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> Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx> Reviewed-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx> --- v2: update unit names, say that we want hex, and put related tag names together v3: more corrections of unit names --- fs/xfs/scrub/trace.h | 4 ++++ fs/xfs/xfs_trace.h | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h index dfb10966af24..a7bbb84f91a7 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 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
