static void
update(
float (* state)[NHOR][NVER],
float (* state_next)[NHOR][NVER],
float (* dstate)[NHOR][NVER],
float (* dstate_next)[NHOR][NVER]
) {
float dt = 0.01;
float v, u, d2vdx2, d2vdy2, dvdt, dudt ,I;
for (int idy = 0; idy < NVER; idy++) {
for (int idx = 0; idx < NVER; idx++) {
v = GET(0, 0);
u = DGET(0, 0);
d2vdx2 = (GET(0, 1) - 2*v + GET(0, -1));
d2vdy2 = (GET(1, 0) - 2*v + GET(-1, 0));
I = 2*(d2vdx2 + d2vdy2);
if (I < 0) {
I = 0;
}
dvdt = 0.04 * v*v + 5*v + 140 - u + I;
dudt = 0.02 * (0.2*v - u);
v = v + dvdt * dt;
u = u + dudt * dt;
if (v >= 30) {
v = -65;
if (u < 10) {
u = u + 8;
}
}
NEXT(0, 0) = v;
DNEXT(0, 0) = u;
}
}
}
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;
}
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;
}
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_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_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;
}
static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
int bindex, struct dentry **wh_old)
{
int err = 0;
struct dentry *hidden_old_dentry;
struct dentry *hidden_new_dentry;
struct dentry *hidden_old_dir_dentry;
struct dentry *hidden_new_dir_dentry;
struct dentry *hidden_wh_dentry;
struct dentry *hidden_wh_dir_dentry;
char *wh_name = NULL;
print_entry(" bindex=%d", bindex);
fist_print_dentry("IN: do_rename, old_dentry", old_dentry);
fist_print_dentry("IN: do_rename, new_dentry", new_dentry);
fist_dprint(7, "do_rename for bindex = %d\n", bindex);
hidden_new_dentry = dtohd_index(new_dentry, bindex);
hidden_old_dentry = dtohd_index(old_dentry, bindex);
if (!hidden_new_dentry) {
hidden_new_dentry =
create_parents(new_dentry->d_parent->d_inode, new_dentry,
bindex);
if (IS_ERR(hidden_new_dentry)) {
fist_dprint(7,
"error creating directory tree for rename, bindex = %d\n",
bindex);
err = PTR_ERR(hidden_new_dentry);
goto out;
}
}
wh_name = alloc_whname(new_dentry->d_name.name, new_dentry->d_name.len);
if (IS_ERR(wh_name)) {
err = PTR_ERR(wh_name);
goto out;
}
hidden_wh_dentry =
LOOKUP_ONE_LEN(wh_name, hidden_new_dentry->d_parent,
new_dentry->d_name.len + WHLEN);
if (IS_ERR(hidden_wh_dentry)) {
err = PTR_ERR(hidden_wh_dentry);
goto out;
}
if (hidden_wh_dentry->d_inode) {
/* get rid of the whiteout that is existing */
if (hidden_new_dentry->d_inode) {
printk(KERN_WARNING
"Both a whiteout and a dentry exist when doing a rename!\n");
err = -EIO;
DPUT(hidden_wh_dentry);
goto out;
}
hidden_wh_dir_dentry = lock_parent(hidden_wh_dentry);
if (!(err = is_robranch_super(old_dentry->d_sb, bindex))) {
err =
vfs_unlink(hidden_wh_dir_dentry->d_inode,
hidden_wh_dentry);
}
DPUT(hidden_wh_dentry);
unlock_dir(hidden_wh_dir_dentry);
if (err)
goto out;
} else
DPUT(hidden_wh_dentry);
DGET(hidden_old_dentry);
hidden_old_dir_dentry = GET_PARENT(hidden_old_dentry);
hidden_new_dir_dentry = GET_PARENT(hidden_new_dentry);
lock_rename(hidden_old_dir_dentry, hidden_new_dir_dentry);
err = is_robranch_super(old_dentry->d_sb, bindex);
if (err)
goto out_unlock;
/* ready to whiteout for old_dentry.
caller will create the actual whiteout,
and must dput(*wh_old) */
if (wh_old) {
char *whname;
whname = alloc_whname(old_dentry->d_name.name,
old_dentry->d_name.len);
err = PTR_ERR(whname);
if (IS_ERR(whname))
goto out_unlock;
*wh_old = LOOKUP_ONE_LEN(whname, hidden_old_dir_dentry,
old_dentry->d_name.len + WHLEN);
KFREE(whname);
err = PTR_ERR(*wh_old);
if (IS_ERR(*wh_old)) {
*wh_old = NULL;
goto out_unlock;
}
}
fist_print_dentry("NEWBEF", new_dentry);
fist_print_dentry("OLDBEF", old_dentry);
err = vfs_rename(hidden_old_dir_dentry->d_inode, hidden_old_dentry,
hidden_new_dir_dentry->d_inode, hidden_new_dentry);
fist_print_dentry("NEWAFT", new_dentry);
fist_print_dentry("OLDAFT", old_dentry);
out_unlock:
unlock_rename(hidden_old_dir_dentry, hidden_new_dir_dentry);
DPUT(hidden_old_dir_dentry);
DPUT(hidden_new_dir_dentry);
DPUT(hidden_old_dentry);
out:
if (!err) {
/* Fixup the newdentry. */
if (bindex < dbstart(new_dentry))
set_dbstart(new_dentry, bindex);
else if (bindex > dbend(new_dentry))
set_dbend(new_dentry, bindex);
}
KFREE(wh_name);
fist_print_dentry("OUT: do_rename, old_dentry", old_dentry);
fist_print_dentry("OUT: do_rename, new_dentry", new_dentry);
print_exit_status(err);
return err;
}
static int 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;
}
