linux-toradex.git/drivers/block/loop.c, branch v2.6.27.21

block: make queue flags non-atomic

2008-04-29T12:48:33+00:00

We can save some atomic ops in the IO path, if we clearly define
the rules of how to modify the queue flags.

Signed-off-by: Jens Axboe

loop: manage partitions in disk image

2008-04-21T07:50:08+00:00

This patch allows to use loop device with partitionned disk image.

Original behavior of loop is not modified.

A new parameter is introduced to define how many partition we want to be
able to manage per loop device. This parameter is "max_part".

For instance, to manage 63 partitions / loop device, we will do:
# modprobe loop max_part=63
# ls -l /dev/loop?*
brw-rw---- 1 root disk 7,   0 2008-03-05 14:55 /dev/loop0
brw-rw---- 1 root disk 7,  64 2008-03-05 14:55 /dev/loop1
brw-rw---- 1 root disk 7, 128 2008-03-05 14:55 /dev/loop2
brw-rw---- 1 root disk 7, 192 2008-03-05 14:55 /dev/loop3
brw-rw---- 1 root disk 7, 256 2008-03-05 14:55 /dev/loop4
brw-rw---- 1 root disk 7, 320 2008-03-05 14:55 /dev/loop5
brw-rw---- 1 root disk 7, 384 2008-03-05 14:55 /dev/loop6
brw-rw---- 1 root disk 7, 448 2008-03-05 14:55 /dev/loop7

And to attach a raw partitionned disk image, the original losetup is used:

# losetup -f etch.img
# ls -l /dev/loop?*
brw-rw---- 1 root disk 7,   0 2008-03-05 14:55 /dev/loop0
brw-rw---- 1 root disk 7,   1 2008-03-05 14:57 /dev/loop0p1
brw-rw---- 1 root disk 7,   2 2008-03-05 14:57 /dev/loop0p2
brw-rw---- 1 root disk 7,   5 2008-03-05 14:57 /dev/loop0p5
brw-rw---- 1 root disk 7,  64 2008-03-05 14:55 /dev/loop1
brw-rw---- 1 root disk 7, 128 2008-03-05 14:55 /dev/loop2
brw-rw---- 1 root disk 7, 192 2008-03-05 14:55 /dev/loop3
brw-rw---- 1 root disk 7, 256 2008-03-05 14:55 /dev/loop4
brw-rw---- 1 root disk 7, 320 2008-03-05 14:55 /dev/loop5
brw-rw---- 1 root disk 7, 384 2008-03-05 14:55 /dev/loop6
brw-rw---- 1 root disk 7, 448 2008-03-05 14:55 /dev/loop7
# mount /dev/loop0p1 /mnt
# ls /mnt
bench  cdrom  home        lib         mnt   root     srv  usr
bin    dev    initrd      lost+found  opt   sbin     sys  var
boot   etc    initrd.img  media       proc  selinux  tmp  vmlinuz
# umount /mnt
# losetup -d /dev/loop0

Of course, the same behavior can be done using kpartx on a loop device,
but modifying loop avoids to stack several layers of block device (loop +
device mapper), this is a very light modification (40% of modifications
are to manage the new parameter).

Signed-off-by: Laurent Vivier 
Signed-off-by: Jens Axboe

Allow auto-destruction of loop devices

2008-02-06T18:41:01+00:00

This allows a flag to be set on loop devices so that when they are
closed for the last time, they'll self-destruct.

In general, so that we can automatically allocate loop devices (as with
losetup -f) and have them disappear when we're done with them.

In particular, right now, so that we can stop relying on the hackish
special-case in umount(8) which kills off loop devices which were set up by
'mount -oloop'.  That means we can stop putting crap in /etc/mtab which
doesn't belong there, which means it can be a symlink to /proc/mounts, which
means yet another writable file on the root filesystem is eliminated and the
'stateless' folks get happier...  and OLPC trac #356 can be closed.

The mount(8) side of that is at
http://marc.info/?l=util-linux-ng&m=119362955431694&w=2

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: David Woodhouse 
Cc: Bernardo Innocenti 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

loop: fix bad bio_alloc() nr_iovec request

2008-01-11T09:14:40+00:00

Don't allocate room for an iovec when it is not needed.

Signed-off-by: Jens Axboe

Convert files to UTF-8 and some cleanups

2007-10-19T21:21:04+00:00

* Convert files to UTF-8.

  * Also correct some people's names
    (one example is Eißfeldt, which was found in a source file.
    Given that the author used an ß at all in a source file
    indicates that the real name has in fact a 'ß' and not an 'ss',
    which is commonly used as a substitute for 'ß' when limited to
    7bit.)

  * Correct town names (Goettingen -> Göttingen)

  * Update Eberhard Mönkeberg's address (http://lkml.org/lkml/2007/1/8/313)

Signed-off-by: Jan Engelhardt 
Signed-off-by: Adrian Bunk

Remove unneeded lock_kernel() in driver/block/loop.c

2007-10-17T15:42:48+00:00

Signed-off-by: Diego Woitasen 
Cc: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

deny partial write for loop dev fd

2007-10-16T16:42:55+00:00

Partial write can be easily supported by LO_CRYPT_NONE mode, but it is not
easy in LO_CRYPT_CRYPTOAPI case, because of its block nature.  I don't know
who still used cryptoapi, but theoretically it is possible.  So let's leave
things as they are.  Loop device doesn't support partial write before
Nick's "write_begin/write_end" patch set, and let's it behave the same way
after.

Signed-off-by: Dmitriy Monakhov 
Cc: Nick Piggin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs: introduce write_begin, write_end, and perform_write aops

2007-10-16T16:42:55+00:00

These are intended to replace prepare_write and commit_write with more
flexible alternatives that are also able to avoid the buffered write
deadlock problems efficiently (which prepare_write is unable to do).

[mark.fasheh@oracle.com: API design contributions, code review and fixes]
[akpm@linux-foundation.org: various fixes]
[dmonakhov@sw.ru: new aop block_write_begin fix]
Signed-off-by: Nick Piggin 
Signed-off-by: Mark Fasheh 
Signed-off-by: Dmitriy Monakhov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Drop 'size' argument from bio_endio and bi_end_io

2007-10-10T07:25:57+00:00

As bi_end_io is only called once when the reqeust is complete,
the 'size' argument is now redundant.  Remove it.

Now there is no need for bio_endio to subtract the size completed
from bi_size.  So don't do that either.

While we are at it, change bi_end_io to return void.

Signed-off-by: Neil Brown 
Signed-off-by: Jens Axboe

[BLOCK] Get rid of request_queue_t typedef

2007-07-24T07:28:11+00:00

Some of the code has been gradually transitioned to using the proper
struct request_queue, but there's lots left. So do a full sweet of
the kernel and get rid of this typedef and replace its uses with
the proper type.

Signed-off-by: Jens Axboe