[PATCH 19/22] xfs: create libxfs helper to exchange two directory entries

Darrick J. Wong
2019-01-01T02:21:19Z

Create a new libxfs function to exchange two directory entries.
The upcoming metadata directory feature will need this to replace a
metadata inode directory entry.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/libxfs/xfs_dir2.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/libxfs/xfs_dir2.h | 4 ++
fs/xfs/xfs_inode.c | 89 +------------------------------------
3 files changed, 119 insertions(+), 86 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_dir2.c b/fs/xfs/libxfs/xfs_dir2.c
index 59f8d887f8ce..fbd5ce580b4a 100644
--- a/fs/xfs/libxfs/xfs_dir2.c
+++ b/fs/xfs/libxfs/xfs_dir2.c
@@ -852,3 +852,115 @@ xfs_dir_remove_child(

return 0;
}
+
+/*
+ * Exchange the entry (@name1, @ip1) in directory @dp1 with the entry (@name2,
+ * @ip2) in directory @dp2, and update '..' @ip1 and @ip2's entries as needed.
+ * @ip1 and @ip2 need not be of the same type.
+ *
+ * All inodes must have the ILOCK held, and both entries must already exist.
+ */
+int
+xfs_dir_exchange(
+ struct xfs_trans *tp,
+ struct xfs_inode *dp1,
+ struct xfs_name *name1,
+ struct xfs_inode *ip1,
+ struct xfs_inode *dp2,
+ struct xfs_name *name2,
+ struct xfs_inode *ip2,
+ unsigned int spaceres)
+{
+ int ip1_flags = 0;
+ int ip2_flags = 0;
+ int dp2_flags = 0;
+ int error;
+
+ /* Swap inode number for dirent in first parent */
+ error = xfs_dir_replace(tp, dp1, name1, ip2->i_ino, spaceres);
+ if (error)
+ return error;
+
+ /* Swap inode number for dirent in second parent */
+ error = xfs_dir_replace(tp, dp2, name2, ip1->i_ino, spaceres);
+ if (error)
+ return error;
+
+ /*
+ * If we're renaming one or more directories across different parents,
+ * update the respective ".." entries (and link counts) to match the new
+ * parents.
+ */
+ if (dp1 != dp2) {
+ dp2_flags = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
+
+ if (S_ISDIR(VFS_I(ip2)->i_mode)) {
+ error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot,
+ dp1->i_ino, spaceres);
+ if (error)
+ return error;
+
+ /* transfer ip2 ".." reference to dp1 */
+ if (!S_ISDIR(VFS_I(ip1)->i_mode)) {
+ error = xfs_droplink(tp, dp2);
+ if (error)
+ return error;
+ error = xfs_bumplink(tp, dp1);
+ if (error)
+ return error;
+ }
+
+ /*
+ * Although ip1 isn't changed here, userspace needs
+ * to be warned about the change, so that applications
+ * relying on it (like backup ones), will properly
+ * notify the change
+ */
+ ip1_flags |= XFS_ICHGTIME_CHG;
+ ip2_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
+ }
+
+ if (S_ISDIR(VFS_I(ip1)->i_mode)) {
+ error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot,
+ dp2->i_ino, spaceres);
+ if (error)
+ return error;
+
+ /* transfer ip1 ".." reference to dp2 */
+ if (!S_ISDIR(VFS_I(ip2)->i_mode)) {
+ error = xfs_droplink(tp, dp1);
+ if (error)
+ return error;
+ error = xfs_bumplink(tp, dp2);
+ if (error)
+ return error;
+ }
+
+ /*
+ * Although ip2 isn't changed here, userspace needs
+ * to be warned about the change, so that applications
+ * relying on it (like backup ones), will properly
+ * notify the change
+ */
+ ip1_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
+ ip2_flags |= XFS_ICHGTIME_CHG;
+ }
+ }
+
+ if (ip1_flags) {
+ xfs_trans_ichgtime(tp, ip1, ip1_flags);
+ xfs_trans_log_inode(tp, ip1, XFS_ILOG_CORE);
+ }
+ if (ip2_flags) {
+ xfs_trans_ichgtime(tp, ip2, ip2_flags);
+ xfs_trans_log_inode(tp, ip2, XFS_ILOG_CORE);
+ }
+ if (dp2_flags) {
+ xfs_trans_ichgtime(tp, dp2, dp2_flags);
+ xfs_trans_log_inode(tp, dp2, XFS_ILOG_CORE);
+ }
+ xfs_trans_ichgtime(tp, dp1, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+ xfs_trans_log_inode(tp, dp1, XFS_ILOG_CORE);
+
+ return 0;
+}
diff --git a/fs/xfs/libxfs/xfs_dir2.h b/fs/xfs/libxfs/xfs_dir2.h
index 3da87780388e..09765f010f90 100644
--- a/fs/xfs/libxfs/xfs_dir2.h
+++ b/fs/xfs/libxfs/xfs_dir2.h
@@ -336,5 +336,9 @@ int xfs_dir_link_existing_child(struct xfs_trans *tp, uint resblks,
int xfs_dir_remove_child(struct xfs_trans *tp, uint resblks,
struct xfs_inode *dp, struct xfs_name *name,
struct xfs_inode *ip);
+int xfs_dir_exchange(struct xfs_trans *tp, struct xfs_inode *dp1,
+ struct xfs_name *name1, struct xfs_inode *ip1,
+ struct xfs_inode *dp2, struct xfs_name *name2,
+ struct xfs_inode *ip2, unsigned int spaceres);

