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J . Bottomley" , "Martin K . Petersen" , Mikulas Patocka , Mike Snitzer Cc: linux-scsi@vger.kernel.org, dm-devel@lists.linux.dev Date: Thu, 27 Nov 2025 16:26:51 +0100 In-Reply-To: <20251121234834.1035028-1-bmarzins@redhat.com> References: <20251121234834.1035028-1-bmarzins@redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.58.1 Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spamd-Result: default: False [-4.51 / 50.00]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.com:s=susede1]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; FUZZY_RATELIMITED(0.00)[rspamd.com]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; RCPT_COUNT_SEVEN(0.00)[7]; TO_DN_SOME(0.00)[]; MIME_TRACE(0.00)[0:+]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_TLS_ALL(0.00)[]; SPAMHAUS_XBL(0.00)[2a07:de40:b281:104:10:150:64:97:from]; RCVD_COUNT_TWO(0.00)[2]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; DNSWL_BLOCKED(0.00)[2a07:de40:b281:104:10:150:64:97:from]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:mid,suse.com:dkim,imap1.dmz-prg2.suse.org:helo,imap1.dmz-prg2.suse.org:rdns]; URIBL_BLOCKED(0.00)[imap1.dmz-prg2.suse.org:helo,imap1.dmz-prg2.suse.org:rdns,suse.com:mid,suse.com:dkim]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; DKIM_TRACE(0.00)[suse.com:+] X-Rspamd-Action: no action X-Spam-Flag: NO X-Spam-Score: -4.51 X-Spam-Level: X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Rspamd-Queue-Id: 0A69E33760 On Fri, 2025-11-21 at 18:48 -0500, Benjamin Marzinski wrote: > If scsi_dh_attached_handler_name() fails to allocate the handler > name, > dm-multipath (its only caller) assumes there is no attached device > handler, and sets the device up incorrectly. Return an error pointer > instead, so multipath can distinguish between failure and success > where > there is no attached device handler. >=20 > Signed-off-by: Benjamin Marzinski > --- > =C2=A0drivers/md/dm-mpath.c=C2=A0 | 8 ++++++++ > =C2=A0drivers/scsi/scsi_dh.c | 8 +++++--- > =C2=A02 files changed, 13 insertions(+), 3 deletions(-) >=20 > diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c > index c18358271618..063dc526fe04 100644 > --- a/drivers/md/dm-mpath.c > +++ b/drivers/md/dm-mpath.c > @@ -950,6 +950,14 @@ static struct pgpath *parse_path(struct > dm_arg_set *as, struct path_selector *ps > =C2=A0 > =C2=A0 q =3D bdev_get_queue(p->path.dev->bdev); > =C2=A0 attached_handler_name =3D scsi_dh_attached_handler_name(q, > GFP_KERNEL); > + if (IS_ERR(attached_handler_name)) { > + if (PTR_ERR(attached_handler_name) =3D=3D -ENODEV) > + attached_handler_name =3D NULL; What's the point of continuing here if we know that the SCSI device doesn't exist? Thanks, Martin > + else { > + r =3D PTR_ERR(attached_handler_name); > + goto bad; > + } > + } > =C2=A0 if (attached_handler_name || m->hw_handler_name) { > =C2=A0 INIT_DELAYED_WORK(&p->activate_path, > activate_path_work); > =C2=A0 r =3D setup_scsi_dh(p->path.dev->bdev, m, > &attached_handler_name, &ti->error); > diff --git a/drivers/scsi/scsi_dh.c b/drivers/scsi/scsi_dh.c > index 7b56e00c7df6..b9d805317814 100644 > --- a/drivers/scsi/scsi_dh.c > +++ b/drivers/scsi/scsi_dh.c > @@ -353,7 +353,8 @@ EXPORT_SYMBOL_GPL(scsi_dh_attach); > =C2=A0 *=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 that may have a device handler att= ached > =C2=A0 * @gfp - the GFP mask used in the kmalloc() call when allocating > memory > =C2=A0 * > - * Returns name of attached handler, NULL if no handler is attached. > + * Returns name of attached handler, NULL if no handler is attached, > or > + * and error pointer if an error occurred. > =C2=A0 * Caller must take care to free the returned string. > =C2=A0 */ > =C2=A0const char *scsi_dh_attached_handler_name(struct request_queue *q, > gfp_t gfp) > @@ -363,10 +364,11 @@ const char > *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp) > =C2=A0 > =C2=A0 sdev =3D scsi_device_from_queue(q); > =C2=A0 if (!sdev) > - return NULL; > + return ERR_PTR(-ENODEV); > =C2=A0 > =C2=A0 if (sdev->handler) > - handler_name =3D kstrdup(sdev->handler->name, gfp); > + handler_name =3D kstrdup(sdev->handler->name, gfp) ? : > + =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 ERR_PTR(-ENOMEM); > =C2=A0 put_device(&sdev->sdev_gendev); > =C2=A0 return handler_name; > =C2=A0}