Re: [PATCH v8 30/32] ext4: Send notifications on error

[Jan Kara <jack@suse.cz>]

On Mon 18-10-21 21:00:13, Gabriel Krisman Bertazi wrote:
> 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.
> 
> It also follows the current dmesg reporting in the format.  The
> filesystem message is composed mostly by the string that would be
> otherwise printed in dmesg.
> 
> A new ext4 specific record format is exposed in the uapi, such that a
> monitoring tool knows what to expect when listening errors of an ext4
> filesystem.
> 
> Reviewed-by: Amir Goldstein <amir73il@gmail.com>
> Reviewed-by: Theodore Ts'o <tytso@mit.edu>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

Looks good to me. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> 
> ---
> Changes since v6:
>   - Report ext4_std_errors agains superblock (jan)
> ---
>  fs/ext4/super.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 88d5d274a868..67183e6b1920 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -46,6 +46,7 @@
>  #include <linux/part_stat.h>
>  #include <linux/kthread.h>
>  #include <linux/freezer.h>
> +#include <linux/fsnotify.h>
>  
>  #include "ext4.h"
>  #include "ext4_extents.h"	/* Needed for trace points definition */
> @@ -759,6 +760,8 @@ void __ext4_error(struct super_block *sb, const char *function,
>  		       sb->s_id, function, line, current->comm, &vaf);
>  		va_end(args);
>  	}
> +	fsnotify_sb_error(sb, NULL, error);
> +
>  	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
>  }
>  
> @@ -789,6 +792,8 @@ void __ext4_error_inode(struct inode *inode, const char *function,
>  			       current->comm, &vaf);
>  		va_end(args);
>  	}
> +	fsnotify_sb_error(inode->i_sb, inode, error);
> +
>  	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
>  			  function, line);
>  }
> @@ -827,6 +832,8 @@ void __ext4_error_file(struct file *file, const char *function,
>  			       current->comm, path, &vaf);
>  		va_end(args);
>  	}
> +	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
> +
>  	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
>  			  function, line);
>  }
> @@ -894,6 +901,7 @@ void __ext4_std_error(struct super_block *sb, const char *function,
>  		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
>  		       sb->s_id, function, line, errstr);
>  	}
> +	fsnotify_sb_error(sb, NULL, errno);
>  
>  	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
>  }
> -- 
> 2.33.0
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR