/* Is a directory logically empty? */
int check_empty(struct dentry *dentry, struct dentry *parent,
struct unionfs_dir_state **namelist)
{
int err = 0;
struct dentry *lower_dentry = NULL;
struct vfsmount *mnt;
struct super_block *sb;
struct file *lower_file;
struct unionfs_rdutil_callback *buf = NULL;
int bindex, bstart, bend, bopaque;
sb = dentry->d_sb;
BUG_ON(!S_ISDIR(dentry->d_inode->i_mode));
err = unionfs_partial_lookup(dentry, parent);
if (err)
goto out;
bstart = dbstart(dentry);
bend = dbend(dentry);
bopaque = dbopaque(dentry);
if (0 <= bopaque && bopaque < bend)
bend = bopaque;
buf = kmalloc(sizeof(struct unionfs_rdutil_callback), GFP_KERNEL);
if (unlikely(!buf)) {
err = -ENOMEM;
goto out;
}
buf->err = 0;
buf->mode = RD_CHECK_EMPTY;
buf->rdstate = alloc_rdstate(dentry->d_inode, bstart);
if (unlikely(!buf->rdstate)) {
err = -ENOMEM;
goto out;
}
/* Process the lower directories with rdutil_callback as a filldir. */
for (bindex = bstart; bindex <= bend; bindex++) {
lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
if (!lower_dentry)
continue;
if (!lower_dentry->d_inode)
continue;
if (!S_ISDIR(lower_dentry->d_inode->i_mode))
continue;
dget(lower_dentry);
mnt = unionfs_mntget(dentry, bindex);
branchget(sb, bindex);
lower_file = dentry_open(lower_dentry, mnt, O_RDONLY);
if (IS_ERR(lower_file)) {
err = PTR_ERR(lower_file);
branchput(sb, bindex);
goto out;
}
do {
buf->filldir_called = 0;
buf->rdstate->bindex = bindex;
err = vfs_readdir(lower_file,
readdir_util_callback, buf);
if (buf->err)
err = buf->err;
} while ((err >= 0) && buf->filldir_called);
/* fput calls dput for lower_dentry */
fput(lower_file);
branchput(sb, bindex);
if (err < 0)
goto out;
}
out:
if (buf) {
if (namelist && !err)
*namelist = buf->rdstate;
else if (buf->rdstate)
free_rdstate(buf->rdstate);
kfree(buf);
}
return err;
}
/* Is a directory logically empty? */
int check_empty(struct dentry *dentry, struct dentry *parent,
struct unionfs_dir_state **namelist)
{
int err = 0;
struct dentry *lower_dentry = NULL;
struct vfsmount *mnt;
struct super_block *sb;
struct file *lower_file;
struct unionfs_rdutil_callback buf = {
.ctx.actor = readdir_util_callback,
};
int bindex, bstart, bend, bopaque;
struct path path;
sb = dentry->d_sb;
BUG_ON(!S_ISDIR(dentry->d_inode->i_mode));
err = unionfs_partial_lookup(dentry, parent);
if (err)
goto out;
bstart = dbstart(dentry);
bend = dbend(dentry);
bopaque = dbopaque(dentry);
if (0 <= bopaque && bopaque < bend)
bend = bopaque;
buf.err = 0;
buf.filldir_called = 0;
buf.mode = RD_CHECK_EMPTY;
buf.ctx.pos = 0; /* XXX: needed?! */
buf.rdstate = alloc_rdstate(dentry->d_inode, bstart);
if (unlikely(!buf.rdstate)) {
err = -ENOMEM;
goto out;
}
/* Process the lower directories with rdutil_callback as a filldir. */
for (bindex = bstart; bindex <= bend; bindex++) {
lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
if (!lower_dentry)
continue;
if (!lower_dentry->d_inode)
continue;
if (!S_ISDIR(lower_dentry->d_inode->i_mode))
continue;
dget(lower_dentry);
mnt = unionfs_mntget(dentry, bindex);
branchget(sb, bindex);
path.dentry = lower_dentry;
path.mnt = mnt;
lower_file = dentry_open(&path, O_RDONLY, current_cred());
path_put(&path);
if (IS_ERR(lower_file)) {
err = PTR_ERR(lower_file);
branchput(sb, bindex);
goto out;
}
do {
buf.filldir_called = 0;
buf.rdstate->bindex = bindex;
err = iterate_dir(lower_file, &buf.ctx);
if (buf.err)
err = buf.err;
} while ((err >= 0) && buf.filldir_called);
/* fput calls dput for lower_dentry */
fput(lower_file);
branchput(sb, bindex);
if (err < 0)
goto out;
}
out:
if (namelist && !err)
*namelist = buf.rdstate;
else if (buf.rdstate)
free_rdstate(buf.rdstate);
return err;
}