Linux: fix reading files larger than the chunk size

Commit 2571b6285d5da8ef62ab38c3a938258ddd7bac4e fixed an issue with
the use of tmpfs as a disk cache and ftruncate() on files in AFS.
But it introduced a problem reading larger files as reported in
RT ticket 129880.

What should be compared against the current cache file size is the
offset into the current chunk, not the overall offset for the whole
file.

FIXES: 129880

Change-Id: I93008c8d0b1d70785b0b8a2e4289a04ac06cbbef
Reviewed-on: http://gerrit.openafs.org/4656
Reviewed-by: Russ Allbery <rra@stanford.edu>
Tested-by: Russ Allbery <rra@stanford.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>

diff --git a/src/afs/LINUX/osi_vnodeops.c b/src/afs/LINUX/osi_vnodeops.c
index 79a61e4..17a1b62 100644 (file)
--- a/src/afs/LINUX/osi_vnodeops.c
+++ b/src/afs/LINUX/osi_vnodeops.c
@@ -1522,7 +1522,7 @@ afs_linux_read_cache(struct file *cachefp, struct page *page,
 
     /* If we're trying to read a page that's past the end of the disk
      * cache file, then just return a zeroed page */
-    if (offset >= i_size_read(cacheinode)) {
+    if (AFS_CHUNKOFFSET(offset) >= i_size_read(cacheinode)) {
        zero_user_segment(page, 0, PAGE_CACHE_SIZE);
        SetPageUptodate(page);
        if (task)