[Bug 219652] READ CAPACITY(16) not used on large USB-attached drive in recent kernels

[bugzilla-daemon@kernel.org]

https://bugzilla.kernel.org/show_bug.cgi?id=219652

--- Comment #7 from Alan Stern (stern@rowland.harvard.edu) ---
The two kernels perform identical USB initializations, and the two SCSI
initializations also start out identically: INQUIRY, TEST UNIT READY, and READ
CAPACITY(10).  Under both kernels, the response to the READ CAPACITY(10) is
0xffffffff blocks with blocksize 0x00000200, no errors.

At that point the bad kernel repeats the READ CAPACITY(10) command, issuing it
a total of 4 times before stopping (the fourth time, the returned value says
0xfffffffe blocks instead of 0xffffffff -- I'm not sure if the device does this
or if usb-storage changes the value in flight, but it doesn't really matter
because the error has already occurred).

By contrast, at that point the good kernel issues READ CAPACITY(16), receiving
a response of 0x15d50a3ae blocks of size 0x00000200, the correct values.

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