xfs_db: report absolute maxlevels for each btree type
Augment the xfs_db btheight command so that the debugger can display the
absolute maximum btree height for each btree type.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
diff --git a/db/btheight.c b/db/btheight.c
index 0e6fa58..7e8f586 100644
--- a/db/btheight.c
+++ b/db/btheight.c
@@ -14,16 +14,17 @@
struct btmap {
const char *tag;
+ xfs_btnum_t btnum;
unsigned int (*maxrecs)(struct xfs_mount *mp, unsigned int blocklen,
bool leaf);
} maps[] = {
- {"bnobt", libxfs_allocbt_maxrecs},
- {"cntbt", libxfs_allocbt_maxrecs},
- {"inobt", libxfs_inobt_maxrecs},
- {"finobt", libxfs_inobt_maxrecs},
- {"bmapbt", libxfs_bmbt_maxrecs},
- {"refcountbt", libxfs_refcountbt_maxrecs},
- {"rmapbt", libxfs_rmapbt_maxrecs},
+ {"bnobt", XFS_BTNUM_BNO, libxfs_allocbt_maxrecs},
+ {"cntbt", XFS_BTNUM_CNT, libxfs_allocbt_maxrecs},
+ {"inobt", XFS_BTNUM_INO, libxfs_inobt_maxrecs},
+ {"finobt", XFS_BTNUM_FINO, libxfs_inobt_maxrecs},
+ {"bmapbt", XFS_BTNUM_BMAP, libxfs_bmbt_maxrecs},
+ {"refcountbt", XFS_BTNUM_REFC, libxfs_refcountbt_maxrecs},
+ {"rmapbt", XFS_BTNUM_RMAP, libxfs_rmapbt_maxrecs},
};
static void
@@ -45,6 +46,7 @@
" -n -- Number of records we want to store.\n"
" -w max -- Show only the best case scenario.\n"
" -w min -- Show only the worst case scenario.\n"
+" -w absmax -- Print the maximum possible btree height for all filesystems.\n"
"\n"
" Supported btree types:\n"
" all "
@@ -222,6 +224,23 @@
#define REPORT_DEFAULT (-1U)
#define REPORT_MAX (1 << 0)
#define REPORT_MIN (1 << 1)
+#define REPORT_ABSMAX (1 << 2)
+
+static void
+report_absmax(const char *tag)
+{
+ struct btmap *m;
+ int i;
+
+ for (i = 0, m = maps; i < ARRAY_SIZE(maps); i++, m++) {
+ if (!strcmp(m->tag, tag)) {
+ printf("%s: %u\n", tag,
+ libxfs_btree_absolute_maxlevels(m->btnum));
+ return;
+ }
+ }
+ printf(_("%s: Don't know how to report max height.\n"), tag);
+}
static void
report(
@@ -233,6 +252,11 @@
unsigned int records_per_block[2];
int ret;
+ if (report_what == REPORT_ABSMAX) {
+ report_absmax(tag);
+ return;
+ }
+
ret = construct_records_per_block(tag, blocksize, records_per_block);
if (ret)
return;
@@ -334,6 +358,8 @@
report_what = REPORT_MIN;
else if (!strcmp(optarg, "max"))
report_what = REPORT_MAX;
+ else if (!strcmp(optarg, "absmax"))
+ report_what = REPORT_ABSMAX;
else {
btheight_help();
return 0;
@@ -345,20 +371,20 @@
}
}
- if (nr_records == 0) {
+ if (report_what != REPORT_ABSMAX && nr_records == 0) {
fprintf(stderr,
_("Number of records must be greater than zero.\n"));
return 0;
}
- if (blocksize > INT_MAX) {
+ if (report_what != REPORT_ABSMAX && blocksize > INT_MAX) {
fprintf(stderr,
_("The largest block size this command will consider is %u bytes.\n"),
INT_MAX);
return 0;
}
- if (blocksize < 128) {
+ if (report_what != REPORT_ABSMAX && blocksize < 128) {
fprintf(stderr,
_("The smallest block size this command will consider is 128 bytes.\n"));
return 0;
diff --git a/libxfs/libxfs_api_defs.h b/libxfs/libxfs_api_defs.h
index 55dcede..8638445 100644
--- a/libxfs/libxfs_api_defs.h
+++ b/libxfs/libxfs_api_defs.h
@@ -48,6 +48,7 @@
#define xfs_bmbt_stage_cursor libxfs_bmbt_stage_cursor
#define xfs_bmdr_maxrecs libxfs_bmdr_maxrecs
+#define xfs_btree_absolute_maxlevels libxfs_btree_absolute_maxlevels
#define xfs_btree_bload libxfs_btree_bload
#define xfs_btree_bload_compute_geometry libxfs_btree_bload_compute_geometry
#define xfs_btree_del_cursor libxfs_btree_del_cursor
diff --git a/man/man8/xfs_db.8 b/man/man8/xfs_db.8
index 307f4a0..a62e2c4 100644
--- a/man/man8/xfs_db.8
+++ b/man/man8/xfs_db.8
@@ -402,7 +402,7 @@
Dump all keys and pointers in intermediate btree nodes, and all records in leaf btree nodes.
.RE
.TP
-.BI "btheight [\-b " blksz "] [\-n " recs "] [\-w " max "|\-w " min "] btree types..."
+.BI "btheight [\-b " blksz "] [\-n " recs "] [\-w " max "|" min "|" absmax "] btree types..."
For a given number of btree records and a btree type, report the number of
records and blocks for each level of the btree, and the total number of blocks.
The btree type must be given after the options.
@@ -435,6 +435,9 @@
is used to specify the number of records to store.
This argument is required.
.TP
+.B \-w absmax
+shows the maximum possible height for the given btree types.
+.TP
.B \-w max
shows only the best case scenario, which is when the btree blocks are
maximally loaded.
