[GFS2] Shrink gfs2_inode (5) - di_nlink

Remove the di_nlink field in favour of inode->i_nlink and
update the nlink handling to use the proper macros. This
saves 4 bytes.

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

4 files changed, 31 insertions, 22 deletions

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 0de9b22f454b..711203984823 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -51,7 +51,6 @@ void gfs2_inode_attr_in(struct gfs2_inode *ip)
         struct gfs2_dinode_host *di = &ip->i_di;
 
         inode->i_ino = ip->i_num.no_addr;
-        inode->i_nlink = di->di_nlink;
         i_size_write(inode, di->di_size);
         inode->i_atime.tv_sec = di->di_atime;
         inode->i_mtime.tv_sec = di->di_mtime;
@@ -214,7 +213,12 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
 
         ip->i_inode.i_uid = be32_to_cpu(str->di_uid);
         ip->i_inode.i_gid = be32_to_cpu(str->di_gid);
-        di->di_nlink = be32_to_cpu(str->di_nlink);
+        /*
+         * We will need to review setting the nlink count here in the
+         * light of the forthcoming ro bind mount work. This is a reminder
+         * to do that.
+         */
+        ip->i_inode.i_nlink = be32_to_cpu(str->di_nlink);
         di->di_size = be64_to_cpu(str->di_size);
         di->di_blocks = be64_to_cpu(str->di_blocks);
         di->di_atime = be64_to_cpu(str->di_atime);
@@ -336,12 +340,12 @@ int gfs2_change_nlink(struct gfs2_inode *ip, int diff)
         u32 nlink;
         int error;
 
-        BUG_ON(ip->i_di.di_nlink != ip->i_inode.i_nlink);
-        nlink = ip->i_di.di_nlink + diff;
+        BUG_ON(diff != 1 && diff != -1);
+        nlink = ip->i_inode.i_nlink + diff;
 
         /* If we are reducing the nlink count, but the new value ends up being
            bigger than the old one, we must have underflowed. */
-        if (diff < 0 && nlink > ip->i_di.di_nlink) {
+        if (diff < 0 && nlink > ip->i_inode.i_nlink) {
                 if (gfs2_consist_inode(ip))
                         gfs2_dinode_print(ip);
                 return -EIO;
@@ -351,16 +355,19 @@ int gfs2_change_nlink(struct gfs2_inode *ip, int diff)
         if (error)
                 return error;
 
-        ip->i_di.di_nlink = nlink;
+        if (diff > 0)
+                inc_nlink(&ip->i_inode);
+        else
+                drop_nlink(&ip->i_inode);
+
         ip->i_di.di_ctime = get_seconds();
-        ip->i_inode.i_nlink = nlink;
 
         gfs2_trans_add_bh(ip->i_gl, dibh, 1);
         gfs2_dinode_out(ip, dibh->b_data);
         brelse(dibh);
         mark_inode_dirty(&ip->i_inode);
 
-        if (ip->i_di.di_nlink == 0) {
+        if (ip->i_inode.i_nlink == 0) {
                 struct gfs2_rgrpd *rgd;
                 struct gfs2_holder ri_gh, rg_gh;
 
@@ -375,7 +382,6 @@ int gfs2_change_nlink(struct gfs2_inode *ip, int diff)
                 if (error)
                         goto out_norgrp;
 
-                clear_nlink(&ip->i_inode);
                 gfs2_unlink_di(&ip->i_inode); /* mark inode unlinked */
                 gfs2_glock_dq_uninit(&rg_gh);
 out_norgrp:
@@ -586,7 +592,7 @@ static int create_ok(struct gfs2_inode *dip, const struct qstr *name,
                 return error;
 
         /*  Don't create entries in an unlinked directory  */
-        if (!dip->i_di.di_nlink)
+        if (!dip->i_inode.i_nlink)
                 return -EPERM;
 
         error = gfs2_dir_search(&dip->i_inode, name, NULL, NULL);
@@ -602,7 +608,7 @@ static int create_ok(struct gfs2_inode *dip, const struct qstr *name,
 
         if (dip->i_di.di_entries == (u32)-1)
                 return -EFBIG;
-        if (S_ISDIR(mode) && dip->i_di.di_nlink == (u32)-1)
+        if (S_ISDIR(mode) && dip->i_inode.i_nlink == (u32)-1)
                 return -EMLINK;
 
         return 0;
@@ -808,7 +814,7 @@ static int link_dinode(struct gfs2_inode *dip, const struct qstr *name,
         error = gfs2_meta_inode_buffer(ip, &dibh);
         if (error)
                 goto fail_end_trans;
-        ip->i_di.di_nlink = 1;
+        ip->i_inode.i_nlink = 1;
         gfs2_trans_add_bh(ip->i_gl, dibh, 1);
         gfs2_dinode_out(ip, dibh->b_data);
         brelse(dibh);
@@ -1016,7 +1022,12 @@ int gfs2_rmdiri(struct gfs2_inode *dip, const struct qstr *name,
         if (error)
                 return error;
 
