bisecting fixing commit since 2762b48e9611529239da2e68cba908dbbec9805f
building syzkaller on fd10362197975cb06b6b7c7616c35c6fd9821da2
testing commit 2762b48e9611529239da2e68cba908dbbec9805f with gcc (GCC) 8.4.1 20210217
kernel signature: 80f2a179cc7569abd1625c561cc7cded52747870037b1ce980e88ed5f8dcad97
run #0: crashed: possible deadlock in ext4_file_write_iter
run #1: crashed: possible deadlock in __generic_file_fsync
run #2: crashed: possible deadlock in __generic_file_fsync
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
reproducer seems to be flaky
testing current HEAD 3242aa3a635c0958671ee1e4b0958dcc7c4e5c79
testing commit 3242aa3a635c0958671ee1e4b0958dcc7c4e5c79 with gcc (GCC) 8.4.1 20210217
kernel signature: 9d694e0c378633659a6cc7e3220c3bc38588cdb5a347aa78cebb5fa10418b3e8
all runs: OK
# git bisect start 3242aa3a635c0958671ee1e4b0958dcc7c4e5c79 2762b48e9611529239da2e68cba908dbbec9805f
Bisecting: 117 revisions left to test after this (roughly 7 steps)
[8ef6c49a63057962a009338f9f00f9c8c53bc640] RDMA/cxgb4: Fix the reported max_recv_sge value

testing commit 8ef6c49a63057962a009338f9f00f9c8c53bc640 with gcc (GCC) 8.4.1 20210217
kernel signature: 452f27b6f38b23bf3db6283f8b1fc7de73936eeb9845d4377f22f16f73d64111
run #0: crashed: possible deadlock in __generic_file_fsync
run #1: OK
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
# git bisect good 8ef6c49a63057962a009338f9f00f9c8c53bc640
Bisecting: 58 revisions left to test after this (roughly 6 steps)
[6e0e334c03366d81ad466fc735fbf309b1edac5f] net: dsa: mv88e6xxx: override existent unicast portvec in port_fdb_add

testing commit 6e0e334c03366d81ad466fc735fbf309b1edac5f with gcc (GCC) 8.4.1 20210217
kernel signature: 5c81fd1bae78cd1f0a212380cc10ad44ff67ca3cdc17a2adcf8ba5ccb447657e
run #0: crashed: possible deadlock in ext4_file_write_iter
run #1: crashed: possible deadlock in __generic_file_fsync
run #2: crashed: possible deadlock in ext4_file_write_iter
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
# git bisect good 6e0e334c03366d81ad466fc735fbf309b1edac5f
Bisecting: 29 revisions left to test after this (roughly 5 steps)
[6c8acb4ef560bba93bbbf1459b74f16a7a34e511] memblock: do not start bottom-up allocations with kernel_end

testing commit 6c8acb4ef560bba93bbbf1459b74f16a7a34e511 with gcc (GCC) 8.4.1 20210217
kernel signature: d018401ae2e853623b28fdef052630beb606e6399b9903faad637ad12c905729
all runs: OK
# git bisect bad 6c8acb4ef560bba93bbbf1459b74f16a7a34e511
Bisecting: 14 revisions left to test after this (roughly 4 steps)
[d24cf6d0d72a871f7fc6d96970bd4745ec59ac77] memcg: fix a crash in wb_workfn when a device disappears

testing commit d24cf6d0d72a871f7fc6d96970bd4745ec59ac77 with gcc (GCC) 8.4.1 20210217
kernel signature: 55fbf620986cde8d03f13b7ecfdddfaf27f490bfec8af24119c389b7ff04c4a9
all runs: OK
# git bisect bad d24cf6d0d72a871f7fc6d96970bd4745ec59ac77
Bisecting: 6 revisions left to test after this (roughly 3 steps)
[82835d76d7c3084ac33001d8d73d33c21a9c14bf] iwlwifi: mvm: take mutex for calling iwl_mvm_get_sync_time()

testing commit 82835d76d7c3084ac33001d8d73d33c21a9c14bf with gcc (GCC) 8.4.1 20210217
kernel signature: 838fff8333547089a299664a532f5e0369ffb0784acffd35a504d641d3568a51
run #0: crashed: possible deadlock in __generic_file_fsync
run #1: crashed: possible deadlock in ext4_file_write_iter
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
# git bisect good 82835d76d7c3084ac33001d8d73d33c21a9c14bf
Bisecting: 3 revisions left to test after this (roughly 2 steps)
[29160df8096f77be81fd96beb61355b0f5bb6bad] SUNRPC: Move simple_get_bytes and simple_get_netobj into private header

testing commit 29160df8096f77be81fd96beb61355b0f5bb6bad with gcc (GCC) 8.4.1 20210217
kernel signature: 8447167d8c5379a11389395f3af8bf91127176ec5289866418c33df7e52fb9eb
run #0: crashed: possible deadlock in ext4_file_write_iter
run #1: OK
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
# git bisect good 29160df8096f77be81fd96beb61355b0f5bb6bad
Bisecting: 1 revision left to test after this (roughly 1 step)
[fe072e50be403fc52c426c15073b8c38ce301416] lib/string: Add strscpy_pad() function

testing commit fe072e50be403fc52c426c15073b8c38ce301416 with gcc (GCC) 8.4.1 20210217
kernel signature: 12e7e1d6ee96c11fe010c02c2dbd570d35ff1fe0fbdd474c6b7abd6000d97d47
run #0: crashed: possible deadlock in __generic_file_fsync
run #1: crashed: possible deadlock in __generic_file_fsync
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
# git bisect good fe072e50be403fc52c426c15073b8c38ce301416
Bisecting: 0 revisions left to test after this (roughly 0 steps)
[fe4c89150d9b2fbfb013c35f4ffc1f8d93d33cca] include/trace/events/writeback.h: fix -Wstringop-truncation warnings

testing commit fe4c89150d9b2fbfb013c35f4ffc1f8d93d33cca with gcc (GCC) 8.4.1 20210217
./include/trace/events/writeback.h:377:3: error: implicit declaration of function 'strncpy_pad'; did you mean 'strscpy_pad'? [-Werror=implicit-function-declaration]
# git bisect skip fe4c89150d9b2fbfb013c35f4ffc1f8d93d33cca
There are only 'skip'ped commits left to test.
The first bad commit could be any of:
fe4c89150d9b2fbfb013c35f4ffc1f8d93d33cca
d24cf6d0d72a871f7fc6d96970bd4745ec59ac77
We cannot bisect more!

Reproducer flagged being flaky
revisions tested: 9, total time: 2h38m6.001226088s (build: 1h12m16.731460781s, test: 1h22m3.42510224s)
bisection is inconclusive, the first good commit could be any of:
fe4c89150d9b2fbfb013c35f4ffc1f8d93d33cca
d24cf6d0d72a871f7fc6d96970bd4745ec59ac77