void unionfs_reinterpose(struct dentry *dentry)
{
struct dentry *hidden_dentry;
struct inode *inode;
int bindex, bstart, bend;
print_entry_location();
verify_locked(dentry);
fist_print_dentry("IN: unionfs_reinterpose: ", dentry);
/* This is pre-allocated inode */
inode = dentry->d_inode;
bstart = dbstart(dentry);
bend = dbend(dentry);
for (bindex = bstart; bindex <= bend; bindex++) {
hidden_dentry = dtohd_index(dentry, bindex);
if (!hidden_dentry)
continue;
if (!hidden_dentry->d_inode)
continue;
if (itohi_index(inode, bindex))
continue;
set_itohi_index(inode, bindex, IGRAB(hidden_dentry->d_inode));
}
ibstart(inode) = dbstart(dentry);
ibend(inode) = dbend(dentry);
fist_print_dentry("OUT: unionfs_reinterpose: ", dentry);
fist_print_inode("OUT: unionfs_reinterpose: ", inode);
print_exit_location();
}
/* like interpose above, but for an already existing dentry */
void unionfs_reinterpose(struct dentry *dentry)
{
struct dentry *lower_dentry;
struct inode *inode;
int bindex, bstart, bend;
verify_locked(dentry);
/* This is pre-allocated inode */
inode = dentry->d_inode;
bstart = dbstart(dentry);
bend = dbend(dentry);
for (bindex = bstart; bindex <= bend; bindex++) {
lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
if (!lower_dentry)
continue;
if (!lower_dentry->d_inode)
continue;
if (unionfs_lower_inode_idx(inode, bindex))
continue;
unionfs_set_lower_inode_idx(inode, bindex,
igrab(lower_dentry->d_inode));
}
ibstart(inode) = dbstart(dentry);
ibend(inode) = dbend(dentry);
}
/* set lower dentry ptr and update bstart & bend if necessary */
static void __set_dentry(struct dentry *upper, struct dentry *lower,
int bindex)
{
unionfs_set_lower_dentry_idx(upper, bindex, lower);
if (likely(dbstart(upper) > bindex))
dbstart(upper) = bindex;
if (likely(dbend(upper) < bindex))
dbend(upper) = bindex;
}
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;
}
/*
* return to user-space the branch indices containing the file in question
*
* We use fd_set and therefore we are limited to the number of the branches
* to FD_SETSIZE, which is currently 1024 - plenty for most people
*/
static int unionfs_ioctl_queryfile(struct file *file, struct dentry *parent,
unsigned int cmd, unsigned long arg)
{
int err = 0;
fd_set branchlist;
int bstart = 0, bend = 0, bindex = 0;
int orig_bstart, orig_bend;
struct dentry *dentry, *lower_dentry;
struct vfsmount *mnt;
dentry = file->f_path.dentry;
orig_bstart = dbstart(dentry);
orig_bend = dbend(dentry);
err = unionfs_partial_lookup(dentry, parent);
if (err)
goto out;
bstart = dbstart(dentry);
bend = dbend(dentry);
FD_ZERO(&branchlist);
for (bindex = bstart; bindex <= bend; bindex++) {
lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
if (!lower_dentry)
continue;
if (likely(lower_dentry->d_inode))
FD_SET(bindex, &branchlist);
/* purge any lower objects after partial_lookup */
if (bindex < orig_bstart || bindex > orig_bend) {
dput(lower_dentry);
unionfs_set_lower_dentry_idx(dentry, bindex, NULL);
iput(unionfs_lower_inode_idx(dentry->d_inode, bindex));
unionfs_set_lower_inode_idx(dentry->d_inode, bindex,
NULL);
mnt = unionfs_lower_mnt_idx(dentry, bindex);
if (!mnt)
continue;
unionfs_mntput(dentry, bindex);
unionfs_set_lower_mnt_idx(dentry, bindex, NULL);
}
}
/* restore original dentry's offsets */
dbstart(dentry) = orig_bstart;
dbend(dentry) = orig_bend;
ibstart(dentry->d_inode) = orig_bstart;
ibend(dentry->d_inode) = orig_bend;
