// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#include "xfs_platform.h"
#include "xfs_fs.h"
#include "xfs_shared.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_trace.h"
#include "xfs_trans_priv.h"
#include "xfs_buf_item.h"
#include "xfs_log.h"
#include "xfs_log_priv.h"
#include "xfs_error.h"
#include "xfs_rtbitmap.h"

#include <linux/iversion.h>

struct kmem_cache       *xfs_ili_cache;         /* inode log item */

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 uint64_t
xfs_inode_item_sort(
        struct xfs_log_item     *lip)
{
        return INODE_ITEM(lip)->ili_inode->i_ino;
}

#ifdef DEBUG_EXPENSIVE
static void
xfs_inode_item_precommit_check(
        struct xfs_inode        *ip)
{
        struct xfs_mount        *mp = ip->i_mount;
        struct xfs_dinode       *dip;
        xfs_failaddr_t          fa;

        dip = kzalloc(mp->m_sb.sb_inodesize, GFP_KERNEL | GFP_NOFS);
        if (!dip) {
                ASSERT(dip != NULL);
                return;
        }

        xfs_inode_to_disk(ip, dip, 0);
        xfs_dinode_calc_crc(mp, dip);
        fa = xfs_dinode_verify(mp, ip->i_ino, dip);
        if (fa) {
                xfs_inode_verifier_error(ip, -EFSCORRUPTED, __func__, dip,
                                sizeof(*dip), fa);
                xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
                ASSERT(fa == NULL);
        }
        kfree(dip);
}
#else
# define xfs_inode_item_precommit_check(ip)     ((void)0)
#endif

/*
 * Prior to finally logging the inode, we have to ensure that all the
 * per-modification inode state changes are applied. This includes VFS inode
 * state updates, format conversions, verifier state synchronisation and
 * ensuring the inode buffer remains in memory whilst the inode is dirty.
 *
 * We have to be careful when we grab the inode cluster buffer due to lock
 * ordering constraints. The unlinked inode modifications (xfs_iunlink_item)
 * require AGI -> inode cluster buffer lock order. The inode cluster buffer is
 * not locked until ->precommit, so it happens after everything else has been
 * modified.
 *
 * Further, we have AGI -> AGF lock ordering, and with O_TMPFILE handling we
 * have AGI -> AGF -> iunlink item -> inode cluster buffer lock order. Hence we
 * cannot safely lock the inode cluster buffer in xfs_trans_log_inode() because
 * it can be called on a inode (e.g. via bumplink/droplink) before we take the
 * AGF lock modifying directory blocks.
 *
 * Rather than force a complete rework of all the transactions to call
 * xfs_trans_log_inode() once and once only at the end of every transaction, we
 * move the pinning of the inode cluster buffer to a ->precommit operation. This
 * matches how the xfs_iunlink_item locks the inode cluster buffer, and it
 * ensures that the inode cluster buffer locking is always done last in a
 * transaction. i.e. we ensure the lock order is always AGI -> AGF -> inode
 * cluster buffer.
 *
 * If we return the inode number as the precommit sort key then we'll also
 * guarantee that the order all inode cluster buffer locking is the same all the
 * inodes and unlink items in the transaction.
 */
static int
xfs_inode_item_precommit(
        struct xfs_trans        *tp,
        struct xfs_log_item     *lip)
{
        struct xfs_inode_log_item *iip = INODE_ITEM(lip);
        struct xfs_inode        *ip = iip->ili_inode;
        struct inode            *inode = VFS_I(ip);
        unsigned int            flags = iip->ili_dirty_flags;

        /*
         * Don't bother with i_lock for the I_DIRTY_TIME check here, as races
         * don't matter - we either will need an extra transaction in 24 hours
         * to log the timestamps, or will clear already cleared fields in the
         * worst case.
         */
        if (inode_state_read_once(inode) & I_DIRTY_TIME) {
                spin_lock(&inode->i_lock);
                inode_state_clear(inode, I_DIRTY_TIME);
                spin_unlock(&inode->i_lock);
        }

        /*
         * If we're updating the inode core or the timestamps and it's possible
         * to upgrade this inode to bigtime format, do so now.
         */
        if ((flags & (XFS_ILOG_CORE | XFS_ILOG_TIMESTAMP)) &&
            xfs_has_bigtime(ip->i_mount) &&
            !xfs_inode_has_bigtime(ip)) {
                ip->i_diflags2 |= XFS_DIFLAG2_BIGTIME;
                flags |= XFS_ILOG_CORE;
        }

