This fixes kernel http://bugzilla.kernel.org/show_bug.cgi?id=11112 (bogus
RTC update IRQs reported) for rtc-at91rm9200 by scrubbing old IRQ status
before enabling IRQs.

It also removes nonfunctional periodic IRQ support from this driver;
only update IRQs are reported, or provided by the hardware.

I suspect some other RTCs probably have versions of #11112; it's easy to
overlook, since most non-RTC drivers don't care about spurious IRQs:
they're not reported to userspace.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Report-by: NW Unruh <unruh@physics.ubc.ca>
Cc: Andrew Victor <avictor.za@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The rtc-s3c.c driver has been using its own ioctl() handling to deal with
alarm and periodic interrupts to handle what should now be done with the
rtc core code.

Change to using the .irq_set_freq and .irq_set_state driver entries and
remove the .ioctl handling.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add the relevant __devinit and __devexit attributes to the rtc-s3c driver.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Resolve http://bugzilla.kernel.org/show_bug.cgi?id=11051 and other bugs
related to the way the HPET glue code in rtc-cmos was incomplete and
inconsistent:

 * Switch the approach so that the basic driver code flow isn't
   changed by having HPET ... instead, just have HPET shadow the
   RTC_CONTROL irq enables and RTC_FREQ_SELECT data.  It's only
   coping with IRQ thievery, after all.

 * Do that consistently (!!) to avoid problems when the HPET code
   is out of sync with the real RTC intent.  Examples include:

   - cmos_procfs(), which now reports correct data

   - cmos_irq_set_state() ... also removing the previous PIE_{ON,OFF}
     ioctl support so only one code path manages "periodic" IRQs

   - cmos_do_shutdown() ... currently a "just in case" change.

   - cmos_suspend() and cmos_resume() ... also handling a bug that
     was specific to HPET's IRQ thievery, where the alarm wasn't
     disabled after waking the system

 * Always call that HPET code under the RTC spinlock (it doesn't do
   its own locking)

Also clean up the HPET glue:

 * Add some comments explaining what's going on.

 * Switch to having just one #ifdef for the HPET glue, and inline
   functions (not #defines) to avoid some compiler warnings.

 * Have the probe message also report when HPET IRQs are involved

This still leaves various holes in the HPET glue, like the emulated update
IRQs being out of sync with the RTC, alarms never using day or month
matches, and many extra IRQs (at 64 Hz).

[akpm@linux-foundation.org: fix build]
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Tomas Janousek <tomi@nomi.cz>
Cc: Bernhard Walle <bwalle@suse.de>
Cc: Carlos R. Mafra <crmafra@ift.unesp.br>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When CONFIG_HPET_EMULATE_RTC is defined the external declaration of
hpet_rtc_interrupt is redundant due to the inclusion of hpet.h.

When !CONFIG_HPET_EMULATE_RTC we make it clear that hpet_rtc_interrupt is
not used by defining it to return zero.
Signed-off-by: NCarlos R. Mafra <crmafra@ift.unesp.br>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert the PCF8583 driver to the new I2C style framework with device_ids
Signed-off-by: NJuergen Beisert <j.beisert@pengutronix.de>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Acked-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Shrink the runtime footprint of the OMAP1 RTC driver a bunch by removing
some old hacks and switching to platform_driver_probe().
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This updates <linux/bcd.h> to define the key routines as constant
functions, which the macros will then call.  Newer code can now call
bcd2bin() instead of SCREAMING BCD2BIN() TO THE FOUR WINDS.

This lets each driver shrink their codespace by using N function calls to
a single (global) copy of those routines, instead of N inlined copies of
these functions per driver.

These routines aren't used in speed-critical code.  Almost all callers are
in the RTC framework.  Typical per-driver savings is near 300 bytes.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: NAdrian Bunk <bunk@kernel.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Support the Dallas/Maxim DS1305 and DS1306 RTC chips.  These use SPI, and
support alarms, NVRAM, and a trickle charger for use when their backup
power supply is a supercap or rechargeable cell.

This basic driver doesn't yet support suspend/resume or wakealarms.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adds kernel driver for M41T94 RTC chip connected via SPI.
I've tested it on two different AT91-based hardwares.

This is third revision of the patch: some comments made by
Alessandro Zummo fixed.

