From: Vyacheslav Dubeyko <slava@xxxxxxxxxxx> Subject: [PATCH v4 07/15] hfsplus: implement check consistency of journal log file This patch implements functionality of checking main HFS+ journal structures (journal info block and journal header) before replaying of journal buffer's transactions. Signed-off-by: Vyacheslav Dubeyko <slava@xxxxxxxxxxx> CC: Al Viro <viro@xxxxxxxxxxxxxxxxxx> CC: Christoph Hellwig <hch@xxxxxxxxxxxxx> Tested-by: Hin-Tak Leung <htl10@xxxxxxxxxxxxxxxxxxxxx> --- fs/hfsplus/journal.c | 161 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 161 insertions(+) diff --git a/fs/hfsplus/journal.c b/fs/hfsplus/journal.c index f0a0815..049cff5 100644 --- a/fs/hfsplus/journal.c +++ b/fs/hfsplus/journal.c @@ -62,6 +62,10 @@ ((sector_t)(blk) << \ (HFSPLUS_SB(sb)->alloc_blksz_shift - HFSPLUS_SECTOR_SHIFT)) +#define TR_START(jnl) \ + (le64_to_cpu(JNL_SWAP64(jnl, HFSPLUS_JH(jnl)->start))) +#define LAST_TR_END(jnl) \ + (le64_to_cpu(JNL_SWAP64(jnl, HFSPLUS_JH(jnl)->end))) #define JHDR_SIZE(jnl) \ (le32_to_cpu(JNL_SWAP32(jnl, HFSPLUS_JH(jnl)->jhdr_size))) @@ -161,6 +165,34 @@ static u32 calc_internal_checksum(u32 seed, unsigned char *ptr, int len) #define HFSPLUS_CALC_CHECKSUM(ptr, len) \ HFSPLUS_CHECKSUM(calc_internal_checksum(0, ptr, len)) +static int hfsplus_replay_journal_header(struct super_block *sb) +{ + struct hfsplus_journal *jnl = HFSPLUS_SB(sb)->jnl; + struct hfsplus_journal_header *jh = jnl->jh; + sector_t jh_blk = JH_BLOCK(sb, jnl); + __le32 calc_cksum; + int err; + + hfs_dbg(JOURNAL, "replay journal header\n"); + + jh->start = JNL_SWAP64(jnl, cpu_to_le64((u64)JHDR_SIZE(jnl))); + jh->end = JNL_SWAP64(jnl, cpu_to_le64((u64)JHDR_SIZE(jnl))); + + jh->checksum = 0; + calc_cksum = HFSPLUS_CALC_CHECKSUM((unsigned char *)jh, sizeof(*jh)); + jh->checksum = JNL_SWAP32(jnl, calc_cksum); + + err = hfsplus_submit_bio(sb, BLOCK_TO_SEC(sb, jh_blk), + jnl->jh_buf, NULL, WRITE_SYNC, NULL); + if (err) { + pr_err("unable to write journal header block %llu\n", + (unsigned long long)jh_blk); + return err; + } + + return 0; +} + /* * hfsplus_create_journal - create journal * @@ -251,6 +283,127 @@ static int hfsplus_create_journal(struct super_block *sb, return 0; } +static inline +bool hfsplus_journal_empty(struct hfsplus_journal *jnl) +{ + return TR_START(jnl) == LAST_TR_END(jnl); +} + +static int hfsplus_replay_journal(struct super_block *sb) +{ + /* TODO: implement */ + return -EINVAL; +} + +static +int hfsplus_check_journal_info_block(struct hfsplus_journal_info_block *jib) +{ + u32 jib_flags; + + jib_flags = be32_to_cpu(jib->flags); + hfs_dbg(JOURNAL, "jib->flags: %#x\n", jib_flags); + + /* Check that journal is on another volume */ + if (jib_flags & HFSPLUS_JOURNAL_ON_OTHER_DEVICE && + !