[PATCH 5.7 187/393] xfs: fix reflink quota reservation accounting error
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STALE2243d
REVIEWED: 1 (0M)
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2020-08-17 18:58:07
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Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
1 review trailer.
From: Darrick J. Wong <redacted>
[ Upstream commit 83895227aba1ade33e81f586aa7b6b1e143096a5 ]
Quota reservations are supposed to account for the blocks that might be
allocated due to a bmap btree split. Reflink doesn't do this, so fix
this to make the quota accounting more accurate before we start
rearranging things.
Fixes: 862bb360ef56 ("xfs: reflink extents from one file to another")
Signed-off-by: Darrick J. Wong <redacted>
Reviewed-by: Brian Foster <redacted>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/xfs/xfs_reflink.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 107bf2a2f3448..d89201d40891f 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c@@ -1003,6 +1003,7 @@ xfs_reflink_remap_extent( xfs_filblks_t rlen; xfs_filblks_t unmap_len; xfs_off_t newlen; + int64_t qres; int error; unmap_len = irec->br_startoff + irec->br_blockcount - destoff;
@@ -1025,13 +1026,19 @@ xfs_reflink_remap_extent( xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_trans_ijoin(tp, ip, 0); - /* If we're not just clearing space, then do we have enough quota? */ - if (real_extent) { - error = xfs_trans_reserve_quota_nblks(tp, ip, - irec->br_blockcount, 0, XFS_QMOPT_RES_REGBLKS); - if (error) - goto out_cancel; - } + /* + * Reserve quota for this operation. We don't know if the first unmap + * in the dest file will cause a bmap btree split, so we always reserve + * at least enough blocks for that split. If the extent being mapped + * in is written, we need to reserve quota for that too. + */ + qres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); + if (real_extent) + qres += irec->br_blockcount; + error = xfs_trans_reserve_quota_nblks(tp, ip, qres, 0, + XFS_QMOPT_RES_REGBLKS); + if (error) + goto out_cancel; trace_xfs_reflink_remap(ip, irec->br_startoff, irec->br_blockcount, irec->br_startblock);
--
2.25.1