[for-linus,1/5] eventfs: Use GFP_NOFS for allocation when eventfs_mutex is held
Commit Message
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.
Link: https://lkml.kernel.org/r/20231121231112.373501894@goodmis.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
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>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
fs/tracefs/event_inode.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
@@ -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;