Merge tag 'bcachefs-2024-03-13' of https://evilpiepirate.org/git/bcachefs

Pull bcachefs updates from Kent Overstreet:

 - Subvolume children btree; this is needed for providing a userspace
   interface for walking subvolumes, which will come later

 - Lots of improvements to directory structure checking

 - Improved journal pipelining, significantly improving performance on
   high iodepth write workloads

 - Discard path improvements: the discard path is more efficient, and no
   longer flushes the journal unnecessarily

 - Buffered write path can now avoid taking the inode lock

 - new mm helper: memalloc_flags_{save|restore}

 - mempool now does kvmalloc mempools

* tag 'bcachefs-2024-03-13' of https://evilpiepirate.org/git/bcachefs: (128 commits)
  bcachefs: time_stats: shrink time_stat_buffer for better alignment
  bcachefs: time_stats: split stats-with-quantiles into a separate structure
  bcachefs: mean_and_variance: put struct mean_and_variance_weighted on a diet
  bcachefs: time_stats: add larger units
  bcachefs: pull out time_stats.[ch]
  bcachefs: reconstruct_alloc cleanup
  bcachefs: fix bch_folio_sector padding
  bcachefs: Fix btree key cache coherency during replay
  bcachefs: Always flush write buffer in delete_dead_inodes()
  bcachefs: Fix order of gc_done passes
  bcachefs: fix deletion of indirect extents in btree_gc
  bcachefs: Prefer struct_size over open coded arithmetic
  bcachefs: Kill unused flags argument to btree_split()
  bcachefs: Check for writing superblocks with nonsense member seq fields
  bcachefs: fix bch2_journal_buf_to_text()
  lib/generic-radix-tree.c: Make nodes more reasonably sized
  bcachefs: copy_(to|from)_user_errcode()
  bcachefs: Split out bkey_types.h
  bcachefs: fix lost journal buf wakeup due to improved pipelining
  bcachefs: intercept mountoption value for bool type
  ...

1 files changed, 64 insertions, 10 deletions

diff --git a/fs/bcachefs/fs-common.c b/fs/bcachefs/fs-common.c
index 1c1ea0f0c692..624e6f963240 100644
--- a/fs/bcachefs/fs-common.c
+++ b/fs/bcachefs/fs-common.c
@@ -107,6 +107,7 @@ int bch2_create_trans(struct btree_trans *trans,
 		u32 new_subvol, dir_snapshot;
 
 		ret = bch2_subvolume_create(trans, new_inode->bi_inum,
+					    dir.subvol,
 					    snapshot_src.subvol,
 					    &new_subvol, &snapshot,
 					    (flags & BCH_CREATE_SNAPSHOT_RO) != 0);
@@ -242,7 +243,7 @@ int bch2_unlink_trans(struct btree_trans *trans,
 		      struct bch_inode_unpacked *dir_u,
 		      struct bch_inode_unpacked *inode_u,
 		      const struct qstr *name,
-		      bool deleting_snapshot)
+		      bool deleting_subvol)
 {
 	struct bch_fs *c = trans->c;
 	struct btree_iter dir_iter = { NULL };
@@ -260,8 +261,8 @@ int bch2_unlink_trans(struct btree_trans *trans,
 
 	dir_hash = bch2_hash_info_init(c, dir_u);
 
-	ret = __bch2_dirent_lookup_trans(trans, &dirent_iter, dir, &dir_hash,
-					 name, &inum, BTREE_ITER_INTENT);
+	ret = bch2_dirent_lookup_trans(trans, &dirent_iter, dir, &dir_hash,
+				       name, &inum, BTREE_ITER_INTENT);
 	if (ret)
 		goto err;
 
@@ -270,18 +271,25 @@ int bch2_unlink_trans(struct btree_trans *trans,
 	if (ret)
 		goto err;
 
-	if (!deleting_snapshot && S_ISDIR(inode_u->bi_mode)) {
+	if (!deleting_subvol && S_ISDIR(inode_u->bi_mode)) {
 		ret = bch2_empty_dir_trans(trans, inum);
 		if (ret)
 			goto err;
 	}
 
-	if (deleting_snapshot && !inode_u->bi_subvol) {
+	if (deleting_subvol && !inode_u->bi_subvol) {
 		ret = -BCH_ERR_ENOENT_not_subvol;
 		goto err;
 	}
 
-	if (deleting_snapshot || inode_u->bi_subvol) {
+	if (inode_u->bi_subvol) {
+		/* Recursive subvolume destroy not allowed (yet?) */
+		ret = bch2_subvol_has_children(trans, inode_u->bi_subvol);
+		if (ret)
+			goto err;
+	}
+
+	if (deleting_subvol || inode_u->bi_subvol) {
 		ret = bch2_subvolume_unlink(trans, inode_u->bi_subvol);
 		if (ret)
 			goto err;
@@ -349,6 +357,22 @@ bool bch2_reinherit_attrs(struct bch_inode_unpacked *dst_u,
 	return ret;
 }
 
+static int subvol_update_parent(struct btree_trans *trans, u32 subvol, u32 new_parent)
+{
+	struct btree_iter iter;
+	struct bkey_i_subvolume *s =
+		bch2_bkey_get_mut_typed(trans, &iter,
+			BTREE_ID_subvolumes, POS(0, subvol),
+			BTREE_ITER_CACHED, subvolume);
+	int ret = PTR_ERR_OR_ZERO(s);
+	if (ret)
+		return ret;
+
+	s->v.fs_path_parent = cpu_to_le32(new_parent);
+	bch2_trans_iter_exit(trans, &iter);
+	return 0;
+}
+
 int bch2_rename_trans(struct btree_trans *trans,
 		      subvol_inum src_dir, struct bch_inode_unpacked *src_dir_u,
 		      subvol_inum dst_dir, struct bch_inode_unpacked *dst_dir_u,
@@ -410,6 +434,36 @@ int bch2_rename_trans(struct btree_trans *trans,
 			goto err;
 	}
 
+	if (src_inode_u->bi_subvol &&
+	    dst_dir.subvol != src_inode_u->bi_parent_subvol) {
+		ret = subvol_update_parent(trans, src_inode_u->bi_subvol, dst_dir.subvol);
+		if (ret)
+			goto err;
+	}
+
+	if (mode == BCH_RENAME_EXCHANGE &&
+	    dst_inode_u->bi_subvol &&
+	    src_dir.subvol != dst_inode_u->bi_parent_subvol) {
+		ret = subvol_update_parent(trans, dst_inode_u->bi_subvol, src_dir.subvol);
+		if (ret)
+			goto err;
+	}
+
+	/* Can't move across subvolumes, unless it's a subvolume root: */
+	if (src_dir.subvol != dst_dir.subvol &&
+	    (!src_inode_u->bi_subvol ||
+	     (dst_inum.inum && !dst_inode_u->bi_subvol))) {
+		ret = -EXDEV;
+		goto err;
+	}
+
+	if (src_inode_u->bi_parent_subvol)
+		src_inode_u->bi_parent_subvol = dst_dir.subvol;
+
+	if ((mode == BCH_RENAME_EXCHANGE) &&
+	    dst_inode_u->bi_parent_subvol)
+		dst_inode_u->bi_parent_subvol = src_dir.subvol;
+
 	src_inode_u->bi_dir		= dst_dir_u->bi_inum;
 	src_inode_u->bi_dir_offset	= dst_offset;
 
@@ -432,10 +486,10 @@ int bch2_rename_trans(struct btree_trans *trans,
 			goto err;
 		}
 
-		if (S_ISDIR(dst_inode_u->bi_mode) &&
-		    bch2_empty_dir_trans(trans, dst_inum)) {
-			ret = -ENOTEMPTY;
-			goto err;
+		if (S_ISDIR(dst_inode_u->bi_mode)) {
+			ret = bch2_empty_dir_trans(trans, dst_inum);
+			if (ret)
+				goto err;
 		}
 	}