[GFS2] Clean up journaled data writing

This patch cleans up the code for writing journaled data into the log.
It also removes the need to allocate a small "tag" structure for each
block written into the log. Instead we just keep count of the outstanding
I/O so that we can be sure that its all been written at the correct time.
Another result of this patch is that a number of ll_rw_block() calls
have become submit_bh() calls, closing some races at the same time.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

10 files changed, 269 insertions, 220 deletions

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 8aa5780862be..eaddfb5a8e6f 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -341,12 +341,6 @@ struct gfs2_quota_data {
         unsigned long qd_last_touched;
 };
 
-struct gfs2_log_buf {
-        struct list_head lb_list;
-        struct buffer_head *lb_bh;
-        struct buffer_head *lb_real;
-};
-
 struct gfs2_trans {
         unsigned long tr_ip;
 
@@ -631,7 +625,8 @@ struct gfs2_sbd {
 
         unsigned long sd_log_flush_time;
         struct rw_semaphore sd_log_flush_lock;
-        struct list_head sd_log_flush_list;
+        atomic_t sd_log_in_flight;
+        wait_queue_head_t sd_log_flush_wait;
 
         unsigned int sd_log_flush_head;
         u64 sd_log_flush_wrapped;
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 4d04e6f19706..ee704676b2f1 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -104,11 +104,8 @@ static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
                         gfs2_assert(sdp, bd->bd_ail == ai);
 
                         if (!buffer_busy(bh)) {
-                                if (!buffer_uptodate(bh)) {
-                                        gfs2_log_unlock(sdp);
+                                if (!buffer_uptodate(bh))
                                         gfs2_io_error_bh(sdp, bh);
-                                        gfs2_log_lock(sdp);
-                                }
                                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
                                 continue;
                         }
@@ -118,9 +115,16 @@ static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
 
                         list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
 
+                        get_bh(bh);
                         gfs2_log_unlock(sdp);
-                        wait_on_buffer(bh);
-                        ll_rw_block(WRITE, 1, &bh);
+                        lock_buffer(bh);
+                        if (test_clear_buffer_dirty(bh)) {
+                                bh->b_end_io = end_buffer_write_sync;
+                                submit_bh(WRITE, bh);
+                        } else {
+                                unlock_buffer(bh);
+                                brelse(bh);
+                        }
                         gfs2_log_lock(sdp);
 
                         retry = 1;
@@ -446,10 +450,10 @@ static unsigned int current_tail(struct gfs2_sbd *sdp)
         return tail;
 }
 
-static inline void log_incr_head(struct gfs2_sbd *sdp)
+void gfs2_log_incr_head(struct gfs2_sbd *sdp)
 {
         if (sdp->sd_log_flush_head == sdp->sd_log_tail)
-                gfs2_assert_withdraw(sdp, sdp->sd_log_flush_head == sdp->sd_log_head);
+                BUG_ON(sdp->sd_log_flush_head != sdp->sd_log_head);
 
         if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
                 sdp->sd_log_flush_head = 0;
@@ -458,6 +462,23 @@ static inline void log_incr_head(struct gfs2_sbd *sdp)
 }
 
 /**
+ * gfs2_log_write_endio - End of I/O for a log buffer
+ * @bh: The buffer head
+ * @uptodate: I/O Status
+ *
+ */
+
+static void gfs2_log_write_endio(struct buffer_head *bh, int uptodate)
+{
+        struct gfs2_sbd *sdp = bh->b_private;
+        bh->b_private = NULL;
+
+        end_buffer_write_sync(bh, uptodate);
+        if (atomic_dec_and_test(&sdp->sd_log_in_flight))
+                wake_up(&sdp->sd_log_flush_wait);
+}
+
+/**
  * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
  * @sdp: The GFS2 superblock
  *
@@ -467,25 +488,42 @@ static inline void log_incr_head(struct gfs2_sbd *sdp)
 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
 {
         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
-        struct gfs2_log_buf *lb;
         struct buffer_head *bh;
 
-        lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
-        list_add(&lb->lb_list, &sdp->sd_log_flush_list);
-
-        bh = lb->lb_bh = sb_getblk(sdp->sd_vfs, blkno);
+        bh = sb_getblk(sdp->sd_vfs, blkno);
         lock_buffer(bh);
         memset(bh->b_data, 0, bh->b_size);
         set_buffer_uptodate(bh);
         clear_buffer_dirty(bh);
-        unlock_buffer(bh);
-
-        log_incr_head(sdp);
+        gfs2_log_incr_head(sdp);
+        atomic_inc(&sdp->sd_log_in_flight);
+        bh->b_private = sdp;
+        bh->b_end_io = gfs2_log_write_endio;
 
         return bh;
 }
 
 /**
+ * gfs2_fake_write_endio - 
+ * @bh: The buffer head
+ * @uptodate: The I/O Status
+ *
+ */
+
+static void gfs2_fake_write_endio(struct buffer_head *bh, int uptodate)
+{
+        struct buffer_head *real_bh = bh->b_private;
+        struct gfs2_sbd *sdp = GFS2_SB(real_bh->b_page->mapping->host);
+
+        end_buffer_write_sync(bh, uptodate);
+        free_buffer_head(bh);
+        unlock_buffer(real_bh);
+        brelse(real_bh);
+        if (atomic_dec_and_test(&sdp->sd_log_in_flight))
+                wake_up(&sdp->sd_log_flush_wait);
+}
+
+/**
  * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
  * @sdp: the filesystem
  * @data: the data the buffer_head should point to
@@ -497,22 +535,20 @@ struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
                                       struct buffer_head *real)
 {
         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
-        struct gfs2_log_buf *lb;
         struct buffer_head *bh;
 
-        lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
-        list_add(&lb->lb_list, &sdp->sd_log_flush_list);
-        lb->lb_real = real;
-
-        bh = lb->lb_bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
+        bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
         atomic_set(&bh->b_count, 1);
-        bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate);
+        bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate) | (1 << BH_Lock);
         set_bh_page(bh, real->b_page, bh_offset(real));
         bh->b_blocknr = blkno;
         bh->b_size = sdp->sd_sb.sb_bsize;
         bh->b_bdev = sdp->sd_vfs->s_bdev;
+        bh->b_private = real;
+        bh->b_end_io = gfs2_fake_write_endio;
 
-        log_incr_head(sdp);
+        gfs2_log_incr_head(sdp);
+        atomic_inc(&sdp->sd_log_in_flight);
 
         return bh;
 }
@@ -579,45 +615,24 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
                 gfs2_assert_withdraw(sdp, !pull);
 
         sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
-        log_incr_head(sdp);
+        gfs2_log_incr_head(sdp);
 }
 
 static void log_flush_commit(struct gfs2_sbd *sdp)
 {
-        struct list_head *head = &sdp->sd_log_flush_list;
-        struct gfs2_log_buf *lb;
-        struct buffer_head *bh;
-        int flushcount = 0;
-
-        while (!list_empty(head)) {
-                lb = list_entry(head->next, struct gfs2_log_buf, lb_list);
-                list_del(&lb->lb_list);
-                bh = lb->lb_bh;
-
-                wait_on_buffer(bh);
-                if (!buffer_uptodate(bh))
-                        gfs2_io_error_bh(sdp, bh);
-                if (lb->lb_real) {
-                        while (atomic_read(&bh->b_count) != 1)  /* Grrrr... */
-                                schedule();
-                        free_buffer_head(bh);
-                } else
-                        brelse(bh);
-                kfree(lb);
-                flushcount++;
+        DEFINE_WAIT(wait);
+
+        if (atomic_read(&sdp->sd_log_in_flight)) {
+                do {
+                        prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
+                                        TASK_UNINTERRUPTIBLE);
+                        if (atomic_read(&sdp->sd_log_in_flight))
+                                io_schedule();
+                } while(atomic_read(&sdp->sd_log_in_flight));
+                finish_wait(&sdp->sd_log_flush_wait, &wait);
         }
 
-        /* If nothing was journaled, the header is unplanned and unwanted. */
-        if (flushcount) {
-                log_write_header(sdp, 0, 0);
-        } else {
-                unsigned int tail;
-                tail = current_tail(sdp);
-
-                gfs2_ail1_empty(sdp, 0);
-                if (sdp->sd_log_tail != tail)
-                        log_pull_tail(sdp, tail);
-        }
+        log_write_header(sdp, 0, 0);
 }
 
 static void gfs2_ordered_write(struct gfs2_sbd *sdp)
@@ -698,10 +713,16 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
         INIT_LIST_HEAD(&ai->ai_ail1_list);
         INIT_LIST_HEAD(&ai->ai_ail2_list);
 
-        gfs2_assert_withdraw(sdp,
-                             sdp->sd_log_num_buf + sdp->sd_log_num_databuf ==
-                             sdp->sd_log_commited_buf +
-                             sdp->sd_log_commited_databuf);
+        if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) {
+                printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf,
+                       sdp->sd_log_commited_buf);
+                gfs2_assert_withdraw(sdp, 0);
+        }
+        if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) {
+                printk(KERN_INFO "GFS2: log databuf %u %u\n",
+                       sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf);
+                gfs2_assert_withdraw(sdp, 0);
+        }
         gfs2_assert_withdraw(sdp,
                         sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
 
@@ -713,7 +734,7 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
         lops_before_commit(sdp);
         gfs2_ordered_wait(sdp);
 
-        if (!list_empty(&sdp->sd_log_flush_list))
+        if (sdp->sd_log_head != sdp->sd_log_flush_head)
                 log_flush_commit(sdp);
         else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
                 gfs2_log_lock(sdp);
diff --git a/fs/gfs2/log.h b/fs/gfs2/log.h
index 639423561b2d..dae282400627 100644
--- a/fs/gfs2/log.h
+++ b/fs/gfs2/log.h
@@ -52,6 +52,7 @@ int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags);
 
 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks);
 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks);
+void gfs2_log_incr_head(struct gfs2_sbd *sdp);
 
 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp);
 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 342c10e12af2..6c27cea761c6 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -91,6 +91,39 @@ static void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
         unlock_buffer(bh);
 }
 
+
+static inline struct gfs2_log_descriptor *bh_log_desc(struct buffer_head *bh)
+{
+        return (struct gfs2_log_descriptor *)bh->b_data;
+}
+
+static inline __be64 *bh_log_ptr(struct buffer_head *bh)
+{
+        struct gfs2_log_descriptor *ld = bh_log_desc(bh);
+        return (__force __be64 *)(ld + 1);
+}
+
+static inline __be64 *bh_ptr_end(struct buffer_head *bh)
+{
+        return (__force __be64 *)(bh->b_data + bh->b_size);
+}
+
+
+static struct buffer_head *gfs2_get_log_desc(struct gfs2_sbd *sdp, u32 ld_type)
+{
+        struct buffer_head *bh = gfs2_log_get_buf(sdp);
+        struct gfs2_log_descriptor *ld = bh_log_desc(bh);
+        ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
+        ld->ld_header.mh_type = cpu_to_be32(GFS2_METATYPE_LD);
+        ld->ld_header.mh_format = cpu_to_be32(GFS2_FORMAT_LD);
+        ld->ld_type = cpu_to_be32(ld_type);
+        ld->ld_length = 0;
+        ld->ld_data1 = 0;
+        ld->ld_data2 = 0;
+        memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
+        return bh;
+}
+
 static void __glock_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
 {
         struct gfs2_glock *gl;
@@ -181,7 +214,6 @@ static void buf_lo_before_commit(struct gfs2_sbd *sdp)
         struct gfs2_log_descriptor *ld;
         struct gfs2_bufdata *bd1 = NULL, *bd2;
         unsigned int total;
-        unsigned int offset = BUF_OFFSET;
         unsigned int limit;
         unsigned int num;
         unsigned n;
@@ -198,18 +230,12 @@ static void buf_lo_before_commit(struct gfs2_sbd *sdp)
                 if (total > limit)
                         num = limit;
                 gfs2_log_unlock(sdp);
-                bh = gfs2_log_get_buf(sdp);
+                bh = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_METADATA);
                 gfs2_log_lock(sdp);
-                ld = (struct gfs2_log_descriptor *)bh->b_data;
-                ptr = (__be64 *)(bh->b_data + offset);
-                ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
-                ld->ld_header.mh_type = cpu_to_be32(GFS2_METATYPE_LD);
-                ld->ld_header.mh_format = cpu_to_be32(GFS2_FORMAT_LD);
-                ld->ld_type = cpu_to_be32(GFS2_LOG_DESC_METADATA);
+                ld = bh_log_desc(bh);
+                ptr = bh_log_ptr(bh);
                 ld->ld_length = cpu_to_be32(num + 1);
                 ld->ld_data1 = cpu_to_be32(num);
-                ld->ld_data2 = cpu_to_be32(0);
-                memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
 
                 n = 0;
                 list_for_each_entry_continue(bd1, &sdp->sd_log_le_buf,
@@ -220,17 +246,17 @@ static void buf_lo_before_commit(struct gfs2_sbd *sdp)
                 }
 
                 gfs2_log_unlock(sdp);
-                set_buffer_dirty(bh);
-                ll_rw_block(WRITE, 1, &bh);
+                submit_bh(WRITE, bh);
                 gfs2_log_lock(sdp);
 
                 n = 0;
                 list_for_each_entry_continue(bd2, &sdp->sd_log_le_buf,
                                              bd_le.le_list) {
+                        get_bh(bd2->bd_bh);
                         gfs2_log_unlock(sdp);
+                        lock_buffer(bd2->bd_bh);
                         bh = gfs2_log_fake_buf(sdp, bd2->bd_bh);
-                        set_buffer_dirty(bh);
-                        ll_rw_block(WRITE, 1, &bh);
+                        submit_bh(WRITE, bh);
                         gfs2_log_lock(sdp);
                         if (++n >= num)
                                 break;
@@ -359,17 +385,11 @@ static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
         if (!sdp->sd_log_num_revoke)
                 return;
 
-        bh = gfs2_log_get_buf(sdp);
-        ld = (struct gfs2_log_descriptor *)bh->b_data;
-        ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
-        ld->ld_header.mh_type = cpu_to_be32(GFS2_METATYPE_LD);
-        ld->ld_header.mh_format = cpu_to_be32(GFS2_FORMAT_LD);
-        ld->ld_type = cpu_to_be32(GFS2_LOG_DESC_REVOKE);
+        bh = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_REVOKE);
+        ld = bh_log_desc(bh);
         ld->ld_length = cpu_to_be32(gfs2_struct2blk(sdp, sdp->sd_log_num_revoke,
                                                     sizeof(u64)));
         ld->ld_data1 = cpu_to_be32(sdp->sd_log_num_revoke);
-        ld->ld_data2 = cpu_to_be32(0);
-        memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
         offset = sizeof(struct gfs2_log_descriptor);
 
         while (!list_empty(head)) {
@@ -378,8 +398,7 @@ static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
                 sdp->sd_log_num_revoke--;
 
                 if (offset + sizeof(u64) > sdp->sd_sb.sb_bsize) {
-                        set_buffer_dirty(bh);
-                        ll_rw_block(WRITE, 1, &bh);
+                        submit_bh(WRITE, bh);
 
                         bh = gfs2_log_get_buf(sdp);
                         mh = (struct gfs2_meta_header *)bh->b_data;
@@ -396,8 +415,7 @@ static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
         }
         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
 
