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2011-03-10sunrpc: Propagate errors from xs_bind() through xs_create_sock()Ben Hutchings
xs_create_sock() is supposed to return a pointer or an ERR_PTR-encoded error, but it currently returns 0 if xs_bind() fails. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Cc: stable@kernel.org [v2.6.37] Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-10SUNRPC: Remove resource leak in svc_rdma_send_error()Jesper Juhl
We leak the memory allocated to 'ctxt' when we return after 'ib_dma_mapping_error()' returns !=0. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-10SUNRPC: Close a race in __rpc_wait_for_completion_task()Trond Myklebust
Although they run as rpciod background tasks, under normal operation (i.e. no SIGKILL), functions like nfs_sillyrename(), nfs4_proc_unlck() and nfs4_do_close() want to be fully synchronous. This means that when we exit, we want all references to the rpc_task to be gone, and we want any dentry references etc. held by that task to be released. For this reason these functions call __rpc_wait_for_completion_task(), followed by rpc_put_task() in the expectation that the latter will be releasing the last reference to the rpc_task, and thus ensuring that the callback_ops->rpc_release() has been called synchronously. This patch fixes a race which exists due to the fact that rpciod calls rpc_complete_task() (in order to wake up the callers of __rpc_wait_for_completion_task()) and then subsequently calls rpc_put_task() without ensuring that these two steps are done atomically. In order to avoid adding new spin locks, the patch uses the existing waitqueue spin lock to order the rpc_task reference count releases between the waiting process and rpciod. The common case where nobody is waiting for completion is optimised for by checking if the RPC_TASK_ASYNC flag is cleared and/or if the rpc_task reference count is 1: in those cases we drop trying to grab the spin lock, and immediately free up the rpc_task. Those few processes that need to put the rpc_task from inside an asynchronous context and that do not care about ordering are given a new helper: rpc_put_task_async(). Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-25NFS do not find client in NFSv4 pg_authenticateAndy Adamson
The information required to find the nfs_client cooresponding to the incoming back channel request is contained in the NFS layer. Perform minimal checking in the RPC layer pg_authenticate method, and push more detailed checking into the NFS layer where the nfs_client can be found. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-14Merge branch 'for-2.6.38' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
* '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.
2011-01-11Merge branch 'nfs-for-2.6.38' of ↵Linus Torvalds
git://git.linux-nfs.org/projects/trondmy/nfs-2.6 * 'nfs-for-2.6.38' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (89 commits) NFS fix the setting of exchange id flag NFS: Don't use vm_map_ram() in readdir NFSv4: Ensure continued open and lockowner name uniqueness NFS: Move cl_delegations to the nfs_server struct NFS: Introduce nfs_detach_delegations() NFS: Move cl_state_owners and related fields to the nfs_server struct NFS: Allow walking nfs_client.cl_superblocks list outside client.c pnfs: layout roc code pnfs: update nfs4_callback_recallany to handle layouts pnfs: add CB_LAYOUTRECALL handling pnfs: CB_LAYOUTRECALL xdr code pnfs: change lo refcounting to atomic_t pnfs: check that partial LAYOUTGET return is ignored pnfs: add layout to client list before sending rpc pnfs: serialize LAYOUTGET(openstateid) pnfs: layoutget rpc code cleanup pnfs: change how lsegs are removed from layout list pnfs: change layout state seqlock to a spinlock pnfs: add prefix to struct pnfs_layout_hdr fields pnfs: add prefix to struct pnfs_layout_segment fields ...
