user/sven/linux.git/include/trace, branch v4.19.207

bdi: use bdi_dev_name() to get device name

2021-08-08T06:54:29Z

[ Upstream commit d51cfc53ade3189455a1b88ec7a2ff0c24597cf8 ] Use the common interface bdi_dev_name() to get device name. Signed-off-by: Yufen Yu Signed-off-by: Christoph Hellwig Reviewed-by: Greg Kroah-Hartman Reviewed-by: Jan Kara Reviewed-by: Bart Van Assche Add missing include BFQ Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

memcg: fix a crash in wb_workfn when a device disappears

2021-02-13T12:51:15Z

[ Upstream commit 68f23b89067fdf187763e75a56087550624fdbee ] Without memcg, there is a one-to-one mapping between the bdi and bdi_writeback structures. In this world, things are fairly straightforward; the first thing bdi_unregister() does is to shutdown the bdi_writeback structure (or wb), and part of that writeback ensures that no other work queued against the wb, and that the wb is fully drained. With memcg, however, there is a one-to-many relationship between the bdi and bdi_writeback structures; that is, there are multiple wb objects which can all point to a single bdi. There is a refcount which prevents the bdi object from being released (and hence, unregistered). So in theory, the bdi_unregister() *should* only get called once its refcount goes to zero (bdi_put will drop the refcount, and when it is zero, release_bdi gets called, which calls bdi_unregister). Unfortunately, del_gendisk() in block/gen_hd.c never got the memo about the Brave New memcg World, and calls bdi_unregister directly. It does this without informing the file system, or the memcg code, or anything else. This causes the root wb associated with the bdi to be unregistered, but none of the memcg-specific wb's are shutdown. So when one of these wb's are woken up to do delayed work, they try to dereference their wb->bdi->dev to fetch the device name, but unfortunately bdi->dev is now NULL, thanks to the bdi_unregister() called by del_gendisk(). As a result, *boom*. Fortunately, it looks like the rest of the writeback path is perfectly happy with bdi->dev and bdi->owner being NULL, so the simplest fix is to create a bdi_dev_name() function which can handle bdi->dev being NULL. This also allows us to bulletproof the writeback tracepoints to prevent them from dereferencing a NULL pointer and crashing the kernel if one is tracing with memcg's enabled, and an iSCSI device dies or a USB storage stick is pulled. The most common way of triggering this will be hotremoval of a device while writeback with memcg enabled is going on. It was triggering several times a day in a heavily loaded production environment. Google Bug Id: 145475544 Link: https://lore.kernel.org/r/20191227194829.150110-1-tytso@mit.edu Link: http://lkml.kernel.org/r/20191228005211.163952-1-tytso@mit.edu Signed-off-by: Theodore Ts'o Cc: Chris Mason Cc: Tejun Heo Cc: Jens Axboe Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

include/trace/events/writeback.h: fix -Wstringop-truncation warnings

2021-02-13T12:51:15Z

[ Upstream commit d1a445d3b86c9341ce7a0954c23be0edb5c9bec5 ] There are many of those warnings. In file included from ./arch/powerpc/include/asm/paca.h:15, from ./arch/powerpc/include/asm/current.h:13, from ./include/linux/thread_info.h:21, from ./include/asm-generic/preempt.h:5, from ./arch/powerpc/include/generated/asm/preempt.h:1, from ./include/linux/preempt.h:78, from ./include/linux/spinlock.h:51, from fs/fs-writeback.c:19: In function 'strncpy', inlined from 'perf_trace_writeback_page_template' at ./include/trace/events/writeback.h:56:1: ./include/linux/string.h:260:9: warning: '__builtin_strncpy' specified bound 32 equals destination size [-Wstringop-truncation] return __builtin_strncpy(p, q, size); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Fix it by using the new strscpy_pad() which was introduced in "lib/string: Add strscpy_pad() function" and will always be NUL-terminated instead of strncpy(). Also, change strlcpy() to use strscpy_pad() in this file for consistency. Link: http://lkml.kernel.org/r/1564075099-27750-1-git-send-email-cai@lca.pw Fixes: 455b2864686d ("writeback: Initial tracing support") Fixes: 028c2dd184c0 ("writeback: Add tracing to balance_dirty_pages") Fixes: e84d0a4f8e39 ("writeback: trace event writeback_queue_io") Fixes: b48c104d2211 ("writeback: trace event bdi_dirty_ratelimit") Fixes: cc1676d917f3 ("writeback: Move requeueing when I_SYNC set to writeback_sb_inodes()") Fixes: 9fb0a7da0c52 ("writeback: add more tracepoints") Signed-off-by: Qian Cai Reviewed-by: Jan Kara Cc: Tobin C. Harding Cc: Steven Rostedt (VMware) Cc: Ingo Molnar Cc: Tejun Heo Cc: Dave Chinner Cc: Fengguang Wu Cc: Jens Axboe Cc: Joe Perches Cc: Kees Cook Cc: Jann Horn Cc: Jonathan Corbet Cc: Nitin Gote Cc: Rasmus Villemoes Cc: Stephen Kitt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

