From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vyacheslav Dubeyko Subject: [PATCH 08/14] hfsplus: implement get and verify block list header functionality Date: Thu, 26 Dec 2013 13:46:54 +0400 Message-ID: <1388051214.4168.70.camel@slavad-ubuntu> Reply-To: slava@dubeyko.com Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Al Viro , ChristophHellwig , Hin-Tak Leung , Andrew Morton To: Linux FS devel list Return-path: Received: from alt-proxy13.mail.unifiedlayer.com ([67.222.34.81]:59175 "HELO alt-proxy13.mail.unifiedlayer.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752379Ab3LZJr2 (ORCPT ); Thu, 26 Dec 2013 04:47:28 -0500 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Vyacheslav Dubeyko Subject: [PATCH 08/14] hfsplus: implement get and verify block list header functionality This patch implements functionality of reading of block list's header from journal log and veryfing of it. Signed-off-by: Vyacheslav Dubeyko CC: Al Viro CC: Christoph Hellwig CC: Hin-Tak Leung --- fs/hfsplus/journal.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) diff --git a/fs/hfsplus/journal.c b/fs/hfsplus/journal.c index 852af82..891be19 100644 --- a/fs/hfsplus/journal.c +++ b/fs/hfsplus/journal.c @@ -49,6 +49,18 @@ #define JHDR_SIZE(jh) \ (le32_to_cpu(((struct hfsplus_journal_header *)(jh))->jhdr_size)) +#define TR_MAX_BLOCKS(blhdr) \ + (le16_to_cpu(((struct hfsplus_blhdr *)(blhdr))->max_blocks)) +#define TR_BLOCKS(blhdr) \ + (le16_to_cpu(((struct hfsplus_blhdr *)(blhdr))->num_blocks)) +#define TR_BYTES(blhdr) \ + (le32_to_cpu(((struct hfsplus_blhdr *)(blhdr))->bytes_used)) +#define TR_SEQ_NUM(blhdr) \ + (le32_to_cpu(((struct hfsplus_blhdr *)(blhdr))->binfo[0].block.seq_num)) +#define NEED_CHECK_CSUM(blhdr) \ + (le32_to_cpu(((struct hfsplus_blhdr *)(blhdr))->flags) & \ + HFSPLUS_BLHDR_CHECK_CHECKSUMS) + /* * struct hfsplus_blist_desc - descriptor of block list buffer * @start_sec: start sector of block list @@ -295,12 +307,102 @@ static void hfsplus_deinit_block_list_desc(struct hfsplus_blist_desc *desc) kfree(desc->dst_buf); } +static struct hfsplus_blhdr *hfsplus_get_blhdr(struct super_block *sb, + sector_t start_sector, + struct hfsplus_blist_desc *desc) +{ + struct hfsplus_blhdr *blhdr; + int err; + + hfs_dbg(JREPLAY, "get block list header: start_sector %lu\n", + start_sector); + + BUG_ON(!desc->blist_buf); + + if (desc->start_sec == start_sector && desc->cur_sec == start_sector) + return &desc->blhdr; + + err = hfsplus_submit_bio(sb, start_sector, + desc->blist_buf, (void **)&blhdr, READA, + &desc->available_bytes); + if (err) { + pr_err("can't read block list header\n"); + return NULL; + } + + desc->start_sec = start_sector; + desc->cur_sec = start_sector; + memcpy((void *)&desc->blhdr, (const void *)blhdr, sizeof(*blhdr)); + desc->binfo = &blhdr->binfo[0]; + + return &desc->blhdr; +} + static inline bool hfsplus_journal_empty(struct hfsplus_journal_header *jh) { return TR_START(jh) == LAST_TR_END(jh); } +static inline +bool hfsplus_transaction_seq_num_valid(u32 prev_seq_num, + struct hfsplus_blhdr *blhdr) +{ + if (prev_seq_num != 0) { + u32 seq = TR_SEQ_NUM(blhdr); + + if ((seq != 0) && (seq != prev_seq_num) && + (seq != (prev_seq_num + 1))) { + pr_err("transaction seq number %u invalid\n", + TR_SEQ_NUM(blhdr)); + return false; + } + } + + return true; +} + +static +int hfsplus_verify_blhdr(u32 prev_seq_num, struct hfsplus_blhdr *blhdr) +{ + __le32 blhdr_checksum, cksum; + + if (!hfsplus_transaction_seq_num_valid(prev_seq_num, blhdr)) + return -EIO; + + if (TR_BLOCKS(blhdr) == 0 || TR_BYTES(blhdr) == 0) { + pr_err("corrupted block list header\n"); + hfs_dbg(JOURNAL, "num_blocks %u, max_blocks %u\n", + TR_BLOCKS(blhdr), TR_BYTES(blhdr)); + return -EIO; + } + + if (TR_BLOCKS(blhdr) > TR_MAX_BLOCKS(blhdr)) { + pr_err("corrupted block list header\n"); + hfs_dbg(JOURNAL, "num_blocks %u, max_blocks %u\n", + TR_BLOCKS(blhdr), TR_MAX_BLOCKS(blhdr)); + return -EIO; + } + + if (!NEED_CHECK_CSUM(blhdr)) + return 0; /* don't check checksums */ + + blhdr_checksum = blhdr->checksum; + blhdr->checksum = 0; + + cksum = HFSPLUS_CALC_CHECKSUM((unsigned char *)blhdr, sizeof(*blhdr)); + if (le32_to_cpu(cksum) != le32_to_cpu(blhdr_checksum)) { + blhdr->checksum = blhdr_checksum; + pr_err("corrupted block list header\n"); + hfs_dbg(JOURNAL, "calculated CRC %#x, blhdr_checksum %#x\n", + cksum, be32_to_cpu(blhdr_checksum)); + return -EIO; + } + + blhdr->checksum = blhdr_checksum; + return 0; +} + static int hfsplus_replay_journal(struct super_block *sb); static -- 1.7.9.5