6 files changed, 95 insertions, 49 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 32b43ad154b9..0b28b36e7915 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3181,9 +3181,9 @@ static int set_journal_csum_feature_set(struct super_block *sb)
 
         if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
-                /* journal checksum v2 */
+                /* journal checksum v3 */
                 compat = 0;
-                incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
+                incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
         } else {
                 /* journal checksum v1 */
                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
@@ -3205,6 +3205,7 @@ static int set_journal_csum_feature_set(struct super_block *sb)
                 jbd2_journal_clear_features(sbi->s_journal,
                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
+                                JBD2_FEATURE_INCOMPAT_CSUM_V3 |
                                 JBD2_FEATURE_INCOMPAT_CSUM_V2);
         }
 
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 6fac74349856..b73e0215baa7 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -97,7 +97,7 @@ static void jbd2_commit_block_csum_set(journal_t *j, struct buffer_head *bh)
         struct commit_header *h;
         __u32 csum;
 
-        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (!jbd2_journal_has_csum_v2or3(j))
                 return;
 
         h = (struct commit_header *)(bh->b_data);
@@ -313,11 +313,11 @@ static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
         return checksum;
 }
 
-static void write_tag_block(int tag_bytes, journal_block_tag_t *tag,
+static void write_tag_block(journal_t *j, journal_block_tag_t *tag,
                                    unsigned long long block)
 {
         tag->t_blocknr = cpu_to_be32(block & (u32)~0);
-        if (tag_bytes > JBD2_TAG_SIZE32)
+        if (JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_64BIT))
                 tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
 }
 
@@ -327,7 +327,7 @@ static void jbd2_descr_block_csum_set(journal_t *j,
         struct jbd2_journal_block_tail *tail;
         __u32 csum;
 
-        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (!jbd2_journal_has_csum_v2or3(j))
                 return;
 
         tail = (struct jbd2_journal_block_tail *)(bh->b_data + j->j_blocksize -
@@ -340,12 +340,13 @@ static void jbd2_descr_block_csum_set(journal_t *j,
 static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
                                     struct buffer_head *bh, __u32 sequence)
 {
+        journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
         struct page *page = bh->b_page;
         __u8 *addr;
         __u32 csum32;
         __be32 seq;
 
-        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (!jbd2_journal_has_csum_v2or3(j))
                 return;
 
         seq = cpu_to_be32(sequence);
@@ -355,8 +356,10 @@ static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
                              bh->b_size);
         kunmap_atomic(addr);
 
-        /* We only have space to store the lower 16 bits of the crc32c. */
-        tag->t_checksum = cpu_to_be16(csum32);
+        if (JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V3))
+                tag3->t_checksum = cpu_to_be32(csum32);
+        else
+                tag->t_checksum = cpu_to_be16(csum32);
 }
 /*
  * jbd2_journal_commit_transaction
@@ -396,7 +399,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         LIST_HEAD(io_bufs);
         LIST_HEAD(log_bufs);
 
-        if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (jbd2_journal_has_csum_v2or3(journal))
                 csum_size = sizeof(struct jbd2_journal_block_tail);
 
         /*
@@ -690,7 +693,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
                         tag_flag |= JBD2_FLAG_SAME_UUID;
 
                 tag = (journal_block_tag_t *) tagp;
-                write_tag_block(tag_bytes, tag, jh2bh(jh)->b_blocknr);
+                write_tag_block(journal, tag, jh2bh(jh)->b_blocknr);
                 tag->t_flags = cpu_to_be16(tag_flag);
                 jbd2_block_tag_csum_set(journal, tag, wbuf[bufs],
                                         commit_transaction->t_tid);
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 67b8e303946c..19d74d86d99c 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -124,7 +124,7 @@ EXPORT_SYMBOL(__jbd2_debug);
 /* Checksumming functions */
 static int jbd2_verify_csum_type(journal_t *j, journal_superblock_t *sb)
 {
-        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (!jbd2_journal_has_csum_v2or3(j))
                 return 1;
 
         return sb->s_checksum_type == JBD2_CRC32C_CHKSUM;
@@ -145,7 +145,7 @@ static __be32 jbd2_superblock_csum(journal_t *j, journal_superblock_t *sb)
 
 static int jbd2_superblock_csum_verify(journal_t *j, journal_superblock_t *sb)
 {
-        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (!jbd2_journal_has_csum_v2or3(j))
                 return 1;
 
         return sb->s_checksum == jbd2_superblock_csum(j, sb);
@@ -153,7 +153,7 @@ static int jbd2_superblock_csum_verify(journal_t *j, journal_superblock_t *sb)
 
 static void jbd2_superblock_csum_set(journal_t *j, journal_superblock_t *sb)
 {
-        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (!jbd2_journal_has_csum_v2or3(j))
                 return;
 
         sb->s_checksum = jbd2_superblock_csum(j, sb);
@@ -1522,21 +1522,29 @@ static int journal_get_superblock(journal_t *journal)
                 goto out;
         }
 
