Btrfs: Avoid superfluous tree-log writeout

[firefly-linux-kernel-4.4.55.git] / fs / block_dev.c

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 8bed0557d88c17ac9600a179f8127d855e509bab..e65efa2f267a89f04cd69262eb0cef53e4646253 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -246,7 +246,8 @@ struct super_block *freeze_bdev(struct block_device *bdev)
        if (!sb)
                goto out;
        if (sb->s_flags & MS_RDONLY) {
-               deactivate_locked_super(sb);
+               sb->s_frozen = SB_FREEZE_TRANS;
+               up_write(&sb->s_umount);
                mutex_unlock(&bdev->bd_fsfreeze_mutex);
                return sb;
        }
@@ -307,7 +308,7 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb)
        BUG_ON(sb->s_bdev != bdev);
        down_write(&sb->s_umount);
        if (sb->s_flags & MS_RDONLY)
-               goto out_deactivate;
+               goto out_unfrozen;
 
        if (sb->s_op->unfreeze_fs) {
                error = sb->s_op->unfreeze_fs(sb);
@@ -321,11 +322,11 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb)
                }
        }
 
+out_unfrozen:
        sb->s_frozen = SB_UNFROZEN;
        smp_wmb();
        wake_up(&sb->s_wait_unfrozen);
 
-out_deactivate:
        if (sb)
                deactivate_locked_super(sb);
 out_unlock:
@@ -403,7 +404,7 @@ static loff_t block_llseek(struct file *file, loff_t offset, int origin)
  *     NULL first argument is nfsd_sync_dir() and that's not a directory.
  */
  
-static int block_fsync(struct file *filp, struct dentry *dentry, int datasync)
+int block_fsync(struct file *filp, struct dentry *dentry, int datasync)
 {
        return sync_blockdev(I_BDEV(filp->f_mapping->host));
 }
@@ -422,6 +423,7 @@ static struct inode *bdev_alloc_inode(struct super_block *sb)
                return NULL;
        return &ei->vfs_inode;
 }
+EXPORT_SYMBOL(block_fsync);
 
 static void bdev_destroy_inode(struct inode *inode)
 {
@@ -1173,10 +1175,12 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
        /*
         * hooks: /n/, see "layering violations".
         */
-       ret = devcgroup_inode_permission(bdev->bd_inode, perm);
-       if (ret != 0) {
-               bdput(bdev);
-               return ret;
+       if (!for_part) {
+               ret = devcgroup_inode_permission(bdev->bd_inode, perm);
+               if (ret != 0) {
+                       bdput(bdev);
+                       return ret;
+               }
        }
 
        lock_kernel();