nfsd-6.7 fixes:

- Fix several long-standing bugs in the duplicate reply cache
 - Fix a memory leak
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Merge tag 'nfsd-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd fixes from Chuck Lever:

 - Fix several long-standing bugs in the duplicate reply cache

 - Fix a memory leak

* tag 'nfsd-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  NFSD: Fix checksum mismatches in the duplicate reply cache
  NFSD: Fix "start of NFS reply" pointer passed to nfsd_cache_update()
  NFSD: Update nfsd_cache_append() to use xdr_stream
  nfsd: fix file memleak on client_opens_release
This commit is contained in:
Linus Torvalds 2023-11-18 11:23:32 -08:00
commit bb28378af3
4 changed files with 65 additions and 40 deletions

View File

@ -84,8 +84,8 @@ int nfsd_net_reply_cache_init(struct nfsd_net *nn);
void nfsd_net_reply_cache_destroy(struct nfsd_net *nn);
int nfsd_reply_cache_init(struct nfsd_net *);
void nfsd_reply_cache_shutdown(struct nfsd_net *);
int nfsd_cache_lookup(struct svc_rqst *rqstp,
struct nfsd_cacherep **cacherep);
int nfsd_cache_lookup(struct svc_rqst *rqstp, unsigned int start,
unsigned int len, struct nfsd_cacherep **cacherep);
void nfsd_cache_update(struct svc_rqst *rqstp, struct nfsd_cacherep *rp,
int cachetype, __be32 *statp);
int nfsd_reply_cache_stats_show(struct seq_file *m, void *v);

View File

@ -2804,7 +2804,7 @@ static int client_opens_release(struct inode *inode, struct file *file)
/* XXX: alternatively, we could get/drop in seq start/stop */
drop_client(clp);
return 0;
return seq_release(inode, file);
}
static const struct file_operations client_states_fops = {

View File

@ -369,33 +369,52 @@ nfsd_reply_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
return freed;
}
/*
* Walk an xdr_buf and get a CRC for at most the first RC_CSUMLEN bytes
/**
* nfsd_cache_csum - Checksum incoming NFS Call arguments
* @buf: buffer containing a whole RPC Call message
* @start: starting byte of the NFS Call header
* @remaining: size of the NFS Call header, in bytes
*
* Compute a weak checksum of the leading bytes of an NFS procedure
* call header to help verify that a retransmitted Call matches an
* entry in the duplicate reply cache.
*
* To avoid assumptions about how the RPC message is laid out in
* @buf and what else it might contain (eg, a GSS MIC suffix), the
* caller passes us the exact location and length of the NFS Call
* header.
*
* Returns a 32-bit checksum value, as defined in RFC 793.
*/
static __wsum
nfsd_cache_csum(struct svc_rqst *rqstp)
static __wsum nfsd_cache_csum(struct xdr_buf *buf, unsigned int start,
unsigned int remaining)
{
unsigned int base, len;
struct xdr_buf subbuf;
__wsum csum = 0;
void *p;
int idx;
unsigned int base;
__wsum csum;
struct xdr_buf *buf = &rqstp->rq_arg;
const unsigned char *p = buf->head[0].iov_base;
size_t csum_len = min_t(size_t, buf->head[0].iov_len + buf->page_len,
RC_CSUMLEN);
size_t len = min(buf->head[0].iov_len, csum_len);
if (remaining > RC_CSUMLEN)
remaining = RC_CSUMLEN;
if (xdr_buf_subsegment(buf, &subbuf, start, remaining))
return csum;
/* rq_arg.head first */
csum = csum_partial(p, len, 0);
csum_len -= len;
if (subbuf.head[0].iov_len) {
len = min_t(unsigned int, subbuf.head[0].iov_len, remaining);
csum = csum_partial(subbuf.head[0].iov_base, len, csum);
remaining -= len;
}
/* Continue into page array */
idx = buf->page_base / PAGE_SIZE;
base = buf->page_base & ~PAGE_MASK;
while (csum_len) {
p = page_address(buf->pages[idx]) + base;
len = min_t(size_t, PAGE_SIZE - base, csum_len);
idx = subbuf.page_base / PAGE_SIZE;
base = subbuf.page_base & ~PAGE_MASK;
while (remaining) {
p = page_address(subbuf.pages[idx]) + base;
len = min_t(unsigned int, PAGE_SIZE - base, remaining);
csum = csum_partial(p, len, csum);
csum_len -= len;
remaining -= len;
base = 0;
++idx;
}
@ -466,6 +485,8 @@ out:
/**
* nfsd_cache_lookup - Find an entry in the duplicate reply cache
* @rqstp: Incoming Call to find
* @start: starting byte in @rqstp->rq_arg of the NFS Call header
* @len: size of the NFS Call header, in bytes
* @cacherep: OUT: DRC entry for this request
*
* Try to find an entry matching the current call in the cache. When none
@ -479,7 +500,8 @@ out:
* %RC_REPLY: Reply from cache
* %RC_DROPIT: Do not process the request further
*/
int nfsd_cache_lookup(struct svc_rqst *rqstp, struct nfsd_cacherep **cacherep)
int nfsd_cache_lookup(struct svc_rqst *rqstp, unsigned int start,
unsigned int len, struct nfsd_cacherep **cacherep)
{
struct nfsd_net *nn;
struct nfsd_cacherep *rp, *found;
@ -495,7 +517,7 @@ int nfsd_cache_lookup(struct svc_rqst *rqstp, struct nfsd_cacherep **cacherep)
goto out;
}
csum = nfsd_cache_csum(rqstp);
csum = nfsd_cache_csum(&rqstp->rq_arg, start, len);
/*
* Since the common case is a cache miss followed by an insert,
@ -641,24 +663,17 @@ void nfsd_cache_update(struct svc_rqst *rqstp, struct nfsd_cacherep *rp,
return;
}
/*
* Copy cached reply to current reply buffer. Should always fit.
* FIXME as reply is in a page, we should just attach the page, and
* keep a refcount....
*/
static int
nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *data)
{
struct kvec *vec = &rqstp->rq_res.head[0];
__be32 *p;
if (vec->iov_len + data->iov_len > PAGE_SIZE) {
printk(KERN_WARNING "nfsd: cached reply too large (%zd).\n",
data->iov_len);
return 0;
}
memcpy((char*)vec->iov_base + vec->iov_len, data->iov_base, data->iov_len);
vec->iov_len += data->iov_len;
return 1;
p = xdr_reserve_space(&rqstp->rq_res_stream, data->iov_len);
if (unlikely(!p))
return false;
memcpy(p, data->iov_base, data->iov_len);
xdr_commit_encode(&rqstp->rq_res_stream);
return true;
}
/*

View File

@ -981,6 +981,8 @@ int nfsd_dispatch(struct svc_rqst *rqstp)
const struct svc_procedure *proc = rqstp->rq_procinfo;
__be32 *statp = rqstp->rq_accept_statp;
struct nfsd_cacherep *rp;
unsigned int start, len;
__be32 *nfs_reply;
/*
* Give the xdr decoder a chance to change this if it wants
@ -988,6 +990,13 @@ int nfsd_dispatch(struct svc_rqst *rqstp)
*/
rqstp->rq_cachetype = proc->pc_cachetype;
/*
* ->pc_decode advances the argument stream past the NFS
* Call header, so grab the header's starting location and
* size now for the call to nfsd_cache_lookup().
*/
start = xdr_stream_pos(&rqstp->rq_arg_stream);
len = xdr_stream_remaining(&rqstp->rq_arg_stream);
if (!proc->pc_decode(rqstp, &rqstp->rq_arg_stream))
goto out_decode_err;
@ -1001,7 +1010,7 @@ int nfsd_dispatch(struct svc_rqst *rqstp)
smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter | 1);
rp = NULL;
switch (nfsd_cache_lookup(rqstp, &rp)) {
switch (nfsd_cache_lookup(rqstp, start, len, &rp)) {
case RC_DOIT:
break;
case RC_REPLY:
@ -1010,6 +1019,7 @@ int nfsd_dispatch(struct svc_rqst *rqstp)
goto out_dropit;
}
nfs_reply = xdr_inline_decode(&rqstp->rq_res_stream, 0);
*statp = proc->pc_func(rqstp);
if (test_bit(RQ_DROPME, &rqstp->rq_flags))
goto out_update_drop;
@ -1023,7 +1033,7 @@ int nfsd_dispatch(struct svc_rqst *rqstp)
*/
smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter + 1);
nfsd_cache_update(rqstp, rp, rqstp->rq_cachetype, statp + 1);
nfsd_cache_update(rqstp, rp, rqstp->rq_cachetype, nfs_reply);
out_cached_reply:
return 1;