If no handler (such as rpc.mountd) has opened
a cache 'channel', the sunrpc cache responds to
all lookup requests with -ENOENT. This is particularly
important for the auth.unix.gid cache which is
optional.
If the channel was open briefly and an upcall was written to it,
this upcall remains pending even when the handler closes the
channel. When an upcall is pending, the code currently
doesn't check if there are still listeners, it only performs
that check before sending an upcall.
As the cache treads a recently closes channel (closed less than
30 seconds ago) as "potentially still open", there is a
reasonable sized window when a request can become pending
in a closed channel, and thereby block lookups indefinitely.
This can easily be demonstrated by running
cat /proc/net/rpc/auth.unix.gid/channel
and then trying to mount an NFS filesystem from this host. It
will block indefinitely (unless mountd is run with --manage-gids,
or krb5 is used).
When cache_check() finds that an upcall is pending, it should
perform the "cache_listeners_exist()" exist test. If no
listeners do exist, the request should be negated.
With this change in place, there can still be a 30second wait on
mount, until the cache gives up waiting for a handler to come
back, but this is much better than an indefinite wait.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
A recent commit added a call to cache_fresh_locked()
when an expired item was found.
The call sets the CACHE_VALID flag, so it is important
that the item actually is valid.
There are two ways it could be valid:
1/ If ->update has been called to fill in relevant content
2/ if CACHE_NEGATIVE is set, to say that content doesn't exist.
An expired item that is waiting for an update will be neither.
Setting CACHE_VALID will mean that a subsequent call to cache_put()
will be likely to dereference uninitialised pointers.
So we must make sure the item is valid, and we already have code to do
that in try_to_negate_entry(). This takes the hash lock and so cannot
be used directly, so take out the two lines that we need and use them.
Now cache_fresh_locked() is certain to be called only on
a valid item.
Cc: stable@kernel.org # 2.6.35
Fixes: 4ecd55ea07 ("sunrpc: fix cache_head leak due to queued request")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
After commit d202cce896, an expired cache_head can be removed from the
cache_detail's hash.
However, the expired cache_head may be waiting for a reply from a
previously submitted request. Such a cache_head has an increased
refcounter and therefore it won't be freed after cache_put(freeme).
Because the cache_head was removed from the hash it cannot be found
during cache_clean() and can be leaked forever, together with stalled
cache_request and other taken resources.
In our case we noticed it because an entry in the export cache was
holding a reference on a filesystem.
Fixes d202cce896 ("sunrpc: never return expired entries in sunrpc_cache_lookup")
Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: stable@kernel.org # 2.6.35
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: NeilBrown <neilb@suse.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>
Clean up the cache code by removing the non-RCU protected lookup.
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>
This is a trivial split into lookup and insert functions, no change in
behavior.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
server xdr decoding (with an eye towards eliminating a data copy in the
RDMA case).
I did some refactoring of the delegation code in preparation for
eliminating some delegation self-conflicts and implementing write
delegations.
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Merge tag 'nfsd-4.17' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
"Chuck Lever did a bunch of work on nfsd tracepoints, on RDMA, and on
server xdr decoding (with an eye towards eliminating a data copy in
the RDMA case).
I did some refactoring of the delegation code in preparation for
eliminating some delegation self-conflicts and implementing write
delegations"
* tag 'nfsd-4.17' of git://linux-nfs.org/~bfields/linux: (40 commits)
nfsd: fix incorrect umasks
sunrpc: remove incorrect HMAC request initialization
NFSD: Clean up legacy NFS SYMLINK argument XDR decoders
NFSD: Clean up legacy NFS WRITE argument XDR decoders
nfsd: Trace NFSv4 COMPOUND execution
nfsd: Add I/O trace points in the NFSv4 read proc
nfsd: Add I/O trace points in the NFSv4 write path
nfsd: Add "nfsd_" to trace point names
nfsd: Record request byte count, not count of vectors
nfsd: Fix NFSD trace points
svc: Report xprt dequeue latency
sunrpc: Report per-RPC execution stats
sunrpc: Re-purpose trace_svc_process
sunrpc: Save remote presentation address in svc_xprt for trace events
sunrpc: Simplify trace_svc_recv
sunrpc: Simplify do_enqueue tracing
sunrpc: Move trace_svc_xprt_dequeue()
sunrpc: Update show_svc_xprt_flags() to include recently added flags
svc: Simplify ->xpo_secure_port
sunrpc: Remove unneeded pointer dereference
...