-        set_buffer_dirty(bh);
-        ll_rw_block(WRITE, 1, &bh);
+        submit_bh(WRITE, bh);
 }
 
 static void revoke_lo_before_scan(struct gfs2_jdesc *jd,
@@ -562,118 +580,110 @@ out:
         unlock_buffer(bd->bd_bh);
 }
 
-static int gfs2_check_magic(struct buffer_head *bh)
+static void gfs2_check_magic(struct buffer_head *bh)
 {
-        struct page *page = bh->b_page;
         void *kaddr;
         __be32 *ptr;
-        int rv = 0;
 
-        kaddr = kmap_atomic(page, KM_USER0);
+        clear_buffer_escaped(bh);
+        kaddr = kmap_atomic(bh->b_page, KM_USER0);
         ptr = kaddr + bh_offset(bh);
         if (*ptr == cpu_to_be32(GFS2_MAGIC))
-                rv = 1;
+                set_buffer_escaped(bh);
         kunmap_atomic(kaddr, KM_USER0);
-
-        return rv;
 }
 
-/**
- * databuf_lo_before_commit - Scan the data buffers, writing as we go
- *
- */
-
-static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
+static void gfs2_write_blocks(struct gfs2_sbd *sdp, struct buffer_head *bh,
+                              struct list_head *list, struct list_head *done,
+                              unsigned int n)
 {
-        struct gfs2_bufdata *bd1 = NULL, *bd2;
-        struct buffer_head *bh = NULL,*bh1 = NULL;
+        struct buffer_head *bh1;
         struct gfs2_log_descriptor *ld;
-        unsigned int limit;
-        unsigned int total;
-        unsigned int num, n;
-        __be64 *ptr = NULL;
-        int magic;
+        struct gfs2_bufdata *bd;
+        __be64 *ptr;
 
+        if (!bh)
+                return;
 
-        limit = databuf_limit(sdp);
+        ld = bh_log_desc(bh);
+        ld->ld_length = cpu_to_be32(n + 1);
+        ld->ld_data1 = cpu_to_be32(n);
 
+        ptr = bh_log_ptr(bh);
+        
+        get_bh(bh);
+        submit_bh(WRITE, bh);
         gfs2_log_lock(sdp);
-        total = sdp->sd_log_num_databuf;
-        bd2 = bd1 = list_prepare_entry(bd1, &sdp->sd_log_le_databuf,
-                                       bd_le.le_list);
-        while(total) {
-                num = total;
-                if (num > limit)
-                        num = limit;
-
-                gfs2_log_unlock(sdp);
-                bh = gfs2_log_get_buf(sdp);
-                gfs2_log_lock(sdp);
-
-                ld = (struct gfs2_log_descriptor *)bh->b_data;
-                ptr = (__be64 *)(bh->b_data + DATABUF_OFFSET);
-                ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
-                ld->ld_header.mh_type = cpu_to_be32(GFS2_METATYPE_LD);
-                ld->ld_header.mh_format = cpu_to_be32(GFS2_FORMAT_LD);
-                ld->ld_type = cpu_to_be32(GFS2_LOG_DESC_JDATA);
-                ld->ld_length = cpu_to_be32(num + 1);
-                ld->ld_data1 = cpu_to_be32(num);
-                ld->ld_data2 = cpu_to_be32(0);
-                memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
-
-                n = 0;
-                list_for_each_entry_continue(bd1, &sdp->sd_log_le_databuf,
-                                             bd_le.le_list) {
-                        bh1 = bd1->bd_bh;
-
-                        magic = gfs2_check_magic(bh1);
-                        *ptr++ = cpu_to_be64(bh1->b_blocknr);
-                        *ptr++ = cpu_to_be64((__u64)magic);
-                        clear_buffer_escaped(bh1);
-                        if (unlikely(magic != 0))
-                                set_buffer_escaped(bh1);
-                        if (++n >= num)
-                                break;
+        while(!list_empty(list)) {
+                bd = list_entry(list->next, struct gfs2_bufdata, bd_le.le_list);
+                list_move_tail(&bd->bd_le.le_list, done);
+                get_bh(bd->bd_bh);
+                while (be64_to_cpu(*ptr) != bd->bd_bh->b_blocknr) {
+                        gfs2_log_incr_head(sdp);
+                        ptr += 2;
                 }
                 gfs2_log_unlock(sdp);
-                if (bh) {
-                        set_buffer_dirty(bh);
-                        ll_rw_block(WRITE, 1, &bh);
-                        bh = NULL;
-                        ptr = NULL;
+                lock_buffer(bd->bd_bh);
+                if (buffer_escaped(bd->bd_bh)) {
+                        void *kaddr;
+                        bh1 = gfs2_log_get_buf(sdp);
+                        kaddr = kmap_atomic(bd->bd_bh->b_page, KM_USER0);
+                        memcpy(bh1->b_data, kaddr + bh_offset(bd->bd_bh),
+                               bh1->b_size);
+                        kunmap_atomic(kaddr, KM_USER0);
+                        *(__be32 *)bh1->b_data = 0;
+                        clear_buffer_escaped(bd->bd_bh);
+                        unlock_buffer(bd->bd_bh);
+                        brelse(bd->bd_bh);
+                } else {
+                        bh1 = gfs2_log_fake_buf(sdp, bd->bd_bh);
                 }
-                n = 0;
+                submit_bh(WRITE, bh1);
                 gfs2_log_lock(sdp);
-                list_for_each_entry_continue(bd2, &sdp->sd_log_le_databuf,
-                                             bd_le.le_list) {
-                        if (!bd2->bd_bh)
-                                continue;
-                        /* copy buffer if it needs escaping */
+                ptr += 2;
+        }
+        gfs2_log_unlock(sdp);
+        brelse(bh);
+}
+
+/**
+ * databuf_lo_before_commit - Scan the data buffers, writing as we go
+ *
+ */
+
+static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
+{
+        struct gfs2_bufdata *bd = NULL;
+        struct buffer_head *bh = NULL;
+        unsigned int n = 0;
+        __be64 *ptr = NULL, *end = NULL;
+        LIST_HEAD(processed);
+        LIST_HEAD(in_progress);
+
+        gfs2_log_lock(sdp);
+        while (!list_empty(&sdp->sd_log_le_databuf)) {
+                if (ptr == end) {
                         gfs2_log_unlock(sdp);
-                        if (unlikely(buffer_escaped(bd2->bd_bh))) {
-                                void *kaddr;
-                                struct page *page = bd2->bd_bh->b_page;
-                                bh = gfs2_log_get_buf(sdp);
-                                kaddr = kmap_atomic(page, KM_USER0);
-                                memcpy(bh->b_data,
-                                       kaddr + bh_offset(bd2->bd_bh),
-                                       sdp->sd_sb.sb_bsize);
-                                kunmap_atomic(kaddr, KM_USER0);
-                                *(__be32 *)bh->b_data = 0;
-                        } else {
-                                bh = gfs2_log_fake_buf(sdp, bd2->bd_bh);
-                        }
-                        set_buffer_dirty(bh);
-                        ll_rw_block(WRITE, 1, &bh);
+                        gfs2_write_blocks(sdp, bh, &in_progress, &processed, n);
+                        n = 0;
+                        bh = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_JDATA);
+                        ptr = bh_log_ptr(bh);
+                        end = bh_ptr_end(bh) - 1;
                         gfs2_log_lock(sdp);
-                        if (++n >= num)
-                                break;
+                        continue;
                 }
-                bh = NULL;
-                BUG_ON(total < num);
-                total -= num;
+                bd = list_entry(sdp->sd_log_le_databuf.next, struct gfs2_bufdata, bd_le.le_list);
+                list_move_tail(&bd->bd_le.le_list, &in_progress);
+                gfs2_check_magic(bd->bd_bh);
+                *ptr++ = cpu_to_be64(bd->bd_bh->b_blocknr);
+                *ptr++ = cpu_to_be64(buffer_escaped(bh) ? 1 : 0);
+                n++;
         }
         gfs2_log_unlock(sdp);
+        gfs2_write_blocks(sdp, bh, &in_progress, &processed, n);
+        gfs2_log_lock(sdp);
+        list_splice(&processed, &sdp->sd_log_le_databuf);
+        gfs2_log_unlock(sdp);
 }
 
 static int databuf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
@@ -807,10 +817,10 @@ const struct gfs2_log_operations gfs2_databuf_lops = {
 
 const struct gfs2_log_operations *gfs2_log_ops[] = {
         &gfs2_glock_lops,
+        &gfs2_databuf_lops,
         &gfs2_buf_lops,
-        &gfs2_revoke_lops,
         &gfs2_rg_lops,
-        &gfs2_databuf_lops,
+        &gfs2_revoke_lops,
         NULL,
 };
 
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index 19097bc7c81d..1d80f2d42122 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -297,6 +297,37 @@ void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
                 unlock_page(bh->b_page);
 }
 
+void gfs2_remove_from_journal(struct buffer_head *bh, struct gfs2_trans *tr, int meta)
+{
+        struct gfs2_sbd *sdp = GFS2_SB(bh->b_page->mapping->host);
+        struct gfs2_bufdata *bd = bh->b_private;
+        if (test_clear_buffer_pinned(bh)) {
+                list_del_init(&bd->bd_le.le_list);
+                if (meta) {
+                        gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
+                        sdp->sd_log_num_buf--;
+                        tr->tr_num_buf_rm++;
+                } else {
+                        gfs2_assert_warn(sdp, sdp->sd_log_num_databuf);
+                        sdp->sd_log_num_databuf--;
+                        tr->tr_num_databuf_rm++;
+                }
+                tr->tr_touched = 1;
+                brelse(bh);
+        }
+        if (bd) {
+                if (bd->bd_ail) {
+                        gfs2_remove_from_ail(NULL, bd);
+                        bh->b_private = NULL;
+                        bd->bd_bh = NULL;
+                        bd->bd_blkno = bh->b_blocknr;
+                        gfs2_trans_add_revoke(sdp, bd);
+                }
+        }
+        clear_buffer_dirty(bh);
+        clear_buffer_uptodate(bh);
+}
+
 /**
  * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
  * @ip: the inode who owns the buffers
@@ -313,33 +344,11 @@ void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
         while (blen) {
                 bh = getbuf(ip->i_gl, bstart, NO_CREATE);
                 if (bh) {
-                        struct gfs2_bufdata *bd;
-
                         lock_buffer(bh);
                         gfs2_log_lock(sdp);
-                        bd = bh->b_private;
-                        if (test_clear_buffer_pinned(bh)) {
-                                struct gfs2_trans *tr = current->journal_info;
-                                list_del_init(&bd->bd_le.le_list);
-                                gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
-                                sdp->sd_log_num_buf--;
-                                tr->tr_num_buf_rm++;
-                                brelse(bh);
-                        }
-                        if (bd) {
-                                if (bd->bd_ail) {
-                                        gfs2_remove_from_ail(NULL, bd);
-                                        bh->b_private = NULL;
-                                        bd->bd_bh = NULL;
-                                        bd->bd_blkno = bh->b_blocknr;
-                                        gfs2_trans_add_revoke(sdp, bd);
-                                }
-                        }
-                        clear_buffer_dirty(bh);
-                        clear_buffer_uptodate(bh);
+                        gfs2_remove_from_journal(bh, current->journal_info, 1);
                         gfs2_log_unlock(sdp);
                         unlock_buffer(bh);
-
                         brelse(bh);
                 }
 
diff --git a/fs/gfs2/meta_io.h b/fs/gfs2/meta_io.h
index fd67f07cd60e..b7048222ebb4 100644
--- a/fs/gfs2/meta_io.h
+++ b/fs/gfs2/meta_io.h
@@ -51,6 +51,9 @@ int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh);
 void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
                          int meta);
 
+void gfs2_remove_from_journal(struct buffer_head *bh, struct gfs2_trans *tr,
+                              int meta);
+
 void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen);
 
 void gfs2_meta_cache_flush(struct gfs2_inode *ip);
diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
index dd1ea491ddcb..b7baf1831912 100644
--- a/fs/gfs2/ops_address.c
+++ b/fs/gfs2/ops_address.c
@@ -414,7 +414,8 @@ static int gfs2_prepare_write(struct file *file, struct page *page,
         if (ind_blocks || data_blocks)
                 rblocks += RES_STATFS + RES_QUOTA;
 
-        error = gfs2_trans_begin(sdp, rblocks, 0);
+        error = gfs2_trans_begin(sdp, rblocks,
+                                 PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize);
         if (error)
                 goto out_trans_fail;
 
@@ -625,10 +626,10 @@ static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
         clear_buffer_dirty(bh);
         bd = bh->b_private;
         if (bd) {
-                if (!list_empty(&bd->bd_le.le_list)) {
-                        if (!buffer_pinned(bh))
-                                list_del_init(&bd->bd_le.le_list);
-                }
+                if (!list_empty(&bd->bd_le.le_list) && !buffer_pinned(bh))
+                        list_del_init(&bd->bd_le.le_list);
+                else
+                        gfs2_remove_from_journal(bh, current->journal_info, 0);
         }
         bh->b_bdev = NULL;
         clear_buffer_mapped(bh);
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 35f3dfa9bfb1..1ac9afa58c65 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -89,7 +89,8 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb)
         INIT_LIST_HEAD(&sdp->sd_ail2_list);
 
         init_rwsem(&sdp->sd_log_flush_lock);
-        INIT_LIST_HEAD(&sdp->sd_log_flush_list);
+        atomic_set(&sdp->sd_log_in_flight, 0);
+        init_waitqueue_head(&sdp->sd_log_flush_wait);
 
         INIT_LIST_HEAD(&sdp->sd_revoke_list);
 
diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c
index 2cbe5a321e89..291f0c7eaa3b 100644
--- a/fs/gfs2/ops_inode.c
+++ b/fs/gfs2/ops_inode.c
@@ -905,12 +905,17 @@ static int gfs2_permission(struct inode *inode, int mask, struct nameidata *nd)
 static int setattr_size(struct inode *inode, struct iattr *attr)
 {
         struct gfs2_inode *ip = GFS2_I(inode);
+        struct gfs2_sbd *sdp = GFS2_SB(inode);
         int error;
 
         if (attr->ia_size != ip->i_di.di_size) {
-                error = vmtruncate(inode, attr->ia_size);
+                error = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks);
                 if (error)
                         return error;
+                error = vmtruncate(inode, attr->ia_size);
+                gfs2_trans_end(sdp);
+                if (error) 
+                        return error;
         }
 
         error = gfs2_truncatei(ip, attr->ia_size);
diff --git a/fs/gfs2/ops_super.c b/fs/gfs2/ops_super.c
index 4316690d86f6..950f31460e8b 100644
--- a/fs/gfs2/ops_super.c
+++ b/fs/gfs2/ops_super.c
@@ -455,12 +455,15 @@ static void gfs2_delete_inode(struct inode *inode)
         }
 
         error = gfs2_dinode_dealloc(ip);
-        /*
-         * Must do this before unlock to avoid trying to write back
-         * potentially dirty data now that inode no longer exists
-         * on disk.
-         */
+        if (error)
+                goto out_unlock;
+
+        error = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks);
+        if (error)
+                goto out_unlock;
+        /* Needs to be done before glock release & also in a transaction */
         truncate_inode_pages(&inode->i_data, 0);
+        gfs2_trans_end(sdp);
 
 out_unlock:
         gfs2_glock_dq(&ip->i_iopen_gh);