Xen devel - Aug 2010 - [PATCH] remus: unbreak after 21488:dd6bbdc42033

# HG changeset patch
# User Brendan Cully <brendan@cs.ubc.ca>
# Date 1282162001 25200
# Node ID f266eb91ae67e6233a3e163918b4c05df4ec0031
# Parent  74b9fe513d8591ca14233590062079b042abb68d
remus: unbreak after 21488:dd6bbdc42033

The aforementioned patch missed several calls to read_exact, causing spurious
timeouts under Remus.

Signed-off-by: Brendan Cully <brendan@cs.ubc.ca>

diff --git a/tools/libxc/xc_domain_restore.c b/tools/libxc/xc_domain_restore.c
--- a/tools/libxc/xc_domain_restore.c
+++ b/tools/libxc/xc_domain_restore.c
@@ -77,10 +77,14 @@
         len = read(fd, buf + offset, size - offset);
         if ( (len == -1) && ((errno == EINTR) || (errno == EAGAIN)) )
             continue;
-        if ( len == 0 )
+        if ( len == 0 ) {
+            ERROR("0-length read");
             errno = 0;
-        if ( len <= 0 )
+        }
+        if ( len <= 0 ) {
+            ERROR("read_exact_timed failed (read rc: %d, errno: %d)",
len, errno);
             return -1;
+        }
         offset += len;
     }
 
@@ -694,8 +698,8 @@
         return pagebuf_get_one(xch, ctx, buf, fd, dom);
     } else if (count == -3) {
         /* Skip padding 4 bytes then read the EPT identity PT location. */
-        if ( read_exact(fd, &buf->identpt, sizeof(uint32_t)) ||
-             read_exact(fd, &buf->identpt, sizeof(uint64_t)) )
+        if ( RDEXACT(fd, &buf->identpt, sizeof(uint32_t)) ||
+             RDEXACT(fd, &buf->identpt, sizeof(uint64_t)) )
         {
             PERROR("error read the address of the EPT identity map");
             return -1;
@@ -704,8 +708,8 @@
         return pagebuf_get_one(xch, ctx, buf, fd, dom);
     } else if ( count == -4 )  {
         /* Skip padding 4 bytes then read the vm86 TSS location. */
-        if ( read_exact(fd, &buf->vm86_tss, sizeof(uint32_t)) ||
-             read_exact(fd, &buf->vm86_tss, sizeof(uint64_t)) )
+        if ( RDEXACT(fd, &buf->vm86_tss, sizeof(uint32_t)) ||
+             RDEXACT(fd, &buf->vm86_tss, sizeof(uint64_t)) )
         {
             PERROR("error read the address of the vm86 TSS");
             return -1;
@@ -729,10 +733,10 @@
     } else if ( count == -7 ) {
         uint32_t tsc_mode, khz, incarn;
         uint64_t nsec;
-        if ( read_exact(fd, &tsc_mode, sizeof(uint32_t)) ||
-             read_exact(fd, &nsec, sizeof(uint64_t)) ||
-             read_exact(fd, &khz, sizeof(uint32_t)) ||
-             read_exact(fd, &incarn, sizeof(uint32_t)) ||
+        if ( RDEXACT(fd, &tsc_mode, sizeof(uint32_t)) ||
+             RDEXACT(fd, &nsec, sizeof(uint64_t)) ||
+             RDEXACT(fd, &khz, sizeof(uint32_t)) ||
+             RDEXACT(fd, &incarn, sizeof(uint32_t)) ||
              xc_domain_set_tsc_info(xch, dom, tsc_mode, nsec, khz, incarn) ) {
             PERROR("error reading/restoring tsc info");
             return -1;
@@ -740,8 +744,8 @@
         return pagebuf_get_one(xch, ctx, buf, fd, dom);
     } else if (count == -8 ) {
         /* Skip padding 4 bytes then read the console pfn location. */
-        if ( read_exact(fd, &buf->console_pfn, sizeof(uint32_t)) ||
-             read_exact(fd, &buf->console_pfn, sizeof(uint64_t)) )
+        if ( RDEXACT(fd, &buf->console_pfn, sizeof(uint32_t)) ||
+             RDEXACT(fd, &buf->console_pfn, sizeof(uint64_t)) )
         {
             PERROR("error read the address of the console pfn");
             return -1;
@@ -768,7 +772,7 @@
         }
         buf->pfn_types = ptmp;
     }
-    if ( read_exact(fd, buf->pfn_types + oldcount, count *
sizeof(*(buf->pfn_types)))) {
+    if ( RDEXACT(fd, buf->pfn_types + oldcount, count *
sizeof(*(buf->pfn_types)))) {
         PERROR("Error when reading region pfn types");
         return -1;
     }
@@ -795,7 +799,7 @@
         }
         buf->pages = ptmp;
     }
-    if ( read_exact(fd, buf->pages + oldcount * PAGE_SIZE, countpages *
PAGE_SIZE) ) {
+    if ( RDEXACT(fd, buf->pages + oldcount * PAGE_SIZE, countpages *
PAGE_SIZE) ) {
         PERROR("Error when reading pages");
         return -1;
     }

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

Brendan Cully writes ("[Xen-devel] [PATCH] remus: unbreak after
21488:dd6bbdc42033"):
> remus: unbreak after 21488:dd6bbdc42033
> 
> The aforementioned patch missed several calls to read_exact, causing
spurious
> timeouts under Remus.
Sorry for breaking it!  I have applied your patch, thanks.

Ian.

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel