[thirdparty/xfsprogs-dev.git] / libxfs / xfs_inode_fork.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
 * All Rights Reserved.
 */

#include "libxfs_priv.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_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_bmap.h"
#include "xfs_trace.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_dir2_priv.h"
#include "xfs_attr_leaf.h"
#include "xfs_types.h"
#include "xfs_errortag.h"
#include "xfs_health.h"
#include "xfs_symlink_remote.h"
#include "xfs_rtrmap_btree.h"
#include "xfs_rtrefcount_btree.h"

struct kmem_cache *xfs_ifork_cache;

void
xfs_init_local_fork(
        struct xfs_inode        *ip,
        int                     whichfork,
        const void              *data,
        int64_t                 size)
{
        struct xfs_ifork        *ifp = xfs_ifork_ptr(ip, whichfork);
        int                     mem_size = size;
        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) {
                char *new_data = kmalloc(mem_size,
                                GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_NOFAIL);

                memcpy(new_data, data, size);
                if (zero_terminate)
                        new_data[size] = '\0';

                ifp->if_data = new_data;
        } else {
                ifp->if_data = NULL;
        }

        ifp->if_bytes = size;
}

/*
 * The file is in-lined in the on-disk inode.
 */
STATIC int
xfs_iformat_local(
        struct xfs_inode        *ip,
        struct xfs_dinode       *dip,
        int                     whichfork,
        int                     size)
{
        /*
         * If the size is unreasonable, then something
         * is wrong and we just bail out rather than crash in
         * kmalloc() or memcpy() below.
         */
        if (unlikely(size > XFS_DFORK_SIZE(dip, ip->i_mount, whichfork))) {
                xfs_warn(ip->i_mount,
        "corrupt inode %llu (bad size %d for local fork, size = %zd).",
                        (unsigned long long) ip->i_ino, size,
                        XFS_DFORK_SIZE(dip, ip->i_mount, whichfork));
                xfs_inode_verifier_error(ip, -EFSCORRUPTED,
                                "xfs_iformat_local", dip, sizeof(*dip),
                                __this_address);
                xfs_inode_mark_sick(ip, XFS_SICK_INO_CORE);
                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);
        xfs_extnum_t            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 kmalloc() or memcpy() below.
         */
        if (unlikely(size < 0 || size > XFS_DFORK_SIZE(dip, mp, whichfork))) {
                xfs_warn(ip->i_mount, "corrupt inode %llu ((a)extents = %llu).",
                        ip->i_ino, nex);
                xfs_inode_verifier_error(ip, -EFSCORRUPTED,
                                "xfs_iformat_extents(1)", dip, sizeof(*dip),
                                __this_address);
                xfs_inode_mark_sick(ip, XFS_SICK_INO_CORE);
                return -EFSCORRUPTED;
        }

        ifp->if_bytes = 0;
        ifp->if_data = 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_failaddr_t  fa;

                        xfs_bmbt_disk_get_all(dp, &new);
                        fa = xfs_bmap_validate_extent(ip, whichfork, &new);
                        if (fa) {
                                xfs_inode_verifier_error(ip, -EFSCORRUPTED,
                                                "xfs_iformat_extents(2)",
                                                dp, sizeof(*dp), fa);
                                xfs_inode_mark_sick(ip, XFS_SICK_INO_CORE);
                                return xfs_bmap_complain_bad_rec(ip, whichfork,
                                                fa, &new);
                        }

                        xfs_iext_insert(ip, &icur, &new, state);
                        trace_xfs_read_extent(ip, &icur, state, _THIS_IP_);
                        xfs_iext_next(ifp, &icur);
                }
        }
        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(
        struct xfs_inode        *ip,
        struct xfs_dinode       *dip,
        int                     whichfork)
{
        struct xfs_mount        *mp = ip->i_mount;
        xfs_bmdr_block_t        *dfp;
        struct xfs_ifork        *ifp;
        struct xfs_btree_block  *broot;
        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(ifp->if_nextents <= XFS_IFORK_MAXEXT(ip, whichfork) ||
                     nrecs == 0 ||
                     xfs_bmdr_space_calc(nrecs) >
                                        XFS_DFORK_SIZE(dip, mp, whichfork) ||
                     ifp->if_nextents > ip->i_nblocks) ||
                     level == 0 || level > XFS_BM_MAXLEVELS(mp, whichfork)) {
                xfs_warn(mp, "corrupt inode %llu (btree).",
                                        (unsigned long long) ip->i_ino);
                xfs_inode_verifier_error(ip, -EFSCORRUPTED,
                                "xfs_iformat_btree", dfp, size,
                                __this_address);
                xfs_inode_mark_sick(ip, XFS_SICK_INO_CORE);
                return -EFSCORRUPTED;
        }

        broot = xfs_broot_alloc(ifp, size);
        /*
         * 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),
                         broot, size);

        ifp->if_bytes = 0;
        ifp->if_data = NULL;
        ifp->if_height = 0;
        return 0;
}

int
xfs_iformat_data_fork(
        struct xfs_inode        *ip,
        struct xfs_dinode       *dip)
{
        struct inode            *inode = VFS_I(ip);
        int                     error;

