Merge tag 'bcachefs-2024-01-21' of https://evilpiepirate.org/git/bcachefs

Pull more bcachefs updates from Kent Overstreet:
 "Some fixes, Some refactoring, some minor features:

   - Assorted prep work for disk space accounting rewrite

   - BTREE_TRIGGER_ATOMIC: after combining our trigger callbacks, this
     makes our trigger context more explicit

   - A few fixes to avoid excessive transaction restarts on
     multithreaded workloads: fstests (in addition to ktest tests) are
     now checking slowpath counters, and that's shaking out a few bugs

   - Assorted tracepoint improvements

   - Starting to break up bcachefs_format.h and move on disk types so
     they're with the code they belong to; this will make room to start
     documenting the on disk format better.

   - A few minor fixes"

* tag 'bcachefs-2024-01-21' of https://evilpiepirate.org/git/bcachefs: (46 commits)
  bcachefs: Improve inode_to_text()
  bcachefs: logged_ops_format.h
  bcachefs: reflink_format.h
  bcachefs; extents_format.h
  bcachefs: ec_format.h
  bcachefs: subvolume_format.h
  bcachefs: snapshot_format.h
  bcachefs: alloc_background_format.h
  bcachefs: xattr_format.h
  bcachefs: dirent_format.h
  bcachefs: inode_format.h
  bcachefs; quota_format.h
  bcachefs: sb-counters_format.h
  bcachefs: counters.c -> sb-counters.c
  bcachefs: comment bch_subvolume
  bcachefs: bch_snapshot::btime
  bcachefs: add missing __GFP_NOWARN
  bcachefs: opts->compression can now also be applied in the background
  bcachefs: Prep work for variable size btree node buffers
  bcachefs: grab s_umount only if snapshotting
  ...

1 files changed, 5 insertions, 6 deletions

diff --git a/fs/bcachefs/fs-ioctl.c b/fs/bcachefs/fs-ioctl.c
index 1cbc5807bc80..3a4c24c28e7f 100644
--- a/fs/bcachefs/fs-ioctl.c
+++ b/fs/bcachefs/fs-ioctl.c
@@ -337,11 +337,12 @@ static long __bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
 	if (arg.flags & BCH_SUBVOL_SNAPSHOT_RO)
 		create_flags |= BCH_CREATE_SNAPSHOT_RO;
 
-	/* why do we need this lock? */
-	down_read(&c->vfs_sb->s_umount);
-
-	if (arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE)
+	if (arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE) {
+		/* sync_inodes_sb enforce s_umount is locked */
+		down_read(&c->vfs_sb->s_umount);
 		sync_inodes_sb(c->vfs_sb);
+		up_read(&c->vfs_sb->s_umount);
+	}
 retry:
 	if (arg.src_ptr) {
 		error = user_path_at(arg.dirfd,
@@ -425,8 +426,6 @@ err2:
 		goto retry;
 	}
 err1:
-	up_read(&c->vfs_sb->s_umount);
-
 	return error;
 }