| Message ID | 20220609211130.5108-5-logang@deltatee.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | Bug fixes and testing improvments | expand |
On Thu, 9 Jun 2022 15:11:20 -0600 Logan Gunthorpe <logang@deltatee.com> wrote: > --- > Grow.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/Grow.c b/Grow.c > index 8a242b0f8725..ba5dc1aead64 100644 > --- a/Grow.c > +++ b/Grow.c > @@ -3506,7 +3506,6 @@ started: > return 0; > } > > - close(fd); > /* Now we just need to kick off the reshape and watch, while > * handling backups of the data... > * This is all done by a forked background process. > @@ -3527,6 +3526,9 @@ started: > break; > } > > + /* Close unused file descriptor in the forked process */ > + close(fd); > + > /* If another array on the same devices is busy, the > * reshape will wait for them. This would mean that > * the first section that we suspend will stay suspended Please use close_fd() helper to invalidate fd too.
diff --git a/Grow.c b/Grow.c index 8a242b0f8725..ba5dc1aead64 100644 --- a/Grow.c +++ b/Grow.c @@ -3506,7 +3506,6 @@ started: return 0; } - close(fd); /* Now we just need to kick off the reshape and watch, while * handling backups of the data... * This is all done by a forked background process. @@ -3527,6 +3526,9 @@ started: break; } + /* Close unused file descriptor in the forked process */ + close(fd); + /* If another array on the same devices is busy, the * reshape will wait for them. This would mean that * the first section that we suspend will stay suspended
The test 07reshape-grow fails most of the time. But it succeeds around 1 in 5 times. When it does succeed, it causes the tests to die because mdadm has segfaulted. The segfault was caused by mdadm attempting to repoen a file descriptor that was already closed. The backtrace of the segfault was: #0 __strncmp_avx2 () at ../sysdeps/x86_64/multiarch/strcmp-avx2.S:101 #1 0x000056146e31d44b in devnm2devid (devnm=0x0) at util.c:956 #2 0x000056146e31dab4 in open_dev_flags (devnm=0x0, flags=0) at util.c:1072 #3 0x000056146e31db22 in open_dev (devnm=0x0) at util.c:1079 #4 0x000056146e3202e8 in reopen_mddev (mdfd=4) at util.c:2244 #5 0x000056146e329f36 in start_array (mdfd=4, mddev=0x7ffc55342450 "/dev/md0", content=0x7ffc55342860, st=0x56146fc78660, ident=0x7ffc55342f70, best=0x56146fc6f5d0, bestcnt=10, chosen_drive=0, devices=0x56146fc706b0, okcnt=5, sparecnt=0, rebuilding_cnt=0, journalcnt=0, c=0x7ffc55342e90, clean=1, avail=0x56146fc78720 "\001\001\001\001\001", start_partial_ok=0, err_ok=0, was_forced=0) at Assemble.c:1206 #6 0x000056146e32c36e in Assemble (st=0x56146fc78660, mddev=0x7ffc55342450 "/dev/md0", ident=0x7ffc55342f70, devlist=0x56146fc6e2d0, c=0x7ffc55342e90) at Assemble.c:1914 #7 0x000056146e312ac9 in main (argc=11, argv=0x7ffc55343238) at mdadm.c:1510 The file descriptor was closed early in Grow_continue(). The noted commit moved the close() call to close the fd above the fork which caused the parent process to return with a closed fd. This meant reshape_array() and Grow_continue() would return in the parent with the fd forked. The fd would eventually be passed to reopen_mddev() which returned an unhandled NULL from fd2devnm() which would then be dereferenced in devnm2devid. Fix this by moving the close() call below the fork. This appears to fix the 07revert-grow test. Fixes: 77b72fa82813 ("mdadm/Grow: prevent md's fd from being occupied during delayed time") Cc: Alex Wu <alexwu@synology.com> Cc: BingJing Chang <bingjingc@synology.com> Cc: Danny Shih <dannyshih@synology.com> Cc: ChangSyun Peng <allenpeng@synology.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> --- Grow.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)