Fix pylint warnings on event_analyzing_sample.py #12

spoorthys1303 · 2023-10-11T14:34:27Z

Patch fixes the pylint warnings such as bad indentations, snake_case naming styles, missing-function-docstring, Unnecessary parens.

Other warnings such as too many arguments, too few public methods are ignored as they are required according to the functionality of the program.

Patch fixes the pylint warnings such as bad indentations, snake_case naming styles, missing-function-docstring, Unnecessary parens. Other warnings such as too many arguments, too few public methods are ignored as they are required according to the functionality of the program. Signed-off-by: Spoorthy S <[email protected]>

Fix an error detected by memory sanitizer: ``` ==4033==WARNING: MemorySanitizer: use-of-uninitialized-value #0 0x55fb0fbedfc7 in read_alias_info tools/perf/util/pmu.c:457:6 SamirMulani#1 0x55fb0fbea339 in check_info_data tools/perf/util/pmu.c:1434:2 SamirMulani#2 0x55fb0fbea339 in perf_pmu__check_alias tools/perf/util/pmu.c:1504:9 SamirMulani#3 0x55fb0fbdca85 in parse_events_add_pmu tools/perf/util/parse-events.c:1429:32 SamirMulani#4 0x55fb0f965230 in parse_events_parse tools/perf/util/parse-events.y:299:6 SamirMulani#5 0x55fb0fbdf6b2 in parse_events__scanner tools/perf/util/parse-events.c:1822:8 SamirMulani#6 0x55fb0fbdf8c1 in __parse_events tools/perf/util/parse-events.c:2094:8 SamirMulani#7 0x55fb0fa8ffa9 in parse_events tools/perf/util/parse-events.h:41:9 SamirMulani#8 0x55fb0fa8ffa9 in test_event tools/perf/tests/parse-events.c:2393:8 SamirMulani#9 0x55fb0fa8f458 in test__pmu_events tools/perf/tests/parse-events.c:2551:15 SamirMulani#10 0x55fb0fa6d93f in run_test tools/perf/tests/builtin-test.c:242:9 SamirMulani#11 0x55fb0fa6d93f in test_and_print tools/perf/tests/builtin-test.c:271:8 SamirMulani#12 0x55fb0fa6d082 in __cmd_test tools/perf/tests/builtin-test.c:442:5 SamirMulani#13 0x55fb0fa6d082 in cmd_test tools/perf/tests/builtin-test.c:564:9 torvalds#14 0x55fb0f942720 in run_builtin tools/perf/perf.c:322:11 torvalds#15 0x55fb0f942486 in handle_internal_command tools/perf/perf.c:375:8 torvalds#16 0x55fb0f941dab in run_argv tools/perf/perf.c:419:2 torvalds#17 0x55fb0f941dab in main tools/perf/perf.c:535:3 ``` Fixes: 7b723db ("perf pmu: Be lazy about loading event info files from sysfs") Signed-off-by: Ian Rogers <[email protected]> Cc: James Clark <[email protected]> Cc: Kan Liang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Namhyung Kim <[email protected]>

Fuzzing found that an invalid tracepoint name would create a memory leak with an address sanitizer build: ``` $ perf stat -e '*:o/' true event syntax error: '*:o/' \___ parser error Run 'perf list' for a list of valid events Usage: perf stat [<options>] [<command>] -e, --event <event> event selector. use 'perf list' to list available events ================================================================= ==59380==ERROR: LeakSanitizer: detected memory leaks Direct leak of 4 byte(s) in 2 object(s) allocated from: #0 0x7f38ac07077b in __interceptor_strdup ../../../../src/libsanitizer/asan/asan_interceptors.cpp:439 SamirMulani#1 0x55f2f41be73b in str util/parse-events.l:49 SamirMulani#2 0x55f2f41d08e8 in parse_events_lex util/parse-events.l:338 SamirMulani#3 0x55f2f41dc3b1 in parse_events_parse util/parse-events-bison.c:1464 SamirMulani#4 0x55f2f410b8b3 in parse_events__scanner util/parse-events.c:1822 SamirMulani#5 0x55f2f410d1b9 in __parse_events util/parse-events.c:2094 SamirMulani#6 0x55f2f410e57f in parse_events_option util/parse-events.c:2279 SamirMulani#7 0x55f2f4427b56 in get_value tools/lib/subcmd/parse-options.c:251 SamirMulani#8 0x55f2f4428d98 in parse_short_opt tools/lib/subcmd/parse-options.c:351 SamirMulani#9 0x55f2f4429d80 in parse_options_step tools/lib/subcmd/parse-options.c:539 SamirMulani#10 0x55f2f442acb9 in parse_options_subcommand tools/lib/subcmd/parse-options.c:654 SamirMulani#11 0x55f2f3ec99fc in cmd_stat tools/perf/builtin-stat.c:2501 SamirMulani#12 0x55f2f4093289 in run_builtin tools/perf/perf.c:322 SamirMulani#13 0x55f2f40937f5 in handle_internal_command tools/perf/perf.c:375 torvalds#14 0x55f2f4093bbd in run_argv tools/perf/perf.c:419 torvalds#15 0x55f2f409412b in main tools/perf/perf.c:535 SUMMARY: AddressSanitizer: 4 byte(s) leaked in 2 allocation(s). ``` Fix by adding the missing destructor. Fixes: 865582c ("perf tools: Adds the tracepoint name parsing support") Signed-off-by: Ian Rogers <[email protected]> Cc: He Kuang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Namhyung Kim <[email protected]>

Once unix_sk(sk)->addr is assigned under net->unx.table.locks and unix_sk(sk)->bindlock, *(unix_sk(sk)->addr) and unix_sk(sk)->path are fully set up, and unix_sk(sk)->addr is never changed. unix_getname() and unix_copy_addr() access the two fields locklessly, and commit ae3b564 ("missing barriers in some of unix_sock ->addr and ->path accesses") added smp_store_release() and smp_load_acquire() pairs. In other functions, we still read unix_sk(sk)->addr locklessly to check if the socket is bound, and KCSAN complains about it. [0] Given these functions have no dependency for *(unix_sk(sk)->addr) and unix_sk(sk)->path, READ_ONCE() is enough to annotate the data-race. Note that it is safe to access unix_sk(sk)->addr locklessly if the socket is found in the hash table. For example, the lockless read of otheru->addr in unix_stream_connect() is safe. Note also that newu->addr there is of the child socket that is still not accessible from userspace, and smp_store_release() publishes the address in case the socket is accept()ed and unix_getname() / unix_copy_addr() is called. [0]: BUG: KCSAN: data-race in unix_bind / unix_listen write (marked) to 0xffff88805f8d1840 of 8 bytes by task 13723 on cpu 0: __unix_set_addr_hash net/unix/af_unix.c:329 [inline] unix_bind_bsd net/unix/af_unix.c:1241 [inline] unix_bind+0x881/0x1000 net/unix/af_unix.c:1319 __sys_bind+0x194/0x1e0 net/socket.c:1847 __do_sys_bind net/socket.c:1858 [inline] __se_sys_bind net/socket.c:1856 [inline] __x64_sys_bind+0x40/0x50 net/socket.c:1856 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x4f/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x46/0x4e read to 0xffff88805f8d1840 of 8 bytes by task 13724 on cpu 1: unix_listen+0x72/0x180 net/unix/af_unix.c:734 __sys_listen+0xdc/0x160 net/socket.c:1881 __do_sys_listen net/socket.c:1890 [inline] __se_sys_listen net/socket.c:1888 [inline] __x64_sys_listen+0x2e/0x40 net/socket.c:1888 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x4f/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x46/0x4e value changed: 0x0000000000000000 -> 0xffff88807b5b1b40 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 13724 Comm: syz-executor.4 Not tainted 6.8.0-12822-gcd51db110a7e SamirMulani#12 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzkaller <[email protected]> Signed-off-by: Kuniyuki Iwashima <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Paolo Abeni <[email protected]>

