Commit Graph

3011 Commits

Author SHA1 Message Date
Linus Torvalds 51de017007 Merge tag 'nfs-for-3.9-5' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull another nfs fixlet from Trond Myklebust:
 "I suddenly noticed that a one-line issue that I _thought_ I had fixed
  with the nfs41_walk_client_list patch was apparently still there in
  the pull request I sent earlier today.  I'm very sorry for not
  catching that in time.

   - Fix a brain fart in nfs41_walk_client_list"

* tag 'nfs-for-3.9-5' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv4: Doh! Typo in the fix to nfs41_walk_client_list
2013-04-10 10:26:49 -07:00
Trond Myklebust eb04e0ac19 NFSv4: Doh! Typo in the fix to nfs41_walk_client_list
Make sure that we set the status to 0 on success. Missed in testing
because it never appears when doing multiple mounts to _different_
servers.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: <stable@vger.kernel.org> # 3.7.x: 7b1f1fd: NFSv4/4.1: Fix bugs in nfs4[01]_walk_client_list
2013-04-10 12:57:29 -04:00
Linus Torvalds f94eeb423b Merge tag 'nfs-for-3.9-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
 - fix for memory corruption issues in nfs4[01]_walk_client_list (stable)
 - fix for an Oopsable bug in rpc_clone_client (stable)
 - another state manager deadlock in the NFSv4 open code
 - memory leaks in nfs4_discover_server_trunking and rpc_new_client

* tag 'nfs-for-3.9-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv4: Fix another potential state manager deadlock
  SUNRPC: Fix a potential memory leak in rpc_new_client
  NFSv4/4.1: Fix bugs in nfs4[01]_walk_client_list
  NFSv4: Fix a memory leak in nfs4_discover_server_trunking
  SUNRPC: Remove extra xprt_put()
2013-04-10 09:00:51 -07:00
Trond Myklebust fa332941c0 NFSv4: Fix another potential state manager deadlock
Don't hold the NFSv4 sequence id while we check for open permission.
The call to ACCESS may block due to reboot recovery.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-09 13:19:35 -04:00
Trond Myklebust 7b1f1fd184 NFSv4/4.1: Fix bugs in nfs4[01]_walk_client_list
It is unsafe to use list_for_each_entry_safe() here, because
when we drop the nn->nfs_client_lock, we pin the _current_ list
entry and ensure that it stays in the list, but we don't do the
same for the _next_ list entry. Use of list_for_each_entry() is
therefore the correct thing to do.

Also fix the refcounting in nfs41_walk_client_list().

Finally, ensure that the nfs_client has finished being initialised
and, in the case of NFSv4.1, that the session is set up.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
Cc: stable@vger.kernel.org [>= 3.7]
2013-04-05 16:59:19 -04:00
Trond Myklebust b193d59a48 NFSv4: Fix a memory leak in nfs4_discover_server_trunking
When we assign a new rpc_client to clp->cl_rpcclient, we need to destroy
the old one.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org [>=3.7]
2013-04-05 16:59:15 -04:00
Linus Torvalds 5d538483ea Merge tag 'nfs-for-3.9-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
 - Fix an NFSv4 idmapper regression
 - Fix an Oops in the pNFS blocks client
 - Fix up various issues with pNFS layoutcommit
 - Ensure correct read ordering of variables in
   rpc_wake_up_task_queue_locked

* tag 'nfs-for-3.9-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  SUNRPC: Add barriers to ensure read ordering in rpc_wake_up_task_queue_locked
  NFSv4.1: Add a helper pnfs_commit_and_return_layout
  NFSv4.1: Always clear the NFS_INO_LAYOUTCOMMIT in layoutreturn
  NFSv4.1: Fix a race in pNFS layoutcommit
  pnfs-block: removing DM device maybe cause oops when call dev_remove
  NFSv4: Fix the string length returned by the idmapper
2013-03-26 14:23:45 -07:00
Trond Myklebust 240286725d NFSv4.1: Add a helper pnfs_commit_and_return_layout
In order to be able to safely return the layout in nfs4_proc_setattr,
we need to block new uses of the layout, wait for all outstanding
users of the layout to complete, commit the layout and then return it.

