linux-kernel - [PATCH 2/2] afs: Fix waiting for writeback then skipping folio

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230619134204.922713-3-dhowells@redhat.com>
Date:   Mon, 19 Jun 2023 14:42:04 +0100
From:   David Howells <dhowells@...hat.com>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     David Howells <dhowells@...hat.com>,
        Marc Dionne <marc.dionne@...istor.com>,
        linux-afs@...ts.infradead.org, linux-fsdevel@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        "Vishal Moola (Oracle)" <vishal.moola@...il.com>
Subject: [PATCH 2/2] afs: Fix waiting for writeback then skipping folio

From: "Vishal Moola (Oracle)" <vishal.moola@...il.com>

Commit acc8d8588cb7 converted afs_writepages_region() to write back a
folio batch. The function waits for writeback to a folio, but then
proceeds to the rest of the batch without trying to write that folio
again. This patch fixes has it attempt to write the folio again.

[DH: Also remove an 'else' that adding a goto makes redundant]

Fixes: acc8d8588cb7 ("afs: convert afs_writepages_region() to use filemap_get_folios_tag()")
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@...il.com>
Signed-off-by: David Howells <dhowells@...hat.com>
cc: Marc Dionne <marc.dionne@...istor.com>
cc: linux-afs@...ts.infradead.org
Link: https://lore.kernel.org/r/20230607204120.89416-2-vishal.moola@gmail.com/
---
 fs/afs/write.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/afs/write.c b/fs/afs/write.c
index fd433024070e..8750b99c3f56 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -731,6 +731,7 @@ static int afs_writepages_region(struct address_space *mapping,
 			 * (changing page->mapping to NULL), or even swizzled
 			 * back from swapper_space to tmpfs file mapping
 			 */
+try_again:
 			if (wbc->sync_mode != WB_SYNC_NONE) {
 				ret = folio_lock_killable(folio);
 				if (ret < 0) {
@@ -757,9 +758,10 @@ static int afs_writepages_region(struct address_space *mapping,
 #ifdef CONFIG_AFS_FSCACHE
 					folio_wait_fscache(folio);
 #endif
-				} else {
-					start += folio_size(folio);
+					goto try_again;
 				}
+
+				start += folio_size(folio);
 				if (wbc->sync_mode == WB_SYNC_NONE) {
 					if (skips >= 5 || need_resched()) {
 						*_next = start;