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 | |
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>
-rw-r--r-- | libfdisk/docs/libfdisk-sections.txt | 3 | ||||
-rw-r--r-- | libfdisk/src/context.c | 104 | ||||
-rw-r--r-- | libfdisk/src/fdiskP.h | 5 | ||||
-rw-r--r-- | libfdisk/src/label.c | 6 | ||||
-rw-r--r-- | libfdisk/src/libfdisk.h.in | 4 | ||||
-rw-r--r-- | libfdisk/src/libfdisk.sym | 6 |
6 files changed, 113 insertions, 15 deletions
diff --git a/libfdisk/docs/libfdisk-sections.txt b/libfdisk/docs/libfdisk-sections.txt index f69c6671c..dd8df21ef 100644 --- a/libfdisk/docs/libfdisk-sections.txt +++ b/libfdisk/docs/libfdisk-sections.txt @@ -293,7 +293,9 @@ fdisk_deassign_device fdisk_enable_bootbits_protection fdisk_enable_details fdisk_enable_listonly +fdisk_enable_wipe fdisk_get_alignment_offset +fdisk_get_collision fdisk_get_devfd fdisk_get_devname fdisk_get_first_lba @@ -313,6 +315,7 @@ fdisk_get_unit fdisk_get_units_per_sector fdisk_has_label fdisk_has_protected_bootbits +fdisk_has_wipe fdisk_is_details fdisk_is_labeltype fdisk_is_listonly 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")); diff --git a/libfdisk/src/fdiskP.h b/libfdisk/src/fdiskP.h index 2961095c9..494eda989 100644 --- a/libfdisk/src/fdiskP.h +++ b/libfdisk/src/fdiskP.h @@ -355,8 +355,11 @@ struct fdisk_context { display_in_cyl_units : 1, /* for obscure labels */ display_details : 1, /* expert display mode */ protect_bootbits : 1, /* don't zeroize fll irst sector */ + wipe_device : 1, /* wipe device before write */ listonly : 1; /* list partition, nothing else */ + char *collision; /* name of already existing FS/PT */ + int sizeunit; /* SIZE fields, FDISK_SIZEUNIT_* */ /* alignment */ @@ -386,6 +389,8 @@ struct fdisk_context { struct fdisk_script *script; /* what we want to follow */ }; +int fdisk_wipe_collisions(struct fdisk_context *cxt); + /* partition.c */ int fdisk_partition_next_partno(struct fdisk_partition *pa, struct fdisk_context *cxt, diff --git a/libfdisk/src/label.c b/libfdisk/src/label.c index bcb02ba3a..f2580cf03 100644 --- a/libfdisk/src/label.c +++ b/libfdisk/src/label.c @@ -303,6 +303,12 @@ int fdisk_write_disklabel(struct fdisk_context *cxt) return -EINVAL; if (!cxt->label->op->write) return -ENOSYS; + + if (cxt->collision && cxt->wipe_device) { + int rc = fdisk_wipe_collisions(cxt); + if (rc) + return rc; + } return cxt->label->op->write(cxt); } diff --git a/libfdisk/src/libfdisk.h.in b/libfdisk/src/libfdisk.h.in index f99dee8cd..7bcacd6da 100644 --- a/libfdisk/src/libfdisk.h.in +++ b/libfdisk/src/libfdisk.h.in @@ -190,6 +190,10 @@ int fdisk_is_details(struct fdisk_context *cxt); int fdisk_enable_listonly(struct fdisk_context *cxt, int enable); int fdisk_is_listonly(struct fdisk_context *cxt); +int fdisk_enable_wipe(struct fdisk_context *cxt, int enable); +int fdisk_has_wipe(struct fdisk_context *cxt); +const char *fdisk_get_collision(struct fdisk_context *cxt); + int fdisk_set_unit(struct fdisk_context *cxt, const char *str); const char *fdisk_get_unit(struct fdisk_context *cxt, int n); int fdisk_use_cylinders(struct fdisk_context *cxt); diff --git a/libfdisk/src/libfdisk.sym b/libfdisk/src/libfdisk.sym index c4d0a2526..6a412bc20 100644 --- a/libfdisk/src/libfdisk.sym +++ b/libfdisk/src/libfdisk.sym @@ -253,3 +253,9 @@ FDISK_2.27 { fdisk_get_disklabel_item; fdisk_script_enable_json; } FDISK_2.26; + +FDISK_2.28 { + fdisk_enable_wipe; + fdisk_get_collision; + fdisk_has_wipe; +} FDISK_2.27; |