        /*
         * Initialize the extent count early, as the per-format routines may
         * depend on it.  Use release semantics to set needextents /after/ we
         * set the format. This ensures that we can use acquire semantics on
         * needextents in xfs_need_iread_extents() and be guaranteed to see a
         * valid format value after that load.
         */
        ip->i_df.if_format = dip->di_format;
        ip->i_df.if_nextents = xfs_dfork_data_extents(dip);
        smp_store_release(&ip->i_df.if_needextents,
                           ip->i_df.if_format == XFS_DINODE_FMT_BTREE ? 1 : 0);

        switch (inode->i_mode & S_IFMT) {
        case S_IFIFO:
        case S_IFCHR:
        case S_IFBLK:
        case S_IFSOCK:
                ip->i_disk_size = 0;
                inode->i_rdev = xfs_to_linux_dev_t(xfs_dinode_get_rdev(dip));
                return 0;
        case S_IFREG:
        case S_IFLNK:
        case S_IFDIR:
                switch (ip->i_df.if_format) {
                case XFS_DINODE_FMT_LOCAL:
                        error = xfs_iformat_local(ip, dip, XFS_DATA_FORK,
                                        be64_to_cpu(dip->di_size));
                        if (!error)
                                error = xfs_ifork_verify_local_data(ip);
                        return error;
                case XFS_DINODE_FMT_EXTENTS:
                        return xfs_iformat_extents(ip, dip, XFS_DATA_FORK);
                case XFS_DINODE_FMT_BTREE:
                        return xfs_iformat_btree(ip, dip, XFS_DATA_FORK);
                case XFS_DINODE_FMT_META_BTREE:
                        switch (ip->i_metatype) {
                        case XFS_METAFILE_RTRMAP:
                                return xfs_iformat_rtrmap(ip, dip);
                        case XFS_METAFILE_RTREFCOUNT:
                                return xfs_iformat_rtrefcount(ip, dip);
                        default:
                                break;
                        }
                        fallthrough;
                default:
                        xfs_inode_verifier_error(ip, -EFSCORRUPTED, __func__,
                                        dip, sizeof(*dip), __this_address);
                        xfs_inode_mark_sick(ip, XFS_SICK_INO_CORE);
                        return -EFSCORRUPTED;
                }
                break;
        default:
                xfs_inode_verifier_error(ip, -EFSCORRUPTED, __func__, dip,
                                sizeof(*dip), __this_address);
                xfs_inode_mark_sick(ip, XFS_SICK_INO_CORE);
                return -EFSCORRUPTED;
        }
}

static uint16_t
xfs_dfork_attr_shortform_size(
        struct xfs_dinode               *dip)
{
        struct xfs_attr_sf_hdr          *sf = XFS_DFORK_APTR(dip);

        return be16_to_cpu(sf->totsize);
}

void
xfs_ifork_init_attr(
        struct xfs_inode        *ip,
        enum xfs_dinode_fmt     format,
        xfs_extnum_t            nextents)
{
        /*
         * Initialize the extent count early, as the per-format routines may
         * depend on it.  Use release semantics to set needextents /after/ we
         * set the format. This ensures that we can use acquire semantics on
         * needextents in xfs_need_iread_extents() and be guaranteed to see a
         * valid format value after that load.
         */
        ip->i_af.if_format = format;
        ip->i_af.if_nextents = nextents;
        smp_store_release(&ip->i_af.if_needextents,
                           ip->i_af.if_format == XFS_DINODE_FMT_BTREE ? 1 : 0);
}

void
xfs_ifork_zap_attr(
        struct xfs_inode        *ip)
{
        xfs_idestroy_fork(&ip->i_af);
        memset(&ip->i_af, 0, sizeof(struct xfs_ifork));
        ip->i_af.if_format = XFS_DINODE_FMT_EXTENTS;
}

int
xfs_iformat_attr_fork(
        struct xfs_inode        *ip,
        struct xfs_dinode       *dip)
{
        xfs_extnum_t            naextents = xfs_dfork_attr_extents(dip);
        int                     error = 0;

        /*
         * Initialize the extent count early, as the per-format routines may
         * depend on it.
         */
        xfs_ifork_init_attr(ip, dip->di_aformat, naextents);

        switch (ip->i_af.if_format) {
        case XFS_DINODE_FMT_LOCAL:
                error = xfs_iformat_local(ip, dip, XFS_ATTR_FORK,
                                xfs_dfork_attr_shortform_size(dip));
                if (!error)
                        error = xfs_ifork_verify_local_attr(ip);
                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:
                xfs_inode_verifier_error(ip, error, __func__, dip,
                                sizeof(*dip), __this_address);
                xfs_inode_mark_sick(ip, XFS_SICK_INO_CORE);
                error = -EFSCORRUPTED;
                break;
        }

        if (error)
                xfs_ifork_zap_attr(ip);
        return error;
}

/*
 * Allocate the if_broot component of an inode fork so that it is @new_size
 * bytes in size, using __GFP_NOLOCKDEP like all the other code that
 * initializes a broot during inode load.  Returns if_broot.
 */
struct xfs_btree_block *
xfs_broot_alloc(
        struct xfs_ifork        *ifp,
        size_t                  new_size)
{
        ASSERT(ifp->if_broot == NULL);

        ifp->if_broot = kmalloc(new_size,
                                GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_NOFAIL);
        ifp->if_broot_bytes = new_size;
        return ifp->if_broot;
}

/*
 * Reallocate the if_broot component of an inode fork so that it is @new_size
 * bytes in size.  Returns if_broot.
 */
struct xfs_btree_block *
xfs_broot_realloc(
        struct xfs_ifork        *ifp,
        size_t                  new_size)
{
        /* No size change?  No action needed. */
        if (new_size == ifp->if_broot_bytes)
                return ifp->if_broot;

        /* New size is zero, free it. */
        if (new_size == 0) {
                ifp->if_broot_bytes = 0;
                kfree(ifp->if_broot);
                ifp->if_broot = NULL;
                return NULL;
        }

        /*
         * Shrinking the iroot means we allocate a new smaller object and copy
         * it.  We don't trust krealloc not to nop on realloc-down.
         */
        if (ifp->if_broot_bytes > 0 && ifp->if_broot_bytes > new_size) {
                struct xfs_btree_block  *old_broot = ifp->if_broot;

                ifp->if_broot = kmalloc(new_size, GFP_KERNEL | __GFP_NOFAIL);
                ifp->if_broot_bytes = new_size;
                memcpy(ifp->if_broot, old_broot, new_size);
                kfree(old_broot);
                return ifp->if_broot;
        }

        /*
         * Growing the iroot means we can krealloc.  This may get us the same
         * object.
         */
        ifp->if_broot = krealloc(ifp->if_broot, new_size,
                        GFP_KERNEL | __GFP_NOFAIL);
        ifp->if_broot_bytes = new_size;
        return ifp->if_broot;
}

/*
 * 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 krealloc() or kmalloc() 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(
        struct xfs_inode        *ip,
        int64_t                 byte_diff,
        int                     whichfork)
{
        struct xfs_ifork        *ifp = xfs_ifork_ptr(ip, whichfork);
        int64_t                 new_size = ifp->if_bytes + byte_diff;

        ASSERT(new_size >= 0);
        ASSERT(new_size <= xfs_inode_fork_size(ip, whichfork));

        if (byte_diff) {
                ifp->if_data = krealloc(ifp->if_data, new_size,
                                        GFP_KERNEL | __GFP_NOFAIL);
                if (new_size == 0)
                        ifp->if_data = NULL;
                ifp->if_bytes = new_size;
        }

        return ifp->if_data;
}

/* Free all memory and reset a fork back to its initial state. */
void
xfs_idestroy_fork(
        struct xfs_ifork        *ifp)
{
        if (ifp->if_broot != NULL) {
                kfree(ifp->if_broot);
                ifp->if_broot = NULL;
        }

        switch (ifp->if_format) {
        case XFS_DINODE_FMT_LOCAL:
                kfree(ifp->if_data);
                ifp->if_data = NULL;
                break;
        case XFS_DINODE_FMT_EXTENTS:
        case XFS_DINODE_FMT_BTREE:
                if (ifp->if_height)
                        xfs_iext_destroy(ifp);
                break;
        }
}

/*
 * 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;
        int64_t                 copied = 0;

        xfs_assert_ilocked(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_bmap_validate_extent(ip, whichfork, &rec) == NULL);
                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(
        struct xfs_inode        *ip,
        struct xfs_dinode       *dip,
        struct xfs_inode_log_item *iip,
        int                     whichfork)
{
        char                    *cp;
        struct xfs_ifork        *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 (ifp->if_format) {
        case XFS_DINODE_FMT_LOCAL:
                if ((iip->ili_fields & dataflag[whichfork]) &&
                    (ifp->if_bytes > 0)) {
                        ASSERT(ifp->if_data != NULL);
                        ASSERT(ifp->if_bytes <= xfs_inode_fork_size(ip, whichfork));
                        memcpy(cp, ifp->if_data, ifp->if_bytes);
                }
                break;

        case XFS_DINODE_FMT_EXTENTS:
                if ((iip->ili_fields & extflag[whichfork]) &&
                    (ifp->if_bytes > 0)) {
                        ASSERT(ifp->if_nextents > 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_inode_fork_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;

        case XFS_DINODE_FMT_META_BTREE:
                ASSERT(whichfork == XFS_DATA_FORK);

                if (!(iip->ili_fields & brootflag[whichfork]))
                        break;

                switch (ip->i_metatype) {
                case XFS_METAFILE_RTRMAP:
                        xfs_iflush_rtrmap(ip, dip);
                        break;
                case XFS_METAFILE_RTREFCOUNT:
                        xfs_iflush_rtrefcount(ip, dip);
                        break;
                default:
                        ASSERT(0);
                        break;
                }
                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_af;
        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_cache_zalloc(xfs_ifork_cache,
                                GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_NOFAIL);
        ip->i_cowfp->if_format = XFS_DINODE_FMT_EXTENTS;
}

/* Verify the inline contents of the data fork of an inode. */
int
xfs_ifork_verify_local_data(
        struct xfs_inode        *ip)
{
        xfs_failaddr_t          fa = NULL;

        switch (VFS_I(ip)->i_mode & S_IFMT) {
        case S_IFDIR: {
                struct xfs_mount        *mp = ip->i_mount;
                struct xfs_ifork        *ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
                struct xfs_dir2_sf_hdr  *sfp = ifp->if_data;

                fa = xfs_dir2_sf_verify(mp, sfp, ifp->if_bytes);
                break;
        }
        case S_IFLNK: {
                struct xfs_ifork        *ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);

                fa = xfs_symlink_shortform_verify(ifp->if_data, ifp->if_bytes);
                break;
        }
        default:
                break;
        }

        if (fa) {
                xfs_inode_verifier_error(ip, -EFSCORRUPTED, "data fork",
                                ip->i_df.if_data, ip->i_df.if_bytes, fa);
                return -EFSCORRUPTED;
        }

        return 0;
}

/* Verify the inline contents of the attr fork of an inode. */
int
xfs_ifork_verify_local_attr(
        struct xfs_inode        *ip)
{
        struct xfs_ifork        *ifp = &ip->i_af;
        xfs_failaddr_t          fa;

        if (!xfs_inode_has_attr_fork(ip)) {
                fa = __this_address;
        } else {
                struct xfs_ifork                *ifp = &ip->i_af;

                ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);
                fa = xfs_attr_shortform_verify(ifp->if_data, ifp->if_bytes);
        }
        if (fa) {
                xfs_inode_verifier_error(ip, -EFSCORRUPTED, "attr fork",
                                ifp->if_data, ifp->if_bytes, fa);
                return -EFSCORRUPTED;
        }

        return 0;
}

/*
 * Check if the inode fork supports adding nr_to_add more extents.
 *
 * If it doesn't but we can upgrade it to large extent counters, do the upgrade.
 * If we can't upgrade or are already using big counters but still can't fit the
 * additional extents, return -EFBIG.
 */
int
xfs_iext_count_extend(
        struct xfs_trans        *tp,
        struct xfs_inode        *ip,
        int                     whichfork,
        uint                    nr_to_add)
{
        struct xfs_mount        *mp = ip->i_mount;
        bool                    has_large =
                xfs_inode_has_large_extent_counts(ip);
        struct xfs_ifork        *ifp = xfs_ifork_ptr(ip, whichfork);
        uint64_t                nr_exts;

        ASSERT(nr_to_add <= XFS_MAX_EXTCNT_UPGRADE_NR);

        if (whichfork == XFS_COW_FORK)
                return 0;

        /* no point in upgrading if if_nextents overflows */
        nr_exts = ifp->if_nextents + nr_to_add;
        if (nr_exts < ifp->if_nextents)
                return -EFBIG;

        if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_REDUCE_MAX_IEXTENTS) &&
            nr_exts > 10)
                return -EFBIG;

        if (nr_exts > xfs_iext_max_nextents(has_large, whichfork)) {
                if (has_large || !xfs_has_large_extent_counts(mp))
                        return -EFBIG;
                ip->i_diflags2 |= XFS_DIFLAG2_NREXT64;
                xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
        }
        return 0;
}

/* Decide if a file mapping is on the realtime device or not. */
bool
xfs_ifork_is_realtime(
        struct xfs_inode        *ip,
        int                     whichfork)
{
        return XFS_IS_REALTIME_INODE(ip) && whichfork != XFS_ATTR_FORK;
}