int unionfs_rmdir(struct inode *dir, struct dentry *dentry)
{
int err = 0;
struct unionfs_dir_state *namelist = NULL;
print_entry_location();
lock_dentry(dentry);
fist_print_dentry("IN unionfs_rmdir: ", dentry);
/* check if this unionfs directory is empty or not */
err = check_empty(dentry, &namelist);
if (err) {
goto out;
}
if (IS_SET(dir->i_sb, DELETE_WHITEOUT)) {
/* Delete the first directory. */
err = unionfs_rmdir_first(dir, dentry, namelist);
/* create whiteout */
if (!err) {
err = create_whiteout(dentry, dbstart(dentry));
} else {
int new_err;
if (dbstart(dentry) == 0)
goto out;
/* exit if the error returned was NOT -EROFS */
if (!IS_COPYUP_ERR(err))
goto out;
new_err = create_whiteout(dentry, dbstart(dentry) - 1);
if (new_err != -EEXIST)
err = new_err;
}
} else {
/* delete all. */
err = unionfs_rmdir_all(dir, dentry, namelist);
}
out:
/* call d_drop so the system "forgets" about us */
if (!err)
d_drop(dentry);
if (namelist)
free_rdstate(namelist);
unlock_dentry(dentry);
print_exit_status(err);
return err;
}
int unionfs_rmdir(struct inode *dir, struct dentry *dentry)
{
int err = 0;
struct unionfs_dir_state *namelist = NULL;
unionfs_lock_dentry(dentry);
/* check if this unionfs directory is empty or not */
err = check_empty(dentry, &namelist);
if (err)
goto out;
err = unionfs_rmdir_first(dir, dentry, namelist);
/* create whiteout */
if (!err)
err = create_whiteout(dentry, dbstart(dentry));
else {
int new_err;
if (dbstart(dentry) == 0)
goto out;
/* exit if the error returned was NOT -EROFS */
if (!IS_COPYUP_ERR(err))
goto out;
new_err = create_whiteout(dentry, dbstart(dentry) - 1);
if (new_err != -EEXIST)
err = new_err;
}
out:
/* call d_drop so the system "forgets" about us */
if (!err)
d_drop(dentry);
if (namelist)
free_rdstate(namelist);
unionfs_unlock_dentry(dentry);
return err;
}
static int unionfs_readdir(struct file *file, void *dirent, filldir_t filldir)
{
int err = 0;
struct file *lower_file = NULL;
struct dentry *dentry = file->f_path.dentry;
struct dentry *parent;
struct inode *inode = NULL;
struct unionfs_getdents_callback buf;
struct unionfs_dir_state *uds;
int bend;
loff_t offset;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_PARENT);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
err = unionfs_file_revalidate(file, parent, false);
if (unlikely(err))
goto out;
inode = dentry->d_inode;
uds = UNIONFS_F(file)->rdstate;
if (!uds) {
if (file->f_pos == DIREOF) {
goto out;
} else if (file->f_pos > 0) {
uds = find_rdstate(inode, file->f_pos);
if (unlikely(!uds)) {
err = -ESTALE;
goto out;
}
UNIONFS_F(file)->rdstate = uds;
} else {
init_rdstate(file);
uds = UNIONFS_F(file)->rdstate;
}
}
bend = fbend(file);
while (uds->bindex <= bend) {
lower_file = unionfs_lower_file_idx(file, uds->bindex);
if (!lower_file) {
uds->bindex++;
uds->dirpos = 0;
continue;
}
/* prepare callback buffer */
buf.filldir_called = 0;
buf.filldir_error = 0;
buf.entries_written = 0;
buf.dirent = dirent;
buf.filldir = filldir;
buf.rdstate = uds;
buf.sb = inode->i_sb;
/* Read starting from where we last left off. */
offset = vfs_llseek(lower_file, uds->dirpos, SEEK_SET);
if (offset < 0) {
err = offset;
goto out;
}
err = vfs_readdir(lower_file, unionfs_filldir, &buf);
/* Save the position for when we continue. */
offset = vfs_llseek(lower_file, 0, SEEK_CUR);
if (offset < 0) {
err = offset;
goto out;
}
uds->dirpos = offset;
/* Copy the atime. */
fsstack_copy_attr_atime(inode,
lower_file->f_path.dentry->d_inode);
if (err < 0)
goto out;
if (buf.filldir_error)
break;
if (!buf.entries_written) {
uds->bindex++;
uds->dirpos = 0;
}
}
if (!buf.filldir_error && uds->bindex >= bend) {
/* Save the number of hash entries for next time. */
UNIONFS_I(inode)->hashsize = uds->hashentries;
free_rdstate(uds);
UNIONFS_F(file)->rdstate = NULL;
file->f_pos = DIREOF;
} else {
file->f_pos = rdstate2offset(uds);
}
out:
if (!err)
unionfs_check_file(file);
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
return err;
}
/*
* This is not meant to be a generic repositioning function. If you do
* things that aren't supported, then we return EINVAL.
*
* What is allowed:
* (1) seeking to the same position that you are currently at
* This really has no effect, but returns where you are.
* (2) seeking to the beginning of the file
* This throws out all state, and lets you begin again.
*/
static loff_t unionfs_dir_llseek(struct file *file, loff_t offset, int origin)
{
struct unionfs_dir_state *rdstate;
struct dentry *dentry = file->f_path.dentry;
struct dentry *parent;
loff_t err;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_PARENT);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
err = unionfs_file_revalidate(file, parent, false);
if (unlikely(err))
goto out;
rdstate = UNIONFS_F(file)->rdstate;
/*
* we let users seek to their current position, but not anywhere
* else.
*/
if (!offset) {
switch (origin) {
case SEEK_SET:
if (rdstate) {
free_rdstate(rdstate);
UNIONFS_F(file)->rdstate = NULL;
}
init_rdstate(file);
err = 0;
break;
case SEEK_CUR:
err = file->f_pos;
break;
case SEEK_END:
/* Unsupported, because we would break everything. */
err = -EINVAL;
break;
}
} else {
switch (origin) {
case SEEK_SET:
if (rdstate) {
if (offset == rdstate2offset(rdstate))
err = offset;
else if (file->f_pos == DIREOF)
err = DIREOF;
else
err = -EINVAL;
} else {
struct inode *inode;
inode = dentry->d_inode;
rdstate = find_rdstate(inode, offset);
if (rdstate) {
UNIONFS_F(file)->rdstate = rdstate;
err = rdstate->offset;
} else {
err = -EINVAL;
}
}
break;
case SEEK_CUR:
case SEEK_END:
/* Unsupported, because we would break everything. */
err = -EINVAL;
break;
}
}
out:
if (!err)
unionfs_check_file(file);
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
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 = 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;
}
int unionfs_rmdir(struct inode *dir, struct dentry *dentry)
{
int err = 0;
struct unionfs_dir_state *namelist = NULL;
print_entry_location();
lock_dentry(dentry);
fist_print_dentry("IN unionfs_rmdir: ", dentry);
/* check if this unionfs directory is empty or not */
err = check_empty(dentry, &namelist);
if (err) {
#if 0
/* vfs_rmdir(our caller) unhashed the dentry. This will recover
* the Unionfs inode number for the directory itself, but the
* children are already lost. It seems that tmpfs manages its
* way around this by upping the refcount on everything.
*
* Even if we do this, we still lose the inode numbers of the
* children. The best way to fix this is to fix the VFS (or
* use persistent inode maps). */
if (d_unhashed(dentry))
d_rehash(dentry);
#endif
goto out;
}
#ifdef UNIONFS_DELETE_ALL
if (IS_SET(dir->i_sb, DELETE_ALL)) {
/* delete all. */
err = unionfs_rmdir_all(dir, dentry, namelist);
} else { /* Delete the first directory. */
#endif
err = unionfs_rmdir_first(dir, dentry, namelist);
/* create whiteout */
if (!err) {
err = create_whiteout(dentry, dbstart(dentry));
} else {
int new_err;
if (dbstart(dentry) == 0)
goto out;
/* exit if the error returned was NOT -EROFS */
if (!IS_COPYUP_ERR(err))
goto out;
new_err = create_whiteout(dentry, dbstart(dentry) - 1);
if (new_err != -EEXIST)
err = new_err;
}
#ifdef UNIONFS_DELETE_ALL
}
#endif
out:
/* call d_drop so the system "forgets" about us */
if (!err)
d_drop(dentry);
if (namelist)
free_rdstate(namelist);
unlock_dentry(dentry);
print_exit_status(err);
return 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;
}
/* 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;
}
/*
* The locking rules in unionfs_rename are complex. We could use a simpler
* superblock-level name-space lock for renames and copy-ups.
*/
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;
struct dentry *old_parent, *new_parent;
int valid = true;
unionfs_read_lock(old_dentry->d_sb, UNIONFS_SMUTEX_CHILD);
old_parent = dget_parent(old_dentry);
new_parent = dget_parent(new_dentry);
/* un/lock parent dentries only if they differ from old/new_dentry */
if (old_parent != old_dentry &&
old_parent != new_dentry)
unionfs_lock_dentry(old_parent, UNIONFS_DMUTEX_REVAL_PARENT);
if (new_parent != old_dentry &&
new_parent != new_dentry &&
new_parent != old_parent)
unionfs_lock_dentry(new_parent, UNIONFS_DMUTEX_REVAL_CHILD);
unionfs_double_lock_dentry(old_dentry, new_dentry);
valid = __unionfs_d_revalidate(old_dentry, old_parent, false);
if (!valid) {
err = -ESTALE;
goto out;
}
if (!d_deleted(new_dentry) && new_dentry->d_inode) {
valid = __unionfs_d_revalidate(new_dentry, new_parent, false);
if (!valid) {
err = -ESTALE;
goto out;
}
}
if (!S_ISDIR(old_dentry->d_inode->i_mode))
err = unionfs_partial_lookup(old_dentry, old_parent);
else
err = may_rename_dir(old_dentry, old_parent);
if (err)
goto out;
err = unionfs_partial_lookup(new_dentry, new_parent);
if (err)
goto out;
/*
* if new_dentry is already lower because of whiteout,
* simply override it even if the whited-out dir is not empty.
*/
wh_dentry = find_first_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 = NULL;
/* check if this unionfs directory is empty or not */
err = check_empty(new_dentry, new_parent, &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, old_parent,
new_dir, new_dentry, new_parent);
if (err)
goto out;
/*
* force re-lookup since the dir on ro branch is not renamed, and
* lower dentries still indicate the un-renamed ones.
*/
if (S_ISDIR(old_dentry->d_inode->i_mode))
atomic_dec(&UNIONFS_D(old_dentry)->generation);
else
unionfs_postcopyup_release(old_dentry);
if (new_dentry->d_inode && !S_ISDIR(new_dentry->d_inode->i_mode)) {
unionfs_postcopyup_release(new_dentry);
unionfs_postcopyup_setmnt(new_dentry);
if (!unionfs_lower_inode(new_dentry->d_inode)) {
/*
* If we get here, it means that no copyup was
* needed, and that a file by the old name already
* existing on the destination branch; that file got
* renamed earlier in this function, so all we need
* to do here is set the lower inode.
*/
struct inode *inode;
inode = unionfs_lower_inode(old_dentry->d_inode);
igrab(inode);
unionfs_set_lower_inode_idx(new_dentry->d_inode,
dbstart(new_dentry),
inode);
}
}
/* if all of this renaming succeeded, update our times */
unionfs_copy_attr_times(old_dentry->d_inode);
unionfs_copy_attr_times(new_dentry->d_inode);
unionfs_check_inode(old_dir);
unionfs_check_inode(new_dir);
unionfs_check_dentry(old_dentry);
unionfs_check_dentry(new_dentry);
out:
if (err) /* clear the new_dentry stuff created */
d_drop(new_dentry);
unionfs_double_unlock_dentry(old_dentry, new_dentry);
if (new_parent != old_dentry &&
new_parent != new_dentry &&
new_parent != old_parent)
unionfs_unlock_dentry(new_parent);
if (old_parent != old_dentry &&
old_parent != new_dentry)
unionfs_unlock_dentry(old_parent);
dput(new_parent);
dput(old_parent);
unionfs_read_unlock(old_dentry->d_sb);
return err;
}