-        if (JBD2_HAS_COMPAT_FEATURE(journal, JBD2_FEATURE_COMPAT_CHECKSUM) &&
-            JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2)) {
+        if (jbd2_journal_has_csum_v2or3(journal) &&
+            JBD2_HAS_COMPAT_FEATURE(journal, JBD2_FEATURE_COMPAT_CHECKSUM)) {
                 /* Can't have checksum v1 and v2 on at the same time! */
                 printk(KERN_ERR "JBD2: Can't enable checksumming v1 and v2 "
                        "at the same time!\n");
                 goto out;
         }
 
+        if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2) &&
+            JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V3)) {
+                /* Can't have checksum v2 and v3 at the same time! */
+                printk(KERN_ERR "JBD2: Can't enable checksumming v2 and v3 "
+                       "at the same time!\n");
+                goto out;
+        }
+
         if (!jbd2_verify_csum_type(journal, sb)) {
                 printk(KERN_ERR "JBD2: Unknown checksum type\n");
                 goto out;
         }
 
         /* Load the checksum driver */
-        if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2)) {
+        if (jbd2_journal_has_csum_v2or3(journal)) {
                 journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
                 if (IS_ERR(journal->j_chksum_driver)) {
                         printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n");
@@ -1553,7 +1561,7 @@ static int journal_get_superblock(journal_t *journal)
         }
 
         /* Precompute checksum seed for all metadata */
-        if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (jbd2_journal_has_csum_v2or3(journal))
                 journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid,
                                                    sizeof(sb->s_uuid));
 
@@ -1813,8 +1821,14 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
         if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
                 return 0;
 
-        /* Asking for checksumming v2 and v1?  Only give them v2. */
-        if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V2 &&
+        /* If enabling v2 checksums, turn on v3 instead */
+        if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V2) {
+                incompat &= ~JBD2_FEATURE_INCOMPAT_CSUM_V2;
+                incompat |= JBD2_FEATURE_INCOMPAT_CSUM_V3;
+        }
+
+        /* Asking for checksumming v3 and v1?  Only give them v3. */
+        if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V3 &&
             compat & JBD2_FEATURE_COMPAT_CHECKSUM)
                 compat &= ~JBD2_FEATURE_COMPAT_CHECKSUM;
 
@@ -1823,8 +1837,8 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
 
         sb = journal->j_superblock;
 
-        /* If enabling v2 checksums, update superblock */
-        if (INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V2)) {
+        /* If enabling v3 checksums, update superblock */
+        if (INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) {
                 sb->s_checksum_type = JBD2_CRC32C_CHKSUM;
                 sb->s_feature_compat &=
                         ~cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM);
@@ -1842,8 +1856,7 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
                 }
 
                 /* Precompute checksum seed for all metadata */
-                if (JBD2_HAS_INCOMPAT_FEATURE(journal,
-                                              JBD2_FEATURE_INCOMPAT_CSUM_V2))
+                if (jbd2_journal_has_csum_v2or3(journal))
                         journal->j_csum_seed = jbd2_chksum(journal, ~0,
                                                            sb->s_uuid,
                                                            sizeof(sb->s_uuid));
@@ -1852,7 +1865,8 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
         /* If enabling v1 checksums, downgrade superblock */
         if (COMPAT_FEATURE_ON(JBD2_FEATURE_COMPAT_CHECKSUM))
                 sb->s_feature_incompat &=
-                        ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_CSUM_V2);
+                        ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_CSUM_V2 |
+                                     JBD2_FEATURE_INCOMPAT_CSUM_V3);
 
         sb->s_feature_compat    |= cpu_to_be32(compat);
         sb->s_feature_ro_compat |= cpu_to_be32(ro);
@@ -2165,16 +2179,20 @@ int jbd2_journal_blocks_per_page(struct inode *inode)
  */
 size_t journal_tag_bytes(journal_t *journal)
 {
-        journal_block_tag_t tag;
-        size_t x = 0;
+        size_t sz;
+
+        if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V3))
+                return sizeof(journal_block_tag3_t);
+
+        sz = sizeof(journal_block_tag_t);
 
         if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
-                x += sizeof(tag.t_checksum);
+                sz += sizeof(__u16);
 
         if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
-                return x + JBD2_TAG_SIZE64;
+                return sz;
         else
-                return x + JBD2_TAG_SIZE32;
+                return sz - sizeof(__u32);
 }
 
