jbd2: remove journal_head from descriptor buffers

Similarly as for metadata buffers, also log descriptor buffers don't
really need the journal head. So strip it and remove BJ_LogCtl list.

Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 2735fef..65ec076 100644 (file)
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -691,7 +691,6 @@ void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transact
        J_ASSERT(transaction->t_buffers == NULL);
        J_ASSERT(transaction->t_forget == NULL);
        J_ASSERT(transaction->t_shadow_list == NULL);
-       J_ASSERT(transaction->t_log_list == NULL);
        J_ASSERT(transaction->t_checkpoint_list == NULL);
        J_ASSERT(transaction->t_checkpoint_io_list == NULL);
        J_ASSERT(atomic_read(&transaction->t_updates) == 0);

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 57bd2ff..7c6f7ee 100644 (file)
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -85,8 +85,7 @@ nope:
        __brelse(bh);
 }
 
-static void jbd2_commit_block_csum_set(journal_t *j,
-                                      struct journal_head *descriptor)
+static void jbd2_commit_block_csum_set(journal_t *j, struct buffer_head *bh)
 {
        struct commit_header *h;
        __u32 csum;
@@ -94,12 +93,11 @@ static void jbd2_commit_block_csum_set(journal_t *j,
        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
                return;
 
-       h = (struct commit_header *)(jh2bh(descriptor)->b_data);
+       h = (struct commit_header *)(bh->b_data);
        h->h_chksum_type = 0;
        h->h_chksum_size = 0;
        h->h_chksum[0] = 0;
-       csum = jbd2_chksum(j, j->j_csum_seed, jh2bh(descriptor)->b_data,
-                          j->j_blocksize);
+       csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
        h->h_chksum[0] = cpu_to_be32(csum);
 }
 
@@ -116,7 +114,6 @@ static int journal_submit_commit_record(journal_t *journal,
                                        struct buffer_head **cbh,
                                        __u32 crc32_sum)
 {
-       struct journal_head *descriptor;
        struct commit_header *tmp;
        struct buffer_head *bh;
        int ret;
@@ -127,12 +124,10 @@ static int journal_submit_commit_record(journal_t *journal,
        if (is_journal_aborted(journal))
                return 0;
 
-       descriptor = jbd2_journal_get_descriptor_buffer(journal);
-       if (!descriptor)
+       bh = jbd2_journal_get_descriptor_buffer(journal);
+       if (!bh)
                return 1;
 
-       bh = jh2bh(descriptor);
-
        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);
@@ -146,9 +141,9 @@ static int journal_submit_commit_record(journal_t *journal,
                tmp->h_chksum_size      = JBD2_CRC32_CHKSUM_SIZE;
                tmp->h_chksum[0]        = cpu_to_be32(crc32_sum);
        }
-       jbd2_commit_block_csum_set(journal, descriptor);
+       jbd2_commit_block_csum_set(journal, bh);
 
-       JBUFFER_TRACE(descriptor, "submit commit block");
+       BUFFER_TRACE(bh, "submit commit block");
        lock_buffer(bh);
        clear_buffer_dirty(bh);
        set_buffer_uptodate(bh);
@@ -180,7 +175,6 @@ static int journal_wait_on_commit_record(journal_t *journal,
        if (unlikely(!buffer_uptodate(bh)))
                ret = -EIO;
        put_bh(bh);            /* One for getblk() */
-       jbd2_journal_put_journal_head(bh2jh(bh));
 
        return ret;
 }
@@ -321,7 +315,7 @@ static void write_tag_block(int tag_bytes, journal_block_tag_t *tag,
 }
 
 static void jbd2_descr_block_csum_set(journal_t *j,
-                                     struct journal_head *descriptor)
+                                     struct buffer_head *bh)
 {
        struct jbd2_journal_block_tail *tail;
        __u32 csum;
@@ -329,12 +323,10 @@ static void jbd2_descr_block_csum_set(journal_t *j,
        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
                return;
 
-       tail = (struct jbd2_journal_block_tail *)
-                       (jh2bh(descriptor)->b_data + j->j_blocksize -
+       tail = (struct jbd2_journal_block_tail *)(bh->b_data + j->j_blocksize -
                        sizeof(struct jbd2_journal_block_tail));
        tail->t_checksum = 0;
-       csum = jbd2_chksum(j, j->j_csum_seed, jh2bh(descriptor)->b_data,
-                          j->j_blocksize);
+       csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
        tail->t_checksum = cpu_to_be32(csum);
 }
 
@@ -369,7 +361,8 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 {
        struct transaction_stats_s stats;
        transaction_t *commit_transaction;
-       struct journal_head *jh, *descriptor;
+       struct journal_head *jh;
+       struct buffer_head *descriptor;
        struct buffer_head **wbuf = journal->j_wbuf;
        int bufs;
        int flags;
@@ -394,6 +387,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
        int update_tail;
        int csum_size = 0;
        LIST_HEAD(io_bufs);
+       LIST_HEAD(log_bufs);
 
        if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
                csum_size = sizeof(struct jbd2_journal_block_tail);
@@ -547,7 +541,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 
        blk_start_plug(&plug);
        jbd2_journal_write_revoke_records(journal, commit_transaction,
-                                         WRITE_SYNC);
+                                         &log_bufs, WRITE_SYNC);
        blk_finish_plug(&plug);
 
        jbd_debug(3, "JBD2: commit phase 2\n");
@@ -573,8 +567,8 @@ void jbd2_journal_commit_transaction(journal_t *journal)
                 atomic_read(&commit_transaction->t_outstanding_credits));
 
        err = 0;
-       descriptor = NULL;
        bufs = 0;
+       descriptor = NULL;
        blk_start_plug(&plug);
        while (commit_transaction->t_buffers) {
 
@@ -606,8 +600,6 @@ void jbd2_journal_commit_transaction(journal_t *journal)
                   record the metadata buffer. */
 
                if (!descriptor) {
-                       struct buffer_head *bh;
-
                        J_ASSERT (bufs == 0);
 
                        jbd_debug(4, "JBD2: get descriptor\n");
@@ -618,26 +610,26 @@ void jbd2_journal_commit_transaction(journal_t *journal)
                                continue;
                        }
 
-                       bh = jh2bh(descriptor);
                        jbd_debug(4, "JBD2: got buffer %llu (%p)\n",
-                               (unsigned long long)bh->b_blocknr, bh->b_data);
-                       header = (journal_header_t *)&bh->b_data[0];
+                               (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 = &bh->b_data[sizeof(journal_header_t)];
-                       space_left = bh->b_size - sizeof(journal_header_t);
+                       tagp = &descriptor->b_data[sizeof(journal_header_t)];
+                       space_left = descriptor->b_size -
+                                               sizeof(journal_header_t);
                        first_tag = 1;
-                       set_buffer_jwrite(bh);
-                       set_buffer_dirty(bh);
-                       wbuf[bufs++] = bh;
+                       set_buffer_jwrite(descriptor);
+                       set_buffer_dirty(descriptor);
+                       wbuf[bufs++] = descriptor;
 
                        /* Record it so that we can wait for IO
                            completion later */
-                       BUFFER_TRACE(bh, "ph3: file as descriptor");
-                       jbd2_journal_file_buffer(descriptor, commit_transaction,
-                                       BJ_LogCtl);
+                       BUFFER_TRACE(descriptor, "ph3: file as descriptor");
+                       jbd2_file_log_bh(&log_bufs, descriptor);
                }
 
                /* Where is the buffer to be written? */
@@ -864,26 +856,19 @@ start_journal_io:
        jbd_debug(3, "JBD2: commit phase 4\n");
 
        /* Here we wait for the revoke record and descriptor record buffers */
- wait_for_ctlbuf:
-       while (commit_transaction->t_log_list != NULL) {
+       while (!list_empty(&log_bufs)) {
                struct buffer_head *bh;
 
-               jh = commit_transaction->t_log_list->b_tprev;
-               bh = jh2bh(jh);
-               if (buffer_locked(bh)) {
-                       wait_on_buffer(bh);
-                       goto wait_for_ctlbuf;
-               }
-               if (cond_resched())
-                       goto wait_for_ctlbuf;
+               bh = list_entry(log_bufs.prev, struct buffer_head, b_assoc_buffers);
+               wait_on_buffer(bh);
+               cond_resched();
 
                if (unlikely(!buffer_uptodate(bh)))
                        err = -EIO;
 
                BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
                clear_buffer_jwrite(bh);
-               jbd2_journal_unfile_buffer(journal, jh);
-               jbd2_journal_put_journal_head(jh);
+               jbd2_unfile_log_bh(bh);
                __brelse(bh);           /* One for getblk */
                /* AKPM: bforget here */
        }
@@ -934,7 +919,6 @@ start_journal_io:
        J_ASSERT(commit_transaction->t_buffers == NULL);
        J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
        J_ASSERT(commit_transaction->t_shadow_list == NULL);
-       J_ASSERT(commit_transaction->t_log_list == NULL);
 
 restart_loop:
        /*

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 45cdc08..b0a8d1e 100644 (file)
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -790,7 +790,7 @@ 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 journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
+struct buffer_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
 {
        struct buffer_head *bh;
        unsigned long long blocknr;
@@ -809,7 +809,7 @@ struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
        set_buffer_uptodate(bh);
        unlock_buffer(bh);
        BUFFER_TRACE(bh, "return this buffer");
-       return jbd2_journal_add_journal_head(bh);
+       return bh;
 }
 
 /*

diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c
index f30b80b..198c9c1 100644 (file)
--- a/fs/jbd2/revoke.c
+++ b/fs/jbd2/revoke.c
@@ -122,9 +122,10 @@ struct jbd2_revoke_table_s
 
 #ifdef __KERNEL__
 static void write_one_revoke_record(journal_t *, transaction_t *,
-                                   struct journal_head **, int *,
+                                   struct list_head *,
+                                   struct buffer_head **, int *,
                                    struct jbd2_revoke_record_s *, int);
-static void flush_descriptor(journal_t *, struct journal_head *, int, int);
+static void flush_descriptor(journal_t *, struct buffer_head *, int, int);
 #endif
 
 /* Utility functions to maintain the revoke table */
@@ -531,9 +532,10 @@ void jbd2_journal_switch_revoke_table(journal_t *journal)
  */
 void jbd2_journal_write_revoke_records(journal_t *journal,
                                       transaction_t *transaction,
+                                      struct list_head *log_bufs,
                                       int write_op)
 {
-       struct journal_head *descriptor;
+       struct buffer_head *descriptor;
        struct jbd2_revoke_record_s *record;
        struct jbd2_revoke_table_s *revoke;
        struct list_head *hash_list;
@@ -553,7 +555,7 @@ void jbd2_journal_write_revoke_records(journal_t *journal,
                while (!list_empty(hash_list)) {
                        record = (struct jbd2_revoke_record_s *)
                                hash_list->next;
-                       write_one_revoke_record(journal, transaction,
+                       write_one_revoke_record(journal, transaction, log_bufs,
                                                &descriptor, &offset,
                                                record, write_op);
                        count++;
@@ -573,13 +575,14 @@ void jbd2_journal_write_revoke_records(journal_t *journal,
 
 static void write_one_revoke_record(journal_t *journal,
                                    transaction_t *transaction,
-                                   struct journal_head **descriptorp,
+                                   struct list_head *log_bufs,
+                                   struct buffer_head **descriptorp,
                                    int *offsetp,
                                    struct jbd2_revoke_record_s *record,
                                    int write_op)
 {
        int csum_size = 0;
-       struct journal_head *descriptor;
+       struct buffer_head *descriptor;
        int offset;
        journal_header_t *header;
 
@@ -609,26 +612,26 @@ static void write_one_revoke_record(journal_t *journal,
                descriptor = jbd2_journal_get_descriptor_buffer(journal);
                if (!descriptor)
                        return;
-               header = (journal_header_t *) &jh2bh(descriptor)->b_data[0];
+               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 */
-               JBUFFER_TRACE(descriptor, "file as BJ_LogCtl");
-               jbd2_journal_file_buffer(descriptor, transaction, BJ_LogCtl);
+               BUFFER_TRACE(descriptor, "file in log_bufs");
+               jbd2_file_log_bh(log_bufs, descriptor);
 
                offset = sizeof(jbd2_journal_revoke_header_t);
                *descriptorp = descriptor;
        }
 
        if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT)) {
-               * ((__be64 *)(&jh2bh(descriptor)->b_data[offset])) =
+               * ((__be64 *)(&descriptor->b_data[offset])) =
                        cpu_to_be64(record->blocknr);
                offset += 8;
 
        } else {
-               * ((__be32 *)(&jh2bh(descriptor)->b_data[offset])) =
+               * ((__be32 *)(&descriptor->b_data[offset])) =
                        cpu_to_be32(record->blocknr);
                offset += 4;
        }
@@ -636,8 +639,7 @@ static void write_one_revoke_record(journal_t *journal,
        *offsetp = offset;
 }
 
-static void jbd2_revoke_csum_set(journal_t *j,
-                                struct journal_head *descriptor)
+static void jbd2_revoke_csum_set(journal_t *j, struct buffer_head *bh)
 {
        struct jbd2_journal_revoke_tail *tail;
        __u32 csum;
@@ -645,12 +647,10 @@ static void jbd2_revoke_csum_set(journal_t *j,
        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
                return;
 
