[PATCH v2 15/20] insert: fsync new directory after rename
Peter Wang
novalazy at gmail.com
Sat Nov 24 17:16:41 PST 2012
After moving the file from the 'tmp' to the 'new' directory,
fsync on the 'new' directory for durability.
---
notmuch-insert.c | 39 ++++++++++++++++++++++++++++++++-------
1 file changed, 32 insertions(+), 7 deletions(-)
diff --git a/notmuch-insert.c b/notmuch-insert.c
index f09c579..831b322 100644
--- a/notmuch-insert.c
+++ b/notmuch-insert.c
@@ -143,10 +143,10 @@ maildir_create_folder (void *ctx, const char *dir)
/* Open a unique file in the Maildir 'tmp' directory.
* Returns the file descriptor on success, or -1 on failure.
* On success, file paths into the 'tmp' and 'new' directories are returned
- * via tmppath and newpath. */
+ * via tmppath and newpath, and the path of the 'new' directory in newdir. */
static int
maildir_open_tmp_file (void *ctx, const char *dir,
- char **tmppath, char **newpath)
+ char **tmppath, char **newpath, char **newdir)
{
pid_t pid;
char hostname[256];
@@ -183,8 +183,9 @@ maildir_open_tmp_file (void *ctx, const char *dir,
return -1;
}
+ *newdir = talloc_asprintf (ctx, "%s/new", dir);
*newpath = talloc_asprintf (ctx, "%s/new/%s", dir, filename);
- if (! *newpath) {
+ if (! *newdir || ! *newpath) {
fprintf (stderr, "Out of memory\n");
close (fd);
unlink (*tmppath);
@@ -204,14 +205,31 @@ maildir_open_tmp_file (void *ctx, const char *dir,
* http://wiki.dovecot.org/MailboxFormat/Maildir#Mail_delivery
*/
static notmuch_bool_t
-maildir_move_tmp_to_new (const char *tmppath, const char *newpath)
+maildir_move_tmp_to_new (const char *tmppath, const char *newpath,
+ const char *newdir)
{
+ notmuch_bool_t ret;
+ int fd;
+
if (rename (tmppath, newpath) != 0) {
fprintf (stderr, "Error: rename() failed: %s\n", strerror (errno));
return FALSE;
}
- return TRUE;
+ /* Sync the 'new' directory after rename for durability. */
+ ret = TRUE;
+ fd = open (newdir, O_RDONLY);
+ if (fd == -1) {
+ fprintf (stderr, "Error: open() dir failed: %s\n", strerror (errno));
+ ret = FALSE;
+ }
+ if (ret && fsync (fd) != 0) {
+ fprintf (stderr, "Error: fsync() dir failed: %s\n", strerror (errno));
+ ret = FALSE;
+ }
+ if (fd != -1)
+ close (fd);
+ return ret;
}
/* Copy the contents of fdin into fdout. */
@@ -307,6 +325,12 @@ add_file_to_database (notmuch_database_t *notmuch, const char *path,
notmuch_message_thaw (message);
+ /* notmuch_message_tags_to_maildir_flags may rename the message file
+ * once more, and does so without fsyncing the directory afterwards.
+ * rename() is atomic so after a crash the file should appear under
+ * the old or new name. notmuch new should be able to rename the file
+ * again if required, so another fsync is not required, I think.
+ */
notmuch_message_tags_to_maildir_flags (message);
notmuch_message_destroy (message);
@@ -321,10 +345,11 @@ insert_message (void *ctx, notmuch_database_t *notmuch, int fdin,
{
char *tmppath;
char *newpath;
+ char *newdir;
int fdout;
notmuch_bool_t ret;
- fdout = maildir_open_tmp_file (ctx, dir, &tmppath, &newpath);
+ fdout = maildir_open_tmp_file (ctx, dir, &tmppath, &newpath, &newdir);
if (fdout < 0) {
return FALSE;
}
@@ -335,7 +360,7 @@ insert_message (void *ctx, notmuch_database_t *notmuch, int fdin,
}
close (fdout);
if (ret) {
- ret = maildir_move_tmp_to_new (tmppath, newpath);
+ ret = maildir_move_tmp_to_new (tmppath, newpath, newdir);
}
if (!ret) {
unlink (tmppath);
--
1.7.12.1
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