/*-
 * SPDX-License-Identifier: (BSD-2-Clause AND BSD-3-Clause)
 *
 * Copyright (c) 2002 Networks Associates Technology, Inc.
 * All rights reserved.
 *
 * This software was developed for the FreeBSD Project by Marshall
 * Kirk McKusick and Network Associates Laboratories, the Security
 * Research Division of Network Associates, Inc. under DARPA/SPAWAR
 * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
 * research program
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 *
 * 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.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/lock.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/vnode.h>
#include <sys/vmmeter.h>

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

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

/*
 * Balloc defines the structure of filesystem storage
 * by allocating the physical blocks on a device given
 * the inode and the logical block number in a file.
 * This is the allocation strategy for UFS1. Below is
 * the allocation strategy for UFS2.
 */
int
ffs_balloc_ufs1(struct vnode *vp, off_t startoffset, int size,
    struct ucred *cred, int flags, struct buf **bpp)
{
        struct inode *ip;
        struct ufs1_dinode *dp;
        ufs_lbn_t lbn, lastlbn;
        struct fs *fs;
        ufs1_daddr_t nb;
        struct buf *bp, *nbp;
        struct mount *mp;
        struct ufsmount *ump;
        struct indir indirs[UFS_NIADDR + 2];
        int deallocated, osize, nsize, num, i, error;
        ufs2_daddr_t newb;
        ufs1_daddr_t *bap, pref;
        ufs1_daddr_t *allocib, *blkp, *allocblk, allociblk[UFS_NIADDR + 1];
        ufs2_daddr_t *lbns_remfree, lbns[UFS_NIADDR + 1];
        int unwindidx = -1;
        int saved_inbdflush;
        int gbflags, reclaimed;

        ip = VTOI(vp);
        dp = ip->i_din1;
        fs = ITOFS(ip);
        mp = ITOVFS(ip);
        ump = ITOUMP(ip);
        lbn = lblkno(fs, startoffset);
        size = blkoff(fs, startoffset) + size;
        reclaimed = 0;
        if (size > fs->fs_bsize)
                panic("ffs_balloc_ufs1: blk too big");
        *bpp = NULL;
        if (flags & IO_EXT)
                return (EOPNOTSUPP);
        if (lbn < 0)
                return (EFBIG);
        gbflags = (flags & BA_UNMAPPED) != 0 ? GB_UNMAPPED : 0;

        vn_seqc_write_begin(vp);

        /*
         * If the next write will extend the file into a new block,
         * and the file is currently composed of a fragment
         * this fragment has to be extended to be a full block.
         */
        lastlbn = lblkno(fs, ip->i_size);
        if (lastlbn < UFS_NDADDR && lastlbn < lbn) {
                nb = lastlbn;
                osize = blksize(fs, ip, nb);
                if (osize < fs->fs_bsize && osize > 0) {
                        UFS_LOCK(ump);
                        error = ffs_realloccg(ip, nb, dp->di_db[nb],
                           ffs_blkpref_ufs1(ip, lastlbn, (int)nb,
                           &dp->di_db[0]), osize, (int)fs->fs_bsize, flags,
                           cred, &bp);
                        if (error)
                                goto done;
                        if (DOINGSOFTDEP(vp))
                                softdep_setup_allocdirect(ip, nb,
                                    dbtofsb(fs, bp->b_blkno), dp->di_db[nb],
                                    fs->fs_bsize, osize, bp);
                        ip->i_size = smalllblktosize(fs, nb + 1);
                        dp->di_size = ip->i_size;
                        dp->di_db[nb] = dbtofsb(fs, bp->b_blkno);
                        UFS_INODE_SET_FLAG(ip,
                            IN_SIZEMOD | IN_CHANGE | IN_UPDATE | IN_IBLKDATA);
                        if (flags & IO_SYNC)
                                bwrite(bp);
                        else if (DOINGASYNC(vp))
                                bdwrite(bp);
                        else
                                bawrite(bp);
                }
        }
        /*
         * The first UFS_NDADDR blocks are direct blocks
         */
        if (lbn < UFS_NDADDR) {
                if (flags & BA_METAONLY)
                        panic("ffs_balloc_ufs1: BA_METAONLY for direct block");
                nb = dp->di_db[lbn];
                if (nb != 0 && ip->i_size >= smalllblktosize(fs, lbn + 1)) {
                        if ((flags & BA_CLRBUF) != 0) {
                                error = bread(vp, lbn, fs->fs_bsize, NOCRED,
                                    &bp);
                                if (error != 0)
                                        goto done;
                        } else {
                                bp = getblk(vp, lbn, fs->fs_bsize, 0, 0,
                                    gbflags);
                                if (bp == NULL) {
                                        error = EIO;
                                        goto done;
                                }
                                vfs_bio_clrbuf(bp);
                        }
                        bp->b_blkno = fsbtodb(fs, nb);
                        *bpp = bp;
                        error = 0;
                        goto done;
                }
                if (nb != 0) {
                        /*
                         * Consider need to reallocate a fragment.
                         */
                        osize = fragroundup(fs, blkoff(fs, ip->i_size));
                        nsize = fragroundup(fs, size);
                        if (nsize <= osize) {
                                error = bread(vp, lbn, osize, NOCRED, &bp);
                                if (error)
                                        goto done;
                                bp->b_blkno = fsbtodb(fs, nb);
                        } else {
                                UFS_LOCK(ump);
                                error = ffs_realloccg(ip, lbn, dp->di_db[lbn],
                                    ffs_blkpref_ufs1(ip, lbn, (int)lbn,
                                    &dp->di_db[0]), osize, nsize, flags,
                                    cred, &bp);
                                if (error)
                                        goto done;
                                if (DOINGSOFTDEP(vp))
                                        softdep_setup_allocdirect(ip, lbn,
                                            dbtofsb(fs, bp->b_blkno), nb,
                                            nsize, osize, bp);
                        }
                } else {
                        if (ip->i_size < smalllblktosize(fs, lbn + 1))
                                nsize = fragroundup(fs, size);
                        else
                                nsize = fs->fs_bsize;
                        UFS_LOCK(ump);
                        error = ffs_alloc(ip, lbn,
                            ffs_blkpref_ufs1(ip, lbn, (int)lbn, &dp->di_db[0]),
                            nsize, flags, cred, &newb);
                        if (error)
                                goto done;
                        bp = getblk(vp, lbn, nsize, 0, 0, gbflags);
                        bp->b_blkno = fsbtodb(fs, newb);
                        if (flags & BA_CLRBUF)
                                vfs_bio_clrbuf(bp);
                        if (DOINGSOFTDEP(vp))
                                softdep_setup_allocdirect(ip, lbn, newb, 0,
                                    nsize, 0, bp);
                }
                dp->di_db[lbn] = dbtofsb(fs, bp->b_blkno);
                UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE | IN_IBLKDATA);
                *bpp = bp;
                error = 0;
                goto done;
        }
        /*
         * Determine the number of levels of indirection.
         */
        pref = 0;
        if ((error = ufs_getlbns(vp, lbn, indirs, &num)) != 0)
                goto done;
#ifdef INVARIANTS
        if (num < 1)
                panic ("ffs_balloc_ufs1: ufs_getlbns returned indirect block");
#endif
        saved_inbdflush = curthread_pflags_set(TDP_INBDFLUSH);
        /*
         * Fetch the first indirect block allocating if necessary.
         */
        --num;
        nb = dp->di_ib[indirs[0].in_off];
        allocib = NULL;
        allocblk = allociblk;
        lbns_remfree = lbns;
        if (nb == 0) {
                UFS_LOCK(ump);
                pref = ffs_blkpref_ufs1(ip, lbn, -indirs[0].in_off - 1,
                    (ufs1_daddr_t *)0);
                if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
                    flags, cred, &newb)) != 0) {
                        curthread_pflags_restore(saved_inbdflush);
                        goto done;
                }
                pref = newb + fs->fs_frag;
                nb = newb;
                MPASS(allocblk < allociblk + nitems(allociblk));
                MPASS(lbns_remfree < lbns + nitems(lbns));
                *allocblk++ = nb;
                *lbns_remfree++ = indirs[1].in_lbn;
                bp = getblk(vp, indirs[1].in_lbn, fs->fs_bsize, 0, 0, gbflags);
                bp->b_blkno = fsbtodb(fs, nb);
                vfs_bio_clrbuf(bp);
                if (DOINGSOFTDEP(vp)) {
                        softdep_setup_allocdirect(ip,
                            UFS_NDADDR + indirs[0].in_off, newb, 0,
                            fs->fs_bsize, 0, bp);
                        bdwrite(bp);
                } else if ((flags & IO_SYNC) == 0 && DOINGASYNC(vp)) {
                        if (bp->b_bufsize == fs->fs_bsize)
                                bp->b_flags |= B_CLUSTEROK;
                        bdwrite(bp);
                } else {
                        if ((error = bwrite(bp)) != 0)
                                goto fail;
                }
                allocib = &dp->di_ib[indirs[0].in_off];
                *allocib = nb;
                UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE | IN_IBLKDATA);
        }
        /*
         * Fetch through the indirect blocks, allocating as necessary.
         */
retry:
        for (i = 1;;) {
                error = bread(vp,
                    indirs[i].in_lbn, (int)fs->fs_bsize, NOCRED, &bp);
                if (error) {
                        goto fail;
                }
                bap = (ufs1_daddr_t *)bp->b_data;
                nb = bap[indirs[i].in_off];
                if ((error = UFS_CHECK_BLKNO(mp, ip->i_number, nb,
                    fs->fs_bsize)) != 0) {
                        brelse(bp);
                        goto fail;
                }
                if (i == num)
                        break;
                i += 1;
                if (nb != 0) {
                        bqrelse(bp);
                        continue;
                }
                UFS_LOCK(ump);
                /*
                 * If parent indirect has just been allocated, try to cluster
                 * immediately following it.
                 */
                if (pref == 0)
                        pref = ffs_blkpref_ufs1(ip, lbn, i - num - 1,
                            (ufs1_daddr_t *)0);
                if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
                    flags | IO_BUFLOCKED, cred, &newb)) != 0) {
                        brelse(bp);
                        UFS_LOCK(ump);
                        if (DOINGSOFTDEP(vp) && ++reclaimed == 1) {
                                softdep_request_cleanup(fs, vp, cred,
                                    FLUSH_BLOCKS_WAIT);
                                UFS_UNLOCK(ump);
                                goto retry;
                        }
                        if (!ffs_fsfail_cleanup_locked(ump, error) &&
                            ppsratecheck(&ump->um_last_fullmsg,
                            &ump->um_secs_fullmsg, 1)) {
                                UFS_UNLOCK(ump);
                                ffs_fserr(fs, ip->i_number, "filesystem full");
                                uprintf("\n%s: write failed, filesystem "
                                    "is full\n", fs->fs_fsmnt);
                        } else {
                                UFS_UNLOCK(ump);
                        }
                        goto fail;
                }
                pref = newb + fs->fs_frag;
                nb = newb;
                MPASS(allocblk < allociblk + nitems(allociblk));
                MPASS(lbns_remfree < lbns + nitems(lbns));
                *allocblk++ = nb;
                *lbns_remfree++ = indirs[i].in_lbn;
                nbp = getblk(vp, indirs[i].in_lbn, fs->fs_bsize, 0, 0, 0);
                nbp->b_blkno = fsbtodb(fs, nb);
                vfs_bio_clrbuf(nbp);
                if (DOINGSOFTDEP(vp)) {
                        softdep_setup_allocindir_meta(nbp, ip, bp,
                            indirs[i - 1].in_off, nb);
                        bdwrite(nbp);
                } else if ((flags & IO_SYNC) == 0 && DOINGASYNC(vp)) {
                        if (nbp->b_bufsize == fs->fs_bsize)
                                nbp->b_flags |= B_CLUSTEROK;
                        bdwrite(nbp);
                } else {
                        if ((error = bwrite(nbp)) != 0) {
                                brelse(bp);
                                goto fail;
                        }
                }
                bap[indirs[i - 1].in_off] = nb;
                if (allocib == NULL && unwindidx < 0)
                        unwindidx = i - 1;
                /*
                 * If required, write synchronously, otherwise use
                 * delayed write.
                 */
                if (flags & IO_SYNC) {
                        bwrite(bp);
                } else {
                        if (bp->b_bufsize == fs->fs_bsize)
                                bp->b_flags |= B_CLUSTEROK;
                        bdwrite(bp);
                }
        }
        /*
         * If asked only for the indirect block, then return it.
         */
        if (flags & BA_METAONLY) {
                curthread_pflags_restore(saved_inbdflush);
                *bpp = bp;
                error = 0;
                goto done;
        }
        /*
         * Get the data block, allocating if necessary.
         */
        if (nb == 0) {
                UFS_LOCK(ump);
                /*
                 * If allocating metadata at the front of the cylinder
                 * group and parent indirect block has just been allocated,
                 * then cluster next to it if it is the first indirect in
                 * the file. Otherwise it has been allocated in the metadata
                 * area, so we want to find our own place out in the data area.
                 */
                if (pref == 0 || (lbn > UFS_NDADDR && fs->fs_metaspace != 0))
                        pref = ffs_blkpref_ufs1(ip, lbn, indirs[i].in_off,
                            &bap[0]);
                error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
                    flags | IO_BUFLOCKED, cred, &newb);
                if (error) {
                        brelse(bp);
                        UFS_LOCK(ump);
                        if (DOINGSOFTDEP(vp) && ++reclaimed == 1) {
                                softdep_request_cleanup(fs, vp, cred,
                                    FLUSH_BLOCKS_WAIT);
                                UFS_UNLOCK(ump);
                                goto retry;
                        }
                        if (!ffs_fsfail_cleanup_locked(ump, error) &&
                            ppsratecheck(&ump->um_last_fullmsg,
                            &ump->um_secs_fullmsg, 1)) {
                                UFS_UNLOCK(ump);
                                ffs_fserr(fs, ip->i_number, "filesystem full");
                                uprintf("\n%s: write failed, filesystem "
                                    "is full\n", fs->fs_fsmnt);
                        } else {
                                UFS_UNLOCK(ump);
                        }
                        goto fail;
                }
                nb = newb;
                MPASS(allocblk < allociblk + nitems(allociblk));
                MPASS(lbns_remfree < lbns + nitems(lbns));
                *allocblk++ = nb;
                *lbns_remfree++ = lbn;
                nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0, gbflags);
                nbp->b_blkno = fsbtodb(fs, nb);
                if (flags & BA_CLRBUF)
                        vfs_bio_clrbuf(nbp);
                if (DOINGSOFTDEP(vp))
                        softdep_setup_allocindir_page(ip, lbn, bp,
                            indirs[i].in_off, nb, 0, nbp);
                bap[indirs[i].in_off] = nb;
                /*
                 * If required, write synchronously, otherwise use
                 * delayed write.
                 */
                if (flags & IO_SYNC) {
                        bwrite(bp);
                } else {
                        if (bp->b_bufsize == fs->fs_bsize)
                                bp->b_flags |= B_CLUSTEROK;
                        bdwrite(bp);
                }
                curthread_pflags_restore(saved_inbdflush);
                *bpp = nbp;
                error = 0;
                goto done;
        }
        brelse(bp);
        if (flags & BA_CLRBUF) {
                int seqcount = (flags & BA_SEQMASK) >> BA_SEQSHIFT;
                if (seqcount != 0 &&
                    (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0 &&
                    !(vm_page_count_severe() || buf_dirty_count_severe())) {
                        error = cluster_read(vp, ip->i_size, lbn,
                            (int)fs->fs_bsize, NOCRED,
                            MAXBSIZE, seqcount, gbflags, &nbp);
                } else {
                        error = bread_gb(vp, lbn, (int)fs->fs_bsize, NOCRED,
                            gbflags, &nbp);
                }
                if (error) {
                        brelse(nbp);
                        goto fail;
                }
        } else {
                nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0, gbflags);
                nbp->b_blkno = fsbtodb(fs, nb);
        }
        curthread_pflags_restore(saved_inbdflush);
        *bpp = nbp;
        error = 0;
        goto done;
fail:
        curthread_pflags_restore(saved_inbdflush);
        /*
         * If we have failed to allocate any blocks, simply return the error.
         * This is the usual case and avoids the need to fsync the file.
         */
        if (allocblk == allociblk && allocib == NULL && unwindidx == -1)
                goto done;
        /*
         * If we have failed part way through block allocation, we
         * have to deallocate any indirect blocks that we have allocated.
         * We have to fsync the file before we start to get rid of all
         * of its dependencies so that we do not leave them dangling.
         * We have to sync it at the end so that the soft updates code
         * does not find any untracked changes. Although this is really
         * slow, running out of disk space is not expected to be a common
         * occurrence. The error return from fsync is ignored as we already
         * have an error to return to the user.
         *
         * XXX Still have to journal the free below
         */
        (void) ffs_syncvnode(vp, MNT_WAIT, 0);
        for (deallocated = 0, blkp = allociblk, lbns_remfree = lbns;
             blkp < allocblk; blkp++, lbns_remfree++) {
                /*
                 * We shall not leave the freed blocks on the vnode
                 * buffer object lists.
                 */
                bp = getblk(vp, *lbns_remfree, fs->fs_bsize, 0, 0,
                    GB_NOCREAT | GB_UNMAPPED);
                if (bp != NULL) {
                        KASSERT(bp->b_blkno == fsbtodb(fs, *blkp),
                            ("mismatch1 l %jd %jd b %ju %ju",
                            (intmax_t)bp->b_lblkno, (uintmax_t)*lbns_remfree,
                            (uintmax_t)bp->b_blkno,
                            (uintmax_t)fsbtodb(fs, *blkp)));
                        bp->b_flags |= B_INVAL | B_RELBUF | B_NOCACHE;
                        bp->b_flags &= ~(B_ASYNC | B_CACHE);
                        brelse(bp);
                }
                deallocated += fs->fs_bsize;
        }
        if (allocib != NULL) {
                *allocib = 0;
        } else if (unwindidx >= 0) {
                int r;

                r = bread(vp, indirs[unwindidx].in_lbn, 
                    (int)fs->fs_bsize, NOCRED, &bp);
                if (r) {
                        panic("Could not unwind indirect block, error %d", r);
                        brelse(bp);
                } else {
                        bap = (ufs1_daddr_t *)bp->b_data;
                        bap[indirs[unwindidx].in_off] = 0;
                        if (flags & IO_SYNC) {
                                bwrite(bp);
                        } else {
                                if (bp->b_bufsize == fs->fs_bsize)
                                        bp->b_flags |= B_CLUSTEROK;
                                bdwrite(bp);
                        }
                }
        }
        if (deallocated) {
#ifdef QUOTA
                /*
                 * Restore user's disk quota because allocation failed.
                 */
                (void) chkdq(ip, -btodb(deallocated), cred, FORCE);
#endif
                dp->di_blocks -= btodb(deallocated);
                UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE);
        }
        (void) ffs_syncvnode(vp, MNT_WAIT, 0);
        /*
         * After the buffers are invalidated and on-disk pointers are
         * cleared, free the blocks.
         */
        for (blkp = allociblk; blkp < allocblk; blkp++) {
#ifdef INVARIANTS
                if (blkp == allociblk)
                        lbns_remfree = lbns;
                bp = getblk(vp, *lbns_remfree, fs->fs_bsize, 0, 0,
                    GB_NOCREAT | GB_UNMAPPED);
                if (bp != NULL) {
                        panic("zombie1 %jd %ju %ju",
                            (intmax_t)bp->b_lblkno, (uintmax_t)bp->b_blkno,
                            (uintmax_t)fsbtodb(fs, *blkp));
                }
                lbns_remfree++;
#endif
                ffs_blkfree(ump, fs, ump->um_devvp, *blkp, fs->fs_bsize,
                    ip->i_number, vp->v_type, NULL, SINGLETON_KEY);
        }
done:
        vn_seqc_write_end(vp);
        return (error);
}

/*
 * Balloc defines the structure of file system storage
 * by allocating the physical blocks on a device given
 * the inode and the logical block number in a file.
 * This is the allocation strategy for UFS2. Above is
 * the allocation strategy for UFS1.
 */
int
ffs_balloc_ufs2(struct vnode *vp, off_t startoffset, int size,
    struct ucred *cred, int flags, struct buf **bpp)
{
        struct inode *ip;
        struct ufs2_dinode *dp;
        ufs_lbn_t lbn, lastlbn;
        struct fs *fs;
        struct buf *bp, *nbp;
        struct mount *mp;
        struct ufsmount *ump;
        struct indir indirs[UFS_NIADDR + 2];
        ufs2_daddr_t nb, newb, *bap, pref;
        ufs2_daddr_t *allocib, *blkp, *allocblk, allociblk[UFS_NIADDR + 1];
        ufs2_daddr_t *lbns_remfree, lbns[UFS_NIADDR + 1];
        int deallocated, osize, nsize, num, i, error;
        int unwindidx = -1;
        int saved_inbdflush;
        int gbflags, gbwflag, reclaimed;

        ip = VTOI(vp);
        dp = ip->i_din2;
        fs = ITOFS(ip);
        mp = ITOVFS(ip);
        ump = ITOUMP(ip);
        lbn = lblkno(fs, startoffset);
        size = blkoff(fs, startoffset) + size;
        reclaimed = 0;
        if (size > fs->fs_bsize)
                panic("ffs_balloc_ufs2: blk too big");
        *bpp = NULL;
        if (lbn < 0)
                return (EFBIG);
        gbflags = (flags & BA_UNMAPPED) != 0 ? GB_UNMAPPED : 0;
#ifdef WITNESS
        gbwflag = IS_SNAPSHOT(ip) ? GB_NOWITNESS : 0;
        gbflags |= gbwflag;
#else
        gbwflag = 0;
#endif

        vn_seqc_write_begin(vp);

        /*
         * Check for allocating external data.
         */
        if (flags & IO_EXT) {
                if (lbn >= UFS_NXADDR) {
                        error = EFBIG;
                        goto done;
                }

                /*
                 * If the next write will extend the data into a new block,
                 * and the data is currently composed of a fragment
                 * this fragment has to be extended to be a full block.
                 */
                lastlbn = lblkno(fs, dp->di_extsize);
                if (lastlbn < lbn) {
                        nb = lastlbn;
                        osize = sblksize(fs, dp->di_extsize, nb);
                        if (osize < fs->fs_bsize && osize > 0) {
                                UFS_LOCK(ump);
                                error = ffs_realloccg(ip, -1 - nb,
                                    dp->di_extb[nb],
                                    ffs_blkpref_ufs2(ip, lastlbn, (int)nb,
                                    &dp->di_extb[0]), osize,
                                    (int)fs->fs_bsize, flags, cred, &bp);
                                if (error)
                                        goto done;
                                if (DOINGSOFTDEP(vp))
                                        softdep_setup_allocext(ip, nb,
                                            dbtofsb(fs, bp->b_blkno),
                                            dp->di_extb[nb],
                                            fs->fs_bsize, osize, bp);
                                dp->di_extsize = smalllblktosize(fs, nb + 1);
                                dp->di_extb[nb] = dbtofsb(fs, bp->b_blkno);
                                bp->b_xflags |= BX_ALTDATA;
                                UFS_INODE_SET_FLAG(ip,
                                    IN_SIZEMOD | IN_CHANGE | IN_IBLKDATA);
                                if (flags & IO_SYNC)
                                        bwrite(bp);
                                else
                                        bawrite(bp);
                        }
                }
                /*
                 * All blocks are direct blocks
                 */
                if (flags & BA_METAONLY)
                        panic("ffs_balloc_ufs2: BA_METAONLY for ext block");
                nb = dp->di_extb[lbn];
                if (nb != 0 && dp->di_extsize >= smalllblktosize(fs, lbn + 1)) {
                        error = bread_gb(vp, -1 - lbn, fs->fs_bsize, NOCRED,
                            gbflags, &bp);
                        if (error)
                                goto done;
                        bp->b_blkno = fsbtodb(fs, nb);
                        bp->b_xflags |= BX_ALTDATA;
                        *bpp = bp;
                        goto done;
                }
                if (nb != 0) {
                        /*
                         * Consider need to reallocate a fragment.
                         */
                        osize = fragroundup(fs, blkoff(fs, dp->di_extsize));
                        nsize = fragroundup(fs, size);
                        if (nsize <= osize) {
                                error = bread_gb(vp, -1 - lbn, osize, NOCRED,
                                    gbflags, &bp);
                                if (error)
                                        goto done;
                                bp->b_blkno = fsbtodb(fs, nb);
                                bp->b_xflags |= BX_ALTDATA;
                        } else {
                                UFS_LOCK(ump);
                                error = ffs_realloccg(ip, -1 - lbn,
                                    dp->di_extb[lbn],
                                    ffs_blkpref_ufs2(ip, lbn, (int)lbn,
                                    &dp->di_extb[0]), osize, nsize, flags,
                                    cred, &bp);
                                if (error)
                                        goto done;
                                bp->b_xflags |= BX_ALTDATA;
                                if (DOINGSOFTDEP(vp))
                                        softdep_setup_allocext(ip, lbn,
                                            dbtofsb(fs, bp->b_blkno), nb,
                                            nsize, osize, bp);
                        }
                } else {
                        if (dp->di_extsize < smalllblktosize(fs, lbn + 1))
                                nsize = fragroundup(fs, size);
                        else
                                nsize = fs->fs_bsize;
                        UFS_LOCK(ump);
                        error = ffs_alloc(ip, lbn,
                           ffs_blkpref_ufs2(ip, lbn, (int)lbn, &dp->di_extb[0]),
                           nsize, flags, cred, &newb);
                        if (error)
                                goto done;
                        bp = getblk(vp, -1 - lbn, nsize, 0, 0, gbflags);
                        bp->b_blkno = fsbtodb(fs, newb);
                        bp->b_xflags |= BX_ALTDATA;
                        if (flags & BA_CLRBUF)
                                vfs_bio_clrbuf(bp);
                        if (DOINGSOFTDEP(vp))
                                softdep_setup_allocext(ip, lbn, newb, 0,
                                    nsize, 0, bp);
                }
                dp->di_extb[lbn] = dbtofsb(fs, bp->b_blkno);
                UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_IBLKDATA);
                *bpp = bp;
                error = 0;
                goto done;
        }
        /*
         * If the next write will extend the file into a new block,
         * and the file is currently composed of a fragment
         * this fragment has to be extended to be a full block.
         */
        lastlbn = lblkno(fs, ip->i_size);
        if (lastlbn < UFS_NDADDR && lastlbn < lbn) {
                nb = lastlbn;
                osize = blksize(fs, ip, nb);
                if (osize < fs->fs_bsize && osize > 0) {
                        UFS_LOCK(ump);
                        error = ffs_realloccg(ip, nb, dp->di_db[nb],
                            ffs_blkpref_ufs2(ip, lastlbn, (int)nb,
                            &dp->di_db[0]), osize, (int)fs->fs_bsize,
                            flags, cred, &bp);
                        if (error)
                                goto done;
                        if (DOINGSOFTDEP(vp))
                                softdep_setup_allocdirect(ip, nb,
                                    dbtofsb(fs, bp->b_blkno),
                                    dp->di_db[nb],
                                    fs->fs_bsize, osize, bp);
                        ip->i_size = smalllblktosize(fs, nb + 1);
                        dp->di_size = ip->i_size;
                        dp->di_db[nb] = dbtofsb(fs, bp->b_blkno);
                        UFS_INODE_SET_FLAG(ip,
                            IN_SIZEMOD |IN_CHANGE | IN_UPDATE | IN_IBLKDATA);
                        if (flags & IO_SYNC)
                                bwrite(bp);
                        else
                                bawrite(bp);
                }
        }
        /*
         * The first UFS_NDADDR blocks are direct blocks
         */
        if (lbn < UFS_NDADDR) {
                if (flags & BA_METAONLY)
                        panic("ffs_balloc_ufs2: BA_METAONLY for direct block");
                nb = dp->di_db[lbn];
                if (nb != 0 && ip->i_size >= smalllblktosize(fs, lbn + 1)) {
                        if ((flags & BA_CLRBUF) != 0) {
                                error = bread_gb(vp, lbn, fs->fs_bsize, NOCRED,
                                    gbflags, &bp);
                                if (error != 0)
                                        goto done;
                        } else {
                                bp = getblk(vp, lbn, fs->fs_bsize, 0, 0,
                                    gbflags);
                                if (bp == NULL) {
                                        error = EIO;
                                        goto done;
                                }
                                vfs_bio_clrbuf(bp);
                        }
                        bp->b_blkno = fsbtodb(fs, nb);
                        *bpp = bp;
                        error = 0;
                        goto done;
                }
                if (nb != 0) {
                        /*
                         * Consider need to reallocate a fragment.
                         */
                        osize = fragroundup(fs, blkoff(fs, ip->i_size));
                        nsize = fragroundup(fs, size);
                        if (nsize <= osize) {
                                error = bread_gb(vp, lbn, osize, NOCRED,
                                    gbflags, &bp);
                                if (error)
                                        goto done;
                                bp->b_blkno = fsbtodb(fs, nb);
                        } else {
                                UFS_LOCK(ump);
                                error = ffs_realloccg(ip, lbn, dp->di_db[lbn],
                                    ffs_blkpref_ufs2(ip, lbn, (int)lbn,
                                    &dp->di_db[0]), osize, nsize, flags,
                                    cred, &bp);
                                if (error)
                                        goto done;
                                if (DOINGSOFTDEP(vp))
                                        softdep_setup_allocdirect(ip, lbn,
                                            dbtofsb(fs, bp->b_blkno), nb,
                                            nsize, osize, bp);
                        }
                } else {
                        if (ip->i_size < smalllblktosize(fs, lbn + 1))
                                nsize = fragroundup(fs, size);
                        else
                                nsize = fs->fs_bsize;
                        UFS_LOCK(ump);
                        error = ffs_alloc(ip, lbn,
                            ffs_blkpref_ufs2(ip, lbn, (int)lbn,
                                &dp->di_db[0]), nsize, flags, cred, &newb);
                        if (error)
                                goto done;
                        bp = getblk(vp, lbn, nsize, 0, 0, gbflags);
                        bp->b_blkno = fsbtodb(fs, newb);
                        if (flags & BA_CLRBUF)
                                vfs_bio_clrbuf(bp);
                        if (DOINGSOFTDEP(vp))
                                softdep_setup_allocdirect(ip, lbn, newb, 0,
                                    nsize, 0, bp);
                }
                dp->di_db[lbn] = dbtofsb(fs, bp->b_blkno);
                UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE | IN_IBLKDATA);
                *bpp = bp;
                error = 0;
                goto done;
        }
        /*
         * Determine the number of levels of indirection.
         */
        pref = 0;
        if ((error = ufs_getlbns(vp, lbn, indirs, &num)) != 0)
                goto done;
#ifdef INVARIANTS
        if (num < 1)
                panic ("ffs_balloc_ufs2: ufs_getlbns returned indirect block");
#endif
        saved_inbdflush = curthread_pflags_set(TDP_INBDFLUSH);
        /*
         * Fetch the first indirect block allocating if necessary.
         */
        --num;
        nb = dp->di_ib[indirs[0].in_off];
        allocib = NULL;
        allocblk = allociblk;
        lbns_remfree = lbns;
        if (nb == 0) {
                UFS_LOCK(ump);
                pref = ffs_blkpref_ufs2(ip, lbn, -indirs[0].in_off - 1,
                    (ufs2_daddr_t *)0);
                if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
                    flags, cred, &newb)) != 0) {
                        curthread_pflags_restore(saved_inbdflush);
                        goto done;
                }
                pref = newb + fs->fs_frag;
                nb = newb;
                MPASS(allocblk < allociblk + nitems(allociblk));
                MPASS(lbns_remfree < lbns + nitems(lbns));
                *allocblk++ = nb;
                *lbns_remfree++ = indirs[1].in_lbn;
                bp = getblk(vp, indirs[1].in_lbn, fs->fs_bsize, 0, 0,
                    GB_UNMAPPED | gbwflag);
                bp->b_blkno = fsbtodb(fs, nb);
                vfs_bio_clrbuf(bp);
                if (DOINGSOFTDEP(vp)) {
                        softdep_setup_allocdirect(ip,
                            UFS_NDADDR + indirs[0].in_off, newb, 0,
                            fs->fs_bsize, 0, bp);
                        bdwrite(bp);
                } else if ((flags & IO_SYNC) == 0 && DOINGASYNC(vp)) {
                        if (bp->b_bufsize == fs->fs_bsize)
                                bp->b_flags |= B_CLUSTEROK;
                        bdwrite(bp);
                } else {
                        if ((error = bwrite(bp)) != 0)
                                goto fail;
                }
                allocib = &dp->di_ib[indirs[0].in_off];
                *allocib = nb;
                UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE | IN_IBLKDATA);
        }
        /*
         * Fetch through the indirect blocks, allocating as necessary.
         */
retry:
        for (i = 1;;) {
                error = bread_gb(vp, indirs[i].in_lbn, (int)fs->fs_bsize,
                    NOCRED, gbwflag, &bp);
                if (error) {
                        goto fail;
                }
                bap = (ufs2_daddr_t *)bp->b_data;
                nb = bap[indirs[i].in_off];
                if ((error = UFS_CHECK_BLKNO(mp, ip->i_number, nb,
                    fs->fs_bsize)) != 0) {
                        brelse(bp);
                        goto fail;
                }
                if (i == num)
                        break;
                i += 1;
                if (nb != 0) {
                        bqrelse(bp);
                        continue;
                }
                UFS_LOCK(ump);
                /*
                 * If parent indirect has just been allocated, try to cluster
                 * immediately following it.
                 */
                if (pref == 0)
                        pref = ffs_blkpref_ufs2(ip, lbn, i - num - 1,
                            (ufs2_daddr_t *)0);
                if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
                    flags | IO_BUFLOCKED, cred, &newb)) != 0) {
                        brelse(bp);
                        UFS_LOCK(ump);
                        if (DOINGSOFTDEP(vp) && ++reclaimed == 1) {
                                softdep_request_cleanup(fs, vp, cred,
                                    FLUSH_BLOCKS_WAIT);
                                UFS_UNLOCK(ump);
                                goto retry;
                        }
                        if (!ffs_fsfail_cleanup_locked(ump, error) &&
                            ppsratecheck(&ump->um_last_fullmsg,
                            &ump->um_secs_fullmsg, 1)) {
                                UFS_UNLOCK(ump);
                                ffs_fserr(fs, ip->i_number, "filesystem full");
                                uprintf("\n%s: write failed, filesystem "
                                    "is full\n", fs->fs_fsmnt);
                        } else {
                                UFS_UNLOCK(ump);
                        }
                        goto fail;
                }
                pref = newb + fs->fs_frag;
                nb = newb;
                MPASS(allocblk < allociblk + nitems(allociblk));
                MPASS(lbns_remfree < lbns + nitems(lbns));
                *allocblk++ = nb;
                *lbns_remfree++ = indirs[i].in_lbn;
                nbp = getblk(vp, indirs[i].in_lbn, fs->fs_bsize, 0, 0,
                    GB_UNMAPPED);
                nbp->b_blkno = fsbtodb(fs, nb);
                vfs_bio_clrbuf(nbp);
                if (DOINGSOFTDEP(vp)) {
                        softdep_setup_allocindir_meta(nbp, ip, bp,
                            indirs[i - 1].in_off, nb);
                        bdwrite(nbp);
                } else if ((flags & IO_SYNC) == 0 && DOINGASYNC(vp)) {
                        if (nbp->b_bufsize == fs->fs_bsize)
                                nbp->b_flags |= B_CLUSTEROK;
                        bdwrite(nbp);
                } else {
                        if ((error = bwrite(nbp)) != 0) {
                                brelse(bp);
                                goto fail;
                        }
                }
                bap[indirs[i - 1].in_off] = nb;
                if (allocib == NULL && unwindidx < 0)
                        unwindidx = i - 1;
                /*
                 * If required, write synchronously, otherwise use
                 * delayed write.
                 */
                if (flags & IO_SYNC) {
                        bwrite(bp);
                } else {
                        if (bp->b_bufsize == fs->fs_bsize)
                                bp->b_flags |= B_CLUSTEROK;
                        bdwrite(bp);
                }
        }
        /*
         * If asked only for the indirect block, then return it.
         */
        if (flags & BA_METAONLY) {
                curthread_pflags_restore(saved_inbdflush);
                *bpp = bp;
                error = 0;
                goto done;
        }
        /*
         * Get the data block, allocating if necessary.
         */
        if (nb == 0) {
                UFS_LOCK(ump);
                /*
                 * If allocating metadata at the front of the cylinder
                 * group and parent indirect block has just been allocated,
                 * then cluster next to it if it is the first indirect in
                 * the file. Otherwise it has been allocated in the metadata
                 * area, so we want to find our own place out in the data area.
                 */
                if (pref == 0 || (lbn > UFS_NDADDR && fs->fs_metaspace != 0))
                        pref = ffs_blkpref_ufs2(ip, lbn, indirs[i].in_off,
                            &bap[0]);
                error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
                    flags | IO_BUFLOCKED, cred, &newb);
                if (error) {
                        brelse(bp);
                        UFS_LOCK(ump);
                        if (DOINGSOFTDEP(vp) && ++reclaimed == 1) {
                                softdep_request_cleanup(fs, vp, cred,
                                    FLUSH_BLOCKS_WAIT);
                                UFS_UNLOCK(ump);
                                goto retry;
                        }
                        if (!ffs_fsfail_cleanup_locked(ump, error) &&
                            ppsratecheck(&ump->um_last_fullmsg,
                            &ump->um_secs_fullmsg, 1)) {
                                UFS_UNLOCK(ump);
                                ffs_fserr(fs, ip->i_number, "filesystem full");
                                uprintf("\n%s: write failed, filesystem "
                                    "is full\n", fs->fs_fsmnt);
                        } else {
                                UFS_UNLOCK(ump);
                        }
                        goto fail;
                }
                nb = newb;
                MPASS(allocblk < allociblk + nitems(allociblk));
                MPASS(lbns_remfree < lbns + nitems(lbns));
                *allocblk++ = nb;
                *lbns_remfree++ = lbn;
                nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0, gbflags);
                nbp->b_blkno = fsbtodb(fs, nb);
                if (flags & BA_CLRBUF)
                        vfs_bio_clrbuf(nbp);
                if (DOINGSOFTDEP(vp))
                        softdep_setup_allocindir_page(ip, lbn, bp,
                            indirs[i].in_off, nb, 0, nbp);
                bap[indirs[i].in_off] = nb;
                /*
                 * If required, write synchronously, otherwise use
                 * delayed write.
                 */
                if (flags & IO_SYNC) {
                        bwrite(bp);
                } else {
                        if (bp->b_bufsize == fs->fs_bsize)
                                bp->b_flags |= B_CLUSTEROK;
                        bdwrite(bp);
                }
                curthread_pflags_restore(saved_inbdflush);
                *bpp = nbp;
                error = 0;
                goto done;
        }
        brelse(bp);
        /*
         * If requested clear invalid portions of the buffer.  If we
         * have to do a read-before-write (typical if BA_CLRBUF is set),
         * try to do some read-ahead in the sequential case to reduce
         * the number of I/O transactions.
         */
        if (flags & BA_CLRBUF) {
                int seqcount = (flags & BA_SEQMASK) >> BA_SEQSHIFT;
                if (seqcount != 0 &&
                    (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0 &&
                    !(vm_page_count_severe() || buf_dirty_count_severe())) {
                        error = cluster_read(vp, ip->i_size, lbn,
                            (int)fs->fs_bsize, NOCRED,
                            MAXBSIZE, seqcount, gbflags, &nbp);
                } else {
                        error = bread_gb(vp, lbn, (int)fs->fs_bsize,
                            NOCRED, gbflags, &nbp);
                }
                if (error) {
                        brelse(nbp);
                        goto fail;
                }
        } else {
                nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0, gbflags);
                nbp->b_blkno = fsbtodb(fs, nb);
        }
        curthread_pflags_restore(saved_inbdflush);
        *bpp = nbp;
        error = 0;
        goto done;
fail:
        curthread_pflags_restore(saved_inbdflush);
        /*
         * If we have failed to allocate any blocks, simply return the error.
         * This is the usual case and avoids the need to fsync the file.
         */
        if (allocblk == allociblk && allocib == NULL && unwindidx == -1)
                goto done;
        /*
         * If we have failed part way through block allocation, we
         * have to deallocate any indirect blocks that we have allocated.
         * We have to fsync the file before we start to get rid of all
         * of its dependencies so that we do not leave them dangling.
         * We have to sync it at the end so that the soft updates code
         * does not find any untracked changes. Although this is really
         * slow, running out of disk space is not expected to be a common
         * occurrence. The error return from fsync is ignored as we already
         * have an error to return to the user.
         *
         * XXX Still have to journal the free below
         */
        (void) ffs_syncvnode(vp, MNT_WAIT, 0);
        for (deallocated = 0, blkp = allociblk, lbns_remfree = lbns;
             blkp < allocblk; blkp++, lbns_remfree++) {
                /*
                 * We shall not leave the freed blocks on the vnode
                 * buffer object lists.
                 */
                bp = getblk(vp, *lbns_remfree, fs->fs_bsize, 0, 0,
                    GB_NOCREAT | GB_UNMAPPED | gbwflag);
                if (bp != NULL) {
                        KASSERT(bp->b_blkno == fsbtodb(fs, *blkp),
                            ("mismatch2 l %jd %jd b %ju %ju",
                            (intmax_t)bp->b_lblkno, (uintmax_t)*lbns_remfree,
                            (uintmax_t)bp->b_blkno,
                            (uintmax_t)fsbtodb(fs, *blkp)));
                        bp->b_flags |= B_INVAL | B_RELBUF | B_NOCACHE;
                        bp->b_flags &= ~(B_ASYNC | B_CACHE);
                        brelse(bp);
                }
                deallocated += fs->fs_bsize;
        }
        if (allocib != NULL) {
                *allocib = 0;
        } else if (unwindidx >= 0) {
                int r;

                r = bread_gb(vp, indirs[unwindidx].in_lbn,
                    (int)fs->fs_bsize, NOCRED, gbwflag, &bp);
                if (r) {
                        panic("Could not unwind indirect block, error %d", r);
                        brelse(bp);
                } else {
                        bap = (ufs2_daddr_t *)bp->b_data;
                        bap[indirs[unwindidx].in_off] = 0;
                        if (flags & IO_SYNC) {
                                bwrite(bp);
                        } else {
                                if (bp->b_bufsize == fs->fs_bsize)
                                        bp->b_flags |= B_CLUSTEROK;
                                bdwrite(bp);
                        }
                }
        }
        if (deallocated) {
#ifdef QUOTA
                /*
                 * Restore user's disk quota because allocation failed.
                 */
                (void) chkdq(ip, -btodb(deallocated), cred, FORCE);
#endif
                dp->di_blocks -= btodb(deallocated);
                UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE);
        }
        (void) ffs_syncvnode(vp, MNT_WAIT, 0);
        /*
         * After the buffers are invalidated and on-disk pointers are
         * cleared, free the blocks.
         */
        for (blkp = allociblk; blkp < allocblk; blkp++) {
#ifdef INVARIANTS
                if (blkp == allociblk)
                        lbns_remfree = lbns;
                bp = getblk(vp, *lbns_remfree, fs->fs_bsize, 0, 0,
                    GB_NOCREAT | GB_UNMAPPED | gbwflag);
                if (bp != NULL) {
                        panic("zombie2 %jd %ju %ju",
                            (intmax_t)bp->b_lblkno, (uintmax_t)bp->b_blkno,
                            (uintmax_t)fsbtodb(fs, *blkp));
                }
                lbns_remfree++;
#endif
                ffs_blkfree(ump, fs, ump->um_devvp, *blkp, fs->fs_bsize,
                    ip->i_number, vp->v_type, NULL, SINGLETON_KEY);
        }
done:
        vn_seqc_write_end(vp);
        return (error);
}