/*
* when removing a dir, rename it to a unique temporary whiteout-ed name first
* in order to be revertible and save time for removing many child whiteouts
* under the dir.
* returns 1 when there are too many child whiteout and caller should remove
* them asynchronously. returns 0 when the number of children is enough small to
* remove now or the branch fs is a remote fs.
* otherwise return an error.
*/
static int renwh_and_rmdir(struct dentry *dentry, aufs_bindex_t bindex,
struct au_nhash *whlist, struct inode *dir)
{
int rmdir_later, err, dirwh;
struct dentry *h_dentry;
struct super_block *sb;
struct inode *inode;
sb = dentry->d_sb;
SiMustAnyLock(sb);
h_dentry = au_h_dptr(dentry, bindex);
err = au_whtmp_ren(h_dentry, au_sbr(sb, bindex));
if (unlikely(err))
goto out;
/* stop monitoring */
inode = d_inode(dentry);
au_hn_free(au_hi(inode, bindex));
if (!au_test_fs_remote(h_dentry->d_sb)) {
dirwh = au_sbi(sb)->si_dirwh;
rmdir_later = (dirwh <= 1);
if (!rmdir_later)
rmdir_later = au_nhash_test_longer_wh(whlist, bindex,
dirwh);
if (rmdir_later)
return rmdir_later;
}
err = au_whtmp_rmdir(dir, bindex, h_dentry, whlist);
if (unlikely(err)) {
AuIOErr("rmdir %pd, b%d failed, %d. ignored\n",
h_dentry, bindex, err);
err = 0;
}
out:
AuTraceErr(err);
return err;
}
static int do_rename(struct au_ren_args *a)
{
int err;
struct dentry *d, *h_d;
/* prepare workqueue args for asynchronous rmdir */
h_d = a->dst_h_dentry;
if (au_ftest_ren(a->flags, ISDIR) && h_d->d_inode) {
err = -ENOMEM;
a->thargs = au_whtmp_rmdir_alloc(a->src_dentry->d_sb, GFP_NOFS);
if (unlikely(!a->thargs))
goto out;
a->h_dst = dget(h_d);
}
/* create whiteout for src_dentry */
if (au_ftest_ren(a->flags, WHSRC)) {
a->src_bwh = au_dbwh(a->src_dentry);
AuDebugOn(a->src_bwh >= 0);
a->src_wh_dentry
= au_wh_create(a->src_dentry, a->btgt, a->src_h_parent);
err = PTR_ERR(a->src_wh_dentry);
if (IS_ERR(a->src_wh_dentry))
goto out_thargs;
}
/* lookup whiteout for dentry */
if (au_ftest_ren(a->flags, WHDST)) {
h_d = au_wh_lkup(a->dst_h_parent, &a->dst_dentry->d_name,
a->br);
err = PTR_ERR(h_d);
if (IS_ERR(h_d))
goto out_whsrc;
if (!h_d->d_inode)
dput(h_d);
else
a->dst_wh_dentry = h_d;
}
/* rename dentry to tmpwh */
if (a->thargs) {
err = au_whtmp_ren(a->dst_h_dentry, a->br);
if (unlikely(err))
goto out_whdst;
d = a->dst_dentry;
au_set_h_dptr(d, a->btgt, NULL);
err = au_lkup_neg(d, a->btgt);
if (unlikely(err))
goto out_whtmp;
a->dst_h_dentry = au_h_dptr(d, a->btgt);
}
/* cpup src */
if (a->dst_h_dentry->d_inode && a->src_bstart != a->btgt) {
struct mutex *h_mtx = &a->src_h_dentry->d_inode->i_mutex;
struct file *h_file;
mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
AuDebugOn(au_dbstart(a->src_dentry) != a->src_bstart);
h_file = au_h_open_pre(a->src_dentry, a->src_bstart);
if (IS_ERR(h_file)) {
err = PTR_ERR(h_file);
h_file = NULL;
} else
err = au_sio_cpup_simple(a->src_dentry, a->btgt, -1,
!AuCpup_DTIME);
mutex_unlock(h_mtx);
au_h_open_post(a->src_dentry, a->src_bstart, h_file);
if (unlikely(err))
goto out_whtmp;
}
/* rename by vfs_rename or cpup */
d = a->dst_dentry;
if (au_ftest_ren(a->flags, ISDIR)
&& (a->dst_wh_dentry
|| au_dbdiropq(d) == a->btgt
/* hide the lower to keep xino */
|| a->btgt < au_dbend(d)
|| au_opt_test(au_mntflags(d->d_sb), ALWAYS_DIROPQ)))
au_fset_ren(a->flags, DIROPQ);
err = au_ren_or_cpup(a);
if (unlikely(err))
/* leave the copied-up one */
goto out_whtmp;
/* make dir opaque */
if (au_ftest_ren(a->flags, DIROPQ)) {
err = au_ren_diropq(a);
if (unlikely(err))
goto out_rename;
}
/* update target timestamps */
AuDebugOn(au_dbstart(a->src_dentry) != a->btgt);
a->h_path.dentry = au_h_dptr(a->src_dentry, a->btgt);
vfsub_update_h_iattr(&a->h_path, /*did*/NULL); /*ignore*/
a->src_inode->i_ctime = a->h_path.dentry->d_inode->i_ctime;
/* remove whiteout for dentry */
if (a->dst_wh_dentry) {
a->h_path.dentry = a->dst_wh_dentry;
err = au_wh_unlink_dentry(a->dst_h_dir, &a->h_path,
a->dst_dentry);
if (unlikely(err))
goto out_diropq;
}
/* remove whtmp */
if (a->thargs)
au_ren_del_whtmp(a); /* ignore this error */
err = 0;
goto out_success;
out_diropq:
if (au_ftest_ren(a->flags, DIROPQ))
au_ren_rev_diropq(err, a);
out_rename:
if (!au_ftest_ren(a->flags, CPUP))
au_ren_rev_rename(err, a);
else
au_ren_rev_cpup(err, a);
dput(a->h_dst);
out_whtmp:
if (a->thargs)
au_ren_rev_whtmp(err, a);
out_whdst:
dput(a->dst_wh_dentry);
a->dst_wh_dentry = NULL;
out_whsrc:
if (a->src_wh_dentry)
au_ren_rev_whsrc(err, a);
out_success:
dput(a->src_wh_dentry);
dput(a->dst_wh_dentry);
out_thargs:
if (a->thargs) {
dput(a->h_dst);
au_whtmp_rmdir_free(a->thargs);
a->thargs = NULL;
}
out:
return err;
}