evin/ms-nfs41-client
3
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

namecache: limit the number of delegations

Browse source 
to prevent delegations from claiming all available slots in the attribute cache, nfs41_name_cache_insert() now returns ERROR_TOO_MANY_OPEN_FILES when the number of delegated entries reaches 50% of the cache capacity.  see comment 'delegations and cache feedback' in name_cache.c for details

when nfs41_open() sees this error from nfs41_name_cache_insert(), it calls new function nfs41_client_delegation_return_lru() to return the least-recently-used delegation and, if successful, loops back to nfs41_name_cache_insert().  nfs41_client_delegation_return_lru() returns NFS4ERR_BADHANDLE if all delegations are currently in use (associated with an existing open), in which case nfs41_open() returns the newly-granted delegation

Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
This commit is contained in:
Casey Bodley 2011-08-19 12:04:30 -04:00 • committed by unknown
parent a0d4403a99
commit 7b07dcebb8
4 changed files with 145 additions and 27 deletions
Download patch file Download diff file Expand all files Collapse all files

68
daemon/nfs41_ops.c
View file

@ -34,6 +34,7 @@
#include "nfs41_compound.h"
#include "nfs41_xdr.h"
#include "name_cache.h"
#include "delegation.h"
#include "daemon_debug.h"
#include "util.h"
@ -329,6 +330,47 @@ static void open_delegation_return(
delegation->type = OPEN_DELEGATE_NONE;
}
static void open_update_cache(
IN nfs41_session *session,
IN nfs41_path_fh *parent,
IN nfs41_path_fh *file,
IN open_delegation4 *delegation,
IN change_info4 *changeinfo,
IN nfs41_getattr_res *dir_attrs,
IN nfs41_getattr_res *file_attrs)
{
struct nfs41_name_cache *cache = session_name_cache(session);
uint32_t status;
/* update the attributes of the parent directory */
memcpy(&dir_attrs->info->attrmask, &dir_attrs->obj_attributes.attrmask,
sizeof(bitmap4));
nfs41_attr_cache_update(cache, parent->fh.fileid, dir_attrs->info);
/* add the file handle and attributes to the name cache */
memcpy(&file_attrs->info->attrmask, &file_attrs->obj_attributes.attrmask,
sizeof(bitmap4));
retry_cache_insert:
AcquireSRWLockShared(&file->path->lock);
status = nfs41_name_cache_insert(cache, file->path->path, &file->name,
&file->fh, file_attrs->info, changeinfo, delegation->type);
ReleaseSRWLockShared(&file->path->lock);
if (status == ERROR_TOO_MANY_OPEN_FILES) {
/* the cache won't accept any more delegations; ask the client to
* return a delegation to free up a slot in the attribute cache */
status = nfs41_client_delegation_return_lru(session->client);
if (status == NFS4_OK)
goto retry_cache_insert;
}
if (status) {
/* if we can't make room in the cache, return this
* delegation immediately to free resources on the server */
open_delegation_return(session, file, delegation);
}
}
int nfs41_open(
IN nfs41_session *session,
IN nfs41_path_fh *parent,
@ -345,7 +387,7 @@ int nfs41_open(
OUT open_delegation4 *delegation,
OUT OPTIONAL nfs41_file_info *info)
{
int status, attr_status;
int status;
nfs41_compound compound;
nfs_argop4 argops[8];
nfs_resop4 resops[8];
@ -473,28 +515,12 @@ int nfs41_open(
if (status)
goto out;
/* update the attributes of the parent directory */
memcpy(&dir_info.attrmask, &pgetattr_res.obj_attributes.attrmask,
sizeof(bitmap4));
nfs41_attr_cache_update(session_name_cache(session),
parent->fh.fileid, &dir_info);
/* add the file handle and attributes to the name cache */
memcpy(&info->attrmask, &getattr_res.obj_attributes.attrmask,
sizeof(bitmap4));
AcquireSRWLockShared(&file->path->lock);
attr_status = nfs41_name_cache_insert(session_name_cache(session),
file->path->path, &file->name, &file->fh,
info, &open_res.resok4.cinfo, delegation->type);
ReleaseSRWLockShared(&file->path->lock);
/* if we fail to cache the attributes, return the delegation
* immediately to free resources on the server */
if (attr_status)
open_delegation_return(session, file, delegation);
if (create == OPEN4_CREATE)
nfs41_superblock_space_changed(file->fh.superblock);
/* update the name/attr cache with the results */
open_update_cache(session, parent, file, delegation,
&open_res.resok4.cinfo, &pgetattr_res, &getattr_res);
out:
return status;
}