In order to make the file and line number reporting work
correctly, this has been moved back into the header file.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Convert a semaphore to a mutex in locking.c and also tidy
up one or two loose ends.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This is one of the changes related to journal recovery I mentioned a
couple weeks ago.  We can get into a situation where there are only
readonly nodes currently mounting the fs, but there are journals that need
to be recovered.  Since the readonly nodes can't recover journals, the
next rw mounter needs to go through and check all journals and recover any
that are dirty (i.e. what the first node to mount the fs does).  This rw
mounter needs to skip the journals held by the existing readonly nodes.
Skipping those journals amounts to using the TRY flag on the journal locks
so acquiring the lock of a journal held by a readonly node will fail
instead of blocking indefinately.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

At some stage, a mutex was added to gfs2_glock_put() without
checking all its call sites. Two of them were called from
under a spinlock causing random delays at various points and
crashes.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Signed-off-by: NJens Axboe <axboe@suse.de>

Local variable res was initialized to 0 - no check needed here.
Signed-off-by: NCarsten Otte <cotte@de.ibm.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Convert a for-loop that explicitly references "NR_CPUS" into the
potentially more efficient for_each_possible_cpu() construct.
Signed-off-by: NJohn Hawkes <hawkes@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the call to nfs_intent_set_file() fails to open a file in
nfs4_proc_create(), we should return an error.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

There are places in the kernel where we look up files in fd tables and
access the file structure without holding refereces to the file.  So, we
need special care to avoid the race between looking up files in the fd
table and tearing down of the file in another CPU.  Otherwise, one might
see a NULL f_dentry or such torn down version of the file.  This patch
fixes those special places where such a race may happen.
Signed-off-by: NDipankar Sarma <dipankar@in.ibm.com>
Acked-by: N"Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In kernel bugzilla #6248 (http://bugzilla.kernel.org/show_bug.cgi?id=6248),
Adrian Bunk <bunk@stusta.de> notes that CONFIG_HUGETLBFS is missing Kconfig
help text.
Signed-off-by: NArthur Othieno <apgo@patchbomb.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

While we can currently walk through thread groups, process groups, and
sessions with just the rcu_read_lock, this opens the door to walking the
entire task list.

We already have all of the other RCU guarantees so there is no cost in
doing this, this should be enough so that proc can stop taking the
tasklist lock during readdir.

prev_task was killed because it has no users, and using it will miss new
tasks when doing an rcu traversal.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Since ->map() no longer locks the page, we need to adjust the handling
of those pages (and stealing) a little. This now passes full regressions
again.
Signed-off-by: NJens Axboe <axboe@suse.de>

- We need to adjust *ppos for writes as well.
- Copy back modified offset value if one was passed in, similar to
  what sendfile does.
Signed-off-by: NJens Axboe <axboe@suse.de>

We need to ensure that we only drop a lock that is ordered last, to avoid
ABBA deadlocks with competing processes.
Signed-off-by: NJens Axboe <axboe@suse.de>

- generic_file_splice_read() more readable and correct
- Don't bail on page allocation with NONBLOCK set, just don't allow
  direct blocking on IO (eg lock_page).
Signed-off-by: NJens Axboe <axboe@suse.de>

We need to check i_size after doing a blocking readpage.
Signed-off-by: NJens Axboe <axboe@suse.de>

Came up through a quick grep for other cases similar to the ftruncate()
one in commit 0a489cb3.

Also, add a comment, so that people who read the code understand why we
do what looks like a no-op.

(Again, this won't actually matter to any sane user, since libc will
save and restore the register gcc stomps on, but it's still wrong to
stomp on it)
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Gcc thinks it owns the incoming argument stack, but that's not true for
"asmlinkage" functions, and it corrupts the caller-set-up argument stack
when it pushes the third argument onto the stack.  Which can result in
%ebx getting corrupted in user space.

Now, normally nobody sane would ever notice, since libc will save and
restore %ebx anyway over the system call, but it's still wrong.

I'd much rather have "asmlinkage" tell gcc directly that it doesn't own
the stack, but no such attribute exists, so we're stuck with our hacky
manual "prevent_tail_call()" macro once more (we've had the same issue
before with sys_waitpid() and sys_wait4()).

Thanks to Hans-Werner Hilse <hilse@sub.uni-goettingen.de> for reporting
the issue and testing the fix.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When allocating memory to sort directory entries, use vmalloc()
rather than kmalloc() since for larger directories, the required
size can easily be graeter than the 128k maximum of kmalloc().

Also adding the first steps towards getting the AOP_TRUNCATED_PAGE
return code get in the glock code by flagging all places where we
request a glock and we are holding a page lock.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Missed unlock_super()call is added in error condition code path.
Signed-off-by: NLeonid Ananiev <leonid.i.ananiev@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

As noted further on the this file, some block devices have a / in their
name, so fix the "block:..." symlink name the same as the /sys/block name.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

[BLOCK] delay all uevents until partition table is scanned

Here we delay the annoucement of all block device events until the
disk's partition table is scanned and all partition devices are already
created and sysfs is populated.

We have a bunch of old bugs for removable storage handling where we
probe successfully for a filesystem on the raw disk, but at the
same time the kernel recognizes a partition table and creates partition
devices.
Currently there is no sane way to tell if partitions will show up or not
at the time the disk device is announced to userspace. With the delayed
events we can simply skip any probe for a filesystem on the raw disk when
we find already present partitions.
Signed-off-by: NKay Sievers <kay.sievers@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

It works like this:
  Open the file
  Read all the contents.
  Call poll requesting POLLERR or POLLPRI (so select/exceptfds works)
  When poll returns,
     close the file and go to top of loop.
   or lseek to start of file and go back to the 'read'.

Events are signaled by an object manager calling
   sysfs_notify(kobj, dir, attr);

If the dir is non-NULL, it is used to find a subdirectory which
contains the attribute (presumably created by sysfs_create_group).

This has a cost of one int  per attribute, one wait_queuehead per kobject,
one int per open file.

The name "sysfs_notify" may be confused with the inotify
functionality.  Maybe it would be nice to support inotify for sysfs
attributes as well?

This patch also uses sysfs_notify to allow /sys/block/md*/md/sync_action
to be pollable
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This is two distinct changes.
 - Not changing our real parents.
 - Not changing our ptrace parents.

Not changing our real parents is trivially correct because both tasks
have the same real parents as they are part of a thread group.  Now that
we demote the leader to a thread there is no longer any reason to change
it's parentage.

Not changing our ptrace parents is a user visible change if someone
looks hard enough.  I don't think user space applications will care or
even notice.

In the practical and I think common case a debugger will have attached
to all of the threads using the same ptrace flags.  From my quick skim
of strace and gdb that appears to be the case.  Which if true means
debuggers will not notice a change.

Before this point we have already generated a ptrace event in do_exit
that reports the leaders pid has died so de_thread is visible to a
debugger.  Which means attempting to hide this case by copying flags
around appears excessive.

By not doing anything it avoids all of the weird locking issues between
de_thread and ptrace attach, and removes one case from consideration for
fixing the ptrace locking.

This only addresses Oleg's first concern with ptrace_attach, that of the
problems caused by reparenting.  Oleg's second concern is essentially a
race between ptrace_attach and release_task that causes an oops when we
get to force_sig_specific.  There is nothing special about de_thread
with respect to that race.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

A typo in the directory code was causing postmark to fail
somewhere in the allocation code, since it was unable to
find newly allocated directory leaf blocks under certain
circumstances.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

It's cleaner to allocate a new request, otherwise the uid/gid/pid
fields of the request won't be filled in.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>

Request is already initialized in fuse_request_alloc() so no need to
do it again in fuse_get_req().
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>

Properly accounting the number of waiting requests was forgotten in
"clean up request accounting" patch.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>

A deadlock was possible, when the last reference to the superblock was
held due to a background request containing a file reference.

Releasing the file would release the vfsmount which in turn would
release the superblock.  Since sbput_sem is held during the fput() and
fuse_put_super() tries to acquire this same semaphore, a deadlock
results.

The chosen soltuion is to get rid of sbput_sem, and instead use the
spinlock to ensure the referenced inodes/file are released only once.
Since the actual release may sleep, defer these outside the locked
region, but using local variables instead of the structure members.

This is a much more rubust solution.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>

A small update to the journaling code to change the way that
the "extra" blocks are accounted for in the journal. These are
used at a rate of one per 503 metadata blocks or one per 251
journaled data blocks (or just one if the total number of journaled
blocks in the transaction is smaller). Since we are using them at
two different rates the old method of accounting for them no longer
works and we count them up as required.

Since the "per transaction" accounting can't handle this (there is no
fixed number of header blocks per transaction) we have to account for
it in the general journal code. We now require that each transaction
reserves more blocks than it actually needs to take account of the
possible extra blocks.

Also a final fix to dir.c to ensure that all ref counts are handled
correctly.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Basically an in-kernel implementation of tee, which uses splice and the
pipe buffers as an intelligent way to pass data around by reference.

Where the user space tee consumes the input and produces a stdout and
file output, this syscall merely duplicates the data inside a pipe to
another pipe. No data is copied, the output just grabs a reference to the
input pipe data.
Signed-off-by: NJens Axboe <axboe@suse.de>

We need not use ->f_pos as the offset for the file input/output. If the
user passed an offset pointer in through sys_splice(), just use that and
leave ->f_pos alone.
Signed-off-by: NJens Axboe <axboe@suse.de>

Keep unused openowners around for at least one lease period, to avoid the need
for as many open confirmations and to allow handing out more delegations.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It's very easy for the server to DOS itself by just giving out too many
delegations.

For now we just solve the problem with a dumb hard limit.  Eventually we'll
want a smarter policy.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We should be shutting down rpciod for the callback channel when we shut down
the server.

Also note that we do rpciod_up() and create the callback client *before*
setting cb_set--the cb_set only determines whether the initial null was
succesful.  So cb_set is not a reliable determiner of whether we need to clean
up, only cb_client is.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Some obvious cleanup.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We need to make sure the laundromat work doesn't reschedule itself just when
we try to cancel it.  Also, we shouldn't be waiting for it to finish running
while holding the state lock, as that's a potential deadlock.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>