Skip to content

Commit

Permalink
Merge tag 'io_uring-5.7-2020-05-01' of git://git.kernel.dk/linux-block
Browse files Browse the repository at this point in the history 
Pull io_uring fixes from Jens Axboe:

 - Fix for statx not grabbing the file table, making AT_EMPTY_PATH fail

 - Cover a few cases where async poll can handle retry, eliminating the
   need for an async thread

 - fallback request busy/free fix (Bijan)

 - syzbot reported SQPOLL thread exit fix for non-preempt (Xiaoguang)

 - Fix extra put of req for sync_file_range (Pavel)

 - Always punt splice async. We'll improve this for 5.8, but wanted to
   eliminate the inode mutex lock from the non-blocking path for 5.7
   (Pavel)

* tag 'io_uring-5.7-2020-05-01' of git://git.kernel.dk/linux-block:
  io_uring: punt splice async because of inode mutex
  io_uring: check non-sync defer_list carefully
  io_uring: fix extra put in sync_file_range()
  io_uring: use cond_resched() in io_ring_ctx_wait_and_kill()
  io_uring: use proper references for fallback_req locking
  io_uring: only force async punt if poll based retry can't handle it
  io_uring: enable poll retry for any file with ->read_iter / ->write_iter
  io_uring: statx must grab the file table for valid fd
  • Loading branch information
@torvalds
torvalds committed May 2, 2020
2 parents 052c467 + 2fb3e82 commit cf01853
Showing 1 changed file with 31 additions and 27 deletions.
58 changes: 31 additions & 27 deletions fs/io_uring.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -524,6 +524,7 @@ enum {
REQ_F_OVERFLOW_BIT,
REQ_F_POLLED_BIT,
REQ_F_BUFFER_SELECTED_BIT,
REQ_F_NO_FILE_TABLE_BIT,

/* not a real bit, just to check we're not overflowing the space */
__REQ_F_LAST_BIT,
Expand Down Expand Up @@ -577,6 +578,8 @@ enum {
REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
/* buffer already selected */
REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
/* doesn't need file table for this request */
REQ_F_NO_FILE_TABLE = BIT(REQ_F_NO_FILE_TABLE_BIT),
};

struct async_poll {
Expand Down Expand Up @@ -799,6 +802,7 @@ static const struct io_op_def io_op_defs[] = {
.needs_file = 1,
.fd_non_neg = 1,
.needs_fs = 1,
.file_table = 1,
},
[IORING_OP_READ] = {
.needs_mm = 1,
Expand Down Expand Up @@ -1291,7 +1295,7 @@ static struct io_kiocb *io_get_fallback_req(struct io_ring_ctx *ctx)
struct io_kiocb *req;

req = ctx->fallback_req;
if (!test_and_set_bit_lock(0, (unsigned long *) ctx->fallback_req))
if (!test_and_set_bit_lock(0, (unsigned long *) &ctx->fallback_req))
return req;

return NULL;
Expand Down Expand Up @@ -1378,7 +1382,7 @@ static void __io_free_req(struct io_kiocb *req)
if (likely(!io_is_fallback_req(req)))
kmem_cache_free(req_cachep, req);
else
clear_bit_unlock(0, (unsigned long *) req->ctx->fallback_req);
clear_bit_unlock(0, (unsigned long *) &req->ctx->fallback_req);
}

struct req_batch {
Expand Down Expand Up @@ -2034,7 +2038,7 @@ static struct file *__io_file_get(struct io_submit_state *state, int fd)
* any file. For now, just ensure that anything potentially problematic is done
* inline.
*/
static bool io_file_supports_async(struct file *file)
static bool io_file_supports_async(struct file *file, int rw)
{
umode_t mode = file_inode(file)->i_mode;

