Skip to content

L
linux
Switch branch/tag
  1. 09 Jun, 2009 1 commit
    • Tejun Heo's avatar
      CUSE: implement CUSE - Character device in Userspace · 151060ac
      Tejun Heo authored 
      CUSE enables implementing character devices in userspace.  With recent
additions of ioctl and poll support, FUSE already has most of what's
necessary to implement character devices.  All CUSE has to do is
bonding all those components - FUSE, chardev and the driver model -
nicely.

When client opens /dev/cuse, kernel starts conversation with
CUSE_INIT.  The client tells CUSE which device it wants to create.  As
the previous patch made fuse_file usable without associated
fuse_inode, CUSE doesn't create super block or inodes.  It attaches
fuse_file to cdev file->private_data during open and set ff->fi to
NULL.  The rest of the operation is almost identical to FUSE direct IO
case.

Each CUSE device has a corresponding directory /sys/class/cuse/DEVNAME
(which is symlink to /sys/devices/virtual/class/DEVNAME if
SYSFS_DEPRECATED is turned off) which hosts "waiting" and "abort"
among other things.  Those two files have the same meaning as the FUSE
control files.

The only notable lacking feature compared to in-kernel implementation
is mmap support.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
      151060ac
  3. 28 Apr, 2009 14 commits
  5. 22 Apr, 2009 5 commits
    • Linus Torvalds's avatar
      Linux 2.6.30-rc3 · 09106974
      Linus Torvalds authored
      09106974
    • Arjan van de Ven's avatar
      driver synchronization: make scsi_wait_scan more advanced · d4d5291c
      Arjan van de Ven authored 
      There is currently only one way for userspace to say "wait for my storage
device to get ready for the modules I just loaded": to load the
scsi_wait_scan module. Expectations of userspace are that once this
module is loaded, all the (storage) devices for which the drivers
were loaded before the module load are present.

Now, there are some issues with the implementation, and the async
stuff got caught in the middle of this: The existing code only
waits for the scsy async probing to finish, but it did not take
into account at all that probing might not have begun yet.
(Russell ran into this problem on his computer and the fix works for him)

This patch fixes this more thoroughly than the previous "fix", which
had some bad side effects (namely, for kernel code that wanted to wait for
the scsi scan it would also do an async sync, which would deadlock if you did
it from async context already.. there's a report about that on lkml):
The patch makes the module first wait for all device driver probes, and then it
will wait for the scsi parallel scan to finish.
Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Tested-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d4d5291c
    • Jonathan Corbet's avatar
      Trivial: fix a typo in slow-work.h · 5dd559f0
      Jonathan Corbet authored 
      Fix a comment typo in slow-work.h

...a trivial mistake, but it will mess up kerneldoc if nothing else.
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5dd559f0
    • David Howells's avatar
      PERCPU: Collect the DECLARE/DEFINE declarations together · 5028eaa9
      David Howells authored 
      Collect the DECLARE/DEFINE declarations together in linux/percpu-defs.h so
that they're in one place, and give them descriptive comments, particularly
the SHARED_ALIGNED variant.

It would be nice to collect these in linux/percpu.h, but that's not possible
without sorting out the severe #include recursion between the x86 arch headers
and the general headers (and possibly other arches too).
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5028eaa9
    • David Howells's avatar
      FRV: Fix the section attribute on UP DECLARE_PER_CPU() · 9b8de747
      David Howells authored 
      In non-SMP mode, the variable section attribute specified by DECLARE_PER_CPU()
does not agree with that specified by DEFINE_PER_CPU().  This means that
architectures that have a small data section references relative to a base
register may throw up linkage errors due to too great a displacement between
where the base register points and the per-CPU variable.

On FRV, the .h declaration says that the variable is in the .sdata section, but
the .c definition says it's actually in the .data section.  The linker throws
up the following errors:

kernel/built-in.o: In function `release_task':
kernel/exit.c:78: relocation truncated to fit: R_FRV_GPREL12 against symbol `per_cpu__process_counts' defined in .data section in kernel/built-in.o
kernel/exit.c:78: relocation truncated to fit: R_FRV_GPREL12 against symbol `per_cpu__process_counts' defined in .data section in kernel/built-in.o

To fix this, DECLARE_PER_CPU() should simply apply the same section attribute
as does DEFINE_PER_CPU().  However, this is made slightly more complex by
virtue of the fact that there are several variants on DEFINE, so these need to
be matched by variants on DECLARE.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9b8de747
  7. 21 Apr, 2009 20 commits
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7