xfs: zero inode fork buffer at allocation

[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"

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, 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) {
                /*
                 * As we round up the allocation here, we need to ensure the
                 * bytes we don't copy data into are zeroed because the log
                 * vectors still copy them into the journal.
                 */
                real_size = roundup(mem_size, 4);
                ifp->if_u1.if_data = kmem_zalloc(real_size, 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;
}

/*
 * 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
         * 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 = %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);
                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 kmem_alloc() 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);
                return -EFSCORRUPTED;
        }

        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_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);
                                return -EFSCORRUPTED;
                        }

                        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;
        /* 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(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 %Lu (btree).",
                                        (unsigned long long) ip->i_ino);
                xfs_inode_verifier_error(ip, -EFSCORRUPTED,
                                "xfs_iformat_btree", dfp, size,
                                __this_address);
                return -EFSCORRUPTED;
        }

        ifp->if_broot_bytes = size;
        ifp->if_broot = kmem_alloc(size, 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_bytes = 0;
        ifp->if_u1.if_root = 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.
         */
        ip->i_df.if_format = dip->di_format;
        ip->i_df.if_nextents = xfs_dfork_data_extents(dip);

        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);
                default:
                        xfs_inode_verifier_error(ip, -EFSCORRUPTED, __func__,
                                        dip, sizeof(*dip), __this_address);
                        return -EFSCORRUPTED;
                }
                break;
        default:
                xfs_inode_verifier_error(ip, -EFSCORRUPTED, __func__, dip,
                                sizeof(*dip), __this_address);
                return -EFSCORRUPTED;
        }
}

static uint16_t
xfs_dfork_attr_shortform_size(
        struct xfs_dinode               *dip)
{
        struct xfs_attr_shortform       *atp =
                (struct xfs_attr_shortform *)XFS_DFORK_APTR(dip);

        return be16_to_cpu(atp->hdr.totsize);
}

struct xfs_ifork *
xfs_ifork_alloc(
        enum xfs_dinode_fmt     format,
        xfs_extnum_t            nextents)
{
        struct xfs_ifork        *ifp;

        ifp = kmem_cache_zalloc(xfs_ifork_cache, GFP_NOFS | __GFP_NOFAIL);
        ifp->if_format = format;
        ifp->if_nextents = nextents;
        return ifp;
}

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.
         */
        ip->i_afp = xfs_ifork_alloc(dip->di_aformat, naextents);

        switch (ip->i_afp->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);
                error = -EFSCORRUPTED;
                break;
        }

        if (error) {
                kmem_cache_free(xfs_ifork_cache, ip->i_afp);
                ip->i_afp = NULL;
        }
        return error;
}

/*
 * 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;
        struct xfs_ifork        *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_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 = krealloc(ifp->if_broot, new_size,
                                         GFP_NOFS | __GFP_NOFAIL);
                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_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;
        }

        /*
         * 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(
        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_IFORK_SIZE(ip, whichfork));

        if (byte_diff == 0)
                return;

        if (new_size == 0) {
                kmem_free(ifp->if_u1.if_data);
                ifp->if_u1.if_data = NULL;
                ifp->if_bytes = 0;
                return;
        }

        /*
         * 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, and use __GFP_ZERO to ensure that size
         * extensions always zero the unused roundup area.
         */
        ifp->if_u1.if_data = krealloc(ifp->if_u1.if_data, roundup(new_size, 4),
                                      GFP_NOFS | __GFP_NOFAIL | __GFP_ZERO);
        ifp->if_bytes = new_size;
}

void
xfs_idestroy_fork(
        struct xfs_ifork        *ifp)
{
        if (ifp->if_broot != NULL) {
                kmem_free(ifp->if_broot);
                ifp->if_broot = NULL;
        }

        switch (ifp->if_format) {
        case XFS_DINODE_FMT_LOCAL:
                kmem_free(ifp->if_u1.if_data);
                ifp->if_u1.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;

        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_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_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:
                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_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_cache_zalloc(xfs_ifork_cache,
                                       GFP_NOFS | __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:
                fa = xfs_dir2_sf_verify(ip);
                break;
        case S_IFLNK:
                fa = xfs_symlink_shortform_verify(ip);
                break;
        default:
                break;
        }

        if (fa) {
                xfs_inode_verifier_error(ip, -EFSCORRUPTED, "data fork",
                                ip->i_df.if_u1.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_afp;
        xfs_failaddr_t          fa;

        if (!ifp)
                fa = __this_address;
        else
                fa = xfs_attr_shortform_verify(ip);

        if (fa) {
                xfs_inode_verifier_error(ip, -EFSCORRUPTED, "attr fork",
                                ifp ? ifp->if_u1.if_data : NULL,
                                ifp ? ifp->if_bytes : 0, fa);
                return -EFSCORRUPTED;
        }

        return 0;
}

int
xfs_iext_count_may_overflow(
        struct xfs_inode        *ip,
        int                     whichfork,
        int                     nr_to_add)
{
        struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
        uint64_t                max_exts;
        uint64_t                nr_exts;

        if (whichfork == XFS_COW_FORK)
                return 0;

        max_exts = xfs_iext_max_nextents(xfs_inode_has_large_extent_counts(ip),
                                whichfork);

        if (XFS_TEST_ERROR(false, ip->i_mount, XFS_ERRTAG_REDUCE_MAX_IEXTENTS))
                max_exts = 10;

        nr_exts = ifp->if_nextents + nr_to_add;
        if (nr_exts < ifp->if_nextents || nr_exts > max_exts)
                return -EFBIG;

        return 0;
}

/*
 * Upgrade this inode's extent counter fields to be able to handle a potential
 * increase in the extent count by nr_to_add.  Normally this is the same
 * quantity that caused xfs_iext_count_may_overflow() to return -EFBIG.
 */
int
xfs_iext_count_upgrade(
        struct xfs_trans        *tp,
        struct xfs_inode        *ip,
        uint                    nr_to_add)
{
        ASSERT(nr_to_add <= XFS_MAX_EXTCNT_UPGRADE_NR);

        if (!xfs_has_large_extent_counts(ip->i_mount) ||
            xfs_inode_has_large_extent_counts(ip) ||
            XFS_TEST_ERROR(false, ip->i_mount, XFS_ERRTAG_REDUCE_MAX_IEXTENTS))
                return -EFBIG;

        ip->i_diflags2 |= XFS_DIFLAG2_NREXT64;
        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

        return 0;
}