From: Darrick J. Wong <djwong@xxxxxxxxxx>
Create a new libxfs function to remove a (name, inode) entry from a
directory. The upcoming metadata directory feature will need this to
create a metadata directory tree.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
libxfs/xfs_dir2.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++
libxfs/xfs_dir2.h | 3 ++
2 files changed, 76 insertions(+)
diff --git a/libxfs/xfs_dir2.c b/libxfs/xfs_dir2.c
index 8755ef615f8..a0853d766f2 100644
--- a/libxfs/xfs_dir2.c
+++ b/libxfs/xfs_dir2.c
@@ -876,3 +876,76 @@ xfs_dir_link_existing_child(
xfs_bumplink(tp, ip);
return 0;
}
+
+/*
+ * Given a directory @dp, a child @ip, and a @name, remove the (@name, @ip)
+ * entry from the directory. Both inodes must have the ILOCK held.
+ */
+int
+xfs_dir_remove_child(
+ struct xfs_trans *tp,
+ uint resblks,
+ struct xfs_inode *dp,
+ struct xfs_name *name,
+ struct xfs_inode *ip)
+{
+ int error;
+
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+ ASSERT(xfs_isilocked(dp, XFS_ILOCK_EXCL));
+
+ /*
+ * If we're removing a directory perform some additional validation.
+ */
+ if (S_ISDIR(VFS_I(ip)->i_mode)) {
+ ASSERT(VFS_I(ip)->i_nlink >= 2);
+ if (VFS_I(ip)->i_nlink != 2)
+ return -ENOTEMPTY;
+ if (!xfs_dir_isempty(ip))
+ return -ENOTEMPTY;
+
+ /* Drop the link from ip's "..". */
+ error = xfs_droplink(tp, dp);
+ if (error)
+ return error;
+
+ /* Drop the "." link from ip to self. */
+ error = xfs_droplink(tp, ip);
+ if (error)
+ return error;
+
+ /*
+ * Point the unlinked child directory's ".." entry to the root
+ * directory to eliminate back-references to inodes that may
+ * get freed before the child directory is closed. If the fs
+ * gets shrunk, this can lead to dirent inode validation errors.
+ */
+ if (dp->i_ino != tp->t_mountp->m_sb.sb_rootino) {
+ error = xfs_dir_replace(tp, ip, &xfs_name_dotdot,
+ tp->t_mountp->m_sb.sb_rootino, 0);
+ if (error)
+ return error;
+ }
+ } else {
+ /*
+ * When removing a non-directory we need to log the parent
+ * inode here. For a directory this is done implicitly
+ * by the xfs_droplink call for the ".." entry.
+ */
+ xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
+ }
+ xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+
+ /* Drop the link from dp to ip. */
+ error = xfs_droplink(tp, ip);
+ if (error)
+ return error;
+
+ error = xfs_dir_removename(tp, dp, name, ip->i_ino, resblks);
+ if (error) {
+ ASSERT(error != -ENOENT);
+ return error;
+ }
+
+ return 0;
+}
diff --git a/libxfs/xfs_dir2.h b/libxfs/xfs_dir2.h
index 4afade8b087..e35deb273d8 100644
--- a/libxfs/xfs_dir2.h
+++ b/libxfs/xfs_dir2.h
@@ -259,5 +259,8 @@ int xfs_dir_create_new_child(struct xfs_trans *tp, uint resblks,
int xfs_dir_link_existing_child(struct xfs_trans *tp, uint resblks,
struct xfs_inode *dp, struct xfs_name *name,
struct xfs_inode *ip);
+int xfs_dir_remove_child(struct xfs_trans *tp, uint resblks,
+ struct xfs_inode *dp, struct xfs_name *name,
+ struct xfs_inode *ip);
#endif /* __XFS_DIR2_H__ */
