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
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