[RESEND][PATCH] ima: Set and clear FMODE_CAN_READ in ima_calc_file_hash()

[Christoph Hellwig]

On Mon, Nov 16, 2020 at 08:52:19AM +0000, Roberto Sassu wrote:
> FMODE_CAN_READ was not set because f_mode does not have
> FMODE_READ. In the patch, I check if the former can be set
> similarly to the way it is done in file_table.c and open.c.
> 
> Is there a better way to read a file when the file was not opened
> for reading and a new file descriptor cannot be created?

You can't open a file not open for reading.  The file system or device
driver might have to prepare read-specific resources in ->open to
support reads.  So what you'll have to do is to open a new instance
of the file that is open for reading.