diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_refcount.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_refcount.c | 43 |
1 files changed, 31 insertions, 12 deletions
diff --git a/fs/xfs/libxfs/xfs_refcount.c b/fs/xfs/libxfs/xfs_refcount.c index b177ef33cd4c..82a38d86ebad 100644 --- a/fs/xfs/libxfs/xfs_refcount.c +++ b/fs/xfs/libxfs/xfs_refcount.c @@ -1629,13 +1629,28 @@ xfs_refcount_recover_cow_leftovers( if (mp->m_sb.sb_agblocks >= XFS_REFC_COW_START) return -EOPNOTSUPP; - error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp); + INIT_LIST_HEAD(&debris); + + /* + * In this first part, we use an empty transaction to gather up + * all the leftover CoW extents so that we can subsequently + * delete them. The empty transaction is used to avoid + * a buffer lock deadlock if there happens to be a loop in the + * refcountbt because we're allowed to re-grab a buffer that is + * already attached to our transaction. When we're done + * recording the CoW debris we cancel the (empty) transaction + * and everything goes away cleanly. + */ + error = xfs_trans_alloc_empty(mp, &tp); if (error) return error; - cur = xfs_refcountbt_init_cursor(mp, NULL, agbp, agno, NULL); + + error = xfs_alloc_read_agf(mp, tp, agno, 0, &agbp); + if (error) + goto out_trans; + cur = xfs_refcountbt_init_cursor(mp, tp, agbp, agno, NULL); /* Find all the leftover CoW staging extents. */ - INIT_LIST_HEAD(&debris); memset(&low, 0, sizeof(low)); memset(&high, 0, sizeof(high)); low.rc.rc_startblock = XFS_REFC_COW_START; @@ -1645,10 +1660,11 @@ xfs_refcount_recover_cow_leftovers( if (error) goto out_cursor; xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); - xfs_buf_relse(agbp); + xfs_trans_brelse(tp, agbp); + xfs_trans_cancel(tp); /* Now iterate the list to free the leftovers */ - list_for_each_entry(rr, &debris, rr_list) { + list_for_each_entry_safe(rr, n, &debris, rr_list) { /* Set up transaction. */ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp); if (error) @@ -1676,8 +1692,16 @@ xfs_refcount_recover_cow_leftovers( error = xfs_trans_commit(tp); if (error) goto out_free; + + list_del(&rr->rr_list); + kmem_free(rr); } + return error; +out_defer: + xfs_defer_cancel(&dfops); +out_trans: + xfs_trans_cancel(tp); out_free: /* Free the leftover list */ list_for_each_entry_safe(rr, n, &debris, rr_list) { @@ -1688,11 +1712,6 @@ out_free: out_cursor: xfs_btree_del_cursor(cur, XFS_BTREE_ERROR); - xfs_buf_relse(agbp); - goto out_free; - -out_defer: - xfs_defer_cancel(&dfops); - xfs_trans_cancel(tp); - goto out_free; + xfs_trans_brelse(tp, agbp); + goto out_trans; } |