diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-10-27 14:10:32 -1000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-10-27 14:10:32 -1000 |
| commit | 56567a20b22bdbf85c3e55eee3bf2bd23fa2f108 (patch) | |
| tree | 4399adee6ec6ba2a43b1a57cf573cac5c231e6ee | |
| parent | 2dc4e0f45593abc53d58d0073b3b314f864c522b (diff) | |
| parent | 838b35bb6a89c36da07ca39520ec071d9250334d (diff) | |
Merge tag 'io_uring-6.6-2023-10-27' of git://git.kernel.dk/linux
Pull io_uring fixes from Jens Axboe:
"Fix for an issue reported where reading fdinfo could find a NULL
thread as we didn't properly synchronize, and then a disable for the
IOCB_DIO_CALLER_COMP optimization as a recent reported highlighted how
that could lead to deadlocks if the task issued async O_DIRECT writes
and then proceeded to do sync fallocate() calls"
* tag 'io_uring-6.6-2023-10-27' of git://git.kernel.dk/linux:
io_uring/rw: disable IOCB_DIO_CALLER_COMP
io_uring/fdinfo: lock SQ thread while retrieving thread cpu/pid
| -rw-r--r-- | io_uring/fdinfo.c | 18 | ||||
| -rw-r--r-- | io_uring/rw.c | 9 |
2 files changed, 12 insertions, 15 deletions
diff --git a/io_uring/fdinfo.c b/io_uring/fdinfo.c index c53678875416..f04a43044d91 100644 --- a/io_uring/fdinfo.c +++ b/io_uring/fdinfo.c @@ -53,7 +53,6 @@ static __cold int io_uring_show_cred(struct seq_file *m, unsigned int id, __cold void io_uring_show_fdinfo(struct seq_file *m, struct file *f) { struct io_ring_ctx *ctx = f->private_data; - struct io_sq_data *sq = NULL; struct io_overflow_cqe *ocqe; struct io_rings *r = ctx->rings; unsigned int sq_mask = ctx->sq_entries - 1, cq_mask = ctx->cq_entries - 1; @@ -64,6 +63,7 @@ __cold void io_uring_show_fdinfo(struct seq_file *m, struct file *f) unsigned int cq_shift = 0; unsigned int sq_shift = 0; unsigned int sq_entries, cq_entries; + int sq_pid = -1, sq_cpu = -1; bool has_lock; unsigned int i; @@ -143,13 +143,19 @@ __cold void io_uring_show_fdinfo(struct seq_file *m, struct file *f) has_lock = mutex_trylock(&ctx->uring_lock); if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) { - sq = ctx->sq_data; - if (!sq->thread) - sq = NULL; + struct io_sq_data *sq = ctx->sq_data; + + if (mutex_trylock(&sq->lock)) { + if (sq->thread) { + sq_pid = task_pid_nr(sq->thread); + sq_cpu = task_cpu(sq->thread); + } + mutex_unlock(&sq->lock); + } } - seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1); - seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1); + seq_printf(m, "SqThread:\t%d\n", sq_pid); + seq_printf(m, "SqThreadCpu:\t%d\n", sq_cpu); seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files); for (i = 0; has_lock && i < ctx->nr_user_files; i++) { struct file *f = io_file_from_index(&ctx->file_table, i); diff --git a/io_uring/rw.c b/io_uring/rw.c index c8c822fa7980..807d83ab756e 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -913,15 +913,6 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags) kiocb_start_write(kiocb); kiocb->ki_flags |= IOCB_WRITE; - /* - * For non-polled IO, set IOCB_DIO_CALLER_COMP, stating that our handler - * groks deferring the completion to task context. This isn't - * necessary and useful for polled IO as that can always complete - * directly. - */ - if (!(kiocb->ki_flags & IOCB_HIPRI)) - kiocb->ki_flags |= IOCB_DIO_CALLER_COMP; - if (likely(req->file->f_op->write_iter)) ret2 = call_write_iter(req->file, kiocb, &s->iter); else if (req->file->f_op->write) |