Prefer the direct use of octal for permissions.
Done with checkpatch -f --types=SYMBOLIC_PERMS --fix-inplace
and some typing.
Miscellanea:
o Whitespace neatening around these conversions.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The interface for flushing the sunrpc auth cache was poorly
designed and has caused problems a number of times.
The design is that you write a timestamp, and all entries
created before that time are discarded.
The most obvious problem is that this is not what people
actually want. They want to just flush the whole cache.
The 1-second granularity can be a problem, as can the use
of wall-clock time.
A current problem is that code will write the current time to
this file - expecting it to clear everything - and if the
seconds number ticks over before this timestamp is checked,
the test "then >= now" fails, and a full flush isn't forced.
So lets just drop the subtleties and always flush the whole
cache. The worst this could do is impose an extra cost
refilling it, but that would require someone to be using
non-standard tools.
We still report an error if the string written is not a number,
but we cause any valid number to flush the whole cache.
Reported-by: "Wang, Alan 1. (NSB - CN/Hangzhou)" <alan.1.wang@nokia-sbell.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:
for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done
with de-mangling cleanups yet to come.
NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.
The next patch from Al will sort out the final differences, and we
should be all done.
Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull poll annotations from Al Viro:
"This introduces a __bitwise type for POLL### bitmap, and propagates
the annotations through the tree. Most of that stuff is as simple as
'make ->poll() instances return __poll_t and do the same to local
variables used to hold the future return value'.
Some of the obvious brainos found in process are fixed (e.g. POLLIN
misspelled as POLL_IN). At that point the amount of sparse warnings is
low and most of them are for genuine bugs - e.g. ->poll() instance
deciding to return -EINVAL instead of a bitmap. I hadn't touched those
in this series - it's large enough as it is.
Another problem it has caught was eventpoll() ABI mess; select.c and
eventpoll.c assumed that corresponding POLL### and EPOLL### were
equal. That's true for some, but not all of them - EPOLL### are
arch-independent, but POLL### are not.
The last commit in this series separates userland POLL### values from
the (now arch-independent) kernel-side ones, converting between them
in the few places where they are copied to/from userland. AFAICS, this
is the least disruptive fix preserving poll(2) ABI and making epoll()
work on all architectures.
As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and
it will trigger only on what would've triggered EPOLLWRBAND on other
architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered
at all on sparc. With this patch they should work consistently on all
architectures"
* 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
make kernel-side POLL... arch-independent
eventpoll: no need to mask the result of epi_item_poll() again
eventpoll: constify struct epoll_event pointers
debugging printk in sg_poll() uses %x to print POLL... bitmap
annotate poll(2) guts
9p: untangle ->poll() mess
->si_band gets POLL... bitmap stored into a user-visible long field
ring_buffer_poll_wait() return value used as return value of ->poll()
the rest of drivers/*: annotate ->poll() instances
media: annotate ->poll() instances
fs: annotate ->poll() instances
ipc, kernel, mm: annotate ->poll() instances
net: annotate ->poll() instances
apparmor: annotate ->poll() instances
tomoyo: annotate ->poll() instances
sound: annotate ->poll() instances
acpi: annotate ->poll() instances
crypto: annotate ->poll() instances
block: annotate ->poll() instances
x86: annotate ->poll() instances
...
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>
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
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Merge tag 'nfs-for-4.11-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
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
...
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.
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Merge tag 'nfsd-4.11' of git://linux-nfs.org/~bfields/linux
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
...
Record flush/channel/content entries is useless, remove them.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
User always free the cache_detail after sunrpc_destroy_cache_detail(),
so, it must cleanup up entries that left in the cache_detail,
otherwise, NULL reference may be caused when using the left entries.
Also, NeriBrown suggests "write a stand-alone cache_purge()."
v3, move the cache_fresh_unlocked() out of write lock,
v2, a stand-alone cache_purge(), not only for sunrpc_destroy_cache_detail
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: NeilBrown <neilb@suse.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>
Since we need to change the implementation, stop exposing internals.
Provide kref_read() to read the current reference count; typically
used for debug messages.
Kills two anti-patterns:
atomic_read(&kref->refcount)
kref->refcount.counter
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sunrpc uses workqueue to clean cache regulary. There is no real dependency
of executing work on the cpu which queueing it.
On a idle system, especially for a heterogeneous systems like big.LITTLE,
it is observed that the big idle cpu was woke up many times just to service
this work, which against the principle of power saving. It would be better
if we can schedule it on a cpu which the scheduler believes to be the most
appropriate one.