writeback: Drop I_DIRTY_TIME_EXPIRE

2021-01-30T12:32:13Z

commit 5fcd57505c002efc5823a7355e21f48dd02d5a51 upstream. The only use of I_DIRTY_TIME_EXPIRE is to detect in __writeback_single_inode() that inode got there because flush worker decided it's time to writeback the dirty inode time stamps (either because we are syncing or because of age). However we can detect this directly in __writeback_single_inode() and there's no need for the strange propagation with I_DIRTY_TIME_EXPIRE flag. Reviewed-by: Christoph Hellwig Signed-off-by: Jan Kara Signed-off-by: Eric Biggers Signed-off-by: Greg Kroah-Hartman

scsi: target: core: Add CONTROL field for trace events

2020-10-30T09:38:29Z

[ Upstream commit 7010645ba7256992818b518163f46bd4cdf8002a ] trace-cmd report doesn't show events from target subsystem because scsi_command_size() leaks through event format string: [target:target_sequencer_start] function scsi_command_size not defined [target:target_cmd_complete] function scsi_command_size not defined Addition of scsi_command_size() to plugin_scsi.c in trace-cmd doesn't help because an expression is used inside TP_printk(). trace-cmd event parser doesn't understand minus sign inside [ ]: Error: expected ']' but read '-' Rather than duplicating kernel code in plugin_scsi.c, provide a dedicated field for CONTROL byte. Link: https://lore.kernel.org/r/20200929125957.83069-1-r.bolshakov@yadro.com Reviewed-by: Mike Christie Signed-off-by: Roman Bolshakov Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

sctp: move trace_sctp_probe_path into sctp_outq_sack

2020-10-01T11:14:30Z

[ Upstream commit f643ee295c1c63bc117fb052d4da681354d6f732 ] The original patch bringed in the "SCTP ACK tracking trace event" feature was committed at Dec.20, 2017, it replaced jprobe usage with trace events, and bringed in two trace events, one is TRACE_EVENT(sctp_probe), another one is TRACE_EVENT(sctp_probe_path). The original patch intended to trigger the trace_sctp_probe_path in TRACE_EVENT(sctp_probe) as below code, +TRACE_EVENT(sctp_probe, + + TP_PROTO(const struct sctp_endpoint *ep, + const struct sctp_association *asoc, + struct sctp_chunk *chunk), + + TP_ARGS(ep, asoc, chunk), + + TP_STRUCT__entry( + __field(__u64, asoc) + __field(__u32, mark) + __field(__u16, bind_port) + __field(__u16, peer_port) + __field(__u32, pathmtu) + __field(__u32, rwnd) + __field(__u16, unack_data) + ), + + TP_fast_assign( + struct sk_buff *skb = chunk->skb; + + __entry->asoc = (unsigned long)asoc; + __entry->mark = skb->mark; + __entry->bind_port = ep->base.bind_addr.port; + __entry->peer_port = asoc->peer.port; + __entry->pathmtu = asoc->pathmtu; + __entry->rwnd = asoc->peer.rwnd; + __entry->unack_data = asoc->unack_data; + + if (trace_sctp_probe_path_enabled()) { + struct sctp_transport *sp; + + list_for_each_entry(sp, &asoc->peer.transport_addr_list, + transports) { + trace_sctp_probe_path(sp, asoc); + } + } + ), But I found it did not work when I did testing, and trace_sctp_probe_path had no output, I finally found that there is trace buffer lock operation(trace_event_buffer_reserve) in include/trace/trace_events.h: static notrace void \ trace_event_raw_event_##call(void *__data, proto) \ { \ struct trace_event_file *trace_file = __data; \ struct trace_event_data_offsets_##call __maybe_unused __data_offsets;\ struct trace_event_buffer fbuffer; \ struct trace_event_raw_##call *entry; \ int __data_size; \ \ if (trace_trigger_soft_disabled(trace_file)) \ return; \ \ __data_size = trace_event_get_offsets_##call(&__data_offsets, args); \ \ entry = trace_event_buffer_reserve(&fbuffer, trace_file, \ sizeof(*entry) + __data_size); \ \ if (!entry) \ return; \ \ tstruct \ \ { assign; } \ \ trace_event_buffer_commit(&fbuffer); \ } The reason caused no output of trace_sctp_probe_path is that trace_sctp_probe_path written in TP_fast_assign part of TRACE_EVENT(sctp_probe), and it will be placed( { assign; } ) after the trace_event_buffer_reserve() when compiler expands Macro, entry = trace_event_buffer_reserve(&fbuffer, trace_file, \ sizeof(*entry) + __data_size); \ \ if (!entry) \ return; \ \ tstruct \ \ { assign; } \ so trace_sctp_probe_path finally can not acquire trace_event_buffer and return no output, that is to say the nest of tracepoint entry function is not allowed. The function call flow is: trace_sctp_probe() -> trace_event_raw_event_sctp_probe() -> lock buffer -> trace_sctp_probe_path() -> trace_event_raw_event_sctp_probe_path() --nested -> buffer has been locked and return no output. This patch is to remove trace_sctp_probe_path from the TP_fast_assign part of TRACE_EVENT(sctp_probe) to avoid the nest of entry function, and trigger sctp_probe_path_trace in sctp_outq_sack. After this patch, you can enable both events individually, # cd /sys/kernel/debug/tracing # echo 1 > events/sctp/sctp_probe/enable # echo 1 > events/sctp/sctp_probe_path/enable Or, you can enable all the events under sctp. # echo 1 > events/sctp/enable Signed-off-by: Kevin Kou Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

