[PATCH] fabrics: fix return value of hostnqn_read_file()

Sun Sep 5 17:57:19 PDT 2021

From: Chaitanya Kulkarni <kch at nvidia.com>

Current code returns the value of strdup and callers of
hostnqn_read_file() check for the NULL value in order to determine the
success or failure.

The value return by the strdup will never be NULL unless strdup()
results in an error that is making function return success all the time
resulting in blktests failures.

Check the string value to NULL before we return the pointer.

Signed-off-by: Chaitanya Kulkarni <kch at nvidia.com>
---
Test Log:-

root at dev nvme-cli ((HEAD detached at v1.15)) # cdblktests 
root at dev blktests (master) # ./check tests/nvme/004
nvme/004 (test nvme and nvmet UUID NS descriptors)           [failed]
    runtime  1.451s  ...  0.072s
    --- tests/nvme/004.out	2021-08-29 01:09:20.287901783 -0700
    +++ /mnt/data/blktests/results/nodev/nvme/004.out.bad	2021-09-05 17:47:34.344388492 -0700
    @@ -1,5 +1,6 @@
     Running nvme/004
    -91fdba0d-f87b-4c25-b80f-db7be1418b9e
    -uuid.91fdba0d-f87b-4c25-b80f-db7be1418b9e
    -NQN:blktests-subsystem-1 disconnected 1 controller(s)
    +Failed to write to /dev/nvme-fabrics: Invalid argument
    +cat: /sys/block/n1/uuid: No such file or directory
    +cat: /sys/block/n1/wwid: No such file or directory
    ...
    (Run 'diff -u tests/nvme/004.out /mnt/data/blktests/results/nodev/nvme/004.out.bad' to see the entire diff)
root at dev blktests (master) # cat /mnt/data/blktests/results/nodev/nvme/004.out.bad
Running nvme/004
Failed to write to /dev/nvme-fabrics: Invalid argument
cat: /sys/block/n1/uuid: No such file or directory
cat: /sys/block/n1/wwid: No such file or directory
NQN:blktests-subsystem-1 disconnected 0 controller(s)
Test complete
root at dev blktests (master) # dmesg  -c 
[187767.848420] run blktests nvme/004 at 2021-09-05 17:47:34
[187767.870446] loop0: detected capacity change from 0 to 2097152
[187767.885230] nvmet: adding nsid 1 to subsystem blktests-subsystem-1
[187767.888098] nvme_fabrics: unknown parameter or missing value 'hostnqn=' in ctrl creation request
root at dev blktests (master) # cd ../
root at dev data # cd nvme-cli/
root at dev nvme-cli ((HEAD detached at v1.15)) # git am 0001-fabrics-fix-return-value-of-hostnqn_read_file.patch
Applying: fabrics: fix return value of hostnqn_read_file()
root at dev nvme-cli ((HEAD detached from v1.15)) # makej install 
NVME_VERSION = 1.15.1.ga91e
    CC fabrics.o
make -C Documentation install-no-build
install -d /usr/share/bash-completion/completions
install -d /usr/share/zsh/site-functions
install -d /etc/nvme
install -d /usr/lib/systemd/system
install -d /etc/udev/rules.d
install -d /usr/lib/dracut/dracut.conf.d
install -m 644 -T ./completions/_nvme /usr/share/zsh/site-functions/_nvme
install -m 644 -T ./completions/bash-nvme-completion.sh /usr/share/bash-completion/completions/nvme
touch /etc/nvme/hostnqn
install -m 644 ./nvmf-autoconnect/systemd/* /usr/lib/systemd/system
install -m 644 ./nvmf-autoconnect/udev-rules/* /etc/udev/rules.d
install -m 644 70-nvmf-autoconnect.conf /usr/lib/dracut/dracut.conf.d
touch /etc/nvme/hostid
if [ ! -f /etc/nvme/discovery.conf ]; then \
	install -m 644 -T ./etc/discovery.conf.in /etc/nvme/discovery.conf; \
fi
if [ ! -s /etc/nvme/hostnqn ]; then \
	echo `/usr/sbin/nvme gen-hostnqn` > /etc/nvme/hostnqn; \
fi
if [ ! -s /etc/nvme/hostid ]; then \
	uuidgen > /etc/nvme/hostid; \
fi
make[1]: Entering directory '/mnt/data/nvme-cli/Documentation'
install -d -m 755 /usr/local/share/man/man1
install -m 644 nvme-admin-passthru.1 nvme-ana-log.1 nvme-attach-ns.1 nvme-capacity-mgmt.1 nvme-changed-ns-list-log.1 nvme-compare.1 nvme-connect-all.1 nvme-connect.1 nvme-copy.1 nvme-create-ns.1 nvme-delete-ns.1 nvme-dera-stat.1 nvme-detach-ns.1 nvme-device-self-test.1 nvme-dir-receive.1 nvme-dir-send.1 nvme-disconnect-all.1 nvme-disconnect.1 nvme-discover.1 nvme-dsm.1 nvme-effects-log.1 nvme-endurance-event-agg-log.1 nvme-endurance-log.1 nvme-error-log.1 nvme-flush.1 nvme-format.1 nvme-fw-commit.1 nvme-fw-download.1 nvme-fw-log.1 nvme-gen-hostnqn.1 nvme-get-feature.1 nvme-get-lba-status.1 nvme-get-log.1 nvme-get-ns-id.1 nvme-get-property.1 nvme-help.1 nvme-huawei-id-ctrl.1 nvme-huawei-list.1 nvme-id-ctrl.1 nvme-id-domain.1 nvme-id-iocs.1 nvme-id-ns.1 nvme-id-nvmset.1 nvme-intel-id-ctrl.1 nvme-intel-internal-log.1 nvme-intel-lat-stats.1 nvme-intel-market-name.1 nvme-intel-smart-log-add.1 nvme-intel-temp-stats.1 nvme-io-passthru.1 nvme-lba-status-log.1 nvme-list-ctrl.1 nvme-list-ns.1 nvme-list-subsys.1 nvme-list.1 nvme-lnvm-create.1 nvme-lnvm-diag-bbtbl.1 nvme-lnvm-diag-set-bbtbl.1 nvme-lnvm-factory.1 nvme-lnvm-id-ns.1 nvme-lnvm-info.1 nvme-lnvm-init.1 nvme-lnvm-list.1 nvme-lnvm-remove.1 nvme-micron-clear-pcie-errors.1 nvme-micron-internal-log.1 nvme-micron-nand-stats.1 nvme-micron-pcie-stats.1 nvme-micron-selective-download.1 nvme-micron-smart-add-log.1 nvme-micron-temperature-stats.1 nvme-netapp-ontapdevices.1 nvme-netapp-smdevices.1 nvme-ns-descs.1 nvme-ns-rescan.1 nvme-nvm-id-ctrl.1 nvme-persistent-event-log.1 nvme-predictable-lat-log.1 nvme-pred-lat-event-agg-log.1 nvme-primary-ctrl-caps.1 nvme-read.1 nvme-reset.1 nvme-resv-acquire.1 nvme-resv-notif-log.1 nvme-resv-register.1 nvme-resv-release.1 nvme-resv-report.1 nvme-rpmb.1 nvme-sanitize-log.1 nvme-sanitize.1 nvme-security-recv.1 nvme-security-send.1 nvme-self-test-log.1 nvme-set-feature.1 nvme-set-property.1 nvme-show-hostnqn.1 nvme-show-regs.1 nvme-smart-log.1 nvme-subsystem-reset.1 nvme-telemetry-log.1 nvme-toshiba-clear-pcie-correctable-errors.1 nvme-toshiba-vs-internal-log.1 nvme-toshiba-vs-smart-add-log.1 nvme-transcend-badblock.1 nvme-transcend-healthvalue.1 nvme-verify.1 nvme-virtium-save-smart-to-vtview-log.1 nvme-virtium-show-identify.1 nvme-wdc-capabilities.1 nvme-wdc-cap-diag.1 nvme-wdc-clear-assert-dump.1 nvme-wdc-clear-fw-activate-history.1 nvme-wdc-clear-pcie-correctable-errors.1 nvme-wdc-cloud-SSD-plugin-version.1 nvme-wdc-drive-essentials.1 nvme-wdc-drive-log.1 nvme-wdc-drive-resize.1 nvme-wdc-enc-get-log.1 nvme-wdc-get-crash-dump.1 nvme-wdc-get-drive-status.1 nvme-wdc-get-pfail-dump.1 nvme-wdc-id-ctrl.1 nvme-wdc-log-page-directory.1 nvme-wdc-namespace-resize.1 nvme-wdc-purge-monitor.1 nvme-wdc-purge.1 nvme-wdc-vs-drive-info.1 nvme-wdc-vs-error-reason-identifier.1 nvme-wdc-vs-fw-activate-history.1 nvme-wdc-vs-internal-log.1 nvme-wdc-vs-nand-stats.1 nvme-wdc-vs-smart-add-log.1 nvme-wdc-vs-telemetry-controller-option.1 nvme-wdc-vs-temperature-stats.1 nvme-write.1 nvme-write-uncor.1 nvme-write-zeroes.1 nvme-zns-changed-zone-list.1 nvme-zns-close-zone.1 nvme-zns-finish-zone.1 nvme-zns-id-ctrl.1 nvme-zns-id-ns.1 nvme-zns-offline-zone.1 nvme-zns-open-zone.1 nvme-zns-report-zones.1 nvme-zns-reset-zone.1 nvme-zns-set-zone-desc.1 nvme-zns-zone-append.1 nvme-zns-zone-mgmt-recv.1 nvme-zns-zone-mgmt-send.1 nvme.1 /usr/local/share/man/man1
make[1]: Leaving directory '/mnt/data/nvme-cli/Documentation'
    CC nvme
rm -f /usr/local/sbin/nvme
install -d /usr/sbin
install -m 755 nvme /usr/sbin
root at dev nvme-cli ((HEAD detached from v1.15)) # cd ../
root at dev data # cdblktests 
root at dev blktests (master) # !./check
./check tests/nvme/004
nvme/004 (test nvme and nvmet UUID NS descriptors)           [passed]
    runtime  0.072s  ...  1.441s
---
 fabrics.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fabrics.c b/fabrics.c
index 39bee97..4e1ff61 100644
--- a/fabrics.c
+++ b/fabrics.c
@@ -855,7 +855,7 @@ static char *hostnqn_read_file(void)
 
 out:
 	fclose(f);
-	return ret;
+	return strcmp(ret, "") == 0 ? NULL : ret;
 }
 
 static char *hostnqn_generate_systemd(void)
-- 
2.29.0