After apply this patch, system_wq will be replaced by
system_power_efficient_wq for sunrpc. This functionality is enabled when
CONFIG_WQ_POWER_EFFICIENT is selected.
Signed-off-by: Ke Wang <ke.wang@spreadtrum.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sunrpc_cache_pipe_upcall() can detect a race if CACHE_PENDING is no longer
set. In this case it aborts the queuing of the upcall.
However it has already taken a new counted reference on "h" and
doesn't "put" it, even though it frees the data structure holding the reference.
So let's delay the "cache_get" until we know we need it.
Fixes: f9e1aedc6c ("sunrpc/cache: remove races with queuing an upcall.")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The qword_get() function NUL-terminates its output buffer. If the input
string is in hex format \xXXXX... and the same length as the output
buffer, there is an off-by-one:
int qword_get(char **bpp, char *dest, int bufsize)
{
...
while (len < bufsize) {
...
*dest++ = (h << 4) | l;
len++;
}
...
*dest = '\0';
return len;
}
This patch ensures the NUL terminator doesn't fall outside the output
buffer.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).
Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
Cleanup.
Just store cache_detail in seq_file's private,
an allocated handle is redundant.
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>
The current semantics of string_escape_mem are inadequate for one of its
current users, vsnprintf(). If that is to honour its contract, it must
know how much space would be needed for the entire escaped buffer, and
string_escape_mem provides no way of obtaining that (short of allocating a
large enough buffer (~4 times input string) to let it play with, and
that's definitely a big no-no inside vsnprintf).
So change the semantics for string_escape_mem to be more snprintf-like:
Return the size of the output that would be generated if the destination
buffer was big enough, but of course still only write to the part of dst
it is allowed to, and (contrary to snprintf) don't do '\0'-termination.
It is then up to the caller to detect whether output was truncated and to
append a '\0' if desired. Also, we must output partial escape sequences,
otherwise a call such as snprintf(buf, 3, "%1pE", "\123") would cause
printf to write a \0 to buf[2] but leaving buf[0] and buf[1] with whatever
they previously contained.
This also fixes a bug in the escaped_string() helper function, which used
to unconditionally pass a length of "end-buf" to string_escape_mem();
since the latter doesn't check osz for being insanely large, it would
happily write to dst. For example, kasprintf(GFP_KERNEL, "something and
then %pE", ...); is an easy way to trigger an oops.
In test-string_helpers.c, the -ENOMEM test is replaced with testing for
getting the expected return value even if the buffer is too small. We
also ensure that nothing is written (by relying on a NULL pointer deref)
if the output size is 0 by passing NULL - this has to work for
kasprintf("%pE") to work.
In net/sunrpc/cache.c, I think qword_add still has the same semantics.
Someone should definitely double-check this.
In fs/proc/array.c, I made the minimum possible change, but longer-term it
should stop poking around in seq_file internals.
[andriy.shevchenko@linux.intel.com: simplify qword_add]
[andriy.shevchenko@linux.intel.com: add missed curly braces]
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
POLL_OUT isn't what callers of ->poll() are expecting to see; it's
actually __SI_POLL | 2 and it's a siginfo code, not a poll bitmap
bit...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
Cc: Bruce Fields <bfields@fieldses.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is nice kernel helper to escape a given strings by provided rules. Let's
use it instead of custom approach.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[bfields@redhat.com: fix length calculation]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Pull nfsd updates from Bruce Fields:
- Handle some loose ends from the vfs read delegation support.
(For example nfsd can stop breaking leases on its own in a
fewer places where it can now depend on the vfs to.)
- Make life a little easier for NFSv4-only configurations
(thanks to Kinglong Mee).
- Fix some gss-proxy problems (thanks Jeff Layton).
- miscellaneous bug fixes and cleanup
* 'for-3.14' of git://linux-nfs.org/~bfields/linux: (38 commits)
nfsd: consider CLAIM_FH when handing out delegation
nfsd4: fix delegation-unlink/rename race
nfsd4: delay setting current_fh in open
nfsd4: minor nfs4_setlease cleanup
gss_krb5: use lcm from kernel lib
nfsd4: decrease nfsd4_encode_fattr stack usage
nfsd: fix encode_entryplus_baggage stack usage
nfsd4: simplify xdr encoding of nfsv4 names
nfsd4: encode_rdattr_error cleanup
nfsd4: nfsd4_encode_fattr cleanup
minor svcauth_gss.c cleanup
nfsd4: better VERIFY comment
nfsd4: break only delegations when appropriate
NFSD: Fix a memory leak in nfsd4_create_session
sunrpc: get rid of use_gssp_lock
sunrpc: fix potential race between setting use_gss_proxy and the upcall rpc_clnt
sunrpc: don't wait for write before allowing reads from use-gss-proxy file
nfsd: get rid of unused function definition
Define op_iattr for nfsd4_open instead using macro
NFSD: fix compile warning without CONFIG_NFSD_V3
...
