x86/amd-iommu: Add per IOMMU reference counting

[linux/fpc-iii.git] / fs / xfs / xfs_inode_item.c

/*
 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms 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.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_buf_item.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_trans_priv.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_rw.h"
#include "xfs_error.h"


kmem_zone_t     *xfs_ili_zone;          /* inode log item zone */

/*
 * This returns the number of iovecs needed to log the given inode item.
 *
 * We need one iovec for the inode log format structure, one for the
 * inode core, and possibly one for the inode data/extents/b-tree root
 * and one for the inode attribute data/extents/b-tree root.
 */
STATIC uint
xfs_inode_item_size(
        xfs_inode_log_item_t    *iip)
{
        uint            nvecs;
        xfs_inode_t     *ip;

        ip = iip->ili_inode;
        nvecs = 2;

        /*
         * Only log the data/extents/b-tree root if there is something
         * left to log.
         */
        iip->ili_format.ilf_fields |= XFS_ILOG_CORE;

        switch (ip->i_d.di_format) {
        case XFS_DINODE_FMT_EXTENTS:
                iip->ili_format.ilf_fields &=
                        ~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
                          XFS_ILOG_DEV | XFS_ILOG_UUID);
                if ((iip->ili_format.ilf_fields & XFS_ILOG_DEXT) &&
                    (ip->i_d.di_nextents > 0) &&
                    (ip->i_df.if_bytes > 0)) {
                        ASSERT(ip->i_df.if_u1.if_extents != NULL);
                        nvecs++;
                } else {
                        iip->ili_format.ilf_fields &= ~XFS_ILOG_DEXT;
                }
                break;

        case XFS_DINODE_FMT_BTREE:
                ASSERT(ip->i_df.if_ext_max ==
                       XFS_IFORK_DSIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t));
                iip->ili_format.ilf_fields &=
                        ~(XFS_ILOG_DDATA | XFS_ILOG_DEXT |
                          XFS_ILOG_DEV | XFS_ILOG_UUID);
                if ((iip->ili_format.ilf_fields & XFS_ILOG_DBROOT) &&
                    (ip->i_df.if_broot_bytes > 0)) {
                        ASSERT(ip->i_df.if_broot != NULL);
                        nvecs++;
                } else {
                        ASSERT(!(iip->ili_format.ilf_fields &
                                 XFS_ILOG_DBROOT));
#ifdef XFS_TRANS_DEBUG
                        if (iip->ili_root_size > 0) {
                                ASSERT(iip->ili_root_size ==
                                       ip->i_df.if_broot_bytes);
                                ASSERT(memcmp(iip->ili_orig_root,
                                            ip->i_df.if_broot,
                                            iip->ili_root_size) == 0);
                        } else {
                                ASSERT(ip->i_df.if_broot_bytes == 0);
                        }
#endif
                        iip->ili_format.ilf_fields &= ~XFS_ILOG_DBROOT;
                }
                break;

        case XFS_DINODE_FMT_LOCAL:
                iip->ili_format.ilf_fields &=
                        ~(XFS_ILOG_DEXT | XFS_ILOG_DBROOT |
                          XFS_ILOG_DEV | XFS_ILOG_UUID);
                if ((iip->ili_format.ilf_fields & XFS_ILOG_DDATA) &&
                    (ip->i_df.if_bytes > 0)) {
                        ASSERT(ip->i_df.if_u1.if_data != NULL);
                        ASSERT(ip->i_d.di_size > 0);
                        nvecs++;
                } else {
                        iip->ili_format.ilf_fields &= ~XFS_ILOG_DDATA;
                }
                break;

        case XFS_DINODE_FMT_DEV:
                iip->ili_format.ilf_fields &=
                        ~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
                          XFS_ILOG_DEXT | XFS_ILOG_UUID);
                break;

        case XFS_DINODE_FMT_UUID:
                iip->ili_format.ilf_fields &=
                        ~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
                          XFS_ILOG_DEXT | XFS_ILOG_DEV);
                break;

        default:
                ASSERT(0);
                break;
        }

        /*
         * If there are no attributes associated with this file,
         * then there cannot be anything more to log.
         * Clear all attribute-related log flags.
         */
        if (!XFS_IFORK_Q(ip)) {
                iip->ili_format.ilf_fields &=
                        ~(XFS_ILOG_ADATA | XFS_ILOG_ABROOT | XFS_ILOG_AEXT);
                return nvecs;
        }

