ubifs: Set page uptodate in the correct place

[ Upstream commit 723012cab7 ]

Page cache reads are lockless, so setting the freshly allocated page
uptodate before we've overwritten it with the data it's supposed to have
in it will allow a simultaneous reader to see old data.  Move the call
to SetPageUptodate into ubifs_write_end(), which is after we copied the
new data into the page.

Fixes: 1e51764a3c ("UBIFS: add new flash file system")
Cc: stable@vger.kernel.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2024-01-24 17:52:44 +00:00 committed by Greg Kroah-Hartman
parent c8cc05de8e
commit 142d87c958
1 changed files with 4 additions and 9 deletions

View File

@ -261,9 +261,6 @@ static int write_begin_slow(struct address_space *mapping,
return err;
}
}
SetPageUptodate(page);
ClearPageError(page);
}
if (PagePrivate(page))
@ -462,9 +459,6 @@ static int ubifs_write_begin(struct file *file, struct address_space *mapping,
return err;
}
}
SetPageUptodate(page);
ClearPageError(page);
}
err = allocate_budget(c, page, ui, appending);
@ -474,10 +468,8 @@ static int ubifs_write_begin(struct file *file, struct address_space *mapping,
* If we skipped reading the page because we were going to
* write all of it, then it is not up to date.
*/
if (skipped_read) {
if (skipped_read)
ClearPageChecked(page);
ClearPageUptodate(page);
}
/*
* Budgeting failed which means it would have to force
* write-back but didn't, because we set the @fast flag in the
@ -568,6 +560,9 @@ static int ubifs_write_end(struct file *file, struct address_space *mapping,
goto out;
}
if (len == PAGE_SIZE)
SetPageUptodate(page);
if (!PagePrivate(page)) {
attach_page_private(page, (void *)1);
atomic_long_inc(&c->dirty_pg_cnt);