#endif /* __XFS_DIR2_H__ */
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index a882563118c8..3bed0db609bd 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -2034,96 +2034,13 @@ xfs_cross_rename(
struct xfs_inode *ip2,
int spaceres)
{
- int error = 0;
- int ip1_flags = 0;
- int ip2_flags = 0;
- int dp2_flags = 0;
-
- /* Swap inode number for dirent in first parent */
- error = xfs_dir_replace(tp, dp1, name1, ip2->i_ino, spaceres);
- if (error)
- goto out_trans_abort;
+ int error;

- /* Swap inode number for dirent in second parent */
- error = xfs_dir_replace(tp, dp2, name2, ip1->i_ino, spaceres);
+ error = xfs_dir_exchange(tp, dp1, name1, ip1, dp2, name2, ip2,
+ spaceres);
if (error)
goto out_trans_abort;

- /*
- * If we're renaming one or more directories across different parents,
- * update the respective ".." entries (and link counts) to match the new
- * parents.
- */
- if (dp1 != dp2) {
- dp2_flags = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
-
- if (S_ISDIR(VFS_I(ip2)->i_mode)) {
- error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot,
- dp1->i_ino, spaceres);
- if (error)
- goto out_trans_abort;
-
- /* transfer ip2 ".." reference to dp1 */
- if (!S_ISDIR(VFS_I(ip1)->i_mode)) {
- error = xfs_droplink(tp, dp2);
- if (error)
- goto out_trans_abort;
- error = xfs_bumplink(tp, dp1);
- if (error)
- goto out_trans_abort;
- }
-
- /*
- * Although ip1 isn't changed here, userspace needs
- * to be warned about the change, so that applications
- * relying on it (like backup ones), will properly
- * notify the change
- */
- ip1_flags |= XFS_ICHGTIME_CHG;
- ip2_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
- }
-
- if (S_ISDIR(VFS_I(ip1)->i_mode)) {
- error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot,
- dp2->i_ino, spaceres);
- if (error)
- goto out_trans_abort;
-
- /* transfer ip1 ".." reference to dp2 */
- if (!S_ISDIR(VFS_I(ip2)->i_mode)) {
- error = xfs_droplink(tp, dp1);
- if (error)
- goto out_trans_abort;
- error = xfs_bumplink(tp, dp2);
- if (error)
- goto out_trans_abort;
- }
-
- /*
- * Although ip2 isn't changed here, userspace needs
- * to be warned about the change, so that applications
- * relying on it (like backup ones), will properly
- * notify the change
- */
- ip1_flags |= XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG;
- ip2_flags |= XFS_ICHGTIME_CHG;
- }
- }
-
- if (ip1_flags) {
- xfs_trans_ichgtime(tp, ip1, ip1_flags);
- xfs_trans_log_inode(tp, ip1, XFS_ILOG_CORE);
- }
- if (ip2_flags) {
- xfs_trans_ichgtime(tp, ip2, ip2_flags);
- xfs_trans_log_inode(tp, ip2, XFS_ILOG_CORE);
- }
- if (dp2_flags) {
- xfs_trans_ichgtime(tp, dp2, dp2_flags);
- xfs_trans_log_inode(tp, dp2, XFS_ILOG_CORE);
- }
- xfs_trans_ichgtime(tp, dp1, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
- xfs_trans_log_inode(tp, dp1, XFS_ILOG_CORE);
return xfs_finish_rename(tp);