zonefs: Do not propagate iomap_dio_rw() ENOTBLK error to user space

The call to invalidate_inode_pages2_range() in __iomap_dio_rw() may
fail, in which case -ENOTBLK is returned and this error code is
propagated back to user space trhough iomap_dio_rw() ->
zonefs_file_dio_write() return chain. This error code is fairly obscure
and may confuse the user. Avoid this and be consistent with the behavior
of zonefs_file_dio_append() for similar invalidate_inode_pages2_range()
errors by returning -EBUSY to user space when iomap_dio_rw() returns
-ENOTBLK.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Fixes: 8dcc1a9d90c1 ("fs: New zonefs file system")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>

diff --git a/fs/zonefs/file.c b/fs/zonefs/file.c
index c6ab273..132f01d 100644 (file)
--- a/fs/zonefs/file.c
+++ b/fs/zonefs/file.c
@@ -581,11 +581,21 @@ static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from)
                append = sync;
        }
 
-       if (append)
+       if (append) {
                ret = zonefs_file_dio_append(iocb, from);
-       else
+       } else {
+               /*
+                * iomap_dio_rw() may return ENOTBLK if there was an issue with
+                * page invalidation. Overwrite that error code with EBUSY to
+                * be consistent with zonefs_file_dio_append() return value for
+                * similar issues.
+                */
                ret = iomap_dio_rw(iocb, from, &zonefs_write_iomap_ops,
                                   &zonefs_write_dio_ops, 0, NULL, 0);
+               if (ret == -ENOTBLK)
+                       ret = -EBUSY;
+       }
+
        if (zonefs_zone_is_seq(z) &&
            (ret > 0 || ret == -EIOCBQUEUED)) {
                if (ret > 0)