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[FreeBSD/FreeBSD.git] / sys / gnu / fs / xfs / xfs_inode.c

/*
 * Copyright (c) 2000-2003 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"
#include "xfs_macros.h"
#include "xfs_types.h"
#include "xfs_inum.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_alloc_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_btree.h"
#include "xfs_imap.h"
#include "xfs_alloc.h"
#include "xfs_ialloc.h"
#include "xfs_attr_sf.h"
#include "xfs_dir_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode_item.h"
#include "xfs_inode.h"
#include "xfs_bmap.h"
#include "xfs_buf_item.h"
#include "xfs_rw.h"
#include "xfs_error.h"
#include "xfs_bit.h"
#include "xfs_utils.h"
#include "xfs_dir2_trace.h"
#include "xfs_quota.h"
#include "xfs_mac.h"
#include "xfs_acl.h"


kmem_zone_t *xfs_ifork_zone;
kmem_zone_t *xfs_inode_zone;
kmem_zone_t *xfs_chashlist_zone;

/*
 * Used in xfs_itruncate().  This is the maximum number of extents
 * freed from a file in a single transaction.
 */
#define XFS_ITRUNC_MAX_EXTENTS  2

STATIC int xfs_iflush_int(xfs_inode_t *, xfs_buf_t *);
STATIC int xfs_iformat_local(xfs_inode_t *, xfs_dinode_t *, int, int);
STATIC int xfs_iformat_extents(xfs_inode_t *, xfs_dinode_t *, int);
STATIC int xfs_iformat_btree(xfs_inode_t *, xfs_dinode_t *, int);


#ifdef DEBUG
/*
 * Make sure that the extents in the given memory buffer
 * are valid.
 */
STATIC void
xfs_validate_extents(
        xfs_bmbt_rec_t          *ep,
        int                     nrecs,
        int                     disk,
        xfs_exntfmt_t           fmt)
{
        xfs_bmbt_irec_t         irec;
        xfs_bmbt_rec_t          rec;
        int                     i;

        for (i = 0; i < nrecs; i++) {
                rec.l0 = get_unaligned((__uint64_t*)&ep->l0);
                rec.l1 = get_unaligned((__uint64_t*)&ep->l1);
                if (disk)
                        xfs_bmbt_disk_get_all(&rec, &irec);
                else
                        xfs_bmbt_get_all(&rec, &irec);
                if (fmt == XFS_EXTFMT_NOSTATE)
                        ASSERT(irec.br_state == XFS_EXT_NORM);
                ep++;
        }
}
#else /* DEBUG */
#define xfs_validate_extents(ep, nrecs, disk, fmt)
#endif /* DEBUG */

/*
 * Check that none of the inode's in the buffer have a next
 * unlinked field of 0.
 */
#if defined(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 number within a file
 * system 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.
 *
 * Use xfs_imap() to determine the size and location of the
 * buffer to read from disk.
 */
int
xfs_inotobp(
        xfs_mount_t     *mp,
        xfs_trans_t     *tp,
        xfs_ino_t       ino,
        xfs_dinode_t    **dipp,
        xfs_buf_t       **bpp,
        int             *offset)
{
        int             di_ok;
        xfs_imap_t      imap;
        xfs_buf_t       *bp;
        int             error;
        xfs_dinode_t    *dip;

        /*
         * Call the space managment code to find the location of the
         * inode on disk.
         */
        imap.im_blkno = 0;
        error = xfs_imap(mp, tp, ino, &imap, XFS_IMAP_LOOKUP);
        if (error != 0) {
                cmn_err(CE_WARN,
        "xfs_inotobp: xfs_imap()  returned an "
        "error %d on %s.  Returning error.", error, mp->m_fsname);
                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)) {
                cmn_err(CE_WARN,
        "xfs_inotobp: inode number (%d + %d) maps to a block outside the bounds "
        "of the file system %s.  Returning EINVAL.",
                        imap.im_blkno, imap.im_len,mp->m_fsname);
                return XFS_ERROR(EINVAL);
        }

        /*
         * 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) {
                cmn_err(CE_WARN,
        "xfs_inotobp: xfs_trans_read_buf()  returned an "
        "error %d on %s.  Returning error.", error, mp->m_fsname);
                return error;
        }
        dip = (xfs_dinode_t *)xfs_buf_offset(bp, 0);
        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 (unlikely(XFS_TEST_ERROR(!di_ok, mp, XFS_ERRTAG_ITOBP_INOTOBP,
                        XFS_RANDOM_ITOBP_INOTOBP))) {
                XFS_CORRUPTION_ERROR("xfs_inotobp", XFS_ERRLEVEL_LOW, mp, dip);
                xfs_trans_brelse(tp, bp);
                cmn_err(CE_WARN,
        "xfs_inotobp: XFS_TEST_ERROR()  returned an "
        "error on %s.  Returning EFSCORRUPTED.",  mp->m_fsname);
                return XFS_ERROR(EFSCORRUPTED);
        }

        xfs_inobp_check(mp, bp);

        /*
         * 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;
        *offset = imap.im_boffset;
        return 0;
}


/*
 * 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)) {
#ifdef DEBUG
                        xfs_fs_cmn_err(CE_ALERT, mp, "xfs_itobp: "
                                        "(imap.im_blkno (0x%llx) "
                                        "+ imap.im_len (0x%llx)) > "
                                        " XFS_FSB_TO_BB(mp, "
                                        "mp->m_sb.sb_dblocks) (0x%llx)",
                                        (unsigned long long) imap.im_blkno,
                                        (unsigned long long) imap.im_len,
                                        XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks));
#endif /* DEBUG */
                        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) {
#ifdef DEBUG
                xfs_fs_cmn_err(CE_ALERT, mp, "xfs_itobp: "
                                "xfs_trans_read_buf() returned error %d, "
                                "imap.im_blkno 0x%llx, imap.im_len 0x%llx",
                                error, (unsigned long long) imap.im_blkno,
                                (unsigned long long) imap.im_len);
#endif /* DEBUG */
                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 (unlikely(XFS_TEST_ERROR(!di_ok, mp, XFS_ERRTAG_ITOBP_INOTOBP,
                                 XFS_RANDOM_ITOBP_INOTOBP))) {
#ifdef DEBUG
                        prdev("bad inode magic/vsn daddr %lld #%d (magic=%x)",
                                mp->m_ddev_targp,
                                (unsigned long long)imap.im_blkno, i,
                                INT_GET(dip->di_core.di_magic, ARCH_CONVERT));
#endif
                        XFS_CORRUPTION_ERROR("xfs_itobp", XFS_ERRLEVEL_HIGH,
                                             mp, dip);
                        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 (unlikely(
            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 = %Lu."
                        "  Unmount and run xfs_repair.",
                        (unsigned long long)ip->i_ino,
                        (int)(INT_GET(dip->di_core.di_nextents, ARCH_CONVERT)
                            + INT_GET(dip->di_core.di_anextents, ARCH_CONVERT)),
                        (unsigned long long)
                        INT_GET(dip->di_core.di_nblocks, ARCH_CONVERT));
                XFS_CORRUPTION_ERROR("xfs_iformat(1)", XFS_ERRLEVEL_LOW,
                                     ip->i_mount, dip);
                return XFS_ERROR(EFSCORRUPTED);
        }

        if (unlikely(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.",
                        (unsigned long long)ip->i_ino,
                        (int)(INT_GET(dip->di_core.di_forkoff, ARCH_CONVERT)));
                XFS_CORRUPTION_ERROR("xfs_iformat(2)", XFS_ERRLEVEL_LOW,
                                     ip->i_mount, dip);
                return XFS_ERROR(EFSCORRUPTED);
        }

        switch (ip->i_d.di_mode & S_IFMT) {
        case S_IFIFO:
        case S_IFCHR:
        case S_IFBLK:
        case S_IFSOCK:
                if (unlikely(INT_GET(dip->di_core.di_format, ARCH_CONVERT) != XFS_DINODE_FMT_DEV)) {
                        XFS_CORRUPTION_ERROR("xfs_iformat(3)", XFS_ERRLEVEL_LOW,
                                              ip->i_mount, dip);
                        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 S_IFREG:
        case S_IFLNK:
        case S_IFDIR:
                switch (INT_GET(dip->di_core.di_format, ARCH_CONVERT)) {
                case XFS_DINODE_FMT_LOCAL:
                        /*
                         * no local regular files yet
                         */
                        if (unlikely((INT_GET(dip->di_core.di_mode, ARCH_CONVERT) & S_IFMT) == S_IFREG)) {
                                xfs_fs_cmn_err(CE_WARN, ip->i_mount,
                                        "corrupt inode (local format for regular file) %Lu.  Unmount and run xfs_repair.",
                                        (unsigned long long) ip->i_ino);
                                XFS_CORRUPTION_ERROR("xfs_iformat(4)",
                                                     XFS_ERRLEVEL_LOW,
                                                     ip->i_mount, dip);
                                return XFS_ERROR(EFSCORRUPTED);
                        }

                        di_size = INT_GET(dip->di_core.di_size, ARCH_CONVERT);
                        if (unlikely(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.",
                                        (unsigned long long) ip->i_ino,
                                        (long long) di_size);
                                XFS_CORRUPTION_ERROR("xfs_iformat(5)",
                                                     XFS_ERRLEVEL_LOW,
                                                     ip->i_mount, dip);
                                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:
                        XFS_ERROR_REPORT("xfs_iformat(6)", XFS_ERRLEVEL_LOW,
                                         ip->i_mount);
                        return XFS_ERROR(EFSCORRUPTED);
                }
                break;

        default:
                XFS_ERROR_REPORT("xfs_iformat(7)", XFS_ERRLEVEL_LOW, ip->i_mount);
                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 memcpy() below.
         */
        if (unlikely(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.",
                        (unsigned long long) ip->i_ino, size,
                        XFS_DFORK_SIZE_ARCH(dip, ip->i_mount, whichfork, ARCH_CONVERT));
                XFS_CORRUPTION_ERROR("xfs_iformat_local", XFS_ERRLEVEL_LOW,
                                     ip->i_mount, dip);
                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)
                memcpy(ifp->if_u1.if_data,
                        XFS_DFORK_PTR_ARCH(dip, whichfork, ARCH_CONVERT), 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_bmbt_rec_t  *ep, *dp;
        xfs_ifork_t     *ifp;
        int             nex;
        int             real_size;
        int             size;
        int             i;

        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 memcpy() below.
         */
        if (unlikely(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.",
                        (unsigned long long) ip->i_ino, nex);
                XFS_CORRUPTION_ERROR("xfs_iformat_extents(1)", XFS_ERRLEVEL_LOW,
                                     ip->i_mount, dip);
                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) {
                dp = (xfs_bmbt_rec_t *)
                        XFS_DFORK_PTR_ARCH(dip, whichfork, ARCH_CONVERT);
                xfs_validate_extents(dp, nex, 1, XFS_EXTFMT_INODE(ip));
                ep = ifp->if_u1.if_extents;
                for (i = 0; i < nex; i++, ep++, dp++) {
                        ep->l0 = INT_GET(get_unaligned((__uint64_t*)&dp->l0),
                                                                ARCH_CONVERT);
                        ep->l1 = INT_GET(get_unaligned((__uint64_t*)&dp->l1),
                                                                ARCH_CONVERT);
                }
                xfs_bmap_trace_exlist("xfs_iformat_extents", ip, nex,
                        whichfork);
                if (whichfork != XFS_DATA_FORK ||
                        XFS_EXTFMT_INODE(ip) == XFS_EXTFMT_NOSTATE)
                                if (unlikely(xfs_check_nostate_extents(
                                    ifp->if_u1.if_extents, nex))) {
                                        XFS_ERROR_REPORT("xfs_iformat_extents(2)",
                                                         XFS_ERRLEVEL_LOW,
                                                         ip->i_mount);
                                        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 (unlikely(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.",
                        (unsigned long long) ip->i_ino);
                XFS_ERROR_REPORT("xfs_iformat_btree", XFS_ERRLEVEL_LOW,
                                 ip->i_mount);
                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 *)buf;
        xfs_dinode_core_t       *mem_core = (xfs_dinode_core_t *)dip;

        ASSERT(dir);
        if (arch == ARCH_NOCONVERT) {
                if (dir > 0) {
                        memcpy((xfs_caddr_t)mem_core, (xfs_caddr_t)buf_core,
                                sizeof(xfs_dinode_core_t));
                } else {
                        memcpy((xfs_caddr_t)buf_core, (xfs_caddr_t)mem_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) {
                memcpy(mem_core->di_pad, buf_core->di_pad,
                        sizeof(buf_core->di_pad));
        } else {
                memcpy(buf_core->di_pad, mem_core->di_pad,
                        sizeof(buf_core->di_pad));
        }

        INT_XLATE(buf_core->di_flushiter, mem_core->di_flushiter, dir, arch);

        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_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_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);
#ifdef DEBUG
                xfs_fs_cmn_err(CE_ALERT, mp, "xfs_iread: "
                                "dip->di_core.di_magic (0x%x) != "
                                "XFS_DINODE_MAGIC (0x%x)",
                                INT_GET(dip->di_core.di_magic, ARCH_CONVERT),
                                XFS_DINODE_MAGIC);
#endif /* DEBUG */
                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);
#ifdef DEBUG
                        xfs_fs_cmn_err(CE_ALERT, mp, "xfs_iread: "
                                        "xfs_iformat() returned error %d",
                                        error);
#endif /* DEBUG */
                        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);
                ip->i_d.di_flushiter = INT_GET(dip->di_core.di_flushiter, 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);
        }

        /* XXXKAN: initialize i_reclaim */
        bzero(&ip->i_reclaim, sizeof(&ip->i_reclaim));

        /*
         * 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 (unlikely(XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE)) {
                XFS_ERROR_REPORT("xfs_iread_extents", XFS_ERRLEVEL_LOW,
                                 ip->i_mount);
                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 valid (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_t *)ifp->if_u1.if_extents,
                XFS_IFORK_NEXTENTS(ip, whichfork), 0, XFS_EXTFMT_INODE(ip));
        return 0;
}

/*
 * Allocate an inode on disk and return a copy of its in-core version.
 * The in-core inode is locked exclusively.  Set mode, nlink, and rdev
 * appropriately within the inode.  The uid and gid for the inode are
 * set according to the contents of the given cred structure.
 *
 * Use xfs_dialloc() to allocate the on-disk inode. If xfs_dialloc()
 * has a free inode available, call xfs_iget()
 * to obtain the in-core version of the allocated inode.  Finally,
 * fill in the inode and log its initial contents.  In this case,
 * ialloc_context would be set to NULL and call_again set to false.
 *
 * If xfs_dialloc() does not have an available inode,
 * it will replenish its supply by doing an allocation. Since we can
 * only do one allocation within a transaction without deadlocks, we
 * must commit the current transaction before returning the inode itself.
 * In this case, therefore, we will set call_again to true and return.
 * The caller should then commit the current transaction, start a new
 * transaction, and call xfs_ialloc() again to actually get the inode.
 *
 * To ensure that some other process does not grab the inode that
 * was allocated during the first call to xfs_ialloc(), this routine
 * also returns the [locked] bp pointing to the head of the freelist
 * as ialloc_context.  The caller should hold this buffer across
 * the commit and pass it back into this routine on the second call.
 */
int
xfs_ialloc(
        xfs_trans_t     *tp,
        xfs_inode_t     *pip,
        mode_t          mode,
        nlink_t         nlink,
        xfs_dev_t       rdev,
        cred_t          *cr,
        xfs_prid_t      prid,
        int             okalloc,
        xfs_buf_t       **ialloc_context,
        boolean_t       *call_again,
        xfs_inode_t     **ipp)
{
        xfs_ino_t       ino;
        xfs_inode_t     *ip;
        xfs_vnode_t     *vp;
        uint            flags;
        int             error;

        /*
         * Call the space management code to pick
         * the on-disk inode to be allocated.
         */
        ASSERT(pip != NULL);
        error = xfs_dialloc(tp, pip ? pip->i_ino : 0, mode, okalloc,
                            ialloc_context, call_again, &ino);
        if (error != 0) {
                return error;
        }
        if (*call_again || ino == NULLFSINO) {
                *ipp = NULL;
                return 0;
        }
        ASSERT(*ialloc_context == NULL);

        /*
         * Get the in-core inode with the lock held exclusively.
         * This is because we're setting fields here we need
         * to prevent others from looking at until we're done.
         */
        error = xfs_trans_iget(tp->t_mountp, tp, ino, XFS_ILOCK_EXCL, &ip);
        if (error != 0) {
                return error;
        }
        ASSERT(ip != NULL);
        vp = XFS_ITOV(ip);
        ASSERT(vp != NULL);
        vp->v_type = IFTOVT(mode);
        ip->i_d.di_mode = (__uint16_t)mode;
        ip->i_d.di_onlink = 0;
        ip->i_d.di_nlink = nlink;
        ASSERT(ip->i_d.di_nlink == nlink);
        ip->i_d.di_uid = curthread->td_ucred->cr_uid;
        ip->i_d.di_gid = curthread->td_ucred->cr_groups[0];
        ip->i_d.di_projid = prid;
        memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));

        /*
         * If the superblock version is up to where we support new format
         * inodes and this is currently an old format inode, then change
         * the inode version number now.  This way we only do the conversion
         * here rather than here and in the flush/logging code.
         */
        if (XFS_SB_VERSION_HASNLINK(&tp->t_mountp->m_sb) &&
            ip->i_d.di_version == XFS_DINODE_VERSION_1) {
                ip->i_d.di_version = XFS_DINODE_VERSION_2;
                /*
                 * We've already zeroed the old link count, the projid field,
                 * and the pad field.
                 */
        }

        /*
         * Project ids won't be stored on disk if we are using a version 1 inode.
         */
        if ( (prid != 0) && (ip->i_d.di_version == XFS_DINODE_VERSION_1))
                xfs_bump_ino_vers2(tp, ip);

        if (XFS_INHERIT_GID(pip, vp->v_vfsp)) {
                ip->i_d.di_gid = pip->i_d.di_gid;
                if ((pip->i_d.di_mode & S_ISGID) && (mode & S_IFMT) == S_IFDIR) {
                        ip->i_d.di_mode |= S_ISGID;
                }
        }

        /*
         * If the group ID of the new file does not match the effective group
         * ID or one of the supplementary group IDs, the S_ISGID bit is cleared
         * (and only if the irix_sgid_inherit compatibility variable is set).
         */
        if ((irix_sgid_inherit) &&
            (ip->i_d.di_mode & S_ISGID) &&
            (!groupmember((gid_t)ip->i_d.di_gid, curthread->td_ucred))) {
                ip->i_d.di_mode &= ~S_ISGID;
        }

        ip->i_d.di_size = 0;
        ip->i_d.di_nextents = 0;
        ASSERT(ip->i_d.di_nblocks == 0);
        xfs_ichgtime(ip, XFS_ICHGTIME_CHG|XFS_ICHGTIME_ACC|XFS_ICHGTIME_MOD);
        /*
         * di_gen will have been taken care of in xfs_iread.
         */
        ip->i_d.di_extsize = 0;
        ip->i_d.di_dmevmask = 0;
        ip->i_d.di_dmstate = 0;
        ip->i_d.di_flags = 0;
        flags = XFS_ILOG_CORE;
        switch (mode & S_IFMT) {
        case S_IFIFO:
        case S_IFCHR:
        case S_IFBLK:
        case S_IFSOCK:
                ip->i_d.di_format = XFS_DINODE_FMT_DEV;
                ip->i_df.if_u2.if_rdev = rdev;
                ip->i_df.if_flags = 0;
                flags |= XFS_ILOG_DEV;
                break;
        case S_IFREG:
        case S_IFDIR:
                if (pip->i_d.di_flags &
                    (XFS_DIFLAG_NOATIME|XFS_DIFLAG_NODUMP|XFS_DIFLAG_SYNC)) {
                        if ((pip->i_d.di_flags & XFS_DIFLAG_NOATIME) &&
                            xfs_inherit_noatime)
                                ip->i_d.di_flags |= XFS_DIFLAG_NOATIME;
                        if ((pip->i_d.di_flags & XFS_DIFLAG_NODUMP) &&
                            xfs_inherit_nodump)
                                ip->i_d.di_flags |= XFS_DIFLAG_NODUMP;
                        if ((pip->i_d.di_flags & XFS_DIFLAG_SYNC) &&
                            xfs_inherit_sync)
                                ip->i_d.di_flags |= XFS_DIFLAG_SYNC;
                }
        case S_IFLNK:
                ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
                ip->i_df.if_flags = XFS_IFEXTENTS;
                ip->i_df.if_bytes = ip->i_df.if_real_bytes = 0;
                ip->i_df.if_u1.if_extents = NULL;
                break;
        default:
                ASSERT(0);
        }
        /*
         * Attribute fork settings for new inode.
         */
        ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
        ip->i_d.di_anextents = 0;

        /*
         * Log the new values stuffed into the inode.
         */
        xfs_trans_log_inode(tp, ip, flags);

        /* now that we have a v_type we can set Linux inode ops (& unlock) */
        XVFS_INIT_VNODE(XFS_MTOVFS(tp->t_mountp), vp, XFS_ITOBHV(ip), 1);

        *ipp = ip;
        return 0;
}

/*
 * Check to make sure that there are no blocks allocated to the
 * file beyond the size of the file.  We don't check this for
 * files with fixed size extents or real time extents, but we
 * at least do it for regular files.
 */
#ifdef DEBUG
void
xfs_isize_check(
        xfs_mount_t     *mp,
        xfs_inode_t     *ip,
        xfs_fsize_t     isize)
{
        xfs_fileoff_t   map_first;
        int             nimaps;
        xfs_bmbt_irec_t imaps[2];

        if ((ip->i_d.di_mode & S_IFMT) != S_IFREG)
                return;

        if ( ip->i_d.di_flags & XFS_DIFLAG_REALTIME )
                return;

        nimaps = 2;
        map_first = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
        /*
         * The filesystem could be shutting down, so bmapi may return
         * an error.
         */
        if (xfs_bmapi(NULL, ip, map_first,
                         (XFS_B_TO_FSB(mp,
                                       (xfs_ufsize_t)XFS_MAXIOFFSET(mp)) -
                          map_first),
                         XFS_BMAPI_ENTIRE, NULL, 0, imaps, &nimaps,
                         NULL))
            return;
        ASSERT(nimaps == 1);
        ASSERT(imaps[0].br_startblock == HOLESTARTBLOCK);
}
#endif  /* DEBUG */

/*
 * Calculate the last possible buffered byte in a file.  This must
 * include data that was buffered beyond the EOF by the write code.
 * This also needs to deal with overflowing the xfs_fsize_t type
 * which can happen for sizes near the limit.
 *
 * We also need to take into account any blocks beyond the EOF.  It
 * may be the case that they were buffered by a write which failed.
 * In that case the pages will still be in memory, but the inode size
 * will never have been updated.
 */
xfs_fsize_t
xfs_file_last_byte(
        xfs_inode_t     *ip)
{
        xfs_mount_t     *mp;
        xfs_fsize_t     last_byte;
        xfs_fileoff_t   last_block;
        xfs_fileoff_t   size_last_block;
        int             error;

        ASSERT(ismrlocked(&(ip->i_iolock), MR_UPDATE | MR_ACCESS));

        mp = ip->i_mount;
        /*
         * Only check for blocks beyond the EOF if the extents have
         * been read in.  This eliminates the need for the inode lock,
         * and it also saves us from looking when it really isn't
         * necessary.
         */
        if (ip->i_df.if_flags & XFS_IFEXTENTS) {
                error = xfs_bmap_last_offset(NULL, ip, &last_block,
                        XFS_DATA_FORK);
                if (error) {
                        last_block = 0;
                }
        } else {
                last_block = 0;
        }
        size_last_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)ip->i_d.di_size);
        last_block = XFS_FILEOFF_MAX(last_block, size_last_block);

        last_byte = XFS_FSB_TO_B(mp, last_block);
        if (last_byte < 0) {
                return XFS_MAXIOFFSET(mp);
        }
        last_byte += (1 << mp->m_writeio_log);
        if (last_byte < 0) {
                return XFS_MAXIOFFSET(mp);
        }
        return last_byte;
}

#if defined(XFS_RW_TRACE)
STATIC void
xfs_itrunc_trace(
        int             tag,
        xfs_inode_t     *ip,
        int             flag,
        xfs_fsize_t     new_size,
        xfs_off_t       toss_start,
        xfs_off_t       toss_finish)
{
        if (ip->i_rwtrace == NULL) {
                return;
        }

        ktrace_enter(ip->i_rwtrace,
                     (void*)((long)tag),
                     (void*)ip,
                     (void*)(unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff),
                     (void*)(unsigned long)(ip->i_d.di_size & 0xffffffff),
                     (void*)((long)flag),
                     (void*)(unsigned long)((new_size >> 32) & 0xffffffff),
                     (void*)(unsigned long)(new_size & 0xffffffff),
                     (void*)(unsigned long)((toss_start >> 32) & 0xffffffff),
                     (void*)(unsigned long)(toss_start & 0xffffffff),
                     (void*)(unsigned long)((toss_finish >> 32) & 0xffffffff),
                     (void*)(unsigned long)(toss_finish & 0xffffffff),
                     (void*)(unsigned long)current_cpu(),
                     (void*)0,
                     (void*)0,
                     (void*)0,
                     (void*)0);
}
#else
#define xfs_itrunc_trace(tag, ip, flag, new_size, toss_start, toss_finish)
#endif

/*
 * Start the truncation of the file to new_size.  The new size
 * must be smaller than the current size.  This routine will
 * clear the buffer and page caches of file data in the removed
 * range, and xfs_itruncate_finish() will remove the underlying
 * disk blocks.
 *
 * The inode must have its I/O lock locked EXCLUSIVELY, and it
 * must NOT have the inode lock held at all.  This is because we're
 * calling into the buffer/page cache code and we can't hold the
 * inode lock when we do so.
 *
 * The flags parameter can have either the value XFS_ITRUNC_DEFINITE
 * or XFS_ITRUNC_MAYBE.  The XFS_ITRUNC_MAYBE value should be used
 * in the case that the caller is locking things out of order and
 * may not be able to call xfs_itruncate_finish() with the inode lock
 * held without dropping the I/O lock.  If the caller must drop the
 * I/O lock before calling xfs_itruncate_finish(), then xfs_itruncate_start()
 * must be called again with all the same restrictions as the initial
 * call.
 */
void
xfs_itruncate_start(
        xfs_inode_t     *ip,
        uint            flags,
        xfs_fsize_t     new_size)
{
        xfs_fsize_t     last_byte;
        xfs_off_t       toss_start;
        xfs_mount_t     *mp;
        xfs_vnode_t     *vp;

        ASSERT(ismrlocked(&ip->i_iolock, MR_UPDATE) != 0);
        ASSERT((new_size == 0) || (new_size <= ip->i_d.di_size));
        ASSERT((flags == XFS_ITRUNC_DEFINITE) ||
               (flags == XFS_ITRUNC_MAYBE));

        mp = ip->i_mount;
        vp = XFS_ITOV(ip);
        /*
         * Call VOP_TOSS_PAGES() or VOP_FLUSHINVAL_PAGES() to get rid of pages and buffers
         * overlapping the region being removed.  We have to use
         * the less efficient VOP_FLUSHINVAL_PAGES() in the case that the
         * caller may not be able to finish the truncate without
         * dropping the inode's I/O lock.  Make sure
         * to catch any pages brought in by buffers overlapping
         * the EOF by searching out beyond the isize by our
         * block size. We round new_size up to a block boundary
         * so that we don't toss things on the same block as
         * new_size but before it.
         *
         * Before calling VOP_TOSS_PAGES() or VOP_FLUSHINVAL_PAGES(), make sure to
         * call remapf() over the same region if the file is mapped.
         * This frees up mapped file references to the pages in the
         * given range and for the VOP_FLUSHINVAL_PAGES() case it ensures
         * that we get the latest mapped changes flushed out.
         */
        toss_start = XFS_B_TO_FSB(mp, (xfs_ufsize_t)new_size);
        toss_start = XFS_FSB_TO_B(mp, toss_start);
        if (toss_start < 0) {
                /*
                 * The place to start tossing is beyond our maximum
                 * file size, so there is no way that the data extended
                 * out there.
                 */
                return;
        }
        last_byte = xfs_file_last_byte(ip);
        xfs_itrunc_trace(XFS_ITRUNC_START, ip, flags, new_size, toss_start,
                         last_byte);
        if (last_byte > toss_start) {
                if (flags & XFS_ITRUNC_DEFINITE) {
                        XVOP_TOSS_PAGES(vp, toss_start, -1, FI_REMAPF_LOCKED);
                } else {
                        XVOP_FLUSHINVAL_PAGES(vp, toss_start, -1, FI_REMAPF_LOCKED);
                }
        }

#ifdef DEBUG
        if (new_size == 0) {
                ASSERT(VN_CACHED(vp) == 0);
        }
#endif
}

/*
 * Shrink the file to the given new_size.  The new
 * size must be smaller than the current size.
 * This will free up the underlying blocks
 * in the removed range after a call to xfs_itruncate_start()
 * or xfs_atruncate_start().
 *
 * The transaction passed to this routine must have made
 * a permanent log reservation of at least XFS_ITRUNCATE_LOG_RES.
 * This routine may commit the given transaction and
 * start new ones, so make sure everything involved in
 * the transaction is tidy before calling here.
 * Some transaction will be returned to the caller to be
 * committed.  The incoming transaction must already include
 * the inode, and both inode locks must be held exclusively.
 * The inode must also be "held" within the transaction.  On
 * return the inode will be "held" within the returned transaction.
 * This routine does NOT require any disk space to be reserved
 * for it within the transaction.
 *
 * The fork parameter must be either xfs_attr_fork or xfs_data_fork,
 * and it indicates the fork which is to be truncated.  For the
 * attribute fork we only support truncation to size 0.
 *
 * We use the sync parameter to indicate whether or not the first
 * transaction we perform might have to be synchronous.  For the attr fork,
 * it needs to be so if the unlink of the inode is not yet known to be
 * permanent in the log.  This keeps us from freeing and reusing the
 * blocks of the attribute fork before the unlink of the inode becomes
 * permanent.
 *
 * For the data fork, we normally have to run synchronously if we're
 * being called out of the inactive path or we're being called
 * out of the create path where we're truncating an existing file.
 * Either way, the truncate needs to be sync so blocks don't reappear
 * in the file with altered data in case of a crash.  wsync filesystems
 * can run the first case async because anything that shrinks the inode
 * has to run sync so by the time we're called here from inactive, the
 * inode size is permanently set to 0.
 *
 * Calls from the truncate path always need to be sync unless we're
 * in a wsync filesystem and the file has already been unlinked.
 *
 * The caller is responsible for correctly setting the sync parameter.
 * It gets too hard for us to guess here which path we're being called
 * out of just based on inode state.
 */
int
xfs_itruncate_finish(
        xfs_trans_t     **tp,
        xfs_inode_t     *ip,
        xfs_fsize_t     new_size,
        int             fork,
        int             sync)
{
        xfs_fsblock_t   first_block;
        xfs_fileoff_t   first_unmap_block;
        xfs_fileoff_t   last_block;
        xfs_filblks_t   unmap_len=0;
        xfs_mount_t     *mp;
        xfs_trans_t     *ntp;
        int             done;
        int             committed;
        xfs_bmap_free_t free_list;
        int             error;

        ASSERT(ismrlocked(&ip->i_iolock, MR_UPDATE) != 0);
        ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0);
        ASSERT((new_size == 0) || (new_size <= ip->i_d.di_size));
        ASSERT(*tp != NULL);
        ASSERT((*tp)->t_flags & XFS_TRANS_PERM_LOG_RES);
        ASSERT(ip->i_transp == *tp);
        ASSERT(ip->i_itemp != NULL);
        ASSERT(ip->i_itemp->ili_flags & XFS_ILI_HOLD);


        ntp = *tp;
        mp = (ntp)->t_mountp;
        ASSERT(! XFS_NOT_DQATTACHED(mp, ip));

        /*
         * We only support truncating the entire attribute fork.
         */
        if (fork == XFS_ATTR_FORK) {
                new_size = 0LL;
        }
        first_unmap_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)new_size);
        xfs_itrunc_trace(XFS_ITRUNC_FINISH1, ip, 0, new_size, 0, 0);
        /*
         * The first thing we do is set the size to new_size permanently
         * on disk.  This way we don't have to worry about anyone ever
         * being able to look at the data being freed even in the face
         * of a crash.  What we're getting around here is the case where
         * we free a block, it is allocated to another file, it is written
         * to, and then we crash.  If the new data gets written to the
         * file but the log buffers containing the free and reallocation
         * don't, then we'd end up with garbage in the blocks being freed.
         * As long as we make the new_size permanent before actually
         * freeing any blocks it doesn't matter if they get writtten to.
         *
         * The callers must signal into us whether or not the size
         * setting here must be synchronous.  There are a few cases
         * where it doesn't have to be synchronous.  Those cases
         * occur if the file is unlinked and we know the unlink is
         * permanent or if the blocks being truncated are guaranteed
         * to be beyond the inode eof (regardless of the link count)
         * and the eof value is permanent.  Both of these cases occur
         * only on wsync-mounted filesystems.  In those cases, we're
         * guaranteed that no user will ever see the data in the blocks
         * that are being truncated so the truncate can run async.
         * In the free beyond eof case, the file may wind up with
         * more blocks allocated to it than it needs if we crash
         * and that won't get fixed until the next time the file
         * is re-opened and closed but that's ok as that shouldn't
         * be too many blocks.
         *
         * However, we can't just make all wsync xactions run async
         * because there's one call out of the create path that needs
         * to run sync where it's truncating an existing file to size
         * 0 whose size is > 0.
         *
         * It's probably possible to come up with a test in this
         * routine that would correctly distinguish all the above
         * cases from the values of the function parameters and the
         * inode state but for sanity's sake, I've decided to let the
         * layers above just tell us.  It's simpler to correctly figure
         * out in the layer above exactly under what conditions we
         * can run async and I think it's easier for others read and
         * follow the logic in case something has to be changed.
         * cscope is your friend -- rcc.
         *
         * The attribute fork is much simpler.
         *
         * For the attribute fork we allow the caller to tell us whether
         * the unlink of the inode that led to this call is yet permanent
         * in the on disk log.  If it is not and we will be freeing extents
         * in this inode then we make the first transaction synchronous
         * to make sure that the unlink is permanent by the time we free
         * the blocks.
         */
        if (fork == XFS_DATA_FORK) {
                if (ip->i_d.di_nextents > 0) {
                        ip->i_d.di_size = new_size;
                        xfs_trans_log_inode(ntp, ip, XFS_ILOG_CORE);
                }
        } else if (sync) {
                ASSERT(!(mp->m_flags & XFS_MOUNT_WSYNC));
                if (ip->i_d.di_anextents > 0)
                        xfs_trans_set_sync(ntp);
        }
        ASSERT(fork == XFS_DATA_FORK ||
                (fork == XFS_ATTR_FORK &&
                        ((sync && !(mp->m_flags & XFS_MOUNT_WSYNC)) ||
                         (sync == 0 && (mp->m_flags & XFS_MOUNT_WSYNC)))));

        /*
         * Since it is possible for space to become allocated beyond
         * the end of the file (in a crash where the space is allocated
         * but the inode size is not yet updated), simply remove any
         * blocks which show up between the new EOF and the maximum
         * possible file size.  If the first block to be removed is
         * beyond the maximum file size (ie it is the same as last_block),
         * then there is nothing to do.
         */
        last_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
        ASSERT(first_unmap_block <= last_block);
        done = 0;
        if (last_block == first_unmap_block) {
                done = 1;
        } else {
                unmap_len = last_block - first_unmap_block + 1;
        }
        while (!done) {
                /*
                 * Free up up to XFS_ITRUNC_MAX_EXTENTS.  xfs_bunmapi()
                 * will tell us whether it freed the entire range or
                 * not.  If this is a synchronous mount (wsync),
                 * then we can tell bunmapi to keep all the
                 * transactions asynchronous since the unlink
                 * transaction that made this inode inactive has
                 * already hit the disk.  There's no danger of
                 * the freed blocks being reused, there being a
                 * crash, and the reused blocks suddenly reappearing
                 * in this file with garbage in them once recovery
                 * runs.
                 */
                XFS_BMAP_INIT(&free_list, &first_block);
                error = xfs_bunmapi(ntp, ip, first_unmap_block,
                                    unmap_len,
                                    XFS_BMAPI_AFLAG(fork) |
                                      (sync ? 0 : XFS_BMAPI_ASYNC),
                                    XFS_ITRUNC_MAX_EXTENTS,
                                    &first_block, &free_list, &done);
                if (error) {
                        /*
                         * If the bunmapi call encounters an error,
                         * return to the caller where the transaction
                         * can be properly aborted.  We just need to
                         * make sure we're not holding any resources
                         * that we were not when we came in.
                         */
                        xfs_bmap_cancel(&free_list);
                        return error;
                }

                /*
                 * Duplicate the transaction that has the permanent
                 * reservation and commit the old transaction.
                 */
                error = xfs_bmap_finish(tp, &free_list, first_block,
                                        &committed);
                ntp = *tp;
                if (error) {
                        /*
                         * If the bmap finish call encounters an error,
                         * return to the caller where the transaction
                         * can be properly aborted.  We just need to
                         * make sure we're not holding any resources
                         * that we were not when we came in.
                         *
                         * Aborting from this point might lose some
                         * blocks in the file system, but oh well.
                         */
                        xfs_bmap_cancel(&free_list);
                        if (committed) {
                                /*
                                 * If the passed in transaction committed
                                 * in xfs_bmap_finish(), then we want to
                                 * add the inode to this one before returning.
                                 * This keeps things simple for the higher
                                 * level code, because it always knows that
                                 * the inode is locked and held in the
                                 * transaction that returns to it whether
                                 * errors occur or not.  We don't mark the
                                 * inode dirty so that this transaction can
                                 * be easily aborted if possible.
                                 */
                                xfs_trans_ijoin(ntp, ip,
                                        XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
                                xfs_trans_ihold(ntp, ip);
                        }
                        return error;
                }

                if (committed) {
                        /*
                         * The first xact was committed,
                         * so add the inode to the new one.
                         * Mark it dirty so it will be logged
                         * and moved forward in the log as
                         * part of every commit.
                         */
                        xfs_trans_ijoin(ntp, ip,
                                        XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
                        xfs_trans_ihold(ntp, ip);
                        xfs_trans_log_inode(ntp, ip, XFS_ILOG_CORE);
                }
                ntp = xfs_trans_dup(ntp);
                (void) xfs_trans_commit(*tp, 0, NULL);
                *tp = ntp;
                error = xfs_trans_reserve(ntp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
                                          XFS_TRANS_PERM_LOG_RES,
                                          XFS_ITRUNCATE_LOG_COUNT);
                /*
                 * Add the inode being truncated to the next chained
                 * transaction.
                 */
                xfs_trans_ijoin(ntp, ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
                xfs_trans_ihold(ntp, ip);
                if (error)
                        return (error);
        }
        /*
         * Only update the size in the case of the data fork, but
         * always re-log the inode so that our permanent transaction
         * can keep on rolling it forward in the log.
         */
        if (fork == XFS_DATA_FORK) {
                xfs_isize_check(mp, ip, new_size);
                ip->i_d.di_size = new_size;
        }
        xfs_trans_log_inode(ntp, ip, XFS_ILOG_CORE);
        ASSERT((new_size != 0) ||
               (fork == XFS_ATTR_FORK) ||
               (ip->i_delayed_blks == 0));
        ASSERT((new_size != 0) ||
               (fork == XFS_ATTR_FORK) ||
               (ip->i_d.di_nextents == 0));
        xfs_itrunc_trace(XFS_ITRUNC_FINISH2, ip, 0, new_size, 0, 0);
        return 0;
}


/*
 * xfs_igrow_start
 *
 * Do the first part of growing a file: zero any data in the last
 * block that is beyond the old EOF.  We need to do this before
 * the inode is joined to the transaction to modify the i_size.
 * That way we can drop the inode lock and call into the buffer
 * cache to get the buffer mapping the EOF.
 */
int
xfs_igrow_start(
        xfs_inode_t     *ip,
        xfs_fsize_t     new_size,
        cred_t          *credp)
{
        xfs_fsize_t     isize;
        int             error;

        ASSERT(ismrlocked(&(ip->i_lock), MR_UPDATE) != 0);
        ASSERT(ismrlocked(&(ip->i_iolock), MR_UPDATE) != 0);
        ASSERT(new_size > ip->i_d.di_size);

        error = 0;
        isize = ip->i_d.di_size;
        /*
         * Zero any pages that may have been created by
         * xfs_write_file() beyond the end of the file
         * and any blocks between the old and new file sizes.
         */
        error = xfs_zero_eof(XFS_ITOV(ip), &ip->i_iocore, new_size, isize,
                                new_size);
        return error;
}

/*
 * xfs_igrow_finish
 *
 * This routine is called to extend the size of a file.
 * The inode must have both the iolock and the ilock locked
 * for update and it must be a part of the current transaction.
 * The xfs_igrow_start() function must have been called previously.
 * If the change_flag is not zero, the inode change timestamp will
 * be updated.
 */
void
xfs_igrow_finish(
        xfs_trans_t     *tp,
        xfs_inode_t     *ip,
        xfs_fsize_t     new_size,
        int             change_flag)
{
        ASSERT(ismrlocked(&(ip->i_lock), MR_UPDATE) != 0);
        ASSERT(ismrlocked(&(ip->i_iolock), MR_UPDATE) != 0);
        ASSERT(ip->i_transp == tp);
        ASSERT(new_size > ip->i_d.di_size);

        /*
         * Update the file size.  Update the inode change timestamp
         * if change_flag set.
         */
        ip->i_d.di_size = new_size;
        if (change_flag)
                xfs_ichgtime(ip, XFS_ICHGTIME_CHG);
        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

}


/*
 * This is called when the inode's link count goes to 0.
 * We place the on-disk inode on a list in the AGI.  It
 * will be pulled from this list when the inode is freed.
 */
int
xfs_iunlink(
        xfs_trans_t     *tp,
        xfs_inode_t     *ip)
{
        xfs_mount_t     *mp;
        xfs_agi_t       *agi;
        xfs_dinode_t    *dip;
        xfs_buf_t       *agibp;
        xfs_buf_t       *ibp;
        xfs_agnumber_t  agno;
        xfs_daddr_t     agdaddr;
        xfs_agino_t     agino;
        short           bucket_index;
        int             offset;
        int             error;
        int             agi_ok;

        ASSERT(ip->i_d.di_nlink == 0);
        ASSERT(ip->i_d.di_mode != 0);
        ASSERT(ip->i_transp == tp);

        mp = tp->t_mountp;

        agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
        agdaddr = XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp));

        /*
         * Get the agi buffer first.  It ensures lock ordering
         * on the list.
         */
        error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, agdaddr,
                                   XFS_FSS_TO_BB(mp, 1), 0, &agibp);
        if (error) {
                return error;
        }
        /*
         * Validate the magic number of the agi block.
         */
        agi = XFS_BUF_TO_AGI(agibp);
        agi_ok =
                INT_GET(agi->agi_magicnum, ARCH_CONVERT) == XFS_AGI_MAGIC &&
                XFS_AGI_GOOD_VERSION(INT_GET(agi->agi_versionnum, ARCH_CONVERT));
        if (unlikely(XFS_TEST_ERROR(!agi_ok, mp, XFS_ERRTAG_IUNLINK,
                        XFS_RANDOM_IUNLINK))) {
                XFS_CORRUPTION_ERROR("xfs_iunlink", XFS_ERRLEVEL_LOW, mp, agi);
                xfs_trans_brelse(tp, agibp);
                return XFS_ERROR(EFSCORRUPTED);
        }
        /*
         * Get the index into the agi hash table for the
         * list this inode will go on.
         */
        agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
        ASSERT(agino != 0);
        bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
        ASSERT(!INT_ISZERO(agi->agi_unlinked[bucket_index], ARCH_CONVERT));
        ASSERT(INT_GET(agi->agi_unlinked[bucket_index], ARCH_CONVERT) != agino);

        if (INT_GET(agi->agi_unlinked[bucket_index], ARCH_CONVERT) != NULLAGINO) {
                /*
                 * There is already another inode in the bucket we need
                 * to add ourselves to.  Add us at the front of the list.
                 * Here we put the head pointer into our next pointer,
                 * and then we fall through to point the head at us.
                 */
                error = xfs_itobp(mp, tp, ip, &dip, &ibp, 0);
                if (error) {
                        return error;
                }
                ASSERT(INT_GET(dip->di_next_unlinked, ARCH_CONVERT) == NULLAGINO);
                ASSERT(!INT_ISZERO(dip->di_next_unlinked, ARCH_CONVERT));
                /* both on-disk, don't endian flip twice */
                dip->di_next_unlinked = agi->agi_unlinked[bucket_index];
                offset = ip->i_boffset +
                        offsetof(xfs_dinode_t, di_next_unlinked);
                xfs_trans_inode_buf(tp, ibp);
                xfs_trans_log_buf(tp, ibp, offset,
                                  (offset + sizeof(xfs_agino_t) - 1));
                xfs_inobp_check(mp, ibp);
        }

        /*
         * Point the bucket head pointer at the inode being inserted.
         */
        ASSERT(agino != 0);
        INT_SET(agi->agi_unlinked[bucket_index], ARCH_CONVERT, agino);
        offset = offsetof(xfs_agi_t, agi_unlinked) +
                (sizeof(xfs_agino_t) * bucket_index);
        xfs_trans_log_buf(tp, agibp, offset,
                          (offset + sizeof(xfs_agino_t) - 1));
        return 0;
}

/*
 * Pull the on-disk inode from the AGI unlinked list.
 */
STATIC int
xfs_iunlink_remove(
        xfs_trans_t     *tp,
        xfs_inode_t     *ip)
{
        xfs_ino_t       next_ino;
        xfs_mount_t     *mp;
        xfs_agi_t       *agi;
        xfs_dinode_t    *dip;
        xfs_buf_t       *agibp;
        xfs_buf_t       *ibp;
        xfs_agnumber_t  agno;
        xfs_daddr_t     agdaddr;
        xfs_agino_t     agino;
        xfs_agino_t     next_agino;
        xfs_buf_t       *last_ibp;
        xfs_dinode_t    *last_dip;
        short           bucket_index;
        int             offset, last_offset;
        int             error;
        int             agi_ok;

        /*
         * First pull the on-disk inode from the AGI unlinked list.
         */
        mp = tp->t_mountp;

        agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
        agdaddr = XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp));

        /*
         * Get the agi buffer first.  It ensures lock ordering
         * on the list.
         */
        error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, agdaddr,
                                   XFS_FSS_TO_BB(mp, 1), 0, &agibp);
        if (error) {
                cmn_err(CE_WARN,
                        "xfs_iunlink_remove: xfs_trans_read_buf()  returned an error %d on %s.  Returning error.",
                        error, mp->m_fsname);
                return error;
        }
        /*
         * Validate the magic number of the agi block.
         */
        agi = XFS_BUF_TO_AGI(agibp);
        agi_ok =
                INT_GET(agi->agi_magicnum, ARCH_CONVERT) == XFS_AGI_MAGIC &&
                XFS_AGI_GOOD_VERSION(INT_GET(agi->agi_versionnum, ARCH_CONVERT));
        if (unlikely(XFS_TEST_ERROR(!agi_ok, mp, XFS_ERRTAG_IUNLINK_REMOVE,
                        XFS_RANDOM_IUNLINK_REMOVE))) {
                XFS_CORRUPTION_ERROR("xfs_iunlink_remove", XFS_ERRLEVEL_LOW,
                                     mp, agi);
                xfs_trans_brelse(tp, agibp);
                cmn_err(CE_WARN,
                        "xfs_iunlink_remove: XFS_TEST_ERROR()  returned an error on %s.  Returning EFSCORRUPTED.",
                         mp->m_fsname);
                return XFS_ERROR(EFSCORRUPTED);
        }
        /*
         * Get the index into the agi hash table for the
         * list this inode will go on.
         */
        agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
        ASSERT(agino != 0);
        bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
        ASSERT(INT_GET(agi->agi_unlinked[bucket_index], ARCH_CONVERT) != NULLAGINO);
        ASSERT(!INT_ISZERO(agi->agi_unlinked[bucket_index], ARCH_CONVERT));

        if (INT_GET(agi->agi_unlinked[bucket_index], ARCH_CONVERT) == agino) {
                /*
                 * We're at the head of the list.  Get the inode's
                 * on-disk buffer to see if there is anyone after us
                 * on the list.  Only modify our next pointer if it
                 * is not already NULLAGINO.  This saves us the overhead
                 * of dealing with the buffer when there is no need to
                 * change it.
                 */
                error = xfs_itobp(mp, tp, ip, &dip, &ibp, 0);
                if (error) {
                        cmn_err(CE_WARN,
                                "xfs_iunlink_remove: xfs_itobp()  returned an error %d on %s.  Returning error.",
                                error, mp->m_fsname);
                        return error;
                }
                next_agino = INT_GET(dip->di_next_unlinked, ARCH_CONVERT);
                ASSERT(next_agino != 0);
                if (next_agino != NULLAGINO) {
                        INT_SET(dip->di_next_unlinked, ARCH_CONVERT, NULLAGINO);
                        offset = ip->i_boffset +
                                offsetof(xfs_dinode_t, di_next_unlinked);
                        xfs_trans_inode_buf(tp, ibp);
                        xfs_trans_log_buf(tp, ibp, offset,
                                          (offset + sizeof(xfs_agino_t) - 1));
                        xfs_inobp_check(mp, ibp);
                } else {
                        xfs_trans_brelse(tp, ibp);
                }
                /*
                 * Point the bucket head pointer at the next inode.
                 */
                ASSERT(next_agino != 0);
                ASSERT(next_agino != agino);
                INT_SET(agi->agi_unlinked[bucket_index], ARCH_CONVERT, next_agino);
                offset = offsetof(xfs_agi_t, agi_unlinked) +
                        (sizeof(xfs_agino_t) * bucket_index);
                xfs_trans_log_buf(tp, agibp, offset,
                                  (offset + sizeof(xfs_agino_t) - 1));
        } else {
                /*
                 * We need to search the list for the inode being freed.
                 */
                next_agino = INT_GET(agi->agi_unlinked[bucket_index], ARCH_CONVERT);
                last_ibp = NULL;
                while (next_agino != agino) {
                        /*
                         * If the last inode wasn't the one pointing to
                         * us, then release its buffer since we're not
                         * going to do anything with it.
                         */
                        if (last_ibp != NULL) {
                                xfs_trans_brelse(tp, last_ibp);
                        }
                        next_ino = XFS_AGINO_TO_INO(mp, agno, next_agino);
                        error = xfs_inotobp(mp, tp, next_ino, &last_dip,
                                            &last_ibp, &last_offset);
                        if (error) {
                                cmn_err(CE_WARN,
                        "xfs_iunlink_remove: xfs_inotobp()  returned an error %d on %s.  Returning error.",
                                        error, mp->m_fsname);
                                return error;
                        }
                        next_agino = INT_GET(last_dip->di_next_unlinked, ARCH_CONVERT);
                        ASSERT(next_agino != NULLAGINO);
                        ASSERT(next_agino != 0);
                }
                /*
                 * Now last_ibp points to the buffer previous to us on
                 * the unlinked list.  Pull us from the list.
                 */
                error = xfs_itobp(mp, tp, ip, &dip, &ibp, 0);
                if (error) {
                        cmn_err(CE_WARN,
                                "xfs_iunlink_remove: xfs_itobp()  returned an error %d on %s.  Returning error.",
                                error, mp->m_fsname);
                        return error;
                }
                next_agino = INT_GET(dip->di_next_unlinked, ARCH_CONVERT);
                ASSERT(next_agino != 0);
                ASSERT(next_agino != agino);
                if (next_agino != NULLAGINO) {
                        INT_SET(dip->di_next_unlinked, ARCH_CONVERT, NULLAGINO);
                        offset = ip->i_boffset +
                                offsetof(xfs_dinode_t, di_next_unlinked);
                        xfs_trans_inode_buf(tp, ibp);
                        xfs_trans_log_buf(tp, ibp, offset,
                                          (offset + sizeof(xfs_agino_t) - 1));
                        xfs_inobp_check(mp, ibp);
                } else {
                        xfs_trans_brelse(tp, ibp);
                }
                /*
                 * Point the previous inode on the list to the next inode.
                 */
                INT_SET(last_dip->di_next_unlinked, ARCH_CONVERT, next_agino);
                ASSERT(next_agino != 0);
                offset = last_offset + offsetof(xfs_dinode_t, di_next_unlinked);
                xfs_trans_inode_buf(tp, last_ibp);
                xfs_trans_log_buf(tp, last_ibp, offset,
                                  (offset + sizeof(xfs_agino_t) - 1));
                xfs_inobp_check(mp, last_ibp);
        }
        return 0;
}

static __inline__ int xfs_inode_clean(xfs_inode_t *ip)
{
        return (((ip->i_itemp == NULL) ||
                !(ip->i_itemp->ili_format.ilf_fields & XFS_ILOG_ALL)) &&
                (ip->i_update_core == 0));
}

STATIC void
xfs_ifree_cluster(
        xfs_inode_t     *free_ip,
        xfs_trans_t     *tp,
        xfs_ino_t       inum)
{
        xfs_mount_t             *mp = free_ip->i_mount;
        int                     blks_per_cluster;
        int                     nbufs;
        int                     ninodes;
        int                     i, j, found, pre_flushed;
        xfs_daddr_t             blkno;
        xfs_buf_t               *bp;
        xfs_ihash_t             *ih;
        xfs_inode_t             *ip, **ip_found;
        xfs_inode_log_item_t    *iip;
        xfs_log_item_t          *lip;
        SPLDECL(s);

        if (mp->m_sb.sb_blocksize >= XFS_INODE_CLUSTER_SIZE(mp)) {
                blks_per_cluster = 1;
                ninodes = mp->m_sb.sb_inopblock;
                nbufs = XFS_IALLOC_BLOCKS(mp);
        } else {
                blks_per_cluster = XFS_INODE_CLUSTER_SIZE(mp) /
                                        mp->m_sb.sb_blocksize;
                ninodes = blks_per_cluster * mp->m_sb.sb_inopblock;
                nbufs = XFS_IALLOC_BLOCKS(mp) / blks_per_cluster;
        }

        ip_found = kmem_alloc(ninodes * sizeof(xfs_inode_t *), KM_NOFS);

        for (j = 0; j < nbufs; j++, inum += ninodes) {
                blkno = XFS_AGB_TO_DADDR(mp, XFS_INO_TO_AGNO(mp, inum),
                                         XFS_INO_TO_AGBNO(mp, inum));


                /*
                 * Look for each inode in memory and attempt to lock it,
                 * we can be racing with flush and tail pushing here.
                 * any inode we get the locks on, add to an array of
                 * inode items to process later.
                 *
                 * The get the buffer lock, we could beat a flush
                 * or tail pushing thread to the lock here, in which
                 * case they will go looking for the inode buffer
                 * and fail, we need some other form of interlock
                 * here.
                 */
                found = 0;
                for (i = 0; i < ninodes; i++) {
                        ih = XFS_IHASH(mp, inum + i);
                        read_lock(&ih->ih_lock);
                        for (ip = ih->ih_next; ip != NULL; ip = ip->i_next) {
                                if (ip->i_ino == inum + i)
                                        break;
                        }

                        /* Inode not in memory or we found it already,
                         * nothing to do
                         */
                        if (!ip || (ip->i_flags & XFS_ISTALE)) {
                                read_unlock(&ih->ih_lock);
                                continue;
                        }

                        if (xfs_inode_clean(ip)) {
                                read_unlock(&ih->ih_lock);
                                continue;
                        }

                        /* If we can get the locks then add it to the
                         * list, otherwise by the time we get the bp lock
                         * below it will already be attached to the
                         * inode buffer.
                         */

                        /* This inode will already be locked - by us, lets
                         * keep it that way.
                         */

                        if (ip == free_ip) {
                                if (xfs_iflock_nowait(ip)) {
                                        ip->i_flags |= XFS_ISTALE;

                                        if (xfs_inode_clean(ip)) {
                                                xfs_ifunlock(ip);
                                        } else {
                                                ip_found[found++] = ip;
                                        }
                                }
                                read_unlock(&ih->ih_lock);
                                continue;
                        }

                        if (xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) {
                                if (xfs_iflock_nowait(ip)) {
                                        ip->i_flags |= XFS_ISTALE;

                                        if (xfs_inode_clean(ip)) {
                                                xfs_ifunlock(ip);
                                                xfs_iunlock(ip, XFS_ILOCK_EXCL);
                                        } else {
                                                ip_found[found++] = ip;
                                        }
                                } else {
                                        xfs_iunlock(ip, XFS_ILOCK_EXCL);
                                }
                        }

                        read_unlock(&ih->ih_lock);
                }

                bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, blkno, 
                                        mp->m_bsize * blks_per_cluster,
                                        XFS_BUF_LOCK);

                pre_flushed = 0;
                lip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *);
                while (lip) {
                        if (lip->li_type == XFS_LI_INODE) {
                                iip = (xfs_inode_log_item_t *)lip;
                                ASSERT(iip->ili_logged == 1);
                                lip->li_cb = (void(*)(xfs_buf_t*,xfs_log_item_t*)) xfs_istale_done;
                                AIL_LOCK(mp,s);
                                iip->ili_flush_lsn = iip->ili_item.li_lsn;
                                AIL_UNLOCK(mp, s);
                                iip->ili_inode->i_flags |= XFS_ISTALE;
                                pre_flushed++;
                        }
                        lip = lip->li_bio_list;
                }

                for (i = 0; i < found; i++) {
                        ip = ip_found[i];
                        iip = ip->i_itemp;

                        if (!iip) {
                                ip->i_update_core = 0;
                                xfs_ifunlock(ip);
                                xfs_iunlock(ip, XFS_ILOCK_EXCL);
                                continue;
                        }

                        iip->ili_last_fields = iip->ili_format.ilf_fields;
                        iip->ili_format.ilf_fields = 0;
                        iip->ili_logged = 1;
                        AIL_LOCK(mp,s);
                        iip->ili_flush_lsn = iip->ili_item.li_lsn;
                        AIL_UNLOCK(mp, s);

                        xfs_buf_attach_iodone(bp,
                                (void(*)(xfs_buf_t*,xfs_log_item_t*))
                                xfs_istale_done, (xfs_log_item_t *)iip);
                        if (ip != free_ip) {
                                xfs_iunlock(ip, XFS_ILOCK_EXCL);
                        }
                }

                if (found || pre_flushed)
                        xfs_trans_stale_inode_buf(tp, bp);
                xfs_trans_binval(tp, bp);
        }

        kmem_free(ip_found, ninodes * sizeof(xfs_inode_t *));
}

/*
 * This is called to return an inode to the inode free list.
 * The inode should already be truncated to 0 length and have
 * no pages associated with it.  This routine also assumes that
 * the inode is already a part of the transaction.
 *
 * The on-disk copy of the inode will have been added to the list
 * of unlinked inodes in the AGI. We need to remove the inode from
 * that list atomically with respect to freeing it here.
 */
int
xfs_ifree(
        xfs_trans_t     *tp,
        xfs_inode_t     *ip,
        xfs_bmap_free_t *flist)
{
        int                     error;
        int                     delete;
        xfs_ino_t               first_ino;

        ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE));
        ASSERT(ip->i_transp == tp);
        ASSERT(ip->i_d.di_nlink == 0);
        ASSERT(ip->i_d.di_nextents == 0);
        ASSERT(ip->i_d.di_anextents == 0);
        ASSERT((ip->i_d.di_size == 0) ||
               ((ip->i_d.di_mode & S_IFMT) != S_IFREG));
        ASSERT(ip->i_d.di_nblocks == 0);

        /*
         * Pull the on-disk inode from the AGI unlinked list.
         */
        error = xfs_iunlink_remove(tp, ip);
        if (error != 0) {
                return error;
        }

        error = xfs_difree(tp, ip->i_ino, flist, &delete, &first_ino);
        if (error != 0) {
                return error;
        }
        ip->i_d.di_mode = 0;            /* mark incore inode as free */
        ip->i_d.di_flags = 0;
        ip->i_d.di_dmevmask = 0;
        ip->i_d.di_forkoff = 0;         /* mark the attr fork not in use */
        ip->i_df.if_ext_max =
                XFS_IFORK_DSIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t);
        ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
        ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
        /*
         * Bump the generation count so no one will be confused
         * by reincarnations of this inode.
         */
        ip->i_d.di_gen++;
        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

        if (delete) {
                xfs_ifree_cluster(ip, tp, first_ino);
        }

        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);
                memmove(np, op, 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.
                 */
                memcpy(new_broot, ifp->if_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);
                memcpy(np, op, 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);
                memcpy(np, op, 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) {
                                memcpy(ifp->if_u2.if_inline_ext,
                                        ifp->if_u1.if_extents, 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);
                        memcpy(ifp->if_u1.if_extents, ifp->if_u2.if_inline_ext,
                              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_NOFS);
                }
        }
        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);
                        memcpy(ifp->if_u2.if_inline_data, ifp->if_u1.if_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);
                        memcpy(ifp->if_u1.if_data, ifp->if_u2.if_inline_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;
        }
}

/*
 * This is called free all the memory associated with an inode.
 * It must free the inode itself and any buffers allocated for
 * if_extents/if_data and if_broot.  It must also free the lock
 * associated with the inode.
 */
void
xfs_idestroy(
        xfs_inode_t     *ip)
{

        switch (ip->i_d.di_mode & S_IFMT) {
        case S_IFREG:
        case S_IFDIR:
        case S_IFLNK:
                xfs_idestroy_fork(ip, XFS_DATA_FORK);
                break;
        }
        if (ip->i_afp)
                xfs_idestroy_fork(ip, XFS_ATTR_FORK);
        mrfree(&ip->i_lock);
        mrfree(&ip->i_iolock);
        freesema(&ip->i_flock);
#ifdef XFS_BMAP_TRACE
        ktrace_free(ip->i_xtrace);
#endif
#ifdef XFS_BMBT_TRACE
        ktrace_free(ip->i_btrace);
#endif
#ifdef XFS_RW_TRACE
        ktrace_free(ip->i_rwtrace);
#endif
#ifdef XFS_ILOCK_TRACE
        ktrace_free(ip->i_lock_trace);
#endif
#ifdef XFS_DIR2_TRACE
        ktrace_free(ip->i_dir_trace);
#endif
        if (ip->i_itemp) {
                /* XXXdpd should be able to assert this but shutdown
                 * is leaving the AIL behind. */
                ASSERT(((ip->i_itemp->ili_item.li_flags & XFS_LI_IN_AIL) == 0) ||
                       XFS_FORCED_SHUTDOWN(ip->i_mount));
                xfs_inode_item_destroy(ip);
        }
        kmem_zone_free(xfs_inode_zone, ip);
}


/*
 * Increment the pin count of the given buffer.
 * This value is protected by ipinlock spinlock in the mount structure.
 */
void
xfs_ipin(
        xfs_inode_t     *ip)
{
        ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE));

        atomic_inc(&ip->i_pincount);
}

/*
 * Decrement the pin count of the given inode, and wake up
 * anyone in xfs_iwait_unpin() if the count goes to 0.  The
 * inode must have been previoulsy pinned with a call to xfs_ipin().
 */
void
xfs_iunpin(
        xfs_inode_t     *ip)
{
        ASSERT(atomic_read(&ip->i_pincount) > 0);

        if (atomic_dec_and_test(&ip->i_pincount)) {
#if XXXKAN
                /*
                 * Should I mark FreeBSD vnode as dirty here?
                 */
                printf("%s:%d: Should I mark FreeBSD vnode as dirty here?\n",
                    __FILE__, __LINE__);
                xfs_vnode_t     *vp = XFS_ITOV_NULL(ip);

                /* make sync come back and flush this inode */
                if (vp) {
                        struct inode    *inode = LINVFS_GET_IP(vp);

                        if (!(inode->i_state & I_NEW))
                                mark_inode_dirty_sync(inode);
                }
#endif

                wakeup(&ip->i_ipin_wait);
        }
}

/*
 * This is called to wait for the given inode to be unpinned.
 * It will sleep until this happens.  The caller must have the
 * inode locked in at least shared mode so that the buffer cannot
 * be subsequently pinned once someone is waiting for it to be
 * unpinned.
 */
STATIC void
xfs_iunpin_wait(
        xfs_inode_t     *ip)
{
        xfs_inode_log_item_t    *iip;
        xfs_lsn_t       lsn;

        ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE | MR_ACCESS));

        if (atomic_read(&ip->i_pincount) == 0) {
                return;
        }

        iip = ip->i_itemp;
        if (iip && iip->ili_last_lsn) {
                lsn = iip->ili_last_lsn;
        } else {
                lsn = (xfs_lsn_t)0;
        }

        /*
         * Give the log a push so we don't wait here too long.
         */
        xfs_log_force(ip->i_mount, lsn, XFS_LOG_FORCE);

        /*
         * XXXKAN: xfs_iunpin is not locking inode
         * at all?
         */
        while(atomic_read(&ip->i_pincount) != 0)
                tsleep(&ip->i_ipin_wait, PRIBIO, "iunpin", 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
 * memcpy() 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_t          *buffer,
        int                     whichfork)
{
        int                     copied;
        xfs_bmbt_rec_t          *dest_ep;
        xfs_bmbt_rec_t          *ep;
#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);

        /*
         * 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.
         */
        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;
                }

                /* Translate to on disk format */
                put_unaligned(INT_GET(ep->l0, ARCH_CONVERT),
                              (__uint64_t*)&dest_ep->l0);
                put_unaligned(INT_GET(ep->l1, ARCH_CONVERT),
                              (__uint64_t*)&dest_ep->l1);
                dest_ep++;
                ep++;
                copied++;
        }
        ASSERT(copied != 0);
        xfs_validate_extents(buffer, copied, 1, XFS_EXTFMT_INODE(ip));

        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.
 */
/*ARGSUSED*/
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));
                        memcpy(cp, ifp->if_u1.if_data, ifp->if_bytes);
                }
                if (whichfork == XFS_DATA_FORK) {
                        if (unlikely(XFS_DIR_SHORTFORM_VALIDATE_ONDISK(mp, dip))) {
                                XFS_ERROR_REPORT("xfs_iflush_fork",
                                                 XFS_ERRLEVEL_LOW, mp);
                                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_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);
                        memcpy(&dip->di_u.di_muuid, &ip->i_df.if_u2.if_uuid,
                                sizeof(uuid_t));
                }
                break;

        default:
                ASSERT(0);
                break;
        }

        return 0;
}

/*
 * xfs_iflush() will write a modified inode's changes out to the
 * inode's on disk home.  The caller must have the inode lock held
 * in at least shared mode and the inode flush semaphore must be
 * held as well.  The inode lock will still be held upon return from
 * the call and the caller is free to unlock it.
 * The inode flush lock will be unlocked when the inode reaches the disk.
 * The flags indicate how the inode's buffer should be written out.
 */
int
xfs_iflush(
        xfs_inode_t             *ip,
        uint                    flags)
{
        xfs_inode_log_item_t    *iip;
        xfs_buf_t               *bp;
        xfs_dinode_t            *dip;
        xfs_mount_t             *mp;
        int                     error;
        /* REFERENCED */
        xfs_chash_t             *ch;
        xfs_inode_t             *iq;
        int                     clcount;        /* count of inodes clustered */
        int                     bufwasdelwri;
        enum { INT_DELWRI = (1 << 0), INT_ASYNC = (1 << 1) };
        SPLDECL(s);

        XFS_STATS_INC(xs_iflush_count);

        ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE|MR_ACCESS));
        ASSERT(valusema(&ip->i_flock) <= 0);
        ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
               ip->i_d.di_nextents > ip->i_df.if_ext_max);

        iip = ip->i_itemp;
        mp = ip->i_mount;

        /*
         * If the inode isn't dirty, then just release the inode
         * flush lock and do nothing.
         */
        if ((ip->i_update_core == 0) &&
            ((iip == NULL) || !(iip->ili_format.ilf_fields & XFS_ILOG_ALL))) {
                ASSERT((iip != NULL) ?
                         !(iip->ili_item.li_flags & XFS_LI_IN_AIL) : 1);
                xfs_ifunlock(ip);
                return 0;
        }

        /*
         * We can't flush the inode until it is unpinned, so
         * wait for it.  We know noone new can pin it, because
         * we are holding the inode lock shared and you need
         * to hold it exclusively to pin the inode.
         */
        xfs_iunpin_wait(ip);

        /*
         * This may have been unpinned because the filesystem is shutting
         * down forcibly. If that's the case we must not write this inode
         * to disk, because the log record didn't make it to disk!
         */
        if (XFS_FORCED_SHUTDOWN(mp)) {
                ip->i_update_core = 0;
                if (iip)
                        iip->ili_format.ilf_fields = 0;
                xfs_ifunlock(ip);
                return XFS_ERROR(EIO);
        }

        /*
         * Get the buffer containing the on-disk inode.
         */
        error = xfs_itobp(mp, NULL, ip, &dip, &bp, 0);
        if (error != 0) {
                xfs_ifunlock(ip);
                return error;
        }

        /*
         * Decide how buffer will be flushed out.  This is done before
         * the call to xfs_iflush_int because this field is zeroed by it.
         */
        if (iip != NULL && iip->ili_format.ilf_fields != 0) {
                /*
                 * Flush out the inode buffer according to the directions
                 * of the caller.  In the cases where the caller has given
                 * us a choice choose the non-delwri case.  This is because
                 * the inode is in the AIL and we need to get it out soon.
                 */
                switch (flags) {
                case XFS_IFLUSH_SYNC:
                case XFS_IFLUSH_DELWRI_ELSE_SYNC:
                        flags = 0;
                        break;
                case XFS_IFLUSH_ASYNC:
                case XFS_IFLUSH_DELWRI_ELSE_ASYNC:
                        flags = INT_ASYNC;
                        break;
                case XFS_IFLUSH_DELWRI:
                        flags = INT_DELWRI;
                        break;
                default:
                        ASSERT(0);
                        flags = 0;
                        break;
                }
        } else {
                switch (flags) {
                case XFS_IFLUSH_DELWRI_ELSE_SYNC:
                case XFS_IFLUSH_DELWRI_ELSE_ASYNC:
                case XFS_IFLUSH_DELWRI:
                        flags = INT_DELWRI;
                        break;
                case XFS_IFLUSH_ASYNC:
                        flags = INT_ASYNC;
                        break;
                case XFS_IFLUSH_SYNC:
                        flags = 0;
                        break;
                default:
                        ASSERT(0);
                        flags = 0;
                        break;
                }
        }

        /*
         * First flush out the inode that xfs_iflush was called with.
         */
        error = xfs_iflush_int(ip, bp);
        if (error) {
                goto corrupt_out;
        }

        /*
         * inode clustering:
         * see if other inodes can be gathered into this write
         */

        ip->i_chash->chl_buf = bp;

        ch = XFS_CHASH(mp, ip->i_blkno);
        s = mutex_spinlock(&ch->ch_lock);

        clcount = 0;
        for (iq = ip->i_cnext; iq != ip; iq = iq->i_cnext) {
                /*
                 * Do an un-protected check to see if the inode is dirty and
                 * is a candidate for flushing.  These checks will be repeated
                 * later after the appropriate locks are acquired.
                 */
                iip = iq->i_itemp;
                if ((iq->i_update_core == 0) &&
                    ((iip == NULL) ||
                     !(iip->ili_format.ilf_fields & XFS_ILOG_ALL)) &&
                      xfs_ipincount(iq) == 0) {
                        continue;
                }

                /*
                 * Try to get locks.  If any are unavailable,
                 * then this inode cannot be flushed and is skipped.
                 */

                /* get inode locks (just i_lock) */
                if (xfs_ilock_nowait(iq, XFS_ILOCK_SHARED)) {
                        /* get inode flush lock */
                        if (xfs_iflock_nowait(iq)) {
                                /* check if pinned */
                                if (xfs_ipincount(iq) == 0) {
                                        /* arriving here means that
                                         * this inode can be flushed.
                                         * first re-check that it's
                                         * dirty
                                         */
                                        iip = iq->i_itemp;
                                        if ((iq->i_update_core != 0)||
                                            ((iip != NULL) &&
                                             (iip->ili_format.ilf_fields & XFS_ILOG_ALL))) {
                                                clcount++;
                                                error = xfs_iflush_int(iq, bp);
                                                if (error) {
                                                        xfs_iunlock(iq,
                                                                    XFS_ILOCK_SHARED);
                                                        goto cluster_corrupt_out;
                                                }
                                        } else {
                                                xfs_ifunlock(iq);
                                        }
                                } else {
                                        xfs_ifunlock(iq);
                                }
                        }
                        xfs_iunlock(iq, XFS_ILOCK_SHARED);
                }
        }
        mutex_spinunlock(&ch->ch_lock, s);

        if (clcount) {
                XFS_STATS_INC(xs_icluster_flushcnt);
                XFS_STATS_ADD(xs_icluster_flushinode, clcount);
        }

        /*
         * If the buffer is pinned then push on the log so we won't
         * get stuck waiting in the write for too long.
         */
        if (XFS_BUF_ISPINNED(bp)){
                xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE);
        }

        if (flags & INT_DELWRI) {
                xfs_bdwrite(mp, bp);
        } else if (flags & INT_ASYNC) {
                xfs_bawrite(mp, bp);
        } else {
                error = xfs_bwrite(mp, bp);
        }
        return error;

corrupt_out:
        xfs_buf_relse(bp);
        xfs_force_shutdown(mp, XFS_CORRUPT_INCORE);
        xfs_iflush_abort(ip);
        /*
         * Unlocks the flush lock
         */
        return XFS_ERROR(EFSCORRUPTED);

cluster_corrupt_out:
        /* Corruption detected in the clustering loop.  Invalidate the
         * inode buffer and shut down the filesystem.
         */
        mutex_spinunlock(&ch->ch_lock, s);

        /*
         * Clean up the buffer.  If it was B_DELWRI, just release it --
         * brelse can handle it with no problems.  If not, shut down the
         * filesystem before releasing the buffer.
         */
        if ((bufwasdelwri= XFS_BUF_ISDELAYWRITE(bp))) {
                xfs_buf_relse(bp);
        }

        xfs_force_shutdown(mp, XFS_CORRUPT_INCORE);

        if(!bufwasdelwri)  {
                /*
                 * Just like incore_relse: if we have b_iodone functions,
                 * mark the buffer as an error and call them.  Otherwise
                 * mark it as stale and brelse.
                 */
                if (XFS_BUF_IODONE_FUNC(bp)) {
                        XFS_BUF_CLR_BDSTRAT_FUNC(bp);
                        XFS_BUF_UNDONE(bp);
                        XFS_BUF_STALE(bp);
                        XFS_BUF_SHUT(bp);
                        XFS_BUF_ERROR(bp,EIO);
                        xfs_biodone(bp);
                } else {
                        XFS_BUF_STALE(bp);
                        xfs_buf_relse(bp);
                }
        }

        xfs_iflush_abort(iq);
        /*
         * Unlocks the flush lock
         */
        return XFS_ERROR(EFSCORRUPTED);
}


STATIC int
xfs_iflush_int(
        xfs_inode_t             *ip,
        xfs_buf_t               *bp)
{
        xfs_inode_log_item_t    *iip;
        xfs_dinode_t            *dip;
        xfs_mount_t             *mp;
#ifdef XFS_TRANS_DEBUG
        int                     first;
#endif
        SPLDECL(s);

        ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE|MR_ACCESS));
        ASSERT(valusema(&ip->i_flock) <= 0);
        ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
               ip->i_d.di_nextents > ip->i_df.if_ext_max);

        iip = ip->i_itemp;
        mp = ip->i_mount;


        /*
         * If the inode isn't dirty, then just release the inode
         * flush lock and do nothing.
         */
        if ((ip->i_update_core == 0) &&
            ((iip == NULL) || !(iip->ili_format.ilf_fields & XFS_ILOG_ALL))) {
                xfs_ifunlock(ip);
                return 0;
        }

        /* set *dip = inode's place in the buffer */
        dip = (xfs_dinode_t *)xfs_buf_offset(bp, ip->i_boffset);

        /*
         * Clear i_update_core before copying out the data.
         * This is for coordination with our timestamp updates
         * that don't hold the inode lock. They will always
         * update the timestamps BEFORE setting i_update_core,
         * so if we clear i_update_core after they set it we
         * are guaranteed to see their updates to the timestamps.
         * I believe that this depends on strongly ordered memory
         * semantics, but we have that.  We use the SYNCHRONIZE
         * macro to make sure that the compiler does not reorder
         * the i_update_core access below the data copy below.
         */
        ip->i_update_core = 0;
        SYNCHRONIZE();

        if (XFS_TEST_ERROR(INT_GET(dip->di_core.di_magic,ARCH_CONVERT) != XFS_DINODE_MAGIC,
                               mp, XFS_ERRTAG_IFLUSH_1, XFS_RANDOM_IFLUSH_1)) {
                xfs_cmn_err(XFS_PTAG_IFLUSH, CE_ALERT, mp,
                    "xfs_iflush: Bad inode %Lu magic number 0x%x, ptr 0x%p",
                        ip->i_ino, (int) INT_GET(dip->di_core.di_magic, ARCH_CONVERT), dip);
                goto corrupt_out;
        }
        if (XFS_TEST_ERROR(ip->i_d.di_magic != XFS_DINODE_MAGIC,
                                mp, XFS_ERRTAG_IFLUSH_2, XFS_RANDOM_IFLUSH_2)) {
                xfs_cmn_err(XFS_PTAG_IFLUSH, CE_ALERT, mp,
                        "xfs_iflush: Bad inode %Lu, ptr 0x%p, magic number 0x%x",
                        ip->i_ino, ip, ip->i_d.di_magic);
                goto corrupt_out;
        }
        if ((ip->i_d.di_mode & S_IFMT) == S_IFREG) {
                if (XFS_TEST_ERROR(
                    (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
                    (ip->i_d.di_format != XFS_DINODE_FMT_BTREE),
                    mp, XFS_ERRTAG_IFLUSH_3, XFS_RANDOM_IFLUSH_3)) {
                        xfs_cmn_err(XFS_PTAG_IFLUSH, CE_ALERT, mp,
                                "xfs_iflush: Bad regular inode %Lu, ptr 0x%p",
                                ip->i_ino, ip);
                        goto corrupt_out;
                }
        } else if ((ip->i_d.di_mode & S_IFMT) == S_IFDIR) {
                if (XFS_TEST_ERROR(
                    (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
                    (ip->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
                    (ip->i_d.di_format != XFS_DINODE_FMT_LOCAL),
                    mp, XFS_ERRTAG_IFLUSH_4, XFS_RANDOM_IFLUSH_4)) {
                        xfs_cmn_err(XFS_PTAG_IFLUSH, CE_ALERT, mp,
                                "xfs_iflush: Bad directory inode %Lu, ptr 0x%p",
                                ip->i_ino, ip);
                        goto corrupt_out;
                }
        }
        if (XFS_TEST_ERROR(ip->i_d.di_nextents + ip->i_d.di_anextents >
                                ip->i_d.di_nblocks, mp, XFS_ERRTAG_IFLUSH_5,
                                XFS_RANDOM_IFLUSH_5)) {
                xfs_cmn_err(XFS_PTAG_IFLUSH, CE_ALERT, mp,
                        "xfs_iflush: detected corrupt incore inode %Lu, total extents = %d, nblocks = %Ld, ptr 0x%p",
                        ip->i_ino,
                        ip->i_d.di_nextents + ip->i_d.di_anextents,
                        ip->i_d.di_nblocks,
                        ip);
                goto corrupt_out;
        }
        if (XFS_TEST_ERROR(ip->i_d.di_forkoff > mp->m_sb.sb_inodesize,
                                mp, XFS_ERRTAG_IFLUSH_6, XFS_RANDOM_IFLUSH_6)) {
                xfs_cmn_err(XFS_PTAG_IFLUSH, CE_ALERT, mp,
                        "xfs_iflush: bad inode %Lu, forkoff 0x%x, ptr 0x%p",
                        ip->i_ino, ip->i_d.di_forkoff, ip);
                goto corrupt_out;
        }
        /*
         * bump the flush iteration count, used to detect flushes which
         * postdate a log record during recovery.
         */

        ip->i_d.di_flushiter++;

        /*
         * Copy the dirty parts of the inode into the on-disk
         * inode.  We always copy out the core of the inode,
         * because if the inode is dirty at all the core must
         * be.
         */
        xfs_xlate_dinode_core((xfs_caddr_t)&(dip->di_core), &(ip->i_d),
                -1, ARCH_CONVERT);

        /* Wrap, we never let the log put out DI_MAX_FLUSH */
        if (ip->i_d.di_flushiter == DI_MAX_FLUSH)
                ip->i_d.di_flushiter = 0;

        /*
         * If this is really an old format inode and the superblock version
         * has not been updated to support only new format inodes, then
         * convert back to the old inode format.  If the superblock version
         * has been updated, then make the conversion permanent.
         */
        ASSERT(ip->i_d.di_version == XFS_DINODE_VERSION_1 ||
               XFS_SB_VERSION_HASNLINK(&mp->m_sb));
        if (ip->i_d.di_version == XFS_DINODE_VERSION_1) {
                if (!XFS_SB_VERSION_HASNLINK(&mp->m_sb)) {
                        /*
                         * Convert it back.
                         */
                        ASSERT(ip->i_d.di_nlink <= XFS_MAXLINK_1);
                        INT_SET(dip->di_core.di_onlink, ARCH_CONVERT, ip->i_d.di_nlink);
                } else {
                        /*
                         * The superblock version has already been bumped,
                         * so just make the conversion to the new inode
                         * format permanent.
                         */
                        ip->i_d.di_version = XFS_DINODE_VERSION_2;
                        INT_SET(dip->di_core.di_version, ARCH_CONVERT, XFS_DINODE_VERSION_2);
                        ip->i_d.di_onlink = 0;
                        INT_ZERO(dip->di_core.di_onlink, ARCH_CONVERT);
                        memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
                        memset(&(dip->di_core.di_pad[0]), 0,
                              sizeof(dip->di_core.di_pad));
                        ASSERT(ip->i_d.di_projid == 0);
                }
        }

        if (xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK, bp) == EFSCORRUPTED) {
                goto corrupt_out;
        }

        if (XFS_IFORK_Q(ip)) {
                /*
                 * The only error from xfs_iflush_fork is on the data fork.
                 */
                (void) xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK, bp);
        }
        xfs_inobp_check(mp, bp);

        /*
         * We've recorded everything logged in the inode, so we'd
         * like to clear the ilf_fields bits so we don't log and
         * flush things unnecessarily.  However, we can't stop
         * logging all this information until the data we've copied
         * into the disk buffer is written to disk.  If we did we might
         * overwrite the copy of the inode in the log with all the
         * data after re-logging only part of it, and in the face of
         * a crash we wouldn't have all the data we need to recover.
         *
         * What we do is move the bits to the ili_last_fields field.
         * When logging the inode, these bits are moved back to the
         * ilf_fields field.  In the xfs_iflush_done() routine we
         * clear ili_last_fields, since we know that the information
         * those bits represent is permanently on disk.  As long as
         * the flush completes before the inode is logged again, then
         * both ilf_fields and ili_last_fields will be cleared.
         *
         * We can play with the ilf_fields bits here, because the inode
         * lock must be held exclusively in order to set bits there
         * and the flush lock protects the ili_last_fields bits.
         * Set ili_logged so the flush done
         * routine can tell whether or not to look in the AIL.
         * Also, store the current LSN of the inode so that we can tell
         * whether the item has moved in the AIL from xfs_iflush_done().
         * In order to read the lsn we need the AIL lock, because
         * it is a 64 bit value that cannot be read atomically.
         */
        if (iip != NULL && iip->ili_format.ilf_fields != 0) {
                iip->ili_last_fields = iip->ili_format.ilf_fields;
                iip->ili_format.ilf_fields = 0;
                iip->ili_logged = 1;

                ASSERT(sizeof(xfs_lsn_t) == 8); /* don't lock if it shrinks */
                AIL_LOCK(mp,s);
                iip->ili_flush_lsn = iip->ili_item.li_lsn;
                AIL_UNLOCK(mp, s);

                /*
                 * Attach the function xfs_iflush_done to the inode's
                 * buffer.  This will remove the inode from the AIL
                 * and unlock the inode's flush lock when the inode is
                 * completely written to disk.
                 */
                xfs_buf_attach_iodone(bp, (void(*)(xfs_buf_t*,xfs_log_item_t*))
                                      xfs_iflush_done, (xfs_log_item_t *)iip);

                ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL);
                ASSERT(XFS_BUF_IODONE_FUNC(bp) != NULL);
        } else {
                /*
                 * We're flushing an inode which is not in the AIL and has
                 * not been logged but has i_update_core set.  For this
                 * case we can use a B_DELWRI flush and immediately drop
                 * the inode flush lock because we can avoid the whole
                 * AIL state thing.  It's OK to drop the flush lock now,
                 * because we've already locked the buffer and to do anything
                 * you really need both.
                 */
                if (iip != NULL) {
                        ASSERT(iip->ili_logged == 0);
                        ASSERT(iip->ili_last_fields == 0);
                        ASSERT((iip->ili_item.li_flags & XFS_LI_IN_AIL) == 0);
                }
                xfs_ifunlock(ip);
        }

        return 0;

corrupt_out:
        return XFS_ERROR(EFSCORRUPTED);
}

/*
 * Flush all inactive inodes in mp.  Return true if no user references
 * were found, false otherwise.
 */
int
xfs_iflush_all(
        xfs_mount_t     *mp,
        int             flag)
{
        int             busy;
        int             done;
        int             purged;
        xfs_inode_t     *ip;
        vmap_t          vmap;
        xfs_vnode_t     *vp;

        busy = done = 0;
        while (!done) {
                purged = 0;
                XFS_MOUNT_ILOCK(mp);
                ip = mp->m_inodes;
                if (ip == NULL) {
                        break;
                }
                do {
                        /* Make sure we skip markers inserted by sync */
                        if (ip->i_mount == NULL) {
                                ip = ip->i_mnext;
                                continue;
                        }

                        /*
                         * It's up to our caller to purge the root
                         * and quota vnodes later.
                         */
                        vp = XFS_ITOV_NULL(ip);

                        if (!vp) {
                                XFS_MOUNT_IUNLOCK(mp);
                                xfs_finish_reclaim(ip, 0, XFS_IFLUSH_ASYNC);
                                purged = 1;
                                break;
                        }

                        if (vn_count(vp) != 0) {
                                if (vn_count(vp) == 1 &&
                                    (ip == mp->m_rootip ||
                                     (mp->m_quotainfo &&
                                      (ip->i_ino == mp->m_sb.sb_uquotino ||
                                       ip->i_ino == mp->m_sb.sb_gquotino)))) {

                                        ip = ip->i_mnext;
                                        continue;
                                }
                                if (!(flag & XFS_FLUSH_ALL)) {
                                        busy = 1;
                                        done = 1;
                                        break;
                                }
                                /*
                                 * Ignore busy inodes but continue flushing
                                 * others.
                                 */
                                ip = ip->i_mnext;
                                continue;
                        }
                        /*
                         * Sample vp mapping while holding mp locked on MP
                         * systems, so we don't purge a reclaimed or
                         * nonexistent vnode.  We break from the loop
                         * since we know that we modify
                         * it by pulling ourselves from it in xfs_reclaim()
                         * called via vn_purge() below.  Set ip to the next
                         * entry in the list anyway so we'll know below
                         * whether we reached the end or not.
                         */
                        VMAP(vp, vmap);
                        XFS_MOUNT_IUNLOCK(mp);

                        vn_purge(vp, &vmap);

                        purged = 1;
                        break;
                } while (ip != mp->m_inodes);
                /*
                 * We need to distinguish between when we exit the loop
                 * after a purge and when we simply hit the end of the
                 * list.  We can't use the (ip == mp->m_inodes) test,
                 * because when we purge an inode at the start of the list
                 * the next inode on the list becomes mp->m_inodes.  That
                 * would cause such a test to bail out early.  The purged
                 * variable tells us how we got out of the loop.
                 */
                if (!purged) {
                        done = 1;
                }
        }
        XFS_MOUNT_IUNLOCK(mp);
        return !busy;
}


/*
 * xfs_iaccess: check accessibility of inode for mode.
 */
int
xfs_iaccess(
        xfs_inode_t     *ip,
        mode_t          mode,
        cred_t          *cr)
{
        xfs_vnode_t     *vp;
        int             error;
        mode_t          imode;

        vp = XFS_ITOV(ip);
        imode = (ip->i_d.di_mode & MODEMASK) | VTTOIF(vp->v_type);

        if (mode & S_IWUSR) {
                xfs_mount_t     *mp = ip->i_mount;

                if ((XVFSTOMNT(XFS_MTOVFS(mp))->mnt_flag & MNT_RDONLY) &&
                    (S_ISREG(imode) || S_ISDIR(imode) || S_ISLNK(imode)))
                        return XFS_ERROR(EROFS);

#if XXXKAN
                if (IS_IMMUTABLE(inode))
                        return XFS_ERROR(EACCES);
#endif
        }

        /*
         * If there's an Access Control List it's used instead of
         * the mode bits.
         */
        if ((error = _ACL_XFS_IACCESS(ip, mode, cr)) != -1)
                return error ? XFS_ERROR(error) : 0;


        error = vaccess(vp->v_type, imode, ip->i_d.di_uid, ip->i_d.di_gid,
            mode, cr, NULL);

        return (error);
}

/*
 * 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 );
}

/*
 * Change the requested timestamp in the given inode.
 * We don't lock across timestamp updates, and we don't log them but
 * we do record the fact that there is dirty information in core.
 *
 * NOTE -- callers MUST combine XFS_ICHGTIME_MOD or XFS_ICHGTIME_CHG
 *              with XFS_ICHGTIME_ACC to be sure that access time
 *              update will take.  Calling first with XFS_ICHGTIME_ACC
 *              and then XFS_ICHGTIME_MOD may fail to modify the access
 *              timestamp if the filesystem is mounted noacctm.
 */
void
xfs_ichgtime(xfs_inode_t *ip,
             int flags)
{
        timespec_t      tv;
        xfs_vnode_t     *vp = XFS_ITOV(ip);
        /*
         * We're not supposed to change timestamps in readonly-mounted
         * filesystems.  Throw it away if anyone asks us.
         */
        if (unlikely(vp->v_vfsp->vfs_flag & VFS_RDONLY))
                return;

        /*
         * Don't update access timestamps on reads if mounted "noatime"
         * Throw it away if anyone asks us.
         */
        if ((ip->i_mount->m_flags & XFS_MOUNT_NOATIME ||
            (ip->i_d.di_flags & XFS_DIFLAG_NOATIME)) &&
            ((flags & (XFS_ICHGTIME_ACC|XFS_ICHGTIME_MOD|XFS_ICHGTIME_CHG))
                        == XFS_ICHGTIME_ACC))
                return;

        nanotime(&tv);
        if (flags & XFS_ICHGTIME_MOD) {
                VN_MTIMESET(vp, &tv);
                ip->i_d.di_mtime.t_sec = (__int32_t)tv.tv_sec;
        }
        if (flags & XFS_ICHGTIME_ACC) {
                VN_ATIMESET(vp, &tv);
                ip->i_d.di_atime.t_sec = (__int32_t)tv.tv_sec;
        }
        if (flags & XFS_ICHGTIME_CHG) {
                VN_CTIMESET(vp, &tv);
                ip->i_d.di_ctime.t_sec = (__int32_t)tv.tv_sec;
        }

        /*
         * We update the i_update_core field _after_ changing
         * the timestamps in order to coordinate properly with
         * xfs_iflush() so that we don't lose timestamp updates.
         * This keeps us from having to hold the inode lock
         * while doing this.  We use the SYNCHRONIZE macro to
         * ensure that the compiler does not reorder the update
         * of i_update_core above the timestamp updates above.
         */
        SYNCHRONIZE();
        ip->i_update_core = 1;
#if XXXKAN
        if (!(inode->i_state & I_LOCK))
                mark_inode_dirty_sync(inode);

        printf("xfs_ichgtime mark vnode dirty\n");
#endif
}

#ifdef XFS_ILOCK_TRACE
ktrace_t        *xfs_ilock_trace_buf;

void
xfs_ilock_trace(xfs_inode_t *ip, int lock, unsigned int lockflags, inst_t *ra)
{
        ktrace_enter(ip->i_lock_trace,
                     (void *)ip,
                     (void *)(unsigned long)lock, /* 1 = LOCK, 3=UNLOCK, etc */
                     (void *)(unsigned long)lockflags, /* XFS_ILOCK_EXCL etc */
                     (void *)ra,                /* caller of ilock */
                     (void *)(unsigned long)current_cpu(),
                     (void *)(unsigned long)current_pid(),
                     0,0,0,0,0,0,0,0,0,0);
}
#endif