Logo Search packages:      
Sourcecode: linux version File versions  Download package

dir.c

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * dir.c
 *
 * Creates, reads, walks and deletes directory-nodes
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 *
 *  Portions of this code from linux/fs/ext3/dir.c
 *
 *  Copyright (C) 1992, 1993, 1994, 1995
 *  Remy Card (card@masi.ibp.fr)
 *  Laboratoire MASI - Institut Blaise pascal
 *  Universite Pierre et Marie Curie (Paris VI)
 *
 *   from
 *
 *   linux/fs/minix/dir.c
 *
 *   Copyright (C) 1991, 1992 Linux Torvalds
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>

#define MLOG_MASK_PREFIX ML_NAMEI
#include <cluster/masklog.h>

#include "ocfs2.h"

#include "alloc.h"
#include "dir.h"
#include "dlmglue.h"
#include "extent_map.h"
#include "file.h"
#include "inode.h"
#include "journal.h"
#include "namei.h"
#include "suballoc.h"
#include "super.h"
#include "uptodate.h"

#include "buffer_head_io.h"

#define NAMEI_RA_CHUNKS  2
#define NAMEI_RA_BLOCKS  4
#define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
#define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))

static unsigned char ocfs2_filetype_table[] = {
      DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
};

static int ocfs2_extend_dir(struct ocfs2_super *osb,
                      struct inode *dir,
                      struct buffer_head *parent_fe_bh,
                      unsigned int blocks_wanted,
                      struct buffer_head **new_de_bh);
static int ocfs2_do_extend_dir(struct super_block *sb,
                         handle_t *handle,
                         struct inode *dir,
                         struct buffer_head *parent_fe_bh,
                         struct ocfs2_alloc_context *data_ac,
                         struct ocfs2_alloc_context *meta_ac,
                         struct buffer_head **new_bh);

/*
 * bh passed here can be an inode block or a dir data block, depending
 * on the inode inline data flag.
 */
static int ocfs2_check_dir_entry(struct inode * dir,
                         struct ocfs2_dir_entry * de,
                         struct buffer_head * bh,
                         unsigned long offset)
{
      const char *error_msg = NULL;
      const int rlen = le16_to_cpu(de->rec_len);

      if (rlen < OCFS2_DIR_REC_LEN(1))
            error_msg = "rec_len is smaller than minimal";
      else if (rlen % 4 != 0)
            error_msg = "rec_len % 4 != 0";
      else if (rlen < OCFS2_DIR_REC_LEN(de->name_len))
            error_msg = "rec_len is too small for name_len";
      else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize)
            error_msg = "directory entry across blocks";

      if (error_msg != NULL)
            mlog(ML_ERROR, "bad entry in directory #%llu: %s - "
                 "offset=%lu, inode=%llu, rec_len=%d, name_len=%d\n",
                 (unsigned long long)OCFS2_I(dir)->ip_blkno, error_msg,
                 offset, (unsigned long long)le64_to_cpu(de->inode), rlen,
                 de->name_len);
      return error_msg == NULL ? 1 : 0;
}

static inline int ocfs2_match(int len,
                        const char * const name,
                        struct ocfs2_dir_entry *de)
{
      if (len != de->name_len)
            return 0;
      if (!de->inode)
            return 0;
      return !memcmp(name, de->name, len);
}

/*
 * Returns 0 if not found, -1 on failure, and 1 on success
 */
static int inline ocfs2_search_dirblock(struct buffer_head *bh,
                              struct inode *dir,
                              const char *name, int namelen,
                              unsigned long offset,
                              char *first_de,
                              unsigned int bytes,
                              struct ocfs2_dir_entry **res_dir)
{
      struct ocfs2_dir_entry *de;
      char *dlimit, *de_buf;
      int de_len;
      int ret = 0;

      mlog_entry_void();

      de_buf = first_de;
      dlimit = de_buf + bytes;

      while (de_buf < dlimit) {
            /* this code is executed quadratically often */
            /* do minimal checking `by hand' */

            de = (struct ocfs2_dir_entry *) de_buf;

            if (de_buf + namelen <= dlimit &&
                ocfs2_match(namelen, name, de)) {
                  /* found a match - just to be sure, do a full check */
                  if (!ocfs2_check_dir_entry(dir, de, bh, offset)) {
                        ret = -1;
                        goto bail;
                  }
                  *res_dir = de;
                  ret = 1;
                  goto bail;
            }

            /* prevent looping on a bad block */
            de_len = le16_to_cpu(de->rec_len);
            if (de_len <= 0) {
                  ret = -1;
                  goto bail;
            }

            de_buf += de_len;
            offset += de_len;
      }

bail:
      mlog_exit(ret);
      return ret;
}

static struct buffer_head *ocfs2_find_entry_id(const char *name,
                                     int namelen,
                                     struct inode *dir,
                                     struct ocfs2_dir_entry **res_dir)
{
      int ret, found;
      struct buffer_head *di_bh = NULL;
      struct ocfs2_dinode *di;
      struct ocfs2_inline_data *data;

      ret = ocfs2_read_block(OCFS2_SB(dir->i_sb), OCFS2_I(dir)->ip_blkno,
                         &di_bh, OCFS2_BH_CACHED, dir);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      di = (struct ocfs2_dinode *)di_bh->b_data;
      data = &di->id2.i_data;

      found = ocfs2_search_dirblock(di_bh, dir, name, namelen, 0,
                              data->id_data, i_size_read(dir), res_dir);
      if (found == 1)
            return di_bh;

      brelse(di_bh);
out:
      return NULL;
}

static struct buffer_head *ocfs2_find_entry_el(const char *name, int namelen,
                                     struct inode *dir,
                                     struct ocfs2_dir_entry **res_dir)
{
      struct super_block *sb;
      struct buffer_head *bh_use[NAMEI_RA_SIZE];
      struct buffer_head *bh, *ret = NULL;
      unsigned long start, block, b;
      int ra_max = 0;         /* Number of bh's in the readahead
                           buffer, bh_use[] */
      int ra_ptr = 0;         /* Current index into readahead
                           buffer */
      int num = 0;
      int nblocks, i, err;

      mlog_entry_void();

      sb = dir->i_sb;

      nblocks = i_size_read(dir) >> sb->s_blocksize_bits;
      start = OCFS2_I(dir)->ip_dir_start_lookup;
      if (start >= nblocks)
            start = 0;
      block = start;

restart:
      do {
            /*
             * We deal with the read-ahead logic here.
             */
            if (ra_ptr >= ra_max) {
                  /* Refill the readahead buffer */
                  ra_ptr = 0;
                  b = block;
                  for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
                        /*
                         * Terminate if we reach the end of the
                         * directory and must wrap, or if our
                         * search has finished at this block.
                         */
                        if (b >= nblocks || (num && block == start)) {
                              bh_use[ra_max] = NULL;
                              break;
                        }
                        num++;

                        bh = ocfs2_bread(dir, b++, &err, 1);
                        bh_use[ra_max] = bh;
                  }
            }
            if ((bh = bh_use[ra_ptr++]) == NULL)
                  goto next;
            wait_on_buffer(bh);
            if (!buffer_uptodate(bh)) {
                  /* read error, skip block & hope for the best */
                  ocfs2_error(dir->i_sb, "reading directory %llu, "
                            "offset %lu\n",
                            (unsigned long long)OCFS2_I(dir)->ip_blkno,
                            block);
                  brelse(bh);
                  goto next;
            }
            i = ocfs2_search_dirblock(bh, dir, name, namelen,
                                block << sb->s_blocksize_bits,
                                bh->b_data, sb->s_blocksize,
                                res_dir);
            if (i == 1) {
                  OCFS2_I(dir)->ip_dir_start_lookup = block;
                  ret = bh;
                  goto cleanup_and_exit;
            } else {
                  brelse(bh);
                  if (i < 0)
                        goto cleanup_and_exit;
            }
      next:
            if (++block >= nblocks)
                  block = 0;
      } while (block != start);

      /*
       * If the directory has grown while we were searching, then
       * search the last part of the directory before giving up.
       */
      block = nblocks;
      nblocks = i_size_read(dir) >> sb->s_blocksize_bits;
      if (block < nblocks) {
            start = 0;
            goto restart;
      }

cleanup_and_exit:
      /* Clean up the read-ahead blocks */
      for (; ra_ptr < ra_max; ra_ptr++)
            brelse(bh_use[ra_ptr]);

      mlog_exit_ptr(ret);
      return ret;
}

/*
 * Try to find an entry of the provided name within 'dir'.
 *
 * If nothing was found, NULL is returned. Otherwise, a buffer_head
 * and pointer to the dir entry are passed back.
 *
 * Caller can NOT assume anything about the contents of the
 * buffer_head - it is passed back only so that it can be passed into
 * any one of the manipulation functions (add entry, delete entry,
 * etc). As an example, bh in the extent directory case is a data
 * block, in the inline-data case it actually points to an inode.
 */
struct buffer_head *ocfs2_find_entry(const char *name, int namelen,
                             struct inode *dir,
                             struct ocfs2_dir_entry **res_dir)
{
      *res_dir = NULL;

      if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
            return ocfs2_find_entry_id(name, namelen, dir, res_dir);

      return ocfs2_find_entry_el(name, namelen, dir, res_dir);
}

/*
 * Update inode number and type of a previously found directory entry.
 */
int ocfs2_update_entry(struct inode *dir, handle_t *handle,
                   struct buffer_head *de_bh, struct ocfs2_dir_entry *de,
                   struct inode *new_entry_inode)
{
      int ret;

      /*
       * The same code works fine for both inline-data and extent
       * based directories, so no need to split this up.
       */

      ret = ocfs2_journal_access(handle, dir, de_bh,
                           OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      de->inode = cpu_to_le64(OCFS2_I(new_entry_inode)->ip_blkno);
      ocfs2_set_de_type(de, new_entry_inode->i_mode);

      ocfs2_journal_dirty(handle, de_bh);

out:
      return ret;
}

static int __ocfs2_delete_entry(handle_t *handle, struct inode *dir,
                        struct ocfs2_dir_entry *de_del,
                        struct buffer_head *bh, char *first_de,
                        unsigned int bytes)
{
      struct ocfs2_dir_entry *de, *pde;
      int i, status = -ENOENT;

      mlog_entry("(0x%p, 0x%p, 0x%p, 0x%p)\n", handle, dir, de_del, bh);

      i = 0;
      pde = NULL;
      de = (struct ocfs2_dir_entry *) first_de;
      while (i < bytes) {
            if (!ocfs2_check_dir_entry(dir, de, bh, i)) {
                  status = -EIO;
                  mlog_errno(status);
                  goto bail;
            }
            if (de == de_del)  {
                  status = ocfs2_journal_access(handle, dir, bh,
                                          OCFS2_JOURNAL_ACCESS_WRITE);
                  if (status < 0) {
                        status = -EIO;
                        mlog_errno(status);
                        goto bail;
                  }
                  if (pde)
                        pde->rec_len =
                              cpu_to_le16(le16_to_cpu(pde->rec_len) +
                                        le16_to_cpu(de->rec_len));
                  else
                        de->inode = 0;
                  dir->i_version++;
                  status = ocfs2_journal_dirty(handle, bh);
                  goto bail;
            }
            i += le16_to_cpu(de->rec_len);
            pde = de;
            de = (struct ocfs2_dir_entry *)((char *)de + le16_to_cpu(de->rec_len));
      }
bail:
      mlog_exit(status);
      return status;
}

static inline int ocfs2_delete_entry_id(handle_t *handle,
                              struct inode *dir,
                              struct ocfs2_dir_entry *de_del,
                              struct buffer_head *bh)
{
      int ret;
      struct buffer_head *di_bh = NULL;
      struct ocfs2_dinode *di;
      struct ocfs2_inline_data *data;

      ret = ocfs2_read_block(OCFS2_SB(dir->i_sb), OCFS2_I(dir)->ip_blkno,
                         &di_bh, OCFS2_BH_CACHED, dir);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      di = (struct ocfs2_dinode *)di_bh->b_data;
      data = &di->id2.i_data;

      ret = __ocfs2_delete_entry(handle, dir, de_del, bh, data->id_data,
                           i_size_read(dir));

      brelse(di_bh);
out:
      return ret;
}

static inline int ocfs2_delete_entry_el(handle_t *handle,
                              struct inode *dir,
                              struct ocfs2_dir_entry *de_del,
                              struct buffer_head *bh)
{
      return __ocfs2_delete_entry(handle, dir, de_del, bh, bh->b_data,
                            bh->b_size);
}

/*
 * ocfs2_delete_entry deletes a directory entry by merging it with the
 * previous entry
 */
int ocfs2_delete_entry(handle_t *handle,
                   struct inode *dir,
                   struct ocfs2_dir_entry *de_del,
                   struct buffer_head *bh)
{
      if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
            return ocfs2_delete_entry_id(handle, dir, de_del, bh);

      return ocfs2_delete_entry_el(handle, dir, de_del, bh);
}

/*
 * Check whether 'de' has enough room to hold an entry of
 * 'new_rec_len' bytes.
 */
static inline int ocfs2_dirent_would_fit(struct ocfs2_dir_entry *de,
                               unsigned int new_rec_len)
{
      unsigned int de_really_used;

      /* Check whether this is an empty record with enough space */
      if (le64_to_cpu(de->inode) == 0 &&
          le16_to_cpu(de->rec_len) >= new_rec_len)
            return 1;

      /*
       * Record might have free space at the end which we can
       * use.
       */
      de_really_used = OCFS2_DIR_REC_LEN(de->name_len);
      if (le16_to_cpu(de->rec_len) >= (de_really_used + new_rec_len))
          return 1;

      return 0;
}

/* we don't always have a dentry for what we want to add, so people
 * like orphan dir can call this instead.
 *
 * If you pass me insert_bh, I'll skip the search of the other dir
 * blocks and put the record in there.
 */
int __ocfs2_add_entry(handle_t *handle,
                  struct inode *dir,
                  const char *name, int namelen,
                  struct inode *inode, u64 blkno,
                  struct buffer_head *parent_fe_bh,
                  struct buffer_head *insert_bh)
{
      unsigned long offset;
      unsigned short rec_len;
      struct ocfs2_dir_entry *de, *de1;
      struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_fe_bh->b_data;
      struct super_block *sb = dir->i_sb;
      int retval, status;
      unsigned int size = sb->s_blocksize;
      char *data_start = insert_bh->b_data;

      mlog_entry_void();

      if (!namelen)
            return -EINVAL;

      if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
            data_start = di->id2.i_data.id_data;
            size = i_size_read(dir);

            BUG_ON(insert_bh != parent_fe_bh);
      }

      rec_len = OCFS2_DIR_REC_LEN(namelen);
      offset = 0;
      de = (struct ocfs2_dir_entry *) data_start;
      while (1) {
            BUG_ON((char *)de >= (size + data_start));

