mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race

[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_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_trans_priv.h"
#include "xfs_buf_item.h"
#include "xfs_log.h"


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

static inline struct xfs_inode_log_item *INODE_ITEM(struct xfs_log_item *lip)
{
        return container_of(lip, struct xfs_inode_log_item, ili_item);
}

STATIC void
xfs_inode_item_data_fork_size(
        struct xfs_inode_log_item *iip,
        int                     *nvecs,
        int                     *nbytes)
{
        struct xfs_inode        *ip = iip->ili_inode;

        switch (ip->i_d.di_format) {
        case XFS_DINODE_FMT_EXTENTS:
                if ((iip->ili_fields & XFS_ILOG_DEXT) &&
                    ip->i_d.di_nextents > 0 &&
                    ip->i_df.if_bytes > 0) {
                        /* worst case, doesn't subtract delalloc extents */
                        *nbytes += XFS_IFORK_DSIZE(ip);
                        *nvecs += 1;
                }
                break;
        case XFS_DINODE_FMT_BTREE:
                if ((iip->ili_fields & XFS_ILOG_DBROOT) &&
                    ip->i_df.if_broot_bytes > 0) {
                        *nbytes += ip->i_df.if_broot_bytes;
                        *nvecs += 1;
                }
                break;
        case XFS_DINODE_FMT_LOCAL:
                if ((iip->ili_fields & XFS_ILOG_DDATA) &&
                    ip->i_df.if_bytes > 0) {
                        *nbytes += roundup(ip->i_df.if_bytes, 4);
                        *nvecs += 1;
                }
                break;

        case XFS_DINODE_FMT_DEV:
        case XFS_DINODE_FMT_UUID:
                break;
        default:
                ASSERT(0);
                break;
        }
}

STATIC void
xfs_inode_item_attr_fork_size(
        struct xfs_inode_log_item *iip,
        int                     *nvecs,
        int                     *nbytes)
{
        struct xfs_inode        *ip = iip->ili_inode;

        switch (ip->i_d.di_aformat) {
        case XFS_DINODE_FMT_EXTENTS:
                if ((iip->ili_fields & XFS_ILOG_AEXT) &&
                    ip->i_d.di_anextents > 0 &&
                    ip->i_afp->if_bytes > 0) {
                        /* worst case, doesn't subtract unused space */
                        *nbytes += XFS_IFORK_ASIZE(ip);
                        *nvecs += 1;
                }
                break;
        case XFS_DINODE_FMT_BTREE:
                if ((iip->ili_fields & XFS_ILOG_ABROOT) &&
                    ip->i_afp->if_broot_bytes > 0) {
                        *nbytes += ip->i_afp->if_broot_bytes;
                        *nvecs += 1;
                }
                break;
        case XFS_DINODE_FMT_LOCAL:
                if ((iip->ili_fields & XFS_ILOG_ADATA) &&
                    ip->i_afp->if_bytes > 0) {
                        *nbytes += roundup(ip->i_afp->if_bytes, 4);
                        *nvecs += 1;
                }
                break;
        default:
                ASSERT(0);
                break;
        }
}

/*
 * 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 void
xfs_inode_item_size(
        struct xfs_log_item     *lip,
        int                     *nvecs,
        int                     *nbytes)
{
        struct xfs_inode_log_item *iip = INODE_ITEM(lip);
        struct xfs_inode        *ip = iip->ili_inode;

        *nvecs += 2;
        *nbytes += sizeof(struct xfs_inode_log_format) +
                   xfs_log_dinode_size(ip->i_d.di_version);

        xfs_inode_item_data_fork_size(iip, nvecs, nbytes);
        if (XFS_IFORK_Q(ip))
                xfs_inode_item_attr_fork_size(iip, nvecs, nbytes);
}

STATIC void
xfs_inode_item_format_data_fork(
        struct xfs_inode_log_item *iip,
        struct xfs_inode_log_format *ilf,
        struct xfs_log_vec      *lv,
        struct xfs_log_iovec    **vecp)
{
        struct xfs_inode        *ip = iip->ili_inode;
        size_t                  data_bytes;

        switch (ip->i_d.di_format) {
        case XFS_DINODE_FMT_EXTENTS:
                iip->ili_fields &=
                        ~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
                          XFS_ILOG_DEV | XFS_ILOG_UUID);

                if ((iip->ili_fields & XFS_ILOG_DEXT) &&
                    ip->i_d.di_nextents > 0 &&
                    ip->i_df.if_bytes > 0) {
                        struct xfs_bmbt_rec *p;

                        ASSERT(ip->i_df.if_u1.if_extents != NULL);
                        ASSERT(xfs_iext_count(&ip->i_df) > 0);

                        p = xlog_prepare_iovec(lv, vecp, XLOG_REG_TYPE_IEXT);
                        data_bytes = xfs_iextents_copy(ip, p, XFS_DATA_FORK);
                        xlog_finish_iovec(lv, *vecp, data_bytes);

                        ASSERT(data_bytes <= ip->i_df.if_bytes);

                        ilf->ilf_dsize = data_bytes;
                        ilf->ilf_size++;
                } else {
                        iip->ili_fields &= ~XFS_ILOG_DEXT;
                }
                break;
        case XFS_DINODE_FMT_BTREE:
                iip->ili_fields &=
                        ~(XFS_ILOG_DDATA | XFS_ILOG_DEXT |
                          XFS_ILOG_DEV | XFS_ILOG_UUID);

                if ((iip->ili_fields & XFS_ILOG_DBROOT) &&
                    ip->i_df.if_broot_bytes > 0) {
                        ASSERT(ip->i_df.if_broot != NULL);
                        xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_IBROOT,
                                        ip->i_df.if_broot,
                                        ip->i_df.if_broot_bytes);
                        ilf->ilf_dsize = ip->i_df.if_broot_bytes;
                        ilf->ilf_size++;
                } else {
                        ASSERT(!(iip->ili_fields &
                                 XFS_ILOG_DBROOT));
                        iip->ili_fields &= ~XFS_ILOG_DBROOT;
                }
                break;
        case XFS_DINODE_FMT_LOCAL:
                iip->ili_fields &=
                        ~(XFS_ILOG_DEXT | XFS_ILOG_DBROOT |
                          XFS_ILOG_DEV | XFS_ILOG_UUID);
                if ((iip->ili_fields & XFS_ILOG_DDATA) &&
                    ip->i_df.if_bytes > 0) {
                        /*
                         * 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);
                        ASSERT(ip->i_df.if_u1.if_data != NULL);
                        ASSERT(ip->i_d.di_size > 0);
                        xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_ILOCAL,
                                        ip->i_df.if_u1.if_data, data_bytes);
                        ilf->ilf_dsize = (unsigned)data_bytes;
                        ilf->ilf_size++;
                } else {
                        iip->ili_fields &= ~XFS_ILOG_DDATA;
                }
                break;
        case XFS_DINODE_FMT_DEV:
                iip->ili_fields &=
                        ~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
                          XFS_ILOG_DEXT | XFS_ILOG_UUID);
                if (iip->ili_fields & XFS_ILOG_DEV)
                        ilf->ilf_u.ilfu_rdev = ip->i_df.if_u2.if_rdev;
                break;
        case XFS_DINODE_FMT_UUID:
                iip->ili_fields &=
                        ~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
                          XFS_ILOG_DEXT | XFS_ILOG_DEV);
                if (iip->ili_fields & XFS_ILOG_UUID)
                        ilf->ilf_u.ilfu_uuid = ip->i_df.if_u2.if_uuid;
                break;
        default:
                ASSERT(0);
                break;
        }
}

