bisecting fixing commit since 312017a460d5ea31d646e7148e400e13db799ddc building syzkaller on eef6e5808d6507716d331b9eff67fdd991be891a testing commit 312017a460d5ea31d646e7148e400e13db799ddc with gcc (GCC) 8.1.0 kernel signature: c4275337fe38ead45bf5226c327aeb1f6393d762f572d6b4a2f6a76b688b5001 all runs: crashed: possible deadlock in refcount_dec_and_mutex_lock testing current HEAD 88d6de67e390b6093f2c11189ad022988a9e2961 testing commit 88d6de67e390b6093f2c11189ad022988a9e2961 with gcc (GCC) 8.1.0 kernel signature: 1975327d01dc491f3fb9256bd05259ef5dfc8b57a02e55570f21beb0e9260bfe all runs: OK # git bisect start 88d6de67e390b6093f2c11189ad022988a9e2961 312017a460d5ea31d646e7148e400e13db799ddc Bisecting: 804 revisions left to test after this (roughly 10 steps) [10dfea16e4469165d3e997322384f994012d209a] RDMA/bnxt_re: Fix Send Work Entry state check while polling completions testing commit 10dfea16e4469165d3e997322384f994012d209a with gcc (GCC) 8.1.0 kernel signature: c63590b0fd9635340e1c772ea96a9c0e5843b6cd9959f3a895e0f5cf115cf145 all runs: OK # git bisect bad 10dfea16e4469165d3e997322384f994012d209a Bisecting: 401 revisions left to test after this (roughly 9 steps) [6aba5758c40068be17a672d623567cd6290354e8] usbip: Fix receive error in vhci-hcd when using scatter-gather testing commit 6aba5758c40068be17a672d623567cd6290354e8 with gcc (GCC) 8.1.0 kernel signature: a617a64f65c567f2aabab8fd808ae51daeb3065e6e02ebe9ae0ae713f675633b all runs: crashed: possible deadlock in refcount_dec_and_mutex_lock # git bisect good 6aba5758c40068be17a672d623567cd6290354e8 Bisecting: 200 revisions left to test after this (roughly 8 steps) [07c0735e85397f5f7efc18dc21be03aab8ba8ee2] ata: ahci_brcm: BCM7425 AHCI requires AHCI_HFLAG_DELAY_ENGINE testing commit 07c0735e85397f5f7efc18dc21be03aab8ba8ee2 with gcc (GCC) 8.1.0 kernel signature: 9b224caaf201edad05596c39d6f2521d99f794405b276faa4e4f0298899a125e all runs: OK # git bisect bad 07c0735e85397f5f7efc18dc21be03aab8ba8ee2 Bisecting: 100 revisions left to test after this (roughly 7 steps) [74c4ed6c9cd4b6ff96ee989f6df60979e1794155] bonding: fix active-backup transition after link failure testing commit 74c4ed6c9cd4b6ff96ee989f6df60979e1794155 with gcc (GCC) 8.1.0 kernel signature: e33585296cbfad743ce7edb1209ba871ed2ad326d213da8eceaa1e759ac6b7e5 all runs: OK # git bisect bad 74c4ed6c9cd4b6ff96ee989f6df60979e1794155 Bisecting: 49 revisions left to test after this (roughly 6 steps) [7f9ac150f6b91d9ccff1e3a4792255f4c4db8393] scsi: lpfc: Fix duplicate unreg_rpi error in port offline flow testing commit 7f9ac150f6b91d9ccff1e3a4792255f4c4db8393 with gcc (GCC) 8.1.0 kernel signature: 4cbe8f868a2a361e6bc4c9b57a8469e254e4eed07cfe02955b77220efdef8e02 all runs: OK # git bisect bad 7f9ac150f6b91d9ccff1e3a4792255f4c4db8393 Bisecting: 24 revisions left to test after this (roughly 5 steps) [d097dd7d140767069d5c79280a32e6557a69ef0f] scsi: lpfc: Fix discovery failures when target device connectivity bounces testing commit d097dd7d140767069d5c79280a32e6557a69ef0f with gcc (GCC) 8.1.0 kernel signature: 3be7677d094e384f996652b1dd4de54db2cff76133a576c9d080bf3c5d29319d all runs: OK # git bisect bad d097dd7d140767069d5c79280a32e6557a69ef0f Bisecting: 12 revisions left to test after this (roughly 4 steps) [f5a054b7dd13430510bacfca17eff648616b2985] x86/MCE/AMD: Do not use rdmsr_safe_on_cpu() in smca_configure() testing commit f5a054b7dd13430510bacfca17eff648616b2985 with gcc (GCC) 8.1.0 kernel signature: 9a812e11ddd291b34d395bd332172515a925c52c36fc015e37936774e390367d all runs: crashed: possible deadlock in refcount_dec_and_mutex_lock # git bisect good f5a054b7dd13430510bacfca17eff648616b2985 Bisecting: 6 revisions left to test after this (roughly 3 steps) [c99c356c6abfa59943b79ef41b1a442e5fd46642] mmc: sdhci: Update the tuning failed messages to pr_debug level testing commit