ssize_t unionfs_read(struct file * file, char *buf, size_t count, loff_t * ppos)
{
int err = -EINVAL;
struct file *hidden_file = NULL;
loff_t pos = *ppos;
print_entry_location();
if ((err = unionfs_file_revalidate(file, 0)))
goto out;
fist_print_file("entering read()", file);
PASSERT(ftopd(file));
hidden_file = ftohf(file);
PASSERT(hidden_file);
if (!hidden_file->f_op || !hidden_file->f_op->read)
goto out;
err = hidden_file->f_op->read(hidden_file, buf, count, &pos);
*ppos = pos;
if (err >= 0) {
/* atime should also be updated for reads of size zero or more */
fist_copy_attr_atime(file->f_dentry->d_inode,
hidden_file->f_dentry->d_inode);
}
memcpy(&(file->f_ra), &(hidden_file->f_ra),
sizeof(struct file_ra_state));
out:
fist_print_file("leaving read()", file);
print_exit_status(err);
return err;
}
STATIC int
base0fs_readlink(struct dentry *dentry, char *buf, int bufsiz)
{
int err;
struct dentry *lower_dentry;
print_entry_location();
lower_dentry = base0fs_lower_dentry(dentry);/* CPW: Moved below print_entry_location */
fist_print_dentry("base0fs_readlink IN", dentry);
if (!lower_dentry->d_inode->i_op ||
!lower_dentry->d_inode->i_op->readlink) {
err = -EINVAL;
goto out;
}
err = lower_dentry->d_inode->i_op->readlink(lower_dentry,
buf,
bufsiz);
if (err > 0)
fist_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode);
out:
print_exit_status(err);
return err;
}
int unionfs_readlink(struct dentry *dentry, char __user * buf, int bufsiz)
{
int err;
struct dentry *hidden_dentry;
print_entry_location();
lock_dentry(dentry);
hidden_dentry = dtohd(dentry);
fist_print_dentry("unionfs_readlink IN", dentry);
if (!hidden_dentry->d_inode->i_op ||
!hidden_dentry->d_inode->i_op->readlink) {
err = -EINVAL;
goto out;
}
err = hidden_dentry->d_inode->i_op->readlink(hidden_dentry,
buf, bufsiz);
if (err > 0)
fist_copy_attr_atime(dentry->d_inode, hidden_dentry->d_inode);
out:
unlock_dentry(dentry);
print_exit_status(err);
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 *
base0fs_lookup(inode_t *dir,
struct dentry *dentry,
struct nameidata* nd_unused_in_this_fxn /* XXX: fix code if ever used */ )
{
int err = 0;
struct dentry *lower_dir_dentry;
struct dentry *lower_dentry = NULL;
struct vfsmount *lower_mount;
const char *name;
vnode_t *this_vnode;
struct dentry *this_dir;
unsigned int namelen;
print_entry_location();
lower_dir_dentry = base0fs_lower_dentry(dentry->d_parent); /* CPW: Moved below print_entry_location */
name = dentry->d_name.name;
namelen = dentry->d_name.len;
fist_checkinode(dir, "base0fs_lookup");
this_vnode = dir;
this_dir = lower_dir_dentry;
fist_print_dentry("base0fs_lookup IN", dentry);
fist_print_dentry("base0fs_lookup: dentry->d_parent IN", dentry->d_parent);
fist_print_dentry("base0fs_lookup: lower_dir_dentry IN", lower_dir_dentry);
fist_print_inode("base0fs_lookup: dir IN", dir);
if (lower_dir_dentry->d_inode)
fist_print_inode("base0fs_lookup: lower_dir_dentry->d_inode",
lower_dir_dentry->d_inode);
/* must initialize dentry operations */
dentry->d_op = &base0fs_dops;
;
/* increase refcount of base dentry (lookup_one[_len] will decrement) */
// THIS IS RIGHT! (don't "fix" it)
// NO THIS IS WRONG IN 2.3.99-pre6. lookup_one[_len] will NOT decrement
// dget(lower_dir_dentry);
lock_inode(lower_dir_dentry->d_inode);
/* will allocate a new lower dentry if needed */
lower_dentry = lookup_one_len(name, lower_dir_dentry, namelen);
unlock_inode(lower_dir_dentry->d_inode);
if (IS_ERR(lower_dentry)) {
/*
* this produces an unusual dentry: one that has neither an
* inode, nor a private structure attached to it. All cleanup
* methods (d_delete, d_release, etc) must be prepared to deal
* with such dentries. Ion 09/29/2001
*/
err = PTR_ERR(lower_dentry);
goto out;
}
lower_mount = mntget(DENTRY_TO_LVFSMNT(dentry->d_parent));
;
if (lower_dentry->d_inode && lower_dentry->d_inode->i_sb) {
struct super_block *lower_sb = lower_dentry->d_inode->i_sb;
if (lower_sb->s_dev == sProcDev || lower_sb->s_dev == sDevDev) {
d_drop(dentry); /* Don't leak our dentry. */
return lower_dentry;
}
}
/* update parent directory's atime */
fist_copy_attr_atime(dir, lower_dir_dentry->d_inode);
/* link the upper and lower dentries */
DENTRY_TO_PRIVATE_SM(dentry) = (struct base0fs_dentry_info *) KMALLOC(sizeof(struct base0fs_dentry_info), GFP_KERNEL);
if (!DENTRY_TO_PRIVATE(dentry)) {
err = -ENOMEM;
goto out_dput;
}
DENTRY_TO_PRIVATE(dentry)->wdi_dentry = lower_dentry;
DENTRY_TO_PRIVATE(dentry)->wdi_mnt = lower_mount;
/* lookup is special: it needs to handle negative dentries */
if (!lower_dentry->d_inode) {
d_add(dentry, NULL);
fist_print_dentry("base0fs_lookup OUT lower_dentry", lower_dentry);
goto out;
}
fist_dprint(6, "lookup \"%s\" -> inode %lu\n", name, lower_dentry->d_inode->i_ino);
err = base0fs_interpose(lower_dentry, dentry, dir->i_sb, 1);
if (err)
goto out_free;
fist_checkinode(dentry->d_inode, "base0fs_lookup OUT: dentry->d_inode:");
fist_checkinode(dir, "base0fs_lookup OUT: dir");
fist_print_dentry("base0fs_lookup OUT lower_dentry", lower_dentry);
fist_print_inode("base0fs_lookup OUT lower_inode", lower_dentry->d_inode);
/* All is well */
goto out;
out_free:
d_drop(dentry); /* so that our bad dentry will get destroyed */
KFREE(DENTRY_TO_PRIVATE(dentry));
DENTRY_TO_PRIVATE_SM(dentry) = NULL; /* be safe */
out_dput:
if (lower_dentry)
dput(lower_dentry);
out:
fist_print_dentry("base0fs_lookup OUT", dentry);
print_exit_status(err);
return ERR_PTR(err);
}
