From 6285bc231277419255f3498d3eb5ddc9f8e7fe79 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Tue, 2 Oct 2012 10:25:51 -0500 Subject: [PATCH] ceph: avoid 32-bit page index overflow A pgoff_t is defined (by default) to have type (unsigned long). On architectures such as i686 that's a 32-bit type. The ceph address space code was attempting to produce 64 bit offsets by shifting a page's index by PAGE_CACHE_SHIFT, but the result was not what was desired because the shift occurred before the result got promoted to 64 bits. Fix this by converting all uses of page->index used in this way to use the page_offset() macro, which ensures the 64-bit result has the intended value. This fixes http://tracker.newdream.net/issues/3112 Reported-by: Mohamed Pakkeer Signed-off-by: Alex Elder Reviewed-by: Sage Weil --- fs/ceph/addr.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 4469b63c9b7b..22b6e4583faa 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -205,7 +205,7 @@ static int readpage_nounlock(struct file *filp, struct page *page) dout("readpage inode %p file %p page %p index %lu\n", inode, filp, page, page->index); err = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout, - page->index << PAGE_CACHE_SHIFT, &len, + (u64) page_offset(page), &len, ci->i_truncate_seq, ci->i_truncate_size, &page, 1, 0); if (err == -ENOENT) @@ -286,7 +286,7 @@ static int start_read(struct inode *inode, struct list_head *page_list, int max) int nr_pages = 0; int ret; - off = page->index << PAGE_CACHE_SHIFT; + off = (u64) page_offset(page); /* count pages */ next_index = page->index; @@ -426,7 +426,7 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc) struct ceph_inode_info *ci; struct ceph_fs_client *fsc; struct ceph_osd_client *osdc; - loff_t page_off = page->index << PAGE_CACHE_SHIFT; + loff_t page_off = page_offset(page); int len = PAGE_CACHE_SIZE; loff_t i_size; int err = 0; @@ -817,8 +817,7 @@ get_more_pages: /* ok */ if (locked_pages == 0) { /* prepare async write request */ - offset = (unsigned long long)page->index - << PAGE_CACHE_SHIFT; + offset = (u64) page_offset(page); len = wsize; req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout, @@ -1180,7 +1179,7 @@ static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) struct inode *inode = vma->vm_file->f_dentry->d_inode; struct page *page = vmf->page; struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; - loff_t off = page->index << PAGE_CACHE_SHIFT; + loff_t off = page_offset(page); loff_t size, len; int ret; -- 2.20.1