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inode.c

/*
 * 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/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/posix_acl.h>
#include <linux/sort.h>
#include <linux/gfs2_ondisk.h>
#include <linux/crc32.h>
#include <linux/lm_interface.h>
#include <linux/security.h>

#include "gfs2.h"
#include "incore.h"
#include "acl.h"
#include "bmap.h"
#include "dir.h"
#include "eattr.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "log.h"
#include "meta_io.h"
#include "ops_address.h"
#include "ops_file.h"
#include "ops_inode.h"
#include "quota.h"
#include "rgrp.h"
#include "trans.h"
#include "util.h"

struct gfs2_inum_range_host {
      u64 ir_start;
      u64 ir_length;
};

static int iget_test(struct inode *inode, void *opaque)
{
      struct gfs2_inode *ip = GFS2_I(inode);
      u64 *no_addr = opaque;

      if (ip->i_no_addr == *no_addr &&
          inode->i_private != NULL)
            return 1;

      return 0;
}

static int iget_set(struct inode *inode, void *opaque)
{
      struct gfs2_inode *ip = GFS2_I(inode);
      u64 *no_addr = opaque;

      inode->i_ino = (unsigned long)*no_addr;
      ip->i_no_addr = *no_addr;
      return 0;
}

struct inode *gfs2_ilookup(struct super_block *sb, u64 no_addr)
{
      unsigned long hash = (unsigned long)no_addr;
      return ilookup5(sb, hash, iget_test, &no_addr);
}

static struct inode *gfs2_iget(struct super_block *sb, u64 no_addr)
{
      unsigned long hash = (unsigned long)no_addr;
      return iget5_locked(sb, hash, iget_test, iget_set, &no_addr);
}

struct gfs2_skip_data {
      u64   no_addr;
      int   skipped;
};

static int iget_skip_test(struct inode *inode, void *opaque)
{
      struct gfs2_inode *ip = GFS2_I(inode);
      struct gfs2_skip_data *data = opaque;

      if (ip->i_no_addr == data->no_addr && inode->i_private != NULL){
            if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)){
                  data->skipped = 1;
                  return 0;
            }
            return 1;
      }
      return 0;
}

static int iget_skip_set(struct inode *inode, void *opaque)
{
      struct gfs2_inode *ip = GFS2_I(inode);
      struct gfs2_skip_data *data = opaque;

      if (data->skipped)
            return 1;
      inode->i_ino = (unsigned long)(data->no_addr);
      ip->i_no_addr = data->no_addr;
      return 0;
}

static struct inode *gfs2_iget_skip(struct super_block *sb,
                            u64 no_addr)
{
      struct gfs2_skip_data data;
      unsigned long hash = (unsigned long)no_addr;

      data.no_addr = no_addr;
      data.skipped = 0;
      return iget5_locked(sb, hash, iget_skip_test, iget_skip_set, &data);
}

/**
 * GFS2 lookup code fills in vfs inode contents based on info obtained
 * from directory entry inside gfs2_inode_lookup(). This has caused issues
 * with NFS code path since its get_dentry routine doesn't have the relevant
 * directory entry when gfs2_inode_lookup() is invoked. Part of the code
 * segment inside gfs2_inode_lookup code needs to get moved around.
 *
 * Clean up I_LOCK and I_NEW as well.
 **/

void gfs2_set_iop(struct inode *inode)
{
      umode_t mode = inode->i_mode;

      if (S_ISREG(mode)) {
            inode->i_op = &gfs2_file_iops;
            inode->i_fop = &gfs2_file_fops;
            inode->i_mapping->a_ops = &gfs2_file_aops;
      } else if (S_ISDIR(mode)) {
            inode->i_op = &gfs2_dir_iops;
            inode->i_fop = &gfs2_dir_fops;
      } else if (S_ISLNK(mode)) {
            inode->i_op = &gfs2_symlink_iops;
      } else {
            inode->i_op = &gfs2_dev_iops;
      }

      unlock_new_inode(inode);
}

/**
 * gfs2_inode_lookup - Lookup an inode
 * @sb: The super block
 * @no_addr: The inode number
 * @type: The type of the inode
 * @skip_freeing: set this not return an inode if it is currently being freed.
 *
 * Returns: A VFS inode, or an error
 */

struct inode *gfs2_inode_lookup(struct super_block *sb, 
                        unsigned int type,
                        u64 no_addr,
                        u64 no_formal_ino, int skip_freeing)
{
      struct inode *inode;
      struct gfs2_inode *ip;
      struct gfs2_glock *io_gl;
      int error;

      if (skip_freeing)
            inode = gfs2_iget_skip(sb, no_addr);
      else
            inode = gfs2_iget(sb, no_addr);
      ip = GFS2_I(inode);

      if (!inode)
            return ERR_PTR(-ENOBUFS);

      if (inode->i_state & I_NEW) {
            struct gfs2_sbd *sdp = GFS2_SB(inode);
            inode->i_private = ip;
            ip->i_no_formal_ino = no_formal_ino;

            error = gfs2_glock_get(sdp, no_addr, &gfs2_inode_glops, CREATE, &ip->i_gl);
            if (unlikely(error))
                  goto fail;
            ip->i_gl->gl_object = ip;

            error = gfs2_glock_get(sdp, no_addr, &gfs2_iopen_glops, CREATE, &io_gl);
            if (unlikely(error))
                  goto fail_put;

            set_bit(GIF_INVALID, &ip->i_flags);
            error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);
            if (unlikely(error))
                  goto fail_iopen;
            ip->i_iopen_gh.gh_gl->gl_object = ip;

            gfs2_glock_put(io_gl);

            if ((type == DT_UNKNOWN) && (no_formal_ino == 0))
                  goto gfs2_nfsbypass;

            inode->i_mode = DT2IF(type);

            /*
             * We must read the inode in order to work out its type in
             * this case. Note that this doesn't happen often as we normally
             * know the type beforehand. This code path only occurs during
             * unlinked inode recovery (where it is safe to do this glock,
             * which is not true in the general case).
             */
            if (type == DT_UNKNOWN) {
                  struct gfs2_holder gh;
                  error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
                  if (unlikely(error))
                        goto fail_glock;
                  /* Inode is now uptodate */
                  gfs2_glock_dq_uninit(&gh);
            }

            gfs2_set_iop(inode);
      }

gfs2_nfsbypass:
      return inode;
fail_glock:
      gfs2_glock_dq(&ip->i_iopen_gh);
fail_iopen:
      gfs2_glock_put(io_gl);
fail_put:
      ip->i_gl->gl_object = NULL;
      gfs2_glock_put(ip->i_gl);
fail:
      iput(inode);
      return ERR_PTR(error);
}

static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
{
      struct gfs2_dinode_host *di = &ip->i_di;
      const struct gfs2_dinode *str = buf;

      if (ip->i_no_addr != be64_to_cpu(str->di_num.no_addr)) {
            if (gfs2_consist_inode(ip))
                  gfs2_dinode_print(ip);
            return -EIO;
      }
      ip->i_no_formal_ino = be64_to_cpu(str->di_num.no_formal_ino);
      ip->i_inode.i_mode = be32_to_cpu(str->di_mode);
      ip->i_inode.i_rdev = 0;
      switch (ip->i_inode.i_mode & S_IFMT) {
      case S_IFBLK:
      case S_IFCHR:
            ip->i_inode.i_rdev = MKDEV(be32_to_cpu(str->di_major),
                                 be32_to_cpu(str->di_minor));
            break;
      };

      ip->i_inode.i_uid = be32_to_cpu(str->di_uid);
      ip->i_inode.i_gid = be32_to_cpu(str->di_gid);
      /*
       * We will need to review setting the nlink count here in the
       * light of the forthcoming ro bind mount work. This is a reminder
       * to do that.
       */
      ip->i_inode.i_nlink = be32_to_cpu(str->di_nlink);
      di->di_size = be64_to_cpu(str->di_size);
      i_size_write(&ip->i_inode, di->di_size);
      di->di_blocks = be64_to_cpu(str->di_blocks);
      gfs2_set_inode_blocks(&ip->i_inode);
      ip->i_inode.i_atime.tv_sec = be64_to_cpu(str->di_atime);
      ip->i_inode.i_atime.tv_nsec = be32_to_cpu(str->di_atime_nsec);
      ip->i_inode.i_mtime.tv_sec = be64_to_cpu(str->di_mtime);
      ip->i_inode.i_mtime.tv_nsec = be32_to_cpu(str->di_mtime_nsec);
      ip->i_inode.i_ctime.tv_sec = be64_to_cpu(str->di_ctime);
      ip->i_inode.i_ctime.tv_nsec = be32_to_cpu(str->di_ctime_nsec);

      di->di_goal_meta = be64_to_cpu(str->di_goal_meta);
      di->di_goal_data = be64_to_cpu(str->di_goal_data);
      di->di_generation = be64_to_cpu(str->di_generation);

      di->di_flags = be32_to_cpu(str->di_flags);
      gfs2_set_inode_flags(&ip->i_inode);
      di->di_height = be16_to_cpu(str->di_height);

      di->di_depth = be16_to_cpu(str->di_depth);
      di->di_entries = be32_to_cpu(str->di_entries);

      di->di_eattr = be64_to_cpu(str->di_eattr);
      return 0;
}

static void gfs2_inode_bh(struct gfs2_inode *ip, struct buffer_head *bh)
{
      ip->i_cache[0] = bh;
}

/**
 * gfs2_inode_refresh - Refresh the incore copy of the dinode
 * @ip: The GFS2 inode
 *
 * Returns: errno
 */

int gfs2_inode_refresh(struct gfs2_inode *ip)
{
      struct buffer_head *dibh;
      int error;

      error = gfs2_meta_inode_buffer(ip, &dibh);
      if (error)
            return error;

      if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), dibh, GFS2_METATYPE_DI)) {
            brelse(dibh);
            return -EIO;
      }

      error = gfs2_dinode_in(ip, dibh->b_data);
      brelse(dibh);
      clear_bit(GIF_INVALID, &ip->i_flags);

      return error;
}

int gfs2_dinode_dealloc(struct gfs2_inode *ip)
{
      struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
      struct gfs2_alloc *al;
      struct gfs2_rgrpd *rgd;
      int error;

      if (ip->i_di.di_blocks != 1) {
            if (gfs2_consist_inode(ip))
                  gfs2_dinode_print(ip);
            return -EIO;
      }

      al = gfs2_alloc_get(ip);

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

      error = gfs2_rindex_hold(sdp, &al->al_ri_gh);
      if (error)
            goto out_qs;

      rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr);
      if (!rgd) {
            gfs2_consist_inode(ip);
            error = -EIO;
            goto out_rindex_relse;
      }

