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root/fs/gfs2/eattr.c

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DEFINITIONS

This source file includes following definitions.
  1. ea_calc_size
  2. ea_check_size
  3. ea_foreach_i
  4. ea_foreach
  5. ea_find_i
  6. gfs2_ea_find
  7. ea_dealloc_unstuffed
  8. ea_remove_unstuffed
  9. ea_list_i
  10. gfs2_ea_list
  11. ea_get_unstuffed
  12. gfs2_ea_get_copy
  13. gfs2_ea_get_i
  14. gfs2_ea_get
  15. ea_alloc_blk
  16. ea_write
  17. ea_alloc_skeleton
  18. ea_init_i
  19. ea_init
  20. ea_split_ea
  21. ea_set_remove_stuffed
  22. ea_set_simple_noalloc
  23. ea_set_simple_alloc
  24. ea_set_simple
  25. ea_set_block
  26. ea_set_i
  27. ea_set_remove_unstuffed
  28. gfs2_ea_set_i
  29. gfs2_ea_set
  30. ea_remove_stuffed
  31. gfs2_ea_remove_i
  32. gfs2_ea_remove
  33. ea_acl_chmod_unstuffed
  34. gfs2_ea_acl_chmod
  35. ea_dealloc_indirect
  36. ea_dealloc_block
  37. gfs2_ea_dealloc

/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License version 2.
 */

#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/xattr.h>
#include <linux/gfs2_ondisk.h>
#include <linux/lm_interface.h>
#include <asm/uaccess.h>

#include "gfs2.h"
#include "incore.h"
#include "acl.h"
#include "eaops.h"
#include "eattr.h"
#include "glock.h"
#include "inode.h"
#include "meta_io.h"
#include "quota.h"
#include "rgrp.h"
#include "trans.h"
#include "util.h"

/**
 * ea_calc_size - returns the acutal number of bytes the request will take up
 *                (not counting any unstuffed data blocks)
 * @sdp:
 * @er:
 * @size:
 *
 * Returns: 1 if the EA should be stuffed
 */

static int ea_calc_size(struct gfs2_sbd *sdp, struct gfs2_ea_request *er,
                        unsigned int *size)
{
        *size = GFS2_EAREQ_SIZE_STUFFED(er);
        if (*size <= sdp->sd_jbsize)
                return 1;

        *size = GFS2_EAREQ_SIZE_UNSTUFFED(sdp, er);

        return 0;
}

static int ea_check_size(struct gfs2_sbd *sdp, struct gfs2_ea_request *er)
{
        unsigned int size;

        if (er->er_data_len > GFS2_EA_MAX_DATA_LEN)
                return -ERANGE;

        ea_calc_size(sdp, er, &size);

        /* This can only happen with 512 byte blocks */
        if (size > sdp->sd_jbsize)
                return -ERANGE;

        return 0;
}

typedef int (*ea_call_t) (struct gfs2_inode *ip, struct buffer_head *bh,
                          struct gfs2_ea_header *ea,
                          struct gfs2_ea_header *prev, void *private);

static int ea_foreach_i(struct gfs2_inode *ip, struct buffer_head *bh,
                        ea_call_t ea_call, void *data)
{
        struct gfs2_ea_header *ea, *prev = NULL;
        int error = 0;

        if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_EA))
                return -EIO;

        for (ea = GFS2_EA_BH2FIRST(bh);; prev = ea, ea = GFS2_EA2NEXT(ea)) {
                if (!GFS2_EA_REC_LEN(ea))
                        goto fail;
                if (!(bh->b_data <= (char *)ea && (char *)GFS2_EA2NEXT(ea) <=
                                                  bh->b_data + bh->b_size))
                        goto fail;
                if (!GFS2_EATYPE_VALID(ea->ea_type))
                        goto fail;

                error = ea_call(ip, bh, ea, prev, data);
                if (error)
                        return error;

                if (GFS2_EA_IS_LAST(ea)) {
                        if ((char *)GFS2_EA2NEXT(ea) !=
                            bh->b_data + bh->b_size)
                                goto fail;
                        break;
                }
        }

        return error;

fail:
        gfs2_consist_inode(ip);
        return -EIO;
}

static int ea_foreach(struct gfs2_inode *ip, ea_call_t ea_call, void *data)
{
        struct buffer_head *bh, *eabh;
        __be64 *eablk, *end;
        int error;

        error = gfs2_meta_read(ip->i_gl, ip->i_di.di_eattr, DIO_WAIT, &bh);
        if (error)
                return error;

        if (!(ip->i_di.di_flags & GFS2_DIF_EA_INDIRECT)) {
                error = ea_foreach_i(ip, bh, ea_call, data);
                goto out;
        }

        if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_IN)) {
                error = -EIO;
                goto out;
        }

        eablk = (__be64 *)(bh->b_data + sizeof(struct gfs2_meta_header));
        end = eablk + GFS2_SB(&ip->i_inode)->sd_inptrs;

        for (; eablk < end; eablk++) {
                u64 bn;

                if (!*eablk)
                        break;
                bn = be64_to_cpu(*eablk);

                error = gfs2_meta_read(ip->i_gl, bn, DIO_WAIT, &eabh);
                if (error)
                        break;
                error = ea_foreach_i(ip, eabh, ea_call, data);
                brelse(eabh);
                if (error)
                        break;
        }
out:
        brelse(bh);
        return error;
}

struct ea_find {
        struct gfs2_ea_request *ef_er;
        struct gfs2_ea_location *ef_el;
};

static int ea_find_i(struct gfs2_inode *ip, struct buffer_head *bh,
                     struct gfs2_ea_header *ea, struct gfs2_ea_header *prev,
                     void *private)
{
        struct ea_find *ef = private;
        struct gfs2_ea_request *er = ef->ef_er;

        if (ea->ea_type == GFS2_EATYPE_UNUSED)
                return 0;

