xfs_inode_item.c

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/*
 * 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_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_trans_priv.h"
#include "xfs_bmap_btree.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_error.h"
#include "xfs_trace.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);
}


/*
 * 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(
    struct xfs_log_item *lip)
{
    struct xfs_inode_log_item *iip = INODE_ITEM(lip);
    struct xfs_inode    *ip = iip->ili_inode;
    uint            nvecs = 2;

    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)
            nvecs++;
        break;

    case XFS_DINODE_FMT_BTREE:
        if ((iip->ili_fields & XFS_ILOG_DBROOT) &&
            ip->i_df.if_broot_bytes > 0)
            nvecs++;
        break;

    case XFS_DINODE_FMT_LOCAL:
        if ((iip->ili_fields & XFS_ILOG_DDATA) &&
            ip->i_df.if_bytes > 0)
            nvecs++;
        break;

    case XFS_DINODE_FMT_DEV:
    case XFS_DINODE_FMT_UUID:
        break;

    default:
        ASSERT(0);
        break;
    }

    if (!XFS_IFORK_Q(ip))
        return nvecs;


    /*
     * Log any necessary attribute data.
     */
    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)
            nvecs++;
        break;

    case XFS_DINODE_FMT_BTREE:
        if ((iip->ili_fields & XFS_ILOG_ABROOT) &&
            ip->i_afp->if_broot_bytes > 0)
            nvecs++;
        break;

    case XFS_DINODE_FMT_LOCAL:
        if ((iip->ili_fields & XFS_ILOG_ADATA) &&
            ip->i_afp->if_bytes > 0)
            nvecs++;
        break;

    default:
        ASSERT(0);
        break;
    }

    return nvecs;
}

/*
 * xfs_inode_item_format_extents - convert in-core extents to on-disk form
 *
 * For either the data or attr fork in extent format, we need to endian convert
 * the in-core extent as we place them into the on-disk inode. In this case, we
 * need to do this conversion before we write the extents into the log. Because
 * we don't have the disk inode to write into here, we allocate a buffer and
 * format the extents into it via xfs_iextents_copy(). We free the buffer in
 * the unlock routine after the copy for the log has been made.
 *
 * In the case of the data fork, the in-core and on-disk fork sizes can be
 * different due to delayed allocation extents. We only log on-disk extents
 * here, so always use the physical fork size to determine the size of the
 * buffer we need to allocate.
 */
STATIC void
xfs_inode_item_format_extents(
    struct xfs_inode    *ip,
    struct xfs_log_iovec    *vecp,
    int         whichfork,
    int         type)
{
    xfs_bmbt_rec_t      *ext_buffer;

    ext_buffer = kmem_alloc(XFS_IFORK_SIZE(ip, whichfork), KM_SLEEP);
    if (whichfork == XFS_DATA_FORK)
        ip->i_itemp->ili_extents_buf = ext_buffer;
    else
        ip->i_itemp->ili_aextents_buf = ext_buffer;

    vecp->i_addr = ext_buffer;
    vecp->i_len = xfs_iextents_copy(ip, ext_buffer, whichfork);
    vecp->i_type = type;
}

/*
 * 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(
    struct xfs_log_item *lip,
    struct xfs_log_iovec    *vecp)
{
    struct xfs_inode_log_item *iip = INODE_ITEM(lip);
    struct xfs_inode    *ip = iip->ili_inode;
    uint            nvecs;
    size_t          data_bytes;
    xfs_mount_t     *mp;

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

    vecp->i_addr = &ip->i_d;
    vecp->i_len  = sizeof(struct xfs_icdinode);
    vecp->i_type = XLOG_REG_TYPE_ICORE;
    vecp++;
    nvecs++;

    /*
     * 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:
        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) {
            ASSERT(ip->i_df.if_u1.if_extents != NULL);
            ASSERT(ip->i_df.if_bytes / sizeof(xfs_bmbt_rec_t) > 0);
            ASSERT(iip->ili_extents_buf == NULL);