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

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

      gfs2_trans_add_gl(ip->i_gl);

      gfs2_free_di(rgd, ip);

      gfs2_trans_end(sdp);
      clear_bit(GLF_STICKY, &ip->i_gl->gl_flags);

out_rg_gunlock:
      gfs2_glock_dq_uninit(&al->al_rgd_gh);
out_rindex_relse:
      gfs2_glock_dq_uninit(&al->al_ri_gh);
out_qs:
      gfs2_quota_unhold(ip);
out:
      gfs2_alloc_put(ip);
      return error;
}

/**
 * gfs2_change_nlink - Change nlink count on inode
 * @ip: The GFS2 inode
 * @diff: The change in the nlink count required
 *
 * Returns: errno
 */
int gfs2_change_nlink(struct gfs2_inode *ip, int diff)
{
      struct buffer_head *dibh;
      u32 nlink;
      int error;

      BUG_ON(diff != 1 && diff != -1);
      nlink = ip->i_inode.i_nlink + diff;

      /* If we are reducing the nlink count, but the new value ends up being
         bigger than the old one, we must have underflowed. */
      if (diff < 0 && nlink > ip->i_inode.i_nlink) {
            if (gfs2_consist_inode(ip))
                  gfs2_dinode_print(ip);
            return -EIO;
      }

      error = gfs2_meta_inode_buffer(ip, &dibh);
      if (error)
            return error;

      if (diff > 0)
            inc_nlink(&ip->i_inode);
      else
            drop_nlink(&ip->i_inode);

      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);
      mark_inode_dirty(&ip->i_inode);

      if (ip->i_inode.i_nlink == 0)
            gfs2_unlink_di(&ip->i_inode); /* mark inode unlinked */

      return error;
}

struct inode *gfs2_lookup_simple(struct inode *dip, const char *name)
{
      struct qstr qstr;
      struct inode *inode;
      gfs2_str2qstr(&qstr, name);
      inode = gfs2_lookupi(dip, &qstr, 1, NULL);
      /* gfs2_lookupi has inconsistent callers: vfs
       * related routines expect NULL for no entry found,
       * gfs2_lookup_simple callers expect ENOENT
       * and do not check for NULL.
       */
      if (inode == NULL)
            return ERR_PTR(-ENOENT);
      else
            return inode;
}


/**
 * gfs2_lookupi - Look up a filename in a directory and return its inode
 * @d_gh: An initialized holder for the directory glock
 * @name: The name of the inode to look for
 * @is_root: If 1, ignore the caller's permissions
 * @i_gh: An uninitialized holder for the new inode glock
 *
 * This can be called via the VFS filldir function when NFS is doing
 * a readdirplus and the inode which its intending to stat isn't
 * already in cache. In this case we must not take the directory glock
 * again, since the readdir call will have already taken that lock.
 *
 * Returns: errno
 */

struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,
                     int is_root, struct nameidata *nd)
{
      struct super_block *sb = dir->i_sb;
      struct gfs2_inode *dip = GFS2_I(dir);
      struct gfs2_holder d_gh;
      int error = 0;
      struct inode *inode = NULL;
      int unlock = 0;

      if (!name->len || name->len > GFS2_FNAMESIZE)
            return ERR_PTR(-ENAMETOOLONG);

      if ((name->len == 1 && memcmp(name->name, ".", 1) == 0) ||
          (name->len == 2 && memcmp(name->name, "..", 2) == 0 &&
           dir == sb->s_root->d_inode)) {
            igrab(dir);
            return dir;
      }

      if (gfs2_glock_is_locked_by_me(dip->i_gl) == 0) {
            error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
            if (error)
                  return ERR_PTR(error);
            unlock = 1;
      }

      if (!is_root) {
            error = permission(dir, MAY_EXEC, NULL);
            if (error)
                  goto out;
      }

      inode = gfs2_dir_search(dir, name);
      if (IS_ERR(inode))
            error = PTR_ERR(inode);
out:
      if (unlock)
            gfs2_glock_dq_uninit(&d_gh);
      if (error == -ENOENT)
            return NULL;
      return inode ? inode : ERR_PTR(error);
}

static void gfs2_inum_range_in(struct gfs2_inum_range_host *ir, const void *buf)
{
      const struct gfs2_inum_range *str = buf;

      ir->ir_start = be64_to_cpu(str->ir_start);
      ir->ir_length = be64_to_cpu(str->ir_length);
}

static void gfs2_inum_range_out(const struct gfs2_inum_range_host *ir, void *buf)
{
      struct gfs2_inum_range *str = buf;

      str->ir_start = cpu_to_be64(ir->ir_start);
      str->ir_length = cpu_to_be64(ir->ir_length);
}

static int pick_formal_ino_1(struct gfs2_sbd *sdp, u64 *formal_ino)
{
      struct gfs2_inode *ip = GFS2_I(sdp->sd_ir_inode);
      struct buffer_head *bh;
      struct gfs2_inum_range_host ir;
      int error;

      error = gfs2_trans_begin(sdp, RES_DINODE, 0);
      if (error)
            return error;
      mutex_lock(&sdp->sd_inum_mutex);

      error = gfs2_meta_inode_buffer(ip, &bh);
      if (error) {
            mutex_unlock(&sdp->sd_inum_mutex);
            gfs2_trans_end(sdp);
            return error;
      }

      gfs2_inum_range_in(&ir, bh->b_data + sizeof(struct gfs2_dinode));

      if (ir.ir_length) {
            *formal_ino = ir.ir_start++;
            ir.ir_length--;
            gfs2_trans_add_bh(ip->i_gl, bh, 1);
            gfs2_inum_range_out(&ir,
                            bh->b_data + sizeof(struct gfs2_dinode));
            brelse(bh);
            mutex_unlock(&sdp->sd_inum_mutex);
            gfs2_trans_end(sdp);
            return 0;
      }

      brelse(bh);

      mutex_unlock(&sdp->sd_inum_mutex);
      gfs2_trans_end(sdp);

      return 1;
}

static int pick_formal_ino_2(struct gfs2_sbd *sdp, u64 *formal_ino)
{
      struct gfs2_inode *ip = GFS2_I(sdp->sd_ir_inode);
      struct gfs2_inode *m_ip = GFS2_I(sdp->sd_inum_inode);
      struct gfs2_holder gh;
      struct buffer_head *bh;
      struct gfs2_inum_range_host ir;
      int error;

      error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
      if (error)
            return error;

      error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
      if (error)
            goto out;
      mutex_lock(&sdp->sd_inum_mutex);

      error = gfs2_meta_inode_buffer(ip, &bh);
      if (error)
            goto out_end_trans;

      gfs2_inum_range_in(&ir, bh->b_data + sizeof(struct gfs2_dinode));

      if (!ir.ir_length) {
            struct buffer_head *m_bh;
            u64 x, y;
            __be64 z;

            error = gfs2_meta_inode_buffer(m_ip, &m_bh);
            if (error)
                  goto out_brelse;

            z = *(__be64 *)(m_bh->b_data + sizeof(struct gfs2_dinode));
            x = y = be64_to_cpu(z);
            ir.ir_start = x;
            ir.ir_length = GFS2_INUM_QUANTUM;
            x += GFS2_INUM_QUANTUM;
            if (x < y)
                  gfs2_consist_inode(m_ip);
            z = cpu_to_be64(x);
            gfs2_trans_add_bh(m_ip->i_gl, m_bh, 1);
            *(__be64 *)(m_bh->b_data + sizeof(struct gfs2_dinode)) = z;

            brelse(m_bh);
      }

      *formal_ino = ir.ir_start++;
      ir.ir_length--;

      gfs2_trans_add_bh(ip->i_gl, bh, 1);
      gfs2_inum_range_out(&ir, bh->b_data + sizeof(struct gfs2_dinode));

out_brelse:
      brelse(bh);
out_end_trans:
      mutex_unlock(&sdp->sd_inum_mutex);
      gfs2_trans_end(sdp);
out:
      gfs2_glock_dq_uninit(&gh);
      return error;
}

static int pick_formal_ino(struct gfs2_sbd *sdp, u64 *inum)
{
      int error;

      error = pick_formal_ino_1(sdp, inum);
      if (error <= 0)
            return error;

      error = pick_formal_ino_2(sdp, inum);

      return error;
}

/**
 * create_ok - OK to create a new on-disk inode here?
 * @dip:  Directory in which dinode is to be created
 * @name:  Name of new dinode
 * @mode:
 *
 * Returns: errno
 */

static int create_ok(struct gfs2_inode *dip, const struct qstr *name,
                 unsigned int mode)
{
      int error;

      error = permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, NULL);
      if (error)
            return error;

      /*  Don't create entries in an unlinked directory  */
      if (!dip->i_inode.i_nlink)
            return -EPERM;

      error = gfs2_dir_check(&dip->i_inode, name, NULL);
      switch (error) {
      case -ENOENT:
            error = 0;
            break;
      case 0:
            return -EEXIST;
      default:
            return error;
      }

      if (dip->i_di.di_entries == (u32)-1)
            return -EFBIG;
      if (S_ISDIR(mode) && dip->i_inode.i_nlink == (u32)-1)
            return -EMLINK;

      return 0;
}

static void munge_mode_uid_gid(struct gfs2_inode *dip, unsigned int *mode,
                         unsigned int *uid, unsigned int *gid)
{
      if (GFS2_SB(&dip->i_inode)->sd_args.ar_suiddir &&
          (dip->i_inode.i_mode & S_ISUID) && dip->i_inode.i_uid) {
            if (S_ISDIR(*mode))
                  *mode |= S_ISUID;
            else if (dip->i_inode.i_uid != current->fsuid)
                  *mode &= ~07111;
            *uid = dip->i_inode.i_uid;
      } else
            *uid = current->fsuid;

      if (dip->i_inode.i_mode & S_ISGID) {
            if (S_ISDIR(*mode))
                  *mode |= S_ISGID;
            *gid = dip->i_inode.i_gid;
      } else
            *gid = current->fsgid;
}

static int alloc_dinode(struct gfs2_inode *dip, u64 *no_addr, u64 *generation)
{
      struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
      int error;

      gfs2_alloc_get(dip);

      dip->i_alloc.al_requested = RES_DINODE;
      error = gfs2_inplace_reserve(dip);
      if (error)
            goto out;

      error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS, 0);
      if (error)
            goto out_ipreserv;

      *no_addr = gfs2_alloc_di(dip, generation);

      gfs2_trans_end(sdp);

out_ipreserv:
      gfs2_inplace_release(dip);
out:
      gfs2_alloc_put(dip);
      return error;
}

/**
 * init_dinode - Fill in a new dinode structure
 * @dip: the directory this inode is being created in
 * @gl: The glock covering the new inode
 * @inum: the inode number
 * @mode: the file permissions
 * @uid:
 * @gid:
 *
 */

static void init_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,
                  const struct gfs2_inum_host *inum, unsigned int mode,
                  unsigned int uid, unsigned int gid,
                  const u64 *generation, dev_t dev, struct buffer_head **bhp)
{
      struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
      struct gfs2_dinode *di;
      struct buffer_head *dibh;
      struct timespec tv = CURRENT_TIME;

      dibh = gfs2_meta_new(gl, inum->no_addr);
      gfs2_trans_add_bh(gl, dibh, 1);
      gfs2_metatype_set(dibh, GFS2_METATYPE_DI, GFS2_FORMAT_DI);
      gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
      di = (struct gfs2_dinode *)dibh->b_data;

      di->di_num.no_formal_ino = cpu_to_be64(inum->no_formal_ino);
      di->di_num.no_addr = cpu_to_be64(inum->no_addr);
      di->di_mode = cpu_to_be32(mode);
      di->di_uid = cpu_to_be32(uid);
      di->di_gid = cpu_to_be32(gid);
      di->di_nlink = 0;
      di->di_size = 0;
      di->di_blocks = cpu_to_be64(1);
      di->di_atime = di->di_mtime = di->di_ctime = cpu_to_be64(tv.tv_sec);
      di->di_major = cpu_to_be32(MAJOR(dev));
      di->di_minor = cpu_to_be32(MINOR(dev));
      di->di_goal_meta = di->di_goal_data = cpu_to_be64(inum->no_addr);
      di->di_generation = cpu_to_be64(*generation);
      di->di_flags = 0;

      if (S_ISREG(mode)) {
            if ((dip->i_di.di_flags & GFS2_DIF_INHERIT_JDATA) ||
                gfs2_tune_get(sdp, gt_new_files_jdata))
                  di->di_flags |= cpu_to_be32(GFS2_DIF_JDATA);
            if ((dip->i_di.di_flags & GFS2_DIF_INHERIT_DIRECTIO) ||
                gfs2_tune_get(sdp, gt_new_files_directio))
                  di->di_flags |= cpu_to_be32(GFS2_DIF_DIRECTIO);
      } else if (S_ISDIR(mode)) {
            di->di_flags |= cpu_to_be32(dip->i_di.di_flags &
                                  GFS2_DIF_INHERIT_DIRECTIO);
            di->di_flags |= cpu_to_be32(dip->i_di.di_flags &
                                  GFS2_DIF_INHERIT_JDATA);
      }

      di->__pad1 = 0;
      di->di_payload_format = cpu_to_be32(S_ISDIR(mode) ? GFS2_FORMAT_DE : 0);
      di->di_height = 0;
      di->__pad2 = 0;
      di->__pad3 = 0;
      di->di_depth = 0;
      di->di_entries = 0;
      memset(&di->__pad4, 0, sizeof(di->__pad4));
      di->di_eattr = 0;
      di->di_atime_nsec = cpu_to_be32(tv.tv_nsec);
      di->di_mtime_nsec = cpu_to_be32(tv.tv_nsec);
      di->di_ctime_nsec = cpu_to_be32(tv.tv_nsec);
      memset(&di->di_reserved, 0, sizeof(di->di_reserved));
      
      set_buffer_uptodate(dibh);

      *bhp = dibh;
}

static int make_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,
                   unsigned int mode, const struct gfs2_inum_host *inum,
                   const u64 *generation, dev_t dev, struct buffer_head **bhp)
{
      struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
      unsigned int uid, gid;
      int error;

      munge_mode_uid_gid(dip, &mode, &uid, &gid);
      gfs2_alloc_get(dip);

      error = gfs2_quota_lock(dip, uid, gid);
      if (error)
            goto out;

      error = gfs2_quota_check(dip, uid, gid);
      if (error)
            goto out_quota;

      error = gfs2_trans_begin(sdp, RES_DINODE + RES_QUOTA, 0);
      if (error)
            goto out_quota;

      init_dinode(dip, gl, inum, mode, uid, gid, generation, dev, bhp);
      gfs2_quota_change(dip, +1, uid, gid);
      gfs2_trans_end(sdp);

out_quota:
      gfs2_quota_unlock(dip);
out:
      gfs2_alloc_put(dip);
      return error;
}

static int link_dinode(struct gfs2_inode *dip, const struct qstr *name,
                   struct gfs2_inode *ip)
{
      struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
      struct gfs2_alloc *al;
      int alloc_required;
      struct buffer_head *dibh;
      int error;

      al = gfs2_alloc_get(dip);

      error = gfs2_quota_lock(dip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
      if (error)
            goto fail;

      error = alloc_required = gfs2_diradd_alloc_required(&dip->i_inode, name);
      if (alloc_required < 0)
            goto fail;
      if (alloc_required) {
            error = gfs2_quota_check(dip, dip->i_inode.i_uid, dip->i_inode.i_gid);
            if (error)
                  goto fail_quota_locks;

            al->al_requested = sdp->sd_max_dirres;

            error = gfs2_inplace_reserve(dip);
            if (error)
                  goto fail_quota_locks;

            error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +
                               al->al_rgd->rd_length +
                               2 * RES_DINODE +
                               RES_STATFS + RES_QUOTA, 0);
            if (error)
                  goto fail_ipreserv;
      } else {
            error = gfs2_trans_begin(sdp, RES_LEAF + 2 * RES_DINODE, 0);
            if (error)
                  goto fail_quota_locks;
      }

      error = gfs2_dir_add(&dip->i_inode, name, ip, IF2DT(ip->i_inode.i_mode));
      if (error)
            goto fail_end_trans;

      error = gfs2_meta_inode_buffer(ip, &dibh);
      if (error)
            goto fail_end_trans;
      ip->i_inode.i_nlink = 1;
      gfs2_trans_add_bh(ip->i_gl, dibh, 1);
      gfs2_dinode_out(ip, dibh->b_data);
      brelse(dibh);
      return 0;

fail_end_trans:
      gfs2_trans_end(sdp);

fail_ipreserv:
      if (dip->i_alloc.al_rgd)
            gfs2_inplace_release(dip);

fail_quota_locks:
      gfs2_quota_unlock(dip);

fail:
      gfs2_alloc_put(dip);
      return error;
}

static int gfs2_security_init(struct gfs2_inode *dip, struct gfs2_inode *ip)
{
      int err;
      size_t len;
      void *value;
      char *name;
      struct gfs2_ea_request er;

      err = security_inode_init_security(&ip->i_inode, &dip->i_inode,
                                 &name, &value, &len);

      if (err) {
            if (err == -EOPNOTSUPP)
                  return 0;
            return err;
      }

      memset(&er, 0, sizeof(struct gfs2_ea_request));

      er.er_type = GFS2_EATYPE_SECURITY;
      er.er_name = name;
      er.er_data = value;
      er.er_name_len = strlen(name);
      er.er_data_len = len;

      err = gfs2_ea_set_i(ip, &er);

      kfree(value);
      kfree(name);

      return err;
}

/**
 * gfs2_createi - Create a new inode
 * @ghs: An array of two holders
 * @name: The name of the new file
 * @mode: the permissions on the new inode
 *
 * @ghs[0] is an initialized holder for the directory
 * @ghs[1] is the holder for the inode lock
 *
 * If the return value is not NULL, the glocks on both the directory and the new
 * file are held.  A transaction has been started and an inplace reservation
 * is held, as well.
 *
 * Returns: An inode
 */

struct inode *gfs2_createi(struct gfs2_holder *ghs, const struct qstr *name,
                     unsigned int mode, dev_t dev)
{
      struct inode *inode = NULL;
      struct gfs2_inode *dip = ghs->gh_gl->gl_object;
      struct inode *dir = &dip->i_inode;
      struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
      struct gfs2_inum_host inum = { .no_addr = 0, .no_formal_ino = 0 };
      int error;
      u64 generation;
      struct buffer_head *bh=NULL;

      if (!name->len || name->len > GFS2_FNAMESIZE)
            return ERR_PTR(-ENAMETOOLONG);

      gfs2_holder_reinit(LM_ST_EXCLUSIVE, 0, ghs);
      error = gfs2_glock_nq(ghs);
      if (error)
            goto fail;

      error = create_ok(dip, name, mode);
      if (error)
            goto fail_gunlock;

      error = pick_formal_ino(sdp, &inum.no_formal_ino);
      if (error)
            goto fail_gunlock;

      error = alloc_dinode(dip, &inum.no_addr, &generation);
      if (error)
            goto fail_gunlock;

      error = gfs2_glock_nq_num(sdp, inum.no_addr, &gfs2_inode_glops,
                          LM_ST_EXCLUSIVE, GL_SKIP, ghs + 1);
      if (error)
            goto fail_gunlock;

      error = make_dinode(dip, ghs[1].gh_gl, mode, &inum, &generation, dev, &bh);
      if (error)
            goto fail_gunlock2;

      inode = gfs2_inode_lookup(dir->i_sb, IF2DT(mode),
                              inum.no_addr,
                              inum.no_formal_ino, 0);
      if (IS_ERR(inode))
            goto fail_gunlock2;

      gfs2_inode_bh(GFS2_I(inode), bh);

      error = gfs2_inode_refresh(GFS2_I(inode));
      if (error)
            goto fail_gunlock2;

      error = gfs2_acl_create(dip, GFS2_I(inode));
      if (error)
            goto fail_gunlock2;

      error = gfs2_security_init(dip, GFS2_I(inode));
      if (error)
            goto fail_gunlock2;

      error = link_dinode(dip, name, GFS2_I(inode));
      if (error)
            goto fail_gunlock2;

      if (!inode)
            return ERR_PTR(-ENOMEM);
      return inode;

fail_gunlock2:
      gfs2_glock_dq_uninit(ghs + 1);
      if (inode)
            iput(inode);
fail_gunlock:
      gfs2_glock_dq(ghs);
fail:
      return ERR_PTR(error);
}

/**
 * gfs2_rmdiri - Remove a directory
 * @dip: The parent directory of the directory to be removed
 * @name: The name of the directory to be removed
 * @ip: The GFS2 inode of the directory to be removed
 *
 * Assumes Glocks on dip and ip are held
 *
 * Returns: errno
 */

int gfs2_rmdiri(struct gfs2_inode *dip, const struct qstr *name,
            struct gfs2_inode *ip)
{
      struct qstr dotname;
      int error;

      if (ip->i_di.di_entries != 2) {
            if (gfs2_consist_inode(ip))
                  gfs2_dinode_print(ip);
            return -EIO;
      }

      error = gfs2_dir_del(dip, name);
      if (error)
            return error;

      error = gfs2_change_nlink(dip, -1);
      if (error)
            return error;

      gfs2_str2qstr(&dotname, ".");
      error = gfs2_dir_del(ip, &dotname);
      if (error)
            return error;

      gfs2_str2qstr(&dotname, "..");
      error = gfs2_dir_del(ip, &dotname);
      if (error)
            return error;

