[JFFS2] Track parent inode for directories (for NFS export)

To support NFS export, we need to know the parent inode of directories.
Rather than growing the jffs2_inode_cache structure, share space with
the nlink field -- which was always set to 1 for directories anyway.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 20 insertions, 11 deletions

diff --git a/fs/jffs2/build.c b/fs/jffs2/build.c
index d58f845ccb8..c5e1450d79f 100644
--- a/fs/jffs2/build.c
+++ b/fs/jffs2/build.c
@@ -46,7 +46,7 @@ next_inode(int *i, struct jffs2_inode_cache *ic, struct jffs2_sb_info *c)
 
 
 static void jffs2_build_inode_pass1(struct jffs2_sb_info *c,
-                                        struct jffs2_inode_cache *ic)
+                                    struct jffs2_inode_cache *ic)
 {
         struct jffs2_full_dirent *fd;
 
@@ -68,11 +68,17 @@ static void jffs2_build_inode_pass1(struct jffs2_sb_info *c,
                         continue;
                 }
 
-                if (child_ic->nlink++ && fd->type == DT_DIR) {
-                        JFFS2_ERROR("child dir \"%s\" (ino #%u) of dir ino #%u appears to be a hard link\n",
-                                fd->name, fd->ino, ic->ino);
-                        /* TODO: What do we do about it? */
-                }
+                if (fd->type == DT_DIR) {
+                        if (child_ic->pino_nlink) {
+                                JFFS2_ERROR("child dir \"%s\" (ino #%u) of dir ino #%u appears to be a hard link\n",
+                                            fd->name, fd->ino, ic->ino);
+                                /* TODO: What do we do about it? */
+                        } else {
+                                child_ic->pino_nlink = ic->ino;
+                        }
+                } else
+                        child_ic->pino_nlink++;
+
                 dbg_fsbuild("increased nlink for child \"%s\" (ino #%u)\n", fd->name, fd->ino);
                 /* Can't free scan_dents so far. We might need them in pass 2 */
         }
@@ -125,7 +131,7 @@ static int jffs2_build_filesystem(struct jffs2_sb_info *c)
         dbg_fsbuild("pass 2 starting\n");
 
         for_each_inode(i, c, ic) {
-                if (ic->nlink)
+                if (ic->pino_nlink)
                         continue;
 
                 jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
@@ -232,16 +238,19 @@ static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *c,
                         /* Reduce nlink of the child. If it's now zero, stick it on the
                            dead_fds list to be cleaned up later. Else just free the fd */
 
-                        child_ic->nlink--;
+                        if (fd->type == DT_DIR)
+                                child_ic->pino_nlink = 0;
+                        else
+                                child_ic->pino_nlink--;
 
-                        if (!child_ic->nlink) {
-                                dbg_fsbuild("inode #%u (\"%s\") has now got zero nlink, adding to dead_fds list.\n",
+                        if (!child_ic->pino_nlink) {
+                                dbg_fsbuild("inode #%u (\"%s\") now has no links; adding to dead_fds list.\n",
                                           fd->ino, fd->name);
                                 fd->next = *dead_fds;
                                 *dead_fds = fd;
                         } else {
                                 dbg_fsbuild("inode #%u (\"%s\") has now got nlink %d. Ignoring.\n",
-                                          fd->ino, fd->name, child_ic->nlink);
+                                          fd->ino, fd->name, child_ic->pino_nlink);
                                 jffs2_free_full_dirent(fd);
                         }
                 }