Merge tag 'fs_for_v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull misc fs updates from Jan Kara:
 "The new quotactl_fd() syscall (remake of quotactl_path() syscall that
  got introduced & disabled in 5.13 cycle), and couple of udf, reiserfs,
  isofs, and writeback fixes and cleanups"

* tag 'fs_for_v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  writeback: fix obtain a reference to a freeing memcg css
  quota: remove unnecessary oom message
  isofs: remove redundant continue statement
  quota: Wire up quotactl_fd syscall
  quota: Change quotactl_path() systcall to an fd-based one
  reiserfs: Remove unneed check in reiserfs_write_full_page()
  udf: Fix NULL pointer dereference in udf_symlink function
  reiserfs: add check for invalid 1st journal block

1 files changed, 7 insertions, 2 deletions

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 8c7e9e51a398..06d04a74ab6c 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -567,9 +567,14 @@ static void inode_switch_wbs(struct inode *inode, int new_wb_id)
 	/* find and pin the new wb */
 	rcu_read_lock();
 	memcg_css = css_from_id(new_wb_id, &memory_cgrp_subsys);
-	if (memcg_css)
-		isw->new_wb = wb_get_create(bdi, memcg_css, GFP_ATOMIC);
+	if (memcg_css && !css_tryget(memcg_css))
+		memcg_css = NULL;
 	rcu_read_unlock();
+	if (!memcg_css)
+		goto out_free;
+
+	isw->new_wb = wb_get_create(bdi, memcg_css, GFP_ATOMIC);
+	css_put(memcg_css);
 	if (!isw->new_wb)
 		goto out_free;