[PATCH 18/22] xfs: create libxfs helper to remove an existing inode/name from a directory

Darrick J. Wong
2019-01-01T02:21:11Z

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 <darrick.wong@oracle.com>
---
fs/xfs/libxfs/xfs_dir2.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/libxfs/xfs_dir2.h | 3 ++
fs/xfs/xfs_inode.c | 42 +-------------------------------
3 files changed, 64 insertions(+), 41 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_dir2.c b/fs/xfs/libxfs/xfs_dir2.c
index 4cd2afa234ca..59f8d887f8ce 100644
--- a/fs/xfs/libxfs/xfs_dir2.c
+++ b/fs/xfs/libxfs/xfs_dir2.c
@@ -792,3 +792,63 @@ xfs_dir_link_existing_child(

return xfs_bumplink(tp, ip);
}
+
+/*
+ * 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;
+ } 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/fs/xfs/libxfs/xfs_dir2.h b/fs/xfs/libxfs/xfs_dir2.h
index 7e713fcb4c40..3da87780388e 100644
--- a/fs/xfs/libxfs/xfs_dir2.h
+++ b/fs/xfs/libxfs/xfs_dir2.h
@@ -333,5 +333,8 @@ 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__ */
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 93a03cbbb9af..a882563118c8 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1926,50 +1926,10 @@ xfs_remove(
xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);

- /*
- * If we're removing a directory perform some additional validation.
- */
- if (is_dir) {
- ASSERT(VFS_I(ip)->i_nlink >= 2);
- if (VFS_I(ip)->i_nlink != 2) {
- error = -ENOTEMPTY;
- goto out_trans_cancel;
- }
- if (!xfs_dir_isempty(ip)) {
- error = -ENOTEMPTY;
- goto out_trans_cancel;
- }
-
- /* Drop the link from ip's "..". */
- error = xfs_droplink(tp, dp);
- if (error)
- goto out_trans_cancel;
-
- /* Drop the "." link from ip to self. */
- error = xfs_droplink(tp, ip);
- if (error)
- goto out_trans_cancel;
- } 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);
+ error = xfs_dir_remove_child(tp, resblks, dp, name, ip);
if (error)
goto out_trans_cancel;

- error = xfs_dir_removename(tp, dp, name, ip->i_ino, resblks);
- if (error) {
- ASSERT(error != -ENOENT);
- goto out_trans_cancel;
- }
-
/*
* If this is a synchronous mount, make sure that the
* remove transaction goes to disk before returning to