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>

diff --git a/fs/jffs2/gc.c b/fs/jffs2/gc.c
index 846a794..31dce61 100644 (file)
--- 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 */