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-rw-r--r--io_uring/io_uring.h10
-rw-r--r--io_uring/rsrc.c3
-rw-r--r--io_uring/rw.c25
3 files changed, 33 insertions, 5 deletions
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index 9d70b2cf7b1e..70b6675941ff 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -284,7 +284,14 @@ static inline bool io_sqring_full(struct io_ring_ctx *ctx)
{
struct io_rings *r = ctx->rings;
- return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries;
+ /*
+ * SQPOLL must use the actual sqring head, as using the cached_sq_head
+ * is race prone if the SQPOLL thread has grabbed entries but not yet
+ * committed them to the ring. For !SQPOLL, this doesn't matter, but
+ * since this helper is just used for SQPOLL sqring waits (or POLLOUT),
+ * just read the actual sqring head unconditionally.
+ */
+ return READ_ONCE(r->sq.tail) - READ_ONCE(r->sq.head) == ctx->sq_entries;
}
static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
@@ -320,6 +327,7 @@ static inline int io_run_task_work(void)
if (current->io_uring) {
unsigned int count = 0;
+ __set_current_state(TASK_RUNNING);
tctx_task_work_run(current->io_uring, UINT_MAX, &count);
if (count)
ret = true;
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 33a3d156a85b..6f3b6de230bd 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -1176,7 +1176,8 @@ static int io_clone_buffers(struct io_ring_ctx *ctx, struct io_ring_ctx *src_ctx
for (i = 0; i < nbufs; i++) {
struct io_mapped_ubuf *src = src_ctx->user_bufs[i];
- refcount_inc(&src->refs);
+ if (src != &dummy_ubuf)
+ refcount_inc(&src->refs);
user_bufs[i] = src;
}
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 80ae3c2ebb70..155938f10093 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -807,7 +807,7 @@ static int io_rw_init_file(struct io_kiocb *req, fmode_t mode, int rw_type)
* reliably. If not, or it IOCB_NOWAIT is set, don't retry.
*/
if (kiocb->ki_flags & IOCB_NOWAIT ||
- ((file->f_flags & O_NONBLOCK && (req->flags & REQ_F_SUPPORT_NOWAIT))))
+ ((file->f_flags & O_NONBLOCK && !(req->flags & REQ_F_SUPPORT_NOWAIT))))
req->flags |= REQ_F_NOWAIT;
if (ctx->flags & IORING_SETUP_IOPOLL) {
@@ -1014,6 +1014,25 @@ int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags)
return IOU_OK;
}
+static bool io_kiocb_start_write(struct io_kiocb *req, struct kiocb *kiocb)
+{
+ struct inode *inode;
+ bool ret;
+
+ if (!(req->flags & REQ_F_ISREG))
+ return true;
+ if (!(kiocb->ki_flags & IOCB_NOWAIT)) {
+ kiocb_start_write(kiocb);
+ return true;
+ }
+
+ inode = file_inode(kiocb->ki_filp);
+ ret = sb_start_write_trylock(inode->i_sb);
+ if (ret)
+ __sb_writers_release(inode->i_sb, SB_FREEZE_WRITE);
+ return ret;
+}
+
int io_write(struct io_kiocb *req, unsigned int issue_flags)
{
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
@@ -1051,8 +1070,8 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags)
if (unlikely(ret))
return ret;
- if (req->flags & REQ_F_ISREG)
- kiocb_start_write(kiocb);
+ if (unlikely(!io_kiocb_start_write(req, kiocb)))
+ return -EAGAIN;
kiocb->ki_flags |= IOCB_WRITE;
if (likely(req->file->f_op->write_iter))