int unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
int err = 0;
struct dentry *wh_dentry;
print_entry_location();
double_lock_dentry(old_dentry, new_dentry);
fist_checkinode(old_dir, "unionfs_rename-old_dir");
fist_checkinode(new_dir, "unionfs_rename-new_dir");
fist_print_dentry("IN: unionfs_rename, old_dentry", old_dentry);
fist_print_dentry("IN: unionfs_rename, new_dentry", new_dentry);
if (!S_ISDIR(old_dentry->d_inode->i_mode))
err = unionfs_partial_lookup(old_dentry);
else
err = may_rename_dir(old_dentry);
if (err)
goto out;
err = unionfs_partial_lookup(new_dentry);
if (err)
goto out;
/*
* if new_dentry is already hidden because of whiteout,
* simply override it even if the whiteouted dir is not empty.
*/
wh_dentry = lookup_whiteout(new_dentry);
if (!IS_ERR(wh_dentry))
DPUT(wh_dentry);
else if (new_dentry->d_inode) {
if (S_ISDIR(old_dentry->d_inode->i_mode) !=
S_ISDIR(new_dentry->d_inode->i_mode)) {
err =
S_ISDIR(old_dentry->d_inode->
i_mode) ? -ENOTDIR : -EISDIR;
goto out;
}
if (S_ISDIR(old_dentry->d_inode->i_mode)) {
/* check if this unionfs directory is empty or not */
err = check_empty(new_dentry, NULL);
if (err)
goto out;
/* Handle the case where we are overwriting directories
* that are not really empty because of whiteout or
* non-whiteout entries.
*/
}
}
#ifdef UNIONFS_DELETE_ALL
if (IS_SET(old_dir->i_sb, DELETE_ALL))
err = unionfs_rename_all(old_dir, old_dentry, new_dir,
new_dentry);
else
#endif
err = unionfs_rename_whiteout(old_dir, old_dentry, new_dir,
new_dentry);
out:
fist_checkinode(new_dir, "post unionfs_rename-new_dir");
fist_print_dentry("OUT: unionfs_rename, old_dentry", old_dentry);
if (err) {
/* clear the new_dentry stuff created */
d_drop(new_dentry);
} else {
/* force re-lookup since the dir on ro branch is not renamed,
and hidden dentries still indicate the un-renamed ones. */
if (S_ISDIR(old_dentry->d_inode->i_mode))
atomic_dec(&dtopd(old_dentry)->udi_generation);
fist_print_dentry("OUT: unionfs_rename, new_dentry",
new_dentry);
}
unlock_dentry(new_dentry);
unlock_dentry(old_dentry);
print_exit_status(err);
return err;
}
/*
* Main (and complex) driver function for Unionfs's lookup
*
* Returns: NULL (ok), ERR_PTR if an error occurred, or a non-null non-error
* PTR if d_splice returned a different dentry.
*
* If lookupmode is INTERPOSE_PARTIAL/REVAL/REVAL_NEG, the passed dentry's
* inode info must be locked. If lookupmode is INTERPOSE_LOOKUP (i.e., a
* newly looked-up dentry), then unionfs_lookup_backend will return a locked
* dentry's info, which the caller must unlock.
*/
struct dentry *unionfs_lookup_full(struct dentry *dentry,
struct dentry *parent, int lookupmode)
{
int err = 0;
struct dentry *lower_dentry = NULL;
struct vfsmount *lower_mnt;
struct vfsmount *lower_dir_mnt;
struct dentry *wh_lower_dentry = NULL;
struct dentry *lower_dir_dentry = NULL;
struct dentry *d_interposed = NULL;
int bindex, bstart, bend, bopaque;
int opaque, num_positive = 0;
const char *name;
int namelen;
int pos_start, pos_end;
/*
* We should already have a lock on this dentry in the case of a
* partial lookup, or a revalidation. Otherwise it is returned from
* new_dentry_private_data already locked.
*/
verify_locked(dentry);
verify_locked(parent);
/* must initialize dentry operations */
dentry->d_op = &unionfs_dops;
/* We never partial lookup the root directory. */
if (IS_ROOT(dentry))
goto out;
name = dentry->d_name.name;
namelen = dentry->d_name.len;
/* No dentries should get created for possible whiteout names. */
if (!is_validname(name)) {
err = -EPERM;
goto out_free;
}
/* Now start the actual lookup procedure. */
bstart = dbstart(parent);
bend = dbend(parent);
bopaque = dbopaque(parent);
BUG_ON(bstart < 0);
/* adjust bend to bopaque if needed */
if ((bopaque >= 0) && (bopaque < bend))
bend = bopaque;
/* lookup all possible dentries */
for (bindex = bstart; bindex <= bend; bindex++) {
lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
lower_mnt = unionfs_lower_mnt_idx(dentry, bindex);
/* skip if we already have a positive lower dentry */
if (lower_dentry) {
if (dbstart(dentry) < 0)
dbstart(dentry) = bindex;
if (bindex > dbend(dentry))
dbend(dentry) = bindex;
if (lower_dentry->d_inode)
num_positive++;
continue;
}
lower_dir_dentry =
unionfs_lower_dentry_idx(parent, bindex);
/* if the lower dentry's parent does not exist, skip this */
if (!lower_dir_dentry || !lower_dir_dentry->d_inode)
continue;
/* also skip it if the parent isn't a directory. */
if (!S_ISDIR(lower_dir_dentry->d_inode->i_mode))
continue; /* XXX: should be BUG_ON */
/* check for whiteouts: stop lookup if found */
wh_lower_dentry = lookup_whiteout(name, lower_dir_dentry);
if (IS_ERR(wh_lower_dentry)) {
err = PTR_ERR(wh_lower_dentry);
goto out_free;
}
if (wh_lower_dentry->d_inode) {
dbend(dentry) = dbopaque(dentry) = bindex;
if (dbstart(dentry) < 0)
dbstart(dentry) = bindex;
dput(wh_lower_dentry);
break;
}
dput(wh_lower_dentry);
/* Now do regular lookup; lookup @name */
lower_dir_mnt = unionfs_lower_mnt_idx(parent, bindex);
lower_mnt = NULL; /* XXX: needed? */
lower_dentry = __lookup_one(lower_dir_dentry, lower_dir_mnt,
name, &lower_mnt);
if (IS_ERR(lower_dentry)) {
err = PTR_ERR(lower_dentry);
goto out_free;
}
unionfs_set_lower_dentry_idx(dentry, bindex, lower_dentry);
if (!lower_mnt)
lower_mnt = unionfs_mntget(dentry->d_sb->s_root,
bindex);
unionfs_set_lower_mnt_idx(dentry, bindex, lower_mnt);
/* adjust dbstart/end */
if (dbstart(dentry) < 0)
dbstart(dentry) = bindex;
if (bindex > dbend(dentry))
dbend(dentry) = bindex;
/*
* We always store the lower dentries above, and update
* dbstart/dbend, even if the whole unionfs dentry is
* negative (i.e., no lower inodes).
*/
if (!lower_dentry->d_inode)
continue;
num_positive++;
/*
* check if we just found an opaque directory, if so, stop
* lookups here.
*/
if (!S_ISDIR(lower_dentry->d_inode->i_mode))
continue;
opaque = is_opaque_dir(dentry, bindex);
if (opaque < 0) {
err = opaque;
goto out_free;
} else if (opaque) {
dbend(dentry) = dbopaque(dentry) = bindex;
break;
}
dbend(dentry) = bindex;
/* update parent directory's atime with the bindex */
fsstack_copy_attr_atime(parent->d_inode,
lower_dir_dentry->d_inode);
}
/* sanity checks, then decide if to process a negative dentry */
BUG_ON(dbstart(dentry) < 0 && dbend(dentry) >= 0);
BUG_ON(dbstart(dentry) >= 0 && dbend(dentry) < 0);
if (num_positive > 0)
goto out_positive;
/*** handle NEGATIVE dentries ***/
/*
* If negative, keep only first lower negative dentry, to save on
* memory.
*/
if (dbstart(dentry) < dbend(dentry)) {
path_put_lowers(dentry, dbstart(dentry) + 1,
dbend(dentry), false);
dbend(dentry) = dbstart(dentry);
}
if (lookupmode == INTERPOSE_PARTIAL)
goto out;
if (lookupmode == INTERPOSE_LOOKUP) {
/*
* If all we found was a whiteout in the first available
* branch, then create a negative dentry for a possibly new
* file to be created.
*/
if (dbopaque(dentry) < 0)
goto out;
/* XXX: need to get mnt here */
bindex = dbstart(dentry);
if (unionfs_lower_dentry_idx(dentry, bindex))
goto out;
lower_dir_dentry =
unionfs_lower_dentry_idx(parent, bindex);
if (!lower_dir_dentry || !lower_dir_dentry->d_inode)
goto out;
if (!S_ISDIR(lower_dir_dentry->d_inode->i_mode))
goto out; /* XXX: should be BUG_ON */
/* XXX: do we need to cross bind mounts here? */
lower_dentry = lookup_one_len(name, lower_dir_dentry, namelen);
if (IS_ERR(lower_dentry)) {
err = PTR_ERR(lower_dentry);
goto out;
}
/* XXX: need to mntget/mntput as needed too! */
unionfs_set_lower_dentry_idx(dentry, bindex, lower_dentry);
/* XXX: wrong mnt for crossing bind mounts! */
lower_mnt = unionfs_mntget(dentry->d_sb->s_root, bindex);
unionfs_set_lower_mnt_idx(dentry, bindex, lower_mnt);
goto out;
}
/* if we're revalidating a positive dentry, don't make it negative */
if (lookupmode != INTERPOSE_REVAL)
d_add(dentry, NULL);
goto out;
out_positive:
/*** handle POSITIVE dentries ***/
/*
* This unionfs dentry is positive (at least one lower inode
* exists), so scan entire dentry from beginning to end, and remove
* any negative lower dentries, if any. Then, update dbstart/dbend
* to reflect the start/end of positive dentries.
*/
pos_start = pos_end = -1;
for (bindex = bstart; bindex <= bend; bindex++) {
lower_dentry = unionfs_lower_dentry_idx(dentry,
bindex);
if (lower_dentry && lower_dentry->d_inode) {
if (pos_start < 0)
pos_start = bindex;
if (bindex > pos_end)
pos_end = bindex;
continue;
}
path_put_lowers(dentry, bindex, bindex, false);
}
if (pos_start >= 0)
dbstart(dentry) = pos_start;
if (pos_end >= 0)
dbend(dentry) = pos_end;
/* Partial lookups need to re-interpose, or throw away older negs. */
if (lookupmode == INTERPOSE_PARTIAL) {
if (dentry->d_inode) {
unionfs_reinterpose(dentry);
goto out;
}
/*
* This dentry was positive, so it is as if we had a
* negative revalidation.
*/
lookupmode = INTERPOSE_REVAL_NEG;
update_bstart(dentry);
}
/*
* Interpose can return a dentry if d_splice returned a different
* dentry.
*/
d_interposed = unionfs_interpose(dentry, dentry->d_sb, lookupmode);
if (IS_ERR(d_interposed))
err = PTR_ERR(d_interposed);
else if (d_interposed)
dentry = d_interposed;
if (!err)
goto out;
d_drop(dentry);
out_free:
/* should dput/mntput all the underlying dentries on error condition */
if (dbstart(dentry) >= 0)
path_put_lowers_all(dentry, false);
/* free lower_paths unconditionally */
kfree(UNIONFS_D(dentry)->lower_paths);
UNIONFS_D(dentry)->lower_paths = NULL;
out:
if (dentry && UNIONFS_D(dentry)) {
BUG_ON(dbstart(dentry) < 0 && dbend(dentry) >= 0);
BUG_ON(dbstart(dentry) >= 0 && dbend(dentry) < 0);
}
if (d_interposed && UNIONFS_D(d_interposed)) {
BUG_ON(dbstart(d_interposed) < 0 && dbend(d_interposed) >= 0);
BUG_ON(dbstart(d_interposed) >= 0 && dbend(d_interposed) < 0);
}
if (!err && d_interposed)
return d_interposed;
return ERR_PTR(err);
}
int unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
int err = 0;
struct dentry *wh_dentry;
double_lock_dentry(old_dentry, new_dentry);
if (!S_ISDIR(old_dentry->d_inode->i_mode))
err = unionfs_partial_lookup(old_dentry);
else
err = may_rename_dir(old_dentry);
if (err)
goto out;
err = unionfs_partial_lookup(new_dentry);
if (err)
goto out;
/*
* if new_dentry is already hidden because of whiteout,
* simply override it even if the whiteouted dir is not empty.
*/
wh_dentry = lookup_whiteout(new_dentry);
if (!IS_ERR(wh_dentry))
dput(wh_dentry);
else if (new_dentry->d_inode) {
if (S_ISDIR(old_dentry->d_inode->i_mode) !=
S_ISDIR(new_dentry->d_inode->i_mode)) {
err = S_ISDIR(old_dentry->d_inode->i_mode) ?
-ENOTDIR : -EISDIR;
goto out;
}
if (S_ISDIR(new_dentry->d_inode->i_mode)) {
struct unionfs_dir_state *namelist;
/* check if this unionfs directory is empty or not */
err = check_empty(new_dentry, &namelist);
if (err)
goto out;
if (!is_robranch(new_dentry))
err = delete_whiteouts(new_dentry,
dbstart(new_dentry),
namelist);
free_rdstate(namelist);
if (err)
goto out;
}
}
err = do_unionfs_rename(old_dir, old_dentry, new_dir, new_dentry);
out:
if (err)
/* clear the new_dentry stuff created */
d_drop(new_dentry);
else
/* force re-lookup since the dir on ro branch is not renamed,
and hidden dentries still indicate the un-renamed ones. */
if (S_ISDIR(old_dentry->d_inode->i_mode))
atomic_dec(&UNIONFS_D(old_dentry)->generation);
unionfs_unlock_dentry(new_dentry);
unionfs_unlock_dentry(old_dentry);
return err;
}
