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| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2014-12-03 22:40:26 +0100 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2014-12-04 13:41:58 +0100 |
| commit | e8801a7418dda995a70f30874aef77e6d064828e (patch) | |
| tree | ee4e691009b468c5397216b9e5776c6c239cc51e /include/scsi/scsi_cmnd.h | |
| parent | swiotlb-xen: pass dev_addr to swiotlb_tbl_unmap_single (diff) | |
| download | linux-e8801a7418dda995a70f30874aef77e6d064828e.tar.xz linux-e8801a7418dda995a70f30874aef77e6d064828e.zip | |
xen/pciback: Don't deadlock when unbinding.
As commit 0a9fd0152929db372ff61b0d6c280fdd34ae8bdb
'xen/pciback: Document the entry points for 'pcistub_put_pci_dev''
explained there are four entry points in this function.
Two of them are when the user fiddles in the SysFS to
unbind a device which might be in use by a guest or not.
Both 'unbind' states will cause a deadlock as the the PCI lock has
already been taken, which then pci_device_reset tries to take.
We can simplify this by requiring that all callers of
pcistub_put_pci_dev MUST hold the device lock. And then
we can just call the lockless version of pci_device_reset.
To make it even simpler we will modify xen_pcibk_release_pci_dev
to quality whether it should take a lock or not - as it ends
up calling xen_pcibk_release_pci_dev and needs to hold the lock.
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'include/scsi/scsi_cmnd.h')
0 files changed, 0 insertions, 0 deletions