12 files changed, 46 insertions, 65 deletions

diff --git a/fs/block_dev.c b/fs/block_dev.c
index d8dc3512e927..a063d4d8ac39 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1660,12 +1660,8 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
         blk_start_plug(&plug);
         ret = __generic_file_write_iter(iocb, from);
-        if (ret > 0) {
-                ssize_t err;
-                err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
-                if (err < 0)
-                        ret = err;
-        }
+        if (ret > 0)
+                ret = generic_write_sync(iocb, ret);
         blk_finish_plug(&plug);
         return ret;
 }
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 35ce146cceec..ea9f10bb089c 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1851,11 +1851,8 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
         spin_lock(&BTRFS_I(inode)->lock);
         BTRFS_I(inode)->last_sub_trans = root->log_transid;
         spin_unlock(&BTRFS_I(inode)->lock);
-        if (num_written > 0) {
-                err = generic_write_sync(iocb, pos, num_written);
-                if (err < 0)
-                        num_written = err;
-        }
+        if (num_written > 0)
+                num_written = generic_write_sync(iocb, num_written);
 
         if (sync)
                 atomic_dec(&BTRFS_I(inode)->sync_writers);
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index b22b68ccfbe5..9b51d4936a29 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2687,11 +2687,8 @@ cifs_writev(struct kiocb *iocb, struct iov_iter *from)
 out:
         inode_unlock(inode);
 
-        if (rc > 0) {
-                ssize_t err = generic_write_sync(iocb, iocb->ki_pos - rc, rc);
-                if (err < 0)
-                        rc = err;
-        }
+        if (rc > 0)
+                rc = generic_write_sync(iocb, rc);
         up_read(&cinode->lock_sem);
         return rc;
 }
diff --git a/fs/direct-io.c b/fs/direct-io.c
index f7bcc0193dee..3bf3f20f8ecc 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -256,6 +256,7 @@ static ssize_t dio_complete(struct dio *dio, ssize_t ret, bool is_async)
         if (dio->end_io) {
                 int err;
 
+                // XXX: ki_pos??
                 err = dio->end_io(dio->iocb, offset, ret, dio->private);
                 if (err)
                         ret = err;
@@ -265,15 +266,15 @@ static ssize_t dio_complete(struct dio *dio, ssize_t ret, bool is_async)
                 inode_dio_end(dio->inode);
 
         if (is_async) {
-                if (dio->rw & WRITE) {
-                        int err;
-
-                        err = generic_write_sync(dio->iocb, offset,
-                                                 transferred);
-                        if (err < 0 && ret > 0)
-                                ret = err;
-                }
+                /*
+                 * generic_write_sync expects ki_pos to have been updated
+                 * already, but the submission path only does this for
+                 * synchronous I/O.
+                 */
+                dio->iocb->ki_pos += transferred;
 
+                if (dio->rw & WRITE)
+                        ret = generic_write_sync(dio->iocb,  transferred);
                 dio->iocb->ki_complete(dio->iocb, ret, 0);
         }
 
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 1417e129be51..00ff6912adb3 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -169,13 +169,8 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
         ret = __generic_file_write_iter(iocb, from);
         inode_unlock(inode);
 
-        if (ret > 0) {
-                ssize_t err;
-
-                err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
-                if (err < 0)
-                        ret = err;
-        }
+        if (ret > 0)
+                ret = generic_write_sync(iocb, ret);
         if (o_direct)
                 blk_finish_plug(&plug);
 
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 51ed8388e66c..28f75a1fe4a7 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1882,13 +1882,8 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
         }
         inode_unlock(inode);
 
-        if (ret > 0) {
-                ssize_t err;
-
-                err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
-                if (err < 0)
-                        ret = err;
-        }
+        if (ret > 0)
+                ret = generic_write_sync(iocb, ret);
         return ret;
 }
 
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index be86de9a77d7..0b9fca040b0c 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -1054,7 +1054,9 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter)
                         if (i_size_read(inode) < iocb->ki_pos)
                                 i_size_write(inode, iocb->ki_pos);
                         spin_unlock(&inode->i_lock);
-                        generic_write_sync(iocb, pos, result);
+
+                        /* XXX: should check the generic_write_sync retval */
+                        generic_write_sync(iocb, result);
                 }
         }
         nfs_direct_req_release(dreq);
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index 10dc38cc02bb..5622ed5a201e 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -1952,12 +1952,9 @@ static ssize_t ntfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
                 written = ntfs_perform_write(file, from, iocb->ki_pos);
         current->backing_dev_info = NULL;
         inode_unlock(vi);
-        if (likely(written > 0)) {
-                err = generic_write_sync(iocb, iocb->ki_pos, written);
-                if (err < 0)
-                        written = 0;
-        }
         iocb->ki_pos += written;
+        if (likely(written > 0))
+                written = generic_write_sync(iocb, written);
         return written ? written : err;
 }
 
diff --git a/fs/udf/file.c b/fs/udf/file.c
index 8e3d1ae53b11..632570617327 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -152,9 +152,7 @@ out:
 
         if (retval > 0) {
                 mark_inode_dirty(inode);
-                err = generic_write_sync(iocb, iocb->ki_pos - retval, retval);
-                if (err < 0)
-                        retval = err;
+                retval = generic_write_sync(iocb, retval);
         }
 
         return retval;
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index b5d70e77195d..cd3540997d65 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -903,14 +903,10 @@ xfs_file_write_iter(
                 ret = xfs_file_buffered_aio_write(iocb, from);
 
         if (ret > 0) {
-                ssize_t err;
-
                 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
 
                 /* Handle various SYNC-type writes */
-                err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
-                if (err < 0)
-                        ret = err;
+                ret = generic_write_sync(iocb, ret);
         }
         return ret;
 }
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 310ca1ed9293..f6a8ed864651 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2487,13 +2487,25 @@ extern int filemap_fdatawrite_range(struct address_space *mapping,
 extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
                            int datasync);
 extern int vfs_fsync(struct file *file, int datasync);
-static inline int generic_write_sync(struct kiocb *iocb, loff_t pos, loff_t count)
-{
-        if (!(iocb->ki_flags & IOCB_DSYNC))
-                return 0;
-        return vfs_fsync_range(iocb->ki_filp, pos, pos + count - 1,
-                               (iocb->ki_flags & IOCB_SYNC) ? 0 : 1);
+
+/*
+ * Sync the bytes written if this was a synchronous write.  Expect ki_pos
+ * to already be updated for the write, and will return either the amount
+ * of bytes passed in, or an error if syncing the file failed.
+ */
+static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count)
+{
+        if (iocb->ki_flags & IOCB_DSYNC) {
+                int ret = vfs_fsync_range(iocb->ki_filp,
+                                iocb->ki_pos - count, iocb->ki_pos - 1,
+                                (iocb->ki_flags & IOCB_SYNC) ? 0 : 1);
+                if (ret)
+                        return ret;
+        }
+
+        return count;
 }
+
 extern void emergency_sync(void);
 extern void emergency_remount(void);
 #ifdef CONFIG_BLOCK
diff --git a/mm/filemap.c b/mm/filemap.c
index 8345d6d3436a..182b21825255 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2791,13 +2791,8 @@ ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
                 ret = __generic_file_write_iter(iocb, from);
         inode_unlock(inode);
 
-        if (ret > 0) {
-                ssize_t err;
-
-                err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
-                if (err < 0)
-                        ret = err;
-        }
+        if (ret > 0)
+                ret = generic_write_sync(iocb, ret);
         return ret;
 }
 EXPORT_SYMBOL(generic_file_write_iter);