Commit 0a9b00e5 authored by Paulo Alcantara's avatar Paulo Alcantara Committed by Steve French
Browse files

smb: client: get rid of TCP_Server_Info::refpath_lock 



TCP_Server_Info::leaf_fullpath is allocated in cifs_get_tcp_session()
and never changed afterwards, so there is no need to serialize its
access.

Signed-off-by: default avatarPaulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 2948f0d4

fs/smb/client/cifsglob.h

+2 −11
Original line number Diff line number Diff line
@@ -811,18 +811,9 @@ struct TCP_Server_Info { 
	bool use_swn_dstaddr;

	struct sockaddr_storage swn_dstaddr;

#endif

	struct mutex refpath_lock; /* protects leaf_fullpath */

	/*

	 * leaf_fullpath: Canonical DFS referral path related to this

	 *                connection.

	 *                It is used in DFS cache refresher, reconnect and may

	 *                change due to nested DFS links.

	 *

	 * Protected by @refpath_lock and @srv_lock.  The @refpath_lock is

	 * mostly used for not requiring a copy of @leaf_fullpath when getting

	 * cached or new DFS referrals (which might also sleep during I/O).

	 * While @srv_lock is held for making string and NULL comparisons against

	 * both fields as in mount(2) and cache refresh.

	 * Canonical DFS referral path used in cifs_reconnect() for failover as

	 * well as in DFS cache refresher.

	 *

	 * format: \\HOST\SHARE[\OPTIONAL PATH]

	 */

fs/smb/client/connect.c

+4 −16
Original line number Diff line number Diff line
@@ -492,7 +492,7 @@ static int reconnect_target_locked(struct TCP_Server_Info *server, 
static int reconnect_dfs_server(struct TCP_Server_Info *server)

{

	struct dfs_cache_tgt_iterator *target_hint = NULL;



	const char *ref_path = server->leaf_fullpath + 1;

	DFS_CACHE_TGT_LIST(tl);

	int num_targets = 0;

	int rc = 0;
@@ -505,10 +505,8 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server) 
	 * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after

	 * refreshing the referral, so, in this case, default it to 1.

	 */

	mutex_lock(&server->refpath_lock);

	if (!dfs_cache_noreq_find(server->leaf_fullpath + 1, NULL, &tl))

	if (!dfs_cache_noreq_find(ref_path, NULL, &tl))

		num_targets = dfs_cache_get_nr_tgts(&tl);

	mutex_unlock(&server->refpath_lock);

	if (!num_targets)

		num_targets = 1;
@@ -552,9 +550,7 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server) 
		mod_delayed_work(cifsiod_wq, &server->reconnect, 0);

	} while (server->tcpStatus == CifsNeedReconnect);



	mutex_lock(&server->refpath_lock);

	dfs_cache_noreq_update_tgthint(server->leaf_fullpath + 1, target_hint);

	mutex_unlock(&server->refpath_lock);

	dfs_cache_noreq_update_tgthint(ref_path, target_hint);

	dfs_cache_free_tgts(&tl);



	/* Need to set up echo worker again once connection has been established */
@@ -569,13 +565,8 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server) 


int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)

{

	mutex_lock(&server->refpath_lock);

	if (!server->leaf_fullpath) {

		mutex_unlock(&server->refpath_lock);

	if (!server->leaf_fullpath)

		return __cifs_reconnect(server, mark_smb_session);

	}

	mutex_unlock(&server->refpath_lock);



	return reconnect_dfs_server(server);

}

#else
@@ -1754,9 +1745,6 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx, 
	INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);

	INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);

	mutex_init(&tcp_ses->reconnect_mutex);

#ifdef CONFIG_CIFS_DFS_UPCALL

	mutex_init(&tcp_ses->refpath_lock);

#endif

	memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,

	       sizeof(tcp_ses->srcaddr));

	memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,

fs/smb/client/dfs_cache.c

+1 −3
Original line number Diff line number Diff line
@@ -1141,13 +1141,11 @@ static char *get_ses_refpath(struct cifs_ses *ses) 
	struct TCP_Server_Info *server = ses->server;

	char *path = ERR_PTR(-ENOENT);



	mutex_lock(&server->refpath_lock);

	if (server->leaf_fullpath) {

		path = kstrdup(server->leaf_fullpath + 1, GFP_ATOMIC);

		path = kstrdup(server->leaf_fullpath + 1, GFP_KERNEL);

		if (!path)

			path = ERR_PTR(-ENOMEM);

	}

	mutex_unlock(&server->refpath_lock);

	return path;

}