        /*
         * Log any necessary attribute data.
         */
        switch (ip->i_d.di_aformat) {
        case XFS_DINODE_FMT_EXTENTS:
                iip->ili_format.ilf_fields &=
                        ~(XFS_ILOG_ADATA | XFS_ILOG_ABROOT);
                if ((iip->ili_format.ilf_fields & XFS_ILOG_AEXT) &&
                    (ip->i_d.di_anextents > 0) &&
                    (ip->i_afp->if_bytes > 0)) {
                        ASSERT(ip->i_afp->if_u1.if_extents != NULL);
                        nvecs++;
                } else {
                        iip->ili_format.ilf_fields &= ~XFS_ILOG_AEXT;
                }
                break;

        case XFS_DINODE_FMT_BTREE:
                iip->ili_format.ilf_fields &=
                        ~(XFS_ILOG_ADATA | XFS_ILOG_AEXT);
                if ((iip->ili_format.ilf_fields & XFS_ILOG_ABROOT) &&
                    (ip->i_afp->if_broot_bytes > 0)) {
                        ASSERT(ip->i_afp->if_broot != NULL);
                        nvecs++;
                } else {
                        iip->ili_format.ilf_fields &= ~XFS_ILOG_ABROOT;
                }
                break;

        case XFS_DINODE_FMT_LOCAL:
                iip->ili_format.ilf_fields &=
                        ~(XFS_ILOG_AEXT | XFS_ILOG_ABROOT);
                if ((iip->ili_format.ilf_fields & XFS_ILOG_ADATA) &&
                    (ip->i_afp->if_bytes > 0)) {
                        ASSERT(ip->i_afp->if_u1.if_data != NULL);
                        nvecs++;
                } else {
                        iip->ili_format.ilf_fields &= ~XFS_ILOG_ADATA;
                }
                break;

        default:
                ASSERT(0);
                break;
        }

        return nvecs;
}

/*
 * This is called to fill in the vector of log iovecs for the
 * given inode log item.  It fills the first item with an inode
 * log format structure, the second with the on-disk inode structure,
 * and a possible third and/or fourth with the inode data/extents/b-tree
 * root and inode attributes data/extents/b-tree root.
 */
STATIC void
xfs_inode_item_format(
        xfs_inode_log_item_t    *iip,
        xfs_log_iovec_t         *log_vector)
{
        uint                    nvecs;
        xfs_log_iovec_t         *vecp;
        xfs_inode_t             *ip;
        size_t                  data_bytes;
        xfs_bmbt_rec_t          *ext_buffer;
        int                     nrecs;
        xfs_mount_t             *mp;

        ip = iip->ili_inode;
        vecp = log_vector;

        vecp->i_addr = (xfs_caddr_t)&iip->ili_format;
        vecp->i_len  = sizeof(xfs_inode_log_format_t);
        XLOG_VEC_SET_TYPE(vecp, XLOG_REG_TYPE_IFORMAT);
        vecp++;
        nvecs        = 1;

        /*
         * Make sure the linux inode is dirty. We do this before
         * clearing i_update_core as the VFS will call back into
         * XFS here and set i_update_core, so we need to dirty the
         * inode first so that the ordering of i_update_core and
         * unlogged modifications still works as described below.
         */
        xfs_mark_inode_dirty_sync(ip);

        /*
         * Clear i_update_core if the timestamps (or any other
         * non-transactional modification) need flushing/logging
         * and we're about to log them with the rest of the core.
         *
         * This is the same logic as xfs_iflush() but this code can't
         * run at the same time as xfs_iflush because we're in commit
         * processing here and so we have the inode lock held in
         * exclusive mode.  Although it doesn't really matter
         * for the timestamps if both routines were to grab the
         * timestamps or not.  That would be ok.
         *
         * We 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
         * either here.  Likewise, if they set it after we clear it
         * here, we'll see it either on the next commit of this
         * inode or the next time the inode gets flushed via
         * xfs_iflush().  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.
         */
        if (ip->i_update_core)  {
                ip->i_update_core = 0;
                SYNCHRONIZE();
        }

        /*
         * Make sure to get the latest timestamps from the Linux inode.
         */
        xfs_synchronize_times(ip);

        vecp->i_addr = (xfs_caddr_t)&ip->i_d;
        vecp->i_len  = sizeof(struct xfs_icdinode);
        XLOG_VEC_SET_TYPE(vecp, XLOG_REG_TYPE_ICORE);
        vecp++;
        nvecs++;
        iip->ili_format.ilf_fields |= XFS_ILOG_CORE;

        /*
         * If this is really an old format inode, then we need to
         * log it as such.  This means that we have to copy the link
         * count from the new field to the old.  We don't have to worry
         * about the new fields, because nothing trusts them as long as
         * the old inode version number is there.  If the superblock already
         * has a new version number, then we don't bother converting back.
         */
        mp = ip->i_mount;
        ASSERT(ip->i_d.di_version == 1 || xfs_sb_version_hasnlink(&mp->m_sb));
        if (ip->i_d.di_version == 1) {
                if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
                        /*
                         * Convert it back.
                         */
                        ASSERT(ip->i_d.di_nlink <= XFS_MAXLINK_1);
                        ip->i_d.di_onlink = 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 = 2;
                        ip->i_d.di_onlink = 0;
                        memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
                }
        }

        switch (ip->i_d.di_format) {
        case XFS_DINODE_FMT_EXTENTS:
                ASSERT(!(iip->ili_format.ilf_fields &
                         (XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
                          XFS_ILOG_DEV | XFS_ILOG_UUID)));
                if (iip->ili_format.ilf_fields & XFS_ILOG_DEXT) {
                        ASSERT(ip->i_df.if_bytes > 0);
                        ASSERT(ip->i_df.if_u1.if_extents != NULL);
                        ASSERT(ip->i_d.di_nextents > 0);
                        ASSERT(iip->ili_extents_buf == NULL);
                        nrecs = ip->i_df.if_bytes /
                                (uint)sizeof(xfs_bmbt_rec_t);
                        ASSERT(nrecs > 0);
#ifdef XFS_NATIVE_HOST
                        if (nrecs == ip->i_d.di_nextents) {
                                /*
                                 * There are no delayed allocation
                                 * extents, so just point to the
                                 * real extents array.
                                 */
                                vecp->i_addr =
                                        (char *)(ip->i_df.if_u1.if_extents);
                                vecp->i_len = ip->i_df.if_bytes;
                                XLOG_VEC_SET_TYPE(vecp, XLOG_REG_TYPE_IEXT);
                        } else
#endif
                        {
                                /*
                                 * There are delayed allocation extents
                                 * in the inode, or we need to convert
                                 * the extents to on disk format.
                                 * Use xfs_iextents_copy()
                                 * to copy only the real extents into
                                 * a separate buffer.  We'll free the
                                 * buffer in the unlock routine.
                                 */
                                ext_buffer = kmem_alloc(ip->i_df.if_bytes,
                                        KM_SLEEP);
                                iip->ili_extents_buf = ext_buffer;
                                vecp->i_addr = (xfs_caddr_t)ext_buffer;
                                vecp->i_len = xfs_iextents_copy(ip, ext_buffer,
                                                XFS_DATA_FORK);
                                XLOG_VEC_SET_TYPE(vecp, XLOG_REG_TYPE_IEXT);
                        }
                        ASSERT(vecp->i_len <= ip->i_df.if_bytes);
                        iip->ili_format.ilf_dsize = vecp->i_len;
                        vecp++;
                        nvecs++;
                }
                break;

        case XFS_DINODE_FMT_BTREE:
                ASSERT(!(iip->ili_format.ilf_fields &
                         (XFS_ILOG_DDATA | XFS_ILOG_DEXT |
                          XFS_ILOG_DEV | XFS_ILOG_UUID)));
                if (iip->ili_format.ilf_fields & XFS_ILOG_DBROOT) {
                        ASSERT(ip->i_df.if_broot_bytes > 0);
                        ASSERT(ip->i_df.if_broot != NULL);
                        vecp->i_addr = (xfs_caddr_t)ip->i_df.if_broot;
                        vecp->i_len = ip->i_df.if_broot_bytes;
                        XLOG_VEC_SET_TYPE(vecp, XLOG_REG_TYPE_IBROOT);
                        vecp++;
                        nvecs++;
                        iip->ili_format.ilf_dsize = ip->i_df.if_broot_bytes;
                }
                break;

        case XFS_DINODE_FMT_LOCAL:
                ASSERT(!(iip->ili_format.ilf_fields &
                         (XFS_ILOG_DBROOT | XFS_ILOG_DEXT |
                          XFS_ILOG_DEV | XFS_ILOG_UUID)));
                if (iip->ili_format.ilf_fields & XFS_ILOG_DDATA) {
                        ASSERT(ip->i_df.if_bytes > 0);
                        ASSERT(ip->i_df.if_u1.if_data != NULL);
                        ASSERT(ip->i_d.di_size > 0);

                        vecp->i_addr = (xfs_caddr_t)ip->i_df.if_u1.if_data;
                        /*
                         * Round i_bytes up to a word boundary.
                         * The underlying memory is guaranteed to
                         * to be there by xfs_idata_realloc().
                         */
                        data_bytes = roundup(ip->i_df.if_bytes, 4);
                        ASSERT((ip->i_df.if_real_bytes == 0) ||
                               (ip->i_df.if_real_bytes == data_bytes));
                        vecp->i_len = (int)data_bytes;
                        XLOG_VEC_SET_TYPE(vecp, XLOG_REG_TYPE_ILOCAL);
                        vecp++;
                        nvecs++;
                        iip->ili_format.ilf_dsize = (unsigned)data_bytes;
                }
                break;

        case XFS_DINODE_FMT_DEV:
                ASSERT(!(iip->ili_format.ilf_fields &
                         (XFS_ILOG_DBROOT | XFS_ILOG_DEXT |
                          XFS_ILOG_DDATA | XFS_ILOG_UUID)));
                if (iip->ili_format.ilf_fields & XFS_ILOG_DEV) {
                        iip->ili_format.ilf_u.ilfu_rdev =
                                ip->i_df.if_u2.if_rdev;
                }
                break;

        case XFS_DINODE_FMT_UUID:
                ASSERT(!(iip->ili_format.ilf_fields &
                         (XFS_ILOG_DBROOT | XFS_ILOG_DEXT |
                          XFS_ILOG_DDATA | XFS_ILOG_DEV)));
                if (iip->ili_format.ilf_fields & XFS_ILOG_UUID) {
                        iip->ili_format.ilf_u.ilfu_uuid =
                                ip->i_df.if_u2.if_uuid;
                }
                break;

        default:
                ASSERT(0);
                break;
        }

        /*
         * If there are no attributes associated with the file,
         * then we're done.
         * Assert that no attribute-related log flags are set.
         */
        if (!XFS_IFORK_Q(ip)) {
                ASSERT(nvecs == iip->ili_item.li_desc->lid_size);
                iip->ili_format.ilf_size = nvecs;
                ASSERT(!(iip->ili_format.ilf_fields &
                         (XFS_ILOG_ADATA | XFS_ILOG_ABROOT | XFS_ILOG_AEXT)));
                return;
        }

        switch (ip->i_d.di_aformat) {
        case XFS_DINODE_FMT_EXTENTS:
                ASSERT(!(iip->ili_format.ilf_fields &
                         (XFS_ILOG_ADATA | XFS_ILOG_ABROOT)));
                if (iip->ili_format.ilf_fields & XFS_ILOG_AEXT) {
                        ASSERT(ip->i_afp->if_bytes > 0);
                        ASSERT(ip->i_afp->if_u1.if_extents != NULL);
                        ASSERT(ip->i_d.di_anextents > 0);
#ifdef DEBUG
                        nrecs = ip->i_afp->if_bytes /
                                (uint)sizeof(xfs_bmbt_rec_t);
#endif
                        ASSERT(nrecs > 0);
                        ASSERT(nrecs == ip->i_d.di_anextents);
#ifdef XFS_NATIVE_HOST
                        /*
                         * There are not delayed allocation extents
                         * for attributes, so just point at the array.
                         */
                        vecp->i_addr = (char *)(ip->i_afp->if_u1.if_extents);
                        vecp->i_len = ip->i_afp->if_bytes;
#else
                        ASSERT(iip->ili_aextents_buf == NULL);
                        /*
                         * Need to endian flip before logging
                         */
                        ext_buffer = kmem_alloc(ip->i_afp->if_bytes,
                                KM_SLEEP);
                        iip->ili_aextents_buf = ext_buffer;
                        vecp->i_addr = (xfs_caddr_t)ext_buffer;
                        vecp->i_len = xfs_iextents_copy(ip, ext_buffer,
                                        XFS_ATTR_FORK);
#endif
                        XLOG_VEC_SET_TYPE(vecp, XLOG_REG_TYPE_IATTR_EXT);
                        iip->ili_format.ilf_asize = vecp->i_len;
                        vecp++;
                        nvecs++;
                }
                break;

        case XFS_DINODE_FMT_BTREE:
                ASSERT(!(iip->ili_format.ilf_fields &
                         (XFS_ILOG_ADATA | XFS_ILOG_AEXT)));
                if (iip->ili_format.ilf_fields & XFS_ILOG_ABROOT) {
                        ASSERT(ip->i_afp->if_broot_bytes > 0);
                        ASSERT(ip->i_afp->if_broot != NULL);
                        vecp->i_addr = (xfs_caddr_t)ip->i_afp->if_broot;
                        vecp->i_len = ip->i_afp->if_broot_bytes;
                        XLOG_VEC_SET_TYPE(vecp, XLOG_REG_TYPE_IATTR_BROOT);
                        vecp++;
                        nvecs++;
                        iip->ili_format.ilf_asize = ip->i_afp->if_broot_bytes;
                }
                break;

        case XFS_DINODE_FMT_LOCAL:
                ASSERT(!(iip->ili_format.ilf_fields &
                         (XFS_ILOG_ABROOT | XFS_ILOG_AEXT)));
                if (iip->ili_format.ilf_fields & XFS_ILOG_ADATA) {
                        ASSERT(ip->i_afp->if_bytes > 0);
                        ASSERT(ip->i_afp->if_u1.if_data != NULL);

                        vecp->i_addr = (xfs_caddr_t)ip->i_afp->if_u1.if_data;
                        /*
                         * Round i_bytes up to a word boundary.
                         * The underlying memory is guaranteed to
                         * to be there by xfs_idata_realloc().
                         */
                        data_bytes = roundup(ip->i_afp->if_bytes, 4);
                        ASSERT((ip->i_afp->if_real_bytes == 0) ||
                               (ip->i_afp->if_real_bytes == data_bytes));
                        vecp->i_len = (int)data_bytes;
                        XLOG_VEC_SET_TYPE(vecp, XLOG_REG_TYPE_IATTR_LOCAL);
                        vecp++;
                        nvecs++;
                        iip->ili_format.ilf_asize = (unsigned)data_bytes;
                }
                break;

        default:
                ASSERT(0);
                break;
        }

        ASSERT(nvecs == iip->ili_item.li_desc->lid_size);
        iip->ili_format.ilf_size = nvecs;
}


/*
 * This is called to pin the inode associated with the inode log
 * item in memory so it cannot be written out.  Do this by calling
 * xfs_ipin() to bump the pin count in the inode while holding the
 * inode pin lock.
 */
STATIC void
xfs_inode_item_pin(
        xfs_inode_log_item_t    *iip)
{
        ASSERT(xfs_isilocked(iip->ili_inode, XFS_ILOCK_EXCL));
        xfs_ipin(iip->ili_inode);
}


/*
 * This is called to unpin the inode associated with the inode log
 * item which was previously pinned with a call to xfs_inode_item_pin().
 * Just call xfs_iunpin() on the inode to do this.
 */
/* ARGSUSED */
STATIC void
xfs_inode_item_unpin(
        xfs_inode_log_item_t    *iip,
        int                     stale)
{
        xfs_iunpin(iip->ili_inode);
}

/* ARGSUSED */
STATIC void
xfs_inode_item_unpin_remove(
        xfs_inode_log_item_t    *iip,
        xfs_trans_t             *tp)
{
        xfs_iunpin(iip->ili_inode);
}

/*
 * This is called to attempt to lock the inode associated with this
 * inode log item, in preparation for the push routine which does the actual
 * iflush.  Don't sleep on the inode lock or the flush lock.
 *
 * If the flush lock is already held, indicating that the inode has
 * been or is in the process of being flushed, then (ideally) we'd like to
 * see if the inode's buffer is still incore, and if so give it a nudge.
 * We delay doing so until the pushbuf routine, though, to avoid holding
 * the AIL lock across a call to the blackhole which is the buffer cache.
 * Also we don't want to sleep in any device strategy routines, which can happen
 * if we do the subsequent bawrite in here.
 */
STATIC uint
xfs_inode_item_trylock(
        xfs_inode_log_item_t    *iip)
{
        register xfs_inode_t    *ip;

        ip = iip->ili_inode;

        if (xfs_ipincount(ip) > 0) {
                return XFS_ITEM_PINNED;
        }

        if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) {
                return XFS_ITEM_LOCKED;
        }

        if (!xfs_iflock_nowait(ip)) {
                /*
                 * If someone else isn't already trying to push the inode
                 * buffer, we get to do it.
                 */
                if (iip->ili_pushbuf_flag == 0) {
                        iip->ili_pushbuf_flag = 1;
#ifdef DEBUG
                        iip->ili_push_owner = current_pid();
#endif
                        /*
                         * Inode is left locked in shared mode.
                         * Pushbuf routine gets to unlock it.
                         */
                        return XFS_ITEM_PUSHBUF;
                } else {
                        /*
                         * We hold the AIL lock, so we must specify the
                         * NONOTIFY flag so that we won't double trip.
                         */
                        xfs_iunlock(ip, XFS_ILOCK_SHARED|XFS_IUNLOCK_NONOTIFY);
                        return XFS_ITEM_FLUSHING;
                }
                /* NOTREACHED */
        }

        /* Stale items should force out the iclog */
        if (ip->i_flags & XFS_ISTALE) {
                xfs_ifunlock(ip);
                xfs_iunlock(ip, XFS_ILOCK_SHARED|XFS_IUNLOCK_NONOTIFY);
                return XFS_ITEM_PINNED;
        }

#ifdef DEBUG
        if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
                ASSERT(iip->ili_format.ilf_fields != 0);
                ASSERT(iip->ili_logged == 0);
                ASSERT(iip->ili_item.li_flags & XFS_LI_IN_AIL);
        }
#endif
        return XFS_ITEM_SUCCESS;
}

/*
 * Unlock the inode associated with the inode log item.
 * Clear the fields of the inode and inode log item that
 * are specific to the current transaction.  If the
 * hold flags is set, do not unlock the inode.
 */
STATIC void
xfs_inode_item_unlock(
        xfs_inode_log_item_t    *iip)
{
        uint            hold;
        uint            iolocked;
        uint            lock_flags;
        xfs_inode_t     *ip;

        ASSERT(iip != NULL);
        ASSERT(iip->ili_inode->i_itemp != NULL);
        ASSERT(xfs_isilocked(iip->ili_inode, XFS_ILOCK_EXCL));
        ASSERT((!(iip->ili_inode->i_itemp->ili_flags &
                  XFS_ILI_IOLOCKED_EXCL)) ||
               xfs_isilocked(iip->ili_inode, XFS_IOLOCK_EXCL));
        ASSERT((!(iip->ili_inode->i_itemp->ili_flags &
                  XFS_ILI_IOLOCKED_SHARED)) ||
               xfs_isilocked(iip->ili_inode, XFS_IOLOCK_SHARED));
        /*
         * Clear the transaction pointer in the inode.
         */
        ip = iip->ili_inode;
        ip->i_transp = NULL;

        /*
         * If the inode needed a separate buffer with which to log
         * its extents, then free it now.
         */
        if (iip->ili_extents_buf != NULL) {
                ASSERT(ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS);
                ASSERT(ip->i_d.di_nextents > 0);
                ASSERT(iip->ili_format.ilf_fields & XFS_ILOG_DEXT);
                ASSERT(ip->i_df.if_bytes > 0);
                kmem_free(iip->ili_extents_buf);
                iip->ili_extents_buf = NULL;
        }
        if (iip->ili_aextents_buf != NULL) {
                ASSERT(ip->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS);
                ASSERT(ip->i_d.di_anextents > 0);
                ASSERT(iip->ili_format.ilf_fields & XFS_ILOG_AEXT);
                ASSERT(ip->i_afp->if_bytes > 0);
                kmem_free(iip->ili_aextents_buf);
                iip->ili_aextents_buf = NULL;
        }

        /*
         * Figure out if we should unlock the inode or not.
         */
        hold = iip->ili_flags & XFS_ILI_HOLD;

        /*
         * Before clearing out the flags, remember whether we
         * are holding the inode's IO lock.
         */
        iolocked = iip->ili_flags & XFS_ILI_IOLOCKED_ANY;

        /*
         * Clear out the fields of the inode log item particular
         * to the current transaction.
         */
        iip->ili_flags = 0;

        /*
         * Unlock the inode if XFS_ILI_HOLD was not set.
         */
        if (!hold) {
                lock_flags = XFS_ILOCK_EXCL;
                if (iolocked & XFS_ILI_IOLOCKED_EXCL) {
                        lock_flags |= XFS_IOLOCK_EXCL;
                } else if (iolocked & XFS_ILI_IOLOCKED_SHARED) {
                        lock_flags |= XFS_IOLOCK_SHARED;
                }
                xfs_iput(iip->ili_inode, lock_flags);
        }
}

/*
 * This is called to find out where the oldest active copy of the
 * inode log item in the on disk log resides now that the last log
 * write of it completed at the given lsn.  Since we always re-log
 * all dirty data in an inode, the latest copy in the on disk log
 * is the only one that matters.  Therefore, simply return the
 * given lsn.
 */
/*ARGSUSED*/
STATIC xfs_lsn_t
xfs_inode_item_committed(
        xfs_inode_log_item_t    *iip,
        xfs_lsn_t               lsn)
{
        return (lsn);
}

/*
 * This gets called by xfs_trans_push_ail(), when IOP_TRYLOCK
 * failed to get the inode flush lock but did get the inode locked SHARED.
 * Here we're trying to see if the inode buffer is incore, and if so whether it's
 * marked delayed write. If that's the case, we'll initiate a bawrite on that
 * buffer to expedite the process.
 *
 * We aren't holding the AIL lock (or the flush lock) when this gets called,
 * so it is inherently race-y.
 */
STATIC void
xfs_inode_item_pushbuf(
        xfs_inode_log_item_t    *iip)
{
        xfs_inode_t     *ip;
        xfs_mount_t     *mp;
        xfs_buf_t       *bp;
        uint            dopush;

        ip = iip->ili_inode;

        ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED));

        /*
         * The ili_pushbuf_flag keeps others from
         * trying to duplicate our effort.
         */
        ASSERT(iip->ili_pushbuf_flag != 0);
        ASSERT(iip->ili_push_owner == current_pid());

        /*
         * If a flush is not in progress anymore, chances are that the
         * inode was taken off the AIL. So, just get out.
         */
        if (completion_done(&ip->i_flush) ||
            ((iip->ili_item.li_flags & XFS_LI_IN_AIL) == 0)) {
                iip->ili_pushbuf_flag = 0;
                xfs_iunlock(ip, XFS_ILOCK_SHARED);
                return;
        }

        mp = ip->i_mount;
        bp = xfs_incore(mp->m_ddev_targp, iip->ili_format.ilf_blkno,
                    iip->ili_format.ilf_len, XFS_INCORE_TRYLOCK);

        if (bp != NULL) {
                if (XFS_BUF_ISDELAYWRITE(bp)) {
                        /*
                         * We were racing with iflush because we don't hold
                         * the AIL lock or the flush lock. However, at this point,
                         * we have the buffer, and we know that it's dirty.
                         * So, it's possible that iflush raced with us, and
                         * this item is already taken off the AIL.
                         * If not, we can flush it async.
                         */
                        dopush = ((iip->ili_item.li_flags & XFS_LI_IN_AIL) &&
                                  !completion_done(&ip->i_flush));
                        iip->ili_pushbuf_flag = 0;
                        xfs_iunlock(ip, XFS_ILOCK_SHARED);
                        xfs_buftrace("INODE ITEM PUSH", bp);
                        if (XFS_BUF_ISPINNED(bp)) {
                                xfs_log_force(mp, (xfs_lsn_t)0,
                                              XFS_LOG_FORCE);
                        }
                        if (dopush) {
                                int     error;
                                error = xfs_bawrite(mp, bp);
                                if (error)
                                        xfs_fs_cmn_err(CE_WARN, mp,
                "xfs_inode_item_pushbuf: pushbuf error %d on iip %p, bp %p",
                                                        error, iip, bp);
                        } else {
                                xfs_buf_relse(bp);
                        }
                } else {
                        iip->ili_pushbuf_flag = 0;
                        xfs_iunlock(ip, XFS_ILOCK_SHARED);
                        xfs_buf_relse(bp);
                }
                return;
        }
        /*
         * We have to be careful about resetting pushbuf flag too early (above).
         * Even though in theory we can do it as soon as we have the buflock,
         * we don't want others to be doing work needlessly. They'll come to
         * this function thinking that pushing the buffer is their
         * responsibility only to find that the buffer is still locked by
         * another doing the same thing
         */
        iip->ili_pushbuf_flag = 0;
        xfs_iunlock(ip, XFS_ILOCK_SHARED);
        return;
}


/*
 * This is called to asynchronously write the inode associated with this
 * inode log item out to disk. The inode will already have been locked by
 * a successful call to xfs_inode_item_trylock().
 */
STATIC void
xfs_inode_item_push(
        xfs_inode_log_item_t    *iip)
{
        xfs_inode_t     *ip;

        ip = iip->ili_inode;

        ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED));
        ASSERT(!completion_done(&ip->i_flush));
        /*
         * Since we were able to lock the inode's flush lock and
         * we found it on the AIL, the inode must be dirty.  This
         * is because the inode is removed from the AIL while still
         * holding the flush lock in xfs_iflush_done().  Thus, if
         * we found it in the AIL and were able to obtain the flush
         * lock without sleeping, then there must not have been
         * anyone in the process of flushing the inode.
         */
        ASSERT(XFS_FORCED_SHUTDOWN(ip->i_mount) ||
               iip->ili_format.ilf_fields != 0);

        /*
         * Write out the inode.  The completion routine ('iflush_done') will
         * pull it from the AIL, mark it clean, unlock the flush lock.
         */
        (void) xfs_iflush(ip, XFS_IFLUSH_ASYNC);
        xfs_iunlock(ip, XFS_ILOCK_SHARED);

        return;
}

/*
 * XXX rcc - this one really has to do something.  Probably needs
 * to stamp in a new field in the incore inode.
 */
/* ARGSUSED */
STATIC void
xfs_inode_item_committing(
        xfs_inode_log_item_t    *iip,
        xfs_lsn_t               lsn)
{
        iip->ili_last_lsn = lsn;
        return;
}

/*
 * This is the ops vector shared by all buf log items.
 */
static struct xfs_item_ops xfs_inode_item_ops = {
        .iop_size       = (uint(*)(xfs_log_item_t*))xfs_inode_item_size,
        .iop_format     = (void(*)(xfs_log_item_t*, xfs_log_iovec_t*))
                                        xfs_inode_item_format,
        .iop_pin        = (void(*)(xfs_log_item_t*))xfs_inode_item_pin,
        .iop_unpin      = (void(*)(xfs_log_item_t*, int))xfs_inode_item_unpin,
        .iop_unpin_remove = (void(*)(xfs_log_item_t*, xfs_trans_t*))
                                        xfs_inode_item_unpin_remove,
        .iop_trylock    = (uint(*)(xfs_log_item_t*))xfs_inode_item_trylock,
        .iop_unlock     = (void(*)(xfs_log_item_t*))xfs_inode_item_unlock,
        .iop_committed  = (xfs_lsn_t(*)(xfs_log_item_t*, xfs_lsn_t))
                                        xfs_inode_item_committed,
        .iop_push       = (void(*)(xfs_log_item_t*))xfs_inode_item_push,
        .iop_pushbuf    = (void(*)(xfs_log_item_t*))xfs_inode_item_pushbuf,
        .iop_committing = (void(*)(xfs_log_item_t*, xfs_lsn_t))
                                        xfs_inode_item_committing
};


/*
 * Initialize the inode log item for a newly allocated (in-core) inode.
 */
void
xfs_inode_item_init(
        xfs_inode_t     *ip,
        xfs_mount_t     *mp)
{
        xfs_inode_log_item_t    *iip;

        ASSERT(ip->i_itemp == NULL);
        iip = ip->i_itemp = kmem_zone_zalloc(xfs_ili_zone, KM_SLEEP);

        iip->ili_item.li_type = XFS_LI_INODE;
        iip->ili_item.li_ops = &xfs_inode_item_ops;
        iip->ili_item.li_mountp = mp;
        iip->ili_item.li_ailp = mp->m_ail;
        iip->ili_inode = ip;

        /*
           We have zeroed memory. No need ...
           iip->ili_extents_buf = NULL;
           iip->ili_pushbuf_flag = 0;
         */

        iip->ili_format.ilf_type = XFS_LI_INODE;
        iip->ili_format.ilf_ino = ip->i_ino;
        iip->ili_format.ilf_blkno = ip->i_imap.im_blkno;
        iip->ili_format.ilf_len = ip->i_imap.im_len;
        iip->ili_format.ilf_boffset = ip->i_imap.im_boffset;
}

/*
 * Free the inode log item and any memory hanging off of it.
 */
void
xfs_inode_item_destroy(
        xfs_inode_t     *ip)
{
#ifdef XFS_TRANS_DEBUG
        if (ip->i_itemp->ili_root_size != 0) {
                kmem_free(ip->i_itemp->ili_orig_root);
        }
#endif
        kmem_zone_free(xfs_ili_zone, ip->i_itemp);
}


/*
 * This is the inode flushing I/O completion routine.  It is called
 * from interrupt level when the buffer containing the inode is
 * flushed to disk.  It is responsible for removing the inode item
 * from the AIL if it has not been re-logged, and unlocking the inode's
 * flush lock.
 */
/*ARGSUSED*/
void
xfs_iflush_done(
        xfs_buf_t               *bp,
        xfs_inode_log_item_t    *iip)
{
        xfs_inode_t             *ip = iip->ili_inode;
        struct xfs_ail          *ailp = iip->ili_item.li_ailp;

        /*
         * We only want to pull the item from the AIL if it is
         * actually there and its location in the log has not
         * changed since we started the flush.  Thus, we only bother
         * if the ili_logged flag is set and the inode's lsn has not
         * changed.  First we check the lsn outside
         * the lock since it's cheaper, and then we recheck while
         * holding the lock before removing the inode from the AIL.
         */
        if (iip->ili_logged &&
            (iip->ili_item.li_lsn == iip->ili_flush_lsn)) {
                spin_lock(&ailp->xa_lock);
                if (iip->ili_item.li_lsn == iip->ili_flush_lsn) {
                        /* xfs_trans_ail_delete() drops the AIL lock. */
                        xfs_trans_ail_delete(ailp, (xfs_log_item_t*)iip);
                } else {
                        spin_unlock(&ailp->xa_lock);
                }
        }

        iip->ili_logged = 0;

        /*
         * Clear the ili_last_fields bits now that we know that the
         * data corresponding to them is safely on disk.
         */
        iip->ili_last_fields = 0;

        /*
         * Release the inode's flush lock since we're done with it.
         */
        xfs_ifunlock(ip);

        return;
}

/*
 * This is the inode flushing abort routine.  It is called
 * from xfs_iflush when the filesystem is shutting down to clean
 * up the inode state.
 * It is responsible for removing the inode item
 * from the AIL if it has not been re-logged, and unlocking the inode's
 * flush lock.
 */
void
xfs_iflush_abort(
        xfs_inode_t             *ip)
{
        xfs_inode_log_item_t    *iip = ip->i_itemp;
        xfs_mount_t             *mp;

        iip = ip->i_itemp;
        mp = ip->i_mount;
        if (iip) {
                struct xfs_ail  *ailp = iip->ili_item.li_ailp;
                if (iip->ili_item.li_flags & XFS_LI_IN_AIL) {
                        spin_lock(&ailp->xa_lock);
                        if (iip->ili_item.li_flags & XFS_LI_IN_AIL) {
                                /* xfs_trans_ail_delete() drops the AIL lock. */
                                xfs_trans_ail_delete(ailp, (xfs_log_item_t *)iip);
                        } else
                                spin_unlock(&ailp->xa_lock);
                }
                iip->ili_logged = 0;
                /*
                 * Clear the ili_last_fields bits now that we know that the
                 * data corresponding to them is safely on disk.
                 */
                iip->ili_last_fields = 0;
                /*
                 * Clear the inode logging fields so no more flushes are
                 * attempted.
                 */
                iip->ili_format.ilf_fields = 0;
        }
        /*
         * Release the inode's flush lock since we're done with it.
         */
        xfs_ifunlock(ip);
}

void
xfs_istale_done(
        xfs_buf_t               *bp,
        xfs_inode_log_item_t    *iip)
{
        xfs_iflush_abort(iip->ili_inode);
}

/*
 * convert an xfs_inode_log_format struct from either 32 or 64 bit versions
 * (which can have different field alignments) to the native version
 */
int
xfs_inode_item_format_convert(
        xfs_log_iovec_t         *buf,
        xfs_inode_log_format_t  *in_f)
{
        if (buf->i_len == sizeof(xfs_inode_log_format_32_t)) {
                xfs_inode_log_format_32_t *in_f32;

                in_f32 = (xfs_inode_log_format_32_t *)buf->i_addr;
                in_f->ilf_type = in_f32->ilf_type;
                in_f->ilf_size = in_f32->ilf_size;
                in_f->ilf_fields = in_f32->ilf_fields;
                in_f->ilf_asize = in_f32->ilf_asize;
                in_f->ilf_dsize = in_f32->ilf_dsize;
                in_f->ilf_ino = in_f32->ilf_ino;
                /* copy biggest field of ilf_u */
                memcpy(in_f->ilf_u.ilfu_uuid.__u_bits,
                       in_f32->ilf_u.ilfu_uuid.__u_bits,
                       sizeof(uuid_t));
                in_f->ilf_blkno = in_f32->ilf_blkno;
                in_f->ilf_len = in_f32->ilf_len;
                in_f->ilf_boffset = in_f32->ilf_boffset;
                return 0;
        } else if (buf->i_len == sizeof(xfs_inode_log_format_64_t)){
                xfs_inode_log_format_64_t *in_f64;

                in_f64 = (xfs_inode_log_format_64_t *)buf->i_addr;
                in_f->ilf_type = in_f64->ilf_type;
                in_f->ilf_size = in_f64->ilf_size;
                in_f->ilf_fields = in_f64->ilf_fields;
                in_f->ilf_asize = in_f64->ilf_asize;
                in_f->ilf_dsize = in_f64->ilf_dsize;
                in_f->ilf_ino = in_f64->ilf_ino;
                /* copy biggest field of ilf_u */
                memcpy(in_f->ilf_u.ilfu_uuid.__u_bits,
                       in_f64->ilf_u.ilfu_uuid.__u_bits,
                       sizeof(uuid_t));
                in_f->ilf_blkno = in_f64->ilf_blkno;
                in_f->ilf_len = in_f64->ilf_len;
                in_f->ilf_boffset = in_f64->ilf_boffset;
                return 0;
        }
        return EFSCORRUPTED;
}