static int __ocfs2_page_mkwrite(struct file *file, struct buffer_head *di_bh,
struct page *page)
{
int ret = VM_FAULT_NOPAGE;
struct inode *inode = file_inode(file);
struct address_space *mapping = inode->i_mapping;
loff_t pos = page_offset(page);
unsigned int len = PAGE_CACHE_SIZE;
pgoff_t last_index;
struct page *locked_page = NULL;
void *fsdata;
loff_t size = i_size_read(inode);
last_index = (size - 1) >> PAGE_CACHE_SHIFT;
/*
* There are cases that lead to the page no longer bebongs to the
* mapping.
* 1) pagecache truncates locally due to memory pressure.
* 2) pagecache truncates when another is taking EX lock against
* inode lock. see ocfs2_data_convert_worker.
*
* The i_size check doesn't catch the case where nodes truncated and
* then re-extended the file. We'll re-check the page mapping after
* taking the page lock inside of ocfs2_write_begin_nolock().
*
* Let VM retry with these cases.
*/
if ((page->mapping != inode->i_mapping) ||
(!PageUptodate(page)) ||
(page_offset(page) >= size))
goto out;
/*
* Call ocfs2_write_begin() and ocfs2_write_end() to take
* advantage of the allocation code there. We pass a write
* length of the whole page (chopped to i_size) to make sure
* the whole thing is allocated.
*
* Since we know the page is up to date, we don't have to
* worry about ocfs2_write_begin() skipping some buffer reads
* because the "write" would invalidate their data.
*/
if (page->index == last_index)
len = ((size - 1) & ~PAGE_CACHE_MASK) + 1;
ret = ocfs2_write_begin_nolock(file, mapping, pos, len, 0, &locked_page,
&fsdata, di_bh, page);
if (ret) {
if (ret != -ENOSPC)
mlog_errno(ret);
if (ret == -ENOMEM)
ret = VM_FAULT_OOM;
else
ret = VM_FAULT_SIGBUS;
goto out;
}
if (!locked_page) {
ret = VM_FAULT_NOPAGE;
goto out;
}
ret = ocfs2_write_end_nolock(mapping, pos, len, len, locked_page,
fsdata);
BUG_ON(ret != len);
ret = VM_FAULT_LOCKED;
out:
return ret;
}
static int __ocfs2_page_mkwrite(struct inode *inode, struct buffer_head *di_bh,
struct page *page)
{
int ret;
struct address_space *mapping = inode->i_mapping;
loff_t pos = page_offset(page);
unsigned int len = PAGE_CACHE_SIZE;
pgoff_t last_index;
struct page *locked_page = NULL;
void *fsdata;
loff_t size = i_size_read(inode);
/*
* Another node might have truncated while we were waiting on
* cluster locks.
*/
last_index = size >> PAGE_CACHE_SHIFT;
if (page->index > last_index) {
ret = -EINVAL;
goto out;
}
/*
* The i_size check above doesn't catch the case where nodes
* truncated and then re-extended the file. We'll re-check the
* page mapping after taking the page lock inside of
* ocfs2_write_begin_nolock().
*/
if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
/*
* the page has been umapped in ocfs2_data_downconvert_worker.
* So return 0 here and let VFS retry.
*/
ret = 0;
goto out;
}
/*
* Call ocfs2_write_begin() and ocfs2_write_end() to take
* advantage of the allocation code there. We pass a write
* length of the whole page (chopped to i_size) to make sure
* the whole thing is allocated.
*
* Since we know the page is up to date, we don't have to
* worry about ocfs2_write_begin() skipping some buffer reads
* because the "write" would invalidate their data.
*/
if (page->index == last_index)
len = size & ~PAGE_CACHE_MASK;
ret = ocfs2_write_begin_nolock(mapping, pos, len, 0, &locked_page,
&fsdata, di_bh, page);
if (ret) {
if (ret != -ENOSPC)
mlog_errno(ret);
goto out;
}
ret = ocfs2_write_end_nolock(mapping, pos, len, len, locked_page,
fsdata);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
BUG_ON(ret != len);
ret = 0;
out:
return ret;
}
