X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=fs%2Fblock_dev.c;h=257b00e9842808721780d1af1c09aa2f35558d35;hb=6feb9891da4f8b04ffca69c00eb56bb7c1b64dc4;hp=889287019599a861d90a51d6808cfb2d032fc255;hpb=016aa2ed1cc9cf704cf76d8df07751b6daa9750f;p=cascardo%2Flinux.git

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 889287019599..257b00e98428 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -55,11 +55,13 @@ EXPORT_SYMBOL(I_BDEV);
 static void bdev_inode_switch_bdi(struct inode *inode,
 			struct backing_dev_info *dst)
 {
-	spin_lock(&inode_lock);
+	spin_lock(&inode_wb_list_lock);
+	spin_lock(&inode->i_lock);
 	inode->i_data.backing_dev_info = dst;
 	if (inode->i_state & I_DIRTY)
 		list_move(&inode->i_wb_list, &dst->wb.b_dirty);
-	spin_unlock(&inode_lock);
+	spin_unlock(&inode->i_lock);
+	spin_unlock(&inode_wb_list_lock);
 }
 
 static sector_t max_block(struct block_device *bdev)
@@ -651,7 +653,7 @@ void bd_forget(struct inode *inode)
  * @whole: whole block device containing @bdev, may equal @bdev
  * @holder: holder trying to claim @bdev
  *
- * Test whther @bdev can be claimed by @holder.
+ * Test whether @bdev can be claimed by @holder.
  *
  * CONTEXT:
  * spin_lock(&bdev_lock).
@@ -1087,6 +1089,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 	if (!disk)
 		goto out;
 
+	disk_block_events(disk);
 	mutex_lock_nested(&bdev->bd_mutex, for_part);
 	if (!bdev->bd_openers) {
 		bdev->bd_disk = disk;
@@ -1099,6 +1102,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 			if (!bdev->bd_part)
 				goto out_clear;
 
+			ret = 0;
 			if (disk->fops->open) {
 				ret = disk->fops->open(bdev, mode);
 				if (ret == -ERESTARTSYS) {
@@ -1108,15 +1112,25 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 					 */
 					disk_put_part(bdev->bd_part);
 					bdev->bd_part = NULL;
-					module_put(disk->fops->owner);
-					put_disk(disk);
 					bdev->bd_disk = NULL;
 					mutex_unlock(&bdev->bd_mutex);
+					disk_unblock_events(disk);
+					module_put(disk->fops->owner);
+					put_disk(disk);
 					goto restart;
 				}
-				if (ret)
-					goto out_clear;
 			}
+			/*
+			 * If the device is invalidated, rescan partition
+			 * if open succeeded or failed with -ENOMEDIUM.
+			 * The latter is necessary to prevent ghost
+			 * partitions on a removed medium.
+			 */
+			if (bdev->bd_invalidated && (!ret || ret == -ENOMEDIUM))
+				rescan_partitions(disk, bdev);
+			if (ret)
+				goto out_clear;
+
 			if (!bdev->bd_openers) {
 				bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
 				bdi = blk_get_backing_dev_info(bdev);
@@ -1124,8 +1138,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 					bdi = &default_backing_dev_info;
 				bdev_inode_switch_bdi(bdev->bd_inode, bdi);
 			}
-			if (bdev->bd_invalidated)
-				rescan_partitions(disk, bdev);
 		} else {
 			struct block_device *whole;
 			whole = bdget_disk(disk, 0);
@@ -1148,23 +1160,25 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 			bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
 		}
 	} else {
-		module_put(disk->fops->owner);
-		put_disk(disk);
-		disk = NULL;
 		if (bdev->bd_contains == bdev) {
-			if (bdev->bd_disk->fops->open) {
+			ret = 0;
+			if (bdev->bd_disk->fops->open)
 				ret = bdev->bd_disk->fops->open(bdev, mode);
-				if (ret)
-					goto out_unlock_bdev;
-			}
-			if (bdev->bd_invalidated)
+			/* the same as first opener case, read comment there */
+			if (bdev->bd_invalidated && (!ret || ret == -ENOMEDIUM))
 				rescan_partitions(bdev->bd_disk, bdev);
+			if (ret)
+				goto out_unlock_bdev;
 		}
+		/* only one opener holds refs to the module and disk */
+		module_put(disk->fops->owner);
+		put_disk(disk);
 	}
 	bdev->bd_openers++;
 	if (for_part)
 		bdev->bd_part_count++;
 	mutex_unlock(&bdev->bd_mutex);
+	disk_unblock_events(disk);
 	return 0;
 
  out_clear:
@@ -1177,10 +1191,10 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 	bdev->bd_contains = NULL;
  out_unlock_bdev:
 	mutex_unlock(&bdev->bd_mutex);
- out:
-	if (disk)
-		module_put(disk->fops->owner);
+	disk_unblock_events(disk);
+	module_put(disk->fops->owner);
 	put_disk(disk);
+ out:
 	bdput(bdev);
 
 	return ret;
@@ -1446,14 +1460,13 @@ int blkdev_put(struct block_device *bdev, fmode_t mode)
 		if (bdev_free) {
 			if (bdev->bd_write_holder) {
 				disk_unblock_events(bdev->bd_disk);
-				bdev->bd_write_holder = false;
-			} else
 				disk_check_events(bdev->bd_disk);
+				bdev->bd_write_holder = false;
+			}
 		}
 
 		mutex_unlock(&bdev->bd_mutex);
-	} else
-		disk_check_events(bdev->bd_disk);
+	}
 
 	return __blkdev_put(bdev, mode, 0);
 }
@@ -1527,7 +1540,6 @@ static int blkdev_releasepage(struct page *page, gfp_t wait)
 static const struct address_space_operations def_blk_aops = {
 	.readpage	= blkdev_readpage,
 	.writepage	= blkdev_writepage,
-	.sync_page	= block_sync_page,
 	.write_begin	= blkdev_write_begin,
 	.write_end	= blkdev_write_end,
 	.writepages	= generic_writepages,