From: Darrick J. Wong <djwong@xxxxxxxxxx> 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 <djwong@xxxxxxxxxx> --- fs/xfs/scrub/trace.h | 4 ++++ fs/xfs/xfs_trace.h | 24 ++++++++++++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h index e9b81b7645c1..20f34548bfe5 100644 --- a/fs/xfs/scrub/trace.h +++ b/fs/xfs/scrub/trace.h @@ -2,6 +2,10 @@ /* * Copyright (C) 2017 Oracle. All Rights Reserved. * Author: Darrick J. Wong <darrick.wong@xxxxxxxxxx> + * + * NOTE: none of these tracepoints shall be considered a stable kernel ABI + * as they can change at any time. See xfs_trace.h for documentation of + * specific units found in tracepoint output. */ #undef TRACE_SYSTEM #define TRACE_SYSTEM xfs_scrub diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index a72cd56afc8c..c46dd4fea3e3 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -2,6 +2,30 @@ /* * 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: + * + * ino: filesystem inode number + * agino: per-AG inode number + * agno: allocation group number + * agbno: per-AG block number in fs blocks + * owner: reverse-mapping owner, usually inodes + * daddr: physical block number in 512b 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 + * fileoff: file offset, in fs blocks + * pos: file offset, in bytes + * forkoff: inode fork offset, in bytes + * icount: number of inode records + * disize: ondisk file size, in bytes + * isize: incore file size, in bytes + * fsbcount: number of blocks in an extent, in fs blocks + * bbcount: number of blocks in a physical extent, in 512b blocks + * bytecount: number of bytes */ #undef TRACE_SYSTEM #define TRACE_SYSTEM xfs
