Commit 3c72d3ee authored Mar 28, 2025 by Kent Overstreet

bcachefs: Fix WARN() in bch2_bkey_pick_read_device()



syzbot discovered that this one is possible: we have pointers, but none
of them are to valid devices.

Reported-by:  <syzbot+336a6e6a2dbb7d4dba9a@syzkaller.appspotmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

parent af3d4c27

fs/bcachefs/errcode.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -310,6 +310,7 @@
		x(BCH_ERR_data_write, data_write_misaligned) \
		x(BCH_ERR_decompress, data_read) \
		x(BCH_ERR_data_read, no_device_to_read_from) \
		x(BCH_ERR_data_read, no_devices_valid) \
		x(BCH_ERR_data_read, data_read_io_err) \
		x(BCH_ERR_data_read, data_read_csum_err) \
		x(BCH_ERR_data_read, data_read_retry) \

fs/bcachefs/extents.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -227,8 +227,11 @@ int bch2_bkey_pick_read_device(struct bch_fs *c, struct bkey_s_c k,
		if (have_io_errors)
		return -BCH_ERR_data_read_io_err;

		WARN_ONCE(1, "unhandled error case in %s\n", __func__);
		return -EINVAL;
		/*
		* If we get here, we have pointers (bkey_ptrs_validate() ensures that),
		* but they don't point to valid devices:
		*/
		return -BCH_ERR_no_devices_valid;
		}

		/* KEY_TYPE_btree_ptr: */