[SCSI] libsas: fix domain_device leak

Arrange for the deallocation of a struct domain_device object when it no
longer has:
1/ any children
2/ references by any scsi_targets
3/ references by a lldd

The comment about domain_device lifetime in
Documentation/scsi/libsas.txt is stale as it appears mainline never had
a version of a struct domain_device that was registered as a kobject.
We now manage domain_device reference counts on behalf of external
agents.

Reviewed-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This commit is contained in:
Dan Williams
2011-11-17 17:59:47 -08:00
committed by James Bottomley
parent 6f4e75a49f
commit 735f7d2fed
6 changed files with 56 additions and 41 deletions

View File

@@ -398,21 +398,6 @@ struct sas_task {
task_done -- callback when the task has finished execution
};
When an external entity, entity other than the LLDD or the
SAS Layer, wants to work with a struct domain_device, it
_must_ call kobject_get() when getting a handle on the
device and kobject_put() when it is done with the device.
This does two things:
A) implements proper kfree() for the device;
B) increments/decrements the kref for all players:
domain_device
all domain_device's ... (if past an expander)
port
host adapter
pci device
and up the ladder, etc.
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