aio: all callers of aio_{read,write,fsync,poll} treat 0 and -EIOCBQUEUED the same way

... so just make them return 0 when caller does not need to destroy iocb

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/aio.c b/fs/aio.c
index ae59775..6098b6b 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1461,11 +1461,11 @@ static int aio_setup_rw(int rw, struct iocb *iocb, struct iovec **iovec,
        return import_iovec(rw, buf, len, UIO_FASTIOV, iovec, iter);
 }
 
-static inline ssize_t aio_rw_ret(struct kiocb *req, ssize_t ret)
+static inline void aio_rw_done(struct kiocb *req, ssize_t ret)
 {
        switch (ret) {
        case -EIOCBQUEUED:
-               return ret;
+               break;
        case -ERESTARTSYS:
        case -ERESTARTNOINTR:
        case -ERESTARTNOHAND:
@@ -1478,7 +1478,6 @@ static inline ssize_t aio_rw_ret(struct kiocb *req, ssize_t ret)
                /*FALLTHRU*/
        default:
                aio_complete_rw(req, ret, 0);
-               return 0;
        }
 }
 
@@ -1507,10 +1506,10 @@ static ssize_t aio_read(struct kiocb *req, struct iocb *iocb, bool vectored,
                goto out_fput;
        ret = rw_verify_area(READ, file, &req->ki_pos, iov_iter_count(&iter));
        if (!ret)
-               ret = aio_rw_ret(req, call_read_iter(file, req, &iter));
+               aio_rw_done(req, call_read_iter(file, req, &iter));
        kfree(iovec);
 out_fput:
-       if (unlikely(ret && ret != -EIOCBQUEUED))
+       if (unlikely(ret))
                fput(file);
        return ret;
 }
@@ -1552,11 +1551,11 @@ static ssize_t aio_write(struct kiocb *req, struct iocb *iocb, bool vectored,
                        __sb_writers_release(file_inode(file)->i_sb, SB_FREEZE_WRITE);
                }
                req->ki_flags |= IOCB_WRITE;
-               ret = aio_rw_ret(req, call_write_iter(file, req, &iter));
+               aio_rw_done(req, call_write_iter(file, req, &iter));
        }
        kfree(iovec);
 out_fput:
-       if (unlikely(ret && ret != -EIOCBQUEUED))
+       if (unlikely(ret))
                fput(file);
        return ret;
 }
@@ -1587,7 +1586,7 @@ static int aio_fsync(struct fsync_iocb *req, struct iocb *iocb, bool datasync)
        req->datasync = datasync;
        INIT_WORK(&req->work, aio_fsync_work);
        schedule_work(&req->work);
-       return -EIOCBQUEUED;
+       return 0;
 }
 
 /* need to use list_del_init so we can check if item was present */
@@ -1715,7 +1714,7 @@ static ssize_t aio_poll(struct aio_kiocb *aiocb, struct iocb *iocb)
 done:
        if (mask)
                __aio_poll_complete(aiocb, mask);
-       return -EIOCBQUEUED;
+       return 0;
 out_fail:
        fput(req->file);
        return -EINVAL; /* same as no support for IOCB_CMD_POLL */
@@ -1800,12 +1799,11 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
        }
 
        /*
-        * If ret is -EIOCBQUEUED, ownership of the file reference acquired
-        * above passed to the file system, which at this point might have
-        * dropped the reference, so we must be careful to not reference it
-        * once we have called into the file system.
+        * If ret is 0, we'd either done aio_complete() ourselves or have
+        * arranged for that to be done asynchronously.  Anything non-zero
+        * means that we need to destroy req ourselves.
         */
-       if (ret && ret != -EIOCBQUEUED)
+       if (ret)
                goto out_put_req;
        return 0;
 out_put_req: