return NULL;
}
+
+/*
+ * Given a path, return TRUE if path is a ZVOL.
+ */
+boolean_t
+zvol_is_zvol(const char *device)
+{
+ struct block_device *bdev;
+ unsigned int major;
+
+ bdev = lookup_bdev(device);
+ if (IS_ERR(bdev))
+ return (B_FALSE);
+
+ major = MAJOR(bdev->bd_dev);
+ bdput(bdev);
+
+ if (major == zvol_major)
+ return (B_TRUE);
+
+ return (B_FALSE);
+}
+
/*
* ZFS_IOC_CREATE callback handles dmu zvol and zap object creation.
*/
* Callback vectors for replaying records.
* Only TX_WRITE is needed for zvol.
*/
-zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = {
- (zil_replay_func_t *)zvol_replay_err, /* no such transaction type */
- (zil_replay_func_t *)zvol_replay_err, /* TX_CREATE */
- (zil_replay_func_t *)zvol_replay_err, /* TX_MKDIR */
- (zil_replay_func_t *)zvol_replay_err, /* TX_MKXATTR */
- (zil_replay_func_t *)zvol_replay_err, /* TX_SYMLINK */
- (zil_replay_func_t *)zvol_replay_err, /* TX_REMOVE */
- (zil_replay_func_t *)zvol_replay_err, /* TX_RMDIR */
- (zil_replay_func_t *)zvol_replay_err, /* TX_LINK */
- (zil_replay_func_t *)zvol_replay_err, /* TX_RENAME */
- (zil_replay_func_t *)zvol_replay_write, /* TX_WRITE */
- (zil_replay_func_t *)zvol_replay_err, /* TX_TRUNCATE */
- (zil_replay_func_t *)zvol_replay_err, /* TX_SETATTR */
- (zil_replay_func_t *)zvol_replay_err, /* TX_ACL */
+zil_replay_func_t zvol_replay_vector[TX_MAX_TYPE] = {
+ (zil_replay_func_t)zvol_replay_err, /* no such transaction type */
+ (zil_replay_func_t)zvol_replay_err, /* TX_CREATE */
+ (zil_replay_func_t)zvol_replay_err, /* TX_MKDIR */
+ (zil_replay_func_t)zvol_replay_err, /* TX_MKXATTR */
+ (zil_replay_func_t)zvol_replay_err, /* TX_SYMLINK */
+ (zil_replay_func_t)zvol_replay_err, /* TX_REMOVE */
+ (zil_replay_func_t)zvol_replay_err, /* TX_RMDIR */
+ (zil_replay_func_t)zvol_replay_err, /* TX_LINK */
+ (zil_replay_func_t)zvol_replay_err, /* TX_RENAME */
+ (zil_replay_func_t)zvol_replay_write, /* TX_WRITE */
+ (zil_replay_func_t)zvol_replay_err, /* TX_TRUNCATE */
+ (zil_replay_func_t)zvol_replay_err, /* TX_SETATTR */
+ (zil_replay_func_t)zvol_replay_err, /* TX_ACL */
};
/*
struct request *req = (struct request *)arg;
struct request_queue *q = req->q;
zvol_state_t *zv = q->queuedata;
- uint64_t offset = blk_rq_pos(req) << 9;
- uint64_t size = blk_rq_bytes(req);
+ uint64_t start = blk_rq_pos(req) << 9;
+ uint64_t end = start + blk_rq_bytes(req);
int error;
rl_t *rl;
ASSERT(!(current->flags & PF_NOFS));
current->flags |= PF_NOFS;
- if (offset + size > zv->zv_volsize) {
- blk_end_request(req, -EIO, size);
+ if (end > zv->zv_volsize) {
+ blk_end_request(req, -EIO, blk_rq_bytes(req));
goto out;
}
- if (size == 0) {
- blk_end_request(req, 0, size);
+ /*
+ * Align the request to volume block boundaries. If we don't,
+ * then this will force dnode_free_range() to zero out the
+ * unaligned parts, which is slow (read-modify-write) and
+ * useless since we are not freeing any space by doing so.
+ */
+ start = P2ROUNDUP(start, zv->zv_volblocksize);
+ end = P2ALIGN(end, zv->zv_volblocksize);
+
+ if (start >= end) {
+ blk_end_request(req, 0, blk_rq_bytes(req));
goto out;
}
- rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_WRITER);
+ rl = zfs_range_lock(&zv->zv_znode, start, end - start, RL_WRITER);
- error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, offset, size);
+ error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, start, end - start);
/*
* TODO: maybe we should add the operation to the log.
zfs_range_unlock(rl);
- blk_end_request(req, -error, size);
+ blk_end_request(req, -error, blk_rq_bytes(req));
out:
current->flags &= ~PF_NOFS;
}
{
objset_t *os;
uint64_t volsize;
+ int locked = 0;
int error;
uint64_t ro;
+ /*
+ * In all other cases the spa_namespace_lock is taken before the
+ * bdev->bd_mutex lock. But in this case the Linux __blkdev_get()
+ * function calls fops->open() with the bdev->bd_mutex lock held.
+ *
+ * To avoid a potential lock inversion deadlock we preemptively
+ * try to take the spa_namespace_lock(). Normally it will not
+ * be contended and this is safe because spa_open_common() handles
+ * the case where the caller already holds the spa_namespace_lock.
+ *
+ * When it is contended we risk a lock inversion if we were to
+ * block waiting for the lock. Luckily, the __blkdev_get()
+ * function allows us to return -ERESTARTSYS which will result in
+ * bdev->bd_mutex being dropped, reacquired, and fops->open() being
+ * called again. This process can be repeated safely until both
+ * locks are acquired.
+ */
+ if (!mutex_owned(&spa_namespace_lock)) {
+ locked = mutex_tryenter(&spa_namespace_lock);
+ if (!locked)
+ return (-ERESTARTSYS);
+ }
+
/* lie and say we're read-only */
error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, 1, zvol_tag, &os);
if (error)
- return (-error);
+ goto out_mutex;
error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize);
if (error) {
- dmu_objset_disown(os, zvol_tag);
- return (-error);
+ dmu_objset_disown(os, zvol_tag);
+ goto out_mutex;
}
zv->zv_objset = os;
error = dmu_bonus_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dbuf);
if (error) {
- dmu_objset_disown(os, zvol_tag);
- return (-error);
+ dmu_objset_disown(os, zvol_tag);
+ goto out_mutex;
}
set_capacity(zv->zv_disk, volsize >> 9);
zv->zv_zilog = zil_open(os, zvol_get_data);
VERIFY(dsl_prop_get_integer(zv->zv_name, "readonly", &ro, NULL) == 0);
- if (ro || dmu_objset_is_snapshot(os)) {
- set_disk_ro(zv->zv_disk, 1);
- zv->zv_flags |= ZVOL_RDONLY;
+ if (ro || dmu_objset_is_snapshot(os) ||
+ !spa_writeable(dmu_objset_spa(os))) {
+ set_disk_ro(zv->zv_disk, 1);
+ zv->zv_flags |= ZVOL_RDONLY;
} else {
- set_disk_ro(zv->zv_disk, 0);
- zv->zv_flags &= ~ZVOL_RDONLY;
+ set_disk_ro(zv->zv_disk, 0);
+ zv->zv_flags &= ~ZVOL_RDONLY;
}
+out_mutex:
+ if (locked)
+ mutex_exit(&spa_namespace_lock);
+
return (-error);
}
{
zil_close(zv->zv_zilog);
zv->zv_zilog = NULL;
+
dmu_buf_rele(zv->zv_dbuf, zvol_tag);
zv->zv_dbuf = NULL;
+
+ /*
+ * Evict cached data
+ */
+ if (dsl_dataset_is_dirty(dmu_objset_ds(zv->zv_objset)) &&
+ !(zv->zv_flags & ZVOL_RDONLY))
+ txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
+ (void) dmu_objset_evict_dbufs(zv->zv_objset);
+
dmu_objset_disown(zv->zv_objset, zvol_tag);
zv->zv_objset = NULL;
}
mutex_enter(&zvol_state_lock);
