diff options
author | Karel Zak | 2016-02-18 12:42:06 +0100 |
---|---|---|
committer | Karel Zak | 2016-02-18 12:58:12 +0100 |
commit | 6cbb7371b349c63c6f3ba59a14acb0afc8ca3bde (patch) | |
tree | 5aaf4727f1285dc7eec602a51c7144b8c160abaf /libfdisk/src/context.c | |
parent | unshare: fix busyloop and reduce racing probability (diff) | |
download | kernel-qcow2-util-linux-6cbb7371b349c63c6f3ba59a14acb0afc8ca3bde.tar.gz kernel-qcow2-util-linux-6cbb7371b349c63c6f3ba59a14acb0afc8ca3bde.tar.xz kernel-qcow2-util-linux-6cbb7371b349c63c6f3ba59a14acb0afc8ca3bde.zip |
libfdisk: add API to control signatures wiping
Now libfdisk warns if another filesystem/RAID/PT signature is detected
on the device. It seems better and user-friendly to make it possible to
wipe the signatures when we write a new disk label to the device.
This patch adds to the library API
fdisk_enable_wipe()
fdisk_has_wipe()
fdisk_get_collision()
to control this new feature. The device modification is done by
libblkid (the same we use in some mkfs-like utils).
Signed-off-by: Karel Zak <kzak@redhat.com>
Diffstat (limited to 'libfdisk/src/context.c')
-rw-r--r-- | libfdisk/src/context.c | 104 |
1 files changed, 89 insertions, 15 deletions
diff --git a/libfdisk/src/context.c b/libfdisk/src/context.c index 1f6118cd0..73d72ecb8 100644 --- a/libfdisk/src/context.c +++ b/libfdisk/src/context.c @@ -335,6 +335,50 @@ int fdisk_enable_bootbits_protection(struct fdisk_context *cxt, int enable) } /** + * fdisk_enable_wipe + * @cxt: fdisk context + * @enable: 1 or 0 + * + * The library removes all filesystem/RAID signatures before write PT. This is + * no-op if any collision has not been detected by fdisk_assign_device(). See + * fdisk_has_collision(). The default is not wipe a device. + * + * Returns: 0 on success, < 0 on error. + */ +int fdisk_enable_wipe(struct fdisk_context *cxt, int enable) +{ + if (!cxt) + return -EINVAL; + cxt->wipe_device = enable ? 1 : 0; + return 0; +} + +/** + * fdisk_has_wipe + * @cxt: fdisk context + * + * Returns the current wipe setting. See fdisk_enable_wipe(). + * + * Returns: 0 on success, < 0 on error. + */ +int fdisk_has_wipe(struct fdisk_context *cxt) +{ + return cxt && cxt->wipe_device; +} + + +/** + * fdisk_get_collision + * @cxt: fdisk context + * + * Returns: name of the filesystem or RAID detected on the device or NULL. + */ +const char *fdisk_get_collision(struct fdisk_context *cxt) +{ + return cxt->collision; +} + +/** * fdisk_get_npartitions: * @cxt: context * @@ -427,6 +471,9 @@ static void reset_context(struct fdisk_context *cxt) free(cxt->dev_path); cxt->dev_path = NULL; + free(cxt->collision); + cxt->collision = NULL; + cxt->dev_fd = -1; cxt->firstsector = NULL; cxt->firstsector_bufsz = 0; @@ -445,18 +492,15 @@ static void reset_context(struct fdisk_context *cxt) * * Returns: 0 if nothing found, < 0 on error, 1 if found a signature */ -static int warn_wipe(struct fdisk_context *cxt) +static int check_collisions(struct fdisk_context *cxt) { #ifdef HAVE_LIBBLKID - blkid_probe pr; -#endif int rc = 0; + blkid_probe pr; assert(cxt); + assert(cxt->dev_fd >= 0); - if (fdisk_has_label(cxt) || cxt->dev_fd < 0) - return -EINVAL; -#ifdef HAVE_LIBBLKID DBG(CXT, ul_debugobj(cxt, "wipe check: initialize libblkid prober")); pr = blkid_new_probe(); @@ -478,18 +522,48 @@ static int warn_wipe(struct fdisk_context *cxt) if (blkid_probe_lookup_value(pr, "TYPE", &name, 0) == 0 || blkid_probe_lookup_value(pr, "PTTYPE", &name, 0) == 0) { - fdisk_warnx(cxt, _( - "%s: device contains a valid '%s' signature; it is " - "strongly recommended to wipe the device with " - "wipefs(8) if this is unexpected, in order to " - "avoid possible collisions"), cxt->dev_path, name); - rc = 1; + cxt->collision = strdup(name); + if (!cxt->collision) + rc = -ENOMEM; } } blkid_free_probe(pr); -#endif return rc; +#elif + return 0; +#endif +} + +int fdisk_wipe_collisions(struct fdisk_context *cxt) +{ +#ifdef HAVE_LIBBLKID + blkid_probe pr; + int rc; + + assert(cxt); + assert(cxt->dev_fd >= 0); + + DBG(CXT, ul_debugobj(cxt, "wipe: initialize libblkid prober")); + + pr = blkid_new_probe(); + if (!pr) + return -ENOMEM; + rc = blkid_probe_set_device(pr, cxt->dev_fd, 0, 0); + if (rc) + return rc; + + blkid_probe_enable_superblocks(pr, 1); + blkid_probe_set_superblocks_flags(pr, BLKID_SUBLKS_MAGIC); + blkid_probe_enable_partitions(pr, 1); + blkid_probe_set_partitions_flags(pr, BLKID_PARTS_MAGIC); + + while (blkid_do_probe(pr) == 0) + blkid_do_wipe(pr, FALSE); + + blkid_free_probe(pr); +#endif + return 0; } /** @@ -564,8 +638,8 @@ int fdisk_assign_device(struct fdisk_context *cxt, /* warn about obsolete stuff on the device if we aren't in * list-only mode and there is not PT yet */ - if (!fdisk_is_listonly(cxt) && !fdisk_has_label(cxt)) - warn_wipe(cxt); + if (!fdisk_is_listonly(cxt) && !fdisk_has_label(cxt) && check_collisions(cxt) < 0) + goto fail; DBG(CXT, ul_debugobj(cxt, "initialized for %s [%s]", fname, readonly ? "READ-ONLY" : "READ-WRITE")); |