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
...
Pull VFS updates from Al Viro,
Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).
7kloc removed.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
don't bother with deferred freeing of fdtables
proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
proc: Make the PROC_I() and PDE() macros internal to procfs
proc: Supply a function to remove a proc entry by PDE
take cgroup_open() and cpuset_open() to fs/proc/base.c
ppc: Clean up scanlog
ppc: Clean up rtas_flash driver somewhat
hostap: proc: Use remove_proc_subtree()
drm: proc: Use remove_proc_subtree()
drm: proc: Use minor->index to label things, not PDE->name
drm: Constify drm_proc_list[]
zoran: Don't print proc_dir_entry data in debug
reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
proc: Supply an accessor for getting the data from a PDE's parent
airo: Use remove_proc_subtree()
rtl8192u: Don't need to save device proc dir PDE
rtl8187se: Use a dir under /proc/net/r8180/
proc: Add proc_mkdir_data()
proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
proc: Move PDE_NET() to fs/proc/proc_net.c
...
There are at least two users of isodigit(). Let's make it a public
function of ctype.h.
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>
The only part of proc_dir_entry the code outside of fs/proc
really cares about is PDE(inode)->data. Provide a helper
for that; static inline for now, eventually will be moved
to fs/proc, along with the knowledge of struct proc_dir_entry
layout.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If kmalloc() fails in cache_open(), module cd->owner left locked.
The patch adds module_put(cd->owner) on this path.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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
...
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>
The reason to move cache_request() callback call from
sunrpc_cache_pipe_upcall() to cache_read() is that this garantees, that cache
access will be done userspace process context (only userspace process have
proper root context).
This is required for NFSd support in container: svc_export_request() (which is
cache_request callback) calls d_path(), which, in turn, traverse dentry up to
current->fs->root. Kernel threads always have global root, while container
have be in "root jail" - i.e. have it's own nested root.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Passing this pointer is redundant since it's stored on cache_detail structure,
which is also passed to sunrpc_cache_pipe_upcall () function.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
For most of SUNRPC caches (except NFS DNS cache) cache_detail->cache_upcall is
redundant since all that it's implementations are doing is calling
sunrpc_cache_pipe_upcall() with proper function address argument.
Cache request function address is now stored on cache_detail structure and
thus all the code can be simplified.
Now, for those cache details, which doesn't have cache_upcall callback (the
only one, which still has is nfs_dns_resolve_template)
sunrpc_cache_pipe_upcall will be called instead.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The write function doesn't be implemented in file content, and it's meaningless
to write data into this file directly. Remove write permission from it.
Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Replace BUG_ON() with WARN_ON_ONCE() in two parts of cache_read().
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Initalizers for deferrable delayed_work are confused.
* __DEFERRED_WORK_INITIALIZER()
* DECLARE_DEFERRED_WORK()
* INIT_DELAYED_WORK_DEFERRABLE()
Rename them to
* __DEFERRABLE_WORK_INITIALIZER()
* DECLARE_DEFERRABLE_WORK()
* INIT_DEFERRABLE_WORK()
This patch doesn't cause any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Entries that are in a sunrpc cache but are not valid should be reported
with a leading '#' so they look like a comment.
Commit d202cce896 (sunrpc: never return expired entries in sunrpc_cache_lookup)
broke this for expired entries.
This particularly applies to entries that have been replaced by newer entries.
sunrpc_cache_update sets the expiry of the replaced entry to '0', but it
remains in the cache until the next 'cache_clean'.
The result is that if you
echo 0 2000000000 1 0 > /proc/net/rpc/auth.unix.gid/channel
several times, then
cat /proc/net/rpc/auth.unix.gid/content
It will display multiple entries for the one uid, which is at least confusing:
#uid cnt: gids...
0 1: 0
0 1: 0
0 1: 0
With this patch, expired entries are marked as comments so you get
#uid cnt: gids...
0 1: 0
# 0 1: 0
# 0 1: 0
These expired entries will never be seen by cache_check() as they are always
*after* a non-expired entry with the same key - so the extra check is only
needed in c_show()
Signed-off-by: NeilBrown <neilb@suse.de>
--
It's not a big problem, but it had me confused for a while, so it could
well confuse others.
Thanks,
NeilBrown
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Use of "unsigned int" is preferred to bare "unsigned" in net tree.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is no point in passing a zero length string here and quite a
few of that cache_parse() implementations will Oops if count is
zero.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
All cache users now uses network-namespace-aware routines, so generic ones
are obsolete.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
This patch prepares infrastructure for network namespace aware cache detail
allocation.
