/*
* test if @dentry dir can be rename source or not.
* if it can, return 0 and @children is filled.
* success means,
* - it is a logically empty dir.
* - or, it exists on writable branch and has no children including whiteouts
* on the lower branch.
*/
static int may_rename_srcdir(struct dentry *dentry, aufs_bindex_t btgt)
{
int err;
unsigned int rdhash;
aufs_bindex_t bstart;
bstart = au_dbstart(dentry);
if (bstart != btgt) {
struct au_nhash whlist;
SiMustAnyLock(dentry->d_sb);
rdhash = au_sbi(dentry->d_sb)->si_rdhash;
if (!rdhash)
rdhash = au_rdhash_est(au_dir_size(/*file*/NULL,
dentry));
err = au_nhash_alloc(&whlist, rdhash, GFP_NOFS);
if (unlikely(err))
goto out;
err = au_test_empty(dentry, &whlist);
au_nhash_wh_free(&whlist);
goto out;
}
if (bstart == au_dbtaildir(dentry))
return 0; /* success */
err = au_test_empty_lower(dentry);
out:
if (err == -ENOTEMPTY) {
AuWarn1("renaming dir who has child(ren) on multiple branches,"
" is not supported\n");
err = -EXDEV;
}
return err;
}
int aufs_rmdir(struct inode *dir, struct dentry *dentry)
{
int err, rmdir_later;
aufs_bindex_t bwh, bindex, bstart;
struct au_dtime dt;
struct au_pin pin;
struct inode *inode;
struct dentry *parent, *wh_dentry, *h_dentry;
struct au_whtmp_rmdir *args;
IMustLock(dir);
err = aufs_read_lock(dentry, AuLock_DW | AuLock_FLUSH | AuLock_GEN);
if (unlikely(err))
goto out;
err = au_alive_dir(dentry);
if (unlikely(err))
goto out_unlock;
inode = dentry->d_inode;
IMustLock(inode);
err = -ENOTDIR;
if (unlikely(!S_ISDIR(inode->i_mode)))
goto out_unlock; /* possible? */
err = -ENOMEM;
args = au_whtmp_rmdir_alloc(dir->i_sb, GFP_NOFS);
if (unlikely(!args))
goto out_unlock;
parent = dentry->d_parent; /* dir inode is locked */
di_write_lock_parent(parent);
err = au_test_empty(dentry, &args->whlist);
if (unlikely(err))
goto out_parent;
bstart = au_dbstart(dentry);
bwh = au_dbwh(dentry);
bindex = -1;
wh_dentry = lock_hdir_create_wh(dentry, /*isdir*/1, &bindex, &dt, &pin);
err = PTR_ERR(wh_dentry);
if (IS_ERR(wh_dentry))
goto out_parent;
h_dentry = au_h_dptr(dentry, bstart);
dget(h_dentry);
rmdir_later = 0;
if (bindex == bstart) {
err = renwh_and_rmdir(dentry, bstart, &args->whlist, dir);
if (err > 0) {
rmdir_later = err;
err = 0;
}
} else {
/* stop monitoring */
au_hn_free(au_hi(inode, bstart));
/* dir inode is locked */
IMustLock(wh_dentry->d_parent->d_inode);
err = 0;
}
if (!err) {
vfsub_dead_dir(inode);
au_set_dbdiropq(dentry, -1);
epilog(dir, dentry, bindex);
if (rmdir_later) {
au_whtmp_kick_rmdir(dir, bstart, h_dentry, args);
args = NULL;
}
goto out_unpin; /* success */
}
/* revert */
AuLabel(revert);
if (wh_dentry) {
int rerr;
rerr = do_revert(err, dir, bindex, bwh, wh_dentry, dentry, &dt);
if (rerr)
err = rerr;
}
out_unpin:
au_unpin(&pin);
dput(wh_dentry);
dput(h_dentry);
out_parent:
di_write_unlock(parent);
if (args)
au_whtmp_rmdir_free(args);
out_unlock:
aufs_read_unlock(dentry, AuLock_DW);
out:
AuTraceErr(err);
return err;
}
/*
* test if @dentry dir can be rename destination or not.
* success means, it is a logically empty dir.
*/
static int may_rename_dstdir(struct dentry *dentry, struct au_nhash *whlist)
{
return au_test_empty(dentry, whlist);
}