// 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_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"


kmem_zone_t     *xfs_efi_zone;
kmem_zone_t     *xfs_efd_zone;

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);
}

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_zone_free(xfs_efi_zone, 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.
 */
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)) {
                xfs_trans_ail_remove(&efip->efi_item, SHUTDOWN_LOG_IO_ERROR);
                xfs_efi_item_free(efip);
        }
}

/*
 * This returns the number of iovecs needed to log the given efi item.
 * We only need 1 iovec for an efi item.  It just logs the efi_log_format
 * structure.
 */
static inline int
xfs_efi_item_sizeof(
        struct xfs_efi_log_item *efip)
{
        return sizeof(struct xfs_efi_log_format) +
               (efip->efi_format.efi_nextents - 1) * sizeof(xfs_extent_t);
}

STATIC void
xfs_efi_item_size(
        struct xfs_log_item     *lip,
        int                     *nvecs,
        int                     *nbytes)
{
        *nvecs += 1;
        *nbytes += xfs_efi_item_sizeof(EFI_ITEM(lip));
}

/*
 * 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_item_sizeof(efip));
}


/*
 * 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));
}

static const struct xfs_item_ops xfs_efi_item_ops = {
        .iop_size       = xfs_efi_item_size,
        .iop_format     = xfs_efi_item_format,
        .iop_unpin      = xfs_efi_item_unpin,
        .iop_release    = xfs_efi_item_release,
};


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

{
        struct xfs_efi_log_item *efip;
        uint                    size;

        ASSERT(nextents > 0);
        if (nextents > XFS_EFI_MAX_FAST_EXTENTS) {
                size = (uint)(sizeof(xfs_efi_log_item_t) +
                        ((nextents - 1) * sizeof(xfs_extent_t)));
                efip = kmem_zalloc(size, 0);
        } else {
                efip = kmem_zone_zalloc(xfs_efi_zone, 0);
        }

        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.
 */
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 = sizeof(xfs_efi_log_format_t) + 
                (src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_t);  
        uint len32 = sizeof(xfs_efi_log_format_32_t) + 
                (src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_32_t);  
        uint len64 = sizeof(xfs_efi_log_format_64_t) + 
                (src_efi_fmt->efi_nextents - 1) * sizeof(xfs_extent_64_t);  

        if (buf->i_len == len) {
                memcpy((char *)dst_efi_fmt, (char*)src_efi_fmt, len);
                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;
        }
        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_zone_free(xfs_efd_zone, efdp);
}

/*
 * This returns the number of iovecs needed to log the given efd item.
 * We only need 1 iovec for an efd item.  It just logs the efd_log_format
 * structure.
 */
static inline int
xfs_efd_item_sizeof(
        struct xfs_efd_log_item *efdp)
{
        return sizeof(xfs_efd_log_format_t) +
               (efdp->efd_format.efd_nextents - 1) * sizeof(xfs_extent_t);
}

STATIC void
xfs_efd_item_size(
        struct xfs_log_item     *lip,
        int                     *nvecs,
        int                     *nbytes)
{
        *nvecs += 1;
        *nbytes += xfs_efd_item_sizeof(EFD_ITEM(lip));
}

/*
 * 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_item_sizeof(efdp));
}

/*
 * 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 const struct xfs_item_ops xfs_efd_item_ops = {
        .flags          = XFS_ITEM_RELEASE_WHEN_COMMITTED,
        .iop_size       = xfs_efd_item_size,
        .iop_format     = xfs_efd_item_format,
        .iop_release    = xfs_efd_item_release,
};

/*
 * 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 = kmem_zalloc(sizeof(struct xfs_efd_log_item) +
                                (nextents - 1) * sizeof(struct xfs_extent),
                                0);
        } else {
                efdp = kmem_zone_zalloc(xfs_efd_zone, 0);
        }

        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;
}

/*
 * 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,
        xfs_fsblock_t                   start_block,
        xfs_extlen_t                    ext_len,
        const struct xfs_owner_info     *oinfo,
        bool                            skip_discard)
{
        struct xfs_mount                *mp = tp->t_mountp;
        struct xfs_extent               *extp;
        uint                            next_extent;
        xfs_agnumber_t                  agno = XFS_FSB_TO_AGNO(mp, start_block);
        xfs_agblock_t                   agbno = XFS_FSB_TO_AGBNO(mp,
                                                                start_block);
        int                             error;

        trace_xfs_bmap_free_deferred(tp->t_mountp, agno, 0, agbno, ext_len);

        error = __xfs_free_extent(tp, start_block, ext_len,
                                  oinfo, XFS_AG_RESV_NONE, 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;
        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 = start_block;
        extp->ext_len = ext_len;
        efdp->efd_next_extent++;

        return error;
}

/* Sort bmap items by AG. */
static int
xfs_extent_free_diff_items(
        void                            *priv,
        struct list_head                *a,
        struct list_head                *b)
{
        struct xfs_mount                *mp = priv;
        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  XFS_FSB_TO_AGNO(mp, ra->xefi_startblock) -
                XFS_FSB_TO_AGNO(mp, rb->xefi_startblock);
}

/* Get an EFI. */
STATIC void *
xfs_extent_free_create_intent(
        struct xfs_trans                *tp,
        unsigned int                    count)
{
        struct xfs_efi_log_item         *efip;

        ASSERT(tp != NULL);
        ASSERT(count > 0);

        efip = xfs_efi_init(tp->t_mountp, count);
        ASSERT(efip != NULL);

        /*
         * Get a log_item_desc to point at the new item.
         */
        xfs_trans_add_item(tp, &efip->efi_item);
        return efip;
}

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

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

        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 = free->xefi_startblock;
        extp->ext_len = free->xefi_blockcount;
}

/* Get an EFD so we can process all the free extents. */
STATIC void *
xfs_extent_free_create_done(
        struct xfs_trans                *tp,
        void                            *intent,
        unsigned int                    count)
{
        return xfs_trans_get_efd(tp, intent, count);
}

/* Process a free extent. */
STATIC int
xfs_extent_free_finish_item(
        struct xfs_trans                *tp,
        struct list_head                *item,
        void                            *done_item,
        void                            **state)
{
        struct xfs_extent_free_item     *free;
        int                             error;

        free = container_of(item, struct xfs_extent_free_item, xefi_list);
        error = xfs_trans_free_extent(tp, done_item,
                        free->xefi_startblock,
                        free->xefi_blockcount,
                        &free->xefi_oinfo, free->xefi_skip_discard);
        kmem_free(free);
        return error;
}

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

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

        free = container_of(item, struct xfs_extent_free_item, xefi_list);
        kmem_free(free);
}

const struct xfs_defer_op_type xfs_extent_free_defer_type = {
        .max_items      = XFS_EFI_MAX_FAST_EXTENTS,
        .diff_items     = xfs_extent_free_diff_items,
        .create_intent  = xfs_extent_free_create_intent,
        .abort_intent   = xfs_extent_free_abort_intent,
        .log_item       = xfs_extent_free_log_item,
        .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 list_head                *item,
        void                            *done_item,
        void                            **state)
{
        struct xfs_mount                *mp = tp->t_mountp;
        struct xfs_efd_log_item         *efdp = done_item;
        struct xfs_extent_free_item     *free;
        struct xfs_extent               *extp;
        struct xfs_buf                  *agbp;
        int                             error;
        xfs_agnumber_t                  agno;
        xfs_agblock_t                   agbno;
        uint                            next_extent;

        free = container_of(item, struct xfs_extent_free_item, xefi_list);
        ASSERT(free->xefi_blockcount == 1);
        agno = XFS_FSB_TO_AGNO(mp, free->xefi_startblock);
        agbno = XFS_FSB_TO_AGBNO(mp, free->xefi_startblock);

        trace_xfs_agfl_free_deferred(mp, agno, 0, agbno, free->xefi_blockcount);

        error = xfs_alloc_read_agf(mp, tp, agno, 0, &agbp);
        if (!error)
                error = xfs_free_agfl_block(tp, agno, agbno, agbp,
                                            &free->xefi_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 = free->xefi_startblock;
        extp->ext_len = free->xefi_blockcount;
        efdp->efd_next_extent++;

        kmem_free(free);
        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,
        .diff_items     = xfs_extent_free_diff_items,
        .create_intent  = xfs_extent_free_create_intent,
        .abort_intent   = xfs_extent_free_abort_intent,
        .log_item       = xfs_extent_free_log_item,
        .create_done    = xfs_extent_free_create_done,
        .finish_item    = xfs_agfl_free_finish_item,
        .cancel_item    = xfs_extent_free_cancel_item,
};

/*
 * Process an extent free intent item that was recovered from
 * the log.  We need to free the extents that it describes.
 */
int
xfs_efi_recover(
        struct xfs_mount        *mp,
        struct xfs_efi_log_item *efip)
{
        struct xfs_efd_log_item *efdp;
        struct xfs_trans        *tp;
        int                     i;
        int                     error = 0;
        xfs_extent_t            *extp;
        xfs_fsblock_t           startblock_fsb;

        ASSERT(!test_bit(XFS_EFI_RECOVERED, &efip->efi_flags));

        /*
         * 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++) {
                extp = &efip->efi_format.efi_extents[i];
                startblock_fsb = XFS_BB_TO_FSB(mp,
                                   XFS_FSB_TO_DADDR(mp, extp->ext_start));
                if (startblock_fsb == 0 ||
                    extp->ext_len == 0 ||
                    startblock_fsb >= mp->m_sb.sb_dblocks ||
                    extp->ext_len >= mp->m_sb.sb_agblocks) {
                        /*
                         * This will pull the EFI from the AIL and
                         * free the memory associated with it.
                         */
                        set_bit(XFS_EFI_RECOVERED, &efip->efi_flags);
                        xfs_efi_release(efip);
                        return -EIO;
                }
        }

        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++) {
                extp = &efip->efi_format.efi_extents[i];
                error = xfs_trans_free_extent(tp, efdp, extp->ext_start,
                                              extp->ext_len,
                                              &XFS_RMAP_OINFO_ANY_OWNER, false);
                if (error)
                        goto abort_error;

        }

        set_bit(XFS_EFI_RECOVERED, &efip->efi_flags);
        error = xfs_trans_commit(tp);
        return error;

abort_error:
        xfs_trans_cancel(tp);
        return error;
}