writeback: Fix sync livelock due to b_dirty_time processing

2020-09-03T09:24:28Z

commit f9cae926f35e8230330f28c7b743ad088611a8de upstream. When we are processing writeback for sync(2), move_expired_inodes() didn't set any inode expiry value (older_than_this). This can result in writeback never completing if there's steady stream of inodes added to b_dirty_time list as writeback rechecks dirty lists after each writeback round whether there's more work to be done. Fix the problem by using sync(2) start time is inode expiry value when processing b_dirty_time list similarly as for ordinarily dirtied inodes. This requires some refactoring of older_than_this handling which simplifies the code noticeably as a bonus. Fixes: 0ae45f63d4ef ("vfs: add support for a lazytime mount option") CC: stable@vger.kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

rxrpc: Fix trace string

2020-07-22T07:32:13Z

commit aadf9dcef9d4cd68c73a4ab934f93319c4becc47 upstream. The trace symbol printer (__print_symbolic()) ignores symbols that map to an empty string and prints the hex value instead. Fix the symbol for rxrpc_cong_no_change to " -" instead of "" to avoid this. Fixes: b54a134a7de4 ("rxrpc: Fix handling of enums-to-string translation in tracing") Signed-off-by: David Howells Signed-off-by: Greg Kroah-Hartman

rxrpc: Trace discarded ACKs

2020-05-27T15:37:46Z

[ Upstream commit d1f129470e6cb79b8b97fecd12689f6eb49e27fe ] Add a tracepoint to track received ACKs that are discarded due to being outside of the Tx window. Signed-off-by: David Howells Signed-off-by: Sasha Levin

