From 51a3ae72d23d89d35a4a67059b39e870d66a2495 Mon Sep 17 00:00:00 2001 From: Dmitry Khasanov Date: Fri, 5 Jul 2013 17:44:53 +0700 Subject: [PATCH] Readd zpool_clear_label() from OpenSolaris This patch restores the zpool_clear_label() function from OpenSolaris. This was removed by commit d603ed6 because it wasn't clear we had a use for it in ZoL. However, this functionality is a prerequisite for adding the 'zpool labelclear' command from FreeBSD. As part of bringing this change in the zpool_clear_label() function was changed to use fstat64_blk(2) for compatibility with Linux. Signed-off-by: Brian Behlendorf Issue #1126 --- lib/libzfs/libzfs_import.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/lib/libzfs/libzfs_import.c b/lib/libzfs/libzfs_import.c index 791aaad..58b6043 100644 --- a/lib/libzfs/libzfs_import.c +++ b/lib/libzfs/libzfs_import.c @@ -900,6 +900,36 @@ zpool_read_label(int fd, nvlist_t **config) return (0); } +/* + * Given a file descriptor, clear (zero) the label information. This function + * is currently only used in the appliance stack as part of the ZFS sysevent + * module. + */ +int +zpool_clear_label(int fd) +{ + struct stat64 statbuf; + int l; + vdev_label_t *label; + uint64_t size; + + if (fstat64_blk(fd, &statbuf) == -1) + return (0); + size = P2ALIGN_TYPED(statbuf.st_size, sizeof (vdev_label_t), uint64_t); + + if ((label = calloc(sizeof (vdev_label_t), 1)) == NULL) + return (-1); + + for (l = 0; l < VDEV_LABELS; l++) { + if (pwrite64(fd, label, sizeof (vdev_label_t), + label_offset(size, l)) != sizeof (vdev_label_t)) + return (-1); + } + + free(label); + return (0); +} + #ifdef HAVE_LIBBLKID /* * Use libblkid to quickly search for zfs devices -- 1.8.3.1