/* Implement the diskfs_lookup callback from the diskfs library. See
<hurd/diskfs.h> for the interface specification. */
error_t
diskfs_lookup_hard (struct node *dp, const char *name, enum lookup_type type,
struct node **npp, struct dirstat *ds, struct protid *cred)
{
error_t err = 0;
struct lookup_context ctx;
int namelen;
int spec_dotdot;
void *buf;
void *blockaddr;
ino_t id;
if ((type == REMOVE) || (type == RENAME))
assert (npp);
if (npp)
*npp = 0;
spec_dotdot = type & SPEC_DOTDOT;
type &= ~SPEC_DOTDOT;
namelen = strlen (name);
/* This error is constant, but the errors for CREATE and REMOVE depend
on whether NAME exists. */
if (type == RENAME)
return EROFS;
buf = disk_image + (dp->dn->file_start << store->log2_block_size);
for (blockaddr = buf;
blockaddr < buf + dp->dn_stat.st_size;
blockaddr += logical_sector_size)
{
err = dirscanblock (blockaddr, name, namelen, &ctx.dr, &ctx.rr);
if (!err)
break;
if (err != ENOENT)
return err;
}
if ((!err && type == REMOVE)
|| (err == ENOENT && type == CREATE))
err = EROFS;
if (err)
return err;
err = cache_id (ctx.dr, &ctx.rr, &id);
if (err)
return err;
/* Load the inode */
if (namelen == 2 && name[0] == '.' && name[1] == '.')
{
if (dp == diskfs_root_node)
err = EAGAIN;
else if (spec_dotdot)
{
/* renames and removes can't get this far. */
assert (type == LOOKUP);
diskfs_nput (dp);
err = diskfs_cached_lookup_context (id, npp, &ctx);
}
else
{
/* We don't have to do the normal rigamarole, because
we are permanently read-only, so things are necessarily
quiescent. Just be careful to honor the locking order. */
pthread_mutex_unlock (&dp->lock);
err = diskfs_cached_lookup_context (id, npp, &ctx);
pthread_mutex_lock (&dp->lock);
}
}
else if (namelen == 1 && name[0] == '.')
{
*npp = dp;
diskfs_nref (dp);
}
else
err = diskfs_cached_lookup_context (id, npp, &ctx);
release_rrip (&ctx.rr);
return err;
}
/* Implement the diskfs_lookup callback from the diskfs library. See
<hurd/diskfs.h> for the interface specification. */
error_t
diskfs_lookup_hard (struct node *dp, const char *name, enum lookup_type type,
struct node **npp, struct dirstat *ds, struct protid *cred)
{
error_t err;
ino_t inum;
int namelen;
int spec_dotdot;
struct node *np = 0;
int retry_dotdot = 0;
vm_prot_t prot =
(type == LOOKUP) ? VM_PROT_READ : (VM_PROT_READ | VM_PROT_WRITE);
memory_object_t memobj;
vm_address_t buf = 0;
vm_size_t buflen = 0;
int blockaddr;
int idx, lastidx;
int looped;
if ((type == REMOVE) || (type == RENAME))
assert (npp);
if (npp)
*npp = 0;
spec_dotdot = type & SPEC_DOTDOT;
type &= ~SPEC_DOTDOT;
namelen = strlen (name);
if (namelen > FAT_NAME_MAX)
return ENAMETOOLONG;
try_again:
if (ds)
{
ds->type = LOOKUP;
ds->mapbuf = 0;
ds->mapextent = 0;
}
if (buf)
{
munmap ((caddr_t) buf, buflen);
buf = 0;
}
if (ds && (type == CREATE || type == RENAME))
ds->stat = LOOKING;
/* Map in the directory contents. */
memobj = diskfs_get_filemap (dp, prot);
if (memobj == MACH_PORT_NULL)
return errno;
buf = 0;
/* We allow extra space in case we have to do an EXTEND. */
buflen = round_page (dp->dn_stat.st_size + DIRBLKSIZ);
err = vm_map (mach_task_self (),
&buf, buflen, 0, 1, memobj, 0, 0, prot, prot, 0);
mach_port_deallocate (mach_task_self (), memobj);
inum = 0;
diskfs_set_node_atime (dp);
/* Start the lookup at DP->dn->dir_idx. */
idx = dp->dn->dir_idx;
if (idx << LOG2_DIRBLKSIZ > dp->dn_stat.st_size)
idx = 0; /* just in case */
blockaddr = buf + (idx << LOG2_DIRBLKSIZ);
looped = (idx == 0);
lastidx = idx;
if (lastidx == 0)
lastidx = dp->dn_stat.st_size >> LOG2_DIRBLKSIZ;
while (!looped || idx < lastidx)
{
err = dirscanblock (blockaddr, dp, idx, name, namelen, type, ds, &inum);
if (!err)
{
dp->dn->dir_idx = idx;
break;
}
if (err != ENOENT)
{
munmap ((caddr_t) buf, buflen);
return err;
}
blockaddr += DIRBLKSIZ;
idx++;
if (blockaddr - buf >= dp->dn_stat.st_size && !looped)
{
/* We've gotten to the end; start back at the beginning. */
looped = 1;
blockaddr = buf;
idx = 0;
}
}
diskfs_set_node_atime (dp);
if (diskfs_synchronous)
diskfs_node_update (dp, 1);
/* If err is set here, it's ENOENT, and we don't want to
think about that as an error yet. */
err = 0;
if (inum && npp)
{
if (namelen != 2 || name[0] != '.' || name[1] != '.')
{
if (inum == dp->cache_id)
{
np = dp;
diskfs_nref (np);
}
else
{
err = diskfs_cached_lookup_in_dirbuf (inum, &np, buf);
if (err)
goto out;
}
}
/* We are looking up "..". */
/* Check to see if this is the root of the filesystem. */
else if (dp == diskfs_root_node)
{
err = EAGAIN;
goto out;
}
/* We can't just do diskfs_cached_lookup, because we would then
deadlock. So we do this. Ick. */
else if (retry_dotdot)
{
/* Check to see that we got the same answer as last time. */
if (inum != retry_dotdot)
{
/* Drop what we *thought* was .. (but isn't any more) and
try *again*. */
diskfs_nput (np);
mutex_unlock (&dp->lock);
err = diskfs_cached_lookup_in_dirbuf (inum, &np, buf);
mutex_lock (&dp->lock);
if (err)
goto out;
retry_dotdot = inum;
goto try_again;
}
/* Otherwise, we got it fine and np is already set properly. */
}
else if (!spec_dotdot)
{
/* Lock them in the proper order, and then
repeat the directory scan to see if this is still
right. */
mutex_unlock (&dp->lock);
err = diskfs_cached_lookup_in_dirbuf (inum, &np, buf);
mutex_lock (&dp->lock);
if (err)
goto out;
retry_dotdot = inum;
goto try_again;
}
/* Here below are the spec dotdot cases. */
else if (type == RENAME || type == REMOVE)
np = ifind (inum);
else if (type == LOOKUP)
{
diskfs_nput (dp);
err = diskfs_cached_lookup_in_dirbuf (inum, &np, buf);
if (err)
goto out;
}
else
assert (0);
}
if ((type == CREATE || type == RENAME) && !inum && ds && ds->stat == LOOKING)
{
/* We didn't find any room, so mark ds to extend the dir. */
ds->type = CREATE;
ds->stat = EXTEND;
ds->idx = dp->dn_stat.st_size >> LOG2_DIRBLKSIZ;
}