        /*
         * Inode verifiers do not check that the extent size hints are an
         * integer multiple of the rt extent size on a directory with
         * rtinherit flags set.  If we're logging a directory that is
         * misconfigured in this way, clear the bad hints.
         */
        if (ip->i_diflags & XFS_DIFLAG_RTINHERIT) {
                if ((ip->i_diflags & XFS_DIFLAG_EXTSZINHERIT) &&
                    xfs_extlen_to_rtxmod(ip->i_mount, ip->i_extsize) > 0) {
                        ip->i_diflags &= ~(XFS_DIFLAG_EXTSIZE |
                                           XFS_DIFLAG_EXTSZINHERIT);
                        ip->i_extsize = 0;
                        flags |= XFS_ILOG_CORE;
                }
                if ((ip->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE) &&
                    xfs_extlen_to_rtxmod(ip->i_mount, ip->i_cowextsize) > 0) {
                        ip->i_diflags2 &= ~XFS_DIFLAG2_COWEXTSIZE;
                        ip->i_cowextsize = 0;
                        flags |= XFS_ILOG_CORE;
                }
        }

        spin_lock(&iip->ili_lock);
        if (!iip->ili_item.li_buf) {
                struct xfs_buf  *bp;
                int             error;

                /*
                 * We hold the ILOCK here, so this inode is not going to be
                 * flushed while we are here. Further, because there is no
                 * buffer attached to the item, we know that there is no IO in
                 * progress, so nothing will clear the ili_fields while we read
                 * in the buffer. Hence we can safely drop the spin lock and
                 * read the buffer knowing that the state will not change from
                 * here.
                 */
                spin_unlock(&iip->ili_lock);
                error = xfs_imap_to_bp(ip->i_mount, tp, &ip->i_imap, &bp);
                if (error)
                        return error;

                /*
                 * We need an explicit buffer reference for the log item but
                 * don't want the buffer to remain attached to the transaction.
                 * Hold the buffer but release the transaction reference once
                 * we've attached the inode log item to the buffer log item
                 * list.
                 */
                xfs_buf_hold(bp);
                spin_lock(&iip->ili_lock);
                iip->ili_item.li_buf = bp;
                bp->b_iodone = xfs_buf_inode_iodone;
                list_add_tail(&iip->ili_item.li_bio_list, &bp->b_li_list);
                xfs_trans_brelse(tp, bp);
        }

        /*
         * Store the dirty flags back into the inode item as this state is used
         * later on in xfs_inode_item_committing() to determine whether the
         * transaction is relevant to fsync state or not.
         */
        iip->ili_dirty_flags = flags;

        /*
         * Convert the flags on-disk fields that have been modified in the
         * transaction so that ili_fields tracks the changes correctly.
         */
        if (flags & XFS_ILOG_IVERSION)
                flags = ((flags & ~XFS_ILOG_IVERSION) | XFS_ILOG_CORE);

        /*
         * Always OR in the bits from the ili_last_fields field.  This is to
         * coordinate with the xfs_iflush() and xfs_buf_inode_iodone() routines
         * in the eventual clearing of the ili_fields bits.  See the big comment
         * in xfs_iflush() for an explanation of this coordination mechanism.
         */
        iip->ili_fields |= (flags | iip->ili_last_fields);
        spin_unlock(&iip->ili_lock);

        xfs_inode_item_precommit_check(ip);
        return 0;
}

/*
 * The logged size of an inode fork is always the current size of the inode
 * fork. This means that when an inode fork is relogged, the size of the logged
 * region is determined by the current state, not the combination of the
 * previously logged state + the current state. This is different relogging
 * behaviour to most other log items which will retain the size of the
 * previously logged changes when smaller regions are relogged.
 *
 * Hence operations that remove data from the inode fork (e.g. shortform
 * dir/attr remove, extent form extent removal, etc), the size of the relogged
 * inode gets -smaller- rather than stays the same size as the previously logged
 * size and this can result in the committing transaction reducing the amount of
 * space being consumed by the CIL.
 */
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_df.if_format) {
        case XFS_DINODE_FMT_EXTENTS:
                if ((iip->ili_fields & XFS_ILOG_DEXT) &&
                    ip->i_df.if_nextents > 0 &&
                    ip->i_df.if_bytes > 0) {
                        /* worst case, doesn't subtract delalloc extents */
                        *nbytes += xfs_inode_data_fork_size(ip);
                        *nvecs += 1;
                }
                break;
        case XFS_DINODE_FMT_BTREE:
        case XFS_DINODE_FMT_META_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 += xlog_calc_iovec_len(ip->i_df.if_bytes);
                        *nvecs += 1;
                }
                break;

        case XFS_DINODE_FMT_DEV:
                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_af.if_format) {
        case XFS_DINODE_FMT_EXTENTS:
                if ((iip->ili_fields & XFS_ILOG_AEXT) &&
                    ip->i_af.if_nextents > 0 &&
                    ip->i_af.if_bytes > 0) {
                        /* worst case, doesn't subtract unused space */
                        *nbytes += xfs_inode_attr_fork_size(ip);
                        *nvecs += 1;
                }
                break;
        case XFS_DINODE_FMT_BTREE:
                if ((iip->ili_fields & XFS_ILOG_ABROOT) &&
                    ip->i_af.if_broot_bytes > 0) {
                        *nbytes += ip->i_af.if_broot_bytes;
                        *nvecs += 1;
                }
                break;
        case XFS_DINODE_FMT_LOCAL:
                if ((iip->ili_fields & XFS_ILOG_ADATA) &&
                    ip->i_af.if_bytes > 0) {
                        *nbytes += xlog_calc_iovec_len(ip->i_af.if_bytes);
                        *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_mount);

        xfs_inode_item_data_fork_size(iip, nvecs, nbytes);
        if (xfs_inode_has_attr_fork(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 xlog_format_buf  *lfb)
{
        struct xfs_inode        *ip = iip->ili_inode;
        size_t                  data_bytes;

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

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

                        ASSERT(xfs_iext_count(&ip->i_df) > 0);

                        p = xlog_format_start(lfb, XLOG_REG_TYPE_IEXT);
                        data_bytes = xfs_iextents_copy(ip, p, XFS_DATA_FORK);
                        xlog_format_commit(lfb, 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:
        case XFS_DINODE_FMT_META_BTREE:
                iip->ili_fields &=
                        ~(XFS_ILOG_DDATA | XFS_ILOG_DEXT | XFS_ILOG_DEV);

                if ((iip->ili_fields & XFS_ILOG_DBROOT) &&
                    ip->i_df.if_broot_bytes > 0) {
                        ASSERT(ip->i_df.if_broot != NULL);
                        xlog_format_copy(lfb, 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);
                if ((iip->ili_fields & XFS_ILOG_DDATA) &&
                    ip->i_df.if_bytes > 0) {
                        ASSERT(ip->i_df.if_data != NULL);
                        ASSERT(ip->i_disk_size > 0);
                        xlog_format_copy(lfb, XLOG_REG_TYPE_ILOCAL,
                                        ip->i_df.if_data,
                                        ip->i_df.if_bytes);
                        ilf->ilf_dsize = (unsigned)ip->i_df.if_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);
                if (iip->ili_fields & XFS_ILOG_DEV)
                        ilf->ilf_u.ilfu_rdev = sysv_encode_dev(VFS_I(ip)->i_rdev);
                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 xlog_format_buf  *lfb)
{
        struct xfs_inode        *ip = iip->ili_inode;
        size_t                  data_bytes;

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

                if ((iip->ili_fields & XFS_ILOG_AEXT) &&
                    ip->i_af.if_nextents > 0 &&
                    ip->i_af.if_bytes > 0) {
                        struct xfs_bmbt_rec *p;

                        ASSERT(xfs_iext_count(&ip->i_af) ==
                                ip->i_af.if_nextents);

                        p = xlog_format_start(lfb, XLOG_REG_TYPE_IATTR_EXT);
                        data_bytes = xfs_iextents_copy(ip, p, XFS_ATTR_FORK);
                        xlog_format_commit(lfb, 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_af.if_broot_bytes > 0) {
                        ASSERT(ip->i_af.if_broot != NULL);

                        xlog_format_copy(lfb, XLOG_REG_TYPE_IATTR_BROOT,
                                        ip->i_af.if_broot,
                                        ip->i_af.if_broot_bytes);
                        ilf->ilf_asize = ip->i_af.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_af.if_bytes > 0) {
                        ASSERT(ip->i_af.if_data != NULL);
                        xlog_format_copy(lfb, XLOG_REG_TYPE_IATTR_LOCAL,
                                        ip->i_af.if_data,
                                        ip->i_af.if_bytes);
                        ilf->ilf_asize = (unsigned)ip->i_af.if_bytes;
                        ilf->ilf_size++;
                } else {
                        iip->ili_fields &= ~XFS_ILOG_ADATA;
                }
                break;
        default:
                ASSERT(0);
                break;
        }
}

/*
 * Convert an incore timestamp to a log timestamp.  Note that the log format
 * specifies host endian format!
 */
static inline xfs_log_timestamp_t
xfs_inode_to_log_dinode_ts(
        struct xfs_inode                *ip,
        const struct timespec64         tv)
{
        struct xfs_log_legacy_timestamp *lits;
        xfs_log_timestamp_t             its;

        if (xfs_inode_has_bigtime(ip))
                return xfs_inode_encode_bigtime(tv);

        lits = (struct xfs_log_legacy_timestamp *)&its;
        lits->t_sec = tv.tv_sec;
        lits->t_nsec = tv.tv_nsec;

        return its;
}

/*
 * The legacy DMAPI fields are only present in the on-disk and in-log inodes,
 * but not in the in-memory one.  But we are guaranteed to have an inode buffer
 * in memory when logging an inode, so we can just copy it from the on-disk
 * inode to the in-log inode here so that recovery of file system with these
 * fields set to non-zero values doesn't lose them.  For all other cases we zero
 * the fields.
 */
static void
xfs_copy_dm_fields_to_log_dinode(
        struct xfs_inode        *ip,
        struct xfs_log_dinode   *to)
{
        struct xfs_dinode       *dip;

        dip = xfs_buf_offset(ip->i_itemp->ili_item.li_buf,
                             ip->i_imap.im_boffset);

        if (xfs_iflags_test(ip, XFS_IPRESERVE_DM_FIELDS)) {
                to->di_dmevmask = be32_to_cpu(dip->di_dmevmask);
                to->di_dmstate = be16_to_cpu(dip->di_dmstate);
        } else {
                to->di_dmevmask = 0;
                to->di_dmstate = 0;
        }
}

static inline void
xfs_inode_to_log_dinode_iext_counters(
        struct xfs_inode        *ip,
        struct xfs_log_dinode   *to)
{
        if (xfs_inode_has_large_extent_counts(ip)) {
                to->di_big_nextents = xfs_ifork_nextents(&ip->i_df);
                to->di_big_anextents = xfs_ifork_nextents(&ip->i_af);
                to->di_nrext64_pad = 0;
        } else {
                to->di_nextents = xfs_ifork_nextents(&ip->i_df);
                to->di_anextents = xfs_ifork_nextents(&ip->i_af);
        }
}

static void
xfs_inode_to_log_dinode(
        struct xfs_inode        *ip,
        struct xfs_log_dinode   *to,
        xfs_lsn_t               lsn)
{
        struct inode            *inode = VFS_I(ip);

        to->di_magic = XFS_DINODE_MAGIC;
        to->di_format = xfs_ifork_format(&ip->i_df);
        to->di_uid = i_uid_read(inode);
        to->di_gid = i_gid_read(inode);
        to->di_projid_lo = ip->i_projid & 0xffff;
        to->di_projid_hi = ip->i_projid >> 16;

        to->di_atime = xfs_inode_to_log_dinode_ts(ip, inode_get_atime(inode));
        to->di_mtime = xfs_inode_to_log_dinode_ts(ip, inode_get_mtime(inode));
        to->di_ctime = xfs_inode_to_log_dinode_ts(ip, inode_get_ctime(inode));
        to->di_nlink = inode->i_nlink;
        to->di_gen = inode->i_generation;
        to->di_mode = inode->i_mode;

        to->di_size = ip->i_disk_size;
        to->di_nblocks = ip->i_nblocks;
        to->di_extsize = ip->i_extsize;
        to->di_forkoff = ip->i_forkoff;
        to->di_aformat = xfs_ifork_format(&ip->i_af);
        to->di_flags = ip->i_diflags;

        xfs_copy_dm_fields_to_log_dinode(ip, to);

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

        if (xfs_has_v3inodes(ip->i_mount)) {
                to->di_version = 3;
                to->di_changecount = inode_peek_iversion(inode);
                to->di_crtime = xfs_inode_to_log_dinode_ts(ip, ip->i_crtime);
                to->di_flags2 = ip->i_diflags2;
                /* also covers the di_used_blocks union arm: */
                to->di_cowextsize = ip->i_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_v3_pad = 0;

                /* dummy value for initialisation */
                to->di_crc = 0;

                if (xfs_is_metadir_inode(ip))
                        to->di_metatype = ip->i_metatype;
                else
                        to->di_metatype = 0;
        } else {
                to->di_version = 2;
                to->di_flushiter = ip->i_flushiter;
                memset(to->di_v2_pad, 0, sizeof(to->di_v2_pad));
                to->di_metatype = 0;
        }

        xfs_inode_to_log_dinode_iext_counters(ip, to);
}

/*
 * 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 xlog_format_buf  *lfb)
{
        struct xfs_log_dinode   *dic;

        dic = xlog_format_start(lfb, XLOG_REG_TYPE_ICORE);
        xfs_inode_to_log_dinode(ip, dic, ip->i_itemp->ili_item.li_lsn);
        xlog_format_commit(lfb, xfs_log_dinode_size(ip->i_mount));
}

/*
 * 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 xlog_format_buf  *lfb)
{
        struct xfs_inode_log_item *iip = INODE_ITEM(lip);
        struct xfs_inode        *ip = iip->ili_inode;
        struct xfs_inode_log_format *ilf;

        ilf = xlog_format_start(lfb, 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;
        memset(&ilf->ilf_u, 0, sizeof(ilf->ilf_u));
        xlog_format_commit(lfb, sizeof(*ilf));

        xfs_inode_item_format_core(ip, lfb);
        xfs_inode_item_format_data_fork(iip, ilf, lfb);
        if (xfs_inode_has_attr_fork(ip)) {
                xfs_inode_item_format_attr_fork(iip, ilf, lfb);
        } 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;

        xfs_assert_ilocked(ip, XFS_ILOCK_EXCL);
        ASSERT(lip->li_buf);

        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.
 *
 * Note that unpin can race with inode cluster buffer freeing marking the buffer
 * stale. In that case, flush completions are run from the buffer unpin call,
 * which may happen before the inode is unpinned. If we lose the race, there
 * will be no buffer attached to the log item, but the inode will be marked
 * XFS_ISTALE.
 */
STATIC void
xfs_inode_item_unpin(
        struct xfs_log_item     *lip,
        int                     remove)
{
        struct xfs_inode_log_item *iip = INODE_ITEM(lip);
        struct xfs_inode        *ip = iip->ili_inode;

        trace_xfs_inode_unpin(ip, _RET_IP_);
        ASSERT(lip->li_buf || xfs_iflags_test(ip, XFS_ISTALE));
        ASSERT(atomic_read(&ip->i_pincount) > 0);

        /*
         * If this is the last unpin, then the inode no longer needs a journal
         * flush to persist it. Hence we can clear the commit sequence numbers
         * as a fsync/fdatasync operation on the inode at this point is a no-op.
         */
        if (atomic_dec_and_lock(&ip->i_pincount, &iip->ili_lock)) {
                iip->ili_commit_seq = 0;
                iip->ili_datasync_seq = 0;
                spin_unlock(&iip->ili_lock);
                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)
                __releases(&lip->li_ailp->ail_lock)
                __acquires(&lip->li_ailp->ail_lock)
{
        struct xfs_inode_log_item *iip = INODE_ITEM(lip);
        struct xfs_inode        *ip = iip->ili_inode;
        struct xfs_buf          *bp = lip->li_buf;
        struct xfs_ail          *ailp = lip->li_ailp;
        uint                    rval = XFS_ITEM_SUCCESS;
        int                     error;

        if (!bp || (ip->i_flags & XFS_ISTALE)) {
                /*
                 * Inode item/buffer is being aborted due to cluster
                 * buffer deletion. Trigger a log force to have that operation
                 * completed and items removed from the AIL before the next push
                 * attempt.
                 */
                trace_xfs_inode_push_stale(ip, _RET_IP_);
                return XFS_ITEM_PINNED;
        }

        if (xfs_ipincount(ip) > 0 || xfs_buf_ispinned(bp)) {
                trace_xfs_inode_push_pinned(ip, _RET_IP_);
                return XFS_ITEM_PINNED;
        }

        if (xfs_iflags_test(ip, XFS_IFLUSHING))
                return XFS_ITEM_FLUSHING;

        if (!xfs_buf_trylock(bp))
                return XFS_ITEM_LOCKED;

        spin_unlock(&ailp->ail_lock);

