fs/ufs/quota_ufs.c

	quota_ufs.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */


#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Routines used in checking limits on file system usage.
 */

#include <sys/types.h>
#include <sys/t_lock.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/systm.h>
#include <sys/kmem.h>
#include <sys/signal.h>
#include <sys/cred.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/proc.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/buf.h>
#include <sys/uio.h>
#include <sys/fs/ufs_inode.h>
#include <sys/fs/ufs_fs.h>
#include <sys/fs/ufs_quota.h>
#include <sys/errno.h>
#include <sys/cmn_err.h>
#include <sys/session.h>
#include <sys/debug.h>

/*
 * Find the dquot structure that should
 * be used in checking i/o on inode ip.
 */
struct dquot *
getinoquota(struct inode *ip)
{
    struct dquot *dqp, *xdqp;
    struct ufsvfs *ufsvfsp = ip->i_ufsvfs;

    ASSERT(RW_LOCK_HELD(&ufsvfsp->vfs_dqrwlock));
    ASSERT(RW_WRITE_HELD(&ip->i_contents));
    /*
     * Check for quotas enabled.
     */
    if ((ufsvfsp->vfs_qflags & MQ_ENABLED) == 0) {
        return (NULL);
    }

    /*
     * Check for someone doing I/O to quota file.
     */
    if (ip == ufsvfsp->vfs_qinod) {
        return (NULL);
    }

    /*
     * Check for a legal inode, e.g. not a shadow inode,
     * not a extended attribute directory inode and a valid mode.
     */
    ASSERT((ip->i_mode & IFMT) != IFSHAD);
    ASSERT((ip->i_mode & IFMT) != IFATTRDIR);
    ASSERT(ip->i_mode);

    if (getdiskquota((uid_t)ip->i_uid, ufsvfsp, 0, &xdqp)) {
        return (NULL);
    }
    dqp = xdqp;
    mutex_enter(&dqp->dq_lock);
    ASSERT(ip->i_uid == dqp->dq_uid);

    if (dqp->dq_fhardlimit == 0 && dqp->dq_fsoftlimit == 0 &&
        dqp->dq_bhardlimit == 0 && dqp->dq_bsoftlimit == 0) {
        dqput(dqp);
        mutex_exit(&dqp->dq_lock);
        dqp = NULL;
    } else {
        mutex_exit(&dqp->dq_lock);
    }
    return (dqp);
}

/*
 * Update disk usage, and take corrective action.
 */
int
chkdq(struct inode *ip, long change, int force, struct cred *cr,
    char **uerrp, size_t *lenp)
{
    struct dquot *dqp;
    uint64_t ncurblocks;
    struct ufsvfs *ufsvfsp = ip->i_ufsvfs;
    int error = 0;
    long abs_change;
    char *msg1 =
"!quota_ufs: over hard disk limit (pid %d, uid %d, inum %d, fs %s)\n";
    char *msg2 =
"!quota_ufs: Warning: over disk limit (pid %d, uid %d, inum %d, fs %s)\n";
    char *msg3 =
"!quota_ufs: over disk and time limit (pid %d, uid %d, inum %d, fs %s)\n";
    char *msg4 =
"!quota_ufs: Warning: quota overflow (pid %d, uid %d, inum %d, fs %s)\n";
    char *errmsg = NULL;
    time_t now;

    /*
     * Shadow inodes do not need to hold the vfs_dqrwlock lock.
     */
    ASSERT((ip->i_mode & IFMT) == IFSHAD ||
        RW_LOCK_HELD(&ufsvfsp->vfs_dqrwlock));
    ASSERT(RW_WRITE_HELD(&ip->i_contents));

    if (change == 0)
        return (0);
    dqp = ip->i_dquot;

    /*
     * Make sure the quota info record matches the owner.
     */
    ASSERT(dqp == NULL || ip->i_uid == dqp->dq_uid);

#ifdef DEBUG
    /*
     * Shadow inodes and extended attribute directories
     * should not have quota info records.
     */
    if ((ip->i_mode & IFMT) == IFSHAD || (ip->i_mode & IFMT) == IFATTRDIR) {
        ASSERT(dqp == NULL);
    }
    /*
     * Paranoia for verifying that quotas are okay.
     */
    else {
        struct dquot *expect_dq;
        int mismatch_ok = 0;

        /* Get current quota information */
        expect_dq = getinoquota(ip);
        /*
         * We got NULL back from getinoquota(), but there is
         * no error code return from that interface and some
         * errors are "ok" because we may be testing via error
         * injection.  If this is not the quota inode then we
         * use getdiskquota() to see if there is an error and
         * if the error is ok.
         */
        if (expect_dq == NULL && ip != ufsvfsp->vfs_qinod) {
            int error;
            struct dquot *xdqp;

            error = getdiskquota((uid_t)ip->i_uid, ufsvfsp, 0,
                        &xdqp);
            switch (error) {
            /*
             * Either the error was transient or the quota
             * info record has no limits which gets optimized
             * out by getinoquota().
             */
            case 0:
                if (xdqp->dq_fhardlimit == 0 &&
                    xdqp->dq_fsoftlimit == 0 &&
                    xdqp->dq_bhardlimit == 0 &&
                    xdqp->dq_bsoftlimit == 0) {
                    mutex_enter(&xdqp->dq_lock);
                    dqput(xdqp);
                    mutex_exit(&xdqp->dq_lock);
                } else {
                    expect_dq = xdqp;
                }
                break;

            case ESRCH: /* quotas are not enabled */
            case EINVAL:    /* error flag set on cached record */
            case EUSERS:    /* quota table is full */
            case EIO:   /* I/O error */
                mismatch_ok = 1;
                break;
            }
        }

        /*
         * Make sure dqp and the current quota info agree.
         * The first part of the #ifndef is the quick way to
         * do the check and should be part of the standard
         * DEBUG code. The #else part is useful if you are
         * actually chasing an inconsistency and don't want
         * to have to look at stack frames to figure which
         * variable has what value.
         */
#ifndef CHASE_QUOTA
        ASSERT(mismatch_ok || dqp == expect_dq);
#else /* CHASE_QUOTA */
        if (expect_dq == NULL) {
            /*
             * If you hit this ASSERT() you know that quota
             * subsystem does not expect quota info for this
             * inode, but the inode has it.
             */
            ASSERT(mismatch_ok || dqp == NULL);
        } else {
            /*
             * If you hit this ASSERT() you know that quota
             * subsystem expects quota info for this inode,
             * but the inode does not have it.
             */
            ASSERT(dqp);
            /*
             * If you hit this ASSERT() you know that quota
             * subsystem expects quota info for this inode
             * and the inode has quota info, but the two
             * quota info pointers are not the same.
             */
            ASSERT(dqp == expect_dq);
        }
#endif /* !CHASE_QUOTA */
        /*
         * Release for getinoquota() above or getdiskquota()
         * call when error is transient.
         */
        if (expect_dq) {
            mutex_enter(&expect_dq->dq_lock);
            dqput(expect_dq);
            mutex_exit(&expect_dq->dq_lock);
        }
    }
#endif /* DEBUG */

    /*
     * Shadow inodes and extended attribute directories
     * do not have quota info records.
     */
    if (dqp == NULL)
        return (0);
    /*
     * Quotas are not enabled on this file system so there is nothing
     * more to do.
     */
    if ((ufsvfsp->vfs_qflags & MQ_ENABLED) == 0) {
        return (0);
    }
    mutex_enter(&dqp->dq_lock);
    if (change < 0) {
        dqp->dq_flags |= DQ_MOD;
        abs_change = -change;   /* abs_change must be positive */
        if (dqp->dq_curblocks < abs_change)
            dqp->dq_curblocks = 0;
        else
            dqp->dq_curblocks += change;
        if (dqp->dq_curblocks < dqp->dq_bsoftlimit)
            dqp->dq_btimelimit = 0;
        dqp->dq_flags &= ~DQ_BLKS;
        TRANS_QUOTA(dqp);
        mutex_exit(&dqp->dq_lock);
        return (0);
    }

    /*
     * Adding 'change' to dq_curblocks could cause an overflow.
     * So store the result in a 64-bit variable and check for
     * overflow below.
     */
    ncurblocks = (uint64_t)dqp->dq_curblocks + change;

    /*
     * Allocation. Check hard and soft limits.
     * Skip checks for uid 0 owned files.
     * This check used to require both euid and ip->i_uid
     * to be 0; but there are no quotas for uid 0 so
     * it really doesn't matter who is writing to the
     * root owned file.  And even root cannot write
     * past a user's quota limit.
     */
    if (ip->i_uid == 0)
        goto out;

    /*
     * Disallow allocation if it would bring the current usage over
     * the hard limit or if the user is over his soft limit and his time
     * has run out.
     */
    if (dqp->dq_bhardlimit && ncurblocks >= (uint64_t)dqp->dq_bhardlimit &&
        !force) {
        /* If the user was not informed yet and the caller  */
        /* is the owner of the file             */
        if ((dqp->dq_flags & DQ_BLKS) == 0 &&
            ip->i_uid == crgetruid(cr)) {
            errmsg = msg1;
            dqp->dq_flags |= DQ_BLKS;
        }
        error = EDQUOT;
        goto out;
    }
    if (dqp->dq_bsoftlimit && ncurblocks >= (uint64_t)dqp->dq_bsoftlimit) {
        now = gethrestime_sec();
        if (dqp->dq_curblocks < dqp->dq_bsoftlimit ||
            dqp->dq_btimelimit == 0) {
            dqp->dq_flags |= DQ_MOD;
            dqp->dq_btimelimit = now +
                ((struct ufsvfs *)ITOV(ip)->v_vfsp->vfs_data)
                ->vfs_btimelimit;
            if (ip->i_uid == crgetruid(cr)) {
                errmsg = msg2;
            }
        } else if (now > dqp->dq_btimelimit && !force) {
            /* If the user was not informed yet and the */
            /* caller is the owner of the file      */
            if ((dqp->dq_flags & DQ_BLKS) == 0 &&
                ip->i_uid == crgetruid(cr)) {
                errmsg = msg3;
                dqp->dq_flags |= DQ_BLKS;
            }
            error = EDQUOT;
        }
    }
out:
    if (error == 0) {
        dqp->dq_flags |= DQ_MOD;
        /*
         * ncurblocks can be bigger than the maximum
         * number that can be represented in 32-bits.
         * When copying ncurblocks to dq_curblocks
         * (an unsigned 32-bit quantity), make sure there
         * is no overflow.  The only way this can happen
         * is if "force" is set.  Otherwise, this allocation
         * would have exceeded the hard limit check above
         * (since the hard limit is a 32-bit quantity).
         */
        if (ncurblocks > 0xffffffffLL) {
            dqp->dq_curblocks = 0xffffffff;
            errmsg = msg4;
        } else {
            dqp->dq_curblocks = ncurblocks;
        }
    }

    if (dqp->dq_flags & DQ_MOD)
        TRANS_QUOTA(dqp);

    mutex_exit(&dqp->dq_lock);
    /*
     * Check for any error messages to be sent
     */
    if (errmsg != NULL) {
        /*
         * Send message to the error log.
         */
        if (uerrp != NULL) {
            /*
             * Set up message caller should send to user;
             * gets copied to the message buffer as a side-
             * effect of the caller's uprintf().
             */
            *lenp = strlen(errmsg) + 20 + 20 +
                strlen(ip->i_fs->fs_fsmnt) + 1;
            *uerrp = (char *)kmem_alloc(*lenp, KM_NOSLEEP);
            if (*uerrp != NULL) {
                /* errmsg+1 => skip leading ! */
                (void) sprintf(*uerrp, errmsg+1,
                    (int)ttoproc(curthread)->p_pid,
                    (int)ip->i_uid, (int)ip->i_number,
                    ip->i_fs->fs_fsmnt);
            }
        } else {
            /*
             * Caller doesn't care, so just copy to the
             * message buffer.
             */
            cmn_err(CE_NOTE, errmsg,
                (int)ttoproc(curthread)->p_pid,
                (int)ip->i_uid, (int)ip->i_number,
                ip->i_fs->fs_fsmnt);
        }
    }
    return (error);
}

/*
 * Check the inode limit, applying corrective action.
 */
int
chkiq(struct ufsvfs *ufsvfsp, int change, struct inode *ip, uid_t uid,
    int force, struct cred *cr, char **uerrp, size_t *lenp)
{
    struct dquot *dqp, *xdqp;
    unsigned int ncurfiles;
    char *errmsg = NULL;
    char *err1 =
"!quota_ufs: over file hard limit (pid %d, uid %d, fs %s)\n";
    char *err2 =
"!quota_ufs: Warning: too many files (pid %d, uid %d, fs %s)\n";
    char *err3 =
"!quota_ufs: over file and time limit (pid %d, uid %d, fs %s)\n";
    int error = 0;
    time_t now;

    ASSERT(RW_READ_HELD(&ufsvfsp->vfs_dqrwlock));
    /*
     * Change must be either a single increment or decrement.
     * If change is an increment, then ip must be NULL.
     */
    ASSERT(change == 1 || change == -1);
    ASSERT(change != 1 || ip == NULL);

    /*
     * Quotas are not enabled so bail out now.
     */
    if ((ufsvfsp->vfs_qflags & MQ_ENABLED) == 0) {
        return (0);
    }

    /*
     * Free a specific inode.
     */
    if (change == -1 && ip) {
        dqp = ip->i_dquot;
        /*
         * Shadow inodes and extended attribute directories
         * do not have quota info records.
         */
        if (dqp == NULL)
            return (0);
        mutex_enter(&dqp->dq_lock);
        if (dqp->dq_curfiles) {
            dqp->dq_curfiles--;
            dqp->dq_flags |= DQ_MOD;
        }
        if (dqp->dq_curfiles < dqp->dq_fsoftlimit) {
            dqp->dq_ftimelimit = 0;
            dqp->dq_flags |= DQ_MOD;
        }
        dqp->dq_flags &= ~DQ_FILES;
        if (dqp->dq_flags & DQ_MOD)
            TRANS_QUOTA(dqp);
        mutex_exit(&dqp->dq_lock);
        return (0);
    }

