From: Timo Sirainen <timo.sirainen@dovecot.fi>
Date: Wed, 10 Aug 2016 16:15:56 +0000 (+0300)
Subject: quota: If quota lookup updates vsize header, lock it earlier to avoid a deadlock.
X-Git-Tag: 2.2.26~373
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=19e19b1b2d69114096dd66b74df2539da663054b;p=thirdparty%2Fdovecot%2Fcore.git

quota: If quota lookup updates vsize header, lock it earlier to avoid a deadlock.
---

diff --git a/src/plugins/quota/quota-private.h b/src/plugins/quota/quota-private.h
index 49c10e7ceb..baba1111f5 100644
--- a/src/plugins/quota/quota-private.h
+++ b/src/plugins/quota/quota-private.h
@@ -210,5 +210,6 @@ bool quota_warning_match(const struct quota_warning_rule *w,
 			 uint64_t bytes_before, uint64_t bytes_current,
 			 uint64_t count_before, uint64_t count_current);
 bool quota_transaction_is_over(struct quota_transaction_context *ctx, uoff_t size);
+int quota_transaction_set_limits(struct quota_transaction_context *ctx);
 
 #endif
diff --git a/src/plugins/quota/quota-storage.c b/src/plugins/quota/quota-storage.c
index 14270d8df2..d54059ed9e 100644
--- a/src/plugins/quota/quota-storage.c
+++ b/src/plugins/quota/quota-storage.c
@@ -230,6 +230,9 @@ quota_copy(struct mail_save_context *ctx, struct mail *mail)
 		}
 		ctx->dest_mail = qt->tmp_mail;
 	}
+	/* get quota before copying any mails. this avoids .vsize.lock
+	   deadlocks with backends that lock mails for expunging/copying. */
+	(void)quota_transaction_set_limits(qt);
 
 	if (qbox->module_ctx.super.copy(ctx, mail) < 0)
 		return -1;
@@ -284,6 +287,9 @@ quota_save_begin(struct mail_save_context *ctx, struct istream *input)
 		}
 		ctx->dest_mail = qt->tmp_mail;
 	}
+	/* get quota before copying any mails. this avoids .vsize.lock
+	   deadlocks with backends that lock mails for expunging/copying. */
+	(void)quota_transaction_set_limits(qt);
 
 	return qbox->module_ctx.super.save_begin(ctx, input);
 }
diff --git a/src/plugins/quota/quota.c b/src/plugins/quota/quota.c
index 80bf60065d..05002da445 100644
--- a/src/plugins/quota/quota.c
+++ b/src/plugins/quota/quota.c
@@ -783,7 +783,7 @@ struct quota_transaction_context *quota_transaction_begin(struct mailbox *box)
 	return ctx;
 }
 
-static int quota_transaction_set_limits(struct quota_transaction_context *ctx)
+int quota_transaction_set_limits(struct quota_transaction_context *ctx)
 {
 	struct quota_root *const *roots;
 	const char *mailbox_name;
@@ -792,6 +792,8 @@ static int quota_transaction_set_limits(struct quota_transaction_context *ctx)
 	bool use_grace, ignored;
 	int ret;
 
+	if (ctx->limits_set)
+		return 0;
 	ctx->limits_set = TRUE;
 	mailbox_name = mailbox_get_vname(ctx->box);
 	/* use quota_grace only for LDA/LMTP */
@@ -1101,10 +1103,8 @@ int quota_try_alloc(struct quota_transaction_context *ctx,
 	uoff_t size;
 	int ret;
 
-	if (!ctx->limits_set) {
-		if (quota_transaction_set_limits(ctx) < 0)
-			return -1;
-	}
+	if (quota_transaction_set_limits(ctx) < 0)
+		return -1;
 
 	if (ctx->no_quota_updates)
 		return 1;
@@ -1142,10 +1142,8 @@ int quota_test_alloc(struct quota_transaction_context *ctx,
 	if (ctx->failed)
 		return -1;
 
-	if (!ctx->limits_set) {
-		if (quota_transaction_set_limits(ctx) < 0)
-			return -1;
-	}
+	if (quota_transaction_set_limits(ctx) < 0)
+		return -1;
 	if (ctx->no_quota_updates)
 		return 1;
 	/* this is a virtual function mainly for trash plugin and similar,