2011-01-11rpc: allow xprt_class->setup to return a preexisting xprtJ. Bruce Fields
This allows us to reuse the xprt associated with a server connection if one has already been set up. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-11rpc: keep backchannel xprt as long as server connectionJ. Bruce Fields
Multiple backchannels can share the same tcp connection; from rfc 5661 section 2.10.3.1: A connection's association with a session is not exclusive. A connection associated with the channel(s) of one session may be simultaneously associated with the channel(s) of other sessions including sessions associated with other client IDs. However, multiple backchannels share a connection, they must all share the same xid stream (hence the same rpc_xprt); the only way we have to match replies with calls at the rpc layer is using the xid. So, keep the rpc_xprt around as long as the connection lasts, in case we're asked to use the connection as a backchannel again. Requests to create new backchannel clients over a given server connection should results in creating new clients that reuse the existing rpc_xprt. But to start, just reject attempts to associate multiple rpc_xprt's with the same underlying bc_xprt. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-11rpc: move sk_bc_xprt to svc_xprtJ. Bruce Fields
This seems obviously transport-level information even if it's currently used only by the server socket code. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-10Merge branch 'bugfixes' into nfs-for-2.6.38Trond Myklebust
Conflicts: fs/nfs/nfs2xdr.c fs/nfs/nfs3xdr.c fs/nfs/nfs4xdr.c
2011-01-10NFS: Don't use vm_map_ram() in readdirTrond Myklebust
vm_map_ram() is not available on NOMMU platforms, and causes trouble on incoherrent architectures such as ARM when we access the page data through both the direct and the virtual mapping. The alternative is to use the direct mapping to access page data for the case when we are not crossing a page boundary, but to copy the data into a linear scratch buffer when we are accessing data that spans page boundaries. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Tested-by: Marc Kleine-Budde <mkl@pengutronix.de> Cc: stable@kernel.org [2.6.37]
2011-01-08Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (33 commits) usb: don't use flush_scheduled_work() speedtch: don't abuse struct delayed_work media/video: don't use flush_scheduled_work() media/video: explicitly flush request_module work ioc4: use static work_struct for ioc4_load_modules() init: don't call flush_scheduled_work() from do_initcalls() s390: don't use flush_scheduled_work() rtc: don't use flush_scheduled_work() mmc: update workqueue usages mfd: update workqueue usages dvb: don't use flush_scheduled_work() leds-wm8350: don't use flush_scheduled_work() mISDN: don't use flush_scheduled_work() macintosh/ams: don't use flush_scheduled_work() vmwgfx: don't use flush_scheduled_work() tpm: don't use flush_scheduled_work() sonypi: don't use flush_scheduled_work() hvsi: don't use flush_scheduled_work() xen: don't use flush_scheduled_work() gdrom: don't use flush_scheduled_work() ... Fixed up trivial conflict in drivers/media/video/bt8xx/bttv-input.c as per Tejun.
2011-01-07Merge branch 'vfs-scale-working' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin * 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits) fs: scale mntget/mntput fs: rename vfsmount counter helpers fs: implement faster dentry memcmp fs: prefetch inode data in dcache lookup fs: improve scalability of pseudo filesystems fs: dcache per-inode inode alias locking fs: dcache per-bucket dcache hash locking bit_spinlock: add required includes kernel: add bl_list xfs: provide simple rcu-walk ACL implementation btrfs: provide simple rcu-walk ACL implementation ext2,3,4: provide simple rcu-walk ACL implementation fs: provide simple rcu-walk generic_check_acl implementation fs: provide rcu-walk aware permission i_ops fs: rcu-walk aware d_revalidate method fs: cache optimise dentry and inode for rcu-walk fs: dcache reduce branches in lookup path fs: dcache remove d_mounted fs: fs_struct use seqlock fs: rcu-walk for path lookup ...
2011-01-07fs: dcache reduce branches in lookup pathNick Piggin
Reduce some branches and memory accesses in dcache lookup by adding dentry flags to indicate common d_ops are set, rather than having to check them. This saves a pointer memory access (dentry->d_op) in common path lookup situations, and saves another pointer load and branch in cases where we have d_op but not the particular operation. Patched with: git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: icache RCU free inodesNick Piggin
