From: Naoto Kobayashi <naoto.kobayashi4c@gmail.com>
To: Theodore Ts'o <tytso@mit.edu>, Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Naoto Kobayashi <naoto.kobayashi4c@gmail.com>,
linux-ext4@vger.kernel.org
Subject: [PATCH v2 0/3] ext4: Prevent memory reclaim from re-entering the filesystem and deadlocking
Date: Fri, 27 Dec 2019 17:05:20 +0900 [thread overview]
Message-ID: <20191227080523.31808-1-naoto.kobayashi4c@gmail.com> (raw)
This series aims to prevent ext4_kvmalloc() from re-entering
the filesystem and deadlocking. Although __vmalloc() doesn't
support GFP_NOFS[1], all of the user of ext4_kvmalloc are using
GFP_NOFS (e.g. fs/ext4/resize.c::add_new_gdb), causing the memory
reclaim to re-enter the filesystem.
To fix this issue, use memalloc_nfs_save/restore() that get
__vmalloc() to drop __GFP_FS.
[1] linux-tree/Documentation/core-api/gfp-mask-fs-io.rst
Changes since v1:
- Add Patch 1 to delete ext4_kvzvalloc() that is not used anywhere.
- Add Patch 2 to rename ext4_kvmalloc() to ext4_kvmalloc_nofs() and
drop its flags argument since all the users of ext4_kvmalloc() are
using GFP_NOFS
Thanks,
Naoto Kobayashi (3):
ext4: Delete ext4_kvzvalloc()
ext4: Rename ext4_kvmalloc() to ext4_kvmalloc_nofs() and drop its
flags argument
ext4: Prevent ext4_kvmalloc_nofs() from re-entering the filesystem and
deadlocking
fs/ext4/ext4.h | 3 +--
fs/ext4/resize.c | 10 ++++------
fs/ext4/super.c | 21 +++++++--------------
fs/ext4/xattr.c | 2 +-
4 files changed, 13 insertions(+), 23 deletions(-)
--
2.16.6
next reply other threads:[~2019-12-27 8:05 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-27 8:05 Naoto Kobayashi [this message]
2019-12-27 8:05 ` [PATCH v2 1/3] ext4: Delete ext4_kvzvalloc() Naoto Kobayashi
2020-01-09 9:51 ` Jan Kara
2020-01-13 22:32 ` Theodore Y. Ts'o
2019-12-27 8:05 ` [PATCH v2 2/3] ext4: Rename ext4_kvmalloc() to ext4_kvmalloc_nofs() and drop its flags argument Naoto Kobayashi
2020-01-09 10:00 ` Jan Kara
2020-01-13 22:32 ` Theodore Y. Ts'o
2020-01-16 12:37 ` Jan Kara
2020-01-16 15:12 ` Theodore Y. Ts'o
2020-01-16 15:50 ` [PATCH] ext4: drop ext4_kvmalloc() Theodore Ts'o
2020-01-17 10:30 ` Jan Kara
2020-01-17 16:36 ` Theodore Y. Ts'o
2019-12-27 8:05 ` [PATCH v2 3/3] ext4: Prevent ext4_kvmalloc_nofs() from re-entering the filesystem and deadlocking Naoto Kobayashi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191227080523.31808-1-naoto.kobayashi4c@gmail.com \
--to=naoto.kobayashi4c@gmail.com \
--cc=adilger.kernel@dilger.ca \
--cc=linux-ext4@vger.kernel.org \
--cc=tytso@mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).