STATIC void
xfs_inode_item_format_attr_fork(
        struct xfs_inode_log_item *iip,
        struct xfs_inode_log_format *ilf,
        struct xfs_log_vec      *lv,
        struct xfs_log_iovec    **vecp)
{
        struct xfs_inode        *ip = iip->ili_inode;
        size_t                  data_bytes;

        switch (ip->i_d.di_aformat) {
        case XFS_DINODE_FMT_EXTENTS:
                iip->ili_fields &=
                        ~(XFS_ILOG_ADATA | XFS_ILOG_ABROOT);

                if ((iip->ili_fields & XFS_ILOG_AEXT) &&
                    ip->i_d.di_anextents > 0 &&
                    ip->i_afp->if_bytes > 0) {
                        struct xfs_bmbt_rec *p;

                        ASSERT(xfs_iext_count(ip->i_afp) ==
                                ip->i_d.di_anextents);
                        ASSERT(ip->i_afp->if_u1.if_extents != NULL);

                        p = xlog_prepare_iovec(lv, vecp, XLOG_REG_TYPE_IATTR_EXT);
                        data_bytes = xfs_iextents_copy(ip, p, XFS_ATTR_FORK);
                        xlog_finish_iovec(lv, *vecp, data_bytes);

                        ilf->ilf_asize = data_bytes;
                        ilf->ilf_size++;
                } else {
                        iip->ili_fields &= ~XFS_ILOG_AEXT;
                }
                break;
        case XFS_DINODE_FMT_BTREE:
                iip->ili_fields &=
                        ~(XFS_ILOG_ADATA | XFS_ILOG_AEXT);

                if ((iip->ili_fields & XFS_ILOG_ABROOT) &&
                    ip->i_afp->if_broot_bytes > 0) {
                        ASSERT(ip->i_afp->if_broot != NULL);

                        xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_IATTR_BROOT,
                                        ip->i_afp->if_broot,
                                        ip->i_afp->if_broot_bytes);
                        ilf->ilf_asize = ip->i_afp->if_broot_bytes;
                        ilf->ilf_size++;
                } else {
                        iip->ili_fields &= ~XFS_ILOG_ABROOT;
                }
                break;
        case XFS_DINODE_FMT_LOCAL:
                iip->ili_fields &=
                        ~(XFS_ILOG_AEXT | XFS_ILOG_ABROOT);

                if ((iip->ili_fields & XFS_ILOG_ADATA) &&
                    ip->i_afp->if_bytes > 0) {
                        /*
                         * 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);
                        ASSERT(ip->i_afp->if_u1.if_data != NULL);
                        xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_IATTR_LOCAL,
                                        ip->i_afp->if_u1.if_data,
                                        data_bytes);
                        ilf->ilf_asize = (unsigned)data_bytes;
                        ilf->ilf_size++;
                } else {
                        iip->ili_fields &= ~XFS_ILOG_ADATA;
                }
                break;
        default:
                ASSERT(0);
                break;
        }
}

static void
xfs_inode_to_log_dinode(
        struct xfs_inode        *ip,
        struct xfs_log_dinode   *to,
        xfs_lsn_t               lsn)
{
        struct xfs_icdinode     *from = &ip->i_d;
        struct inode            *inode = VFS_I(ip);

        to->di_magic = XFS_DINODE_MAGIC;

        to->di_version = from->di_version;
        to->di_format = from->di_format;
        to->di_uid = from->di_uid;
        to->di_gid = from->di_gid;
        to->di_projid_lo = from->di_projid_lo;
        to->di_projid_hi = from->di_projid_hi;

        memset(to->di_pad, 0, sizeof(to->di_pad));
        memset(to->di_pad3, 0, sizeof(to->di_pad3));
        to->di_atime.t_sec = inode->i_atime.tv_sec;
        to->di_atime.t_nsec = inode->i_atime.tv_nsec;
        to->di_mtime.t_sec = inode->i_mtime.tv_sec;
        to->di_mtime.t_nsec = inode->i_mtime.tv_nsec;
        to->di_ctime.t_sec = inode->i_ctime.tv_sec;
        to->di_ctime.t_nsec = inode->i_ctime.tv_nsec;
        to->di_nlink = inode->i_nlink;
        to->di_gen = inode->i_generation;
        to->di_mode = inode->i_mode;

        to->di_size = from->di_size;
        to->di_nblocks = from->di_nblocks;
        to->di_extsize = from->di_extsize;
        to->di_nextents = from->di_nextents;
        to->di_anextents = from->di_anextents;
        to->di_forkoff = from->di_forkoff;
        to->di_aformat = from->di_aformat;
        to->di_dmevmask = from->di_dmevmask;
        to->di_dmstate = from->di_dmstate;
        to->di_flags = from->di_flags;

