btrfs: tree-log: make the return value for log syncing consistent

Currently we will return 1 or -EAGAIN if we decide we need to commit
the transaction rather than sync the log.  In practice this doesn't
really matter, we interpret any !0 and !BTRFS_NO_LOG_SYNC as needing to
commit the transaction.  However this makes it hard to figure out what
the correct thing to do is.

Fix this up by defining BTRFS_LOG_FORCE_COMMIT and using this in all the
places where we want to force the transaction to be committed.

CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/btrfs/tree-log.h b/fs/btrfs/tree-log.h
index 1620f8170629..57ab5f3b8dc7 100644
--- a/fs/btrfs/tree-log.h
+++ b/fs/btrfs/tree-log.h
@@ -12,6 +12,9 @@
 /* return value for btrfs_log_dentry_safe that means we don't need to log it at all */
 #define BTRFS_NO_LOG_SYNC 256
 
+/* We can't use the tree log for whatever reason, force a transaction commit */
+#define BTRFS_LOG_FORCE_COMMIT				(1)
+
 struct btrfs_log_ctx {
 	int log_ret;
 	int log_transid;