xfs_repair: new secondary superblock search method 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. version history: ---- v1: http://oss.sgi.com/archives/xfs/2016-02/msg00304.html v2: patch 2 whitespace fixups v3: patch 2 correct functionality; style fixups v4: patch 1,2 properly see to style and whitespace fixups v5: patch 2 move guess_default_geometry() to sb.c plus very minor style/whitespace fixups. ---- 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; } /* -- 2.5.0 _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