This patch removes the net_random and net_srandom macros and replaces
them with direct calls to the prandom ones. As new commits only seem to
use prandom_u32 there is no use to keep them around.
This change makes it easier to grep for users of prandom_u32.
Signed-off-by: Aruna-Hewapathirane <aruna.hewapathirane@gmail.com>
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
hex_pack_byte() is a fast way to convert a byte in its ASCII representation. We
may use it instead of custom approach.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Pull more vfs stuff from Al Viro:
"O_TMPFILE ABI changes, Oleg's fput() series, misc cleanups, including
making simple_lookup() usable for filesystems with non-NULL s_d_op,
which allows us to get rid of quite a bit of ugliness"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
sunrpc: now we can just set ->s_d_op
cgroup: we can use simple_lookup() now
efivarfs: we can use simple_lookup() now
make simple_lookup() usable for filesystems that set ->s_d_op
configfs: don't open-code d_alloc_name()
__rpc_lookup_create_exclusive: pass string instead of qstr
rpc_create_*_dir: don't bother with qstr
llist: llist_add() can use llist_add_batch()
llist: fix/simplify llist_add() and llist_add_batch()
fput: turn "list_head delayed_fput_list" into llist_head
fs/file_table.c:fput(): add comment
Safer ABI for O_TMPFILE
When a cache entry is replaced, the "expiry_time" get set to
zero by a call to "cache_fresh_locked(..., 0)" at the end of
"sunrpc_cache_update".
This low expiry time makes cache_check() think that the 'refresh_age'
is negative, so the 'age' is comparatively large and a refresh is
triggered.
However refreshing a replaced entry it pointless, it cannot achieve
anything useful.
So teach cache_check to ignore a low refresh_age when expiry_time
is zero.
Reported-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
commit d202cce896
sunrpc: never return expired entries in sunrpc_cache_lookup
moved the 'entry is expired' test from cache_check to
sunrpc_cache_lookup, so that it happened early and some races could
safely be ignored.
However the ip_map (in svcauth_unix.c) has a separate single-item
cache which allows quick lookup without locking. An entry in this
case would not be subject to the expiry test and so could be used
well after it has expired.
This is not normally a big problem because the first time it is used
after it is expired an up-call will be scheduled to refresh the entry
(if it hasn't been scheduled already) and the old entry will then
be invalidated. So on the second attempt to use it after it has
expired, ip_map_cached_get will discard it.
However that is subtle and not ideal, so replace the "!cache_valid"
test with "cache_is_expired".
In doing this we drop the test on the "CACHE_VALID" bit. This is
unnecessary as the bit is never cleared, and an entry will only
be cached if the bit is set.
Reported-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
It is possible for a race to set CACHE_PENDING after cache_clean()
has removed a cache entry from the cache.
If CACHE_PENDING is still set when the entry is finally 'put',
the cache_dequeue() will never happen and we can leak memory.
So set a new flag 'CACHE_CLEANED' when we remove something from
the cache, and don't queue any upcall if it is set.
If CACHE_PENDING is set before CACHE_CLEANED, the call that
cache_clean() makes to cache_fresh_unlocked() will free memory
as needed. If CACHE_PENDING is set after CACHE_CLEANED, the
test in sunrpc_cache_pipe_upcall will ensure that the memory
is not allocated.
Reported-by: <bstroesser@ts.fujitsu.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
cache_fresh_unlocked() is called when a cache entry
has been updated and ensures that if there were any
pending upcalls, they are cleared.
So every time we update a cache entry, we should call this,
and this should be the only way that we try to clear
pending calls (that sort of uniformity makes code sooo much
easier to read).
try_to_negate_entry() will (possibly) mark an entry as
negative. If it doesn't, it is because the entry already
is VALID.
So the entry will be valid on exit, so it is appropriate to
call cache_fresh_unlocked().
