Check for failure of malloc() and realloc() when allocating space for

VFD entries.  On platforms where dereferencing a null pointer doesn't
lead to coredump, it's possible that this omission could have led to
unpleasant behavior like deleting the wrong file.

diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index 5967ae18050abbbf3348a86802858c05c121cf77..27e53f41c8b0af422936d5f819be6b7dcafd22f4 100644 (file)
--- a/src/backend/storage/file/fd.c
+++ b/src/backend/storage/file/fd.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/storage/file/fd.c,v 1.75 2001/04/03 02:31:52 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/storage/file/fd.c,v 1.76 2001/04/03 04:07:02 tgl Exp $
  *
  * NOTES:
  *
@@ -484,7 +484,8 @@ AllocateVfd(void)
    {
        /* initialize header entry first time through */
        VfdCache = (Vfd *) malloc(sizeof(Vfd));
-       Assert(VfdCache != NULL);
+       if (VfdCache == NULL)
+           elog(FATAL, "AllocateVfd: no room for VFD array");
        MemSet((char *) &(VfdCache[0]), 0, sizeof(Vfd));
        VfdCache->fd = VFD_CLOSED;
 
@@ -506,17 +507,23 @@ AllocateVfd(void)
         * However, there's not much point in starting *real* small.
         */
        Size        newCacheSize = SizeVfdCache * 2;
+       Vfd        *newVfdCache;
 
        if (newCacheSize < 32)
            newCacheSize = 32;
 
-       VfdCache = (Vfd *) realloc(VfdCache, sizeof(Vfd) * newCacheSize);
-       Assert(VfdCache != NULL);
+       /*
+        * Be careful not to clobber VfdCache ptr if realloc fails;
+        * we will need it during proc_exit cleanup!
+        */
+       newVfdCache = (Vfd *) realloc(VfdCache, sizeof(Vfd) * newCacheSize);
+       if (newVfdCache == NULL)
+           elog(FATAL, "AllocateVfd: no room to enlarge VFD array");
+       VfdCache = newVfdCache;
 
        /*
         * Initialize the new entries and link them into the free list.
         */
-
        for (i = SizeVfdCache; i < newCacheSize; i++)
        {
            MemSet((char *) &(VfdCache[i]), 0, sizeof(Vfd));
@@ -529,7 +536,6 @@ AllocateVfd(void)
        /*
         * Record the new size
         */
-
        SizeVfdCache = newCacheSize;
    }
 
@@ -553,6 +559,7 @@ FreeVfd(File file)
        free(vfdP->fileName);
        vfdP->fileName = NULL;
    }
+   vfdP->fdstate = 0x0;
 
    vfdP->nextFree = VfdCache[0].nextFree;
    VfdCache[0].nextFree = file;
@@ -678,7 +685,9 @@ fileNameOpenFile(FileName fileName,
 
    Insert(file);
 
-   vfdP->fileName = malloc(strlen(fileName) + 1);
+   vfdP->fileName = (char *) malloc(strlen(fileName) + 1);
+   if (vfdP->fileName == NULL)
+       elog(FATAL, "fileNameOpenFile: no room to save VFD filename");
    strcpy(vfdP->fileName, fileName);
 
    /* Saved flags are adjusted to be OK for re-opening file */