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NFSv4.2 copy do not allocate memory under the lock 

Bruce pointed out that we shouldn't allocate memory while holding
a lock in the nfs4_callback_offload() and handle_async_copy()
that deal with a racing CB_OFFLOAD and reply to COPY case.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
hifive-unleashed-5.1
Olga Kornievskaia 2018-11-21 11:24:22 -05:00 committed by Trond Myklebust
parent aeabb3c961
commit 99f2c55591
2 changed files with 21 additions and 20 deletions
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22
fs/nfs/callback_proc.c
View File

@ -686,20 +686,24 @@ __be32 nfs4_callback_offload(void *data, void *dummy,
{
struct cb_offloadargs *args = data;
struct nfs_server *server;
struct nfs4_copy_state *copy;
struct nfs4_copy_state *copy, *tmp_copy;
bool found = false;
copy = kzalloc(sizeof(struct nfs4_copy_state), GFP_NOFS);
if (!copy)
return htonl(NFS4ERR_SERVERFAULT);
spin_lock(&cps->clp->cl_lock);
rcu_read_lock();
list_for_each_entry_rcu(server, &cps->clp->cl_superblocks,
client_link) {
list_for_each_entry(copy, &server->ss_copies, copies) {
list_for_each_entry(tmp_copy, &server->ss_copies, copies) {
if (memcmp(args->coa_stateid.other,
copy->stateid.other,
tmp_copy->stateid.other,
sizeof(args->coa_stateid.other)))
continue;
nfs4_copy_cb_args(copy, args);
complete(&copy->completion);
nfs4_copy_cb_args(tmp_copy, args);
complete(&tmp_copy->completion);
found = true;
goto out;
}
@ -707,15 +711,11 @@ __be32 nfs4_callback_offload(void *data, void *dummy,
out:
rcu_read_unlock();
if (!found) {
copy = kzalloc(sizeof(struct nfs4_copy_state), GFP_NOFS);
if (!copy) {
spin_unlock(&cps->clp->cl_lock);
return htonl(NFS4ERR_SERVERFAULT);
}
memcpy(&copy->stateid, &args->coa_stateid, NFS4_STATEID_SIZE);
nfs4_copy_cb_args(copy, args);
list_add_tail(&copy->copies, &cps->clp->pending_cb_stateids);
}
} else
kfree(copy);
spin_unlock(&cps->clp->cl_lock);
return 0;

19
fs/nfs/nfs42proc.c
View File

@ -137,31 +137,32 @@ static int handle_async_copy(struct nfs42_copy_res *res,
struct file *dst,
nfs4_stateid *src_stateid)
{
struct nfs4_copy_state *copy;
struct nfs4_copy_state *copy, *tmp_copy;
int status = NFS4_OK;
bool found_pending = false;
struct nfs_open_context *ctx = nfs_file_open_context(dst);
copy = kzalloc(sizeof(struct nfs4_copy_state), GFP_NOFS);
if (!copy)
return -ENOMEM;
spin_lock(&server->nfs_client->cl_lock);
list_for_each_entry(copy, &server->nfs_client->pending_cb_stateids,
list_for_each_entry(tmp_copy, &server->nfs_client->pending_cb_stateids,
copies) {
if (memcmp(&res->write_res.stateid, &copy->stateid,
if (memcmp(&res->write_res.stateid, &tmp_copy->stateid,
NFS4_STATEID_SIZE))
continue;
found_pending = true;
list_del(&copy->copies);
list_del(&tmp_copy->copies);
break;
}
if (found_pending) {
spin_unlock(&server->nfs_client->cl_lock);
kfree(copy);
copy = tmp_copy;
goto out;
}
copy = kzalloc(sizeof(struct nfs4_copy_state), GFP_NOFS);
if (!copy) {
spin_unlock(&server->nfs_client->cl_lock);
return -ENOMEM;
}
memcpy(&copy->stateid, &res->write_res.stateid, NFS4_STATEID_SIZE);
init_completion(&copy->completion);
copy->parent_state = ctx->state;