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Currently we only use cstate->current_fh,
will also be used by nfsd41 code.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Implement the destory_session operation confoming to
http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-26
[use sessionid_lock spin lock]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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A session inactivity time compound (lease renewal) or a compound where the
sequence operation has sa_cachethis set to FALSE do not require any pages
to be held in the v4.1 DRC. This is because struct nfsd4_slot is already
caching the session information.
Add logic to the nfs41 server to not cache response pages for solo sequence
responses.
Return nfserr_replay_uncached_rep on the operation following the sequence
operation when sa_cachethis is FALSE.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: use cstate session in nfsd4_replay_cache_entry]
[nfsd41: rename nfsd4_no_page_in_cache]
[nfsd41 rename nfsd4_enc_no_page_replay]
[nfsd41 nfsd4_is_solo_sequence]
[nfsd41 change nfsd4_not_cached return]
Signed-off-by: Andy Adamson <andros@netapp.com>
[changed return type to bool]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41 drop parens in nfsd4_is_solo_sequence call]
Signed-off-by: Andy Adamson <andros@netapp.com>
[changed "== 0" to "!"]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Replace the nfs4_client cl_seqid field with a single struct nfs41_slot used
for the create session replay cache.
The CREATE_SESSION slot sets the sl_session pointer to NULL. Otherwise, the
slot and it's replay cache are used just like the session slots.
Fix unconfirmed create_session replay response by initializing the
create_session slot sequence id to 0.
A future patch will set the CREATE_SESSION cache when a SEQUENCE operation
preceeds the CREATE_SESSION operation. This compound is currently only cached
in the session slot table.
Signed-off-by: Andy Adamson<andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: use bool inuse for slot state]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: revert portion of nfsd4_set_cache_entry]
Signed-off-by: Andy Adamson <andros@netpp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Implement the create_session operation confoming to
http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-26
Look up the client id (generated by the server on exchange_id,
given by the client on create_session).
If neither a confirmed or unconfirmed client is found
then the client id is stale
If a confirmed cilent is found (i.e. we already received
create_session for it) then compare the sequence id
to determine if it's a replay or possibly a mis-ordered rpc.
If the seqid is in order, update the confirmed client seqid
and procedd with updating the session parameters.
If an unconfirmed client_id is found then verify the creds
and seqid. If both match move the client id to confirmed state
and proceed with processing the create_session.
Currently, we do not support persistent sessions, and RDMA.
alloc_init_session generates a new sessionid and creates
a session structure.
NFSD_PAGES_PER_SLOT is used for the max response cached calculation, and for
the counting of DRC pages using the hard limits set in struct srv_serv.
A note on NFSD_PAGES_PER_SLOT:
Other patches in this series allow for NFSD_PAGES_PER_SLOT + 1 pages to be
cached in a DRC slot when the response size is less than NFSD_PAGES_PER_SLOT *
PAGE_SIZE but xdr_buf pages are used. e.g. a READDIR operation will encode a
small amount of data in the xdr_buf head, and then the READDIR in the xdr_buf
pages. So, the hard limit calculation use of pages by a session is
underestimated by the number of cached operations using the xdr_buf pages.
Yet another patch caches no pages for the solo sequence operation, or any
compound where cache_this is False. So the hard limit calculation use of
pages by a session is overestimated by the number of these operations in the
cache.
TODO: improve resource pre-allocation and negotiate session
parameters accordingly. Respect and possibly adjust
backchannel attributes.
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
[nfsd41: remove headerpadsz from channel attributes]
Our client and server only support a headerpadsz of 0.
[nfsd41: use DRC limits in fore channel init]
[nfsd41: do not change CREATE_SESSION back channel attrs]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[use sessionid_lock spin lock]
[nfsd41: use bool inuse for slot state]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41 remove sl_session from alloc_init_session]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[simplify nfsd4_encode_create_session error handling]
[nfsd41: fix comment style in init_forechannel_attrs]
[nfsd41: allocate struct nfsd4_session and slot table in one piece]
[nfsd41: no need to INIT_LIST_HEAD in alloc_init_session just prior to list_add]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Signed-off-by: Andy Adamson<andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Replay a request in nfsd4_sequence.
Add a minorversion to struct nfsd4_compound_state.
Pass the current slot to nfs4svc_encode_compound res via struct
nfsd4_compoundres to set an NFSv4.1 DRC entry.
Signed-off-by: Andy Adamson<andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: use bool inuse for slot state]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: use cstate session in nfs4svc_encode_compoundres]
[nfsd41 replace nfsd4_set_cache_entry]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Use no more than 1/128th of the number of free pages at nfsd startup for the
v4.1 DRC.
This is an arbitrary default which should probably end up under the control
of an administrator.
Signed-off-by: Andy Adamson <andros@netapp.com>
[moved added fields in struct svc_serv under CONFIG_NFSD_V4_1]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[fix set_max_drc calculation of sv_drc_max_pages]
[moved NFSD_DRC_SIZE_SHIFT's declaration up in header file]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Cache all the result pages, including the rpc header in rq_respages[0],
for a request in the slot table cache entry.
Cache the statp pointer from nfsd_dispatch which points into rq_respages[0]
just past the rpc header. When setting a cache entry, calculate and save the
length of the nfs data minus the rpc header for rq_respages[0].
When replaying a cache entry, replace the cached rpc header with the
replayed request rpc result header, unless there is not enough room in the
cached results first page. In that case, use the cached rpc header.
The sessions fore channel maxresponse size cached is set to NFSD_PAGES_PER_SLOT
* PAGE_SIZE. For compounds we are cacheing with operations such as READDIR
that use the xdr_buf->pages to hold data, we choose to cache the extra page of
data rather than copying data from xdr_buf->pages into the xdr_buf->head page.
[nfsd41: limit cache to maxresponsesize_cached]
[nfsd41: mv nfsd4_set_statp under CONFIG_NFSD_V4_1]
[nfsd41: rename nfsd4_move_pages]
[nfsd41: rename page_no variable]
[nfsd41: rename nfsd4_set_cache_entry]
[nfsd41: fix nfsd41_copy_replay_data comment]
[nfsd41: add to nfsd4_set_cache_entry]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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!= 0 only.
Signed-off-by: Andy Adamson<andros@netapp.com>
[nfsd41: do not verify nfserr_sequence_pos for minorversion 0]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Implement the sequence operation conforming to
http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-26
Check for stale clientid (as derived from the sessionid).
Enforce slotid range and exactly-once semantics using
the slotid and seqid.
If everything went well renew the client lease and
mark the slot INPROGRESS.
Add a struct nfsd4_slot pointer to struct nfsd4_compound_state.
To be used for sessions DRC replay.
[nfsd41: rename sequence catchthis to cachethis]
Signed-off-by: Andy Adamson<andros@netapp.com>
[pulled some code to set cstate->slot from "nfsd DRC logic"]
[use sessionid_lock spin lock]
[nfsd41: use bool inuse for slot state]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd: add a struct nfsd4_slot pointer to struct nfsd4_compound_state]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: add nfsd4_session pointer to nfsd4_compound_state]
[nfsd41: set cstate session]
[nfsd41: use cstate session in nfsd4_sequence]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[simplify nfsd4_encode_sequence error handling]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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We need to distinguish between client names provided by NFSv4.0 clients
SETCLIENTID and those provided by NFSv4.1 via EXCHANGE_ID when looking
up the clientid by string.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Andy Adamson <andros@netapp.com>
[nfsd41: use boolean values for use_exchange_id argument]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: simplify match_clientid_establishment logic]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Implement the exchange_id operation confoming to
http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-28
Based on the client provided name, hash a client id.