-        error = gfs2_change_nlink(ip, -2);
+        /* It looks odd, but it really should be done twice */
+        error = gfs2_change_nlink(ip, -1);
+        if (error)
+                return error;
+
+        error = gfs2_change_nlink(ip, -1);
         if (error)
                 return error;
 
diff --git a/fs/gfs2/ondisk.c b/fs/gfs2/ondisk.c
index e224f6a22641..b4e354b18815 100644
--- a/fs/gfs2/ondisk.c
+++ b/fs/gfs2/ondisk.c
@@ -164,7 +164,7 @@ void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
         str->di_mode = cpu_to_be32(ip->i_inode.i_mode);
         str->di_uid = cpu_to_be32(ip->i_inode.i_uid);
         str->di_gid = cpu_to_be32(ip->i_inode.i_gid);
-        str->di_nlink = cpu_to_be32(di->di_nlink);
+        str->di_nlink = cpu_to_be32(ip->i_inode.i_nlink);
         str->di_size = cpu_to_be64(di->di_size);
         str->di_blocks = cpu_to_be64(di->di_blocks);
         str->di_atime = cpu_to_be64(di->di_atime);
@@ -191,7 +191,6 @@ void gfs2_dinode_print(const struct gfs2_inode *ip)
 
         gfs2_inum_print(&ip->i_num);
 
-        pv(di, di_nlink, "%u");
         printk(KERN_INFO "  di_size = %llu\n", (unsigned long long)di->di_size);
         printk(KERN_INFO "  di_blocks = %llu\n", (unsigned long long)di->di_blocks);
         printk(KERN_INFO "  di_atime = %lld\n", (long long)di->di_atime);
diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c
index efbcec3311bb..06176dee1550 100644
--- a/fs/gfs2/ops_inode.c
+++ b/fs/gfs2/ops_inode.c
@@ -169,7 +169,7 @@ static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
         }
 
         error = -EINVAL;
-        if (!dip->i_di.di_nlink)
+        if (!dip->i_inode.i_nlink)
                 goto out_gunlock;
         error = -EFBIG;
         if (dip->i_di.di_entries == (u32)-1)
@@ -178,10 +178,10 @@ static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
         if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
                 goto out_gunlock;
         error = -EINVAL;
-        if (!ip->i_di.di_nlink)
+        if (!ip->i_inode.i_nlink)
                 goto out_gunlock;
         error = -EMLINK;
-        if (ip->i_di.di_nlink == (u32)-1)
+        if (ip->i_inode.i_nlink == (u32)-1)
                 goto out_gunlock;
 
         alloc_required = error = gfs2_diradd_alloc_required(dir, &dentry->d_name);
@@ -386,7 +386,7 @@ static int gfs2_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 
         ip = ghs[1].gh_gl->gl_object;
 
-        ip->i_di.di_nlink = 2;
+        ip->i_inode.i_nlink = 2;
         ip->i_di.di_size = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode);
         ip->i_di.di_flags |= GFS2_DIF_JDATA;
         ip->i_di.di_payload_format = GFS2_FORMAT_DE;
@@ -636,7 +636,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
                 };
 
                 if (odip != ndip) {
-                        if (!ndip->i_di.di_nlink) {
+                        if (!ndip->i_inode.i_nlink) {
                                 error = -EINVAL;
                                 goto out_gunlock;
                         }
@@ -645,7 +645,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
                                 goto out_gunlock;
                         }
                         if (S_ISDIR(ip->i_inode.i_mode) &&
-                            ndip->i_di.di_nlink == (u32)-1) {
+                            ndip->i_inode.i_nlink == (u32)-1) {
                                 error = -EMLINK;
                                 goto out_gunlock;
                         }
diff --git a/include/linux/gfs2_ondisk.h b/include/linux/gfs2_ondisk.h
index 896c7f81a637..c61517b35b2e 100644
--- a/include/linux/gfs2_ondisk.h
+++ b/include/linux/gfs2_ondisk.h
@@ -322,7 +322,6 @@ struct gfs2_dinode {
 };
 
 struct gfs2_dinode_host {
-        __u32 di_nlink; /* number of links to this file */
         __u64 di_size;  /* number of bytes in file */
         __u64 di_blocks;        /* number of blocks in file */
         __u64 di_atime; /* time last accessed */