From 84e1e99f112dead8f9ba036c02d24a9f5ce7f544 Mon Sep 17 00:00:00 2001 From: David Chinner Date: Mon, 18 Jun 2007 16:50:27 +1000 Subject: [XFS] Prevent ENOSPC from aborting transactions that need to succeed During delayed allocation extent conversion or unwritten extent conversion, we need to reserve some blocks for transactions reservations. We need to reserve these blocks in case a btree split occurs and we need to allocate some blocks. Unfortunately, we've only ever reserved the number of data blocks we are allocating, so in both the unwritten and delalloc case we can get ENOSPC to the transaction reservation. This is bad because in both cases we cannot report the failure to the writing application. The fix is two-fold: 1 - leverage the reserved block infrastructure XFS already has to reserve a small pool of blocks by default to allow specially marked transactions to dip into when we are at ENOSPC. Default setting is min(5%, 1024 blocks). 2 - convert critical transaction reservations to be allowed to dip into this pool. Spots changed are delalloc conversion, unwritten extent conversion and growing a filesystem at ENOSPC. This also allows growing the filesytsem to succeed at ENOSPC. SGI-PV: 964468 SGI-Modid: xfs-linux-melb:xfs-kern:28865a Signed-off-by: David Chinner Signed-off-by: Tim Shimmin --- fs/xfs/xfs_fsops.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'fs/xfs/xfs_fsops.c') diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c index ddd45e5b9383..2251a49f3e17 100644 --- a/fs/xfs/xfs_fsops.c +++ b/fs/xfs/xfs_fsops.c @@ -177,6 +177,7 @@ xfs_growfs_data_private( up_write(&mp->m_peraglock); } tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFS); + tp->t_flags |= XFS_TRANS_RESERVE; if ((error = xfs_trans_reserve(tp, XFS_GROWFS_SPACE_RES(mp), XFS_GROWDATA_LOG_RES(mp), 0, 0, 0))) { xfs_trans_cancel(tp, 0); @@ -499,8 +500,9 @@ xfs_reserve_blocks( unsigned long s; /* If inval is null, report current values and return */ - if (inval == (__uint64_t *)NULL) { + if (!outval) + return EINVAL; outval->resblks = mp->m_resblks; outval->resblks_avail = mp->m_resblks_avail; return 0; @@ -563,8 +565,10 @@ retry: } } out: - outval->resblks = mp->m_resblks; - outval->resblks_avail = mp->m_resblks_avail; + if (outval) { + outval->resblks = mp->m_resblks; + outval->resblks_avail = mp->m_resblks_avail; + } XFS_SB_UNLOCK(mp, s); if (fdblks_delta) { -- cgit v1.2.1