14 Nov, 2008
1 commit
-
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
Reviewed-by: James Morris
Acked-by: Serge Hallyn
Cc: Al Viro
Signed-off-by: James Morris
24 Oct, 2008
1 commit
-
* 'proc' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc: (35 commits)
proc: remove fs/proc/proc_misc.c
proc: move /proc/vmcore creation to fs/proc/vmcore.c
proc: move pagecount stuff to fs/proc/page.c
proc: move all /proc/kcore stuff to fs/proc/kcore.c
proc: move /proc/schedstat boilerplate to kernel/sched_stats.h
proc: move /proc/modules boilerplate to kernel/module.c
proc: move /proc/diskstats boilerplate to block/genhd.c
proc: move /proc/zoneinfo boilerplate to mm/vmstat.c
proc: move /proc/vmstat boilerplate to mm/vmstat.c
proc: move /proc/pagetypeinfo boilerplate to mm/vmstat.c
proc: move /proc/buddyinfo boilerplate to mm/vmstat.c
proc: move /proc/vmallocinfo to mm/vmalloc.c
proc: move /proc/slabinfo boilerplate to mm/slub.c, mm/slab.c
proc: move /proc/slab_allocators boilerplate to mm/slab.c
proc: move /proc/interrupts boilerplate code to fs/proc/interrupts.c
proc: move /proc/stat to fs/proc/stat.c
proc: move rest of /proc/partitions code to block/genhd.c
proc: move /proc/cpuinfo code to fs/proc/cpuinfo.c
proc: move /proc/devices code to fs/proc/devices.c
proc: move rest of /proc/locks to fs/locks.c
...
23 Oct, 2008
1 commit
-
Signed-off-by: Alexey Dobriyan
21 Oct, 2008
1 commit
-
Signed-off-by: Al Viro
27 Jul, 2008
1 commit
-
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.cThis is flag day, yes.
Signed-off-by: Alexey Dobriyan
Acked-by: Pekka Enberg
Acked-by: Christoph Lameter
Cc: Jon Tollefson
Cc: Nick Piggin
Cc: Matt Mackall
[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
Signed-off-by: Linus Torvalds
26 Jul, 2008
3 commits
-
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
Cc: "J. Bruce Fields"
Cc: Trond Myklebust
Cc: Matthew Wilcox
Cc: David Teigland
Cc: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Extract common code into a function.
Signed-off-by: Miklos Szeredi
Cc: "J. Bruce Fields"
Cc: Trond Myklebust
Cc: Matthew Wilcox
Cc: David Teigland
Cc: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Use a special error value FILE_LOCK_DEFERRED to mean that a locking
operation returned asynchronously. This is returned byposix_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
Cc: Trond Myklebust
Cc: "J. Bruce Fields"
Cc: Matthew Wilcox
Cc: David Teigland
Cc: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Jun, 2008
1 commit
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fl_insert and fl_remove are not used right now in the kernel. Remove them.
Signed-off-by: Denis V. Lunev
Cc: Matthew Wilcox
Cc: Alexander Viro
Cc: "J. Bruce Fields"
Signed-off-by: Andrew Morton
Signed-off-by: Al Viro
12 May, 2008
1 commit
-
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
02b67cc3ba36bdba351d6c3a00593f4ec550d9d3 "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
07 May, 2008
1 commit
-
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
02 May, 2008
1 commit
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Initial splitoff of the low-level stuff; taken to fdtable.h
Signed-off-by: Al Viro
26 Apr, 2008
6 commits
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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 errorERROR: "__locks_copy_lock" [fs/lockd/lockd.ko] undefined!
with CONFIG_LOCKD=m.
Fix this by exporting __locks_copy_lock().
Signed-off-by: Roland Dreier
Signed-off-by: Linus Torvalds -
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
Cc: Trond Myklebust -
fcntl_setlease() has a struct dentry* that is used only once; this patch
removes it.Signed-off-by: David M. Richter
Signed-off-by: J. Bruce Fields -
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
Signed-off-by: J. Bruce Fields -
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
Signed-off-by: J. Bruce Fields -
Fixes a return-value mixup from 85c59580b30c82aa771aa33b37217a6b6851bc14
"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
Signed-off-by: J. Bruce Fields
19 Apr, 2008
1 commit
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None of these files use any of the functionality promised by
asm/semaphore.h.Signed-off-by: Matthew Wilcox
15 Apr, 2008
1 commit
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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:
7723ec9777d9832849b76475b1a21a2872a40d20 "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
Tested-by: Miklos Szeredi
Cc: Trond Myklebust
Cc: Marc Eshel
Signed-off-by: Linus Torvalds
20 Mar, 2008
1 commit
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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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Feb, 2008
1 commit
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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
Reviewed-by: Oleg Nesterov
Cc: "Eric W. Biederman"
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Feb, 2008
3 commits
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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
Acked-by: Serge Hallyn
Cc: "Eric W. Biederman"
Signed-off-by: Andrew Morton
Signed-off-by: J. Bruce Fields -
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
Signed-off-by: J. Bruce Fields -
For such a short function (with such a long comment),
posix_locks_deadlock() seems to cause a lot of confusion. Attempt to
make it a bit clearer:- Remove the initial posix_same_owner() check, which can never
pass (since this is only called in the case that block_fl and
caller_fl conflict)
- Use an explicit loop (and a helper function) instead of a goto.
- Rewrite the comment, attempting a clearer explanation, and
removing some uninteresting historical detail.Signed-off-by: J. Bruce Fields
31 Oct, 2007
1 commit
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It's currently possible to send posix_locks_deadlock() into an infinite
loop (under the BKL).For now, fix this just by bailing out after a few iterations. We may
want to fix this in a way that better clarifies the semantics of
deadlock detection. But that will take more time, and this minimal fix
is probably adequate for any realistic scenario, and is simple enough to
be appropriate for applying to stable kernels now.Thanks to George Davis for reporting the problem.
Cc: "George G. Davis"
Signed-off-by: J. Bruce Fields
Acked-by: Alan Cox
Signed-off-by: Linus Torvalds
17 Oct, 2007
1 commit
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Slab constructors currently have a flags parameter that is never used. And
the order of the arguments is opposite to other slab functions. The object
pointer is placed before the kmem_cache pointer.Convert
ctor(void *object, struct kmem_cache *s, unsigned long flags)
to
ctor(struct kmem_cache *s, void *object)
throughout the kernel
[akpm@linux-foundation.org: coupla fixes]
Signed-off-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Oct, 2007
9 commits
-
Currently /proc/locks is shown with a proc_read function, but its behavior
is rather complex as it has to manually handle current offset and buffer
length. On the other hand, files that show objects from lists can be
easily reimplemented using the sequential files and the seq_list_XXX()
helpers.This saves (as usually) 16 lines of code and more than 200 from
the .text section.[akpm@linux-foundation.org: no externs in C]
[akpm@linux-foundation.org: warning fixes]
Signed-off-by: Pavel Emelyanov
Cc: "J. Bruce Fields"
Cc: Trond Myklebust
Signed-off-by: Andrew Morton -
fs/locks.c: use list_for_each_entry() instead of list_for_each() in
posix_locks_deadlock() and get_locks_status()Signed-off-by: Matthias Kaehlcke
Signed-off-by: Andrew Morton -
The combination of S_ISGID bit set and S_IXGRP bit unset is used to mark the
inode as "mandatory lockable" and there's a macro for this check called
MANDATORY_LOCK(inode). However, fs/locks.c and some filesystems still perform
the explicit i_mode checking. Besides, Andrew pointed out, that this macro is
buggy itself, as it dereferences the inode arg twice.Convert this macro into static inline function and switch its users to it,
making the code shorter and more readable.The __mandatory_lock() helper is to be used in places where the IS_MANDLOCK()
for superblock is already known to be true.Signed-off-by: Pavel Emelyanov
Cc: Trond Myklebust
Cc: "J. Bruce Fields"
Cc: David Howells
Cc: Eric Van Hensbergen
Cc: Ron Minnich
Cc: Latchesar Ionkov
Cc: Steven Whitehouse
Signed-off-by: Andrew Morton -
This code is run under lock_kernel(), which is dropped during
sleeping operations, so the following race is possible:CPU1: CPU2:
vfs_setlease(); vfs_setlease();
lock_kernel();
lock_kernel(); /* spin */
generic_setlease():
...
for (before = ...)
/* here we found some lease after
* which we will insert the new one
*/
fl = locks_alloc_lock();
/* go to sleep in this allocation and
* drop the BKL
*/
generic_setlease():
...
for (before = ...)
