1 files changed, 102 insertions, 93 deletions

diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c
index e2be8aedb26e..59f6b8e32cc9 100644
--- a/fs/smb/client/cached_dir.c
+++ b/fs/smb/client/cached_dir.c
@@ -15,6 +15,7 @@
 static struct cached_fid *init_cached_dir(const char *path);
 static void free_cached_dir(struct cached_fid *cfid);
 static void smb2_close_cached_fid(struct kref *ref);
+static void cfids_laundromat_worker(struct work_struct *work);
 
 static struct cached_fid *find_or_create_cached_dir(struct cached_fids *cfids,
 						    const char *path,
@@ -31,7 +32,7 @@ static struct cached_fid *find_or_create_cached_dir(struct cached_fids *cfids,
 			 * fully cached or it may be in the process of
 			 * being deleted due to a lease break.
 			 */
-			if (!cfid->has_lease) {
+			if (!cfid->time || !cfid->has_lease) {
 				spin_unlock(&cfids->cfid_list_lock);
 				return NULL;
 			}
@@ -169,15 +170,18 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 		return -ENOENT;
 	}
 	/*
-	 * At this point we either have a lease already and we can just
-	 * return it. If not we are guaranteed to be the only thread accessing
-	 * this cfid.
+	 * Return cached fid if it has a lease.  Otherwise, it is either a new
+	 * entry or laundromat worker removed it from @cfids->entries.  Caller
+	 * will put last reference if the latter.
 	 */
+	spin_lock(&cfids->cfid_list_lock);
 	if (cfid->has_lease) {
+		spin_unlock(&cfids->cfid_list_lock);
 		*ret_cfid = cfid;
 		kfree(utf16_path);
 		return 0;
 	}
+	spin_unlock(&cfids->cfid_list_lock);
 
 	/*
 	 * Skip any prefix paths in @path as lookup_positive_unlocked() ends up
@@ -189,9 +193,19 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 	npath = path_no_prefix(cifs_sb, path);
 	if (IS_ERR(npath)) {
 		rc = PTR_ERR(npath);
-		kfree(utf16_path);
-		return rc;
+		goto out;
+	}
+
+	if (!npath[0]) {
+		dentry = dget(cifs_sb->root);
+	} else {
+		dentry = path_to_dentry(cifs_sb, npath);
+		if (IS_ERR(dentry)) {
+			rc = -ENOENT;
+			goto out;
+		}
 	}
+	cfid->dentry = dentry;
 
 	/*
 	 * We do not hold the lock for the open because in case
@@ -245,6 +259,15 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 
 	smb2_set_related(&rqst[1]);
 
+	/*
+	 * Set @cfid->has_lease to true before sending out compounded request so
+	 * its lease reference can be put in cached_dir_lease_break() due to a
+	 * potential lease break right after the request is sent or while @cfid
+	 * is still being cached.  Concurrent processes won't be to use it yet
+	 * due to @cfid->time being zero.
+	 */
+	cfid->has_lease = true;
+
 	rc = compound_send_recv(xid, ses, server,
 				flags, 2, rqst,
 				resp_buftype, rsp_iov);
@@ -259,6 +282,8 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 	cfid->tcon = tcon;
 	cfid->is_open = true;
 
+	spin_lock(&cfids->cfid_list_lock);
+
 	o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;
 	oparms.fid->persistent_fid = o_rsp->PersistentFileId;
 	oparms.fid->volatile_fid = o_rsp->VolatileFileId;
@@ -266,18 +291,25 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 	oparms.fid->mid = le64_to_cpu(o_rsp->hdr.MessageId);
 #endif /* CIFS_DEBUG2 */
 
