/*
* Implementation of the diskquota system for the LINUX operating
* system. QUOTA is implemented using the BSD systemcall interface as
* the means of communication with the user level. Currently only the
* ext2-filesystem has support for diskquotas. Other filesystems may
* be added in future time. This file contains the generic routines
* called by the different filesystems on allocation of an inode or
* block. These routines take care of the administration needed to
* have a consistent diskquota tracking system. The ideas of both
* user and group quotas are based on the Melbourne quota system as
* used on BSD derived systems. The internal implementation is
* based on the LINUX inode-subsystem with added complexity of the
* diskquota system. This implementation is not based on any BSD
* kernel sourcecode.
*
* Version: $Id: dquot.c,v 5.6 1995/11/15 20:30:27 mvw Exp mvw $
*
* Author: Marco van Wieringen <mvw@mcs.ow.nl> <mvw@tnix.net>
*
* Fixes: Dmitry Gorodchanin <begemot@bgm.rosprint.net>, 11 Feb 96
* removed race conditions in dqput(), dqget() and iput().
*
* (C) Copyright 1994, 1995 Marco van Wieringen
*
*/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/stat.h>
#include <linux/tty.h>
#include <linux/malloc.h>
#include <linux/mount.h>
#include <asm/segment.h>
#define __DQUOT_VERSION__ "dquot_5.6.0"
static char quotamessage[MAX_QUOTA_MESSAGE];
static char *quotatypes[] = INITQFNAMES;
static int nr_dquots = 0, nr_free_dquots = 0;
static struct dquot *hash_table[NR_DQHASH];
static struct dquot *first_dquot;
static struct dqstats dqstats;
static struct wait_queue *dquot_wait = (struct wait_queue *)NULL;
extern void add_dquot_ref(kdev_t dev, short type);
extern void reset_dquot_ptrs(kdev_t dev, short type);
#ifndef min
#define min(a,b) ((a) < (b)) ? (a) : (b)
#endif
/*
* Functions for management of the hashlist.
*/
static inline int const hashfn(kdev_t dev, unsigned int id, short type)
{
return((HASHDEV(dev) ^ id) * (MAXQUOTAS - type)) % NR_DQHASH;
}
static inline struct dquot **const hash(kdev_t dev, unsigned int id, short type)
{
return(hash_table + hashfn(dev, id, type));
}
static inline int has_quota_enabled(kdev_t dev, short type)
{
struct vfsmount *vfsmnt;
return((vfsmnt = lookup_vfsmnt(dev)) != (struct vfsmount *)NULL &&
(vfsmnt->mnt_quotas[type] != (struct file *)NULL));
}
static void insert_dquot_free(struct dquot *dquot)
{
dquot->dq_next = first_dquot;
dquot->dq_prev = first_dquot->dq_prev;
dquot->dq_next->dq_prev = dquot;
dquot->dq_prev->dq_next = dquot;
first_dquot = dquot;
}
static void remove_dquot_free(struct dquot *dquot)
{
if (first_dquot == dquot)
first_dquot = first_dquot->dq_next;
if (dquot->dq_next)
dquot->dq_next->dq_prev = dquot->dq_prev;
if (dquot->dq_prev)
dquot->dq_prev->dq_next = dquot->dq_next;
dquot->dq_next = dquot->dq_prev = NODQUOT;
}
static void insert_dquot_hash(struct dquot *dquot)
{
struct dquot **hash_ent;
hash_ent = hash(dquot->dq_dev, dquot->dq_id, dquot->dq_type);
dquot->dq_hash_next = *hash_ent;
dquot->dq_hash_prev = NODQUOT;
if (dquot->dq_hash_next)
dquot->dq_hash_next->dq_hash_prev = dquot;
*hash_ent = dquot;
}
static void remove_dquot_hash(struct dquot *dquot)
{
struct dquot **hash_ent;
hash_ent = hash(dquot->dq_dev, dquot->dq_id, dquot->dq_type);
if (*hash_ent == dquot)
*hash_ent = dquot->dq_hash_next;
if (dquot->dq_hash_next)
dquot->dq_hash_next->dq_hash_prev = dquot->dq_hash_prev;
if (dquot->dq_hash_prev)
dquot->dq_hash_prev->dq_hash_next = dquot->dq_hash_next;
dquot->dq_hash_prev = dquot->dq_hash_next = NODQUOT;
}
static void put_last_free(struct dquot *dquot)
{
remove_dquot_free(dquot);
dquot->dq_prev = first_dquot->dq_prev;
dquot->dq_prev->dq_next = dquot;
dquot->dq_next = first_dquot;
dquot->dq_next->dq_prev = dquot;
}
static void grow_dquots(void)
{
struct dquot *dquot;
int cnt;
if (!(dquot = (struct dquot*) get_free_page(GFP_KERNEL)))
return;
dqstats.pages_allocated++;
cnt = PAGE_SIZE / sizeof(struct dquot);
nr_dquots += cnt;
nr_free_dquots += cnt;
if (!first_dquot) {
dquot->dq_next = dquot->dq_prev = first_dquot = dquot++;
cnt--;
}
for (; cnt; cnt--)
insert_dquot_free(dquot++);
}
/*
* Functions for locking and waiting on dquots.
*/
static void __wait_on_dquot(struct dquot *dquot)
{
struct wait_queue wait = {current, NULL};
add_wait_queue(&dquot->dq_wait, &wait);
repeat:
current->state = TASK_UNINTERRUPTIBLE;
if (dquot->dq_flags & DQ_LOCKED) {
dquot->dq_flags |= DQ_WANT;
schedule();
goto repeat;
}
remove_wait_queue(&dquot->dq_wait, &wait);
current->state = TASK_RUNNING;
}
static inline void wait_on_dquot(struct dquot *dquot)
{
if (dquot->dq_flags & DQ_LOCKED)
__wait_on_dquot(dquot);
}
static inline void lock_dquot(struct dquot *dquot)
{
wait_on_dquot(dquot);
dquot->dq_flags |= DQ_LOCKED;
}
static inline void unlock_dquot(struct dquot *dquot)
{
dquot->dq_flags &= ~DQ_LOCKED;
if (dquot->dq_flags & DQ_WANT) {
dquot->dq_flags &= ~DQ_WANT;
wake_up(&dquot->dq_wait);
}
}
/*
* Note that we don't want to disturb any wait-queues when we discard
* an dquot.
*
* FIXME: As soon as we have a nice solution for the inode problem we
* can also fix this one. I.e. the volatile part.
*/
static void clear_dquot(struct dquot * dquot)
{
struct wait_queue *wait;
wait_on_dquot(dquot);
remove_dquot_hash(dquot);
remove_dquot_free(dquot);
wait = ((volatile struct dquot *) dquot)->dq_wait;
if (dquot->dq_count)
nr_free_dquots++;
memset(dquot, 0, sizeof(*dquot));
((volatile struct dquot *) dquot)->dq_wait = wait;
insert_dquot_free(dquot);
}
static void write_dquot(struct dquot *dquot)
{
short type = dquot->dq_type;
struct file *filp = dquot->dq_mnt->mnt_quotas[type];
unsigned short fs;
if (!(dquot->dq_flags & DQ_MOD) || (filp == (struct file *)NULL))
return;
lock_dquot(dquot);
down(&dquot->dq_mnt->mnt_sem);
if (filp->f_op->lseek) {
if (filp->f_op->lseek(filp->f_inode, filp,
dqoff(dquot->dq_id), 0) != dqoff(dquot->dq_id)) {
up(&dquot->dq_mnt->mnt_sem);
unlock_dquot(dquot);
return;
}
} else
filp->f_pos = dqoff(dquot->dq_id);
fs = get_fs();
set_fs(KERNEL_DS);
if (filp->f_op->write(filp->f_inode, filp,
(char *)&dquot->dq_dqb, sizeof(struct dqblk)) == sizeof(struct dqblk))
dquot->dq_flags &= ~DQ_MOD;
up(&dquot->dq_mnt->mnt_sem);
set_fs(fs);
unlock_dquot(dquot);
dqstats.writes++;
}
static void read_dquot(struct dquot *dquot)
{
short type = dquot->dq_type;
struct file *filp = dquot->dq_mnt->mnt_quotas[type];
unsigned short fs;
if (filp == (struct file *)NULL)
return;
lock_dquot(dquot);
down(&dquot->dq_mnt->mnt_sem);
if (filp->f_op->lseek) {
if (filp->f_op->lseek(filp->f_inode, filp,
dqoff(dquot->dq_id), 0) != dqoff(dquot->dq_id)) {
up(&dquot->dq_mnt->mnt_sem);
unlock_dquot(dquot);
return;
}
} else
filp->f_pos = dqoff(dquot->dq_id);
fs = get_fs();
set_fs(KERNEL_DS);
filp->f_op->read(filp->f_inode, filp, (char *)&dquot->dq_dqb, sizeof(struct dqblk));
up(&dquot->dq_mnt->mnt_sem);
set_fs(fs);
if (dquot->dq_bhardlimit == 0 && dquot->dq_bsoftlimit == 0 &&
dquot->dq_ihardlimit == 0 && dquot->dq_isoftlimit == 0)
dquot->dq_flags |= DQ_FAKE;
unlock_dquot(dquot);
dqstats.reads++;
}
int sync_dquots(kdev_t dev, short type)
{
struct dquot *dquot = first_dquot;
int i;
dqstats.syncs++;
for (i = 0; i < nr_dquots * 2; i++, dquot = dquot->dq_next) {
if (dev == NODEV || dquot->dq_count == 0 || dquot->dq_dev != dev)
continue;
if (type != -1 && dquot->dq_type != type)
continue;
wait_on_dquot(dquot);
if (dquot->dq_flags & DQ_MOD)
write_dquot(dquot);
}
return(0);
}
/*
* Trash the cache for a certain type on a device.
*/
void invalidate_dquots(kdev_t dev, short type)
{
struct dquot *dquot, *next;
int cnt;
next = first_dquot;
for (cnt = nr_dquots ; cnt > 0 ; cnt--) {
dquot = next;
next = dquot->dq_next;
if (dquot->dq_dev != dev || dquot->dq_type != type)
continue;
if (dquot->dq_flags & DQ_LOCKED) {
printk("VFS: dquot busy on removed device %s\n", kdevname(dev));
continue;
}
if (dquot->dq_flags & DQ_MOD)
write_dquot(dquot);
dqstats.drops++;
clear_dquot(dquot);
}
}
static inline void dquot_incr_inodes(struct dquot *dquot, unsigned long number)
{
lock_dquot(dquot);
dquot->dq_curinodes += number;
dquot->dq_flags |= DQ_MOD;
unlock_dquot(dquot);
}
static inline void dquot_incr_blocks(struct dquot *dquot, unsigned long number)
{
lock_dquot(dquot);
dquot->dq_curblocks += number;
dquot->dq_flags |= DQ_MOD;
unlock_dquot(dquot);
}
static inline void dquot_decr_inodes(struct dquot *dquot, unsigned long number)
{
lock_dquot(dquot);
if (dquot->dq_curinodes > number)
dquot->dq_curinodes -= number;
else
dquot->dq_curinodes = 0;
if (dquot->dq_curinodes < dquot->dq_isoftlimit)
dquot->dq_itime = (time_t) 0;
dquot->dq_flags &= ~DQ_INODES;
dquot->dq_flags |= DQ_MOD;
unlock_dquot(dquot);
}
static inline void dquot_decr_blocks(struct dquot *dquot, unsigned long number)
{
lock_dquot(dquot);
if (dquot->dq_curblocks > number)
dquot->dq_curblocks -= number;
else
dquot->dq_curblocks = 0;
if (dquot->dq_curblocks < dquot->dq_bsoftlimit)
dquot->dq_btime = (time_t) 0;
dquot->dq_flags &= ~DQ_BLKS;
dquot->dq_flags |= DQ_MOD;
unlock_dquot(dquot);
}
static inline int need_print_warning(short type, struct dquot *dquot)
{
switch (type) {
case USRQUOTA:
return(current->fsuid == dquot->dq_id);
case GRPQUOTA:
return(current->fsgid == dquot->dq_id);
}
return(0);
}
static int check_idq(struct dquot *dquot, short type, u_long short inodes)
{
if (inodes <= 0 || dquot->dq_flags & DQ_FAKE)
return(QUOTA_OK);
if (dquot->dq_ihardlimit &&
(dquot->dq_curinodes + inodes) > dquot->dq_ihardlimit && !fsuser()) {
if ((dquot->dq_flags & DQ_INODES) == 0 &&
need_print_warning(type, dquot)) {
sprintf(quotamessage, "%s: write failed, %s file limit reached\r\n",
dquot->dq_mnt->mnt_dirname, quotatypes[type]);
tty_write_message(current->tty, quotamessage);
dquot->dq_flags |= DQ_INODES;
}
return(NO_QUOTA);
}
if (dquot->dq_isoftlimit &&
(dquot->dq_curinodes + inodes) > dquot->dq_isoftlimit &&
dquot->dq_itime && CURRENT_TIME >= dquot->dq_itime && !fsuser()) {
if (need_print_warning(type, dquot)) {
sprintf(quotamessage, "%s: warning, %s file quota exceeded too long.\r\n",
dquot->dq_mnt->mnt_dirname, quotatypes[type]);
tty_write_message(current->tty, quotamessage);
}
return(NO_QUOTA);
}
if (dquot->dq_isoftlimit &&
(dquot->dq_curinodes + inodes) > dquot->dq_isoftlimit &&
dquot->dq_itime == 0 && !fsuser()) {
if (need_print_warning(type, dquot)) {
sprintf(quotamessage, "%s: warning, %s file quota exceeded\r\n",
