/*      $OpenBSD: ffs_vnops.c,v 1.103 2025/03/27 23:30:54 tedu Exp $    */
/*      $NetBSD: ffs_vnops.c,v 1.7 1996/05/11 18:27:24 mycroft Exp $    */

/*
 * 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_vnops.c 8.10 (Berkeley) 8/10/94
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/resourcevar.h>
#include <sys/kernel.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/signalvar.h>
#include <sys/pool.h>
#include <sys/event.h>
#include <sys/specdev.h>

#include <miscfs/fifofs/fifo.h>

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

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

const struct vops ffs_vops = {
        .vop_lookup     = ufs_lookup,
        .vop_create     = ufs_create,
        .vop_mknod      = ufs_mknod,
        .vop_open       = ufs_open,
        .vop_close      = ufs_close,
        .vop_access     = ufs_access,
        .vop_getattr    = ufs_getattr,
        .vop_setattr    = ufs_setattr,
        .vop_read       = ffs_read,
        .vop_write      = ffs_write,
        .vop_ioctl      = ufs_ioctl,
        .vop_kqfilter   = ufs_kqfilter,
        .vop_revoke     = vop_generic_revoke,
        .vop_fsync      = ffs_fsync,
        .vop_remove     = ufs_remove,
        .vop_link       = ufs_link,
        .vop_rename     = ufs_rename,
        .vop_mkdir      = ufs_mkdir,
        .vop_rmdir      = ufs_rmdir,
        .vop_symlink    = ufs_symlink,
        .vop_readdir    = ufs_readdir,
        .vop_readlink   = ufs_readlink,
        .vop_abortop    = vop_generic_abortop,
        .vop_inactive   = ufs_inactive,
        .vop_reclaim    = ffs_reclaim,
        .vop_lock       = ufs_lock,
        .vop_unlock     = ufs_unlock,
        .vop_bmap       = ufs_bmap,
        .vop_strategy   = ufs_strategy,
        .vop_print      = ufs_print,
        .vop_islocked   = ufs_islocked,
        .vop_pathconf   = ufs_pathconf,
        .vop_advlock    = ufs_advlock,
        .vop_bwrite     = vop_generic_bwrite
};

const struct vops ffs_specvops = {
        .vop_close      = ufsspec_close,
        .vop_access     = ufs_access,
        .vop_getattr    = ufs_getattr,
        .vop_setattr    = ufs_setattr,
        .vop_read       = ufsspec_read,
        .vop_write      = ufsspec_write,
        .vop_fsync      = ffs_fsync,
        .vop_inactive   = ufs_inactive,
        .vop_reclaim    = ffs_reclaim,
        .vop_lock       = ufs_lock,
        .vop_unlock     = ufs_unlock,
        .vop_print      = ufs_print,
        .vop_islocked   = ufs_islocked,

        /* XXX: Keep in sync with spec_vops */
        .vop_lookup     = vop_generic_lookup,
        .vop_create     = vop_generic_badop,
        .vop_mknod      = vop_generic_badop,
        .vop_open       = spec_open,
        .vop_ioctl      = spec_ioctl,
        .vop_kqfilter   = spec_kqfilter,
        .vop_revoke     = vop_generic_revoke,
        .vop_remove     = vop_generic_badop,
        .vop_link       = vop_generic_badop,
        .vop_rename     = vop_generic_badop,
        .vop_mkdir      = vop_generic_badop,
        .vop_rmdir      = vop_generic_badop,
        .vop_symlink    = vop_generic_badop,
        .vop_readdir    = vop_generic_badop,
        .vop_readlink   = vop_generic_badop,
        .vop_abortop    = vop_generic_badop,
        .vop_bmap       = vop_generic_bmap,
        .vop_strategy   = spec_strategy,
        .vop_pathconf   = spec_pathconf,
        .vop_advlock    = spec_advlock,
        .vop_bwrite     = vop_generic_bwrite,
};

#ifdef FIFO
const struct vops ffs_fifovops = {
        .vop_close      = ufsfifo_close,
        .vop_access     = ufs_access,
        .vop_getattr    = ufs_getattr,
        .vop_setattr    = ufs_setattr,
        .vop_read       = ufsfifo_read,
        .vop_write      = ufsfifo_write,
        .vop_fsync      = ffs_fsync,
        .vop_inactive   = ufs_inactive,
        .vop_reclaim    = ffsfifo_reclaim,
        .vop_lock       = ufs_lock,
        .vop_unlock     = ufs_unlock,
        .vop_print      = ufs_print,
        .vop_islocked   = ufs_islocked,
        .vop_bwrite     = vop_generic_bwrite,

        /* XXX: Keep in sync with fifo_vops */
        .vop_lookup     = vop_generic_lookup,
        .vop_create     = vop_generic_badop,
        .vop_mknod      = vop_generic_badop,
        .vop_open       = fifo_open,
        .vop_ioctl      = fifo_ioctl,
        .vop_kqfilter   = fifo_kqfilter,
        .vop_revoke     = vop_generic_revoke,
        .vop_remove     = vop_generic_badop,
        .vop_link       = vop_generic_badop,
        .vop_rename     = vop_generic_badop,
        .vop_mkdir      = vop_generic_badop,
        .vop_rmdir      = vop_generic_badop,
        .vop_symlink    = vop_generic_badop,
        .vop_readdir    = vop_generic_badop,
        .vop_readlink   = vop_generic_badop,
        .vop_abortop    = vop_generic_badop,
        .vop_bmap       = vop_generic_bmap,
        .vop_strategy   = vop_generic_badop,
        .vop_pathconf   = fifo_pathconf,
        .vop_advlock    = fifo_advlock
};
#endif /* FIFO */

/*
 * Vnode op for reading.
 */
int
ffs_read(void *v)
{
        struct vop_read_args *ap = v;
        struct vnode *vp;
        struct inode *ip;
        struct uio *uio;
        struct fs *fs;
        struct buf *bp;
        daddr_t lbn, nextlbn;
        off_t bytesinfile;
        int size, xfersize, blkoffset;
        mode_t mode;
        int error;

        vp = ap->a_vp;
        ip = VTOI(vp);
        mode = DIP(ip, mode);
        uio = ap->a_uio;

#ifdef DIAGNOSTIC
        if (uio->uio_rw != UIO_READ)
                panic("ffs_read: mode");

        if (vp->v_type == VLNK) {
                if (DIP(ip, size) < ip->i_ump->um_maxsymlinklen)
                        panic("ffs_read: short symlink");
        } else if (vp->v_type != VREG && vp->v_type != VDIR)
                panic("ffs_read: type %d", vp->v_type);
#endif
        fs = ip->i_fs;
        if (uio->uio_offset < 0)
                return (EINVAL);
        if (uio->uio_resid == 0)
                return (0);

        for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
                if ((bytesinfile = DIP(ip, size) - uio->uio_offset) <= 0)
                        break;
                lbn = lblkno(fs, uio->uio_offset);
                nextlbn = lbn + 1;
                size = fs->fs_bsize;    /* WAS blksize(fs, ip, lbn); */
                blkoffset = blkoff(fs, uio->uio_offset);
                xfersize = fs->fs_bsize - blkoffset;
                if (uio->uio_resid < xfersize)
                        xfersize = uio->uio_resid;
                if (bytesinfile < xfersize)
                        xfersize = bytesinfile;

                if (lblktosize(fs, nextlbn) >= DIP(ip, size))
                        error = bread(vp, lbn, size, &bp);
                else if (lbn - 1 == ip->i_ci.ci_lastr ||
                    uio->uio_resid > xfersize) {
                        error = bread_cluster(vp, lbn, size, &bp);
                } else
                        error = bread(vp, lbn, size, &bp);

                if (error)
                        break;
                ip->i_ci.ci_lastr = lbn;

                /*
                 * We should only get non-zero b_resid when an I/O error
                 * has occurred, which should cause us to break above.
                 * However, if the short read did not cause an error,
                 * then we want to ensure that we do not uiomove bad
                 * or uninitialized data.
                 */
                size -= bp->b_resid;
                if (size < xfersize) {
                        if (size == 0)
                                break;
                        xfersize = size;
                }
                error = uiomove(bp->b_data + blkoffset, xfersize, uio);
                if (error)
                        break;
                brelse(bp);
        }
        if (bp != NULL)
                brelse(bp);
        if (!(vp->v_mount->mnt_flag & MNT_NOATIME) ||
            (ip->i_flag & (IN_CHANGE | IN_UPDATE))) {
                ip->i_flag |= IN_ACCESS;
        }
        return (error);
}

/*
 * Vnode op for writing.
 */
int
ffs_write(void *v)
{
        struct vop_write_args *ap = v;
        struct vnode *vp;
        struct uio *uio;
        struct inode *ip;
        struct fs *fs;
        struct buf *bp;
        daddr_t lbn;
        off_t osize;
        int blkoffset, error, extended, flags, ioflag, size, xfersize;
        size_t resid;
        ssize_t overrun;

        extended = 0;
        ioflag = ap->a_ioflag;
        uio = ap->a_uio;
        vp = ap->a_vp;
        ip = VTOI(vp);

#ifdef DIAGNOSTIC
        if (uio->uio_rw != UIO_WRITE)
                panic("ffs_write: mode");
#endif

        /*
         * If writing 0 bytes, succeed and do not change
         * update time or file offset (standards compliance)
         */
        if (uio->uio_resid == 0)
                return (0);

        switch (vp->v_type) {
        case VREG:
                if (ioflag & IO_APPEND)
                        uio->uio_offset = DIP(ip, size);
                if ((DIP(ip, flags) & APPEND) && uio->uio_offset != DIP(ip, size))
                        return (EPERM);
                /* FALLTHROUGH */
        case VLNK:
                break;
        case VDIR:
                if ((ioflag & IO_SYNC) == 0)
                        panic("ffs_write: nonsync dir write");
                break;
        default:
                panic("ffs_write: type %d", vp->v_type);
        }

        fs = ip->i_fs;
        if (uio->uio_offset < 0 ||
            (u_int64_t)uio->uio_offset + uio->uio_resid > fs->fs_maxfilesize)
                return (EFBIG);

        /* do the filesize rlimit check */
        if ((error = vn_fsizechk(vp, uio, ioflag, &overrun)))
                return (error);

        resid = uio->uio_resid;
        osize = DIP(ip, size);
        flags = ioflag & IO_SYNC ? B_SYNC : 0;

        for (error = 0; uio->uio_resid > 0;) {
                lbn = lblkno(fs, uio->uio_offset);
                blkoffset = blkoff(fs, uio->uio_offset);
                xfersize = fs->fs_bsize - blkoffset;
                if (uio->uio_resid < xfersize)
                        xfersize = uio->uio_resid;
                if (fs->fs_bsize > xfersize)
                        flags |= B_CLRBUF;
                else
                        flags &= ~B_CLRBUF;

                if ((error = UFS_BUF_ALLOC(ip, uio->uio_offset, xfersize,
                         ap->a_cred, flags, &bp)) != 0)
                        break;
                if (uio->uio_offset + xfersize > DIP(ip, size)) {
                        DIP_ASSIGN(ip, size, uio->uio_offset + xfersize);
                        uvm_vnp_setsize(vp, DIP(ip, size));
                        extended = 1;
                }
                (void)uvm_vnp_uncache(vp);

                size = blksize(fs, ip, lbn) - bp->b_resid;
                if (size < xfersize)
                        xfersize = size;

                error = uiomove(bp->b_data + blkoffset, xfersize, uio);
                /*
                 * If the buffer is not already filled and we encounter an
                 * error while trying to fill it, we have to clear out any
                 * garbage data from the pages instantiated for the buffer.
                 * If we do not, a failed uiomove() during a write can leave
                 * the prior contents of the pages exposed to a userland mmap.
                 *
                 * Note that we don't need to clear buffers that were
                 * allocated with the B_CLRBUF flag set.
                 */
                if (error != 0 && !(flags & B_CLRBUF))
                        memset(bp->b_data + blkoffset, 0, xfersize);

                if (ioflag & IO_NOCACHE)
                        bp->b_flags |= B_NOCACHE;

                if (ioflag & IO_SYNC)
                        (void)bwrite(bp);
                else if (xfersize + blkoffset == fs->fs_bsize) {
                        bawrite(bp);
                } else
                        bdwrite(bp);

                if (error || xfersize == 0)
                        break;
                ip->i_flag |= IN_CHANGE | IN_UPDATE;
        }
        /*
         * If we successfully wrote any data, and we are not the superuser
         * we clear the setuid and setgid bits as a precaution against
         * tampering.
         */
        if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0 &&
            !vnoperm(vp))
                DIP_ASSIGN(ip, mode, DIP(ip, mode) & ~(ISUID | ISGID));
        if (resid > uio->uio_resid)
                VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0));
        if (error) {
                if (ioflag & IO_UNIT) {
                        (void)UFS_TRUNCATE(ip, osize,
                            ioflag & IO_SYNC, ap->a_cred);
                        uio->uio_offset -= resid - uio->uio_resid;
                        uio->uio_resid = resid;
                }
        } else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) {
                error = UFS_UPDATE(ip, 1);
        }
        /* correct the result for writes clamped by vn_fsizechk() */
        uio->uio_resid += overrun;
        return (error);
}

/*
 * Synch an open file.
 */
int
ffs_fsync(void *v)
{
        struct vop_fsync_args *ap = v;
        struct vnode *vp = ap->a_vp;
        struct buf *bp, *nbp;
        int s, error, passes, skipmeta;

        /*
         * Flush all dirty buffers associated with a vnode.
         */
        passes = NIADDR + 1;
        skipmeta = 0;
        if (ap->a_waitfor == MNT_WAIT)
                skipmeta = 1;
        s = splbio();
loop:
        LIST_FOREACH(bp, &vp->v_dirtyblkhd, b_vnbufs) {
                bp->b_flags &= ~B_SCANNED;
        }
        LIST_FOREACH_SAFE(bp, &vp->v_dirtyblkhd, b_vnbufs, nbp) {
                /* 
                 * Reasons to skip this buffer: it has already been considered
                 * on this pass, this pass is the first time through on a
                 * synchronous flush request and the buffer being considered
                 * is metadata, the buffer has dependencies that will cause
                 * it to be redirtied and it has not already been deferred,
                 * or it is already being written.
                 */
                if (bp->b_flags & (B_BUSY | B_SCANNED))
                        continue;
                if ((bp->b_flags & B_DELWRI) == 0)
                        panic("ffs_fsync: not dirty");
                if (skipmeta && bp->b_lblkno < 0)
                        continue;

                bufcache_take(bp);
                buf_acquire(bp);
                bp->b_flags |= B_SCANNED;
                splx(s);
                /*
                 * On our final pass through, do all I/O synchronously
                 * so that we can find out if our flush is failing
                 * because of write errors.
                 */
                if (passes > 0 || ap->a_waitfor != MNT_WAIT)
                        (void) bawrite(bp);
                else if ((error = bwrite(bp)) != 0)
                        return (error);
                s = splbio();
                /*
                 * Since we may have slept during the I/O, we need
                 * to start from a known point.
                 */
                nbp = LIST_FIRST(&vp->v_dirtyblkhd);
        }
        if (skipmeta) {
                skipmeta = 0;
                goto loop;
        }
        if (ap->a_waitfor == MNT_WAIT) {
                vwaitforio(vp, 0, "ffs_fsync", INFSLP);

                /*
                 * Ensure that any filesystem metadata associated
                 * with the vnode has been written.
                 */
                splx(s);
                /* XXX softdep was here. reconsider this locking dance */
                s = splbio();
                if (!LIST_EMPTY(&vp->v_dirtyblkhd)) {
                        /*
                         * Block devices associated with filesystems may
                         * have new I/O requests posted for them even if
                         * the vnode is locked, so no amount of trying will
                         * get them clean. Thus we give block devices a
                         * good effort, then just give up. For all other file
                         * types, go around and try again until it is clean.
                         */
                        if (passes > 0) {
                                passes -= 1;
                                goto loop;
                        }
#ifdef DIAGNOSTIC
                        if (vp->v_type != VBLK)
                                vprint("ffs_fsync: dirty", vp);
#endif
                }
        }
        splx(s);
        return (UFS_UPDATE(VTOI(vp), ap->a_waitfor == MNT_WAIT));
}

/*
 * Reclaim an inode so that it can be used for other purposes.
 */
int
ffs_reclaim(void *v)
{
        struct vop_reclaim_args *ap = v;
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        int error;

        if ((error = ufs_reclaim(vp)) != 0)
                return (error);

        if (ip->i_din1 != NULL) {
#ifdef FFS2
                if (ip->i_ump->um_fstype == UM_UFS2)
                        pool_put(&ffs_dinode2_pool, ip->i_din2);
                else
#endif
                        pool_put(&ffs_dinode1_pool, ip->i_din1);
        }

        pool_put(&ffs_ino_pool, ip);

        vp->v_data = NULL;

        return (0);
}

#ifdef FIFO
int
ffsfifo_reclaim(void *v)
{
        fifo_reclaim(v);
        return (ffs_reclaim(v));
}
#endif