The second parameter of wait_for_completion_interruptible_timeout()
is a jiffies value whose type is "unsigned long". Avoid an
unnecessary and potentially fraught implicit type conversion at the
wait_for_completion_interruptible_timeout() call site in
cache_wait_req().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Trond points out in commit 277f27e2f2 ("SUNRPC/cache: Allow
garbage collection of invalid cache entries") that we allow invalid
cache entries to persist indefinitely. That fix, however,
reintroduces the problem fixed by Kinglong Mee's commit d6fc8821c2
("SUNRPC/Cache: Always treat the invalid cache as unexpired"), where
an invalid cache entry is immediately removed by a flush before
mountd responds to it. The result is that the server thread that
should be waiting for mountd to fill in that entry instead gets an
-ETIMEDOUT return from cache_check(). Symptoms are the server
becoming unresponsive after a restart, reproduceable by running
pynfs 4.1 test REBT5.
Instead, take a compromise approach: allow invalid cache entries to
be removed after they expire, but not to be removed by a cache
flush.
Fixes: 277f27e2f2 ("SUNRPC/cache: Allow garbage collection ... ")
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
If the cache entry never gets initialised, we want the garbage
collector to be able to evict it. Otherwise if the upcall daemon
fails to initialise the entry, we end up never expiring it.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
[ cel: resolved a merge conflict ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
If the rpc.mountd daemon goes down, then that should not cause all
exports to start failing with ESTALE errors. Let's explicitly
distinguish between the cache upcall cases that need to time out,
and those that do not.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The timestamps for the cache are all in boottime seconds, so they
don't overflow 32-bit values, but the use of time_t is deprecated
because it generally does overflow when used with wall-clock time.
There are multiple possible ways of avoiding it:
- leave time_t, which is safe here, but forces others to
look into this code to determine that it is over and over.
- use a more generic type, like 'int' or 'long', which is known
to be sufficient here but loses the documentation of referring
to timestamps
- use ktime_t everywhere, and convert into seconds in the few
places where we want realtime-seconds. The conversion is
sometimes expensive, but not more so than the conversion we
do today.
- use time64_t to clarify that this code is safe. Nothing would
change for 64-bit architectures, but it is slightly less
efficient on 32-bit architectures.
Without a clear winner of the three approaches above, this picks
the last one, favouring readability over a small performance
loss on 32-bit architectures.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
When the exports table is changed, exportfs will usually write a new
time to the "flush" file in the nfsd.export cache procfile. This tells
the kernel to flush any entries that are older than that value.
This gives us a mechanism to tell whether an unexport might have
occurred. Add a new ->flush cache_detail operation that is called after
flushing the cache whenever someone writes to a "flush" file.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The sunrpc cache interface is susceptible to being fooled by a rogue
process just reading a 'channel' file. If this happens the kernel
may think a valid daemon exists to service the cache when it does not.
For example, the following may fool the kernel:
cat /proc/net/rpc/auth.unix.gid/channel
Change the tracking of readers to writers when considering whether a
listener exists as all valid daemon processes either open a channel
file O_RDWR or O_WRONLY. While this does not prevent a rogue process
from "stealing" a message from the kernel, it does at least improve
the kernels perception of whether a valid process servicing the cache
exists.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Now that the reader functions are all RCU protected, use a regular
spinlock rather than a reader/writer lock.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Instead of the reader/writer spinlock, allow cache lookups to use RCU
for looking up entries. This is more efficient since modifications can
occur while other entries are being looked up.
Note that for now, we keep the reader/writer spinlock until all users
have been converted to use RCU-safe freeing of their cache entries.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Make the struct cache_detail *tmpl argument of the function
cache_create_net as const as it is only getting passed to kmemup having
the argument as const void *.
Add const to the prototype too.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Pull NFS client updates from Anna Schumaker:
"Highlights include:
Stable bugfixes:
- NFSv4: Fix memory and state leak in _nfs4_open_and_get_state
- xprtrdma: Fix Read chunk padding
- xprtrdma: Per-connection pad optimization
- xprtrdma: Disable pad optimization by default
- xprtrdma: Reduce required number of send SGEs
- nlm: Ensure callback code also checks that the files match
- pNFS/flexfiles: If the layout is invalid, it must be updated before
retrying
- NFSv4: Fix reboot recovery in copy offload
- Revert "NFSv4.1: Handle NFS4ERR_BADSESSION/NFS4ERR_DEADSESSION
replies to OP_SEQUENCE"
- NFSv4: fix getacl head length estimation
- NFSv4: fix getacl ERANGE for sum ACL buffer sizes
Features:
- Add and use dprintk_cont macros
- Various cleanups to NFS v4.x to reduce code duplication and
complexity
- Remove unused cr_magic related code
- Improvements to sunrpc "read from buffer" code
- Clean up sunrpc timeout code and allow changing TCP timeout
parameters
- Remove duplicate mw_list management code in xprtrdma
- Add generic functions for encoding and decoding xdr streams
Bugfixes:
- Clean up nfs_show_mountd_netid
- Make layoutreturn_ops static and use NULL instead of 0 to fix
sparse warnings
- Properly handle -ERESTARTSYS in nfs_rename()
- Check if register_shrinker() failed during rpcauth_init()
- Properly clean up procfs/pipefs entries
- Various NFS over RDMA related fixes
- Silence unititialized variable warning in sunrpc"
* tag 'nfs-for-4.11-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (64 commits)
NFSv4: fix getacl ERANGE for some ACL buffer sizes
NFSv4: fix getacl head length estimation
Revert "NFSv4.1: Handle NFS4ERR_BADSESSION/NFS4ERR_DEADSESSION replies to OP_SEQUENCE"
NFSv4: Fix reboot recovery in copy offload
pNFS/flexfiles: If the layout is invalid, it must be updated before retrying
NFSv4: Clean up owner/group attribute decode
SUNRPC: Add a helper function xdr_stream_decode_string_dup()
NFSv4: Remove bogus "struct nfs_client" argument from decode_ace()
NFSv4: Fix the underestimation of delegation XDR space reservation
NFSv4: Replace callback string decode function with a generic
NFSv4: Replace the open coded decode_opaque_inline() with the new generic
NFSv4: Replace ad-hoc xdr encode/decode helpers with xdr_stream_* generics
SUNRPC: Add generic helpers for xdr_stream encode/decode
sunrpc: silence uninitialized variable warning
nlm: Ensure callback code also checks that the files match
sunrpc: Allow xprt->ops->timer method to sleep
xprtrdma: Refactor management of mw_list field
xprtrdma: Handle stale connection rejection
xprtrdma: Properly recover FRWRs with in-flight FASTREG WRs
xprtrdma: Shrink send SGEs array
...
Pull nfsd updates from Bruce Fields:
"The nfsd update this round is mainly a lot of miscellaneous cleanups
and bugfixes.
A couple changes could theoretically break working setups on upgrade.
I don't expect complaints in practice, but they seem worth calling out
just in case:
- NFS security labels are now off by default; a new security_label
export flag reenables it per export. But, having them on by default
is a disaster, as it generally only makes sense if all your clients
and servers have similar enough selinux policies. Thanks to Jason
Tibbitts for pointing this out.
- NFSv4/UDP support is off. It was never really supported, and the
spec explicitly forbids it. We only ever left it on out of
laziness; thanks to Jeff Layton for finally fixing that"
* tag 'nfsd-4.11' of git://linux-nfs.org/~bfields/linux: (34 commits)
nfsd: Fix display of the version string
nfsd: fix configuration of supported minor versions
sunrpc: don't register UDP port with rpcbind when version needs congestion control
nfs/nfsd/sunrpc: enforce transport requirements for NFSv4
sunrpc: flag transports as having congestion control
sunrpc: turn bitfield flags in svc_version into bools
nfsd: remove superfluous KERN_INFO
nfsd: special case truncates some more
nfsd: minor nfsd_setattr cleanup
NFSD: Reserve adequate space for LOCKT operation
NFSD: Get response size before operation for all RPCs
nfsd/callback: Drop a useless data copy when comparing sessionid
nfsd/callback: skip the callback tag
nfsd/callback: Cleanup callback cred on shutdown
nfsd/idmap: return nfserr_inval for 0-length names
SUNRPC/Cache: Always treat the invalid cache as unexpired
SUNRPC: Drop all entries from cache_detail when cache_purge()
svcrdma: Poll CQs in "workqueue" mode
svcrdma: Combine list fields in struct svc_rdma_op_ctxt
svcrdma: Remove unused sc_dto_q field
...
