[GFS2] Clean up gfs2_trans_add_revoke()

The following alters gfs2_trans_add_revoke() to take a struct
gfs2_bufdata as an argument. This eliminates the memory allocation which
was previously required by making use of the already existing struct
gfs2_bufdata. It makes some sanity checks to ensure that the
gfs2_bufdata has been removed from all the lists before its recycled as
a revoke structure. This saves one memory allocation and one free per
revoke structure.

Also as a result, and to simplify the locking, since there is no longer
any blocking code in gfs2_trans_add_revoke() we must hold the log lock
whenever this function is called. This reduces the amount of times we
take and unlock the log lock.

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

diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index b17346a355bf3ba710ab4cd3007b82359bdb6908..4670dcb2a87734b12643e11991b817de454693a4 100644 (file)
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -41,7 +41,6 @@ static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
        struct list_head *head = &gl->gl_ail_list;
        struct gfs2_bufdata *bd;
        struct buffer_head *bh;
-       u64 blkno;
        int error;
 
        blocks = atomic_read(&gl->gl_ail_count);
@@ -57,15 +56,12 @@ static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
                bd = list_entry(head->next, struct gfs2_bufdata,
                                bd_ail_gl_list);
                bh = bd->bd_bh;
-               blkno = bh->b_blocknr;
-               gfs2_assert_withdraw(sdp, !buffer_busy(bh));
-
                gfs2_remove_from_ail(NULL, bd);
-               gfs2_log_unlock(sdp);
-
-               gfs2_trans_add_revoke(sdp, blkno);
-
-               gfs2_log_lock(sdp);
+               bd->bd_bh = NULL;
+               bh->b_private = NULL;
+               bd->bd_blkno = bh->b_blocknr;
+               gfs2_assert_withdraw(sdp, !buffer_busy(bh));
+               gfs2_trans_add_revoke(sdp, bd);
        }
        gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
        gfs2_log_unlock(sdp);

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 20fa528d457d9be337cb335f3b103c003b6b8cea..4d04e6f19706f3206612f14ea579cea621afa52b 100644 (file)
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -71,8 +71,8 @@ unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
 void gfs2_remove_from_ail(struct address_space *mapping, struct gfs2_bufdata *bd)
 {
        bd->bd_ail = NULL;
-       list_del(&bd->bd_ail_st_list);
-       list_del(&bd->bd_ail_gl_list);
+       list_del_init(&bd->bd_ail_st_list);
+       list_del_init(&bd->bd_ail_gl_list);
        atomic_dec(&bd->bd_gl->gl_ail_count);
        if (mapping)
                gfs2_meta_cache_flush(GFS2_I(mapping->host));

diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 4cbef4c23a6b04a38f9562899b73396ac9d735f9..342c10e12af2f994e0f073e330de43d7efb53b1e 100644 (file)
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -343,11 +343,8 @@ static void revoke_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
        tr = current->journal_info;
        tr->tr_touched = 1;
        tr->tr_num_revoke++;
-
-       gfs2_log_lock(sdp);
        sdp->sd_log_num_revoke++;
        list_add(&le->le_list, &sdp->sd_log_le_revoke);
-       gfs2_log_unlock(sdp);
 }
 
 static void revoke_lo_before_commit(struct gfs2_sbd *sdp)

diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index d762e4f7044e79f5ad8725abe582ba88096793ca..19097bc7c81d11628b1e879a1d7ce382395306b6 100644 (file)
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -313,42 +313,31 @@ 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 = bh->b_private;
+                       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;
-                               struct gfs2_inode *bh_ip =
-                                       GFS2_I(bh->b_page->mapping->host);
-
-                               gfs2_log_lock(sdp);
                                list_del_init(&bd->bd_le.le_list);
                                gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
                                sdp->sd_log_num_buf--;
-                               gfs2_log_unlock(sdp);
-                               if (bh_ip->i_inode.i_private != NULL)
-                                       tr->tr_num_databuf_rm++;
-                               else
-                                       tr->tr_num_buf_rm++;
+                               tr->tr_num_buf_rm++;
                                brelse(bh);
                        }
                        if (bd) {
-                               gfs2_log_lock(sdp);
                                if (bd->bd_ail) {
-                                       u64 blkno = bh->b_blocknr;
-                                       bd->bd_ail = NULL;
-                                       list_del(&bd->bd_ail_st_list);
-                                       list_del(&bd->bd_ail_gl_list);
-                                       atomic_dec(&bd->bd_gl->gl_ail_count);
-                                       brelse(bh);
-                                       gfs2_log_unlock(sdp);
-                                       gfs2_trans_add_revoke(sdp, blkno);
-                               } else
-                                       gfs2_log_unlock(sdp);
+                                       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);
+                               }
                        }
-
-                       lock_buffer(bh);
                        clear_buffer_dirty(bh);
                        clear_buffer_uptodate(bh);
+                       gfs2_log_unlock(sdp);
                        unlock_buffer(bh);
 
                        brelse(bh);

diff --git a/fs/gfs2/trans.c b/fs/gfs2/trans.c
index 01cc27fefd8435c3a7c88f33554afd3c66e3fae7..717983e2c2ae3a6b262dd5e29c7a0abb29f1bc8a 100644 (file)
--- a/fs/gfs2/trans.c
+++ b/fs/gfs2/trans.c
@@ -142,12 +142,12 @@ void gfs2_trans_add_bh(struct gfs2_glock *gl, struct buffer_head *bh, int meta)
        lops_add(sdp, &bd->bd_le);
 }
 
-void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, u64 blkno)
+void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 {
-       struct gfs2_bufdata *bd = kmem_cache_alloc(gfs2_bufdata_cachep,
-                                         GFP_NOFS | __GFP_NOFAIL);
+       BUG_ON(!list_empty(&bd->bd_le.le_list));
+       BUG_ON(!list_empty(&bd->bd_ail_st_list));
+       BUG_ON(!list_empty(&bd->bd_ail_gl_list));
        lops_init_le(&bd->bd_le, &gfs2_revoke_lops);
-       bd->bd_blkno = blkno;
        lops_add(sdp, &bd->bd_le);
 }
 
@@ -160,7 +160,7 @@ void gfs2_trans_add_unrevoke(struct gfs2_sbd *sdp, u64 blkno)
 
        list_for_each_entry(bd, &sdp->sd_log_le_revoke, bd_le.le_list) {
                if (bd->bd_blkno == blkno) {
-                       list_del(&bd->bd_le.le_list);
+                       list_del_init(&bd->bd_le.le_list);
                        gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke);
                        sdp->sd_log_num_revoke--;
                        found = 1;

diff --git a/fs/gfs2/trans.h b/fs/gfs2/trans.h
index 23d4cbe1de5b7b81b0c5e460bc7578704f8efece..043d5f4b9c4c34d5c519e574563219decd4603a1 100644 (file)
--- a/fs/gfs2/trans.h
+++ b/fs/gfs2/trans.h
@@ -32,7 +32,7 @@ void gfs2_trans_end(struct gfs2_sbd *sdp);
 
 void gfs2_trans_add_gl(struct gfs2_glock *gl);
 void gfs2_trans_add_bh(struct gfs2_glock *gl, struct buffer_head *bh, int meta);
-void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, u64 blkno);
+void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd);
 void gfs2_trans_add_unrevoke(struct gfs2_sbd *sdp, u64 blkno);
 void gfs2_trans_add_rg(struct gfs2_rgrpd *rgd);