RCU free the struct inode. This will allow: - Subsequent store-free path walking patch. The inode must be consulted for permissions when walking, so an RCU inode reference is a must. - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want to take i_lock no longer need to take sb_inode_list_lock to walk the list in the first place. This will simplify and optimize locking. - Could remove some nested trylock loops in dcache code - Could potentially simplify things a bit in VM land. Do not need to take the page lock to follow page->mapping. The downsides of this is the performance cost of using RCU. In a simple creat/unlink microbenchmark, performance drops by about 10% due to inability to reuse cache-hot slab objects. As iterations increase and RCU freeing starts kicking over, this increases to about 20%. In cases where inode lifetimes are longer (ie. many inodes may be allocated during the average life span of a single inode), a lot of this cache reuse is not applicable, so the regression caused by this patch is smaller. The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU, however this adds some complexity to list walking and store-free path walking, so I prefer to implement this at a later date, if it is shown to be a win in real situations. I haven't found a regression in any non-micro benchmark so I doubt it will be a problem. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: change d_delete semanticsNick Piggin
Change d_delete from a dentry deletion notification to a dentry caching advise, more like ->drop_inode. Require it to be constant and idempotent, and not take d_lock. This is how all existing filesystems use the callback anyway. This makes fine grained dentry locking of dput and dentry lru scanning much simpler. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-06NFS rename client back channel transport fieldAndy Adamson
Differentiate from server backchannel Signed-off-by: Andy Adamson <andros@netapp.com> Acked-by: Bruce Fields <bfields@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06NFS associate sessionid with callback connectionAndy Adamson
The sessions based callback service is started prior to the CREATE_SESSION call so that it can handle CB_NULL requests which can be sent before the CREATE_SESSION call returns and the session ID is known. Set the callback sessionid after a sucessful CREATE_SESSION. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06SUNRPC register and unregister the back channel transportAndy Adamson
Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06SUNRPC new transport for the NFSv4.1 shared back channelAndy Adamson
Move the current sock create and destroy routines into the new transport ops. Back channel socket will be destroyed by the svc_closs_all call in svc_destroy. Added check: only TCP supported on shared back channel. Signed-off-by: Andy Adamson <andros@netapp.com> Acked-by: Bruce Fields <bfields@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06SUNRPC fix bc_send printAndy Adamson
Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06SUNRPC move svc_drop to caller of svc_process_commonAndy Adamson
The NFSv4.1 shared back channel does not need to call svc_drop because the callback service never outlives the single connection it services, and it reuses it's buffers and keeps the trasport. Signed-off-by: Andy Adamson <andros@netapp.com> Acked-by: Bruce Fields <bfields@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-04svcrpc: ensure cache_check caller sees updated entryJ. Bruce Fields
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>
2011-01-04svcrpc: take lock on turning entry NEGATIVE in cache_checkJ. Bruce Fields
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>
2011-01-04svcrpc: simpler request droppingJ. Bruce Fields
Currently we use -EAGAIN returns to determine when to drop a deferred request. On its own, that is error-prone, as it makes us treat -EAGAIN returns from other functions specially to prevent inadvertent dropping. So, use a flag on the request instead. Returning an error on request deferral is still required, to prevent further processing, but we no longer need worry that an error return on its own could result in a drop. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-04svcrpc: avoid double reply caused by deferral raceJ. Bruce Fields
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>
2011-01-04SUNRPC: Remove more code when NFSD_DEPRECATED is not configuredJ. Bruce Fields
Signed-off-by: NeilBrown <neilb@suse.de> [bfields@redhat.com: moved svcauth_unix_purge outside ifdef's.] Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-04svcrpc: modifying valid sunrpc cache entries is racyJ. Bruce Fields
Once a sunrpc cache entry is VALID, we should be replacing it (and allowing any concurrent users to destroy it on last put) instead of trying to update it in place. Otherwise someone referencing the ip_map we're modifying here could try to use the m_client just as we're putting the last reference. The bug should only be seen by users of the legacy nfsd interfaces. (Thanks to Neil for suggestion to use sunrpc_invalidate.) Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-04kernel panic when mount NFSv4Trond Myklebust
On Tue, 2010-12-14 at 16:58 +0800, Mi Jinlong wrote: > Hi, > > When testing NFSv4 at RHEL6 with kernel 2.6.32, I got a kernel panic > at NFS client's __rpc_create_common function. > > The panic place is: > rpc_mkpipe > __rpc_lookup_create() <=== find pipefile *idmap* > __rpc_mkpipe() <=== pipefile is *idmap* > __rpc_create_common() > ****** BUG_ON(!d_unhashed(dentry)); ****** *panic* > > It means that the dentry's d_flags have be set DCACHE_UNHASHED, > but it should not be set here. > > Is someone known this bug? or give me some idea? > > A reproduce program is append, but it can't reproduce the bug every time. > the export is: "/nfsroot *(rw,no_root_squash,fsid=0,insecure)" > > And the panic message is append. > > ============================================================================ > #!/bin/sh > > LOOPTOTAL=768 > LOOPCOUNT=0 > ret=0 > > while [ $LOOPCOUNT -ne $LOOPTOTAL ] > do > ((LOOPCOUNT += 1)) > service nfs restart > /usr/sbin/rpc.idmapd > mount -t nfs4 127.0.0.1:/ /mnt|| return 1; > ls -l /var/lib/nfs/rpc_pipefs/nfs/*/ > umount /mnt > echo $LOOPCOUNT > done > > =============================================================================== > Code: af 60 01 00 00 89 fa 89 f0 e8 64 cf 89 f0 e8 5c 7c 64 cf 31 c0 8b 5c 24 10 8b > 74 24 14 8b 7c 24 18 8b 6c 24 1c 83 c4 20 c3 <0f> 0b eb fc 8b 46 28 c7 44 24 08 20 > de ee f0 c7 44 24 04 56 ea > EIP:[<f0ee92ea>] __rpc_create_common+0x8a/0xc0 [sunrpc] SS:ESP 0068:eccb5d28 > ---[ end trace 8f5606cd08928ed2]--- > Kernel panic - not syncing: Fatal exception > Pid:7131, comm: mount.nfs4 Tainted: G D -------------------2.6.32 #1 > Call Trace: > [<c080ad18>] ? panic+0x42/0xed > [<c080e42c>] ? oops_end+0xbc/0xd0 > [<c040b090>] ? do_invalid_op+0x0/0x90 > [<c040b10f>] ? do_invalid_op+0x7f/0x90 > [<f0ee92ea>] ? __rpc_create_common+0x8a/0xc0[sunrpc] > [<f0edc433>] ? rpc_free_task+0x33/0x70[sunrpc] > [<f0ed6508>] ? prc_call_sync+0x48/0x60[sunrpc] > [<f0ed656e>] ? rpc_ping+0x4e/0x60[sunrpc] > [<f0ed6eaf>] ? rpc_create+0x38f/0x4f0[sunrpc] > [<c080d80b>] ? error_code+0x73/0x78 > [<f0ee92ea>] ? __rpc_create_common+0x8a/0xc0[sunrpc] > [<c0532bda>] ? d_lookup+0x2a/0x40 > [<f0ee94b1>] ? rpc_mkpipe+0x111/0x1b0[sunrpc] > [<f10a59f4>] ? nfs_create_rpc_client+0xb4/0xf0[nfs] > [<f10d6c6d>] ? nfs_fscache_get_client_cookie+0x1d/0x50[nfs] > [<f10d3fcb>] ? nfs_idmap_new+0x7b/0x140[nfs] > [<c05e76aa>] ? strlcpy+0x3a/0x60 > [<f10a60ca>] ? nfs4_set_client+0xea/0x2b0[nfs] > [<f10a6d0c>] ? nfs4_create_server+0xac/0x1b0[nfs] > [<c04f1400>] ? krealloc+0x40/0x50 > [<f10b0e8b>] ? nfs4_remote_get_sb+0x6b/0x250[nfs] > [<c04f14ec>] ? kstrdup+0x3c/0x60 > [<c0520739>] ? vfs_kern_mount+0x69/0x170 > [<f10b1a3c>] ? nfs_do_root_mount+0x6c/0xa0[nfs] > [<f10b1b47>] ? nfs4_try_mount+0x37/0xa0[nfs] > [<f10afe6d>] ? nfs4_validate_text_mount_data+-x7d/0xf0[nfs] > [<f10b1c42>] ? nfs4_get_sb+0x92/0x2f0 > [<c0520739>] ? vfs_kern_mount+0x69/0x170 > [<c05366d2>] ? get_fs_type+0x32/0xb0 > [<c052089f>] ? do_kern_mount+0x3f/0xe0 > [<c053954f>] ? do_mount+0x2ef/0x740 > [<c0537740>] ? copy_mount_options+0xb0/0x120 > [<c0539a0e>] ? sys_mount+0x6e/0xa0 Hi, Does the following patch fix the problem? Cheers Trond -------------------------- SUNRPC: Fix a BUG in __rpc_create_common From: Trond Myklebust <Trond.Myklebust@netapp.com> Mi Jinlong reports: When testing NFSv4 at RHEL6 with kernel 2.6.32, I got a kernel panic at NFS client's __rpc_create_common function. The panic place is: rpc_mkpipe __rpc_lookup_create() <=== find pipefile *idmap* __rpc_mkpipe() <=== pipefile is *idmap* __rpc_create_common() ****** BUG_ON(!d_unhashed(dentry)); ****** *panic* The test is wrong: we can find ourselves with a hashed negative dentry here if the idmapper tried to look up the file before we got round to creating it. Just replace the BUG_ON() with a d_drop(dentry). Reported-by: Mi Jinlong <mijinlong@cn.fujitsu.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-27Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: net/ipv4/fib_frontend.c
2010-12-21net/sunrpc/clnt.c: Convert sprintf_symbol to %psJoe Perches
Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-17net/sunrpc/auth_gss/gss_krb5_crypto.c: Use normal negative error value returnJoe Perches
And remove unnecessary double semicolon too. No effect to code, as test is != 0. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-12-17net: sunrpc: kill unused macrosShan Wei