So tidy up try_to_negate_entry() to do that, and remove
partial open-coded cache_fresh_unlocked() from the one
call-site of try_to_negate_entry().
In the other branch of the 'switch(cache_make_upcall())',
we again have a partial open-coded version of cache_fresh_unlocked().
Replace that with a real call.
And again in cache_clean(), use a real call to cache_fresh_unlocked().
These call sites might previously have called
cache_revisit_request() if CACHE_PENDING wasn't set.
This is never necessary because cache_revisit_request() can
only do anything if the item is in the cache_defer_hash,
However any time that an item is added to the cache_defer_hash
(setup_deferral), the code immediately tests CACHE_PENDING,
and removes the entry again if it is clear. So all other
places we only need to 'cache_revisit_request' if we've
just cleared CACHE_PENDING.
Reported-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We currently queue an upcall after setting CACHE_PENDING,
and dequeue after clearing CACHE_PENDING.
So a request should only be present when CACHE_PENDING is set.
However we don't combine the test and the enqueue/dequeue in
a protected region, so it is possible (if unlikely) for a race
to result in a request being queued without CACHE_PENDING set,
or a request to be absent despite CACHE_PENDING.
So: include a test for CACHE_PENDING inside the regions of
enqueue and dequeue where queue_lock is held, and abort
the operation if the value is not as expected.
Also remove the early 'return' from cache_dequeue() to ensure that it
always removes all entries: As there is no locking between setting
CACHE_PENDING and calling sunrpc_cache_pipe_upcall it is not
inconceivable for some other thread to clear CACHE_PENDING and then
someone else to set it and call sunrpc_cache_pipe_upcall, both before
the original threads completed the call.
With this, it perfectly safe and correct to:
- call cache_dequeue() if and only if we have just
cleared CACHE_PENDING
- call sunrpc_cache_pipe_upcall() (via cache_make_upcall)
if and only if we have just set CACHE_PENDING.
Reported-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The cache_detail(*detail) in function cache_is_valid is not used any
more.
Signed-off-by: fanchaoting <fanchaoting@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Pull nfsd changes from J Bruce Fields:
"Highlights include:
- Some more DRC cleanup and performance work from Jeff Layton
- A gss-proxy upcall from Simo Sorce: currently krb5 mounts to the
server using credentials from Active Directory often fail due to
limitations of the svcgssd upcall interface. This replacement
lifts those limitations. The existing upcall is still supported
for backwards compatibility.
- More NFSv4.1 support: at this point, if a user with a current
client who upgrades from 4.0 to 4.1 should see no regressions. In
theory we do everything a 4.1 server is required to do. Patches
for a couple minor exceptions are ready for 3.11, and with those
and some more testing I'd like to turn 4.1 on by default in 3.11."
Fix up semantic conflict as per Stephen Rothwell and linux-next:
Commit 030d794bf4 ("SUNRPC: Use gssproxy upcall for server RPCGSS
authentication") adds two new users of "PDE(inode)->data", but we're
supposed to use "PDE_DATA(inode)" instead since commit d9dda78bad
("procfs: new helper - PDE_DATA(inode)").
The old PDE() macro is no longer available since commit c30480b92c
("proc: Make the PROC_I() and PDE() macros internal to procfs")
* 'for-3.10' of git://linux-nfs.org/~bfields/linux: (60 commits)
NFSD: SECINFO doesn't handle unsupported pseudoflavors correctly
NFSD: Simplify GSS flavor encoding in nfsd4_do_encode_secinfo()
nfsd: make symbol nfsd_reply_cache_shrinker static
svcauth_gss: fix error return code in rsc_parse()
nfsd4: don't remap EISDIR errors in rename
svcrpc: fix gss-proxy to respect user namespaces
SUNRPC: gssp_procedures[] can be static
SUNRPC: define {create,destroy}_use_gss_proxy_proc_entry in !PROC case
nfsd4: better error return to indicate SSV non-support
nfsd: fix EXDEV checking in rename
SUNRPC: Use gssproxy upcall for server RPCGSS authentication.
SUNRPC: Add RPC based upcall mechanism for RPCGSS auth
SUNRPC: conditionally return endtime from import_sec_context
SUNRPC: allow disabling idle timeout
SUNRPC: attempt AF_LOCAL connect on setup
nfsd: Decode and send 64bit time values
nfsd4: put_client_renew_locked can be static
nfsd4: remove unused macro
nfsd4: remove some useless code
nfsd4: implement SEQ4_STATUS_RECALLABLE_STATE_REVOKED
...