svcrdma: Fix trace point use-after-free race

2020-05-02T15:25:51Z

commit e28b4fc652c1830796a4d3e09565f30c20f9a2cf upstream. I hit this while testing nfsd-5.7 with kernel memory debugging enabled on my server: Mar 30 13:21:45 klimt kernel: BUG: unable to handle page fault for address: ffff8887e6c279a8 Mar 30 13:21:45 klimt kernel: #PF: supervisor read access in kernel mode Mar 30 13:21:45 klimt kernel: #PF: error_code(0x0000) - not-present page Mar 30 13:21:45 klimt kernel: PGD 3601067 P4D 3601067 PUD 87c519067 PMD 87c3e2067 PTE 800ffff8193d8060 Mar 30 13:21:45 klimt kernel: Oops: 0000 [#1] SMP DEBUG_PAGEALLOC PTI Mar 30 13:21:45 klimt kernel: CPU: 2 PID: 1933 Comm: nfsd Not tainted 5.6.0-rc6-00040-g881e87a3c6f9 #1591 Mar 30 13:21:45 klimt kernel: Hardware name: Supermicro Super Server/X10SRL-F, BIOS 1.0c 09/09/2015 Mar 30 13:21:45 klimt kernel: RIP: 0010:svc_rdma_post_chunk_ctxt+0xab/0x284 [rpcrdma] Mar 30 13:21:45 klimt kernel: Code: c1 83 34 02 00 00 29 d0 85 c0 7e 72 48 8b bb a0 02 00 00 48 8d 54 24 08 4c 89 e6 48 8b 07 48 8b 40 20 e8 5a 5c 2b e1 41 89 c6 <8b> 45 20 89 44 24 04 8b 05 02 e9 01 00 85 c0 7e 33 e9 5e 01 00 00 Mar 30 13:21:45 klimt kernel: RSP: 0018:ffffc90000dfbdd8 EFLAGS: 00010286 Mar 30 13:21:45 klimt kernel: RAX: 0000000000000000 RBX: ffff8887db8db400 RCX: 0000000000000030 Mar 30 13:21:45 klimt kernel: RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000246 Mar 30 13:21:45 klimt kernel: RBP: ffff8887e6c27988 R08: 0000000000000000 R09: 0000000000000004 Mar 30 13:21:45 klimt kernel: R10: ffffc90000dfbdd8 R11: 00c068ef00000000 R12: ffff8887eb4e4a80 Mar 30 13:21:45 klimt kernel: R13: ffff8887db8db634 R14: 0000000000000000 R15: ffff8887fc931000 Mar 30 13:21:45 klimt kernel: FS: 0000000000000000(0000) GS:ffff88885bd00000(0000) knlGS:0000000000000000 Mar 30 13:21:45 klimt kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Mar 30 13:21:45 klimt kernel: CR2: ffff8887e6c279a8 CR3: 000000081b72e002 CR4: 00000000001606e0 Mar 30 13:21:45 klimt kernel: Call Trace: Mar 30 13:21:45 klimt kernel: ? svc_rdma_vec_to_sg+0x7f/0x7f [rpcrdma] Mar 30 13:21:45 klimt kernel: svc_rdma_send_write_chunk+0x59/0xce [rpcrdma] Mar 30 13:21:45 klimt kernel: svc_rdma_sendto+0xf9/0x3ae [rpcrdma] Mar 30 13:21:45 klimt kernel: ? nfsd_destroy+0x51/0x51 [nfsd] Mar 30 13:21:45 klimt kernel: svc_send+0x105/0x1e3 [sunrpc] Mar 30 13:21:45 klimt kernel: nfsd+0xf2/0x149 [nfsd] Mar 30 13:21:45 klimt kernel: kthread+0xf6/0xfb Mar 30 13:21:45 klimt kernel: ? kthread_queue_delayed_work+0x74/0x74 Mar 30 13:21:45 klimt kernel: ret_from_fork+0x3a/0x50 Mar 30 13:21:45 klimt kernel: Modules linked in: ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue ib_umad ib_ipoib mlx4_ib sb_edac x86_pkg_temp_thermal iTCO_wdt iTCO_vendor_support coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel glue_helper crypto_simd cryptd pcspkr rpcrdma i2c_i801 rdma_ucm lpc_ich mfd_core ib_iser rdma_cm iw_cm ib_cm mei_me raid0 libiscsi mei sg scsi_transport_iscsi ioatdma wmi ipmi_si ipmi_devintf ipmi_msghandler acpi_power_meter nfsd nfs_acl lockd auth_rpcgss grace sunrpc ip_tables xfs libcrc32c mlx4_en sd_mod sr_mod cdrom mlx4_core crc32c_intel igb nvme i2c_algo_bit ahci i2c_core libahci nvme_core dca libata t10_pi qedr dm_mirror dm_region_hash dm_log dm_mod dax qede qed crc8 ib_uverbs ib_core Mar 30 13:21:45 klimt kernel: CR2: ffff8887e6c279a8 Mar 30 13:21:45 klimt kernel: ---[ end trace 87971d2ad3429424 ]--- It's absolutely not safe to use resources pointed to by the @send_wr argument of ib_post_send() _after_ that function returns. Those resources are typically freed by the Send completion handler, which can run before ib_post_send() returns. Thus the trace points currently around ib_post_send() in the server's RPC/RDMA transport are a hazard, even when they are disabled. Rearrange them so that they touch the Work Request only _before_ ib_post_send() is invoked. Fixes: bd2abef33394 ("svcrdma: Trace key RDMA API events") Fixes: 4201c7464753 ("svcrdma: Introduce svc_rdma_send_ctxt") Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman