jffs2: Fix serious write stall due to erase

Drop the alloc_sem before erasing flash in
jffs2_garbage_collect_pass().
Otherwise writes are put on hold until the erase
has finised.

Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/fs/jffs2/gc.c b/fs/jffs2/gc.c
index 846a79452497..31dce611337c 100644
--- a/fs/jffs2/gc.c
+++ b/fs/jffs2/gc.c
@@ -219,13 +219,14 @@ int jffs2_garbage_collect_pass(struct jffs2_sb_info *c)
         if (!list_empty(&c->erase_complete_list) ||
             !list_empty(&c->erase_pending_list)) {
                 spin_unlock(&c->erase_completion_lock);
+                mutex_unlock(&c->alloc_sem);
                 D1(printk(KERN_DEBUG "jffs2_garbage_collect_pass() erasing pending blocks\n"));
-                if (jffs2_erase_pending_blocks(c, 1)) {
-                        mutex_unlock(&c->alloc_sem);
+                if (jffs2_erase_pending_blocks(c, 1))
                         return 0;
-                }
+
                 D1(printk(KERN_DEBUG "No progress from erasing blocks; doing GC anyway\n"));
                 spin_lock(&c->erase_completion_lock);
+                mutex_lock(&c->alloc_sem);
         }
 
         /* First, work out which block we're garbage-collecting */