aio: Kill aio_rw_vect_retry()

This code doesn't serve any purpose anymore, since the aio retry
infrastructure has been removed.

This change should be safe because aio_read/write are also used for
synchronous IO, and called from do_sync_read()/do_sync_write() - and
there's no looping done in the sync case (the read and write syscalls).

Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Zach Brown <zab@redhat.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>

1 files changed, 18 insertions, 73 deletions

diff --git a/fs/aio.c b/fs/aio.c
index 57b02791d04e..d00904db69b7 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -707,7 +707,7 @@ static inline struct kiocb *aio_get_req(struct kioctx *ctx)
         if (unlikely(!req))
                 goto out_put;
 
-        atomic_set(&req->ki_users, 2);
+        atomic_set(&req->ki_users, 1);
         req->ki_ctx = ctx;
         return req;
 out_put:
@@ -1051,75 +1051,9 @@ SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx)
         return -EINVAL;
 }
 
-static void aio_advance_iovec(struct kiocb *iocb, ssize_t ret)
-{
-        struct iovec *iov = &iocb->ki_iovec[iocb->ki_cur_seg];
-
-        BUG_ON(ret <= 0);
-
-        while (iocb->ki_cur_seg < iocb->ki_nr_segs && ret > 0) {
-                ssize_t this = min((ssize_t)iov->iov_len, ret);
-                iov->iov_base += this;
-                iov->iov_len -= this;
-                iocb->ki_left -= this;
-                ret -= this;
-                if (iov->iov_len == 0) {
-                        iocb->ki_cur_seg++;
-                        iov++;
-                }
-        }
-
-        /* the caller should not have done more io than what fit in
-         * the remaining iovecs */
-        BUG_ON(ret > 0 && iocb->ki_left == 0);
-}
-
 typedef ssize_t (aio_rw_op)(struct kiocb *, const struct iovec *,
                             unsigned long, loff_t);
 
-static ssize_t aio_rw_vect_retry(struct kiocb *iocb, int rw, aio_rw_op *rw_op)
-{
-        struct file *file = iocb->ki_filp;
-        struct address_space *mapping = file->f_mapping;
-        struct inode *inode = mapping->host;
-        ssize_t ret = 0;
-
-        /* This matches the pread()/pwrite() logic */
-        if (iocb->ki_pos < 0)
-                return -EINVAL;
-
-        if (rw == WRITE)
-                file_start_write(file);
-        do {
-                ret = rw_op(iocb, &iocb->ki_iovec[iocb->ki_cur_seg],
-                            iocb->ki_nr_segs - iocb->ki_cur_seg,
-                            iocb->ki_pos);
-                if (ret > 0)
-                        aio_advance_iovec(iocb, ret);
-
-        /* retry all partial writes.  retry partial reads as long as its a
-         * regular file. */
-        } while (ret > 0 && iocb->ki_left > 0 &&
-                 (rw == WRITE ||
-                  (!S_ISFIFO(inode->i_mode) && !S_ISSOCK(inode->i_mode))));
-        if (rw == WRITE)
-                file_end_write(file);
-
-        /* This means we must have transferred all that we could */
-        /* No need to retry anymore */
-        if ((ret == 0) || (iocb->ki_left == 0))
-                ret = iocb->ki_nbytes - iocb->ki_left;
-
-        /* If we managed to write some out we return that, rather than
-         * the eventual error. */
-        if (rw == WRITE
-            && ret < 0 && ret != -EIOCBQUEUED
-            && iocb->ki_nbytes - iocb->ki_left)
-                ret = iocb->ki_nbytes - iocb->ki_left;
-
-        return ret;
-}
-
 static ssize_t aio_setup_vectored_rw(int rw, struct kiocb *kiocb, bool compat)
 {
         ssize_t ret;
@@ -1204,9 +1138,22 @@ rw_common:
                         return ret;
 
                 req->ki_nbytes = ret;
-                req->ki_left = ret;
 
-                ret = aio_rw_vect_retry(req, rw, rw_op);
+                /* XXX: move/kill - rw_verify_area()? */
+                /* This matches the pread()/pwrite() logic */
+                if (req->ki_pos < 0) {
+                        ret = -EINVAL;
+                        break;
+                }
+
+                if (rw == WRITE)
+                        file_start_write(file);
+
+                ret = rw_op(req, req->ki_iovec,
+                            req->ki_nr_segs, req->ki_pos);
+
+                if (rw == WRITE)
+                        file_end_write(file);
                 break;
 
         case IOCB_CMD_FDSYNC:
@@ -1301,19 +1248,17 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
         req->ki_pos = iocb->aio_offset;
 
         req->ki_buf = (char __user *)(unsigned long)iocb->aio_buf;
-        req->ki_left = req->ki_nbytes = iocb->aio_nbytes;
+        req->ki_nbytes = iocb->aio_nbytes;
         req->ki_opcode = iocb->aio_lio_opcode;
 
         ret = aio_run_iocb(req, compat);
         if (ret)
                 goto out_put_req;
 
-        aio_put_req(req);       /* drop extra ref to req */
         return 0;
 out_put_req:
         put_reqs_available(ctx, 1);
-        aio_put_req(req);       /* drop extra ref to req */
-        aio_put_req(req);       /* drop i/o ref to req */
+        aio_put_req(req);
         return ret;
 }