Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs fixes from Al Viro:
 "A couple of fixes, both -stable fodder.  The O_SYNC bug is fairly
  old..."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix a kmap leak in virtio_console
  fix O_SYNC|O_APPEND syncing the wrong range on write()

8 files changed, 17 insertions, 31 deletions

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index feea87cc6b8f..6928d094451d 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -890,12 +890,10 @@ static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
         } else {
                 /* Failback to copying a page */
                 struct page *page = alloc_page(GFP_KERNEL);
-                char *src = buf->ops->map(pipe, buf, 1);
-                char *dst;
+                char *src;
 
                 if (!page)
                         return -ENOMEM;
-                dst = kmap(page);
 
                 offset = sd->pos & ~PAGE_MASK;
 
@@ -903,9 +901,8 @@ static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
                 if (len + offset > PAGE_SIZE)
                         len = PAGE_SIZE - offset;
 
-                memcpy(dst + offset, src + buf->offset, len);
-
-                kunmap(page);
+                src = buf->ops->map(pipe, buf, 1);
+                memcpy(page_address(page) + offset, src + buf->offset, len);
                 buf->ops->unmap(pipe, buf, src);
 
                 sg_set_page(&(sgl->sg[sgl->n]), page, len, offset);
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 853d6d1cc822..a7eda8ebfacc 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2559,8 +2559,8 @@ cifs_writev(struct kiocb *iocb, const struct iovec *iov,
         if (rc > 0) {
                 ssize_t err;
 
-                err = generic_write_sync(file, pos, rc);
-                if (err < 0 && rc > 0)
+                err = generic_write_sync(file, iocb->ki_pos - rc, rc);
+                if (err < 0)
                         rc = err;
         }
 
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 43e64f6022eb..1a5073959f32 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -152,7 +152,7 @@ ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
         if (ret > 0) {
                 ssize_t err;
 
-                err = generic_write_sync(file, pos, ret);
+                err = generic_write_sync(file, iocb->ki_pos - ret, ret);
                 if (err < 0 && ret > 0)
                         ret = err;
         }
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index ea4ba9daeb47..db9bd8a31725 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -2134,7 +2134,7 @@ static ssize_t ntfs_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
         ret = ntfs_file_aio_write_nolock(iocb, iov, nr_segs, &iocb->ki_pos);
         mutex_unlock(&inode->i_mutex);
         if (ret > 0) {
-                int err = generic_write_sync(file, pos, ret);
+                int err = generic_write_sync(file, iocb->ki_pos - ret, ret);
                 if (err < 0)
                         ret = err;
         }
diff --git a/fs/sync.c b/fs/sync.c
index f15537452231..e8ba024a055b 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -222,23 +222,6 @@ SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
         return do_fsync(fd, 1);
 }
 
-/**
- * generic_write_sync - perform syncing after a write if file / inode is sync
- * @file:       file to which the write happened
- * @pos:        offset where the write started
- * @count:      length of the write
- *
- * This is just a simple wrapper about our general syncing function.
- */
-int generic_write_sync(struct file *file, loff_t pos, loff_t count)
-{
-        if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host))
-                return 0;
-        return vfs_fsync_range(file, pos, pos + count - 1,
-                               (file->f_flags & __O_SYNC) ? 0 : 1);
-}
-EXPORT_SYMBOL(generic_write_sync);
-
 /*
  * sys_sync_file_range() permits finely controlled syncing over a segment of
  * a file in the range offset .. (offset+nbytes-1) inclusive.  If nbytes is
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 2e7989e3a2d6..64b48eade91d 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -799,7 +799,7 @@ xfs_file_aio_write(
                 XFS_STATS_ADD(xs_write_bytes, ret);
 
                 /* Handle various SYNC-type writes */
-                err = generic_write_sync(file, pos, ret);
+                err = generic_write_sync(file, iocb->ki_pos - ret, ret);
                 if (err < 0)
                         ret = err;
         }
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d79678c188ad..60829565e552 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2274,7 +2274,13 @@ 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);
-extern int generic_write_sync(struct file *file, loff_t pos, loff_t count);
+static inline int generic_write_sync(struct file *file, loff_t pos, loff_t count)
+{
+        if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host))
+                return 0;
+        return vfs_fsync_range(file, pos, pos + count - 1,
+                               (file->f_flags & __O_SYNC) ? 0 : 1);
+}
 extern void emergency_sync(void);
 extern void emergency_remount(void);
 #ifdef CONFIG_BLOCK
diff --git a/mm/filemap.c b/mm/filemap.c
index d56d3c145b9f..7a13f6ac5421 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2553,8 +2553,8 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
         if (ret > 0) {
                 ssize_t err;
 
-                err = generic_write_sync(file, pos, ret);
-                if (err < 0 && ret > 0)
+                err = generic_write_sync(file, iocb->ki_pos - ret, ret);
+                if (err < 0)
                         ret = err;
         }
         return ret;