syzkaller reported data-race of sk->sk_hash in unix_autobind() [0], and the same ones exist in unix_bind_bsd() and unix_bind_abstract(). The three bind() functions prefetch sk->sk_hash locklessly and use it later after validating that unix_sk(sk)->addr is NULL under unix_sk(sk)->bindlock. The prefetched sk->sk_hash is the hash value of unbound socket set in unix_create1() and does not change until bind() completes. There could be a chance that sk->sk_hash changes after the lockless read. However, in such a case, non-NULL unix_sk(sk)->addr is visible under unix_sk(sk)->bindlock, and bind() returns -EINVAL without using the prefetched value. The KCSAN splat is false-positive, but let's silence it by reading sk->sk_hash under unix_sk(sk)->bindlock. [0]: BUG: KCSAN: data-race in unix_autobind / unix_autobind write to 0xffff888034a9fb88 of 4 bytes by task 4468 on cpu 0: __unix_set_addr_hash net/unix/af_unix.c:331 [inline] unix_autobind+0x47a/0x7d0 net/unix/af_unix.c:1185 unix_dgram_connect+0x7e3/0x890 net/unix/af_unix.c:1373 __sys_connect_file+0xd7/0xe0 net/socket.c:2048 __sys_connect+0x114/0x140 net/socket.c:2065 __do_sys_connect net/socket.c:2075 [inline] __se_sys_connect net/socket.c:2072 [inline] __x64_sys_connect+0x40/0x50 net/socket.c:2072 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x4f/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x46/0x4e read to 0xffff888034a9fb88 of 4 bytes by task 4465 on cpu 1: unix_autobind+0x28/0x7d0 net/unix/af_unix.c:1134 unix_dgram_connect+0x7e3/0x890 net/unix/af_unix.c:1373 __sys_connect_file+0xd7/0xe0 net/socket.c:2048 __sys_connect+0x114/0x140 net/socket.c:2065 __do_sys_connect net/socket.c:2075 [inline] __se_sys_connect net/socket.c:2072 [inline] __x64_sys_connect+0x40/0x50 net/socket.c:2072 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x4f/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x46/0x4e value changed: 0x000000e4 -> 0x000001e3 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 4465 Comm: syz-executor.0 Not tainted 6.8.0-12822-gcd51db110a7e SamirMulani#12 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Fixes: afd20b9 ("af_unix: Replace the big lock with small locks.") Reported-by: syzkaller <[email protected]> Signed-off-by: Kuniyuki Iwashima <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Paolo Abeni <[email protected]>

…PLES event" This reverts commit 7d1405c. This causes segfaults in some cases, as reported by Milian: ``` sudo /usr/bin/perf record -z --call-graph dwarf -e cycles -e raw_syscalls:sys_enter ls ... [ perf record: Woken up 3 times to write data ] malloc(): invalid next size (unsorted) Aborted ``` Backtrace with GDB + debuginfod: ``` malloc(): invalid next size (unsorted) Thread 1 "perf" received signal SIGABRT, Aborted. __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44 Downloading source file /usr/src/debug/glibc/glibc/nptl/pthread_kill.c 44 return INTERNAL_SYSCALL_ERROR_P (ret) ? INTERNAL_SYSCALL_ERRNO (ret) : 0; (gdb) bt #0 __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44 SamirMulani#1 0x00007ffff6ea8eb3 in __pthread_kill_internal (threadid=<optimized out>, signo=6) at pthread_kill.c:78 SamirMulani#2 0x00007ffff6e50a30 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/ raise.c:26 SamirMulani#3 0x00007ffff6e384c3 in __GI_abort () at abort.c:79 SamirMulani#4 0x00007ffff6e39354 in __libc_message_impl (fmt=fmt@entry=0x7ffff6fc22ea "%s\n") at ../sysdeps/posix/libc_fatal.c:132 SamirMulani#5 0x00007ffff6eb3085 in malloc_printerr (str=str@entry=0x7ffff6fc5850 "malloc(): invalid next size (unsorted)") at malloc.c:5772 SamirMulani#6 0x00007ffff6eb657c in _int_malloc (av=av@entry=0x7ffff6ff6ac0 <main_arena>, bytes=bytes@entry=368) at malloc.c:4081 SamirMulani#7 0x00007ffff6eb877e in __libc_calloc (n=<optimized out>, elem_size=<optimized out>) at malloc.c:3754 SamirMulani#8 0x000055555569bdb6 in perf_session.do_write_header () SamirMulani#9 0x00005555555a373a in __cmd_record.constprop.0 () SamirMulani#10 0x00005555555a6846 in cmd_record () SamirMulani#11 0x000055555564db7f in run_builtin () SamirMulani#12 0x000055555558ed77 in main () ``` Valgrind memcheck: ``` ==45136== Invalid write of size 8 ==45136== at 0x2B38A5: perf_event__synthesize_id_sample (in /usr/bin/perf) ==45136== by 0x157069: __cmd_record.constprop.0 (in /usr/bin/perf) ==45136== by 0x15A845: cmd_record (in /usr/bin/perf) ==45136== by 0x201B7E: run_builtin (in /usr/bin/perf) ==45136== by 0x142D76: main (in /usr/bin/perf) ==45136== Address 0x6a866a8 is 0 bytes after a block of size 40 alloc'd ==45136== at 0x4849BF3: calloc (vg_replace_malloc.c:1675) ==45136== by 0x3574AB: zalloc (in /usr/bin/perf) ==45136== by 0x1570E0: __cmd_record.constprop.0 (in /usr/bin/perf) ==45136== by 0x15A845: cmd_record (in /usr/bin/perf) ==45136== by 0x201B7E: run_builtin (in /usr/bin/perf) ==45136== by 0x142D76: main (in /usr/bin/perf) ==45136== ==45136== Syscall param write(buf) points to unaddressable byte(s) ==45136== at 0x575953D: __libc_write (write.c:26) ==45136== by 0x575953D: write (write.c:24) ==45136== by 0x35761F: ion (in /usr/bin/perf) ==45136== by 0x357778: writen (in /usr/bin/perf) ==45136== by 0x1548F7: record__write (in /usr/bin/perf) ==45136== by 0x15708A: __cmd_record.constprop.0 (in /usr/bin/perf) ==45136== by 0x15A845: cmd_record (in /usr/bin/perf) ==45136== by 0x201B7E: run_builtin (in /usr/bin/perf) ==45136== by 0x142D76: main (in /usr/bin/perf) ==45136== Address 0x6a866a8 is 0 bytes after a block of size 40 alloc'd ==45136== at 0x4849BF3: calloc (vg_replace_malloc.c:1675) ==45136== by 0x3574AB: zalloc (in /usr/bin/perf) ==45136== by 0x1570E0: __cmd_record.constprop.0 (in /usr/bin/perf) ==45136== by 0x15A845: cmd_record (in /usr/bin/perf) ==45136== by 0x201B7E: run_builtin (in /usr/bin/perf) ==45136== by 0x142D76: main (in /usr/bin/perf) ==45136== ----- Closes: https://lore.kernel.org/linux-perf-users/23879991.0LEYPuXRzz@milian-workstation/ Reported-by: Milian Wolff <[email protected]> Tested-by: Milian Wolff <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Kan Liang <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: [email protected] # 6.8+ Link: https://lore.kernel.org/lkml/Zl9ksOlHJHnKM70p@x1 Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

We have been seeing crashes on duplicate keys in btrfs_set_item_key_safe(): BTRFS critical (device vdb): slot 4 key (450 108 8192) new key (450 108 8192) ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.c:2620! invalid opcode: 0000 [SamirMulani#1] PREEMPT SMP PTI CPU: 0 PID: 3139 Comm: xfs_io Kdump: loaded Not tainted 6.9.0 SamirMulani#6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:btrfs_set_item_key_safe+0x11f/0x290 [btrfs] With the following stack trace: #0 btrfs_set_item_key_safe (fs/btrfs/ctree.c:2620:4) SamirMulani#1 btrfs_drop_extents (fs/btrfs/file.c:411:4) SamirMulani#2 log_one_extent (fs/btrfs/tree-log.c:4732:9) SamirMulani#3 btrfs_log_changed_extents (fs/btrfs/tree-log.c:4955:9) SamirMulani#4 btrfs_log_inode (fs/btrfs/tree-log.c:6626:9) SamirMulani#5 btrfs_log_inode_parent (fs/btrfs/tree-log.c:7070:8) SamirMulani#6 btrfs_log_dentry_safe (fs/btrfs/tree-log.c:7171:8) SamirMulani#7 btrfs_sync_file (fs/btrfs/file.c:1933:8) SamirMulani#8 vfs_fsync_range (fs/sync.c:188:9) SamirMulani#9 vfs_fsync (fs/sync.c:202:9) SamirMulani#10 do_fsync (fs/sync.c:212:9) SamirMulani#11 __do_sys_fdatasync (fs/sync.c:225:9) SamirMulani#12 __se_sys_fdatasync (fs/sync.c:223:1) SamirMulani#13 __x64_sys_fdatasync (fs/sync.c:223:1) torvalds#14 do_syscall_x64 (arch/x86/entry/common.c:52:14) torvalds#15 do_syscall_64 (arch/x86/entry/common.c:83:7) torvalds#16 entry_SYSCALL_64+0xaf/0x14c (arch/x86/entry/entry_64.S:121) So we're logging a changed extent from fsync, which is splitting an extent in the log tree. But this split part already exists in the tree, triggering the BUG(). This is the state of the log tree at the time of the crash, dumped with drgn (https://github.com/osandov/drgn/blob/main/contrib/btrfs_tree.py) to get more details than btrfs_print_leaf() gives us: >>> print_extent_buffer(prog.crashed_thread().stack_trace()[0]["eb"]) leaf 33439744 level 0 items 72 generation 9 owner 18446744073709551610 leaf 33439744 flags 0x100000000000000 fs uuid e5bd3946-400c-4223-8923-190ef1f18677 chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da item 0 key (450 INODE_ITEM 0) itemoff 16123 itemsize 160 generation 7 transid 9 size 8192 nbytes 8473563889606862198 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 204 flags 0x10(PREALLOC) atime 1716417703.220000000 (2024-05-22 15:41:43) ctime 1716417704.983333333 (2024-05-22 15:41:44) mtime 1716417704.983333333 (2024-05-22 15:41:44) otime 17592186044416.000000000 (559444-03-08 01:40:16) item 1 key (450 INODE_REF 256) itemoff 16110 itemsize 13 index 195 namelen 3 name: 193 item 2 key (450 XATTR_ITEM 1640047104) itemoff 16073 itemsize 37 location key (0 UNKNOWN.0 0) type XATTR transid 7 data_len 1 name_len 6 name: user.a data a item 3 key (450 EXTENT_DATA 0) itemoff 16020 itemsize 53 generation 9 type 1 (regular) extent data disk byte 303144960 nr 12288 extent data offset 0 nr 4096 ram 12288 extent compression 0 (none) item 4 key (450 EXTENT_DATA 4096) itemoff 15967 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 4096 nr 8192 item 5 key (450 EXTENT_DATA 8192) itemoff 15914 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 8192 nr 4096 ... So the real problem happened earlier: notice that items 4 (4k-12k) and 5 (8k-12k) overlap. Both are prealloc extents. Item 4 straddles i_size and item 5 starts at i_size. Here is the state of the filesystem tree at the time of the crash: >>> root = prog.crashed_thread().stack_trace()[2]["inode"].root >>> ret, nodes, slots = btrfs_search_slot(root, BtrfsKey(450, 0, 0)) >>> print_extent_buffer(nodes[0]) leaf 30425088 level 0 items 184 generation 9 owner 5 leaf 30425088 flags 0x100000000000000 fs uuid e5bd3946-400c-4223-8923-190ef1f18677 chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da ... item 179 key (450 INODE_ITEM 0) itemoff 4907 itemsize 160 generation 7 transid 7 size 4096 nbytes 12288 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 6 flags 0x10(PREALLOC) atime 1716417703.220000000 (2024-05-22 15:41:43) ctime 1716417703.220000000 (2024-05-22 15:41:43) mtime 1716417703.220000000 (2024-05-22 15:41:43) otime 1716417703.220000000 (2024-05-22 15:41:43) item 180 key (450 INODE_REF 256) itemoff 4894 itemsize 13 index 195 namelen 3 name: 193 item 181 key (450 XATTR_ITEM 1640047104) itemoff 4857 itemsize 37 location key (0 UNKNOWN.0 0) type XATTR transid 7 data_len 1 name_len 6 name: user.a data a item 182 key (450 EXTENT_DATA 0) itemoff 4804 itemsize 53 generation 9 type 1 (regular) extent data disk byte 303144960 nr 12288 extent data offset 0 nr 8192 ram 12288 extent compression 0 (none) item 183 key (450 EXTENT_DATA 8192) itemoff 4751 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 8192 nr 4096 Item 5 in the log tree corresponds to item 183 in the filesystem tree, but nothing matches item 4. Furthermore, item 183 is the last item in the leaf. btrfs_log_prealloc_extents() is responsible for logging prealloc extents beyond i_size. It first truncates any previously logged prealloc extents that start beyond i_size. Then, it walks the filesystem tree and copies the prealloc extent items to the log tree. If it hits the end of a leaf, then it calls btrfs_next_leaf(), which unlocks the tree and does another search. However, while the filesystem tree is unlocked, an ordered extent completion may modify the tree. In particular, it may insert an extent item that overlaps with an extent item that was already copied to the log tree. This may manifest in several ways depending on the exact scenario, including an EEXIST error that is silently translated to a full sync, overlapping items in the log tree, or this crash. This particular crash is triggered by the following sequence of events: - Initially, the file has i_size=4k, a regular extent from 0-4k, and a prealloc extent beyond i_size from 4k-12k. The prealloc extent item is the last item in its B-tree leaf. - The file is fsync'd, which copies its inode item and both extent items to the log tree. - An xattr is set on the file, which sets the BTRFS_INODE_COPY_EVERYTHING flag. - The range 4k-8k in the file is written using direct I/O. i_size is extended to 8k, but the ordered extent is still in flight. - The file is fsync'd. Since BTRFS_INODE_COPY_EVERYTHING is set, this calls copy_inode_items_to_log(), which calls btrfs_log_prealloc_extents(). - btrfs_log_prealloc_extents() finds the 4k-12k prealloc extent in the filesystem tree. Since it starts before i_size, it skips it. Since it is the last item in its B-tree leaf, it calls btrfs_next_leaf(). - btrfs_next_leaf() unlocks the path. - The ordered extent completion runs, which converts the 4k-8k part of the prealloc extent to written and inserts the remaining prealloc part from 8k-12k. - btrfs_next_leaf() does a search and finds the new prealloc extent 8k-12k. - btrfs_log_prealloc_extents() copies the 8k-12k prealloc extent into the log tree. Note that it overlaps with the 4k-12k prealloc extent that was copied to the log tree by the first fsync. - fsync calls btrfs_log_changed_extents(), which tries to log the 4k-8k extent that was written. - This tries to drop the range 4k-8k in the log tree, which requires adjusting the start of the 4k-12k prealloc extent in the log tree to 8k. - btrfs_set_item_key_safe() sees that there is already an extent starting at 8k in the log tree and calls BUG(). Fix this by detecting when we're about to insert an overlapping file extent item in the log tree and truncating the part that would overlap. CC: [email protected] # 6.1+ Reviewed-by: Filipe Manana <[email protected]> Signed-off-by: Omar Sandoval <[email protected]> Signed-off-by: David Sterba <[email protected]>

Guilherme reported a crash in perf mem record. It's because the perf_mem_event->name was NULL on his machine. It should just return a NULL string when it has no format string in the name. The backtrace at the crash is below: Program received signal SIGSEGV, Segmentation fault. __strchrnul_avx2 () at ../sysdeps/x86_64/multiarch/strchr-avx2.S:67 67 vmovdqu (%rdi), %ymm2 (gdb) bt #0 __strchrnul_avx2 () at ../sysdeps/x86_64/multiarch/strchr-avx2.S:67 SamirMulani#1 0x00007ffff6c982de in __find_specmb (format=0x0) at printf-parse.h:82 SamirMulani#2 __printf_buffer (buf=buf@entry=0x7fffffffc760, format=format@entry=0x0, ap=ap@entry=0x7fffffffc880, mode_flags=mode_flags@entry=0) at vfprintf-internal.c:649 SamirMulani#3 0x00007ffff6cb7840 in __vsnprintf_internal (string=<optimized out>, maxlen=<optimized out>, format=0x0, args=0x7fffffffc880, mode_flags=mode_flags@entry=0) at vsnprintf.c:96 SamirMulani#4 0x00007ffff6cb787f in ___vsnprintf (string=<optimized out>, maxlen=<optimized out>, format=<optimized out>, args=<optimized out>) at vsnprintf.c:103 SamirMulani#5 0x00005555557b9391 in scnprintf (buf=0x555555fe9320 <mem_loads_name> "", size=100, fmt=0x0) at ../lib/vsprintf.c:21 SamirMulani#6 0x00005555557b74c3 in perf_pmu__mem_events_name (i=0, pmu=0x555556832180) at util/mem-events.c:106 SamirMulani#7 0x00005555557b7ab9 in perf_mem_events__record_args (rec_argv=0x55555684c000, argv_nr=0x7fffffffca20) at util/mem-events.c:252 SamirMulani#8 0x00005555555e370d in __cmd_record (argc=3, argv=0x7fffffffd760, mem=0x7fffffffcd80) at builtin-mem.c:156 SamirMulani#9 0x00005555555e49c4 in cmd_mem (argc=4, argv=0x7fffffffd760) at builtin-mem.c:514 SamirMulani#10 0x000055555569716c in run_builtin (p=0x555555fcde80 <commands+672>, argc=8, argv=0x7fffffffd760) at perf.c:349 SamirMulani#11 0x0000555555697402 in handle_internal_command (argc=8, argv=0x7fffffffd760) at perf.c:402 SamirMulani#12 0x0000555555697560 in run_argv (argcp=0x7fffffffd59c, argv=0x7fffffffd590) at perf.c:446 SamirMulani#13 0x00005555556978a6 in main (argc=8, argv=0x7fffffffd760) at perf.c:562 Reported-by: Guilherme Amadio <[email protected]> Reviewed-by: Kan Liang <[email protected]> Closes: https://lore.kernel.org/linux-perf-users/[email protected] Signed-off-by: Namhyung Kim <[email protected]> Link: https://lore.kernel.org/r/[email protected]

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Fix pylint warnings on event_analyzing_sample.py #12

Fix pylint warnings on event_analyzing_sample.py #12

spoorthys1303 commented Oct 11, 2023

Fix pylint warnings on event_analyzing_sample.py #12

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Fix pylint warnings on event_analyzing_sample.py #12

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spoorthys1303 commented Oct 11, 2023