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/* Directories for tmpfs.
Copyright (C) 2000,01,02 Free Software Foundation, Inc.
This file is part of the GNU Hurd.
The GNU Hurd is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
The GNU Hurd is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with the GNU Hurd; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
#include <stddef.h>
#include <unistd.h>
#include <sys/mman.h>
#include "tmpfs.h"
#include <stdlib.h>
error_t
diskfs_init_dir (struct node *dp, struct node *pdp, struct protid *cred)
{
dp->dn->u.dir.dotdot = pdp->dn;
dp->dn->u.dir.entries = 0;
/* Increase hardlink count for parent directory */
pdp->dn_stat.st_nlink++;
/* Take '.' directory into account */
dp->dn_stat.st_nlink++;
return 0;
}
error_t
diskfs_clear_directory (struct node *dp, struct node *pdp,
struct protid *cred)
{
if (dp->dn->u.dir.entries != 0)
return ENOTEMPTY;
assert (dp->dn_stat.st_size == 0);
assert (dp->dn->u.dir.dotdot == pdp->dn);
/* Decrease hardlink count for parent directory */
pdp->dn_stat.st_nlink--;
/* Take '.' directory into account */
dp->dn_stat.st_nlink--;
return 0;
}
int
diskfs_dirempty (struct node *dp, struct protid *cred)
{
return dp->dn->u.dir.entries == 0;
}
error_t
diskfs_get_directs (struct node *dp, int entry, int n,
char **data, size_t *datacnt,
vm_size_t bufsiz, int *amt)
{
struct tmpfs_dirent *d;
struct dirent *entp;
int i;
if (bufsiz == 0)
bufsiz = dp->dn_stat.st_size
+ 2 * ((offsetof (struct dirent, d_name[3]) + 7) & ~7);
if (bufsiz > *datacnt)
{
*data = mmap (0, bufsiz, PROT_READ|PROT_WRITE, MAP_ANON, 0, 0);
if (*data == MAP_FAILED)
return ENOMEM;
}
/* We always synthesize the first two entries (. and ..) on the fly. */
entp = (struct dirent *) *data;
i = 0;
if (i++ >= entry)
{
entp->d_fileno = dp->dn_stat.st_ino;
entp->d_type = DT_DIR;
entp->d_namlen = 1;
entp->d_name[0] = '.';
entp->d_name[1] = '\0';
entp->d_reclen = (&entp->d_name[2] - (char *) entp + 7) & ~7;
entp = (void *) entp + entp->d_reclen;
}
if (i++ >= entry)
{
if (dp->dn->u.dir.dotdot == 0)
{
assert (dp == diskfs_root_node);
/* Use something not zero and not an st_ino value for any node in
this filesystem. Since we use pointer values, 2 will never
be a valid number. */
entp->d_fileno = 2;
}
else
entp->d_fileno = (ino_t) (uintptr_t) dp->dn->u.dir.dotdot;
entp->d_type = DT_DIR;
entp->d_namlen = 2;
entp->d_name[0] = '.';
entp->d_name[1] = '.';
entp->d_name[2] = '\0';
entp->d_reclen = (&entp->d_name[3] - (char *) entp + 7) & ~7;
entp = (void *) entp + entp->d_reclen;
}
/* Skip ahead to the desired entry. */
for (d = dp->dn->u.dir.entries; i < entry && d != 0; d = d->next)
++i;
if (i < entry)
{
assert (d == 0);
*datacnt = 0;
*amt = 0;
return 0;
}
/* Now fill in the buffer with real entries. */
for (; d != 0; d = d->next, i++)
{
size_t rlen = (offsetof (struct dirent, d_name[1]) + d->namelen + 7) & ~7;
if (rlen + (char *) entp - *data > bufsiz || (n >= 0 && i > n))
break;
entp->d_fileno = (ino_t) (uintptr_t) d->dn;
entp->d_type = DT_UNKNOWN;
entp->d_namlen = d->namelen;
memcpy (entp->d_name, d->name, d->namelen + 1);
entp->d_reclen = rlen;
entp = (void *) entp + rlen;
}
*datacnt = (char *) entp - *data;
*amt = i - entry;
return 0;
}
struct dirstat
{
struct tmpfs_dirent **prevp;
int dotdot;
};
const size_t diskfs_dirstat_size = sizeof (struct dirstat);
void
diskfs_null_dirstat (struct dirstat *ds)
{
ds->prevp = 0;
}
error_t
diskfs_drop_dirstat (struct node *dp, struct dirstat *ds)
{
/* No need to clear the pointers. */
return 0;
}
error_t
diskfs_lookup_hard (struct node *dp,
const char *name, enum lookup_type type,
struct node **np, struct dirstat *ds,
struct protid *cred)
{
const size_t namelen = strlen (name);
struct tmpfs_dirent *d, **prevp;
if (type == REMOVE || type == RENAME)
assert (np);
if (ds)
ds->dotdot = type & SPEC_DOTDOT;
if (namelen == 1 && name[0] == '.')
