[PATCH 40/51] [GFS2] Clean up gfs2_trans_add_revoke()

swhiteho
2007-10-04T09:32:51Z

From: Steven Whitehouse <swhiteho@redhat.com>

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 b17346a..4670dcb 100644
--- 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 20fa528..4d04e6f 100644
--- 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 4cbef4c..342c10e 100644
--- 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 d762e4f..19097bc 100644
--- 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 01cc27f..717983e 100644
--- 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 23d4cbe..043d5f4 100644
--- 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);

--
1.5.1.2