dir: check DNew return code

Commit 0284e65f97861e888d95576f22a93cd681813c39 'dir: Explicitly state
buffer locations for data' changed DNew and DRead to return a return
code.  However, the callers of DNew were not modified to check the new
return code.  (This commit applied only to the implementations dealing
with AFS directories, in afs/afs_buffer.c and dir/dir.c.  The ubik
implmentations of DNew and DRead, dealing with ubik databases, were not
modified.)

Modify all (non-ubik) callers of DNew to check the return code.  In
addition, modify code as needed so return codes are properly propagated
to the callers.

While here, add Doxygen comments for AddPage and FindBlobs.

Change-Id: Iabde6499745dd351f3fcda73c9f52c440a36490e
Reviewed-on: https://gerrit.openafs.org/13801
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>

diff --git a/src/dir/dir.c b/src/dir/dir.c
index 0fb6bff..00e7ea6 100644 (file)
--- a/src/dir/dir.c
+++ b/src/dir/dir.c
@@ -72,7 +72,7 @@ extern int DNew(struct dcache *adc, int page, struct DirBuffer *);
 
 /* Local static prototypes */
 static int FindBlobs(dir_file_t, int);
-static void AddPage(dir_file_t, int);
+static int AddPage(dir_file_t, int);
 static void FreeBlobs(dir_file_t, int, int);
 static int FindItem(dir_file_t, char *, struct DirBuffer *,
                    struct DirBuffer *);
@@ -199,7 +199,15 @@ afs_dir_Delete(dir_file_t dir, char *entry)
     return 0;
 }
 
-/* Find a bunch of contiguous entries; at least nblobs in a row. */
+/*!
+ * Find a bunch of contiguous entries; at least nblobs in a row.
+ *
+ * \param dir      pointer to the directory object
+ * \param nblobs    number of contiguous entries we need
+ *
+ * \return element number (directory entry) of the requested space
+ * \retval -1          failed to find 'nblobs' contiguous entries
+ */
 static int
 FindBlobs(dir_file_t dir, int nblobs)
 {
@@ -209,6 +217,7 @@ FindBlobs(dir_file_t dir, int nblobs)
     struct DirHeader *dhp;
     struct PageHeader *pp;
     int pgcount;
+    int code;
 
     /* read the dir header in first. */
     if (DRead(dir, 0, &headerbuf) != 0)
@@ -228,12 +237,16 @@ FindBlobs(dir_file_t dir, int nblobs)
                }
                if (i > pgcount - 1) {
                    /* this page is bigger than last allocated page */
-                   AddPage(dir, i);
+                   code = AddPage(dir, i);
+                   if (code)
+                       break;
                    dhp->header.pgcount = htons(i + 1);
                }
            } else if (dhp->alloMap[i] == EPP) {
                /* Add the page to the directory. */
-               AddPage(dir, i);
+               code = AddPage(dir, i);
+               if (code)
+                   break;
                dhp->alloMap[i] = EPP - 1;
                dhp->header.pgcount = htons(i + 1);
            }
@@ -268,20 +281,32 @@ FindBlobs(dir_file_t dir, int nblobs)
            DRelease(&pagebuf, 0);      /* This dir page is unchanged. */
        }
     }
-    /* If we make it here, the directory is full. */
+    /* If we make it here, the directory is full, or we encountered an I/O error. */
     DRelease(&headerbuf, 1);
     return -1;
 }
 
-static void
+/*!
+ * Add a page to a directory object.
+ *
+ * \param dir      pointer to the directory object
+ * \param pageno    page number to add
+ *
+ * \retval 0       succcess
+ * \retval non-zero return error from DNew
+ */
+static int
 AddPage(dir_file_t dir, int pageno)
 {                              /* Add a page to a directory. */
     int i;
     struct PageHeader *pp;
     struct DirBuffer pagebuf;
+    int code;
 
     /* Get a new buffer labelled dir,pageno */
-    DNew(dir, pageno, &pagebuf);
+    code = DNew(dir, pageno, &pagebuf);
+    if (code)
+       return code;
     pp = (struct PageHeader *)pagebuf.data;
 
     pp->tag = htons(1234);
@@ -292,6 +317,7 @@ AddPage(dir_file_t dir, int pageno)
     for (i = 1; i < EPP / 8; i++)      /* It's a constant */
        pp->freebitmap[i] = 0;
     DRelease(&pagebuf, 1);
+    return 0;
 }
 
 /* Free a whole bunch of directory entries. */
@@ -346,7 +372,9 @@ afs_dir_MakeDir(dir_file_t dir, afs_int32 * me, afs_int32 * parent)
     struct DirHeader *dhp;
     int code;
 
-    DNew(dir, 0, &buffer);
+    code = DNew(dir, 0, &buffer);
+    if (code)
+       return code;
     dhp = (struct DirHeader *)buffer.data;
 
     dhp->header.pgcount = htons(1);