[GFS2] Clean up inode number handling

This patch cleans up the inode number handling code. The main difference
is that instead of looking up the inodes using a struct gfs2_inum_host
we now use just the no_addr member of this structure. The tests relating
to no_formal_ino can then be done by the calling code. This has
advantages in that we want to do different things in different code
paths if the no_formal_ino doesn't match. In the NFS patch we want to
return -ESTALE, but in the ->lookup() path, its a bug in the fs if the
no_formal_ino doesn't match and thus we can withdraw in this case.

In order to later fix bz #201012, we need to be able to look up an inode
without knowing no_formal_ino, as the only information that is known to
us is the on-disk location of the inode in question.

This patch will also help us to fix bz #236099 at a later date by
cleaning up a lot of the code in that area.

There are no user visible changes as a result of this patch and there
are no changes to the on-disk format either.

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

1 files changed, 43 insertions, 13 deletions

diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c
index a96fa07b3f3b..9cdd71cef59c 100644
--- a/fs/gfs2/dir.c
+++ b/fs/gfs2/dir.c
@@ -1456,7 +1456,7 @@ int gfs2_dir_read(struct inode *inode, u64 *offset, void *opaque,
                 if (dip->i_di.di_entries != g.offset) {
                         fs_warn(sdp, "Number of entries corrupt in dir %llu, "
                                 "ip->i_di.di_entries (%u) != g.offset (%u)\n",
-                                (unsigned long long)dip->i_num.no_addr,
+                                (unsigned long long)dip->i_no_addr,
                                 dip->i_di.di_entries,
                                 g.offset);
                         error = -EIO;
@@ -1488,24 +1488,54 @@ out:
  * Returns: errno
  */
 
-int gfs2_dir_search(struct inode *dir, const struct qstr *name,
-                    struct gfs2_inum_host *inum, unsigned int *type)
+struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name)
 {
         struct buffer_head *bh;
         struct gfs2_dirent *dent;
+        struct inode *inode;
+
+        dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
+        if (dent) {
+                if (IS_ERR(dent))
+                        return ERR_PTR(PTR_ERR(dent));
+                inode = gfs2_inode_lookup(dir->i_sb,
+                                          be64_to_cpu(dent->de_inum.no_addr),
+                                          be16_to_cpu(dent->de_type));
+                brelse(bh);
+                return inode;
+        }
+        return ERR_PTR(-ENOENT);
+}
+
+int gfs2_dir_check(struct inode *dir, const struct qstr *name,
+                   const struct gfs2_inode *ip)
+{
+        struct buffer_head *bh;
+        struct gfs2_dirent *dent;
+        int ret = -ENOENT;
 
         dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
         if (dent) {
                 if (IS_ERR(dent))
                         return PTR_ERR(dent);
-                if (inum)
-                        gfs2_inum_in(inum, (char *)&dent->de_inum);
-                if (type)
-                        *type = be16_to_cpu(dent->de_type);
+                if (ip) {
+                        if (be64_to_cpu(dent->de_inum.no_addr) != ip->i_no_addr)
+                                goto out;
+                        if (be64_to_cpu(dent->de_inum.no_formal_ino) !=
+                            ip->i_no_formal_ino)
+                                goto out;
+                        if (unlikely(IF2DT(ip->i_inode.i_mode) !=
+                            be16_to_cpu(dent->de_type))) {
+                                gfs2_consist_inode(GFS2_I(dir));
+                                ret = -EIO;
+                                goto out;
+                        }
+                }
+                ret = 0;
+out:
                 brelse(bh);
-                return 0;
         }
-        return -ENOENT;
+        return ret;
 }
 
 static int dir_new_leaf(struct inode *inode, const struct qstr *name)
@@ -1565,7 +1595,7 @@ static int dir_new_leaf(struct inode *inode, const struct qstr *name)
  */
 
 int gfs2_dir_add(struct inode *inode, const struct qstr *name,
-                 const struct gfs2_inum_host *inum, unsigned type)
+                 const struct gfs2_inode *nip, unsigned type)
 {
         struct gfs2_inode *ip = GFS2_I(inode);
         struct buffer_head *bh;
@@ -1580,7 +1610,7 @@ int gfs2_dir_add(struct inode *inode, const struct qstr *name,
                         if (IS_ERR(dent))
                                 return PTR_ERR(dent);
                         dent = gfs2_init_dirent(inode, dent, name, bh);
-                        gfs2_inum_out(inum, (char *)&dent->de_inum);
+                        gfs2_inum_out(nip, dent);
                         dent->de_type = cpu_to_be16(type);
                         if (ip->i_di.di_flags & GFS2_DIF_EXHASH) {
                                 leaf = (struct gfs2_leaf *)bh->b_data;
@@ -1700,7 +1730,7 @@ int gfs2_dir_del(struct gfs2_inode *dip, const struct qstr *name)
  */
 
 int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
-                   struct gfs2_inum_host *inum, unsigned int new_type)
+                   const struct gfs2_inode *nip, unsigned int new_type)
 {
         struct buffer_head *bh;
         struct gfs2_dirent *dent;
@@ -1715,7 +1745,7 @@ int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
                 return PTR_ERR(dent);
 
         gfs2_trans_add_bh(dip->i_gl, bh, 1);
-        gfs2_inum_out(inum, (char *)&dent->de_inum);
+        gfs2_inum_out(nip, dent);
         dent->de_type = cpu_to_be16(new_type);
 
         if (dip->i_di.di_flags & GFS2_DIF_EXHASH) {