Revision two added support for century bit and fixes.
Signed-off-by: NKim B. Heino <Kim.Heino@bluegiga.com>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove implicit use of BKL in ioctl() from the RTC framework.

Instead, the rtc->ops_lock is used.  That's the same lock that already
protects the RTC operations when they're issued through the exported
rtc_*() calls in drivers/rtc/interface.c ...  making this a bugfix, not
just a cleanup, since both ioctl calls and set_alarm() need to update IRQ
enable flags and that implies a common lock (which RTC drivers as a rule
do not provide on their own).

A new comment at the declaration of "struct rtc_class_ops" summarizes
current locking rules.  It's not clear to me that the exceptions listed
there should exist ...  if not, those are pre-existing problems which can
be fixed in a patch that doesn't relate to BKL removal.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Jonathan Corbet <corbet@lwn.net>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For now just wrap the main logic, but this driver is a prime candidate for
someone wanting to eliminate the lock entirely

[lizf@cn.fujitsu.com: fix build failure]
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace printk(KERN_INFO ...) calls with appropriate pr_info(...)
equivalents.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexander Bigga <ab@mycable.de>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Sort the header inclusions for readability.  No functional changes.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexander Bigga <ab@mycable.de>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The ioctls AUTOFS_IOC_TOGGLEREGHOST and AUTOFS_IOC_ASKREGHOST were added
several years ago but what they were intended for has never been
implemented (as far as I'm aware noone uses them) so remove them.
Signed-off-by: NIan Kent <raven@themaw.net>
Reviewed-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch re-orgnirzes the checking for and waiting on active expires and
elininates redundant checks.
Signed-off-by: NIan Kent <raven@themaw.net>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Appologies, somehow I seem to have sent an out dated version of this
patch. Here is an additional patch that brings the patch up to date.
Signed-off-by: NIan Kent <raven@themaw.net>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For direct and offset type mounts that are covered by another mount we
cannot check the AUTOFS_INF_EXPIRING flag during a path walk which leads
to lookups walking into an expiring mount while it is being expired.

For example, for the direct multi-mount map entry with a couple of
offsets:

/race/mm1  /      <server1>:/<path1>
           /om1   <server2>:/<path2>
           /om2   <server1>:/<path3>

an autofs trigger mount is mounted on /race/mm1 and when accessed it is
over mounted and trigger mounts made for /race/mm1/om1 and /race/mm1/om2.
So it isn't possible for path walks to see the expiring flag at all and
they happily walk into the file system while it is expiring.

When expiring these mounts follow_down() must stop at the autofs mount and
all processes must block in the ->follow_link() method (except the daemon)
until the expire is complete.  This is done by decrementing the d_mounted
field of the autofs trigger mount root dentry until the expire is
completed.  In ->follow_link() all processes wait on the expire and the
mount following is completed for the daemon until the expire is complete.
Signed-off-by: NIan Kent <raven@themaw.net>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The selection of a dentry for expiration and the setting of the
AUTOFS_INF_EXPIRING flag isn't done atomically which can lead to lookups
walking into an expiring mount.

What happens is that an expire is initiated by the daemon and a dentry is
selected for expire but, since there is no lock held between the selection
and setting of the expiring flag, a process may find the flag clear and
continue walking into the mount tree at the same time the daemon attempts
the expire it.
Signed-off-by: NIan Kent <raven@themaw.net>
Reviewed-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are two cases for which a dentry that has a pending mount request
does not wait for completion.  One is via autofs4_revalidate() and the
other via autofs4_follow_link().

In revalidate, after the mount point directory is created, but before the
mount is done, the check in try_to_fill_dentry() can can fail to send the
dentry to the wait queue since the dentry is positive and the lookup flags
may contain only LOOKUP_FOLLOW.  Although we don't trigger a mount for the
LOOKUP_FOLLOW flag, if ther's one pending we might as well wait and use
the mounted dentry for the lookup.

In autofs4_follow_link() the dentry is not checked to see if it is pending
so it may fail to call try_to_fill_dentry() and not wait for mount
completion.

A dentry that is pending must always be sent to the wait queue.
Signed-off-by: NIan Kent <raven@themaw.net>
Reviewed-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The mount triggering functionality of readdir and related functions is no
longer used (and is quite broken as well).  The unused portions have been
removed.
Signed-off-by: NIan Kent <raven@themaw.net>
Reviewed-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We have been seeing mount requests comming to the automount daemon for
keys of the form "<map key>/<non key directory>" which are lookups for
invalid map keys.  But we can check for this in the kernel module and
return a fail immediately, without having to send a request to the daemon.

