Commit Graph

1468 Commits

Author SHA1 Message Date
felix
cc2e7ebbeb SUNRPC: Fix RPC client cleaned up the freed pipefs dentries
[ Upstream commit bfca5fb4e97c46503ddfc582335917b0cc228264 ]

RPC client pipefs dentries cleanup is in separated rpc_remove_pipedir()
workqueue,which takes care about pipefs superblock locking.
In some special scenarios, when kernel frees the pipefs sb of the
current client and immediately alloctes a new pipefs sb,
rpc_remove_pipedir function would misjudge the existence of pipefs
sb which is not the one it used to hold. As a result,
the rpc_remove_pipedir would clean the released freed pipefs dentries.

To fix this issue, rpc_remove_pipedir should check whether the
current pipefs sb is consistent with the original pipefs sb.

This error can be catched by KASAN:
=========================================================
[  250.497700] BUG: KASAN: slab-use-after-free in dget_parent+0x195/0x200
[  250.498315] Read of size 4 at addr ffff88800a2ab804 by task kworker/0:18/106503
[  250.500549] Workqueue: events rpc_free_client_work
[  250.501001] Call Trace:
[  250.502880]  kasan_report+0xb6/0xf0
[  250.503209]  ? dget_parent+0x195/0x200
[  250.503561]  dget_parent+0x195/0x200
[  250.503897]  ? __pfx_rpc_clntdir_depopulate+0x10/0x10
[  250.504384]  rpc_rmdir_depopulate+0x1b/0x90
[  250.504781]  rpc_remove_client_dir+0xf5/0x150
[  250.505195]  rpc_free_client_work+0xe4/0x230
[  250.505598]  process_one_work+0x8ee/0x13b0
...
[   22.039056] Allocated by task 244:
[   22.039390]  kasan_save_stack+0x22/0x50
[   22.039758]  kasan_set_track+0x25/0x30
[   22.040109]  __kasan_slab_alloc+0x59/0x70
[   22.040487]  kmem_cache_alloc_lru+0xf0/0x240
[   22.040889]  __d_alloc+0x31/0x8e0
[   22.041207]  d_alloc+0x44/0x1f0
[   22.041514]  __rpc_lookup_create_exclusive+0x11c/0x140
[   22.041987]  rpc_mkdir_populate.constprop.0+0x5f/0x110
[   22.042459]  rpc_create_client_dir+0x34/0x150
[   22.042874]  rpc_setup_pipedir_sb+0x102/0x1c0
[   22.043284]  rpc_client_register+0x136/0x4e0
[   22.043689]  rpc_new_client+0x911/0x1020
[   22.044057]  rpc_create_xprt+0xcb/0x370
[   22.044417]  rpc_create+0x36b/0x6c0
...
[   22.049524] Freed by task 0:
[   22.049803]  kasan_save_stack+0x22/0x50
[   22.050165]  kasan_set_track+0x25/0x30
[   22.050520]  kasan_save_free_info+0x2b/0x50
[   22.050921]  __kasan_slab_free+0x10e/0x1a0
[   22.051306]  kmem_cache_free+0xa5/0x390
[   22.051667]  rcu_core+0x62c/0x1930
[   22.051995]  __do_softirq+0x165/0x52a
[   22.052347]
[   22.052503] Last potentially related work creation:
[   22.052952]  kasan_save_stack+0x22/0x50
[   22.053313]  __kasan_record_aux_stack+0x8e/0xa0
[   22.053739]  __call_rcu_common.constprop.0+0x6b/0x8b0
[   22.054209]  dentry_free+0xb2/0x140
[   22.054540]  __dentry_kill+0x3be/0x540
[   22.054900]  shrink_dentry_list+0x199/0x510
[   22.055293]  shrink_dcache_parent+0x190/0x240
[   22.055703]  do_one_tree+0x11/0x40
[   22.056028]  shrink_dcache_for_umount+0x61/0x140
[   22.056461]  generic_shutdown_super+0x70/0x590
[   22.056879]  kill_anon_super+0x3a/0x60
[   22.057234]  rpc_kill_sb+0x121/0x200

Fixes: 0157d021d2 ("SUNRPC: handle RPC client pipefs dentries by network namespace aware routines")
Signed-off-by: felix <fuzhen5@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-28 17:19:49 +00:00
Trond Myklebust
993b5662f3 SUNRPC: Silence compiler complaints about tautological comparisons
On 64-bit systems, the compiler will complain that the comparison
between SIZE_MAX and the 32-bit unsigned int 'len' is unnecessary.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-09-15 15:50:39 -04:00
Anna Schumaker
c656a4d548 Revert "SUNRPC: clean up integer overflow check"
This reverts commit e87cf8a28e.

This commit was added to silence a tautological comparison warning, but
removing the 'len' value check before calling xdr_inline_decode() is
really not what we want.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-09-15 15:50:24 -04:00
Linus Torvalds
99d99825fc Merge tag 'nfs-for-6.6-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
Pull NFS client updates from Anna Schumaker:
 "New Features:
   - Enable the NFS v4.2 READ_PLUS operation by default

  Stable Fixes:
   - NFSv4/pnfs: minor fix for cleanup path in nfs4_get_device_info
   - NFS: Fix a potential data corruption

  Bugfixes:
   - Fix various READ_PLUS issues including:
      - smatch warnings
      - xdr size calculations
      - scratch buffer handling
      - 32bit / highmem xdr page handling
   - Fix checkpatch errors in file.c
   - Fix redundant readdir request after an EOF
   - Fix handling of COPY ERR_OFFLOAD_NO_REQ
   - Fix assignment of xprtdata.cred

  Cleanups:
   - Remove unused xprtrdma function declarations
   - Clean up an integer overflow check to avoid a warning
   - Clean up #includes in dns_resolve.c
   - Clean up nfs4_get_device_info so we don't pass a NULL pointer
     to __free_page()
   - Clean up sunrpc TCP socket timeout configuration
   - Guard against READDIR loops when entry names are too long
   - Use EXCHID4_FLAG_USE_PNFS_DS for DS servers"

* tag 'nfs-for-6.6-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (22 commits)
  pNFS: Fix assignment of xprtdata.cred
  NFSv4.2: fix handling of COPY ERR_OFFLOAD_NO_REQ
  NFS: Guard against READDIR loop when entry names exceed MAXNAMELEN
  NFSv4.1: use EXCHGID4_FLAG_USE_PNFS_DS for DS server
  NFS/pNFS: Set the connect timeout for the pNFS flexfiles driver
  SUNRPC: Don't override connect timeouts in rpc_clnt_add_xprt()
  SUNRPC: Allow specification of TCP client connect timeout at setup
  SUNRPC: Refactor and simplify connect timeout
  SUNRPC: Set the TCP_SYNCNT to match the socket timeout
  NFS: Fix a potential data corruption
  nfs: fix redundant readdir request after get eof
  nfs/blocklayout: Use the passed in gfp flags
  filemap: Fix errors in file.c
  NFSv4/pnfs: minor fix for cleanup path in nfs4_get_device_info
  NFS: Move common includes outside ifdef
  SUNRPC: clean up integer overflow check
  xprtrdma: Remove unused function declaration rpcrdma_bc_post_recv()
  NFS: Enable the READ_PLUS operation by default
  SUNRPC: kmap() the xdr pages during decode
  NFSv4.2: Rework scratch handling for READ_PLUS (again)
  ...
2023-08-31 15:36:41 -07:00
Yue Haibing
899525e892 SUNRPC: Remove unused declaration rpc_modcount()
These declarations are never implemented since the beginning of git
history. Remove these, then merge the two #ifdef block for
simplification.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Yue Haibing
07dc19dbd1 SUNRPC: Remove unused declarations
Commit c7d7ec8f04 ("SUNRPC: Remove svc_shutdown_net()") removed
svc_close_net() implementation but left declaration in place. Remove
it.

Commit 1f11a034cd ("SUNRPC new transport for the NFSv4.1 shared
back channel") removed svc_sock_create()/svc_sock_destroy() but not
the declarations.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
NeilBrown
2a4557452a SUNRPC: Remove return value of svc_pool_wake_idle_thread()
The returned value is not used (any more), so don't return it.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Chuck Lever
f208e9508a SUNRPC: Count ingress RPC messages per svc_pool
svc_xprt_enqueue() can be costly, since it involves selecting and
waking up a process.

More than one enqueue is done per incoming RPC. For example,
svc_data_ready() enqueues, and so does svc_xprt_receive(). Also, if
an RPC message requires more than one call to ->recvfrom() to
receive it fully, each one of those calls does an enqueue.

To get a sense of the average number of transport enqueue operations
needed to process an incoming RPC message, re-use the "packets" pool
stat. Track the number of complete RPC messages processed by each
thread pool.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Chuck Lever
850bac3ae4 SUNRPC: Deduplicate thread wake-up code
Refactor: Extract the loop that finds an idle service thread from
svc_xprt_enqueue() and svc_wake_up(). Both functions do just about
the same thing.

Note that svc_wake_up() currently does not hold the RCU read lock
while waking the target thread. It indeed should hold the lock, just
as svc_xprt_enqueue() does, to ensure the rqstp does not vanish
during the wake-up. This patch adds the RCU lock for svc_wake_up().

Note that shrinking the pool thread count is rare, and calls to
svc_wake_up() are also quite infrequent. In practice, this race is
very unlikely to be hit, so we are not marking the lock fix for
stable backport at this time.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Chuck Lever
78c542f916 SUNRPC: Add enum svc_auth_status
In addition to the benefits of using an enum rather than a set of
macros, we now have a named type that can improve static type
checking of function return values.

As part of this change, I removed a stale comment from svcauth.h;
the return values from current implementations of the
auth_ops::release method are all zero/negative errno, not the SVC_OK
enum values as the old comment suggested.

Suggested-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Chuck Lever
d75e490f35 SUNRPC: change svc_xprt::xpt_flags bits to enum
When a sequence of numbers are needed for internal-use only, an enum is
typically best.  The sequence will inevitably need to be changed one
day, and having an enum means the developer doesn't need to think about
renumbering after insertion or deletion.  Such patches will be easier
to review.

Suggested-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
NeilBrown
a6b4ec3903 SUNRPC: change svc_rqst::rq_flags bits to enum
When a sequence of numbers are needed for internal-use only, an enum is
typically best.  The sequence will inevitably need to be changed one
day, and having an enum means the developer doesn't need to think about
renumbering after insertion or deletion.  Such patches will be easier
to review.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
NeilBrown
3275694adf SUNRPC: change svc_pool::sp_flags bits to enum
When a sequence of numbers are needed for internal-use only, an enum is
typically best.  The sequence will inevitably need to be changed one
day, and having an enum means the developer doesn't need to think about
renumbering after insertion or deletion.  Such patches will be easier
to review.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
NeilBrown
ba4bba6c97 SUNRPC: change cache_head.flags bits to enum
When a sequence of numbers are needed for internal-use only, an enum is
typically best.  The sequence will inevitably need to be changed one
day, and having an enum means the developer doesn't need to think about
renumbering after insertion or deletion.  Such patches will be easier
to review.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
NeilBrown
c743b4259c SUNRPC: remove timeout arg from svc_recv()
Most svc threads have no interest in a timeout.
nfsd sets it to 1 hour, but this is a wart of no significance.

lockd uses the timeout so that it can call nlmsvc_retry_blocked().
It also sometimes calls svc_wake_up() to ensure this is called.

So change lockd to be consistent and always use svc_wake_up() to trigger
nlmsvc_retry_blocked() - using a timer instead of a timeout to
svc_recv().

And change svc_recv() to not take a timeout arg.

This makes the sp_threads_timedout counter always zero.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
NeilBrown
7b719e2bf3 SUNRPC: change svc_recv() to return void.
svc_recv() currently returns a 0 on success or one of two errors:
 - -EAGAIN means no message was successfully received
 - -EINTR means the thread has been told to stop

Previously nfsd would stop as the result of a signal as well as
following kthread_stop().  In that case the difference was useful: EINTR
means stop unconditionally.  EAGAIN means stop if kthread_should_stop(),
continue otherwise.