        if (ea->ea_type == er->er_type) {
                if (ea->ea_name_len == er->er_name_len &&
                    !memcmp(GFS2_EA2NAME(ea), er->er_name, ea->ea_name_len)) {
                        struct gfs2_ea_location *el = ef->ef_el;
                        get_bh(bh);
                        el->el_bh = bh;
                        el->el_ea = ea;
                        el->el_prev = prev;
                        return 1;
                }
        }

        return 0;
}

int gfs2_ea_find(struct gfs2_inode *ip, struct gfs2_ea_request *er,
                 struct gfs2_ea_location *el)
{
        struct ea_find ef;
        int error;

        ef.ef_er = er;
        ef.ef_el = el;

        memset(el, 0, sizeof(struct gfs2_ea_location));

        error = ea_foreach(ip, ea_find_i, &ef);
        if (error > 0)
                return 0;

        return error;
}

/**
 * ea_dealloc_unstuffed -
 * @ip:
 * @bh:
 * @ea:
 * @prev:
 * @private:
 *
 * Take advantage of the fact that all unstuffed blocks are
 * allocated from the same RG.  But watch, this may not always
 * be true.
 *
 * Returns: errno
 */

static int ea_dealloc_unstuffed(struct gfs2_inode *ip, struct buffer_head *bh,
                                struct gfs2_ea_header *ea,
                                struct gfs2_ea_header *prev, void *private)
{
        int *leave = private;
        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
        struct gfs2_rgrpd *rgd;
        struct gfs2_holder rg_gh;
        struct buffer_head *dibh;
        __be64 *dataptrs;
        u64 bn = 0;
        u64 bstart = 0;
        unsigned int blen = 0;
        unsigned int blks = 0;
        unsigned int x;
        int error;

        if (GFS2_EA_IS_STUFFED(ea))
                return 0;

        dataptrs = GFS2_EA2DATAPTRS(ea);
        for (x = 0; x < ea->ea_num_ptrs; x++, dataptrs++) {
                if (*dataptrs) {
                        blks++;
                        bn = be64_to_cpu(*dataptrs);
                }
        }
        if (!blks)
                return 0;

        rgd = gfs2_blk2rgrpd(sdp, bn);
        if (!rgd) {
                gfs2_consist_inode(ip);
                return -EIO;
        }

        error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, &rg_gh);
        if (error)
                return error;

        error = gfs2_trans_begin(sdp, rgd->rd_length + RES_DINODE +
                                 RES_EATTR + RES_STATFS + RES_QUOTA, blks);
        if (error)
                goto out_gunlock;

        gfs2_trans_add_bh(ip->i_gl, bh, 1);

        dataptrs = GFS2_EA2DATAPTRS(ea);
        for (x = 0; x < ea->ea_num_ptrs; x++, dataptrs++) {
                if (!*dataptrs)
                        break;
                bn = be64_to_cpu(*dataptrs);

                if (bstart + blen == bn)
                        blen++;
                else {
                        if (bstart)
                                gfs2_free_meta(ip, bstart, blen);
                        bstart = bn;
                        blen = 1;
                }

                *dataptrs = 0;
                gfs2_add_inode_blocks(&ip->i_inode, -1);
        }
        if (bstart)
                gfs2_free_meta(ip, bstart, blen);

        if (prev && !leave) {
                u32 len;

                len = GFS2_EA_REC_LEN(prev) + GFS2_EA_REC_LEN(ea);
                prev->ea_rec_len = cpu_to_be32(len);

                if (GFS2_EA_IS_LAST(ea))
                        prev->ea_flags |= GFS2_EAFLAG_LAST;
        } else {
                ea->ea_type = GFS2_EATYPE_UNUSED;
                ea->ea_num_ptrs = 0;
        }

        error = gfs2_meta_inode_buffer(ip, &dibh);
        if (!error) {
                ip->i_inode.i_ctime = CURRENT_TIME;
                gfs2_trans_add_bh(ip->i_gl, dibh, 1);
                gfs2_dinode_out(ip, dibh->b_data);
                brelse(dibh);
        }

        gfs2_trans_end(sdp);

out_gunlock:
        gfs2_glock_dq_uninit(&rg_gh);
        return error;
}

static int ea_remove_unstuffed(struct gfs2_inode *ip, struct buffer_head *bh,
                               struct gfs2_ea_header *ea,
                               struct gfs2_ea_header *prev, int leave)
{
        struct gfs2_alloc *al;
        int error;

        al = gfs2_alloc_get(ip);
        if (!al)
                return -ENOMEM;

        error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
        if (error)
                goto out_alloc;

        error = gfs2_rindex_hold(GFS2_SB(&ip->i_inode), &al->al_ri_gh);
        if (error)
                goto out_quota;

        error = ea_dealloc_unstuffed(ip, bh, ea, prev, (leave) ? &error : NULL);

        gfs2_glock_dq_uninit(&al->al_ri_gh);

out_quota:
        gfs2_quota_unhold(ip);
out_alloc:
        gfs2_alloc_put(ip);
        return error;
}

struct ea_list {
        struct gfs2_ea_request *ei_er;
        unsigned int ei_size;
};

static int ea_list_i(struct gfs2_inode *ip, struct buffer_head *bh,
                     struct gfs2_ea_header *ea, struct gfs2_ea_header *prev,
                     void *private)
{
        struct ea_list *ei = private;
        struct gfs2_ea_request *er = ei->ei_er;
        unsigned int ea_size = gfs2_ea_strlen(ea);

        if (ea->ea_type == GFS2_EATYPE_UNUSED)
                return 0;

        if (er->er_data_len) {
                char *prefix = NULL;
                unsigned int l = 0;
                char c = 0;

                if (ei->ei_size + ea_size > er->er_data_len)
                        return -ERANGE;

                switch (ea->ea_type) {
                case GFS2_EATYPE_USR:
                        prefix = "user.";
                        l = 5;
                        break;
                case GFS2_EATYPE_SYS:
                        prefix = "system.";
                        l = 7;
                        break;
                case GFS2_EATYPE_SECURITY:
                        prefix = "security.";
                        l = 9;
                        break;
                }

                BUG_ON(l == 0);

                memcpy(er->er_data + ei->ei_size, prefix, l);
                memcpy(er->er_data + ei->ei_size + l, GFS2_EA2NAME(ea),
                       ea->ea_name_len);
                memcpy(er->er_data + ei->ei_size + ea_size - 1, &c, 1);
        }

        ei->ei_size += ea_size;

        return 0;
}

/**
 * gfs2_ea_list -
 * @ip:
 * @er:
 *
 * Returns: actual size of data on success, -errno on error
 */

int gfs2_ea_list(struct gfs2_inode *ip, struct gfs2_ea_request *er)
{
        struct gfs2_holder i_gh;
        int error;

        if (!er->er_data || !er->er_data_len) {
                er->er_data = NULL;
                er->er_data_len = 0;
        }

        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
        if (error)
                return error;

        if (ip->i_di.di_eattr) {
                struct ea_list ei = { .ei_er = er, .ei_size = 0 };

                error = ea_foreach(ip, ea_list_i, &ei);
                if (!error)
                        error = ei.ei_size;
        }

        gfs2_glock_dq_uninit(&i_gh);

        return error;
}

/**
 * ea_get_unstuffed - actually copies the unstuffed data into the
 *                    request buffer
 * @ip: The GFS2 inode
 * @ea: The extended attribute header structure
 * @data: The data to be copied
 *
 * Returns: errno
 */

static int ea_get_unstuffed(struct gfs2_inode *ip, struct gfs2_ea_header *ea,
                            char *data)
{
        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
        struct buffer_head **bh;
        unsigned int amount = GFS2_EA_DATA_LEN(ea);
        unsigned int nptrs = DIV_ROUND_UP(amount, sdp->sd_jbsize);
        __be64 *dataptrs = GFS2_EA2DATAPTRS(ea);
        unsigned int x;
        int error = 0;

        bh = kcalloc(nptrs, sizeof(struct buffer_head *), GFP_NOFS);
        if (!bh)
                return -ENOMEM;

        for (x = 0; x < nptrs; x++) {
                error = gfs2_meta_read(ip->i_gl, be64_to_cpu(*dataptrs), 0,
                                       bh + x);
                if (error) {
                        while (x--)
                                brelse(bh[x]);
                        goto out;
                }
                dataptrs++;
        }

        for (x = 0; x < nptrs; x++) {
                error = gfs2_meta_wait(sdp, bh[x]);
                if (error) {
                        for (; x < nptrs; x++)
                                brelse(bh[x]);
                        goto out;
                }
                if (gfs2_metatype_check(sdp, bh[x], GFS2_METATYPE_ED)) {
                        for (; x < nptrs; x++)
                                brelse(bh[x]);
                        error = -EIO;
                        goto out;
                }

                memcpy(data, bh[x]->b_data + sizeof(struct gfs2_meta_header),
                       (sdp->sd_jbsize > amount) ? amount : sdp->sd_jbsize);

                amount -= sdp->sd_jbsize;
                data += sdp->sd_jbsize;

                brelse(bh[x]);
        }

out:
        kfree(bh);
        return error;
}

int gfs2_ea_get_copy(struct gfs2_inode *ip, struct gfs2_ea_location *el,
                     char *data)
{
        if (GFS2_EA_IS_STUFFED(el->el_ea)) {
                memcpy(data, GFS2_EA2DATA(el->el_ea), GFS2_EA_DATA_LEN(el->el_ea));
                return 0;
        } else
                return ea_get_unstuffed(ip, el->el_ea, data);
}

/**
 * gfs2_ea_get_i -
 * @ip: The GFS2 inode
 * @er: The request structure
 *
 * Returns: actual size of data on success, -errno on error
 */

int gfs2_ea_get_i(struct gfs2_inode *ip, struct gfs2_ea_request *er)
{
        struct gfs2_ea_location el;
        int error;

        if (!ip->i_di.di_eattr)
                return -ENODATA;

        error = gfs2_ea_find(ip, er, &el);
        if (error)
                return error;
        if (!el.el_ea)
                return -ENODATA;

        if (er->er_data_len) {
                if (GFS2_EA_DATA_LEN(el.el_ea) > er->er_data_len)
                        error =  -ERANGE;
                else
                        error = gfs2_ea_get_copy(ip, &el, er->er_data);
        }
        if (!error)
                error = GFS2_EA_DATA_LEN(el.el_ea);

        brelse(el.el_bh);

        return error;
}

/**
 * gfs2_ea_get -
 * @ip: The GFS2 inode
 * @er: The request structure
 *
 * Returns: actual size of data on success, -errno on error
 */

int gfs2_ea_get(struct gfs2_inode *ip, struct gfs2_ea_request *er)
{
        struct gfs2_holder i_gh;
        int error;

        if (!er->er_name_len ||
            er->er_name_len > GFS2_EA_MAX_NAME_LEN)
                return -EINVAL;
        if (!er->er_data || !er->er_data_len) {
                er->er_data = NULL;
                er->er_data_len = 0;
        }