zv = zvol_find_by_dev(dev);
- kobj = zv ? get_disk(zv->zv_disk) : ERR_PTR(-ENOENT);
+ kobj = zv ? get_disk(zv->zv_disk) : NULL;
mutex_exit(&zvol_state_lock);
return kobj;
zvol_alloc(dev_t dev, const char *name)
{
zvol_state_t *zv;
+ int error = 0;
zv = kmem_zalloc(sizeof (zvol_state_t), KM_SLEEP);
- if (zv == NULL)
- goto out;
zv->zv_queue = blk_init_queue(zvol_request, &zv->zv_lock);
if (zv->zv_queue == NULL)
goto out_kmem;
+#ifdef HAVE_ELEVATOR_CHANGE
+ error = elevator_change(zv->zv_queue, "noop");
+#endif /* HAVE_ELEVATOR_CHANGE */
+ if (error) {
+ printk("ZFS: Unable to set \"%s\" scheduler for zvol %s: %d\n",
+ "noop", name, error);
+ goto out_queue;
+ }
+
#ifdef HAVE_BLK_QUEUE_FLUSH
blk_queue_flush(zv->zv_queue, VDEV_REQ_FLUSH | VDEV_REQ_FUA);
#else
blk_cleanup_queue(zv->zv_queue);
out_kmem:
kmem_free(zv, sizeof (zvol_state_t));
-out:
+
return NULL;
}
}
static int
-__zvol_create_minor(const char *name)
+__zvol_snapdev_hidden(const char *name)
+{
+ uint64_t snapdev;
+ char *parent;
+ char *atp;
+ int error = 0;
+
+ parent = kmem_alloc(MAXPATHLEN, KM_SLEEP);
+ (void) strlcpy(parent, name, MAXPATHLEN);
+
+ if ((atp = strrchr(parent, '@')) != NULL) {
+ *atp = '\0';
+ error = dsl_prop_get_integer(parent, "snapdev", &snapdev, NULL);
+ if ((error == 0) && (snapdev == ZFS_SNAPDEV_HIDDEN))
+ error = ENODEV;
+ }
+ kmem_free(parent, MAXPATHLEN);
+ return (error);
+}
+
+static int
+__zvol_create_minor(const char *name, boolean_t ignore_snapdev)
{
zvol_state_t *zv;
objset_t *os;
goto out;
}
+ if (ignore_snapdev == B_FALSE) {
+ error = __zvol_snapdev_hidden(name);
+ if (error)
+ goto out;
+ }
+
doi = kmem_alloc(sizeof(dmu_object_info_t), KM_SLEEP);
error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, zvol_tag, &os);
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zv->zv_queue);
#endif
- if (zil_replay_disable)
- zil_destroy(dmu_objset_zil(os), B_FALSE);
- else
- zil_replay(os, zv, zvol_replay_vector);
+ if (spa_writeable(dmu_objset_spa(os))) {
+ if (zil_replay_disable)
+ zil_destroy(dmu_objset_zil(os), B_FALSE);
+ else
+ zil_replay(os, zv, zvol_replay_vector);
+ }
+ zv->zv_objset = NULL;
out_dmu_objset_disown:
dmu_objset_disown(os, zvol_tag);
- zv->zv_objset = NULL;
out_doi:
kmem_free(doi, sizeof(dmu_object_info_t));
out:
int error;
mutex_enter(&zvol_state_lock);
- error = __zvol_create_minor(name);
+ error = __zvol_create_minor(name, B_FALSE);
mutex_exit(&zvol_state_lock);
return (error);
if (strchr(dsname, '/') == NULL)
return 0;
- (void) __zvol_create_minor(dsname);
+ (void) __zvol_create_minor(dsname, B_FALSE);
return (0);
}
kmem_free(str, MAXNAMELEN);
}
+static int
+snapdev_snapshot_changed_cb(const char *dsname, void *arg) {
+ uint64_t snapdev = *(uint64_t *) arg;
+
+ if (strchr(dsname, '@') == NULL)
+ return 0;
+
+ switch (snapdev) {
+ case ZFS_SNAPDEV_VISIBLE:
+ mutex_enter(&zvol_state_lock);
+ (void) __zvol_create_minor(dsname, B_TRUE);
+ mutex_exit(&zvol_state_lock);
+ break;
+ case ZFS_SNAPDEV_HIDDEN:
+ (void) zvol_remove_minor(dsname);
+ break;
+ }
+ return 0;
+}
+
+int
+zvol_set_snapdev(const char *dsname, uint64_t snapdev) {
+ (void) dmu_objset_find((char *) dsname, snapdev_snapshot_changed_cb,
+ &snapdev, DS_FIND_SNAPSHOTS | DS_FIND_CHILDREN);
+ /* caller should continue to modify snapdev property */
+ return (-1);
+}
+
+
int
zvol_init(void)
{
git://git.camperquake.de / zfs.git / blobdiff