dquot->dq_mnt->mnt_dirname, quotatypes[type]);
tty_write_message(current->tty, quotamessage);
}
dquot->dq_itime = CURRENT_TIME + dquot->dq_mnt->mnt_iexp[type];
}
return(QUOTA_OK);
}
static int check_bdq(struct dquot *dquot, short type, u_long blocks)
{
if (blocks <= 0 || dquot->dq_flags & DQ_FAKE)
return(QUOTA_OK);
if (dquot->dq_bhardlimit &&
(dquot->dq_curblocks + blocks) > dquot->dq_bhardlimit && !fsuser()) {
if ((dquot->dq_flags & DQ_BLKS) == 0 &&
need_print_warning(type, dquot)) {
sprintf(quotamessage, "%s: write failed, %s disk limit reached.\r\n",
dquot->dq_mnt->mnt_dirname, quotatypes[type]);
tty_write_message(current->tty, quotamessage);
dquot->dq_flags |= DQ_BLKS;
}
return(NO_QUOTA);
}
if (dquot->dq_bsoftlimit &&
(dquot->dq_curblocks + blocks) > dquot->dq_bsoftlimit &&
dquot->dq_btime && CURRENT_TIME >= dquot->dq_btime && !fsuser()) {
if (need_print_warning(type, dquot)) {
sprintf(quotamessage, "%s: write failed, %s disk quota exceeded too long.\r\n",
dquot->dq_mnt->mnt_dirname, quotatypes[type]);
tty_write_message(current->tty, quotamessage);
}
return(NO_QUOTA);
}
if (dquot->dq_bsoftlimit &&
(dquot->dq_curblocks + blocks) > dquot->dq_bsoftlimit &&
dquot->dq_btime == 0 && !fsuser()) {
if (need_print_warning(type, dquot)) {
sprintf(quotamessage, "%s: warning, %s disk quota exceeded\r\n",
dquot->dq_mnt->mnt_dirname, quotatypes[type]);
tty_write_message(current->tty, quotamessage);
}
dquot->dq_btime = CURRENT_TIME + dquot->dq_mnt->mnt_bexp[type];
}
return(QUOTA_OK);
}
static void dqput(struct dquot *dquot)
{
if (!dquot)
return;
/*
* If the dq_mnt pointer isn't initialized this entry needs no
* checking and doesn't need to be written. It just an empty
* dquot that is put back into the freelist.
*/
if (dquot->dq_mnt != (struct vfsmount *)NULL) {
dqstats.drops++;
wait_on_dquot(dquot);
if (!dquot->dq_count) {
printk("VFS: dqput: trying to free free dquot\n");
printk("VFS: device %s, dquot of %s %d\n", kdevname(dquot->dq_dev),
quotatypes[dquot->dq_type], dquot->dq_id);
return;
}
repeat:
if (dquot->dq_count > 1) {
dquot->dq_count--;
return;
}
wake_up(&dquot_wait);
if (dquot->dq_flags & DQ_MOD) {
write_dquot(dquot); /* we can sleep - so do again */
wait_on_dquot(dquot);
goto repeat;
}
}
if (dquot->dq_count) {
dquot->dq_count--;
nr_free_dquots++;
}
return;
}
static struct dquot *get_empty_dquot(void)
{
struct dquot *dquot, *best;
int cnt;
if (nr_dquots < NR_DQUOTS && nr_free_dquots < (nr_dquots >> 2))
grow_dquots();
repeat:
dquot = first_dquot;
best = NODQUOT;
for (cnt = 0; cnt < nr_dquots; dquot = dquot->dq_next, cnt++) {
if (!dquot->dq_count) {
if (!best)
best = dquot;
if (!(dquot->dq_flags & DQ_MOD) && !(dquot->dq_flags & DQ_LOCKED)) {
best = dquot;
break;
}
}
}
if (!best || best->dq_flags & DQ_MOD || best->dq_flags & DQ_LOCKED)
if (nr_dquots < NR_DQUOTS) {
grow_dquots();
goto repeat;
}
dquot = best;
if (!dquot) {
printk("VFS: No free dquots - contact mvw@mcs.ow.org\n");
sleep_on(&dquot_wait);
goto repeat;
}
if (dquot->dq_flags & DQ_LOCKED) {
wait_on_dquot(dquot);
goto repeat;
}
if (dquot->dq_flags & DQ_MOD) {
write_dquot(dquot);
goto repeat;
}
if (dquot->dq_count)
goto repeat;
clear_dquot(dquot);
dquot->dq_count = 1;
nr_free_dquots--;
if (nr_free_dquots < 0) {
printk ("VFS: get_empty_dquot: bad free dquot count.\n");
nr_free_dquots = 0;
}
return(dquot);
}
static struct dquot *dqget(kdev_t dev, unsigned int id, short type)
{
struct dquot *dquot, *empty;
struct vfsmount *vfsmnt;
if ((vfsmnt = lookup_vfsmnt(dev)) == (struct vfsmount *)NULL ||
(vfsmnt->mnt_quotas[type] == (struct file *)0))
return(NODQUOT);
dqstats.lookups++;
empty = get_empty_dquot();
repeat:
dquot = *(hash(dev, id, type));
while (dquot) {
if (dquot->dq_dev != dev || dquot->dq_id != id) {
dquot = dquot->dq_hash_next;
continue;
}
wait_on_dquot(dquot);
if (dquot->dq_dev != dev || dquot->dq_id != id)
goto repeat;
if (!dquot->dq_count)
nr_free_dquots--;
dquot->dq_count++;
if (empty)
dqput(empty);
dqstats.cache_hits++;
return(dquot);
}
if (!empty)
return(NODQUOT);
dquot = empty;
dquot->dq_id = id;
dquot->dq_type = type;
dquot->dq_dev = dev;
dquot->dq_mnt = vfsmnt;
put_last_free(dquot);
insert_dquot_hash(dquot);
read_dquot(dquot);
return(dquot);
}
/*
* Initialize a dquot-struct with new quota info. This is used by the
* systemcall interface functions.
*/
static int set_dqblk(kdev_t dev, int id, short type, int flags, struct dqblk *dqblk)
{
struct dquot *dquot;
struct dqblk dq_dqblk;
int error;
if (dqblk == (struct dqblk *)NULL)
return(-EFAULT);
if (flags & QUOTA_SYSCALL) {
if ((error = verify_area(VERIFY_READ, dqblk, sizeof(struct dqblk))) != 0)
return(error);
memcpy_fromfs(&dq_dqblk, dqblk, sizeof(struct dqblk));
} else {
memcpy(&dq_dqblk, dqblk, sizeof(struct dqblk));
}
if ((dquot = dqget(dev, id, type)) != NODQUOT) {
lock_dquot(dquot);
if (id > 0 && ((flags & SET_QUOTA) || (flags & SET_QLIMIT))) {
dquot->dq_bhardlimit = dq_dqblk.dqb_bhardlimit;
dquot->dq_bsoftlimit = dq_dqblk.dqb_bsoftlimit;
dquot->dq_ihardlimit = dq_dqblk.dqb_ihardlimit;
dquot->dq_isoftlimit = dq_dqblk.dqb_isoftlimit;
}
if ((flags & SET_QUOTA) || (flags & SET_USE)) {
if (dquot->dq_isoftlimit &&
dquot->dq_curinodes < dquot->dq_isoftlimit &&
dq_dqblk.dqb_curinodes >= dquot->dq_isoftlimit)
dquot->dq_itime = CURRENT_TIME + dquot->dq_mnt->mnt_iexp[type];
dquot->dq_curinodes = dq_dqblk.dqb_curinodes;
if (dquot->dq_curinodes < dquot->dq_isoftlimit)
dquot->dq_flags &= ~DQ_INODES;
if (dquot->dq_bsoftlimit &&
dquot->dq_curblocks < dquot->dq_bsoftlimit &&
dq_dqblk.dqb_curblocks >= dquot->dq_bsoftlimit)
dquot->dq_btime = CURRENT_TIME + dquot->dq_mnt->mnt_bexp[type];
dquot->dq_curblocks = dq_dqblk.dqb_curblocks;
if (dquot->dq_curblocks < dquot->dq_bsoftlimit)
dquot->dq_flags &= ~DQ_BLKS;
}
if (id == 0) {
/*
* Change in expiretimes, change them in dq_mnt.
*/
dquot->dq_mnt->mnt_bexp[type] = dquot->dq_btime = dq_dqblk.dqb_btime;
dquot->dq_mnt->mnt_iexp[type] = dquot->dq_itime = dq_dqblk.dqb_itime;
}
if (dq_dqblk.dqb_bhardlimit == 0 && dq_dqblk.dqb_bsoftlimit == 0 &&
dq_dqblk.dqb_ihardlimit == 0 && dq_dqblk.dqb_isoftlimit == 0)
dquot->dq_flags |= DQ_FAKE;
else
dquot->dq_flags &= ~DQ_FAKE;
dquot->dq_flags |= DQ_MOD;
unlock_dquot(dquot);
dqput(dquot);
}
return(0);
}
static int get_quota(kdev_t dev, int id, short type, struct dqblk *dqblk)
{
struct dquot *dquot;
int error;
if (has_quota_enabled(dev, type)) {
if (dqblk == (struct dqblk *)NULL)
return(-EFAULT);
if ((error = verify_area(VERIFY_WRITE, dqblk, sizeof(struct dqblk))) != 0)
return(error);
if ((dquot = dqget(dev, id, type)) != NODQUOT) {
memcpy_tofs(dqblk, (char *)&dquot->dq_dqb, sizeof(struct dqblk));
dqput(dquot);
return(0);
}
}
return(-ESRCH);
}
static int get_stats(caddr_t addr)
{
int error;
if ((error = verify_area(VERIFY_WRITE, addr, sizeof(struct dqstats))) != 0)
return(error);
dqstats.allocated_dquots = nr_dquots;
dqstats.free_dquots = nr_free_dquots;
memcpy_tofs(addr, (caddr_t)&dqstats, sizeof(struct dqstats));
return(0);
}
/*
* Initialize pointer in a inode to the right dquots.
*/
void dquot_initialize(struct inode *inode, short type)
{
unsigned int id = 0;
short cnt;
struct dquot *tmp;
if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) {
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
if (type != -1 && cnt != type)
continue;
if (!has_quota_enabled(inode->i_dev, cnt))
continue;
if (inode->i_dquot[cnt] == NODQUOT) {
switch (cnt) {
case USRQUOTA:
id = inode->i_uid;
break;
case GRPQUOTA:
id = inode->i_gid;
break;
}
tmp = dqget(inode->i_dev, id, cnt);
/* We may sleep in dqget(), so check it again.
* Dmitry Gorodchanin 02/11/96
*/
if (inode->i_dquot[cnt] != NODQUOT) {
dqput(tmp);
continue;
}
inode->i_dquot[cnt] = tmp;
inode->i_flags |= S_WRITE;
}
}
}
}
void dquot_drop(struct inode *inode)
{
short cnt;
struct dquot * tmp;
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
if (inode->i_dquot[cnt] == NODQUOT)
continue;
/* We can sleep at dqput(). So we must do it this way.
* Dmitry Gorodchanin 02/11/96
*/
tmp = inode->i_dquot[cnt];
inode->i_dquot[cnt] = NODQUOT;
dqput(tmp);
}
inode->i_flags &= ~S_WRITE;
}
/*
* This is a simple algorithm that calculates the size of a file in blocks.
* This is only used on filesystems that do not have a i_blocks count.
*/
static u_long isize_to_blocks(size_t isize, size_t blksize)
{
u_long blocks;
u_long indirect;
if (!blksize)
blksize = BLOCK_SIZE;
blocks = (isize / blksize) + ((isize % blksize) ? 1 : 0);
if (blocks > 10) {
indirect = ((blocks - 11) >> 8) + 1; /* single indirect blocks */
if (blocks > (10 + 256)) {
indirect += ((blocks - 267) >> 16) + 1; /* double indirect blocks */
if (blocks > (10 + 256 + (256 << 8)))
indirect++; /* triple indirect blocks */
}
blocks += indirect;
}
return(blocks);
}
/*
* Externally referenced functions through dquot_operations.
*/
int dquot_alloc_block(const struct inode *inode, unsigned long number)
{
unsigned short cnt;
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
if (inode->i_dquot[cnt] == NODQUOT)
continue;
if (check_bdq(inode->i_dquot[cnt], cnt, number))
return(NO_QUOTA);
}
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
if (inode->i_dquot[cnt] == NODQUOT)
continue;
dquot_incr_blocks(inode->i_dquot[cnt], number);
}
return(QUOTA_OK);
}
int dquot_alloc_inode(const struct inode *inode, unsigned long number)
{
unsigned short cnt;
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
if (inode->i_dquot[cnt] == NODQUOT)
continue;
if (check_idq(inode->i_dquot[cnt], cnt, number))
return(NO_QUOTA);
}
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
if (inode->i_dquot[cnt] == NODQUOT)
continue;
dquot_incr_inodes(inode->i_dquot[cnt], number);
}
return(QUOTA_OK);
}
void dquot_free_block(const struct inode *inode, unsigned long number)
{
unsigned short cnt;
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
if (inode->i_dquot[cnt] == NODQUOT)
continue;
dquot_decr_blocks(inode->i_dquot[cnt], number);
}
}
void dquot_free_inode(const struct inode *inode, unsigned long number)
{
unsigned short cnt;
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
if (inode->i_dquot[cnt] == NODQUOT)
continue;
dquot_decr_inodes(inode->i_dquot[cnt], number);
}
}
/*
* Transfer the number of inode and blocks from one diskquota to an other.
*/
int dquot_transfer(struct inode *inode, struct iattr *iattr, char direction)
{
unsigned long blocks;
struct dquot *transfer_from[MAXQUOTAS];
struct dquot *transfer_to[MAXQUOTAS];
short cnt, disc;
/*
* Find out if this filesystems uses i_blocks.
*/
if (inode->i_blksize == 0)
blocks = isize_to_blocks(inode->i_size, BLOCK_SIZE);
else
blocks = (inode->i_blocks / 2);
/*
* Build the transfer_from and transfer_to lists and check quotas to see
* if operation is permitted.
*/
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
transfer_from[cnt] = NODQUOT;
transfer_to[cnt] = NODQUOT;
if (!has_quota_enabled(inode->i_dev, cnt))
continue;
switch (cnt) {
case USRQUOTA:
if (inode->i_uid == iattr->ia_uid)
continue;
transfer_from[cnt] = dqget(inode->i_dev, (direction) ? iattr->ia_uid : inode->i_uid, cnt);
transfer_to[cnt] = dqget(inode->i_dev, (direction) ? inode->i_uid : iattr->ia_uid, cnt);
break;
case GRPQUOTA:
if (inode->i_gid == iattr->ia_gid)
continue;
transfer_from[cnt] = dqget(inode->i_dev, (direction) ? iattr->ia_gid : inode->i_gid, cnt);
transfer_to[cnt] = dqget(inode->i_dev, (direction) ? inode->i_gid : iattr->ia_gid, cnt);
break;
}
if (check_idq(transfer_to[cnt], cnt, 1) == NO_QUOTA ||
check_bdq(transfer_to[cnt], cnt, blocks) == NO_QUOTA) {
for (disc = 0; disc <= cnt; disc++) {
dqput(transfer_from[disc]);
dqput(transfer_to[disc]);
}
return(NO_QUOTA);
}
}
/*
* Finally perform the needed transfer from transfer_from to transfer_to.
* And release any pointer to dquots not needed anymore.
*/
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
/*
* Skip changes for same uid or gid or for non-existing quota-type.
*/
if (transfer_from[cnt] == NODQUOT && transfer_to[cnt] == NODQUOT)
continue;
if (transfer_from[cnt] != NODQUOT) {
dquot_decr_inodes(transfer_from[cnt], 1);
dquot_decr_blocks(transfer_from[cnt], blocks);
}
if (transfer_to[cnt] != NODQUOT) {
dquot_incr_inodes(transfer_to[cnt], 1);
dquot_incr_blocks(transfer_to[cnt], blocks);
}
if (inode->i_dquot[cnt] != NODQUOT) {
dqput(transfer_from[cnt]);
dqput(inode->i_dquot[cnt]);
inode->i_dquot[cnt] = transfer_to[cnt];
} else {
dqput(transfer_from[cnt]);
dqput(transfer_to[cnt]);
}
}
return(QUOTA_OK);
}
void dquot_init(void)
{
printk(KERN_NOTICE "VFS: Diskquotas version %s initialized\r\n",
__DQUOT_VERSION__);
memset(hash_table, 0, sizeof(hash_table));
memset((caddr_t)&dqstats, 0, sizeof(dqstats));
first_dquot = NODQUOT;
}
/*
* Definitions of diskquota operations.
