From 4b4c1326fd7c7210d23d9dd3bfc51f2b6477bb9e Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Fri, 19 Jan 2018 09:05:48 -0800 Subject: [PATCH] xfs: treat CoW fork operations as delalloc for quota accounting Since the CoW fork only exists in memory, it is incorrect to update the on-disk quota block counts when we modify the CoW fork. Unlike the data fork, even real extents in the CoW fork are only delalloc-style reservations (on-disk they're owned by the refcountbt) so they must not be tracked in the on disk quota info. Ensure the i_delayed_blks accounting reflects this too. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/xfs/libxfs/xfs_bmap.c | 32 ++++++++++++++++++++++++++++++-- fs/xfs/xfs_reflink.c | 15 +++++++++++---- 2 files changed, 41 insertions(+), 6 deletions(-) diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index 4582f5547ae3..cad21fd0c45d 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -3343,8 +3343,35 @@ xfs_bmap_btalloc_accounting( struct xfs_bmalloca *ap, struct xfs_alloc_arg *args) { - if (!(ap->flags & XFS_BMAPI_COWFORK)) - ap->ip->i_d.di_nblocks += args->len; + if (ap->flags & XFS_BMAPI_COWFORK) { + /* + * COW fork blocks are in-core only and thus are treated as + * in-core quota reservation (like delalloc blocks) even when + * converted to real blocks. The quota reservation is not + * accounted to disk until blocks are remapped to the data + * fork. So if these blocks were previously delalloc, we + * already have quota reservation and there's nothing to do + * yet. + */ + if (ap->wasdel) + return; + + /* + * Otherwise, we've allocated blocks in a hole. The transaction + * has acquired in-core quota reservation for this extent. + * Rather than account these as real blocks, however, we reduce + * the transaction quota reservation based on the allocation. + * This essentially transfers the transaction quota reservation + * to that of a delalloc extent. + */ + ap->ip->i_delayed_blks += args->len; + xfs_trans_mod_dquot_byino(ap->tp, ap->ip, XFS_TRANS_DQ_RES_BLKS, + -(long)args->len); + return; + } + + /* data/attr fork only */ + ap->ip->i_d.di_nblocks += args->len; xfs_trans_log_inode(ap->tp, ap->ip, XFS_ILOG_CORE); if (ap->wasdel) ap->ip->i_delayed_blks -= args->len; @@ -4820,6 +4847,7 @@ xfs_bmap_del_extent_cow( xfs_iext_insert(ip, icur, &new, state); break; } + ip->i_delayed_blks -= del->br_blockcount; } /* diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 85a119e1463b..c4f0aff86f96 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -599,10 +599,6 @@ xfs_reflink_cancel_cow_blocks( del.br_startblock, del.br_blockcount, NULL); - /* Update quota accounting */ - xfs_trans_mod_dquot_byino(*tpp, ip, XFS_TRANS_DQ_BCOUNT, - -(long)del.br_blockcount); - /* Roll the transaction */ xfs_defer_ijoin(&dfops, ip); error = xfs_defer_finish(tpp, &dfops); @@ -613,6 +609,13 @@ xfs_reflink_cancel_cow_blocks( /* Remove the mapping from the CoW fork. */ xfs_bmap_del_extent_cow(ip, &icur, &got, &del); + + /* Remove the quota reservation */ + error = xfs_trans_reserve_quota_nblks(NULL, ip, + -(long)del.br_blockcount, 0, + XFS_QMOPT_RES_REGBLKS); + if (error) + break; } else { /* Didn't do anything, push cursor back. */ xfs_iext_prev(ifp, &icur); @@ -795,6 +798,10 @@ xfs_reflink_end_cow( if (error) goto out_defer; + /* Charge this new data fork mapping to the on-disk quota. */ + xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_DELBCOUNT, + (long)del.br_blockcount); + /* Remove the mapping from the CoW fork. */ xfs_bmap_del_extent_cow(ip, &icur, &got, &del); -- 2.30.2