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Subject: Re: [PATCH v3 12/13] ext4: switch to the new mount api
From:   Jon Hunter <jonathanh@nvidia.com>
To:     Lukas Czerner <lczerner@redhat.com>
Cc:     linux-ext4@vger.kernel.org, tytso@mit.edu,
        linux-fsdevel@vger.kernel.org,
        "linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>
References: <20211021114508.21407-1-lczerner@redhat.com>
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 <286d36c9-e9ab-b896-e23c-2a95c6385817@nvidia.com>
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Date:   Fri, 14 Jan 2022 09:40:19 +0000
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On 13/01/2022 16:10, Jon Hunter wrote:

...

> OK, I see what is happening. It appears that our test harness always 
> tries to mount a device called /dev/mmcblk1. Prior to this change there 
> was not kernel error generated and looking at the logs I would see ...
> 
> mount: /mnt: special device /dev/mmcblk1 does not exist.
> 
> Following this change, now a kernel warning is generated and I see ...
> 
> [  137.078994] /dev/mmcblk1: Can't open blockdev
> mount: /mnt: special device /dev/mmcblk1 does not exist.
> 
> So there is a change in behaviour but at the same time the error looks 
> correct. So sorry for the false-positive.


Looking some more, previously, mount_bdev was being called and this has ...

         bdev = blkdev_get_by_path(dev_name, mode, fs_type);
         if (IS_ERR(bdev))
                 return ERR_CAST(bdev);

And now we are calling get_tree_bdev() and this has ...

         bdev = blkdev_get_by_path(fc->source, mode, fc->fs_type);
         if (IS_ERR(bdev)) {
                 errorf(fc, "%s: Can't open blockdev", fc->source);
                 return PTR_ERR(bdev);
         }

Hence, the difference. I was interested to know what had changed.

Cheers
Jon

-- 
nvpublic