Cross Reference: /net/sunrpc/cache.c

History log of /net/sunrpc/cache.c
Revision	Date	Author	Comments
ecca063b31b88d31ee79e9d958ea78023659554e	15-Apr-2014	Kinglong Mee <kinglongmee@gmail.com>	SUNRPC: Fix printk that is not only for nfsd Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
63862b5bef7349dd1137e4c70702c67d77565785	11-Jan-2014	Aruna-Hewapathirane <aruna.hewapathirane@gmail.com>	net: replace macros net_random and net_srandom with direct calls to prandom This patch removes the net_random and net_srandom macros and replaces them with direct calls to the prandom ones. As new commits only seem to use prandom_u32 there is no use to keep them around. This change makes it easier to grep for users of prandom_u32. Signed-off-by: Aruna-Hewapathirane <aruna.hewapathirane@gmail.com> Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
056785ea51a657f55953f6b0195baac2cceb1f16	12-Dec-2013	Andy Shevchenko <andriy.shevchenko@linux.intel.com>	net/sunrpc/cache: simplify code by using hex_pack_byte() hex_pack_byte() is a fast way to convert a byte in its ASCII representation. We may use it instead of custom approach. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
a95e691f9c4a6e24fdeab6d7feae6d5411fe8a69	14-Jul-2013	Al Viro <viro@zeniv.linux.org.uk>	rpc_create_*_dir: don't bother with qstr just pass the name Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
0bebc633f1428163c9659fd16b34c745e60a0757	12-Jun-2013	NeilBrown <neilb@suse.de>	sunrpc: Don't schedule an upcall on a replaced cache entry. When a cache entry is replaced, the "expiry_time" get set to zero by a call to "cache_fresh_locked(..., 0)" at the end of "sunrpc_cache_update". This low expiry time makes cache_check() think that the 'refresh_age' is negative, so the 'age' is comparatively large and a refresh is triggered. However refreshing a replaced entry it pointless, it cannot achieve anything useful. So teach cache_check to ignore a low refresh_age when expiry_time is zero. Reported-by: Bodo Stroesser <bstroesser@ts.fujitsu.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
7715cde86857d4bb40f43f1ee971cf906eaf1b9c	12-Jun-2013	NeilBrown <neilb@suse.de>	net/sunrpc: xpt_auth_cache should be ignored when expired. commit d202cce8963d9268ff355a386e20243e8332b308 sunrpc: never return expired entries in sunrpc_cache_lookup moved the 'entry is expired' test from cache_check to sunrpc_cache_lookup, so that it happened early and some races could safely be ignored. However the ip_map (in svcauth_unix.c) has a separate single-item cache which allows quick lookup without locking. An entry in this case would not be subject to the expiry test and so could be used well after it has expired. This is not normally a big problem because the first time it is used after it is expired an up-call will be scheduled to refresh the entry (if it hasn't been scheduled already) and the old entry will then be invalidated. So on the second attempt to use it after it has expired, ip_map_cached_get will discard it. However that is subtle and not ideal, so replace the "!cache_valid" test with "cache_is_expired". In doing this we drop the test on the "CACHE_VALID" bit. This is unnecessary as the bit is never cleared, and an entry will only be cached if the bit is set. Reported-by: Bodo Stroesser <bstroesser@ts.fujitsu.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
013920eb5db97e99a4c30c8400f1c616e2a8b0a2	12-Jun-2013	NeilBrown <neilb@suse.de>	sunrpc/cache: ensure items removed from cache do not have pending upcalls. It is possible for a race to set CACHE_PENDING after cache_clean() has removed a cache entry from the cache. If CACHE_PENDING is still set when the entry is finally 'put', the cache_dequeue() will never happen and we can leak memory. So set a new flag 'CACHE_CLEANED' when we remove something from the cache, and don't queue any upcall if it is set. If CACHE_PENDING is set before CACHE_CLEANED, the call that cache_clean() makes to cache_fresh_unlocked() will free memory as needed. If CACHE_PENDING is set after CACHE_CLEANED, the test in sunrpc_cache_pipe_upcall will ensure that the memory is not allocated. Reported-by: <bstroesser@ts.fujitsu.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2a1c7f53fd31e46f51780b61eb99fffef4c3c5a6	12-Jun-2013	NeilBrown <neilb@suse.de>	sunrpc/cache: use cache_fresh_unlocked consistently and correctly. cache_fresh_unlocked() is called when a cache entry has been updated and ensures that if there were any pending upcalls, they are cleared. So every time we update a cache entry, we should call this, and this should be the only way that we try to clear pending calls (that sort of uniformity makes code sooo much easier to read). try_to_negate_entry() will (possibly) mark an entry as negative. If it doesn't, it is because the entry already is VALID. So the entry will be valid on exit, so it is appropriate to call cache_fresh_unlocked(). So tidy up try_to_negate_entry() to do that, and remove partial open-coded cache_fresh_unlocked() from the one call-site of try_to_negate_entry(). In the other branch of the 'switch(cache_make_upcall())', we again have a partial open-coded version of cache_fresh_unlocked(). Replace that with a real call. And again in cache_clean(), use a real call to cache_fresh_unlocked(). These call sites might previously have called cache_revisit_request() if CACHE_PENDING wasn't set. This is never necessary because cache_revisit_request() can only do anything if the item is in the cache_defer_hash, However any time that an item is added to the cache_defer_hash (setup_deferral), the code immediately tests CACHE_PENDING, and removes the entry again if it is clear. So all other places we only need to 'cache_revisit_request' if we've just cleared CACHE_PENDING. Reported-by: Bodo Stroesser <bstroesser@ts.fujitsu.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
f9e1aedc6c79f18bb56caa3735b94217c4ec1e0c	12-Jun-2013	NeilBrown <neilb@suse.de>	sunrpc/cache: remove races with queuing an upcall. We currently queue an upcall after setting CACHE_PENDING, and dequeue after clearing CACHE_PENDING. So a request should only be present when CACHE_PENDING is set. However we don't combine the test and the enqueue/dequeue in a protected region, so it is possible (if unlikely) for a race to result in a request being queued without CACHE_PENDING set, or a request to be absent despite CACHE_PENDING. So: include a test for CACHE_PENDING inside the regions of enqueue and dequeue where queue_lock is held, and abort the operation if the value is not as expected. Also remove the early 'return' from cache_dequeue() to ensure that it always removes all entries: As there is no locking between setting CACHE_PENDING and calling sunrpc_cache_pipe_upcall it is not inconceivable for some other thread to clear CACHE_PENDING and then someone else to set it and call sunrpc_cache_pipe_upcall, both before the original threads completed the call. With this, it perfectly safe and correct to: - call cache_dequeue() if and only if we have just cleared CACHE_PENDING - call sunrpc_cache_pipe_upcall() (via cache_make_upcall) if and only if we have just set CACHE_PENDING. Reported-by: Bodo Stroesser <bstroesser@ts.fujitsu.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
b6040f9706c4c81cc50b50855ed70840f022bebb	28-Mar-2013	chaoting fan <tingchaofan@gmail.com>	sunrpc: the cache_detail in cache_is_valid is unused any more The cache_detail(*detail) in function cache_is_valid is not used any more. Signed-off-by: fanchaoting <fanchaoting@cn.fujitsu.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2e0fb404c86d6c86dc33e284310eb5d28d192dcf	30-Apr-2013	Andy Shevchenko <andriy.shevchenko@linux.intel.com>	lib, net: make isodigit() public and use it There are at least two users of isodigit(). Let's make it a public function of ctype.h. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
d9dda78bad879595d8c4220a067fc029d6484a16	01-Apr-2013	Al Viro <viro@zeniv.linux.org.uk>	procfs: new helper - PDE_DATA(inode) The only part of proc_dir_entry the code outside of fs/proc really cares about is PDE(inode)->data. Provide a helper for that; static inline for now, eventually will be moved to fs/proc, along with the knowledge of struct proc_dir_entry layout. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
