[PATCH 1/5] xfsprogs: libxcmd: don't clobber fs_table on realloc()

[Alex Elder]

In fs_table_insert(), realloc() is called to resize the global
fs_table.  If it fails, it overwrites a previously valid fs_table
pointer with NULL.

Instead, assign the return value to a local temporary and overwrite
fs_table only if the realloc() call succeeds.  The only defined
errno value for a realloc() failure is ENOMEM, so return that
explicitly in the event it fails.

Signed-off-by: Alex Elder <aelder at sgi.com>
---
 libxcmd/paths.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/libxcmd/paths.c b/libxcmd/paths.c
index 1dbe0be..0e02eb7 100644
--- a/libxcmd/paths.c
+++ b/libxcmd/paths.c
@@ -102,6 +102,7 @@ fs_table_insert(
 	char		*fsrt)
 {
 	dev_t		datadev, logdev, rtdev;
+	struct fs_path	*tmp_fs_table;
 
 	if (!dir || !fsname)
 		return EINVAL;
@@ -114,9 +115,10 @@ fs_table_insert(
 	if (fsrt && (fsrt = fs_device_number(fsrt, &rtdev, 1)) == NULL)
 		return errno;
 
-	fs_table = realloc(fs_table, sizeof(fs_path_t) * (fs_count + 1));
-	if (!fs_table)
-		return errno;
+	tmp_fs_table = realloc(fs_table, sizeof(fs_path_t) * (fs_count + 1));
+	if (!tmp_fs_table)
+		return ENOMEM;
+	fs_table = tmp_fs_table;
 
 	fs_path = &fs_table[fs_count];
 	fs_path->fs_dir = dir;
-- 
1.7.6.2