From: NeilBrown <neilb@suse.de>
To: Andrew Morton <akpm@linux-foundation.org>,
Theodore Ts'o <tytso@mit.edu>,
Andreas Dilger <adilger.kernel@dilger.ca>,
"Darrick J. Wong" <djwong@kernel.org>,
Matthew Wilcox <willy@infradead.org>,
Mel Gorman <mgorman@suse.de>, Michal Hocko <mhocko@suse.com>,
". Dave Chinner" <david@fromorbit.com>,
Jonathan Corbet <corbet@lwn.net>
Cc: linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org
Subject: [PATCH 4/6] EXT4: remove congestion_wait from ext4_bio_write_page, and simplify
Date: Fri, 17 Sep 2021 12:56:57 +1000 [thread overview]
Message-ID: <163184741781.29351.8660877195340279243.stgit@noble.brown> (raw)
In-Reply-To: <163184698512.29351.4735492251524335974.stgit@noble.brown>
congestion_wait() is indistinguishable from
schedule_timeout_uninterruptible(). It is best avoided and should be
deprecated.
It is not needed in ext4_bio_write_page(). There are two cases.
If there are no ->io_bio yet, then it is appropriate to use __GFP_NOFAIL
which does the waiting in a better place. The code already uses this
flag on the second attempt. This patch changes to it always use that
flag for this case.
If there *are* ->io_bio (in which case the allocation was non-blocking)
we submit the io and return the first case. No waiting is needed in
this case.
So remove the congestion_wait() call, and simplify the code so that the
two cases are somewhat clearer.
Remove the "if (io->io_bio)" before calling ext4_io_submit() as that
test is performed internally by that function.
Signed-off-by: NeilBrown <neilb@suse.de>
---
fs/ext4/page-io.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index f038d578d8d8..3b6ece0d3ad6 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -506,7 +506,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
* can't happen in the common case of blocksize == PAGE_SIZE.
*/
if (fscrypt_inode_uses_fs_layer_crypto(inode) && nr_to_submit) {
- gfp_t gfp_flags = GFP_NOFS;
+ gfp_t gfp_flags;
unsigned int enc_bytes = round_up(len, i_blocksize(inode));
/*
@@ -514,21 +514,18 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
* a waiting mask (i.e. request guaranteed allocation) on the
* first page of the bio. Otherwise it can deadlock.
*/
+ retry_encrypt:
if (io->io_bio)
gfp_flags = GFP_NOWAIT | __GFP_NOWARN;
- retry_encrypt:
+ else
+ gfp_flags = GFP_NOFS | __GFP_NOFAIL;
bounce_page = fscrypt_encrypt_pagecache_blocks(page, enc_bytes,
0, gfp_flags);
if (IS_ERR(bounce_page)) {
ret = PTR_ERR(bounce_page);
if (ret == -ENOMEM &&
(io->io_bio || wbc->sync_mode == WB_SYNC_ALL)) {
- gfp_flags = GFP_NOFS;
- if (io->io_bio)
- ext4_io_submit(io);
- else
- gfp_flags |= __GFP_NOFAIL;
- congestion_wait(BLK_RW_ASYNC, HZ/50);
+ ext4_io_submit(io);
goto retry_encrypt;
}
next prev parent reply other threads:[~2021-09-17 3:00 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-17 2:56 [PATCH 0/6 v2] congestion_wait() and GFP_NOFAIL NeilBrown
2021-09-17 2:56 ` [PATCH 6/6] XFS: remove congestion_wait() loop from xfs_buf_alloc_pages() NeilBrown
2021-09-17 2:56 ` [PATCH 5/6] XFS: remove congestion_wait() loop from kmem_alloc() NeilBrown
2021-09-17 21:45 ` Dave Chinner
2021-09-17 2:56 ` [PATCH 1/6] MM: Support __GFP_NOFAIL in alloc_pages_bulk_*() and improve doco NeilBrown
2021-09-17 14:42 ` Mel Gorman
2021-09-20 23:48 ` NeilBrown
2021-10-05 9:16 ` Vlastimil Babka
2021-09-17 2:56 ` [PATCH 3/6] EXT4: Remove ENOMEM/congestion_wait() loops NeilBrown
2021-09-17 2:56 ` NeilBrown [this message]
2021-09-17 2:56 ` [PATCH 2/6] MM: improve documentation for __GFP_NOFAIL NeilBrown
2021-10-05 9:20 ` Vlastimil Babka
2021-10-05 11:09 ` Michal Hocko
2021-10-05 12:27 ` Vlastimil Babka
2021-10-06 23:14 ` Dave Chinner
2021-10-07 10:07 ` Michal Hocko
2021-10-07 23:15 ` NeilBrown
2021-10-08 7:48 ` Michal Hocko
2021-10-08 22:36 ` Dave Chinner
2021-10-11 11:57 ` Michal Hocko
2021-10-11 21:49 ` NeilBrown
2021-10-18 10:23 ` Michal Hocko
2021-10-19 4:32 ` NeilBrown
2021-10-19 13:59 ` Michal Hocko
2021-10-22 0:09 ` NeilBrown
2021-10-13 2:32 ` Dave Chinner
2021-10-13 8:26 ` Michal Hocko
2021-10-14 11:32 ` David Sterba
2021-10-14 11:46 ` Michal Hocko
-- strict thread matches above, loose matches on Subject: below --
2021-09-14 0:13 [PATCH 0/6] congestion_wait() and GFP_NOFAIL NeilBrown
2021-09-14 0:13 ` [PATCH 4/6] EXT4: remove congestion_wait from ext4_bio_write_page, and simplify NeilBrown
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