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[/] [or1k_old/] [trunk/] [uclinux/] [uClinux-2.0.x/] [fs/] [dquot.c] - Blame information for rev 1782

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/*
 * 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 1.1.1.1 2001-09-10 07:44:38 simons Exp $
 *
 * Author:  Marco van Wieringen <mvw@mcs.ow.nl> <mvw@tnix.net>
 *
 * Fixes:   Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96
 *          removed race conditions in dqput(), dqget() and iput().
 *          Nick Kralevich <nickkral@cal.alumni.berkeley.edu>, 21 Jul 97
 *          Fixed a condition where user and group quotas could get mixed up.
 *
 * (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
        {
                int p = dqoff(dquot->dq_id);
                if(p>=0)
                        filp->f_pos = p;
        }
        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->dq_type != type) {
                        dquot = dquot->dq_hash_next;
                        continue;
                }
                wait_on_dquot(dquot);
                if (dquot->dq_dev != dev || dquot->dq_id != id ||
                    dquot->dq_type != type)
                        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) || S_ISFIFO(inode->i_mode) || S_ISSOCK(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);
 
 
        /*
         *      This shouldnt be needed but the goal is to fix 2.0 not
         *      do things in best of Torvalds style. Thats for 2.1...
         */
 
        if(S_ISFIFO(inode->i_mode)||S_ISSOCK(inode->i_mode))
                blocks = 0;
 
        /*
         * 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);
        }
 
        if (id & ~0xFFFF)
                return(-EINVAL);
 
        flags |= QUOTA_SYSCALL;
        if (has_quota_enabled(dev, type))
                return(set_dqblk(dev, id, type, flags, (struct dqblk *) addr));
        return(-ESRCH);
}
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[/] [or1k_old/] [trunk/] [uclinux/] [uClinux-2.0.x/] [fs/] [dquot.c] - Blame information for rev 1782

Line No.	Rev	Author	Line
1	199	simons	`/*`
2			`* Implementation of the diskquota system for the LINUX operating`
3			`* system. QUOTA is implemented using the BSD systemcall interface as`
4			`* the means of communication with the user level. Currently only the`
5			`* ext2-filesystem has support for diskquotas. Other filesystems may`
6			`* be added in future time. This file contains the generic routines`
7			`* called by the different filesystems on allocation of an inode or`
8			`* block. These routines take care of the administration needed to`
9			`* have a consistent diskquota tracking system. The ideas of both`
10			`* user and group quotas are based on the Melbourne quota system as`
11			`* used on BSD derived systems. The internal implementation is`
12			`* based on the LINUX inode-subsystem with added complexity of the`
13			`* diskquota system. This implementation is not based on any BSD`
14			`* kernel sourcecode.`
15			`*`
16			`* Version: $Id: dquot.c,v 1.1.1.1 2001-09-10 07:44:38 simons Exp $`
17			`*`
18			`* Author: Marco van Wieringen <mvw@mcs.ow.nl> <mvw@tnix.net>`
19			`*`
20			`* Fixes: Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96`
21			`* removed race conditions in dqput(), dqget() and iput().`
22			`* Nick Kralevich <nickkral@cal.alumni.berkeley.edu>, 21 Jul 97`
23			`* Fixed a condition where user and group quotas could get mixed up.`
24			`*`
25			`* (C) Copyright 1994, 1995 Marco van Wieringen`
26			`*`
27			`*/`
28
29			`#include <linux/errno.h>`
30			`#include <linux/kernel.h>`
31			`#include <linux/sched.h>`
32			`#include <linux/types.h>`
33			`#include <linux/string.h>`
34			`#include <linux/fcntl.h>`
35			`#include <linux/stat.h>`
36			`#include <linux/tty.h>`
37			`#include <linux/malloc.h>`
38			`#include <linux/mount.h>`
39
40			`#include <asm/segment.h>`