c99c356c6abfa59943b79ef41b1a442e5fd46642 with gcc (GCC) 8.1.0 kernel signature: e1d9a77658c71b78a9da70e267191f7a4df5032a3ebd325b9d3e8813ab1a3ef0 all runs: crashed: possible deadlock in refcount_dec_and_mutex_lock # git bisect good c99c356c6abfa59943b79ef41b1a442e5fd46642 Bisecting: 3 revisions left to test after this (roughly 2 steps) [07aaeed0e5886a15b75ce3a92aeff0ea77f48301] mmc: sdhci: Add a quirk for broken command queuing testing commit 07aaeed0e5886a15b75ce3a92aeff0ea77f48301 with gcc (GCC) 8.1.0 kernel signature: e93cec78614ae07cd2b3cbc8f324bcef30327f21031ede7dafa0dfe1b557449f run #0: crashed: possible deadlock in refcount_dec_and_mutex_lock run #1: crashed: possible deadlock in refcount_dec_and_mutex_lock run #2: crashed: possible deadlock in refcount_dec_and_mutex_lock run #3: crashed: possible deadlock in refcount_dec_and_mutex_lock run #4: crashed: possible deadlock in refcount_dec_and_mutex_lock run #5: crashed: possible deadlock in refcount_dec_and_mutex_lock run #6: crashed: possible deadlock in refcount_dec_and_mutex_lock run #7: crashed: possible deadlock in refcount_dec_and_mutex_lock run #8: crashed: possible deadlock in refcount_dec_and_mutex_lock run #9: OK # git bisect good 07aaeed0e5886a15b75ce3a92aeff0ea77f48301 Bisecting: 1 revision left to test after this (roughly 1 step) [ecfb25a7b1cdbeaf8017c3e5d724f62c74f06569] perf probe: Fix to show function entry line as probe-able testing commit ecfb25a7b1cdbeaf8017c3e5d724f62c74f06569 with gcc (GCC) 8.1.0 kernel signature: 9e7e6ebaca6399ff39668d54723f24f90254bb1587f57fa54a085012a24636d3 all runs: OK # git bisect bad ecfb25a7b1cdbeaf8017c3e5d724f62c74f06569 Bisecting: 0 revisions left to test after this (roughly 0 steps) [e83a26a49356a3dbd4f54102abe17fc594643698] nbd: fix shutdown and recv work deadlock v2 testing commit e83a26a49356a3dbd4f54102abe17fc594643698 with gcc (GCC) 8.1.0 kernel signature: c1f3f365734164e93cafad0652262b618e3d11bba459bd7cfa399900cf487911 all runs: OK # git bisect bad e83a26a49356a3dbd4f54102abe17fc594643698 e83a26a49356a3dbd4f54102abe17fc594643698 is the first bad commit commit e83a26a49356a3dbd4f54102abe17fc594643698 Author: Mike Christie Date: Sun Dec 8 16:51:50 2019 -0600 nbd: fix shutdown and recv work deadlock v2 commit 1c05839aa973cfae8c3db964a21f9c0eef8fcc21 upstream. This fixes a regression added with: commit e9e006f5fcf2bab59149cb38a48a4817c1b538b4 Author: Mike Christie Date: Sun Aug 4 14:10:06 2019 -0500 nbd: fix max number of supported devs where we can deadlock during device shutdown. The problem occurs if the recv_work's nbd_config_put occurs after nbd_start_device_ioctl has returned and the userspace app has droppped its reference via closing the device and running nbd_release. The recv_work nbd_config_put call would then drop the refcount to zero and try to destroy the config which would try to do destroy_workqueue from the recv work. This patch just has nbd_start_device_ioctl do a flush_workqueue when it wakes so we know after the ioctl returns running works have exited. This also fixes a possible race where we could try to reuse the device while old recv_works are still running. Cc: stable@vger.kernel.org Fixes: e9e006f5fcf2 ("nbd: fix max number of supported devs") Signed-off-by: Mike Christie Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman drivers/block/nbd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) culprit signature: c1f3f365734164e93cafad0652262b618e3d11bba459bd7cfa399900cf487911 parent signature: e93cec78614ae07cd2b3cbc8f324bcef30327f21031ede7dafa0dfe1b557449f revisions tested: 13, total time: 4h27m52.459125495s (build: 2h2m3.498800926s, test: 2h24m6.675249343s) first good commit: e83a26a49356a3dbd4f54102abe17fc594643698 nbd: fix shutdown and recv work deadlock v2 cc: ["axboe@kernel.dk" "gregkh@linuxfoundation.org" "mchristi@redhat.com"]