{
if (np != 0)
{
*np = dp;
diskfs_nref (dp);
}
return 0;
}
if (namelen == 2 && name[0] == '.' && name[1] == '.')
{
struct disknode *dddn = dp->dn->u.dir.dotdot;
error_t err;
assert (np != 0);
if (dddn == 0) /* root directory */
return EAGAIN;
if (type == (REMOVE|SPEC_DOTDOT) || type == (RENAME|SPEC_DOTDOT))
{
*np = *dddn->hprevp;
assert (*np);
assert ((*np)->dn == dddn);
assert (*dddn->hprevp == *np);
return 0;
}
else
{
pthread_mutex_unlock (&dp->lock);
err = diskfs_cached_lookup ((ino_t) (intptr_t) dddn, np);
if (type == (LOOKUP|SPEC_DOTDOT))
diskfs_nrele (dp);
else
pthread_mutex_lock (&dp->lock);
if (err)
*np = 0;
return err;
}
}
for (d = *(prevp = &dp->dn->u.dir.entries); d != 0;
d = *(prevp = &d->next))
if (d->namelen == namelen && !memcmp (d->name, name, namelen))
{
if (ds)
ds->prevp = prevp;
if (np)
return diskfs_cached_lookup ((ino_t) (uintptr_t) d->dn, np);
else
return 0;
}
if (ds)
ds->prevp = prevp;
if (np)
*np = 0;
return ENOENT;
}
error_t
diskfs_direnter_hard (struct node *dp, const char *name,
struct node *np, struct dirstat *ds,
struct protid *cred)
{
const size_t namelen = strlen (name);
const size_t entsize
= (offsetof (struct dirent, d_name[1]) + namelen + 7) & ~7;
struct tmpfs_dirent *new;
if (round_page (tmpfs_space_used + entsize) / vm_page_size
> tmpfs_page_limit)
return ENOSPC;
new = malloc (offsetof (struct tmpfs_dirent, name) + namelen + 1);
if (new == 0)
return ENOSPC;
new->next = 0;
new->dn = np->dn;
new->namelen = namelen;
memcpy (new->name, name, namelen + 1);
*ds->prevp = new;
dp->dn_stat.st_size += entsize;
adjust_used (entsize);
dp->dn_stat.st_blocks = ((sizeof *dp->dn + dp->dn->translen
+ dp->dn_stat.st_size + 511)
/ 512);
return 0;
}
error_t
diskfs_dirrewrite_hard (struct node *dp, struct node *np,
struct dirstat *ds)
{
if (ds->dotdot)
dp->dn->u.dir.dotdot = np->dn;
else
(*ds->prevp)->dn = np->dn;
return 0;
}
error_t
diskfs_dirremove_hard (struct node *dp, struct dirstat *ds)
{
struct tmpfs_dirent *d = *ds->prevp;
const size_t entsize
= (offsetof (struct dirent, d_name[1]) + d->namelen + 7) & ~7;
*ds->prevp = d->next;
if (dp->dirmod_reqs != 0)
diskfs_notice_dirchange (dp, DIR_CHANGED_UNLINK, d->name);
free (d);
adjust_used (-entsize);
dp->dn_stat.st_size -= entsize;
dp->dn_stat.st_blocks = ((sizeof *dp->dn + dp->dn->translen
+ dp->dn_stat.st_size + 511)
/ 512);
return 0;
}
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