block: fix mis-synchronisation in blkdev_issue_zeroout()

[mv-sheeva.git] / block / blk-lib.c

diff --git a/block/blk-lib.c b/block/blk-lib.c
index eec78becb35500d8c5a922c91f5ea94c16336ee9..bd3e8df4d5e2b45a0ae89d90de025cfbaa12eed9 100644 (file)
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -109,7 +109,6 @@ struct bio_batch
        atomic_t                done;
        unsigned long           flags;
        struct completion       *wait;
-       bio_end_io_t            *end_io;
 };
 
 static void bio_batch_end_io(struct bio *bio, int err)
@@ -122,12 +121,9 @@ static void bio_batch_end_io(struct bio *bio, int err)
                else
                        clear_bit(BIO_UPTODATE, &bb->flags);
        }
-       if (bb) {
-               if (bb->end_io)
-                       bb->end_io(bio, err);
-               atomic_inc(&bb->done);
-               complete(bb->wait);
-       }
+       if (bb)
+               if (atomic_dec_and_test(&bb->done))
+                       complete(bb->wait);
        bio_put(bio);
 }
 
@@ -150,13 +146,12 @@ int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
        int ret;
        struct bio *bio;
        struct bio_batch bb;
-       unsigned int sz, issued = 0;
+       unsigned int sz;
        DECLARE_COMPLETION_ONSTACK(wait);
 
-       atomic_set(&bb.done, 0);
+       atomic_set(&bb.done, 1);
        bb.flags = 1 << BIO_UPTODATE;
        bb.wait = &wait;
-       bb.end_io = NULL;
 
 submit:
        ret = 0;
@@ -185,12 +180,12 @@ submit:
                                break;
                }
                ret = 0;
-               issued++;
+               atomic_inc(&bb.done);
                submit_bio(WRITE, bio);
        }
 
        /* Wait for bios in-flight */
-       while (issued != atomic_read(&bb.done))
+       if (!atomic_dec_and_test(&bb.done))
                wait_for_completion(&wait);
 
        if (!test_bit(BIO_UPTODATE, &bb.flags))