ocfs2_zero_extend() does its zeroing block by block, but it calls a<snip>
function named ocfs2_write_zero_page(). Let's have
ocfs2_write_zero_page() handle the page level. From
ocfs2_zero_extend()'s perspective, it is now page-at-a-time.
Signed-off-by: Joel Becker<joel.becker@xxxxxxxxxx>
---
fs/ocfs2/aops.c | 30 --------------
fs/ocfs2/file.c | 119 +++++++++++++++++++++++++++++++++++++++----------------
2 files changed, 85 insertions(+), 64 deletions(-)
-static int ocfs2_write_zero_page(struct inode *inode,Sorry for not noticing this yesterday night. This can't work and will overflow and bug out. I met with a similar bug in reflink test. See commit d622b89.
- u64 size)
+static int ocfs2_write_zero_page(struct inode *inode, u64 abs_from,
+ u64 abs_to)
{
struct address_space *mapping = inode->i_mapping;
struct page *page;
- unsigned long index;
- unsigned int offset;
+ unsigned long index = abs_from>> PAGE_CACHE_SHIFT;
handle_t *handle = NULL;
int ret;
+ unsigned zero_from, zero_to, block_start, block_end;
- offset = (size& (PAGE_CACHE_SIZE-1)); /* Within page */
- /* ugh. in prepare/commit_write, if from==to==start of block, we
- ** skip the prepare. make sure we never send an offset for the start
- ** of a block
- */
- if ((offset& (inode->i_sb->s_blocksize - 1)) == 0) {
- offset++;
- }
- index = size>> PAGE_CACHE_SHIFT;
+ BUG_ON(abs_from>= abs_to);
+ BUG_ON(abs_to> ((index + 1)<< PAGE_CACHE_SHIFT));
+ BUG_ON(abs_from& (inode->i_blkbits - 1));Do we really need to check block_start < PAGE_CACHE_SIZE? I think just check block_start < zero_to is enough since you have limit zero_to with PAGE_CACHE_SIZE. What's more, it looks more natural(see below), does it?
page = grab_cache_page(mapping, index);
if (!page) {
@@ -754,31 +781,52 @@ static int ocfs2_write_zero_page(struct inode *inode,
goto out;
}
- ret = ocfs2_prepare_write_nolock(inode, page, offset, offset);
- if (ret< 0) {
- mlog_errno(ret);
- goto out_unlock;
- }
+ /* Get the offsets within the page that we want to zero */
+ zero_from = abs_from& (PAGE_CACHE_SIZE - 1);
+ zero_to = abs_to& (PAGE_CACHE_SIZE - 1);
+ if (!zero_to)
+ zero_to = PAGE_CACHE_SIZE;
- if (ocfs2_should_order_data(inode)) {
- handle = ocfs2_start_walk_page_trans(inode, page, offset,
- offset);
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
- handle = NULL;
+ /* We know that zero_from is block aligned */
+ for (block_start = zero_from;
+ (block_start< PAGE_CACHE_SIZE)&& (block_start< zero_to);
+ block_start = block_end) {