One note about adding network namespace link to cache structure. It's going to
be used later in NFS DNS cache parsing routine (nfs_dns_parse for rpc_pton()
call).
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
This precursor patch splits SUNRPC cache creation and PipeFS registartion.
It's required for latter split of NFS DNS resolver cache creation per network
namespace context and PipeFS registration/unregistration on MOUNT/UMOUNT
events.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* 'for-3.3' of git://linux-nfs.org/~bfields/linux: (31 commits)
nfsd4: nfsd4_create_clid_dir return value is unused
NFSD: Change name of extended attribute containing junction
svcrpc: don't revert to SVC_POOL_DEFAULT on nfsd shutdown
svcrpc: fix double-free on shutdown of nfsd after changing pool mode
nfsd4: be forgiving in the absence of the recovery directory
nfsd4: fix spurious 4.1 post-reboot failures
NFSD: forget_delegations should use list_for_each_entry_safe
NFSD: Only reinitilize the recall_lru list under the recall lock
nfsd4: initialize special stateid's at compile time
NFSd: use network-namespace-aware cache registering routines
SUNRPC: create svc_xprt in proper network namespace
svcrpc: update outdated BKL comment
nfsd41: allow non-reclaim open-by-fh's in 4.1
svcrpc: avoid memory-corruption on pool shutdown
svcrpc: destroy server sockets all at once
svcrpc: make svc_delete_xprt static
nfsd: Fix oops when parsing a 0 length export
nfsd4: Use kmemdup rather than duplicating its implementation
nfsd4: add a separate (lockowner, inode) lookup
nfsd4: fix CONFIG_NFSD_FAULT_INJECTION compile error
...
v2: cache_register_net() and cache_unregister_net() GPL exports added
This is a cleanup patch. Hope, some day generic cache_register() and
cache_unregister() will be removed.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Supposes cache_check runs simultaneously with an update on a different
CPU:
cache_check task doing update
^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^
1. test for CACHE_VALID 1'. set entry->data
& !CACHE_NEGATIVE
2. use entry->data 2'. set CACHE_VALID
If the two memory writes performed in step 1' and 2' appear misordered
with respect to the reads in step 1 and 2, then the caller could get
stale data at step 2 even though it saw CACHE_VALID set on the cache
entry.
Add memory barriers to prevent this.
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We attempt to turn a cache entry negative in place. But that entry may
already have been filled in by some other task since we last checked
whether it was valid, so we could be modifying an already-valid entry.
If nothing else there's a likely leak in such a case when the entry is
eventually put() and contents are not freed because it has
CACHE_NEGATIVE set.
So, take the cache_lock just as sunrpc_cache_update() does.
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Commit d29068c431 "sunrpc: Simplify cache_defer_req and related
functions." asserted that cache_check() could determine success or
failure of cache_defer_req() by checking the CACHE_PENDING bit.
This isn't quite right.
We need to know whether cache_defer_req() created a deferred request,
in which case sending an rpc reply has become the responsibility of the
deferred request, and it is important that we not send our own reply,
resulting in two different replies to the same request.
And the CACHE_PENDING bit doesn't tell us that; we could have
succesfully created a deferred request at the same time as another
thread cleared the CACHE_PENDING bit.
So, partially revert that commit, to ensure that cache_check() returns
-EAGAIN if and only if a deferred request has been created.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: NeilBrown <neilb@suse.de>
* 'for-2.6.37' of git://linux-nfs.org/~bfields/linux: (99 commits)
svcrpc: svc_tcp_sendto XPT_DEAD check is redundant
svcrpc: no need for XPT_DEAD check in svc_xprt_enqueue
svcrpc: assume svc_delete_xprt() called only once
svcrpc: never clear XPT_BUSY on dead xprt
nfsd4: fix connection allocation in sequence()
nfsd4: only require krb5 principal for NFSv4.0 callbacks
nfsd4: move minorversion to client
nfsd4: delay session removal till free_client
nfsd4: separate callback change and callback probe
nfsd4: callback program number is per-session
nfsd4: track backchannel connections
nfsd4: confirm only on succesful create_session
nfsd4: make backchannel sequence number per-session
nfsd4: use client pointer to backchannel session
nfsd4: move callback setup into session init code
nfsd4: don't cache seq_misordered replies
SUNRPC: Properly initialize sock_xprt.srcaddr in all cases
SUNRPC: Use conventional switch statement when reclassifying sockets
sunrpc/xprtrdma: clean up workqueue usage
sunrpc: Turn list_for_each-s into the ..._entry-s
...
Fix up trivial conflicts (two different deprecation notices added in
separate branches) in Documentation/feature-removal-schedule.txt
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
vfs: make no_llseek the default
vfs: don't use BKL in default_llseek
llseek: automatically add .llseek fop
libfs: use generic_file_llseek for simple_attr
mac80211: disallow seeks in minstrel debug code
lirc: make chardev nonseekable
viotape: use noop_llseek
raw: use explicit llseek file operations
ibmasmfs: use generic_file_llseek
spufs: use llseek in all file operations
arm/omap: use generic_file_llseek in iommu_debug
lkdtm: use generic_file_llseek in debugfs
net/wireless: use generic_file_llseek in debugfs
drm: use noop_llseek
The sunrpc cache_ioctl function does not need the big kernel lock
because it uses its own queue_lock already.
rpc_pipe_ioctl apparently should be using i_lock like the other
operations on the pipe file descriptor do.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.
The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.
New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time. Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.
The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.
Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.
Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.
===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
// but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}
@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}
@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}
@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}
@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}
@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}
@ fops0 @
identifier fops;
@@
struct file_operations fops = {
...
};
@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
.llseek = llseek_f,
...
};
@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
.read = read_f,
...
};
@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
.write = write_f,
...
};
@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
.open = open_f,
...
};
// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
... .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};
@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
... .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};
// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
... .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};
// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};
// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};
@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+ .llseek = default_llseek, /* write accesses f_pos */
};
// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////
@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
.write = write_f,
.read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};
@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};
@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};
@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
We limit the number of 'defer' requests to DFR_MAX.
The imposition of this limit is spread about a bit - sometime we don't
add new things to the list, sometimes we remove old things.
Also it is currently applied to requests which we are 'waiting' for
rather than 'deferring'. This doesn't seem ideal as 'waiting'
requests are naturally limited by the number of threads.
So gather the DFR_MAX handling code to one place and only apply it to
requests that are actually being deferred.
This means that not all 'cache_deferred_req' structures go on the
'cache_defer_list, so we need to be careful when adding and removing
things.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The return value from cache_defer_req is somewhat confusing.
Various different error codes are returned, but the single caller is
only interested in success or failure.
In fact it can measure this success or failure itself by checking
CACHE_PENDING, which makes the point of the code more explicit.
So change cache_defer_req to return 'void' and test CACHE_PENDING
after it completes, to see if the request was actually deferred or
not.
Similarly setup_deferral and cache_wait_req don't need a return value,
so make them void and remove some code.
The call to cache_revisit_request (to guard against a race) is only
needed for the second call to setup_deferral, so move it out of
setup_deferral to after that second call. With the first call the
race is handled differently (by explicitly calling
'wait_for_completion').
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
If we set up to wait for a cache item to be filled in, and then find
that it is no longer pending, it could be that some other thread is
in 'cache_revisit_request' and has moved our request to its 'pending' list.
So when our setup_deferral calls cache_revisit_request it will find nothing to
put on the pending list, and do nothing.
We then return from cache_wait_req, thus leaving the 'sleeper'
on-stack structure open to being corrupted by subsequent stack usage.
However that 'sleeper' could still be on the 'pending' list that the
other thread is looking at and so any corruption could cause it to behave badly.
To avoid this race we simply take the same path as if the
'wait_for_completion_interruptible_timeout' was interrupted and if the
sleeper is no longer on the list (which it won't be) we wait on the
completion - which will ensure that any other cache_revisit_request
will have let go of the sleeper.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Existing calls do the same, but for the init_net.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
commit 6610f720e9
broke cache_clean_deferred as entries are no longer added to the
pending list for subsequent revisiting.
So put those requests back on the pending list.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Being a hash table, hlist is the best option.
There is currently some ugliness were we treat "->next == NULL" as
a special case to avoid having to initialise the whole array.
This change nicely gets rid of that case.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The last_close field of a cache_detail is initialized to zero, so the
condition
detail->last_close < seconds_since_boot() - 30
may be false even for a cache that was never opened.
However, we want to immediately fail upcalls to caches that were never
opened: in the case of the auth_unix_gid cache, especially, which may
never be opened by mountd (if the --manage-gids option is not set), we
want to fail the upcall immediately. Otherwise client requests will be
dropped unnecessarily on reboot.
Also document these conditions.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Attempt to make obvious the first-try-sleeping-then-try-deferral logic
by putting that logic into a top-level function that calls helpers.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The current practice of waiting for cache updates by queueing the
whole request to be retried has (at least) two problems.
1/ With NFSv4, requests can be quite complex and re-trying a whole
request when a later part fails should only be a last-resort, not a
normal practice.
2/ Large requests, and in particular any 'write' request, will not be
queued by the current code and doing so would be undesirable.
In many cases only a very sort wait is needed before the cache gets
valid data.
So, providing the underlying transport permits it by setting
->thread_wait,
arrange to wait briefly for an upcall to be completed (as reflected in
the clearing of CACHE_PENDING).
If the short wait was not long enough and CACHE_PENDING is still set,
fall back on the old approach.
The 'thread_wait' value is set to 5 seconds when there are spare
threads, and 1 second when there are no spare threads.
These values are probably much higher than needed, but will ensure
some forward progress.
Note that as we only request an update for a non-valid item, and as
non-valid items are updated in place it is extremely unlikely that
cache_check will return -ETIMEDOUT. Normally cache_defer_req will
sleep for a short while and then find that the item is_valid.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This protects us from confusion when the wallclock time changes.
We convert to and from wallclock when setting or reading expiry
times.
Also use seconds since boot for last_clost time.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This patch makes the cache_cleaner workqueue deferrable, to prevent
unnecessary system wake-ups, which is very important for embedded
battery-powered devices.
do_cache_clean() is called every 30 seconds at the moment, and often
makes the system wake up from its power-save sleep state. With this
change, when the workqueue uses a deferrable timer, the
do_cache_clean() invocation will be delayed and combined with the
closest "real" wake-up. This improves the power consumption situation.
Note, I tried to create a DECLARE_DELAYED_WORK_DEFERRABLE() helper
macro, similar to DECLARE_DELAYED_WORK(), but failed because of the
way the timer wheel core stores the deferrable flag (it is the
LSBit in the time->base pointer). My attempt to define a static
variable with this bit set ended up with the "initializer element is
not constant" error.
Thus, I have to use run-time initialization, so I created a new
cache_initialize() function which is called once when sunrpc is
being initialized.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* 'bkl/ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing:
uml: Pushdown the bkl from harddog_kern ioctl
sunrpc: Pushdown the bkl from sunrpc cache ioctl
sunrpc: Pushdown the bkl from ioctl
autofs4: Pushdown the bkl from ioctl
uml: Convert to unlocked_ioctls to remove implicit BKL
ncpfs: BKL ioctl pushdown
coda: Clean-up whitespace problems in pioctl.c
coda: BKL ioctl pushdown
drivers: Push down BKL into various drivers
isdn: Push down BKL into ioctl functions
scsi: Push down BKL into ioctl functions
dvb: Push down BKL into ioctl functions
smbfs: Push down BKL into ioctl function
coda/psdev: Remove BKL from ioctl function
um/mmapper: Remove BKL usage
sn_hwperf: Kill BKL usage
hfsplus: Push down BKL into ioctl function
Pushdown the bkl to cache_ioctl_pipefs.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Nfs <linux-nfs@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Kacur <jkacur@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
* 'for-2.6.35' of git://linux-nfs.org/~bfields/linux: (45 commits)
Revert "nfsd4: distinguish expired from stale stateids"
nfsd: safer initialization order in find_file()
nfs4: minor callback code simplification, comment
NFSD: don't report compiled-out versions as present
nfsd4: implement reclaim_complete
nfsd4: nfsd4_destroy_session must set callback client under the state lock
nfsd4: keep a reference count on client while in use
nfsd4: mark_client_expired
nfsd4: introduce nfs4_client.cl_refcount
nfsd4: refactor expire_client
nfsd4: extend the client_lock to cover cl_lru
nfsd4: use list_move in move_to_confirmed
nfsd4: fold release_session into expire_client
nfsd4: rename sessionid_lock to client_lock
nfsd4: fix bare destroy_session null dereference
nfsd4: use local variable in nfs4svc_encode_compoundres
nfsd: further comment typos
sunrpc: centralise most calls to svc_xprt_received
nfsd4: fix unlikely race in session replay case
nfsd4: fix filehandle comment
...
Now that cache_ioctl_procfs() calls the bkl explicitly, we need to
include the relevant header as well.
This fixes the following build error:
net/sunrpc/cache.c: In function 'cache_ioctl_procfs':
net/sunrpc/cache.c:1355: error: implicit declaration of function 'lock_kernel'
net/sunrpc/cache.c:1359: error: implicit declaration of function 'unlock_kernel'
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Push down the bkl from procfs's ioctl main handler to its users.
Only three procfs users implement an ioctl (non unlocked) handler.
