[PATCH] direct-io: don't introduce another read of inode->i_blkbits

[Jens Axboe]

On 01/09/2017 10:27 PM, Chandan Rajendra wrote:
> On Monday, January 09, 2017 04:42:58 PM Jeff Moyer wrote:
>> Commit 20ce44d545844 ("do_direct_IO: Use inode->i_blkbits to compute
>> block count to be cleaned") introduced a regression: if the block size
>> of the block device is changed while a direct I/O request is being
>> setup, it can result in a panic.  See commit ab73857e354ab ("direct-io:
>> don't read inode->i_blkbits multiple times") for the reasoning, and
>> commit b87570f5d3496 ("Fix a crash when block device is read and block
>> size is changed at the same time") for a more detailed problem
>> description and reproducer.
>>
>> Fixes: 20ce44d545844
>> Signed-off-by: Jeff Moyer <jmoyer at redhat.com>
>>
>> ---
>> Chandan, can you please test this to ensure this still fixes your problem?
> 
> This patch fixes the failure,
> 
> Tested-by: Chandan Rajendra <chandan at linux.vnet.ibm.com>
> 

I've updated the patch, thanks guys.

-- 
Jens Axboe