      /* It looks odd, but it really should be done twice */
      error = gfs2_change_nlink(ip, -1);
      if (error)
            return error;

      error = gfs2_change_nlink(ip, -1);
      if (error)
            return error;

      return error;
}

/*
 * gfs2_unlink_ok - check to see that a inode is still in a directory
 * @dip: the directory
 * @name: the name of the file
 * @ip: the inode
 *
 * Assumes that the lock on (at least) @dip is held.
 *
 * Returns: 0 if the parent/child relationship is correct, errno if it isn't
 */

int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name,
               const struct gfs2_inode *ip)
{
      int error;

      if (IS_IMMUTABLE(&ip->i_inode) || IS_APPEND(&ip->i_inode))
            return -EPERM;

      if ((dip->i_inode.i_mode & S_ISVTX) &&
          dip->i_inode.i_uid != current->fsuid &&
          ip->i_inode.i_uid != current->fsuid && !capable(CAP_FOWNER))
            return -EPERM;

      if (IS_APPEND(&dip->i_inode))
            return -EPERM;

      error = permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, NULL);
      if (error)
            return error;

      error = gfs2_dir_check(&dip->i_inode, name, ip);
      if (error)
            return error;

      return 0;
}

/*
 * gfs2_ok_to_move - check if it's ok to move a directory to another directory
 * @this: move this
 * @to: to here
 *
 * Follow @to back to the root and make sure we don't encounter @this
 * Assumes we already hold the rename lock.
 *
 * Returns: errno
 */

int gfs2_ok_to_move(struct gfs2_inode *this, struct gfs2_inode *to)
{
      struct inode *dir = &to->i_inode;
      struct super_block *sb = dir->i_sb;
      struct inode *tmp;
      struct qstr dotdot;
      int error = 0;

      gfs2_str2qstr(&dotdot, "..");

      igrab(dir);

      for (;;) {
            if (dir == &this->i_inode) {
                  error = -EINVAL;
                  break;
            }
            if (dir == sb->s_root->d_inode) {
                  error = 0;
                  break;
            }

            tmp = gfs2_lookupi(dir, &dotdot, 1, NULL);
            if (IS_ERR(tmp)) {
                  error = PTR_ERR(tmp);
                  break;
            }

            iput(dir);
            dir = tmp;
      }

      iput(dir);

      return error;
}

/**
 * gfs2_readlinki - return the contents of a symlink
 * @ip: the symlink's inode
 * @buf: a pointer to the buffer to be filled
 * @len: a pointer to the length of @buf
 *
 * If @buf is too small, a piece of memory is kmalloc()ed and needs
 * to be freed by the caller.
 *
 * Returns: errno
 */

int gfs2_readlinki(struct gfs2_inode *ip, char **buf, unsigned int *len)
{
      struct gfs2_holder i_gh;
      struct buffer_head *dibh;
      unsigned int x;
      int error;

      gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &i_gh);
      error = gfs2_glock_nq_atime(&i_gh);
      if (error) {
            gfs2_holder_uninit(&i_gh);
            return error;
      }

      if (!ip->i_di.di_size) {
            gfs2_consist_inode(ip);
            error = -EIO;
            goto out;
      }

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

      x = ip->i_di.di_size + 1;
      if (x > *len) {
            *buf = kmalloc(x, GFP_KERNEL);
            if (!*buf) {
                  error = -ENOMEM;
                  goto out_brelse;
            }
      }

      memcpy(*buf, dibh->b_data + sizeof(struct gfs2_dinode), x);
      *len = x;

out_brelse:
      brelse(dibh);
out:
      gfs2_glock_dq_uninit(&i_gh);
      return error;
}

/**
 * gfs2_glock_nq_atime - Acquire a hold on an inode's glock, and
 *       conditionally update the inode's atime
 * @gh: the holder to acquire
 *
 * Tests atime (access time) for gfs2_read, gfs2_readdir and gfs2_mmap
 * Update if the difference between the current time and the inode's current
 * atime is greater than an interval specified at mount.
 *
 * Returns: errno
 */

int gfs2_glock_nq_atime(struct gfs2_holder *gh)
{
      struct gfs2_glock *gl = gh->gh_gl;
      struct gfs2_sbd *sdp = gl->gl_sbd;
      struct gfs2_inode *ip = gl->gl_object;
      s64 quantum = gfs2_tune_get(sdp, gt_atime_quantum);
      unsigned int state;
      int flags;
      int error;
      struct timespec tv = CURRENT_TIME;

      if (gfs2_assert_warn(sdp, gh->gh_flags & GL_ATIME) ||
          gfs2_assert_warn(sdp, !(gh->gh_flags & GL_ASYNC)) ||
          gfs2_assert_warn(sdp, gl->gl_ops == &gfs2_inode_glops))
            return -EINVAL;

      state = gh->gh_state;
      flags = gh->gh_flags;

      error = gfs2_glock_nq(gh);
      if (error)
            return error;

      if (test_bit(SDF_NOATIME, &sdp->sd_flags) ||
          (sdp->sd_vfs->s_flags & MS_RDONLY))
            return 0;

      if (tv.tv_sec - ip->i_inode.i_atime.tv_sec >= quantum) {
            gfs2_glock_dq(gh);
            gfs2_holder_reinit(LM_ST_EXCLUSIVE, gh->gh_flags & ~LM_FLAG_ANY,
                           gh);
            error = gfs2_glock_nq(gh);
            if (error)
                  return error;

            /* Verify that atime hasn't been updated while we were
               trying to get exclusive lock. */

            tv = CURRENT_TIME;
            if (tv.tv_sec - ip->i_inode.i_atime.tv_sec >= quantum) {
                  struct buffer_head *dibh;
                  struct gfs2_dinode *di;

                  error = gfs2_trans_begin(sdp, RES_DINODE, 0);
                  if (error == -EROFS)
                        return 0;
                  if (error)
                        goto fail;

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

                  ip->i_inode.i_atime = tv;

                  gfs2_trans_add_bh(ip->i_gl, dibh, 1);
                  di = (struct gfs2_dinode *)dibh->b_data;
                  di->di_atime = cpu_to_be64(ip->i_inode.i_atime.tv_sec);
                  di->di_atime_nsec = cpu_to_be32(ip->i_inode.i_atime.tv_nsec);
                  brelse(dibh);

                  gfs2_trans_end(sdp);
            }

            /* If someone else has asked for the glock,
               unlock and let them have it. Then reacquire
               in the original state. */
            if (gfs2_glock_is_blocking(gl)) {
                  gfs2_glock_dq(gh);
                  gfs2_holder_reinit(state, flags, gh);
                  return gfs2_glock_nq(gh);
            }
      }

      return 0;

fail_end_trans:
      gfs2_trans_end(sdp);
fail:
      gfs2_glock_dq(gh);
      return error;
}

static int
__gfs2_setattr_simple(struct gfs2_inode *ip, struct iattr *attr)
{
      struct buffer_head *dibh;
      int 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);
      }
      return error;
}

/**
 * gfs2_setattr_simple -
 * @ip:
 * @attr:
 *
 * Called with a reference on the vnode.
 *
 * Returns: errno
 */

int gfs2_setattr_simple(struct gfs2_inode *ip, struct iattr *attr)
{
      int error;

      if (current->journal_info)
            return __gfs2_setattr_simple(ip, attr);

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

      error = __gfs2_setattr_simple(ip, attr);
      gfs2_trans_end(GFS2_SB(&ip->i_inode));
      return error;
}

void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
{
      const struct gfs2_dinode_host *di = &ip->i_di;
      struct gfs2_dinode *str = buf;

      str->di_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
      str->di_header.mh_type = cpu_to_be32(GFS2_METATYPE_DI);
      str->di_header.__pad0 = 0;
      str->di_header.mh_format = cpu_to_be32(GFS2_FORMAT_DI);
      str->di_header.__pad1 = 0;
      str->di_num.no_addr = cpu_to_be64(ip->i_no_addr);
      str->di_num.no_formal_ino = cpu_to_be64(ip->i_no_formal_ino);
      str->di_mode = cpu_to_be32(ip->i_inode.i_mode);
      str->di_uid = cpu_to_be32(ip->i_inode.i_uid);
      str->di_gid = cpu_to_be32(ip->i_inode.i_gid);
      str->di_nlink = cpu_to_be32(ip->i_inode.i_nlink);
      str->di_size = cpu_to_be64(di->di_size);
      str->di_blocks = cpu_to_be64(di->di_blocks);
      str->di_atime = cpu_to_be64(ip->i_inode.i_atime.tv_sec);
      str->di_mtime = cpu_to_be64(ip->i_inode.i_mtime.tv_sec);
      str->di_ctime = cpu_to_be64(ip->i_inode.i_ctime.tv_sec);

      str->di_goal_meta = cpu_to_be64(di->di_goal_meta);
      str->di_goal_data = cpu_to_be64(di->di_goal_data);
      str->di_generation = cpu_to_be64(di->di_generation);

      str->di_flags = cpu_to_be32(di->di_flags);
      str->di_height = cpu_to_be16(di->di_height);
      str->di_payload_format = cpu_to_be32(S_ISDIR(ip->i_inode.i_mode) &&
                                   !(ip->i_di.di_flags & GFS2_DIF_EXHASH) ?
                                   GFS2_FORMAT_DE : 0);
      str->di_depth = cpu_to_be16(di->di_depth);
      str->di_entries = cpu_to_be32(di->di_entries);

      str->di_eattr = cpu_to_be64(di->di_eattr);
      str->di_atime_nsec = cpu_to_be32(ip->i_inode.i_atime.tv_nsec);
      str->di_mtime_nsec = cpu_to_be32(ip->i_inode.i_mtime.tv_nsec);
      str->di_ctime_nsec = cpu_to_be32(ip->i_inode.i_ctime.tv_nsec);
}

void gfs2_dinode_print(const struct gfs2_inode *ip)
{
      const struct gfs2_dinode_host *di = &ip->i_di;

      printk(KERN_INFO "  no_formal_ino = %llu\n",
             (unsigned long long)ip->i_no_formal_ino);
      printk(KERN_INFO "  no_addr = %llu\n",
             (unsigned long long)ip->i_no_addr);
      printk(KERN_INFO "  di_size = %llu\n", (unsigned long long)di->di_size);
      printk(KERN_INFO "  di_blocks = %llu\n",
             (unsigned long long)di->di_blocks);
      printk(KERN_INFO "  di_goal_meta = %llu\n",
             (unsigned long long)di->di_goal_meta);
      printk(KERN_INFO "  di_goal_data = %llu\n",
             (unsigned long long)di->di_goal_data);
      printk(KERN_INFO "  di_flags = 0x%.8X\n", di->di_flags);
      printk(KERN_INFO "  di_height = %u\n", di->di_height);
      printk(KERN_INFO "  di_depth = %u\n", di->di_depth);
      printk(KERN_INFO "  di_entries = %u\n", di->di_entries);
      printk(KERN_INFO "  di_eattr = %llu\n",
             (unsigned long long)di->di_eattr);
}


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