Merge tag 'md-3.5-fixes' of git://neil.brown.name/md

Pull three md bugfixes from NeilBrown:
 "One of the bugs was introduced in 3.5-rc1.  Others have been there for
  longer."

* tag 'md-3.5-fixes' of git://neil.brown.name/md:
  md/raid1: close some possible races on write errors during resync
  md: avoid crash when stopping md array races with closing other open fds.
  md: fix bug in handling of new_data_offset

2 files changed, 32 insertions, 15 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index a4c219e3c859..d5ab4493c8be 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2931,6 +2931,7 @@ offset_store(struct md_rdev *rdev, const char *buf, size_t len)
                  * can be sane */
                 return -EBUSY;
         rdev->data_offset = offset;
+        rdev->new_data_offset = offset;
         return len;
 }
 
@@ -3926,8 +3927,8 @@ array_state_show(struct mddev *mddev, char *page)
         return sprintf(page, "%s\n", array_states[st]);
 }
 
-static int do_md_stop(struct mddev * mddev, int ro, int is_open);
-static int md_set_readonly(struct mddev * mddev, int is_open);
+static int do_md_stop(struct mddev * mddev, int ro, struct block_device *bdev);
+static int md_set_readonly(struct mddev * mddev, struct block_device *bdev);
 static int do_md_run(struct mddev * mddev);
 static int restart_array(struct mddev *mddev);
 
@@ -3943,14 +3944,14 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
                 /* stopping an active array */
                 if (atomic_read(&mddev->openers) > 0)
                         return -EBUSY;
-                err = do_md_stop(mddev, 0, 0);
+                err = do_md_stop(mddev, 0, NULL);
                 break;
         case inactive:
                 /* stopping an active array */
                 if (mddev->pers) {
                         if (atomic_read(&mddev->openers) > 0)
                                 return -EBUSY;
-                        err = do_md_stop(mddev, 2, 0);
+                        err = do_md_stop(mddev, 2, NULL);
                 } else
                         err = 0; /* already inactive */
                 break;
@@ -3958,7 +3959,7 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
                 break; /* not supported yet */
         case readonly:
                 if (mddev->pers)
-                        err = md_set_readonly(mddev, 0);
+                        err = md_set_readonly(mddev, NULL);
                 else {
                         mddev->ro = 1;
                         set_disk_ro(mddev->gendisk, 1);
@@ -3968,7 +3969,7 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
         case read_auto:
                 if (mddev->pers) {
                         if (mddev->ro == 0)
-                                err = md_set_readonly(mddev, 0);
+                                err = md_set_readonly(mddev, NULL);
                         else if (mddev->ro == 1)
                                 err = restart_array(mddev);
                         if (err == 0) {
@@ -5351,15 +5352,17 @@ void md_stop(struct mddev *mddev)
 }
 EXPORT_SYMBOL_GPL(md_stop);
 
-static int md_set_readonly(struct mddev *mddev, int is_open)
+static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
 {
         int err = 0;
         mutex_lock(&mddev->open_mutex);
-        if (atomic_read(&mddev->openers) > is_open) {
+        if (atomic_read(&mddev->openers) > !!bdev) {
                 printk("md: %s still in use.\n",mdname(mddev));
                 err = -EBUSY;
                 goto out;
         }
+        if (bdev)
+                sync_blockdev(bdev);
         if (mddev->pers) {
                 __md_stop_writes(mddev);
 
@@ -5381,18 +5384,26 @@ out:
  *   0 - completely stop and dis-assemble array
  *   2 - stop but do not disassemble array
  */
-static int do_md_stop(struct mddev * mddev, int mode, int is_open)
+static int do_md_stop(struct mddev * mddev, int mode,
+                      struct block_device *bdev)
 {
         struct gendisk *disk = mddev->gendisk;
         struct md_rdev *rdev;
 
         mutex_lock(&mddev->open_mutex);
-        if (atomic_read(&mddev->openers) > is_open ||
+        if (atomic_read(&mddev->openers) > !!bdev ||
             mddev->sysfs_active) {
                 printk("md: %s still in use.\n",mdname(mddev));
                 mutex_unlock(&mddev->open_mutex);
                 return -EBUSY;
         }
+        if (bdev)
+                /* It is possible IO was issued on some other
+                 * open file which was closed before we took ->open_mutex.
+                 * As that was not the last close __blkdev_put will not
+                 * have called sync_blockdev, so we must.
+                 */
+                sync_blockdev(bdev);
 
         if (mddev->pers) {
                 if (mddev->ro)
@@ -5466,7 +5477,7 @@ static void autorun_array(struct mddev *mddev)
         err = do_md_run(mddev);
         if (err) {
                 printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
-                do_md_stop(mddev, 0, 0);
+                do_md_stop(mddev, 0, NULL);
         }
 }
 
@@ -6481,11 +6492,11 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
                         goto done_unlock;
 
                 case STOP_ARRAY:
-                        err = do_md_stop(mddev, 0, 1);
+                        err = do_md_stop(mddev, 0, bdev);
                         goto done_unlock;
 
                 case STOP_ARRAY_RO:
-                        err = md_set_readonly(mddev, 1);
+                        err = md_set_readonly(mddev, bdev);
                         goto done_unlock;
 
                 case BLKROSET:
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 240ff3125040..cacd008d6864 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1818,8 +1818,14 @@ static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
 
         if (atomic_dec_and_test(&r1_bio->remaining)) {
                 /* if we're here, all write(s) have completed, so clean up */
-                md_done_sync(mddev, r1_bio->sectors, 1);
-                put_buf(r1_bio);
+                int s = r1_bio->sectors;
+                if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
+                    test_bit(R1BIO_WriteError, &r1_bio->state))
+                        reschedule_retry(r1_bio);
+                else {
+                        put_buf(r1_bio);
+                        md_done_sync(mddev, s, 1);
+                }
         }
 }