From e5f2e54a902de721d9cf4e7f7c35612131654cd7 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Wed, 18 Aug 2021 20:04:44 -0700 Subject: xfs: start documenting common units and tags used in tracepoints Because there are a lot of tracepoints that express numeric data with an associated unit and tag, document what they are to help everyone else keep these thigns straight. Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner Reviewed-by: Carlos Maiolino --- fs/xfs/xfs_trace.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'fs/xfs/xfs_trace.h') diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index 676b66173bb1..6d025a231d3e 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -2,6 +2,41 @@ /* * Copyright (c) 2009, Christoph Hellwig * All Rights Reserved. + * + * NOTE: none of these tracepoints shall be considered a stable kernel ABI + * as they can change at any time. + * + * Current conventions for printing numbers measuring specific units: + * + * agno: allocation group number + * + * agino: per-AG inode number + * ino: filesystem inode number + * + * agbno: per-AG block number in fs blocks + * startblock: physical block number for file mappings. This is either a + * segmented fsblock for data device mappings, or a rfsblock + * for realtime device mappings + * fsbcount: number of blocks in an extent, in fs blocks + * + * daddr: physical block number in 512b blocks + * bbcount: number of blocks in a physical extent, in 512b blocks + * + * owner: reverse-mapping owner, usually inodes + * + * fileoff: file offset, in fs blocks + * pos: file offset, in bytes + * bytecount: number of bytes + * + * disize: ondisk file size, in bytes + * isize: incore file size, in bytes + * + * forkoff: inode fork offset, in bytes + * + * ireccount: number of inode records + * + * Numbers describing space allocations (blocks, extents, inodes) should be + * formatted in hexadecimal. */ #undef TRACE_SYSTEM #define TRACE_SYSTEM xfs -- cgit v1.2.3