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UPSTREAM: io_uring: update kiocb->ki_pos at execution time

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commit d34e1e5b396a0dbaa4a29b7138df662cfb9d8e8e upstream.

Update kiocb->ki_pos at execution time rather than in io_prep_rw().
io_prep_rw() happens before the job is enqueued to a worker and so the
offset might be read multiple times before being executed once.

Ensures that the file position in a set of _linked_ SQEs will be only
obtained after earlier SQEs have completed, and so will include their
incremented file position.

Change-Id: I3c5abbf6a337ec1958fd6600c5feb44fb61a5772
Signed-off-by: Dylan Yudaken <dylany@fb.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Bug: 268174392
(cherry picked from commit ea528ecac3)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Dylan Yudaken
2022-02-22 02:55:02 -08:00
committed by Treehugger Robot
parent b543e0d210
commit 84e34d2ef5
1 changed files with 18 additions and 8 deletions
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26
io_uring/io_uring.c
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@@ -2929,14 +2929,6 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
req->flags |= REQ_F_ISREG;
kiocb->ki_pos = READ_ONCE(sqe->off);
if (kiocb->ki_pos == -1) {
if (!(file->f_mode & FMODE_STREAM)) {
req->flags |= REQ_F_CUR_POS;
kiocb->ki_pos = file->f_pos;
} else {
kiocb->ki_pos = 0;
}
}
kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp));
kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
@@ -3018,6 +3010,20 @@ static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
}
}
static inline void io_kiocb_update_pos(struct io_kiocb *req)
{
struct kiocb *kiocb = &req->rw.kiocb;
if (kiocb->ki_pos == -1) {
if (!(req->file->f_mode & FMODE_STREAM)) {
req->flags |= REQ_F_CUR_POS;
kiocb->ki_pos = req->file->f_pos;
} else {
kiocb->ki_pos = 0;
}
}
}
static void kiocb_done(struct kiocb *kiocb, ssize_t ret,
unsigned int issue_flags)
{
@@ -3573,6 +3579,8 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags)
return ret ?: -EAGAIN;
}
io_kiocb_update_pos(req);
ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), req->result);
if (unlikely(ret)) {
kfree(iovec);
@@ -3707,6 +3715,8 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags)
(req->flags & REQ_F_ISREG))
goto copy_iov;
io_kiocb_update_pos(req);
ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), req->result);
if (unlikely(ret))
goto out_free;