Turn them into unlocked_ioctl and push down the Devil inside.
v2: PDE(inode)->data doesn't need to be under bkl
v3: And don't forget to git-add the result
v4: Use wrappers to pushdown instead of an invasive and error prone
handlers surgery.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: John Kacur <jkacur@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Don't forget to release the module refcnt if seq_open() returns failure.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
If sunrpc_cache_lookup finds an expired entry, remove it from
the cache and return a freshly created non-VALID entry instead.
This ensures that we only ever get a usable entry, or an
entry that will become usable once an update arrives.
i.e. we will never need to repeat the lookup.
This allows us to remove the 'is_expired' test from cache_check
(i.e. from cache_is_valid). cache_check should never get an expired
entry as 'lookup' will never return one. If it does happen - due to
inconvenient timing - then just accept it as still valid, it won't be
very much past it's use-by date.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This removes a tiny bit of code duplication, but more important
prepares for following patch which will perform the expiry check in
cache_lookup and the rest of the validity check in cache_check.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
currently expired entries remain in the auth caches as long
as there is a reference.
This was needed long ago when the auth_domain cache used the same
cache infrastructure. But since that (being a very different sort
of cache) was separated, this test is no longer needed.
So remove the test on refcnt and tidy up the surrounding code.
This allows the cache_dequeue call (which needed to be there to
drop a potentially awkward reference) can be moved outside of the
spinlock which is a better place for it.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Not including net/atm/
Compiled tested x86 allyesconfig only
Added a > 80 column line or two, which I ignored.
Existing checkpatch plaints willfully, cheerfully ignored.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In cache_defer_req, 'dreq' is used for two significantly different
values that happen to be of the same type.
This is both confusing, and makes it hard to extend the range of one of
the values as we will in the next patch.
So introduce 'discard' to take one of the values.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Using list_del_init is generally safer than list_del, and it will
allow us, in a subsequent patch, to see if an entry has already been
processed or not.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The extra call to cache_revisit_request in cache_fresh_unlocked is not
needed, as should have been fairly clear at the time of
commit 4013edea9a
If there are requests to be revisited, then we can be sure that
CACHE_PENDING is set, so the second call is sufficient.
So remove the first call.
Then remove the 'new' parameter,
then remove the return value for cache_fresh_locked which is only used
to provide the value for 'new'.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
As "cache_defer_req" does not sound like a predicate, having it return
a boolean value can be confusing. It is more consistent to return
0 for success and negative for error.
Exactly what error code to return is not important as we don't
differentiate between reasons why the request wasn't deferred,
we only care about whether it was deferred or not.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Otherwise we Oops if the module containing the cache detail is removed
before all cache readers have closed the file.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
For events that are rare, such as referral DNS lookups, it makes limited
sense to have a daemon constantly listening for upcalls on a channel. An
alternative in those cases might simply be to run the app that fills the
cache using call_usermodehelper_exec() and friends.
The following patch allows the cache_detail to specify alternative upcall
mechanisms for these particular cases.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
While we do want to protect against multiple concurrent readers and writers
on each upcall/downcall pipe, we don't want to limit concurrent reading and
writing to separate caches.
This patch therefore replaces the static buffer 'write_buf', which can only
be used by one writer at a time, with use of the page cache as the
temporary buffer for downcalls. We still fall back to using the the old
global buffer if the downcall is larger than PAGE_CACHE_SIZE, since this is
apparently needed by the SPKM security context initialisation.
It then replaces the use of the global 'queue_io_mutex' with the
inode->i_mutex in cache_read() and cache_write().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Also ensure that we destroy those files before we destroy the cache_detail.
Otherwise, user processes might attempt to write into uninitialised caches.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If cache_defer_req did not leave the request on a queue, then it could
possibly have waited long enough that the cache became valid. So check the
status after the call.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
While deferred requests normally get revisited quite quickly,
it is possible for a request to remain in the deferral queue
when the cache item is discarded. We can easily make sure that
doesn't happen by calling cache_revisit_request just before
the final 'put'.
Also there is a small chance that a race would cause one thread to
defer a request against a cache item while another thread is failing
to queue an upcall for that item. So when the upcall fails, make
sure to revisit all deferred requests.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
'loose' was a mis-spelling of 'lose', and even that wasn't a good
word choice.
So give this function a more useful name.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Align cache_clean work.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.
We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.
But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.
->read_proc/->write_proc were just fixed to not require ->owner for
protection.
rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.
Removing ->owner will also make PDE smaller.
So, let's nuke it.
Kudos to Jeff Layton for reminding about this, let's say, oversight.
http://bugzilla.kernel.org/show_bug.cgi?id=12454
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Simply replace proc_create and further data assigned with proc_create_data.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
NeilBrown