Commit Graph

171 Commits

Author SHA1 Message Date
Jeff Layton 7012b02a2b locks: move file_lock_list to a set of percpu hlist_heads and convert file_lock_lock to an lglock
The file_lock_list is only used for /proc/locks. The vastly common case
is for locks to be put onto the list and come off again, without ever
being traversed.

Help optimize for this use-case by moving to percpu hlist_head-s. At the
same time, we can make the locking less contentious by moving to an
lglock. When iterating over the lists for /proc/locks, we must take the
global lock and then iterate over each CPU's list in turn.

This change necessitates a new fl_link_cpu field to keep track of which
CPU the entry is on. On x86_64 at least, this field is placed within an
existing hole in the struct to avoid growing the size.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-08 13:36:42 +04:00
Al Viro 84d08fa888 helper for reading ->d_count
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-05 18:59:33 +04:00
Jeff Layton 7b2296afb3 locks: give the blocked_hash its own spinlock
There's no reason we have to protect the blocked_hash and file_lock_list
with the same spinlock. With the tests I have, breaking it in two gives
a barely measurable performance benefit, but it seems reasonable to make
this locking as granular as possible.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:46 +04:00
Jeff Layton 3999e49364 locks: add a new "lm_owner_key" lock operation
Currently, the hashing that the locking code uses to add these values
to the blocked_hash is simply calculated using fl_owner field. That's
valid in most cases except for server-side lockd, which validates the
owner of a lock based on fl_owner and fl_pid.

In the case where you have a small number of NFS clients doing a lot
of locking between different processes, you could end up with all
the blocked requests sitting in a very small number of hash buckets.

Add a new lm_owner_key operation to the lock_manager_operations that
will generate an unsigned long to use as the key in the hashtable.
That function is only implemented for server-side lockd, and simply
XORs the fl_owner and fl_pid.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:45 +04:00
Jeff Layton 48f7418654 locks: turn the blocked_list into a hashtable
Break up the blocked_list into a hashtable, using the fl_owner as a key.
This speeds up searching the hash chains, which is especially significant
for deadlock detection.

Note that the initial implementation assumes that hashing on fl_owner is
sufficient. In most cases it should be, with the notable exception being
server-side lockd, which compares ownership using a tuple of the
nlm_host and the pid sent in the lock request. So, this may degrade to a
single hash bucket when you only have a single NFS client. That will be
addressed in a later patch.

The careful observer may note that this patch leaves the file_lock_list
alone. There's much less of a case for turning the file_lock_list into a
hashtable. The only user of that list is the code that generates
/proc/locks, and it always walks the entire list.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:44 +04:00
Jeff Layton 139ca04ee5 locks: convert fl_link to a hlist_node
Testing has shown that iterating over the blocked_list for deadlock
detection turns out to be a bottleneck. In order to alleviate that,
begin the process of turning it into a hashtable. We start by turning
the fl_link into a hlist_node and the global lists into hlists. A later
patch will do the conversion of the blocked_list to a hashtable.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:44 +04:00
Jeff Layton 4e8c765d38 locks: avoid taking global lock if possible when waking up blocked waiters
Since we always hold the i_lock when inserting a new waiter onto the
fl_block list, we can avoid taking the global lock at all if we find
that it's empty when we go to wake up blocked waiters.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:43 +04:00
Jeff Layton 1c8c601a8c locks: protect most of the file_lock handling with i_lock
Having a global lock that protects all of this code is a clear
scalability problem. Instead of doing that, move most of the code to be
protected by the i_lock instead. The exceptions are the global lists
that the ->fl_link sits on, and the ->fl_block list.

->fl_link is what connects these structures to the
global lists, so we must ensure that we hold those locks when iterating
over or updating these lists.

Furthermore, sound deadlock detection requires that we hold the
blocked_list state steady while checking for loops. We also must ensure
that the search and update to the list are atomic.

For the checking and insertion side of the blocked_list, push the
acquisition of the global lock into __posix_lock_file and ensure that
checking and update of the  blocked_list is done without dropping the
lock in between.

On the removal side, when waking up blocked lock waiters, take the
global lock before walking the blocked list and dequeue the waiters from
the global list prior to removal from the fl_block list.

With this, deadlock detection should be race free while we minimize
excessive file_lock_lock thrashing.

Finally, in order to avoid a lock inversion problem when handling
/proc/locks output we must ensure that manipulations of the fl_block
list are also protected by the file_lock_lock.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:42 +04:00
Jeff Layton 8897469171 locks: encapsulate the fl_link list handling
Move the fl_link list handling routines into a separate set of helpers.
Also ensure that locks and requests are always put on global lists
last (after fully initializing them) and are taken off before unintializing
them.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:41 +04:00
Jeff Layton b9746ef80f locks: make "added" in __posix_lock_file a bool
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:40 +04:00
Jeff Layton 1cb3601259 locks: comment cleanups and clarifications
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:39 +04:00
Jeff Layton d4f22d19df locks: make generic_add_lease and generic_delete_lease static
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:39 +04:00
Jeff Layton 1a9e64a711 cifs: use posix_unblock_lock instead of locks_delete_block
commit 66189be74 (CIFS: Fix VFS lock usage for oplocked files) exported
the locks_delete_block symbol. There's already an exported helper
function that provides this capability however, so make cifs use that
instead and turn locks_delete_block back into a static function.

Note that if fl->fl_next == NULL then this lock has already been through
locks_delete_block(), so we should be OK to ignore an ENOENT error here
and simply not retry the lock.

Cc: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:38 +04:00
Jeff Layton f891a29f46 locks: drop the unused filp argument to posix_unblock_lock
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:37 +04:00
Al Viro 496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
J. Bruce Fields f474af7051 UAPI Disintegration 2012-10-09
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nfs: disintegrate UAPI for nfs

This is to complete part of the Userspace API (UAPI) disintegration for which
the preparatory patches were pulled recently.  After these patches, userspace
headers will be segregated into:

        include/uapi/linux/.../foo.h

for the userspace interface stuff, and:

        include/linux/.../foo.h

for the strictly kernel internal stuff.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-10-09 18:35:22 -04:00
Al Viro 2903ff019b switch simple cases of fget_light to fdget
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26 22:20:08 -04:00
Jeff Layton 0ee5c6d632 vfs: don't treat fl_type as a bitmap
The rules for fl_type are rather convoluted. Typically it's treated as
holding specific values, except in the case of LOCK_MAND, in which case
it can be or'ed with LOCK_READ|LOCK_WRITE.

On some arches F_WRLCK == 2 and F_UNLCK == 3, so and'ing with F_WRLCK will also
catch the F_UNLCK case. It's unlikely in either case here that we'd ever see
F_UNLCK since those shouldn't end up on any lists, but it's still best to be
consistent.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-08-20 18:39:42 -04:00
J. Bruce Fields 068535f1fe locks: remove unused lm_release_private
In commit 3b6e2723f3 ("locks: prevent side-effects of
locks_release_private before file_lock is initialized") we removed the
last user of lm_release_private without removing the field itself.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01 09:01:46 -07:00
Linus Torvalds 08843b79fb Merge branch 'nfsd-next' of git://linux-nfs.org/~bfields/linux
Pull nfsd changes from J. Bruce Fields:
 "This has been an unusually quiet cycle--mostly bugfixes and cleanup.
  The one large piece is Stanislav's work to containerize the server's
  grace period--but that in itself is just one more step in a
  not-yet-complete project to allow fully containerized nfs service.

  There are a number of outstanding delegation, container, v4 state, and
  gss patches that aren't quite ready yet; 3.7 may be wilder."

* 'nfsd-next' of git://linux-nfs.org/~bfields/linux: (35 commits)
  NFSd: make boot_time variable per network namespace
  NFSd: make grace end flag per network namespace
  Lockd: move grace period management from lockd() to per-net functions
  LockD: pass actual network namespace to grace period management functions
  LockD: manage grace list per network namespace
  SUNRPC: service request network namespace helper introduced
  NFSd: make nfsd4_manager allocated per network namespace context.
  LockD: make lockd manager allocated per network namespace
  LockD: manage grace period per network namespace
  Lockd: add more debug to host shutdown functions
  Lockd: host complaining function introduced
  LockD: manage used host count per networks namespace
  LockD: manage garbage collection timeout per networks namespace
  LockD: make garbage collector network namespace aware.
  LockD: mark host per network namespace on garbage collect
  nfsd4: fix missing fault_inject.h include
  locks: move lease-specific code out of locks_delete_lock
  locks: prevent side-effects of locks_release_private before file_lock is initialized
  NFSd: set nfsd_serv to NULL after service destruction
  NFSd: introduce nfsd_destroy() helper
  ...
2012-07-31 14:42:28 -07:00
J. Bruce Fields 96d6d59cea locks: move lease-specific code out of locks_delete_lock
No point putting something only used by one caller into common code.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-07-27 16:18:00 -04:00
Filipe Brandenburger 3b6e2723f3 locks: prevent side-effects of locks_release_private before file_lock is initialized
When calling fcntl(fd, F_SETLEASE, lck) [with lck=F_WRLCK or F_RDLCK],
the custom signal or owner (if any were previously set using F_SETSIG
or F_SETOWN fcntls) would be reset when F_SETLEASE was called for the
second time on the same file descriptor.

This bug is a regression of 2.6.37 and is described here:
https://bugzilla.kernel.org/show_bug.cgi?id=43336

This patch reverts a commit from Oct 2004 (with subject "nfs4 lease:
move the f_delown processing") which originally introduced the
lm_release_private callback.

Signed-off-by: Filipe Brandenburger <filbranden@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-07-27 09:39:55 -04:00
J. Bruce Fields 0ec4f431eb locks: fix checking of fcntl_setlease argument
The only checks of the long argument passed to fcntl(fd,F_SETLEASE,.)
are done after converting the long to an int.  Thus some illegal values
may be let through and cause problems in later code.

[ They actually *don't* cause problems in mainline, as of Dave Jones's
  commit 8d657eb3b4 "Remove easily user-triggerable BUG from
  generic_setlease", but we should fix this anyway.  And this patch will
  be necessary to fix real bugs on earlier kernels. ]

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-23 12:46:01 -07:00
Dave Jones 8d657eb3b4 Remove easily user-triggerable BUG from generic_setlease
This can be trivially triggered from userspace by passing in something unexpected.

    kernel BUG at fs/locks.c:1468!
    invalid opcode: 0000 [#1] SMP
    RIP: 0010:generic_setlease+0xc2/0x100
    Call Trace:
      __vfs_setlease+0x35/0x40
      fcntl_setlease+0x76/0x150
      sys_fcntl+0x1c6/0x810
      system_call_fastpath+0x1a/0x1f

Signed-off-by: Dave Jones <davej@redhat.com>
Cc: stable@kernel.org # 3.2+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-13 10:50:23 -07:00
Al Viro bdc689594b switch flock to fget_light/fput_light
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-29 23:28:31 -04:00
Linus Torvalds 644473e9c6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace enhancements from Eric Biederman:
 "This is a course correction for the user namespace, so that we can
  reach an inexpensive, maintainable, and reasonably complete
  implementation.

  Highlights:
   - Config guards make it impossible to enable the user namespace and
     code that has not been converted to be user namespace safe.

   - Use of the new kuid_t type ensures the if you somehow get past the
     config guards the kernel will encounter type errors if you enable
     user namespaces and attempt to compile in code whose permission
     checks have not been updated to be user namespace safe.

   - All uids from child user namespaces are mapped into the initial
     user namespace before they are processed.  Removing the need to add
     an additional check to see if the user namespace of the compared
     uids remains the same.

   - With the user namespaces compiled out the performance is as good or
     better than it is today.

   - For most operations absolutely nothing changes performance or
     operationally with the user namespace enabled.

   - The worst case performance I could come up with was timing 1
     billion cache cold stat operations with the user namespace code
     enabled.  This went from 156s to 164s on my laptop (or 156ns to
     164ns per stat operation).

   - (uid_t)-1 and (gid_t)-1 are reserved as an internal error value.
     Most uid/gid setting system calls treat these value specially
     anyway so attempting to use -1 as a uid would likely cause
     entertaining failures in userspace.

   - If setuid is called with a uid that can not be mapped setuid fails.
     I have looked at sendmail, login, ssh and every other program I
     could think of that would call setuid and they all check for and
     handle the case where setuid fails.

