xnu-1228.tar.gz

[apple/xnu.git] / bsd / ufs / ufs / ufs_readwrite.c

/*
 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*-
 * Copyright (c) 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)ufs_readwrite.c     8.11 (Berkeley) 5/8/95
 */

#include <sys/buf_internal.h>
#include <sys/uio_internal.h>


#define BLKSIZE(a, b, c)        blksize(a, b, c)
#define FS                      struct fs
#define I_FS                    i_fs



/*
 * Vnode op for reading.
 */
/* ARGSUSED */
ffs_read(ap)
        struct vnop_read_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int a_ioflag;
                vfs_context_t a_context;
        } */ *ap;
{
        return(ffs_read_internal(ap->a_vp, ap->a_uio, ap->a_ioflag));
}


int
ffs_read_internal(vnode_t vp, struct uio *uio, int ioflag)
{
        struct  inode *ip;
        FS      *fs;
        buf_t   bp = (struct buf *)0;
        ufs_daddr_t lbn, nextlbn;
        off_t bytesinfile;
        long size, xfersize, blkoffset;
        int error;
        u_short mode;
#if REV_ENDIAN_FS
        int rev_endian=0;
#endif /* REV_ENDIAN_FS */

        ip = VTOI(vp);
        mode = ip->i_mode;

#if REV_ENDIAN_FS
        rev_endian=(vp->v_mount->mnt_flag & MNT_REVEND);
#endif /* REV_ENDIAN_FS */

#if DIAGNOSTIC
        if (uio->uio_rw != UIO_READ)
                panic("ffs_read: invalid uio_rw = %x", uio->uio_rw);

        if (vp->v_type == VLNK) {
                if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
                        panic("ffs_read: short symlink = %d", ip->i_size);
        } else if (vp->v_type != VREG && vp->v_type != VDIR)
                panic("ffs_read: invalid v_type = %x", vp->v_type);
#endif
        fs = ip->I_FS;
        if (uio->uio_offset < 0)
                return (EINVAL);
        if (uio->uio_offset > fs->fs_maxfilesize)
                return (EFBIG);

        if (UBCINFOEXISTS(vp)) {
                error = cluster_read(vp, uio, (off_t)ip->i_size, ioflag);
        } else {
        for (error = 0, bp = NULL; uio_resid(uio) > 0; 
            bp = NULL) {
                char *buf_data;

                if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
                        break;
                lbn = lblkno(fs, uio->uio_offset);
                nextlbn = lbn + 1;
                size = BLKSIZE(fs, ip, lbn);
                blkoffset = blkoff(fs, uio->uio_offset);
                xfersize = fs->fs_bsize - blkoffset;
                // LP64todo - fix this
                if (uio_resid(uio) < xfersize)
                        xfersize = uio_resid(uio);
                if (bytesinfile < xfersize)
                        xfersize = bytesinfile;

                if (lblktosize(fs, nextlbn) >= ip->i_size)
                        error = (int)buf_bread(vp, (daddr64_t)((unsigned)lbn), size, NOCRED, &bp);
                else if (lbn - 1 == ip->i_lastr && !(vp->v_flag & VRAOFF)) {
                        int nextsize = BLKSIZE(fs, ip, nextlbn);
                        error = (int)buf_breadn(vp, (daddr64_t)((unsigned)lbn),
                                                size, &nextlbn, &nextsize, 1, NOCRED, &bp);
                } else
                        error = (int)buf_bread(vp, lbn, size, NOCRED, &bp);
                if (error)
                        break;
                ip->i_lastr = lbn;

                /*
                 * We should only get non-zero buffer 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 -= buf_resid(bp);
                if (size < xfersize) {
                        if (size == 0)
                                break;
                        xfersize = size;
                }
                buf_data = (char *)buf_dataptr(bp);
#if REV_ENDIAN_FS
                if (rev_endian && S_ISDIR(mode)) {
                        byte_swap_dir_block_in(buf_data + blkoffset, xfersize);
                }
#endif /* REV_ENDIAN_FS */
                if (error =
                    uiomove(buf_data + blkoffset, (int)xfersize, uio)) {
#if REV_ENDIAN_FS
                        if (rev_endian && S_ISDIR(mode)) {
                        byte_swap_dir_block_in(buf_data + blkoffset, xfersize);
                        }
#endif /* REV_ENDIAN_FS */
                        break;
        }

#if REV_ENDIAN_FS
                if (rev_endian && S_ISDIR(mode)) {
                        byte_swap_dir_out(buf_data + blkoffset, xfersize);
                }
#endif /* REV_ENDIAN_FS */
                if (S_ISREG(mode) && (xfersize + blkoffset == fs->fs_bsize ||
                    uio->uio_offset == ip->i_size))
                        buf_markaged(bp);
                buf_brelse(bp);
        }
        }
        if (bp != NULL)
                buf_brelse(bp);
        if ((vnode_vfsvisflags(vp) & MNT_NOATIME) == 0)
                ip->i_flag |= IN_ACCESS;
        return (error);
}

/*
 * Vnode op for writing.
 */
ffs_write(ap)
        struct vnop_write_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int a_ioflag;
                vfs_context_t a_context;
        } */ *ap;
{
        return(ffs_write_internal(ap->a_vp, ap->a_uio, ap->a_ioflag, vfs_context_ucred(ap->a_context)));
}


ffs_write_internal(vnode_t vp, struct uio *uio, int ioflag, kauth_cred_t cred)
{
        buf_t   bp;
        proc_t  p;
        struct  inode *ip;
        FS      *fs;
        ufs_daddr_t lbn;
        off_t osize;
        int blkoffset, flags, resid, rsd,  size, xfersize;
        int save_error=0, save_size=0;
        int blkalloc = 0;
        int error = 0;
        int file_extended = 0;
        int doingdirectory = 0;
        user_ssize_t clippedsize = 0;   /* Truncate writes near fs->fs_maxfilesize */
        user_ssize_t residcount, oldcount;
        int partialwrite=0;

#if REV_ENDIAN_FS
        int rev_endian=0;
#endif /* REV_ENDIAN_FS */

        ip = VTOI(vp);
#if REV_ENDIAN_FS
        rev_endian=(vp->v_mount->mnt_flag & MNT_REVEND);
#endif /* REV_ENDIAN_FS */

#if DIAGNOSTIC
        if (uio->uio_rw != UIO_WRITE)
                panic("ffs_write: uio_rw = %x\n", uio->uio_rw);
#endif

        switch (vp->v_type) {
        case VREG:
                if (ioflag & IO_APPEND)
                        uio->uio_offset = ip->i_size;
                if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
                        return (EPERM);
                /* FALLTHROUGH */
        case VLNK:
                break;
        case VDIR:
                doingdirectory = 1;
                if ((ioflag & IO_SYNC) == 0)
                        panic("ffs_write: nonsync dir write");
                break;
        default:
                panic("ffs_write: invalid v_type=%x", vp->v_type);
        }

        fs = ip->I_FS;
        if (uio->uio_offset < 0)
                return (EFBIG);
        if ( uio_resid(uio) > fs->fs_maxfilesize - uio->uio_offset ) {
                residcount = uio_resid(uio);
                clippedsize = residcount - (fs->fs_maxfilesize - uio->uio_offset);
                if (clippedsize >= residcount) {
                return (EFBIG);
                } else {
                        uio_setresid(uio, residcount - clippedsize);
                        partialwrite = 1;
                }
        }
        if (uio_resid(uio) == 0)
                return (0);

        // LP64todo - fix this
        resid = uio_resid(uio);
        osize = ip->i_size;
        flags = 0;
        if ((ioflag & IO_SYNC) && !((vp)->v_mount->mnt_flag & MNT_ASYNC))
                flags = B_SYNC;

    if (UBCINFOEXISTS(vp)) {
        off_t filesize;
        off_t endofwrite;
        off_t local_offset;
        off_t head_offset;
        int local_flags;
        int first_block;
        int fboff;
        int fblk;
        int loopcount;