        /*
         * We need to hold a reference for flushing the cluster buffer as it may
         * fail the buffer without IO submission. In which case, we better get a
         * reference for that completion because otherwise we don't get a
         * reference for IO until we queue the buffer for delwri submission.
         */
        xfs_buf_hold(bp);
        error = xfs_iflush_cluster(bp);
        if (!error) {
                if (!xfs_buf_delwri_queue(bp, buffer_list))
                        rval = XFS_ITEM_FLUSHING;
                xfs_buf_relse(bp);
        } else {
                /*
                 * Release the buffer if we were unable to flush anything. On
                 * any other error, the buffer has already been released.
                 */
                if (error == -EAGAIN)
                        xfs_buf_relse(bp);
                rval = XFS_ITEM_LOCKED;
        }

        /*
         * The buffer no longer protects the log item from reclaim, so
         * do not reference lip after this point.
         */
        spin_lock(&ailp->ail_lock);
        return rval;
}

/*
 * Unlock the inode associated with the inode log item.
 */
STATIC void
xfs_inode_item_release(
        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);
        xfs_assert_ilocked(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;
}

/*
 * The modification is now complete, so before we unlock the inode we need to
 * update the commit sequence numbers for data integrity journal flushes. We
 * always record the commit sequence number (ili_commit_seq) so that anything
 * that needs a full journal sync will capture all of this modification.
 *
 * We then
 * check if the changes will impact a datasync (O_DSYNC) journal flush. If the
 * changes will require a datasync flush, then we also record the sequence in
 * ili_datasync_seq.
 *
 * These commit sequence numbers will get cleared atomically with the inode being
 * unpinned (i.e. pin count goes to zero), and so it will only be set when the
 * inode is dirty in the journal. This removes the need for checking if the
 * inode is pinned to determine if a journal flush is necessary, and hence
 * removes the need for holding the ILOCK_SHARED in xfs_file_fsync() to
 * serialise pin counts against commit sequence number updates.
 *
 */
STATIC void
xfs_inode_item_committing(
        struct xfs_log_item     *lip,
        xfs_csn_t               seq)
{
        struct xfs_inode_log_item *iip = INODE_ITEM(lip);

        spin_lock(&iip->ili_lock);
        iip->ili_commit_seq = seq;
        if (iip->ili_dirty_flags & ~(XFS_ILOG_IVERSION | XFS_ILOG_TIMESTAMP))
                iip->ili_datasync_seq = seq;
        spin_unlock(&iip->ili_lock);

        /*
         * Clear the per-transaction dirty flags now that we have finished
         * recording the transaction's inode modifications in the CIL and are
         * about to release and (maybe) unlock the inode.
         */
        iip->ili_dirty_flags = 0;

        return xfs_inode_item_release(lip);
}

static const struct xfs_item_ops xfs_inode_item_ops = {
        .iop_sort       = xfs_inode_item_sort,
        .iop_precommit  = xfs_inode_item_precommit,
        .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_release    = xfs_inode_item_release,
        .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_cache_zalloc(xfs_ili_cache,
                                              GFP_KERNEL | __GFP_NOFAIL);

        iip->ili_inode = ip;
        spin_lock_init(&iip->ili_lock);
        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(
        struct xfs_inode        *ip)
{
        struct xfs_inode_log_item *iip = ip->i_itemp;

        ASSERT(iip->ili_item.li_buf == NULL);

        ip->i_itemp = NULL;
        kvfree(iip->ili_item.li_lv_shadow);
        kmem_cache_free(xfs_ili_cache, iip);
}


/*
 * 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 inode's lsn has not changed.
 */
static void
xfs_iflush_ail_updates(
        struct xfs_ail          *ailp,
        struct list_head        *list)
{
        struct xfs_log_item     *lip;
        xfs_lsn_t               tail_lsn = 0;

        /* this is an opencoded batch version of xfs_trans_ail_delete */
        spin_lock(&ailp->ail_lock);
        list_for_each_entry(lip, list, li_bio_list) {
                xfs_lsn_t       lsn;

                clear_bit(XFS_LI_FAILED, &lip->li_flags);
                if (INODE_ITEM(lip)->ili_flush_lsn != lip->li_lsn)
                        continue;

                /*
                 * dgc: Not sure how this happens, but it happens very
                 * occassionaly via generic/388.  xfs_iflush_abort() also
                 * silently handles this same "under writeback but not in AIL at
                 * shutdown" condition via xfs_trans_ail_delete().
                 */
                if (!test_bit(XFS_LI_IN_AIL, &lip->li_flags)) {
                        ASSERT(xlog_is_shutdown(lip->li_log));
                        continue;
                }

                lsn = xfs_ail_delete_one(ailp, lip);
                if (!tail_lsn && lsn)
                        tail_lsn = lsn;
        }
        xfs_ail_update_finish(ailp, tail_lsn);
}

/*
 * Walk the list of inodes that have completed their IOs. If they are clean
 * remove them from the list and dissociate them from the buffer. Buffers that
 * are still dirty remain linked to the buffer and on the list. Caller must
 * handle them appropriately.
 */
static void
xfs_iflush_finish(
        struct xfs_buf          *bp,
        struct list_head        *list)
{
        struct xfs_log_item     *lip, *n;

        list_for_each_entry_safe(lip, n, list, li_bio_list) {
                struct xfs_inode_log_item *iip = INODE_ITEM(lip);
                bool    drop_buffer = false;

                spin_lock(&iip->ili_lock);

                /*
                 * Remove the reference to the cluster buffer if the inode is
                 * clean in memory and drop the buffer reference once we've
                 * dropped the locks we hold.
                 */
                ASSERT(iip->ili_item.li_buf == bp);
                if (!iip->ili_fields) {
                        iip->ili_item.li_buf = NULL;
                        list_del_init(&lip->li_bio_list);
                        drop_buffer = true;
                }
                iip->ili_last_fields = 0;
                iip->ili_flush_lsn = 0;
                clear_bit(XFS_LI_FLUSHING, &lip->li_flags);
                spin_unlock(&iip->ili_lock);
                xfs_iflags_clear(iip->ili_inode, XFS_IFLUSHING);
                if (drop_buffer)
                        xfs_buf_rele(bp);
        }
}

/*
 * Inode buffer IO completion routine.  It is responsible for removing inodes
 * attached to the buffer from the AIL if they have not been re-logged and
 * completing the inode flush.
 */
void
xfs_buf_inode_iodone(
        struct xfs_buf          *bp)
{
        struct xfs_log_item     *lip, *n;
        LIST_HEAD(flushed_inodes);
        LIST_HEAD(ail_updates);

        /*
         * Pull the attached inodes from the buffer one at a time and take the
         * appropriate action on them.
         */
        list_for_each_entry_safe(lip, n, &bp->b_li_list, li_bio_list) {
                struct xfs_inode_log_item *iip = INODE_ITEM(lip);

                if (xfs_iflags_test(iip->ili_inode, XFS_ISTALE)) {
                        xfs_iflush_abort(iip->ili_inode);
                        continue;
                }
                if (!iip->ili_last_fields)
                        continue;

                /* Do an unlocked check for needing the AIL lock. */
                if (iip->ili_flush_lsn == lip->li_lsn ||
                    test_bit(XFS_LI_FAILED, &lip->li_flags))
                        list_move_tail(&lip->li_bio_list, &ail_updates);
                else
                        list_move_tail(&lip->li_bio_list, &flushed_inodes);
        }

        if (!list_empty(&ail_updates)) {
                xfs_iflush_ail_updates(bp->b_mount->m_ail, &ail_updates);
                list_splice_tail(&ail_updates, &flushed_inodes);
        }

        xfs_iflush_finish(bp, &flushed_inodes);
        if (!list_empty(&flushed_inodes))
                list_splice_tail(&flushed_inodes, &bp->b_li_list);
}

/*
 * Clear the inode logging fields so no more flushes are attempted.  If we are
 * on a buffer list, it is now safe to remove it because the buffer is
 * guaranteed to be locked. The caller will drop the reference to the buffer
 * the log item held.
 */
static void
xfs_iflush_abort_clean(
        struct xfs_inode_log_item *iip)
{
        iip->ili_last_fields = 0;
        iip->ili_fields = 0;
        iip->ili_flush_lsn = 0;
        iip->ili_item.li_buf = NULL;
        list_del_init(&iip->ili_item.li_bio_list);
        clear_bit(XFS_LI_FLUSHING, &iip->ili_item.li_flags);
}