a7823c797b4d29727499f0a75ddf3ed07af8ad0a	22-Mar-2013	Alexey Khoroshilov <khoroshilov@ispras.ru>	SUNRPC/cache: add module_put() on error path in cache_open() If kmalloc() fails in cache_open(), module cd->owner left locked. The patch adds module_put(cd->owner) on this path. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
b67bfe0d42cac56c512dd5da4b1b347a23f4b70a	28-Feb-2013	Sasha Levin <sasha.levin@oracle.com>	hlist: drop the node parameter from iterators 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 <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
496ad9aa8ef448058e36ca7a787c61f2e63f0f54	23-Jan-2013	Al Viro <viro@zeniv.linux.org.uk>	new helper: file_inode(file) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
d94af6dea9cd680fb795dbc409a7360f1c63dc34	04-Feb-2013	Stanislav Kinsbursky <skinsbursky@parallels.com>	SUNRPC: move cache_detail->cache_request callback call to cache_read() The reason to move cache_request() callback call from sunrpc_cache_pipe_upcall() to cache_read() is that this garantees, that cache access will be done userspace process context (only userspace process have proper root context). This is required for NFSd support in container: svc_export_request() (which is cache_request callback) calls d_path(), which, in turn, traverse dentry up to current->fs->root. Kernel threads always have global root, while container have be in "root jail" - i.e. have it's own nested root. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
21cd1254d3402a72927ed744e8ac1a7cf532f1ea	04-Feb-2013	Stanislav Kinsbursky <skinsbursky@parallels.com>	SUNRPC: remove "cache_request" argument in sunrpc_cache_pipe_upcall() function Passing this pointer is redundant since it's stored on cache_detail structure, which is also passed to sunrpc_cache_pipe_upcall () function. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2d4383383b0b04ca380b67aa2d7397d0b399dcbf	04-Feb-2013	Stanislav Kinsbursky <skinsbursky@parallels.com>	SUNRPC: rework cache upcall logic For most of SUNRPC caches (except NFS DNS cache) cache_detail->cache_upcall is redundant since all that it's implementations are doing is calling sunrpc_cache_pipe_upcall() with proper function address argument. Cache request function address is now stored on cache_detail structure and thus all the code can be simplified. Now, for those cache details, which doesn't have cache_upcall callback (the only one, which still has is nfs_dns_resolve_template) sunrpc_cache_pipe_upcall will be called instead. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
ec1686761753ead775e9474a6265323a4c555bc6	04-Jan-2013	Yanchuan Nian <ycnian@gmail.com>	nfsd: Remove write permission from file content The write function doesn't be implemented in file content, and it's meaningless to write data into this file directly. Remove write permission from it. Signed-off-by: Yanchuan Nian <ycnian@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
0db74d9a2d2b312dd2cff066c5b97b8e626e403a	23-Oct-2012	Weston Andros Adamson <dros@netapp.com>	SUNRPC: remove BUG_ON calls from cache_read Replace BUG_ON() with WARN_ON_ONCE() in two parts of cache_read(). Signed-off-by: Weston Andros Adamson <dros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
212ba90696ab4884e2025b0b13726d67aadc2cd4	17-Jul-2012	Sasha Levin <levinsasha928@gmail.com>	SUNRPC: Prevent kernel stack corruption on long values of flush The buffer size in read_flush() is too small for the longest possible values for it. This can lead to a kernel stack corruption: [ 43.047329] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff833e64b4 [ 43.047329] [ 43.049030] Pid: 6015, comm: trinity-child18 Tainted: G W 3.5.0-rc7-next-20120716-sasha #221 [ 43.050038] Call Trace: [ 43.050435] [<ffffffff836c60c2>] panic+0xcd/0x1f4 [ 43.050931] [<ffffffff833e64b4>] ? read_flush.isra.7+0xe4/0x100 [ 43.051602] [<ffffffff810e94e6>] __stack_chk_fail+0x16/0x20 [ 43.052206] [<ffffffff833e64b4>] read_flush.isra.7+0xe4/0x100 [ 43.052951] [<ffffffff833e6500>] ? read_flush_pipefs+0x30/0x30 [ 43.053594] [<ffffffff833e652c>] read_flush_procfs+0x2c/0x30 [ 43.053596] [<ffffffff812b9a8c>] proc_reg_read+0x9c/0xd0 [ 43.053596] [<ffffffff812b99f0>] ? proc_reg_write+0xd0/0xd0 [ 43.053596] [<ffffffff81250d5b>] do_loop_readv_writev+0x4b/0x90 [ 43.053596] [<ffffffff81250fd6>] do_readv_writev+0xf6/0x1d0 [ 43.053596] [<ffffffff812510ee>] vfs_readv+0x3e/0x60 [ 43.053596] [<ffffffff812511b8>] sys_readv+0x48/0xb0 [ 43.053596] [<ffffffff8378167d>] system_call_fastpath+0x1a/0x1f Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Cc: stable@kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
