In case reading of block 0 during open() fails, it is not the right thing
to let open() succeed.

Fix this by introducing FD_OPEN_SHOULD_FAIL_BIT flag, and setting it in
case the bio callback encounters an error while trying to read block 0.

As a bonus, this works around certain broken userspace (blkid), which is
not able to properly handle read()s returning IO errors. Hence be nice to
those, and bail out during open() already; if block 0 is not readable,
read()s are not going to provide any meaningful data anyway.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NMichael Kerrisk <mtk.manpages@gmail.com>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: NDave Jones <davej@redhat.com>

Fix headers_check error introduced by 390192b3:

include/linux/fd.h:6: included file 'linux/compat.h' is not exported
Signed-off-by: NJohannes Stezenbach <js@sig21.net>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

On Linux x86_64 host with 32bit userspace, running
qemu or even just "qemu-img create -f qcow2 some.img 1G"
causes a kernel warning:

ioctl32(qemu-img:5296): Unknown cmd fd(3) cmd(00005326){t:'S';sz:0} arg(7fffffff) on some.img
ioctl32(qemu-img:5296): Unknown cmd fd(3) cmd(801c0204){t:02;sz:28} arg(fff77350) on some.img

ioctl 00005326 is CDROM_DRIVE_STATUS,
ioctl 801c0204 is FDGETPRM.

The warning appears because the Linux compat-ioctl handler for these
ioctls only applies to block devices, while qemu also uses the ioctls on
plain files.
Signed-off-by: NJohannes Stezenbach <js@sig21.net>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

The current floppy_struct allows floppies to number sectors starting
from 0 or 1.  This patch allows arbitrary first-sector numbers - for
example, 0xC1 for Amstrad CPC disks.

This extends the existing 1-bit field (FD_ZEROBASED, bit 2 of stretch)
to 8 bits (FD_SECTMASK, bits 2 to 9).

Currently 0x00 denotes a first sector number of 1, and 0x01 denotes a
first sector number of 0.  We extend this by interpreting FD_SECTMASK
as the first sector number with the LSB flipped.
Signed-off-by: NKeith Wansbrough <keith@lochan.org>
Cc: Alain Knaff <alain@linux.lu>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Karel Zak <kzak@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!