static void au_ren_refresh(struct au_ren_args *a)
{
aufs_bindex_t bend, bindex;
struct dentry *d, *h_d;
struct inode *i, *h_i;
struct super_block *sb;
d = a->dst_dentry;
d_drop(d);
if (a->h_dst)
/* already dget-ed by au_ren_or_cpup() */
au_set_h_dptr(d, a->btgt, a->h_dst);
i = a->dst_inode;
if (i) {
if (!au_ftest_ren(a->flags, ISDIR))
vfsub_drop_nlink(i);
else {
vfsub_dead_dir(i);
au_cpup_attr_timesizes(i);
}
au_update_dbrange(d, /*do_put_zero*/1);
} else {
bend = a->btgt;
for (bindex = au_dbstart(d); bindex < bend; bindex++)
au_set_h_dptr(d, bindex, NULL);
bend = au_dbend(d);
for (bindex = a->btgt + 1; bindex <= bend; bindex++)
au_set_h_dptr(d, bindex, NULL);
au_update_dbrange(d, /*do_put_zero*/0);
}
d = a->src_dentry;
au_set_dbwh(d, -1);
bend = au_dbend(d);
for (bindex = a->btgt + 1; bindex <= bend; bindex++) {
h_d = au_h_dptr(d, bindex);
if (h_d)
au_set_h_dptr(d, bindex, NULL);
}
au_set_dbend(d, a->btgt);
sb = d->d_sb;
i = a->src_inode;
if (au_opt_test(au_mntflags(sb), PLINK) && au_plink_test(i))
return; /* success */
bend = au_ibend(i);
for (bindex = a->btgt + 1; bindex <= bend; bindex++) {
h_i = au_h_iptr(i, bindex);
if (h_i) {
au_xino_write(sb, bindex, h_i->i_ino, /*ino*/0);
/* ignore this error */
au_set_h_iptr(i, bindex, NULL, 0);
}
}
au_set_ibend(i, a->btgt);
}
static void au_ren_rev_whsrc(int err, struct au_ren_args *a)
{
int rerr;
a->h_path.dentry = a->src_wh_dentry;
rerr = au_wh_unlink_dentry(a->src_h_dir, &a->h_path, a->src_dentry);
au_set_dbwh(a->src_dentry, a->src_bwh);
if (rerr)
RevertFailure("unlink %.*s", AuDLNPair(a->src_wh_dentry));
}
int au_wh_unlink_dentry(struct inode *h_dir, struct path *h_path,
struct dentry *dentry)
{
int err;
err = do_unlink_wh(h_dir, h_path);
if (!err && dentry)
au_set_dbwh(dentry, -1);
return err;
}
/*
* when an error happened, remove the created whiteout and revert everything.
*/
static int do_revert(int err, struct inode *dir, aufs_bindex_t bindex,
aufs_bindex_t bwh, struct dentry *wh_dentry,
struct dentry *dentry, struct au_dtime *dt)
{
int rerr;
struct path h_path = {
.dentry = wh_dentry,
.mnt = au_sbr_mnt(dir->i_sb, bindex)
};
rerr = au_wh_unlink_dentry(au_h_iptr(dir, bindex), &h_path, dentry);
if (!rerr) {
au_set_dbwh(dentry, bwh);
au_dtime_revert(dt);
return 0;
}
AuIOErr("%.*s reverting whiteout failed(%d, %d)\n",
AuDLNPair(dentry), err, rerr);
return -EIO;
}
/* ---------------------------------------------------------------------- */
int aufs_unlink(struct inode *dir, struct dentry *dentry)
{
int err;
aufs_bindex_t bwh, bindex, bstart;
struct au_dtime dt;
struct au_pin pin;
struct path h_path;
struct inode *inode, *h_dir;
struct dentry *parent, *wh_dentry;
IMustLock(dir);
err = aufs_read_lock(dentry, AuLock_DW | AuLock_GEN);
if (unlikely(err))
goto out;
err = au_d_hashed_positive(dentry);
if (unlikely(err))
goto out_unlock;
inode = dentry->d_inode;
IMustLock(inode);
err = -EISDIR;
if (unlikely(S_ISDIR(inode->i_mode)))
goto out_unlock; /* possible? */
bstart = au_dbstart(dentry);
bwh = au_dbwh(dentry);
bindex = -1;
parent = dentry->d_parent; /* dir inode is locked */
di_write_lock_parent(parent);
wh_dentry = lock_hdir_create_wh(dentry, /*isdir*/0, &bindex, &dt, &pin);
err = PTR_ERR(wh_dentry);
if (IS_ERR(wh_dentry))
goto out_parent;
h_path.mnt = au_sbr_mnt(dentry->d_sb, bstart);
h_path.dentry = au_h_dptr(dentry, bstart);
dget(h_path.dentry);
if (bindex == bstart) {
h_dir = au_pinned_h_dir(&pin);
err = vfsub_unlink(h_dir, &h_path, /*force*/0);
} else {
/* dir inode is locked */
h_dir = wh_dentry->d_parent->d_inode;
IMustLock(h_dir);
err = 0;
}
if (!err) {
vfsub_drop_nlink(inode);
epilog(dir, dentry, bindex);
/* update target timestamps */
if (bindex == bstart) {
vfsub_update_h_iattr(&h_path, /*did*/NULL); /*ignore*/
inode->i_ctime = h_path.dentry->d_inode->i_ctime;
} else
/* todo: this timestamp may be reverted later */
inode->i_ctime = h_dir->i_ctime;
goto out_unpin; /* success */
}
/* 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_path.dentry);
out_parent:
di_write_unlock(parent);
out_unlock:
aufs_read_unlock(dentry, AuLock_DW);
out:
return err;
}
/*
* returns positive/negative dentry, NULL or an error.
* NULL means whiteout-ed or not-found.
*/
static struct dentry*
au_do_lookup(struct dentry *h_parent, struct dentry *dentry,
aufs_bindex_t bindex, struct qstr *wh_name,
struct au_do_lookup_args *args)
{
struct dentry *h_dentry;
struct inode *h_inode, *inode;
struct au_branch *br;
int wh_found, opq;
unsigned char wh_able;
const unsigned char allow_neg = !!au_ftest_lkup(args->flags, ALLOW_NEG);
wh_found = 0;
br = au_sbr(dentry->d_sb, bindex);
wh_able = !!au_br_whable(br->br_perm);
if (wh_able)
wh_found = au_wh_test(h_parent, wh_name, br, /*try_sio*/0);
h_dentry = ERR_PTR(wh_found);
if (!wh_found)
goto real_lookup;
if (unlikely(wh_found < 0))
goto out;
/* We found a whiteout */
/* au_set_dbend(dentry, bindex); */
au_set_dbwh(dentry, bindex);
if (!allow_neg)
return NULL; /* success */
real_lookup:
h_dentry = au_lkup_one(&dentry->d_name, h_parent, br, args->nd);
if (IS_ERR(h_dentry))
goto out;
h_inode = h_dentry->d_inode;
if (!h_inode) {
if (!allow_neg)
goto out_neg;
} else if (wh_found
|| (args->type && args->type != (h_inode->i_mode & S_IFMT)))
goto out_neg;
if (au_dbend(dentry) <= bindex)
au_set_dbend(dentry, bindex);
if (au_dbstart(dentry) < 0 || bindex < au_dbstart(dentry))
au_set_dbstart(dentry, bindex);
au_set_h_dptr(dentry, bindex, h_dentry);
inode = dentry->d_inode;
if (!h_inode || !S_ISDIR(h_inode->i_mode) || !wh_able
|| (inode && !S_ISDIR(inode->i_mode)))
goto out; /* success */
mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
opq = au_diropq_test(h_dentry, br);
mutex_unlock(&h_inode->i_mutex);
if (opq > 0)
au_set_dbdiropq(dentry, bindex);
else if (unlikely(opq < 0)) {
au_set_h_dptr(dentry, bindex, NULL);
h_dentry = ERR_PTR(opq);
}
goto out;
out_neg:
dput(h_dentry);
h_dentry = NULL;
out:
return h_dentry;
}
/*
* when an error happened, remove the created whiteout and revert everything.
