From: Michal Hocko <mhocko@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>,
<linux-fsdevel@vger.kernel.org>
Cc: <linux-mm@kvack.org>, Dave Chinner <david@fromorbit.com>,
djwong@kernel.org, "Theodore Ts'o" <tytso@mit.edu>,
Chris Mason <clm@fb.com>, David Sterba <dsterba@suse.cz>,
Jan Kara <jack@suse.cz>,
ceph-devel@vger.kernel.org, cluster-devel@redhat.com,
linux-nfs@vger.kernel.org, logfs@logfs.org,
linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org,
linux-btrfs@vger.kernel.org, linux-mtd@lists.infradead.org,
reiserfs-devel@vger.kernel.org,
linux-ntfs-dev@lists.sourceforge.net,
linux-f2fs-devel@lists.sourceforge.net,
linux-afs@lists.infradead.org,
LKML <linux-kernel@vger.kernel.org>,
Michal Hocko <mhocko@suse.com>
Subject: [PATCH 6/7] jbd2: mark the transaction context with the scope GFP_NOFS context
Date: Mon, 6 Mar 2017 14:14:07 +0100 [thread overview]
Message-ID: <20170306131408.9828-7-mhocko@kernel.org> (raw)
In-Reply-To: <20170306131408.9828-1-mhocko@kernel.org>
From: Michal Hocko <mhocko@suse.com>
now that we have memalloc_nofs_{save,restore} api we can mark the whole
transaction context as implicitly GFP_NOFS. All allocations will
automatically inherit GFP_NOFS this way. This means that we do not have
to mark any of those requests with GFP_NOFS and moreover all the
ext4_kv[mz]alloc(GFP_NOFS) are also safe now because even the hardcoded
GFP_KERNEL allocations deep inside the vmalloc will be NOFS now.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
fs/jbd2/transaction.c | 12 ++++++++++++
include/linux/jbd2.h | 2 ++
2 files changed, 14 insertions(+)
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 5e659ee08d6a..d8f09f34285f 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -29,6 +29,7 @@
#include <linux/backing-dev.h>
#include <linux/bug.h>
#include <linux/module.h>
+#include <linux/sched/mm.h>
#include <trace/events/jbd2.h>
@@ -388,6 +389,11 @@ static int start_this_handle(journal_t *journal, handle_t *handle,
rwsem_acquire_read(&journal->j_trans_commit_map, 0, 0, _THIS_IP_);
jbd2_journal_free_transaction(new_transaction);
+ /*
+ * Make sure that no allocations done while the transaction is
+ * open is going to recurse back to the fs layer.
+ */
+ handle->saved_alloc_context = memalloc_nofs_save();
return 0;
}
@@ -466,6 +472,7 @@ handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks,
trace_jbd2_handle_start(journal->j_fs_dev->bd_dev,
handle->h_transaction->t_tid, type,
line_no, nblocks);
+
return handle;
}
EXPORT_SYMBOL(jbd2__journal_start);
@@ -1760,6 +1767,11 @@ int jbd2_journal_stop(handle_t *handle)
if (handle->h_rsv_handle)
jbd2_journal_free_reserved(handle->h_rsv_handle);
free_and_exit:
+ /*
+ * scope of th GFP_NOFS context is over here and so we can
+ * restore the original alloc context.
+ */
+ memalloc_nofs_restore(handle->saved_alloc_context);
jbd2_free_handle(handle);
return err;
}
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index dfaa1f4dcb0c..606b6bce3a5b 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -491,6 +491,8 @@ struct jbd2_journal_handle
unsigned long h_start_jiffies;
unsigned int h_requested_credits;
+
+ unsigned int saved_alloc_context;
};
--
2.11.0
next prev parent reply other threads:[~2017-03-06 13:46 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-06 13:14 [PATCH 0/7 v5] scope GFP_NOFS api Michal Hocko
2017-03-06 13:14 ` [PATCH 1/7] lockdep: teach lockdep about memalloc_noio_save Michal Hocko
2017-03-06 13:14 ` [PATCH 2/7] lockdep: allow to disable reclaim lockup detection Michal Hocko
2017-03-06 13:14 ` [PATCH 3/7] xfs: abstract PF_FSTRANS to PF_MEMALLOC_NOFS Michal Hocko
2017-03-06 13:14 ` [PATCH 4/7] mm: introduce memalloc_nofs_{save,restore} API Michal Hocko
2017-03-06 21:22 ` Andrew Morton
2017-03-07 15:09 ` Michal Hocko
2017-03-09 11:42 ` David Sterba
2017-03-06 13:14 ` [PATCH 5/7] xfs: use memalloc_nofs_{save,restore} instead of memalloc_noio* Michal Hocko
2017-03-06 13:14 ` Michal Hocko [this message]
2017-03-06 13:14 ` [PATCH 7/7] jbd2: make the whole kjournald2 kthread NOFS safe Michal Hocko
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=20170306131408.9828-7-mhocko@kernel.org \
--to=mhocko@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=ceph-devel@vger.kernel.org \
--cc=clm@fb.com \
--cc=cluster-devel@redhat.com \
--cc=david@fromorbit.com \
--cc=djwong@kernel.org \
--cc=dsterba@suse.cz \
--cc=jack@suse.cz \
--cc=linux-afs@lists.infradead.org \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-f2fs-devel@lists.sourceforge.net \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-mtd@lists.infradead.org \
--cc=linux-nfs@vger.kernel.org \
--cc=linux-ntfs-dev@lists.sourceforge.net \
--cc=linux-xfs@vger.kernel.org \
--cc=logfs@logfs.org \
--cc=mhocko@suse.com \
--cc=reiserfs-devel@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).