xfs_db: print transaction reservation type information

Create a new xfs_db command to print the transaction reservation info for
a given filesystem.  This will make it easier to compare the calculations
made by the kernel and xfsprogs in case there is a discrepancy.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

5 files changed, 68 insertions, 1 deletions

diff --git a/db/command.c b/db/command.c
index 5ff3c4f0b4..12ae5b781b 100644
--- a/db/command.c
+++ b/db/command.c
@@ -138,6 +138,7 @@ init_commands(void)
 	hash_init();
 	inode_init();
 	input_init();
+	logres_init();
 	logformat_init();
 	io_init();
 	metadump_init();
diff --git a/db/logformat.c b/db/logformat.c
index 70097bc184..b290bd3547 100644
--- a/db/logformat.c
+++ b/db/logformat.c
@@ -147,3 +147,62 @@ logformat_init(void)
 
 	add_command(&logformat_cmd);
 }
+
+static void
+print_logres(
+	int			i,
+	struct xfs_trans_res	*res)
+{
+	dbprintf(_("type %d logres %u logcount %d flags 0x%x\n"),
+		i, res->tr_logres, res->tr_logcount, res->tr_logflags);
+}
+
+int
+logres_f(
+	int			argc,
+	char			**argv)
+{
+	struct xfs_trans_res	resv;
+	struct xfs_trans_res	*res;
+	struct xfs_trans_res	*end_res;
+	int			i;
+
+	res = (struct xfs_trans_res *)M_RES(mp);
+	end_res = (struct xfs_trans_res *)(M_RES(mp) + 1);
+	for (i = 0; res < end_res; i++, res++)
+		print_logres(i, res);
+	libxfs_log_get_max_trans_res(mp, &resv);
+	print_logres(-1, &resv);
+
+	return 0;
+}
+
+static void
+logres_help(void)
+{
+	dbprintf(_(
+"\n"
+" The 'logres' command prints information about all log reservation types.\n"
+" This includes the reservation space, the intended transaction roll count,\n"
+" and the reservation flags, if any.\n"
+"\n"
+	));
+}
+
+static const struct cmdinfo logres_cmd = {
+	.name =		"logres",
+	.altname =	NULL,
+	.cfunc =	logres_f,
+	.argmin =	0,
+	.argmax =	0,
+	.canpush =	0,
+	.args =		NULL,
+	.oneline =	N_("dump log reservations"),
+	.help =		logres_help,
+};
+
+void
+logres_init(void)
+{
+	add_command(&logres_cmd);
+}
diff --git a/db/logformat.h b/db/logformat.h
index f9763ee315..60396c07db 100644
--- a/db/logformat.h
+++ b/db/logformat.h
@@ -17,3 +17,4 @@
  */
 
 void logformat_init(void);
+void logres_init(void);
diff --git a/libxfs/libxfs_api_defs.h b/libxfs/libxfs_api_defs.h
index d2ab02a5dc..5d56340c06 100644
--- a/libxfs/libxfs_api_defs.h
+++ b/libxfs/libxfs_api_defs.h
@@ -60,7 +60,7 @@
 #define xfs_trans_roll			libxfs_trans_roll
 #define xfs_trans_get_buf_map		libxfs_trans_get_buf_map
 #define xfs_trans_resv_calc		libxfs_trans_resv_calc
-
+#define xfs_log_get_max_trans_res	libxfs_log_get_max_trans_res
 #define xfs_attr_get			libxfs_attr_get
 #define xfs_attr_set			libxfs_attr_set
 #define xfs_attr_remove			libxfs_attr_remove
diff --git a/man/man8/xfs_db.8 b/man/man8/xfs_db.8
index 37018a7a37..524b1ef61a 100644
--- a/man/man8/xfs_db.8
+++ b/man/man8/xfs_db.8
@@ -690,6 +690,12 @@ Start logging output to
 .IR filename ,
 stop logging, or print the current logging status.
 .TP
+.B logres
+Print transaction reservation size information for each transaction type.
+This makes it easier to find discrepancies in the reservation calculations
+between xfsprogs and the kernel, which will help when diagnosing minimum
+log size calculation errors.
+.TP
 .BI "metadump [\-egow] " filename
 Dumps metadata to a file. See
 .BR xfs_metadump (8)