jffs2: Erase pending blocks in GC pass, avoid invalid -EIO return

jffs2_garbage_collect_pass() would previously return -EAGAIN if it
couldn't find anything to garbage collect from, and there were blocks on
the erase_pending_list. If the blocks were actually in the process of
being erased, though, then they wouldn't be on that list. Check for
nr_erasing_blocks being non-zero instead.

Fix jffs2_reserve_space() to wait for the in-progress erases to
complete, when jffs2_garbage_collect_pass() returns -EAGAIN.

And fix jffs2_erase_succeeded() to actually wake up the erase_wait wq
that jffs2_reserve_space() is now using.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/fs/jffs2/erase.c b/fs/jffs2/erase.c
index b2d2b6a..563c857 100644 (file)
--- a/fs/jffs2/erase.c
+++ b/fs/jffs2/erase.c
@@ -172,6 +172,7 @@ static void jffs2_erase_succeeded(struct jffs2_sb_info *c, struct jffs2_eraseblo
        mutex_unlock(&c->erase_free_sem);
        /* Ensure that kupdated calls us again to mark them clean */
        jffs2_erase_pending_trigger(c);
+       wake_up(&c->erase_wait);
 }
 
 static void jffs2_erase_failed(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, uint32_t bad_offset)

diff --git a/fs/jffs2/gc.c b/fs/jffs2/gc.c
index 3b6f2fa..1ea4a84 100644 (file)
--- a/fs/jffs2/gc.c
+++ b/fs/jffs2/gc.c
@@ -214,6 +214,19 @@ int jffs2_garbage_collect_pass(struct jffs2_sb_info *c)
                return ret;
        }
 
+       /* If there are any blocks which need erasing, erase them now */
+       if (!list_empty(&c->erase_complete_list) ||
+           !list_empty(&c->erase_pending_list)) {
+               spin_unlock(&c->erase_completion_lock);
+               D1(printk(KERN_DEBUG "jffs2_garbage_collect_pass() erasing pending blocks\n"));
+               if (jffs2_erase_pending_blocks(c, 1)) {
+                       mutex_unlock(&c->alloc_sem);
+                       return 0;
+               }
+               D1(printk(KERN_DEBUG "No progress from erasing blocks; doing GC anyway\n"));
+               spin_lock(&c->erase_completion_lock);
+       }
+
        /* First, work out which block we're garbage-collecting */
        jeb = c->gcblock;
 
@@ -222,7 +235,7 @@ int jffs2_garbage_collect_pass(struct jffs2_sb_info *c)
 
        if (!jeb) {
                /* Couldn't find a free block. But maybe we can just erase one and make 'progress'? */
-               if (!list_empty(&c->erase_pending_list)) {
+               if (c->nr_erasing_blocks) {
                        spin_unlock(&c->erase_completion_lock);
                        mutex_unlock(&c->alloc_sem);
                        return -EAGAIN;

diff --git a/fs/jffs2/nodemgmt.c b/fs/jffs2/nodemgmt.c
index 191359d..08e2c69 100644 (file)
--- a/fs/jffs2/nodemgmt.c
+++ b/fs/jffs2/nodemgmt.c
@@ -116,9 +116,21 @@ int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
 
                        ret = jffs2_garbage_collect_pass(c);
 
-                       if (ret == -EAGAIN)
-                               jffs2_erase_pending_blocks(c, 1);
-                       else if (ret)
+                       if (ret == -EAGAIN) {
+                               spin_lock(&c->erase_completion_lock);
+                               if (c->nr_erasing_blocks &&
+                                   list_empty(&c->erase_pending_list) &&
+                                   list_empty(&c->erase_complete_list)) {
+                                       DECLARE_WAITQUEUE(wait, current);
+                                       set_current_state(TASK_UNINTERRUPTIBLE);
+                                       add_wait_queue(&c->erase_wait, &wait);
+                                       D1(printk(KERN_DEBUG "%s waiting for erase to complete\n", __func__));
+                                       spin_unlock(&c->erase_completion_lock);
+
+                                       schedule();
+                               } else
+                                       spin_unlock(&c->erase_completion_lock);
+                       } else if (ret)
                                return ret;
 
                        cond_resched();