        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
        if (error)
                return error;

        error = gfs2_ea_ops[er->er_type]->eo_get(ip, er);

        gfs2_glock_dq_uninit(&i_gh);

        return error;
}

/**
 * ea_alloc_blk - allocates a new block for extended attributes.
 * @ip: A pointer to the inode that's getting extended attributes
 * @bhp: Pointer to pointer to a struct buffer_head
 *
 * Returns: errno
 */

static int ea_alloc_blk(struct gfs2_inode *ip, struct buffer_head **bhp)
{
        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
        struct gfs2_ea_header *ea;
        unsigned int n = 1;
        u64 block;

        block = gfs2_alloc_block(ip, &n);
        gfs2_trans_add_unrevoke(sdp, block, 1);
        *bhp = gfs2_meta_new(ip->i_gl, block);
        gfs2_trans_add_bh(ip->i_gl, *bhp, 1);
        gfs2_metatype_set(*bhp, GFS2_METATYPE_EA, GFS2_FORMAT_EA);
        gfs2_buffer_clear_tail(*bhp, sizeof(struct gfs2_meta_header));

        ea = GFS2_EA_BH2FIRST(*bhp);
        ea->ea_rec_len = cpu_to_be32(sdp->sd_jbsize);
        ea->ea_type = GFS2_EATYPE_UNUSED;
        ea->ea_flags = GFS2_EAFLAG_LAST;
        ea->ea_num_ptrs = 0;

        gfs2_add_inode_blocks(&ip->i_inode, 1);

        return 0;
}

/**
 * ea_write - writes the request info to an ea, creating new blocks if
 *            necessary
 * @ip: inode that is being modified
 * @ea: the location of the new ea in a block
 * @er: the write request
 *
 * Note: does not update ea_rec_len or the GFS2_EAFLAG_LAST bin of ea_flags
 *
 * returns : errno
 */

static int ea_write(struct gfs2_inode *ip, struct gfs2_ea_header *ea,
                    struct gfs2_ea_request *er)
{
        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);

        ea->ea_data_len = cpu_to_be32(er->er_data_len);
        ea->ea_name_len = er->er_name_len;
        ea->ea_type = er->er_type;
        ea->__pad = 0;

        memcpy(GFS2_EA2NAME(ea), er->er_name, er->er_name_len);

        if (GFS2_EAREQ_SIZE_STUFFED(er) <= sdp->sd_jbsize) {
                ea->ea_num_ptrs = 0;
                memcpy(GFS2_EA2DATA(ea), er->er_data, er->er_data_len);
        } else {
                __be64 *dataptr = GFS2_EA2DATAPTRS(ea);
                const char *data = er->er_data;
                unsigned int data_len = er->er_data_len;
                unsigned int copy;
                unsigned int x;

                ea->ea_num_ptrs = DIV_ROUND_UP(er->er_data_len, sdp->sd_jbsize);
                for (x = 0; x < ea->ea_num_ptrs; x++) {
                        struct buffer_head *bh;
                        u64 block;
                        int mh_size = sizeof(struct gfs2_meta_header);
                        unsigned int n = 1;

                        block = gfs2_alloc_block(ip, &n);
                        gfs2_trans_add_unrevoke(sdp, block, 1);
                        bh = gfs2_meta_new(ip->i_gl, block);
                        gfs2_trans_add_bh(ip->i_gl, bh, 1);
                        gfs2_metatype_set(bh, GFS2_METATYPE_ED, GFS2_FORMAT_ED);

                        gfs2_add_inode_blocks(&ip->i_inode, 1);

                        copy = data_len > sdp->sd_jbsize ? sdp->sd_jbsize :
                                                           data_len;
                        memcpy(bh->b_data + mh_size, data, copy);
                        if (copy < sdp->sd_jbsize)
                                memset(bh->b_data + mh_size + copy, 0,
                                       sdp->sd_jbsize - copy);

                        *dataptr++ = cpu_to_be64(bh->b_blocknr);
                        data += copy;
                        data_len -= copy;

                        brelse(bh);
                }

                gfs2_assert_withdraw(sdp, !data_len);
        }

        return 0;
}

typedef int (*ea_skeleton_call_t) (struct gfs2_inode *ip,
                                   struct gfs2_ea_request *er, void *private);

static int ea_alloc_skeleton(struct gfs2_inode *ip, struct gfs2_ea_request *er,
                             unsigned int blks,
                             ea_skeleton_call_t skeleton_call, void *private)
{
        struct gfs2_alloc *al;
        struct buffer_head *dibh;
        int error;

        al = gfs2_alloc_get(ip);
        if (!al)
                return -ENOMEM;

        error = gfs2_quota_lock_check(ip);
        if (error)
                goto out;

        al->al_requested = blks;

        error = gfs2_inplace_reserve(ip);
        if (error)
                goto out_gunlock_q;

        error = gfs2_trans_begin(GFS2_SB(&ip->i_inode),
                                 blks + al->al_rgd->rd_length +
                                 RES_DINODE + RES_STATFS + RES_QUOTA, 0);
        if (error)
                goto out_ipres;

        error = skeleton_call(ip, er, private);
        if (error)
                goto out_end_trans;

        error = gfs2_meta_inode_buffer(ip, &dibh);
        if (!error) {
                if (er->er_flags & GFS2_ERF_MODE) {
                        gfs2_assert_withdraw(GFS2_SB(&ip->i_inode),
                                            (ip->i_inode.i_mode & S_IFMT) ==
                                            (er->er_mode & S_IFMT));
                        ip->i_inode.i_mode = er->er_mode;
                }
                ip->i_inode.i_ctime = CURRENT_TIME;
                gfs2_trans_add_bh(ip->i_gl, dibh, 1);
                gfs2_dinode_out(ip, dibh->b_data);
                brelse(dibh);
        }

out_end_trans:
        gfs2_trans_end(GFS2_SB(&ip->i_inode));
out_ipres:
        gfs2_inplace_release(ip);
out_gunlock_q:
        gfs2_quota_unlock(ip);
out:
        gfs2_alloc_put(ip);
        return error;
}

static int ea_init_i(struct gfs2_inode *ip, struct gfs2_ea_request *er,
                     void *private)
{
        struct buffer_head *bh;
        int error;

        error = ea_alloc_blk(ip, &bh);
        if (error)
                return error;

        ip->i_di.di_eattr = bh->b_blocknr;
        error = ea_write(ip, GFS2_EA_BH2FIRST(bh), er);

        brelse(bh);

        return error;
}

/**
 * ea_init - initializes a new eattr block
 * @ip:
 * @er:
 *
 * Returns: errno
 */

static int ea_init(struct gfs2_inode *ip, struct gfs2_ea_request *er)
{
        unsigned int jbsize = GFS2_SB(&ip->i_inode)->sd_jbsize;
        unsigned int blks = 1;

        if (GFS2_EAREQ_SIZE_STUFFED(er) > jbsize)
                blks += DIV_ROUND_UP(er->er_data_len, jbsize);

        return ea_alloc_skeleton(ip, er, blks, ea_init_i, NULL);
}

static struct gfs2_ea_header *ea_split_ea(struct gfs2_ea_header *ea)
{
        u32 ea_size = GFS2_EA_SIZE(ea);
        struct gfs2_ea_header *new = (struct gfs2_ea_header *)((char *)ea +
                                     ea_size);
        u32 new_size = GFS2_EA_REC_LEN(ea) - ea_size;
        int last = ea->ea_flags & GFS2_EAFLAG_LAST;

        ea->ea_rec_len = cpu_to_be32(ea_size);
        ea->ea_flags ^= last;

        new->ea_rec_len = cpu_to_be32(new_size);
        new->ea_flags = last;

        return new;
}

static void ea_set_remove_stuffed(struct gfs2_inode *ip,
                                  struct gfs2_ea_location *el)
{
        struct gfs2_ea_header *ea = el->el_ea;
        struct gfs2_ea_header *prev = el->el_prev;
        u32 len;

        gfs2_trans_add_bh(ip->i_gl, el->el_bh, 1);

        if (!prev || !GFS2_EA_IS_STUFFED(ea)) {
                ea->ea_type = GFS2_EATYPE_UNUSED;
                return;
        } else if (GFS2_EA2NEXT(prev) != ea) {
                prev = GFS2_EA2NEXT(prev);
                gfs2_assert_withdraw(GFS2_SB(&ip->i_inode), GFS2_EA2NEXT(prev) == ea);
        }

        len = GFS2_EA_REC_LEN(prev) + GFS2_EA_REC_LEN(ea);
        prev->ea_rec_len = cpu_to_be32(len);

        if (GFS2_EA_IS_LAST(ea))
                prev->ea_flags |= GFS2_EAFLAG_LAST;
}

struct ea_set {
        int ea_split;

        struct gfs2_ea_request *es_er;
        struct gfs2_ea_location *es_el;

        struct buffer_head *es_bh;
        struct gfs2_ea_header *es_ea;
};

static int ea_set_simple_noalloc(struct gfs2_inode *ip, struct buffer_head *bh,
                                 struct gfs2_ea_header *ea, struct ea_set *es)
{
        struct gfs2_ea_request *er = es->es_er;
        struct buffer_head *dibh;
        int error;

        error = gfs2_trans_begin(GFS2_SB(&ip->i_inode), RES_DINODE + 2 * RES_EATTR, 0);
        if (error)
                return error;

        gfs2_trans_add_bh(ip->i_gl, bh, 1);

        if (es->ea_split)
                ea = ea_split_ea(ea);

        ea_write(ip, ea, er);

        if (es->es_el)
                ea_set_remove_stuffed(ip, es->es_el);

        error = gfs2_meta_inode_buffer(ip, &dibh);
        if (error)
                goto out;

        if (er->er_flags & GFS2_ERF_MODE) {
                gfs2_assert_withdraw(GFS2_SB(&ip->i_inode),
                        (ip->i_inode.i_mode & S_IFMT) == (er->er_mode & S_IFMT));
                ip->i_inode.i_mode = er->er_mode;
        }
        ip->i_inode.i_ctime = CURRENT_TIME;
        gfs2_trans_add_bh(ip->i_gl, dibh, 1);
        gfs2_dinode_out(ip, dibh->b_data);
        brelse(dibh);
out:
        gfs2_trans_end(GFS2_SB(&ip->i_inode));
        return error;
}

static int ea_set_simple_alloc(struct gfs2_inode *ip,
                               struct gfs2_ea_request *er, void *private)
{
        struct ea_set *es = private;
        struct gfs2_ea_header *ea = es->es_ea;
        int error;

        gfs2_trans_add_bh(ip->i_gl, es->es_bh, 1);

        if (es->ea_split)
                ea = ea_split_ea(ea);

        error = ea_write(ip, ea, er);
        if (error)
                return error;

        if (es->es_el)
                ea_set_remove_stuffed(ip, es->es_el);

        return 0;
}

static int ea_set_simple(struct gfs2_inode *ip, struct buffer_head *bh,
                         struct gfs2_ea_header *ea, struct gfs2_ea_header *prev,
                         void *private)
{
        struct ea_set *es = private;
        unsigned int size;
        int stuffed;
        int error;

        stuffed = ea_calc_size(GFS2_SB(&ip->i_inode), es->es_er, &size);

        if (ea->ea_type == GFS2_EATYPE_UNUSED) {
                if (GFS2_EA_REC_LEN(ea) < size)
                        return 0;
                if (!GFS2_EA_IS_STUFFED(ea)) {
                        error = ea_remove_unstuffed(ip, bh, ea, prev, 1);
                        if (error)
                                return error;
                }
                es->ea_split = 0;
        } else if (GFS2_EA_REC_LEN(ea) - GFS2_EA_SIZE(ea) >= size)
                es->ea_split = 1;
        else
                return 0;

        if (stuffed) {
                error = ea_set_simple_noalloc(ip, bh, ea, es);
                if (error)
                        return error;
        } else {
                unsigned int blks;

                es->es_bh = bh;
                es->es_ea = ea;
                blks = 2 + DIV_ROUND_UP(es->es_er->er_data_len,
                                        GFS2_SB(&ip->i_inode)->sd_jbsize);

                error = ea_alloc_skeleton(ip, es->es_er, blks,
                                          ea_set_simple_alloc, es);
                if (error)
                        return error;
        }

        return 1;
}

static int ea_set_block(struct gfs2_inode *ip, struct gfs2_ea_request *er,
                        void *private)
{
        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
        struct buffer_head *indbh, *newbh;
        __be64 *eablk;
        int error;
        int mh_size = sizeof(struct gfs2_meta_header);

        if (ip->i_di.di_flags & GFS2_DIF_EA_INDIRECT) {
                __be64 *end;

                error = gfs2_meta_read(ip->i_gl, ip->i_di.di_eattr, DIO_WAIT,
                                       &indbh);
                if (error)
                        return error;

                if (gfs2_metatype_check(sdp, indbh, GFS2_METATYPE_IN)) {
                        error = -EIO;
                        goto out;
                }

                eablk = (__be64 *)(indbh->b_data + mh_size);
                end = eablk + sdp->sd_inptrs;

                for (; eablk < end; eablk++)
                        if (!*eablk)
                                break;

                if (eablk == end) {
                        error = -ENOSPC;
                        goto out;
                }

                gfs2_trans_add_bh(ip->i_gl, indbh, 1);
        } else {
                u64 blk;
                unsigned int n = 1;
                blk = gfs2_alloc_block(ip, &n);
                gfs2_trans_add_unrevoke(sdp, blk, 1);
                indbh = gfs2_meta_new(ip->i_gl, blk);
                gfs2_trans_add_bh(ip->i_gl, indbh, 1);
                gfs2_metatype_set(indbh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
                gfs2_buffer_clear_tail(indbh, mh_size);

                eablk = (__be64 *)(indbh->b_data + mh_size);
                *eablk = cpu_to_be64(ip->i_di.di_eattr);
                ip->i_di.di_eattr = blk;
                ip->i_di.di_flags |= GFS2_DIF_EA_INDIRECT;
                gfs2_add_inode_blocks(&ip->i_inode, 1);

                eablk++;
        }

        error = ea_alloc_blk(ip, &newbh);
        if (error)
                goto out;

        *eablk = cpu_to_be64((u64)newbh->b_blocknr);
        error = ea_write(ip, GFS2_EA_BH2FIRST(newbh), er);
        brelse(newbh);
        if (error)
                goto out;

        if (private)
                ea_set_remove_stuffed(ip, private);

out:
        brelse(indbh);
        return error;
}

static int ea_set_i(struct gfs2_inode *ip, struct gfs2_ea_request *er,
                    struct gfs2_ea_location *el)
{
        struct ea_set es;
        unsigned int blks = 2;
        int error;

        memset(&es, 0, sizeof(struct ea_set));
        es.es_er = er;
        es.es_el = el;

        error = ea_foreach(ip, ea_set_simple, &es);
        if (error > 0)
                return 0;
        if (error)
                return error;

        if (!(ip->i_di.di_flags & GFS2_DIF_EA_INDIRECT))
                blks++;
        if (GFS2_EAREQ_SIZE_STUFFED(er) > GFS2_SB(&ip->i_inode)->sd_jbsize)
                blks += DIV_ROUND_UP(er->er_data_len, GFS2_SB(&ip->i_inode)->sd_jbsize);

        return ea_alloc_skeleton(ip, er, blks, ea_set_block, el);
}

static int ea_set_remove_unstuffed(struct gfs2_inode *ip,
                                   struct gfs2_ea_location *el)
{
        if (el->el_prev && GFS2_EA2NEXT(el->el_prev) != el->el_ea) {
                el->el_prev = GFS2_EA2NEXT(el->el_prev);
                gfs2_assert_withdraw(GFS2_SB(&ip->i_inode),
                                     GFS2_EA2NEXT(el->el_prev) == el->el_ea);
        }

        return ea_remove_unstuffed(ip, el->el_bh, el->el_ea, el->el_prev,0);
}

int gfs2_ea_set_i(struct gfs2_inode *ip, struct gfs2_ea_request *er)
{
        struct gfs2_ea_location el;
        int error;

        if (!ip->i_di.di_eattr) {
                if (er->er_flags & XATTR_REPLACE)
                        return -ENODATA;
                return ea_init(ip, er);
        }

        error = gfs2_ea_find(ip, er, &el);
        if (error)
                return error;

        if (el.el_ea) {
                if (ip->i_di.di_flags & GFS2_DIF_APPENDONLY) {
                        brelse(el.el_bh);
                        return -EPERM;
                }

                error = -EEXIST;
                if (!(er->er_flags & XATTR_CREATE)) {
                        int unstuffed = !GFS2_EA_IS_STUFFED(el.el_ea);
                        error = ea_set_i(ip, er, &el);
                        if (!error && unstuffed)
                                ea_set_remove_unstuffed(ip, &el);
                }

                brelse(el.el_bh);
        } else {
                error = -ENODATA;
                if (!(er->er_flags & XATTR_REPLACE))
                        error = ea_set_i(ip, er, NULL);
        }

        return error;
}

int gfs2_ea_set(struct gfs2_inode *ip, struct gfs2_ea_request *er)
{
        struct gfs2_holder i_gh;
        int error;

        if (!er->er_name_len || er->er_name_len > GFS2_EA_MAX_NAME_LEN)
                return -EINVAL;
        if (!er->er_data || !er->er_data_len) {
                er->er_data = NULL;
                er->er_data_len = 0;
        }
        error = ea_check_size(GFS2_SB(&ip->i_inode), er);
        if (error)
                return error;

        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
        if (error)
                return error;

        if (IS_IMMUTABLE(&ip->i_inode))
                error = -EPERM;
        else
                error = gfs2_ea_ops[er->er_type]->eo_set(ip, er);

        gfs2_glock_dq_uninit(&i_gh);

        return error;
}

static int ea_remove_stuffed(struct gfs2_inode *ip, struct gfs2_ea_location *el)
{
        struct gfs2_ea_header *ea = el->el_ea;
        struct gfs2_ea_header *prev = el->el_prev;
        struct buffer_head *dibh;
        int error;

        error = gfs2_trans_begin(GFS2_SB(&ip->i_inode), RES_DINODE + RES_EATTR, 0);
        if (error)
                return error;

        gfs2_trans_add_bh(ip->i_gl, el->el_bh, 1);

        if (prev) {
                u32 len;

                len = GFS2_EA_REC_LEN(prev) + GFS2_EA_REC_LEN(ea);
                prev->ea_rec_len = cpu_to_be32(len);

                if (GFS2_EA_IS_LAST(ea))
                        prev->ea_flags |= GFS2_EAFLAG_LAST;
        } else
                ea->ea_type = GFS2_EATYPE_UNUSED;

        error = gfs2_meta_inode_buffer(ip, &dibh);
        if (!error) {
                ip->i_inode.i_ctime = CURRENT_TIME;
                gfs2_trans_add_bh(ip->i_gl, dibh, 1);
                gfs2_dinode_out(ip, dibh->b_data);
                brelse(dibh);
        }

        gfs2_trans_end(GFS2_SB(&ip->i_inode));

        return error;
}

int gfs2_ea_remove_i(struct gfs2_inode *ip, struct gfs2_ea_request *er)
{
        struct gfs2_ea_location el;
        int error;

        if (!ip->i_di.di_eattr)
                return -ENODATA;

        error = gfs2_ea_find(ip, er, &el);
        if (error)
                return error;
        if (!el.el_ea)
                return -ENODATA;

        if (GFS2_EA_IS_STUFFED(el.el_ea))
                error = ea_remove_stuffed(ip, &el);
        else
                error = ea_remove_unstuffed(ip, el.el_bh, el.el_ea, el.el_prev,
                                            0);

        brelse(el.el_bh);

        return error;
}

/**
 * gfs2_ea_remove - sets (or creates or replaces) an extended attribute
 * @ip: pointer to the inode of the target file
 * @er: request information
 *
 * Returns: errno
 */

int gfs2_ea_remove(struct gfs2_inode *ip, struct gfs2_ea_request *er)
{
        struct gfs2_holder i_gh;
        int error;

        if (!er->er_name_len || er->er_name_len > GFS2_EA_MAX_NAME_LEN)
                return -EINVAL;

        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
        if (error)
                return error;

        if (IS_IMMUTABLE(&ip->i_inode) || IS_APPEND(&ip->i_inode))
                error = -EPERM;
        else
                error = gfs2_ea_ops[er->er_type]->eo_remove(ip, er);

        gfs2_glock_dq_uninit(&i_gh);

        return error;
}

static int ea_acl_chmod_unstuffed(struct gfs2_inode *ip,
                                  struct gfs2_ea_header *ea, char *data)
{
        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
        struct buffer_head **bh;
        unsigned int amount = GFS2_EA_DATA_LEN(ea);
        unsigned int nptrs = DIV_ROUND_UP(amount, sdp->sd_jbsize);
        __be64 *dataptrs = GFS2_EA2DATAPTRS(ea);
        unsigned int x;
        int error;

        bh = kcalloc(nptrs, sizeof(struct buffer_head *), GFP_NOFS);
        if (!bh)
                return -ENOMEM;

        error = gfs2_trans_begin(sdp, nptrs + RES_DINODE, 0);
        if (error)
                goto out;

        for (x = 0; x < nptrs; x++) {
                error = gfs2_meta_read(ip->i_gl, be64_to_cpu(*dataptrs), 0,
                                       bh + x);
                if (error) {
                        while (x--)
                                brelse(bh[x]);
                        goto fail;
                }
                dataptrs++;
        }

        for (x = 0; x < nptrs; x++) {
                error = gfs2_meta_wait(sdp, bh[x]);
                if (error) {
                        for (; x < nptrs; x++)
                                brelse(bh[x]);
                        goto fail;
                }
                if (gfs2_metatype_check(sdp, bh[x], GFS2_METATYPE_ED)) {
                        for (; x < nptrs; x++)
                                brelse(bh[x]);
                        error = -EIO;
                        goto fail;
                }

                gfs2_trans_add_bh(ip->i_gl, bh[x], 1);

                memcpy(bh[x]->b_data + sizeof(struct gfs2_meta_header), data,
                       (sdp->sd_jbsize > amount) ? amount : sdp->sd_jbsize);

                amount -= sdp->sd_jbsize;
                data += sdp->sd_jbsize;

                brelse(bh[x]);
        }

out:
        kfree(bh);
        return error;

fail:
        gfs2_trans_end(sdp);
        kfree(bh);
        return error;
}

int gfs2_ea_acl_chmod(struct gfs2_inode *ip, struct gfs2_ea_location *el,
                      struct iattr *attr, char *data)
{
        struct buffer_head *dibh;
        int error;

        if (GFS2_EA_IS_STUFFED(el->el_ea)) {
                error = gfs2_trans_begin(GFS2_SB(&ip->i_inode), RES_DINODE + RES_EATTR, 0);
                if (error)
                        return error;

                gfs2_trans_add_bh(ip->i_gl, el->el_bh, 1);
                memcpy(GFS2_EA2DATA(el->el_ea), data,
                       GFS2_EA_DATA_LEN(el->el_ea));
        } else
                error = ea_acl_chmod_unstuffed(ip, el->el_ea, data);

        if (error)
                return error;

        error = gfs2_meta_inode_buffer(ip, &dibh);
        if (!error) {
                error = inode_setattr(&ip->i_inode, attr);
                gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
                gfs2_trans_add_bh(ip->i_gl, dibh, 1);
                gfs2_dinode_out(ip, dibh->b_data);
                brelse(dibh);
        }

        gfs2_trans_end(GFS2_SB(&ip->i_inode));

        return error;
}

static int ea_dealloc_indirect(struct gfs2_inode *ip)
{
        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
        struct gfs2_rgrp_list rlist;
        struct buffer_head *indbh, *dibh;
        __be64 *eablk, *end;
        unsigned int rg_blocks = 0;
        u64 bstart = 0;
        unsigned int blen = 0;
        unsigned int blks = 0;
        unsigned int x;
        int error;

        memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));

        error = gfs2_meta_read(ip->i_gl, ip->i_di.di_eattr, DIO_WAIT, &indbh);
        if (error)
                return error;

        if (gfs2_metatype_check(sdp, indbh, GFS2_METATYPE_IN)) {
                error = -EIO;
                goto out;
        }

        eablk = (__be64 *)(indbh->b_data + sizeof(struct gfs2_meta_header));
        end = eablk + sdp->sd_inptrs;

        for (; eablk < end; eablk++) {
                u64 bn;

                if (!*eablk)
                        break;
                bn = be64_to_cpu(*eablk);

                if (bstart + blen == bn)
                        blen++;
                else {
                        if (bstart)
                                gfs2_rlist_add(sdp, &rlist, bstart);
                        bstart = bn;
                        blen = 1;
                }
                blks++;
        }
        if (bstart)
                gfs2_rlist_add(sdp, &rlist, bstart);
        else
                goto out;

        gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE);

        for (x = 0; x < rlist.rl_rgrps; x++) {
                struct gfs2_rgrpd *rgd;
                rgd = rlist.rl_ghs[x].gh_gl->gl_object;
                rg_blocks += rgd->rd_length;
        }

        error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
        if (error)
                goto out_rlist_free;

        error = gfs2_trans_begin(sdp, rg_blocks + RES_DINODE + RES_INDIRECT +
                                 RES_STATFS + RES_QUOTA, blks);
        if (error)
                goto out_gunlock;

        gfs2_trans_add_bh(ip->i_gl, indbh, 1);

        eablk = (__be64 *)(indbh->b_data + sizeof(struct gfs2_meta_header));
        bstart = 0;
        blen = 0;

        for (; eablk < end; eablk++) {
                u64 bn;

                if (!*eablk)
                        break;
                bn = be64_to_cpu(*eablk);

                if (bstart + blen == bn)
                        blen++;
                else {
                        if (bstart)
                                gfs2_free_meta(ip, bstart, blen);
                        bstart = bn;
                        blen = 1;
                }

                *eablk = 0;
                gfs2_add_inode_blocks(&ip->i_inode, -1);
        }
        if (bstart)
                gfs2_free_meta(ip, bstart, blen);

        ip->i_di.di_flags &= ~GFS2_DIF_EA_INDIRECT;

        error = gfs2_meta_inode_buffer(ip, &dibh);
        if (!error) {
                gfs2_trans_add_bh(ip->i_gl, dibh, 1);
                gfs2_dinode_out(ip, dibh->b_data);
                brelse(dibh);
        }

        gfs2_trans_end(sdp);

out_gunlock:
        gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
out_rlist_free:
        gfs2_rlist_free(&rlist);
out:
        brelse(indbh);
        return error;
}

static int ea_dealloc_block(struct gfs2_inode *ip)
{
        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
        struct gfs2_alloc *al = ip->i_alloc;
        struct gfs2_rgrpd *rgd;
        struct buffer_head *dibh;
        int error;

        rgd = gfs2_blk2rgrpd(sdp, ip->i_di.di_eattr);
        if (!rgd) {
                gfs2_consist_inode(ip);
                return -EIO;
        }

        error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0,
                                   &al->al_rgd_gh);
        if (error)
                return error;

        error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_DINODE + RES_STATFS +
                                 RES_QUOTA, 1);
        if (error)
                goto out_gunlock;

        gfs2_free_meta(ip, ip->i_di.di_eattr, 1);

        ip->i_di.di_eattr = 0;
        gfs2_add_inode_blocks(&ip->i_inode, -1);

        error = gfs2_meta_inode_buffer(ip, &dibh);
        if (!error) {
                gfs2_trans_add_bh(ip->i_gl, dibh, 1);
                gfs2_dinode_out(ip, dibh->b_data);
                brelse(dibh);
        }

        gfs2_trans_end(sdp);

out_gunlock:
        gfs2_glock_dq_uninit(&al->al_rgd_gh);
        return error;
}

/**
 * gfs2_ea_dealloc - deallocate the extended attribute fork
 * @ip: the inode
 *
 * Returns: errno
 */

int gfs2_ea_dealloc(struct gfs2_inode *ip)
{
        struct gfs2_alloc *al;
        int error;

        al = gfs2_alloc_get(ip);
        if (!al)
                return -ENOMEM;

        error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
        if (error)
                goto out_alloc;

        error = gfs2_rindex_hold(GFS2_SB(&ip->i_inode), &al->al_ri_gh);
        if (error)
                goto out_quota;

        error = ea_foreach(ip, ea_dealloc_unstuffed, NULL);
        if (error)
                goto out_rindex;

        if (ip->i_di.di_flags & GFS2_DIF_EA_INDIRECT) {
                error = ea_dealloc_indirect(ip);
                if (error)
                        goto out_rindex;
        }

        error = ea_dealloc_block(ip);

out_rindex:
        gfs2_glock_dq_uninit(&al->al_ri_gh);
out_quota:
        gfs2_quota_unhold(ip);
out_alloc:
        gfs2_alloc_put(ip);
        return error;
}


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