If a confirmed one is found, compare the op's creds and
verifier. If the creds match and the verifier is different
then expire the old client (client re-incarnated), otherwise,
if both match, assume it's a replay and ignore it.
If an unconfirmed client is found, then copy the new creds
and verifer if need update, otherwise assume replay.
The client is moved to a confirmed state on create_session.
In the nfs41 branch set the exchange_id flags to
EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_SUPP_MOVED_REFER
(pNFS is not supported, Referrals are supported,
Migration is not.).
Address various scenarios from section 18.35 of the spec:
1. Check for EXCHGID4_FLAG_UPD_CONFIRMED_REC_A and set
EXCHGID4_FLAG_CONFIRMED_R as appropriate.
2. Return error codes per 18.35.4 scenarios.
3. Update client records or generate new client ids depending on
scenario.
Note: 18.35.4 case 3 probably still needs revisiting. The handling
seems not quite right.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Andy Adamosn <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: use utsname for major_id (and copy to server_scope)]
[nfsd41: fix handling of various exchange id scenarios]
Signed-off-by: Mike Sager <sager@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: reverse use of EXCHGID4_INVAL_FLAG_MASK_A]
[simplify nfsd4_encode_exchange_id error handling]
[nfsd41: embed an xdr_netobj in nfsd4_exchange_id]
[nfsd41: return nfserr_serverfault for spa_how == SP4_MACH_CRED]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Define nfsd41_dec_ops vector and add it to nfsd4_minorversion for
minorversion 1.
Note: nfsd4_enc_ops vector is shared for v4.0 and v4.1
since we don't need to filter out obsolete ops as this is
done in the decoding phase.
exchange_id, create_session, destroy_session, and sequence ops are
implemented as stubs returning nfserr_opnotsupp at this stage.
[was nfsd41: xdr stubs]
[get rid of CONFIG_NFSD_V4_1]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Simple sessionid hashing using its monotonically increasing sequence number.
Locking considerations:
sessionid_hashtbl access is controlled by the sessionid_lock spin lock.
It must be taken for insert, delete, and lookup.
nfsd4_sequence looks up the session id and if the session is found,
it calls nfsd4_get_session (still under the sessionid_lock).
nfsd4_destroy_session calls nfsd4_put_session after unhashing
it, so when the session's kref reaches zero it's going to get freed.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[we don't use a prime for sessionid hash table size]
[use sessionid_lock spin lock]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[add CONFIG_NFSD_V4_1 to fix v4.0 regression bug]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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[get rid of CONFIG_NFSD_V4_1]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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This patch provides basic data structures representing the nfs41
sessions and slots, plus helpers for keeping a reference count
on the session and freeing it.
Note that our server only support a headerpadsz of 0 and
it ignores backchannel attributes at the moment.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: remove headerpadsz from channel attributes]
[nfsd41: embed nfsd4_channel in nfsd4_session]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: use bool inuse for slot state]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41 remove sl_session from nfsd4_slot]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Define all error code present in
http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-29.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: clean up error code definitions]
[nfsd41: change NFSERR_REPLAY_ME]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Define all NFSv4.1 common operation and error code constants.
Note that some of the definitions are used by both the nfs41 client
and the server code. This patch is duplicated in the nfs41 and nfsd41
sessions patchset.
Signed-off-by: Andy Adamson<andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: add exchange id flags]
Signed-off-by: Mike Sager <sager@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[removed server-only hunk changing NFSERR_REPLAY_ME]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: add SEQ4_XX to nfs41-common-protocol]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: generic error code update]
[nfs41: reverse EXCHGID4_INVAL_FLAG_MASK_{A,R}]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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On an NFSv4.1 server cache miss that causes an upcall, NFS4ERR_DELAY will be
returned. It is up to the NFSv4.1 client to resend only the operations that
have not been processed.
Initialize rq_usedeferral to 1 in svc_process(). It sill be turned off in
nfsd4_proc_compound() only when NFSv4.1 Sessions are used.