It is possible to recognise these requests are invalid based on whether
the request dentry is negative and its relation to the autofs file system
root.

For example, given the indirect multi-mount map entry:

idm1  \
    /mm1  <server>:/<path1>
    /mm2  <server>:/<path2>

For a request to mount idm1, IS_ROOT((idm1)->d_parent) will be always be
true and the dentry may be negative.  But directories idm1/mm1 and
idm1/mm2 will always be created as part of the mount request for idm1.  So
any mount request within idm1 itself must have a positive dentry otherwise
the map key is invalid.

In version 4 these multi-mount entries are all mounted and umounted as a
single request and in version 5 the directories idm1/mm1 and idm1/mm2 are
created and an autofs fs mounted on them to act as a mount trigger so the
above is also true.

This also holds true for the autofs version 4 pseudo direct mount feature.
 When this feature is used without the "--ghost" option automount(8) will
create internal submounts as we go down the map key paths which are
essentially normal indirect mounts for which the above holds.  If the
"--ghost" option is given the directories for map keys are created at
daemon startup so valid map entries correspond to postive dentries in the
autofs fs.

autofs version 5 direct mount maps are similar except that the IS_ROOT
check is not needed.  This has been addressed in a previous patch tittled
"autofs4 - detect invalid direct mount requests".

For example, given the direct multi-mount map entry:

/test/dm1  \
    /mm1  <server>:/<path1>
    /mm2  <server>:/<path2>

An autofs fs is mounted on /test/dm1 as a trigger mount and when a mount
is triggered for /test/dm1, the multi-mount offset directories
/test/dm1/mm1 and /test/dm1/mm2 are created and an autofs fs is mounted on
them to act as mount triggers.  So valid direct mount requests must always
have a positive dentry if they correspond to a valid map entry.
Signed-off-by: NIan Kent <raven@themaw.net>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

autofs v5 direct and offset mounts within an autofs filesystem are
triggered by existing autofs triger mounts so the mount point dentry must
be positive.  If the mount point dentry is negative then the trigger
doesn't exist so we can return fail immediately.
Signed-off-by: NIan Kent <raven@themaw.net>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If an autofs mount becomes catatonic before autofs4_wait_release() is
called the wait queue counter will not be decremented down to zero and the
entry will never be freed.  There are also races decrementing the wait
counter in the wait release function.  To deal with this the counter needs
to be updated while holding the wait queue mutex and waiters need to be
woken up unconditionally when the wait is removed from the queue to ensure
we eventually free the wait.
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It is possible for an autofs mount to become catatonic (and for the daemon
communication pipe to become NULL) after a wait has been initiallized but
before the request has been sent to the daemon.  We need to check for this
before sending the request packet.
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It see that the patch tittled "autofs4 - fix pending mount race" is
missing a change that I had recently made.

It's missing a kfree for the case mutex_lock_interruptible() fails
to aquire the wait queue mutex.
Signed-off-by: NIan Kent <raven@themaw.net>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Close a race between a pending mount that is about to finish and a new
lookup for the same directory.

Process P1 triggers a mount of directory foo.  It sets
DCACHE_AUTOFS_PENDING in the ->lookup routine, creates a waitq entry for
'foo', and calls out to the daemon to perform the mount.  The autofs
daemon will then create the directory 'foo', using a new dentry that will
be hashed in the dcache.

Before the mount completes, another process, P2, tries to walk into the
'foo' directory.  The vfs path walking code finds an entry for 'foo' and
calls the revalidate method.  Revalidate finds that the entry is not
PENDING (because PENDING was never set on the dentry created by the
mkdir), but it does find the directory is empty.  Revalidate calls
try_to_fill_dentry, which sets the PENDING flag and then calls into the
autofs4 wait code to trigger or wait for a mount of 'foo'.  The wait code
finds the entry for 'foo' and goes to sleep waiting for the completion of
the mount.

Yet another process, P3, tries to walk into the 'foo' directory.  This
process again finds a dentry in the dcache for 'foo', and calls into the
autofs revalidate code.

