xfs: Add support to RENAME_EXCHANGE flag
Adds a new function named xfs_cross_rename(), responsible for
handling requests from sys_renameat2() using RENAME_EXCHANGE flag.
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 41f804e..9916aef 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -2656,6 +2656,124 @@
}
/*
+ * xfs_cross_rename()
+ *
+ * responsible for handling RENAME_EXCHANGE flag in renameat2() sytemcall
+ */
+STATIC int
+xfs_cross_rename(
+ 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,
+ struct xfs_bmap_free *free_list,
+ xfs_fsblock_t *first_block,
+ 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,
+ first_block, free_list, spaceres);
+ if (error)
+ goto out;
+
+ /* Swap inode number for dirent in second parent */
+ error = xfs_dir_replace(tp, dp2, name2,
+ ip1->i_ino,
+ first_block, free_list, spaceres);
+ if (error)
+ goto out;
+
+ /*
+ * 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(ip2->i_d.di_mode)) {
+ error = xfs_dir_replace(tp, ip2, &xfs_name_dotdot,
+ dp1->i_ino, first_block,
+ free_list, spaceres);
+ if (error)
+ goto out;
+
+ /* transfer ip2 ".." reference to dp1 */
+ if (!S_ISDIR(ip1->i_d.di_mode)) {
+ error = xfs_droplink(tp, dp2);
+ if (error)
+ goto out;
+ error = xfs_bumplink(tp, dp1);
+ if (error)
+ goto out;
+ }
+
+ /*
+ * 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(ip1->i_d.di_mode)) {
+ error = xfs_dir_replace(tp, ip1, &xfs_name_dotdot,
+ dp2->i_ino, first_block,
+ free_list, spaceres);
+ if (error)
+ goto out;
+
+ /* transfer ip1 ".." reference to dp2 */
+ if (!S_ISDIR(ip2->i_d.di_mode)) {
+ error = xfs_droplink(tp, dp1);
+ if (error)
+ goto out;
+ error = xfs_bumplink(tp, dp2);
+ if (error)
+ goto out;
+ }
+
+ /*
+ * 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);
+out:
+ return error;
+}
+
+/*
* xfs_rename
*/
int
@@ -2665,7 +2783,8 @@
xfs_inode_t *src_ip,
xfs_inode_t *target_dp,
struct xfs_name *target_name,
- xfs_inode_t *target_ip)
+ xfs_inode_t *target_ip,
+ unsigned int flags)
{
xfs_trans_t *tp = NULL;
xfs_mount_t *mp = src_dp->i_mount;
@@ -2743,6 +2862,18 @@
}
/*
+ * Handle RENAME_EXCHANGE flags
+ */
+ if (flags & RENAME_EXCHANGE) {
+ error = xfs_cross_rename(tp, src_dp, src_name, src_ip,
+ target_dp, target_name, target_ip,
+ &free_list, &first_block, spaceres);
+ if (error)
+ goto abort_return;
+ goto finish_rename;
+ }
+
+ /*
* Set up the target.
*/
if (target_ip == NULL) {
@@ -2881,6 +3012,7 @@
if (new_parent)
xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);
+finish_rename:
/*
* If this is a synchronous mount, make sure that the
* rename transaction goes to disk before returning to
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 4ed2ba9..f772296 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -338,7 +338,7 @@
int xfs_rename(struct xfs_inode *src_dp, struct xfs_name *src_name,
struct xfs_inode *src_ip, struct xfs_inode *target_dp,
struct xfs_name *target_name,
- struct xfs_inode *target_ip);
+ struct xfs_inode *target_ip, unsigned int flags);
void xfs_ilock(xfs_inode_t *, uint);
int xfs_ilock_nowait(xfs_inode_t *, uint);
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index abb838a..ce80eeb 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -384,19 +384,23 @@
unsigned int flags)
{
struct inode *new_inode = ndentry->d_inode;
+ int omode = 0;
struct xfs_name oname;
struct xfs_name nname;
- /* XFS does not support RENAME_EXCHANGE yet */
- if (flags & ~RENAME_NOREPLACE)
+ if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
return -EINVAL;
- xfs_dentry_to_name(&oname, odentry, 0);
+ /* if we are exchanging files, we need to set i_mode of both files */
+ if (flags & RENAME_EXCHANGE)
+ omode = ndentry->d_inode->i_mode;
+
+ xfs_dentry_to_name(&oname, odentry, omode);
xfs_dentry_to_name(&nname, ndentry, odentry->d_inode->i_mode);
return xfs_rename(XFS_I(odir), &oname, XFS_I(odentry->d_inode),
XFS_I(ndir), &nname,
- new_inode ? XFS_I(new_inode) : NULL);
+ new_inode ? XFS_I(new_inode) : NULL, flags);
}
/*