Handle 5-char filenames in SlruScanDirectory

Original users of slru.c were all producing 4-digit filenames, so that
was all that that code was prepared to handle.  Changes to multixact.c
in the course of commit 0ac5ad5134f made pg_multixact/members create
5-digit filenames once a certain threshold was reached, which
SlruScanDirectory wasn't prepared to deal with; in particular,
5-digit-name files were not removed during truncation.  Change that
routine to make it aware of those files, and have it process them just
like any others.

Right now, some pg_multixact/members directories will contain a mixture
of 4-char and 5-char filenames.  A future commit is expected fix things
so that each slru.c user declares the correct maximum width for the
files it produces, to avoid such unsightly mixtures.

Noticed while investigating bug #8673 reported by Serge Negodyuck.

diff --git a/src/backend/access/transam/slru.c b/src/backend/access/transam/slru.c
index 9dc566e162282c7010a0e05e4baf3d2bb4b6b180..af249022476d8732f3a3bbf27bd3cbc9217ad9ff 100644 (file)
--- a/src/backend/access/transam/slru.c
+++ b/src/backend/access/transam/slru.c
@@ -1293,8 +1293,12 @@ SlruScanDirectory(SlruCtl ctl, SlruScanCallback callback, void *data)
        cldir = AllocateDir(ctl->Dir);
        while ((clde = ReadDir(cldir, ctl->Dir)) != NULL)
        {
-               if (strlen(clde->d_name) == 4 &&
-                       strspn(clde->d_name, "0123456789ABCDEF") == 4)
+               size_t  len;
+
+               len = strlen(clde->d_name);
+
+               if ((len == 4 || len == 5) &&
+                       strspn(clde->d_name, "0123456789ABCDEF") == len)
                {
                        segno = (int) strtol(clde->d_name, NULL, 16);
                        segpage = segno * SLRU_PAGES_PER_SEGMENT;