   - If stat or a similar system call is called from a context in which
     we can not map a uid we lie and return overflowuid.  The LFS
     experience suggests not lying and returning an error code might be
     better, but the historical precedent with uids is different and I
     can not think of anything that would break by lying about a uid we
     can't map.

   - Capabilities are localized to the current user namespace making it
     safe to give the initial user in a user namespace all capabilities.

  My git tree covers all of the modifications needed to convert the core
  kernel and enough changes to make a system bootable to runlevel 1."

Fix up trivial conflicts due to nearby independent changes in fs/stat.c

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
  userns:  Silence silly gcc warning.
  cred: use correct cred accessor with regards to rcu read lock
  userns: Convert the move_pages, and migrate_pages permission checks to use uid_eq
  userns: Convert cgroup permission checks to use uid_eq
  userns: Convert tmpfs to use kuid and kgid where appropriate
  userns: Convert sysfs to use kgid/kuid where appropriate
  userns: Convert sysctl permission checks to use kuid and kgids.
  userns: Convert proc to use kuid/kgid where appropriate
  userns: Convert ext4 to user kuid/kgid where appropriate
  userns: Convert ext3 to use kuid/kgid where appropriate
  userns: Convert ext2 to use kuid/kgid where appropriate.
  userns: Convert devpts to use kuid/kgid where appropriate
  userns: Convert binary formats to use kuid/kgid where appropriate
  userns: Add negative depends on entries to avoid building code that is userns unsafe
  userns: signal remove unnecessary map_cred_ns
  userns: Teach inode_capable to understand inodes whose uids map to other namespaces.
  userns: Fail exec for suid and sgid binaries with ids outside our user namespace.
  userns: Convert stat to return values mapped from kuids and kgids
  userns: Convert user specfied uids and gids in chown into kuids and kgid
  userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs
  ...
2012-05-23 17:42:39 -07:00
Eric W. Biederman 8e96e3b7b8 userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-05-03 03:29:34 -07:00
Pavel Shilovsky 66189be74f CIFS: Fix VFS lock usage for oplocked files
We can deadlock if we have a write oplock and two processes
use the same file handle. In this case the first process can't
unlock its lock if the second process blocked on the lock in the
same time.

Fix it by using posix_lock_file rather than posix_lock_file_wait
under cinode->lock_mutex. If we request a blocking lock and
posix_lock_file indicates that there is another lock that prevents
us, wait untill that lock is released and restart our call.

Cc: stable@kernel.org
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-04-01 13:54:27 -05:00
Linus Torvalds 6d4b9e38d3 vfs: fix handling of lock allocation failure in lease-break case
Bruce Fields notes that commit 778fc546f7 ("locks: fix tracking of
inprogress lease breaks") introduced a possible error pointer
dereference on failure to allocate memory.  locks_conflict() will
dereference the passed-in new lease lock structure that may be an error pointer.

This means an open (without O_NONBLOCK set) on a file with a lease
applied (generally only done when Samba or nfsd (with v4) is running)
could crash if a kmalloc() fails.

So instead of playing games with IS_ERROR() all over the place, just
check the allocation failure early.  That makes the code more
straightforward, and avoids this possible bad pointer dereference.

Based-on-patch-by: J. Bruce Fields <bfields@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-12-26 10:25:26 -08:00
Linus Torvalds 1442d1678c Merge branch 'for-3.2' of git://linux-nfs.org/~bfields/linux
* 'for-3.2' of git://linux-nfs.org/~bfields/linux: (103 commits)
  nfs41: implement DESTROY_CLIENTID operation
  nfsd4: typo logical vs bitwise negate for want_mask
  nfsd4: allow NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL | NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED
  nfsd4: seq->status_flags may be used unitialized
  nfsd41: use SEQ4_STATUS_BACKCHANNEL_FAULT when cb_sequence is invalid
  nfsd4: implement new 4.1 open reclaim types
  nfsd4: remove unneeded CLAIM_DELEGATE_CUR workaround
  nfsd4: warn on open failure after create
  nfsd4: preallocate open stateid in process_open1()
  nfsd4: do idr preallocation with stateid allocation
  nfsd4: preallocate nfs4_file in process_open1()
  nfsd4: clean up open owners on OPEN failure
  nfsd4: simplify process_open1 logic
  nfsd4: make is_open_owner boolean
  nfsd4: centralize renew_client() calls
  nfsd4: typo logical vs bitwise negate
  nfs: fix bug about IPv6 address scope checking
  nfsd4: more robust ignoring of WANT bits in OPEN
  nfsd4: move name-length checks to xdr
  nfsd4: move access/deny validity checks to xdr code
  ...
2011-10-25 15:42:01 +02:00
Paul Bolle 395cf9691d doc: fix broken references
There are numerous broken references to Documentation files (in other
Documentation files, in comments, etc.). These broken references are
caused by typo's in the references, and by renames or removals of the
Documentation files. Some broken references are simply odd.

