target: add helper to iterate over devices

This adds a wrapper around idr_for_each so the xcopy code can loop over
the devices in the next patch.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Mike Christie 2017-06-23 01:18:16 -05:00 committed by Nicholas Bellinger
parent b3af66e243
commit b1943fd454
2 changed files with 47 additions and 0 deletions

View File

@ -904,6 +904,51 @@ struct se_device *target_find_device(int id, bool do_depend)
}
EXPORT_SYMBOL(target_find_device);
struct devices_idr_iter {
int (*fn)(struct se_device *dev, void *data);
void *data;
};
static int target_devices_idr_iter(int id, void *p, void *data)
{
struct devices_idr_iter *iter = data;
struct se_device *dev = p;
/*
* We add the device early to the idr, so it can be used
* by backend modules during configuration. We do not want
* to allow other callers to access partially setup devices,
* so we skip them here.
*/
if (!(dev->dev_flags & DF_CONFIGURED))
return 0;
return iter->fn(dev, iter->data);
}
/**
* target_for_each_device - iterate over configured devices
* @fn: iterator function
* @data: pointer to data that will be passed to fn
*
* fn must return 0 to continue looping over devices. non-zero will break
* from the loop and return that value to the caller.
*/
int target_for_each_device(int (*fn)(struct se_device *dev, void *data),
void *data)
{
struct devices_idr_iter iter;
int ret;
iter.fn = fn;
iter.data = data;
mutex_lock(&g_device_mutex);
ret = idr_for_each(&devices_idr, target_devices_idr_iter, &iter);
mutex_unlock(&g_device_mutex);
return ret;
}
int target_configure_device(struct se_device *dev)
{
struct se_hba *hba = dev->se_hba;

View File

@ -87,6 +87,8 @@ void core_dev_release_virtual_lun0(void);
struct se_device *target_alloc_device(struct se_hba *hba, const char *name);
int target_configure_device(struct se_device *dev);
void target_free_device(struct se_device *);
int target_for_each_device(int (*fn)(struct se_device *dev, void *data),
void *data);
/* target_core_configfs.c */
void target_setup_backend_cits(struct target_backend *);