These macros never be used for several years. Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-12-17sunrpc: svc_sock_names should hold ref to socket being closed.NeilBrown
Currently svc_sock_names calls svc_close_xprt on a svc_sock to which it does not own a reference. As soon as svc_close_xprt sets XPT_CLOSE, the socket could be freed by a separate thread (though this is a very unlikely race). It is safer to hold a reference while calling svc_close_xprt. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-12-17sunrpc: remove xpt_poolNeilBrown
The xpt_pool field is only used for reporting BUGs. And it isn't used correctly. In particular, when it is cleared in svc_xprt_received before XPT_BUSY is cleared, there is no guarantee that either the compiler or the CPU might not re-order to two assignments, just setting xpt_pool to NULL after XPT_BUSY is cleared. If a different cpu were running svc_xprt_enqueue at this moment, it might see XPT_BUSY clear and then xpt_pool non-NULL, and so BUG. This could be fixed by calling smp_mb__before_clear_bit() before the clear_bit. However as xpt_pool isn't really used, it seems safest to simply remove xpt_pool. Another alternate would be to change the clear_bit to clear_bit_unlock, and the test_and_set_bit to test_and_set_bit_lock. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-12-17Merge commit 'v2.6.37-rc6' into for-2.6.38J. Bruce Fields
2010-12-16SUNRPC: New xdr_streams XDR decoder APIChuck Lever
Now that all client-side XDR decoder routines use xdr_streams, there should be no need to support the legacy calling sequence [rpc_rqst *, __be32 *, RPC res *] anywhere. We can construct an xdr_stream in the generic RPC code, instead of in each decoder function. This is a refactoring change. It should not cause different behavior. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-16SUNRPC: New xdr_streams XDR encoder APIChuck Lever
Now that all client-side XDR encoder routines use xdr_streams, there should be no need to support the legacy calling sequence [rpc_rqst *, __be32 *, RPC arg *] anywhere. We can construct an xdr_stream in the generic RPC code, instead of in each encoder function. Also, all the client-side encoder functions return 0 now, making a return value superfluous. Take this opportunity to convert them to return void instead. This is a refactoring change. It should not cause different behavior. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-16SUNRPC: Determine value of "nrprocs" automaticallyChuck Lever
Clean up. Just fixed a panic where the nrprocs field in a different upper layer client was set by hand incorrectly. Use the compiler-generated method used by the other upper layer protocols. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-16SUNRPC: Avoid return code checking in rpcbind XDR encoder functionsChuck Lever
Clean up. The trend in the other XDR encoder functions is to BUG() when encoding problems occur, since a problem here is always due to a local coding error. Then, instead of a status, zero is unconditionally returned. Update the rpcbind XDR encoders to behave this way. To finish the update, use the new-style be32_to_cpup() and cpu_to_be32() macros, and compute the buffer sizes using raw integers instead of sizeof(). This matches the conventions used in other XDR functions. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-15workqueue: convert cancel_rearming_delayed_work[queue]() users to ↵Tejun Heo
cancel_delayed_work_sync() cancel_rearming_delayed_work[queue]() has been superceded by cancel_delayed_work_sync() quite some time ago. Convert all the in-kernel users. The conversions are completely equivalent and trivial. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: "David S. Miller" <davem@davemloft.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: Jeff Garzik <jgarzik@pobox.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Mauro Carvalho Chehab <mchehab@infradead.org> Cc: netdev@vger.kernel.org Cc: Anton Vorontsov <cbou@mail.ru> Cc: David Woodhouse <dwmw2@infradead.org> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Neil Brown <neilb@suse.de> Cc: Alex Elder <aelder@sgi.com> Cc: xfs-masters@oss.sgi.com Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: netfilter-devel@vger.kernel.org Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: linux-nfs@vger.kernel.org
2010-12-08sunrpc: prevent use-after-free on clearing XPT_BUSYNeilBrown
When an xprt is created, it has a refcount of 1, and XPT_BUSY is set. The refcount is *not* owned by the thread that created the xprt (as is clear from the fact that creators never put the reference). Rather, it is owned by the absence of XPT_DEAD. Once XPT_DEAD is set, (And XPT_BUSY is clear) that initial reference is dropped and the xprt can be freed. So when a creator clears XPT_BUSY it is dropping its only reference and so must not touch the xprt again. However svc_recv, after calling ->xpo_accept (and so getting an XPT_BUSY reference on a new xprt), calls svc_xprt_recieved. This clears XPT_BUSY and then svc_xprt_enqueue - this last without owning a reference. This is dangerous and has been seen to leave svc_xprt_enqueue working with an xprt containing garbage. So we need to hold an extra counted reference over that call to svc_xprt_received. For safety, any time we clear XPT_BUSY and then use the xprt again, we first get a reference, and the put it again afterwards. Note that svc_close_all does not need this extra protection as there are no threads running, and the final free can only be called asynchronously from such a thread. Signed-off-by: NeilBrown <neilb@suse.de> Cc: stable@kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-11-22SUNRPC: Fix an infinite loop in call_refresh/call_refreshresultTrond Myklebust
If the rpcauth_refreshcred() call returns an error other than EACCES, ENOMEM or ETIMEDOUT, we currently end up looping forever between call_refresh and call_refreshresult. The correct thing to do here is to exit on all errors except EAGAIN and ETIMEDOUT, for which case we retry 3 times, then return EACCES. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-11-22Net: sunrpc: auth_gss: Makefile: Remove deprecated kbuild goal definitionsTracey Dent
Changed Makefile to use <modules>-y instead of <modules>-objs because -objs is deprecated and not mentioned in Documentation/kbuild/makefiles.txt. Signed-off-by: Tracey Dent <tdent48227@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-19svcrpc: fix wspace-checking raceJ. Bruce Fields
We call svc_xprt_enqueue() after something happens which we think may require handling from a server thread. To avoid such events being lost, svc_xprt_enqueue() must guarantee that there will be a svc_serv() call from a server thread following any such event. It does that by either waking up a server thread itself, or checking that XPT_BUSY is set (in which case somebody else is doing it). But the check of XPT_BUSY could occur just as someone finishes processing some other event, and just before they clear XPT_BUSY. Therefore it's important not to clear XPT_BUSY without subsequently doing another svc_export_enqueue() to check whether the xprt should be requeued. The xpo_wspace() check in svc_xprt_enqueue() breaks this rule, allowing an event to be missed in situations like: data arrives call svc_tcp_data_ready(): call svc_xprt_enqueue(): set BUSY find no write space svc_reserve(): free up write space call svc_enqueue(): test BUSY clear BUSY So, instead, check wspace in the same places that the state flags are checked: before taking BUSY, and in svc_receive(). Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-11-19svcrpc: svc_close_xprt commentJ. Bruce Fields
Neil Brown had to explain to me why we do this here; record the answer for posterity. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-11-19svcrpc: simplify svc_close_allJ. Bruce Fields
There's no need to be fooling with XPT_BUSY now that all the threads are gone. The list_del_init() here could execute at the same time as the svc_xprt_enqueue()'s list_add_tail(), with undefined results. We don't really care at this point, but it might result in a spurious list-corruption warning or something. And svc_close() isn't adding any value; just call svc_delete_xprt() directly. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-11-19nfsd4: centralize more calls to svc_xprt_receivedJ. Bruce Fields
Follow up on b48fa6b99100dc7772af3cd276035fcec9719ceb by moving all the svc_xprt_received() calls for the main xprt to one place. The clearing of XPT_BUSY here is critical to the correctness of the server, so I'd prefer it to be obvious where we do it. The only substantive result is moving svc_xprt_received() after svc_receive_deferred(). Other than a (likely insignificant) delay waking up the next thread, that should be harmless. Also reshuffle the exit code a little to skip a few other steps that we don't care about the in the svc_delete_xprt() case. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-11-19svcrpc: don't set then immediately clear XPT_DEFERREDJ. Bruce Fields
There's no harm to doing this, since the only caller will immediately call svc_enqueue() afterwards, ensuring we don't miss the remaining deferred requests just because XPT_DEFERRED was briefly cleared. But why not just do this the simple way? Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-11-17BKL: remove extraneous #include <smp_lock.h>Arnd Bergmann
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>