linux/fs/lockd, branch v3.13

LOCKD: Don't call utsname()->nodename from nlmclnt_setlockargs

2013-08-05T19:03:46Z

Firstly, nlmclnt_setlockargs can be called from a reclaimer thread, in which case we're in entirely the wrong namespace. Secondly, commit 8aac62706adaaf0fab02c4327761561c8bda9448 (move exit_task_namespaces() outside of exit_notify()) now means that exit_task_work() is called after exit_task_namespaces(), which triggers an Oops when we're freeing up the locks. Fix this by ensuring that we initialise the nlm_host's rpc_client at mount time, so that the cl_nodename field is initialised to the value of utsname()->nodename that the net namespace uses. Then replace the lockd callers of utsname()->nodename. Signed-off-by: Trond Myklebust Cc: Toralf Förster Cc: Oleg Nesterov Cc: Nix Cc: Jeff Layton Cc: stable@vger.kernel.org # 3.10.x

Merge branch 'for-3.11' of git://linux-nfs.org/~bfields/linux

2013-07-17T20:43:55Z

Pull nfsd bugfixes from Bruce Fields: "Just three minor bugfixes" * 'for-3.11' of git://linux-nfs.org/~bfields/linux: svcrdma: underflow issue in decode_write_list() nfsd4: fix minorversion support interface lockd: protect nlm_blocked access in nlmsvc_retry_blocked

lockd: protect nlm_blocked access in nlmsvc_retry_blocked

2013-07-11T21:24:07Z

In nlmsvc_retry_blocked, the check that the list is non-empty and acquiring the pointer of the first entry is unprotected by any lock. This allows a rare race condition when there is only one entry on the list. A function such as nlmsvc_grant_callback() can be called, which will temporarily remove the entry from the list. Between the list_empty() and list_entry(),the list may become empty, causing an invalid pointer to be used as an nlm_block, leading to a possible crash. This patch adds the nlm_block_lock around these calls to prevent concurrent use of the nlm_blocked list. This was a regression introduced by f904be9cc77f361d37d71468b13ff3d1a1823dea "lockd: Mostly remove BKL from the server". Cc: Bryan Schumaker Cc: stable@vger.kernel.org Signed-off-by: David Jeffery Signed-off-by: J. Bruce Fields

drivers: avoid parsing names as kthread_run() format strings

2013-07-03T23:07:41Z

Calling kthread_run with a single name parameter causes it to be handled as a format string. Many callers are passing potentially dynamic string content, so use "%s" in those cases to avoid any potential accidents. Signed-off-by: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

locks: add a new "lm_owner_key" lock operation

2013-06-29T08:57:45Z

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 Acked-by: J. Bruce Fields Signed-off-by: Al Viro

locks: protect most of the file_lock handling with i_lock

2013-06-29T08:57:42Z

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 Signed-off-by: Al Viro

locks: drop the unused filp argument to posix_unblock_lock

2013-06-29T08:57:37Z

Signed-off-by: Jeff Layton Signed-off-by: Al Viro

LOCKD: Ensure that nlmclnt_block resets block->b_status after a server reboot

2013-04-21T22:08:42Z

After a server reboot, the reclaimer thread will recover all the existing locks. For locks that are blocked, however, it will change the value of block->b_status to nlm_lck_denied_grace_period in order to signal that they need to wake up and resend the original blocking lock request. Due to a bug, however, the block->b_status never gets reset after the blocked locks have been woken up, and so the process goes into an infinite loop of resends until the blocked lock is satisfied. Reported-by: Marc Eshel Signed-off-by: Trond Myklebust Cc: stable@vger.kernel.org

Merge branch 'for-3.9' of git://linux-nfs.org/~bfields/linux

2013-03-01T02:02:55Z

Pull nfsd changes from J Bruce Fields: "Miscellaneous bugfixes, plus: - An overhaul of the DRC cache by Jeff Layton. The main effect is just to make it larger. This decreases the chances of intermittent errors especially in the UDP case. But we'll need to watch for any reports of performance regressions. - Containerized nfsd: with some limitations, we now support per-container nfs-service, thanks to extensive work from Stanislav Kinsbursky over the last year." Some notes about conflicts, since there were *two* non-data semantic conflicts here: - idr_remove_all() had been added by a memory leak fix, but has since become deprecated since idr_destroy() does it for us now. - xs_local_connect() had been added by this branch to make AF_LOCAL connections be synchronous, but in the meantime Trond had changed the calling convention in order to avoid a RCU dereference. There were a couple of more obvious actual source-level conflicts due to the hlist traversal changes and one just due to code changes next to each other, but those were trivial. * 'for-3.9' of git://linux-nfs.org/~bfields/linux: (49 commits) SUNRPC: make AF_LOCAL connect synchronous nfsd: fix compiler warning about ambiguous types in nfsd_cache_csum svcrpc: fix rpc server shutdown races svcrpc: make svc_age_temp_xprts enqueue under sv_lock lockd: nlmclnt_reclaim(): avoid stack overflow nfsd: enable NFSv4 state in containers nfsd: disable usermode helper client tracker in container nfsd: use proper net while reading "exports" file nfsd: containerize NFSd filesystem nfsd: fix comments on nfsd_cache_lookup SUNRPC: move cache_detail->cache_request callback call to cache_read() SUNRPC: remove "cache_request" argument in sunrpc_cache_pipe_upcall() function SUNRPC: rework cache upcall logic SUNRPC: introduce cache_detail->cache_request callback NFS: simplify and clean cache library NFS: use SUNRPC cache creation and destruction helper for DNS cache nfsd4: free_stid can be static nfsd: keep a checksum of the first 256 bytes of request sunrpc: trim off trailing checksum before returning decrypted or integrity authenticated buffer sunrpc: fix comment in struct xdr_buf definition ...

hlist: drop the node parameter from iterators

2013-02-28T03:10:24Z

I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin Acked-by: Paul E. McKenney Signed-off-by: Sasha Levin Cc: Wu Fengguang Cc: Marcelo Tosatti Cc: Gleb Natapov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds