KVM: x86/pmu: Add documentation for fixed ctr on PMU filter

[thirdparty/kernel/stable.git] / fs / xfs / xfs_extfree_item.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_shared.h"
#include "xfs_mount.h"
#include "xfs_ag.h"
#include "xfs_defer.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_extfree_item.h"
#include "xfs_log.h"
#include "xfs_btree.h"
#include "xfs_rmap.h"
#include "xfs_alloc.h"
#include "xfs_bmap.h"
#include "xfs_trace.h"
#include "xfs_error.h"
#include "xfs_log_priv.h"
#include "xfs_log_recover.h"

struct kmem_cache       *xfs_efi_cache;
struct kmem_cache       *xfs_efd_cache;

static const struct xfs_item_ops xfs_efi_item_ops;

static inline struct xfs_efi_log_item *EFI_ITEM(struct xfs_log_item *lip)
{
        return container_of(lip, struct xfs_efi_log_item, efi_item);
}

STATIC void
xfs_efi_item_free(
        struct xfs_efi_log_item *efip)
{
        kmem_free(efip->efi_item.li_lv_shadow);
        if (efip->efi_format.efi_nextents > XFS_EFI_MAX_FAST_EXTENTS)
                kmem_free(efip);
        else
                kmem_cache_free(xfs_efi_cache, efip);
}

/*
 * Freeing the efi requires that we remove it from the AIL if it has already
 * been placed there. However, the EFI may not yet have been placed in the AIL
 * when called by xfs_efi_release() from EFD processing due to the ordering of
 * committed vs unpin operations in bulk insert operations. Hence the reference
 * count to ensure only the last caller frees the EFI.
 */
STATIC void
xfs_efi_release(
        struct xfs_efi_log_item *efip)
{
        ASSERT(atomic_read(&efip->efi_refcount) > 0);
        if (!atomic_dec_and_test(&efip->efi_refcount))
                return;

        xfs_trans_ail_delete(&efip->efi_item, 0);
        xfs_efi_item_free(efip);
}

STATIC void
xfs_efi_item_size(
        struct xfs_log_item     *lip,
        int                     *nvecs,
        int                     *nbytes)
{
        struct xfs_efi_log_item *efip = EFI_ITEM(lip);

        *nvecs += 1;
        *nbytes += xfs_efi_log_format_sizeof(efip->efi_format.efi_nextents);
}

/*
 * This is called to fill in the vector of log iovecs for the
 * given efi log item. We use only 1 iovec, and we point that
 * at the efi_log_format structure embedded in the efi item.
 * It is at this point that we assert that all of the extent
 * slots in the efi item have been filled.
 */
STATIC void
xfs_efi_item_format(
        struct xfs_log_item     *lip,
        struct xfs_log_vec      *lv)
{
        struct xfs_efi_log_item *efip = EFI_ITEM(lip);
        struct xfs_log_iovec    *vecp = NULL;

        ASSERT(atomic_read(&efip->efi_next_extent) ==
                                efip->efi_format.efi_nextents);

        efip->efi_format.efi_type = XFS_LI_EFI;
        efip->efi_format.efi_size = 1;

        xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_EFI_FORMAT,
                        &efip->efi_format,
                        xfs_efi_log_format_sizeof(efip->efi_format.efi_nextents));
}


/*
 * The unpin operation is the last place an EFI is manipulated in the log. It is
 * either inserted in the AIL or aborted in the event of a log I/O error. In
 * either case, the EFI transaction has been successfully committed to make it
 * this far. Therefore, we expect whoever committed the EFI to either construct
 * and commit the EFD or drop the EFD's reference in the event of error. Simply
 * drop the log's EFI reference now that the log is done with it.
 */
STATIC void
xfs_efi_item_unpin(
        struct xfs_log_item     *lip,
        int                     remove)
{
        struct xfs_efi_log_item *efip = EFI_ITEM(lip);
        xfs_efi_release(efip);
}

/*
 * The EFI has been either committed or aborted if the transaction has been
 * cancelled. If the transaction was cancelled, an EFD isn't going to be
 * constructed and thus we free the EFI here directly.
 */
STATIC void
xfs_efi_item_release(
        struct xfs_log_item     *lip)
{
        xfs_efi_release(EFI_ITEM(lip));
}

/*
 * Allocate and initialize an efi item with the given number of extents.
 */
STATIC struct xfs_efi_log_item *
xfs_efi_init(
        struct xfs_mount        *mp,
        uint                    nextents)

{
        struct xfs_efi_log_item *efip;

        ASSERT(nextents > 0);
        if (nextents > XFS_EFI_MAX_FAST_EXTENTS) {
                efip = kzalloc(xfs_efi_log_item_sizeof(nextents),
                                GFP_KERNEL | __GFP_NOFAIL);
        } else {
                efip = kmem_cache_zalloc(xfs_efi_cache,
                                         GFP_KERNEL | __GFP_NOFAIL);
        }

        xfs_log_item_init(mp, &efip->efi_item, XFS_LI_EFI, &xfs_efi_item_ops);
        efip->efi_format.efi_nextents = nextents;
        efip->efi_format.efi_id = (uintptr_t)(void *)efip;
        atomic_set(&efip->efi_next_extent, 0);
        atomic_set(&efip->efi_refcount, 2);

        return efip;
}

/*
 * Copy an EFI format buffer from the given buf, and into the destination
 * EFI format structure.
 * The given buffer can be in 32 bit or 64 bit form (which has different padding),
 * one of which will be the native format for this kernel.
 * It will handle the conversion of formats if necessary.
 */
STATIC int
xfs_efi_copy_format(xfs_log_iovec_t *buf, xfs_efi_log_format_t *dst_efi_fmt)
{
        xfs_efi_log_format_t *src_efi_fmt = buf->i_addr;
        uint i;
        uint len = xfs_efi_log_format_sizeof(src_efi_fmt->efi_nextents);
        uint len32 = xfs_efi_log_format32_sizeof(src_efi_fmt->efi_nextents);
        uint len64 = xfs_efi_log_format64_sizeof(src_efi_fmt->efi_nextents);

        if (buf->i_len == len) {
                memcpy(dst_efi_fmt, src_efi_fmt,
                       offsetof(struct xfs_efi_log_format, efi_extents));
                for (i = 0; i < src_efi_fmt->efi_nextents; i++)
                        memcpy(&dst_efi_fmt->efi_extents[i],
                               &src_efi_fmt->efi_extents[i],
                               sizeof(struct xfs_extent));
                return 0;
        } else if (buf->i_len == len32) {
                xfs_efi_log_format_32_t *src_efi_fmt_32 = buf->i_addr;

                dst_efi_fmt->efi_type     = src_efi_fmt_32->efi_type;
                dst_efi_fmt->efi_size     = src_efi_fmt_32->efi_size;
                dst_efi_fmt->efi_nextents = src_efi_fmt_32->efi_nextents;
                dst_efi_fmt->efi_id       = src_efi_fmt_32->efi_id;
                for (i = 0; i < dst_efi_fmt->efi_nextents; i++) {
                        dst_efi_fmt->efi_extents[i].ext_start =
                                src_efi_fmt_32->efi_extents[i].ext_start;
                        dst_efi_fmt->efi_extents[i].ext_len =
                                src_efi_fmt_32->efi_extents[i].ext_len;
                }
                return 0;
        } else if (buf->i_len == len64) {
                xfs_efi_log_format_64_t *src_efi_fmt_64 = buf->i_addr;

                dst_efi_fmt->efi_type     = src_efi_fmt_64->efi_type;
                dst_efi_fmt->efi_size     = src_efi_fmt_64->efi_size;
                dst_efi_fmt->efi_nextents = src_efi_fmt_64->efi_nextents;
                dst_efi_fmt->efi_id       = src_efi_fmt_64->efi_id;
                for (i = 0; i < dst_efi_fmt->efi_nextents; i++) {
                        dst_efi_fmt->efi_extents[i].ext_start =
                                src_efi_fmt_64->efi_extents[i].ext_start;
                        dst_efi_fmt->efi_extents[i].ext_len =
                                src_efi_fmt_64->efi_extents[i].ext_len;
                }
                return 0;
        }
        XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, NULL, buf->i_addr,
                        buf->i_len);
        return -EFSCORRUPTED;
}

static inline struct xfs_efd_log_item *EFD_ITEM(struct xfs_log_item *lip)
{
        return container_of(lip, struct xfs_efd_log_item, efd_item);
}

STATIC void
xfs_efd_item_free(struct xfs_efd_log_item *efdp)
{
        kmem_free(efdp->efd_item.li_lv_shadow);
        if (efdp->efd_format.efd_nextents > XFS_EFD_MAX_FAST_EXTENTS)
                kmem_free(efdp);
        else
                kmem_cache_free(xfs_efd_cache, efdp);
}

STATIC void
xfs_efd_item_size(
        struct xfs_log_item     *lip,
        int                     *nvecs,
        int                     *nbytes)
{
        struct xfs_efd_log_item *efdp = EFD_ITEM(lip);

        *nvecs += 1;
        *nbytes += xfs_efd_log_format_sizeof(efdp->efd_format.efd_nextents);
}

/*
 * This is called to fill in the vector of log iovecs for the
 * given efd log item. We use only 1 iovec, and we point that
 * at the efd_log_format structure embedded in the efd item.
 * It is at this point that we assert that all of the extent
 * slots in the efd item have been filled.
 */
STATIC void
xfs_efd_item_format(
        struct xfs_log_item     *lip,
        struct xfs_log_vec      *lv)
{
        struct xfs_efd_log_item *efdp = EFD_ITEM(lip);
        struct xfs_log_iovec    *vecp = NULL;

        ASSERT(efdp->efd_next_extent == efdp->efd_format.efd_nextents);

        efdp->efd_format.efd_type = XFS_LI_EFD;
        efdp->efd_format.efd_size = 1;

        xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_EFD_FORMAT,
                        &efdp->efd_format,
                        xfs_efd_log_format_sizeof(efdp->efd_format.efd_nextents));
}

/*
 * The EFD is either committed or aborted if the transaction is cancelled. If
 * the transaction is cancelled, drop our reference to the EFI and free the EFD.
 */
STATIC void
xfs_efd_item_release(
        struct xfs_log_item     *lip)
{
        struct xfs_efd_log_item *efdp = EFD_ITEM(lip);

        xfs_efi_release(efdp->efd_efip);
        xfs_efd_item_free(efdp);
}

static struct xfs_log_item *
xfs_efd_item_intent(
        struct xfs_log_item     *lip)
{
        return &EFD_ITEM(lip)->efd_efip->efi_item;
}

static const struct xfs_item_ops xfs_efd_item_ops = {
        .flags          = XFS_ITEM_RELEASE_WHEN_COMMITTED |
                          XFS_ITEM_INTENT_DONE,
        .iop_size       = xfs_efd_item_size,
        .iop_format     = xfs_efd_item_format,
        .iop_release    = xfs_efd_item_release,
        .iop_intent     = xfs_efd_item_intent,
};

/*
 * Allocate an "extent free done" log item that will hold nextents worth of
 * extents.  The caller must use all nextents extents, because we are not
 * flexible about this at all.
 */
static struct xfs_efd_log_item *
xfs_trans_get_efd(
        struct xfs_trans                *tp,
        struct xfs_efi_log_item         *efip,
        unsigned int                    nextents)
{
        struct xfs_efd_log_item         *efdp;

        ASSERT(nextents > 0);

        if (nextents > XFS_EFD_MAX_FAST_EXTENTS) {
                efdp = kzalloc(xfs_efd_log_item_sizeof(nextents),
                                GFP_KERNEL | __GFP_NOFAIL);
        } else {
                efdp = kmem_cache_zalloc(xfs_efd_cache,
                                        GFP_KERNEL | __GFP_NOFAIL);
        }

        xfs_log_item_init(tp->t_mountp, &efdp->efd_item, XFS_LI_EFD,
                          &xfs_efd_item_ops);
        efdp->efd_efip = efip;
        efdp->efd_format.efd_nextents = nextents;
        efdp->efd_format.efd_efi_id = efip->efi_format.efi_id;

        xfs_trans_add_item(tp, &efdp->efd_item);
        return efdp;
}

/*
 * Fill the EFD with all extents from the EFI when we need to roll the
 * transaction and continue with a new EFI.
 *
 * This simply copies all the extents in the EFI to the EFD rather than make
 * assumptions about which extents in the EFI have already been processed. We
 * currently keep the xefi list in the same order as the EFI extent list, but
 * that may not always be the case. Copying everything avoids leaving a landmine
 * were we fail to cancel all the extents in an EFI if the xefi list is
 * processed in a different order to the extents in the EFI.
 */
static void
xfs_efd_from_efi(
        struct xfs_efd_log_item *efdp)
{
        struct xfs_efi_log_item *efip = efdp->efd_efip;
        uint                    i;

        ASSERT(efip->efi_format.efi_nextents > 0);
        ASSERT(efdp->efd_next_extent < efip->efi_format.efi_nextents);

        for (i = 0; i < efip->efi_format.efi_nextents; i++) {
               efdp->efd_format.efd_extents[i] =
                       efip->efi_format.efi_extents[i];
        }
        efdp->efd_next_extent = efip->efi_format.efi_nextents;
}

/*
 * Free an extent and log it to the EFD. Note that the transaction is marked
 * dirty regardless of whether the extent free succeeds or fails to support the
 * EFI/EFD lifecycle rules.
 */
static int
xfs_trans_free_extent(
        struct xfs_trans                *tp,
        struct xfs_efd_log_item         *efdp,
        struct xfs_extent_free_item     *xefi)
{
        struct xfs_owner_info           oinfo = { };
        struct xfs_mount                *mp = tp->t_mountp;
        struct xfs_extent               *extp;
        uint                            next_extent;
        xfs_agblock_t                   agbno = XFS_FSB_TO_AGBNO(mp,
                                                        xefi->xefi_startblock);
        int                             error;

        oinfo.oi_owner = xefi->xefi_owner;
        if (xefi->xefi_flags & XFS_EFI_ATTR_FORK)
                oinfo.oi_flags |= XFS_OWNER_INFO_ATTR_FORK;
        if (xefi->xefi_flags & XFS_EFI_BMBT_BLOCK)
                oinfo.oi_flags |= XFS_OWNER_INFO_BMBT_BLOCK;

        trace_xfs_bmap_free_deferred(tp->t_mountp, xefi->xefi_pag->pag_agno, 0,
                        agbno, xefi->xefi_blockcount);

        error = __xfs_free_extent(tp, xefi->xefi_pag, agbno,
                        xefi->xefi_blockcount, &oinfo, xefi->xefi_agresv,
                        xefi->xefi_flags & XFS_EFI_SKIP_DISCARD);

        /*
         * Mark the transaction dirty, even on error. This ensures the
         * transaction is aborted, which:
         *
         * 1.) releases the EFI and frees the EFD
         * 2.) shuts down the filesystem
         */
        tp->t_flags |= XFS_TRANS_DIRTY | XFS_TRANS_HAS_INTENT_DONE;
        set_bit(XFS_LI_DIRTY, &efdp->efd_item.li_flags);

        /*
         * If we need a new transaction to make progress, the caller will log a
         * new EFI with the current contents. It will also log an EFD to cancel
         * the existing EFI, and so we need to copy all the unprocessed extents
         * in this EFI to the EFD so this works correctly.
         */
        if (error == -EAGAIN) {
                xfs_efd_from_efi(efdp);
                return error;
        }

        next_extent = efdp->efd_next_extent;
        ASSERT(next_extent < efdp->efd_format.efd_nextents);
        extp = &(efdp->efd_format.efd_extents[next_extent]);
        extp->ext_start = xefi->xefi_startblock;
        extp->ext_len = xefi->xefi_blockcount;
        efdp->efd_next_extent++;

        return error;
}

/* Sort bmap items by AG. */
static int
xfs_extent_free_diff_items(
        void                            *priv,
        const struct list_head          *a,
        const struct list_head          *b)
{
        struct xfs_extent_free_item     *ra;
        struct xfs_extent_free_item     *rb;

        ra = container_of(a, struct xfs_extent_free_item, xefi_list);
        rb = container_of(b, struct xfs_extent_free_item, xefi_list);

        return ra->xefi_pag->pag_agno - rb->xefi_pag->pag_agno;
}

/* Log a free extent to the intent item. */
STATIC void
xfs_extent_free_log_item(
        struct xfs_trans                *tp,
        struct xfs_efi_log_item         *efip,
        struct xfs_extent_free_item     *xefi)
{
        uint                            next_extent;
        struct xfs_extent               *extp;

        tp->t_flags |= XFS_TRANS_DIRTY;
        set_bit(XFS_LI_DIRTY, &efip->efi_item.li_flags);

        /*
         * atomic_inc_return gives us the value after the increment;
         * we want to use it as an array index so we need to subtract 1 from
         * it.
         */
        next_extent = atomic_inc_return(&efip->efi_next_extent) - 1;
        ASSERT(next_extent < efip->efi_format.efi_nextents);
        extp = &efip->efi_format.efi_extents[next_extent];
        extp->ext_start = xefi->xefi_startblock;
        extp->ext_len = xefi->xefi_blockcount;
}

static struct xfs_log_item *
xfs_extent_free_create_intent(
        struct xfs_trans                *tp,
        struct list_head                *items,
        unsigned int                    count,
        bool                            sort)
{
        struct xfs_mount                *mp = tp->t_mountp;
        struct xfs_efi_log_item         *efip = xfs_efi_init(mp, count);
        struct xfs_extent_free_item     *xefi;

        ASSERT(count > 0);

        xfs_trans_add_item(tp, &efip->efi_item);
        if (sort)
                list_sort(mp, items, xfs_extent_free_diff_items);
        list_for_each_entry(xefi, items, xefi_list)
                xfs_extent_free_log_item(tp, efip, xefi);
        return &efip->efi_item;
}

/* Get an EFD so we can process all the free extents. */
static struct xfs_log_item *
xfs_extent_free_create_done(
        struct xfs_trans                *tp,
        struct xfs_log_item             *intent,
        unsigned int                    count)
{
        return &xfs_trans_get_efd(tp, EFI_ITEM(intent), count)->efd_item;
}

/* Take a passive ref to the AG containing the space we're freeing. */
void
xfs_extent_free_get_group(
        struct xfs_mount                *mp,
        struct xfs_extent_free_item     *xefi)
{
        xfs_agnumber_t                  agno;

        agno = XFS_FSB_TO_AGNO(mp, xefi->xefi_startblock);
        xefi->xefi_pag = xfs_perag_intent_get(mp, agno);
}

/* Release a passive AG ref after some freeing work. */
static inline void
xfs_extent_free_put_group(
        struct xfs_extent_free_item     *xefi)
{
        xfs_perag_intent_put(xefi->xefi_pag);
}

/* Process a free extent. */
STATIC int
xfs_extent_free_finish_item(
        struct xfs_trans                *tp,
        struct xfs_log_item             *done,
        struct list_head                *item,
        struct xfs_btree_cur            **state)
{
        struct xfs_extent_free_item     *xefi;
        int                             error;

        xefi = container_of(item, struct xfs_extent_free_item, xefi_list);

        error = xfs_trans_free_extent(tp, EFD_ITEM(done), xefi);

        /*
         * Don't free the XEFI if we need a new transaction to complete
         * processing of it.
         */
        if (error == -EAGAIN)
                return error;

        xfs_extent_free_put_group(xefi);
        kmem_cache_free(xfs_extfree_item_cache, xefi);
        return error;
}

/* Abort all pending EFIs. */
STATIC void
xfs_extent_free_abort_intent(
        struct xfs_log_item             *intent)
{
        xfs_efi_release(EFI_ITEM(intent));
}

/* Cancel a free extent. */
STATIC void
xfs_extent_free_cancel_item(
        struct list_head                *item)
{
        struct xfs_extent_free_item     *xefi;

        xefi = container_of(item, struct xfs_extent_free_item, xefi_list);

        xfs_extent_free_put_group(xefi);
        kmem_cache_free(xfs_extfree_item_cache, xefi);
}

const struct xfs_defer_op_type xfs_extent_free_defer_type = {
        .max_items      = XFS_EFI_MAX_FAST_EXTENTS,
        .create_intent  = xfs_extent_free_create_intent,
        .abort_intent   = xfs_extent_free_abort_intent,
        .create_done    = xfs_extent_free_create_done,
        .finish_item    = xfs_extent_free_finish_item,
        .cancel_item    = xfs_extent_free_cancel_item,
};

/*
 * AGFL blocks are accounted differently in the reserve pools and are not
 * inserted into the busy extent list.
 */
STATIC int
xfs_agfl_free_finish_item(
        struct xfs_trans                *tp,
        struct xfs_log_item             *done,
        struct list_head                *item,
        struct xfs_btree_cur            **state)
{
        struct xfs_owner_info           oinfo = { };
        struct xfs_mount                *mp = tp->t_mountp;
        struct xfs_efd_log_item         *efdp = EFD_ITEM(done);
        struct xfs_extent_free_item     *xefi;
        struct xfs_extent               *extp;
        struct xfs_buf                  *agbp;
        int                             error;
        xfs_agblock_t                   agbno;
        uint                            next_extent;

        xefi = container_of(item, struct xfs_extent_free_item, xefi_list);
        ASSERT(xefi->xefi_blockcount == 1);
        agbno = XFS_FSB_TO_AGBNO(mp, xefi->xefi_startblock);
        oinfo.oi_owner = xefi->xefi_owner;

        trace_xfs_agfl_free_deferred(mp, xefi->xefi_pag->pag_agno, 0, agbno,
                        xefi->xefi_blockcount);

        error = xfs_alloc_read_agf(xefi->xefi_pag, tp, 0, &agbp);
        if (!error)
                error = xfs_free_agfl_block(tp, xefi->xefi_pag->pag_agno,
                                agbno, agbp, &oinfo);

        /*
         * Mark the transaction dirty, even on error. This ensures the
         * transaction is aborted, which:
         *
         * 1.) releases the EFI and frees the EFD
         * 2.) shuts down the filesystem
         */
        tp->t_flags |= XFS_TRANS_DIRTY;
        set_bit(XFS_LI_DIRTY, &efdp->efd_item.li_flags);

        next_extent = efdp->efd_next_extent;
        ASSERT(next_extent < efdp->efd_format.efd_nextents);
        extp = &(efdp->efd_format.efd_extents[next_extent]);
        extp->ext_start = xefi->xefi_startblock;
        extp->ext_len = xefi->xefi_blockcount;
        efdp->efd_next_extent++;

        xfs_extent_free_put_group(xefi);
        kmem_cache_free(xfs_extfree_item_cache, xefi);
        return error;
}

/* sub-type with special handling for AGFL deferred frees */
const struct xfs_defer_op_type xfs_agfl_free_defer_type = {
        .max_items      = XFS_EFI_MAX_FAST_EXTENTS,
        .create_intent  = xfs_extent_free_create_intent,
        .abort_intent   = xfs_extent_free_abort_intent,
        .create_done    = xfs_extent_free_create_done,
        .finish_item    = xfs_agfl_free_finish_item,
        .cancel_item    = xfs_extent_free_cancel_item,
};

/* Is this recovered EFI ok? */
static inline bool
xfs_efi_validate_ext(
        struct xfs_mount                *mp,
        struct xfs_extent               *extp)
{
        return xfs_verify_fsbext(mp, extp->ext_start, extp->ext_len);
}

/*
 * Process an extent free intent item that was recovered from
 * the log.  We need to free the extents that it describes.
 */
STATIC int
xfs_efi_item_recover(
        struct xfs_log_item             *lip,
        struct list_head                *capture_list)
{
        struct xfs_efi_log_item         *efip = EFI_ITEM(lip);
        struct xfs_mount                *mp = lip->li_log->l_mp;
        struct xfs_efd_log_item         *efdp;
        struct xfs_trans                *tp;
        int                             i;
        int                             error = 0;
        bool                            requeue_only = false;

        /*
         * First check the validity of the extents described by the
         * EFI.  If any are bad, then assume that all are bad and
         * just toss the EFI.
         */
        for (i = 0; i < efip->efi_format.efi_nextents; i++) {
                if (!xfs_efi_validate_ext(mp,
                                        &efip->efi_format.efi_extents[i])) {
                        XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
                                        &efip->efi_format,
                                        sizeof(efip->efi_format));
                        return -EFSCORRUPTED;
                }
        }

        error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
        if (error)
                return error;
        efdp = xfs_trans_get_efd(tp, efip, efip->efi_format.efi_nextents);

        for (i = 0; i < efip->efi_format.efi_nextents; i++) {
                struct xfs_extent_free_item     fake = {
                        .xefi_owner             = XFS_RMAP_OWN_UNKNOWN,
                        .xefi_agresv            = XFS_AG_RESV_NONE,
                };
                struct xfs_extent               *extp;

                extp = &efip->efi_format.efi_extents[i];

                fake.xefi_startblock = extp->ext_start;
                fake.xefi_blockcount = extp->ext_len;

                if (!requeue_only) {
                        xfs_extent_free_get_group(mp, &fake);
                        error = xfs_trans_free_extent(tp, efdp, &fake);
                        xfs_extent_free_put_group(&fake);
                }

                /*
                 * If we can't free the extent without potentially deadlocking,
                 * requeue the rest of the extents to a new so that they get
                 * run again later with a new transaction context.
                 */
                if (error == -EAGAIN || requeue_only) {
                        error = xfs_free_extent_later(tp, fake.xefi_startblock,
                                        fake.xefi_blockcount,
                                        &XFS_RMAP_OINFO_ANY_OWNER,
                                        fake.xefi_agresv);
                        if (!error) {
                                requeue_only = true;
                                continue;
                        }
                }

                if (error == -EFSCORRUPTED)
                        XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
                                        extp, sizeof(*extp));
                if (error)
                        goto abort_error;

        }

        return xfs_defer_ops_capture_and_commit(tp, capture_list);

abort_error:
        xfs_trans_cancel(tp);
        return error;
}

STATIC bool
xfs_efi_item_match(
        struct xfs_log_item     *lip,
        uint64_t                intent_id)
{
        return EFI_ITEM(lip)->efi_format.efi_id == intent_id;
}

/* Relog an intent item to push the log tail forward. */
static struct xfs_log_item *
xfs_efi_item_relog(
        struct xfs_log_item             *intent,
        struct xfs_trans                *tp)
{
        struct xfs_efd_log_item         *efdp;
        struct xfs_efi_log_item         *efip;
        struct xfs_extent               *extp;
        unsigned int                    count;

        count = EFI_ITEM(intent)->efi_format.efi_nextents;
        extp = EFI_ITEM(intent)->efi_format.efi_extents;

        tp->t_flags |= XFS_TRANS_DIRTY;
        efdp = xfs_trans_get_efd(tp, EFI_ITEM(intent), count);
        efdp->efd_next_extent = count;
        memcpy(efdp->efd_format.efd_extents, extp, count * sizeof(*extp));
        set_bit(XFS_LI_DIRTY, &efdp->efd_item.li_flags);

        efip = xfs_efi_init(tp->t_mountp, count);
        memcpy(efip->efi_format.efi_extents, extp, count * sizeof(*extp));
        atomic_set(&efip->efi_next_extent, count);
        xfs_trans_add_item(tp, &efip->efi_item);
        set_bit(XFS_LI_DIRTY, &efip->efi_item.li_flags);
        return &efip->efi_item;
}

static const struct xfs_item_ops xfs_efi_item_ops = {
        .flags          = XFS_ITEM_INTENT,
        .iop_size       = xfs_efi_item_size,
        .iop_format     = xfs_efi_item_format,
        .iop_unpin      = xfs_efi_item_unpin,
        .iop_release    = xfs_efi_item_release,
        .iop_recover    = xfs_efi_item_recover,
        .iop_match      = xfs_efi_item_match,
        .iop_relog      = xfs_efi_item_relog,
};

/*
 * This routine is called to create an in-core extent free intent
 * item from the efi format structure which was logged on disk.
 * It allocates an in-core efi, copies the extents from the format
 * structure into it, and adds the efi to the AIL with the given
 * LSN.
 */
STATIC int
xlog_recover_efi_commit_pass2(
        struct xlog                     *log,
        struct list_head                *buffer_list,
        struct xlog_recover_item        *item,
        xfs_lsn_t                       lsn)
{
        struct xfs_mount                *mp = log->l_mp;
        struct xfs_efi_log_item         *efip;
        struct xfs_efi_log_format       *efi_formatp;
        int                             error;

        efi_formatp = item->ri_buf[0].i_addr;

        if (item->ri_buf[0].i_len < xfs_efi_log_format_sizeof(0)) {
                XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
                                item->ri_buf[0].i_addr, item->ri_buf[0].i_len);
                return -EFSCORRUPTED;
        }

        efip = xfs_efi_init(mp, efi_formatp->efi_nextents);
        error = xfs_efi_copy_format(&item->ri_buf[0], &efip->efi_format);
        if (error) {
                xfs_efi_item_free(efip);
                return error;
        }
        atomic_set(&efip->efi_next_extent, efi_formatp->efi_nextents);
        /*
         * Insert the intent into the AIL directly and drop one reference so
         * that finishing or canceling the work will drop the other.
         */
        xfs_trans_ail_insert(log->l_ailp, &efip->efi_item, lsn);
        xfs_efi_release(efip);
        return 0;
}

const struct xlog_recover_item_ops xlog_efi_item_ops = {
        .item_type              = XFS_LI_EFI,
        .commit_pass2           = xlog_recover_efi_commit_pass2,
};

/*
 * This routine is called when an EFD format structure is found in a committed
 * transaction in the log. Its purpose is to cancel the corresponding EFI if it
 * was still in the log. To do this it searches the AIL for the EFI with an id
 * equal to that in the EFD format structure. If we find it we drop the EFD
 * reference, which removes the EFI from the AIL and frees it.
 */
STATIC int
xlog_recover_efd_commit_pass2(
        struct xlog                     *log,
        struct list_head                *buffer_list,
        struct xlog_recover_item        *item,
        xfs_lsn_t                       lsn)
{
        struct xfs_efd_log_format       *efd_formatp;
        int                             buflen = item->ri_buf[0].i_len;

        efd_formatp = item->ri_buf[0].i_addr;

        if (buflen < sizeof(struct xfs_efd_log_format)) {
                XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, log->l_mp,
                                efd_formatp, buflen);
                return -EFSCORRUPTED;
        }

        if (item->ri_buf[0].i_len != xfs_efd_log_format32_sizeof(
                                                efd_formatp->efd_nextents) &&
            item->ri_buf[0].i_len != xfs_efd_log_format64_sizeof(
                                                efd_formatp->efd_nextents)) {
                XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, log->l_mp,
                                efd_formatp, buflen);
                return -EFSCORRUPTED;
        }

        xlog_recover_release_intent(log, XFS_LI_EFI, efd_formatp->efd_efi_id);
        return 0;
}

const struct xlog_recover_item_ops xlog_efd_item_ops = {
        .item_type              = XFS_LI_EFD,
        .commit_pass2           = xlog_recover_efd_commit_pass2,
};