jbd2: factor out common descriptor block initialization

Descriptor block header is initialized in several places. Factor out the
common code into jbd2_journal_get_descriptor_buffer().

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

4 files changed, 16 insertions, 19 deletions

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index ae4402d15d46..cf221f3d955a 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -131,14 +131,12 @@ static int journal_submit_commit_record(journal_t *journal,
         if (is_journal_aborted(journal))
                 return 0;
 
-        bh = jbd2_journal_get_descriptor_buffer(journal);
+        bh = jbd2_journal_get_descriptor_buffer(commit_transaction,
+                                                JBD2_COMMIT_BLOCK);
         if (!bh)
                 return 1;
 
         tmp = (struct commit_header *)bh->b_data;
-        tmp->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
-        tmp->h_blocktype = cpu_to_be32(JBD2_COMMIT_BLOCK);
-        tmp->h_sequence = cpu_to_be32(commit_transaction->t_tid);
         tmp->h_commit_sec = cpu_to_be64(now.tv_sec);
         tmp->h_commit_nsec = cpu_to_be32(now.tv_nsec);
 
@@ -379,7 +377,6 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         ktime_t start_time;
         u64 commit_time;
         char *tagp = NULL;
-        journal_header_t *header;
         journal_block_tag_t *tag = NULL;
         int space_left = 0;
         int first_tag = 0;
@@ -615,7 +612,9 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 
                         jbd_debug(4, "JBD2: get descriptor\n");
 
-                        descriptor = jbd2_journal_get_descriptor_buffer(journal);
+                        descriptor = jbd2_journal_get_descriptor_buffer(
+                                                        commit_transaction,
+                                                        JBD2_DESCRIPTOR_BLOCK);
                         if (!descriptor) {
                                 jbd2_journal_abort(journal, -EIO);
                                 continue;
@@ -624,11 +623,6 @@ void jbd2_journal_commit_transaction(journal_t *journal)
                         jbd_debug(4, "JBD2: got buffer %llu (%p)\n",
                                 (unsigned long long)descriptor->b_blocknr,
                                 descriptor->b_data);
-                        header = (journal_header_t *)descriptor->b_data;
-                        header->h_magic     = cpu_to_be32(JBD2_MAGIC_NUMBER);
-                        header->h_blocktype = cpu_to_be32(JBD2_DESCRIPTOR_BLOCK);
-                        header->h_sequence  = cpu_to_be32(commit_transaction->t_tid);
-
                         tagp = &descriptor->b_data[sizeof(journal_header_t)];
                         space_left = descriptor->b_size -
                                                 sizeof(journal_header_t);
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 81e622681c82..28d05bd9a588 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -805,10 +805,13 @@ int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
  * But we don't bother doing that, so there will be coherency problems with
  * mmaps of blockdevs which hold live JBD-controlled filesystems.
  */
-struct buffer_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
+struct buffer_head *
+jbd2_journal_get_descriptor_buffer(transaction_t *transaction, int type)
 {
+        journal_t *journal = transaction->t_journal;
         struct buffer_head *bh;
         unsigned long long blocknr;
+        journal_header_t *header;
         int err;
 
         err = jbd2_journal_next_log_block(journal, &blocknr);
@@ -821,6 +824,10 @@ struct buffer_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
                 return NULL;
         lock_buffer(bh);
         memset(bh->b_data, 0, journal->j_blocksize);
+        header = (journal_header_t *)bh->b_data;
+        header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
+        header->h_blocktype = cpu_to_be32(type);
+        header->h_sequence = cpu_to_be32(transaction->t_tid);
         set_buffer_uptodate(bh);
         unlock_buffer(bh);
         BUFFER_TRACE(bh, "return this buffer");
diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c
index c839332be56b..d1ebb1d41d17 100644
--- a/fs/jbd2/revoke.c
+++ b/fs/jbd2/revoke.c
@@ -570,7 +570,6 @@ static void write_one_revoke_record(transaction_t *transaction,
         int csum_size = 0;
         struct buffer_head *descriptor;
         int sz, offset;
-        journal_header_t *header;
 
         /* If we are already aborting, this all becomes a noop.  We
            still need to go round the loop in
@@ -600,13 +599,10 @@ static void write_one_revoke_record(transaction_t *transaction,
         }
 
         if (!descriptor) {
-                descriptor = jbd2_journal_get_descriptor_buffer(journal);
+                descriptor = jbd2_journal_get_descriptor_buffer(transaction,
+                                                        JBD2_REVOKE_BLOCK);
                 if (!descriptor)
                         return;
-                header = (journal_header_t *)descriptor->b_data;
-                header->h_magic     = cpu_to_be32(JBD2_MAGIC_NUMBER);
-                header->h_blocktype = cpu_to_be32(JBD2_REVOKE_BLOCK);
-                header->h_sequence  = cpu_to_be32(transaction->t_tid);
 
                 /* Record it so that we can wait for IO completion later */
                 BUFFER_TRACE(descriptor, "file in log_bufs");
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 5716d9554e77..3649cb8d3a41 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1137,7 +1137,7 @@ static inline void jbd2_unfile_log_bh(struct buffer_head *bh)
 }
 
 /* Log buffer allocation */
-struct buffer_head *jbd2_journal_get_descriptor_buffer(journal_t *journal);
+struct buffer_head *jbd2_journal_get_descriptor_buffer(transaction_t *, int);
 int jbd2_journal_next_log_block(journal_t *, unsigned long long *);
 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
                               unsigned long *block);