ext4: Send notifications on error

commit 9a089b21 upstream.

Send a FS_ERROR message via fsnotify to a userspace monitoring tool
whenever a ext4 error condition is triggered.  This follows the existing
error conditions in ext4, so it is hooked to the ext4_error* functions.

Link: https://lore.kernel.org/r/20211025192746.66445-30-krisman@collabora.com


Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
[Ajay: - Modified to apply on v5.10.y
       - Added fsnotify for __ext4_abort()]
Signed-off-by: Ajay Kaher <ajay.kaher@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>