        // LP64todo - fix this
        endofwrite = uio->uio_offset + uio_resid(uio);

        if (endofwrite > ip->i_size) {
                filesize = endofwrite;
                file_extended = 1;
        } else 
                filesize = ip->i_size;

        head_offset = ip->i_size;

        /* Go ahead and allocate the block that are going to be written */
        // LP64todo - fix this
        rsd = uio_resid(uio);
        local_offset = uio->uio_offset;
        local_flags = 0;
        if ((ioflag & IO_SYNC) && !((vp)->v_mount->mnt_flag & MNT_ASYNC))
                local_flags = B_SYNC;
        local_flags |= B_NOBUFF;
        
        first_block = 1;
        fboff = 0;
        fblk = 0;
        loopcount = 0;

        for (error = 0; rsd > 0;) {
                blkalloc = 0;
                lbn = lblkno(fs, local_offset);
                blkoffset = blkoff(fs, local_offset);
                xfersize = fs->fs_bsize - blkoffset;
                if (first_block)
                        fboff = blkoffset;
                if (rsd < xfersize)
                        xfersize = rsd;
                if (fs->fs_bsize > xfersize)
                        local_flags |= B_CLRBUF;
                else
                        local_flags &= ~B_CLRBUF;

                /* Allocate block without reading into a buf */
                error = ffs_balloc(ip,
                        lbn, blkoffset + xfersize, cred, 
                        &bp, local_flags, &blkalloc);
                if (error)
                        break;
                if (first_block) {
                        fblk = blkalloc;
                        first_block = 0;
                }
                loopcount++;

                rsd -= xfersize;
                local_offset += (off_t)xfersize;
                if (local_offset > ip->i_size)
                        ip->i_size = local_offset;
        }

        if(error) {
                save_error = error;
                save_size = rsd;
                uio_setresid(uio, (uio_resid(uio) - rsd));
                if (file_extended)
                        filesize -= rsd;
        }

        flags = ioflag & ~(IO_TAILZEROFILL | IO_HEADZEROFILL | IO_NOZEROVALID | IO_NOZERODIRTY);

        if((error == 0) && fblk && fboff) {
                if( fblk > fs->fs_bsize) 
                        panic("ffs_balloc : allocated more than bsize(head)");
                /* We need to zero out the head */
                head_offset = uio->uio_offset - (off_t)fboff ;
                flags |= IO_HEADZEROFILL;
        }

        if((error == 0) && blkalloc && ((blkalloc - xfersize) > 0)) {
                /* We need to zero out the tail */
                if( blkalloc > fs->fs_bsize) 
                        panic("ffs_balloc : allocated more than bsize(tail)");
                local_offset += (blkalloc - xfersize);
                if (loopcount == 1) {
                /* blkalloc is same as fblk; so no need to check again*/
                        local_offset -= fboff;
                }
                flags |= IO_TAILZEROFILL;
                /*  Freshly allocated block; bzero even if 
                 * find a page 
                 */
                /* flags &= ~IO_NOZEROVALID; */
        }
          /*
           * if the write starts beyond the current EOF then
           * we we'll zero fill from the current EOF to where the write begins
           */

          error = cluster_write(vp, uio, osize, filesize, head_offset, local_offset, flags);
        
        if (uio->uio_offset > osize) {
                if (error && ((ioflag & IO_UNIT)==0))
                        (void)ffs_truncate_internal(vp, uio->uio_offset, ioflag & IO_SYNC, cred);
                ip->i_size = uio->uio_offset; 
                ubc_setsize(vp, (off_t)ip->i_size);
        }
         if(save_error) {
                uio_setresid(uio, (uio_resid(uio) + save_size));
                if(!error)
                        error = save_error;     
        }
         ip->i_flag |= IN_CHANGE | IN_UPDATE;
    } else {
        flags = 0;
        if ((ioflag & IO_SYNC) && !((vp)->v_mount->mnt_flag & MNT_ASYNC))
                flags = B_SYNC;

        for (error = 0; uio_resid(uio) > 0;) {
                char *buf_data;

                lbn = lblkno(fs, uio->uio_offset);
                blkoffset = blkoff(fs, uio->uio_offset);
                xfersize = fs->fs_bsize - blkoffset;
                if (uio_resid(uio) < xfersize)
                        // LP64todo - fix this
                        xfersize = uio_resid(uio);

                if (fs->fs_bsize > xfersize)
                        flags |= B_CLRBUF;
                else
                        flags &= ~B_CLRBUF;

                error = ffs_balloc(ip, lbn, blkoffset + xfersize, cred, &bp, flags, 0);
                if (error)
                        break;
                if (uio->uio_offset + xfersize > ip->i_size) {
                        ip->i_size = uio->uio_offset + xfersize;
                        ubc_setsize(vp, (u_long)ip->i_size);
                }

                size = BLKSIZE(fs, ip, lbn) - buf_resid(bp);
                if (size < xfersize)
                        xfersize = size;

                buf_data = (char *)buf_dataptr(bp);

                error = uiomove(buf_data + blkoffset, (int)xfersize, uio);
#if REV_ENDIAN_FS
                if (rev_endian && S_ISDIR(ip->i_mode)) {
                        byte_swap_dir_out(buf_data + blkoffset, xfersize);
                }
#endif /* REV_ENDIAN_FS */
                if (doingdirectory == 0 && (ioflag & IO_SYNC))
                        (void)buf_bwrite(bp);
                else if (xfersize + blkoffset == fs->fs_bsize) {
                        buf_markaged(bp);
                        buf_bdwrite(bp);
                }
                else
                        buf_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_resid(uio) && cred && suser(cred, NULL))
                ip->i_mode &= ~(ISUID | ISGID);
        if (resid > uio_resid(uio))
                VN_KNOTE(vp, NOTE_WRITE | (file_extended ? NOTE_EXTEND : 0));
        if (error) {
                if (ioflag & IO_UNIT) {
                        (void)ffs_truncate_internal(vp, osize, ioflag & IO_SYNC, cred);
                        // LP64todo - fix this
                        uio->uio_offset -= resid - uio_resid(uio);
                        uio_setresid(uio, resid);
                }
        } else if (resid > uio_resid(uio) && (ioflag & IO_SYNC)) {
                struct timeval tv;

                microtime(&tv);         
                error = ffs_update(vp, &tv, &tv, 1);
        }
        if (partialwrite) {
                oldcount = uio_resid(uio);
                uio_setresid(uio, oldcount + clippedsize);
        }
        return (error);
}

/*
 * Vnode op for pagein.
 * Similar to ffs_read()
 */
/* ARGSUSED */
ffs_pagein(ap)
        struct vnop_pagein_args /* {
                struct vnode *a_vp,
                upl_t   a_pl,
                vm_offset_t   a_pl_offset,
                off_t         a_f_offset,
                size_t        a_size,
                int           a_flags
                vfs_context_t a_context;
        } */ *ap;
{
        register struct vnode *vp = ap->a_vp;
        upl_t pl = ap->a_pl;
        size_t size= ap->a_size;
        off_t f_offset = ap->a_f_offset;
        vm_offset_t pl_offset = ap->a_pl_offset;
        int flags  = ap->a_flags;
        register struct inode *ip;
        int error;

        ip = VTOI(vp);

#if DIAGNOSTIC
        if (vp->v_type == VLNK) {
                if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
                        panic("%s: short symlink", "ffs_pagein");
        } else if (vp->v_type != VREG && vp->v_type != VDIR)
                panic("%s: type %d", "ffs_pagein", vp->v_type);
#endif

        error = cluster_pagein(vp, pl, pl_offset, f_offset, size, (off_t)ip->i_size, flags);

        /* ip->i_flag |= IN_ACCESS; */
        return (error);
}

/*
 * Vnode op for pageout.
 * Similar to ffs_write()
 * make sure the buf is not in hash queue when you return
 */
ffs_pageout(ap)
        struct vnop_pageout_args /* {
           struct vnode *a_vp,
           upl_t        a_pl,
           vm_offset_t   a_pl_offset,
           off_t         a_f_offset,
           size_t        a_size,
           int           a_flags
           vfs_context_t a_context;
        } */ *ap;
{
        register struct vnode *vp = ap->a_vp;
        upl_t pl = ap->a_pl;
        size_t size= ap->a_size;
        off_t f_offset = ap->a_f_offset;
        vm_offset_t pl_offset = ap->a_pl_offset;
        int flags  = ap->a_flags;
        register struct inode *ip;
        register FS *fs;
        int error ;
        size_t xfer_size = 0;
        int local_flags=0;
        off_t local_offset;
        int resid, blkoffset;
        size_t xsize, lsize;
        daddr_t lbn;
        int save_error =0, save_size=0;
        vm_offset_t lupl_offset;
        int nocommit = flags & UPL_NOCOMMIT;
        int devBlockSize = 0;
        struct buf *bp;

        ip = VTOI(vp);

        if (vp->v_mount->mnt_flag & MNT_RDONLY) {
                if (!nocommit)
                        ubc_upl_abort_range(pl, pl_offset, size, 
                                UPL_ABORT_FREE_ON_EMPTY);
                return (EROFS);
        }
        fs = ip->I_FS;

        if (f_offset < 0 || f_offset >= ip->i_size) {
                if (!nocommit)
                        ubc_upl_abort_range(pl, pl_offset, size, 
                                UPL_ABORT_FREE_ON_EMPTY);
                return (EINVAL);
        }

        /*
         * once we enable multi-page pageouts we will
         * need to make sure we abort any pages in the upl
         * that we don't issue an I/O for
         */
        if (f_offset + size > ip->i_size)
                xfer_size = ip->i_size - f_offset;
        else
                xfer_size = size;

        devBlockSize = vfs_devblocksize(vnode_mount(vp));

        if (xfer_size & (PAGE_SIZE - 1)) {
                /* if not a multiple of page size
                 * then round up to be a multiple
                 * the physical disk block size
                 */
                xfer_size = (xfer_size + (devBlockSize - 1)) & ~(devBlockSize - 1);
        }

        /*
         * once the block allocation is moved to ufs_blockmap
         * we can remove all the size and offset checks above
         * cluster_pageout does all of this now
         * we need to continue to do it here so as not to
         * allocate blocks that aren't going to be used because
         * of a bogus parameter being passed in
         */
        local_flags = 0;
        resid = xfer_size;
        local_offset = f_offset;
        for (error = 0; resid > 0;) {
                lbn = lblkno(fs, local_offset);
                blkoffset = blkoff(fs, local_offset);
                xsize = fs->fs_bsize - blkoffset;
                if (resid < xsize)
                        xsize = resid;
                /* Allocate block without reading into a buf */
                error = ffs_blkalloc(ip,
                        lbn, blkoffset + xsize, vfs_context_ucred(ap->a_context), 
                        local_flags);
                if (error)
                        break;
                resid -= xsize;
                local_offset += (off_t)xsize;
        }

        if (error) {
                save_size = resid;
                save_error = error;
                xfer_size -= save_size;
        }
        

        error = cluster_pageout(vp, pl, pl_offset, f_offset, round_page_32(xfer_size), ip->i_size, flags);

        if(save_error) {
                lupl_offset = size - save_size;
                resid = round_page_32(save_size);
                if (!nocommit)
                        ubc_upl_abort_range(pl, lupl_offset, resid,
                                UPL_ABORT_FREE_ON_EMPTY);
                if(!error)
                        error= save_error;
        }
        return (error);
}