*/
static int do_revert(int err, struct inode *dir, aufs_bindex_t bindex,
aufs_bindex_t bwh, struct dentry *wh_dentry,
struct dentry *dentry, struct au_dtime *dt)
{
int rerr;
struct path h_path = {
.dentry = wh_dentry,
.mnt = au_sbr_mnt(dir->i_sb, bindex)
};
rerr = au_wh_unlink_dentry(au_h_iptr(dir, bindex), &h_path, dentry);
if (!rerr) {
au_set_dbwh(dentry, bwh);
au_dtime_revert(dt);
return 0;
}
AuIOErr("%pd reverting whiteout failed(%d, %d)\n", dentry, err, rerr);
return -EIO;
}
/* ---------------------------------------------------------------------- */
int aufs_unlink(struct inode *dir, struct dentry *dentry)
{
int err;
aufs_bindex_t bwh, bindex, bstart;
struct inode *inode, *h_dir, *delegated;
struct dentry *parent, *wh_dentry;
/* to reuduce stack size */
struct {
struct au_dtime dt;
struct au_pin pin;
struct path h_path;
} *a;
IMustLock(dir);
err = -ENOMEM;
a = kmalloc(sizeof(*a), GFP_NOFS);
if (unlikely(!a))
goto out;
err = aufs_read_lock(dentry, AuLock_DW | AuLock_GEN);
if (unlikely(err))
goto out_free;
err = au_d_hashed_positive(dentry);
if (unlikely(err))
goto out_unlock;
inode = d_inode(dentry);
IMustLock(inode);
err = -EISDIR;
if (unlikely(d_is_dir(dentry)))
goto out_unlock; /* possible? */
bstart = au_dbstart(dentry);
bwh = au_dbwh(dentry);
bindex = -1;
parent = dentry->d_parent; /* dir inode is locked */
di_write_lock_parent(parent);
wh_dentry = lock_hdir_create_wh(dentry, /*isdir*/0, &bindex, &a->dt,
&a->pin);
err = PTR_ERR(wh_dentry);
if (IS_ERR(wh_dentry))
goto out_parent;
a->h_path.mnt = au_sbr_mnt(dentry->d_sb, bstart);
a->h_path.dentry = au_h_dptr(dentry, bstart);
dget(a->h_path.dentry);
if (bindex == bstart) {
h_dir = au_pinned_h_dir(&a->pin);
delegated = NULL;
err = vfsub_unlink(h_dir, &a->h_path, &delegated, /*force*/0);
if (unlikely(err == -EWOULDBLOCK)) {
pr_warn("cannot retry for NFSv4 delegation"
" for an internal unlink\n");
iput(delegated);
}
} else {
/* dir inode is locked */
h_dir = d_inode(wh_dentry->d_parent);
IMustLock(h_dir);
err = 0;
}
if (!err) {
vfsub_drop_nlink(inode);
epilog(dir, dentry, bindex);
/* update target timestamps */
if (bindex == bstart) {
vfsub_update_h_iattr(&a->h_path, /*did*/NULL);
/*ignore*/
inode->i_ctime = d_inode(a->h_path.dentry)->i_ctime;
} else
/* todo: this timestamp may be reverted later */
inode->i_ctime = h_dir->i_ctime;
goto out_unpin; /* success */
}
/* revert */
if (wh_dentry) {
int rerr;
rerr = do_revert(err, dir, bindex, bwh, wh_dentry, dentry,
&a->dt);
if (rerr)
err = rerr;
}
out_unpin:
au_unpin(&a->pin);
dput(wh_dentry);
dput(a->h_path.dentry);
out_parent:
di_write_unlock(parent);
out_unlock:
aufs_read_unlock(dentry, AuLock_DW);
out_free:
kfree(a);
out:
return err;
}