[PATCH 11/12] fs, nfs: convert nfs_client.cl_count from atomic_t to refcount_t

From: Elena Reshetova
Date: Tue Mar 14 2017 - 03:08:18 EST

Next message: zhichang.yuan: "Re: [PATCH V7 4/7] LPC: Support the device-tree LPC host on Hip06/Hip07 (fwd)"
Previous message: Elena Reshetova: "[PATCH 10/12] fs, nfs: convert nfs_lock_context.count from atomic_t to refcount_t"
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refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@xxxxxxxxx>
Signed-off-by: Hans Liljestrand <ishkamiel@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: David Windsor <dwindsor@xxxxxxxxx>
---
fs/nfs/client.c | 12 ++++++------
fs/nfs/filelayout/filelayout.c | 12 ++++++------
fs/nfs/flexfilelayout/flexfilelayout.c | 12 ++++++------
fs/nfs/nfs4client.c | 16 ++++++++--------
fs/nfs/nfs4proc.c | 12 ++++++------
fs/nfs/nfs4state.c | 6 +++---
include/linux/nfs_fs_sb.h | 3 ++-
7 files changed, 37 insertions(+), 36 deletions(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 91a8d61..6c67d2e 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -163,7 +163,7 @@ struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)

clp->rpc_ops = clp->cl_nfs_mod->rpc_ops;

- atomic_set(&clp->cl_count, 1);
+ refcount_set(&clp->cl_count, 1);
clp->cl_cons_state = NFS_CS_INITING;

memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
@@ -271,10 +271,10 @@ void nfs_put_client(struct nfs_client *clp)
if (!clp)
return;

- dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count));
+ dprintk("--> nfs_put_client({%d})\n", refcount_read(&clp->cl_count));
nn = net_generic(clp->cl_net, nfs_net_id);

- if (atomic_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) {
+ if (refcount_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) {
list_del(&clp->cl_share_link);
nfs_cb_idr_remove_locked(clp);
spin_unlock(&nn->nfs_client_lock);
@@ -319,7 +319,7 @@ static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *dat
sap))
continue;

- atomic_inc(&clp->cl_count);
+ refcount_inc(&clp->cl_count);
return clp;
}
return NULL;
@@ -1029,7 +1029,7 @@ struct nfs_server *nfs_clone_server(struct nfs_server *source,
/* Copy data from the source */
server->nfs_client = source->nfs_client;
server->destroy = source->destroy;
- atomic_inc(&server->nfs_client->cl_count);
+ refcount_inc(&server->nfs_client->cl_count);
nfs_server_copy_userdata(server, source);

server->fsid = fattr->fsid;
@@ -1195,7 +1195,7 @@ static int nfs_server_list_show(struct seq_file *m, void *v)
clp->rpc_ops->version,
rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
- atomic_read(&clp->cl_count),
+ refcount_read(&clp->cl_count),
clp->cl_hostname);
rcu_read_unlock();

diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c
index 18f98e0..526bd6e 100644
--- a/fs/nfs/filelayout/filelayout.c
+++ b/fs/nfs/filelayout/filelayout.c
@@ -498,10 +498,10 @@ filelayout_read_pagelist(struct nfs_pgio_header *hdr)
return PNFS_NOT_ATTEMPTED;

dprintk("%s USE DS: %s cl_count %d\n", __func__,
- ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
+ ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count));

/* No multipath support. Use first DS */
- atomic_inc(&ds->ds_clp->cl_count);
+ refcount_inc(&ds->ds_clp->cl_count);
hdr->ds_clp = ds->ds_clp;
hdr->ds_commit_idx = idx;
fh = nfs4_fl_select_ds_fh(lseg, j);
@@ -542,10 +542,10 @@ filelayout_write_pagelist(struct nfs_pgio_header *hdr, int sync)

dprintk("%s ino %lu sync %d req %zu@%llu DS: %s cl_count %d\n",
__func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
- offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
+ offset, ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count));

hdr->pgio_done_cb = filelayout_write_done_cb;
- atomic_inc(&ds->ds_clp->cl_count);
+ refcount_inc(&ds->ds_clp->cl_count);
hdr->ds_clp = ds->ds_clp;
hdr->ds_commit_idx = idx;
fh = nfs4_fl_select_ds_fh(lseg, j);
@@ -1038,9 +1038,9 @@ static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
goto out_err;

dprintk("%s ino %lu, how %d cl_count %d\n", __func__,
- data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count));
+ data->inode->i_ino, how, refcount_read(&ds->ds_clp->cl_count));
data->commit_done_cb = filelayout_commit_done_cb;
- atomic_inc(&ds->ds_clp->cl_count);
+ refcount_inc(&ds->ds_clp->cl_count);
data->ds_clp = ds->ds_clp;
fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
if (fh)
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
index 18d4c5a..341b02f 100644
--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -1771,10 +1771,10 @@ ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
vers = nfs4_ff_layout_ds_version(lseg, idx);

dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__,
- ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count), vers);
+ ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count), vers);

hdr->pgio_done_cb = ff_layout_read_done_cb;
- atomic_inc(&ds->ds_clp->cl_count);
+ refcount_inc(&ds->ds_clp->cl_count);
hdr->ds_clp = ds->ds_clp;
fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
if (fh)
@@ -1830,11 +1830,11 @@ ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)

dprintk("%s ino %lu sync %d req %zu@%llu DS: %s cl_count %d vers %d\n",
__func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
- offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count),
+ offset, ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count),
vers);

hdr->pgio_done_cb = ff_layout_write_done_cb;
- atomic_inc(&ds->ds_clp->cl_count);
+ refcount_inc(&ds->ds_clp->cl_count);
hdr->ds_clp = ds->ds_clp;
hdr->ds_commit_idx = idx;
fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
@@ -1899,11 +1899,11 @@ static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
vers = nfs4_ff_layout_ds_version(lseg, idx);

dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__,
- data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count),
+ data->inode->i_ino, how, refcount_read(&ds->ds_clp->cl_count),
vers);
data->commit_done_cb = ff_layout_commit_done_cb;
data->cred = ds_cred;
- atomic_inc(&ds->ds_clp->cl_count);
+ refcount_inc(&ds->ds_clp->cl_count);
data->ds_clp = ds->ds_clp;
fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
if (fh)
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index 5ae9d64..6984760 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -506,7 +506,7 @@ int nfs40_walk_client_list(struct nfs_client *new,
/* If "pos" isn't marked ready, we can't trust the
* remaining fields in "pos" */
if (pos->cl_cons_state > NFS_CS_READY) {
- atomic_inc(&pos->cl_count);
+ refcount_inc(&pos->cl_count);
spin_unlock(&nn->nfs_client_lock);

nfs_put_client(prev);
@@ -541,7 +541,7 @@ int nfs40_walk_client_list(struct nfs_client *new,
* way that a SETCLIENTID_CONFIRM to pos can succeed is
* if new and pos point to the same server:
*/
- atomic_inc(&pos->cl_count);
+ refcount_inc(&pos->cl_count);
spin_unlock(&nn->nfs_client_lock);

nfs_put_client(prev);
@@ -558,7 +558,7 @@ int nfs40_walk_client_list(struct nfs_client *new,
prev = NULL;
*result = pos;
dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
- __func__, pos, atomic_read(&pos->cl_count));
+ __func__, pos, refcount_read(&pos->cl_count));
goto out;
case -ERESTARTSYS:
case -ETIMEDOUT:
@@ -750,7 +750,7 @@ int nfs41_walk_client_list(struct nfs_client *new,
* ID and serverowner fields. Wait for CREATE_SESSION
* to finish. */
if (pos->cl_cons_state > NFS_CS_READY) {
- atomic_inc(&pos->cl_count);
+ refcount_inc(&pos->cl_count);
spin_unlock(&nn->nfs_client_lock);

nfs_put_client(prev);
@@ -784,11 +784,11 @@ int nfs41_walk_client_list(struct nfs_client *new,
if (!nfs4_match_client_owner_id(pos, new))
continue;
found:
- atomic_inc(&pos->cl_count);
+ refcount_inc(&pos->cl_count);
*result = pos;
status = 0;
dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
- __func__, pos, atomic_read(&pos->cl_count));
+ __func__, pos, refcount_read(&pos->cl_count));
break;
}

@@ -820,7 +820,7 @@ nfs4_find_client_ident(struct net *net, int cb_ident)
spin_lock(&nn->nfs_client_lock);
clp = idr_find(&nn->cb_ident_idr, cb_ident);
if (clp)
- atomic_inc(&clp->cl_count);
+ refcount_inc(&clp->cl_count);
spin_unlock(&nn->nfs_client_lock);
return clp;
}
@@ -875,7 +875,7 @@ nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
continue;

- atomic_inc(&clp->cl_count);
+ refcount_inc(&clp->cl_count);
spin_unlock(&nn->nfs_client_lock);
return clp;
}
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 2c85c9f..7046e56 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4873,7 +4873,7 @@ static void nfs4_renew_release(void *calldata)
struct nfs4_renewdata *data = calldata;
struct nfs_client *clp = data->client;