err = copy_to_user((void __user *)arg, &branchlist, sizeof(fd_set));
if (unlikely(err))
err = -EFAULT;
out:
return err < 0 ? err : bend;
}
int unionfs_rmdir(struct inode *dir, struct dentry *dentry)
{
int err = 0;
struct unionfs_dir_state *namelist = NULL;
print_entry_location();
lock_dentry(dentry);
fist_print_dentry("IN unionfs_rmdir: ", dentry);
/* check if this unionfs directory is empty or not */
err = check_empty(dentry, &namelist);
if (err) {
goto out;
}
if (IS_SET(dir->i_sb, DELETE_WHITEOUT)) {
/* Delete the first directory. */
err = unionfs_rmdir_first(dir, dentry, namelist);
/* create whiteout */
if (!err) {
err = create_whiteout(dentry, dbstart(dentry));
} else {
int new_err;
if (dbstart(dentry) == 0)
goto out;
/* exit if the error returned was NOT -EROFS */
if (!IS_COPYUP_ERR(err))
goto out;
new_err = create_whiteout(dentry, dbstart(dentry) - 1);
if (new_err != -EEXIST)
err = new_err;
}
} else {
/* delete all. */
err = unionfs_rmdir_all(dir, dentry, namelist);
}
out:
/* call d_drop so the system "forgets" about us */
if (!err)
d_drop(dentry);
if (namelist)
free_rdstate(namelist);
unlock_dentry(dentry);
print_exit_status(err);
return err;
}
static void unionfs_fill_inode(struct dentry *dentry,
struct inode *inode)
{
struct inode *lower_inode;
struct dentry *lower_dentry;
int bindex, bstart, bend;
bstart = dbstart(dentry);
bend = dbend(dentry);
for (bindex = bstart; bindex <= bend; bindex++) {
lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
if (!lower_dentry) {
unionfs_set_lower_inode_idx(inode, bindex, NULL);
continue;
}
/* Initialize the lower inode to the new lower inode. */
if (!lower_dentry->d_inode)
continue;
unionfs_set_lower_inode_idx(inode, bindex,
igrab(lower_dentry->d_inode));
}
ibstart(inode) = dbstart(dentry);
ibend(inode) = dbend(dentry);
/* Use attributes from the first branch. */
lower_inode = unionfs_lower_inode(inode);
/* Use different set of inode ops for symlinks & directories */
if (S_ISLNK(lower_inode->i_mode))
inode->i_op = &unionfs_symlink_iops;
else if (S_ISDIR(lower_inode->i_mode))
inode->i_op = &unionfs_dir_iops;
/* Use different set of file ops for directories */
if (S_ISDIR(lower_inode->i_mode))
inode->i_fop = &unionfs_dir_fops;
/* properly initialize special inodes */
if (S_ISBLK(lower_inode->i_mode) || S_ISCHR(lower_inode->i_mode) ||
S_ISFIFO(lower_inode->i_mode) || S_ISSOCK(lower_inode->i_mode))
init_special_inode(inode, lower_inode->i_mode,
lower_inode->i_rdev);
/* all well, copy inode attributes */
unionfs_copy_attr_all(inode, lower_inode);
fsstack_copy_inode_size(inode, lower_inode);
}
/* unionfs_open helper function: open a directory */
static int __open_dir(struct inode *inode, struct file *file)
{
struct dentry *lower_dentry;
struct file *lower_file;
int bindex, bstart, bend;
struct vfsmount *mnt;
bstart = fbstart(file) = dbstart(file->f_path.dentry);
bend = fbend(file) = dbend(file->f_path.dentry);
for (bindex = bstart; bindex <= bend; bindex++) {
lower_dentry =
unionfs_lower_dentry_idx(file->f_path.dentry, bindex);
if (!lower_dentry)
continue;
dget(lower_dentry);
unionfs_mntget(file->f_path.dentry, bindex);
mnt = unionfs_lower_mnt_idx(file->f_path.dentry, bindex);
lower_file = dentry_open(lower_dentry, mnt, file->f_flags,
current_cred());
if (IS_ERR(lower_file))
return PTR_ERR(lower_file);
unionfs_set_lower_file_idx(file, bindex, lower_file);
/*
* The branchget goes after the open, because otherwise
* we would miss the reference on release.
*/
branchget(inode->i_sb, bindex);
}
return 0;
}
/* open all lower files for a given file */
static int open_all_files(struct file *file)
{
int bindex, bstart, bend, err = 0;
struct file *lower_file;
struct dentry *lower_dentry;
struct dentry *dentry = file->f_path.dentry;
struct super_block *sb = dentry->d_sb;
bstart = dbstart(dentry);
bend = dbend(dentry);
for (bindex = bstart; bindex <= bend; bindex++) {
lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
if (!lower_dentry)
continue;
dget(lower_dentry);
unionfs_mntget(dentry, bindex);
branchget(sb, bindex);
lower_file =
dentry_open(lower_dentry,
unionfs_lower_mnt_idx(dentry, bindex),
file->f_flags, current_cred());
if (IS_ERR(lower_file)) {
branchput(sb, bindex);
err = PTR_ERR(lower_file);
goto out;
} else {
unionfs_set_lower_file_idx(file, bindex, lower_file);
}
}
out:
return err;
}
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;
/* Here we need to remove whiteout entries. */
err = delete_whiteouts(dentry, dbstart(dentry), namelist);
if (err)
goto out;
hidden_dentry = unionfs_lower_dentry(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);
fsstack_copy_attr_times(dir, hidden_dir_dentry->d_inode);
/* propagate number of hard-links */
dentry->d_inode->i_nlink = unionfs_get_nlinks(dentry->d_inode);
out:
if (hidden_dir_dentry)
unlock_dir(hidden_dir_dentry);
return err;
}
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 = dget_parent(dentry);
unionfs_lock_dentry(parent);
bstart = dbstart(parent);
bend = dbend(parent);
wh_dentry = ERR_PTR(-ENOENT);
for (bindex = bstart; bindex <= bend; bindex++) {
hidden_parent = unionfs_lower_dentry_idx(parent, bindex);
if (!hidden_parent)
continue;
wh_dentry = lookup_one_len(whname, hidden_parent,
dentry->d_name.len + UNIONFS_WHLEN);
if (IS_ERR(wh_dentry))
continue;
if (wh_dentry->d_inode)
break;
dput(wh_dentry);
wh_dentry = ERR_PTR(-ENOENT);
}
unionfs_unlock_dentry(parent);
dput(parent);
kfree(whname);
return wh_dentry;
}
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;
}
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();
}
static void unionfs_d_release(struct dentry *dentry)
{
int bindex, bstart, bend;
/* 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.
*/
unionfs_lock_dentry(dentry);
/* this could be a negative dentry, so check first */
if (!UNIONFS_D(dentry)) {
printk(KERN_DEBUG "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 */
printk(KERN_DEBUG "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++) {
dput(unionfs_lower_dentry_idx(dentry, bindex));
mntput(unionfs_lower_mnt_idx(dentry, bindex));
unionfs_set_lower_dentry_idx(dentry, bindex, NULL);
unionfs_set_lower_mnt_idx(dentry, bindex, NULL);
}
/* free private data (unionfs_dentry_info) here */
kfree(UNIONFS_D(dentry)->lower_paths);
UNIONFS_D(dentry)->lower_paths = NULL;
out_free:
/* No need to unlock it, because it is disappeared. */
free_dentry_private_data(UNIONFS_D(dentry));
dentry->d_fsdata = NULL; /* just to be safe */
out:
return;
}
/*
* scan through the lower dentry objects, and set bstart to reflect the
* starting branch
*/
void update_bstart(struct dentry *dentry)
{
int bindex;
int bstart = dbstart(dentry);
int bend = dbend(dentry);
struct dentry *lower_dentry;
for (bindex = bstart; bindex <= bend; bindex++) {
lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
if (!lower_dentry)
continue;
if (lower_dentry->d_inode) {
dbstart(dentry) = bindex;
break;
}
dput(lower_dentry);
unionfs_set_lower_dentry_idx(dentry, bindex, NULL);
}
}
int unionfs_rmdir(struct inode *dir, struct dentry *dentry)
{
int err = 0;
struct unionfs_dir_state *namelist = NULL;
unionfs_lock_dentry(dentry);
/* check if this unionfs directory is empty or not */
err = check_empty(dentry, &namelist);
if (err)
goto out;
err = unionfs_rmdir_first(dir, dentry, namelist);
/* create whiteout */
if (!err)
err = create_whiteout(dentry, dbstart(dentry));
else {
int new_err;
if (dbstart(dentry) == 0)
goto out;
/* exit if the error returned was NOT -EROFS */
if (!IS_COPYUP_ERR(err))
goto out;
new_err = create_whiteout(dentry, dbstart(dentry) - 1);
if (new_err != -EEXIST)
err = new_err;
}
out:
/* call d_drop so the system "forgets" about us */
if (!err)
d_drop(dentry);
if (namelist)
free_rdstate(namelist);
unionfs_unlock_dentry(dentry);
return err;
}
/*
* dput the lower references for old and new dentry & clear a lower dentry
* pointer
*/
static void __clear(struct dentry *dentry, struct dentry *old_lower_dentry,
int old_bstart, int old_bend,
struct dentry *new_lower_dentry, int new_bindex)
{
/* get rid of the lower dentry and all its traces */
unionfs_set_lower_dentry_idx(dentry, new_bindex, NULL);
dbstart(dentry) = old_bstart;
dbend(dentry) = old_bend;
dput(new_lower_dentry);
dput(old_lower_dentry);
}
static void epilog(struct inode *dir, struct dentry *dentry,
aufs_bindex_t bindex)
{
d_drop(dentry);
dentry->d_inode->i_ctime = dir->i_ctime;
if (atomic_read(&dentry->d_count) == 1) {
set_h_dptr(dentry, dbstart(dentry), NULL);
au_update_dbstart(dentry);
}
if (ibstart(dir) == bindex)
au_cpup_attr_timesizes(dir);
dir->i_version++;
}
/*
* Post-copyup helper to release all non-directory source objects of a
* copied-up file. Regular files should have only one lower object.
*/
void unionfs_postcopyup_release(struct dentry *dentry)
{
int bstart, bend;
BUG_ON(S_ISDIR(dentry->d_inode->i_mode));
bstart = dbstart(dentry);
bend = dbend(dentry);
path_put_lowers(dentry, bstart + 1, bend, false);
iput_lowers(dentry->d_inode, bstart + 1, bend, false);
dbend(dentry) = bstart;
ibend(dentry->d_inode) = ibstart(dentry->d_inode) = bstart;
}
/*
* We can't copyup a directory, because it may involve huge numbers of
* children, etc. Doing that in the kernel would be bad, so instead we
* return EXDEV to the user-space utility that caused this, and let the
* user-space recurse and ask us to copy up each file separately.
*/
static int may_rename_dir(struct dentry *dentry, struct dentry *parent)
{
int err, bstart;
err = check_empty(dentry, parent, NULL);
if (err == -ENOTEMPTY) {
if (is_robranch(dentry))
return -EXDEV;
} else if (err) {
return err;
}
bstart = dbstart(dentry);
if (dbend(dentry) == bstart || dbopaque(dentry) == bstart)
return 0;
dbstart(dentry) = bstart + 1;
err = check_empty(dentry, parent, NULL);
dbstart(dentry) = bstart;
if (err == -ENOTEMPTY)
err = -EXDEV;
return err;
}
/*
* unionfs_lookup is the only special function which takes a dentry, yet we
* do NOT want to call __unionfs_d_revalidate_chain because by definition,
* we don't have a valid dentry here yet.
*/
static struct dentry *unionfs_lookup(struct inode *dir,
struct dentry *dentry,
/* XXX: pass flags to lower? */
unsigned int flags_unused)
{
struct dentry *ret, *parent;
int err = 0;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
/*
* As long as we lock/dget the parent, then can skip validating the
* parent now; we may have to rebuild this dentry on the next
* ->d_revalidate, however.
*/
/* allocate dentry private data. We free it in ->d_release */
err = new_dentry_private_data(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(err)) {
ret = ERR_PTR(err);
goto out;
}
ret = unionfs_lookup_full(dentry, parent, INTERPOSE_LOOKUP);
if (!IS_ERR(ret)) {
if (ret)
dentry = ret;
/* lookup_full can return multiple positive dentries */
if (dentry->d_inode && !S_ISDIR(dentry->d_inode->i_mode)) {
BUG_ON(dbstart(dentry) < 0);
unionfs_postcopyup_release(dentry);
}
unionfs_copy_attr_times(dentry->d_inode);
}
unionfs_check_inode(dir);
if (!IS_ERR(ret))
unionfs_check_dentry(dentry);
unionfs_check_dentry(parent);
unionfs_unlock_dentry(dentry); /* locked in new_dentry_private data */
out:
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
return ret;
}
/* perform a delayed copyup of a read-write file on a read-only branch */
static int do_delayed_copyup(struct file *file, struct dentry *parent)
{
int bindex, bstart, bend, err = 0;
struct dentry *dentry = file->f_path.dentry;
struct inode *parent_inode = parent->d_inode;
bstart = fbstart(file);
bend = fbend(file);
BUG_ON(!S_ISREG(dentry->d_inode->i_mode));
unionfs_check_file(file);
for (bindex = bstart - 1; bindex >= 0; bindex--) {
if (!d_deleted(dentry))
err = copyup_file(parent_inode, file, bstart,
bindex,
i_size_read(dentry->d_inode));
else
err = copyup_deleted_file(file, dentry, parent,
bstart, bindex);
/* if succeeded, set lower open-file flags and break */
if (!err) {
struct file *lower_file;
lower_file = unionfs_lower_file_idx(file, bindex);
lower_file->f_flags = file->f_flags;
break;
}
}
if (err || (bstart <= fbstart(file)))
goto out;
bend = fbend(file);
for (bindex = bstart; bindex <= bend; bindex++) {
if (unionfs_lower_file_idx(file, bindex)) {
branchput(dentry->d_sb, bindex);
fput(unionfs_lower_file_idx(file, bindex));
unionfs_set_lower_file_idx(file, bindex, NULL);
}
}
path_put_lowers(dentry, bstart, bend, false);
iput_lowers(dentry->d_inode, bstart, bend, false);
/* for reg file, we only open it "once" */
fbend(file) = fbstart(file);
dbend(dentry) = dbstart(dentry);
ibend(dentry->d_inode) = ibstart(dentry->d_inode);
out:
unionfs_check_file(file);
return err;
}
/* purge a dentry's lower-branch states (dput/mntput, etc.) */
static void __cleanup_dentry(struct dentry *dentry, int bindex,
int old_bstart, int old_bend)
{
int loop_start;
int loop_end;
int new_bstart = -1;
int new_bend = -1;
int i;
loop_start = min(old_bstart, bindex);
loop_end = max(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
*/
for (i = loop_start; i <= loop_end; i++) {
if (!unionfs_lower_dentry_idx(dentry, i))
continue;
if (i == bindex) {
new_bend = i;
if (new_bstart < 0)
new_bstart = i;
continue;
}
if (!unionfs_lower_dentry_idx(dentry, i)->d_inode) {
dput(unionfs_lower_dentry_idx(dentry, i));
unionfs_set_lower_dentry_idx(dentry, i, NULL);
unionfs_mntput(dentry, i);
unionfs_set_lower_mnt_idx(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;
dbstart(dentry) = new_bstart;
dbend(dentry) = new_bend;
}
int au_reopen_nondir(struct file *file)
{
int err;
struct dentry *dentry;
aufs_bindex_t bstart, bindex, bend;
struct file *hidden_file, *h_file_tmp;
dentry = file->f_dentry;
LKTRTrace("%.*s\n", DLNPair(dentry));
DEBUG_ON(S_ISDIR(dentry->d_inode->i_mode)
|| !au_h_dptr(dentry)->d_inode);
bstart = dbstart(dentry);
h_file_tmp = NULL;
if (fbstart(file) == bstart) {
hidden_file = au_h_fptr(file);
if (file->f_mode == hidden_file->f_mode)
return 0; /* success */
h_file_tmp = hidden_file;
get_file(h_file_tmp);
set_h_fptr(file, bstart, NULL);
}
DEBUG_ON(fbstart(file) < bstart
|| ftofi(file)->fi_hfile[0 + bstart].hf_file);
hidden_file = hidden_open(dentry, bstart, file->f_flags & ~O_TRUNC);
//if (LktrCond) {fput(hidden_file); br_put(stobr(dentry->d_sb, bstart));
//hidden_file = ERR_PTR(-1);}
err = PTR_ERR(hidden_file);
if (IS_ERR(hidden_file))
goto out; // close all?
err = 0;
//cpup_file_flags(hidden_file, file);
set_fbstart(file, bstart);
set_h_fptr(file, bstart, hidden_file);
memcpy(&hidden_file->f_ra, &file->f_ra, sizeof(file->f_ra)); //??
/* close lower files */
bend = fbend(file);
for (bindex = bstart + 1; bindex <= bend; bindex++)
set_h_fptr(file, bindex, NULL);
set_fbend(file, bstart);
out:
if (h_file_tmp)
fput(h_file_tmp);
TraceErr(err);
return err;
}
/* open the highest priority file for a given upper file */
static int open_highest_file(struct file *file, bool willwrite)
{
int bindex, bstart, bend, err = 0;
struct file *lower_file;
struct dentry *lower_dentry;
struct dentry *dentry = file->f_path.dentry;
struct dentry *parent = dget_parent(dentry);
struct inode *parent_inode = parent->d_inode;
struct super_block *sb = dentry->d_sb;
bstart = dbstart(dentry);
bend = dbend(dentry);
lower_dentry = unionfs_lower_dentry(dentry);
if (willwrite && IS_WRITE_FLAG(file->f_flags) && is_robranch(dentry)) {
for (bindex = bstart - 1; bindex >= 0; bindex--) {
err = copyup_file(parent_inode, file, bstart, bindex,
i_size_read(dentry->d_inode));
if (!err)
break;
}
atomic_set(&UNIONFS_F(file)->generation,
atomic_read(&UNIONFS_I(dentry->d_inode)->
generation));
goto out;
}
dget(lower_dentry);
unionfs_mntget(dentry, bstart);
lower_file = dentry_open(lower_dentry,
unionfs_lower_mnt_idx(dentry, bstart),
file->f_flags, current_cred());
if (IS_ERR(lower_file)) {
err = PTR_ERR(lower_file);
goto out;
}
branchget(sb, bstart);
unionfs_set_lower_file(file, lower_file);
/* Fix up the position. */
lower_file->f_pos = file->f_pos;
memcpy(&lower_file->f_ra, &file->f_ra, sizeof(struct file_ra_state));
out:
dput(parent);
return err;
}
/*
* Post-copyup helper to ensure we have valid mnts: set lower mnt of
* dentry+parents to the first parent node that has an mnt.
*/
void unionfs_postcopyup_setmnt(struct dentry *dentry)
{
struct dentry *parent, *hasone;
int bindex = dbstart(dentry);
if (unionfs_lower_mnt_idx(dentry, bindex))
return;
hasone = dentry->d_parent;
/* this loop should stop at root dentry */
while (!unionfs_lower_mnt_idx(hasone, bindex))
hasone = hasone->d_parent;
parent = dentry;
while (!unionfs_lower_mnt_idx(parent, bindex)) {
unionfs_set_lower_mnt_idx(parent, bindex,
unionfs_mntget(hasone, bindex));
parent = parent->d_parent;
}
}
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);
}
}
int unionfs_ioctl_queryfile(struct file *file, unsigned int cmd,
unsigned long arg)
{
int err = 0;
fd_set branchlist;
int bstart = 0, bend = 0, bindex = 0;
struct dentry *dentry, *hidden_dentry;
print_entry_location();
dentry = file->f_dentry;
lock_dentry(dentry);
if ((err = unionfs_partial_lookup(dentry)))
goto out;
bstart = dbstart(dentry);
bend = dbend(dentry);
FD_ZERO(&branchlist);
for (bindex = bstart; bindex <= bend; bindex++) {
hidden_dentry = dtohd_index(dentry, bindex);
if (!hidden_dentry)
continue;
if (hidden_dentry->d_inode)
FD_SET(bindex, &branchlist);
}
err = copy_to_user((void *)arg, &branchlist, sizeof(fd_set));
if (err) {
err = -EFAULT;
goto out;
}
out:
unlock_dentry(dentry);
err = err < 0 ? err : bend;
print_exit_status(err);
return (err);
}
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;
}
static int unionfs_setattr(struct dentry *dentry, struct iattr *ia)
{
int err = 0;
struct dentry *lower_dentry;
struct dentry *parent;
struct inode *inode;
struct inode *lower_inode;
int bstart, bend, bindex;
loff_t size;
struct iattr lower_ia;
/* check if user has permission to change inode */
err = inode_change_ok(dentry->d_inode, ia);
if (err)
goto out_err;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate(dentry, parent, false, 0))) {
err = -ESTALE;
goto out;
}
bstart = dbstart(dentry);
bend = dbend(dentry);
inode = dentry->d_inode;
/*
* mode change is for clearing setuid/setgid. Allow lower filesystem
* to reinterpret it in its own way.
*/
if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
ia->ia_valid &= ~ATTR_MODE;
lower_dentry = unionfs_lower_dentry(dentry);
if (!lower_dentry) { /* should never happen after above revalidate */
err = -EINVAL;
goto out;
}
/*
* Get the lower inode directly from lower dentry, in case ibstart
* is -1 (which happens when the file is open but unlinked.
*/
lower_inode = lower_dentry->d_inode;
/* check if user has permission to change lower inode */
err = inode_change_ok(lower_inode, ia);
if (err)
goto out;
/* copyup if the file is on a read only branch */
if (is_robranch_super(dentry->d_sb, bstart)
|| __is_rdonly(lower_inode)) {
/* check if we have a branch to copy up to */
if (bstart <= 0) {
err = -EACCES;
goto out;
}
if (ia->ia_valid & ATTR_SIZE)
size = ia->ia_size;
else
size = i_size_read(inode);
/* copyup to next available branch */
for (bindex = bstart - 1; bindex >= 0; bindex--) {
err = copyup_dentry(parent->d_inode,
dentry, bstart, bindex,
dentry->d_name.name,
dentry->d_name.len,
NULL, size);
if (!err)
break;
}
if (err)
goto out;
/* get updated lower_dentry/inode after copyup */
lower_dentry = unionfs_lower_dentry(dentry);
lower_inode = unionfs_lower_inode(inode);
/*
* check for whiteouts in writeable branch, and remove them
* if necessary.
*/
if (lower_dentry) {
err = check_unlink_whiteout(dentry, lower_dentry,
bindex);
if (err > 0) /* ignore if whiteout found and removed */
err = 0;
}
}
/*
* If shrinking, first truncate upper level to cancel writing dirty
* pages beyond the new eof; and also if its' maxbytes is more
* limiting (fail with -EFBIG before making any change to the lower
* level). There is no need to vmtruncate the upper level
* afterwards in the other cases: we fsstack_copy_inode_size from
* the lower level.
*/
if (ia->ia_valid & ATTR_SIZE) {
err = inode_newsize_ok(inode, ia->ia_size);
if (err)
goto out;
truncate_setsize(inode, ia->ia_size);
}
/* notify the (possibly copied-up) lower inode */
/*
* Note: we use lower_dentry->d_inode, because lower_inode may be
* unlinked (no inode->i_sb and i_ino==0. This happens if someone
* tries to open(), unlink(), then ftruncate() a file.
*/
/* prepare our own lower struct iattr (with our own lower file) */
memcpy(&lower_ia, ia, sizeof(lower_ia));
if (ia->ia_valid & ATTR_FILE) {
lower_ia.ia_file = unionfs_lower_file(ia->ia_file);
BUG_ON(!lower_ia.ia_file); // XXX?
}
mutex_lock(&lower_dentry->d_inode->i_mutex);
err = notify_change(lower_dentry, &lower_ia);
mutex_unlock(&lower_dentry->d_inode->i_mutex);
if (err)
goto out;
/* get attributes from the first lower inode */
if (ibstart(inode) >= 0)
unionfs_copy_attr_all(inode, lower_inode);
/*
* unionfs_copy_attr_all will copy the lower times to our inode if
* the lower ones are newer (useful for cache coherency). However,
* ->setattr is the only place in which we may have to copy the
* lower inode times absolutely, to support utimes(2).
*/
if (ia->ia_valid & ATTR_MTIME_SET)
inode->i_mtime = lower_inode->i_mtime;
if (ia->ia_valid & ATTR_CTIME)
inode->i_ctime = lower_inode->i_ctime;
if (ia->ia_valid & ATTR_ATIME_SET)
inode->i_atime = lower_inode->i_atime;
fsstack_copy_inode_size(inode, lower_inode);
out:
if (!err)
unionfs_check_dentry(dentry);
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
out_err:
return err;
}
