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>
diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index 7659cc1..1c08fef 100644
--- a/fs/ntfs/attrib.c
+++ b/fs/ntfs/attrib.c
@@ -2532,14 +2532,7 @@
page = read_mapping_page(mapping, idx, NULL);
if (IS_ERR(page)) {
ntfs_error(vol->sb, "Failed to read first partial "
- "page (sync error, index 0x%lx).", idx);
- return PTR_ERR(page);
- }
- wait_on_page_locked(page);
- if (unlikely(!PageUptodate(page))) {
- ntfs_error(vol->sb, "Failed to read first partial page "
- "(async error, index 0x%lx).", idx);
- page_cache_release(page);
+ "page (error, index 0x%lx).", idx);
return PTR_ERR(page);
}
/*
@@ -2602,14 +2595,7 @@
page = read_mapping_page(mapping, idx, NULL);
if (IS_ERR(page)) {
ntfs_error(vol->sb, "Failed to read last partial page "
- "(sync error, index 0x%lx).", idx);
- return PTR_ERR(page);
- }
- wait_on_page_locked(page);
- if (unlikely(!PageUptodate(page))) {
- ntfs_error(vol->sb, "Failed to read last partial page "
- "(async error, index 0x%lx).", idx);
- page_cache_release(page);
+ "(error, index 0x%lx).", idx);
return PTR_ERR(page);
}
kaddr = kmap_atomic(page, KM_USER0);