-       tail = (struct jbd2_journal_revoke_tail *)
-                       (jh2bh(descriptor)->b_data + j->j_blocksize -
+       tail = (struct jbd2_journal_revoke_tail *)(bh->b_data + j->j_blocksize -
                        sizeof(struct jbd2_journal_revoke_tail));
        tail->r_checksum = 0;
-       csum = jbd2_chksum(j, j->j_csum_seed, jh2bh(descriptor)->b_data,
-                          j->j_blocksize);
+       csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
        tail->r_checksum = cpu_to_be32(csum);
 }
 
@@ -662,25 +662,24 @@ static void jbd2_revoke_csum_set(journal_t *j,
  */
 
 static void flush_descriptor(journal_t *journal,
-                            struct journal_head *descriptor,
+                            struct buffer_head *descriptor,
                             int offset, int write_op)
 {
        jbd2_journal_revoke_header_t *header;
-       struct buffer_head *bh = jh2bh(descriptor);
 
        if (is_journal_aborted(journal)) {
-               put_bh(bh);
+               put_bh(descriptor);
                return;
        }
 
-       header = (jbd2_journal_revoke_header_t *) jh2bh(descriptor)->b_data;
+       header = (jbd2_journal_revoke_header_t *)descriptor->b_data;
        header->r_count = cpu_to_be32(offset);
        jbd2_revoke_csum_set(journal, descriptor);
 
-       set_buffer_jwrite(bh);
-       BUFFER_TRACE(bh, "write");
-       set_buffer_dirty(bh);
-       write_dirty_buffer(bh, write_op);
+       set_buffer_jwrite(descriptor);
+       BUFFER_TRACE(descriptor, "write");
+       set_buffer_dirty(descriptor);
+       write_dirty_buffer(descriptor, write_op);
 }
 #endif
 

diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 9830109..f1c5392 100644 (file)
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1637,9 +1637,6 @@ static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh)
        case BJ_Shadow:
                list = &transaction->t_shadow_list;
                break;
-       case BJ_LogCtl:
-               list = &transaction->t_log_list;
-               break;
        case BJ_Reserved:
                list = &transaction->t_reserved_list;
                break;
@@ -2148,9 +2145,6 @@ void __jbd2_journal_file_buffer(struct journal_head *jh,
        case BJ_Shadow:
                list = &transaction->t_shadow_list;
                break;
-       case BJ_LogCtl:
-               list = &transaction->t_log_list;
-               break;
        case BJ_Reserved:
                list = &transaction->t_reserved_list;
                break;

diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 5721084..b7dc40d 100644 (file)
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -530,12 +530,6 @@ struct transaction_s
         */
        struct journal_head     *t_shadow_list;
 
-       /*
-        * Doubly-linked circular list of control buffers being written to the
-        * log. [j_list_lock]
-        */
-       struct journal_head     *t_log_list;
-
        /*
         * List of inodes whose data we've modified in data=ordered mode.
         * [j_list_lock]
@@ -995,7 +989,7 @@ static inline void jbd2_unfile_log_bh(struct buffer_head *bh)
 }
 
 /* Log buffer allocation */
-extern struct journal_head * jbd2_journal_get_descriptor_buffer(journal_t *);
+struct buffer_head *jbd2_journal_get_descriptor_buffer(journal_t *journal);
 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);
@@ -1179,8 +1173,10 @@ extern int          jbd2_journal_init_revoke_caches(void);
 extern void       jbd2_journal_destroy_revoke(journal_t *);
 extern int        jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *);
 extern int        jbd2_journal_cancel_revoke(handle_t *, struct journal_head *);
-extern void       jbd2_journal_write_revoke_records(journal_t *,
-                                                    transaction_t *, int);
+extern void       jbd2_journal_write_revoke_records(journal_t *journal,
+                                                    transaction_t *transaction,
+                                                    struct list_head *log_bufs,
+                                                    int write_op);
 
 /* Recovery revoke support */
 extern int     jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t);
@@ -1288,9 +1284,8 @@ static inline int jbd_space_needed(journal_t *journal)
 #define BJ_Metadata    1       /* Normal journaled metadata */
 #define BJ_Forget      2       /* Buffer superseded by this transaction */
 #define BJ_Shadow      3       /* Buffer contents being shadowed to the log */
-#define BJ_LogCtl      4       /* Buffer contains log descriptors */
-#define BJ_Reserved    5       /* Buffer is reserved for access by journal */
-#define BJ_Types       6
+#define BJ_Reserved    4       /* Buffer is reserved for access by journal */
+#define BJ_Types       5
 
 extern int jbd_blocks_per_page(struct inode *inode);