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>

6 files changed, 23 insertions, 82 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;
 }
 
diff --git a/fs/block_dev.c b/fs/block_dev.c
index c7bda5cd3da7..8772b155cb30 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1542,7 +1542,7 @@ static ssize_t blkdev_aio_read(struct kiocb *iocb, const struct iovec *iov,
                 return 0;
 
         size -= pos;
-        if (size < iocb->ki_left)
+        if (size < iocb->ki_nbytes)
                 nr_segs = iov_shorten((struct iovec *)iov, nr_segs, size);
         return generic_file_aio_read(iocb, iov, nr_segs, pos);
 }
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 0bd7a55a5f07..91ff089d3412 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -130,7 +130,6 @@ ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_
 
         return -EINVAL;
 #else
-        VM_BUG_ON(iocb->ki_left != PAGE_SIZE);
         VM_BUG_ON(iocb->ki_nbytes != PAGE_SIZE);
 
         if (rw == READ || rw == KERNEL_READ)
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 41000f223ca4..dd1a4901a54b 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2245,7 +2245,7 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
                 file->f_path.dentry->d_name.name,
                 (unsigned int)nr_segs);
 
-        if (iocb->ki_left == 0)
+        if (iocb->ki_nbytes == 0)
                 return 0;
 
         appending = file->f_flags & O_APPEND ? 1 : 0;
@@ -2296,7 +2296,7 @@ relock:
 
         can_do_direct = direct_io;
         ret = ocfs2_prepare_inode_for_write(file, ppos,
-                                            iocb->ki_left, appending,
+                                            iocb->ki_nbytes, appending,
                                             &can_do_direct, &has_refcount);
         if (ret < 0) {
                 mlog_errno(ret);
@@ -2304,7 +2304,7 @@ relock:
         }
 
         if (direct_io && !is_sync_kiocb(iocb))
-                unaligned_dio = ocfs2_is_io_unaligned(inode, iocb->ki_left,
+                unaligned_dio = ocfs2_is_io_unaligned(inode, iocb->ki_nbytes,
                                                       *ppos);
 
         /*
diff --git a/fs/read_write.c b/fs/read_write.c
index 122a3846d9e1..e3cd280b158c 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -367,7 +367,6 @@ ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *pp
 
         init_sync_kiocb(&kiocb, filp);
         kiocb.ki_pos = *ppos;
-        kiocb.ki_left = len;
         kiocb.ki_nbytes = len;
 
         ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos);
@@ -417,7 +416,6 @@ ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, lof
 
         init_sync_kiocb(&kiocb, filp);
         kiocb.ki_pos = *ppos;
-        kiocb.ki_left = len;
         kiocb.ki_nbytes = len;
 
         ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos);
@@ -599,7 +597,6 @@ static ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov,
 
         init_sync_kiocb(&kiocb, filp);
         kiocb.ki_pos = *ppos;
-        kiocb.ki_left = len;
         kiocb.ki_nbytes = len;
 
         ret = fn(&kiocb, iov, nr_segs, kiocb.ki_pos);
diff --git a/fs/udf/file.c b/fs/udf/file.c
index 29569dd08168..c02a27a19c6d 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -141,7 +141,7 @@ static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
         struct file *file = iocb->ki_filp;
         struct inode *inode = file_inode(file);
         int err, pos;
-        size_t count = iocb->ki_left;
+        size_t count = iocb->ki_nbytes;
         struct udf_inode_info *iinfo = UDF_I(inode);
 
         down_write(&iinfo->i_data_sem);