From 8d5f44d3b16cac690f64558161998b75c7066b68 Mon Sep 17 00:00:00 2001 From: Gabriel de Perthuis Date: Sun, 27 Oct 2024 14:37:45 +0000 Subject: [PATCH] Check for a sufficiently recent libblkid before formatting This can prevent data loss as libblkid < 2.40.1 can fail to recognize existing bcachefs filesystems. Reported on #bcache. Signed-off-by: Gabriel de Perthuis --- c_src/tools-util.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/c_src/tools-util.c b/c_src/tools-util.c index 43c9b789..3a76a02e 100644 --- a/c_src/tools-util.c +++ b/c_src/tools-util.c @@ -185,6 +185,24 @@ unsigned get_blocksize(int fd) /* Open a block device, do magic blkid stuff to probe for existing filesystems: */ int open_for_format(struct dev_opts *dev, bool force) { + int blkid_version_code = blkid_get_library_version(NULL, NULL); + if (blkid_version_code < 2401) { + if (force) { + fprintf( + stderr, + "Continuing with out of date libblkid %s because --force was passed.\n", + BLKID_VERSION); + } else { + // Reference for picking 2.40.1: + // https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.40/v2.40.1-ReleaseNotes + // https://github.com/util-linux/util-linux/issues/3103 + die( + "Refusing to format when using libblkid %s\n" + "libblkid >= 2.40.1 is required to check for existing filesystems\n" + "Earlier versions may not recognize some bcachefs filesystems.\n", BLKID_VERSION); + } + } + blkid_probe pr; const char *fs_type = NULL, *fs_label = NULL; size_t fs_type_len, fs_label_len;