From: Timo Sirainen <tss@iki.fi>
Date: Wed, 25 Mar 2009 22:13:36 +0000 (-0400)
Subject: dbox: Fixed race condition when opening a message that was just moved to a different... 
X-Git-Tag: 2.0.alpha1~1038^2~8
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=5af57c4025545884f6c5942f46f3dc3a2824154a;p=thirdparty%2Fdovecot%2Fcore.git

dbox: Fixed race condition when opening a message that was just moved to a different file.

--HG--
branch : HEAD
---

diff --git a/src/lib-storage/index/dbox/dbox-file.c b/src/lib-storage/index/dbox/dbox-file.c
index ce0f3c8ed7..dc1b6032e4 100644
--- a/src/lib-storage/index/dbox/dbox-file.c
+++ b/src/lib-storage/index/dbox/dbox-file.c
@@ -387,13 +387,13 @@ static int dbox_file_open_fd(struct dbox_file *file)
 	return 1;
 }
 
-static int dbox_file_open(struct dbox_file *file, bool *deleted_r)
+int dbox_file_open(struct dbox_file *file, bool *deleted_r)
 {
 	int ret;
 
-	i_assert(file->input == NULL);
-
 	*deleted_r = FALSE;
+	if (file->input != NULL)
+		return 1;
 
 	if (file->fd == -1) {
 		T_BEGIN {
diff --git a/src/lib-storage/index/dbox/dbox-file.h b/src/lib-storage/index/dbox/dbox-file.h
index aa49ee0747..1b8bc313dd 100644
--- a/src/lib-storage/index/dbox/dbox-file.h
+++ b/src/lib-storage/index/dbox/dbox-file.h
@@ -131,9 +131,10 @@ void dbox_files_free(struct dbox_storage *storage);
    for multi files assign map UID. */
 int dbox_file_assign_id(struct dbox_file *file, uint32_t id);
 
-/* Open the file if uid or file_id is not 0, otherwise create it. Returns 1 if
-   ok, 0 if file header is corrupted, -1 if error. If file is deleted,
-   deleted_r=TRUE and 1 is returned. */
+/* Open the file. Returns 1 if ok, 0 if file header is corrupted, -1 if error.
+   If file is deleted, deleted_r=TRUE and 1 is returned. */
+int dbox_file_open(struct dbox_file *file, bool *deleted_r);
+/* Open the file if uid or file_id is not 0, otherwise create it. */
 int dbox_file_open_or_create(struct dbox_file *file, bool *deleted_r);
 /* Close the file handle from the file, but don't free it. */
 void dbox_file_close(struct dbox_file *file);
diff --git a/src/lib-storage/index/dbox/dbox-mail.c b/src/lib-storage/index/dbox/dbox-mail.c
index fde2368a85..8af53b0804 100644
--- a/src/lib-storage/index/dbox/dbox-mail.c
+++ b/src/lib-storage/index/dbox/dbox-mail.c
@@ -113,37 +113,62 @@ static void dbox_mail_set_expunged(struct dbox_mail *mail)
 	mbox->storage->sync_rebuild = TRUE;
 }
 
-static int dbox_mail_open(struct dbox_mail *mail,
-			  uoff_t *offset_r, struct dbox_file **file_r)
+static int dbox_mail_open_init(struct dbox_mail *mail)
 {
 	struct dbox_mailbox *mbox = (struct dbox_mailbox *)mail->imail.ibox;
 	struct mail *_mail = &mail->imail.mail.mail;
 	uint32_t file_id;
 	int ret;
 