*/
struct dquot_operations dquot_operations = {
dquot_initialize,
dquot_drop,
dquot_alloc_block,
dquot_alloc_inode,
dquot_free_block,
dquot_free_inode,
dquot_transfer
};
/*
* Turn quota off on a device. type == -1 ==> quotaoff for all types (umount)
*/
int quota_off(kdev_t dev, short type)
{
struct vfsmount *vfsmnt;
short cnt;
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
if (type != -1 && cnt != type)
continue;
if ((vfsmnt = lookup_vfsmnt(dev)) == (struct vfsmount *)NULL ||
vfsmnt->mnt_quotas[cnt] == (struct file *)NULL)
continue;
vfsmnt->mnt_sb->dq_op = (struct dquot_operations *)NULL;
reset_dquot_ptrs(dev, cnt);
invalidate_dquots(dev, cnt);
close_fp(vfsmnt->mnt_quotas[cnt]);
vfsmnt->mnt_quotas[cnt] = (struct file *)NULL;
vfsmnt->mnt_iexp[cnt] = vfsmnt->mnt_bexp[cnt] = (time_t)NULL;
}
return(0);
}
int quota_on(kdev_t dev, short type, char *path)
{
struct file *filp = (struct file *)NULL;
struct vfsmount *vfsmnt;
struct inode *inode;
struct dquot *dquot;
char *tmp;
int error;
if ((vfsmnt = lookup_vfsmnt(dev)) == (struct vfsmount *)NULL)
return(-ENODEV);
if (vfsmnt->mnt_quotas[type] != (struct file *)NULL)
return(-EBUSY);
if ((error = getname(path, &tmp)) != 0)
return(error);
error = open_namei(tmp, O_RDWR, 0600, &inode, 0);
putname(tmp);
if (error)
return(error);
if (!S_ISREG(inode->i_mode)) {
iput(inode);
return(-EACCES);
}
if ((filp = get_empty_filp()) != (struct file *)NULL) {
filp->f_mode = (O_RDWR + 1) & O_ACCMODE;
filp->f_flags = O_RDWR;
filp->f_inode = inode;
filp->f_pos = 0;
filp->f_reada = 0;
filp->f_op = inode->i_op->default_file_ops;
if (filp->f_op->read || filp->f_op->write) {
if ((error = get_write_access(inode)) == 0) {
if (filp->f_op && filp->f_op->open)
error = filp->f_op->open(inode, filp);
if (error == 0) {
vfsmnt->mnt_quotas[type] = filp;
dquot = dqget(dev, 0, type);
vfsmnt->mnt_iexp[type] = (dquot) ? dquot->dq_itime : MAX_IQ_TIME;
vfsmnt->mnt_bexp[type] = (dquot) ? dquot->dq_btime : MAX_DQ_TIME;
dqput(dquot);
vfsmnt->mnt_sb->dq_op = &dquot_operations;
add_dquot_ref(dev, type);
return(0);
}
put_write_access(inode);
}
} else
error = -EIO;
filp->f_count--;
} else
error = -EMFILE;
iput(inode);
return(error);
}
/*
* Ok this is the systemcall interface, this communicates with
* the userlevel programs. Currently this only supports diskquota
* calls. Maybe we need to add the process quotas etc in the future.
* But we probably better use rlimits for that.
*/
asmlinkage int sys_quotactl(int cmd, const char *special, int id, caddr_t addr)
{
int cmds = 0, type = 0, flags = 0;
struct inode *ino;
kdev_t dev;
cmds = cmd >> SUBCMDSHIFT;
type = cmd & SUBCMDMASK;
if ((u_int) type >= MAXQUOTAS)
return(-EINVAL);
switch (cmds) {
case Q_SYNC:
case Q_GETSTATS:
break;
case Q_GETQUOTA:
if (((type == USRQUOTA && current->uid != id) ||
(type == GRPQUOTA && current->gid != id)) && !fsuser())
return(-EPERM);
break;
default:
if (!fsuser())
return(-EPERM);
}
if (special == (char *)NULL && (cmds == Q_SYNC || cmds == Q_GETSTATS))
dev = 0;
else {
if (namei(special, &ino))
return(-EINVAL);
dev = ino->i_rdev;
if (!S_ISBLK(ino->i_mode)) {
iput(ino);
return(-ENOTBLK);
}
iput(ino);
}
switch (cmds) {
case Q_QUOTAON:
return(quota_on(dev, type, (char *) addr));
case Q_QUOTAOFF:
return(quota_off(dev, type));
case Q_GETQUOTA:
return(get_quota(dev, id, type, (struct dqblk *) addr));
case Q_SETQUOTA:
flags |= SET_QUOTA;
break;
case Q_SETUSE:
flags |= SET_USE;
break;
case Q_SETQLIM:
flags |= SET_QLIMIT;
break;
case Q_SYNC:
return(sync_dquots(dev, type));
case Q_GETSTATS:
return(get_stats(addr));
default:
return(-EINVAL);
}
flags |= QUOTA_SYSCALL;
if (has_quota_enabled(dev, type))
return(set_dqblk(dev, id, type, flags, (struct dqblk *) addr));
return(-ESRCH);
}
