xnu-792.10.96.tar.gz

[apple/xnu.git] / bsd / ufs / ffs / ffs_inode.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
 * Copyright (c) 1982, 1986, 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)ffs_inode.c 8.13 (Berkeley) 4/21/95
 */

#include <rev_endian_fs.h>
#include <vm/vm_pager.h>

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mount_internal.h>
#include <sys/proc_internal.h>  /* for accessing p_stats */
#include <sys/file.h>
#include <sys/buf_internal.h>
#include <sys/vnode_internal.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/trace.h>
#include <sys/resourcevar.h>
#include <sys/ubc.h>
#include <sys/quota.h>

#include <sys/vm.h>

#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/ufs_extern.h>

#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>

#if REV_ENDIAN_FS
#include <ufs/ufs/ufs_byte_order.h>
#include <libkern/OSByteOrder.h>
#endif /* REV_ENDIAN_FS */

static int ffs_indirtrunc(struct inode *, ufs_daddr_t, ufs_daddr_t,
            ufs_daddr_t, int, long *);

/*
 * Update the access, modified, and inode change times as specified by the
 * IACCESS, IUPDATE, and ICHANGE flags respectively. The IMODIFIED flag is
 * used to specify that the inode needs to be updated but that the times have
 * already been set. The access and modified times are taken from the second
 * and third parameters; the inode change time is always taken from the current
 * time. If waitfor is set, then wait for the disk write of the inode to
 * complete.
 */
int
ffs_update(struct vnode *vp, struct timeval *access, struct timeval *modify, int waitfor)
{
        register struct fs *fs;
        struct buf *bp;
        struct inode *ip;
        struct timeval tv;
        errno_t error;
#if REV_ENDIAN_FS
        struct mount *mp=(vp)->v_mount;
        int rev_endian=(mp->mnt_flag & MNT_REVEND);
#endif /* REV_ENDIAN_FS */

        ip = VTOI(vp);
        if (vp->v_mount->mnt_flag & MNT_RDONLY) {
                ip->i_flag &=
                    ~(IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE);
                return (0);
        }
        if ((ip->i_flag &
            (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) == 0)
                return (0);
        if (ip->i_flag & IN_ACCESS)
                ip->i_atime = access->tv_sec;
        if (ip->i_flag & IN_UPDATE) {
                ip->i_mtime = modify->tv_sec;
                ip->i_modrev++;
        }
        if (ip->i_flag & IN_CHANGE) {
                microtime(&tv);
                ip->i_ctime = tv.tv_sec;
        }
        ip->i_flag &= ~(IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE);
        fs = ip->i_fs;
        /*
         * Ensure that uid and gid are correct. This is a temporary
         * fix until fsck has been changed to do the update.
         */
        if (fs->fs_inodefmt < FS_44INODEFMT) {          /* XXX */
                ip->i_din.di_ouid = ip->i_uid;          /* XXX */
                ip->i_din.di_ogid = ip->i_gid;          /* XXX */
        }                                               /* XXX */
        if (error = buf_bread(ip->i_devvp,
                              (daddr64_t)((unsigned)fsbtodb(fs, ino_to_fsba(fs, ip->i_number))),
                (int)fs->fs_bsize, NOCRED, &bp)) {
                buf_brelse(bp);
                return ((int)error);
        }
#if REV_ENDIAN_FS
        if (rev_endian)
                byte_swap_inode_out(ip, ((struct dinode *)buf_dataptr(bp) + ino_to_fsbo(fs, ip->i_number)));
        else {
#endif /* REV_ENDIAN_FS */
        *((struct dinode *)buf_dataptr(bp) + ino_to_fsbo(fs, ip->i_number)) = ip->i_din;
#if REV_ENDIAN_FS
        }
#endif /* REV_ENDIAN_FS */

        if (waitfor && (vp->v_mount->mnt_flag & MNT_ASYNC) == 0)
                return ((int)buf_bwrite(bp));
        else {
                buf_bdwrite(bp);
                return (0);
        }
}


#define SINGLE  0       /* index of single indirect block */
#define DOUBLE  1       /* index of double indirect block */
#define TRIPLE  2       /* index of triple indirect block */

int
ffs_truncate_internal(vnode_t ovp, off_t length, int flags, ucred_t cred)
{
        struct inode    *oip;
        struct fs       *fs;
        ufs_daddr_t lastblock;
        ufs_daddr_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR];
        ufs_daddr_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR];
        buf_t   bp;
        int     offset, size, level, i;
        long    count, nblocks, vflags, blocksreleased = 0;
        struct  timeval tv;
        int     aflags, error, allerror;
        off_t   osize;
        int     devBlockSize=0;
#if QUOTA
        int64_t change;   /* in bytes */
#endif /* QUOTA */

        if (length < 0)
                return (EINVAL);

        oip = VTOI(ovp);
        fs = oip->i_fs;

        if (length > fs->fs_maxfilesize)
                return (EFBIG);

        microtime(&tv);
        if (ovp->v_type == VLNK &&
            oip->i_size < ovp->v_mount->mnt_maxsymlinklen) {
#if DIAGNOSTIC
                if (length != 0)
                        panic("ffs_truncate: partial truncate of symlink");
#endif
                bzero((char *)&oip->i_shortlink, (u_int)oip->i_size);
                oip->i_size = 0;
                oip->i_flag |= IN_CHANGE | IN_UPDATE;
                return (ffs_update(ovp, &tv, &tv, 1));
        }

        if (oip->i_size == length) {
                oip->i_flag |= IN_CHANGE | IN_UPDATE;
                return (ffs_update(ovp, &tv, &tv, 0));
        }
#if QUOTA
        if (error = getinoquota(oip))
                return (error);
#endif
        osize = oip->i_size;

        /*
         * Lengthen the size of the file. We must ensure that the
         * last byte of the file is allocated. Since the smallest
         * value of osize is 0, length will be at least 1.
         */
        if (osize < length) {
                offset = blkoff(fs, length - 1);
                lbn = lblkno(fs, length - 1);
                aflags = B_CLRBUF;
                if (flags & IO_SYNC)
                        aflags |= B_SYNC;
                if (error = ffs_balloc(oip, lbn, offset + 1, cred, &bp, aflags, 0))
                        return (error);
                oip->i_size = length;
                
                if (UBCINFOEXISTS(ovp)) {
                        buf_markinvalid(bp);
                        buf_bwrite(bp);
                        ubc_setsize(ovp, (off_t)length); 
                } else {
                        if (aflags & B_SYNC)
                                buf_bwrite(bp);
                        else
                                buf_bawrite(bp);
                }
                oip->i_flag |= IN_CHANGE | IN_UPDATE;
                return (ffs_update(ovp, &tv, &tv, 1));
        }
        /*
         * Shorten the size of the file. If the file is not being
         * truncated to a block boundry, the contents of the
         * partial block following the end of the file must be
         * zero'ed in case it ever become accessable again because
         * of subsequent file growth.
         */
        if (UBCINFOEXISTS(ovp))
                ubc_setsize(ovp, (off_t)length); 

        vflags = ((length > 0) ? BUF_WRITE_DATA : 0) | BUF_SKIP_META;

        if (vflags & BUF_WRITE_DATA)
                ffs_fsync_internal(ovp, MNT_WAIT);
        allerror = buf_invalidateblks(ovp, vflags, 0, 0);
                
        offset = blkoff(fs, length);
        if (offset == 0) {
                oip->i_size = length;
        } else {
                lbn = lblkno(fs, length);
                aflags = B_CLRBUF;
                if (flags & IO_SYNC)
                        aflags |= B_SYNC;
                if (error = ffs_balloc(oip, lbn, offset, cred, &bp, aflags, 0))
                        return (error);
                oip->i_size = length;
                size = blksize(fs, oip, lbn);
                bzero((char *)buf_dataptr(bp) + offset, (u_int)(size - offset));
                allocbuf(bp, size);
                if (UBCINFOEXISTS(ovp)) {
                        buf_markinvalid(bp);
                        buf_bwrite(bp);
                } else {
                        if (aflags & B_SYNC)
                                buf_bwrite(bp);
                        else
                                buf_bawrite(bp);
                }
        }
        /*
         * Calculate index into inode's block list of
         * last direct and indirect blocks (if any)
         * which we want to keep.  Lastblock is -1 when
         * the file is truncated to 0.
         */
        lastblock = lblkno(fs, length + fs->fs_bsize - 1) - 1;
        lastiblock[SINGLE] = lastblock - NDADDR;
        lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
        lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);

        devBlockSize = vfs_devblocksize(vnode_mount(ovp));
        nblocks = btodb(fs->fs_bsize, devBlockSize);

        /*
         * Update file and block pointers on disk before we start freeing
         * blocks.  If we crash before free'ing blocks below, the blocks
         * will be returned to the free list.  lastiblock values are also
         * normalized to -1 for calls to ffs_indirtrunc below.
         */
        bcopy((caddr_t)&oip->i_db[0], (caddr_t)oldblks, sizeof oldblks);
        for (level = TRIPLE; level >= SINGLE; level--)
                if (lastiblock[level] < 0) {
                        oip->i_ib[level] = 0;
                        lastiblock[level] = -1;
                }
        for (i = NDADDR - 1; i > lastblock; i--)
                oip->i_db[i] = 0;
        oip->i_flag |= IN_CHANGE | IN_UPDATE;
        if (error = ffs_update(ovp, &tv, &tv, MNT_WAIT))
                allerror = error;
        /*
         * Having written the new inode to disk, save its new configuration
         * and put back the old block pointers long enough to process them.
         * Note that we save the new block configuration so we can check it
         * when we are done.
         */
        bcopy((caddr_t)&oip->i_db[0], (caddr_t)newblks, sizeof newblks);
        bcopy((caddr_t)oldblks, (caddr_t)&oip->i_db[0], sizeof oldblks);
        oip->i_size = osize;

        vflags = ((length > 0) ? BUF_WRITE_DATA : 0) | BUF_SKIP_META;

        if (vflags & BUF_WRITE_DATA)
                ffs_fsync_internal(ovp, MNT_WAIT);
        allerror = buf_invalidateblks(ovp, vflags, 0, 0);

        /*
         * Indirect blocks first.
         */
        indir_lbn[SINGLE] = -NDADDR;
        indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
        indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
        for (level = TRIPLE; level >= SINGLE; level--) {
                bn = oip->i_ib[level];
                if (bn != 0) {
                        error = ffs_indirtrunc(oip, indir_lbn[level],
                            fsbtodb(fs, bn), lastiblock[level], level, &count);
                        if (error)
                                allerror = error;
                        blocksreleased += count;
                        if (lastiblock[level] < 0) {
                                oip->i_ib[level] = 0;
                                ffs_blkfree(oip, bn, fs->fs_bsize);
                                blocksreleased += nblocks;
                        }
                }
                if (lastiblock[level] >= 0)
                        goto done;
        }

        /*
         * All whole direct blocks or frags.
         */
        for (i = NDADDR - 1; i > lastblock; i--) {
                register long bsize;

                bn = oip->i_db[i];
                if (bn == 0)
                        continue;
                oip->i_db[i] = 0;
                bsize = blksize(fs, oip, i);
                ffs_blkfree(oip, bn, bsize);
                blocksreleased += btodb(bsize, devBlockSize);
        }
        if (lastblock < 0)
                goto done;

        /*
         * Finally, look for a change in size of the
         * last direct block; release any frags.
         */
        bn = oip->i_db[lastblock];
        if (bn != 0) {
                long oldspace, newspace;

                /*
                 * Calculate amount of space we're giving
                 * back as old block size minus new block size.
                 */
                oldspace = blksize(fs, oip, lastblock);
                oip->i_size = length;
                newspace = blksize(fs, oip, lastblock);
                if (newspace == 0)
                        panic("itrunc: newspace");
                if (oldspace - newspace > 0) {
                        /*
                         * Block number of space to be free'd is
                         * the old block # plus the number of frags
                         * required for the storage we're keeping.
                         */
                        bn += numfrags(fs, newspace);
                        ffs_blkfree(oip, bn, oldspace - newspace);
                        blocksreleased += btodb(oldspace - newspace, devBlockSize);
                }
        }
done:
#if DIAGNOSTIC
        for (level = SINGLE; level <= TRIPLE; level++)
                if (newblks[NDADDR + level] != oip->i_ib[level])
                        panic("itrunc1");
        for (i = 0; i < NDADDR; i++)
                if (newblks[i] != oip->i_db[i])
                        panic("itrunc2");
        if (length == 0 &&
            (vnode_hasdirtyblks(ovp) || vnode_hascleanblks(ovp)))
                panic("itrunc3");
#endif /* DIAGNOSTIC */
        /*
         * Put back the real size.
         */
        oip->i_size = length;
        oip->i_blocks -= blocksreleased;
        if (oip->i_blocks < 0)                  /* sanity */
                oip->i_blocks = 0;
        oip->i_flag |= IN_CHANGE;
#if QUOTA
        change = dbtob((int64_t)blocksreleased,devBlockSize);
        (void) chkdq(oip, -change, NOCRED, 0);
#endif
        return (allerror);
}

/*
 * Release blocks associated with the inode ip and stored in the indirect
 * block bn.  Blocks are free'd in LIFO order up to (but not including)
 * lastbn.  If level is greater than SINGLE, the block is an indirect block
 * and recursive calls to indirtrunc must be used to cleanse other indirect
 * blocks.
 *
 * NB: triple indirect blocks are untested.
 */
static int
ffs_indirtrunc(ip, lbn, dbn, lastbn, level, countp)
        register struct inode *ip;
        ufs_daddr_t lbn, lastbn;
        ufs_daddr_t dbn;
        int level;
        long *countp;
{
        register int i;
        struct buf *bp;
        struct buf *tbp;
        register struct fs *fs = ip->i_fs;
        register ufs_daddr_t *bap;
        struct vnode *vp=ITOV(ip);
        ufs_daddr_t *copy, nb, nlbn, last;
        long blkcount, factor;
        int nblocks, blocksreleased = 0;
        errno_t error = 0, allerror = 0;
        int devBlockSize=0;
        struct mount *mp=vp->v_mount;
#if REV_ENDIAN_FS
        int rev_endian=(mp->mnt_flag & MNT_REVEND);
#endif /* REV_ENDIAN_FS */

        /*
         * Calculate index in current block of last
         * block to be kept.  -1 indicates the entire
         * block so we need not calculate the index.
         */
        factor = 1;
        for (i = SINGLE; i < level; i++)
                factor *= NINDIR(fs);
        last = lastbn;
        if (lastbn > 0)
                last /= factor;

        devBlockSize = vfs_devblocksize(mp);
        nblocks = btodb(fs->fs_bsize, devBlockSize);

        /* Doing a MALLOC here is asking for trouble. We can still
         * deadlock on pagerfile lock, in case we are running
         * low on memory and block in MALLOC
         */

        tbp = buf_geteblk(fs->fs_bsize);
        copy = (ufs_daddr_t *)buf_dataptr(tbp);

        /*
         * Get buffer of block pointers, zero those entries corresponding
         * to blocks to be free'd, and update on disk copy first.  Since
         * double(triple) indirect before single(double) indirect, calls
         * to bmap on these blocks will fail.  However, we already have
         * the on disk address, so we have to set the blkno field
         * explicitly instead of letting buf_bread do everything for us.
         */

        vp = ITOV(ip);
        bp = buf_getblk(vp, (daddr64_t)((unsigned)lbn), (int)fs->fs_bsize, 0, 0, BLK_META);

        if (buf_valid(bp)) {
                /* Braces must be here in case trace evaluates to nothing. */
                trace(TR_BREADHIT, pack(vp, fs->fs_bsize), lbn);
        } else {
                trace(TR_BREADMISS, pack(vp, fs->fs_bsize), lbn);
                current_proc()->p_stats->p_ru.ru_inblock++;     /* pay for read */
                buf_setflags(bp,  B_READ);
                if (buf_count(bp) > buf_size(bp))
                        panic("ffs_indirtrunc: bad buffer size");
                buf_setblkno(bp, (daddr64_t)((unsigned)dbn));
                VNOP_STRATEGY(bp);
                error = buf_biowait(bp);
        }
        if (error) {
                buf_brelse(bp);
                *countp = 0;
                buf_brelse(tbp);
                return ((int)error);
        }

        bap = (ufs_daddr_t *)buf_dataptr(bp);
        bcopy((caddr_t)bap, (caddr_t)copy, (u_int)fs->fs_bsize);
        bzero((caddr_t)&bap[last + 1],
          (u_int)(NINDIR(fs) - (last + 1)) * sizeof (ufs_daddr_t));
        if (last == -1)
                buf_markinvalid(bp);
        if (last != -1 && (vp)->v_mount->mnt_flag & MNT_ASYNC) {
                error = 0;
                buf_bdwrite(bp);
        } else {
                error = buf_bwrite(bp);
                if (error)
                        allerror = error;
        }
        bap = copy;

        /*
         * Recursively free totally unused blocks.
         */
        for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
            i--, nlbn += factor) {
#if     REV_ENDIAN_FS
                if (rev_endian)
                        nb = OSSwapInt32(bap[i]);
                else {
#endif  /* REV_ENDIAN_FS */
                        nb = bap[i];
#if     REV_ENDIAN_FS
                }
#endif  /* REV_ENDIAN_FS */
                if (nb == 0)
                        continue;
                if (level > SINGLE) {
                        if (error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
                            (ufs_daddr_t)-1, level - 1, &blkcount))
                                allerror = error;
                        blocksreleased += blkcount;
                }
                ffs_blkfree(ip, nb, fs->fs_bsize);
                blocksreleased += nblocks;
        }

        /*
         * Recursively free last partial block.
         */
        if (level > SINGLE && lastbn >= 0) {
                last = lastbn % factor;
#if     REV_ENDIAN_FS
                if (rev_endian)
                        nb = OSSwapInt32(bap[i]);
                else {
#endif  /* REV_ENDIAN_FS */
                        nb = bap[i];
#if     REV_ENDIAN_FS
                }
#endif  /* REV_ENDIAN_FS */
                if (nb != 0) {
                        if (error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
                            last, level - 1, &blkcount))
                                allerror = error;
                        blocksreleased += blkcount;
                }
        }
        buf_brelse(tbp);
        *countp = blocksreleased;
        return ((int)allerror);
}