From: Vyacheslav Dubeyko <slava@xxxxxxxxxxx>
Subject: [PATCH v4 09/15] 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 <slava@xxxxxxxxxxx>
CC: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
CC: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Tested-by: Hin-Tak Leung <htl10@xxxxxxxxxxxxxxxxxxxxx>
---
fs/hfsplus/journal.c | 143 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 143 insertions(+)
diff --git a/fs/hfsplus/journal.c b/fs/hfsplus/journal.c
index 265ac49..d3e4823 100644
--- a/fs/hfsplus/journal.c
+++ b/fs/hfsplus/journal.c
@@ -58,6 +58,16 @@
(be64_to_cpu(HFSPLUS_JIB(jnl)->offset) >> \
HFSPLUS_SB(sb)->alloc_blksz_shift)
+static inline sector_t JOURNAL_OFF_TO_SEC(struct super_block *sb)
+{
+ struct hfsplus_journal *jnl = HFSPLUS_JNL(sb);
+ sector_t blk_off = HFSPLUS_SB(sb)->blockoffset;
+ u64 jh_off = be64_to_cpu(HFSPLUS_JIB(jnl)->offset);
+ u64 start = le64_to_cpu(JNL_SWAP64(jnl, HFSPLUS_JH(jnl)->start));
+
+ return blk_off + ((jh_off + start) >> HFSPLUS_SECTOR_SHIFT);
+}
+
#define BLOCK_TO_SEC(sb, blk) \
((sector_t)(blk) << \
(HFSPLUS_SB(sb)->alloc_blksz_shift - HFSPLUS_SECTOR_SHIFT))
@@ -69,6 +79,23 @@
#define JHDR_SIZE(jnl) \
(le32_to_cpu(JNL_SWAP32(jnl, HFSPLUS_JH(jnl)->jhdr_size)))
+#define TR_MAX_BLOCKS(jnl, blhdr) \
+ (le16_to_cpu(JNL_SWAP16(jnl, HFSPLUS_BLHDR_PTR(blhdr)->max_blocks)))
+#define TR_BLOCKS(jnl, blhdr) \
+ (le16_to_cpu(JNL_SWAP16(jnl, HFSPLUS_BLHDR_PTR(blhdr)->num_blocks)))
+#define TR_BYTES(jnl, blhdr) \
+ (le32_to_cpu(JNL_SWAP32(jnl, HFSPLUS_BLHDR_PTR(blhdr)->bytes_used)))
+
+static inline u32 TR_SEQ_NUM(struct hfsplus_journal *jnl,
+ struct hfsplus_blhdr *blhdr)
+{
+ return le32_to_cpu(JNL_SWAP32(jnl, blhdr->binfo[0].block.seq_num));
+}
+
+#define NEED_CHECK_CSUM(jnl, blhdr) \
+ (le32_to_cpu(JNL_SWAP32(jnl, HFSPLUS_BLHDR_PTR(blhdr)->flags)) & \
+ HFSPLUS_BLHDR_CHECK_CHECKSUMS)
+
/*
* struct hfsplus_blist_desc - descriptor of block list buffer
* @start_sec: start sector of block list
@@ -349,15 +376,110 @@ failed_init:
return err;
}
+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 %llu\n",
+ (unsigned long long)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("unable to 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 *jnl)
{
return TR_START(jnl) == LAST_TR_END(jnl);
}
+static inline
+bool hfsplus_transaction_seq_num_valid(struct hfsplus_journal *jnl,
+ u32 prev_seq_num,
+ struct hfsplus_blhdr *blhdr)
+{
+ if (prev_seq_num != 0) {
+ u32 seq = TR_SEQ_NUM(jnl, blhdr);
+
+ if ((seq != 0) && (seq != prev_seq_num) &&
+ (seq != (prev_seq_num + 1))) {
+ pr_err("transaction seq number %u is invalid\n",
+ TR_SEQ_NUM(jnl, blhdr));
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static int hfsplus_verify_blhdr(struct hfsplus_journal *jnl,
+ u32 prev_seq_num,
+ struct hfsplus_blhdr *blhdr)
+{
+ __le32 blhdr_checksum, cksum;
+
+ if (!hfsplus_transaction_seq_num_valid(jnl, prev_seq_num, blhdr))
+ return -EIO;
+
+ if (TR_BLOCKS(jnl, blhdr) == 0 || TR_BYTES(jnl, blhdr) == 0) {
+ pr_err("corrupted block list header\n");
+ hfs_dbg(JOURNAL, "num_blocks %u, max_blocks %u\n",
+ TR_BLOCKS(jnl, blhdr), TR_BYTES(jnl, blhdr));
+ return -EIO;
+ }
+
+ if (TR_BLOCKS(jnl, blhdr) > TR_MAX_BLOCKS(jnl, blhdr)) {
+ pr_err("corrupted block list header\n");
+ hfs_dbg(JOURNAL, "num_blocks %u, max_blocks %u\n",
+ TR_BLOCKS(jnl, blhdr), TR_MAX_BLOCKS(jnl, blhdr));
+ return -EIO;
+ }
+
+ if (!NEED_CHECK_CSUM(jnl, blhdr))
+ return 0; /* don't check checksums */
+
+ blhdr_checksum = JNL_SWAP32(jnl, 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 = JNL_SWAP32(jnl, blhdr_checksum);
+ pr_err("corrupted block list header\n");
+ hfs_dbg(JOURNAL, "calculated CRC %#x, blhdr_checksum %#x\n",
+ le32_to_cpu(cksum), le32_to_cpu(blhdr_checksum));
+ return -EIO;
+ }
+
+ blhdr->checksum = JNL_SWAP32(jnl, blhdr_checksum);
+ return 0;
+}
+
static int hfsplus_replay_journal(struct super_block *sb)
{
+ struct hfsplus_journal *jnl = HFSPLUS_SB(sb)->jnl;
struct hfsplus_blist_desc desc;
+ u32 last_seq_num = 0;
int err;
err = hfsplus_init_block_list_desc(sb, &desc);
@@ -366,9 +488,30 @@ static int hfsplus_replay_journal(struct super_block *sb)
return err;
}
+ /* Go through transactions */
+ while (!hfsplus_journal_empty(jnl)) {
+ struct hfsplus_blhdr *blhdr;
+
+ blhdr = hfsplus_get_blhdr(sb, JOURNAL_OFF_TO_SEC(sb), &desc);
+ if (!blhdr) {
+ err = -EIO;
+ goto failed_journal_replay;
+ }
+
+ hfs_dbg(JREPLAY, "num_blocks: %u, bytes_used: %u\n",
+ TR_BLOCKS(jnl, blhdr), TR_BYTES(jnl, blhdr));
+
+ err = hfsplus_verify_blhdr(jnl, last_seq_num, blhdr);
+ if (err)
+ goto failed_journal_replay;
+
+ last_seq_num = TR_SEQ_NUM(jnl, blhdr);
+ }
+
/* TODO: implement */
return -EINVAL;
+failed_journal_replay:
hfsplus_deinit_block_list_desc(&desc);
return err;
}
--
1.7.9.5
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