ceph_sync_read: stop poking into iov_iter guts (2b777c9d) · Commits · e / devices / android_kernel_sony_msm8998

fs/ceph/file.c

+18 −28

Original line number	Original line	Diff line number	Diff line
	@@ -418,7 +418,7 @@ static ssize_t ceph_sync_read(struct kiocb iocb, struct iov_iter i,
	struct page **pages;		struct page **pages;
	u64 off = iocb->ki_pos;		u64 off = iocb->ki_pos;
	int num_pages, ret;		int num_pages, ret;
	size_t len = i->count;		size_t len = iov_iter_count(i);

	dout("sync_read on file %p %llu~%u %s\n", file, off,		dout("sync_read on file %p %llu~%u %s\n", file, off,
	(unsigned)len,		(unsigned)len,
	@@ -436,25 +436,26 @@ static ssize_t ceph_sync_read(struct kiocb iocb, struct iov_iter i,

	if (file->f_flags & O_DIRECT) {		if (file->f_flags & O_DIRECT) {
	while (iov_iter_count(i)) {		while (iov_iter_count(i)) {
	void __user *data = i->iov[0].iov_base + i->iov_offset;		size_t start;
	size_t len = i->iov[0].iov_len - i->iov_offset;		ssize_t n;

	num_pages = calc_pages_for((unsigned long)data, len);		n = iov_iter_get_pages_alloc(i, &pages, INT_MAX, &start);
	pages = ceph_get_direct_page_vector(data,		if (n < 0)
	num_pages, true);		return n;
	if (IS_ERR(pages))
	return PTR_ERR(pages);		num_pages = (n + start + PAGE_SIZE - 1) / PAGE_SIZE;

	ret = striped_read(inode, off, len,		ret = striped_read(inode, off, n,
	pages, num_pages, checkeof,		pages, num_pages, checkeof,
	1, (unsigned long)data & ~PAGE_MASK);		1, start);

	ceph_put_page_vector(pages, num_pages, true);		ceph_put_page_vector(pages, num_pages, true);

	if (ret <= 0)		if (ret <= 0)
	break;		break;
	off += ret;		off += ret;
	iov_iter_advance(i, ret);		iov_iter_advance(i, ret);
	if (ret < len)		if (ret < n)
	break;		break;
	}		}
	} else {		} else {
	@@ -466,25 +467,14 @@ static ssize_t ceph_sync_read(struct kiocb iocb, struct iov_iter i,
	num_pages, checkeof, 0, 0);		num_pages, checkeof, 0, 0);
	if (ret > 0) {		if (ret > 0) {
	int l, k = 0;		int l, k = 0;
	size_t left = len = ret;		size_t left = ret;

	while (left) {		while (left) {
	void __user *data = i->iov[0].iov_base		int copy = min_t(size_t, PAGE_SIZE, left);
	+ i->iov_offset;		l = copy_page_to_iter(pages[k++], 0, copy, i);
	l = min(i->iov[0].iov_len - i->iov_offset,		off += l;
	left);		left -= l;
			if (l < copy)
	ret = ceph_copy_page_vector_to_user(&pages[k],
	data, off,
	l);
	if (ret > 0) {
	iov_iter_advance(i, ret);
	left -= ret;
	off += ret;
	k = calc_pages_for(iocb->ki_pos,
	len - left + 1) - 1;
	BUG_ON(k >= num_pages && left);
	} else
	break;		break;
	}		}
	}		}

include/linux/ceph/libceph.h

+0 −2

Original line number	Original line	Diff line number	Diff line
	@@ -222,8 +222,6 @@ extern void ceph_copy_to_page_vector(struct page **pages,
	extern void ceph_copy_from_page_vector(struct page **pages,		extern void ceph_copy_from_page_vector(struct page **pages,
	void *data,		void *data,
	loff_t off, size_t len);		loff_t off, size_t len);
	extern int ceph_copy_page_vector_to_user(struct page *pages, void __user data,
	loff_t off, size_t len);
	extern void ceph_zero_page_vector_range(int off, int len, struct page **pages);		extern void ceph_zero_page_vector_range(int off, int len, struct page **pages);

net/ceph/pagevec.c

+4 −31

Original line number	Original line	Diff line number	Diff line
	@@ -53,6 +53,9 @@ void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty)
	set_page_dirty_lock(pages[i]);		set_page_dirty_lock(pages[i]);
	put_page(pages[i]);		put_page(pages[i]);
	}		}
			if (is_vmalloc_addr(pages))
			vfree(pages);
			else
	kfree(pages);		kfree(pages);
	}		}
	EXPORT_SYMBOL(ceph_put_page_vector);		EXPORT_SYMBOL(ceph_put_page_vector);
	@@ -164,36 +167,6 @@ void ceph_copy_from_page_vector(struct page **pages,
	}		}
	EXPORT_SYMBOL(ceph_copy_from_page_vector);		EXPORT_SYMBOL(ceph_copy_from_page_vector);

	/*
	* copy user data from a page vector into a user pointer
	*/
	int ceph_copy_page_vector_to_user(struct page **pages,
	void __user *data,
	loff_t off, size_t len)
	{
	int i = 0;
	int po = off & ~PAGE_CACHE_MASK;
	int left = len;
	int l, bad;

	while (left > 0) {
	l = min_t(int, left, PAGE_CACHE_SIZE-po);
	bad = copy_to_user(data, page_address(pages[i]) + po, l);
	if (bad == l)
	return -EFAULT;
	data += l - bad;
	left -= l - bad;
	if (po) {
	po += l - bad;
	if (po == PAGE_CACHE_SIZE)
	po = 0;
	}
	i++;
	}
	return len;
	}
	EXPORT_SYMBOL(ceph_copy_page_vector_to_user);

	/*		/*
	* Zero an extent within a page vector. Offset is relative to the		* Zero an extent within a page vector. Offset is relative to the
	* start of the first page.		* start of the first page.