/*
 * 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. 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
 * $FreeBSD: src/sys/ufs/ffs/ffs_inode.c,v 1.56.2.5 2002/02/05 18:35:03 dillon Exp $
 */

#include "opt_quota.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/buf.h>
#include <sys/vnode.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/resourcevar.h>
#include <sys/vmmeter.h>

#include <vm/vm.h>
#include <vm/vm_extern.h>

#include "quota.h"
#include "ufsmount.h"
#include "inode.h"
#include "ufs_extern.h"

#include "fs.h"
#include "ffs_extern.h"

#include <vm/vm_page2.h>
#include <sys/buf2.h>

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
 * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.  Write the inode
 * to disk if the IN_MODIFIED flag is set (it may be set initially, or by
 * the timestamp update).  The IN_LAZYMOD flag is set to force a write
 * later if not now.  If we write now, then clear both IN_MODIFIED and
 * IN_LAZYMOD to reflect the presumably successful write, and if waitfor is
 * set, then wait for the write to complete.
 */
int
ffs_update(struct vnode *vp, int waitfor)
{
        struct fs *fs;
        struct buf *bp;
        struct inode *ip;
        int error;

        ufs_itimes(vp);
        ip = VTOI(vp);
        if ((ip->i_flag & IN_MODIFIED) == 0 && waitfor == 0)
                return (0);
        ip->i_flag &= ~(IN_LAZYMOD | IN_MODIFIED);
        fs = ip->i_fs;
        if (fs->fs_ronly)
                return (0);

        /*
         * The vnode type is usually set to VBAD if an unrecoverable I/O
         * error has occured (such as when reading the inode).  Clear the
         * modified bits but do not write anything out in this case.
         */
        if (vp->v_type == VBAD)
                return (0);
        /*
         * 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 */
        error = bread(ip->i_devvp, 
                      fsbtodoff(fs, ino_to_fsba(fs, ip->i_number)),
                      (int)fs->fs_bsize, &bp);
        if (error) {
                brelse(bp);
                return (error);
        }
        if (DOINGSOFTDEP(vp))
                softdep_update_inodeblock(ip, bp, waitfor);
        else if (ip->i_effnlink != ip->i_nlink)
                panic("ffs_update: bad link cnt");
        *((struct ufs1_dinode *)bp->b_data +
            ino_to_fsbo(fs, ip->i_number)) = ip->i_din;
        if (waitfor && !DOINGASYNC(vp)) {
                return (bwrite(bp));
        } else if (vm_paging_severe() || buf_dirty_count_severe()) {
                return (bwrite(bp));
        } else {
                if (bp->b_bufsize == fs->fs_bsize)
                        bp->b_flags |= B_CLUSTEROK;
                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 */
/*
 * Truncate the inode oip to at most length size, freeing the
 * disk blocks.
 */
int
ffs_truncate(struct vnode *vp, off_t length, int flags, struct ucred *cred)
{
        struct vnode *ovp = vp;
        ufs_daddr_t lastblock;
        struct inode *oip;
        ufs_daddr_t bn, lbn, lastiblock[UFS_NIADDR], indir_lbn[UFS_NIADDR];
        ufs_daddr_t oldblks[UFS_NDADDR + UFS_NIADDR];
        ufs_daddr_t newblks[UFS_NDADDR + UFS_NIADDR];
        struct fs *fs;
        struct buf *bp;
        int offset, size, level;
        long count, nblocks, blocksreleased = 0;
        int i;
        int aflags, error, allerror;
        off_t osize;

        oip = VTOI(ovp);
        fs = oip->i_fs;
        if (length < 0)
                return (EINVAL);
        if (length > fs->fs_maxfilesize)
                return (EFBIG);
        if (ovp->v_type == VLNK &&
            (oip->i_size < ovp->v_mount->mnt_maxsymlinklen || oip->i_din.di_blocks == 0)) {
#ifdef DIAGNOSTIC
                if (length != 0)
                        panic("ffs_truncate: partial truncate of symlink");
#endif /* DIAGNOSTIC */
                bzero((char *)&oip->i_shortlink, (uint)oip->i_size);
                oip->i_size = 0;
                oip->i_flag |= IN_CHANGE | IN_UPDATE;
                return (ffs_update(ovp, 1));
        }
        if (oip->i_size == length) {
                oip->i_flag |= IN_CHANGE | IN_UPDATE;
                return (ffs_update(ovp, 0));
        }
        if (fs->fs_ronly)
                panic("ffs_truncate: read-only filesystem");
#ifdef QUOTA
        error = ufs_getinoquota(oip);
        if (error)
                return (error);
#endif
        if (DOINGSOFTDEP(ovp)) {
                if (length > 0 || softdep_slowdown(ovp)) {
                        /*
                         * If a file is only partially truncated, then
                         * we have to clean up the data structures
                         * describing the allocation past the truncation
                         * point. Finding and deallocating those structures
                         * is a lot of work. Since partial truncation occurs
                         * rarely, we solve the problem by syncing the file
                         * so that it will have no data structures left.
                         */
                        if ((error = VOP_FSYNC(ovp, MNT_WAIT, 0)) != 0)
                                return (error);
                } else {
#ifdef QUOTA
                        (void) ufs_chkdq(oip, -oip->i_blocks, NOCRED, 0);
#endif
                        softdep_setup_freeblocks(oip, length);
                        vinvalbuf(ovp, 0, 0, 0);
                        nvnode_pager_setsize(ovp, 0, fs->fs_bsize, 0);
                        oip->i_flag |= IN_CHANGE | IN_UPDATE;
                        return (ffs_update(ovp, 0));
                }
        }
        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.
         *
         * nvextendbuf() only breads the old buffer.  The blocksize
         * of the new buffer must be specified so it knows how large
         * to make the VM object.
         */
        if (osize < length) {
                nvextendbuf(vp, osize, length,
                            blkoffsize(fs, oip, osize), /* oblksize */
                            blkoffresize(fs, length),   /* nblksize */
                            blkoff(fs, osize),
                            blkoff(fs, length),
                            0);

                aflags = B_CLRBUF;
                if (flags & IO_SYNC)
                        aflags |= B_SYNC;
                /* BALLOC will reallocate the fragment at the old EOF */
                error = VOP_BALLOC(ovp, length - 1, 1, cred, aflags, &bp);
                if (error)
                        return (error);
                oip->i_size = length;
                if (bp->b_bufsize == fs->fs_bsize)
                        bp->b_flags |= B_CLUSTEROK;
                if (aflags & B_SYNC)
                        bwrite(bp);
                else
                        bawrite(bp);
                oip->i_flag |= IN_CHANGE | IN_UPDATE;
                return (ffs_update(ovp, 1));
        }

        /*
         * Shorten the size of the file.
         *
         * NOTE: The block size specified in nvtruncbuf() is the blocksize
         *       of the buffer containing length prior to any reallocation
         *       of the block.
         */
        allerror = nvtruncbuf(ovp, length, blkoffsize(fs, oip, length),
                              blkoff(fs, length), 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;
                error = VOP_BALLOC(ovp, length - 1, 1, cred, aflags, &bp);
                if (error)
                        return (error);

                /*
                 * When we are doing soft updates and the UFS_BALLOC
                 * above fills in a direct block hole with a full sized
                 * block that will be truncated down to a fragment below,
                 * we must flush out the block dependency with an FSYNC
                 * so that we do not get a soft updates inconsistency
                 * when we create the fragment below.
                 *
                 * nvtruncbuf() may have re-dirtied the underlying block
                 * as part of its truncation zeroing code.  To avoid a
                 * 'locking against myself' panic in the second fsync we
                 * can simply undirty the bp since the redirtying was
                 * related to areas of the buffer that we are going to
                 * throw away anyway, and we will b*write() the remainder
                 * anyway down below.
                 */
                if (DOINGSOFTDEP(ovp) && lbn < UFS_NDADDR &&
                    fragroundup(fs, blkoff(fs, length)) < fs->fs_bsize) {
                        bundirty(bp);
                        error = VOP_FSYNC(ovp, MNT_WAIT, 0);
                        if (error) {
                                bdwrite(bp);
                                return (error);
                        }
                }
                oip->i_size = length;
                size = blksize(fs, oip, lbn);
#if 0
                /* remove - nvtruncbuf deals with this */
                if (ovp->v_type != VDIR)
                        bzero((char *)bp->b_data + offset,
                            (uint)(size - offset));
#endif
                /* Kirk's code has reallocbuf(bp, size, 1) here */
                allocbuf(bp, size);
                if (bp->b_bufsize == fs->fs_bsize)
                        bp->b_flags |= B_CLUSTEROK;
                if (aflags & B_SYNC)
                        bwrite(bp);
                else
                        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 - UFS_NDADDR;
        lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
        lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
        nblocks = btodb(fs->fs_bsize);

        /*
         * 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.
         */
        for (level = TRIPLE; level >= SINGLE; level--) {
                oldblks[UFS_NDADDR + level] = oip->i_ib[level];
                if (lastiblock[level] < 0) {
                        oip->i_ib[level] = 0;
                        lastiblock[level] = -1;
                }
        }
        for (i = 0; i < UFS_NDADDR; i++) {
                oldblks[i] = oip->i_db[i];
                if (i > lastblock)
                        oip->i_db[i] = 0;
        }
        oip->i_flag |= IN_CHANGE | IN_UPDATE;
        error = ffs_update(ovp, 1);
        if (error && allerror == 0)
                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.
         */
        for (i = 0; i < UFS_NDADDR; i++) {
                newblks[i] = oip->i_db[i];
                oip->i_db[i] = oldblks[i];
        }
        for (i = 0; i < UFS_NIADDR; i++) {
                newblks[UFS_NDADDR + i] = oip->i_ib[i];
                oip->i_ib[i] = oldblks[UFS_NDADDR + i];
        }
        oip->i_size = osize;

        if (error && allerror == 0)
                allerror = error;

        /*
         * Indirect blocks first.
         */
        indir_lbn[SINGLE] = -UFS_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 = UFS_NDADDR - 1; i > lastblock; i--) {
                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);
        }
        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("ffs_truncate: 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);
                }
        }
done:
#ifdef DIAGNOSTIC
        for (level = SINGLE; level <= TRIPLE; level++)
                if (newblks[UFS_NDADDR + level] != oip->i_ib[level])
                        panic("ffs_truncate1");
        for (i = 0; i < UFS_NDADDR; i++)
                if (newblks[i] != oip->i_db[i])
                        panic("ffs_truncate2");
        if (length == 0 && !RB_EMPTY(&ovp->v_rbdirty_tree))
                panic("ffs_truncate3");
#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;
#ifdef QUOTA
        (void) ufs_chkdq(oip, -blocksreleased, 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(struct inode *ip, ufs_daddr_t lbn, ufs_daddr_t dbn,
               ufs_daddr_t lastbn, int level, long *countp)
{
        int i;
        struct buf *bp;
        struct fs *fs = ip->i_fs;
        ufs_daddr_t *bap;
        struct vnode *vp;
        ufs_daddr_t *copy = NULL, nb, nlbn, last;
        long blkcount, factor;
        int nblocks, blocksreleased = 0;
        int error = 0, allerror = 0;

        /*
         * 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;
        nblocks = btodb(fs->fs_bsize);
        /*
         * 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 bio_offset field
         * explicitly instead of letting bread do everything for us.
         */
        vp = ITOV(ip);
        bp = getblk(vp, lblktodoff(fs, lbn), (int)fs->fs_bsize, 0, 0);
        if ((bp->b_flags & B_CACHE) == 0) {
                bp->b_flags &= ~(B_ERROR|B_INVAL);
                bp->b_cmd = BUF_CMD_READ;
                if (bp->b_bcount > bp->b_bufsize)
                        panic("ffs_indirtrunc: bad buffer size");
                /*
                 * BIO is bio2 which chains back to bio1.  We wait
                 * on bio1.
                 */
                bp->b_bio2.bio_offset = dbtodoff(fs, dbn);
                bp->b_bio1.bio_done = biodone_sync;
                bp->b_bio1.bio_flags |= BIO_SYNC;
                vfs_busy_pages(vp, bp);
                /*
                 * Access the block device layer using the device vnode
                 * and the translated block number (bio2) instead of the
                 * file vnode (vp) and logical block number (bio1).
                 *
                 * Even though we are bypassing the vnode layer, we still
                 * want the vnode state to indicate that an I/O on its behalf
                 * is in progress.
                 */
                bio_start_transaction(&bp->b_bio1, &vp->v_track_read);
                vn_strategy(ip->i_devvp, &bp->b_bio2);
                error = biowait(&bp->b_bio1, "biord");
        }
        if (error) {
                brelse(bp);
                *countp = 0;
                return (error);
        }

        bap = (ufs_daddr_t *)bp->b_data;
        if (lastbn != -1) {
                copy = kmalloc(fs->fs_bsize, M_TEMP, M_WAITOK);
                bcopy((caddr_t)bap, (caddr_t)copy, (uint)fs->fs_bsize);
                bzero((caddr_t)&bap[last + 1],
                    (uint)(NINDIR(fs) - (last + 1)) * sizeof (ufs_daddr_t));
                if (DOINGASYNC(vp)) {
                        bawrite(bp);
                } else {
                        error = 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) {
                nb = bap[i];
                if (nb == 0)
                        continue;
                if (level > SINGLE) {
                        if ((error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
                            (ufs_daddr_t)-1, level - 1, &blkcount)) != 0)
                                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;
                nb = bap[i];
                if (nb != 0) {
                        error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
                            last, level - 1, &blkcount);
                        if (error)
                                allerror = error;
                        blocksreleased += blkcount;
                }
        }
        if (copy != NULL) {
                kfree(copy, M_TEMP);
        } else {
                bp->b_flags |= B_INVAL | B_NOCACHE;
                brelse(bp);
        }
                
        *countp = blocksreleased;
        return (allerror);
}