Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.
Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().
Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Morris <jmorris@namei.org>
Kmem cache passed to constructor is only needed for constructors that are
themselves multiplexeres. Nobody uses this "feature", nor does anybody uses
passed kmem cache in non-trivial way, so pass only pointer to object.
Non-trivial places are:
arch/powerpc/mm/init_64.c
arch/powerpc/mm/hugetlbpage.c
This is flag day, yes.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Jon Tollefson <kniht@linux.vnet.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Matt Mackall <mpm@selenic.com>
[akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c]
[akpm@linux-foundation.org: fix mm/slab.c]
[akpm@linux-foundation.org: fix ubifs]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow filesystem's ->lock() method to call posix_lock_file() instead of
posix_lock_file_wait(), and return FILE_LOCK_DEFERRED. This makes it
possible to implement a such a ->lock() function, that works with the lock
manager, which needs the call to be asynchronous.
Now the vfs_lock_file() helper can be used, so this is a cleanup as well.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: David Teigland <teigland@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use a special error value FILE_LOCK_DEFERRED to mean that a locking
operation returned asynchronously. This is returned by
posix_lock_file() for sleeping locks to mean that the lock has been
queued on the block list, and will be woken up when it might become
available and needs to be retried (either fl_lmops->fl_notify() is
called or fl_wait is woken up).
f_op->lock() to mean either the above, or that the filesystem will
call back with fl_lmops->fl_grant() when the result of the locking
operation is known. The filesystem can do this for sleeping as well
as non-sleeping locks.
This is to make sure, that return values of -EAGAIN and -EINPROGRESS by
filesystems are not mistaken to mean an asynchronous locking.
This also makes error handling in fs/locks.c and lockd/svclock.c slightly
cleaner.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: David Teigland <teigland@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It acts exactly like a regular 'cond_resched()', but will not get
optimized away when CONFIG_PREEMPT is set.
Normal kernel code is already preemptable in the presense of
CONFIG_PREEMPT, so cond_resched() is optimized away (see commit
02b67cc3ba "sched: do not do
cond_resched() when CONFIG_PREEMPT").
But when wanting to conditionally reschedule while holding a lock, you
need to use "cond_sched_lock(lock)", and the new function is the BKL
equivalent of that.
Also make fs/locks.c use it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fcntl_setlk()/close() race prevention has a subtle hole - we need to
make sure that if we *do* have an fcntl/close race on SMP box, the
access to descriptor table and inode->i_flock won't get reordered.
As it is, we get STORE inode->i_flock, LOAD descriptor table entry vs.
STORE descriptor table entry, LOAD inode->i_flock with not a single
lock in common on both sides. We do have BKL around the first STORE,
but check in locks_remove_posix() is outside of BKL and for a good
reason - we don't want BKL on common path of close(2).
Solution is to hold ->file_lock around fcheck() in there; that orders
us wrt removal from descriptor table that preceded locks_remove_posix()
on close path and we either come first (in which case eviction will be
handled by the close side) or we'll see the effect of close and do
eviction ourselves. Note that even though it's read-only access,
we do need ->file_lock here - rcu_read_lock() won't be enough to
order the things.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Commit 1a747ee0 ("locks: don't call ->copy_lock methods on return of
conflicting locks") changed fs/lockd/svclock.c to call
__locks_copy_lock() instead of locks_copy_lock(), but lockd can be built
as a module and __locks_copy_lock() is not exported, which causes a
build error
ERROR: "__locks_copy_lock" [fs/lockd/lockd.ko] undefined!
with CONFIG_LOCKD=m.
Fix this by exporting __locks_copy_lock().
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The file_lock structure is used both as a heavy-weight representation of
an active lock, with pointers to reference-counted structures, etc., and
as a simple container for parameters that describe a file lock.
The conflicting lock returned from __posix_lock_file is an example of
the latter; so don't call the filesystem or lock manager callbacks when
copying to it. This also saves the need for an unnecessary
locks_init_lock in the nfsv4 server.
Thanks to Trond for pointing out the error.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
fcntl_setlease() has a struct dentry* that is used only once; this patch
removes it.
Signed-off-by: David M. Richter <richterd@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
In generic_setlease(), the struct file_lock is allocated after tests for the
presence of conflicting readers/writers is done, despite the fact that the
allocation might block; this patch moves the allocation earlier. A subsequent
set of patches will rely on this behavior to properly serialize between a
modified __break_lease() and generic_setlease().
