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authorPeter Jones <pjones@redhat.com>2011-01-13 14:59:47 -0500
committerAlasdair G Kergon <agk@redhat.com>2011-01-13 14:59:47 -0500
commit84c89557a302e18414a011cc52b1abd034860743 (patch)
tree6b6ca2c400b7a6e09da46b051c177317316f0b93 /drivers/md
parentd9bf0b508ddfe19883b982b29a03c02ccbf53806 (diff)
dm ioctl: allow rename to fill empty uuid
Allow the uuid of a mapped device to be set after device creation. Previously the uuid (which is optional) could only be set by DM_DEV_CREATE. If no uuid was supplied it could not be set later. Sometimes it's necessary to create the device before the uuid is known, and in such cases the uuid must be filled in after the creation. This patch extends DM_DEV_RENAME to accept a uuid accompanied by a new flag DM_UUID_FLAG. This can only be done once and if no uuid was previously supplied. It cannot be used to change an existing uuid. DM_VERSION_MINOR is also bumped to 19 to indicate this interface extension is available. Signed-off-by: Peter Jones <pjones@redhat.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-ioctl.c103
1 files changed, 78 insertions, 25 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 4b54618b4159..f3481d922206 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -295,19 +295,55 @@ retry:
295 DMWARN("remove_all left %d open device(s)", dev_skipped); 295 DMWARN("remove_all left %d open device(s)", dev_skipped);
296} 296}
297 297
298/*
299 * Set the uuid of a hash_cell that isn't already set.
300 */
301static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
302{
303 mutex_lock(&dm_hash_cells_mutex);
304 hc->uuid = new_uuid;
305 mutex_unlock(&dm_hash_cells_mutex);
306
307 list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
308}
309
310/*
311 * Changes the name of a hash_cell and returns the old name for
312 * the caller to free.
313 */
314static char *__change_cell_name(struct hash_cell *hc, char *new_name)
315{
316 char *old_name;
317
318 /*
319 * Rename and move the name cell.
320 */
321 list_del(&hc->name_list);
322 old_name = hc->name;
323
324 mutex_lock(&dm_hash_cells_mutex);
325 hc->name = new_name;
326 mutex_unlock(&dm_hash_cells_mutex);
327
328 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
329
330 return old_name;
331}
332
298static struct mapped_device *dm_hash_rename(struct dm_ioctl *param, 333static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
299 const char *new) 334 const char *new)
300{ 335{
301 char *new_name, *old_name; 336 char *new_data, *old_name = NULL;
302 struct hash_cell *hc; 337 struct hash_cell *hc;
303 struct dm_table *table; 338 struct dm_table *table;
304 struct mapped_device *md; 339 struct mapped_device *md;
340 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
305 341
306 /* 342 /*
307 * duplicate new. 343 * duplicate new.
308 */ 344 */
309 new_name = kstrdup(new, GFP_KERNEL); 345 new_data = kstrdup(new, GFP_KERNEL);
310 if (!new_name) 346 if (!new_data)
311 return ERR_PTR(-ENOMEM); 347 return ERR_PTR(-ENOMEM);
312 348
313 down_write(&_hash_lock); 349 down_write(&_hash_lock);
@@ -315,13 +351,19 @@ static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
315 /* 351 /*
316 * Is new free ? 352 * Is new free ?
317 */ 353 */
318 hc = __get_name_cell(new); 354 if (change_uuid)
355 hc = __get_uuid_cell(new);
356 else
357 hc = __get_name_cell(new);
358
319 if (hc) { 359 if (hc) {
320 DMWARN("asked to rename to an already-existing name %s -> %s", 360 DMWARN("Unable to change %s on mapped device %s to one that "
361 "already exists: %s",
362 change_uuid ? "uuid" : "name",
321 param->name, new); 363 param->name, new);
322 dm_put(hc->md); 364 dm_put(hc->md);
323 up_write(&_hash_lock); 365 up_write(&_hash_lock);
324 kfree(new_name); 366 kfree(new_data);
325 return ERR_PTR(-EBUSY); 367 return ERR_PTR(-EBUSY);
326 } 368 }
327 369
@@ -330,22 +372,30 @@ static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
330 */ 372 */
331 hc = __get_name_cell(param->name); 373 hc = __get_name_cell(param->name);
332 if (!hc) { 374 if (!hc) {
333 DMWARN("asked to rename a non-existent device %s -> %s", 375 DMWARN("Unable to rename non-existent device, %s to %s%s",
334 param->name, new); 376 param->name, change_uuid ? "uuid " : "", new);
335 up_write(&_hash_lock); 377 up_write(&_hash_lock);
336 kfree(new_name); 378 kfree(new_data);
337 return ERR_PTR(-ENXIO); 379 return ERR_PTR(-ENXIO);
338 } 380 }
339 381
340 /* 382 /*
341 * rename and move the name cell. 383 * Does this device already have a uuid?
342 */ 384 */
343 list_del(&hc->name_list); 385 if (change_uuid && hc->uuid) {
344 old_name = hc->name; 386 DMWARN("Unable to change uuid of mapped device %s to %s "
345 mutex_lock(&dm_hash_cells_mutex); 387 "because uuid is already set to %s",
346 hc->name = new_name; 388 param->name, new, hc->uuid);
347 mutex_unlock(&dm_hash_cells_mutex); 389 dm_put(hc->md);
348 list_add(&hc->name_list, _name_buckets + hash_str(new_name)); 390 up_write(&_hash_lock);
391 kfree(new_data);
392 return ERR_PTR(-EINVAL);
393 }
394
395 if (change_uuid)
396 __set_cell_uuid(hc, new_data);
397 else
398 old_name = __change_cell_name(hc, new_data);
349 399
350 /* 400 /*
351 * Wake up any dm event waiters. 401 * Wake up any dm event waiters.
@@ -774,21 +824,24 @@ static int invalid_str(char *str, void *end)
774static int dev_rename(struct dm_ioctl *param, size_t param_size) 824static int dev_rename(struct dm_ioctl *param, size_t param_size)
775{ 825{
776 int r; 826 int r;
777 char *new_name = (char *) param + param->data_start; 827 char *new_data = (char *) param + param->data_start;
778 struct mapped_device *md; 828 struct mapped_device *md;
829 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
779 830
780 if (new_name < param->data || 831 if (new_data < param->data ||
781 invalid_str(new_name, (void *) param + param_size) || 832 invalid_str(new_data, (void *) param + param_size) ||
782 strlen(new_name) > DM_NAME_LEN - 1) { 833 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
783 DMWARN("Invalid new logical volume name supplied."); 834 DMWARN("Invalid new mapped device name or uuid string supplied.");
784 return -EINVAL; 835 return -EINVAL;
785 } 836 }
786 837
787 r = check_name(new_name); 838 if (!change_uuid) {
788 if (r) 839 r = check_name(new_data);
789 return r; 840 if (r)
841 return r;
842 }
790 843
791 md = dm_hash_rename(param, new_name); 844 md = dm_hash_rename(param, new_data);
792 if (IS_ERR(md)) 845 if (IS_ERR(md))
793 return PTR_ERR(md); 846 return PTR_ERR(md);
794 847