This patch adds a helper in order to do all this safely.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
2013-03-21 10:31:21 -04:00
Trond Myklebust 2495680434 NFSv4.1: Always clear the NFS_INO_LAYOUTCOMMIT in layoutreturn
Note that clearing NFS_INO_LAYOUTCOMMIT is tricky, since it requires
you to also clear the NFS_LSEG_LAYOUTCOMMIT bits from the layout
segments.
The only two sites that need to do this are the ones that call
pnfs_return_layout() without first doing a layout commit.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Benny Halevy <bhalevy@tonian.com>
Cc: stable@vger.kernel.org
2013-03-21 10:31:21 -04:00
Trond Myklebust a073dbff35 NFSv4.1: Fix a race in pNFS layoutcommit
We need to clear the NFS_LSEG_LAYOUTCOMMIT bits atomically with the
NFS_INO_LAYOUTCOMMIT bit, otherwise we may end up with situations
where the two are out of sync.
The first half of the problem is to ensure that pnfs_layoutcommit_inode
clears the NFS_LSEG_LAYOUTCOMMIT bit through pnfs_list_write_lseg.
We still need to keep the reference to those segments until the RPC call
is finished, so in order to make it clear _where_ those references come
from, we add a helper pnfs_list_write_lseg_done() that cleans up after
pnfs_list_write_lseg.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Benny Halevy <bhalevy@tonian.com>
Cc: stable@vger.kernel.org
2013-03-21 10:31:19 -04:00
fanchaoting 4376c94618 pnfs-block: removing DM device maybe cause oops when call dev_remove
when pnfs block using device mapper,if umounting later,it maybe
cause oops. we apply "1 + sizeof(bl_umount_request)" memory for
msg->data, the memory maybe overflow when we do "memcpy(&dataptr
[sizeof(bl_msg)], &bl_umount_request, sizeof(bl_umount_request))",
because the size of bl_msg is more than 1 byte.

Signed-off-by: fanchaoting<fanchaoting@cn.fujitsu.com>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-03-21 10:11:06 -04:00
Trond Myklebust cf4ab538f1 NFSv4: Fix the string length returned by the idmapper
Functions like nfs_map_uid_to_name() and nfs_map_gid_to_group() are
expected to return a string without any terminating NUL character.
Regression introduced by commit 57e62324e4
(NFS: Store the legacy idmapper result in the keyring).

Reported-by: Dave Chiluk <dave.chiluk@canonical.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
Cc: stable@vger.kernel.org [>=3.4]
2013-03-20 16:45:16 -04:00
Eric W. Biederman fa7614ddd6 fs: Readd the fs module aliases.
I had assumed that the only use of module aliases for filesystems
prior to "fs: Limit sys_mount to only request filesystem modules."
was in request_module.  It turns out I was wrong.  At least mkinitcpio
in Arch linux uses these aliases.

So readd the preexising aliases, to keep from breaking userspace.

Userspace eventually will have to follow and use the same aliases the
kernel does.  So at some point we may be delete these aliases without
problems.  However that day is not today.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-12 18:55:21 -07:00
Eric W. Biederman 7f78e03513 fs: Limit sys_mount to only request filesystem modules.
Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives.  Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work.  While writing this patch I saw a handful of such
cases.  The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module.  The common pattern in the kernel is to call request_module()
without regards to the users permissions.  In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted.  In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-03 19:36:31 -08:00
Linus Torvalds 8d05b3771d Merge tag 'nfs-for-3.9-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
 "We've just concluded another Connectathon interoperability testing
  week, and so here are the fixes for the bugs that were discovered:

   - Don't allow NFS silly-renamed files to be deleted
   - Don't start the retransmission timer when out of socket space
   - Fix a couple of pnfs-related Oopses.
   - Fix one more NFSv4 state recovery deadlock
   - Don't loop forever when LAYOUTGET returns NFS4ERR_LAYOUTTRYLATER"

* tag 'nfs-for-3.9-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  SUNRPC: One line comment fix
  NFSv4.1: LAYOUTGET EDELAY loops timeout to the MDS
  SUNRPC: add call to get configured timeout
  PNFS: set the default DS timeout to 60 seconds
  NFSv4: Fix another open/open_recovery deadlock
  nfs: don't allow nfs_find_actor to match inodes of the wrong type
  NFSv4.1: Hold reference to layout hdr in layoutget
  pnfs: fix resend_to_mds for directio
  SUNRPC: Don't start the retransmission timer when out of socket space
  NFS: Don't allow NFS silly-renamed files to be deleted, no signal
2013-03-02 16:46:07 -08:00
Linus Torvalds b6669737d3 Merge branch 'for-3.9' of git://linux-nfs.org/~bfields/linux
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
  ...
2013-02-28 18:02:55 -08:00
Weston Andros Adamson 3000512137 NFSv4.1: LAYOUTGET EDELAY loops timeout to the MDS
The client will currently try LAYOUTGETs forever if a server is returning
NFS4ERR_LAYOUTTRYLATER or NFS4ERR_RECALLCONFLICT - even if the client no
longer needs the layout (ie process killed, unmounted).

This patch uses the DS timeout value (module parameter 'dataserver_timeo'
via rpc layer) to set an upper limit of how long the client tries LATOUTGETs
in this situation.  Once the timeout is reached, IO is redirected to the MDS.

This also changes how the client checks if a layout is on the clp list
to avoid a double list_add.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-02-28 17:41:35 -08:00
Weston Andros Adamson eb97cbb459 PNFS: set the default DS timeout to 60 seconds
The client should have 60 second default timeouts for DS operations, not 6
seconds.

NFS4_DEF_DS_TIMEO is used as "timeout in tenths of a second" in
nfs_init_timeout_values (and is not used anywhere else).
This matches up with the description of the module param dataserver_timeo.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-02-28 17:35:00 -08:00
Trond Myklebust 7aa262b522 NFSv4: Fix another open/open_recovery deadlock
If we don't release the open seqid before we wait for state recovery,
then we may end up deadlocking the state recovery thread.
This patch addresses a new deadlock that was introduced by
commit c21443c2c7 (NFSv4: Fix a reboot
recovery race when opening a file)

Reported-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-02-28 16:19:59 -08:00
Sasha Levin b67bfe0d42 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>
2013-02-27 19:10:24 -08:00
Tejun Heo d687031265 nfs4client: convert to idr_alloc()
Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:20 -08:00
Tejun Heo d97bec801d nfs: idr_destroy() no longer needs idr_remove_all()
idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.  Drop reference to idr_remove_all().  Note that the code
wasn't completely correct before because idr_remove() on all entries
doesn't necessarily release all idr_layers which could lead to memory
leak.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:14 -08:00
Jeff Layton f6488c9ba5 nfs: don't allow nfs_find_actor to match inodes of the wrong type
Benny Halevy reported the following oops when testing RHEL6:

<7>nfs_update_inode: inode 892950 mode changed, 0040755 to 0100644
<1>BUG: unable to handle kernel NULL pointer dereference at (null)
<1>IP: [<ffffffffa02a52c5>] nfs_closedir+0x15/0x30 [nfs]
<4>PGD 81448a067 PUD 831632067 PMD 0
<4>Oops: 0000 [#1] SMP
<4>last sysfs file: /sys/kernel/mm/redhat_transparent_hugepage/enabled
<4>CPU 6
<4>Modules linked in: fuse bonding 8021q garp ebtable_nat ebtables be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi softdog bridge stp llc xt_physdev ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 xt_multiport iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 dm_round_robin dm_multipath objlayoutdriver2(U) nfs(U) lockd fscache auth_rpcgss nfs_acl sunrpc vhost_net macvtap macvlan tun kvm_intel kvm be2net igb dca ptp pps_core microcode serio_raw sg iTCO_wdt iTCO_vendor_support i7core_edac edac_core shpchp ext4 mbcache jbd2 sd_mod crc_t10dif ahci dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan]
<4>
<4>Pid: 6332, comm: dd Not tainted 2.6.32-358.el6.x86_64 #1 HP ProLiant DL170e G6  /ProLiant DL170e G6
<4>RIP: 0010:[<ffffffffa02a52c5>]  [<ffffffffa02a52c5>] nfs_closedir+0x15/0x30 [nfs]
<4>RSP: 0018:ffff88081458bb98  EFLAGS: 00010292
<4>RAX: ffffffffa02a52b0 RBX: 0000000000000000 RCX: 0000000000000003
<4>RDX: ffffffffa02e45a0 RSI: ffff88081440b300 RDI: ffff88082d5f5760
<4>RBP: ffff88081458bba8 R08: 0000000000000000 R09: 0000000000000000
<4>R10: 0000000000000772 R11: 0000000000400004 R12: 0000000040000008
<4>R13: ffff88082d5f5760 R14: ffff88082d6e8800 R15: ffff88082f12d780
<4>FS:  00007f728f37e700(0000) GS:ffff8800456c0000(0000) knlGS:0000000000000000
<4>CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
<4>CR2: 0000000000000000 CR3: 0000000831279000 CR4: 00000000000007e0
<4>DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
<4>DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
<4>Process dd (pid: 6332, threadinfo ffff88081458a000, task ffff88082fa0e040)
<4>Stack:
<4> 0000000040000008 ffff88081440b300 ffff88081458bbf8 ffffffff81182745
<4><d> ffff88082d5f5760 ffff88082d6e8800 ffff88081458bbf8 ffffffffffffffea
<4><d> ffff88082f12d780 ffff88082d6e8800 ffffffffa02a50a0 ffff88082d5f5760
<4>Call Trace:
<4> [<ffffffff81182745>] __fput+0xf5/0x210
<4> [<ffffffffa02a50a0>] ? do_open+0x0/0x20 [nfs]
<4> [<ffffffff81182885>] fput+0x25/0x30
<4> [<ffffffff8117e23e>] __dentry_open+0x27e/0x360
<4> [<ffffffff811c397a>] ? inotify_d_instantiate+0x2a/0x60
<4> [<ffffffff8117e4b9>] lookup_instantiate_filp+0x69/0x90
<4> [<ffffffffa02a6679>] nfs_intent_set_file+0x59/0x90 [nfs]
<4> [<ffffffffa02a686b>] nfs_atomic_lookup+0x1bb/0x310 [nfs]
<4> [<ffffffff8118e0c2>] __lookup_hash+0x102/0x160
<4> [<ffffffff81225052>] ? selinux_inode_permission+0x72/0xb0
<4> [<ffffffff8118e76a>] lookup_hash+0x3a/0x50
<4> [<ffffffff81192a4b>] do_filp_open+0x2eb/0xdd0
<4> [<ffffffff8104757c>] ? __do_page_fault+0x1ec/0x480
<4> [<ffffffff8119f562>] ? alloc_fd+0x92/0x160
<4> [<ffffffff8117de79>] do_sys_open+0x69/0x140
<4> [<ffffffff811811f6>] ? sys_lseek+0x66/0x80
<4> [<ffffffff8117df90>] sys_open+0x20/0x30
<4> [<ffffffff8100b072>] system_call_fastpath+0x16/0x1b
<4>Code: 65 48 8b 04 25 c8 cb 00 00 83 a8 44 e0 ff ff 01 5b 41 5c c9 c3 90 55 48 89 e5 53 48 83 ec 08 0f 1f 44 00 00 48 8b 9e a0 00 00 00 <48> 8b 3b e8 13 0c f7 ff 48 89 df e8 ab 3d ec e0 48 83 c4 08 31
<1>RIP  [<ffffffffa02a52c5>] nfs_closedir+0x15/0x30 [nfs]
<4> RSP <ffff88081458bb98>
<4>CR2: 0000000000000000

I think this is ultimately due to a bug on the server. The client had
previously found a directory dentry. It then later tried to do an atomic
open on a new (regular file) dentry. The attributes it got back had the
same filehandle as the previously found directory inode. It then tried
to put the filp because it failed the aops tests for O_DIRECT opens, and
oopsed here because the ctx was still NULL.

Obviously the root cause here is a server issue, but we can take steps
to mitigate this on the client. When nfs_fhget is called, we always know
what type of inode it is. In the event that there's a broken or
malicious server on the other end of the wire, the client can end up
crashing because the wrong ops are set on it.

Have nfs_find_actor check that the inode type is correct after checking
the fileid. The fileid check should rarely ever match, so it should only
rarely ever get to this check. In the case where we have a broken
server, we may see two different inodes with the same i_ino, but the
client should be able to cope with them without crashing.

This should fix the oops reported here:

    https://bugzilla.redhat.com/show_bug.cgi?id=913660

Reported-by: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-02-27 17:28:20 -08:00
Linus Torvalds d895cb1af1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile (part one) from Al Viro:
 "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
  locking violations, etc.

  The most visible changes here are death of FS_REVAL_DOT (replaced with
  "has ->d_weak_revalidate()") and a new helper getting from struct file
  to inode.  Some bits of preparation to xattr method interface changes.

  Misc patches by various people sent this cycle *and* ocfs2 fixes from
  several cycles ago that should've been upstream right then.

  PS: the next vfs pile will be xattr stuff."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
  saner proc_get_inode() calling conventions
  proc: avoid extra pde_put() in proc_fill_super()
  fs: change return values from -EACCES to -EPERM
  fs/exec.c: make bprm_mm_init() static
  ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
  ocfs2: fix possible use-after-free with AIO
  ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
  get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
  target: writev() on single-element vector is pointless
  export kernel_write(), convert open-coded instances
  fs: encode_fh: return FILEID_INVALID if invalid fid_type
  kill f_vfsmnt
  vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
  nfsd: handle vfs_getattr errors in acl protocol
  switch vfs_getattr() to struct path
  default SET_PERSONALITY() in linux/elf.h
  ceph: prepopulate inodes only when request is aborted
  d_hash_and_lookup(): export, switch open-coded instances
  9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
  9p: split dropping the acls from v9fs_set_create_acl()
  ...
2013-02-26 20:16:07 -08:00
Jeff Layton ecf3d1f1aa vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
The following set of operations on a NFS client and server will cause

    server# mkdir a
    client# cd a
    server# mv a a.bak
    client# sleep 30  # (or whatever the dir attrcache timeout is)
    client# stat .
    stat: cannot stat `.': Stale NFS file handle

Obviously, we should not be getting an ESTALE error back there since the
inode still exists on the server. The problem is that the lookup code
will call d_revalidate on the dentry that "." refers to, because NFS has
FS_REVAL_DOT set.

nfs_lookup_revalidate will see that the parent directory has changed and
will try to reverify the dentry by redoing a LOOKUP. That of course
fails, so the lookup code returns ESTALE.

The problem here is that d_revalidate is really a bad fit for this case.
What we really want to know at this point is whether the inode is still
good or not, but we don't really care what name it goes by or whether
the dcache is still valid.

Add a new d_op->d_weak_revalidate operation and have complete_walk call
that instead of d_revalidate. The intent there is to allow for a
"weaker" d_revalidate that just checks to see whether the inode is still
good. This is also gives us an opportunity to kill off the FS_REVAL_DOT
special casing.

[AV: changed method name, added note in porting, fixed confusion re
having it possibly called from RCU mode (it won't be)]

Cc: NeilBrown <neilb@suse.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-26 02:46:09 -05:00