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References: <20210629191035.681913-1-krisman@collabora.com> <20210629191035.681913-12-krisman@collabora.com>
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From:   Amir Goldstein <amir73il@gmail.com>
Date:   Wed, 30 Jun 2021 06:44:17 +0300
Message-ID: <CAOQ4uxiDfDez8y2ah_pXzD1bZAQra49jni2VJ2LMv9YFpLHt6Q@mail.gmail.com>
Subject: Re: [PATCH v3 11/15] fsnotify: Introduce helpers to send error_events
To:     Gabriel Krisman Bertazi <krisman@collabora.com>
Cc:     "Darrick J. Wong" <djwong@kernel.org>,
        Theodore Tso <tytso@mit.edu>,
        Dave Chinner <david@fromorbit.com>, Jan Kara <jack@suse.com>,
        David Howells <dhowells@redhat.com>,
        Khazhismel Kumykov <khazhy@google.com>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Ext4 <linux-ext4@vger.kernel.org>, kernel@collabora.com
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On Tue, Jun 29, 2021 at 10:12 PM Gabriel Krisman Bertazi
<krisman@collabora.com> wrote:
>
> Introduce helpers for filesystems interested in reporting FS_ERROR
> events.  When notifying errors, the file system might not have an inode
> to report on the error.  To support this, allow the caller to specify
> the superblock to which the error applies.
>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
>

Reviewed-by: Amir Goldstein <amir73il@gmail.com>

> ---
> Changes since v2:
>   - Drop reference to s_fnotify_marks and guards (Amir)
>
> Changes since v1:
>   - Use the inode argument (Amir)
>   - Protect s_fsnotify_marks with ifdef guard
> ---
>  fs/notify/fsnotify.c             |  2 +-
>  include/linux/fsnotify.h         | 13 +++++++++++++
>  include/linux/fsnotify_backend.h |  1 +
>  3 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
> index 36205a769dde..ac05eb3fb368 100644
> --- a/fs/notify/fsnotify.c
> +++ b/fs/notify/fsnotify.c
> @@ -491,7 +491,7 @@ int __fsnotify(__u32 mask, const struct fsnotify_event_info *event_info)
>                  */
>                 parent = event_info->dir;
>         }
> -       sb = inode->i_sb;
> +       sb = event_info->sb ?: inode->i_sb;
>
>         /*
>          * Optimization: srcu_read_lock() has a memory barrier which can
> diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
> index 8c2c681b4495..684c79ca01b2 100644
> --- a/include/linux/fsnotify.h
> +++ b/include/linux/fsnotify.h
> @@ -326,4 +326,17 @@ static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
>                 fsnotify_dentry(dentry, mask);
>  }
>
> +static inline int fsnotify_sb_error(struct super_block *sb, struct inode *inode,
> +                                   int error)
> +{
> +       struct fs_error_report report = {
> +               .error = error,
> +               .inode = inode,
> +       };
> +
> +       return __fsnotify(FS_ERROR, &(struct fsnotify_event_info) {
> +                       .data = &report, .data_type = FSNOTIFY_EVENT_ERROR,
> +                       .sb = sb});
> +}
> +
>  #endif /* _LINUX_FS_NOTIFY_H */
> diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
> index ea5f5c7cc381..5a32c5010f45 100644
> --- a/include/linux/fsnotify_backend.h
> +++ b/include/linux/fsnotify_backend.h
> @@ -138,6 +138,7 @@ struct fsnotify_event_info {
>         struct inode *dir;
>         const struct qstr *name;
>         struct inode *inode;
> +       struct super_block *sb;
>         u32 cookie;
>  };
>
> --
> 2.32.0
>