#ifdef XFS_NATIVE_HOST
                       if (ip->i_d.di_nextents == ip->i_df.if_bytes /
                                               (uint)sizeof(xfs_bmbt_rec_t)) {
                /*
                 * There are no delayed allocation
                 * extents, so just point to the
                 * real extents array.
                 */
                vecp->i_addr = ip->i_df.if_u1.if_extents;
                vecp->i_len = ip->i_df.if_bytes;
                vecp->i_type = XLOG_REG_TYPE_IEXT;
            } else
#endif
            {
                xfs_inode_item_format_extents(ip, vecp,
                    XFS_DATA_FORK, XLOG_REG_TYPE_IEXT);
            }
            ASSERT(vecp->i_len <= ip->i_df.if_bytes);
            iip->ili_format.ilf_dsize = vecp->i_len;
            vecp++;
            nvecs++;
        } 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);
            vecp->i_addr = ip->i_df.if_broot;
            vecp->i_len = ip->i_df.if_broot_bytes;
            vecp->i_type = XLOG_REG_TYPE_IBROOT;
            vecp++;
            nvecs++;
            iip->ili_format.ilf_dsize = ip->i_df.if_broot_bytes;
        } else {
            ASSERT(!(iip->ili_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_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) {
            ASSERT(ip->i_df.if_u1.if_data != NULL);
            ASSERT(ip->i_d.di_size > 0);

            vecp->i_addr = 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;
            vecp->i_type = XLOG_REG_TYPE_ILOCAL;
            vecp++;
            nvecs++;
            iip->ili_format.ilf_dsize = (unsigned)data_bytes;
        } 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) {
            iip->ili_format.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) {
            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.
     */
    if (!XFS_IFORK_Q(ip)) {
        iip->ili_fields &=
            ~(XFS_ILOG_ADATA | XFS_ILOG_ABROOT | XFS_ILOG_AEXT);
        goto out;
    }

    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) {
            ASSERT(ip->i_afp->if_bytes / sizeof(xfs_bmbt_rec_t) ==
                ip->i_d.di_anextents);
            ASSERT(ip->i_afp->if_u1.if_extents != NULL);
#ifdef XFS_NATIVE_HOST
            /*
             * There are not delayed allocation extents
             * for attributes, so just point at the array.
             */
            vecp->i_addr = ip->i_afp->if_u1.if_extents;
            vecp->i_len = ip->i_afp->if_bytes;
            vecp->i_type = XLOG_REG_TYPE_IATTR_EXT;
#else
            ASSERT(iip->ili_aextents_buf == NULL);
            xfs_inode_item_format_extents(ip, vecp,
                    XFS_ATTR_FORK, XLOG_REG_TYPE_IATTR_EXT);
#endif
            iip->ili_format.ilf_asize = vecp->i_len;
            vecp++;
            nvecs++;
        } 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);

            vecp->i_addr = ip->i_afp->if_broot;
            vecp->i_len = ip->i_afp->if_broot_bytes;
            vecp->i_type = XLOG_REG_TYPE_IATTR_BROOT;
            vecp++;
            nvecs++;
            iip->ili_format.ilf_asize = ip->i_afp->if_broot_bytes;
        } 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) {
            ASSERT(ip->i_afp->if_u1.if_data != NULL);

            vecp->i_addr = 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;
            vecp->i_type = XLOG_REG_TYPE_IATTR_LOCAL;
            vecp++;
            nvecs++;
            iip->ili_format.ilf_asize = (unsigned)data_bytes;
        } else {
            iip->ili_fields &= ~XFS_ILOG_ADATA;
        }
        break;

    default:
        ASSERT(0);
        break;
    }

out:
    /*
     * Now update the log format that goes out to disk from the in-core
     * values.  We always write the inode core to make the arithmetic
     * games in recovery easier, which isn't a big deal as just about any
     * transaction would dirty it anyway.
     */
    iip->ili_format.ilf_fields = XFS_ILOG_CORE |
        (iip->ili_fields & ~XFS_ILOG_TIMESTAMP);
    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.
 */
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);
}

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

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

    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));

    /*
     * 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_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_fields & XFS_ILOG_AEXT);
        ASSERT(ip->i_afp->if_bytes > 0);
        kmem_free(iip->ili_aextents_buf);
        iip->ili_aextents_buf = NULL;
    }

    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
};


/*
 * 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);
    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.
 *
 * 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 (lip->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)
            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)
        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) {
        struct xfs_log_item *log_items[need_ail];
        int i = 0;
        spin_lock(&ailp->xa_lock);
        for (blip = lip; blip; blip = blip->li_bio_list) {
            iip = INODE_ITEM(blip);
            if (iip->ili_logged &&
                blip->li_lsn == iip->ili_flush_lsn) {
                log_items[i++] = blip;
            }
            ASSERT(i <= need_ail);
        }
        /* xfs_trans_ail_delete_bulk() drops the AIL lock. */
        xfs_trans_ail_delete_bulk(ailp, log_items, i,
                      SHUTDOWN_CORRUPT_INCORE);
    }


    /*
     * 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) {
        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, &iip->ili_item,
                        stale ?
                             SHUTDOWN_LOG_IO_ERROR :
                             SHUTDOWN_CORRUPT_INCORE);
            } 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_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 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 = 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 = 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;
}