From 55f224baf83d71b3d2cc24e6387d9f1f6a5a1eda Mon Sep 17 00:00:00 2001 From: Bill O'Donnell Date: Thu, 29 Jun 2017 13:05:00 -0500 Subject: [PATCH] xfs_db: update buffer size when new type is set xfs_db doesn't take sector size into account when setting type. This can result in an errant crc. For example, with a sector size of 4096: xfs_db> agi 0 xfs_db> p crc crc = 0xab85043e (correct) xfs_db> daddr current daddr is 16 xfs_db> daddr 42 xfs_db> daddr 16 xfs_db> type agi Metadata CRC error detected at xfs_agi block 0x10/0x200 xfs_db> p crc crc = 0xab85043e (bad) When xfs_db sets the new daddr in daddr_f, it does so with one BBSIZE sector (512). Changing the type doesn't change the size of the current buffer in iocur_top, so the checksum is calculated on the wrong length for the type (when the actual sector size > BBSIZE (512). For types with fields, reread the buffer to pick up the correct size for the new type when it gets set. Facilitate the reread by setting the cursor with set_cur(). Signed-off-by: Bill O'Donnell Reviewed-by: Carlos Maiolino Reviewed-by: Darrick J. Wong [sandeen: fix up long line, clarify subject & comments] Signed-off-by: Eric Sandeen --- db/io.c | 8 ++++++++ 1 file changed, 8 insertions(+) Index: xfsprogs-rhel7.5/db/io.c =================================================================== --- xfsprogs-rhel7.5.orig/db/io.c +++ xfsprogs-rhel7.5/db/io.c @@ -27,6 +27,7 @@ #include "output.h" #include "init.h" #include "malloc.h" +#include "bit.h" static int pop_f(int argc, char **argv); static void pop_help(void); @@ -567,6 +568,13 @@ set_iocur_type( { struct xfs_buf *bp = iocur_top->bp; + /* adjust buffer size for types with fields & hence fsize() */ + if (t->fields) { + int bb_count; /* type's size in basic blocks */ + + bb_count = BTOBB(byteize(fsize(t->fields, iocur_top->data, 0, 0))); + set_cur(t, iocur_top->bb, bb_count, DB_RING_IGN, NULL); + } iocur_top->typ = t; /* verify the buffer if the type has one. */