| From 0056e65f9e28d83ee1a3fb4f7d0041e838f03c34 Mon Sep 17 00:00:00 2001 |
| From: Linus Torvalds <torvalds@linux-foundation.org> |
| Date: Wed, 30 Jul 2008 14:26:25 -0700 |
| Subject: romfs_readpage: don't report errors for pages beyond i_size |
| |
| From: Linus Torvalds <torvalds@linux-foundation.org> |
| |
| commit 0056e65f9e28d83ee1a3fb4f7d0041e838f03c34 upstream |
| |
| We zero-fill them like we are supposed to, and that's all fine. It's |
| only an error if the 'romfs_copyfrom()' routine isn't able to fill the |
| data that is supposed to be there. |
| |
| Most of the patch is really just re-organizing the code a bit, and using |
| separate variables for the error value and for how much of the page we |
| actually filled from the filesystem. |
| |
| Reported-and-tested-by: Chris Fester <cfester@wms.com> |
| Cc: Alexander Viro <viro@zeniv.linux.org.uk> |
| Cc: Matt Waddel <matt.waddel@freescale.com> |
| Cc: Greg Ungerer <gerg@snapgear.com> |
| Signed-of-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| fs/romfs/inode.c | 37 +++++++++++++++++++++++-------------- |
| 1 file changed, 23 insertions(+), 14 deletions(-) |
| |
| --- a/fs/romfs/inode.c |
| +++ b/fs/romfs/inode.c |
| @@ -418,7 +418,8 @@ static int |
| romfs_readpage(struct file *file, struct page * page) |
| { |
| struct inode *inode = page->mapping->host; |
| - loff_t offset, avail, readlen; |
| + loff_t offset, size; |
| + unsigned long filled; |
| void *buf; |
| int result = -EIO; |
| |
| @@ -430,21 +431,29 @@ romfs_readpage(struct file *file, struct |
| |
| /* 32 bit warning -- but not for us :) */ |
| offset = page_offset(page); |
| - if (offset < i_size_read(inode)) { |
| - avail = inode->i_size-offset; |
| - readlen = min_t(unsigned long, avail, PAGE_SIZE); |
| - if (romfs_copyfrom(inode, buf, ROMFS_I(inode)->i_dataoffset+offset, readlen) == readlen) { |
| - if (readlen < PAGE_SIZE) { |
| - memset(buf + readlen,0,PAGE_SIZE-readlen); |
| - } |
| - SetPageUptodate(page); |
| - result = 0; |
| + size = i_size_read(inode); |
| + filled = 0; |
| + result = 0; |
| + if (offset < size) { |
| + unsigned long readlen; |
| + |
| + size -= offset; |
| + readlen = size > PAGE_SIZE ? PAGE_SIZE : size; |
| + |
| + filled = romfs_copyfrom(inode, buf, ROMFS_I(inode)->i_dataoffset+offset, readlen); |
| + |
| + if (filled != readlen) { |
| + SetPageError(page); |
| + filled = 0; |
| + result = -EIO; |
| } |
| } |
| - if (result) { |
| - memset(buf, 0, PAGE_SIZE); |
| - SetPageError(page); |
| - } |
| + |
| + if (filled < PAGE_SIZE) |
| + memset(buf + filled, 0, PAGE_SIZE-filled); |
| + |
| + if (!result) |
| + SetPageUptodate(page); |
| flush_dcache_page(page); |
| |
| unlock_page(page); |