user/sven/linux.git/kernel/trace/blktrace.c, branch v6.16.2

traceevent/block: Add REQ_ATOMIC flag to block trace events

2025-05-23T15:18:48Z

Filesystems like XFS can implement atomic write I/O using either REQ_ATOMIC flag set in the bio or via CoW operation. It will be useful if we have a flag in trace events to distinguish between the two. This patch adds char 'U' (Untorn writes) to rwbs field of the trace events if REQ_ATOMIC flag is set in the bio. ================= xfs_io-4238 [009] ..... 4148.126843: block_rq_issue: 259,0 WFSU 16384 () 768 + 32 none,0,0 [xfs_io] -0 [009] d.h1. 4148.129864: block_rq_complete: 259,0 WFSU () 768 + 32 none,0,0 [0] =============== xfs_io-4237 [010] ..... 4143.325616: block_rq_issue: 259,0 WS 16384 () 768 + 32 none,0,0 [xfs_io] -0 [010] d.H1. 4143.329138: block_rq_complete: 259,0 WS () 768 + 32 none,0,0 [0] Signed-off-by: Ritesh Harjani (IBM) Reviewed-by: Ojaswin Mujoo Link: https://lore.kernel.org/r/44317cb2ec4588f6a2c1501a96684e6a1196e8ba.1747921498.git.ritesh.list@gmail.com Signed-off-by: Jens Axboe

block: remove bounce buffering support

2025-05-05T19:22:39Z

The block layer bounce buffering support is unused now, remove it. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: John Garry Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20250505081138.3435992-7-hch@lst.de Signed-off-by: Jens Axboe

blktrace: remove redundant return at end of function

2024-12-23T15:17:23Z

A recent change added return 0 before an existing return statement at the end of function blk_trace_setup. The final return is now redundant, so remove it. Fixes: 64d124798244 ("blktrace: move copy_[to|from]_user() out of ->debugfs_lock") Signed-off-by: Colin Ian King Link: https://lore.kernel.org/r/20241204150450.399005-1-colin.i.king@gmail.com Signed-off-by: Jens Axboe

blktrace: move copy_[to|from]_user() out of ->debugfs_lock

2024-12-23T15:17:22Z

Move copy_[to|from]_user() out of ->debugfs_lock and cut the dependency between mm->mmap_lock and q->debugfs_lock, then we avoids lots of lockdep false positive warning. Obviously ->debug_lock isn't needed for copy_[to|from]_user(). The only behavior change is to call blk_trace_remove() in case of setup failure handling by re-grabbing ->debugfs_lock, and this way is just fine since we do cover concurrent setup() & remove(). Reported-by: syzbot+91585b36b538053343e4@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-block/67450fd4.050a0220.1286eb.0007.GAE@google.com/ Closes: https://lore.kernel.org/linux-block/6742e584.050a0220.1cc393.0038.GAE@google.com/ Closes: https://lore.kernel.org/linux-block/6742a600.050a0220.1cc393.002e.GAE@google.com/ Closes: https://lore.kernel.org/linux-block/67420102.050a0220.1cc393.0019.GAE@google.com/ Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20241128125029.4152292-3-ming.lei@redhat.com Signed-off-by: Jens Axboe

blktrace: don't centralize grabbing q->debugfs_mutex in blk_trace_ioctl

2024-12-23T15:17:22Z

Call each handler directly and the handler do grab q->debugfs_mutex, prepare for killing dependency between ->debug_mutex and ->mmap_lock. Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20241128125029.4152292-2-ming.lei@redhat.com Signed-off-by: Jens Axboe

blktrace: convert strncpy() to strscpy_pad()

2024-04-26T04:07:08Z

gcc-9 warns about a possibly non-terminated string copy: kernel/trace/blktrace.c: In function 'do_blk_trace_setup': kernel/trace/blktrace.c:527:2: error: 'strncpy' specified bound 32 equals destination size [-Werror=stringop-truncation] Newer versions are fine here because they see the following explicit nul-termination. Using strscpy_pad() avoids the warning and simplifies the code a little. The padding helps give a clean buffer to userspace. Link: https://lkml.kernel.org/r/20240409140059.3806717-5-arnd@kernel.org Signed-off-by: Arnd Bergmann Acked-by: Justin Stitt Cc: Alexey Starikovskiy Cc: Bob Moore Cc: Jens Axboe Cc: Len Brown Cc: Lin Ming Cc: Masahiro Yamada Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Nathan Chancellor Cc: Nicolas Schier Cc: Rafael J. Wysocki Cc: "Richard Russon (FlatCap)" Cc: Steven Rostedt Signed-off-by: Andrew Morton

block: remove more NULL checks after bdev_get_queue()

2023-02-21T16:23:22Z

bdev_get_queue() never returns NULL. Several commits [1][2] have been made before to remove such superfluous checks, but some still remained. For places where bdev_get_queue() is called solely for NULL checks, it is removed entirely. [1] commit ec9fd2a13d74 ("blk-lib: don't check bdev_get_queue() NULL check") [2] commit fea127b36c93 ("block: remove superfluous check for request queue in bdev_is_zoned()") Signed-off-by: Juhyung Park Reviewed-by: Pankaj Raghav Link: https://lore.kernel.org/r/20230203024029.48260-1-qkrwngud825@gmail.com Signed-off-by: Jens Axboe

trace/blktrace: fix memory leak with using debugfs_lookup()

2023-02-06T16:29:30Z

When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Cc: Jens Axboe Cc: Steven Rostedt Cc: Masami Hiramatsu Cc: linux-block@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-trace-kernel@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Reviewed-by: Bart Van Assche Link: https://lore.kernel.org/r/20230202141956.2299521-1-gregkh@linuxfoundation.org Signed-off-by: Jens Axboe

blktrace: Fix output non-blktrace event when blk_classic option enabled

2022-12-08T16:26:11Z

When the blk_classic option is enabled, non-blktrace events must be filtered out. Otherwise, events of other types are output in the blktrace classic format, which is unexpected. The problem can be triggered in the following ways: # echo 1 > /sys/kernel/debug/tracing/options/blk_classic # echo 1 > /sys/kernel/debug/tracing/events/enable # echo blk > /sys/kernel/debug/tracing/current_tracer # cat /sys/kernel/debug/tracing/trace_pipe Fixes: c71a89615411 ("blktrace: add ftrace plugin") Signed-off-by: Yang Jihong Link: https://lore.kernel.org/r/20221122040410.85113-1-yangjihong1@huawei.com Signed-off-by: Jens Axboe

block: bdev & blktrace: use consistent function doc. notation

2022-12-01T16:16:46Z

Use only one hyphen in kernel-doc notation between the function name and its short description. The is the documented kerenl-doc format. It also fixes the HTML presentation to be consistent with other functions. Signed-off-by: Randy Dunlap Cc: Jens Axboe Cc: linux-block@vger.kernel.org Link: https://lore.kernel.org/r/20221201070331.25685-1-rdunlap@infradead.org Signed-off-by: Jens Axboe