diff options
| author | Darrick J. Wong <djwong@kernel.org> | 2021-05-21 13:52:18 -0700 |
|---|---|---|
| committer | Darrick J. Wong <djwong@kernel.org> | 2021-05-25 18:49:50 -0700 |
| commit | 2bbc99dbf87840c836cd9352c32fbf3f62d0ac81 (patch) | |
| tree | fc1ab53fac9c2f52309d848c5d33ad78840affe8 | |
| parent | 4026226a79ad0e2d0a625464dc12434d5c3e90f3 (diff) | |
xfs: check free AG space when making per-AG reservationsshrink-fixes_2021-05-25
The new online shrink code exposed a gap in the per-AG reservation
code, which is that we only return ENOSPC to callers if the entire fs
doesn't have enough free blocks. Except for debugging mode, the
reservation init code doesn't ever check that there's enough free space
in that AG to cover the reservation.
Not having enough space is not considered an immediate fatal error that
requires filesystem offlining because (a) it's shouldn't be possible to
wind up in that state through normal file operations and (b) even if
one did, freeing data blocks would recover the situation.
However, online shrink now needs to know if shrinking would not leave
enough space so that it can abort the shrink operation. Hence we need
to promote this assertion into an actual error return.
Observed by running xfs/168 with a 1k block size, though in theory this
could happen with any configuration.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
| -rw-r--r-- | fs/xfs/libxfs/xfs_ag_resv.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/fs/xfs/libxfs/xfs_ag_resv.c b/fs/xfs/libxfs/xfs_ag_resv.c index e32a1833d523..aa1383645238 100644 --- a/fs/xfs/libxfs/xfs_ag_resv.c +++ b/fs/xfs/libxfs/xfs_ag_resv.c @@ -325,10 +325,21 @@ out: error2 = xfs_alloc_pagf_init(mp, tp, pag->pag_agno, 0); if (error2) return error2; - ASSERT(xfs_perag_resv(pag, XFS_AG_RESV_METADATA)->ar_reserved + - xfs_perag_resv(pag, XFS_AG_RESV_RMAPBT)->ar_reserved <= - pag->pagf_freeblks + pag->pagf_flcount); } + + /* + * If there isn't enough space in the AG to satisfy the reservation, + * let the caller know that there wasn't enough space. Callers are + * responsible for deciding what to do next, since the AG can stumble + * along with insufficient reservation if data blocks are being freed + * to replenish the AG's free space. + */ + if (!error && + xfs_perag_resv(pag, XFS_AG_RESV_METADATA)->ar_reserved + + xfs_perag_resv(pag, XFS_AG_RESV_RMAPBT)->ar_reserved > + pag->pagf_freeblks + pag->pagf_flcount) + error = -ENOSPC; + return error; } |