/*
 * Abort flushing the inode from a context holding the cluster buffer locked.
 *
 * This is the normal runtime method of aborting writeback of an inode that is
 * attached to a cluster buffer. It occurs when the inode and the backing
 * cluster buffer have been freed (i.e. inode is XFS_ISTALE), or when cluster
 * flushing or buffer IO completion encounters a log shutdown situation.
 *
 * If we need to abort inode writeback and we don't already hold the buffer
 * locked, call xfs_iflush_shutdown_abort() instead as this should only ever be
 * necessary in a shutdown situation.
 */
void
xfs_iflush_abort(
        struct xfs_inode        *ip)
{
        struct xfs_inode_log_item *iip = ip->i_itemp;
        struct xfs_buf          *bp;

        if (!iip) {
                /* clean inode, nothing to do */
                xfs_iflags_clear(ip, XFS_IFLUSHING);
                return;
        }

        /*
         * Remove the inode item from the AIL before we clear its internal
         * state. Whilst the inode is in the AIL, it should have a valid buffer
         * pointer for push operations to access - it is only safe to remove the
         * inode from the buffer once it has been removed from the AIL.
         */
        xfs_trans_ail_delete(&iip->ili_item, 0);

        /*
         * Grab the inode buffer so can we release the reference the inode log
         * item holds on it.
         */
        spin_lock(&iip->ili_lock);
        bp = iip->ili_item.li_buf;
        xfs_iflush_abort_clean(iip);
        spin_unlock(&iip->ili_lock);

        xfs_iflags_clear(ip, XFS_IFLUSHING);
        if (bp)
                xfs_buf_rele(bp);
}

/*
 * Abort an inode flush in the case of a shutdown filesystem. This can be called
 * from anywhere with just an inode reference and does not require holding the
 * inode cluster buffer locked. If the inode is attached to a cluster buffer,
 * it will grab and lock it safely, then abort the inode flush.
 */
void
xfs_iflush_shutdown_abort(
        struct xfs_inode        *ip)
{
        struct xfs_inode_log_item *iip = ip->i_itemp;
        struct xfs_buf          *bp;

        if (!iip) {
                /* clean inode, nothing to do */
                xfs_iflags_clear(ip, XFS_IFLUSHING);
                return;
        }

        spin_lock(&iip->ili_lock);
        bp = iip->ili_item.li_buf;
        if (!bp) {
                spin_unlock(&iip->ili_lock);
                xfs_iflush_abort(ip);
                return;
        }

        /*
         * We have to take a reference to the buffer so that it doesn't get
         * freed when we drop the ili_lock and then wait to lock the buffer.
         * We'll clean up the extra reference after we pick up the ili_lock
         * again.
         */
        xfs_buf_hold(bp);
        spin_unlock(&iip->ili_lock);
        xfs_buf_lock(bp);

        spin_lock(&iip->ili_lock);
        if (!iip->ili_item.li_buf) {
                /*
                 * Raced with another removal, hold the only reference
                 * to bp now. Inode should not be in the AIL now, so just clean
                 * up and return;
                 */
                ASSERT(list_empty(&iip->ili_item.li_bio_list));
                ASSERT(!test_bit(XFS_LI_IN_AIL, &iip->ili_item.li_flags));
                xfs_iflush_abort_clean(iip);
                spin_unlock(&iip->ili_lock);
                xfs_iflags_clear(ip, XFS_IFLUSHING);
                xfs_buf_relse(bp);
                return;
        }

        /*
         * Got two references to bp. The first will get dropped by
         * xfs_iflush_abort() when the item is removed from the buffer list, but
         * we can't drop our reference until _abort() returns because we have to
         * unlock the buffer as well. Hence we abort and then unlock and release
         * our reference to the buffer.
         */
        ASSERT(iip->ili_item.li_buf == bp);
        spin_unlock(&iip->ili_lock);
        xfs_iflush_abort(ip);
        xfs_buf_relse(bp);
}


/*
 * 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 kvec                     *buf,
        struct xfs_inode_log_format     *in_f)
{
        struct xfs_inode_log_format_32  *in_f32 = buf->iov_base;

        if (buf->iov_len != sizeof(*in_f32)) {
                XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, NULL);
                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;
        memcpy(&in_f->ilf_u, &in_f32->ilf_u, sizeof(in_f->ilf_u));
        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;
}