bcachefs: Get ref on c->writes in move.c

There's no point reading an extent in order to move it if the write is
going to fail because we're shutting down. This patch changes the move
path so that moving_io now owns a ref on c->writes - as a bonus,
rebalance and copygc will now notice that we're shutting down and exit
quicker.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

diff --git a/fs/bcachefs/io.c b/fs/bcachefs/io.c
index c22ce1eb6b8b5d57d19fd602652e158fdb625cb6..f137a8e90f072983df98348ce00daaa03d08ae54 100644 (file)
--- a/fs/bcachefs/io.c
+++ b/fs/bcachefs/io.c
@@ -1227,12 +1227,6 @@ again:
                                        BKEY_EXTENT_U64s_MAX))
                        break;
 
-               if ((op->flags & BCH_WRITE_FROM_INTERNAL) &&
-                   percpu_ref_is_dying(&c->writes)) {
-                       ret = -EROFS;
-                       goto err;
-               }
-
                /*
                 * The copygc thread is now global, which means it's no longer
                 * freeing up space on specific disks, which means that

diff --git a/fs/bcachefs/move.c b/fs/bcachefs/move.c
index a19c3117f9febc33c656d3132b89f42e8a647c17..eae93c65e1c712e5c51dbd0d23ec0c65ea83eb03 100644 (file)
--- a/fs/bcachefs/move.c
+++ b/fs/bcachefs/move.c
@@ -52,9 +52,11 @@ struct moving_io {
 static void move_free(struct moving_io *io)
 {
        struct moving_context *ctxt = io->write.ctxt;
+       struct bch_fs *c = ctxt->c;
 
        bch2_data_update_exit(&io->write);
        wake_up(&ctxt->wait);
+       percpu_ref_put(&c->writes);
        kfree(io);
 }
 
@@ -192,6 +194,9 @@ static int bch2_move_extent(struct btree_trans *trans,
        unsigned sectors = k.k->size, pages;
        int ret = -ENOMEM;
 
+       if (!percpu_ref_tryget_live(&c->writes))
+               return -EROFS;
+
        /* write path might have to decompress data: */
        bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
                sectors = max_t(unsigned, sectors, p.crc.uncompressed_size);
@@ -258,6 +263,7 @@ err_free_pages:
 err_free:
        kfree(io);
 err:
+       percpu_ref_put(&c->writes);
        trace_move_alloc_mem_fail(k.k);
        return ret;
 }