From 6dcfac4f13d6b32fbaa60b64a23249999e66af8e Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Fri, 12 Sep 2008 12:27:47 +0300 Subject: [PATCH] UBIFS: TNC / GC race fixes - update GC sequence number if any nodes may have been moved even if GC did not finish the LEB - don't ignore error return when reading Signed-off-by: Adrian Hunter Signed-off-by: Artem Bityutskiy --- fs/ubifs/gc.c | 14 +++++++++++--- fs/ubifs/tnc.c | 2 +- 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/fs/ubifs/gc.c b/fs/ubifs/gc.c index 13f1019c859f..02aba36fe3d4 100644 --- a/fs/ubifs/gc.c +++ b/fs/ubifs/gc.c @@ -334,15 +334,15 @@ int ubifs_garbage_collect_leb(struct ubifs_info *c, struct ubifs_lprops *lp) err = move_nodes(c, sleb); if (err) - goto out; + goto out_inc_seq; err = gc_sync_wbufs(c); if (err) - goto out; + goto out_inc_seq; err = ubifs_change_one_lp(c, lnum, c->leb_size, 0, 0, 0, 0); if (err) - goto out; + goto out_inc_seq; /* Allow for races with TNC */ c->gced_lnum = lnum; @@ -369,6 +369,14 @@ int ubifs_garbage_collect_leb(struct ubifs_info *c, struct ubifs_lprops *lp) out: ubifs_scan_destroy(sleb); return err; + +out_inc_seq: + /* We may have moved at least some nodes so allow for races with TNC */ + c->gced_lnum = lnum; + smp_wmb(); + c->gc_seq += 1; + smp_wmb(); + goto out; } /** diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c index 7da209ab9378..7634c5970887 100644 --- a/fs/ubifs/tnc.c +++ b/fs/ubifs/tnc.c @@ -1476,7 +1476,7 @@ again: } err = fallible_read_node(c, key, &zbr, node); - if (maybe_leb_gced(c, zbr.lnum, gc_seq1)) { + if (err <= 0 || maybe_leb_gced(c, zbr.lnum, gc_seq1)) { /* * The node may have been GC'ed out from under us so try again * while keeping the TNC mutex locked. -- 2.20.1