GFS2: Fix writing to non-page aligned gfs2_quota structures

[safe/jmp/linux-2.6] / fs / gfs2 / aops.c

diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index 0c1d0b8..a739a0a 100644 (file)
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -418,6 +418,7 @@ static int gfs2_jdata_writepages(struct address_space *mapping,
 static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
 {
        struct buffer_head *dibh;
+       u64 dsize = i_size_read(&ip->i_inode);
        void *kaddr;
        int error;
 
@@ -437,9 +438,10 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
                return error;
 
        kaddr = kmap_atomic(page, KM_USER0);
-       memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode),
-              ip->i_disksize);
-       memset(kaddr + ip->i_disksize, 0, PAGE_CACHE_SIZE - ip->i_disksize);
+       if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode)))
+               dsize = (dibh->b_size - sizeof(struct gfs2_dinode));
+       memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
+       memset(kaddr + dsize, 0, PAGE_CACHE_SIZE - dsize);
        kunmap_atomic(kaddr, KM_USER0);
        flush_dcache_page(page);
        brelse(dibh);