ceph: fix page alignment corrections

 dd if=/dev/urandom of=/mnt/fs_depot/dd10 bs=500 seek=8388 count=1
 dd if=/mnt/fs_depot/dd10 of=/root/dd10out bs=500 skip=8388 count=1

Reported-by: Henry C Chang <henry.cy.chang@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 9542f07d0b9306774e7172afed25b6f809503c06..2be0f35afdfb42fff83d2bba2797bd08e34c22d9 100644 (file)
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -290,7 +290,6 @@ static int striped_read(struct inode *inode,
        struct ceph_inode_info *ci = ceph_inode(inode);
        u64 pos, this_len;
        int io_align, page_align;
-       int page_off = off & ~PAGE_CACHE_MASK; /* first byte's offset in page */
        int left, pages_left;
        int read;
        struct page **page_pos;
@@ -326,12 +325,11 @@ more:
             ret, hit_stripe ? " HITSTRIPE" : "", was_short ? " SHORT" : "");
 
        if (ret > 0) {
-               int didpages =
-                       ((pos & ~PAGE_CACHE_MASK) + ret) >> PAGE_CACHE_SHIFT;
+               int didpages = (page_align + ret) >> PAGE_CACHE_SHIFT;
 
                if (read < pos - off) {
                        dout(" zero gap %llu to %llu\n", off + read, pos);
-                       ceph_zero_page_vector_range(page_off + read,
+                       ceph_zero_page_vector_range(page_align + read,
                                                    pos - off - read, pages);
                }
                pos += ret;
@@ -356,7 +354,7 @@ more:
                                left = inode->i_size - pos;
 
                        dout("zero tail %d\n", left);
-                       ceph_zero_page_vector_range(page_off + read, left,
+                       ceph_zero_page_vector_range(page_align + read, left,
                                                    pages);
                        read += left;
                }