Signed-off-by: David M. Richter <richterd@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
In generic_setlease(), we don't need to allocate a new struct file_lock
or check for readers or writers when called with F_UNLCK.
Signed-off-by: David M. Richter <richterd@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Fixes a return-value mixup from 85c59580b3
"locks: Fix potential OOPS in generic_setlease()", in which -ENOMEM replaced
what had been intended to stay -EAGAIN in the variable "error".
Signed-off-by: David M. Richter <richterd@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Miklos Szeredi found the bug:
"Basically what happens is that on the server nlm_fopen() calls
nfsd_open() which returns -EACCES, to which nlm_fopen() returns
NLM_LCK_DENIED.
"On the client this will turn into a -EAGAIN (nlm_stat_to_errno()),
which in will cause fcntl_setlk() to retry forever."
So, for example, opening a file on an nfs filesystem, changing
permissions to forbid further access, then trying to lock the file,
could result in an infinite loop.
And Trond Myklebust identified the culprit, from Marc Eshel and I:
7723ec9777 "locks: factor out
generic/filesystem switch from setlock code"
That commit claimed to just be reshuffling code, but actually introduced
a behavioral change by calling the lock method repeatedly as long as it
returned -EAGAIN.
We assumed this would be safe, since we assumed a lock of type SETLKW
would only return with either success or an error other than -EAGAIN.
However, nfs does can in fact return -EAGAIN in this situation, and
independently of whether that behavior is correct or not, we don't
actually need this change, and it seems far safer not to depend on such
assumptions about the filesystem's ->lock method.
Therefore, revert the problematic part of the original commit. This
leaves vfs_lock_file() and its other callers unchanged, while returning
fcntl_setlk and fcntl_setlk64 to their former behavior.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Tested-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix kernel-doc notation warnings in fs/.
Warning(mmotm-2008-0314-1449//fs/super.c:560): missing initial short description on line:
* mark_files_ro
Warning(mmotm-2008-0314-1449//fs/locks.c:1277): missing initial short description on line:
* lease_get_mtime
Warning(mmotm-2008-0314-1449//fs/locks.c:1277): missing initial short description on line:
* lease_get_mtime
Warning(mmotm-2008-0314-1449//fs/namei.c:1368): missing initial short description on line:
* lookup_one_len: filesystem helper to lookup single pathname component
Warning(mmotm-2008-0314-1449//fs/buffer.c:3221): missing initial short description on line:
* bh_uptodate_or_lock: Test whether the buffer is uptodate
Warning(mmotm-2008-0314-1449//fs/buffer.c:3240): missing initial short description on line:
* bh_submit_read: Submit a locked buffer for reading
Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:30): missing initial short description on line:
* writeback_acquire: attempt to get exclusive writeback access to a device
Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:47): missing initial short description on line:
* writeback_in_progress: determine whether there is writeback in progress
Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:58): missing initial short description on line:
* writeback_release: relinquish exclusive writeback access against a device.
Warning(mmotm-2008-0314-1449//include/linux/jbd.h:351): contents before sections
Warning(mmotm-2008-0314-1449//include/linux/jbd.h:561): contents before sections
Warning(mmotm-2008-0314-1449//fs/jbd/transaction.c:1935): missing initial short description on line:
* void journal_invalidatepage()
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some time ago the xxx_vnr() calls (e.g. pid_vnr or find_task_by_vpid) were
_all_ converted to operate on the current pid namespace. After this each call
like xxx_nr_ns(foo, current->nsproxy->pid_ns) is nothing but a xxx_vnr(foo)
one.
Switch all the xxx_nr_ns() callers to use the xxx_vnr() calls where
appropriate.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fcntl(F_GETLK,..) can return pid of process for not current pid namespace
(if process is belonged to the several namespaces). It is true also for
pids in /proc/locks. So correct behavior is saving pointer to the struct
pid of the process lock owner.
Signed-off-by: Vitaliy Gusev <vgusev@openvz.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
interruptible_sleep_on_locked() is just an open-coded
wait_event_interruptible_timeout(), with the one difference that
interruptible_sleep_on_locked() doesn't bother to check the condition on
which it is waiting, depending instead on the BKL to avoid the case
where it blocks after the wakeup has already been called.
locks_block_on_timeout() is only used in one place, so it's actually
simpler to inline it into its caller.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
