From 59131393434b49a313cfeb11ae880e13149d13b6 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Tue, 21 Jul 2020 11:24:28 -0400 Subject: [PATCH] btrfs: document special case error codes for fs errors We've had some discussions about what to do in certain scenarios for error codes, specifically EUCLEAN and EROFS. Document these near the error handling code so its clear what their intentions are. Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/super.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 58f890f..a4f0bb2 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -67,6 +67,21 @@ static struct file_system_type btrfs_root_fs_type; static int btrfs_remount(struct super_block *sb, int *flags, char *data); +/* + * Generally the error codes correspond to their respective errors, but there + * are a few special cases. + * + * EUCLEAN: Any sort of corruption that we encounter. The tree-checker for + * instance will return EUCLEAN if any of the blocks are corrupted in + * a way that is problematic. We want to reserve EUCLEAN for these + * sort of corruptions. + * + * EROFS: If we check BTRFS_FS_STATE_ERROR and fail out with a return error, we + * need to use EROFS for this case. We will have no idea of the + * original failure, that will have been reported at the time we tripped + * over the error. Each subsequent error that doesn't have any context + * of the original error should use EROFS when handling BTRFS_FS_STATE_ERROR. + */ const char * __attribute_const__ btrfs_decode_error(int errno) { char *errstr = "unknown"; -- 2.7.4