Now threads only exit when kthread_should_stop() so we don't need the
distinction.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
NeilBrown
18e4cf9155 nfsd: Simplify code around svc_exit_thread() call in nfsd()
Previously a thread could exit asynchronously (due to a signal) so some
care was needed to hold nfsd_mutex over the last svc_put() call.  Now a
thread can only exit when svc_set_num_threads() is called, and this is
always called under nfsd_mutex.  So no care is needed.

Not only is the mutex held when a thread exits now, but the svc refcount
is elevated, so the svc_put() in svc_exit_thread() will never be a final
put, so the mutex isn't even needed at this point in the code.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Chuck Lever
89d2d9fbea SUNRPC: Revert e0a912e8dd
Flamegraph analysis showed that the cork/uncork calls consume
nearly a third of the CPU time spent in svc_tcp_sendto(). The
other two consumers are mutex lock/unlock and svc_tcp_sendmsg().

Now that svc_tcp_sendto() coalesces RPC messages properly, there
is no need to introduce artificial delays to prevent sending
partial messages.

After applying this change, I measured a 1.2K read IOPS increase
for 8KB random I/O (several percent) on 56Gb IP over IB.

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Chuck Lever
e18e157bb5 SUNRPC: Send RPC message on TCP with a single sock_sendmsg() call
There is now enough infrastructure in place to combine the stream
record marker into the biovec array used to send each outgoing RPC
message on TCP. The whole message can be more efficiently sent with
a single call to sock_sendmsg() using a bio_vec iterator.

Note that this also helps with RPC-with-TLS: the TLS implementation
can now clearly see where the upper layer message boundaries are.
Before, it would send each component of the xdr_buf (record marker,
head, page payload, tail) in separate TLS records.

Suggested-by: David Howells <dhowells@redhat.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Chuck Lever
2eb2b93581 SUNRPC: Convert svc_tcp_sendmsg to use bio_vecs directly
Add a helper to convert a whole xdr_buf directly into an array of
bio_vecs, then send this array instead of iterating piecemeal over
the xdr_buf containing the outbound RPC message.

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
YueHaibing
f80774787a sunrpc: Remove unused extern declarations
Since commit 49b28684fd ("nfsd: Remove deprecated nfsctl system call and related code.")
these declarations are unused, so can remove it.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Chuck Lever
cb18eca4b8 NFSD: Remove svc_rqst::rq_cacherep
Over time I'd like to see NFS-specific fields moved out of struct
svc_rqst, which is an RPC layer object. These fields are layering
violations.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Trond Myklebust
d2ee413884 SUNRPC: Allow specification of TCP client connect timeout at setup
When we create a TCP transport, the connect timeout parameters are
currently fixed to be 90s. This is problematic in the pNFS flexfiles
case, where we may have multiple mirrors, and we would like to fail over
quickly to the next mirror if a data server is down.

This patch adds the ability to specify the connection parameters at RPC
client creation time.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-08-24 13:24:15 -04:00
Dan Carpenter
e87cf8a28e SUNRPC: clean up integer overflow check
This integer overflow check works as intended but Clang and GCC and warn
about it when compiling with W=1.

    include/linux/sunrpc/xdr.h:539:17: error: comparison is always false
    due to limited range of data type [-Werror=type-limits]

Use size_mul() to prevent the integer overflow.  It silences the warning
and it's cleaner as well.

Reported-by: Dmitry Antipov <dmantipov@yandex.ru>
Closes: https://lore.kernel.org/all/20230601143332.255312-1-dmantipov@yandex.ru/
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-08-24 13:24:15 -04:00
Anna Schumaker
61182c796d SUNRPC: kmap() the xdr pages during decode
If the pages are in HIGHMEM then we need to make sure they're mapped
before trying to read data off of them, otherwise we could end up with a
NULL pointer dereference.

The downside to this is that we need an extra cleanup step at the end of
decode to kunmap() the last page. I introduced an xdr_finish_decode()
function to do this. Right now this function only calls the
unmap_current_page() function, but other generic cleanup steps could be
added in the future if we come across anything else.

Reported-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-08-23 15:58:47 -04:00