        /* log a dummy value to ensure log structure is fully initialised */
        to->di_next_unlinked = NULLAGINO;

        if (from->di_version == 3) {
                to->di_changecount = inode->i_version;
                to->di_crtime.t_sec = from->di_crtime.t_sec;
                to->di_crtime.t_nsec = from->di_crtime.t_nsec;
                to->di_flags2 = from->di_flags2;
                to->di_cowextsize = from->di_cowextsize;
                to->di_ino = ip->i_ino;
                to->di_lsn = lsn;
                memset(to->di_pad2, 0, sizeof(to->di_pad2));
                uuid_copy(&to->di_uuid, &ip->i_mount->m_sb.sb_meta_uuid);
                to->di_flushiter = 0;
        } else {
                to->di_flushiter = from->di_flushiter;
        }
}

/*
 * Format the inode core. Current timestamp data is only in the VFS inode
 * fields, so we need to grab them from there. Hence rather than just copying
 * the XFS inode core structure, format the fields directly into the iovec.
 */
static void
xfs_inode_item_format_core(
        struct xfs_inode        *ip,
        struct xfs_log_vec      *lv,
        struct xfs_log_iovec    **vecp)
{
        struct xfs_log_dinode   *dic;

        dic = xlog_prepare_iovec(lv, vecp, XLOG_REG_TYPE_ICORE);
        xfs_inode_to_log_dinode(ip, dic, ip->i_itemp->ili_item.li_lsn);
        xlog_finish_iovec(lv, *vecp, xfs_log_dinode_size(ip->i_d.di_version));
}

/*
 * 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.
 *
 * Note: Always use the 64 bit inode log format structure so we don't
 * leave an uninitialised hole in the format item on 64 bit systems. Log
 * recovery on 32 bit systems handles this just fine, so there's no reason
 * for not using an initialising the properly padded structure all the time.
 */
STATIC void
xfs_inode_item_format(
        struct xfs_log_item     *lip,
        struct xfs_log_vec      *lv)
{
        struct xfs_inode_log_item *iip = INODE_ITEM(lip);
        struct xfs_inode        *ip = iip->ili_inode;
        struct xfs_log_iovec    *vecp = NULL;
        struct xfs_inode_log_format *ilf;

        ASSERT(ip->i_d.di_version > 1);

        ilf = xlog_prepare_iovec(lv, &vecp, XLOG_REG_TYPE_IFORMAT);
        ilf->ilf_type = XFS_LI_INODE;
        ilf->ilf_ino = ip->i_ino;
        ilf->ilf_blkno = ip->i_imap.im_blkno;
        ilf->ilf_len = ip->i_imap.im_len;
        ilf->ilf_boffset = ip->i_imap.im_boffset;
        ilf->ilf_fields = XFS_ILOG_CORE;
        ilf->ilf_size = 2; /* format + core */

        /*
         * make sure we don't leak uninitialised data into the log in the case
         * when we don't log every field in the inode.
         */
        ilf->ilf_dsize = 0;
        ilf->ilf_asize = 0;
        ilf->ilf_pad = 0;
        uuid_copy(&ilf->ilf_u.ilfu_uuid, &uuid_null);

        xlog_finish_iovec(lv, vecp, sizeof(*ilf));

        xfs_inode_item_format_core(ip, lv, &vecp);
        xfs_inode_item_format_data_fork(iip, ilf, lv, &vecp);
        if (XFS_IFORK_Q(ip)) {
                xfs_inode_item_format_attr_fork(iip, ilf, lv, &vecp);
        } else {
                iip->ili_fields &=
                        ~(XFS_ILOG_ADATA | XFS_ILOG_ABROOT | XFS_ILOG_AEXT);
        }

        /* update the format with the exact fields we actually logged */
        ilf->ilf_fields |= (iip->ili_fields & ~XFS_ILOG_TIMESTAMP);
}

/*
 * This is called to pin the inode associated with the inode log
 * item in memory so it cannot be written out.
 */
STATIC void
xfs_inode_item_pin(
        struct xfs_log_item     *lip)
{
        struct xfs_inode        *ip = INODE_ITEM(lip)->ili_inode;

        ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));

        trace_xfs_inode_pin(ip, _RET_IP_);
        atomic_inc(&ip->i_pincount);
}


/*
 * 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().
 *
 * Also wake up anyone in xfs_iunpin_wait() if the count goes to 0.
 */
STATIC void
xfs_inode_item_unpin(
        struct xfs_log_item     *lip,
        int                     remove)
{
        struct xfs_inode        *ip = INODE_ITEM(lip)->ili_inode;

        trace_xfs_inode_unpin(ip, _RET_IP_);
        ASSERT(atomic_read(&ip->i_pincount) > 0);
        if (atomic_dec_and_test(&ip->i_pincount))
                wake_up_bit(&ip->i_flags, __XFS_IPINNED_BIT);
}

/*
 * Callback used to mark a buffer with XFS_LI_FAILED when items in the buffer
 * have been failed during writeback
 *
 * This informs the AIL that the inode is already flush locked on the next push,
 * and acquires a hold on the buffer to ensure that it isn't reclaimed before
 * dirty data makes it to disk.
 */
STATIC void
xfs_inode_item_error(
        struct xfs_log_item     *lip,
        struct xfs_buf          *bp)
{
        ASSERT(xfs_isiflocked(INODE_ITEM(lip)->ili_inode));
        xfs_set_li_failed(lip, bp);
}

STATIC uint
xfs_inode_item_push(
        struct xfs_log_item     *lip,
        struct list_head        *buffer_list)
                __releases(&lip->li_ailp->xa_lock)
                __acquires(&lip->li_ailp->xa_lock)
{
        struct xfs_inode_log_item *iip = INODE_ITEM(lip);
        struct xfs_inode        *ip = iip->ili_inode;
        struct xfs_buf          *bp = lip->li_buf;
        uint                    rval = XFS_ITEM_SUCCESS;
        int                     error;

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

        /*
         * The buffer containing this item failed to be written back
         * previously. Resubmit the buffer for IO.
         */
        if (lip->li_flags & XFS_LI_FAILED) {
                if (!xfs_buf_trylock(bp))
                        return XFS_ITEM_LOCKED;

                if (!xfs_buf_resubmit_failed_buffers(bp, lip, buffer_list))
                        rval = XFS_ITEM_FLUSHING;

                xfs_buf_unlock(bp);
                return rval;
        }

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

        /*
         * Re-check the pincount now that we stabilized the value by
         * taking the ilock.
         */
        if (xfs_ipincount(ip) > 0) {
                rval = XFS_ITEM_PINNED;
                goto out_unlock;
        }

        /*
         * Stale inode items should force out the iclog.
         */
        if (ip->i_flags & XFS_ISTALE) {
                rval = XFS_ITEM_PINNED;
                goto out_unlock;
        }

        /*
         * Someone else is already flushing the inode.  Nothing we can do
         * here but wait for the flush to finish and remove the item from
         * the AIL.
         */
        if (!xfs_iflock_nowait(ip)) {
                rval = XFS_ITEM_FLUSHING;
                goto out_unlock;
        }

        ASSERT(iip->ili_fields != 0 || XFS_FORCED_SHUTDOWN(ip->i_mount));
        ASSERT(iip->ili_logged == 0 || XFS_FORCED_SHUTDOWN(ip->i_mount));

        spin_unlock(&lip->li_ailp->xa_lock);

        error = xfs_iflush(ip, &bp);
        if (!error) {
                if (!xfs_buf_delwri_queue(bp, buffer_list))
                        rval = XFS_ITEM_FLUSHING;
                xfs_buf_relse(bp);
        }

        spin_lock(&lip->li_ailp->xa_lock);
out_unlock:
        xfs_iunlock(ip, XFS_ILOCK_SHARED);
        return rval;
}

/*
 * 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(
        struct xfs_log_item     *lip)
{
        struct xfs_inode_log_item *iip = INODE_ITEM(lip);
        struct xfs_inode        *ip = iip->ili_inode;
        unsigned short          lock_flags;

        ASSERT(ip->i_itemp != NULL);
        ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));

        lock_flags = iip->ili_lock_flags;
        iip->ili_lock_flags = 0;
        if (lock_flags)
                xfs_iunlock(ip, 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.
 *
 * If the inode has been marked stale because the cluster is being freed, we
 * don't want to (re-)insert this inode into the AIL. There is a race condition
 * where the cluster buffer may be unpinned before the inode is inserted into
 * the AIL during transaction committed processing. If the buffer is unpinned
 * before the inode item has been committed and inserted, then it is possible
 * for the buffer to be written and IO completes before the inode is inserted
 * into the AIL. In that case, we'd be inserting a clean, stale inode into the
 * AIL which will never get removed. It will, however, get reclaimed which
 * triggers an assert in xfs_inode_free() complaining about freein an inode
 * still in the AIL.
 *
 * To avoid this, just unpin the inode directly and return a LSN of -1 so the
 * transaction committed code knows that it does not need to do any further
 * processing on the item.
 */
STATIC xfs_lsn_t
xfs_inode_item_committed(
        struct xfs_log_item     *lip,
        xfs_lsn_t               lsn)
{
        struct xfs_inode_log_item *iip = INODE_ITEM(lip);
        struct xfs_inode        *ip = iip->ili_inode;

        if (xfs_iflags_test(ip, XFS_ISTALE)) {
                xfs_inode_item_unpin(lip, 0);
                return -1;
        }
        return lsn;
}

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

/*
 * This is the ops vector shared by all buf log items.
 */
static const struct xfs_item_ops xfs_inode_item_ops = {
        .iop_size       = xfs_inode_item_size,
        .iop_format     = xfs_inode_item_format,
        .iop_pin        = xfs_inode_item_pin,
        .iop_unpin      = xfs_inode_item_unpin,
        .iop_unlock     = xfs_inode_item_unlock,
        .iop_committed  = xfs_inode_item_committed,
        .iop_push       = xfs_inode_item_push,
        .iop_committing = xfs_inode_item_committing,
        .iop_error      = xfs_inode_item_error
};


/*
 * Initialize the inode log item for a newly allocated (in-core) inode.
 */
void
xfs_inode_item_init(
        struct xfs_inode        *ip,
        struct xfs_mount        *mp)
{
        struct xfs_inode_log_item *iip;

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

        iip->ili_inode = ip;
        xfs_log_item_init(mp, &iip->ili_item, XFS_LI_INODE,
                                                &xfs_inode_item_ops);
}

/*
 * Free the inode log item and any memory hanging off of it.
 */
void
xfs_inode_item_destroy(
        xfs_inode_t     *ip)
{
        kmem_free(ip->i_itemp->ili_item.li_lv_shadow);
        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.
 *
 * To reduce AIL lock traffic as much as possible, we scan the buffer log item
 * list for other inodes that will run this function. We remove them from the
 * buffer list so we can process all the inode IO completions in one AIL lock
 * traversal.
 */
void
xfs_iflush_done(
        struct xfs_buf          *bp,
        struct xfs_log_item     *lip)
{
        struct xfs_inode_log_item *iip;
        struct xfs_log_item     *blip;
        struct xfs_log_item     *next;
        struct xfs_log_item     *prev;
        struct xfs_ail          *ailp = lip->li_ailp;
        int                     need_ail = 0;

        /*
         * Scan the buffer IO completions for other inodes being completed and
         * attach them to the current inode log item.
         */
        blip = bp->b_fspriv;
        prev = NULL;
        while (blip != NULL) {
                if (blip->li_cb != xfs_iflush_done) {
                        prev = blip;
                        blip = blip->li_bio_list;
                        continue;
                }

                /* remove from list */
                next = blip->li_bio_list;
                if (!prev) {
                        bp->b_fspriv = next;
                } else {
                        prev->li_bio_list = next;
                }

                /* add to current list */
                blip->li_bio_list = lip->li_bio_list;
                lip->li_bio_list = blip;

                /*
                 * while we have the item, do the unlocked check for needing
                 * the AIL lock.
                 */
                iip = INODE_ITEM(blip);
                if ((iip->ili_logged && blip->li_lsn == iip->ili_flush_lsn) ||
                    (blip->li_flags & XFS_LI_FAILED))
                        need_ail++;

                blip = next;
        }

        /* make sure we capture the state of the initial inode. */
        iip = INODE_ITEM(lip);
        if ((iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn) ||
            lip->li_flags & XFS_LI_FAILED)
                need_ail++;

        /*
         * 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 (need_ail) {
                bool                    mlip_changed = false;

                /* this is an opencoded batch version of xfs_trans_ail_delete */
                spin_lock(&ailp->xa_lock);
                for (blip = lip; blip; blip = blip->li_bio_list) {
                        if (INODE_ITEM(blip)->ili_logged &&
                            blip->li_lsn == INODE_ITEM(blip)->ili_flush_lsn)
                                mlip_changed |= xfs_ail_delete_one(ailp, blip);
                        else {
                                xfs_clear_li_failed(blip);
                        }
                }

                if (mlip_changed) {
                        if (!XFS_FORCED_SHUTDOWN(ailp->xa_mount))
                                xlog_assign_tail_lsn_locked(ailp->xa_mount);
                        if (list_empty(&ailp->xa_ail))
                                wake_up_all(&ailp->xa_empty);
                }
                spin_unlock(&ailp->xa_lock);

                if (mlip_changed)
                        xfs_log_space_wake(ailp->xa_mount);
        }

        /*
         * clean up and unlock the flush lock now we are done. We can clear the
         * ili_last_fields bits now that we know that the data corresponding to
         * them is safely on disk.
         */
        for (blip = lip; blip; blip = next) {
                next = blip->li_bio_list;
                blip->li_bio_list = NULL;

                iip = INODE_ITEM(blip);
                iip->ili_logged = 0;
                iip->ili_last_fields = 0;
                xfs_ifunlock(iip->ili_inode);
        }
}

/*
 * 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,
        bool                    stale)
{
        xfs_inode_log_item_t    *iip = ip->i_itemp;

        if (iip) {
                if (iip->ili_item.li_flags & XFS_LI_IN_AIL) {
                        xfs_trans_ail_remove(&iip->ili_item,
                                             stale ? SHUTDOWN_LOG_IO_ERROR :
                                                     SHUTDOWN_CORRUPT_INCORE);
                }
                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_fields = 0;
                iip->ili_fsync_fields = 0;
        }
        /*
         * Release the inode's flush lock since we're done with it.
         */
        xfs_ifunlock(ip);
}

void
xfs_istale_done(
        struct xfs_buf          *bp,
        struct xfs_log_item     *lip)
{
        xfs_iflush_abort(INODE_ITEM(lip)->ili_inode, true);
}

/*
 * convert an xfs_inode_log_format struct from the old 32 bit version
 * (which can have different field alignments) to the native 64 bit version
 */
int
xfs_inode_item_format_convert(
        struct xfs_log_iovec            *buf,
        struct xfs_inode_log_format     *in_f)
{
        struct xfs_inode_log_format_32  *in_f32 = buf->i_addr;

        if (buf->i_len != sizeof(*in_f32))
                return -EFSCORRUPTED;

        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 */
        uuid_copy(&in_f->ilf_u.ilfu_uuid, &in_f32->ilf_u.ilfu_uuid);
        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;
}