Fix these broken references, sometimes by dropping the irrelevant text
they were part of.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-09-27 18:08:04 +02:00
J. Bruce Fields 8335ebd94b leases: split up generic_setlease into lock/unlock cases
Eventually we should probably do the same thing to the file operations
as well.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-09-21 10:40:54 -04:00
J. Bruce Fields c1f24ef4ed locks: setlease cleanup
There's an incorrect comment here.  Also clean up the logic: the
"rdlease" and "wrlease" locals are confusingly named, and don't really
add anything since we can make a decision as soon as we hit one of these
cases.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-08-19 13:25:35 -04:00
J. Bruce Fields 778fc546f7 locks: fix tracking of inprogress lease breaks
We currently use a bit in fl_flags to record whether a lease is being
broken, and set fl_type to the type (RDLCK or UNLCK) that it will
eventually have.  This means that once the lease break starts, we forget
what the lease's type *used* to be.  Breaking a read lease will then
result in blocking read opens, even though there's no conflict--because
the lease type is now F_UNLCK and we can no longer tell whether it was
previously a read or write lease.

So, instead keep fl_type as the original type (the type which we
enforce), and keep track of whether we're unlocking or merely
downgrading by replacing the single FL_INPROGRESS flag by
FL_UNLOCK_PENDING and FL_DOWNGRADE_PENDING flags.

To get this right we also need to track separate downgrade and break
times, to handle the case where a write-leased file gets conflicting
opens first for read, then later for write.

(I first considered just eliminating the downgrade behavior
completely--nfsv4 doesn't need it, and nobody as far as I can tell
actually uses it currently--but Jeremy Allison tells me that Windows
oplocks do behave this way, so Samba will probably use this some day.)

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-08-19 13:25:34 -04:00
J. Bruce Fields 710b721696 locks: move F_INPROGRESS from fl_type to fl_flags field
F_INPROGRESS isn't exposed to userspace.  To me it makes more sense in
fl_flags....

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-08-19 13:25:34 -04:00
J. Bruce Fields ab83fa4b49 locks: minor lease cleanup
Use a helper function, to simplify upcoming changes.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-08-19 13:25:33 -04:00
J. Bruce Fields 8fb47a4fbf locks: rename lock-manager ops
Both the filesystem and the lock manager can associate operations with a
lock.  Confusingly, one of them (fl_release_private) actually has the
same name in both operation structures.

It would save some confusion to give the lock-manager ops different
names.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-07-20 20:23:19 -04:00
Miklos Szeredi ee19cc406d fs: locks: remove init_once
From: Miklos Szeredi <mszeredi@suse.cz>

Remove SLAB initialization entirely, as suggested by Bruce and Linus.
Allocate with __GFP_ZERO instead and only initialize list heads.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-07-15 19:00:39 -04:00
Miklos Szeredi a51cb91d81 fs: fix lock initialization
locks_alloc_lock() assumed that the allocated struct file_lock is
already initialized to zero members.  This is only true for the first
allocation of the structure, after reuse some of the members will have
random values.

This will for example result in passing random fl_start values to
userspace in fuse for FL_FLOCK locks, which is an information leak at
best.

