diff options
Diffstat (limited to 'src/block/block_open.c')
| -rw-r--r-- | src/block/block_open.c | 46 |
1 files changed, 31 insertions, 15 deletions
diff --git a/src/block/block_open.c b/src/block/block_open.c index dd0f3f0716a..d9b2f908737 100644 --- a/src/block/block_open.c +++ b/src/block/block_open.c @@ -296,15 +296,21 @@ __wt_desc_init(WT_SESSION_IMPL *session, WT_FH *fh, uint32_t allocsize) WT_RET(__wt_scr_alloc(session, allocsize, &buf)); memset(buf->mem, 0, allocsize); + /* + * Checksum a little-endian version of the header, and write everything + * in little-endian format. The checksum is (potentially) returned in a + * big-endian format, swap it into place in a separate step. + */ desc = buf->mem; desc->magic = WT_BLOCK_MAGIC; desc->majorv = WT_BLOCK_MAJOR_VERSION; desc->minorv = WT_BLOCK_MINOR_VERSION; - - /* Update the checksum. */ desc->cksum = 0; + __wt_block_desc_byteswap(desc); desc->cksum = __wt_cksum(desc, allocsize); - +#ifdef WORDS_BIGENDIAN + desc->cksum = __wt_bswap32(desc->cksum); +#endif ret = __wt_write(session, fh, (wt_off_t)0, (size_t)allocsize, desc); __wt_scr_free(session, &buf); @@ -321,7 +327,7 @@ __desc_read(WT_SESSION_IMPL *session, WT_BLOCK *block) WT_BLOCK_DESC *desc; WT_DECL_ITEM(buf); WT_DECL_RET; - uint32_t cksum; + uint32_t cksum_calculate, cksum_tmp; /* Use a scratch buffer to get correct alignment for direct I/O. */ WT_RET(__wt_scr_alloc(session, block->allocsize, &buf)); @@ -330,14 +336,19 @@ __desc_read(WT_SESSION_IMPL *session, WT_BLOCK *block) WT_ERR(__wt_read(session, block->fh, (wt_off_t)0, (size_t)block->allocsize, buf->mem)); + /* + * Handle little- and big-endian objects. Objects are written in little- + * endian format: save the header checksum, and calculate the checksum + * for the header in its little-endian form. Then, restore the header's + * checksum, and byte-swap the whole thing as necessary, leaving us with + * a calculated checksum that should match the checksum in the header. + */ desc = buf->mem; - WT_ERR(__wt_verbose(session, WT_VERB_BLOCK, - "%s: magic %" PRIu32 - ", major/minor: %" PRIu32 "/%" PRIu32 - ", checksum %#" PRIx32, - block->name, desc->magic, - desc->majorv, desc->minorv, - desc->cksum)); + cksum_tmp = desc->cksum; + desc->cksum = 0; + cksum_calculate = __wt_cksum(desc, block->allocsize); + desc->cksum = cksum_tmp; + __wt_block_desc_byteswap(desc); /* * We fail the open if the checksum fails, or the magic number is wrong @@ -348,10 +359,7 @@ __desc_read(WT_SESSION_IMPL *session, WT_BLOCK *block) * may have entered the wrong file name, and is now frantically pounding * their interrupt key. */ - cksum = desc->cksum; - desc->cksum = 0; - if (desc->magic != WT_BLOCK_MAGIC || - cksum != __wt_cksum(desc, block->allocsize)) + if (desc->magic != WT_BLOCK_MAGIC || desc->cksum != cksum_calculate) WT_ERR_MSG(session, WT_ERROR, "%s does not appear to be a WiredTiger file", block->name); @@ -365,6 +373,14 @@ __desc_read(WT_SESSION_IMPL *session, WT_BLOCK *block) WT_BLOCK_MAJOR_VERSION, WT_BLOCK_MINOR_VERSION, desc->majorv, desc->minorv); + WT_ERR(__wt_verbose(session, WT_VERB_BLOCK, + "%s: magic %" PRIu32 + ", major/minor: %" PRIu32 "/%" PRIu32 + ", checksum %#" PRIx32, + block->name, desc->magic, + desc->majorv, desc->minorv, + desc->cksum)); + err: __wt_scr_free(session, &buf); return (ret); } |