From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: [PATCH 1/4] eventfs: Use GFP_NOFS for allocation when eventfs_mutex is held
Date: Tue, 21 Nov 2023 18:10:04 -0500 [thread overview]
Message-ID: <20231121231112.373501894@goodmis.org> (raw)
In-Reply-To: 20231121231003.516999942@goodmis.org
From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
If memory reclaim happens, it can reclaim file system pages. The file
system pages from eventfs may take the eventfs_mutex on reclaim. This
means that allocation while holding the eventfs_mutex must not call into
filesystem reclaim. A lockdep splat uncovered this.
Fixes: 28e12c09f5aa0 ("eventfs: Save ownership and mode")
Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
fs/tracefs/event_inode.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
index 3eb6c622a74d..56d192f0ead8 100644
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -95,7 +95,7 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry,
if (!(dentry->d_inode->i_mode & S_IFDIR)) {
if (!ei->entry_attrs) {
ei->entry_attrs = kzalloc(sizeof(*ei->entry_attrs) * ei->nr_entries,
- GFP_KERNEL);
+ GFP_NOFS);
if (!ei->entry_attrs) {
ret = -ENOMEM;
goto out;
@@ -627,7 +627,7 @@ static int add_dentries(struct dentry ***dentries, struct dentry *d, int cnt)
{
struct dentry **tmp;
- tmp = krealloc(*dentries, sizeof(d) * (cnt + 2), GFP_KERNEL);
+ tmp = krealloc(*dentries, sizeof(d) * (cnt + 2), GFP_NOFS);
if (!tmp)
return -1;
tmp[cnt] = d;
--
2.42.0
next prev parent reply other threads:[~2023-11-21 23:11 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-21 23:10 [PATCH 0/4] eventfs: Some more minor fixes Steven Rostedt
2023-11-21 23:10 ` Steven Rostedt [this message]
2023-11-21 23:10 ` [PATCH 2/4] eventfs: Move taking of inode_lock into dcache_dir_open_wrapper() Steven Rostedt
2023-11-21 23:10 ` [PATCH 3/4] eventfs: Do not allow NULL parent to eventfs_start_creating() Steven Rostedt
2023-11-21 23:10 ` [PATCH 4/4] eventfs: Make sure that parent->d_inode is locked in creating files/dirs Steven Rostedt
2023-11-22 14:19 ` [PATCH 0/4] eventfs: Some more minor fixes Josef Bacik
2023-11-22 23:40 ` Steven Rostedt
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