fix some conversion overflows
Fix page index to offset conversion overflows in buffer layer, ecryptfs,
and ocfs2.
It would be nice to convert the whole tree to page_offset, but for now
just fix the bugs.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/buffer.c b/fs/buffer.c
index 02ebb1f..0e5ec37 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2221,7 +2221,7 @@
lock_page(page);
size = i_size_read(inode);
if ((page->mapping != inode->i_mapping) ||
- ((page->index << PAGE_CACHE_SHIFT) > size)) {
+ (page_offset(page) > size)) {
/* page got truncated out from underneath us */
goto out_unlock;
}
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 7d5a43c..e4ab7bc 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -409,8 +409,7 @@
if (!PageUptodate(page))
rc = ecryptfs_do_readpage(file, page, page->index);
if (page->index != 0) {
- loff_t end_of_prev_pg_pos =
- (((loff_t)page->index << PAGE_CACHE_SHIFT) - 1);
+ loff_t end_of_prev_pg_pos = page_offset(page) - 1;
if (end_of_prev_pg_pos > i_size_read(page->mapping->host)) {
rc = ecryptfs_truncate(file->f_path.dentry,
@@ -736,7 +735,7 @@
goto out;
}
inode->i_blocks = lower_inode->i_blocks;
- pos = (page->index << PAGE_CACHE_SHIFT) + to;
+ pos = page_offset(page) + to;
if (pos > i_size_read(inode)) {
i_size_write(inode, pos);
ecryptfs_printk(KERN_DEBUG, "Expanded file size to "
diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c
index ee64749..9875615 100644
--- a/fs/ocfs2/mmap.c
+++ b/fs/ocfs2/mmap.c
@@ -89,7 +89,7 @@
{
int ret;
struct address_space *mapping = inode->i_mapping;
- loff_t pos = page->index << PAGE_CACHE_SHIFT;
+ loff_t pos = page_offset(page);
unsigned int len = PAGE_CACHE_SIZE;
pgoff_t last_index;
struct page *locked_page = NULL;