Merge tag 'xtensa-20180225' of git://github.com/jcmvbkbc/linux-xtensa

[cris-mirror.git] / fs / xfs / libxfs / xfs_inode_fork.c

/*
 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include <linux/log2.h>

#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_bmap.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_attr_sf.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_dir2_priv.h"
#include "xfs_attr_leaf.h"
#include "xfs_shared.h"

kmem_zone_t *xfs_ifork_zone;

STATIC int xfs_iformat_local(xfs_inode_t *, xfs_dinode_t *, int, int);
STATIC int xfs_iformat_extents(xfs_inode_t *, xfs_dinode_t *, int);
STATIC int xfs_iformat_btree(xfs_inode_t *, xfs_dinode_t *, int);

/*
 * Copy inode type and data and attr format specific information from the
 * on-disk inode to the in-core inode and fork structures.  For fifos, devices,
 * and sockets this means set i_rdev to the proper value.  For files,
 * directories, and symlinks this means to bring in the in-line data or extent
 * pointers as well as the attribute fork.  For a fork in B-tree format, only
 * the root is immediately brought in-core.  The rest will be read in later when
 * first referenced (see xfs_iread_extents()).
 */
int
xfs_iformat_fork(
        struct xfs_inode        *ip,
        struct xfs_dinode       *dip)
{
        struct inode            *inode = VFS_I(ip);
        struct xfs_attr_shortform *atp;
        int                     size;
        int                     error = 0;
        xfs_fsize_t             di_size;

        switch (inode->i_mode & S_IFMT) {
        case S_IFIFO:
        case S_IFCHR:
        case S_IFBLK:
        case S_IFSOCK:
                ip->i_d.di_size = 0;
                inode->i_rdev = xfs_to_linux_dev_t(xfs_dinode_get_rdev(dip));
                break;

        case S_IFREG:
        case S_IFLNK:
        case S_IFDIR:
                switch (dip->di_format) {
                case XFS_DINODE_FMT_LOCAL:
                        di_size = be64_to_cpu(dip->di_size);
                        size = (int)di_size;
                        error = xfs_iformat_local(ip, dip, XFS_DATA_FORK, size);
                        break;
                case XFS_DINODE_FMT_EXTENTS:
                        error = xfs_iformat_extents(ip, dip, XFS_DATA_FORK);
                        break;
                case XFS_DINODE_FMT_BTREE:
                        error = xfs_iformat_btree(ip, dip, XFS_DATA_FORK);
                        break;
                default:
                        return -EFSCORRUPTED;
                }
                break;

        default:
                return -EFSCORRUPTED;
        }
        if (error)
                return error;

        if (xfs_is_reflink_inode(ip)) {
                ASSERT(ip->i_cowfp == NULL);
                xfs_ifork_init_cow(ip);
        }

        if (!XFS_DFORK_Q(dip))
                return 0;

        ASSERT(ip->i_afp == NULL);
        ip->i_afp = kmem_zone_zalloc(xfs_ifork_zone, KM_SLEEP | KM_NOFS);

        switch (dip->di_aformat) {
        case XFS_DINODE_FMT_LOCAL:
                atp = (xfs_attr_shortform_t *)XFS_DFORK_APTR(dip);
                size = be16_to_cpu(atp->hdr.totsize);

                error = xfs_iformat_local(ip, dip, XFS_ATTR_FORK, size);
                break;
        case XFS_DINODE_FMT_EXTENTS:
                error = xfs_iformat_extents(ip, dip, XFS_ATTR_FORK);
                break;
        case XFS_DINODE_FMT_BTREE:
                error = xfs_iformat_btree(ip, dip, XFS_ATTR_FORK);
                break;
        default:
                error = -EFSCORRUPTED;
                break;
        }
        if (error) {
                kmem_zone_free(xfs_ifork_zone, ip->i_afp);
                ip->i_afp = NULL;
                if (ip->i_cowfp)
                        kmem_zone_free(xfs_ifork_zone, ip->i_cowfp);
                ip->i_cowfp = NULL;
                xfs_idestroy_fork(ip, XFS_DATA_FORK);
        }
        return error;
}

void
xfs_init_local_fork(
        struct xfs_inode        *ip,
        int                     whichfork,
        const void              *data,
        int                     size)
{
        struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
        int                     mem_size = size, real_size = 0;
        bool                    zero_terminate;

        /*
         * If we are using the local fork to store a symlink body we need to
         * zero-terminate it so that we can pass it back to the VFS directly.
         * Overallocate the in-memory fork by one for that and add a zero
         * to terminate it below.
         */
        zero_terminate = S_ISLNK(VFS_I(ip)->i_mode);
        if (zero_terminate)
                mem_size++;

        if (size) {
                real_size = roundup(mem_size, 4);
                ifp->if_u1.if_data = kmem_alloc(real_size, KM_SLEEP | KM_NOFS);
                memcpy(ifp->if_u1.if_data, data, size);
                if (zero_terminate)
                        ifp->if_u1.if_data[size] = '\0';
        } else {
                ifp->if_u1.if_data = NULL;
        }

        ifp->if_bytes = size;
        ifp->if_real_bytes = real_size;
        ifp->if_flags &= ~(XFS_IFEXTENTS | XFS_IFBROOT);
        ifp->if_flags |= XFS_IFINLINE;
}

/*
 * The file is in-lined in the on-disk inode.
 */
STATIC int
xfs_iformat_local(
        xfs_inode_t     *ip,
        xfs_dinode_t    *dip,
        int             whichfork,
        int             size)
{
        /*
         * If the size is unreasonable, then something
         * is wrong and we just bail out rather than crash in
         * kmem_alloc() or memcpy() below.
         */
        if (unlikely(size > XFS_DFORK_SIZE(dip, ip->i_mount, whichfork))) {
                xfs_warn(ip->i_mount,
        "corrupt inode %Lu (bad size %d for local fork, size = %d).",
                        (unsigned long long) ip->i_ino, size,
                        XFS_DFORK_SIZE(dip, ip->i_mount, whichfork));
                XFS_CORRUPTION_ERROR("xfs_iformat_local", XFS_ERRLEVEL_LOW,
                                     ip->i_mount, dip);
                return -EFSCORRUPTED;
        }

        xfs_init_local_fork(ip, whichfork, XFS_DFORK_PTR(dip, whichfork), size);
        return 0;
}

/*
 * The file consists of a set of extents all of which fit into the on-disk
 * inode.
 */
STATIC int
xfs_iformat_extents(
        struct xfs_inode        *ip,
        struct xfs_dinode       *dip,
        int                     whichfork)
{
        struct xfs_mount        *mp = ip->i_mount;
        struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
        int                     state = xfs_bmap_fork_to_state(whichfork);
        int                     nex = XFS_DFORK_NEXTENTS(dip, whichfork);
        int                     size = nex * sizeof(xfs_bmbt_rec_t);
        struct xfs_iext_cursor  icur;
        struct xfs_bmbt_rec     *dp;
        struct xfs_bmbt_irec    new;
        int                     i;

        /*
         * If the number of extents is unreasonable, then something is wrong and
         * we just bail out rather than crash in kmem_alloc() or memcpy() below.
         */
        if (unlikely(size < 0 || size > XFS_DFORK_SIZE(dip, mp, whichfork))) {
                xfs_warn(ip->i_mount, "corrupt inode %Lu ((a)extents = %d).",
                        (unsigned long long) ip->i_ino, nex);
                XFS_CORRUPTION_ERROR("xfs_iformat_extents(1)", XFS_ERRLEVEL_LOW,
                                     mp, dip);
                return -EFSCORRUPTED;
        }

        ifp->if_real_bytes = 0;
        ifp->if_bytes = 0;
        ifp->if_u1.if_root = NULL;
        ifp->if_height = 0;
        if (size) {
                dp = (xfs_bmbt_rec_t *) XFS_DFORK_PTR(dip, whichfork);

                xfs_iext_first(ifp, &icur);
                for (i = 0; i < nex; i++, dp++) {
                        xfs_bmbt_disk_get_all(dp, &new);
                        if (!xfs_bmbt_validate_extent(mp, whichfork, &new)) {
                                XFS_ERROR_REPORT("xfs_iformat_extents(2)",
                                                 XFS_ERRLEVEL_LOW, mp);
                                return -EFSCORRUPTED;
                        }

                        xfs_iext_insert(ip, &icur, &new, state);
                        trace_xfs_read_extent(ip, &icur, state, _THIS_IP_);
                        xfs_iext_next(ifp, &icur);
                }
        }
        ifp->if_flags |= XFS_IFEXTENTS;
        return 0;
}

/*
 * The file has too many extents to fit into
 * the inode, so they are in B-tree format.
 * Allocate a buffer for the root of the B-tree
 * and copy the root into it.  The i_extents
 * field will remain NULL until all of the
 * extents are read in (when they are needed).
 */
STATIC int
xfs_iformat_btree(
        xfs_inode_t             *ip,
        xfs_dinode_t            *dip,
        int                     whichfork)
{
        struct xfs_mount        *mp = ip->i_mount;
        xfs_bmdr_block_t        *dfp;
        xfs_ifork_t             *ifp;
        /* REFERENCED */
        int                     nrecs;
        int                     size;
        int                     level;

        ifp = XFS_IFORK_PTR(ip, whichfork);
        dfp = (xfs_bmdr_block_t *)XFS_DFORK_PTR(dip, whichfork);
        size = XFS_BMAP_BROOT_SPACE(mp, dfp);
        nrecs = be16_to_cpu(dfp->bb_numrecs);
        level = be16_to_cpu(dfp->bb_level);

        /*
         * blow out if -- fork has less extents than can fit in
         * fork (fork shouldn't be a btree format), root btree
         * block has more records than can fit into the fork,
         * or the number of extents is greater than the number of
         * blocks.
         */
        if (unlikely(XFS_IFORK_NEXTENTS(ip, whichfork) <=
                                        XFS_IFORK_MAXEXT(ip, whichfork) ||
                     nrecs == 0 ||
                     XFS_BMDR_SPACE_CALC(nrecs) >
                                        XFS_DFORK_SIZE(dip, mp, whichfork) ||
                     XFS_IFORK_NEXTENTS(ip, whichfork) > ip->i_d.di_nblocks) ||
                     level == 0 || level > XFS_BTREE_MAXLEVELS) {
                xfs_warn(mp, "corrupt inode %Lu (btree).",
                                        (unsigned long long) ip->i_ino);
                XFS_CORRUPTION_ERROR("xfs_iformat_btree", XFS_ERRLEVEL_LOW,
                                         mp, dip);
                return -EFSCORRUPTED;
        }

        ifp->if_broot_bytes = size;
        ifp->if_broot = kmem_alloc(size, KM_SLEEP | KM_NOFS);
        ASSERT(ifp->if_broot != NULL);
        /*
         * Copy and convert from the on-disk structure
         * to the in-memory structure.
         */
        xfs_bmdr_to_bmbt(ip, dfp, XFS_DFORK_SIZE(dip, ip->i_mount, whichfork),
                         ifp->if_broot, size);
        ifp->if_flags &= ~XFS_IFEXTENTS;
        ifp->if_flags |= XFS_IFBROOT;

        ifp->if_real_bytes = 0;
        ifp->if_bytes = 0;
        ifp->if_u1.if_root = NULL;
        ifp->if_height = 0;
        return 0;
}

/*
 * Reallocate the space for if_broot based on the number of records
 * being added or deleted as indicated in rec_diff.  Move the records
 * and pointers in if_broot to fit the new size.  When shrinking this
 * will eliminate holes between the records and pointers created by
 * the caller.  When growing this will create holes to be filled in
 * by the caller.
 *
 * The caller must not request to add more records than would fit in
 * the on-disk inode root.  If the if_broot is currently NULL, then
 * if we are adding records, one will be allocated.  The caller must also
 * not request that the number of records go below zero, although
 * it can go to zero.
 *
 * ip -- the inode whose if_broot area is changing
 * ext_diff -- the change in the number of records, positive or negative,
 *       requested for the if_broot array.
 */
void
xfs_iroot_realloc(
        xfs_inode_t             *ip,
        int                     rec_diff,
        int                     whichfork)
{
        struct xfs_mount        *mp = ip->i_mount;
        int                     cur_max;
        xfs_ifork_t             *ifp;
        struct xfs_btree_block  *new_broot;
        int                     new_max;
        size_t                  new_size;
        char                    *np;
        char                    *op;

        /*
         * Handle the degenerate case quietly.
         */
        if (rec_diff == 0) {
                return;
        }

        ifp = XFS_IFORK_PTR(ip, whichfork);
        if (rec_diff > 0) {
                /*
                 * If there wasn't any memory allocated before, just
                 * allocate it now and get out.
                 */
                if (ifp->if_broot_bytes == 0) {
                        new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, rec_diff);
                        ifp->if_broot = kmem_alloc(new_size, KM_SLEEP | KM_NOFS);
                        ifp->if_broot_bytes = (int)new_size;
                        return;
                }

                /*
                 * If there is already an existing if_broot, then we need
                 * to realloc() it and shift the pointers to their new
                 * location.  The records don't change location because
                 * they are kept butted up against the btree block header.
                 */
                cur_max = xfs_bmbt_maxrecs(mp, ifp->if_broot_bytes, 0);
                new_max = cur_max + rec_diff;
                new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, new_max);
                ifp->if_broot = kmem_realloc(ifp->if_broot, new_size,
                                KM_SLEEP | KM_NOFS);
                op = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
                                                     ifp->if_broot_bytes);
                np = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
                                                     (int)new_size);
                ifp->if_broot_bytes = (int)new_size;
                ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
                        XFS_IFORK_SIZE(ip, whichfork));
                memmove(np, op, cur_max * (uint)sizeof(xfs_fsblock_t));
                return;
        }

        /*
         * rec_diff is less than 0.  In this case, we are shrinking the
         * if_broot buffer.  It must already exist.  If we go to zero
         * records, just get rid of the root and clear the status bit.
         */
        ASSERT((ifp->if_broot != NULL) && (ifp->if_broot_bytes > 0));
        cur_max = xfs_bmbt_maxrecs(mp, ifp->if_broot_bytes, 0);
        new_max = cur_max + rec_diff;
        ASSERT(new_max >= 0);
        if (new_max > 0)
                new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, new_max);
        else
                new_size = 0;
        if (new_size > 0) {
                new_broot = kmem_alloc(new_size, KM_SLEEP | KM_NOFS);
                /*
                 * First copy over the btree block header.
                 */
                memcpy(new_broot, ifp->if_broot,
                        XFS_BMBT_BLOCK_LEN(ip->i_mount));
        } else {
                new_broot = NULL;
                ifp->if_flags &= ~XFS_IFBROOT;
        }

        /*
         * Only copy the records and pointers if there are any.
         */
        if (new_max > 0) {
                /*
                 * First copy the records.
                 */
                op = (char *)XFS_BMBT_REC_ADDR(mp, ifp->if_broot, 1);
                np = (char *)XFS_BMBT_REC_ADDR(mp, new_broot, 1);
                memcpy(np, op, new_max * (uint)sizeof(xfs_bmbt_rec_t));

                /*
                 * Then copy the pointers.
                 */
                op = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
                                                     ifp->if_broot_bytes);
                np = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, new_broot, 1,
                                                     (int)new_size);
                memcpy(np, op, new_max * (uint)sizeof(xfs_fsblock_t));
        }
        kmem_free(ifp->if_broot);
        ifp->if_broot = new_broot;
        ifp->if_broot_bytes = (int)new_size;
        if (ifp->if_broot)
                ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
                        XFS_IFORK_SIZE(ip, whichfork));
        return;
}


/*
 * This is called when the amount of space needed for if_data
 * is increased or decreased.  The change in size is indicated by
 * the number of bytes that need to be added or deleted in the
 * byte_diff parameter.
 *
 * If the amount of space needed has decreased below the size of the
 * inline buffer, then switch to using the inline buffer.  Otherwise,
 * use kmem_realloc() or kmem_alloc() to adjust the size of the buffer
 * to what is needed.
 *
 * ip -- the inode whose if_data area is changing
 * byte_diff -- the change in the number of bytes, positive or negative,
 *       requested for the if_data array.
 */
void
xfs_idata_realloc(
        xfs_inode_t     *ip,
        int             byte_diff,
        int             whichfork)
{
        xfs_ifork_t     *ifp;
        int             new_size;
        int             real_size;

        if (byte_diff == 0) {
                return;
        }

        ifp = XFS_IFORK_PTR(ip, whichfork);
        new_size = (int)ifp->if_bytes + byte_diff;
        ASSERT(new_size >= 0);

        if (new_size == 0) {
                kmem_free(ifp->if_u1.if_data);
                ifp->if_u1.if_data = NULL;
                real_size = 0;
        } else {
                /*
                 * Stuck with malloc/realloc.
                 * For inline data, the underlying buffer must be
                 * a multiple of 4 bytes in size so that it can be
                 * logged and stay on word boundaries.  We enforce
                 * that here.
                 */
                real_size = roundup(new_size, 4);
                if (ifp->if_u1.if_data == NULL) {
                        ASSERT(ifp->if_real_bytes == 0);
                        ifp->if_u1.if_data = kmem_alloc(real_size,
                                                        KM_SLEEP | KM_NOFS);
                } else {
                        /*
                         * Only do the realloc if the underlying size
                         * is really changing.
                         */
                        if (ifp->if_real_bytes != real_size) {
                                ifp->if_u1.if_data =
                                        kmem_realloc(ifp->if_u1.if_data,
                                                        real_size,
                                                        KM_SLEEP | KM_NOFS);
                        }
                }
        }
        ifp->if_real_bytes = real_size;
        ifp->if_bytes = new_size;
        ASSERT(ifp->if_bytes <= XFS_IFORK_SIZE(ip, whichfork));
}

void
xfs_idestroy_fork(
        xfs_inode_t     *ip,
        int             whichfork)
{
        xfs_ifork_t     *ifp;

        ifp = XFS_IFORK_PTR(ip, whichfork);
        if (ifp->if_broot != NULL) {
                kmem_free(ifp->if_broot);
                ifp->if_broot = NULL;
        }

        /*
         * If the format is local, then we can't have an extents
         * array so just look for an inline data array.  If we're
         * not local then we may or may not have an extents list,
         * so check and free it up if we do.
         */
        if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL) {
                if (ifp->if_u1.if_data != NULL) {
                        ASSERT(ifp->if_real_bytes != 0);
                        kmem_free(ifp->if_u1.if_data);
                        ifp->if_u1.if_data = NULL;
                        ifp->if_real_bytes = 0;
                }
        } else if ((ifp->if_flags & XFS_IFEXTENTS) && ifp->if_height) {
                xfs_iext_destroy(ifp);
        }

        ASSERT(ifp->if_real_bytes == 0);

        if (whichfork == XFS_ATTR_FORK) {
                kmem_zone_free(xfs_ifork_zone, ip->i_afp);
                ip->i_afp = NULL;
        } else if (whichfork == XFS_COW_FORK) {
                kmem_zone_free(xfs_ifork_zone, ip->i_cowfp);
                ip->i_cowfp = NULL;
        }
}

/*
 * Convert in-core extents to on-disk form
 *
 * In the case of the data fork, the in-core and on-disk fork sizes can be
 * different due to delayed allocation extents. We only copy on-disk extents
 * here, so callers must always use the physical fork size to determine the
 * size of the buffer passed to this routine.  We will return the size actually
 * used.
 */
int
xfs_iextents_copy(
        struct xfs_inode        *ip,
        struct xfs_bmbt_rec     *dp,
        int                     whichfork)
{
        int                     state = xfs_bmap_fork_to_state(whichfork);
        struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
        struct xfs_iext_cursor  icur;
        struct xfs_bmbt_irec    rec;
        int                     copied = 0;

        ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED));
        ASSERT(ifp->if_bytes > 0);

        for_each_xfs_iext(ifp, &icur, &rec) {
                if (isnullstartblock(rec.br_startblock))
                        continue;
                ASSERT(xfs_bmbt_validate_extent(ip->i_mount, whichfork, &rec));
                xfs_bmbt_disk_set_all(dp, &rec);
                trace_xfs_write_extent(ip, &icur, state, _RET_IP_);
                copied += sizeof(struct xfs_bmbt_rec);
                dp++;
        }

        ASSERT(copied > 0);
        ASSERT(copied <= ifp->if_bytes);
        return copied;
}

/*
 * Each of the following cases stores data into the same region
 * of the on-disk inode, so only one of them can be valid at
 * any given time. While it is possible to have conflicting formats
 * and log flags, e.g. having XFS_ILOG_?DATA set when the fork is
 * in EXTENTS format, this can only happen when the fork has
 * changed formats after being modified but before being flushed.
 * In these cases, the format always takes precedence, because the
 * format indicates the current state of the fork.
 */
void
xfs_iflush_fork(
        xfs_inode_t             *ip,
        xfs_dinode_t            *dip,
        xfs_inode_log_item_t    *iip,
        int                     whichfork)
{
        char                    *cp;
        xfs_ifork_t             *ifp;
        xfs_mount_t             *mp;
        static const short      brootflag[2] =
                { XFS_ILOG_DBROOT, XFS_ILOG_ABROOT };
        static const short      dataflag[2] =
                { XFS_ILOG_DDATA, XFS_ILOG_ADATA };
        static const short      extflag[2] =
                { XFS_ILOG_DEXT, XFS_ILOG_AEXT };

        if (!iip)
                return;
        ifp = XFS_IFORK_PTR(ip, whichfork);
        /*
         * This can happen if we gave up in iformat in an error path,
         * for the attribute fork.
         */
        if (!ifp) {
                ASSERT(whichfork == XFS_ATTR_FORK);
                return;
        }
        cp = XFS_DFORK_PTR(dip, whichfork);
        mp = ip->i_mount;
        switch (XFS_IFORK_FORMAT(ip, whichfork)) {
        case XFS_DINODE_FMT_LOCAL:
                if ((iip->ili_fields & dataflag[whichfork]) &&
                    (ifp->if_bytes > 0)) {
                        ASSERT(ifp->if_u1.if_data != NULL);
                        ASSERT(ifp->if_bytes <= XFS_IFORK_SIZE(ip, whichfork));
                        memcpy(cp, ifp->if_u1.if_data, ifp->if_bytes);
                }
                break;

        case XFS_DINODE_FMT_EXTENTS:
                ASSERT((ifp->if_flags & XFS_IFEXTENTS) ||
                       !(iip->ili_fields & extflag[whichfork]));
                if ((iip->ili_fields & extflag[whichfork]) &&
                    (ifp->if_bytes > 0)) {
                        ASSERT(XFS_IFORK_NEXTENTS(ip, whichfork) > 0);
                        (void)xfs_iextents_copy(ip, (xfs_bmbt_rec_t *)cp,
                                whichfork);
                }
                break;

        case XFS_DINODE_FMT_BTREE:
                if ((iip->ili_fields & brootflag[whichfork]) &&
                    (ifp->if_broot_bytes > 0)) {
                        ASSERT(ifp->if_broot != NULL);
                        ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
                                XFS_IFORK_SIZE(ip, whichfork));
                        xfs_bmbt_to_bmdr(mp, ifp->if_broot, ifp->if_broot_bytes,
                                (xfs_bmdr_block_t *)cp,
                                XFS_DFORK_SIZE(dip, mp, whichfork));
                }
                break;

        case XFS_DINODE_FMT_DEV:
                if (iip->ili_fields & XFS_ILOG_DEV) {
                        ASSERT(whichfork == XFS_DATA_FORK);
                        xfs_dinode_put_rdev(dip,
                                        linux_to_xfs_dev_t(VFS_I(ip)->i_rdev));
                }
                break;

        default:
                ASSERT(0);
                break;
        }
}

/* Convert bmap state flags to an inode fork. */
struct xfs_ifork *
xfs_iext_state_to_fork(
        struct xfs_inode        *ip,
        int                     state)
{
        if (state & BMAP_COWFORK)
                return ip->i_cowfp;
        else if (state & BMAP_ATTRFORK)
                return ip->i_afp;
        return &ip->i_df;
}

/*
 * Initialize an inode's copy-on-write fork.
 */
void
xfs_ifork_init_cow(
        struct xfs_inode        *ip)
{
        if (ip->i_cowfp)
                return;

        ip->i_cowfp = kmem_zone_zalloc(xfs_ifork_zone,
                                       KM_SLEEP | KM_NOFS);
        ip->i_cowfp->if_flags = XFS_IFEXTENTS;
        ip->i_cformat = XFS_DINODE_FMT_EXTENTS;
        ip->i_cnextents = 0;
}

/* Default fork content verifiers. */
struct xfs_ifork_ops xfs_default_ifork_ops = {
        .verify_attr    = xfs_attr_shortform_verify,
        .verify_dir     = xfs_dir2_sf_verify,
        .verify_symlink = xfs_symlink_shortform_verify,
};

/* Verify the inline contents of the data fork of an inode. */
xfs_failaddr_t
xfs_ifork_verify_data(
        struct xfs_inode        *ip,
        struct xfs_ifork_ops    *ops)
{
        /* Non-local data fork, we're done. */
        if (ip->i_d.di_format != XFS_DINODE_FMT_LOCAL)
                return NULL;

        /* Check the inline data fork if there is one. */
        switch (VFS_I(ip)->i_mode & S_IFMT) {
        case S_IFDIR:
                return ops->verify_dir(ip);
        case S_IFLNK:
                return ops->verify_symlink(ip);
        default:
                return NULL;
        }
}

/* Verify the inline contents of the attr fork of an inode. */
xfs_failaddr_t
xfs_ifork_verify_attr(
        struct xfs_inode        *ip,
        struct xfs_ifork_ops    *ops)
{
        /* There has to be an attr fork allocated if aformat is local. */
        if (ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)
                return NULL;
        if (!XFS_IFORK_PTR(ip, XFS_ATTR_FORK))
                return __this_address;
        return ops->verify_attr(ip);
}