/* here we find the "before" pointing
* at the one we found on CPU1
*/
->fl_change(my_before, arg);
lease_modify();
locks_free_lock();
/* and we freed it */
...
unlock_kernel();
locks_insert_lock(before, fl);
/* OOPS! We have just tried to add the lease
* at the tail of already removed one
*/The similar races are already handled in other code - all the
allocations are performed before any checks/updates.Thanks to Kamalesh Babulal for testing and for a bug report on an
earlier version.Signed-off-by: Pavel Emelyanov
Signed-off-by: J. Bruce Fields
Cc: Kamalesh Babulal -
This routine deletes all the elements from the list
with the "while (!list_empty())" loop, and we already
have a list_first_entry() macro to help it look nicer :)Signed-off-by: Pavel Emelyanov
-
This comment wasn't updated when lease support was added, and it makes
essentially the same mistake that the code made before a recent bugfix.Signed-off-by: J. Bruce Fields
-
When the flock_lock_file() is called to change the flock
from F_RDLCK to F_WRLCK or vice versa the existing flock
can be removed without appropriate warning.Look:
for_each_lock(inode, before) {
struct file_lock *fl = *before;
if (IS_POSIX(fl))
break;
if (IS_LEASE(fl))
continue;
if (filp != fl->fl_file)
continue;
if (request->fl_type == fl->fl_type)
goto out;
found = 1;
locks_delete_lock(before); <<<<<< !
break;
}if after this point the subsequent locks_alloc_lock() will
fail the return code will be -ENOMEM, but the existing lock
is already removed.This is a known feature that such "re-locking" is not atomic,
but in the racy case the file should stay locked (although by
some other process), but in this case the file will be unlocked.The proposal is to prepare the lock in advance keeping no chance
to fail in the future code.Found during making the flocks pid-namespaces aware.
(Note: Thanks to Reuben Farrelly for finding a bug in an earlier version
of this patch.)Signed-off-by: Pavel Emelyanov
Signed-off-by: J. Bruce Fields
Cc: Reuben Farrelly -
There's no need for another variable local to this loop; we can use the
variable (of the same name!) already declared at the top of the function,
and not used till later (at which point it's initialized, so this is safe).Signed-off-by: J. Bruce Fields
-
The first argument to posix_locks_conflict() is meant to be a lock request,
and the second a lock from an inode's lock request. It doesn't really
make a difference which order you call them in, since the only
asymmetric test in posix_lock_conflict() is the check whether the second
argument is a posix lock--and every caller already does that check for
some reason.But may as well fix posix_test_lock() to call posix_locks_conflict()
with the arguments in the same order as everywhere else.Signed-off-by: "J. Bruce Fields"
12 Sep, 2007
1 commit
-
The inode->i_flock list contains the leases, flocks and posix
locks in the specified order. However, the flocks are added in
the head of this list thus hiding the leases from F_GETLEASE
command, from time_out_leases() and other code that expects
the leases to come first.The following example will demonstrate this:
#define _GNU_SOURCE
#include
#include
#include
#includestatic void show_lease(int fd)
{
int res;res = fcntl(fd, F_GETLEASE);
switch (res) {
case F_RDLCK:
printf("Read lease\n");
break;
case F_WRLCK:
printf("Write lease\n");
break;
case F_UNLCK:
printf("No leases\n");
break;
default:
printf("Some shit\n");
break;
}
}int main(int argc, char **argv)
{
int fd, res;fd = open(argv[1], O_RDONLY);
if (fd == -1) {
perror("Can't open file");
return 1;
}res = fcntl(fd, F_SETLEASE, F_WRLCK);
if (res == -1) {
perror("Can't set lease");
return 1;
}show_lease(fd);
if (flock(fd, LOCK_SH) == -1) {
perror("Can't flock shared");
return 1;
}show_lease(fd);
return 0;
}The first call to show_lease() will show the write lease set, but
the second will show no leases.Fix the flock adding so that the leases always stay in the head
of this list.Found during making the flocks pid-namespaces aware.
Signed-off-by: Pavel Emelyanov
Acked-by: "J. Bruce Fields"
Cc: Trond Myklebust
Cc: Andrew Morton
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Aug, 2007
1 commit
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Make it a little more clear that this is the default implementation for
the setleast operation.Signed-off-by: Christoph Hellwig
Cc: Steven Whitehouse
Acked-by: "J. Bruce Fields"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Jul, 2007
1 commit
-
Slab destructors were no longer supported after Christoph's
c59def9f222d44bb7e2f0a559f2906191a0862d7 change. They've been
BUGs for both slab and slub, and slob never supported them
either.This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).Signed-off-by: Paul Mundt
19 Jul, 2007
1 commit
-
Thanks to Doug Chapman for pointing out that the comment here is
inconsistent with the function prototype.Signed-off-by: "J. Bruce Fields"