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That's all we know. X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Fam Zheng , Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , Eduardo Habkost , "Michael S. Tsirkin" , qemu-devel@nongnu.org, Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --hnsKUeImFCk/igEn Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, May 11, 2020 at 07:09:51PM +0300, Maxim Levitsky wrote: > This will help us to avoid the scsi device disappearing > after we took a reference to it. >=20 > It doesn't by itself forbid case when we try to access > an unrealized device >=20 > Suggested-by: Stefan Hajnoczi > Signed-off-by: Maxim Levitsky > --- > hw/scsi/virtio-scsi.c | 23 +++++++++++++++-------- > 1 file changed, 15 insertions(+), 8 deletions(-) I'm not very familiar with the SCSI emulation code, but this looks correct. My understanding of what this patch does: This patch keeps SCSIDevice alive between scsi_device_find() and scsi_req_new(). Previously no SCSIDevice ref was taken so the device could have been freed before scsi_req_new() had a chance to take a ref. The TMF case is similar: the SCSIDevice ref must be held during virtio_scsi_do_tmf(). We don't need to worry about the async cancel notifiers because the request being canceled already holds a ref. --hnsKUeImFCk/igEn Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAl7OjDIACgkQnKSrs4Gr c8g+3wf/bDt16k0j0Cz10q+FvN2pWo79kgXFixkdCPwDINRDQ4aJ+n3EgC8o7V1M OrwVDsT6tF3662zv8oB10H9Ork3+zlWdkuuZPu9UNB17HNJ091eFApn4MHuZgm7K 4gLnU3UT0Gu8QxtiqLIApUM0nnCEQ0KjZi3q4dXRSHrB1Qbb3SAmjp+Rb56GKlSz uI4ACNVXcYSk3ZIWuu0PUipDT81xqpzDBBgmBTvYwSu5a8Q41d0zJmcGxWyhlksC VI+b7nRdkpPdu+zDB6i/PRgJ7/FjXwxwashi/jZpR0BHtgZ4aHHhgamGNCflrNhj +teMCwefLJ1tA25QvnyRR8ogFL2ASA== =KcwU -----END PGP SIGNATURE----- --hnsKUeImFCk/igEn--