* Do no longer save device info in the MD cache. To reenable this, use the new option --check-dev

git-svn-id: file:///home/lennart/svn/public/syrep/trunk@84 07ea20a6-d2c5-0310-9e02-9ef735347d72

4 files changed, 32 insertions, 6 deletions

diff --git a/man/syrep.1.xml.in b/man/syrep.1.xml.in
index 76d2d2d..a3c0828 100644
--- a/man/syrep.1.xml.in
+++ b/man/syrep.1.xml.in
@@ -202,6 +202,13 @@
       <optdesc>Use cache in a read only fashion</optdesc>
     </option>
 
+    <option>
+      <p><opt>--check-dev</opt> (option)</p>
+      <optdesc>Store information about the device where the file
+      resides when storing an entry about it in the message digest
+      cache. Since nowadays device identifiers cannot be longer
+      considered stable, this options defaults to off.</optdesc>
+    </option>
    </section>
    <section name="Showing differences between two snapshots">
     <option>
diff --git a/src/cache.c b/src/cache.c
index 6722b55..969b0c0 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -35,6 +35,8 @@
 
 #include "cache.h"
 #include "md5util.h"
+#include "cmdline.h"
+#include "syrep.h"
 
 struct syrep_cache_key {
     uint64_t dev;
@@ -176,23 +178,37 @@ int md_cache_get(struct syrep_md_cache *c, const char *path, uint8_t digest[16])
     }
 
     memset(&k, 0, sizeof(k));
-    k.dev = (uint64_t) st.st_dev;
     k.inode = (uint64_t) st.st_ino;
     k.date = (uint32_t) st.st_mtime;
     k.size = (uint64_t) st.st_size;
 
-    if (!c)
-        j = 0;
-    else
+    j = 0;
+
+    if (c) {
+        k.dev = args.check_dev_flag ? (uint64_t) st.st_dev : (uint64_t) -1;
+        
         if ((j = get(c, &k, digest)) < 0)
             goto finish;
+
+        if (!j) {
+            /* Perhaps the setting of check_dev_flag was different
+             * when this cache was created? So let's try to make the
+             * best use of that cache */
+            k.dev = args.check_dev_flag ? (uint64_t) -1 : (uint64_t) st.st_dev;
+
+            if ((j = get(c, &k, digest)) < 0)
+                goto finish;
+        }
+    }
     
     if (!j)
         if (fdmd5(fd, st.st_size, digest) < 0)
             goto finish;
 
-    if (c && !c->ro)
+    if (c && !c->ro) {
+        k.dev = args.check_dev_flag ? (uint64_t) st.st_dev : (uint64_t) -1;
         put(c, &k, digest, c->timestamp);
+    }
 
     r = 0;
 
diff --git a/src/syrep.c b/src/syrep.c
index f9509d3..c73acbe 100644
--- a/src/syrep.c
+++ b/src/syrep.c
@@ -575,7 +575,9 @@ static int help(FILE *f, const char *argv0) {
             "    --no-cache                         Don't use a message digest cache\n"
             "    --no-purge                         Don't purge obsolete entries from cache\n"
             "                                       after update run\n"
-            "    --ro-cache                         Use read only cache\n\n"
+            "    --ro-cache                         Use read only cache\n"
+            "    --check-dev                        Store information about the device where\n"
+            "                                       a file resides in the MD cache\n\n"
             
             "  --diff SNAPSHOT SNAPSHOT             Show difference between two repositories\n"
             "                                       or snapshots\n"
diff --git a/src/syrep.ggo b/src/syrep.ggo
index 79c6cd5..d6edb52 100644
--- a/src/syrep.ggo
+++ b/src/syrep.ggo
@@ -41,6 +41,7 @@ option "update" - "Update a repository snapshot" flag off
  option "no-purge" - "update: Don't pruge obsolete entries from cache after update run" flag off
  option "ro-cache" - "update: Use read only cache" flag off
  option "progress" p "update: Show progress" flag off
+ option "check-dev" - "update: Honour stat() st_dev field" flag off
 
 option "diff" - "Show difference between two repositories or snapshots" flag off
  option "sizes" s "diff: show file sizes to copy (works online on repositories)" flag off