mm: make read_cache_page synchronous

Ensure pages are uptodate after returning from read_cache_page, which allows
us to cut out most of the filesystem-internal PageUptodate calls.

I didn't have a great look down the call chains, but this appears to fixes 7
possible use-before uptodate in hfs, 2 in hfsplus, 1 in jfs, a few in
ecryptfs, 1 in jffs2, and a possible cleared data overwritten with readpage in
block2mtd.  All depending on whether the filler is async and/or can return
with a !uptodate page.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Nick Piggin
2007-05-06 14:49:04 -07:00
committed by Linus Torvalds
parent 714b8171af
commit 6fe6900e1e
24 changed files with 71 additions and 146 deletions

View File

@@ -569,9 +569,6 @@ unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
NULL);
if (!IS_ERR(page)) {
wait_on_page_locked(page);
if (!PageUptodate(page))
goto fail;
if (PageError(page))
goto fail;
p->v = page;