203b42f7317494ae5e5efc7be6fb7f29c927f102	21-Aug-2012	Tejun Heo <tj@kernel.org>	workqueue: make deferrable delayed_work initializer names consistent Initalizers for deferrable delayed_work are confused. * __DEFERRED_WORK_INITIALIZER() * DECLARE_DEFERRED_WORK() * INIT_DELAYED_WORK_DEFERRABLE() Rename them to * __DEFERRABLE_WORK_INITIALIZER() * DECLARE_DEFERRABLE_WORK() * INIT_DEFERRABLE_WORK() This patch doesn't cause any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org>
200724a7074281e7a0bf1101784a59fecddfa77d	12-Jul-2012	NeilBrown <neilb@suse.de>	SUNRPC/cache: fix reporting of expired cache entries in 'content' file. Entries that are in a sunrpc cache but are not valid should be reported with a leading '#' so they look like a comment. Commit d202cce8963d9 (sunrpc: never return expired entries in sunrpc_cache_lookup) broke this for expired entries. This particularly applies to entries that have been replaced by newer entries. sunrpc_cache_update sets the expiry of the replaced entry to '0', but it remains in the cache until the next 'cache_clean'. The result is that if you echo 0 2000000000 1 0 > /proc/net/rpc/auth.unix.gid/channel several times, then cat /proc/net/rpc/auth.unix.gid/content It will display multiple entries for the one uid, which is at least confusing: #uid cnt: gids... 0 1: 0 0 1: 0 0 1: 0 With this patch, expired entries are marked as comments so you get #uid cnt: gids... 0 1: 0 # 0 1: 0 # 0 1: 0 These expired entries will never be seen by cache_check() as they are always after a non-expired entry with the same key - so the extra check is only needed in c_show() Signed-off-by: NeilBrown <neilb@suse.de> -- It's not a big problem, but it had me confused for a while, so it could well confuse others. Thanks, NeilBrown Signed-off-by: J. Bruce Fields <bfields@redhat.com>
95c961747284a6b83a5e2d81240e214b0fa3464d	15-Apr-2012	Eric Dumazet <eric.dumazet@gmail.com>	net: cleanup unsigned to unsigned int Use of "unsigned int" is preferred to bare "unsigned" in net tree. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
6d8d17499810479eabd10731179c04b2ca22152f	17-Jan-2012	Dan Carpenter <dan.carpenter@oracle.com>	nfsd: don't allow zero length strings in cache_parse() There is no point in passing a zero length string here and quite a few of that cache_parse() implementations will Oops if count is zero. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable@kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2c5f846747526e2b83c5f1b8e69016be0e2e87c0	19-Jan-2012	Stanislav Kinsbursky <skinsbursky@parallels.com>	SUNRPC: generic cache register routines removed All cache users now uses network-namespace-aware routines, so generic ones are obsolete. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: J. Bruce Fields <bfields@redhat.com>
0a402d5a653ee2b613aaba3092a87b1e964622ce	19-Jan-2012	Stanislav Kinsbursky <skinsbursky@parallels.com>	SUNRPC: cache creation and destruction routines introduced This patch prepares infrastructure for network namespace aware cache detail allocation. One note about adding network namespace link to cache structure. It's going to be used later in NFS DNS cache parsing routine (nfs_dns_parse for rpc_pton() call). Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: J. Bruce Fields <bfields@redhat.com>
820f9442e711a81749e70c40f149fc54c4ce0ca8	25-Nov-2011	Stanislav Kinsbursky <skinsbursky@parallels.com>	SUNRPC: split cache creation and PipeFS registration This precursor patch splits SUNRPC cache creation and PipeFS registartion. It's required for latter split of NFS DNS resolver cache creation per network namespace context and PipeFS registration/unregistration on MOUNT/UMOUNT events. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