Note: this isn't an adequate solution on its own. It's acceptable as a way
to get some minimal 4.1 up and working, but we're going to have to find a
way to avoid returning DELAY in all common cases before 4.1 can really be
considered ready.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: reverse rq_nodeferral negative logic]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[sunrpc: initialize rq_usedeferral]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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There's no need for it.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Remove the allocation of struct nfsd4_compound_state.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Fix a build warning about leaking CONFIG_NFSD to userspace.
The nfsd_stats data structure does not need to be available to
userspace; no kernel interface uses it. So move it inside #ifdef
__KERNEL__ and the warning goes away.
Signed-off-by: Greg Banks <gnb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Document the format and semantics of the /proc/fs/nfsd/pool_stats file.
Signed-off-by: Greg Banks <gnb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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There is no need to set rqstp->rq_server to serv, while serv is initialized as rqstp->rq_server at previous line. And between these two lines, there is no change to rqstp->rq_server.
Signed-off-by: ideawu <ideawu@163.com>
Reviewed-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Clean up: Enable the use of const arguments in higher level svc_ APIs
by adding const to the arguments of the helper functions in svc_xprt.h
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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There is an inconsistency seen in the behaviour of nfs compared to other local
filesystems on linux when changing owner or group of a directory. If the
directory has SUID/SGID flags set, on changing owner or group on the directory,
the flags are stripped off on nfs. These flags are maintained on other
filesystems such as ext3.
To reproduce on a nfs share or local filesystem, run the following commands
mkdir test; chmod +s+g test; chown user1 test; ls -ld test
On the nfs share, the flags are stripped and the output seen is
drwxr-xr-x 2 user1 root 4096 Feb 23 2009 test
On other local filesystems(ex: ext3), the flags are not stripped and the output
seen is
drwsr-sr-x 2 user1 root 4096 Feb 23 13:57 test
chown_common() called from sys_chown() will only strip the flags if the inode is
not a directory.
static int chown_common(struct dentry * dentry, uid_t user, gid_t group)
{
..
if (!S_ISDIR(inode->i_mode))
newattrs.ia_valid |=
ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
..
}
See: http://www.opengroup.org/onlinepubs/7990989775/xsh/chown.html
"If the path argument refers to a regular file, the set-user-ID (S_ISUID) and
set-group-ID (S_ISGID) bits of the file mode are cleared upon successful return
from chown(), unless the call is made by a process with appropriate privileges,
in which case it is implementation-dependent whether these bits are altered. If
chown() is successfully invoked on a file that is not a regular file, these
bits may be cleared. These bits are defined in <sys/stat.h>."
The behaviour as it stands does not appear to violate POSIX. However the
actions performed are inconsistent when comparing ext3 and nfs.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Allow the NFSv4 server to make use of TCP autotuning behaviour, which
was previously disabled by setting the sk_userlocks variable.
Set the receive buffers to be big enough to receive the whole RPC
request, and set this for the listening socket, not the accept socket.
Remove the code that readjusts the receive/send buffer sizes for the
accepted socket. Previously this code was used to influence the TCP
window management behaviour, which is no longer needed when autotuning
is enabled.
This can improve IO bandwidth on networks with high bandwidth-delay
products, where a large tcp window is required. It also simplifies
performance tuning, since getting adequate tcp buffers previously
required increasing the number of nfsd threads.
Signed-off-by: Olga Kornievskaia <aglo@citi.umich.edu>
Cc: Jim Rees <rees@umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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The spec allows clients to change ip address, so we shouldn't be
requiring that setclientid always come from the same address. For
example, a client could reboot and get a new dhcpd address, but still
present the same clientid to the server. In that case the server should
revoke the client's previous state and allow it to continue, instead of
(as it currently does) returning a CLID_INUSE error.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Add /proc/fs/nfsd/pool_stats to export to userspace various
statistics about the operation of rpc server thread pools.
This patch is based on a forward-ported version of
knfsd-add-pool-thread-stats which has been shipping in the SGI
"Enhanced NFS" product since 2006 and which was previously
posted:
http://article.gmane.org/gmane.linux.nfs/10375
It has also been updated thus:
* moved EXPORT_SYMBOL() to near the function it exports
* made the new struct struct seq_operations const
* used SEQ_START_TOKEN instead of ((void *)1)
* merged fix from SGI PV 990526 "sunrpc: use dprintk instead of
printk in svc_pool_stats_*()" by Harshula Jayasuriya.
* merged fix from SGI PV 964001 "Crash reading pool_stats before
nfsds are started".
Signed-off-by: Greg Banks <gnb@sgi.com>
Signed-off-by: Harshula Jayasuriya <harshula@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Avoid overloading the CPU scheduler with enormous load averages
when handling high call-rate NFS loads. When the knfsd bottom half
is made aware of an incoming call by the socket layer, it tries to
choose an nfsd thread and wake it up. As long as there are idle
threads, one will be woken up.
If there are lot of nfsd threads (a sensible configuration when
the server is disk-bound or is running an HSM), there will be many
more nfsd threads than CPUs to run them. Under a high call-rate
low service-time workload, the result is that almost every nfsd is
runnable, but only a handful are actually able to run. This situation
causes two significant problems:
1. The CPU scheduler takes over 10% of each CPU, which is robbing
the nfsd threads of valuable CPU time.
2. At a high enough load, the nfsd threads starve userspace threads
of CPU time, to the point where daemons like portmap and rpc.mountd
do not schedule for tens of seconds at a time. Clients attempting
to mount an NFS filesystem timeout at the very first step (opening
a TCP connection to portmap) because portmap cannot wake up from
select() and call accept() in time.
Disclaimer: these effects were observed on a SLES9 kernel, modern
kernels' schedulers may behave more gracefully.
The solution is simple: keep in each svc_pool a counter of the number
of threads which have been woken but have not yet run, and do not wake
any more if that count reaches an arbitrary small threshold.
Testing was on a 4 CPU 4 NIC Altix using 4 IRIX clients, each with 16
synthetic client threads simulating an rsync (i.e. recursive directory
listing) workload reading from an i386 RH9 install image (161480
regular files in 10841 directories) on the server. That tree is small
enough to fill in the server's RAM so no disk traffic was involved.
This setup gives a sustained call rate in excess of 60000 calls/sec
before being CPU-bound on the server. The server was running 128 nfsds.
Profiling showed schedule() taking 6.7% of every CPU, and __wake_up()
taking 5.2%. This patch drops those contributions to 3.0% and 2.2%.
Load average was over 120 before the patch, and 20.9 after.
This patch is a forward-ported version of knfsd-avoid-nfsd-overload
which has been shipping in the SGI "Enhanced NFS" product since 2006.
It has been posted before:
http://article.gmane.org/gmane.linux.nfs/10374
Signed-off-by: Greg Banks <gnb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Stop gathering the data that feeds the 'th' line in /proc/net/rpc/nfsd
because the questionable data provided is not worth the scalability
impact of calculating it. Instead, always report zeroes. The current
approach suffers from three major issues:
1. update_thread_usage() increments buckets by call service
time or call arrival time...in jiffies. On lightly loaded
machines, call service times are usually < 1 jiffy; on
heavily loaded machines call arrival times will be << 1 jiffy.
So a large portion of the updates to the buckets are rounded
down to zero, and the histogram is undercounting.
2. As seen previously on the nfs mailing list, the format in which
the histogram is presented is cryptic, difficult to explain,
and difficult to use.
3. Updating the histogram requires taking a global spinlock and
dirtying the global variables nfsd_last_call, nfsd_busy, and
nfsdstats *twice* on every RPC call, which is a significant
scaling limitation.