-	if (mail->open_file == NULL) {
-		if (dbox_mail_lookup(mbox, mbox->ibox.view, _mail->seq,
-				     &mail->map_uid) < 0)
+	if (mail->map_uid == 0)
+		mail->open_file = dbox_file_init_single(mbox, _mail->uid);
+	else if ((ret = dbox_map_lookup(mbox->storage->map, mail->map_uid,
+					&file_id, &mail->offset)) <= 0) {
+		if (ret < 0)
 			return -1;
-		if (mail->map_uid == 0) {
-			mail->open_file =
-				dbox_file_init_single(mbox, _mail->uid);
-		} else if ((ret = dbox_map_lookup(mbox->storage->map,
-						  mail->map_uid, &file_id,
-						  &mail->offset)) <= 0) {
-			if (ret < 0)
+
+		/* map_uid doesn't exist anymore. either it
+		   got just expunged or the map index is
+		   corrupted. */
+		dbox_mail_set_expunged(mail);
+		return -1;
+	} else {
+		mail->open_file = dbox_file_init_multi(mbox->storage, file_id);
+	}
+	return 0;
+}
+
+static int dbox_mail_open(struct dbox_mail *mail,
+			  uoff_t *offset_r, struct dbox_file **file_r)
+{
+	struct dbox_mailbox *mbox = (struct dbox_mailbox *)mail->imail.ibox;
+	struct mail *_mail = &mail->imail.mail.mail;
+	uint32_t prev_file_id = 0;
+	bool deleted;
+
+	do {
+		if (mail->open_file == NULL) {
+			if (dbox_mail_lookup(mbox, mbox->ibox.view, _mail->seq,
+					     &mail->map_uid) < 0)
+				return -1;
+			if (dbox_mail_open_init(mail) < 0)
 				return -1;
+		}
 
-			/* map_uid doesn't exist anymore. either it
-			   got just expunged or the map index is
-			   corrupted. */
-			dbox_mail_set_expunged(mail);
+		if (dbox_file_open(mail->open_file, &deleted) <= 0)
 			return -1;
-		} else {
-			mail->open_file =
-				dbox_file_init_multi(mbox->storage, file_id);
+		if (deleted) {
+			/* either it's expunged now or moved to another file. */
+			if (mail->open_file->file_id == prev_file_id) {
+				dbox_mail_set_expunged(mail);
+				return -1;
+			}
+			prev_file_id = mail->open_file->file_id;
+			if (dbox_map_refresh(mbox->storage->map) < 0)
+				return -1;
+			dbox_file_unref(&mail->open_file);
 		}
-	}
+	} while (mail->open_file == NULL);
 
 	*file_r = mail->open_file;
 	*offset_r = mail->offset;
@@ -162,10 +187,7 @@ dbox_mail_metadata_read(struct dbox_mail *mail, struct dbox_file **file_r)
 	if (dbox_file_get_mail_stream(*file_r, offset, &size,
 				      NULL, &expunged) <= 0)
 		return -1;
-	if (expunged) {
-		dbox_mail_set_expunged(mail);
-		return -1;
-	}
+	i_assert(!expunged);
 	if (dbox_file_metadata_read(*file_r) <= 0)
 		return -1;
 	return 0;
@@ -339,10 +361,7 @@ dbox_mail_get_stream(struct mail *_mail, struct message_size *hdr_size,
 				"%"PRIuUOFF_T, _mail->uid, offset);
 			return -1;
 		}
-		if (expunged) {
-			dbox_mail_set_expunged(mail);
-			return -1;
-		}
+		i_assert(!expunged);
 		data->physical_size = size;
 		data->stream = input;
 	}
diff --git a/src/lib-storage/index/dbox/dbox-map-private.h b/src/lib-storage/index/dbox/dbox-map-private.h
index 398f4ba5ee..1e5a71ef5b 100644
--- a/src/lib-storage/index/dbox/dbox-map-private.h
+++ b/src/lib-storage/index/dbox/dbox-map-private.h
@@ -44,7 +44,6 @@ struct dbox_map_append_context {
 	unsigned int committed:1;
 };
 
-int dbox_map_refresh(struct dbox_map *map);
 int dbox_map_view_lookup_rec(struct dbox_map *map, struct mail_index_view *view,
 			     uint32_t seq, struct dbox_mail_lookup_rec *rec_r);
 
diff --git a/src/lib-storage/index/dbox/dbox-map.h b/src/lib-storage/index/dbox/dbox-map.h
index e12eef70e2..145d4537d0 100644
--- a/src/lib-storage/index/dbox/dbox-map.h
+++ b/src/lib-storage/index/dbox/dbox-map.h
@@ -32,6 +32,8 @@ void dbox_map_deinit(struct dbox_map **map);
 /* Open the map. This is done automatically for most operations.
    Returns 0 if ok, -1 if error. */
 int dbox_map_open(struct dbox_map *map, bool create_missing);
+/* Refresh the map. Returns 0 if ok, -1 if error. */
+int dbox_map_refresh(struct dbox_map *map);
 
 /* Look up file_id and offset for given map UID. Returns 1 if ok, 0 if UID
    is already expunged, -1 if error. */