/*
* BKL held by caller.
* dentry->d_inode->i_mutex locked
*/
ssize_t unionfs_listxattr(struct dentry *dentry, char *list, size_t size)
{
struct dentry *lower_dentry = NULL;
struct dentry *parent;
int err = -EOPNOTSUPP;
char *encoded_list = NULL;
bool valid;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
valid = __unionfs_d_revalidate(dentry, parent, false);
if (unlikely(!valid)) {
err = -ESTALE;
goto out;
}
lower_dentry = unionfs_lower_dentry(dentry);
encoded_list = list;
err = vfs_listxattr(lower_dentry, encoded_list, size);
out:
unionfs_check_dentry(dentry);
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
return err;
}
static int unionfs_readlink(struct dentry *dentry, char __user *buf,
int bufsiz)
{
int err;
struct dentry *parent;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate(dentry, parent, false, 0))) {
err = -ESTALE;
goto out;
}
err = __unionfs_readlink(dentry, buf, bufsiz);
out:
unionfs_check_dentry(dentry);
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
return err;
}
/*
* BKL held by caller.
* dentry->d_inode->i_mutex locked
*/
int unionfs_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
struct dentry *lower_dentry = NULL;
struct dentry *parent;
int err = -EOPNOTSUPP;
bool valid;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
valid = __unionfs_d_revalidate(dentry, parent, false);
if (unlikely(!valid)) {
err = -ESTALE;
goto out;
}
lower_dentry = unionfs_lower_dentry(dentry);
err = vfs_setxattr(lower_dentry, (char *) name, (void *) value,
size, flags);
out:
unionfs_check_dentry(dentry);
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
return err;
}
/* this @nd *IS* still used */
static void unionfs_put_link(struct dentry *dentry, struct nameidata *nd,
void *cookie)
{
struct dentry *parent;
char *buf;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate(dentry, parent, false)))
printk(KERN_ERR
"unionfs: put_link failed to revalidate dentry\n");
unionfs_check_dentry(dentry);
#if 0
/* XXX: can't run this check b/c this fxn can receive a poisoned 'nd' PTR */
unionfs_check_nd(nd);
#endif
buf = nd_get_link(nd);
if (!IS_ERR(buf))
kfree(buf);
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
}
static int unionfs_create(struct inode *dir, struct dentry *dentry,
umode_t mode, bool want_excl)
{
int err = 0;
struct dentry *lower_dentry = NULL;
struct dentry *lower_parent_dentry = NULL;
struct dentry *parent;
int valid = 0;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
valid = __unionfs_d_revalidate(dentry, parent, false, 0);
if (unlikely(!valid)) {
err = -ESTALE; /* same as what real_lookup does */
goto out;
}
lower_dentry = find_writeable_branch(dir, dentry);
if (IS_ERR(lower_dentry)) {
err = PTR_ERR(lower_dentry);
goto out;
}
lower_parent_dentry = lock_parent(lower_dentry);
if (IS_ERR(lower_parent_dentry)) {
err = PTR_ERR(lower_parent_dentry);
goto out_unlock;
}
err = vfs_create(lower_parent_dentry->d_inode, lower_dentry, mode,
want_excl);
if (!err) {
err = PTR_ERR(unionfs_interpose(dentry, dir->i_sb, 0));
if (!err) {
unionfs_copy_attr_times(dir);
fsstack_copy_inode_size(dir,
lower_parent_dentry->d_inode);
/* update no. of links on parent directory */
set_nlink(dir, unionfs_get_nlinks(dir));
}
}
out_unlock:
unlock_dir(lower_parent_dentry);
out:
if (!err) {
unionfs_postcopyup_setmnt(dentry);
unionfs_check_inode(dir);
unionfs_check_dentry(dentry);
}
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
return err;
}
/* this @nd *IS* still used */
static void unionfs_put_link(struct dentry *dentry, struct nameidata *nd,
void *cookie)
{
struct dentry *parent;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate(dentry, parent, false)))
printk(KERN_ERR
"unionfs: put_link failed to revalidate dentry\n");
unionfs_check_dentry(dentry);
unionfs_check_nd(nd);
kfree(nd_get_link(nd));
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
}
/*
* Revalidate the struct file
* @file: file to revalidate
* @parent: parent dentry (locked by caller)
* @willwrite: true if caller may cause changes to the file; false otherwise.
* Caller must lock/unlock dentry's branch configuration.
*/
int unionfs_file_revalidate(struct file *file, struct dentry *parent,
bool willwrite)
{
struct super_block *sb;
struct dentry *dentry;
int sbgen, dgen;
int err = 0;
dentry = file->f_path.dentry;
sb = dentry->d_sb;
verify_locked(dentry);
verify_locked(parent);
/*
* First revalidate the dentry inside struct file,
* but not unhashed dentries.
*/
if (!d_deleted(dentry) &&
!__unionfs_d_revalidate(dentry, parent, willwrite)) {
err = -ESTALE;
goto out;
}
sbgen = atomic_read(&UNIONFS_SB(sb)->generation);
dgen = atomic_read(&UNIONFS_D(dentry)->generation);
if (unlikely(sbgen > dgen)) { /* XXX: should never happen */
pr_debug("unionfs: failed to revalidate dentry (%s)\n",
dentry->d_name.name);
err = -ESTALE;
goto out;
}
err = __unionfs_file_revalidate(file, dentry, parent, sb,
sbgen, dgen, willwrite);
out:
return err;
}
static int unionfs_setattr(struct dentry *dentry, struct iattr *ia)
{
int err = 0;
struct dentry *lower_dentry;
struct dentry *parent;
struct inode *inode;
struct inode *lower_inode;
int bstart, bend, bindex;
loff_t size;
struct iattr lower_ia;
/* check if user has permission to change inode */
err = inode_change_ok(dentry->d_inode, ia);
if (err)
goto out_err;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate(dentry, parent, false, 0))) {
err = -ESTALE;
goto out;
}
bstart = dbstart(dentry);
bend = dbend(dentry);
inode = dentry->d_inode;
/*
* mode change is for clearing setuid/setgid. Allow lower filesystem
* to reinterpret it in its own way.
*/
if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
ia->ia_valid &= ~ATTR_MODE;
lower_dentry = unionfs_lower_dentry(dentry);
if (!lower_dentry) { /* should never happen after above revalidate */
err = -EINVAL;
goto out;
}
/*
* Get the lower inode directly from lower dentry, in case ibstart
* is -1 (which happens when the file is open but unlinked.
*/
lower_inode = lower_dentry->d_inode;
/* check if user has permission to change lower inode */
err = inode_change_ok(lower_inode, ia);
if (err)
goto out;
/* copyup if the file is on a read only branch */
if (is_robranch_super(dentry->d_sb, bstart)
|| __is_rdonly(lower_inode)) {
/* check if we have a branch to copy up to */
if (bstart <= 0) {
err = -EACCES;
goto out;
}
if (ia->ia_valid & ATTR_SIZE)
size = ia->ia_size;
else
size = i_size_read(inode);
/* copyup to next available branch */
for (bindex = bstart - 1; bindex >= 0; bindex--) {
err = copyup_dentry(parent->d_inode,
dentry, bstart, bindex,
dentry->d_name.name,
dentry->d_name.len,
NULL, size);
if (!err)
break;
}
if (err)
goto out;
/* get updated lower_dentry/inode after copyup */
lower_dentry = unionfs_lower_dentry(dentry);
lower_inode = unionfs_lower_inode(inode);
/*
* check for whiteouts in writeable branch, and remove them
* if necessary.
*/
if (lower_dentry) {
err = check_unlink_whiteout(dentry, lower_dentry,
bindex);
if (err > 0) /* ignore if whiteout found and removed */
err = 0;
}
}
/*
* If shrinking, first truncate upper level to cancel writing dirty
* pages beyond the new eof; and also if its' maxbytes is more
* limiting (fail with -EFBIG before making any change to the lower
* level). There is no need to vmtruncate the upper level
* afterwards in the other cases: we fsstack_copy_inode_size from
* the lower level.
*/
if (ia->ia_valid & ATTR_SIZE) {
err = inode_newsize_ok(inode, ia->ia_size);
if (err)
goto out;
truncate_setsize(inode, ia->ia_size);
}
/* notify the (possibly copied-up) lower inode */
/*
* Note: we use lower_dentry->d_inode, because lower_inode may be
* unlinked (no inode->i_sb and i_ino==0. This happens if someone
* tries to open(), unlink(), then ftruncate() a file.
*/
/* prepare our own lower struct iattr (with our own lower file) */
memcpy(&lower_ia, ia, sizeof(lower_ia));
if (ia->ia_valid & ATTR_FILE) {
lower_ia.ia_file = unionfs_lower_file(ia->ia_file);
BUG_ON(!lower_ia.ia_file); // XXX?
}
mutex_lock(&lower_dentry->d_inode->i_mutex);
err = notify_change(lower_dentry, &lower_ia);
mutex_unlock(&lower_dentry->d_inode->i_mutex);
if (err)
goto out;
/* get attributes from the first lower inode */
if (ibstart(inode) >= 0)
unionfs_copy_attr_all(inode, lower_inode);
/*
* unionfs_copy_attr_all will copy the lower times to our inode if
* the lower ones are newer (useful for cache coherency). However,
* ->setattr is the only place in which we may have to copy the
* lower inode times absolutely, to support utimes(2).
*/
if (ia->ia_valid & ATTR_MTIME_SET)
inode->i_mtime = lower_inode->i_mtime;
if (ia->ia_valid & ATTR_CTIME)
inode->i_ctime = lower_inode->i_ctime;
if (ia->ia_valid & ATTR_ATIME_SET)
inode->i_atime = lower_inode->i_atime;
fsstack_copy_inode_size(inode, lower_inode);
out:
if (!err)
unionfs_check_dentry(dentry);
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
out_err:
return err;
}
static int unionfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
dev_t dev)
{
int err = 0;
struct dentry *lower_dentry = NULL;
struct dentry *wh_dentry = NULL;
struct dentry *lower_parent_dentry = NULL;
struct dentry *parent;
char *name = NULL;
int valid = 0;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
valid = __unionfs_d_revalidate(dentry, parent, false, 0);
if (unlikely(!valid)) {
err = -ESTALE;
goto out;
}
/*
* It's only a bug if this dentry was not negative and couldn't be
* revalidated (shouldn't happen).
*/
BUG_ON(!valid && dentry->d_inode);
lower_dentry = find_writeable_branch(dir, dentry);
if (IS_ERR(lower_dentry)) {
err = PTR_ERR(lower_dentry);
goto out;
}
lower_parent_dentry = lock_parent(lower_dentry);
if (IS_ERR(lower_parent_dentry)) {
err = PTR_ERR(lower_parent_dentry);
goto out_unlock;
}
err = vfs_mknod(lower_parent_dentry->d_inode, lower_dentry, mode, dev);
if (!err) {
err = PTR_ERR(unionfs_interpose(dentry, dir->i_sb, 0));
if (!err) {
unionfs_copy_attr_times(dir);
fsstack_copy_inode_size(dir,
lower_parent_dentry->d_inode);
/* update no. of links on parent directory */
set_nlink(dir, unionfs_get_nlinks(dir));
}
}
out_unlock:
unlock_dir(lower_parent_dentry);
out:
dput(wh_dentry);
kfree(name);
if (!err) {
unionfs_postcopyup_setmnt(dentry);
unionfs_check_inode(dir);
unionfs_check_dentry(dentry);
}
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
return err;
}
static int unionfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
int err = 0;
struct dentry *lower_dentry = NULL;
struct dentry *lower_parent_dentry = NULL;
struct dentry *parent;
int bindex = 0, bstart;
char *name = NULL;
int valid;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
valid = __unionfs_d_revalidate(dentry, parent, false, 0);
if (unlikely(!valid)) {
err = -ESTALE; /* same as what real_lookup does */
goto out;
}
bstart = dbstart(dentry);
lower_dentry = unionfs_lower_dentry(dentry);
/* check for a whiteout in new dentry branch, and delete it */
err = check_unlink_whiteout(dentry, lower_dentry, bstart);
if (err > 0) /* whiteout found and removed successfully */
err = 0;
if (err) {
/* exit if the error returned was NOT -EROFS */
if (!IS_COPYUP_ERR(err))
goto out;
bstart--;
}
/* check if copyup's needed, and mkdir */
for (bindex = bstart; bindex >= 0; bindex--) {
int i;
int bend = dbend(dentry);
if (is_robranch_super(dentry->d_sb, bindex))
continue;
lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
if (!lower_dentry) {
lower_dentry = create_parents(dir, dentry,
dentry->d_name.name,
bindex);
if (!lower_dentry || IS_ERR(lower_dentry)) {
printk(KERN_ERR "unionfs: lower dentry "
" NULL for bindex = %d\n", bindex);
continue;
}
}
lower_parent_dentry = lock_parent(lower_dentry);
if (IS_ERR(lower_parent_dentry)) {
err = PTR_ERR(lower_parent_dentry);
goto out;
}
err = vfs_mkdir(lower_parent_dentry->d_inode, lower_dentry,
mode);
unlock_dir(lower_parent_dentry);
/* did the mkdir succeed? */
if (err)
break;
for (i = bindex + 1; i <= bend; i++) {
/* XXX: use path_put_lowers? */
if (unionfs_lower_dentry_idx(dentry, i)) {
dput(unionfs_lower_dentry_idx(dentry, i));
unionfs_set_lower_dentry_idx(dentry, i, NULL);
}
}
dbend(dentry) = bindex;
/*
* Only INTERPOSE_LOOKUP can return a value other than 0 on
* err.
*/
err = PTR_ERR(unionfs_interpose(dentry, dir->i_sb, 0));
if (!err) {
unionfs_copy_attr_times(dir);
fsstack_copy_inode_size(dir,
lower_parent_dentry->d_inode);
/* update number of links on parent directory */
set_nlink(dir, unionfs_get_nlinks(dir));
}
err = make_dir_opaque(dentry, dbstart(dentry));
if (err) {
printk(KERN_ERR "unionfs: mkdir: error creating "
".wh.__dir_opaque: %d\n", err);
goto out;
}
/* we are done! */
break;
}
out:
if (!dentry->d_inode)
d_drop(dentry);
kfree(name);
if (!err) {
unionfs_copy_attr_times(dentry->d_inode);
unionfs_postcopyup_setmnt(dentry);
}
unionfs_check_inode(dir);
unionfs_check_dentry(dentry);
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
return err;
}
static int unionfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *new_dentry)
{
int err = 0;
struct dentry *lower_old_dentry = NULL;
struct dentry *lower_new_dentry = NULL;
struct dentry *lower_dir_dentry = NULL;
struct dentry *old_parent, *new_parent;
char *name = NULL;
bool valid;
unionfs_read_lock(old_dentry->d_sb, UNIONFS_SMUTEX_CHILD);
old_parent = dget_parent(old_dentry);
new_parent = dget_parent(new_dentry);
unionfs_double_lock_parents(old_parent, new_parent);
unionfs_double_lock_dentry(old_dentry, new_dentry);
valid = __unionfs_d_revalidate(old_dentry, old_parent, false, 0);
if (unlikely(!valid)) {
err = -ESTALE;
goto out;
}
if (new_dentry->d_inode) {
valid = __unionfs_d_revalidate(new_dentry, new_parent, false, 0);
if (unlikely(!valid)) {
err = -ESTALE;
goto out;
}
}
lower_new_dentry = unionfs_lower_dentry(new_dentry);
/* check for a whiteout in new dentry branch, and delete it */
err = check_unlink_whiteout(new_dentry, lower_new_dentry,
dbstart(new_dentry));
if (err > 0) { /* whiteout found and removed successfully */
lower_dir_dentry = dget_parent(lower_new_dentry);
fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
dput(lower_dir_dentry);
set_nlink(dir, unionfs_get_nlinks(dir));
err = 0;
}
if (err)
goto out;
/* check if parent hierachy is needed, then link in same branch */
if (dbstart(old_dentry) != dbstart(new_dentry)) {
lower_new_dentry = create_parents(dir, new_dentry,
new_dentry->d_name.name,
dbstart(old_dentry));
err = PTR_ERR(lower_new_dentry);
if (IS_COPYUP_ERR(err))
goto docopyup;
if (!lower_new_dentry || IS_ERR(lower_new_dentry))
goto out;
}
lower_new_dentry = unionfs_lower_dentry(new_dentry);
lower_old_dentry = unionfs_lower_dentry(old_dentry);
BUG_ON(dbstart(old_dentry) != dbstart(new_dentry));
lower_dir_dentry = lock_parent(lower_new_dentry);
err = is_robranch(old_dentry);
if (!err) {
/* see Documentation/filesystems/unionfs/issues.txt */
lockdep_off();
err = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
lower_new_dentry);
lockdep_on();
}
unlock_dir(lower_dir_dentry);
docopyup:
if (IS_COPYUP_ERR(err)) {
int old_bstart = dbstart(old_dentry);
int bindex;
for (bindex = old_bstart - 1; bindex >= 0; bindex--) {
err = copyup_dentry(old_parent->d_inode,
old_dentry, old_bstart,
bindex, old_dentry->d_name.name,
old_dentry->d_name.len, NULL,
i_size_read(old_dentry->d_inode));
if (err)
continue;
lower_new_dentry =
create_parents(dir, new_dentry,
new_dentry->d_name.name,
bindex);
lower_old_dentry = unionfs_lower_dentry(old_dentry);
lower_dir_dentry = lock_parent(lower_new_dentry);
/* see Documentation/filesystems/unionfs/issues.txt */
lockdep_off();
/* do vfs_link */
err = vfs_link(lower_old_dentry,
lower_dir_dentry->d_inode,
lower_new_dentry);
lockdep_on();
unlock_dir(lower_dir_dentry);
goto check_link;
}
goto out;
}
check_link:
if (err || !lower_new_dentry->d_inode)
goto out;
/* Its a hard link, so use the same inode */
new_dentry->d_inode = igrab(old_dentry->d_inode);
d_add(new_dentry, new_dentry->d_inode);
unionfs_copy_attr_all(dir, lower_new_dentry->d_parent->d_inode);
fsstack_copy_inode_size(dir, lower_new_dentry->d_parent->d_inode);
/* propagate number of hard-links */
set_nlink(old_dentry->d_inode,
unionfs_get_nlinks(old_dentry->d_inode));
/* new dentry's ctime may have changed due to hard-link counts */
unionfs_copy_attr_times(new_dentry->d_inode);
out:
if (!new_dentry->d_inode)
d_drop(new_dentry);
kfree(name);
if (!err)
unionfs_postcopyup_setmnt(new_dentry);
unionfs_check_inode(dir);
unionfs_check_dentry(new_dentry);
unionfs_check_dentry(old_dentry);
unionfs_double_unlock_dentry(old_dentry, new_dentry);
unionfs_double_unlock_parents(old_parent, new_parent);
dput(new_parent);
dput(old_parent);
unionfs_read_unlock(old_dentry->d_sb);
return err;
}
int unionfs_open(struct inode *inode, struct file *file)
{
int err = 0;
struct file *lower_file = NULL;
struct dentry *dentry = file->f_path.dentry;
struct dentry *parent;
int bindex = 0, bstart = 0, bend = 0;
int size;
int valid = 0;
unionfs_read_lock(inode->i_sb, UNIONFS_SMUTEX_PARENT);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
/* don't open unhashed/deleted files */
if (d_deleted(dentry)) {
err = -ENOENT;
goto out_nofree;
}
/* XXX: should I change 'false' below to the 'willwrite' flag? */
valid = __unionfs_d_revalidate(dentry, parent, false);
if (unlikely(!valid)) {
err = -ESTALE;
goto out_nofree;
}
file->private_data =
kzalloc(sizeof(struct unionfs_file_info), GFP_KERNEL);
if (unlikely(!UNIONFS_F(file))) {
err = -ENOMEM;
goto out_nofree;
}
fbstart(file) = -1;
fbend(file) = -1;
atomic_set(&UNIONFS_F(file)->generation,
atomic_read(&UNIONFS_I(inode)->generation));
size = sizeof(struct file *) * sbmax(inode->i_sb);
UNIONFS_F(file)->lower_files = kzalloc(size, GFP_KERNEL);
if (unlikely(!UNIONFS_F(file)->lower_files)) {
err = -ENOMEM;
goto out;
}
size = sizeof(int) * sbmax(inode->i_sb);
UNIONFS_F(file)->saved_branch_ids = kzalloc(size, GFP_KERNEL);
if (unlikely(!UNIONFS_F(file)->saved_branch_ids)) {
err = -ENOMEM;
goto out;
}
bstart = fbstart(file) = dbstart(dentry);
bend = fbend(file) = dbend(dentry);
/*
* open all directories and make the unionfs file struct point to
* these lower file structs
*/
if (S_ISDIR(inode->i_mode))
err = __open_dir(inode, file); /* open a dir */
else
err = __open_file(inode, file, parent); /* open a file */
/* freeing the allocated resources, and fput the opened files */
if (err) {
for (bindex = bstart; bindex <= bend; bindex++) {
lower_file = unionfs_lower_file_idx(file, bindex);
if (!lower_file)
continue;
branchput(dentry->d_sb, bindex);
/* fput calls dput for lower_dentry */
fput(lower_file);
}
}
out:
if (err) {
kfree(UNIONFS_F(file)->lower_files);
kfree(UNIONFS_F(file)->saved_branch_ids);
kfree(UNIONFS_F(file));
}
out_nofree:
if (!err) {
unionfs_postcopyup_setmnt(dentry);
unionfs_copy_attr_times(inode);
unionfs_check_file(file);
unionfs_check_inode(inode);
}
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(inode->i_sb);
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;
}