The revalidate code finds that the PENDING flag is set, and so calls
try_to_fill_dentry.

a) try_to_fill_dentry sets the PENDING flag redundantly for this
   dentry, then calls into the autofs4 wait code.

b) the autofs4 wait code takes the waitq mutex and searches for an
   entry for 'foo'

Between a and b, P1 is woken up because the mount completed.  P1 takes the
wait queue mutex, clears the PENDING flag from the dentry, and removes the
waitqueue entry for 'foo' from the list.

When it releases the waitq mutex, P3 (eventually) acquires it.  At this
time, it looks for an existing waitq for 'foo', finds none, and so creates
a new one and calls out to the daemon to mount the 'foo' directory.

Now, the reason that three processes are required to trigger this race is
that, because the PENDING flag is not set on the dentry created by mkdir,
the window for the race would be way to slim for it to ever occur.
Basically, between the testing of d_mountpoint(dentry) and the taking of
the waitq mutex, the mount would have to complete and the daemon would
have to be woken up, and that in turn would have to wake up P1.  This is
simply impossible.  Add the third process, though, and it becomes slightly
more likely.
Signed-off-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The autofs4_catatonic_mode() function accesses the wait queue without any
locking but can be called at any time.  This could lead to a possible
double free of the name field of the wait and a double fput of the daemon
communication pipe or an fput of a NULL file pointer.
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The autofs_wait_queue already contains all of the fields of the
struct qstr, so change it into a qstr.

This patch, from Jeff Moyer, has been modified a liitle by myself.
Signed-off-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When an open(2) call is made on an autofs mount point directory that
already exists and the O_DIRECTORY flag is not used the needed mount
callback to the daemon is not done. This leads to the path walk
continuing resulting in a callback to the daemon with an incorrect
key. open(2) is called without O_DIRECTORY by the "find" utility but
this should be handled properly anyway.

This happens because autofs needs to use the lookup flags to decide
when to callback to the daemon to perform a mount to prevent mount
storms. For example, an autofs indirect mount map that has the "browse"
option will have the mount point directories are pre-created and the
stat(2) call made by a color ls against each directory will cause all
these directories to be mounted. It is unfortunate we need to resort
to this but mount maps can be quite large. Additionally, if a user
manually umounts an autofs indirect mount the directory isn't removed
which also leads to this situation.

To resolve this autofs needs to use the lookup intent flags to enable
it to make this decision. This patch adds this check and triggers a
call back if any of the lookup intent flags are set as all these calls
warrant a mount attempt be requested.

I know that external VFS code which uses the lookup flags is something
that the VFS would like to eliminate but I have no choice as I can't
see any other way to do this. A VFS dentry or inode operation callback
which returns the lookup "type" (requires a definition) would be
sufficient. But this change is needed now and I'm not aware of the form
that coming VFS changes will take so I'm not willing to propose anything
along these lines.

If anyone can provide an alternate method I would be happy to use it.

[akpm@linux-foundation.org: fix build for concurrent VFS changes]
Signed-off-by: NIan Kent <raven@themaw.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since we now delay hashing of dentrys until the ->mkdir() call, droping
and re-taking the directory mutex within the ->lookup() function when we
are being called by user space is not needed.  This can lead to a race
when other processes are attempting to access the same directory during
mount point directory creation.

In this case we need to hang onto the mutex to ensure we don't get user
processes trying to create a mount request for a newly created dentry
after the mount point entry has already been created.  This ensures that
when we need to check a dentry passed to autofs4_wait(), if it is hashed,
it is always the mount point dentry and not a new dentry created by
another lookup during directory creation.
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The length of the symlink name has been moved but it needs to be set
before allocating space for it in the dentry info struct.  This corrects a
mistake in a recent patch.
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A while ago a patch to resolve a deadlock during directory creation was
merged.  This delayed the hashing of lookup dentrys until the ->mkdir()
(or ->symlink()) operation completed to ensure we always went through
->lookup() instead of also having processes go through ->revalidate() so
our VFS locking remained consistent.

Now we are seeing a couple of side affects of that change in situations
with heavy mount activity.

Two cases have been identified:

1) When a mount request is triggered, due to the delayed hashing, the
   directory created by user space for the mount point doesn't have the
   DCACHE_AUTOFS_PENDING flag set.  In the case of an autofs multi-mount
   where a tree of mount point directories are created this can lead to
   the path walk continuing rather than the dentry being sent to the wait
   queue to wait for request completion.  This is because, if the pending
   flag isn't set, the criteria for deciding this is a mount in progress
   fails to hold, namely that the dentry is not a mount point and has no
   subdirectories.

2) A mount request dentry is initially created negative and unhashed.
   It remains this way until the ->mkdir() callback completes.  Since it
   is unhashed a fresh dentry is used when the user space mount request
   creates the mount point directory.  This leaves the original dentry
   negative and unhashed.  But revalidate has no way to tell the VFS that
   the dentry has changed, other than to force another ->lookup() by
   returning false, which is at best wastefull and at worst not possible.
   This results in an -ENOENT return from the original path walk when in
   fact the mount succeeded.

To resolve this we need to ensure that the same dentry is used in all
calls to ->lookup() during the course of a mount request.  This patch
achieves that by adding the initial dentry to a look aside list and
removes it at ->mkdir() or ->symlink() completion (or when the dentry is
released), since these are the only create operations autofs4 supports.
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch series enables the use of a single dentry for lookups prior to
the dentry being hashed and so we no longer need to redo the lookup.  This
patch reverts the patch of commit
03379044.
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Correct the error of making a positive dentry negative after it has been
instantiated.

The code that makes this error attempts to re-use the dentry from a
concurrent expire and mount to resolve a race and the dentry used for the
lookup must be negative for mounts to trigger in the required cases.  The
fact is that the dentry doesn't need to be re-used because all that is
needed is to preserve the flag that indicates an expire is still
incomplete at the time of the mount request.

This change uses the the dentry to check the flag and wait for the expire
to complete then discards it instead of attempting to re-use it.
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is no good reason to immediately open the lower file, and that can
cause problems with files that the user does not intend to immediately
open, such as device nodes.

This patch removes the persistent file open from the interpose step and
pushes that to the locations where eCryptfs really does need the lower
persistent file, such as just before reading or writing the metadata
stored in the lower file header.

Two functions are jumping to out_dput when they should just be jumping to
out on error paths.  This patch also fixes these.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When creating device nodes, eCryptfs needs to delay actually opening the lower
persistent file until an application tries to open.  Device handles may not be
backed by anything when they first come into existence.

[Valdis.Kletnieks@vt.edu: build fix]
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Cc: <Valdis.Kletnieks@vt.edu}
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fixe sparse warnings:
fs/ecryptfs/inode.c:368:15: warning: cast to restricted __be64
fs/ecryptfs/mmap.c:385:12: warning: incorrect type in assignment (different base types)
fs/ecryptfs/mmap.c:385:12:    expected unsigned long long [unsigned] [assigned] [usertype] file_size
fs/ecryptfs/mmap.c:385:12:    got restricted __be64 [usertype] <noident>
fs/ecryptfs/mmap.c:428:12: warning: incorrect type in assignment (different base types)
fs/ecryptfs/mmap.c:428:12:    expected unsigned long long [unsigned] [assigned] [usertype] file_size
fs/ecryptfs/mmap.c:428:12:    got restricted __be64 [usertype] <noident>
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fixes the following sparse warnings:
fs/ecryptfs/crypto.c:1036:8: warning: cast to restricted __be32
fs/ecryptfs/crypto.c:1038:8: warning: cast to restricted __be32
fs/ecryptfs/crypto.c:1077:10: warning: cast to restricted __be32
fs/ecryptfs/crypto.c:1103:6: warning: incorrect type in assignment (different base types)
fs/ecryptfs/crypto.c:1105:6: warning: incorrect type in assignment (different base types)
fs/ecryptfs/crypto.c:1124:8: warning: incorrect type in assignment (different base types)
fs/ecryptfs/crypto.c:1241:21: warning: incorrect type in assignment (different base types)
fs/ecryptfs/crypto.c:1244:30: warning: incorrect type in assignment (different base types)
fs/ecryptfs/crypto.c:1414:23: warning: cast to restricted __be32
fs/ecryptfs/crypto.c:1417:32: warning: cast to restricted __be16
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Clean up overcomplicated string copy, which also gets rid of this
bogus warning:

fs/ecryptfs/main.c: In function 'ecryptfs_parse_options':
include/asm/arch/string_32.h:75: warning: array subscript is above array bounds
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>