Expand All @@ -2043,7 +2047,13 @@ static bool io_file_supports_async(struct file *file)
if (S_ISREG(mode) && file->f_op != &io_uring_fops)
return true;

return false;
if (!(file->f_mode & FMODE_NOWAIT))
return false;

if (rw == READ)
return file->f_op->read_iter != NULL;

return file->f_op->write_iter != NULL;
}

static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
Expand Down Expand Up @@ -2571,7 +2581,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock)
* If the file doesn't support async, mark it as REQ_F_MUST_PUNT so
* we know to async punt it even if it was opened O_NONBLOCK
*/
if (force_nonblock && !io_file_supports_async(req->file))
if (force_nonblock && !io_file_supports_async(req->file, READ))
goto copy_iov;

iov_count = iov_iter_count(&iter);
Expand All @@ -2594,7 +2604,8 @@ static int io_read(struct io_kiocb *req, bool force_nonblock)
if (ret)
goto out_free;
/* any defer here is final, must blocking retry */
if (!(req->flags & REQ_F_NOWAIT))
if (!(req->flags & REQ_F_NOWAIT) &&
!file_can_poll(req->file))
req->flags |= REQ_F_MUST_PUNT;
return -EAGAIN;
}
Expand Down Expand Up @@ -2662,7 +2673,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock)
* If the file doesn't support async, mark it as REQ_F_MUST_PUNT so
* we know to async punt it even if it was opened O_NONBLOCK
*/
if (force_nonblock && !io_file_supports_async(req->file))
if (force_nonblock && !io_file_supports_async(req->file, WRITE))
goto copy_iov;

/* file path doesn't support NOWAIT for non-direct_IO */
Expand Down Expand Up @@ -2716,7 +2727,8 @@ static int io_write(struct io_kiocb *req, bool force_nonblock)
if (ret)
goto out_free;
/* any defer here is final, must blocking retry */
req->flags |= REQ_F_MUST_PUNT;
if (!file_can_poll(req->file))
req->flags |= REQ_F_MUST_PUNT;
return -EAGAIN;
}
}
Expand Down Expand Up @@ -2756,15 +2768,6 @@ static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return 0;
}

static bool io_splice_punt(struct file *file)
{
if (get_pipe_info(file))
return false;
if (!io_file_supports_async(file))
return true;
return !(file->f_flags & O_NONBLOCK);
}

static int io_splice(struct io_kiocb *req, bool force_nonblock)
{
struct io_splice *sp = &req->splice;
Expand All @@ -2774,11 +2777,8 @@ static int io_splice(struct io_kiocb *req, bool force_nonblock)
loff_t *poff_in, *poff_out;
long ret;

if (force_nonblock) {
if (io_splice_punt(in) || io_splice_punt(out))
return -EAGAIN;
flags |= SPLICE_F_NONBLOCK;
}
if (force_nonblock)
return -EAGAIN;

poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
Expand Down Expand Up @@ -3355,8 +3355,12 @@ static int io_statx(struct io_kiocb *req, bool force_nonblock)
struct kstat stat;
int ret;

if (force_nonblock)
if (force_nonblock) {
/* only need file table for an actual valid fd */
if (ctx->dfd == -1 || ctx->dfd == AT_FDCWD)
req->flags |= REQ_F_NO_FILE_TABLE;
return -EAGAIN;
}

if (vfs_stat_set_lookup_flags(&lookup_flags, ctx->how.flags))
return -EINVAL;
Expand Down Expand Up @@ -3502,7 +3506,7 @@ static void io_sync_file_range_finish(struct io_wq_work **workptr)
if (io_req_cancelled(req))
return;
__io_sync_file_range(req);
io_put_req(req); /* put submission ref */
io_steal_work(req, workptr);
}

static int io_sync_file_range(struct io_kiocb *req, bool force_nonblock)
Expand Down Expand Up @@ -5015,7 +5019,7 @@ static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe)
int ret;

/* Still need defer if there is pending req in defer list. */
if (!req_need_defer(req) && list_empty(&ctx->defer_list))
if (!req_need_defer(req) && list_empty_careful(&ctx->defer_list))
return 0;

if (!req->io && io_alloc_async_ctx(req))
Expand Down Expand Up @@ -5429,7 +5433,7 @@ static int io_grab_files(struct io_kiocb *req)
int ret = -EBADF;
struct io_ring_ctx *ctx = req->ctx;

if (req->work.files)
if (req->work.files || (req->flags & REQ_F_NO_FILE_TABLE))
return 0;
if (!ctx->ring_file)
return -EBADF;
Expand Down Expand Up @@ -7327,7 +7331,7 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
* it could cause shutdown to hang.
*/
while (ctx->sqo_thread && !wq_has_sleeper(&ctx->sqo_wait))
cpu_relax();
cond_resched();

io_kill_timeouts(ctx);
io_poll_remove_all(ctx);
Expand Down

0 comments on commit cf01853

Please sign in to comment.