The kprobes code is already able to cope with reentrant probes, so its
handler must be called outside of the region protected by undef_lock.

If ever this lock is released when handlers are called then this commit
could be reverted.
Signed-off-by: Nicolas Pitre <nico@marvell.com>

Signed-off-by: Nicolas Pitre <nico@marvell.com>

If kprobes installs a breakpoint on a "stmdb sp!, {...}" instruction,
and then single-step it by simulation from the exception context, it will
corrupt the saved regs on the stack from the previous context.

To avoid this, let's add an optional parameter to the svc_entry macro
allowing for a hole to be created on the stack before saving the
interrupted context, and use it in the undef_svc handler when kprobes
is enabled.
Signed-off-by: Nicolas Pitre <nico@marvell.com>

Signed-off-by: Nicolas Pitre <nico@marvell.com>

This is a full implementation of Kprobes including Jprobes and
Kretprobes support.

This ARM implementation does not follow the usual kprobes double-
exception model. The traditional model is where the initial kprobes
breakpoint calls kprobe_handler(), which returns from exception to
execute the instruction in its original context, then immediately
re-enters after a second breakpoint (or single-stepping exception)
into post_kprobe_handler(), each time the probe is hit..  The ARM
implementation only executes one kprobes exception per hit, so no
post_kprobe_handler() phase. All side-effects from the kprobe'd
instruction are resolved before returning from the initial exception.
As a result, all instructions are _always_ effectively boosted
regardless of the type of instruction, and even regardless of whether
or not there is a post-handler for the probe.
Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
Signed-off-by: Quentin Barnes <qbarnes@gmail.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>

This is the code implementing instruction single-stepping for kprobes
on ARM.

To get around the limitation of no Next-PC and no hardware single-
stepping, all kprobe'd instructions are split into three camps:
simulation, emulation, and rejected. "Simulated" instructions are
those instructions which behavior is reproduced by straight C code.
"Emulated" instructions are ones that are copied, slightly altered
and executed directly in the instruction slot to reproduce their
behavior.  "Rejected" instructions are ones that could be simulated,
but work hasn't been put into simulating them. These instructions
should be very rare, if not unencountered, in the kernel. If ever
needed, code could be added to simulate them.

One might wonder why this and the ptrace singlestep facility are not
sharing some code.  Both approaches are fundamentally different because
the ptrace code regains control after the stepped instruction by installing
a breakpoint after the instruction itself, and possibly at the location
where the instruction might be branching to, instead of simulating or
emulating the target instruction.

The ptrace approach isn't suitable for kprobes because the breakpoints
would have to be moved back, and the icache flushed, everytime the
probe is hit to let normal code execution resume, which would have a
significant performance impact. It is also racy on SMP since another
CPU could, with the right timing, sail through the probe point without
being caught.  Because ptrace single-stepping always result in a
different process to be scheduled, the concern for performance is much
less significant.

On the other hand, the kprobes approach isn't (currently) suitable for
ptrace because it has no provision for proper user space memory
protection and translation, and even if that was implemented, the gain
wouldn't be worth the added complexity in the ptrace path compared to
the current approach.

So, until kprobes does support user space, both kprobes and ptrace are
best kept independent and separate.
Signed-off-by: Quentin Barnes <qbarnes@gmail.com>
Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (200 commits)
  [SCSI] usbstorage: use last_sector_bug flag universally
  [SCSI] libsas: abstract STP task status into a function
  [SCSI] ultrastor: clean up inline asm warnings
  [SCSI] aic7xxx: fix firmware build
  [SCSI] aacraid: fib context lock for management ioctls
  [SCSI] ch: remove forward declarations
  [SCSI] ch: fix device minor number management bug
  [SCSI] ch: handle class_device_create failure properly
  [SCSI] NCR5380: fix section mismatch
  [SCSI] sg: fix /proc/scsi/sg/devices when no SCSI devices
  [SCSI] IB/iSER: add logical unit reset support
  [SCSI] don't use __GFP_DMA for sense buffers if not required
  [SCSI] use dynamically allocated sense buffer
  [SCSI] scsi.h: add macro for enclosure bit of inquiry data
  [SCSI] sd: add fix for devices with last sector access problems
  [SCSI] fix pcmcia compile problem
  [SCSI] aacraid: add Voodoo Lite class of cards.
  [SCSI] aacraid: add new driver features flags
  [SCSI] qla2xxx: Update version number to 8.02.00-k7.
  [SCSI] qla2xxx: Issue correct MBC_INITIALIZE_FIRMWARE command.
  ...

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  [CRYPTO] hifn795x: Disallow built-in hifn795x when HW_RANDOM is m

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2: (31 commits)
  ocfs2: clean up bh null checks
  ocfs2: document access rules for blocked_lock_list
  configfs: file.c fix possible recursive locking
  configfs: dir.c fix possible recursive locking
  configfs: Remove EXPERIMENTAL
  ocfs2: bump version number
  ocfs2/dlm: Clear joining_node on hearbeat node down
  ocfs2: convert byte order of constant instead of variable
  ocfs2: Update default cluster timeouts
  ocfs2: printf fixes
  ocfs2: Use generic_file_llseek
  ocfs2: Safer read_inline_data()
  ocfs2: Silence false lockdep warnings
  [PATCH 2/2] ocfs2: cluster aware flock()
  [PATCH 1/2] ocfs2: add flock lock type
  ocfs2: Local alloc window size changeable via mount option
  ocfs2: Support commit= mount option
  ocfs2: Add missing permission checks
  [PATCH 2/2] ocfs2: Implement group add for online resize
  [PATCH 1/2] ocfs2: Add group extend for online resize
  ...

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev: (67 commits)
  fix drivers/ata/sata_fsl.c double-decl
  [libata] Prefer SCSI_SENSE_BUFFERSIZE to sizeof()
  pata_legacy: Merge winbond support
  ata_generic: Cenatek support
  pata_winbond: error return
  pata_serverworks: Fix cable types and cosmetics
  pata_mpc52xx: remove un-needed assignment
  libata: fix off-by-one in error categorization
  ahci: factor out AHCI enabling and enable AHCI before reading CAP
  ata_piix: implement SIDPR SCR access
  ata_piix: convert to prepare - activate initialization
  libata: factor out ata_pci_activate_sff_host() from ata_pci_one()
  [libata] Prefer SCSI_SENSE_BUFFERSIZE to sizeof()
  pata_legacy: resychronize with upstream changes and resubmit
  [libata] pata_legacy: typo fix
  [libata] pata_winbond: update for new ->data_xfer hook
  pata_pcmcia: convert to new data_xfer prototype
  libata annotations and fixes
  libata: use dev_driver_string() instead of "libata" in libata-sff.c
  ata_piix: kill unused constants and flags
  ...

If we know a buffer_head is non-null, then brelse() is unnecessary and
put_bh() can be used instead. Also, an explicit check for NULL is
unnecessary when using brelse(). This patch only covers buffer_head_io.c and
resize.c, which have recently added code which exhibits this problem.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

ocfs2_super->blocked_lock_list and ocfs2_super->blocked_lock_count have some
usage restrictions which aren't immediately obvious to anyone reading the
code. It's a good idea to document this so that we avoid making costly
mistakes in the future.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

configfs_register_subsystem() with default_groups triggers recursive locking.
it seems that mutex_lock_nested is needed.

=============================================
[ INFO: possible recursive locking detected ]
2.6.24-rc6 #145
---------------------------------------------
swapper/1 is trying to acquire lock:
 (&sb->s_type->i_mutex_key#3){--..}, at: [<c40c9a9e>] configfs_add_file+0x2e/0x70

but task is already holding lock:
 (&sb->s_type->i_mutex_key#3){--..}, at: [<c40ca985>] configfs_register_subsystem+0x55/0x130

other info that might help us debug this:
1 lock held by swapper/1:
 #0:  (&sb->s_type->i_mutex_key#3){--..}, at: [<c40ca985>] configfs_register_subsystem+0x55/0x130

stack backtrace:
Pid: 1, comm: swapper Not tainted 2.6.24-rc6 #145
 [<c40053ba>] show_trace_log_lvl+0x1a/0x30
 [<c4005e82>] show_trace+0x12/0x20
 [<c400687e>] dump_stack+0x6e/0x80
 [<c404ec72>] __lock_acquire+0xe62/0x1120
 [<c404efb2>] lock_acquire+0x82/0xa0
 [<c43fda88>] mutex_lock_nested+0x98/0x2e0
 [<c40c9a9e>] configfs_add_file+0x2e/0x70
 [<c40c9b0c>] configfs_create_file+0x2c/0x40
 [<c40ca639>] configfs_attach_item+0x139/0x220
 [<c40ca734>] configfs_attach_group+0x14/0x140
 [<c40ca7e9>] configfs_attach_group+0xc9/0x140
 [<c40ca9f6>] configfs_register_subsystem+0xc6/0x130
 [<c45c8186>] init_netconsole+0x2b6/0x300
 [<c45a75f2>] kernel_init+0x142/0x320
 [<c4004fb3>] kernel_thread_helper+0x7/0x14
 =======================
Signed-off-by: Joonwoo Park <joonwpark81@gmail.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

configfs_register_subsystem() with default_groups triggers recursive locking.
it seems that mutex_lock_nested is needed.

=============================================
[ INFO: possible recursive locking detected ]
2.6.24-rc6 #141
---------------------------------------------
swapper/1 is trying to acquire lock:
 (&sb->s_type->i_mutex_key#3){--..}, at: [<c40ca76f>] configfs_attach_group+0x4f/0x190

but task is already holding lock:
 (&sb->s_type->i_mutex_key#3){--..}, at: [<c40ca9d5>] configfs_register_subsystem+0x55/0x130

other info that might help us debug this:
1 lock held by swapper/1:
 #0:  (&sb->s_type->i_mutex_key#3){--..}, at: [<c40ca9d5>] configfs_register_subsystem+0x55/0x130

stack backtrace:
Pid: 1, comm: swapper Not tainted 2.6.24-rc6 #141
 [<c40053ba>] show_trace_log_lvl+0x1a/0x30
 [<c4005e82>] show_trace+0x12/0x20
 [<c400687e>] dump_stack+0x6e/0x80
 [<c404ec72>] __lock_acquire+0xe62/0x1120
 [<c404efb2>] lock_acquire+0x82/0xa0
 [<c43fdad8>] mutex_lock_nested+0x98/0x2e0
 [<c40ca76f>] configfs_attach_group+0x4f/0x190
 [<c40caa46>] configfs_register_subsystem+0xc6/0x130
 [<c45c8186>] init_netconsole+0x2b6/0x300
 [<c45a75f2>] kernel_init+0x142/0x320
 [<c4004fb3>] kernel_thread_helper+0x7/0x14
 =======================
Signed-off-by: Joonwoo Park <joonwpark81@gmail.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

configfs has been alive and kicking for a while now.  It underpins some
non-EXPERIMENTAL subsystems, such as OCFS2's cluster stack.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

Bump the printed version to 1.5.0. This helps us quickly identify which
version of Ocfs2 a bug filer is running.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

Currently the process of dlm join contains 2 steps: query join and assert join.
After query join, the joined node will set its joining_node. So if the joining
node happens to panic before the 2nd step, the joined node will fail to clear
its joining_node flag because that node isn't in the domain map. It at least
cause 2 problems.
1. All the new join request will fail. So no new node can mount the volume.
2. The joined node can't umount the volume since during the umount process it
   has to wait for the joining_node to be unknown. So the umount will be hanged.

The solution is to clear the joining_node before we check the domain map.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

Convert byte order of constant instead of variable it will be done at
compile time vs run time. Remove unused le32_and_cpu.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

Lots of people are having trouble with the default timeouts, which are too
low. These new values are derived from an informal survey taken on
ocfs2-users, as well as data from bug reports. This should reduce the amount
of cluster disconnects and subsequent fencing seen during normal workloads.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

Explicitely convert loff_t to long long in printf. Just for sure...
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

We should use generic_file_llseek() and not default_llseek() so that
s_maxbytes gets properly checked when seeking.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

In ocfs2_read_inline_data() we should store file size in loff_t. Although
the file size should fit in 32 bits we cannot be sure in case filesystem is
corrupted.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

Create separate lockdep lock classes for system file's i_mutexes. They are
used to guard allocations and similar things and thus rank differently
than i_mutex of a regular file or directory.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

Hook up ocfs2_flock(), using the new flock lock type in dlmglue.c. A new
mount option, "localflocks" is added so that users can revert to old
functionality as need be.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

This adds a new dlmglue lock type which is intended to back flock()
requests.

Since these locks are driven from userspace, usage rules are much more
liberal than the typical Ocfs2 internal cluster lock. As a result, we can't
make use of most dlmglue features - lock caching and lock level
optimizations in particular. Additionally, userspace is free to deadlock
itself, so we have to deal with that in the same way as the rest of the
kernel - by allowing a signal to abort a lock request.

In order to keep ocfs2_cluster_lock() complexity down, ocfs2_file_lock()
does it's own dlm coordination. We still use the same helper functions
though, so duplicated code is kept to a minimum.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

Local alloc is a performance optimization in ocfs2 in which a node
takes a window of bits from the global bitmap and then uses that for
all small local allocations. This window size is fixed to 8MB currently.
This patch allows users to specify the window size in MB including
disabling it by passing in 0. If the number specified is too large,
the fs will use the default value of 8MB.

mount -o localalloc=X /dev/sdX /mntpoint
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

Mostly taken from ext3. This allows the user to set the jbd commit interval,
in seconds. The default of 5 seconds stays the same, but now users can
easily increase the commit interval. Typically, this would be increased in
order to benefit performance at the expense of data-safety.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

Check that an online resize is being driven by a user with permission to
change system resource limits.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

This patch adds the ability for a userspace program to request that a
properly formatted cluster group be added to the main allocation bitmap for
an Ocfs2 file system. The request is made via an ioctl, OCFS2_IOC_GROUP_ADD.
On a high level, this is similar to ext3, but we use a different ioctl as
the structure which has to be passed through is different.

During an online resize, tunefs.ocfs2 will format any new cluster groups
which must be added to complete the resize, and call OCFS2_IOC_GROUP_ADD on
each one. Kernel verifies that the core cluster group information is valid
and then does the work of linking it into the global allocation bitmap.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

This patch adds the ability for a userspace program to request an extend of
last cluster group on an Ocfs2 file system. The request is made via ioctl,
OCFS2_IOC_GROUP_EXTEND. This is derived from EXT3_IOC_GROUP_EXTEND, but is
obviously Ocfs2 specific.

tunefs.ocfs2 would call this for an online-resize operation if the last
cluster group isn't full.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

This patch sets the last_sector_bug flag to 1 for all USB disks. This is
needed to makes the cardreader on various HP multifunction printers work.

Since the performance impact is negible we set this flag for all USB disks to
avoid an unusual_devs.h nightmare.
Signed-off-by: Hans de Goede <j.w.r.degoede@hhs.nl>
Acked-by: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

We need to reserve at least two ioctls for online-resize. Reserve a small
range of ioctls for Ocfs2 use in Documentation/ioctl-number.txt. This should
give us enough room for future growth.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

This value is initialized from global_bitmap->id2.i_chain.cl_cpg. If there
is only 1 group, it will be equal to the total clusters in the volume. So
as for online resize, it should change for all the nodes in the cluster.
It isn't easy and there is no corresponding lock for it.

bitmap_cpg is only used in 2 areas:
1. Check whether the suballoc is too large for us to allocate from the global
   bitmap, so it is little used. And now the suballoc size is 2048, it rarely
   meet this situation and the check is almost useless.
2. Calculate which group a cluster belongs to. We use it during truncate to
   figure out which cluster group an extent belongs too. But we should be OK
   if we increase it though as the cluster group calculated shouldn't change
   and we only ever have a small bitmap_cpg on file systems with a single
   cluster group.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

Currently it is possible to select HW_RANDOM as a module and have
hifn795x built-in.  This causes a build problem because hifn795x
will then call hwrng_register which isn't built-in.

This patch introduces a new config option to control the hifn795x
RNG which lets us avoid this problem.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Remove 'readpages' from the list in ocfs2.txt. Instead of having two
identical lists, I just removed the list in the OCFS2 section of fs/Kconfig
and added a pointer to Documentation/filesystems/ocfs2.txt.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

Add ->readpages support to Ocfs2. This is rather trivial - all it required
is a small update to ocfs2_get_block (for mapping full extents via b_size)
and an ocfs2_readpages() function which partially mirrors ocfs2_readpage().
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

This allows others to use the DLM constants without being tied to the
function API of fs/dlm.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

Call this the "inode_lock" now, since it covers both data and meta data.
This patch makes no functional changes.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

The meta lock now covers both meta data and data, so this just removes the
now-redundant data lock.

Combining locks saves us a round of lock mastery per inode and one less lock
to ping between nodes during read/write.

We don't lose much - since meta locks were always held before a data lock
(and at the same level) ordered writeout mode (the default) ensured that
flushing for the meta data lock also pushed out data anyways.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

In order to extend inode lock coverage to inode data, we use the same data
downconvert worker with only a small modification to only do work for
regular files.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>