cmd/xfs/bmap/Makefile 1.8 Renamed to cmd/xfsprogs/bmap/Makefile

[thirdparty/xfsprogs-dev.git] / libxfs / xfs_inode.c

/*
 * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
 * 
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 * 
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * 
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 * 
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
 * 
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 * 
 * http://www.sgi.com 
 * 
 * For further information regarding this notice, see: 
 * 
 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
 */

#include <xfs.h>

xfs_zone_t *xfs_ifork_zone;
xfs_zone_t *xfs_inode_zone;

#ifdef DEBUG
void
xfs_inobp_check(
        xfs_mount_t     *mp,
        xfs_buf_t       *bp)
{
        int             i;
        int             j;
        xfs_dinode_t    *dip;

        j = mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog;

        for (i = 0; i < j; i++) {
                dip = (xfs_dinode_t *)xfs_buf_offset(bp,
                                        i * mp->m_sb.sb_inodesize);
                if (INT_ISZERO(dip->di_next_unlinked, ARCH_CONVERT))  {
                        xfs_fs_cmn_err(CE_ALERT, mp,
                                "Detected a bogus zero next_unlinked field in incore inode buffer 0x%p.  About to pop an ASSERT.",
                                bp);
                        ASSERT(!INT_ISZERO(dip->di_next_unlinked, ARCH_CONVERT));
                }
        }
}
#endif


/*
 * This routine is called to map an inode to the buffer containing
 * the on-disk version of the inode.  It returns a pointer to the
 * buffer containing the on-disk inode in the bpp parameter, and in
 * the dip parameter it returns a pointer to the on-disk inode within
 * that buffer.
 *
 * If a non-zero error is returned, then the contents of bpp and
 * dipp are undefined.
 *
 * If the inode is new and has not yet been initialized, use xfs_imap()
 * to determine the size and location of the buffer to read from disk.
 * If the inode has already been mapped to its buffer and read in once,
 * then use the mapping information stored in the inode rather than
 * calling xfs_imap().  This allows us to avoid the overhead of looking
 * at the inode btree for small block file systems (see xfs_dilocate()).
 * We can tell whether the inode has been mapped in before by comparing
 * its disk block address to 0.  Only uninitialized inodes will have
 * 0 for the disk block address.
 */
int
xfs_itobp(
        xfs_mount_t     *mp,
        xfs_trans_t     *tp,
        xfs_inode_t     *ip,    
        xfs_dinode_t    **dipp,
        xfs_buf_t       **bpp,
        xfs_daddr_t     bno)
{
        xfs_buf_t       *bp;
        int             error;
        xfs_imap_t      imap;
#ifdef __KERNEL__
        int             i;
        int             ni;
#endif

        if (ip->i_blkno == (xfs_daddr_t)0) {
                /*
                 * Call the space management code to find the location of the
                 * inode on disk.
                 */
                imap.im_blkno = bno;
                error = xfs_imap(mp, tp, ip->i_ino, &imap, XFS_IMAP_LOOKUP);
                if (error != 0) {
                        return error;
                }

                /*
                 * If the inode number maps to a block outside the bounds
                 * of the file system then return NULL rather than calling
                 * read_buf and panicing when we get an error from the
                 * driver.
                 */
                if ((imap.im_blkno + imap.im_len) >
                    XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks)) {
                        return XFS_ERROR(EINVAL);
                }

                /*
                 * Fill in the fields in the inode that will be used to
                 * map the inode to its buffer from now on.
                 */
                ip->i_blkno = imap.im_blkno;
                ip->i_len = imap.im_len;
                ip->i_boffset = imap.im_boffset;
        } else {
                /*
                 * We've already mapped the inode once, so just use the
                 * mapping that we saved the first time.
                 */
                imap.im_blkno = ip->i_blkno;
                imap.im_len = ip->i_len;
                imap.im_boffset = ip->i_boffset;
        }
        ASSERT(bno == 0 || bno == imap.im_blkno);

        /*
         * Read in the buffer.  If tp is NULL, xfs_trans_read_buf() will
         * default to just a read_buf() call.
         */
        error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, imap.im_blkno,
                                   (int)imap.im_len, XFS_BUF_LOCK, &bp);

        if (error) {
                return error;
        }
#ifdef __KERNEL__
        /*
         * Validate the magic number and version of every inode in the buffer
         * (if DEBUG kernel) or the first inode in the buffer, otherwise.
         */
#ifdef DEBUG
        ni = BBTOB(imap.im_len) >> mp->m_sb.sb_inodelog;
#else
        ni = 1;
#endif
        for (i = 0; i < ni; i++) {
                int             di_ok;
                xfs_dinode_t    *dip;

                dip = (xfs_dinode_t *)xfs_buf_offset(bp,
                                        (i << mp->m_sb.sb_inodelog));
                di_ok = INT_GET(dip->di_core.di_magic, ARCH_CONVERT) == XFS_DINODE_MAGIC &&
                            XFS_DINODE_GOOD_VERSION(INT_GET(dip->di_core.di_version, ARCH_CONVERT));
                if (XFS_TEST_ERROR(!di_ok, mp, XFS_ERRTAG_ITOBP_INOTOBP,
                                 XFS_RANDOM_ITOBP_INOTOBP)) {
#ifdef DEBUG
                        prdev("bad inode magic/vsn daddr 0x%Lx #%d (magic=%x)", 
                                mp->m_dev, imap.im_blkno, i,
                                INT_GET(dip->di_core.di_magic, ARCH_CONVERT));
#endif
                        xfs_trans_brelse(tp, bp);
                        return XFS_ERROR(EFSCORRUPTED);
                }
        }
#endif  /* __KERNEL__ */

        xfs_inobp_check(mp, bp);

        /*
         * Mark the buffer as an inode buffer now that it looks good
         */
        XFS_BUF_SET_VTYPE(bp, B_FS_INO);

        /*
         * Set *dipp to point to the on-disk inode in the buffer.
         */
        *dipp = (xfs_dinode_t *)xfs_buf_offset(bp, imap.im_boffset);
        *bpp = bp;
        return 0;
}

/*
 * Move inode type and inode format specific information from the
 * on-disk inode to the in-core inode.  For fifos, devs, and sockets
 * this means set if_rdev to the proper value.  For files, directories,
 * and symlinks this means to bring in the in-line data or extent
 * pointers.  For a file in B-tree format, only the root is immediately
 * brought in-core.  The rest will be in-lined in if_extents when it
 * is first referenced (see xfs_iread_extents()).
 */
STATIC int
xfs_iformat(
        xfs_inode_t             *ip,
        xfs_dinode_t            *dip)
{
        xfs_attr_shortform_t    *atp;
        int                     size;
        int                     error;
        xfs_fsize_t             di_size;
        ip->i_df.if_ext_max =
                XFS_IFORK_DSIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t);
        error = 0;

        if (INT_GET(dip->di_core.di_nextents, ARCH_CONVERT) + 
                INT_GET(dip->di_core.di_anextents, ARCH_CONVERT) >
            INT_GET(dip->di_core.di_nblocks, ARCH_CONVERT)) {
                xfs_fs_cmn_err(CE_WARN, ip->i_mount,
                        "corrupt dinode %Lu, extent total = %d, nblocks = %Ld.  Unmount and run xfs_repair.",
                        ip->i_ino,
                        (int)(INT_GET(dip->di_core.di_nextents, ARCH_CONVERT) + INT_GET(dip->di_core.di_anextents, ARCH_CONVERT)),
                        INT_GET(dip->di_core.di_nblocks, ARCH_CONVERT));
                return XFS_ERROR(EFSCORRUPTED);
        }

        if (INT_GET(dip->di_core.di_forkoff, ARCH_CONVERT) > ip->i_mount->m_sb.sb_inodesize) {
                xfs_fs_cmn_err(CE_WARN, ip->i_mount,
                        "corrupt dinode %Lu, forkoff = 0x%x.  Unmount and run xfs_repair.",
                        ip->i_ino, (int)(INT_GET(dip->di_core.di_forkoff, ARCH_CONVERT)));
                return XFS_ERROR(EFSCORRUPTED);
        }

        switch (ip->i_d.di_mode & IFMT) {
        case IFIFO:
        case IFCHR:
        case IFBLK:
        case IFSOCK:
                if (INT_GET(dip->di_core.di_format, ARCH_CONVERT) != XFS_DINODE_FMT_DEV)
                        return XFS_ERROR(EFSCORRUPTED);
                ip->i_d.di_size = 0;
                ip->i_df.if_u2.if_rdev = INT_GET(dip->di_u.di_dev, ARCH_CONVERT);
                break;

        case IFREG:
        case IFLNK:
        case IFDIR:
                switch (INT_GET(dip->di_core.di_format, ARCH_CONVERT)) {
                case XFS_DINODE_FMT_LOCAL:
                        /*
                         * no local regular files yet
                         */
                        if ((INT_GET(dip->di_core.di_mode, ARCH_CONVERT) & IFMT) == IFREG) {
                                xfs_fs_cmn_err(CE_WARN, ip->i_mount,
                                        "corrupt inode (local format for regular file) %Lu.  Unmount and run xfs_repair.",
                                        ip->i_ino);
                                return XFS_ERROR(EFSCORRUPTED);
                        }
                        
                        di_size=INT_GET(dip->di_core.di_size, ARCH_CONVERT);
                        if (di_size >
                            XFS_DFORK_DSIZE_ARCH(dip, ip->i_mount, ARCH_CONVERT)) {
                                xfs_fs_cmn_err(CE_WARN, ip->i_mount,
                                        "corrupt inode %Lu (bad size %Ld for local inode).  Unmount and run xfs_repair.",
                                        ip->i_ino, di_size);
                                return XFS_ERROR(EFSCORRUPTED);
                        }

                        size = (int)di_size;
                        error = xfs_iformat_local(ip, dip, XFS_DATA_FORK, size);
                        break;
                case XFS_DINODE_FMT_EXTENTS:
                        error = xfs_iformat_extents(ip, dip, XFS_DATA_FORK);
                        break;
                case XFS_DINODE_FMT_BTREE:
                        error = xfs_iformat_btree(ip, dip, XFS_DATA_FORK);
                        break;
                default:
                        return XFS_ERROR(EFSCORRUPTED);
                }
                break;

        default:
                return XFS_ERROR(EFSCORRUPTED);
        }
        if (error) {
                return error;
        }
        if (!XFS_DFORK_Q_ARCH(dip, ARCH_CONVERT))
                return 0;
        ASSERT(ip->i_afp == NULL);
        ip->i_afp = kmem_zone_zalloc(xfs_ifork_zone, KM_SLEEP);
        ip->i_afp->if_ext_max =
                XFS_IFORK_ASIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t);
        switch (INT_GET(dip->di_core.di_aformat, ARCH_CONVERT)) {
        case XFS_DINODE_FMT_LOCAL:
                atp = (xfs_attr_shortform_t *)XFS_DFORK_APTR_ARCH(dip, ARCH_CONVERT);
                size = (int)INT_GET(atp->hdr.totsize, ARCH_CONVERT);
                error = xfs_iformat_local(ip, dip, XFS_ATTR_FORK, size);
                break;
        case XFS_DINODE_FMT_EXTENTS:
                error = xfs_iformat_extents(ip, dip, XFS_ATTR_FORK);
                break;
        case XFS_DINODE_FMT_BTREE:
                error = xfs_iformat_btree(ip, dip, XFS_ATTR_FORK);
                break;
        default:
                error = XFS_ERROR(EFSCORRUPTED);
                break;
        }
        if (error) {
                kmem_zone_free(xfs_ifork_zone, ip->i_afp);
                ip->i_afp = NULL;
                xfs_idestroy_fork(ip, XFS_DATA_FORK);
        }
        return error;
}

/*
 * The file is in-lined in the on-disk inode.
 * If it fits into if_inline_data, then copy
 * it there, otherwise allocate a buffer for it
 * and copy the data there.  Either way, set
 * if_data to point at the data.
 * If we allocate a buffer for the data, make
 * sure that its size is a multiple of 4 and
 * record the real size in i_real_bytes.
 */
STATIC int
xfs_iformat_local(
        xfs_inode_t     *ip,
        xfs_dinode_t    *dip,
        int             whichfork,
        int             size)
{
        xfs_ifork_t     *ifp;
        int             real_size;

        /*
         * If the size is unreasonable, then something
         * is wrong and we just bail out rather than crash in
         * kmem_alloc() or bcopy() below.
         */
        if (size > XFS_DFORK_SIZE_ARCH(dip, ip->i_mount, whichfork, ARCH_CONVERT)) {
                xfs_fs_cmn_err(CE_WARN, ip->i_mount,
                        "corrupt inode %Lu (bad size %d for local fork, size = %d).  Unmount and run xfs_repair.",
                        ip->i_ino, size,
                        XFS_DFORK_SIZE_ARCH(dip, ip->i_mount, whichfork, ARCH_CONVERT));
                return XFS_ERROR(EFSCORRUPTED);
        }
        ifp = XFS_IFORK_PTR(ip, whichfork);
        real_size = 0;
        if (size == 0)
                ifp->if_u1.if_data = NULL;
        else if (size <= sizeof(ifp->if_u2.if_inline_data))
                ifp->if_u1.if_data = ifp->if_u2.if_inline_data;
        else {
                real_size = roundup(size, 4);
                ifp->if_u1.if_data = kmem_alloc(real_size, KM_SLEEP);
        }
        ifp->if_bytes = size;
        ifp->if_real_bytes = real_size;
        if (size)
                bcopy(XFS_DFORK_PTR_ARCH(dip, whichfork, ARCH_CONVERT), ifp->if_u1.if_data, size);
        ifp->if_flags &= ~XFS_IFEXTENTS;
        ifp->if_flags |= XFS_IFINLINE;
        return 0;
}

/*
 * The file consists of a set of extents all
 * of which fit into the on-disk inode.
 * If there are few enough extents to fit into
 * the if_inline_ext, then copy them there.
 * Otherwise allocate a buffer for them and copy
 * them into it.  Either way, set if_extents
 * to point at the extents.
 */
STATIC int
xfs_iformat_extents(
        xfs_inode_t     *ip,
        xfs_dinode_t    *dip,
        int             whichfork)
{
        xfs_ifork_t     *ifp;
        int             nex;
        int             real_size;
        int             size;

        ifp = XFS_IFORK_PTR(ip, whichfork);
        nex = XFS_DFORK_NEXTENTS_ARCH(dip, whichfork, ARCH_CONVERT);
        size = nex * (uint)sizeof(xfs_bmbt_rec_t);

        /*
         * If the number of extents is unreasonable, then something
         * is wrong and we just bail out rather than crash in
         * kmem_alloc() or bcopy() below.
         */
        if (size < 0 || size > XFS_DFORK_SIZE_ARCH(dip, ip->i_mount, whichfork, ARCH_CONVERT)) {
                xfs_fs_cmn_err(CE_WARN, ip->i_mount,
                        "corrupt inode %Lu ((a)extents = %d).  Unmount and run xfs_repair.",
                        ip->i_ino, nex);
                return XFS_ERROR(EFSCORRUPTED);
        }

        real_size = 0;
        if (nex == 0)
                ifp->if_u1.if_extents = NULL;
        else if (nex <= XFS_INLINE_EXTS)
                ifp->if_u1.if_extents = ifp->if_u2.if_inline_ext;
        else {
                ifp->if_u1.if_extents = kmem_alloc(size, KM_SLEEP);
                ASSERT(ifp->if_u1.if_extents != NULL);
                real_size = size;
        }
        ifp->if_bytes = size;
        ifp->if_real_bytes = real_size;
        if (size) {
                xfs_validate_extents(
                        (xfs_bmbt_rec_32_t *)XFS_DFORK_PTR_ARCH(dip, whichfork, ARCH_CONVERT),
                        nex, XFS_EXTFMT_INODE(ip));
                bcopy(XFS_DFORK_PTR_ARCH(dip, whichfork, ARCH_CONVERT), ifp->if_u1.if_extents,
                      size);
                xfs_bmap_trace_exlist("xfs_iformat_extents", ip, nex,
                        whichfork);
                if (whichfork != XFS_DATA_FORK ||
                        XFS_EXTFMT_INODE(ip) == XFS_EXTFMT_NOSTATE)
                                if (xfs_check_nostate_extents(
                                    ifp->if_u1.if_extents, nex))
                                        return XFS_ERROR(EFSCORRUPTED);
        }
        ifp->if_flags |= XFS_IFEXTENTS;
        return 0;
}

/*
 * The file has too many extents to fit into
 * the inode, so they are in B-tree format.
 * Allocate a buffer for the root of the B-tree
 * and copy the root into it.  The i_extents
 * field will remain NULL until all of the
 * extents are read in (when they are needed).
 */
STATIC int
xfs_iformat_btree(
        xfs_inode_t             *ip,
        xfs_dinode_t            *dip,
        int                     whichfork)
{
        xfs_bmdr_block_t        *dfp;
        xfs_ifork_t             *ifp;
        /* REFERENCED */
        int                     nrecs;
        int                     size;

        ifp = XFS_IFORK_PTR(ip, whichfork);
        dfp = (xfs_bmdr_block_t *)XFS_DFORK_PTR_ARCH(dip, whichfork, ARCH_CONVERT);
        size = XFS_BMAP_BROOT_SPACE(dfp);
        nrecs = XFS_BMAP_BROOT_NUMRECS(dfp);

        /*
         * blow out if -- fork has less extents than can fit in
         * fork (fork shouldn't be a btree format), root btree
         * block has more records than can fit into the fork,
         * or the number of extents is greater than the number of
         * blocks.
         */
        if (XFS_IFORK_NEXTENTS(ip, whichfork) <= ifp->if_ext_max
            || XFS_BMDR_SPACE_CALC(nrecs) >
                        XFS_DFORK_SIZE_ARCH(dip, ip->i_mount, whichfork, ARCH_CONVERT)
            || XFS_IFORK_NEXTENTS(ip, whichfork) > ip->i_d.di_nblocks) {
                xfs_fs_cmn_err(CE_WARN, ip->i_mount,
                        "corrupt inode %Lu (btree).  Unmount and run xfs_repair.",
                        ip->i_ino);
                return XFS_ERROR(EFSCORRUPTED);
        }

        ifp->if_broot_bytes = size;
        ifp->if_broot = kmem_alloc(size, KM_SLEEP);
        ASSERT(ifp->if_broot != NULL);
        /*
         * Copy and convert from the on-disk structure
         * to the in-memory structure.
         */
        xfs_bmdr_to_bmbt(dfp, XFS_DFORK_SIZE_ARCH(dip, ip->i_mount, whichfork, ARCH_CONVERT),
                ifp->if_broot, size);
        ifp->if_flags &= ~XFS_IFEXTENTS;
        ifp->if_flags |= XFS_IFBROOT;

        return 0;
}

/*
 * xfs_xlate_dinode_core - translate an xfs_inode_core_t between ondisk
 * and native format
 *
 * buf  = on-disk representation 
 * dip  = native representation 
 * dir  = direction - +ve -> disk to native
 *                    -ve -> native to disk
 * arch = on-disk architecture
 */
 
void 
xfs_xlate_dinode_core(xfs_caddr_t buf, xfs_dinode_core_t *dip, 
    int dir, xfs_arch_t arch)
{
    xfs_dinode_core_t   *buf_core;
    xfs_dinode_core_t   *mem_core;
    
    ASSERT(dir);
    
    buf_core=(xfs_dinode_core_t*)buf;
    mem_core=(xfs_dinode_core_t*)dip;
    
    if (arch == ARCH_NOCONVERT) {
        if (dir>0) {
            bcopy((xfs_caddr_t)buf_core, (xfs_caddr_t)mem_core, sizeof(xfs_dinode_core_t));
        } else {
            bcopy((xfs_caddr_t)mem_core, (xfs_caddr_t)buf_core, sizeof(xfs_dinode_core_t));
        }
        return;
    }
    
    INT_XLATE(buf_core->di_magic,       mem_core->di_magic,        dir, arch);
    INT_XLATE(buf_core->di_mode,        mem_core->di_mode,         dir, arch);
    INT_XLATE(buf_core->di_version,     mem_core->di_version,      dir, arch);
    INT_XLATE(buf_core->di_format,      mem_core->di_format,       dir, arch);
    INT_XLATE(buf_core->di_onlink,      mem_core->di_onlink,       dir, arch);
    INT_XLATE(buf_core->di_uid,         mem_core->di_uid,          dir, arch);
    INT_XLATE(buf_core->di_gid,         mem_core->di_gid,          dir, arch);
    INT_XLATE(buf_core->di_nlink,       mem_core->di_nlink,        dir, arch);
    INT_XLATE(buf_core->di_projid,      mem_core->di_projid,       dir, arch);
    
    if (dir>0) {
        bcopy(buf_core->di_pad, mem_core->di_pad, sizeof(buf_core->di_pad));
    } else {
        bcopy(mem_core->di_pad, buf_core->di_pad, sizeof(buf_core->di_pad));
    }
    
    INT_XLATE(buf_core->di_atime.t_sec, mem_core->di_atime.t_sec,  dir, arch);
    INT_XLATE(buf_core->di_atime.t_nsec,mem_core->di_atime.t_nsec, dir, arch);
    
    INT_XLATE(buf_core->di_mtime.t_sec, mem_core->di_mtime.t_sec,  dir, arch);
    INT_XLATE(buf_core->di_mtime.t_nsec,mem_core->di_mtime.t_nsec, dir, arch);
    
    INT_XLATE(buf_core->di_ctime.t_sec, mem_core->di_ctime.t_sec,  dir, arch);
    INT_XLATE(buf_core->di_ctime.t_nsec,mem_core->di_ctime.t_nsec, dir, arch);
    
    INT_XLATE(buf_core->di_size,        mem_core->di_size,         dir, arch);
    INT_XLATE(buf_core->di_nblocks,     mem_core->di_nblocks,      dir, arch);
    INT_XLATE(buf_core->di_extsize,     mem_core->di_extsize,      dir, arch);
    
    INT_XLATE(buf_core->di_nextents,    mem_core->di_nextents,     dir, arch);
    INT_XLATE(buf_core->di_anextents,   mem_core->di_anextents,    dir, arch);
    INT_XLATE(buf_core->di_forkoff,     mem_core->di_forkoff,      dir, arch);
    INT_XLATE(buf_core->di_aformat,     mem_core->di_aformat,      dir, arch);
    INT_XLATE(buf_core->di_dmevmask,    mem_core->di_dmevmask,     dir, arch);
    INT_XLATE(buf_core->di_dmstate,     mem_core->di_dmstate,      dir, arch);
    INT_XLATE(buf_core->di_flags,       mem_core->di_flags,        dir, arch);
    INT_XLATE(buf_core->di_gen,         mem_core->di_gen,          dir, arch);
    
}

/*
 * Given a mount structure and an inode number, return a pointer
 * to a newly allocated in-core inode coresponding to the given
 * inode number.
 * 
 * Initialize the inode's attributes and extent pointers if it
 * already has them (it will not if the inode has no links).
 */
int
xfs_iread(
        xfs_mount_t     *mp,
        xfs_trans_t     *tp,
        xfs_ino_t       ino,
        xfs_inode_t     **ipp,
        xfs_daddr_t             bno)
{
        xfs_buf_t       *bp;
        xfs_dinode_t    *dip;
        xfs_inode_t     *ip;
        int             error;

        ASSERT(xfs_inode_zone != NULL);

        ip = kmem_zone_zalloc(xfs_inode_zone, KM_SLEEP);
        ip->i_ino = ino;
        ip->i_dev = mp->m_dev;
        ip->i_mount = mp;

        /*
         * Get pointer's to the on-disk inode and the buffer containing it.
         * If the inode number refers to a block outside the file system
         * then xfs_itobp() will return NULL.  In this case we should
         * return NULL as well.  Set i_blkno to 0 so that xfs_itobp() will
         * know that this is a new incore inode.
         */
        error = xfs_itobp(mp, tp, ip, &dip, &bp, bno);

        if (error != 0) {
                kmem_zone_free(xfs_inode_zone, ip);
                return error;
        }

        /*
         * Initialize inode's trace buffers.
         * Do this before xfs_iformat in case it adds entries.
         */
#ifdef XFS_BMAP_TRACE
        ip->i_xtrace = ktrace_alloc(XFS_BMAP_KTRACE_SIZE, KM_SLEEP);
#endif
#ifdef XFS_BMBT_TRACE
        ip->i_btrace = ktrace_alloc(XFS_BMBT_KTRACE_SIZE, KM_SLEEP);
#endif
#ifdef XFS_RW_TRACE
        ip->i_rwtrace = ktrace_alloc(XFS_RW_KTRACE_SIZE, KM_SLEEP);
#endif
#ifdef XFS_STRAT_TRACE
        ip->i_strat_trace = ktrace_alloc(XFS_STRAT_KTRACE_SIZE, KM_SLEEP);
#endif
#ifdef XFS_ILOCK_TRACE
        ip->i_lock_trace = ktrace_alloc(XFS_ILOCK_KTRACE_SIZE, KM_SLEEP);
#endif
#ifdef XFS_DIR2_TRACE
        ip->i_dir_trace = ktrace_alloc(XFS_DIR2_KTRACE_SIZE, KM_SLEEP);
#endif

        /*
         * If we got something that isn't an inode it means someone
         * (nfs or dmi) has a stale handle.
         */
        if (INT_GET(dip->di_core.di_magic, ARCH_CONVERT) != XFS_DINODE_MAGIC) {
                kmem_zone_free(xfs_inode_zone, ip);
                xfs_trans_brelse(tp, bp);
                return XFS_ERROR(EINVAL);
        }

        /*
         * If the on-disk inode is already linked to a directory
         * entry, copy all of the inode into the in-core inode.
         * xfs_iformat() handles copying in the inode format
         * specific information.
         * Otherwise, just get the truly permanent information.
         */
        if (!INT_ISZERO(dip->di_core.di_mode, ARCH_CONVERT)) {
                xfs_xlate_dinode_core((xfs_caddr_t)&dip->di_core, 
                     &(ip->i_d), 1, ARCH_CONVERT);
                error = xfs_iformat(ip, dip);
                if (error)  {
                        kmem_zone_free(xfs_inode_zone, ip);
                        xfs_trans_brelse(tp, bp);
                        return error;
                }
        } else {
                ip->i_d.di_magic = INT_GET(dip->di_core.di_magic, ARCH_CONVERT);
                ip->i_d.di_version = INT_GET(dip->di_core.di_version, ARCH_CONVERT);
                ip->i_d.di_gen = INT_GET(dip->di_core.di_gen, ARCH_CONVERT);
                /*
                 * Make sure to pull in the mode here as well in
                 * case the inode is released without being used.
                 * This ensures that xfs_inactive() will see that
                 * the inode is already free and not try to mess
                 * with the uninitialized part of it.
                 */
                ip->i_d.di_mode = 0;
                /*
                 * Initialize the per-fork minima and maxima for a new
                 * inode here.  xfs_iformat will do it for old inodes.
                 */
                ip->i_df.if_ext_max =
                        XFS_IFORK_DSIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t);
        }       

        /*
         * The inode format changed when we moved the link count and
         * made it 32 bits long.  If this is an old format inode,
         * convert it in memory to look like a new one.  If it gets
         * flushed to disk we will convert back before flushing or
         * logging it.  We zero out the new projid field and the old link
         * count field.  We'll handle clearing the pad field (the remains
         * of the old uuid field) when we actually convert the inode to
         * the new format. We don't change the version number so that we
         * can distinguish this from a real new format inode.
         */
        if (ip->i_d.di_version == XFS_DINODE_VERSION_1) {
                ip->i_d.di_nlink = ip->i_d.di_onlink;
                ip->i_d.di_onlink = 0;
                ip->i_d.di_projid = 0;
        }

        ip->i_delayed_blks = 0;

        /*
         * Mark the buffer containing the inode as something to keep
         * around for a while.  This helps to keep recently accessed
         * meta-data in-core longer.
         */
         XFS_BUF_SET_REF(bp, XFS_INO_REF);

        /*
         * Use xfs_trans_brelse() to release the buffer containing the
         * on-disk inode, because it was acquired with xfs_trans_read_buf()
         * in xfs_itobp() above.  If tp is NULL, this is just a normal
         * brelse().  If we're within a transaction, then xfs_trans_brelse()
         * will only release the buffer if it is not dirty within the
         * transaction.  It will be OK to release the buffer in this case,
         * because inodes on disk are never destroyed and we will be
         * locking the new in-core inode before putting it in the hash
         * table where other processes can find it.  Thus we don't have
         * to worry about the inode being changed just because we released
         * the buffer.
         */
        xfs_trans_brelse(tp, bp);
        *ipp = ip;
        return 0;
}

/*
 * Read in extents from a btree-format inode.
 * Allocate and fill in if_extents.  Real work is done in xfs_bmap.c.
 */
int
xfs_iread_extents(
        xfs_trans_t     *tp,
        xfs_inode_t     *ip,
        int             whichfork)
{
        int             error;
        xfs_ifork_t     *ifp;
        size_t          size;

        if (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE)
                return XFS_ERROR(EFSCORRUPTED);
        size = XFS_IFORK_NEXTENTS(ip, whichfork) * (uint)sizeof(xfs_bmbt_rec_t);
        ifp = XFS_IFORK_PTR(ip, whichfork);
        /*
         * We know that the size is legal (it's checked in iformat_btree)
         */
        ifp->if_u1.if_extents = kmem_alloc(size, KM_SLEEP);
        ASSERT(ifp->if_u1.if_extents != NULL);
        ifp->if_lastex = NULLEXTNUM;
        ifp->if_bytes = ifp->if_real_bytes = (int)size;
        ifp->if_flags |= XFS_IFEXTENTS;
        error = xfs_bmap_read_extents(tp, ip, whichfork);
        if (error) {
                kmem_free(ifp->if_u1.if_extents, size);
                ifp->if_u1.if_extents = NULL;
                ifp->if_bytes = ifp->if_real_bytes = 0;
                ifp->if_flags &= ~XFS_IFEXTENTS;
                return error;
        }
        xfs_validate_extents((xfs_bmbt_rec_32_t *)ifp->if_u1.if_extents,
                XFS_IFORK_NEXTENTS(ip, whichfork), XFS_EXTFMT_INODE(ip));
        return 0;
}

/*
 * Reallocate the space for if_broot based on the number of records
 * being added or deleted as indicated in rec_diff.  Move the records
 * and pointers in if_broot to fit the new size.  When shrinking this
 * will eliminate holes between the records and pointers created by
 * the caller.  When growing this will create holes to be filled in
 * by the caller.
 *
 * The caller must not request to add more records than would fit in
 * the on-disk inode root.  If the if_broot is currently NULL, then
 * if we adding records one will be allocated.  The caller must also
 * not request that the number of records go below zero, although
 * it can go to zero.
 *
 * ip -- the inode whose if_broot area is changing
 * ext_diff -- the change in the number of records, positive or negative,
 *       requested for the if_broot array.
 */
void
xfs_iroot_realloc(
        xfs_inode_t             *ip,
        int                     rec_diff,
        int                     whichfork)
{
        int                     cur_max;
        xfs_ifork_t             *ifp;
        xfs_bmbt_block_t        *new_broot;
        int                     new_max;
        size_t                  new_size;
        char                    *np;
        char                    *op;

        /*
         * Handle the degenerate case quietly.
         */
        if (rec_diff == 0) {
                return;
        }

        ifp = XFS_IFORK_PTR(ip, whichfork);
        if (rec_diff > 0) {
                /*
                 * If there wasn't any memory allocated before, just
                 * allocate it now and get out.
                 */
                if (ifp->if_broot_bytes == 0) {
                        new_size = (size_t)XFS_BMAP_BROOT_SPACE_CALC(rec_diff);
                        ifp->if_broot = (xfs_bmbt_block_t*)kmem_alloc(new_size,
                                                                     KM_SLEEP);
                        ifp->if_broot_bytes = (int)new_size;
                        return;
                }

                /*
                 * If there is already an existing if_broot, then we need
                 * to realloc() it and shift the pointers to their new
                 * location.  The records don't change location because
                 * they are kept butted up against the btree block header.
                 */
                cur_max = XFS_BMAP_BROOT_MAXRECS(ifp->if_broot_bytes);
                new_max = cur_max + rec_diff;
                new_size = (size_t)XFS_BMAP_BROOT_SPACE_CALC(new_max);
                ifp->if_broot = (xfs_bmbt_block_t *) 
                  kmem_realloc(ifp->if_broot,
                                new_size,
                                (size_t)XFS_BMAP_BROOT_SPACE_CALC(cur_max), /* old size */
                                KM_SLEEP);
                op = (char *)XFS_BMAP_BROOT_PTR_ADDR(ifp->if_broot, 1,
                                                      ifp->if_broot_bytes);
                np = (char *)XFS_BMAP_BROOT_PTR_ADDR(ifp->if_broot, 1,
                                                      (int)new_size);
                ifp->if_broot_bytes = (int)new_size;
                ASSERT(ifp->if_broot_bytes <=
                        XFS_IFORK_SIZE(ip, whichfork) + XFS_BROOT_SIZE_ADJ);
                ovbcopy(op, np, cur_max * (uint)sizeof(xfs_dfsbno_t));
                return;
        }

        /*
         * rec_diff is less than 0.  In this case, we are shrinking the
         * if_broot buffer.  It must already exist.  If we go to zero
         * records, just get rid of the root and clear the status bit.
         */
        ASSERT((ifp->if_broot != NULL) && (ifp->if_broot_bytes > 0));
        cur_max = XFS_BMAP_BROOT_MAXRECS(ifp->if_broot_bytes);
        new_max = cur_max + rec_diff;
        ASSERT(new_max >= 0);
        if (new_max > 0)
                new_size = (size_t)XFS_BMAP_BROOT_SPACE_CALC(new_max);
        else
                new_size = 0;
        if (new_size > 0) {
                new_broot = (xfs_bmbt_block_t *)kmem_alloc(new_size, KM_SLEEP);
                /*
                 * First copy over the btree block header.
                 */
                bcopy(ifp->if_broot, new_broot, sizeof(xfs_bmbt_block_t));
        } else {
                new_broot = NULL;
                ifp->if_flags &= ~XFS_IFBROOT;
        }

        /*
         * Only copy the records and pointers if there are any.
         */
        if (new_max > 0) {
                /*
                 * First copy the records.
                 */
                op = (char *)XFS_BMAP_BROOT_REC_ADDR(ifp->if_broot, 1,
                                                     ifp->if_broot_bytes);
                np = (char *)XFS_BMAP_BROOT_REC_ADDR(new_broot, 1,
                                                     (int)new_size);
                bcopy(op, np, new_max * (uint)sizeof(xfs_bmbt_rec_t));  

                /*
                 * Then copy the pointers.
                 */
                op = (char *)XFS_BMAP_BROOT_PTR_ADDR(ifp->if_broot, 1,
                                                     ifp->if_broot_bytes);
                np = (char *)XFS_BMAP_BROOT_PTR_ADDR(new_broot, 1,
                                                     (int)new_size);
                bcopy(op, np, new_max * (uint)sizeof(xfs_dfsbno_t));
        }
        kmem_free(ifp->if_broot, ifp->if_broot_bytes);
        ifp->if_broot = new_broot;
        ifp->if_broot_bytes = (int)new_size;
        ASSERT(ifp->if_broot_bytes <=
                XFS_IFORK_SIZE(ip, whichfork) + XFS_BROOT_SIZE_ADJ);
        return;
}

/*
 * This is called when the amount of space needed for if_extents
 * is increased or decreased.  The change in size is indicated by
 * the number of extents that need to be added or deleted in the
 * ext_diff parameter.
 *
 * If the amount of space needed has decreased below the size of the
 * inline buffer, then switch to using the inline buffer.  Otherwise,
 * use kmem_realloc() or kmem_alloc() to adjust the size of the buffer
 * to what is needed.
 *
 * ip -- the inode whose if_extents area is changing
 * ext_diff -- the change in the number of extents, positive or negative,
 *       requested for the if_extents array.
 */
void
xfs_iext_realloc(
        xfs_inode_t     *ip,
        int             ext_diff,
        int             whichfork)
{
        int             byte_diff;
        xfs_ifork_t     *ifp;
        int             new_size;
        uint            rnew_size;

        if (ext_diff == 0) {
                return;
        }

        ifp = XFS_IFORK_PTR(ip, whichfork);
        byte_diff = ext_diff * (uint)sizeof(xfs_bmbt_rec_t);
        new_size = (int)ifp->if_bytes + byte_diff;
        ASSERT(new_size >= 0);

        if (new_size == 0) {
                if (ifp->if_u1.if_extents != ifp->if_u2.if_inline_ext) {
                        ASSERT(ifp->if_real_bytes != 0);
                        kmem_free(ifp->if_u1.if_extents, ifp->if_real_bytes);
                }
                ifp->if_u1.if_extents = NULL;
                rnew_size = 0;
        } else if (new_size <= sizeof(ifp->if_u2.if_inline_ext)) {
                /*
                 * If the valid extents can fit in if_inline_ext,
                 * copy them from the malloc'd vector and free it.
                 */
                if (ifp->if_u1.if_extents != ifp->if_u2.if_inline_ext) {
                        /*
                         * For now, empty files are format EXTENTS,
                         * so the if_extents pointer is null.
                         */
                        if (ifp->if_u1.if_extents) {
                                bcopy(ifp->if_u1.if_extents,
                                      ifp->if_u2.if_inline_ext, new_size);
                                kmem_free(ifp->if_u1.if_extents,
                                          ifp->if_real_bytes);
                        }
                        ifp->if_u1.if_extents = ifp->if_u2.if_inline_ext;
                }
                rnew_size = 0;
        } else {
                rnew_size = new_size;
                if ((rnew_size & (rnew_size - 1)) != 0)
                        rnew_size = xfs_iroundup(rnew_size);
                /*
                 * Stuck with malloc/realloc.
                 */
                if (ifp->if_u1.if_extents == ifp->if_u2.if_inline_ext) {
                        ifp->if_u1.if_extents = (xfs_bmbt_rec_t *)
                                kmem_alloc(rnew_size, KM_SLEEP);
                        bcopy(ifp->if_u2.if_inline_ext, ifp->if_u1.if_extents,
                              sizeof(ifp->if_u2.if_inline_ext));
                } else if (rnew_size != ifp->if_real_bytes) {
                        ifp->if_u1.if_extents = (xfs_bmbt_rec_t *)
                          kmem_realloc(ifp->if_u1.if_extents,
                                        rnew_size,
                                        ifp->if_real_bytes,
                                        KM_SLEEP);
                }
        }
        ifp->if_real_bytes = rnew_size;
        ifp->if_bytes = new_size;
}


/*
 * This is called when the amount of space needed for if_data
 * is increased or decreased.  The change in size is indicated by
 * the number of bytes that need to be added or deleted in the
 * byte_diff parameter.
 *
 * If the amount of space needed has decreased below the size of the
 * inline buffer, then switch to using the inline buffer.  Otherwise,
 * use kmem_realloc() or kmem_alloc() to adjust the size of the buffer
 * to what is needed.
 *
 * ip -- the inode whose if_data area is changing
 * byte_diff -- the change in the number of bytes, positive or negative,
 *       requested for the if_data array.
 */
void
xfs_idata_realloc(
        xfs_inode_t     *ip,
        int             byte_diff,
        int             whichfork)
{
        xfs_ifork_t     *ifp;
        int             new_size;
        int             real_size;

        if (byte_diff == 0) {
                return;
        }

        ifp = XFS_IFORK_PTR(ip, whichfork);
        new_size = (int)ifp->if_bytes + byte_diff;
        ASSERT(new_size >= 0);

        if (new_size == 0) {
                if (ifp->if_u1.if_data != ifp->if_u2.if_inline_data) {
                        kmem_free(ifp->if_u1.if_data, ifp->if_real_bytes);
                }
                ifp->if_u1.if_data = NULL;
                real_size = 0;
        } else if (new_size <= sizeof(ifp->if_u2.if_inline_data)) {
                /*
                 * If the valid extents/data can fit in if_inline_ext/data,
                 * copy them from the malloc'd vector and free it.
                 */
                if (ifp->if_u1.if_data == NULL) {
                        ifp->if_u1.if_data = ifp->if_u2.if_inline_data;
                } else if (ifp->if_u1.if_data != ifp->if_u2.if_inline_data) {
                        ASSERT(ifp->if_real_bytes != 0);
                        bcopy(ifp->if_u1.if_data, ifp->if_u2.if_inline_data,
                              new_size);
                        kmem_free(ifp->if_u1.if_data, ifp->if_real_bytes);
                        ifp->if_u1.if_data = ifp->if_u2.if_inline_data;
                }
                real_size = 0;
        } else {
                /*
                 * Stuck with malloc/realloc.
                 * For inline data, the underlying buffer must be
                 * a multiple of 4 bytes in size so that it can be
                 * logged and stay on word boundaries.  We enforce
                 * that here.
                 */
                real_size = roundup(new_size, 4);
                if (ifp->if_u1.if_data == NULL) {
                        ASSERT(ifp->if_real_bytes == 0);
                        ifp->if_u1.if_data = kmem_alloc(real_size, KM_SLEEP);
                } else if (ifp->if_u1.if_data != ifp->if_u2.if_inline_data) {
                        /*
                         * Only do the realloc if the underlying size
                         * is really changing.
                         */
                        if (ifp->if_real_bytes != real_size) {
                                ifp->if_u1.if_data =
                                        kmem_realloc(ifp->if_u1.if_data,
                                                        real_size,
                                                        ifp->if_real_bytes,
                                                        KM_SLEEP);
                        }
                } else {
                        ASSERT(ifp->if_real_bytes == 0);
                        ifp->if_u1.if_data = kmem_alloc(real_size, KM_SLEEP);
                        bcopy(ifp->if_u2.if_inline_data, ifp->if_u1.if_data,
                              ifp->if_bytes);
                }
        }
        ifp->if_real_bytes = real_size;
        ifp->if_bytes = new_size;
        ASSERT(ifp->if_bytes <= XFS_IFORK_SIZE(ip, whichfork));
}


/*
 * Map inode to disk block and offset.
 *
 * mp -- the mount point structure for the current file system
 * tp -- the current transaction
 * ino -- the inode number of the inode to be located
 * imap -- this structure is filled in with the information necessary
 *       to retrieve the given inode from disk
 * flags -- flags to pass to xfs_dilocate indicating whether or not
 *       lookups in the inode btree were OK or not
 */
int
xfs_imap(
        xfs_mount_t     *mp,
        xfs_trans_t     *tp,
        xfs_ino_t       ino,
        xfs_imap_t      *imap,
        uint            flags)
{
        xfs_fsblock_t   fsbno;
        int             len;
        int             off;
        int             error;

        fsbno = imap->im_blkno ?
                XFS_DADDR_TO_FSB(mp, imap->im_blkno) : NULLFSBLOCK;
        error = xfs_dilocate(mp, tp, ino, &fsbno, &len, &off, flags);
        if (error != 0) {
                return error;
        }
        imap->im_blkno = XFS_FSB_TO_DADDR(mp, fsbno);
        imap->im_len = XFS_FSB_TO_BB(mp, len);
        imap->im_agblkno = XFS_FSB_TO_AGBNO(mp, fsbno);
        imap->im_ioffset = (ushort)off;
        imap->im_boffset = (ushort)(off << mp->m_sb.sb_inodelog);
        return 0;
}

void
xfs_idestroy_fork(
        xfs_inode_t     *ip,
        int             whichfork)
{
        xfs_ifork_t     *ifp;

        ifp = XFS_IFORK_PTR(ip, whichfork);
        if (ifp->if_broot != NULL) {
                kmem_free(ifp->if_broot, ifp->if_broot_bytes);
                ifp->if_broot = NULL;
        }

        /*
         * If the format is local, then we can't have an extents
         * array so just look for an inline data array.  If we're
         * not local then we may or may not have an extents list,
         * so check and free it up if we do.
         */
        if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL) {
                if ((ifp->if_u1.if_data != ifp->if_u2.if_inline_data) && 
                    (ifp->if_u1.if_data != NULL)) {
                        ASSERT(ifp->if_real_bytes != 0);
                        kmem_free(ifp->if_u1.if_data, ifp->if_real_bytes);
                        ifp->if_u1.if_data = NULL;
                        ifp->if_real_bytes = 0;
                }
        } else if ((ifp->if_flags & XFS_IFEXTENTS) &&
                   (ifp->if_u1.if_extents != NULL) &&
                   (ifp->if_u1.if_extents != ifp->if_u2.if_inline_ext)) {
                ASSERT(ifp->if_real_bytes != 0);
                kmem_free(ifp->if_u1.if_extents, ifp->if_real_bytes);
                ifp->if_u1.if_extents = NULL;
                ifp->if_real_bytes = 0;
        }
        ASSERT(ifp->if_u1.if_extents == NULL ||
               ifp->if_u1.if_extents == ifp->if_u2.if_inline_ext);
        ASSERT(ifp->if_real_bytes == 0);
        if (whichfork == XFS_ATTR_FORK) {
                kmem_zone_free(xfs_ifork_zone, ip->i_afp);
                ip->i_afp = NULL;
        }
}

/*
 * xfs_iroundup: round up argument to next power of two
 */
uint
xfs_iroundup(
        uint    v)
{
        int i;
        uint m;

        if ((v & (v - 1)) == 0)
                return v;
        ASSERT((v & 0x80000000) == 0);
        if ((v & (v + 1)) == 0)
                return v + 1;
        for (i = 0, m = 1; i < 31; i++, m <<= 1) {
                if (v & m)
                        continue;
                v |= m;
                if ((v & (v + 1)) == 0)
                        return v + 1;
        }
        ASSERT(0);
        return( 0 );
}

/*
 * xfs_iextents_copy()
 *
 * This is called to copy the REAL extents (as opposed to the delayed
 * allocation extents) from the inode into the given buffer.  It
 * returns the number of bytes copied into the buffer.
 *
 * If there are no delayed allocation extents, then we can just
 * bcopy() the extents into the buffer.  Otherwise, we need to
 * examine each extent in turn and skip those which are delayed.
 */
int
xfs_iextents_copy(
        xfs_inode_t             *ip,
        xfs_bmbt_rec_32_t       *buffer,
        int                     whichfork)
{
        int                     copied;
        xfs_bmbt_rec_32_t       *dest_ep;
        xfs_bmbt_rec_t          *ep;
#ifdef DEBUG
        xfs_exntfmt_t           fmt = XFS_EXTFMT_INODE(ip);
#endif
#ifdef XFS_BMAP_TRACE
        static char             fname[] = "xfs_iextents_copy";
#endif
        int                     i;
        xfs_ifork_t             *ifp;
        int                     nrecs;
        xfs_fsblock_t           start_block;

        ifp = XFS_IFORK_PTR(ip, whichfork);
        ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE|MR_ACCESS));
        ASSERT(ifp->if_bytes > 0);

        nrecs = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
        xfs_bmap_trace_exlist(fname, ip, nrecs, whichfork);
        ASSERT(nrecs > 0);
        if (nrecs == XFS_IFORK_NEXTENTS(ip, whichfork)) {
                /*
                 * There are no delayed allocation extents,
                 * so just copy everything.
                 */
                ASSERT(ifp->if_bytes <= XFS_IFORK_SIZE(ip, whichfork));
                ASSERT(ifp->if_bytes ==
                       (XFS_IFORK_NEXTENTS(ip, whichfork) *
                        (uint)sizeof(xfs_bmbt_rec_t)));
                bcopy(ifp->if_u1.if_extents, buffer, ifp->if_bytes);
                xfs_validate_extents(buffer, nrecs, fmt);
                return ifp->if_bytes;
        }

        ASSERT(whichfork == XFS_DATA_FORK);
        /*
         * There are some delayed allocation extents in the
         * inode, so copy the extents one at a time and skip
         * the delayed ones.  There must be at least one
         * non-delayed extent.
         */
        ASSERT(nrecs > ip->i_d.di_nextents);
        ep = ifp->if_u1.if_extents;
        dest_ep = buffer;
        copied = 0;
        for (i = 0; i < nrecs; i++) {
                start_block = xfs_bmbt_get_startblock(ep);
                if (ISNULLSTARTBLOCK(start_block)) {
                        /*
                         * It's a delayed allocation extent, so skip it.
                         */
                        ep++;
                        continue;
                }

                *dest_ep = *(xfs_bmbt_rec_32_t *)ep;
                dest_ep++;
                ep++;
                copied++;
        }
        ASSERT(copied != 0);
        ASSERT(copied == ip->i_d.di_nextents);
        ASSERT((copied * (uint)sizeof(xfs_bmbt_rec_t)) <= XFS_IFORK_DSIZE(ip));
        xfs_validate_extents(buffer, copied, fmt);

        return (copied * (uint)sizeof(xfs_bmbt_rec_t));
}                 

/*
 * Each of the following cases stores data into the same region
 * of the on-disk inode, so only one of them can be valid at
 * any given time. While it is possible to have conflicting formats
 * and log flags, e.g. having XFS_ILOG_?DATA set when the fork is
 * in EXTENTS format, this can only happen when the fork has
 * changed formats after being modified but before being flushed.
 * In these cases, the format always takes precedence, because the
 * format indicates the current state of the fork.
 */
STATIC int
xfs_iflush_fork(
        xfs_inode_t             *ip,
        xfs_dinode_t            *dip,
        xfs_inode_log_item_t    *iip,
        int                     whichfork,
        xfs_buf_t               *bp)
{
        char                    *cp;
        xfs_ifork_t             *ifp;
        xfs_mount_t             *mp;
#ifdef XFS_TRANS_DEBUG
        int                     first;
#endif
        static const short      brootflag[2] =
                { XFS_ILOG_DBROOT, XFS_ILOG_ABROOT };
        static const short      dataflag[2] =
                { XFS_ILOG_DDATA, XFS_ILOG_ADATA };
        static const short      extflag[2] =
                { XFS_ILOG_DEXT, XFS_ILOG_AEXT };

        if (iip == NULL)
                return 0;
        ifp = XFS_IFORK_PTR(ip, whichfork);
        /*
         * This can happen if we gave up in iformat in an error path,
         * for the attribute fork.
         */
        if (ifp == NULL) {
                ASSERT(whichfork == XFS_ATTR_FORK);
                return 0;
        }
        cp = XFS_DFORK_PTR_ARCH(dip, whichfork, ARCH_CONVERT);
        mp = ip->i_mount;
        switch (XFS_IFORK_FORMAT(ip, whichfork)) {
        case XFS_DINODE_FMT_LOCAL:
                if ((iip->ili_format.ilf_fields & dataflag[whichfork]) &&
                    (ifp->if_bytes > 0)) {
                        ASSERT(ifp->if_u1.if_data != NULL);
                        ASSERT(ifp->if_bytes <= XFS_IFORK_SIZE(ip, whichfork));
                        bcopy(ifp->if_u1.if_data, cp, ifp->if_bytes);
                }
                if (whichfork == XFS_DATA_FORK) {
                        if (XFS_DIR_SHORTFORM_VALIDATE_ONDISK(mp, dip)) {
                                return XFS_ERROR(EFSCORRUPTED);
                        }
                }
                break;

        case XFS_DINODE_FMT_EXTENTS:
                ASSERT((ifp->if_flags & XFS_IFEXTENTS) ||
                       !(iip->ili_format.ilf_fields & extflag[whichfork]));
                ASSERT((ifp->if_u1.if_extents != NULL) || (ifp->if_bytes == 0));
                ASSERT((ifp->if_u1.if_extents == NULL) || (ifp->if_bytes > 0));
                if ((iip->ili_format.ilf_fields & extflag[whichfork]) &&
                    (ifp->if_bytes > 0)) {
                        ASSERT(XFS_IFORK_NEXTENTS(ip, whichfork) > 0);
                        (void)xfs_iextents_copy(ip, (xfs_bmbt_rec_32_t *)cp,
                                whichfork);
                }
                break;

        case XFS_DINODE_FMT_BTREE:
                if ((iip->ili_format.ilf_fields & brootflag[whichfork]) &&
                    (ifp->if_broot_bytes > 0)) {
                        ASSERT(ifp->if_broot != NULL);
                        ASSERT(ifp->if_broot_bytes <=
                               (XFS_IFORK_SIZE(ip, whichfork) +
                                XFS_BROOT_SIZE_ADJ));
                        xfs_bmbt_to_bmdr(ifp->if_broot, ifp->if_broot_bytes,
                                (xfs_bmdr_block_t *)cp,
                                XFS_DFORK_SIZE_ARCH(dip, mp, whichfork, ARCH_CONVERT));
                }
                break;

        case XFS_DINODE_FMT_DEV:
                if (iip->ili_format.ilf_fields & XFS_ILOG_DEV) {
                        ASSERT(whichfork == XFS_DATA_FORK);
                        INT_SET(dip->di_u.di_dev, ARCH_CONVERT, ip->i_df.if_u2.if_rdev);
                }
                break;
                
        case XFS_DINODE_FMT_UUID:
                if (iip->ili_format.ilf_fields & XFS_ILOG_UUID) {
                        ASSERT(whichfork == XFS_DATA_FORK);
                        bcopy(&ip->i_df.if_u2.if_uuid, &dip->di_u.di_muuid,
                                sizeof(uuid_t));
                }
                break;

        default:
                ASSERT(0);
                break;
        }

        return 0;
}