart_daddr) { + if (xfs_has_zoned(mp) && key0.fmr_physical < rtstart_daddr) { struct xfs_fsmap_irec frec = { .owner = XFS_RMAP_OWN_FS, .len_daddr = rtstart_daddr, }; - /* Adjust the low key if we are continuing from where we left off. */ - if (keys[0].fmr_length > 0) { - info->low_daddr = keys[0].fmr_physical + keys[0].fmr_length; - return 0; + /* + * Adjust the start of the query range if we're picking up from + * a previous round, and only emit the record if we haven't + * already gone past. + */ + key0.fmr_physical += key0.fmr_length; + if (key0.fmr_physical < rtstart_daddr) { + error = xfs_getfsmap_helper(tp, info, &frec); + if (error) + return error; + + key0.fmr_physical = rtstart_daddr; } - /* Fabricate an rmap entry for space occupied by the data dev */ - error = xfs_getfsmap_helper(tp, info, &frec); - if (error) - return error; + /* Zero the other fields to avoid further adjustments. */ + key0.fmr_owner = 0; + key0.fmr_offset = 0; + key0.fmr_length = 0; } - start_rtb = xfs_daddr_to_rtb(mp, rtstart_daddr + keys[0].fmr_physical); - end_rtb = xfs_daddr_to_rtb(mp, rtstart_daddr + - min(eofs - 1, keys[1].fmr_physical)); - + start_rtb = xfs_daddr_to_rtb(mp, key0.fmr_physical); + end_rtb = xfs_daddr_to_rtb(mp, min(eofs - 1, keys[1].fmr_physical)); info->missing_owner = XFS_FMR_OWN_FREE; /* @@ -920,12 +935,12 @@ xfs_getfsmap_rtdev_rmapbt( * low to the fsmap low key and max out the high key to the end * of the rtgroup. */ - info->low.rm_offset = XFS_BB_TO_FSBT(mp, keys[0].fmr_offset); - error = xfs_fsmap_owner_to_rmap(&info->low, &keys[0]); + info->low.rm_offset = XFS_BB_TO_FSBT(mp, key0.fmr_offset); + error = xfs_fsmap_owner_to_rmap(&info->low, &key0); if (error) return error; - info->low.rm_blockcount = XFS_BB_TO_FSBT(mp, keys[0].fmr_length); - xfs_getfsmap_set_irec_flags(&info->low, &keys[0]); + info->low.rm_blockcount = XFS_BB_TO_FSBT(mp, key0.fmr_length); + xfs_getfsmap_set_irec_flags(&info->low, &key0); /* Adjust the low key if we are continuing from where we left off. */ if (info->low.rm_blockcount == 0) {