 /*
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index 00e9703d7dc6..9b329b55ffe3 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -181,7 +181,7 @@ static int jbd2_descr_block_csum_verify(journal_t *j,
         __be32 provided;
         __u32 calculated;
 
-        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (!jbd2_journal_has_csum_v2or3(j))
                 return 1;
 
         tail = (struct jbd2_journal_block_tail *)(buf + j->j_blocksize -
@@ -205,7 +205,7 @@ static int count_tags(journal_t *journal, struct buffer_head *bh)
         int                     nr = 0, size = journal->j_blocksize;
         int                     tag_bytes = journal_tag_bytes(journal);
 
-        if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (jbd2_journal_has_csum_v2or3(journal))
                 size -= sizeof(struct jbd2_journal_block_tail);
 
         tagp = &bh->b_data[sizeof(journal_header_t)];
@@ -338,10 +338,11 @@ int jbd2_journal_skip_recovery(journal_t *journal)
         return err;
 }
 
-static inline unsigned long long read_tag_block(int tag_bytes, journal_block_tag_t *tag)
+static inline unsigned long long read_tag_block(journal_t *journal,
+                                                journal_block_tag_t *tag)
 {
         unsigned long long block = be32_to_cpu(tag->t_blocknr);
-        if (tag_bytes > JBD2_TAG_SIZE32)
+        if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
                 block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32;
         return block;
 }
@@ -384,7 +385,7 @@ static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
         __be32 provided;
         __u32 calculated;
 
-        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (!jbd2_journal_has_csum_v2or3(j))
                 return 1;
 
         h = buf;
@@ -399,17 +400,21 @@ static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
 static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
                                       void *buf, __u32 sequence)
 {
+        journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
         __u32 csum32;
         __be32 seq;
 
-        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (!jbd2_journal_has_csum_v2or3(j))
                 return 1;
 
         seq = cpu_to_be32(sequence);
         csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
         csum32 = jbd2_chksum(j, csum32, buf, j->j_blocksize);
 
-        return tag->t_checksum == cpu_to_be16(csum32);
+        if (JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V3))
+                return tag3->t_checksum == cpu_to_be32(csum32);
+        else
+                return tag->t_checksum == cpu_to_be16(csum32);
 }
 
 static int do_one_pass(journal_t *journal,
@@ -513,8 +518,7 @@ static int do_one_pass(journal_t *journal,
                 switch(blocktype) {
                 case JBD2_DESCRIPTOR_BLOCK:
                         /* Verify checksum first */
-                        if (JBD2_HAS_INCOMPAT_FEATURE(journal,
-                                        JBD2_FEATURE_INCOMPAT_CSUM_V2))
+                        if (jbd2_journal_has_csum_v2or3(journal))
                                 descr_csum_size =
                                         sizeof(struct jbd2_journal_block_tail);
                         if (descr_csum_size > 0 &&
@@ -575,7 +579,7 @@ static int do_one_pass(journal_t *journal,
                                         unsigned long long blocknr;
 
                                         J_ASSERT(obh != NULL);
-                                        blocknr = read_tag_block(tag_bytes,
+                                        blocknr = read_tag_block(journal,
                                                                  tag);
 
                                         /* If the block has been
@@ -814,7 +818,7 @@ static int jbd2_revoke_block_csum_verify(journal_t *j,
         __be32 provided;
         __u32 calculated;
 
-        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (!jbd2_journal_has_csum_v2or3(j))
                 return 1;
 
         tail = (struct jbd2_journal_revoke_tail *)(buf + j->j_blocksize -
diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c
index 198c9c10276d..d5e95a175c92 100644
--- a/fs/jbd2/revoke.c
+++ b/fs/jbd2/revoke.c
@@ -91,8 +91,8 @@
 #include <linux/list.h>
 #include <linux/init.h>
 #include <linux/bio.h>
-#endif
 #include <linux/log2.h>
+#endif
 
 static struct kmem_cache *jbd2_revoke_record_cache;
 static struct kmem_cache *jbd2_revoke_table_cache;
@@ -597,7 +597,7 @@ static void write_one_revoke_record(journal_t *journal,
         offset = *offsetp;
 
         /* Do we need to leave space at the end for a checksum? */
-        if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (jbd2_journal_has_csum_v2or3(journal))
                 csum_size = sizeof(struct jbd2_journal_revoke_tail);
 
         /* Make sure we have a descriptor with space left for the record */
@@ -644,7 +644,7 @@ static void jbd2_revoke_csum_set(journal_t *j, struct buffer_head *bh)
         struct jbd2_journal_revoke_tail *tail;
         __u32 csum;
 
-        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+        if (!jbd2_journal_has_csum_v2or3(j))
                 return;
 
         tail = (struct jbd2_journal_revoke_tail *)(bh->b_data + j->j_blocksize -
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index d5b50a19463c..0dae71e9971c 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -159,7 +159,11 @@ typedef struct journal_header_s
  * journal_block_tag (in the descriptor).  The other h_chksum* fields are
  * not used.
  *
- * Checksum v1 and v2 are mutually exclusive features.
+ * If FEATURE_INCOMPAT_CSUM_V3 is set, the descriptor block uses
+ * journal_block_tag3_t to store a full 32-bit checksum.  Everything else
+ * is the same as v2.
+ *
+ * Checksum v1, v2, and v3 are mutually exclusive features.
  */
 struct commit_header {
         __be32          h_magic;
@@ -179,6 +183,14 @@ struct commit_header {
  * raw struct shouldn't be used for pointer math or sizeof() - use
  * journal_tag_bytes(journal) instead to compute this.
  */
+typedef struct journal_block_tag3_s
+{
+        __be32          t_blocknr;      /* The on-disk block number */
+        __be32          t_flags;        /* See below */
+        __be32          t_blocknr_high; /* most-significant high 32bits. */
+        __be32          t_checksum;     /* crc32c(uuid+seq+block) */
+} journal_block_tag3_t;
+
 typedef struct journal_block_tag_s
 {
         __be32          t_blocknr;      /* The on-disk block number */
@@ -187,9 +199,6 @@ typedef struct journal_block_tag_s
         __be32          t_blocknr_high; /* most-significant high 32bits. */
 } journal_block_tag_t;
 
-#define JBD2_TAG_SIZE32 (offsetof(journal_block_tag_t, t_blocknr_high))
-#define JBD2_TAG_SIZE64 (sizeof(journal_block_tag_t))
-
 /* Tail of descriptor block, for checksumming */
 struct jbd2_journal_block_tail {
         __be32          t_checksum;     /* crc32c(uuid+descr_block) */
@@ -284,6 +293,7 @@ typedef struct journal_superblock_s
 #define JBD2_FEATURE_INCOMPAT_64BIT             0x00000002
 #define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT      0x00000004
 #define JBD2_FEATURE_INCOMPAT_CSUM_V2           0x00000008
+#define JBD2_FEATURE_INCOMPAT_CSUM_V3           0x00000010
 
 /* Features known to this kernel version: */
 #define JBD2_KNOWN_COMPAT_FEATURES      JBD2_FEATURE_COMPAT_CHECKSUM
@@ -291,7 +301,8 @@ typedef struct journal_superblock_s
 #define JBD2_KNOWN_INCOMPAT_FEATURES    (JBD2_FEATURE_INCOMPAT_REVOKE | \
                                         JBD2_FEATURE_INCOMPAT_64BIT | \
                                         JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT | \
-                                        JBD2_FEATURE_INCOMPAT_CSUM_V2)
+                                        JBD2_FEATURE_INCOMPAT_CSUM_V2 | \
+                                        JBD2_FEATURE_INCOMPAT_CSUM_V3)
 
 #ifdef __KERNEL__
 
@@ -1296,6 +1307,15 @@ static inline int tid_geq(tid_t x, tid_t y)
 extern int jbd2_journal_blocks_per_page(struct inode *inode);
 extern size_t journal_tag_bytes(journal_t *journal);
 
+static inline int jbd2_journal_has_csum_v2or3(journal_t *journal)
+{
+        if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2) ||
+            JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V3))
+                return 1;
+
+        return 0;
+}
+
 /*
  * We reserve t_outstanding_credits >> JBD2_CONTROL_BLOCKS_SHIFT for
  * transaction control blocks.