When the first time pynfs runs after rpc/nfsd startup, always get the warning,
"Got error: Connection closed"
I found the problem is caused by,
1. A new startup of nfsd, rpc.mountd, etc,
2. A rpc request from client (pynfs test, or normal mounting),
3. An ip_map cache is created but invalid, so upcall to rpc.mountd,
4. rpc.mountd process the ip_map upcall, before write the valid data to nfsd,
do auth_reload(), and check_useipaddr(),
5. For the first time, old_use_ipaddr = -1, it causes rpc.mountd do write_flush that doing cache_clean,
6. The ip_map cache will be treat as expired and clean,
7. When rpc.mountd write the valid data to nfsd, a new ip_map is created
and updated, the cache_check of old ip_map(doing the upcall) will
return -ETIMEDOUT.
8. RPC layer return SVC_CLOSE and close the xprt after commit 4d712ef1db
"svcauth_gss: Close connection when dropping an incoming message"
NeilBrown suggest in another email,
"If CACHE_VALID is not set, then there is no data in the cache item,
so there is nothing to expire. So it would be nice if cache items that
don't have CACHE_VALID are never treated as expired."
v3, change the order of the two patches
v2, change the checking of CACHE_PENDING to CACHE_VALID
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We currently handle a client PROC_DESTROY request by turning it
CACHE_NEGATIVE, setting the expired time to now, and then waiting for
cache_clean to clean it up later. Since we forgot to set the cache's
nextcheck value, that could take up to 30 minutes. Also, though there's
probably no real bug in this case, setting CACHE_NEGATIVE directly like
this probably isn't a great idea in general.
So let's just remove the entry from the cache directly, and move this
bit of cache manipulation to a helper function.
Signed-off-by: Neil Brown <neilb@suse.com>
Reported-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The caches used to store sunrpc authentication information can be
flushed by writing a timestamp to a file in /proc.
This timestamp has a one-second resolution and any entry in cache that
was last_refreshed *before* that time is treated as expired.
This is problematic as it is not possible to reliably flush the cache
without interrupting NFS service.
If the current time is written to the "flush" file, any entry that was
added since the current second started will still be treated as valid.
If one second beyond than the current time is written to the file
then no entries can be valid until the second ticks over. This will
mean that no NFS request will be handled for up to 1 second.
To resolve this issue we make two changes:
1/ treat an entry as expired if the timestamp when it was last_refreshed
is before *or the same as* the expiry time. This means that current
code which writes out the current time will now flush the cache
reliably.
2/ when a new entry in added to the cache - set the last_refresh timestamp
to 1 second *beyond* the current flush time, when that not in the
past.
This ensures that newly added entries will always be valid.
Now that we have a very reliable way to flush the cache, and also
since we are using "since-boot" timestamps which are monotonic,
change cache_purge() to set the smallest future flush_time which
will work, and leave it there: don't revert to '1'.
Also disable the setting of the 'flush_time' far into the future.
That has never been useful and is now awkward as it would cause
last_refresh times to be strange.
Finally: if a request is made to set the 'flush_time' to the current
second, assume the intent is to flush the cache and advance it, if
necessary, to 1 second beyond the current 'flush_time' so that all
active entries will be deemed to be expired.
As part of this we need to add a 'cache_detail' arg to cache_init()
and cache_fresh_locked() so they can find the current ->flush_time.
Signed-off-by: NeilBrown <neilb@suse.com>
Reported-by: Olaf Kirch <okir@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Switch using list_head for cache_head in cache_detail,
it is useful of remove an cache_head entry directly from cache_detail.
v8, using hash list, not head list
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Nfsd has implement a site of seq_operations functions as sunrpc's cache.
Just exports sunrpc's codes, and remove nfsd's redundant codes.
v8, same as v6
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
1) The kernel sunrpc code needs to handle seconds since epoch
greater than 2147483647. This means functions that parse time
as an int need to handle it as time_t.
2) The kernel changes must be accompanied by userspace changes
in nfs-utils.
Signed-off-by: Harshula Jayasuriya <harshula@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
