munmap_chunk(): invalid pointer

[Nikratio]

Hi,

This is with s3backer compiled from commit 52b36f7:

# nbdkit --unix /tmp/tmpfmhnbd9z/nbd_socket_sb2 --foreground --filter=exitlast --filter=stats --threads 16 --filter=retry s3backer size=50G bucket=nikratio-backup/sb2 region=eu-west-2 statsfile=/home/nikratio/tmp/buckets/nikratio-backup_sb2_stats.txt statsappend=true retries=100 retry-readonly=false retry-delay=30 retry-exponential=no blockSize=32K &
nbdkit: auto-detecting block size and total file size...
nbdkit: auto-detection failed; using configured block size 32k and file size 50g
2022-07-17 12:37:32 INFO: established new mount token 0x1b65667f
2022-07-17 12:37:32 INFO: mounting nikratio-backup

# nbd-client -unix /tmp/tmpfmhnbd9z/nbd_socket_sb2 --timeout 604800 /dev/nbd0
Warning: the oldstyle protocol is no longer supported.
This method now uses the newstyle protocol with a default export
Negotiation: ..size = 51200MB
Connected /dev/nbd0

# mkfs.ext4 /dev/nbd0
mke2fs 1.46.2 (28-Feb-2021)
munmap_chunk(): invalid pointer
[ hanging process ]

[Nikratio]

With Valgrind:

valgrind -- nbdkit --unix /tmp/tmpuv5vkhvu/nbd_socket_sb2 --foreground --filter=exitlast --filter=stats --threads 1 --filter=retry s3backer size=50G bucket=nikratio-backup/sb2 region=eu-west-2 statsfile=/home/nikratio/tmp/buckets/nikratio-backup_sb2_stats.txt statsappend=true s3b_force=true retries=100 retry-readonly=false retry-delay=30 retry-exponential=no blockSize=32K
==248534== Memcheck, a memory error detector
==248534== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==248534== Using Valgrind-3.18.1 and LibVEX; rerun with -h for copyright info
==248534== Command: nbdkit --unix /tmp/tmpuv5vkhvu/nbd_socket_sb2 --foreground --filter=exitlast --filter=stats --threads 1 --filter=retry s3backer size=50G bucket=nikratio-backup/sb2 region=eu-west-2 statsfile=/home/nikratio/tmp/buckets/nikratio-backup_sb2_stats.txt statsappend=true s3b_force=true retries=100 retry-readonly=false retry-delay=30 retry-exponential=no blockSize=32K
==248534== 
nbdkit: auto-detecting block size and total file size...
nbdkit: auto-detection failed; using configured block size 32k and file size 50g
nbdkit: warning: filesystem appears already mounted but you said `--force'
 so I'll proceed anyway even though your data may get corrupted.

2022-07-17 12:50:20 INFO: established new mount token 0x035adf99
2022-07-17 12:50:20 INFO: mounting nikratio-backup

==248534== Thread 22:
==248534== Invalid free() / delete / delete[] / realloc()
==248534==    at 0xC9650FB: free (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==248534==    by 0xD05A5B1: zero_cache_bulk_zero (zero_cache.c:540)
==248534==    by 0xD054405: s3b_nbd_plugin_trim (nbdkit.c:426)
==248534==    by 0x11506D: plugin_trim (plugins.c:737)
==248534==    by 0x10F41A: backend_trim (backend.c:699)
==248534==    by 0xC9758D0: retry_trim (retry.c:333)
==248534==    by 0x10F41A: backend_trim (backend.c:699)
==248534==    by 0xC97D72F: stats_trim(nbdkit_next_ops*, void*, unsigned int, unsigned long, unsigned int, int*) (stats.cpp:526)
==248534==    by 0x10F41A: backend_trim (backend.c:699)
==248534==    by 0x10F41A: backend_trim (backend.c:699)
==248534==    by 0x1162B3: handle_request (protocol.c:262)
==248534==    by 0x1162B3: protocol_recv_request_send_reply (protocol.c:716)
==248534==    by 0x1112A1: handle_single_connection (connections.c:181)
==248534==  Address 0x19935084 is 2,004 bytes inside a block of size 2,048 alloc'd
==248534==    at 0xC9627B5: malloc (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==248534==    by 0xD05A519: zero_cache_bulk_zero (zero_cache.c:504)
==248534==    by 0xD054405: s3b_nbd_plugin_trim (nbdkit.c:426)
==248534==    by 0x11506D: plugin_trim (plugins.c:737)
==248534==    by 0x10F41A: backend_trim (backend.c:699)
==248534==    by 0xC9758D0: retry_trim (retry.c:333)
==248534==    by 0x10F41A: backend_trim (backend.c:699)
==248534==    by 0xC97D72F: stats_trim(nbdkit_next_ops*, void*, unsigned int, unsigned long, unsigned int, int*) (stats.cpp:526)
==248534==    by 0x10F41A: backend_trim (backend.c:699)
==248534==    by 0x10F41A: backend_trim (backend.c:699)
==248534==    by 0x1162B3: handle_request (protocol.c:262)
==248534==    by 0x1162B3: protocol_recv_request_send_reply (protocol.c:716)
==248534==    by 0x1112A1: handle_single_connection (connections.c:181)
==248534== 

[archiecobbs]

Argh, stupid bug on my part. Thanks for the valgrind info which made this easy to fix.

Should be fixed by d6fb1d4.