viced: Check vnode length on read and write

When reading or writing a file vnode, check that the length of the
vnode in the vnode index matches the size of the on-disk file
containing the data for the file. If it does not match, take the
volume offline (and for DAFS, demand-salvage it).

Change-Id: I20e02cd84c8425cf0835c104a8e695a0cb6665d9
Reviewed-on: http://gerrit.openafs.org/4121
Tested-by: Andrew Deason <adeason@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>

diff --git a/src/viced/afsfileprocs.c b/src/viced/afsfileprocs.c
index f634367..86c7404 100644 (file)
--- a/src/viced/afsfileprocs.c
+++ b/src/viced/afsfileprocs.c
@@ -288,6 +288,25 @@ SetVolumeSync(struct AFSVolSync *async, Volume * avol)
     FS_UNLOCK;
 }                              /*SetVolumeSync */
 
+static int
+CheckLength(struct Volume *vp, struct Vnode *vnp, afs_sfsize_t alen)
+{
+    afs_sfsize_t vlen;
+    VN_GET_LEN(vlen, vnp);
+    if (alen != vlen) {
+       afs_int64 alen64 = alen, vlen64 = vlen;
+       ViceLog(0, ("Fid %lu.%lu.%lu has inconsistent length (index "
+                   "%" AFS_INT64_FMT ", inode %" AFS_INT64_FMT "); volume "
+                   "must be salvaged\n",
+                   afs_printable_uint32_lu(vp->hashid),
+                   afs_printable_uint32_lu(Vn_id(vnp)),
+                   afs_printable_uint32_lu(vnp->disk.uniquifier),
+                   vlen64, alen64));
+       return -1;
+    }
+    return 0;
+}
+
 /*
  * Note that this function always returns a held host, so
  * that CallPostamble can block without the host's disappearing.
@@ -7109,6 +7128,11 @@ FetchData_RXStyle(Volume * volptr, Vnode * targetptr,
                    volptr->hashid));
        return EIO;
     }
+    if (CheckLength(volptr, targetptr, tlen)) {
+       FDH_CLOSE(fdP);
+       VTakeOffline(volptr);
+       return VSALVAGE;
+    }
     if (Pos > tlen) {
        Len = 0;
     }
@@ -7345,6 +7369,11 @@ StoreData_RXStyle(Volume * volptr, Vnode * targetptr, struct AFSFid * Fid,
                        volptr->hashid));
            return EIO;
        }
+       if (CheckLength(volptr, targetptr, DataLength)) {
+           FDH_CLOSE(fdP);
+           VTakeOffline(volptr);
+           return VSALVAGE;
+       }
 
        if (linkCount != 1) {
            afs_fsize_t size;