gfs2: eliminate GIF_ORDERED in favor of list_empty

In several places, we used the GIF_ORDERED inode flag to determine
if an inode was on the ordered writes list. However, since we always
held the sd_ordered_lock spin_lock during the manipulation, we can
just as easily check list_empty(&ip->i_ordered) instead.
This allows us to keep more than one ordered writes list to make
journal writing improvements.

This patch eliminates GIF_ORDERED in favor of checking list_empty.

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

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 03ab11f..ca2ec02 100644 (file)
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -399,7 +399,6 @@ enum {
        GIF_QD_LOCKED           = 1,
        GIF_ALLOC_FAILED        = 2,
        GIF_SW_PAGED            = 3,
-       GIF_ORDERED             = 4,
        GIF_FREE_VFS_INODE      = 5,
        GIF_GLOP_PENDING        = 6,
        GIF_DEFERRED_DELETE     = 7,

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 2b05415..a76e55b 100644 (file)
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -613,6 +613,12 @@ static int ip_cmp(void *priv, struct list_head *a, struct list_head *b)
        return 0;
 }
 
+static void __ordered_del_inode(struct gfs2_inode *ip)
+{
+       if (!list_empty(&ip->i_ordered))
+               list_del_init(&ip->i_ordered);
+}
+
 static void gfs2_ordered_write(struct gfs2_sbd *sdp)
 {
        struct gfs2_inode *ip;
@@ -623,8 +629,7 @@ static void gfs2_ordered_write(struct gfs2_sbd *sdp)
        while (!list_empty(&sdp->sd_log_ordered)) {
                ip = list_first_entry(&sdp->sd_log_ordered, struct gfs2_inode, i_ordered);
                if (ip->i_inode.i_mapping->nrpages == 0) {
-                       test_and_clear_bit(GIF_ORDERED, &ip->i_flags);
-                       list_del(&ip->i_ordered);
+                       __ordered_del_inode(ip);
                        continue;
                }
                list_move(&ip->i_ordered, &written);
@@ -643,8 +648,7 @@ static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
        spin_lock(&sdp->sd_ordered_lock);
        while (!list_empty(&sdp->sd_log_ordered)) {
                ip = list_first_entry(&sdp->sd_log_ordered, struct gfs2_inode, i_ordered);
-               list_del(&ip->i_ordered);
-               WARN_ON(!test_and_clear_bit(GIF_ORDERED, &ip->i_flags));
+               __ordered_del_inode(ip);
                if (ip->i_inode.i_mapping->nrpages == 0)
                        continue;
                spin_unlock(&sdp->sd_ordered_lock);
@@ -659,8 +663,7 @@ void gfs2_ordered_del_inode(struct gfs2_inode *ip)
        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 
        spin_lock(&sdp->sd_ordered_lock);
-       if (test_and_clear_bit(GIF_ORDERED, &ip->i_flags))
-               list_del(&ip->i_ordered);
+       __ordered_del_inode(ip);
        spin_unlock(&sdp->sd_ordered_lock);
 }
 

diff --git a/fs/gfs2/log.h b/fs/gfs2/log.h
index c1cd6ae..8965c75 100644 (file)
--- a/fs/gfs2/log.h
+++ b/fs/gfs2/log.h
@@ -53,9 +53,9 @@ static inline void gfs2_ordered_add_inode(struct gfs2_inode *ip)
        if (gfs2_is_jdata(ip) || !gfs2_is_ordered(sdp))
                return;
 
-       if (!test_bit(GIF_ORDERED, &ip->i_flags)) {
+       if (list_empty(&ip->i_ordered)) {
                spin_lock(&sdp->sd_ordered_lock);
-               if (!test_and_set_bit(GIF_ORDERED, &ip->i_flags))
+               if (list_empty(&ip->i_ordered))
                        list_add(&ip->i_ordered, &sdp->sd_log_ordered);
                spin_unlock(&sdp->sd_ordered_lock);
        }

diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
index 733470c..c7393ee 100644 (file)
--- a/fs/gfs2/main.c
+++ b/fs/gfs2/main.c
@@ -39,6 +39,7 @@ static void gfs2_init_inode_once(void *foo)
        atomic_set(&ip->i_sizehint, 0);
        init_rwsem(&ip->i_rw_mutex);
        INIT_LIST_HEAD(&ip->i_trunc_list);
+       INIT_LIST_HEAD(&ip->i_ordered);
        ip->i_qadata = NULL;
        gfs2_holder_mark_uninitialized(&ip->i_rgd_gh);
        memset(&ip->i_res, 0, sizeof(ip->i_res));