From 1f422db663aa291be4af4b079e7d1b0ef0d78af2 Mon Sep 17 00:00:00 2001
From: Magnus Hagander <magnus@hagander.net>
Date: Wed, 7 Dec 2011 12:09:05 +0100
Subject: [PATCH] Avoid using readlink() on platforms that don't support it
We don't have any such platforms now, but might in the future.
Also, detect cases when a tablespace symlink points to a path that
is longer than we can handle, and give a warning.
---
src/backend/replication/basebackup.c | 25 ++++++++++++++++++++++---
1 file changed, 22 insertions(+), 3 deletions(-)
diff --git a/src/backend/replication/basebackup.c b/src/backend/replication/basebackup.c
index ba52ea8e989..2f4ae3b53db 100644
--- a/src/backend/replication/basebackup.c
+++ b/src/backend/replication/basebackup.c
@@ -109,6 +109,7 @@ perform_base_backup(basebackup_options *opt, DIR *tblspcdir)
{
char fullpath[MAXPGPATH];
char linkpath[MAXPGPATH];
+ int rllen;
/* Skip special stuff */
if (strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0)
@@ -116,19 +117,37 @@ perform_base_backup(basebackup_options *opt, DIR *tblspcdir)
snprintf(fullpath, sizeof(fullpath), "pg_tblspc/%s", de->d_name);
- MemSet(linkpath, 0, sizeof(linkpath));
- if (readlink(fullpath, linkpath, sizeof(linkpath) - 1) == -1)
+#if defined(HAVE_READLINK) || defined(WIN32)
+ rllen = readlink(fullpath, linkpath, sizeof(linkpath) - 1);
+ if (rllen < 0)
+ {
+ ereport(WARNING,
+ (errmsg("could not read symbolic link \"%s\": %m", fullpath)));
+ continue;
+ }
+ else if (rllen >= sizeof(linkpath))
{
ereport(WARNING,
- (errmsg("could not read symbolic link \"%s\": %m", fullpath)));
+ (errmsg("symbolic link \"%s\" target is too long", fullpath)));
continue;
}
+ linkpath[rllen] = '\0';
ti = palloc(sizeof(tablespaceinfo));
ti->oid = pstrdup(de->d_name);
ti->path = pstrdup(linkpath);
ti->size = opt->progress ? sendDir(linkpath, strlen(linkpath), true) : -1;
tablespaces = lappend(tablespaces, ti);
+#else
+ /*
+ * If the platform does not have symbolic links, it should not be possible
+ * to have tablespaces - clearly somebody else created them. Warn about it
+ * and ignore.
+ */
+ ereport(WARNING,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("tablespaces are not supported on this platform")));
+#endif
}
/* Add a node for the base directory at the end */
--
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