void create_parents( const fs::path &dpath )
{
string err( "create_parent(): " );
fs::path branch( dpath.branch_path() );
string who("create_parents");
if( dpath.empty() ) {
err.append( "cannot create an empty path." );
throw CannotCreateParents( err );
}
else if( !exists(dpath) ) {
if( branch.empty() ) create_directory( dpath );
else if( !exists(branch) ) {
create_parents( branch );
create_directory( dpath );
}
else if( is_directory(branch) ) create_directory( dpath );
else {
err.append( branch.native_file_string() ); err.append( " is not a directory." );
throw CannotCreateParents( err );
}
}
else if( !is_directory(dpath) ) {
err.append( dpath.native_file_string() ); err.append( " is not a directory." );
throw CannotCreateParents( err );
}
return;
}
void
create_parents (url u) {
if (!exists (url_parent (u))) {
if (!is_root (u)) create_parents (url_parent (u));
mkdir (url_parent (u));
}
}
static int u2fs_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
int err = 0;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path;
struct dentry *ret = NULL;
/* creating parent directories if destination is read-only */
if((U2FS_D(dentry)->lower_path[LEFT].dentry == NULL) &&
(U2FS_D(dentry)->lower_path[LEFT].mnt == NULL)){
ret = create_parents(dir, dentry,
dentry->d_name.name);
if (!ret || IS_ERR(ret)) {
err = PTR_ERR(ret);
if (!IS_COPYUP_ERR(err))
printk(KERN_ERR
"u2fs: create_parents for "
"u2fs_symlink failed"
"err=%d\n", err);
goto out_copyup;
}
u2fs_postcopyup_setmnt(dentry);
u2fs_put_reset_lower_path(dentry, RIGHT);
if(err)
goto out_copyup;
}
u2fs_get_lower_path(dentry, &lower_path, LEFT);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
err = vfs_symlink(lower_parent_dentry->d_inode, lower_dentry, symname);
if (err)
goto out;
err = u2fs_interpose(dentry, dir->i_sb, &lower_path, LEFT);
if (err)
goto out;
fsstack_copy_attr_times(dir, u2fs_lower_inode(dir, LEFT));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_parent_dentry);
u2fs_put_lower_path(dentry, &lower_path);
out_copyup:
return err;
}
void
tmfs_export (url prj_dir, url u, string prj) {
properties ps= tmfs_list_heads_inside (u, prj);
for (int i=0; i<N(ps); i++) {
url v = ps[i][0];
string file= ps[i][1];
cout << "Process " << (prj_dir * v) << "\n";
if (!exists (prj_dir * v)) {
string val= tmfs_load_file (file);
create_parents (prj_dir * v);
save_string (prj_dir * v, val);
cout << "Export " << file << " -> " << (prj_dir * v) << "\n";
}
else {
string val1= load_string (prj_dir * v);
string val2= tmfs_load_file (file);
if (val2 != val1) {
save_string (prj_dir * v, val2);
cout << "Update " << file << " -> " << (prj_dir * v) << "\n";
}
}
}
}
/*
* Copy up a dentry to a file of specified name.
*
* @dir: used to pull the ->i_sb to access other branches
* @dentry: the non-negative dentry whose lower_inode we should copy
* @bstart: the branch of the lower_inode to copy from
* @new_bindex: the branch to create the new file in
* @name: the name of the file to create
* @namelen: length of @name
* @copyup_file: the "struct file" to return (optional)
* @len: how many bytes to copy-up?
*/
int copyup_dentry(struct inode *dir, struct dentry *dentry, int bstart,
int new_bindex, const char *name, int namelen,
struct file **copyup_file, loff_t len)
{
struct dentry *new_lower_dentry;
struct dentry *old_lower_dentry = NULL;
struct super_block *sb;
int err = 0;
int old_bindex;
int old_bstart;
int old_bend;
struct dentry *new_lower_parent_dentry = NULL;
mm_segment_t oldfs;
char *symbuf = NULL;
verify_locked(dentry);
old_bindex = bstart;
old_bstart = dbstart(dentry);
old_bend = dbend(dentry);
BUG_ON(new_bindex < 0);
BUG_ON(new_bindex >= old_bindex);
sb = dir->i_sb;
err = is_robranch_super(sb, new_bindex);
if (err)
goto out;
/* Create the directory structure above this dentry. */
new_lower_dentry = create_parents(dir, dentry, name, new_bindex);
if (IS_ERR(new_lower_dentry)) {
err = PTR_ERR(new_lower_dentry);
goto out;
}
old_lower_dentry = unionfs_lower_dentry_idx(dentry, old_bindex);
/* we conditionally dput this old_lower_dentry at end of function */
dget(old_lower_dentry);
/* For symlinks, we must read the link before we lock the directory. */
if (S_ISLNK(old_lower_dentry->d_inode->i_mode)) {
symbuf = kmalloc(PATH_MAX, GFP_KERNEL);
if (unlikely(!symbuf)) {
__clear(dentry, old_lower_dentry,
old_bstart, old_bend,
new_lower_dentry, new_bindex);
err = -ENOMEM;
goto out_free;
}
oldfs = get_fs();
set_fs(KERNEL_DS);
err = old_lower_dentry->d_inode->i_op->readlink(
old_lower_dentry,
(char __user *)symbuf,
PATH_MAX);
set_fs(oldfs);
if (err < 0) {
__clear(dentry, old_lower_dentry,
old_bstart, old_bend,
new_lower_dentry, new_bindex);
goto out_free;
}
symbuf[err] = '\0';
}
/* Now we lock the parent, and create the object in the new branch. */
new_lower_parent_dentry = lock_parent(new_lower_dentry);
/* create the new inode */
err = __copyup_ndentry(old_lower_dentry, new_lower_dentry,
new_lower_parent_dentry, symbuf);
if (err) {
__clear(dentry, old_lower_dentry,
old_bstart, old_bend,
new_lower_dentry, new_bindex);
goto out_unlock;
}
/* We actually copyup the file here. */
if (S_ISREG(old_lower_dentry->d_inode->i_mode))
err = __copyup_reg_data(dentry, new_lower_dentry, new_bindex,
old_lower_dentry, old_bindex,
copyup_file, len);
if (err)
goto out_unlink;
/* Set permissions. */
err = copyup_permissions(sb, old_lower_dentry, new_lower_dentry);
if (err)
goto out_unlink;
#ifdef CONFIG_UNION_FS_XATTR
/* Selinux uses extended attributes for permissions. */
err = copyup_xattrs(old_lower_dentry, new_lower_dentry);
if (err)
goto out_unlink;
#endif /* CONFIG_UNION_FS_XATTR */
/* do not allow files getting deleted to be re-interposed */
if (!d_deleted(dentry))
unionfs_reinterpose(dentry);
goto out_unlock;
out_unlink:
/*
* copyup failed, because we possibly ran out of space or
* quota, or something else happened so let's unlink; we don't
* really care about the return value of vfs_unlink
*/
vfs_unlink(new_lower_parent_dentry->d_inode, new_lower_dentry);
if (copyup_file) {
/* need to close the file */
fput(*copyup_file);
branchput(sb, new_bindex);
}
/*
* TODO: should we reset the error to something like -EIO?
*
* If we don't reset, the user may get some nonsensical errors, but
* on the other hand, if we reset to EIO, we guarantee that the user
* will get a "confusing" error message.
*/
out_unlock:
unlock_dir(new_lower_parent_dentry);
out_free:
/*
* If old_lower_dentry was not a file, then we need to dput it. If
* it was a file, then it was already dput indirectly by other
* functions we call above which operate on regular files.
*/
if (old_lower_dentry && old_lower_dentry->d_inode &&
!S_ISREG(old_lower_dentry->d_inode->i_mode))
dput(old_lower_dentry);
kfree(symbuf);
if (err) {
/*
* if directory creation succeeded, but inode copyup failed,
* then purge new dentries.
*/
if (dbstart(dentry) < old_bstart &&
ibstart(dentry->d_inode) > dbstart(dentry))
__clear(dentry, NULL, old_bstart, old_bend,
unionfs_lower_dentry(dentry), dbstart(dentry));
goto out;
}
if (!S_ISDIR(dentry->d_inode->i_mode)) {
unionfs_postcopyup_release(dentry);
if (!unionfs_lower_inode(dentry->d_inode)) {
/*
* If we got here, then we copied up to an
* unlinked-open file, whose name is .unionfsXXXXX.
*/
struct inode *inode = new_lower_dentry->d_inode;
atomic_inc(&inode->i_count);
unionfs_set_lower_inode_idx(dentry->d_inode,
ibstart(dentry->d_inode),
inode);
}
}
unionfs_postcopyup_setmnt(dentry);
/* sync inode times from copied-up inode to our inode */
unionfs_copy_attr_times(dentry->d_inode);
unionfs_check_inode(dir);
unionfs_check_dentry(dentry);
out:
return err;
}
static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
int bindex, struct dentry **wh_old)
{
int err = 0;
struct dentry *hidden_old_dentry;
struct dentry *hidden_new_dentry;
struct dentry *hidden_old_dir_dentry;
struct dentry *hidden_new_dir_dentry;
struct dentry *hidden_wh_dentry;
struct dentry *hidden_wh_dir_dentry;
char *wh_name = NULL;
print_entry(" bindex=%d", bindex);
fist_print_dentry("IN: do_rename, old_dentry", old_dentry);
fist_print_dentry("IN: do_rename, new_dentry", new_dentry);
fist_dprint(7, "do_rename for bindex = %d\n", bindex);
hidden_new_dentry = dtohd_index(new_dentry, bindex);
hidden_old_dentry = dtohd_index(old_dentry, bindex);
if (!hidden_new_dentry) {
hidden_new_dentry =
create_parents(new_dentry->d_parent->d_inode, new_dentry,
bindex);
if (IS_ERR(hidden_new_dentry)) {
fist_dprint(7,
"error creating directory tree for rename, bindex = %d\n",
bindex);
err = PTR_ERR(hidden_new_dentry);
goto out;
}
}
wh_name = alloc_whname(new_dentry->d_name.name, new_dentry->d_name.len);
if (IS_ERR(wh_name)) {
err = PTR_ERR(wh_name);
goto out;
}
hidden_wh_dentry =
LOOKUP_ONE_LEN(wh_name, hidden_new_dentry->d_parent,
new_dentry->d_name.len + WHLEN);
if (IS_ERR(hidden_wh_dentry)) {
err = PTR_ERR(hidden_wh_dentry);
goto out;
}
if (hidden_wh_dentry->d_inode) {
/* get rid of the whiteout that is existing */
if (hidden_new_dentry->d_inode) {
printk(KERN_WARNING
"Both a whiteout and a dentry exist when doing a rename!\n");
err = -EIO;
DPUT(hidden_wh_dentry);
goto out;
}
hidden_wh_dir_dentry = lock_parent(hidden_wh_dentry);
if (!(err = is_robranch_super(old_dentry->d_sb, bindex))) {
err =
vfs_unlink(hidden_wh_dir_dentry->d_inode,
hidden_wh_dentry);
}
DPUT(hidden_wh_dentry);
unlock_dir(hidden_wh_dir_dentry);
if (err)
goto out;
} else
DPUT(hidden_wh_dentry);
DGET(hidden_old_dentry);
hidden_old_dir_dentry = GET_PARENT(hidden_old_dentry);
hidden_new_dir_dentry = GET_PARENT(hidden_new_dentry);
lock_rename(hidden_old_dir_dentry, hidden_new_dir_dentry);
err = is_robranch_super(old_dentry->d_sb, bindex);
if (err)
goto out_unlock;
/* ready to whiteout for old_dentry.
caller will create the actual whiteout,
and must dput(*wh_old) */
if (wh_old) {
char *whname;
whname = alloc_whname(old_dentry->d_name.name,
old_dentry->d_name.len);
err = PTR_ERR(whname);
if (IS_ERR(whname))
goto out_unlock;
*wh_old = LOOKUP_ONE_LEN(whname, hidden_old_dir_dentry,
old_dentry->d_name.len + WHLEN);
KFREE(whname);
err = PTR_ERR(*wh_old);
if (IS_ERR(*wh_old)) {
*wh_old = NULL;
goto out_unlock;
}
}
fist_print_dentry("NEWBEF", new_dentry);
fist_print_dentry("OLDBEF", old_dentry);
err = vfs_rename(hidden_old_dir_dentry->d_inode, hidden_old_dentry,
hidden_new_dir_dentry->d_inode, hidden_new_dentry);
fist_print_dentry("NEWAFT", new_dentry);
fist_print_dentry("OLDAFT", old_dentry);
out_unlock:
unlock_rename(hidden_old_dir_dentry, hidden_new_dir_dentry);
DPUT(hidden_old_dir_dentry);
DPUT(hidden_new_dir_dentry);
DPUT(hidden_old_dentry);
out:
if (!err) {
/* Fixup the newdentry. */
if (bindex < dbstart(new_dentry))
set_dbstart(new_dentry, bindex);
else if (bindex > dbend(new_dentry))
set_dbend(new_dentry, bindex);
}
KFREE(wh_name);
fist_print_dentry("OUT: do_rename, old_dentry", old_dentry);
fist_print_dentry("OUT: do_rename, new_dentry", new_dentry);
print_exit_status(err);
return err;
}
static int u2fs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *new_dentry)
{
struct dentry *lower_old_dentry;
struct dentry *lower_new_dentry;
struct dentry *lower_dir_dentry;
u64 file_size_save;
int err=0;
int idx;
struct dentry *ret = NULL;
struct path lower_old_path, lower_new_path;
file_size_save = i_size_read(old_dentry->d_inode);
if((U2FS_D(old_dentry)->lower_path[LEFT].dentry != NULL) &&
(U2FS_D(old_dentry)->lower_path[LEFT].mnt != NULL)){
u2fs_get_lower_path(old_dentry, &lower_old_path, LEFT);
idx = LEFT;
}
else{
u2fs_get_lower_path(old_dentry, &lower_old_path, RIGHT);
idx = RIGHT;
}
/* creating parent directories if destination is read-only */
if((U2FS_D(new_dentry)->lower_path[LEFT].dentry) == NULL &&
(U2FS_D(new_dentry)->lower_path[LEFT].mnt) == NULL){
ret = create_parents(dir, new_dentry,
new_dentry->d_name.name);
if (!ret || IS_ERR(ret)) {
err = PTR_ERR(ret);
if (!IS_COPYUP_ERR(err))
printk(KERN_ERR
"u2fs: create_parents for "
"u2fs_link failed"
"err=%d\n", err);
goto out_copyup;
}
u2fs_postcopyup_setmnt(new_dentry);
u2fs_put_reset_lower_path(new_dentry, RIGHT);
if(err)
goto out_copyup;
}
u2fs_get_lower_path(new_dentry, &lower_new_path, LEFT);
lower_old_dentry = lower_old_path.dentry;
lower_new_dentry = lower_new_path.dentry;
lower_dir_dentry = lock_parent(lower_new_dentry);
err = mnt_want_write(lower_new_path.mnt);
if (err)
goto out_unlock;
err = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
lower_new_dentry);
if (err || !lower_new_dentry->d_inode)
goto out;
err = u2fs_interpose(new_dentry, dir->i_sb, &lower_new_path, LEFT);
if (err)
goto out;
fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
set_nlink(old_dentry->d_inode,
u2fs_lower_inode(old_dentry->d_inode, idx)->i_nlink);
i_size_write(new_dentry->d_inode, file_size_save);
out:
mnt_drop_write(lower_new_path.mnt);
out_unlock:
unlock_dir(lower_dir_dentry);
u2fs_put_lower_path(new_dentry, &lower_new_path);
out_copyup:
u2fs_put_lower_path(old_dentry, &lower_old_path);
return err;
}
static int unionfs_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
int err = 0;
struct dentry *hidden_dentry = NULL;
struct dentry *whiteout_dentry = NULL;
struct dentry *hidden_dir_dentry = NULL;
umode_t mode;
int bindex = 0, bstart;
char *name = NULL;
print_entry_location();
lock_dentry(dentry);
fist_print_dentry("IN unionfs_symlink", dentry);
/* We start out in the leftmost branch. */
bstart = dbstart(dentry);
hidden_dentry = dtohd(dentry);
/* check if whiteout exists in this branch, i.e. lookup .wh.foo first. If present, delete it */
name = alloc_whname(dentry->d_name.name, dentry->d_name.len);
if (IS_ERR(name)) {
err = PTR_ERR(name);
goto out;
}
whiteout_dentry =
LOOKUP_ONE_LEN(name, hidden_dentry->d_parent,
dentry->d_name.len + WHLEN);
if (IS_ERR(whiteout_dentry)) {
err = PTR_ERR(whiteout_dentry);
goto out;
}
if (!whiteout_dentry->d_inode) {
DPUT(whiteout_dentry);
whiteout_dentry = NULL;
} else {
/* found a .wh.foo entry, unlink it and then call vfs_symlink() */
hidden_dir_dentry = lock_parent(whiteout_dentry);
fist_print_generic_dentry("HDD", hidden_dir_dentry);
fist_print_generic_dentry("WD", whiteout_dentry);
if (!(err = is_robranch_super(dentry->d_sb, bstart))) {
err =
vfs_unlink(hidden_dir_dentry->d_inode,
whiteout_dentry);
}
DPUT(whiteout_dentry);
fist_copy_attr_times(dir, hidden_dir_dentry->d_inode);
/* propagate number of hard-links */
dir->i_nlink = get_nlinks(dir);
unlock_dir(hidden_dir_dentry);
if (err) {
/* exit if the error returned was NOT -EROFS */
if (!IS_COPYUP_ERR(err))
goto out;
/* should now try to create symlink in the another branch */
bstart--;
}
}
/* deleted whiteout if it was present, now do a normal vfs_symlink() with
possible recursive directory creation */
for (bindex = bstart; bindex >= 0; bindex--) {
hidden_dentry = dtohd_index(dentry, bindex);
if (!hidden_dentry) {
/* if hidden_dentry is NULL, create the entire
* dentry directory structure in branch 'bindex'. hidden_dentry will NOT be null when
* bindex == bstart because lookup passed as a negative unionfs dentry pointing to a
* lone negative underlying dentry */
hidden_dentry = create_parents(dir, dentry, bindex);
if (!hidden_dentry || IS_ERR(hidden_dentry)) {
if (IS_ERR(hidden_dentry)) {
err = PTR_ERR(hidden_dentry);
}
fist_dprint(8,
"hidden dentry NULL (or error) for bindex = %d\n",
bindex);
continue;
}
}
hidden_dir_dentry = lock_parent(hidden_dentry);
if (!(err = is_robranch_super(dentry->d_sb, bindex))) {
mode = S_IALLUGO;
err =
vfs_symlink(hidden_dir_dentry->d_inode,
hidden_dentry, symname, mode);
}
unlock_dir(hidden_dir_dentry);
if (err || !hidden_dentry->d_inode) {
/* break out of for loop if error returned was NOT -EROFS */
if (!IS_COPYUP_ERR(err))
break;
} else {
err = unionfs_interpose(dentry, dir->i_sb, 0);
if (!err) {
fist_copy_attr_timesizes(dir,
hidden_dir_dentry->
d_inode);
/* update number of links on parent directory */
dir->i_nlink = get_nlinks(dir);
}
break;
}
}
out:
if (!dentry->d_inode)
d_drop(dentry);
KFREE(name);
fist_print_dentry("OUT unionfs_symlink :", dentry);
unlock_dentry(dentry);
print_exit_status(err);
return err;
}
/*
* Find a writeable branch to create new object in. Checks all writeble
* branches of the parent inode, from istart to iend order; if none are
* suitable, also tries branch 0 (which may require a copyup).
*
* Return a lower_dentry we can use to create object in, or ERR_PTR.
*/
static struct dentry *find_writeable_branch(struct inode *parent,
struct dentry *dentry)
{
int err = -EINVAL;
int bindex, istart, iend;
struct dentry *lower_dentry = NULL;
istart = ibstart(parent);
iend = ibend(parent);
if (istart < 0)
goto out;
begin:
for (bindex = istart; bindex <= iend; bindex++) {
/* skip non-writeable branches */
err = is_robranch_super(dentry->d_sb, bindex);
if (err) {
err = -EROFS;
continue;
}
lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
if (!lower_dentry)
continue;
/*
* check for whiteouts in writeable branch, and remove them
* if necessary.
*/
err = check_unlink_whiteout(dentry, lower_dentry, bindex);
if (err > 0) /* ignore if whiteout found and removed */
err = 0;
if (err)
continue;
/* if get here, we can write to the branch */
break;
}
/*
* If istart wasn't already branch 0, and we got any error, then try
* branch 0 (which may require copyup)
*/
if (err && istart > 0) {
istart = iend = 0;
goto begin;
}
/*
* If we tried even branch 0, and still got an error, abort. But if
* the error was an EROFS, then we should try to copyup.
*/
if (err && err != -EROFS)
goto out;
/*
* If we get here, then check if copyup needed. If lower_dentry is
* NULL, create the entire dentry directory structure in branch 0.
*/
if (!lower_dentry) {
bindex = 0;
lower_dentry = create_parents(parent, dentry,
dentry->d_name.name, bindex);
if (IS_ERR(lower_dentry)) {
err = PTR_ERR(lower_dentry);
goto out;
}
}
err = 0; /* all's well */
out:
if (err)
return ERR_PTR(err);
return lower_dentry;
}
static int u2fs_create(struct inode *dir, struct dentry *dentry,
int mode, struct nameidata *nd)
{
int err = 0;
struct dentry *lower_dentry = NULL;
struct dentry *lower_parent_dentry = NULL;
struct dentry *parent= NULL;
struct dentry *ret=NULL;
struct path lower_path, saved_path;
const char *name;
unsigned int namelen;
struct dentry *right_parent_dentry = NULL;
struct dentry *right_lower_dentry = NULL;
/* creating parent directories if destination is read-only */
if((U2FS_D(dentry)->lower_path[LEFT].dentry) == NULL &&
(U2FS_D(dentry)->lower_path[LEFT].mnt) == NULL){
parent = dget_parent(dentry);
right_parent_dentry = U2FS_D(parent)->lower_path[RIGHT].dentry;
ret = create_parents(parent->d_inode, dentry,
dentry->d_name.name);
if (!ret || IS_ERR(ret)) {
err = PTR_ERR(ret);
if (!IS_COPYUP_ERR(err))
printk(KERN_ERR
"u2fs: create_parents for "
"u2fs_create failed"
"err=%d\n", err);
goto out_copyup;
}
u2fs_postcopyup_setmnt(dentry);
u2fs_put_reset_lower_path(dentry, RIGHT);
}
u2fs_get_lower_path(dentry, &lower_path, LEFT);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
pathcpy(&saved_path, &nd->path);
pathcpy(&nd->path, &lower_path);
err = vfs_create(lower_parent_dentry->d_inode, lower_dentry, mode, nd);
pathcpy(&nd->path, &saved_path);
if (err)
goto out;
/* looking if the file already exists in right_dir to link inode */
if((U2FS_D(dentry)->lower_path[RIGHT].dentry) != NULL &&
(U2FS_D(dentry)->lower_path[RIGHT].mnt) != NULL){
name = dentry->d_name.name;
namelen = dentry->d_name.len;
right_lower_dentry = lookup_one_len(name, lower_parent_dentry,
namelen);
dentry->d_inode = right_lower_dentry->d_inode;
u2fs_set_lower_inode(dentry->d_inode, lower_dentry->d_inode,
LEFT);
}
else
err = u2fs_interpose(dentry, dir->i_sb, &lower_path, LEFT);
if (err)
goto out;
fsstack_copy_attr_times(dir, u2fs_lower_inode(dir, LEFT));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_parent_dentry);
u2fs_put_lower_path(dentry, &lower_path);
out_copyup:
if(parent != NULL)
dput(parent);
return err;
}
static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
int bindex, struct dentry **wh_old)
{
int err = 0;
struct dentry *hidden_old_dentry;
struct dentry *hidden_new_dentry;
struct dentry *hidden_old_dir_dentry;
struct dentry *hidden_new_dir_dentry;
struct dentry *hidden_wh_dentry;
struct dentry *hidden_wh_dir_dentry;
char *wh_name = NULL;
hidden_new_dentry = unionfs_lower_dentry_idx(new_dentry, bindex);
hidden_old_dentry = unionfs_lower_dentry_idx(old_dentry, bindex);
if (!hidden_new_dentry) {
hidden_new_dentry =
create_parents(new_dentry->d_parent->d_inode, new_dentry, bindex);
if (IS_ERR(hidden_new_dentry)) {
printk(KERN_DEBUG "error creating directory tree for"
" rename, bindex = %d, err = %ld\n",
bindex, PTR_ERR(hidden_new_dentry));
err = PTR_ERR(hidden_new_dentry);
goto out;
}
}
wh_name = alloc_whname(new_dentry->d_name.name, new_dentry->d_name.len);
if (IS_ERR(wh_name)) {
err = PTR_ERR(wh_name);
goto out;
}
hidden_wh_dentry = lookup_one_len(wh_name, hidden_new_dentry->d_parent,
new_dentry->d_name.len + UNIONFS_WHLEN);
if (IS_ERR(hidden_wh_dentry)) {
err = PTR_ERR(hidden_wh_dentry);
goto out;
}
if (hidden_wh_dentry->d_inode) {
/* get rid of the whiteout that is existing */
if (hidden_new_dentry->d_inode) {
printk(KERN_WARNING "Both a whiteout and a dentry"
" exist when doing a rename!\n");
err = -EIO;
dput(hidden_wh_dentry);
goto out;
}
hidden_wh_dir_dentry = lock_parent(hidden_wh_dentry);
if (!(err = is_robranch_super(old_dentry->d_sb, bindex)))
err = vfs_unlink(hidden_wh_dir_dentry->d_inode,
hidden_wh_dentry);
dput(hidden_wh_dentry);
unlock_dir(hidden_wh_dir_dentry);
if (err)
goto out;
} else
dput(hidden_wh_dentry);
dget(hidden_old_dentry);
hidden_old_dir_dentry = dget_parent(hidden_old_dentry);
hidden_new_dir_dentry = dget_parent(hidden_new_dentry);
lock_rename(hidden_old_dir_dentry, hidden_new_dir_dentry);
err = is_robranch_super(old_dentry->d_sb, bindex);
if (err)
goto out_unlock;
/* ready to whiteout for old_dentry. caller will create the actual
* whiteout, and must dput(*wh_old)
*/
if (wh_old) {
char *whname;
whname = alloc_whname(old_dentry->d_name.name,
old_dentry->d_name.len);
err = PTR_ERR(whname);
if (IS_ERR(whname))
goto out_unlock;
*wh_old = lookup_one_len(whname, hidden_old_dir_dentry,
old_dentry->d_name.len + UNIONFS_WHLEN);
kfree(whname);
err = PTR_ERR(*wh_old);
if (IS_ERR(*wh_old)) {
*wh_old = NULL;
goto out_unlock;
}
}
err = vfs_rename(hidden_old_dir_dentry->d_inode, hidden_old_dentry,
hidden_new_dir_dentry->d_inode, hidden_new_dentry);
out_unlock:
unlock_rename(hidden_old_dir_dentry, hidden_new_dir_dentry);
dput(hidden_old_dir_dentry);
dput(hidden_new_dir_dentry);
dput(hidden_old_dentry);
out:
if (!err) {
/* Fixup the newdentry. */
if (bindex < dbstart(new_dentry))
set_dbstart(new_dentry, bindex);
else if (bindex > dbend(new_dentry))
set_dbend(new_dentry, bindex);
}
kfree(wh_name);
return err;
}
static int __unionfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct dentry *old_parent,
struct inode *new_dir, struct dentry *new_dentry,
struct dentry *new_parent,
int bindex)
{
int err = 0;
struct dentry *lower_old_dentry;
struct dentry *lower_new_dentry;
struct dentry *lower_old_dir_dentry;
struct dentry *lower_new_dir_dentry;
struct dentry *trap;
lower_new_dentry = unionfs_lower_dentry_idx(new_dentry, bindex);
lower_old_dentry = unionfs_lower_dentry_idx(old_dentry, bindex);
if (!lower_new_dentry) {
lower_new_dentry =
create_parents(new_parent->d_inode,
new_dentry, new_dentry->d_name.name,
bindex);
if (IS_ERR(lower_new_dentry)) {
err = PTR_ERR(lower_new_dentry);
if (IS_COPYUP_ERR(err))
goto out;
printk(KERN_ERR "unionfs: error creating directory "
"tree for rename, bindex=%d err=%d\n",
bindex, err);
goto out;
}
}
/* check for and remove whiteout, if any */
err = check_unlink_whiteout(new_dentry, lower_new_dentry, bindex);
if (err > 0) /* ignore if whiteout found and successfully removed */
err = 0;
if (err)
goto out;
/* check of old_dentry branch is writable */
err = is_robranch_super(old_dentry->d_sb, bindex);
if (err)
goto out;
dget(lower_old_dentry);
dget(lower_new_dentry);
lower_old_dir_dentry = dget_parent(lower_old_dentry);
lower_new_dir_dentry = dget_parent(lower_new_dentry);
/* see Documentation/filesystems/unionfs/issues.txt */
lockdep_off();
trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
/* source should not be ancenstor of target */
if (trap == lower_old_dentry) {
err = -EINVAL;
goto out_err_unlock;
}
/* target should not be ancenstor of source */
if (trap == lower_new_dentry) {
err = -ENOTEMPTY;
goto out_err_unlock;
}
err = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
lower_new_dir_dentry->d_inode, lower_new_dentry);
out_err_unlock:
if (!err) {
/* update parent dir times */
fsstack_copy_attr_times(old_dir, lower_old_dir_dentry->d_inode);
fsstack_copy_attr_times(new_dir, lower_new_dir_dentry->d_inode);
}
unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
lockdep_on();
dput(lower_old_dir_dentry);
dput(lower_new_dir_dentry);
dput(lower_old_dentry);
dput(lower_new_dentry);
out:
if (!err) {
/* Fixup the new_dentry. */
if (bindex < dbstart(new_dentry))
dbstart(new_dentry) = bindex;
else if (bindex > dbend(new_dentry))
dbend(new_dentry) = bindex;
}
return err;
}
static int unionfs_mknod(struct inode *dir, struct dentry *dentry, int mode,
dev_t dev)
{
int err = 0;
struct dentry *hidden_dentry = NULL, *whiteout_dentry = NULL;
struct dentry *hidden_parent_dentry = NULL;
int bindex = 0, bstart;
char *name = NULL;
int whiteout_unlinked = 0;
print_entry_location();
lock_dentry(dentry);
fist_print_dentry("IN unionfs_mknod", dentry);
bstart = dbstart(dentry);
hidden_dentry = dtohd(dentry);
// check if whiteout exists in this branch, i.e. lookup .wh.foo first
name = alloc_whname(dentry->d_name.name, dentry->d_name.len);
if (IS_ERR(name)) {
err = PTR_ERR(name);
goto out;
}
whiteout_dentry =
LOOKUP_ONE_LEN(name, hidden_dentry->d_parent,
dentry->d_name.len + WHLEN);
if (IS_ERR(whiteout_dentry)) {
err = PTR_ERR(whiteout_dentry);
goto out;
}
if (!whiteout_dentry->d_inode) {
DPUT(whiteout_dentry);
whiteout_dentry = NULL;
} else {
/* found .wh.foo, unlink it */
hidden_parent_dentry = lock_parent(whiteout_dentry);
//found a.wh.foo entry, remove it then do vfs_mkdir
if (!(err = is_robranch_super(dentry->d_sb, bstart)))
err = vfs_unlink(hidden_parent_dentry->d_inode,
whiteout_dentry);
DPUT(whiteout_dentry);
unlock_dir(hidden_parent_dentry);
if (err) {
if (!IS_COPYUP_ERR(err))
goto out;
bstart--;
} else {
whiteout_unlinked = 1;
}
}
for (bindex = bstart; bindex >= 0; bindex--) {
hidden_dentry = dtohd_index(dentry, bindex);
if (!hidden_dentry) {
hidden_dentry = create_parents(dir, dentry, bindex);
if (!hidden_dentry || IS_ERR(hidden_dentry)) {
fist_dprint(8,
"hidden dentry NULL for bindex = %d\n",
bindex);
continue;
}
}
hidden_parent_dentry = lock_parent(hidden_dentry);
if (IS_ERR(hidden_parent_dentry)) {
err = PTR_ERR(hidden_parent_dentry);
goto out;
}
if (!(err = is_robranch_super(dentry->d_sb, bindex))) {
err = vfs_mknod(hidden_parent_dentry->d_inode,
hidden_dentry, mode, dev);
}
/* XXX this could potentially return a negative hidden_dentry! */
if (err || !hidden_dentry->d_inode) {
unlock_dir(hidden_parent_dentry);
/* break out of for, if error was NOT -EROFS */
if (!IS_COPYUP_ERR(err))
break;
} else {
err = unionfs_interpose(dentry, dir->i_sb, 0);
if (!err) {
fist_copy_attr_timesizes(dir,
hidden_parent_dentry->
d_inode);
/* update number of links on parent directory */
dir->i_nlink = get_nlinks(dir);
}
unlock_dir(hidden_parent_dentry);
break;
}
}
out:
if (!dentry->d_inode)
d_drop(dentry);
if (name) {
KFREE(name);
}
fist_print_dentry("OUT unionfs_mknod :", dentry);
unlock_dentry(dentry);
print_exit_status(err);
return err;
}
static int unionfs_mkdir(struct inode *parent, struct dentry *dentry, int mode)
{
int err = 0;
struct dentry *hidden_dentry = NULL, *whiteout_dentry = NULL;
struct dentry *hidden_parent_dentry = NULL;
int bindex = 0, bstart;
char *name = NULL;
int whiteout_unlinked = 0;
uid_t saved_uid = current->fsuid;
gid_t saved_gid = current->fsgid;
print_entry_location();
lock_dentry(dentry);
fist_print_dentry("IN unionfs_mkdir", dentry);
bstart = dbstart(dentry);
hidden_dentry = dtohd(dentry);
// check if whiteout exists in this branch, i.e. lookup .wh.foo first
name = alloc_whname(dentry->d_name.name, dentry->d_name.len);
if (IS_ERR(name)) {
err = PTR_ERR(name);
goto out;
}
whiteout_dentry =
LOOKUP_ONE_LEN(name, hidden_dentry->d_parent,
dentry->d_name.len + WHLEN);
if (IS_ERR(whiteout_dentry)) {
err = PTR_ERR(whiteout_dentry);
goto out;
}
if (!whiteout_dentry->d_inode) {
DPUT(whiteout_dentry);
whiteout_dentry = NULL;
} else {
hidden_parent_dentry = lock_parent(whiteout_dentry);
/* Set the uid and gid to trick the fs into allowing us to create
* the file */
current->fsuid = hidden_parent_dentry->d_inode->i_uid;
current->fsgid = hidden_parent_dentry->d_inode->i_gid;
//found a.wh.foo entry, remove it then do vfs_mkdir
if (!(err = is_robranch_super(dentry->d_sb, bstart))) {
err =
vfs_unlink(hidden_parent_dentry->d_inode,
whiteout_dentry);
}
DPUT(whiteout_dentry);
current->fsuid = saved_uid;
current->fsgid = saved_gid;
unlock_dir(hidden_parent_dentry);
if (err) {
/* exit if the error returned was NOT -EROFS */
if (!IS_COPYUP_ERR(err))
goto out;
bstart--;
} else {
whiteout_unlinked = 1;
}
}
for (bindex = bstart; bindex >= 0; bindex--) {
hidden_dentry = dtohd_index(dentry, bindex);
if (!hidden_dentry) {
hidden_dentry = create_parents(parent, dentry, bindex);
if (!hidden_dentry || IS_ERR(hidden_dentry)) {
fist_dprint(8,
"hidden dentry NULL for bindex = %d\n",
bindex);
continue;
}
}
hidden_parent_dentry = lock_parent(hidden_dentry);
if (IS_ERR(hidden_parent_dentry)) {
err = PTR_ERR(hidden_parent_dentry);
goto out;
}
if (!(err = is_robranch_super(dentry->d_sb, bindex))) {
err =
vfs_mkdir(hidden_parent_dentry->d_inode,
hidden_dentry, mode);
}
unlock_dir(hidden_parent_dentry);
/* XXX this could potentially return a negative hidden_dentry! */
if (err || !hidden_dentry->d_inode) {
/* break out of for loop if error returned was NOT -EROFS */
if (!IS_COPYUP_ERR(err))
break;
} else {
int i;
int bend = dbend(dentry);
for (i = bindex + 1; i < bend; i++) {
if (dtohd_index(dentry, i)) {
DPUT(dtohd_index(dentry, i));
set_dtohd_index(dentry, i, NULL);
}
}
bend = bindex;
set_dbend(dentry, bend);
err = unionfs_interpose(dentry, parent->i_sb, 0);
if (!err) {
fist_copy_attr_timesizes(parent,
hidden_parent_dentry->
d_inode);
/* update number of links on parent directory */
parent->i_nlink = get_nlinks(parent);
}
whiteout_dentry = LOOKUP_ONE_LEN(UNIONFS_DIR_OPAQUE,
hidden_dentry,
sizeof
(UNIONFS_DIR_OPAQUE) -
1);
if (IS_ERR(whiteout_dentry)) {
err = PTR_ERR(whiteout_dentry);
goto out;
}
down(&hidden_dentry->d_inode->i_sem);
err = vfs_create(hidden_dentry->d_inode,
whiteout_dentry, 0600, NULL);
up(&hidden_dentry->d_inode->i_sem);
DPUT(whiteout_dentry);
if (err) {
fist_dprint(8,
"mkdir: error creating directory override entry: %d\n",
err);
goto out;
}
break;
}
}
out:
if (!dentry->d_inode)
d_drop(dentry);
KFREE(name);
fist_print_dentry("OUT unionfs_mkdir :", dentry);
unlock_dentry(dentry);
print_exit_status(err);
return err;
}
static int unionfs_create(struct inode *parent, struct dentry *dentry,
int mode, struct nameidata *nd)
{
int err = 0;
struct dentry *hidden_dentry = NULL;
struct dentry *whiteout_dentry = NULL;
struct dentry *new_hidden_dentry;
struct dentry *hidden_parent_dentry = NULL;
int bindex = 0, bstart;
char *name = NULL;
print_entry_location();
lock_dentry(dentry);
fist_print_dentry("IN unionfs_create", dentry);
/* We start out in the leftmost branch. */
bstart = dbstart(dentry);
hidden_dentry = dtohd(dentry);
/* check if whiteout exists in this branch, i.e. lookup .wh.foo first */
name = alloc_whname(dentry->d_name.name, dentry->d_name.len);
if (IS_ERR(name)) {
err = PTR_ERR(name);
goto out;
}
whiteout_dentry =
LOOKUP_ONE_LEN(name, hidden_dentry->d_parent,
dentry->d_name.len + WHLEN);
if (IS_ERR(whiteout_dentry)) {
err = PTR_ERR(whiteout_dentry);
whiteout_dentry = NULL;
goto out;
}
if (whiteout_dentry->d_inode) {
/* .wh.foo has been found. */
/* First truncate it and then rename it to foo (hence having
* the same overall effect as a normal create.
*
* XXX: This is not strictly correct. If we have unlinked the
* file and it still has a reference count, then we should
* actually unlink the whiteout so that user's data isn't
* hosed over.
*/
struct dentry *hidden_dir_dentry;
struct iattr newattrs;
down(&whiteout_dentry->d_inode->i_sem);
newattrs.ia_valid = ATTR_CTIME | ATTR_MODE | ATTR_ATIME
| ATTR_MTIME | ATTR_UID | ATTR_GID | ATTR_FORCE
| ATTR_KILL_SUID | ATTR_KILL_SGID;
newattrs.ia_mode = mode & ~current->fs->umask;
newattrs.ia_uid = current->fsuid;
newattrs.ia_gid = current->fsgid;
if (whiteout_dentry->d_inode->i_size != 0) {
newattrs.ia_valid |= ATTR_SIZE;
newattrs.ia_size = 0;
}
err = notify_change(whiteout_dentry, &newattrs);
up(&whiteout_dentry->d_inode->i_sem);
if (err)
printk(KERN_WARNING
"unionfs: %s:%d: notify_change failed: %d, ignoring..\n",
__FILE__, __LINE__, err);
new_hidden_dentry = dtohd(dentry);
DGET(new_hidden_dentry);
hidden_dir_dentry = GET_PARENT(whiteout_dentry);
lock_rename(hidden_dir_dentry, hidden_dir_dentry);
if (!(err = is_robranch_super(dentry->d_sb, bstart))) {
err =
vfs_rename(hidden_dir_dentry->d_inode,
whiteout_dentry,
hidden_dir_dentry->d_inode,
new_hidden_dentry);
}
if (!err) {
fist_copy_attr_timesizes(parent,
new_hidden_dentry->d_parent->
d_inode);
parent->i_nlink = get_nlinks(parent);
}
unlock_rename(hidden_dir_dentry, hidden_dir_dentry);
DPUT(hidden_dir_dentry);
DPUT(new_hidden_dentry);
if (err) {
/* exit if the error returned was NOT -EROFS */
if (!IS_COPYUP_ERR(err))
goto out;
/* We were not able to create the file in this branch,
* so, we try to create it in one branch to left
*/
bstart--;
} else {
/* reset the unionfs dentry to point to the .wh.foo entry. */
/* Discard any old reference. */
DPUT(dtohd(dentry));
/* Trade one reference to another. */
set_dtohd_index(dentry, bstart, whiteout_dentry);
whiteout_dentry = NULL;
err = unionfs_interpose(dentry, parent->i_sb, 0);
goto out;
}
}
for (bindex = bstart; bindex >= 0; bindex--) {
hidden_dentry = dtohd_index(dentry, bindex);
if (!hidden_dentry) {
/* if hidden_dentry is NULL, create the entire
* dentry directory structure in branch 'bindex'.
* hidden_dentry will NOT be null when bindex == bstart
* because lookup passed as a negative unionfs dentry
* pointing to a lone negative underlying dentry */
hidden_dentry = create_parents(parent, dentry, bindex);
if (!hidden_dentry || IS_ERR(hidden_dentry)) {
if (IS_ERR(hidden_dentry))
err = PTR_ERR(hidden_dentry);
continue;
}
}
fist_checkinode(parent, "unionfs_create");
hidden_parent_dentry = lock_parent(hidden_dentry);
if (IS_ERR(hidden_parent_dentry)) {
err = PTR_ERR(hidden_parent_dentry);
goto out;
}
/* We shouldn't create things in a read-only branch. */
if (!(err = is_robranch_super(dentry->d_sb, bindex))) {
//DQ: vfs_create has a different prototype in 2.6
err = vfs_create(hidden_parent_dentry->d_inode,
hidden_dentry, mode, nd);
}
if (err || !hidden_dentry->d_inode) {
unlock_dir(hidden_parent_dentry);
/* break out of for loop if the error wasn't -EROFS */
if (!IS_COPYUP_ERR(err))
break;
} else {
err = unionfs_interpose(dentry, parent->i_sb, 0);
if (!err) {
fist_copy_attr_timesizes(parent,
hidden_parent_dentry->
d_inode);
/* update number of links on parent directory */
parent->i_nlink = get_nlinks(parent);
}
unlock_dir(hidden_parent_dentry);
break;
}
}
out:
DPUT(whiteout_dentry);
KFREE(name);
fist_print_dentry("OUT unionfs_create :", dentry);
unlock_dentry(dentry);
print_exit_status(err);
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;
}
/*
* The locking rules in u2fs_rename are complex. We could use a simpler
* superblock-level name-space lock for renames and copy-ups.
*/
static int u2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
int err = 0;
struct dentry *lower_old_dentry = NULL;
struct dentry *lower_new_dentry = NULL;
struct dentry *lower_old_dir_dentry = NULL;
struct dentry *lower_new_dir_dentry = NULL;
struct dentry *trap = NULL;
struct dentry *ret = NULL;
struct path lower_old_path, lower_new_path;
/* creating parent directories if destination is read-only */
if((U2FS_D(old_dentry)->lower_path[LEFT].dentry) == NULL &&
(U2FS_D(old_dentry)->lower_path[LEFT].mnt) == NULL){
err = create_whiteout(old_dentry);
if(err){
err = -EIO;
goto out_copyup;
}
err = copyup_dentry(old_dir, old_dentry,
old_dentry->d_name.name, old_dentry->d_name.len,
NULL, i_size_read(old_dentry->d_inode));
if(err)
goto out_copyup;
}
if((U2FS_D(new_dentry)->lower_path[LEFT].dentry) == NULL &&
(U2FS_D(new_dentry)->lower_path[LEFT].mnt) == NULL){
ret = create_parents(new_dir, new_dentry,
new_dentry->d_name.name);
if (!ret || IS_ERR(ret)) {
err = PTR_ERR(ret);
if (!IS_COPYUP_ERR(err))
printk(KERN_ERR
"u2fs: create_parents for "
"u2fs_rename failed"
"err=%d\n", err);
goto out_copyup;
}
u2fs_postcopyup_setmnt(new_dentry);
u2fs_put_reset_lower_path(new_dentry, RIGHT);
if(err)
goto out_copyup;
}
u2fs_get_lower_path(old_dentry, &lower_old_path, LEFT);
u2fs_get_lower_path(new_dentry, &lower_new_path, LEFT);
lower_old_dentry = lower_old_path.dentry;
lower_new_dentry = lower_new_path.dentry;
lower_old_dir_dentry = dget_parent(lower_old_dentry);
lower_new_dir_dentry = dget_parent(lower_new_dentry);
trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
/* source should not be ancestor of target */
if (trap == lower_old_dentry) {
err = -EINVAL;
goto out;
}
/* target should not be ancestor of source */
if (trap == lower_new_dentry) {
err = -ENOTEMPTY;
goto out;
}
err = mnt_want_write(lower_old_path.mnt);
if (err)
goto out;
err = mnt_want_write(lower_new_path.mnt);
if (err)
goto out_drop_old_write;
err = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
lower_new_dir_dentry->d_inode, lower_new_dentry);
if (err)
goto out_err;
fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
fsstack_copy_inode_size(new_dir, lower_new_dir_dentry->d_inode);
if (new_dir != old_dir) {
fsstack_copy_attr_all(old_dir,
lower_old_dir_dentry->d_inode);
fsstack_copy_inode_size(old_dir,
lower_old_dir_dentry->d_inode);
}
out_err:
mnt_drop_write(lower_new_path.mnt);
out_drop_old_write:
mnt_drop_write(lower_old_path.mnt);
out:
unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
dput(lower_old_dir_dentry);
dput(lower_new_dir_dentry);
u2fs_put_lower_path(old_dentry, &lower_old_path);
u2fs_put_lower_path(new_dentry, &lower_new_path);
out_copyup:
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 *hidden_old_dentry = NULL;
struct dentry *hidden_new_dentry = NULL;
struct dentry *hidden_dir_dentry = NULL;
struct dentry *whiteout_dentry;
char *name = NULL;
print_entry_location();
double_lock_dentry(new_dentry, old_dentry);
hidden_new_dentry = dtohd(new_dentry);
/* check if whiteout exists in the branch of new dentry, i.e. lookup
* .wh.foo first. If present, delete it */
name = alloc_whname(new_dentry->d_name.name, new_dentry->d_name.len);
if (IS_ERR(name)) {
err = PTR_ERR(name);
goto out;
}
whiteout_dentry =
LOOKUP_ONE_LEN(name, hidden_new_dentry->d_parent,
new_dentry->d_name.len + WHLEN);
if (IS_ERR(whiteout_dentry)) {
err = PTR_ERR(whiteout_dentry);
goto out;
}
if (!whiteout_dentry->d_inode) {
DPUT(whiteout_dentry);
whiteout_dentry = NULL;
} else {
/* found a .wh.foo entry, unlink it and then call vfs_link() */
hidden_dir_dentry = lock_parent(whiteout_dentry);
if (!
(err =
is_robranch_super(new_dentry->d_sb,
dbstart(new_dentry)))) {
err =
vfs_unlink(hidden_dir_dentry->d_inode,
whiteout_dentry);
}
fist_copy_attr_times(dir, hidden_dir_dentry->d_inode);
dir->i_nlink = get_nlinks(dir);
unlock_dir(hidden_dir_dentry);
hidden_dir_dentry = NULL;
DPUT(whiteout_dentry);
if (err)
goto out;
}
if (dbstart(old_dentry) != dbstart(new_dentry)) {
hidden_new_dentry =
create_parents(dir, new_dentry, dbstart(old_dentry));
err = PTR_ERR(hidden_new_dentry);
if (IS_COPYUP_ERR(err))
goto docopyup;
if (!hidden_new_dentry || IS_ERR(hidden_new_dentry))
goto out;
}
hidden_new_dentry = dtohd(new_dentry);
hidden_old_dentry = dtohd(old_dentry);
BUG_ON(dbstart(old_dentry) != dbstart(new_dentry));
hidden_dir_dentry = lock_parent(hidden_new_dentry);
if (!(err = is_robranch(old_dentry)))
err =
vfs_link(hidden_old_dentry, hidden_dir_dentry->d_inode,
hidden_new_dentry);
unlock_dir(hidden_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_dentry->d_parent->
d_inode, old_dentry,
old_bstart, bindex, NULL,
old_dentry->d_inode->i_size);
if (!err) {
hidden_new_dentry =
create_parents(dir, new_dentry, bindex);
hidden_old_dentry = dtohd(old_dentry);
hidden_dir_dentry =
lock_parent(hidden_new_dentry);
/* do vfs_link */
err =
vfs_link(hidden_old_dentry,
hidden_dir_dentry->d_inode,
hidden_new_dentry);
unlock_dir(hidden_dir_dentry);
goto check_link;
}
}
goto out;
}
check_link:
if (err || !hidden_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_instantiate(new_dentry, new_dentry->d_inode);
fist_copy_attr_all(dir, hidden_new_dentry->d_parent->d_inode);
/* propagate number of hard-links */
old_dentry->d_inode->i_nlink = get_nlinks(old_dentry->d_inode);
out:
if (!new_dentry->d_inode)
d_drop(new_dentry);
KFREE(name);
unlock_dentry(new_dentry);
unlock_dentry(old_dentry);
print_exit_status(err);
return err;
}