    /*
     * Allocation or deallocation without a specific inode.
     * Get dquot for for uid, fs.
     */
    if (getdiskquota(uid, ufsvfsp, 0, &xdqp)) {
        return (0);
    }
    dqp = xdqp;
    mutex_enter(&dqp->dq_lock);
    if (dqp->dq_fsoftlimit == 0 && dqp->dq_fhardlimit == 0) {
        dqput(dqp);
        mutex_exit(&dqp->dq_lock);
        return (0);
    }

    /*
     * Skip checks for uid 0 owned files.
     * This check used to require both euid and uid
     * to be 0; but there are no quotas for uid 0 so
     * it really doesn't matter who is writing to the
     * root owned file.  And even root can not write
     * past the user's quota limit.
     */
    if (uid == 0)
        goto out;

    /*
     * Theoretically, this could overflow, but in practice, it
     * won't.  Multi-terabyte file systems are required to have an
     * nbpi value of at least 1MB.  In order to overflow this
     * field, there would have to be 2^32 inodes in the file.
     * That would imply a file system of 2^32 * 1MB, which is
     * 2^(32 + 20), which is 4096 terabytes, which is not
     * contemplated for ufs any time soon.
     */
    ncurfiles = dqp->dq_curfiles + change;

    /*
     * Dissallow allocation if it would bring the current usage over
     * the hard limit or if the user is over his soft limit and his time
     * has run out.
     */
    if (change == 1 && ncurfiles >= dqp->dq_fhardlimit &&
        dqp->dq_fhardlimit && !force) {
        /* If the user was not informed yet and the caller  */
        /* is the owner of the file                 */
        if ((dqp->dq_flags & DQ_FILES) == 0 && uid == crgetruid(cr)) {
            errmsg = err1;
            dqp->dq_flags |= DQ_FILES;
        }
        error = EDQUOT;
    } else if (change == 1 && ncurfiles >= dqp->dq_fsoftlimit &&
            dqp->dq_fsoftlimit) {
        now = gethrestime_sec();
        if (ncurfiles == dqp->dq_fsoftlimit ||
            dqp->dq_ftimelimit == 0) {
            dqp->dq_flags |= DQ_MOD;
            dqp->dq_ftimelimit = now + ufsvfsp->vfs_ftimelimit;
            /* If the caller owns the file */
            if (uid == crgetruid(cr))
                errmsg = err2;
        } else if (now > dqp->dq_ftimelimit && !force) {
            /* If the user was not informed yet and the */
            /* caller is the owner of the file      */
            if ((dqp->dq_flags & DQ_FILES) == 0 &&
                uid == crgetruid(cr)) {
                errmsg = err3;
                dqp->dq_flags |= DQ_FILES;
            }
            error = EDQUOT;
        }
    }
out:
    if (error == 0) {
        dqp->dq_flags |= DQ_MOD;
        dqp->dq_curfiles += change;
    }
    if (dqp->dq_flags & DQ_MOD)
        TRANS_QUOTA(dqp);
    dqput(dqp);
    mutex_exit(&dqp->dq_lock);
    /*
     * Check for any error messages to be sent
     */
    if (errmsg != NULL) {
        /*
         * Send message to the error log.
         */
        if (uerrp != NULL) {
            /*
             * Set up message caller should send to user;
             * gets copied to the message buffer as a side-
             * effect of the caller's uprintf().
             */
            *lenp = strlen(errmsg) + 20 + 20 +
                strlen(ufsvfsp->vfs_fs->fs_fsmnt) + 1;
            *uerrp = (char *)kmem_alloc(*lenp, KM_NOSLEEP);
            if (*uerrp != NULL) {
                /* errmsg+1 => skip leading ! */
                (void) sprintf(*uerrp, errmsg+1,
                    (int)ttoproc(curthread)->p_pid,
                    (int)uid, ufsvfsp->vfs_fs->fs_fsmnt);
            }
        } else {
            /*
             * Caller doesn't care, so just copy to the
             * message buffer.
             */
            cmn_err(CE_NOTE, errmsg,
                (int)ttoproc(curthread)->p_pid,
                (int)uid, ufsvfsp->vfs_fs->fs_fsmnt);
        }
    }
    return (error);
}

/*
 * Release a dquot.
 */
void
dqrele(struct dquot *dqp)
{
    /*
     * Shadow inodes and extended attribute directories
     * do not have quota info records.
     */
    if (dqp != NULL) {
        mutex_enter(&dqp->dq_lock);
        if (dqp->dq_cnt == 1 && dqp->dq_flags & DQ_MOD)
            dqupdate(dqp);
        dqput(dqp);
        mutex_exit(&dqp->dq_lock);
    }
}