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path: root/drivers/md/dm-ioctl.c
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Diffstat (limited to 'drivers/md/dm-ioctl.c')
-rw-r--r--drivers/md/dm-ioctl.c123
1 files changed, 92 insertions, 31 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index a67942931582..1d669322b27c 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -56,6 +56,11 @@ static void dm_hash_remove_all(int keep_open_devices);
*/
static DECLARE_RWSEM(_hash_lock);
+/*
+ * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
+ */
+static DEFINE_MUTEX(dm_hash_cells_mutex);
+
static void init_buckets(struct list_head *buckets)
{
unsigned int i;
@@ -206,7 +211,9 @@ static int dm_hash_insert(const char *name, const char *uuid, struct mapped_devi
list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
}
dm_get(md);
+ mutex_lock(&dm_hash_cells_mutex);
dm_set_mdptr(md, cell);
+ mutex_unlock(&dm_hash_cells_mutex);
up_write(&_hash_lock);
return 0;
@@ -224,9 +231,11 @@ static void __hash_remove(struct hash_cell *hc)
/* remove from the dev hash */
list_del(&hc->uuid_list);
list_del(&hc->name_list);
+ mutex_lock(&dm_hash_cells_mutex);
dm_set_mdptr(hc->md, NULL);
+ mutex_unlock(&dm_hash_cells_mutex);
- table = dm_get_table(hc->md);
+ table = dm_get_live_table(hc->md);
if (table) {
dm_table_event(table);
dm_table_put(table);
@@ -321,13 +330,15 @@ static int dm_hash_rename(uint32_t cookie, const char *old, const char *new)
*/
list_del(&hc->name_list);
old_name = hc->name;
+ mutex_lock(&dm_hash_cells_mutex);
hc->name = new_name;
+ mutex_unlock(&dm_hash_cells_mutex);
list_add(&hc->name_list, _name_buckets + hash_str(new_name));
/*
* Wake up any dm event waiters.
*/
- table = dm_get_table(hc->md);
+ table = dm_get_live_table(hc->md);
if (table) {
dm_table_event(table);
dm_table_put(table);
@@ -512,8 +523,6 @@ static int list_versions(struct dm_ioctl *param, size_t param_size)
return 0;
}
-
-
static int check_name(const char *name)
{
if (strchr(name, '/')) {
@@ -525,6 +534,40 @@ static int check_name(const char *name)
}
/*
+ * On successful return, the caller must not attempt to acquire
+ * _hash_lock without first calling dm_table_put, because dm_table_destroy
+ * waits for this dm_table_put and could be called under this lock.
+ */
+static struct dm_table *dm_get_inactive_table(struct mapped_device *md)
+{
+ struct hash_cell *hc;
+ struct dm_table *table = NULL;
+
+ down_read(&_hash_lock);
+ hc = dm_get_mdptr(md);
+ if (!hc || hc->md != md) {
+ DMWARN("device has been removed from the dev hash table.");
+ goto out;
+ }
+
+ table = hc->new_map;
+ if (table)
+ dm_table_get(table);
+
+out:
+ up_read(&_hash_lock);
+
+ return table;
+}
+
+static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
+ struct dm_ioctl *param)
+{
+ return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
+ dm_get_inactive_table(md) : dm_get_live_table(md);
+}
+
+/*
* Fills in a dm_ioctl structure, ready for sending back to
* userland.
*/
@@ -536,7 +579,7 @@ static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
DM_ACTIVE_PRESENT_FLAG);
- if (dm_suspended(md))
+ if (dm_suspended_md(md))
param->flags |= DM_SUSPEND_FLAG;
param->dev = huge_encode_dev(disk_devt(disk));
@@ -548,18 +591,30 @@ static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
*/
param->open_count = dm_open_count(md);
- if (get_disk_ro(disk))
- param->flags |= DM_READONLY_FLAG;
-
param->event_nr = dm_get_event_nr(md);
+ param->target_count = 0;
- table = dm_get_table(md);
+ table = dm_get_live_table(md);
if (table) {
- param->flags |= DM_ACTIVE_PRESENT_FLAG;
- param->target_count = dm_table_get_num_targets(table);
+ if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
+ if (get_disk_ro(disk))
+ param->flags |= DM_READONLY_FLAG;
+ param->target_count = dm_table_get_num_targets(table);
+ }
dm_table_put(table);
- } else
- param->target_count = 0;
+
+ param->flags |= DM_ACTIVE_PRESENT_FLAG;
+ }
+
+ if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
+ table = dm_get_inactive_table(md);
+ if (table) {
+ if (!(dm_table_get_mode(table) & FMODE_WRITE))
+ param->flags |= DM_READONLY_FLAG;
+ param->target_count = dm_table_get_num_targets(table);
+ dm_table_put(table);
+ }
+ }
return 0;
}
@@ -634,9 +689,9 @@ static struct mapped_device *find_device(struct dm_ioctl *param)
* Sneakily write in both the name and the uuid
* while we have the cell.
*/
- strncpy(param->name, hc->name, sizeof(param->name));
+ strlcpy(param->name, hc->name, sizeof(param->name));
if (hc->uuid)
- strncpy(param->uuid, hc->uuid, sizeof(param->uuid)-1);
+ strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
else
param->uuid[0] = '\0';
@@ -784,7 +839,7 @@ static int do_suspend(struct dm_ioctl *param)
if (param->flags & DM_NOFLUSH_FLAG)
suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
- if (!dm_suspended(md))
+ if (!dm_suspended_md(md))
r = dm_suspend(md, suspend_flags);
if (!r)
@@ -800,7 +855,7 @@ static int do_resume(struct dm_ioctl *param)
unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
struct hash_cell *hc;
struct mapped_device *md;
- struct dm_table *new_map;
+ struct dm_table *new_map, *old_map = NULL;
down_write(&_hash_lock);
@@ -826,14 +881,14 @@ static int do_resume(struct dm_ioctl *param)
suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
if (param->flags & DM_NOFLUSH_FLAG)
suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
- if (!dm_suspended(md))
+ if (!dm_suspended_md(md))
dm_suspend(md, suspend_flags);
- r = dm_swap_table(md, new_map);
- if (r) {
+ old_map = dm_swap_table(md, new_map);
+ if (IS_ERR(old_map)) {
dm_table_destroy(new_map);
dm_put(md);
- return r;
+ return PTR_ERR(old_map);
}
if (dm_table_get_mode(new_map) & FMODE_WRITE)
@@ -842,9 +897,11 @@ static int do_resume(struct dm_ioctl *param)
set_disk_ro(dm_disk(md), 1);
}
- if (dm_suspended(md))
+ if (dm_suspended_md(md))
r = dm_resume(md);
+ if (old_map)
+ dm_table_destroy(old_map);
if (!r) {
dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr);
@@ -982,7 +1039,7 @@ static int dev_wait(struct dm_ioctl *param, size_t param_size)
if (r)
goto out;
- table = dm_get_table(md);
+ table = dm_get_live_or_inactive_table(md, param);
if (table) {
retrieve_status(table, param, param_size);
dm_table_put(table);
@@ -1215,7 +1272,7 @@ static int table_deps(struct dm_ioctl *param, size_t param_size)
if (r)
goto out;
- table = dm_get_table(md);
+ table = dm_get_live_or_inactive_table(md, param);
if (table) {
retrieve_deps(table, param, param_size);
dm_table_put(table);
@@ -1244,13 +1301,13 @@ static int table_status(struct dm_ioctl *param, size_t param_size)
if (r)
goto out;
- table = dm_get_table(md);
+ table = dm_get_live_or_inactive_table(md, param);
if (table) {
retrieve_status(table, param, param_size);
dm_table_put(table);
}
- out:
+out:
dm_put(md);
return r;
}
@@ -1288,10 +1345,15 @@ static int target_message(struct dm_ioctl *param, size_t param_size)
goto out;
}
- table = dm_get_table(md);
+ table = dm_get_live_table(md);
if (!table)
goto out_argv;
+ if (dm_deleting_md(md)) {
+ r = -ENXIO;
+ goto out_table;
+ }
+
ti = dm_table_find_target(table, tmsg->sector);
if (!dm_target_is_valid(ti)) {
DMWARN("Target message sector outside device.");
@@ -1303,6 +1365,7 @@ static int target_message(struct dm_ioctl *param, size_t param_size)
r = -EINVAL;
}
+ out_table:
dm_table_put(table);
out_argv:
kfree(argv);
@@ -1582,8 +1645,7 @@ int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
if (!md)
return -ENXIO;
- dm_get(md);
- down_read(&_hash_lock);
+ mutex_lock(&dm_hash_cells_mutex);
hc = dm_get_mdptr(md);
if (!hc || hc->md != md) {
r = -ENXIO;
@@ -1596,8 +1658,7 @@ int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
strcpy(uuid, hc->uuid ? : "");
out:
- up_read(&_hash_lock);
- dm_put(md);
+ mutex_unlock(&dm_hash_cells_mutex);
return r;
}