/*
* simple tests for the del-entry operations.
* following the checks in vfs, plus the parent-child relationship.
*/
int au_may_del(struct dentry *dentry, aufs_bindex_t bindex,
struct dentry *h_parent, int isdir)
{
int err;
umode_t h_mode;
struct dentry *h_dentry, *h_latest;
struct inode *h_inode;
h_dentry = au_h_dptr(dentry, bindex);
if (d_really_is_positive(dentry)) {
err = -ENOENT;
if (unlikely(d_is_negative(h_dentry)))
goto out;
h_inode = d_inode(h_dentry);
if (unlikely(!h_inode->i_nlink))
goto out;
h_mode = h_inode->i_mode;
if (!isdir) {
err = -EISDIR;
if (unlikely(S_ISDIR(h_mode)))
goto out;
} else if (unlikely(!S_ISDIR(h_mode))) {
err = -ENOTDIR;
goto out;
}
} else {
/* rename(2) case */
err = -EIO;
if (unlikely(d_is_positive(h_dentry)))
goto out;
}
err = -ENOENT;
/* expected parent dir is locked */
if (unlikely(h_parent != h_dentry->d_parent))
goto out;
err = 0;
/*
* rmdir a dir may break the consistency on some filesystem.
* let's try heavy test.
*/
err = -EACCES;
if (unlikely(!au_opt_test(au_mntflags(dentry->d_sb), DIRPERM1)
&& au_test_h_perm(d_inode(h_parent),
MAY_EXEC | MAY_WRITE)))
goto out;
h_latest = au_sio_lkup_one(&dentry->d_name, h_parent);
err = -EIO;
if (IS_ERR(h_latest))
goto out;
if (h_latest == h_dentry)
err = 0;
dput(h_latest);
out:
return err;
}
int au_test_h_perm_sio(struct inode *h_inode, int mask)
{
if (au_test_nfs(h_inode->i_sb)
&& (mask & MAY_WRITE)
&& S_ISDIR(h_inode->i_mode))
mask |= MAY_READ; /* force permission check */
return au_test_h_perm(h_inode, mask);
}
/*
* simple tests for the adding inode operations.
* following the checks in vfs, plus the parent-child relationship.
*/
int au_may_add(struct dentry *dentry, aufs_bindex_t bindex,
struct dentry *h_parent, int isdir, struct au_ndx *ndx)
{
int err, exist;
struct dentry *h_dentry;
struct inode *h_inode;
umode_t h_mode;
LKTRTrace("%.*s/%.*s, b%d, dir %d\n",
AuDLNPair(h_parent), AuDLNPair(dentry), bindex, isdir);
exist = !!dentry->d_inode;
h_dentry = au_h_dptr(dentry, bindex);
h_inode = h_dentry->d_inode;
if (!exist) {
err = -EEXIST;
if (unlikely(h_inode))
goto out;
} else {
/* rename(2) case */
err = -EIO;
if (unlikely(!h_inode || !h_inode->i_nlink))
goto out;
h_mode = h_inode->i_mode;
if (!isdir) {
err = -EISDIR;
if (unlikely(S_ISDIR(h_mode)))
goto out;
} else if (unlikely(!S_ISDIR(h_mode))) {
err = -ENOTDIR;
goto out;
}
}
err = -EIO;
/* expected parent dir is locked */
if (unlikely(h_parent != h_dentry->d_parent))
goto out;
err = 0;
if (au_opt_test(au_mntflags(dentry->d_sb), UDBA_INOTIFY)) {
struct dentry *h_latest;
struct qstr *qstr = &dentry->d_name;
err = -EACCES;
if (unlikely(au_test_h_perm
(h_parent->d_inode, MAY_EXEC | MAY_WRITE,
au_ftest_ndx(ndx->flags, DLGT))))
goto out;
h_latest = au_sio_lkup_one(qstr->name, h_parent, qstr->len,
ndx);
err = PTR_ERR(h_latest);
if (IS_ERR(h_latest))
goto out;
err = -EIO;
dput(h_latest);
/* fuse d_revalidate always return 0 for negative dentries */
if (h_latest == h_dentry || au_test_fuse(h_dentry->d_sb))
err = 0;
}
out:
AuTraceErr(err);
return err;
}