(jib_flags & HFSPLUS_JOURNAL_IN_FS)) { + pr_err("unable to access the HFS+ journal\n"); + return -EOPNOTSUPP; + } + + /* Check that journal is created yet */ + if (jib_flags & HFSPLUS_JOURNAL_NEED_INIT) { + pr_err("HFS+ journal is not created\n"); + return -EIO; + } + + return 0; +} + +static int hfsplus_verify_journal_header(struct hfsplus_journal *jnl) +{ + struct hfsplus_journal_header *jh = jnl->jh; + __le32 magic = cpu_to_le32(HFSPLUS_JOURNAL_HEADER_MAGIC); + __le32 endian = cpu_to_le32(HFSPLUS_JOURNAL_HEADER_ENDIAN); + __le32 jh_checksum; + __le32 checksum; + + if (JNL_SWAP32(jnl, jh->magic) != magic || + JNL_SWAP32(jnl, jh->endian) != endian) { + pr_err("invalid journal header\n"); + return -EIO; + } + + jh_checksum = JNL_SWAP32(jnl, jh->checksum); + + jh->checksum = 0; + checksum = HFSPLUS_CALC_CHECKSUM((unsigned char *)jh, sizeof(*jh)); + + if (le32_to_cpu(checksum) != le32_to_cpu(jh_checksum)) { + jh->checksum = JNL_SWAP32(jnl, jh_checksum); + pr_err("invalid journal header\n"); + hfs_dbg(JOURNAL, "calculated CRC %#x, jh_checksum %#x\n", + checksum, le32_to_cpu(jh_checksum)); + return -EIO; + } + + jh->checksum = JNL_SWAP32(jnl, jh_checksum); + + return 0; +} + +/* + * hfsplus_check_journal - check consistency of journal log file. + * + * @sb: superblock + */ +int hfsplus_check_journal(struct super_block *sb) +{ + struct hfsplus_journal *jnl = HFSPLUS_SB(sb)->jnl; + int err; + + if (!jnl) { + hfs_dbg(JOURNAL, "HFS+ journal absent"); + return 0; + } + + hfs_dbg(JOURNAL, "check HFS+ journal\n"); + + err = hfsplus_check_journal_info_block(jnl->jib); + if (err) + return err; + + err = hfsplus_verify_journal_header(jnl); + if (err) + return err; + + if (test_and_clear_bit(HFSPLUS_SB_NORECOVERY, &HFSPLUS_SB(sb)->flags)) { + pr_info("journal replay is skiped, mounting read-only.\n"); + sb->s_flags |= MS_RDONLY; + return -EROFS; + } + + if (hfsplus_journal_empty(jnl)) { + err = hfsplus_replay_journal_header(sb); + if (unlikely(err)) { + pr_err("journal replay failed, please run fsck.hfsplus\n"); + return err; + } + /* If they're the same, we can mount, it's clean */ + hfs_dbg(JOURNAL, "journal is empty\n"); + return 0; + } else { + /* Try to replay journal */ + err = hfsplus_replay_journal(sb); + if (unlikely(err)) { + pr_err("journal replay failed, please run fsck.hfsplus\n"); + return err; + } + hfs_dbg(JOURNAL, "journal replay is done\n"); + } + + return 0; +} + /* * hfsplus_init_journal - initialize journal object * @@ -328,6 +481,13 @@ int hfsplus_init_journal(struct super_block *sb) jnl->endianness = hfsplus_check_journal_endianness(jnl->jh); if (JIB_FLAGS(jnl) & HFSPLUS_JOURNAL_NEED_INIT) { + if (test_and_clear_bit(HFSPLUS_SB_NORECOVERY, + &HFSPLUS_SB(sb)->flags)) { + sb->s_flags |= MS_RDONLY; + err = -EROFS; + goto finish_journal_init; + } + hfs_dbg(JOURNAL, "create HFS+ journal\n"); err = hfsplus_create_journal(sb, jnl); @@ -359,6 +519,7 @@ int hfsplus_init_journal(struct super_block *sb) goto free_jh_buf; } +finish_journal_init: mutex_init(&jnl->jnl_lock); jnl->sbp = sb; HFSPLUS_SB(sb)->jnl = jnl; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html