Fix by reinitializing those members which may be non-zero after freeing.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-06 10:41:13 -07:00
Linus Torvalds dc87c55120 Merge branch 'for-2.6.39' of git://linux-nfs.org/~bfields/linux
* 'for-2.6.39' of git://linux-nfs.org/~bfields/linux:
  SUNRPC: Remove resource leak in svc_rdma_send_error()
  nfsd: wrong index used in inner loop
  nfsd4: fix comment and remove unused nfsd4_file fields
  nfs41: make sure nfs server return right ca_maxresponsesize_cached
  nfsd: fix compile error
  svcrpc: fix bad argument in unix_domain_find
  nfsd4: fix struct file leak
  nfsd4: minor nfs4state.c reshuffling
  svcrpc: fix rare race on unix_domain creation
  nfsd41: modify the members value of nfsd4_op_flags
  nfsd: add proc file listing kernel's gss_krb5 enctypes
  gss:krb5 only include enctype numbers in gm_upcall_enctypes
  NFSD, VFS: Remove dead code in nfsd_rename()
  nfsd: kill unused macro definition
  locks: use assign_type()
2011-03-24 08:20:39 -07:00
Namhyung Kim f32cb53219 locks: use assign_type()
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-03-07 12:05:09 -05:00
Matt Fleming ae7eb8979c fs/locks.c: Remove stale FIXME left over from BKL conversion
The comment is no longer true as (now that the BKL conversion is
finished) a spinlock _is_ now used to protect file_lock_list,
blocked_list and inode->i_flock.

Signed-off-by: Matt Fleming <matt.fleming@linux.intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2011-03-05 10:55:59 +01:00
Linus Torvalds 18bce371ae Merge branch 'for-2.6.38' of git://linux-nfs.org/~bfields/linux
* 'for-2.6.38' of git://linux-nfs.org/~bfields/linux: (62 commits)
  nfsd4: fix callback restarting
  nfsd: break lease on unlink, link, and rename
  nfsd4: break lease on nfsd setattr
  nfsd: don't support msnfs export option
  nfsd4: initialize cb_per_client
  nfsd4: allow restarting callbacks
  nfsd4: simplify nfsd4_cb_prepare
  nfsd4: give out delegations more quickly in 4.1 case
  nfsd4: add helper function to run callbacks
  nfsd4: make sure sequence flags are set after destroy_session
  nfsd4: re-probe callback on connection loss
  nfsd4: set sequence flag when backchannel is down
  nfsd4: keep finer-grained callback status
  rpc: allow xprt_class->setup to return a preexisting xprt
  rpc: keep backchannel xprt as long as server connection
  rpc: move sk_bc_xprt to svc_xprt
  nfsd4: allow backchannel recovery
  nfsd4: support BIND_CONN_TO_SESSION
  nfsd4: modify session list under cl_lock
  Documentation: fl_mylease no longer exists
  ...

Fix up conflicts in fs/nfsd/vfs.c with the vfs-scale work.  The
vfs-scale work touched some msnfs cases, and this merge removes support
for that entirely, so the conflict was trivial to resolve.
2011-01-14 13:17:26 -08:00
Nick Piggin b7ab39f631 fs: dcache scale dentry refcount
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:21 +11:00
J. Bruce Fields 255c7cf810 locks: minor setlease cleanup
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-04 16:49:29 -05:00
J. Bruce Fields c45821d263 locks: eliminate fl_mylease callback
The nfs server only supports read delegations for now, so we don't care
how conflicts are determined.  All we care is that unlocks are
recognized as matching the leases they are meant to remove.  After the
last patch, a comparison of struct files will work for that purpose.  So
we no longer need this callback.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-04 16:49:28 -05:00
Arnd Bergmann 451a3c24b0 BKL: remove extraneous #include <smp_lock.h>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-17 08:59:32 -08:00
J. Bruce Fields 8896b93f42 locks: remove dead lease error-handling code
A minor oversight from f7347ce4ee,
"fasync: re-organize fasync entry insertion to allow it under a
spinlock": this cleanup-on-error was only needed to handle -ENOMEM.  Now
that we're preallocating it's unneeded.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-11-10 14:31:29 -05:00
J. Bruce Fields 3df057ac9a locks: fix leak on merging leases
We must also free the passed-in lease in the case it wasn't used because
an existing lease was upgrade/downgraded or already existed.

Note the nfsd caller doesn't care because it's fl_change callback
returns an error in those cases.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-11-10 14:31:23 -05:00
Christoph Hellwig bb8430a2c8 locks: remove fl_copy_lock lock_manager operation
This one was only used for a nasty hack in nfsd, which has recently
been removed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-31 06:35:15 -07:00