From 8edbe0cf8b4bbe2cf47513998641797b0aca8ee2 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 10 Oct 2022 11:33:47 -0700 Subject: [PATCH] xfs: check deferred refcount op continuation parameters If we're in the middle of a deferred refcount operation and decide to roll the transaction to avoid overflowing the transaction space, we need to check the new agbno/aglen parameters that we're about to record in the new intent. Specifically, we need to check that the new extent is completely within the filesystem, and that continuation does not put us into a different AG. If the keys of a node block are wrong, the lookup to resume an xfs_refcount_adjust_extents operation can put us into the wrong record block. If this happens, we might not find that we run out of aglen at an exact record boundary, which will cause the loop control to do the wrong thing. The previous patch should take care of that problem, but let's add this extra sanity check to stop corruption problems sooner than later. Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner --- fs/xfs/libxfs/xfs_refcount.c | 38 ++++++++++++++++++++++++++++++++++-- 1 file changed, 36 insertions(+), 2 deletions(-) diff --git a/fs/xfs/libxfs/xfs_refcount.c b/fs/xfs/libxfs/xfs_refcount.c index 1a50ca53304a..542f749d0c6a 100644 --- a/fs/xfs/libxfs/xfs_refcount.c +++ b/fs/xfs/libxfs/xfs_refcount.c @@ -1134,6 +1134,32 @@ xfs_refcount_finish_one_cleanup( xfs_trans_brelse(tp, agbp); } +/* + * Set up a continuation a deferred refcount operation by updating the intent. + * Checks to make sure we're not going to run off the end of the AG. + */ +static inline int +xfs_refcount_continue_op( + struct xfs_btree_cur *cur, + xfs_fsblock_t startblock, + xfs_agblock_t new_agbno, + xfs_extlen_t new_len, + xfs_fsblock_t *new_fsbno) +{ + struct xfs_mount *mp = cur->bc_mp; + struct xfs_perag *pag = cur->bc_ag.pag; + + if (XFS_IS_CORRUPT(mp, !xfs_verify_agbext(pag, new_agbno, new_len))) + return -EFSCORRUPTED; + + *new_fsbno = XFS_AGB_TO_FSB(mp, pag->pag_agno, new_agbno); + + ASSERT(xfs_verify_fsbext(mp, *new_fsbno, new_len)); + ASSERT(pag->pag_agno == XFS_FSB_TO_AGNO(mp, *new_fsbno)); + + return 0; +} + /* * Process one of the deferred refcount operations. We pass back the * btree cursor to maintain our lock on the btree between calls. @@ -1201,12 +1227,20 @@ xfs_refcount_finish_one( case XFS_REFCOUNT_INCREASE: error = xfs_refcount_adjust(rcur, bno, blockcount, &new_agbno, new_len, XFS_REFCOUNT_ADJUST_INCREASE); - *new_fsb = XFS_AGB_TO_FSB(mp, pag->pag_agno, new_agbno); + if (error) + goto out_drop; + if (*new_len > 0) + error = xfs_refcount_continue_op(rcur, startblock, + new_agbno, *new_len, new_fsb); break; case XFS_REFCOUNT_DECREASE: error = xfs_refcount_adjust(rcur, bno, blockcount, &new_agbno, new_len, XFS_REFCOUNT_ADJUST_DECREASE); - *new_fsb = XFS_AGB_TO_FSB(mp, pag->pag_agno, new_agbno); + if (error) + goto out_drop; + if (*new_len > 0) + error = xfs_refcount_continue_op(rcur, startblock, + new_agbno, *new_len, new_fsb); break; case XFS_REFCOUNT_ALLOC_COW: *new_fsb = startblock + blockcount;