Optimize secondary sb search, using similar method to find
fs geometry as that of xfs_mkfs. If this faster method fails
in finding a secondary sb, fall back to original brute force
slower search.
Signed-off-by: Bill O'Donnell <billodo@xxxxxxxxxx>
---
Makefile | 2 +-
repair/Makefile | 4 ++--
repair/sb.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++----
3 files changed, 70 insertions(+), 8 deletions(-)
diff --git a/Makefile b/Makefile
index fca0a42..1d60d9c 100644
--- a/Makefile
+++ b/Makefile
@@ -80,7 +80,7 @@ fsr: libhandle
growfs: libxcmd
io: libxcmd libhandle
quota: libxcmd
-repair: libxlog
+repair: libxlog libxcmd
copy: libxlog
ifeq ($(HAVE_BUILDDEFS), yes)
diff --git a/repair/Makefile b/repair/Makefile
index 251722b..d24ab1f 100644
--- a/repair/Makefile
+++ b/repair/Makefile
@@ -20,8 +20,8 @@ CFILES = agheader.c attr_repair.c avl.c avl64.c bmap.c btree.c \
progress.c prefetch.c rt.c sb.c scan.c threads.c \
versions.c xfs_repair.c
-LLDLIBS = $(LIBXFS) $(LIBXLOG) $(LIBUUID) $(LIBRT) $(LIBPTHREAD)
-LTDEPENDENCIES = $(LIBXFS) $(LIBXLOG)
+LLDLIBS = $(LIBBLKID) $(LIBXFS) $(LIBXLOG) $(LIBUUID) $(LIBRT) $(LIBPTHREAD) $(LIBXCMD)
+LTDEPENDENCIES = $(LIBXFS) $(LIBXLOG) $(LIBXCMD)
LLDFLAGS = -static-libtool-libs
default: depend $(LTCOMMAND)
diff --git a/repair/sb.c b/repair/sb.c
index 4eef14a..7e4708c 100644
--- a/repair/sb.c
+++ b/repair/sb.c
@@ -17,6 +17,7 @@
*/
#include "libxfs.h"
+#include "libxcmd.h"
#include "libxlog.h"
#include "agheader.h"
#include "globals.h"
@@ -85,10 +86,15 @@ copy_sb(xfs_sb_t *source, xfs_sb_t *dest)
}
/*
- * find a secondary superblock, copy it into the sb buffer
+ * find a secondary superblock, copy it into the sb buffer.
+ * start is the point to begin reading BSIZE bytes.
+ * skip contains a byte-count of how far to advance for next read.
*/
-int
-find_secondary_sb(xfs_sb_t *rsb)
+static int
+__find_secondary_sb(
+ xfs_sb_t *rsb,
+ __uint64_t start,
+ __uint64_t skip)
{
xfs_off_t off;
xfs_sb_t *sb;
@@ -117,7 +123,7 @@ find_secondary_sb(xfs_sb_t *rsb)
/*
* skip first sector since we know that's bad
*/
- for (done = 0, off = XFS_AG_MIN_BYTES; !done ; off += bsize) {
+ for (done = 0, off = start; !done ; off += skip) {
/*
* read disk 1 MByte at a time.
*/
@@ -166,7 +172,63 @@ find_secondary_sb(xfs_sb_t *rsb)
}
free(sb);
- return(retval);
+ return retval;
+}
+
+static int
+guess_default_geometry(
+ __uint64_t *agsize,
+ __uint64_t *agcount,
+ libxfs_init_t *x)
+{
+ struct fs_topology ft;
+ int blocklog;
+ __uint64_t dblocks;
+ int multidisk;
+
+ memset(&ft, 0, sizeof(ft));
+ get_topology(x, &ft, 1);
+
+ /*
+ * get geometry from get_topology result.
+ * Use default block size (2^12)
+ */
+ blocklog = 12;
+ multidisk = ft.dswidth | ft.dsunit;
+ dblocks = x->dsize >> (blocklog - BBSHIFT);
+ calc_default_ag_geometry(blocklog, dblocks, multidisk,
+ agsize, agcount);
+
+ return blocklog;
+}
+
+int
+find_secondary_sb(xfs_sb_t *rsb)
+{
+ int retval;
+ __uint64_t agcount;
+ __uint64_t agsize;
+ __uint64_t skip;
+ int blocklog;
+
+ /*
+ * Attempt to find secondary sb with a coarse approach.
+ * Failing that, fallback to a fine-grained approach.
+ */
+ blocklog = guess_default_geometry(&agsize, &agcount, &x);
+
+ /*
+ * use found ag geometry to quickly find secondary sb
+ */
+ skip = agsize << blocklog;
+ retval = __find_secondary_sb(rsb, skip, skip);
+ if (!retval) {
+ /*
+ * fallback: Start at min agsize and scan all blocks
+ */
+ retval = __find_secondary_sb(rsb, XFS_AG_MIN_BYTES, BSIZE);
+ }
+ return retval;
}
/*
--
2.5.5
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