-	if (o_rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE)
+	rc = -EINVAL;
+	if (o_rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE) {
+		spin_unlock(&cfids->cfid_list_lock);
 		goto oshr_free;
+	}
 
 	smb2_parse_contexts(server, o_rsp,
 			    &oparms.fid->epoch,
 			    oparms.fid->lease_key, &oplock,
 			    NULL, NULL);
-	if (!(oplock & SMB2_LEASE_READ_CACHING_HE))
+	if (!(oplock & SMB2_LEASE_READ_CACHING_HE)) {
+		spin_unlock(&cfids->cfid_list_lock);
 		goto oshr_free;
+	}
 	qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base;
-	if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info))
+	if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info)) {
+		spin_unlock(&cfids->cfid_list_lock);
 		goto oshr_free;
+	}
 	if (!smb2_validate_and_copy_iov(
 				le16_to_cpu(qi_rsp->OutputBufferOffset),
 				sizeof(struct smb2_file_all_info),
@@ -285,57 +317,49 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 				(char *)&cfid->file_all_info))
 		cfid->file_all_info_is_valid = true;
 
-	if (!npath[0])
-		dentry = dget(cifs_sb->root);
-	else {
-		dentry = path_to_dentry(cifs_sb, npath);
-		if (IS_ERR(dentry)) {
-			rc = -ENOENT;
-			goto oshr_free;
-		}
-	}
-	cfid->dentry = dentry;
 	cfid->time = jiffies;
-	cfid->has_lease = true;
+	spin_unlock(&cfids->cfid_list_lock);
+	/* At this point the directory handle is fully cached */
+	rc = 0;
 
 oshr_free:
-	kfree(utf16_path);
 	SMB2_open_free(&rqst[0]);
 	SMB2_query_info_free(&rqst[1]);
 	free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
 	free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
-	spin_lock(&cfids->cfid_list_lock);
-	if (rc && !cfid->has_lease) {
+	if (rc) {
+		spin_lock(&cfids->cfid_list_lock);
 		if (cfid->on_list) {
 			list_del(&cfid->entry);
 			cfid->on_list = false;
 			cfids->num_entries--;
 		}
-		rc = -ENOENT;
-	}
-	spin_unlock(&cfids->cfid_list_lock);
-	if (!rc && !cfid->has_lease) {
-		/*
-		 * We are guaranteed to have two references at this point.
-		 * One for the caller and one for a potential lease.
-		 * Release the Lease-ref so that the directory will be closed
-		 * when the caller closes the cached handle.
-		 */
-		kref_put(&cfid->refcount, smb2_close_cached_fid);
+		if (cfid->has_lease) {
+			/*
+			 * We are guaranteed to have two references at this
+			 * point. One for the caller and one for a potential
+			 * lease. Release the Lease-ref so that the directory
+			 * will be closed when the caller closes the cached
+			 * handle.
+			 */
+			cfid->has_lease = false;
+			spin_unlock(&cfids->cfid_list_lock);
+			kref_put(&cfid->refcount, smb2_close_cached_fid);
+			goto out;
+		}
+		spin_unlock(&cfids->cfid_list_lock);
 	}
+out:
 	if (rc) {
 		if (cfid->is_open)
 			SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid,
 				   cfid->fid.volatile_fid);
 		free_cached_dir(cfid);
-		cfid = NULL;
-	}
-
-	if (rc == 0) {
+	} else {
 		*ret_cfid = cfid;
 		atomic_inc(&tcon->num_remote_opens);
 	}
-
+	kfree(utf16_path);
 	return rc;
 }
 
@@ -572,53 +596,51 @@ static void free_cached_dir(struct cached_fid *cfid)
 	kfree(cfid);
 }
 
-static int
-cifs_cfids_laundromat_thread(void *p)
+static void cfids_laundromat_worker(struct work_struct *work)
 {
-	struct cached_fids *cfids = p;
+	struct cached_fids *cfids;
 	struct cached_fid *cfid, *q;
-	struct list_head entry;
+	LIST_HEAD(entry);
 
-	while (!kthread_should_stop()) {
-		ssleep(1);
-		INIT_LIST_HEAD(&entry);
-		if (kthread_should_stop())
-			return 0;
-		spin_lock(&cfids->cfid_list_lock);
-		list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
-			if (time_after(jiffies, cfid->time + HZ * dir_cache_timeout)) {
-				list_del(&cfid->entry);
-				list_add(&cfid->entry, &entry);
-				cfids->num_entries--;
-			}
-		}
-		spin_unlock(&cfids->cfid_list_lock);
+	cfids = container_of(work, struct cached_fids, laundromat_work.work);
 
-		list_for_each_entry_safe(cfid, q, &entry, entry) {
+	spin_lock(&cfids->cfid_list_lock);
+	list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
+		if (cfid->time &&
+		    time_after(jiffies, cfid->time + HZ * dir_cache_timeout)) {
 			cfid->on_list = false;
-			list_del(&cfid->entry);
+			list_move(&cfid->entry, &entry);
+			cfids->num_entries--;
+			/* To prevent race with smb2_cached_lease_break() */
+			kref_get(&cfid->refcount);
+		}
+	}
+	spin_unlock(&cfids->cfid_list_lock);
+
+	list_for_each_entry_safe(cfid, q, &entry, entry) {
+		list_del(&cfid->entry);
+		/*
+		 * Cancel and wait for the work to finish in case we are racing
+		 * with it.
+		 */
+		cancel_work_sync(&cfid->lease_break);
+		if (cfid->has_lease) {
 			/*
-			 * Cancel, and wait for the work to finish in
-			 * case we are racing with it.
+			 * Our lease has not yet been cancelled from the server
+			 * so we need to drop the reference.
 			 */
-			cancel_work_sync(&cfid->lease_break);
-			if (cfid->has_lease) {
-				/*
-				 * We lease has not yet been cancelled from
-				 * the server so we need to drop the reference.
-				 */
-				spin_lock(&cfids->cfid_list_lock);
-				cfid->has_lease = false;
-				spin_unlock(&cfids->cfid_list_lock);
-				kref_put(&cfid->refcount, smb2_close_cached_fid);
-			}
+			spin_lock(&cfids->cfid_list_lock);
+			cfid->has_lease = false;
+			spin_unlock(&cfids->cfid_list_lock);
+			kref_put(&cfid->refcount, smb2_close_cached_fid);
 		}
+		/* Drop the extra reference opened above */
+		kref_put(&cfid->refcount, smb2_close_cached_fid);
 	}
-
-	return 0;
+	queue_delayed_work(cifsiod_wq, &cfids->laundromat_work,
+			   dir_cache_timeout * HZ);
 }
 
-
 struct cached_fids *init_cached_dirs(void)
 {
 	struct cached_fids *cfids;
@@ -629,19 +651,10 @@ struct cached_fids *init_cached_dirs(void)
 	spin_lock_init(&cfids->cfid_list_lock);
 	INIT_LIST_HEAD(&cfids->entries);
 
-	/*
-	 * since we're in a cifs function already, we know that
-	 * this will succeed. No need for try_module_get().
-	 */
-	__module_get(THIS_MODULE);
-	cfids->laundromat = kthread_run(cifs_cfids_laundromat_thread,
-				  cfids, "cifsd-cfid-laundromat");
-	if (IS_ERR(cfids->laundromat)) {
-		cifs_dbg(VFS, "Failed to start cfids laundromat thread.\n");
-		kfree(cfids);
-		module_put(THIS_MODULE);
-		return NULL;
-	}
+	INIT_DELAYED_WORK(&cfids->laundromat_work, cfids_laundromat_worker);
+	queue_delayed_work(cifsiod_wq, &cfids->laundromat_work,
+			   dir_cache_timeout * HZ);
+
 	return cfids;
 }
 
@@ -657,11 +670,7 @@ void free_cached_dirs(struct cached_fids *cfids)
 	if (cfids == NULL)
 		return;
 
-	if (cfids->laundromat) {
-		kthread_stop(cfids->laundromat);
-		cfids->laundromat = NULL;
-		module_put(THIS_MODULE);
-	}
+	cancel_delayed_work_sync(&cfids->laundromat_work);
 
 	spin_lock(&cfids->cfid_list_lock);
 	list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {