1 files changed, 52 insertions, 6 deletions

diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c
index e1848276bab4..1775c2b7528f 100644
--- a/fs/smb/client/cifsfs.c
+++ b/fs/smb/client/cifsfs.c
@@ -121,6 +121,46 @@ unsigned int dir_cache_timeout = 30;
 module_param(dir_cache_timeout, uint, 0644);
 MODULE_PARM_DESC(dir_cache_timeout, "Number of seconds to cache directory contents for which we have a lease. Default: 30 "
 				 "Range: 1 to 65000 seconds, 0 to disable caching dir contents");
+/* Module-wide total cached dirents (in bytes) across all tcons */
+atomic64_t cifs_dircache_bytes_used = ATOMIC64_INIT(0);
+
+/*
+ * Write-only module parameter to drop all cached directory entries across
+ * all CIFS mounts. Echo a non-zero value to trigger.
+ */
+static void cifs_drop_all_dir_caches(void)
+{
+	struct TCP_Server_Info *server;
+	struct cifs_ses *ses;
+	struct cifs_tcon *tcon;
+
+	spin_lock(&cifs_tcp_ses_lock);
+	list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
+		list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
+			if (cifs_ses_exiting(ses))
+				continue;
+			list_for_each_entry(tcon, &ses->tcon_list, tcon_list)
+				invalidate_all_cached_dirs(tcon);
+		}
+	}
+	spin_unlock(&cifs_tcp_ses_lock);
+}
+
+static int cifs_param_set_drop_dir_cache(const char *val, const struct kernel_param *kp)
+{
+	bool bv;
+	int rc = kstrtobool(val, &bv);
+
+	if (rc)
+		return rc;
+	if (bv)
+		cifs_drop_all_dir_caches();
+	return 0;
+}
+
+module_param_call(drop_dir_cache, cifs_param_set_drop_dir_cache, NULL, NULL, 0200);
+MODULE_PARM_DESC(drop_dir_cache, "Write 1 to drop all cached directory entries across all CIFS mounts");
+
 #ifdef CONFIG_CIFS_STATS2
 unsigned int slow_rsp_threshold = 1;
 module_param(slow_rsp_threshold, uint, 0644);
@@ -857,7 +897,7 @@ static int cifs_drop_inode(struct inode *inode)
 
 	/* no serverino => unconditional eviction */
 	return !(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) ||
-		generic_drop_inode(inode);
+		inode_generic_drop(inode);
 }
 
 static const struct super_operations cifs_super_ops = {
@@ -1895,7 +1935,9 @@ init_cifs(void)
 		cifs_dbg(VFS, "dir_cache_timeout set to max of 65000 seconds\n");
 	}
 
-	cifsiod_wq = alloc_workqueue("cifsiod", WQ_FREEZABLE|WQ_MEM_RECLAIM, 0);
+	cifsiod_wq = alloc_workqueue("cifsiod",
+				     WQ_FREEZABLE | WQ_MEM_RECLAIM | WQ_PERCPU,
+				     0);
 	if (!cifsiod_wq) {
 		rc = -ENOMEM;
 		goto out_clean_proc;
@@ -1923,28 +1965,32 @@ init_cifs(void)
 	}
 
 	cifsoplockd_wq = alloc_workqueue("cifsoplockd",
-					 WQ_FREEZABLE|WQ_MEM_RECLAIM, 0);
+					 WQ_FREEZABLE | WQ_MEM_RECLAIM | WQ_PERCPU,
+					 0);
 	if (!cifsoplockd_wq) {
 		rc = -ENOMEM;
 		goto out_destroy_fileinfo_put_wq;
 	}
 
 	deferredclose_wq = alloc_workqueue("deferredclose",
-					   WQ_FREEZABLE|WQ_MEM_RECLAIM, 0);
+					   WQ_FREEZABLE | WQ_MEM_RECLAIM | WQ_PERCPU,
+					   0);
 	if (!deferredclose_wq) {
 		rc = -ENOMEM;
 		goto out_destroy_cifsoplockd_wq;
 	}
 
 	serverclose_wq = alloc_workqueue("serverclose",
-					   WQ_FREEZABLE|WQ_MEM_RECLAIM, 0);
+					   WQ_FREEZABLE | WQ_MEM_RECLAIM | WQ_PERCPU,
+					   0);
 	if (!serverclose_wq) {
 		rc = -ENOMEM;
 		goto out_destroy_deferredclose_wq;
 	}
 
 	cfid_put_wq = alloc_workqueue("cfid_put_wq",
-				      WQ_FREEZABLE|WQ_MEM_RECLAIM, 0);
+				      WQ_FREEZABLE | WQ_MEM_RECLAIM | WQ_PERCPU,
+				      0);
 	if (!cfid_put_wq) {
 		rc = -ENOMEM;
 		goto out_destroy_serverclose_wq;