Commit 147f1404 authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'for-3.16' of git://linux-nfs.org/~bfields/linux

Pull nfsd bugfixes from Bruce Fields:
 "Fixes for a new regression from the xdr encoding rewrite, and a
  delegation problem we've had for a while (made somewhat more annoying
  by the vfs delegation support added in 3.13)"

* 'for-3.16' of git://linux-nfs.org/~bfields/linux:
  NFSD: fix bug for readdir of pseudofs
  NFSD: Don't hand out delegations for 30 seconds after recalling them.
parents 401c58fc f41c5ad2
......@@ -41,6 +41,7 @@
#include <linux/ratelimit.h>
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/sunrpc/addr.h>
#include <linux/hash.h>
#include "xdr4.h"
#include "xdr4cb.h"
#include "vfs.h"
......@@ -364,6 +365,79 @@ static struct nfs4_ol_stateid * nfs4_alloc_stateid(struct nfs4_client *clp)
return openlockstateid(nfs4_alloc_stid(clp, stateid_slab));
}
/*
* When we recall a delegation, we should be careful not to hand it
* out again straight away.
* To ensure this we keep a pair of bloom filters ('new' and 'old')
* in which the filehandles of recalled delegations are "stored".
* If a filehandle appear in either filter, a delegation is blocked.
* When a delegation is recalled, the filehandle is stored in the "new"
* filter.
* Every 30 seconds we swap the filters and clear the "new" one,
* unless both are empty of course.
*
* Each filter is 256 bits. We hash the filehandle to 32bit and use the
* low 3 bytes as hash-table indices.
*
* 'state_lock', which is always held when block_delegations() is called,
* is used to manage concurrent access. Testing does not need the lock
* except when swapping the two filters.
*/
static struct bloom_pair {
int entries, old_entries;
time_t swap_time;
int new; /* index into 'set' */
DECLARE_BITMAP(set[2], 256);
} blocked_delegations;
static int delegation_blocked(struct knfsd_fh *fh)
{
u32 hash;
struct bloom_pair *bd = &blocked_delegations;
if (bd->entries == 0)
return 0;
if (seconds_since_boot() - bd->swap_time > 30) {
spin_lock(&state_lock);
if (seconds_since_boot() - bd->swap_time > 30) {
bd->entries -= bd->old_entries;
bd->old_entries = bd->entries;
memset(bd->set[bd->new], 0,
sizeof(bd->set[0]));
bd->new = 1-bd->new;
bd->swap_time = seconds_since_boot();
}
spin_unlock(&state_lock);
}
hash = arch_fast_hash(&fh->fh_base, fh->fh_size, 0);
if (test_bit(hash&255, bd->set[0]) &&
test_bit((hash>>8)&255, bd->set[0]) &&
test_bit((hash>>16)&255, bd->set[0]))
return 1;
if (test_bit(hash&255, bd->set[1]) &&
test_bit((hash>>8)&255, bd->set[1]) &&
test_bit((hash>>16)&255, bd->set[1]))
return 1;
return 0;
}
static void block_delegations(struct knfsd_fh *fh)
{
u32 hash;
struct bloom_pair *bd = &blocked_delegations;
hash = arch_fast_hash(&fh->fh_base, fh->fh_size, 0);
__set_bit(hash&255, bd->set[bd->new]);
__set_bit((hash>>8)&255, bd->set[bd->new]);
__set_bit((hash>>16)&255, bd->set[bd->new]);
if (bd->entries == 0)
bd->swap_time = seconds_since_boot();
bd->entries += 1;
}
static struct nfs4_delegation *
alloc_init_deleg(struct nfs4_client *clp, struct nfs4_ol_stateid *stp, struct svc_fh *current_fh)
{
......@@ -372,6 +446,8 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_ol_stateid *stp, struct sv
dprintk("NFSD alloc_init_deleg\n");
if (num_delegations > max_delegations)
return NULL;
if (delegation_blocked(&current_fh->fh_handle))
return NULL;
dp = delegstateid(nfs4_alloc_stid(clp, deleg_slab));
if (dp == NULL)
return dp;
......@@ -2770,6 +2846,8 @@ static void nfsd_break_one_deleg(struct nfs4_delegation *dp)
/* Only place dl_time is set; protected by i_lock: */
dp->dl_time = get_seconds();
block_delegations(&dp->dl_fh);
nfsd4_cb_recall(dp);
}
......
......@@ -2687,6 +2687,7 @@ nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
nfserr = nfserr_toosmall;
goto fail;
case nfserr_noent:
xdr_truncate_encode(xdr, start_offset);
goto skip_entry;
default:
/*
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment