GFS2: Switch tr_touched to flag in transaction

This patch eliminates the int variable tr_touched in favor of a
new flag in the transaction. This is a step toward reducing contention
on the gfs2_log_lock spin_lock.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

4 files changed, 23 insertions, 18 deletions

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 00d8dc20ea3a..c45084ac642d 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -470,15 +470,19 @@ struct gfs2_quota_data {
         struct rcu_head qd_rcu;
 };
 
+enum {
+        TR_TOUCHED = 1,
+        TR_ATTACHED = 2,
+        TR_ALLOCED = 3,
+};
+
 struct gfs2_trans {
         unsigned long tr_ip;
 
         unsigned int tr_blocks;
         unsigned int tr_revokes;
         unsigned int tr_reserved;
-        unsigned int tr_touched:1;
-        unsigned int tr_attached:1;
-        unsigned int tr_alloced:1;
+        unsigned long tr_flags;
 
         unsigned int tr_num_buf_new;
         unsigned int tr_num_databuf_new;
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 5028a9d00c17..4fb76c04e65b 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -799,7 +799,7 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl,
 
 static void gfs2_merge_trans(struct gfs2_trans *old, struct gfs2_trans *new)
 {
-        WARN_ON_ONCE(old->tr_attached != 1);
+        WARN_ON_ONCE(!test_bit(TR_ATTACHED, &old->tr_flags));
 
         old->tr_num_buf_new     += new->tr_num_buf_new;
         old->tr_num_databuf_new += new->tr_num_databuf_new;
@@ -823,9 +823,9 @@ static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
         if (sdp->sd_log_tr) {
                 gfs2_merge_trans(sdp->sd_log_tr, tr);
         } else if (tr->tr_num_buf_new || tr->tr_num_databuf_new) {
-                gfs2_assert_withdraw(sdp, tr->tr_alloced);
+                gfs2_assert_withdraw(sdp, test_bit(TR_ALLOCED, &tr->tr_flags));
                 sdp->sd_log_tr = tr;
-                tr->tr_attached = 1;
+                set_bit(TR_ATTACHED, &tr->tr_flags);
         }
 
         sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index 373639a59782..a88a347cffe3 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -293,7 +293,7 @@ int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
         wait_on_buffer(bh);
         if (unlikely(!buffer_uptodate(bh))) {
                 struct gfs2_trans *tr = current->journal_info;
-                if (tr && tr->tr_touched)
+                if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
                         gfs2_io_error_bh(sdp, bh);
                 brelse(bh);
                 *bhp = NULL;
@@ -320,7 +320,7 @@ int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
 
         if (!buffer_uptodate(bh)) {
                 struct gfs2_trans *tr = current->journal_info;
-                if (tr && tr->tr_touched)
+                if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))
                         gfs2_io_error_bh(sdp, bh);
                 return -EIO;
         }
@@ -346,7 +346,7 @@ void gfs2_remove_from_journal(struct buffer_head *bh, int meta)
                         tr->tr_num_buf_rm++;
                 else
                         tr->tr_num_databuf_rm++;
-                tr->tr_touched = 1;
+                set_bit(TR_TOUCHED, &tr->tr_flags);
                 was_pinned = 1;
                 brelse(bh);
         }
diff --git a/fs/gfs2/trans.c b/fs/gfs2/trans.c
index 0c1bde395062..5d7f5b08d600 100644
--- a/fs/gfs2/trans.c
+++ b/fs/gfs2/trans.c
@@ -48,7 +48,7 @@ int gfs2_trans_begin(struct gfs2_sbd *sdp, unsigned int blocks,
         tr->tr_blocks = blocks;
         tr->tr_revokes = revokes;
         tr->tr_reserved = 1;
-        tr->tr_alloced = 1;
+        set_bit(TR_ALLOCED, &tr->tr_flags);
         if (blocks)
                 tr->tr_reserved += 6 + blocks;
         if (revokes)
@@ -78,7 +78,8 @@ static void gfs2_print_trans(const struct gfs2_trans *tr)
 {
         pr_warn("Transaction created at: %pSR\n", (void *)tr->tr_ip);
         pr_warn("blocks=%u revokes=%u reserved=%u touched=%u\n",
-                tr->tr_blocks, tr->tr_revokes, tr->tr_reserved, tr->tr_touched);
+                tr->tr_blocks, tr->tr_revokes, tr->tr_reserved,
+                test_bit(TR_TOUCHED, &tr->tr_flags));
         pr_warn("Buf %u/%u Databuf %u/%u Revoke %u/%u\n",
                 tr->tr_num_buf_new, tr->tr_num_buf_rm,
                 tr->tr_num_databuf_new, tr->tr_num_databuf_rm,
@@ -89,12 +90,12 @@ void gfs2_trans_end(struct gfs2_sbd *sdp)
 {
         struct gfs2_trans *tr = current->journal_info;
         s64 nbuf;
-        int alloced = tr->tr_alloced;
+        int alloced = test_bit(TR_ALLOCED, &tr->tr_flags);
 
         BUG_ON(!tr);
         current->journal_info = NULL;
 
-        if (!tr->tr_touched) {
+        if (!test_bit(TR_TOUCHED, &tr->tr_flags)) {
                 gfs2_log_release(sdp, tr->tr_reserved);
                 if (alloced) {
                         kfree(tr);
@@ -112,8 +113,8 @@ void gfs2_trans_end(struct gfs2_sbd *sdp)
                 gfs2_print_trans(tr);
 
         gfs2_log_commit(sdp, tr);
-        if (alloced && !tr->tr_attached)
-                        kfree(tr);
+        if (alloced && !test_bit(TR_ATTACHED, &tr->tr_flags))
+                kfree(tr);
         up_read(&sdp->sd_log_flush_lock);
 
         if (sdp->sd_vfs->s_flags & MS_SYNCHRONOUS)
@@ -182,7 +183,7 @@ void gfs2_trans_add_data(struct gfs2_glock *gl, struct buffer_head *bh)
                 gfs2_log_lock(sdp);
         }
         gfs2_assert(sdp, bd->bd_gl == gl);
-        tr->tr_touched = 1;
+        set_bit(TR_TOUCHED, &tr->tr_flags);
         if (list_empty(&bd->bd_list)) {
                 set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
                 set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
@@ -201,7 +202,7 @@ static void meta_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
         enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
 
         tr = current->journal_info;
-        tr->tr_touched = 1;
+        set_bit(TR_TOUCHED, &tr->tr_flags);
         if (!list_empty(&bd->bd_list))
                 return;
         set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
@@ -256,7 +257,7 @@ void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 
         BUG_ON(!list_empty(&bd->bd_list));
         gfs2_add_revoke(sdp, bd);
-        tr->tr_touched = 1;
+        set_bit(TR_TOUCHED, &tr->tr_flags);
         tr->tr_num_revoke++;
 }