Re: [Crash-utility] [PATCH v2] diskdump: Add support for reading dumpfiles compressed by Zstandard

-----Original Message----- > @@ -1002,6 +1006,11 @@ is_diskdump(char *file) > dd->flags |= SNAPPY_SUPPORTED; > #endif > > +#ifdef ZSTD > + if ((dctx = ZSTD_createDCtx()) != NULL) > + dd->flags |= ZSTD_SUPPORTED; I found that this part allocates dctx superfluously for split dumpfiles, so sending v2. -- From: Kazuhito Hagio <k-hagio(a)ab.jp.nec.com&gt; Subject: [PATCH] diskdump: Add support for reading dumpfiles compressed by Zstandard Add support for reading dumpfiles compressed by Zstandard (zstd) using makedumpfile. To build crash with zstd support, type "make zstd". Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; --- Makefile | 4 ++++ README | 4 ++-- configure.c | 20 +++++++++++++++++--- defs.h | 4 ++++ diskdump.c | 33 +++++++++++++++++++++++++++++++++ diskdump.h | 1 + help.c | 4 ++-- 7 files changed, 63 insertions(+), 7 deletions(-)

--- a/configure.c +++ b/configure.c @@ -1746,6 +1746,7 @@ add_extra_lib(char *option)

{ int lzo, add_DLZO, add_llzo2; int snappy, add_DSNAPPY, add_lsnappy; + int zstd, add_DZSTD, add_lzstd; int valgrind, add_DVALGRIND; char *cflags, *ldflags; FILE *fp_cflags, *fp_ldflags;

--- a/diskdump.c +++ b/diskdump.c @@ -96,6 +96,10 @@ static struct diskdump_data **dd_list = NULL; static int num_dd = 0; static int num_dumpfiles = 0; +#ifdef ZSTD +static ZSTD_DCtx *dctx = NULL; +#endif + int dumpfile_is_split(void) { return KDUMP_SPLIT(); @@ -1002,6 +1006,13 @@ is_diskdump(char *file) dd->flags |= SNAPPY_SUPPORTED; #endif +#ifdef ZSTD + if (!dctx) + dctx = ZSTD_createDCtx(); + if (dctx) + dd->flags |= ZSTD_SUPPORTED; +#endif +

pc->read_vmcoreinfo = vmcoreinfo_read_string; if ((pc->flags2 & GET_LOG) && KDUMP_CMPRS_VALID()) { @@ -1251,6 +1262,24 @@ cache_page(physaddr_t paddr) ret); return READ_ERROR; } +#endif + } else if (pd.flags & DUMP_DH_COMPRESSED_ZSTD) { + + if (!(dd->flags & ZSTD_SUPPORTED)) { + error(INFO, "%s: uncompess failed: no zstd compression support\n", + DISKDUMP_VALID() ? "diskdump" : "compressed kdump"); + return READ_ERROR; + } +#ifdef ZSTD + retlen = ZSTD_decompressDCtx(dctx, + dd->page_cache_hdr[i].pg_bufptr, block_size, + dd->compressed_page, pd.size); + if (ZSTD_isError(retlen)) { + error(INFO, "%s: uncompress failed: %d (%s)\n", + DISKDUMP_VALID() ? "diskdump" : "compressed kdump", + retlen, ZSTD_getErrorName(retlen)); + return READ_ERROR; + } #endif } else memcpy(dd->page_cache_hdr[i].pg_bufptr, @@ -1806,6 +1835,8 @@ __diskdump_memory_dump(FILE *fp) fprintf(fp, "%sLZO_SUPPORTED", others++ ? "|" : ""); if (dd->flags & SNAPPY_SUPPORTED) fprintf(fp, "%sSNAPPY_SUPPORTED", others++ ? "|" : ""); + if (dd->flags & ZSTD_SUPPORTED) + fprintf(fp, "%sZSTD_SUPPORTED", others++ ? "|" : ""); fprintf(fp, ") %s\n", FLAT_FORMAT() ? "[FLAT]" : ""); fprintf(fp, " dfd: %d\n", dd->dfd); fprintf(fp, " ofp: %lx\n", (ulong)dd->ofp); @@ -1872,6 +1903,8 @@ __diskdump_memory_dump(FILE *fp) fprintf(fp, "DUMP_DH_COMPRESSED_LZO"); if (dh->status & DUMP_DH_COMPRESSED_SNAPPY) fprintf(fp, "DUMP_DH_COMPRESSED_SNAPPY"); + if (dh->status & DUMP_DH_COMPRESSED_ZSTD) + fprintf(fp, "DUMP_DH_COMPRESSED_ZSTD"); if (dh->status & DUMP_DH_COMPRESSED_INCOMPLETE) fprintf(fp, "DUMP_DH_COMPRESSED_INCOMPLETE"); if (dh->status & DUMP_DH_EXCLUDED_VMEMMAP) diff --git a/diskdump.h b/diskdump.h index 28713407b841..c152c7b86616 100644 --- a/diskdump.h +++ b/diskdump.h @@ -86,6 +86,7 @@ struct kdump_sub_header { #define DUMP_DH_COMPRESSED_SNAPPY 0x4 /* page is compressed with snappy */ #define DUMP_DH_COMPRESSED_INCOMPLETE 0x8 /* dumpfile is incomplete */ #define DUMP_DH_EXCLUDED_VMEMMAP 0x10 /* unused vmemmap pages are excluded */ +#define DUMP_DH_COMPRESSED_ZSTD 0x20 /* page is compressed with zstd */ /* descriptor of each page for vmcore */ typedef struct page_desc { diff --git a/help.c b/help.c index 6c262a3ffcbb..f34838d59908 100644 --- a/help.c +++ b/help.c @@ -9420,8 +9420,8 @@ README_ENTER_DIRECTORY, " Traditionally when vmcores are compressed via the makedumpfile(8) facility", " the libz compression library is used, and by default the crash utility", " only supports libz. Recently makedumpfile has been enhanced to optionally", -" use either the LZO or snappy compression libraries. To build crash with", -" either or both of those libraries, type \"make lzo\" or \"make snappy\".", +" use the LZO, snappy or zstd compression libraries. To build crash with any", +" or all of those libraries, type \"make lzo\", \"make snappy\" or \"make zstd\".", "", " crash supports valgrind Memcheck tool on the crash's custom memory allocator.", " To build crash with this feature enabled, type \"make valgrind\" and then run",