Testing on a 4 CPU 4 NIC Altix using 4 IRIX clients each doing
1K streaming reads at full line rate, shows the stats update code
(inlined into nfsd()) takes about 1.7% of each CPU. This patch drops
the contribution from nfsd() into the profile noise.
This patch is a forward-ported version of knfsd-remove-nfsd-threadstats
which has been shipping in the SGI "Enhanced NFS" product since 2006.
In that time, exactly one customer has noticed that the threadstats
were missing. It has been previously posted:
http://article.gmane.org/gmane.linux.nfs/10376
and more recently requested to be posted again.
Signed-off-by: Greg Banks <gnb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Note that we already checked for this invalid case at the top of this
function.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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The main nfsd code was recently modified to no longer do lookups from
withing the readdir callback, to avoid locking problems on certain
filesystems.
This (rather hacky, and overdue for replacement) NFSv4 recovery code has
the same problem. Fix it to build up a list of names (instead of
dentries) and do the lookups afterwards.
Reported symptoms were a deadlock in the xfs code (called from
nfsd4_recdir_load), with /var/lib/nfs on xfs.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Reported-by: David Warren <warren@atmos.washington.edu>
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Currently putpubfh returns NFSERR_OPNOTSUPP, which isn't actually
allowed for v4. The right error is probably NFSERR_NOTSUPP.
But let's just implement it; though rarely seen, it can be used by
Solaris (with a special mount option), is mandated by the rfc, and is
trivial for us to support.
Thanks to Yang Hongyang for pointing out the original problem, and to
Mike Eisler, Tom Talpey, Trond Myklebust, and Dave Noveck for further
argument....
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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If a filesystem being written to via NFS returns a short write count
(as opposed to an error) to nfsd, nfsd treats that as a success for
the entire write, rather than the short count that actually succeeded.
For example, given a 8192 byte write, if the underlying filesystem
only writes 4096 bytes, nfsd will ack back to the nfs client that all
8192 bytes were written. The nfs client does have retry logic for
short writes, but this is never called as the client is told the
complete write succeeded.
There are probably other ways it could happen, but in my case it
happened with a fuse (filesystem in userspace) filesystem which can
rather easily have a partial write.
Here is a patch to properly return the short write count to the
client.
Signed-off-by: David Shaw <dshaw@jabberwocky.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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nfserr_opnotsupp
Thanks for Bill Baker at sun.com for catching this
at Connectathon 2009.
This bug was introduced in 2.6.27
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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The errors returned aren't used. Just return 0 and make them available
to a dprintk(). Also, consistently use -ERRNO errors instead of nfs
errors.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Reviewed-by: Benny Halevy <bhalevy@panasas.com>
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As part of reducing the scope of the client_mutex, and in order to
remove the need for mutexes from the callback code (so that callbacks
can be done as asynchronous rpc calls), move manipulations of the
file_hashtable under the recall_lock.
Update the relevant comments while we're here.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Alexandros Batsakis <batsakis@netapp.com>
Reviewed-by: Benny Halevy <bhalevy@panasas.com>
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Since free_client() is guaranteed to only be called once, and to only
touch the client structure itself (not any common data structures), it
has no need for the state lock.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Alexandros Batsakis <batsakis@netapp.com>
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Use a slightly clearer, more concise name. Also removed unused
argument.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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All users now pass this, so it's meaningless.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Previous cleanup reveals an obvious (though harmless) bug: when
delegreturn gets a stateid that isn't for a delegation, it should return
an error rather than doing nothing.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Delegreturn is enough a special case for preprocess_stateid_op to
warrant just open-coding it in delegreturn.
There should be no change in behavior here; we're just reshuffling code.
Thanks to Yang Hongyang for catching a critical typo.
Reviewed-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Make this check self-documenting.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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I can't recall ever seeing these printk's used to debug a problem. I'll
happily put them back if we see a case where they'd be useful. (Though
if we do that the find_XXX() errors would probably be better
reported in find_XXX() functions themselves.)
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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We no longer need stidp.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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