- if (atomic_read(&clp->cl_count) > 1)
+ if (refcount_read(&clp->cl_count) > 1)
nfs4_schedule_state_renewal(clp);
nfs_put_client(clp);
kfree(data);
@@ -4921,7 +4921,7 @@ static int nfs4_proc_async_renew(struct nfs_client *clp, struct rpc_cred *cred,

if (renew_flags == 0)
return 0;
- if (!atomic_inc_not_zero(&clp->cl_count))
+ if (!refcount_inc_not_zero(&clp->cl_count))
return -EIO;
data = kmalloc(sizeof(*data), GFP_NOFS);
if (data == NULL)
@@ -7588,7 +7588,7 @@ static int _nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred,
struct rpc_task *task;
int status = -EIO;

- if (!atomic_inc_not_zero(&clp->cl_count))
+ if (!refcount_inc_not_zero(&clp->cl_count))
goto out;

status = -ENOMEM;
@@ -8150,7 +8150,7 @@ static void nfs41_sequence_release(void *data)
struct nfs4_sequence_data *calldata = data;
struct nfs_client *clp = calldata->clp;

- if (atomic_read(&clp->cl_count) > 1)
+ if (refcount_read(&clp->cl_count) > 1)
nfs4_schedule_state_renewal(clp);
nfs_put_client(clp);
kfree(calldata);
@@ -8179,7 +8179,7 @@ static void nfs41_sequence_call_done(struct rpc_task *task, void *data)
trace_nfs4_sequence(clp, task->tk_status);
if (task->tk_status < 0) {
dprintk("%s ERROR %d\n", __func__, task->tk_status);
- if (atomic_read(&clp->cl_count) == 1)
+ if (refcount_read(&clp->cl_count) == 1)
goto out;

if (nfs41_sequence_handle_errors(task, clp) == -EAGAIN) {
@@ -8227,7 +8227,7 @@ static struct rpc_task *_nfs41_proc_sequence(struct nfs_client *clp,
.flags = RPC_TASK_ASYNC | RPC_TASK_TIMEOUT,
};

- if (!atomic_inc_not_zero(&clp->cl_count))
+ if (!refcount_inc_not_zero(&clp->cl_count))
return ERR_PTR(-EIO);
calldata = kzalloc(sizeof(*calldata), GFP_NOFS);
if (calldata == NULL) {
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 347cb18..8dd2aef 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1171,7 +1171,7 @@ void nfs4_schedule_state_manager(struct nfs_client *clp)
if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
return;
__module_get(THIS_MODULE);
- atomic_inc(&clp->cl_count);
+ refcount_inc(&clp->cl_count);

/* The rcu_read_lock() is not strictly necessary, as the state
* manager is the only thread that ever changes the rpc_xprt
@@ -1263,7 +1263,7 @@ int nfs4_wait_clnt_recover(struct nfs_client *clp)

might_sleep();

- atomic_inc(&clp->cl_count);
+ refcount_inc(&clp->cl_count);
res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
nfs_wait_bit_killable, TASK_KILLABLE);
if (res)
@@ -2498,7 +2498,7 @@ static void nfs4_state_manager(struct nfs_client *clp)
break;
if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
break;
- } while (atomic_read(&clp->cl_count) > 1);
+ } while (refcount_read(&clp->cl_count) > 1);
return;
out_error:
if (strlen(section))
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index b34097c..8a2be4d 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -9,6 +9,7 @@
#include <linux/sunrpc/xprt.h>

#include <linux/atomic.h>
+#include <linux/refcount.h>

struct nfs4_session;
struct nfs_iostats;
@@ -24,7 +25,7 @@ struct nfs41_impl_id;
* The nfs_client identifies our client state to the server.
*/
struct nfs_client {
- atomic_t cl_count;
+ refcount_t cl_count;
atomic_t cl_mds_count;
int cl_cons_state; /* current construction state (-ve: init error) */
#define NFS_CS_READY 0 /* ready to be used */
--
2.7.4

Next message: zhichang.yuan: "Re: [PATCH V7 4/7] LPC: Support the device-tree LPC host on Hip06/Hip07 (fwd)"
Previous message: Elena Reshetova: "[PATCH 10/12] fs, nfs: convert nfs_lock_context.count from atomic_t to refcount_t"
In reply to: Elena Reshetova: "[PATCH 10/12] fs, nfs: convert nfs_lock_context.count from atomic_t to refcount_t"
Next in thread: Elena Reshetova: "[PATCH 12/12] fs, nfs: convert nfs_cache_array.refcount from atomic_t to refcount_t"
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