static struct dentry *lookup_whiteout(struct dentry *dentry)
{
char *whname;
int bindex = -1, bstart = -1, bend = -1;
struct dentry *parent, *hidden_parent, *wh_dentry;
whname = alloc_whname(dentry->d_name.name, dentry->d_name.len);
if (IS_ERR(whname))
return (void *)whname;
parent = GET_PARENT(dentry);
lock_dentry(parent);
bstart = dbstart(parent);
bend = dbend(parent);
wh_dentry = ERR_PTR(-ENOENT);
for (bindex = bstart; bindex <= bend; bindex++) {
hidden_parent = dtohd_index(parent, bindex);
if (!hidden_parent)
continue;
wh_dentry =
LOOKUP_ONE_LEN(whname, hidden_parent,
dentry->d_name.len + WHLEN);
if (IS_ERR(wh_dentry))
continue;
if (wh_dentry->d_inode)
break;
DPUT(wh_dentry);
wh_dentry = ERR_PTR(-ENOENT);
}
unlock_dentry(parent);
DPUT(parent);
KFREE(whname);
return wh_dentry;
}
/* The rest of these are utility functions for lookup. */
static int is_opaque_dir(struct dentry *dentry, int bindex)
{
int err = 0;
struct dentry *hidden_dentry;
struct dentry *wh_hidden_dentry;
struct inode *hidden_inode;
uid_t saved_uid = current->fsuid;
gid_t saved_gid = current->fsgid;
print_entry_location();
hidden_dentry = dtohd_index(dentry, bindex);
hidden_inode = hidden_dentry->d_inode;
BUG_ON(!S_ISDIR(hidden_inode->i_mode));
current->fsuid = hidden_inode->i_uid;
current->fsgid = hidden_inode->i_gid;
wh_hidden_dentry = LOOKUP_ONE_LEN(UNIONFS_DIR_OPAQUE, hidden_dentry,
sizeof(UNIONFS_DIR_OPAQUE) - 1);
current->fsuid = saved_uid;
current->fsgid = saved_gid;
if (IS_ERR(wh_hidden_dentry)) {
err = PTR_ERR(wh_hidden_dentry);
fist_dprint(1, "LOOKUP_ONE_LEN returned: %d\n", err);
goto out;
}
if (wh_hidden_dentry->d_inode)
err = 1;
DPUT(wh_hidden_dentry);
out:
print_exit_status(err);
return err;
}
/*
* Rename all occurences of source except for the leftmost destination
*/
static int __rename_all(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
fd_set * success_mask, struct rename_info *info)
{
int bindex;
int err = 0;
print_entry_location();
/* Loop through all the branches from right to left and rename all
* instances of source to destination, except the leftmost destination
*/
for (bindex = info->old_bend; bindex >= info->old_bstart; bindex--) {
/* We don't rename if there is no source. */
if (dtohd_index(old_dentry, bindex) == NULL)
continue;
/* we rename the bstart of destination only at the last of
* all operations, so that we don't lose it on error
*/
if (info->clobber && (bindex == info->new_bstart))
continue;
DPUT(info->wh_old);
info->bwh_old = bindex;
/* We shouldn't have a handle on this if there is no inode. */
err =
do_rename(old_dir, old_dentry, new_dir, new_dentry, bindex,
&info->wh_old);
if (!err) {
/* For reverting. */
FD_SET(bindex, success_mask);
/* So we know not to copyup on failures the right */
info->rename_ok = bindex;
} else if (IS_COPYUP_ERR(err)) {
if (info->isdir) {
err = -EXDEV;
break;
}
/* we need a whiteout... */
info->do_whiteout = bindex - 1;
if (bindex == info->old_bstart)
/* ...and a copyup */
info->do_copyup = bindex - 1;
err = 0; /* reset error */
} else
break; /* error is set by do_rename */
}
print_exit_status(err);
return err;
}
static int unionfs_unlink_whiteout(struct inode *dir, struct dentry *dentry)
{
struct dentry *hidden_dentry;
struct dentry *hidden_dir_dentry;
int bindex;
int err = 0;
print_entry_location();
if ((err = unionfs_partial_lookup(dentry)))
goto out;
bindex = dbstart(dentry);
hidden_dentry = dtohd_index(dentry, bindex);
if (!hidden_dentry)
goto out;
hidden_dir_dentry = lock_parent(hidden_dentry);
/* avoid destroying the hidden inode if the file is in use */
DGET(hidden_dentry);
if (!(err = is_robranch_super(dentry->d_sb, bindex)))
err = vfs_unlink(hidden_dir_dentry->d_inode, hidden_dentry);
DPUT(hidden_dentry);
fist_copy_attr_times(dir, hidden_dir_dentry->d_inode);
unlock_dir(hidden_dir_dentry);
if (err) {
if (!IS_COPYUP_ERR(err))
goto out;
}
if (err) {
if (dbstart(dentry) == 0) {
goto out;
}
err = create_whiteout(dentry, dbstart(dentry) - 1);
} else if (dbopaque(dentry) != -1) {
/* There is a hidden lower-priority file with the same name. */
err = create_whiteout(dentry, dbopaque(dentry));
} else {
err = create_whiteout(dentry, dbstart(dentry));
}
out:
if (!err)
dentry->d_inode->i_nlink--;
/* We don't want to leave negative leftover dentries for revalidate. */
if (!err && (dbopaque(dentry) != -1))
update_bstart(dentry);
print_exit_status(err);
return err;
}
/*
* Unlink all destinations (if they exist) to the left of the left-most
* source
*/
static int __rename_all_unlink(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
struct rename_info *info)
{
int bindex;
struct dentry *unlink_dentry;
struct dentry *unlink_dir_dentry;
int err = 0;
print_entry_location();
for (bindex = info->old_bstart - 1; bindex > info->new_bstart; bindex--) {
unlink_dentry = dtohd_index(new_dentry, bindex);
if (!unlink_dentry)
continue;
/* lock, unlink if possible, copyup times, unlock */
unlink_dir_dentry = lock_parent(unlink_dentry);
if (!(err = is_robranch_super(old_dir->i_sb, bindex)))
err =
vfs_unlink(unlink_dir_dentry->d_inode,
unlink_dentry);
fist_copy_attr_times(new_dentry->d_parent->d_inode,
unlink_dir_dentry->d_inode);
new_dentry->d_parent->d_inode->i_nlink =
get_nlinks(new_dentry->d_parent->d_inode);
unlock_dir(unlink_dir_dentry);
if (!err) {
if (bindex != info->new_bstart) {
DPUT(unlink_dentry);
set_dtohd_index(new_dentry, bindex, NULL);
}
} else if (IS_COPYUP_ERR(err)) {
if (info->isdir) {
err = -EXDEV;
break;
}
info->do_copyup = bindex - 1;
err = 0; /* reset error */
} else
break; /* err is set by is_ro_branch_super or vfs_unlink */
}
print_exit_status(err);
return err;
}
void unionfs_d_release(struct dentry *dentry)
{
struct dentry *hidden_dentry;
int bindex, bstart, bend;
print_entry_location();
/* There is no reason to lock the dentry, because we have the only
* reference, but the printing functions verify that we have a lock
* on the dentry before calling dbstart, etc. */
lock_dentry(dentry);
__fist_print_dentry("unionfs_d_release IN dentry", dentry, 0);
/* this could be a negative dentry, so check first */
if (!dtopd(dentry)) {
fist_dprint(6, "dentry without private data: %*s",
dentry->d_name.len, dentry->d_name.name);
goto out;
} else if (dbstart(dentry) < 0) {
/* this is due to a failed lookup */
/* the failed lookup has a dtohd_ptr set to null,
but this is a better check */
fist_dprint(6, "dentry without hidden dentries : %*s",
dentry->d_name.len, dentry->d_name.name);
goto out_free;
}
/* Release all the hidden dentries */
bstart = dbstart(dentry);
bend = dbend(dentry);
for (bindex = bstart; bindex <= bend; bindex++) {
hidden_dentry = dtohd_index(dentry, bindex);
DPUT(hidden_dentry);
set_dtohd_index(dentry, bindex, NULL);
}
/* free private data (unionfs_dentry_info) here */
KFREE(dtohd_ptr(dentry));
dtohd_ptr(dentry) = NULL;
out_free:
/* No need to unlock it, because it is disappeared. */
#ifdef TRACKLOCK
printk("DESTROYLOCK:%p\n", dentry);
#endif
free_dentry_private_data(dtopd(dentry));
dtopd_lhs(dentry) = NULL; /* just to be safe */
out:
print_exit_location();
}
void update_bstart(struct dentry *dentry)
{
int bindex;
int bstart = dbstart(dentry);
int bend = dbend(dentry);
struct dentry *hidden_dentry;
for (bindex = bstart; bindex <= bend; bindex++) {
hidden_dentry = dtohd_index(dentry, bindex);
if (!hidden_dentry)
continue;
if (hidden_dentry->d_inode) {
set_dbstart(dentry, bindex);
break;
}
DPUT(hidden_dentry);
set_dtohd_index(dentry, bindex, NULL);
}
}
static int unionfs_rmdir_first(struct inode *dir, struct dentry *dentry,
struct unionfs_dir_state *namelist)
{
int err;
struct dentry *hidden_dentry;
struct dentry *hidden_dir_dentry = NULL;
print_entry_location();
fist_print_dentry("IN unionfs_rmdir_first: ", dentry);
/* Here we need to remove whiteout entries. */
err = delete_whiteouts(dentry, dbstart(dentry), namelist);
if (err) {
goto out;
}
hidden_dentry = dtohd(dentry);
PASSERT(hidden_dentry);
hidden_dir_dentry = lock_parent(hidden_dentry);
/* avoid destroying the hidden inode if the file is in use */
DGET(hidden_dentry);
if (!(err = is_robranch(dentry))) {
err = vfs_rmdir(hidden_dir_dentry->d_inode, hidden_dentry);
}
DPUT(hidden_dentry);
fist_copy_attr_times(dir, hidden_dir_dentry->d_inode);
/* propagate number of hard-links */
dentry->d_inode->i_nlink = get_nlinks(dentry->d_inode);
out:
if (hidden_dir_dentry) {
unlock_dir(hidden_dir_dentry);
}
fist_print_dentry("OUT unionfs_rmdir_first: ", dentry);
print_exit_status(err);
return err;
}
/*
* The function is nasty, nasty, nasty, but so is rename. :(
*/
static int unionfs_rename_all(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
struct dentry *parent_dentry = NULL;
int err = 0;
int eio;
/* These variables control error handling. */
fd_set success_mask;
char *name = NULL;
/* unfortunately, we have to resort to this, because dbstart/dbend would
return different things in different place of the rename code */
struct rename_info info;
info.rename_ok = FD_SETSIZE; /* The last rename that is ok. */
info.do_copyup = -1; /* Where we should start copyup. */
info.do_whiteout = -1; /* Where we should start whiteouts of the source. */
info.wh_old = NULL;
info.bwh_old = -1;
print_entry_location();
parent_dentry = old_dentry->d_parent;
name = KMALLOC(old_dentry->d_name.len + 1, GFP_KERNEL);
if (!name) {
err = -ENOMEM;
goto out;
}
strncpy(name, old_dentry->d_name.name, old_dentry->d_name.len + 1);
info.new_bstart = dbstart(new_dentry);
info.new_bend = dbend(new_dentry);
info.old_bstart = dbstart(old_dentry);
info.old_bend = dbend(old_dentry);
BUG_ON(info.new_bstart < 0);
BUG_ON(info.old_bstart < 0);
/* The failure mask only can deal with FD_SETSIZE entries. */
BUG_ON(info.old_bend > FD_SETSIZE);
BUG_ON(info.new_bend > FD_SETSIZE);
FD_ZERO(&success_mask);
/* Life is simpler if the dentry doesn't exist. */
info.clobber =
(dtohd_index(new_dentry, info.new_bstart)->d_inode) ? 1 : 0;
info.isdir = S_ISDIR(old_dentry->d_inode->i_mode);
/* rename everything we can */
err =
__rename_all(old_dir, old_dentry, new_dir, new_dentry,
&success_mask, &info);
if (err)
goto revert;
/* unlink destinations even further left */
err =
__rename_all_unlink(old_dir, old_dentry, new_dir, new_dentry,
&info);
if (err)
goto revert;
if (info.clobber) {
/* Now we need to handle the leftmost of the destination. */
err =
__rename_all_clobber(old_dir, old_dentry, new_dir,
new_dentry, &info);
if (err)
goto revert;
}
/* Copy up if necessary */
if (info.do_copyup != -1) {
int bindex;
for (bindex = info.do_copyup; bindex >= 0; bindex--) {
err =
copyup_dentry(old_dentry->d_parent->d_inode,
old_dentry, info.old_bstart, bindex,
NULL, old_dentry->d_inode->i_size);
if (!err) {
DPUT(info.wh_old);
info.bwh_old = bindex;
err =
do_rename(old_dir, old_dentry, new_dir,
new_dentry, bindex, &info.wh_old);
break;
}
}
}
/* Create a whiteout for the source. */
if (info.do_whiteout != -1) {
struct dentry *hidden_parent;
BUG_ON(info.do_whiteout < 0
|| !info.wh_old || IS_ERR(info.wh_old)
|| info.wh_old->d_inode || info.bwh_old < 0);
hidden_parent = lock_parent(info.wh_old);
err = vfs_create(hidden_parent->d_inode, info.wh_old, S_IRUGO,
NULL);
unlock_dir(hidden_parent);
if (!err)
set_dbopaque(old_dentry, info.bwh_old);
else {
/* We can't fix anything now, so we -EIO. */
printk(KERN_WARNING "We can't create a whiteout for the"
"source in rename!\n");
err = -EIO;
goto out;
}
}
/* We are at the point where reverting doesn't happen. */
goto out;
revert:
/* something bad happened, try to revert */
eio =
__rename_all_revert(old_dir, old_dentry, new_dir, new_dentry,
&success_mask, &info);
if (eio)
err = eio;
out:
DPUT(info.wh_old);
KFREE(name);
print_exit_status(err);
return err;
}
/*
* Finish off the rename, by either over writing the last destination or
* unlinking the last destination to the left of us
*/
static int __rename_all_clobber(struct inode *old_dir,
struct dentry *old_dentry,
struct inode *new_dir,
struct dentry *new_dentry,
struct rename_info *info)
{
int err = 0;
print_entry_location();
if (dtohd_index(old_dentry, info->new_bstart)) {
/* rename the last source, knowing we're overwriting something */
DPUT(info->wh_old);
info->bwh_old = info->new_bstart;
err =
do_rename(old_dir, old_dentry, new_dir, new_dentry,
info->new_bstart, &info->wh_old);
if (IS_COPYUP_ERR(err)) {
if (info->isdir) {
err = -EXDEV;
goto out;
}
if (info->rename_ok > info->new_bstart) {
if ((info->do_copyup == -1)
|| (info->new_bstart - 1 < info->do_copyup))
info->do_copyup = info->new_bstart - 1;
}
if ((info->do_whiteout == -1)
|| (info->new_bstart - 1 < info->do_whiteout)) {
info->do_whiteout = info->new_bstart - 1;
}
err = 0; // reset error
}
} else if (info->new_bstart < info->old_bstart) {
/* the newly renamed file would get hidden, let's unlink the
* file to the left of it */
struct dentry *unlink_dentry;
struct dentry *unlink_dir_dentry;
unlink_dentry = dtohd_index(new_dentry, info->new_bstart);
unlink_dir_dentry = lock_parent(unlink_dentry);
if (!(err = is_robranch_super(old_dir->i_sb, info->new_bstart)))
err = vfs_unlink(unlink_dir_dentry->d_inode,
unlink_dentry);
fist_copy_attr_times(new_dentry->d_parent->d_inode,
unlink_dir_dentry->d_inode);
new_dentry->d_parent->d_inode->i_nlink =
get_nlinks(new_dentry->d_parent->d_inode);
unlock_dir(unlink_dir_dentry);
if (IS_COPYUP_ERR(err)) {
if (info->isdir) {
err = -EXDEV;
goto out;
}
if ((info->do_copyup == -1)
|| (info->new_bstart - 1 < info->do_copyup))
info->do_copyup = info->new_bstart - 1;
err = 0; // reset error
}
}
out:
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_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_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;
}
int copyup_named_dentry(struct inode *dir, struct dentry *dentry,
int bstart, int new_bindex, char *name,
int namelen, struct file **copyup_file, int len)
{
struct dentry *new_hidden_dentry;
struct dentry *old_hidden_dentry = NULL;
struct super_block *sb;
struct file *input_file = NULL;
struct file *output_file = NULL;
ssize_t read_bytes, write_bytes;
mm_segment_t old_fs;
int err = 0;
char *buf;
int old_bindex;
int got_branch_input = -1;
int got_branch_output = -1;
int old_bstart;
int old_bend;
int size = len;
struct dentry *new_hidden_parent_dentry;
mm_segment_t oldfs;
char *symbuf = NULL;
uid_t saved_uid = current->fsuid;
gid_t saved_gid = current->fsgid;
print_entry_location();
verify_locked(dentry);
fist_print_dentry("IN: copyup_named_dentry", dentry);
old_bindex = bstart;
old_bstart = dbstart(dentry);
old_bend = dbend(dentry);
ASSERT(new_bindex >= 0);
ASSERT(new_bindex < old_bindex);
PASSERT(dir);
PASSERT(dentry);
sb = dir->i_sb;
if ((err = is_robranch_super(sb, new_bindex)))
goto out;
/* Create the directory structure above this dentry. */
new_hidden_dentry = create_parents_named(dir, dentry, name, new_bindex);
PASSERT(new_hidden_dentry);
if (IS_ERR(new_hidden_dentry)) {
err = PTR_ERR(new_hidden_dentry);
goto out;
}
fist_print_generic_dentry("Copyup Object", new_hidden_dentry);
/* Now we actually create the object. */
old_hidden_dentry = dtohd_index(dentry, old_bindex);
PASSERT(old_hidden_dentry);
PASSERT(old_hidden_dentry->d_inode);
DGET(old_hidden_dentry);
/* For symlinks, we must read the link before we lock the directory. */
if (S_ISLNK(old_hidden_dentry->d_inode->i_mode)) {
PASSERT(old_hidden_dentry->d_inode->i_op);
PASSERT(old_hidden_dentry->d_inode->i_op->readlink);
symbuf = KMALLOC(PATH_MAX, GFP_UNIONFS);
if (!symbuf) {
err = -ENOMEM;
goto copyup_readlink_err;
}
oldfs = get_fs();
set_fs(KERNEL_DS);
err =
old_hidden_dentry->d_inode->i_op->
readlink(old_hidden_dentry, symbuf, PATH_MAX);
set_fs(oldfs);
if (err < 0)
goto copyup_readlink_err;
symbuf[err] = '\0';
}
/* Now we lock the parent, and create the object in the new branch. */
new_hidden_parent_dentry = lock_parent(new_hidden_dentry);
current->fsuid = new_hidden_parent_dentry->d_inode->i_uid;
current->fsgid = new_hidden_parent_dentry->d_inode->i_gid;
if (S_ISDIR(old_hidden_dentry->d_inode->i_mode)) {
err = vfs_mkdir(new_hidden_parent_dentry->d_inode,
new_hidden_dentry, S_IRWXU);
} else if (S_ISLNK(old_hidden_dentry->d_inode->i_mode)) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
err = vfs_symlink(new_hidden_parent_dentry->d_inode,
new_hidden_dentry, symbuf);
#else
err = vfs_symlink(new_hidden_parent_dentry->d_inode,
new_hidden_dentry, symbuf, S_IRWXU);
#endif
} else if (S_ISBLK(old_hidden_dentry->d_inode->i_mode)
|| S_ISCHR(old_hidden_dentry->d_inode->i_mode)
|| S_ISFIFO(old_hidden_dentry->d_inode->i_mode)
|| S_ISSOCK(old_hidden_dentry->d_inode->i_mode)) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
err = vfs_mknod(new_hidden_parent_dentry->d_inode,
new_hidden_dentry,
old_hidden_dentry->d_inode->i_mode,
kdev_t_to_nr(old_hidden_dentry->d_inode->
i_rdev));
#else
err = vfs_mknod(new_hidden_parent_dentry->d_inode,
new_hidden_dentry,
old_hidden_dentry->d_inode->i_mode,
old_hidden_dentry->d_inode->i_rdev);
#endif
} else if (S_ISREG(old_hidden_dentry->d_inode->i_mode)) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
err = vfs_create(new_hidden_parent_dentry->d_inode,
new_hidden_dentry, S_IRWXU);
#else
err = vfs_create(new_hidden_parent_dentry->d_inode,
new_hidden_dentry, S_IRWXU, NULL);
#endif
} else {
char diemsg[100];
snprintf(diemsg, sizeof(diemsg), "Unknown inode type %d\n",
old_hidden_dentry->d_inode->i_mode);
FISTBUG(diemsg);
}
current->fsuid = saved_uid;
current->fsgid = saved_gid;
unlock_dir(new_hidden_parent_dentry);
copyup_readlink_err:
KFREE(symbuf);
if (err) {
/* get rid of the hidden dentry and all its traces */
DPUT(new_hidden_dentry);
set_dtohd_index(dentry, new_bindex, NULL);
set_dbstart(dentry, old_bstart);
set_dbend(dentry, old_bend);
goto out;
}
/* We actually copyup the file here. */
if (S_ISREG(old_hidden_dentry->d_inode->i_mode)) {
mntget(stohiddenmnt_index(sb, old_bindex));
branchget(sb, old_bindex);
got_branch_input = old_bindex;
input_file =
DENTRY_OPEN(old_hidden_dentry,
stohiddenmnt_index(sb, old_bindex), O_RDONLY);
if (IS_ERR(input_file)) {
err = PTR_ERR(input_file);
goto out;
}
if (!input_file->f_op || !input_file->f_op->read) {
err = -EINVAL;
goto out;
}
/* copy the new file */
DGET(new_hidden_dentry);
mntget(stohiddenmnt_index(sb, new_bindex));
branchget(sb, new_bindex);
got_branch_output = new_bindex;
output_file =
DENTRY_OPEN(new_hidden_dentry,
stohiddenmnt_index(sb, new_bindex), O_WRONLY);
if (IS_ERR(output_file)) {
err = PTR_ERR(output_file);
goto out;
}
if (!output_file->f_op || !output_file->f_op->write) {
err = -EINVAL;
goto out;
}
/* allocating a buffer */
buf = (char *)KMALLOC(PAGE_SIZE, GFP_UNIONFS);
if (!buf) {
err = -ENOMEM;
goto out;
}
/* now read PAGE_SIZE bytes from offset 0 in a loop */
old_fs = get_fs();
input_file->f_pos = 0;
output_file->f_pos = 0;
set_fs(KERNEL_DS);
do {
if (len >= PAGE_SIZE)
size = PAGE_SIZE;
else if ((len < PAGE_SIZE) && (len > 0))
size = len;
len -= PAGE_SIZE;
read_bytes =
input_file->f_op->read(input_file, buf, size,
&input_file->f_pos);
if (read_bytes <= 0) {
err = read_bytes;
break;
}
write_bytes =
output_file->f_op->write(output_file, buf,
read_bytes,
&output_file->f_pos);
if (write_bytes < 0 || (write_bytes < read_bytes)) {
err = -EIO;
break;
}
} while ((read_bytes > 0) && (len > 0));
set_fs(old_fs);
KFREE(buf);
}
/* Set permissions. */
if ((err =
copyup_permissions(sb, old_hidden_dentry, new_hidden_dentry)))
goto out;
/* Selinux uses extended attributes for permissions. */
#if defined(UNIONFS_XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20))
if ((err = copyup_xattrs(old_hidden_dentry, new_hidden_dentry)))
goto out;
#endif
/* do not allow files getting deleted to be reinterposed */
if (!d_deleted(dentry))
unionfs_reinterpose(dentry);
out:
if (input_file && !IS_ERR(input_file)) {
fput(input_file);
} else {
/* since input file was not opened, we need to explicitly
* dput the old_hidden_dentry
*/
DPUT(old_hidden_dentry);
}
/* in any case, we have to branchput */
if (got_branch_input >= 0)
branchput(sb, got_branch_input);
if (output_file) {
if (copyup_file && !err) {
*copyup_file = output_file;
} else {
fput(output_file);
branchput(sb, got_branch_output);
}
}
fist_print_dentry("OUT: copyup_dentry", dentry);
fist_print_inode("OUT: copyup_dentry", dentry->d_inode);
print_exit_status(err);
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;
}
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;
}
static int parse_dirs_option(struct super_block *sb, struct unionfs_dentry_info
*hidden_root_info, char *options)
{
struct nameidata nd;
char *name;
int err = 0;
int branches = 1;
int bindex = 0;
int i = 0;
int j = 0;
struct dentry *dent1 = NULL;
struct dentry *dent2 = NULL;
if (options[0] == '\0') {
printk(KERN_WARNING "unionfs: no branches specified\n");
err = -EINVAL;
goto out;
}
/* Each colon means we have a separator, this is really just a rough
* guess, since strsep will handle empty fields for us. */
for (i = 0; options[i]; i++) {
if (options[i] == ':')
branches++;
}
/* allocate space for underlying pointers to hidden dentry */
if (!(stopd(sb)->usi_data = alloc_new_data(branches))) {
err = -ENOMEM;
goto out;
}
if (!(hidden_root_info->udi_dentry = alloc_new_dentries(branches))) {
err = -ENOMEM;
goto out;
}
/* now parsing the string b1:b2=rw:b3=ro:b4 */
branches = 0;
while ((name = strsep(&options, ":")) != NULL) {
int perms;
if (!*name)
continue;
branches++;
/* strip off =rw or =ro if it is specified. */
perms = parse_branch_mode(name);
if (!bindex && !(perms & MAY_WRITE)) {
err = -EINVAL;
goto out;
}
fist_dprint(4, "unionfs: using directory: %s (%c%c%c)\n",
name, perms & MAY_READ ? 'r' : '-',
perms & MAY_WRITE ? 'w' : '-',
perms & MAY_NFSRO ? 'n' : '-');
err = path_lookup(name, LOOKUP_FOLLOW, &nd);
RECORD_PATH_LOOKUP(&nd);
if (err) {
printk(KERN_WARNING "unionfs: error accessing "
"hidden directory '%s' (error %d)\n", name, err);
goto out;
}
if ((err = check_branch(&nd))) {
printk(KERN_WARNING "unionfs: hidden directory "
"'%s' is not a valid branch\n", name);
path_release(&nd);
RECORD_PATH_RELEASE(&nd);
goto out;
}
hidden_root_info->udi_dentry[bindex] = nd.dentry;
set_stohiddenmnt_index(sb, bindex, nd.mnt);
set_branchperms(sb, bindex, perms);
set_branch_count(sb, bindex, 0);
if (hidden_root_info->udi_bstart < 0)
hidden_root_info->udi_bstart = bindex;
hidden_root_info->udi_bend = bindex;
bindex++;
}
if (branches == 0) {
printk(KERN_WARNING "unionfs: no branches specified\n");
err = -EINVAL;
goto out;
}
BUG_ON(branches != (hidden_root_info->udi_bend + 1));
/* ensure that no overlaps exist in the branches */
for (i = 0; i < branches; i++) {
for (j = i + 1; j < branches; j++) {
dent1 = hidden_root_info->udi_dentry[i];
dent2 = hidden_root_info->udi_dentry[j];
if (is_branch_overlap(dent1, dent2)) {
goto out_overlap;
}
}
}
out_overlap:
if (i != branches) {
printk(KERN_WARNING "unionfs: branches %d and %d overlap\n", i,
j);
err = -EINVAL;
goto out;
}
out:
if (err) {
for (i = 0; i < branches; i++) {
if (hidden_root_info->udi_dentry[i])
DPUT(hidden_root_info->udi_dentry[i]);
}
KFREE(hidden_root_info->udi_dentry);
KFREE(stopd(sb)->usi_data);
/* MUST clear the pointers to prevent potential double free if
* the caller dies later on
*/
hidden_root_info->udi_dentry = NULL;
stopd(sb)->usi_data = NULL;
}
return err;
}
struct dentry *unionfs_lookup_backend(struct dentry *dentry, int lookupmode)
{
int err = 0;
struct dentry *hidden_dentry = NULL;
struct dentry *wh_hidden_dentry = NULL;
struct dentry *hidden_dir_dentry = NULL;
struct dentry *parent_dentry = NULL;
int bindex, bstart, bend, bopaque;
int dentry_count = 0; /* Number of positive dentries. */
int first_dentry_offset = -1;
struct dentry *first_hidden_dentry = NULL;
int locked_parent = 0;
int locked_child = 0;
int opaque;
char *whname = NULL;
const char *name;
int namelen;
print_entry("mode = %d", lookupmode);
/* 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. */
if (lookupmode == INTERPOSE_PARTIAL || lookupmode == INTERPOSE_REVAL
|| lookupmode == INTERPOSE_REVAL_NEG) {
verify_locked(dentry);
} else {
BUG_ON(dtopd_nocheck(dentry) != NULL);
locked_child = 1;
}
if (lookupmode != INTERPOSE_PARTIAL)
if ((err = new_dentry_private_data(dentry)))
goto out;
/* must initialize dentry operations */
dentry->d_op = &unionfs_dops;
parent_dentry = GET_PARENT(dentry);
/* We never partial lookup the root directory. */
if (parent_dentry != dentry) {
lock_dentry(parent_dentry);
locked_parent = 1;
} else {
DPUT(parent_dentry);
parent_dentry = NULL;
goto out;
}
fist_print_dentry("IN unionfs_lookup (parent)", parent_dentry);
fist_print_dentry("IN unionfs_lookup (child)", dentry);
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_dentry);
bend = dbend(parent_dentry);
bopaque = dbopaque(parent_dentry);
BUG_ON(bstart < 0);
/* It would be ideal if we could convert partial lookups to only have
* to do this work when they really need to. It could probably improve
* performance quite a bit, and maybe simplify the rest of the code. */
if (lookupmode == INTERPOSE_PARTIAL) {
bstart++;
if ((bopaque != -1) && (bopaque < bend))
bend = bopaque;
}
fist_dprint(8, "bstart = %d, bend = %d\n", bstart, bend);
for (bindex = bstart; bindex <= bend; bindex++) {
hidden_dentry = dtohd_index(dentry, bindex);
if (lookupmode == INTERPOSE_PARTIAL && hidden_dentry)
continue;
BUG_ON(hidden_dentry != NULL);
hidden_dir_dentry = dtohd_index(parent_dentry, bindex);
/* if the parent hidden dentry does not exist skip this */
if (!(hidden_dir_dentry && hidden_dir_dentry->d_inode))
continue;
/* also skip it if the parent isn't a directory. */
if (!S_ISDIR(hidden_dir_dentry->d_inode->i_mode))
continue;
/* Reuse the whiteout name because its value doesn't change. */
if (!whname) {
whname = alloc_whname(name, namelen);
if (IS_ERR(whname)) {
err = PTR_ERR(whname);
goto out_free;
}
}
/* check if whiteout exists in this branch: lookup .wh.foo */
wh_hidden_dentry = LOOKUP_ONE_LEN(whname, hidden_dir_dentry,
namelen + WHLEN);
if (IS_ERR(wh_hidden_dentry)) {
DPUT(first_hidden_dentry);
err = PTR_ERR(wh_hidden_dentry);
goto out_free;
}
if (wh_hidden_dentry->d_inode) {
/* We found a whiteout so lets give up. */
fist_dprint(8, "whiteout found in %d\n", bindex);
if (S_ISREG(wh_hidden_dentry->d_inode->i_mode)) {
set_dbend(dentry, bindex);
set_dbopaque(dentry, bindex);
DPUT(wh_hidden_dentry);
break;
}
err = -EIO;
printk(KERN_NOTICE "EIO: Invalid whiteout entry type"
" %d.\n", wh_hidden_dentry->d_inode->i_mode);
DPUT(wh_hidden_dentry);
DPUT(first_hidden_dentry);
goto out_free;
}
DPUT(wh_hidden_dentry);
wh_hidden_dentry = NULL;
/* Now do regular lookup; lookup foo */
hidden_dentry = LOOKUP_ONE_LEN(name, hidden_dir_dentry,
namelen);
fist_print_generic_dentry("hidden result", hidden_dentry);
if (IS_ERR(hidden_dentry)) {
DPUT(first_hidden_dentry);
err = PTR_ERR(hidden_dentry);
goto out_free;
}
/* Store the first negative dentry specially, because if they
* are all negative we need this for future creates. */
if (!hidden_dentry->d_inode) {
if (!first_hidden_dentry && (dbstart(dentry) == -1)) {
first_hidden_dentry = hidden_dentry;
first_dentry_offset = bindex;
} else {
DPUT(hidden_dentry);
}
continue;
}
/* number of positive dentries */
dentry_count++;
/* store underlying dentry */
if (dbstart(dentry) == -1)
set_dbstart(dentry, bindex);
set_dtohd_index(dentry, bindex, hidden_dentry);
set_dbend(dentry, bindex);
/* update parent directory's atime with the bindex */
fist_copy_attr_atime(parent_dentry->d_inode,
hidden_dir_dentry->d_inode);
/* We terminate file lookups here. */
if (!S_ISDIR(hidden_dentry->d_inode->i_mode)) {
if (lookupmode == INTERPOSE_PARTIAL)
continue;
if (dentry_count == 1)
goto out_positive;
/* This can only happen with mixed D-*-F-* */
BUG_ON(!S_ISDIR(dtohd(dentry)->d_inode->i_mode));
continue;
}
opaque = is_opaque_dir(dentry, bindex);
if (opaque < 0) {
DPUT(first_hidden_dentry);
err = opaque;
goto out_free;
}
if (opaque) {
set_dbend(dentry, bindex);
set_dbopaque(dentry, bindex);
break;
}
}
if (dentry_count)
goto out_positive;
else
goto out_negative;
out_negative:
if (lookupmode == INTERPOSE_PARTIAL)
goto out;
/* If we've only got negative dentries, then use the leftmost one. */
if (lookupmode == INTERPOSE_REVAL) {
if (dentry->d_inode) {
itopd(dentry->d_inode)->uii_stale = 1;
}
goto out;
}
/* This should only happen if we found a whiteout. */
if (first_dentry_offset == -1) {
first_hidden_dentry = LOOKUP_ONE_LEN(name, hidden_dir_dentry,
namelen);
first_dentry_offset = bindex;
if (IS_ERR(first_hidden_dentry)) {
err = PTR_ERR(first_hidden_dentry);
goto out;
}
}
set_dtohd_index(dentry, first_dentry_offset, first_hidden_dentry);
set_dbstart(dentry, first_dentry_offset);
set_dbend(dentry, first_dentry_offset);
if (lookupmode == INTERPOSE_REVAL_NEG)
BUG_ON(dentry->d_inode != NULL);
else
d_add(dentry, NULL);
goto out;
/* This part of the code is for positive dentries. */
out_positive:
BUG_ON(dentry_count <= 0);
/* If we're holding onto the first negative dentry throw it out. */
DPUT(first_hidden_dentry);
/* Partial lookups need to reinterpose, or throw away older negs. */
if (lookupmode == INTERPOSE_PARTIAL) {
if (dentry->d_inode) {
unionfs_reinterpose(dentry);
goto out;
}
/* This somehow turned positive, so it is as if we had a
* negative revalidation. */
lookupmode = INTERPOSE_REVAL_NEG;
update_bstart(dentry);
bstart = dbstart(dentry);
bend = dbend(dentry);
}
err = unionfs_interpose(dentry, dentry->d_sb, lookupmode);
if (err)
goto out_drop;
fist_checkinode(dentry->d_inode, "unionfs_lookup OUT: child");
fist_checkinode(parent_dentry->d_inode, "unionfs_lookup OUT: dir");
goto out;
out_drop:
d_drop(dentry);
out_free:
/* should dput all the underlying dentries on error condition */
bstart = dbstart(dentry);
if (bstart >= 0) {
bend = dbend(dentry);
for (bindex = bstart; bindex <= bend; bindex++)
DPUT(dtohd_index(dentry, bindex));
}
KFREE(dtohd_ptr(dentry));
dtohd_ptr(dentry) = NULL;
set_dbstart(dentry, -1);
set_dbend(dentry, -1);
out:
if (!err && dtopd(dentry)) {
BUG_ON(dbend(dentry) > dtopd(dentry)->udi_bcount);
BUG_ON(dbend(dentry) > sbmax(dentry->d_sb));
BUG_ON(dbstart(dentry) < 0);
}
KFREE(whname);
fist_print_dentry("OUT unionfs_lookup (parent)", parent_dentry);
fist_print_dentry("OUT unionfs_lookup (child)", dentry);
if (locked_parent)
unlock_dentry(parent_dentry);
DPUT(parent_dentry);
if (locked_child)
unlock_dentry(dentry);
print_exit_status(err);
return ERR_PTR(err);
}
static struct dentry *unionfs_d_alloc_root(struct super_block *sb)
{
struct dentry *ret = NULL;
if (sb) {
static const struct qstr name = {.name = "/",.len = 1 };
ret = d_alloc(NULL, &name);
if (ret) {
ret->d_op = &unionfs_dops;
ret->d_sb = sb;
ret->d_parent = ret;
}
}
return ret;
}
static int unionfs_read_super(struct super_block *sb, void *raw_data,
int silent)
{
int err = 0;
struct unionfs_dentry_info *hidden_root_info = NULL;
int bindex, bstart, bend;
unsigned long long maxbytes;
print_entry_location();
if (!raw_data) {
printk(KERN_WARNING
"unionfs_read_super: missing data argument\n");
err = -EINVAL;
goto out;
}
/*
* Allocate superblock private data
*/
stopd_lhs(sb) = KZALLOC(sizeof(struct unionfs_sb_info), GFP_KERNEL);
if (!stopd(sb)) {
printk(KERN_WARNING "%s: out of memory\n", __FUNCTION__);
err = -ENOMEM;
goto out;
}
stopd(sb)->b_end = -1;
atomic_set(&stopd(sb)->usi_generation, 1);
init_rwsem(&stopd(sb)->usi_rwsem);
hidden_root_info = unionfs_parse_options(sb, raw_data);
if (IS_ERR(hidden_root_info)) {
printk(KERN_WARNING
"unionfs_read_super: error while parsing options (err = %ld)\n",
PTR_ERR(hidden_root_info));
err = PTR_ERR(hidden_root_info);
hidden_root_info = NULL;
goto out_free;
}
if (hidden_root_info->udi_bstart == -1) {
err = -ENOENT;
goto out_free;
}
/* set the hidden superblock field of upper superblock */
bstart = hidden_root_info->udi_bstart;
BUG_ON(bstart != 0);
sbend(sb) = bend = hidden_root_info->udi_bend;
for (bindex = bstart; bindex <= bend; bindex++) {
struct dentry *d;
d = hidden_root_info->udi_dentry[bindex];
set_stohs_index(sb, bindex, d->d_sb);
}
/* Unionfs: Max Bytes is the maximum bytes from among all the branches */
maxbytes = -1;
for (bindex = bstart; bindex <= bend; bindex++)
if (maxbytes < stohs_index(sb, bindex)->s_maxbytes)
maxbytes = stohs_index(sb, bindex)->s_maxbytes;
sb->s_maxbytes = maxbytes;
sb->s_op = &unionfs_sops;
sb->s_export_op = &unionfs_export_ops;
/*
* we can't use d_alloc_root if we want to use
* our own interpose function unchanged,
* so we simply call our own "fake" d_alloc_root
*/
sb->s_root = unionfs_d_alloc_root(sb);
if (!sb->s_root) {
err = -ENOMEM;
goto out_dput;
}
/* link the upper and lower dentries */
dtopd_lhs(sb->s_root) = NULL;
if ((err = new_dentry_private_data(sb->s_root)))
goto out_freedpd;
/* Set the hidden dentries for s_root */
for (bindex = bstart; bindex <= bend; bindex++) {
struct dentry *d;
d = hidden_root_info->udi_dentry[bindex];
set_dtohd_index(sb->s_root, bindex, d);
}
set_dbstart(sb->s_root, bstart);
set_dbend(sb->s_root, bend);
/* Set the generation number to one, since this is for the mount. */
atomic_set(&dtopd(sb->s_root)->udi_generation, 1);
/* call interpose to create the upper level inode */
if ((err = unionfs_interpose(sb->s_root, sb, 0)))
goto out_freedpd;
unlock_dentry(sb->s_root);
goto out;
out_freedpd:
if (dtopd(sb->s_root)) {
KFREE(dtohd_ptr(sb->s_root));
free_dentry_private_data(dtopd(sb->s_root));
}
DPUT(sb->s_root);
out_dput:
if (hidden_root_info && !IS_ERR(hidden_root_info)) {
for (bindex = hidden_root_info->udi_bstart;
bindex <= hidden_root_info->udi_bend; bindex++) {
struct dentry *d;
d = hidden_root_info->udi_dentry[bindex];
if (d)
DPUT(d);
if (stopd(sb) && stohiddenmnt_index(sb, bindex))
mntput(stohiddenmnt_index(sb, bindex));
}
KFREE(hidden_root_info->udi_dentry);
KFREE(hidden_root_info);
hidden_root_info = NULL;
}
out_free:
KFREE(stopd(sb)->usi_data);
KFREE(stopd(sb));
stopd_lhs(sb) = NULL;
out:
if (hidden_root_info && !IS_ERR(hidden_root_info)) {
KFREE(hidden_root_info->udi_dentry);
KFREE(hidden_root_info);
}
print_exit_status(err);
return err;
}
/*
* Parse mount options. See the manual page for usage instructions.
*
* Returns the dentry object of the lower-level (hidden) directory;
* We want to mount our stackable file system on top of that hidden directory.
*
* Sets default debugging level to N, if any.
*/
static struct unionfs_dentry_info *unionfs_parse_options(struct super_block *sb,
char *options)
{
struct unionfs_dentry_info *hidden_root_info;
char *optname;
int err = 0;
int bindex;
int dirsfound = 0;
#ifdef UNIONFS_IMAP
int imapfound = 0;
#endif
print_entry_location();
/* allocate private data area */
err = -ENOMEM;
hidden_root_info =
KZALLOC(sizeof(struct unionfs_dentry_info), GFP_KERNEL);
if (!hidden_root_info)
goto out_error;
hidden_root_info->udi_bstart = -1;
hidden_root_info->udi_bend = -1;
hidden_root_info->udi_bopaque = -1;
while ((optname = strsep(&options, ",")) != NULL) {
char *optarg;
char *endptr;
int intval;
if (!*optname) {
continue;
}
optarg = strchr(optname, '=');
if (optarg) {
*optarg++ = '\0';
}
/* All of our options take an argument now. Insert ones that
* don't, above this check. */
if (!optarg) {
printk("unionfs: %s requires an argument.\n", optname);
err = -EINVAL;
goto out_error;
}
if (!strcmp("dirs", optname)) {
if (++dirsfound > 1) {
printk(KERN_WARNING
"unionfs: multiple dirs specified\n");
err = -EINVAL;
goto out_error;
}
err = parse_dirs_option(sb, hidden_root_info, optarg);
if (err)
goto out_error;
continue;
}
#ifdef UNIONFS_IMAP
if (!strcmp("imap", optname)) {
if (++imapfound > 1) {
printk(KERN_WARNING
"unionfs: multiple imap specified\n");
err = -EINVAL;
goto out_error;
}
err = parse_imap_option(sb, hidden_root_info, optarg);
if (err)
goto out_error;
continue;
}
#endif
if (!strcmp("delete", optname)) {
if (!strcmp("whiteout", optarg)) {
/* default */
#ifdef UNIONFS_DELETE_ALL
} else if (!strcmp("all", optarg)) {
MOUNT_FLAG(sb) |= DELETE_ALL;
#endif
} else {
printk(KERN_WARNING
"unionfs: invalid delete option '%s'\n",
optarg);
err = -EINVAL;
goto out_error;
}
continue;
}
if (!strcmp("copyup", optname)) {
if (!strcmp("preserve", optarg)) {
/* default */
} else if (!strcmp("currentuser", optarg)) {
MOUNT_FLAG(sb) |= COPYUP_CURRENT_USER;
} else {
printk(KERN_WARNING
"unionfs: could not parse copyup option value '%s'\n",
optarg);
err = -EINVAL;
goto out_error;
}
continue;
}
/* All of these options require an integer argument. */
intval = simple_strtoul(optarg, &endptr, 0);
if (*endptr) {
printk(KERN_WARNING
"unionfs: invalid %s option '%s'\n",
optname, optarg);
err = -EINVAL;
goto out_error;
}
if (!strcmp("debug", optname)) {
fist_set_debug_value(intval);
continue;
}
err = -EINVAL;
printk(KERN_WARNING
"unionfs: unrecognized option '%s'\n", optname);
goto out_error;
}
if (dirsfound != 1) {
printk(KERN_WARNING "unionfs: dirs option required\n");
err = -EINVAL;
goto out_error;
}
goto out;
out_error:
if (hidden_root_info && hidden_root_info->udi_dentry) {
for (bindex = hidden_root_info->udi_bstart;
bindex >= 0 && bindex <= hidden_root_info->udi_bend;
bindex++) {
struct dentry *d;
d = hidden_root_info->udi_dentry[bindex];
DPUT(d);
if (stohiddenmnt_index(sb, bindex))
mntput(stohiddenmnt_index(sb, bindex));
}
}
KFREE(hidden_root_info->udi_dentry);
KFREE(hidden_root_info);
KFREE(stopd(sb)->usi_data);
stopd(sb)->usi_data = NULL;
hidden_root_info = ERR_PTR(err);
out:
print_exit_location();
return hidden_root_info;
}
static int unionfs_unlink_whiteout(struct inode *dir, struct dentry *dentry)
{
int err = 0;
struct dentry *hidden_old_dentry;
struct dentry *hidden_wh_dentry = NULL;
struct dentry *hidden_old_dir_dentry, *hidden_new_dir_dentry;
char *name = NULL;
struct iattr newattrs;
print_entry_location();
fist_print_dentry("IN unionfs_unlink_whiteout: ", dentry);
/* create whiteout, get the leftmost underlying dentry and rename it */
hidden_old_dentry = dtohd(dentry);
/* lookup .wh.foo first, MUST NOT EXIST */
name = KMALLOC(dentry->d_name.len + sizeof(".wh."), GFP_UNIONFS);
if (!name) {
err = -ENOMEM;
goto out;
}
strcpy(name, ".wh.");
strncat(name, dentry->d_name.name, dentry->d_name.len);
name[4 + dentry->d_name.len] = '\0';
hidden_wh_dentry =
LOOKUP_ONE_LEN(name, hidden_old_dentry->d_parent,
dentry->d_name.len + 4);
if (IS_ERR(hidden_wh_dentry)) {
err = PTR_ERR(hidden_wh_dentry);
goto out;
}
ASSERT(hidden_wh_dentry->d_inode == NULL);
DGET(hidden_old_dentry);
hidden_old_dir_dentry = GET_PARENT(hidden_old_dentry);
hidden_new_dir_dentry = GET_PARENT(hidden_wh_dentry);
double_lock(hidden_old_dir_dentry, hidden_new_dir_dentry);
if (!(err = is_robranch(dentry))) {
if (S_ISREG(hidden_old_dentry->d_inode->i_mode)) {
err = vfs_rename(hidden_old_dir_dentry->d_inode,
hidden_old_dentry,
hidden_new_dir_dentry->d_inode,
hidden_wh_dentry);
} else {
err = vfs_unlink(hidden_old_dir_dentry->d_inode,
hidden_old_dentry);
if (!err)
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
err = vfs_create(hidden_new_dir_dentry->d_inode,
hidden_wh_dentry, 0666, NULL);
#else
err = vfs_create(hidden_new_dir_dentry->d_inode,
hidden_wh_dentry, 0666);
#endif
}
}
double_unlock(hidden_old_dir_dentry, hidden_new_dir_dentry);
DPUT(hidden_old_dentry);
DPUT(hidden_wh_dentry);
if (!err) {
hidden_wh_dentry = LOOKUP_ONE_LEN(name,
hidden_old_dentry->d_parent,
dentry->d_name.len + 4);
if (IS_ERR(hidden_wh_dentry)) {
err = PTR_ERR(hidden_wh_dentry);
goto out;
}
PASSERT(hidden_wh_dentry->d_inode);
down(&hidden_wh_dentry->d_inode->i_sem);
newattrs.ia_valid = ATTR_CTIME;
if (hidden_wh_dentry->d_inode->i_size != 0) {
newattrs.ia_valid |= ATTR_SIZE;
newattrs.ia_size = 0;
}
/* We discard this error, because the entry is whited out
* even if we fail here. */
notify_change(hidden_wh_dentry, &newattrs);
up(&hidden_wh_dentry->d_inode->i_sem);
DPUT(hidden_wh_dentry);
}
if (err) {
if (dbstart(dentry) == 0)
goto out;
/* exit if the error returned was NOT -EROFS */
if (!IS_COPYUP_ERR(err))
goto out;
err = create_whiteout(dentry, dbstart(dentry) - 1);
} else {
fist_copy_attr_all(dir, hidden_new_dir_dentry->d_inode);
}
out:
KFREE(name);
print_exit_status(err);
return err;
}
/*
* THIS IS A BOOLEAN FUNCTION: returns 1 if valid, 0 otherwise.
*/
int unionfs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
int valid = 1; /* default is valid (1); invalid is 0. */
struct dentry *hidden_dentry;
int bindex, bstart, bend;
int sbgen, dgen;
int positive = 0;
int locked = 0;
int restart = 0;
int interpose_flag;
print_util_entry_location();
restart:
verify_locked(dentry);
/* if the dentry is unhashed, do NOT revalidate */
if (d_deleted(dentry)) {
fist_dprint(6, "unhashed dentry being revalidated: %*s\n",
dentry->d_name.len, dentry->d_name.name);
goto out;
}
BUG_ON(dbstart(dentry) == -1);
if (dentry->d_inode)
positive = 1;
dgen = atomic_read(&dtopd(dentry)->udi_generation);
sbgen = atomic_read(&stopd(dentry->d_sb)->usi_generation);
/* If we are working on an unconnected dentry, then there is no
* revalidation to be done, because this file does not exist within the
* namespace, and Unionfs operates on the namespace, not data.
*/
if (sbgen != dgen) {
struct dentry *result;
int pdgen;
unionfs_read_lock(dentry->d_sb);
locked = 1;
/* The root entry should always be valid */
BUG_ON(IS_ROOT(dentry));
/* We can't work correctly if our parent isn't valid. */
pdgen = atomic_read(&dtopd(dentry->d_parent)->udi_generation);
if (!restart && (pdgen != sbgen)) {
unionfs_read_unlock(dentry->d_sb);
locked = 0;
/* We must be locked before our parent. */
if (!
(dentry->d_parent->d_op->
d_revalidate(dentry->d_parent, nd))) {
valid = 0;
goto out;
}
restart = 1;
goto restart;
}
BUG_ON(pdgen != sbgen);
/* Free the pointers for our inodes and this dentry. */
bstart = dbstart(dentry);
bend = dbend(dentry);
if (bstart >= 0) {
struct dentry *hidden_dentry;
for (bindex = bstart; bindex <= bend; bindex++) {
hidden_dentry =
dtohd_index_nocheck(dentry, bindex);
if (!hidden_dentry)
continue;
DPUT(hidden_dentry);
}
}
set_dbstart(dentry, -1);
set_dbend(dentry, -1);
interpose_flag = INTERPOSE_REVAL_NEG;
if (positive) {
interpose_flag = INTERPOSE_REVAL;
down(&dentry->d_inode->i_sem);
bstart = ibstart(dentry->d_inode);
bend = ibend(dentry->d_inode);
if (bstart >= 0) {
struct inode *hidden_inode;
for (bindex = bstart; bindex <= bend; bindex++) {
hidden_inode =
itohi_index(dentry->d_inode,
bindex);
if (!hidden_inode)
continue;
IPUT(hidden_inode);
}
}
KFREE(itohi_ptr(dentry->d_inode));
itohi_ptr(dentry->d_inode) = NULL;
ibstart(dentry->d_inode) = -1;
ibend(dentry->d_inode) = -1;
up(&dentry->d_inode->i_sem);
}
result = unionfs_lookup_backend(dentry, interpose_flag);
if (result) {
if (IS_ERR(result)) {
valid = 0;
goto out;
}
/* current unionfs_lookup_backend() doesn't return
a valid dentry */
DPUT(dentry);
dentry = result;
}
if (positive && itopd(dentry->d_inode)->uii_stale) {
make_stale_inode(dentry->d_inode);
d_drop(dentry);
valid = 0;
goto out;
}
goto out;
}
/* The revalidation must occur across all branches */
bstart = dbstart(dentry);
bend = dbend(dentry);
BUG_ON(bstart == -1);
for (bindex = bstart; bindex <= bend; bindex++) {
hidden_dentry = dtohd_index(dentry, bindex);
if (!hidden_dentry || !hidden_dentry->d_op
|| !hidden_dentry->d_op->d_revalidate)
continue;
if (!hidden_dentry->d_op->d_revalidate(hidden_dentry, nd))
valid = 0;
}
if (!dentry->d_inode)
valid = 0;
if (valid)
fist_copy_attr_all(dentry->d_inode, itohi(dentry->d_inode));
out:
if (locked)
unionfs_read_unlock(dentry->d_sb);
fist_print_dentry("revalidate out", dentry);
print_util_exit_status(valid);
return valid;
}
static int unionfs_unlink_all(struct inode *dir, struct dentry *dentry)
{
struct dentry *hidden_dentry;
struct dentry *hidden_dir_dentry;
int bstart, bend, bindex;
int err = 0;
int global_err = 0;
print_entry_location();
if ((err = unionfs_partial_lookup(dentry)))
goto out;
bstart = dbstart(dentry);
bend = dbend(dentry);
for (bindex = bend; bindex >= bstart; bindex--) {
hidden_dentry = dtohd_index(dentry, bindex);
if (!hidden_dentry)
continue;
hidden_dir_dentry = lock_parent(hidden_dentry);
/* avoid destroying the hidden inode if the file is in use */
DGET(hidden_dentry);
if (!(err = is_robranch_super(dentry->d_sb, bindex)))
err = vfs_unlink(hidden_dir_dentry->d_inode,
hidden_dentry);
DPUT(hidden_dentry);
fist_copy_attr_times(dir, hidden_dir_dentry->d_inode);
unlock_dir(hidden_dir_dentry);
if (err) {
/* passup the last error we got */
if (!IS_COPYUP_ERR(err))
goto out;
global_err = err;
}
}
/* check if encountered error in the above loop */
if (global_err) {
/* If we failed in the leftmost branch, then err will be set
* and we should move one over to create the whiteout.
* Otherwise, we should try in the leftmost branch. */
if (err) {
if (dbstart(dentry) == 0) {
goto out;
}
err = create_whiteout(dentry, dbstart(dentry) - 1);
} else {
err = create_whiteout(dentry, dbstart(dentry));
}
} else if (dbopaque(dentry) != -1) {
/* There is a hidden lower-priority file with the same name. */
err = create_whiteout(dentry, dbopaque(dentry));
}
out:
/* propagate number of hard-links */
if (dentry->d_inode->i_nlink != 0) {
dentry->d_inode->i_nlink = get_nlinks(dentry->d_inode);
if (!err && global_err)
dentry->d_inode->i_nlink--;
}
/* We don't want to leave negative leftover dentries for revalidate. */
if (!err && (global_err || dbopaque(dentry) != -1))
update_bstart(dentry);
print_exit_status(err);
return err;
}
static int unionfs_rename_whiteout(struct inode *old_dir,
struct dentry *old_dentry,
struct inode *new_dir,
struct dentry *new_dentry)
{
int err = 0;
int bindex, bwh_old;
int old_bstart, old_bend;
int new_bstart, new_bend;
int do_copyup = -1;
struct dentry *parent_dentry;
int local_err = 0;
int eio = 0;
int revert = 0;
struct dentry *wh_old = NULL;
print_entry_location();
old_bstart = dbstart(old_dentry);
bwh_old = old_bstart;
old_bend = dbend(old_dentry);
parent_dentry = old_dentry->d_parent;
new_bstart = dbstart(new_dentry);
new_bend = dbend(new_dentry);
/* Rename source to destination. */
err = do_rename(old_dir, old_dentry, new_dir, new_dentry, old_bstart,
&wh_old);
if (err) {
if (!IS_COPYUP_ERR(err)) {
goto out;
}
do_copyup = old_bstart - 1;
} else {
revert = 1;
}
/* Unlink all instances of destination that exist to the left of
* bstart of source. On error, revert back, goto out.
*/
for (bindex = old_bstart - 1; bindex >= new_bstart; bindex--) {
struct dentry *unlink_dentry;
struct dentry *unlink_dir_dentry;
unlink_dentry = dtohd_index(new_dentry, bindex);
if (!unlink_dentry) {
continue;
}
unlink_dir_dentry = lock_parent(unlink_dentry);
if (!(err = is_robranch_super(old_dir->i_sb, bindex))) {
err =
vfs_unlink(unlink_dir_dentry->d_inode,
unlink_dentry);
}
fist_copy_attr_times(new_dentry->d_parent->d_inode,
unlink_dir_dentry->d_inode);
/* propagate number of hard-links */
new_dentry->d_parent->d_inode->i_nlink =
get_nlinks(new_dentry->d_parent->d_inode);
unlock_dir(unlink_dir_dentry);
if (!err) {
if (bindex != new_bstart) {
DPUT(unlink_dentry);
set_dtohd_index(new_dentry, bindex, NULL);
}
} else if (IS_COPYUP_ERR(err)) {
do_copyup = bindex - 1;
} else if (revert) {
DPUT(wh_old);
goto revert;
}
}
if (do_copyup != -1) {
for (bindex = do_copyup; bindex >= 0; bindex--) {
/* copyup the file into some left directory, so that you can rename it */
err =
copyup_dentry(old_dentry->d_parent->d_inode,
old_dentry, old_bstart, bindex, NULL,
old_dentry->d_inode->i_size);
if (!err) {
DPUT(wh_old);
bwh_old = bindex;
err =
do_rename(old_dir, old_dentry, new_dir,
new_dentry, bindex, &wh_old);
break;
}
}
}
/* Create whiteout for source, only if:
* (1) There is more than one underlying instance of source.
* (2) We did a copy_up
*/
if ((old_bstart != old_bend) || (do_copyup != -1)) {
struct dentry *hidden_parent;
BUG_ON(!wh_old || IS_ERR(wh_old) || wh_old->d_inode
|| bwh_old < 0);
hidden_parent = lock_parent(wh_old);
local_err = vfs_create(hidden_parent->d_inode, wh_old, S_IRUGO,
NULL);
unlock_dir(hidden_parent);
if (!local_err)
set_dbopaque(old_dentry, bwh_old);
else {
/* We can't fix anything now, so we cop-out and use -EIO. */
printk
("<0>We can't create a whiteout for the source in rename!\n");
err = -EIO;
}
}
out:
DPUT(wh_old);
print_exit_status(err);
return err;
revert:
/* Do revert here. */
local_err = unionfs_refresh_hidden_dentry(new_dentry, old_bstart);
if (local_err) {
printk(KERN_WARNING
"Revert failed in rename: the new refresh failed.\n");
eio = -EIO;
}
local_err = unionfs_refresh_hidden_dentry(old_dentry, old_bstart);
if (local_err) {
printk(KERN_WARNING
"Revert failed in rename: the old refresh failed.\n");
eio = -EIO;
goto revert_out;
}
if (!dtohd_index(new_dentry, bindex)
|| !dtohd_index(new_dentry, bindex)->d_inode) {
printk(KERN_WARNING
"Revert failed in rename: the object disappeared from under us!\n");
eio = -EIO;
goto revert_out;
}
if (dtohd_index(old_dentry, bindex)
&& dtohd_index(old_dentry, bindex)->d_inode) {
printk(KERN_WARNING
"Revert failed in rename: the object was created underneath us!\n");
eio = -EIO;
goto revert_out;
}
local_err =
do_rename(new_dir, new_dentry, old_dir, old_dentry, old_bstart,
NULL);
/* If we can't fix it, then we cop-out with -EIO. */
if (local_err) {
printk(KERN_WARNING "Revert failed in rename!\n");
eio = -EIO;
}
local_err = unionfs_refresh_hidden_dentry(new_dentry, bindex);
if (local_err)
eio = -EIO;
local_err = unionfs_refresh_hidden_dentry(old_dentry, bindex);
if (local_err)
eio = -EIO;
revert_out:
if (eio)
err = eio;
print_exit_status(err);
return err;
}
/* This must be called with the super block already locked. */
int unionfs_ioctl_delbranch(struct super_block *sb, unsigned long arg)
{
struct dentry *hidden_dentry;
struct inode *hidden_inode;
struct super_block *hidden_sb;
struct vfsmount *hidden_mnt;
struct dentry *root_dentry;
struct inode *root_inode;
int err = 0;
int pmindex, i, gen;
print_entry("branch = %lu ", arg);
lock_dentry(sb->s_root);
err = -EBUSY;
if (sbmax(sb) == 1)
goto out;
err = -EINVAL;
if (arg < 0 || arg > stopd(sb)->b_end)
goto out;
err = -EBUSY;
if (branch_count(sb, arg))
goto out;
if ((err = newputmap(sb)))
goto out;
pmindex = stopd(sb)->usi_lastputmap;
pmindex -= stopd(sb)->usi_firstputmap;
atomic_inc(&stopd(sb)->usi_generation);
gen = atomic_read(&stopd(sb)->usi_generation);
root_dentry = sb->s_root;
root_inode = sb->s_root->d_inode;
hidden_dentry = dtohd_index(root_dentry, arg);
hidden_mnt = stohiddenmnt_index(sb, arg);
hidden_inode = itohi_index(root_inode, arg);
hidden_sb = stohs_index(sb, arg);
DPUT(hidden_dentry);
iput(hidden_inode);
mntput(hidden_mnt);
for (i = arg; i <= (sbend(sb) - 1); i++) {
set_branch_count(sb, i, branch_count(sb, i + 1));
set_stohiddenmnt_index(sb, i, stohiddenmnt_index(sb, i + 1));
set_stohs_index(sb, i, stohs_index(sb, i + 1));
set_branchperms(sb, i, branchperms(sb, i + 1));
set_dtohd_index(root_dentry, i,
dtohd_index(root_dentry, i + 1));
set_itohi_index(root_inode, i, itohi_index(root_inode, i + 1));
stopd(sb)->usi_putmaps[pmindex]->map[i + 1] = i;
}
set_dtohd_index(root_dentry, sbend(sb), NULL);
set_itohi_index(root_inode, sbend(sb), NULL);
set_stohiddenmnt_index(sb, sbend(sb), NULL);
set_stohs_index(sb, sbend(sb), NULL);
stopd(sb)->b_end--;
set_dbend(root_dentry, dbend(root_dentry) - 1);
dtopd(root_dentry)->udi_bcount--;
itopd(root_inode)->b_end--;
atomic_set(&dtopd(root_dentry)->udi_generation, gen);
atomic_set(&itopd(root_inode)->uii_generation, gen);
fixputmaps(sb);
/* This doesn't open a file, so we might have to free the map here. */
if (atomic_read(&stopd(sb)->usi_putmaps[pmindex]->count) == 0) {
KFREE(stopd(sb)->usi_putmaps[pmindex]);
stopd(sb)->usi_putmaps[pmindex] = NULL;
}
out:
unlock_dentry(sb->s_root);
print_exit_status(err);
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;
}
/* This function replicates the directory structure upto given dentry
* in the bindex branch. */
struct dentry *create_parents_named(struct inode *dir, struct dentry *dentry,
const char *name, int bindex)
{
int err;
struct dentry *child_dentry;
struct dentry *parent_dentry;
struct dentry *hidden_parent_dentry = NULL;
struct dentry *hidden_dentry = NULL;
const char *childname;
unsigned int childnamelen;
int old_kmalloc_size;
int kmalloc_size;
int num_dentry;
int count;
int old_bstart;
int old_bend;
struct dentry **path = NULL;
struct dentry **tmp_path;
print_entry_location();
verify_locked(dentry);
/* There is no sense allocating any less than the minimum. */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
kmalloc_size = malloc_sizes[0].cs_size;
#else
kmalloc_size = 32;
#endif
num_dentry = kmalloc_size / sizeof(struct dentry *);
if ((err = is_robranch_super(dir->i_sb, bindex))) {
hidden_dentry = ERR_PTR(err);
goto out;
}
fist_print_dentry("IN: create_parents_named", dentry);
fist_dprint(8, "name = %s\n", name);
old_bstart = dbstart(dentry);
old_bend = dbend(dentry);
path = (struct dentry **)KMALLOC(kmalloc_size, GFP_KERNEL);
memset(path, 0, kmalloc_size);
/* assume the negative dentry of unionfs as the parent dentry */
parent_dentry = dentry;
count = 0;
/* This loop finds the first parent that exists in the given branch.
* We start building the directory structure from there. At the end
* of the loop, the following should hold:
* child_dentry is the first nonexistent child
* parent_dentry is the first existent parent
* path[0] is the = deepest child
* path[count] is the first child to create
*/
do {
child_dentry = parent_dentry;
/* find the parent directory dentry in unionfs */
parent_dentry = child_dentry->d_parent;
lock_dentry(parent_dentry);
/* find out the hidden_parent_dentry in the given branch */
hidden_parent_dentry = dtohd_index(parent_dentry, bindex);
/* store the child dentry */
path[count++] = child_dentry;
if (count == num_dentry) {
old_kmalloc_size = kmalloc_size;
kmalloc_size *= 2;
num_dentry = kmalloc_size / sizeof(struct dentry *);
tmp_path =
(struct dentry **)KMALLOC(kmalloc_size, GFP_KERNEL);
if (!tmp_path) {
hidden_dentry = ERR_PTR(-ENOMEM);
goto out;
}
memset(tmp_path, 0, kmalloc_size);
memcpy(tmp_path, path, old_kmalloc_size);
KFREE(path);
path = tmp_path;
tmp_path = NULL;
}
} while (!hidden_parent_dentry);
count--;
/* This is basically while(child_dentry != dentry). This loop is
* horrible to follow and should be replaced with cleaner code. */
while (1) {
PASSERT(child_dentry);
PASSERT(parent_dentry);
PASSERT(parent_dentry->d_inode);
// get hidden parent dir in the current branch
hidden_parent_dentry = dtohd_index(parent_dentry, bindex);
unlock_dentry(parent_dentry);
PASSERT(hidden_parent_dentry);
PASSERT(hidden_parent_dentry->d_inode);
// init the values to lookup
childname = child_dentry->d_name.name;
childnamelen = child_dentry->d_name.len;
if (child_dentry != dentry) {
// lookup child in the underlying file system
hidden_dentry =
LOOKUP_ONE_LEN(childname, hidden_parent_dentry,
childnamelen);
if (IS_ERR(hidden_dentry))
goto out;
} else {
int loop_start;
int loop_end;
int new_bstart = -1;
int new_bend = -1;
int i;
/* is the name a whiteout of the childname ? */
//lookup the whiteout child in the underlying file system
hidden_dentry =
LOOKUP_ONE_LEN(name, hidden_parent_dentry,
strlen(name));
if (IS_ERR(hidden_dentry))
goto out;
/* Replace the current dentry (if any) with the new one. */
DPUT(dtohd_index(dentry, bindex));
set_dtohd_index(dentry, bindex, hidden_dentry);
loop_start =
(old_bstart < bindex) ? old_bstart : bindex;
loop_end = (old_bend > bindex) ? old_bend : bindex;
/* This loop sets the bstart and bend for the new
* dentry by traversing from left to right.
* It also dputs all negative dentries except
* bindex (the newly looked dentry
*/
for (i = loop_start; i <= loop_end; i++) {
if (!dtohd_index(dentry, i))
continue;
if (i == bindex) {
new_bend = i;
if (new_bstart < 0)
new_bstart = i;
continue;
}
if (!dtohd_index(dentry, i)->d_inode) {
DPUT(dtohd_index(dentry, i));
set_dtohd_index(dentry, i, NULL);
} else {
if (new_bstart < 0)
new_bstart = i;
new_bend = i;
}
}
if (new_bstart < 0)
new_bstart = bindex;
if (new_bend < 0)
new_bend = bindex;
set_dbstart(dentry, new_bstart);
set_dbend(dentry, new_bend);
break;
}
if (hidden_dentry->d_inode) {
/* since this already exists we dput to avoid
* multiple references on the same dentry */
DPUT(hidden_dentry);
} else {
uid_t saved_uid = current->fsuid;
gid_t saved_gid = current->fsgid;
/* its a negative dentry, create a new dir */
hidden_parent_dentry = lock_parent(hidden_dentry);
current->fsuid = hidden_parent_dentry->d_inode->i_uid;
current->fsgid = hidden_parent_dentry->d_inode->i_gid;
err = vfs_mkdir(hidden_parent_dentry->d_inode,
hidden_dentry, S_IRWXUGO);
current->fsuid = saved_uid;
current->fsgid = saved_gid;
unlock_dir(hidden_parent_dentry);
if (err || !hidden_dentry->d_inode) {
DPUT(hidden_dentry);
hidden_dentry = ERR_PTR(err);
goto out;
}
err =
copyup_permissions(dir->i_sb, child_dentry,
hidden_dentry);
if (err) {
DPUT(hidden_dentry);
hidden_dentry = ERR_PTR(err);
goto out;
}
set_itohi_index(child_dentry->d_inode, bindex,
igrab(hidden_dentry->d_inode));
if (ibstart(child_dentry->d_inode) > bindex)
ibstart(child_dentry->d_inode) = bindex;
if (ibend(child_dentry->d_inode) < bindex)
ibend(child_dentry->d_inode) = bindex;
set_dtohd_index(child_dentry, bindex, hidden_dentry);
if (dbstart(child_dentry) > bindex)
set_dbstart(child_dentry, bindex);
if (dbend(child_dentry) < bindex)
set_dbend(child_dentry, bindex);
}
parent_dentry = child_dentry;
child_dentry = path[--count];
}
out:
KFREE(path);
fist_print_dentry("OUT: create_parents_named", dentry);
print_exit_pointer(hidden_dentry);
return hidden_dentry;
}
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;
}