64f1426f3c4f8dde9ac9bf3f3b19b88d17f2bae6	25-Jul-2011	Al Viro <viro@zeniv.linux.org.uk>	sunrpc: propagate umode_t Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
f5c8593b94190aabdcf207a544f082c7816c4fe6	06-Dec-2011	Stanislav Kinsbursky <skinsbursky@parallels.com>	NFSd: use network-namespace-aware cache registering routines v2: cache_register_net() and cache_unregister_net() GPL exports added This is a cleanup patch. Hope, some day generic cache_register() and cache_unregister() will be removed. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
fdef7aa5d4020fd94ffcbf0078d6bd9e5a111e19	04-Jan-2011	J. Bruce Fields <bfields@redhat.com>	svcrpc: ensure cache_check caller sees updated entry Supposes cache_check runs simultaneously with an update on a different CPU: cache_check task doing update ^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^ 1. test for CACHE_VALID 1'. set entry->data & !CACHE_NEGATIVE 2. use entry->data 2'. set CACHE_VALID If the two memory writes performed in step 1' and 2' appear misordered with respect to the reads in step 1 and 2, then the caller could get stale data at step 2 even though it saw CACHE_VALID set on the cache entry. Add memory barriers to prevent this. Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
6bab93f87ec703bf6650875881b11f9f27d7da56	03-Jan-2011	J. Bruce Fields <bfields@redhat.com>	svcrpc: take lock on turning entry NEGATIVE in cache_check We attempt to turn a cache entry negative in place. But that entry may already have been filled in by some other task since we last checked whether it was valid, so we could be modifying an already-valid entry. If nothing else there's a likely leak in such a case when the entry is eventually put() and contents are not freed because it has CACHE_NEGATIVE set. So, take the cache_lock just as sunrpc_cache_update() does. Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
d76d1815f3e72fb627ad7f95ef63120b0a557c9c	03-Jan-2011	J. Bruce Fields <bfields@redhat.com>	svcrpc: avoid double reply caused by deferral race Commit d29068c431599fa "sunrpc: Simplify cache_defer_req and related functions." asserted that cache_check() could determine success or failure of cache_defer_req() by checking the CACHE_PENDING bit. This isn't quite right. We need to know whether cache_defer_req() created a deferred request, in which case sending an rpc reply has become the responsibility of the deferred request, and it is important that we not send our own reply, resulting in two different replies to the same request. And the CACHE_PENDING bit doesn't tell us that; we could have succesfully created a deferred request at the same time as another thread cleared the CACHE_PENDING bit. So, partially revert that commit, to ensure that cache_check() returns -EAGAIN if and only if a deferred request has been created. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Acked-by: NeilBrown <neilb@suse.de>
a6f8dbc654c3dddc5ac98cf59a88447a90e99ece	04-Oct-2010	Arnd Bergmann <arnd@arndb.de>	sunrpc: remove the big kernel lock The sunrpc cache_ioctl function does not need the big kernel lock because it uses its own queue_lock already. rpc_pipe_ioctl apparently should be using i_lock like the other operations on the pipe file descriptor do. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
6038f373a3dc1f1c26496e60b6c40b164716f07e	15-Aug-2010	Arnd Bergmann <arnd@arndb.de>	llseek: automatically add .llseek fop All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode i, struct file f) { <+... ( nonseekable_open(...) \| nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file f, char p, size_t s, loff_t off) { <+... ( off = E \| off += E \| func(..., off, ...) \| E = off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file f, char p, size_t s, loff_t off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file f, const char p, size_t s, loff_t off) { <+... ( off = E \| off += E \| func(..., off, ...) \| E = off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file f, const char p, size_t s, loff_t off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable / }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, / open uses nonseekable / }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, / we have seq_read / }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, / readdir is present / }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, / read accesses f_pos / }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, / write accesses f_pos / }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, / read and write both use no f_pos / }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, / write uses no f_pos / }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, / read uses no f_pos / }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, / no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
e33534d54f1fde3e541f64fa5ad0dd379fc45fa7	07-Oct-2010	NeilBrown <neilb@suse.de>	sunrpc/cache: centralise handling of size limit on deferred list. We limit the number of 'defer' requests to DFR_MAX. The imposition of this limit is spread about a bit - sometime we don't add new things to the list, sometimes we remove old things. Also it is currently applied to requests which we are 'waiting' for rather than 'deferring'. This doesn't seem ideal as 'waiting' requests are naturally limited by the number of threads. So gather the DFR_MAX handling code to one place and only apply it to requests that are actually being deferred. This means that not all 'cache_deferred_req' structures go on the 'cache_defer_list, so we need to be careful when adding and removing things. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
d29068c431599fa96729556846562eb18429092d	07-Oct-2010	NeilBrown <neilb@suse.de>	sunrpc: Simplify cache_defer_req and related functions. The return value from cache_defer_req is somewhat confusing. Various different error codes are returned, but the single caller is only interested in success or failure. In fact it can measure this success or failure itself by checking CACHE_PENDING, which makes the point of the code more explicit. So change cache_defer_req to return 'void' and test CACHE_PENDING after it completes, to see if the request was actually deferred or not. Similarly setup_deferral and cache_wait_req don't need a return value, so make them void and remove some code. The call to cache_revisit_request (to guard against a race) is only needed for the second call to setup_deferral, so move it out of setup_deferral to after that second call. With the first call the race is handled differently (by explicitly calling 'wait_for_completion'). Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
277f68dbba397997c7f3dc843d14afa1654bb80e	21-Sep-2010	NeilBrown <neilb@suse.de>	sunrpc: fix race in new cache_wait code. If we set up to wait for a cache item to be filled in, and then find that it is no longer pending, it could be that some other thread is in 'cache_revisit_request' and has moved our request to its 'pending' list. So when our setup_deferral calls cache_revisit_request it will find nothing to put on the pending list, and do nothing. We then return from cache_wait_req, thus leaving the 'sleeper' on-stack structure open to being corrupted by subsequent stack usage. However that 'sleeper' could still be on the 'pending' list that the other thread is looking at and so any corruption could cause it to behave badly. To avoid this race we simply take the same path as if the 'wait_for_completion_interruptible_timeout' was interrupted and if the sleeper is no longer on the list (which it won't be) we wait on the completion - which will ensure that any other cache_revisit_request will have let go of the sleeper. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
4f42d0d53ca4737f82937edb0efc83564c124853	27-Sep-2010	Pavel Emelyanov <xemul@parallels.com>	sunrpc: Make the /proc/net/rpc appear in net namespaces Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
593ce16b943ea37d4ec62c377b32d7f3f4085e84	27-Sep-2010	Pavel Emelyanov <xemul@parallels.com>	sunrpc: Add routines that allow registering per-net caches Existing calls do the same, but for the init_net. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: J. Bruce Fields <bfields@redhat.com>