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romfs_readpage: don't report errors for pages beyond i_size

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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>
This commit is contained in:
Linus Torvalds 2008-07-30 14:26:25 -07:00
parent 660fc1f4d8
commit 0056e65f9e
1 changed files with 23 additions and 14 deletions
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37
fs/romfs/inode.c
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@ -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 page * page)
/* 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);