            /* These checks should've already been passed by the
             * prepare function, but I guess we can leave them
             * here anyway. */
            if (!ocfs2_check_dir_entry(dir, de, insert_bh, offset)) {
                  retval = -ENOENT;
                  goto bail;
            }
            if (ocfs2_match(namelen, name, de)) {
                  retval = -EEXIST;
                  goto bail;
            }

            if (ocfs2_dirent_would_fit(de, rec_len)) {
                  dir->i_mtime = dir->i_ctime = CURRENT_TIME;
                  retval = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh);
                  if (retval < 0) {
                        mlog_errno(retval);
                        goto bail;
                  }

                  status = ocfs2_journal_access(handle, dir, insert_bh,
                                          OCFS2_JOURNAL_ACCESS_WRITE);
                  /* By now the buffer is marked for journaling */
                  offset += le16_to_cpu(de->rec_len);
                  if (le64_to_cpu(de->inode)) {
                        de1 = (struct ocfs2_dir_entry *)((char *) de +
                              OCFS2_DIR_REC_LEN(de->name_len));
                        de1->rec_len =
                              cpu_to_le16(le16_to_cpu(de->rec_len) -
                              OCFS2_DIR_REC_LEN(de->name_len));
                        de->rec_len = cpu_to_le16(OCFS2_DIR_REC_LEN(de->name_len));
                        de = de1;
                  }
                  de->file_type = OCFS2_FT_UNKNOWN;
                  if (blkno) {
                        de->inode = cpu_to_le64(blkno);
                        ocfs2_set_de_type(de, inode->i_mode);
                  } else
                        de->inode = 0;
                  de->name_len = namelen;
                  memcpy(de->name, name, namelen);

                  dir->i_version++;
                  status = ocfs2_journal_dirty(handle, insert_bh);
                  retval = 0;
                  goto bail;
            }
            offset += le16_to_cpu(de->rec_len);
            de = (struct ocfs2_dir_entry *) ((char *) de + le16_to_cpu(de->rec_len));
      }

      /* when you think about it, the assert above should prevent us
       * from ever getting here. */
      retval = -ENOSPC;
bail:

      mlog_exit(retval);
      return retval;
}

static int ocfs2_dir_foreach_blk_id(struct inode *inode,
                            u64 *f_version,
                            loff_t *f_pos, void *priv,
                            filldir_t filldir, int *filldir_err)
{
      int ret, i, filldir_ret;
      unsigned long offset = *f_pos;
      struct buffer_head *di_bh = NULL;
      struct ocfs2_dinode *di;
      struct ocfs2_inline_data *data;
      struct ocfs2_dir_entry *de;

      ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), OCFS2_I(inode)->ip_blkno,
                         &di_bh, OCFS2_BH_CACHED, inode);
      if (ret) {
            mlog(ML_ERROR, "Unable to read inode block for dir %llu\n",
                 (unsigned long long)OCFS2_I(inode)->ip_blkno);
            goto out;
      }

      di = (struct ocfs2_dinode *)di_bh->b_data;
      data = &di->id2.i_data;

      while (*f_pos < i_size_read(inode)) {
revalidate:
            /* If the dir block has changed since the last call to
             * readdir(2), then we might be pointing to an invalid
             * dirent right now.  Scan from the start of the block
             * to make sure. */
            if (*f_version != inode->i_version) {
                  for (i = 0; i < i_size_read(inode) && i < offset; ) {
                        de = (struct ocfs2_dir_entry *)
                              (data->id_data + i);
                        /* It's too expensive to do a full
                         * dirent test each time round this
                         * loop, but we do have to test at
                         * least that it is non-zero.  A
                         * failure will be detected in the
                         * dirent test below. */
                        if (le16_to_cpu(de->rec_len) <
                            OCFS2_DIR_REC_LEN(1))
                              break;
                        i += le16_to_cpu(de->rec_len);
                  }
                  *f_pos = offset = i;
                  *f_version = inode->i_version;
            }

            de = (struct ocfs2_dir_entry *) (data->id_data + *f_pos);
            if (!ocfs2_check_dir_entry(inode, de, di_bh, *f_pos)) {
                  /* On error, skip the f_pos to the end. */
                  *f_pos = i_size_read(inode);
                  goto out;
            }
            offset += le16_to_cpu(de->rec_len);
            if (le64_to_cpu(de->inode)) {
                  /* We might block in the next section
                   * if the data destination is
                   * currently swapped out.  So, use a
                   * version stamp to detect whether or
                   * not the directory has been modified
                   * during the copy operation.
                   */
                  u64 version = *f_version;
                  unsigned char d_type = DT_UNKNOWN;

                  if (de->file_type < OCFS2_FT_MAX)
                        d_type = ocfs2_filetype_table[de->file_type];

                  filldir_ret = filldir(priv, de->name,
                                    de->name_len,
                                    *f_pos,
                                    le64_to_cpu(de->inode),
                                    d_type);
                  if (filldir_ret) {
                        if (filldir_err)
                              *filldir_err = filldir_ret;
                        break;
                  }
                  if (version != *f_version)
                        goto revalidate;
            }
            *f_pos += le16_to_cpu(de->rec_len);
      }

out:
      brelse(di_bh);

      return 0;
}

static int ocfs2_dir_foreach_blk_el(struct inode *inode,
                            u64 *f_version,
                            loff_t *f_pos, void *priv,
                            filldir_t filldir, int *filldir_err)
{
      int error = 0;
      unsigned long offset, blk, last_ra_blk = 0;
      int i, stored;
      struct buffer_head * bh, * tmp;
      struct ocfs2_dir_entry * de;
      int err;
      struct super_block * sb = inode->i_sb;
      unsigned int ra_sectors = 16;

      stored = 0;
      bh = NULL;

      offset = (*f_pos) & (sb->s_blocksize - 1);

      while (!error && !stored && *f_pos < i_size_read(inode)) {
            blk = (*f_pos) >> sb->s_blocksize_bits;
            bh = ocfs2_bread(inode, blk, &err, 0);
            if (!bh) {
                  mlog(ML_ERROR,
                       "directory #%llu contains a hole at offset %lld\n",
                       (unsigned long long)OCFS2_I(inode)->ip_blkno,
                       *f_pos);
                  *f_pos += sb->s_blocksize - offset;
                  continue;
            }

            /* The idea here is to begin with 8k read-ahead and to stay
             * 4k ahead of our current position.
             *
             * TODO: Use the pagecache for this. We just need to
             * make sure it's cluster-safe... */
            if (!last_ra_blk
                || (((last_ra_blk - blk) << 9) <= (ra_sectors / 2))) {
                  for (i = ra_sectors >> (sb->s_blocksize_bits - 9);
                       i > 0; i--) {
                        tmp = ocfs2_bread(inode, ++blk, &err, 1);
                        if (tmp)
                              brelse(tmp);
                  }
                  last_ra_blk = blk;
                  ra_sectors = 8;
            }

revalidate:
            /* If the dir block has changed since the last call to
             * readdir(2), then we might be pointing to an invalid
             * dirent right now.  Scan from the start of the block
             * to make sure. */
            if (*f_version != inode->i_version) {
                  for (i = 0; i < sb->s_blocksize && i < offset; ) {
                        de = (struct ocfs2_dir_entry *) (bh->b_data + i);
                        /* It's too expensive to do a full
                         * dirent test each time round this
                         * loop, but we do have to test at
                         * least that it is non-zero.  A
                         * failure will be detected in the
                         * dirent test below. */
                        if (le16_to_cpu(de->rec_len) <
                            OCFS2_DIR_REC_LEN(1))
                              break;
                        i += le16_to_cpu(de->rec_len);
                  }
                  offset = i;
                  *f_pos = ((*f_pos) & ~(sb->s_blocksize - 1))
                        | offset;
                  *f_version = inode->i_version;
            }

            while (!error && *f_pos < i_size_read(inode)
                   && offset < sb->s_blocksize) {
                  de = (struct ocfs2_dir_entry *) (bh->b_data + offset);
                  if (!ocfs2_check_dir_entry(inode, de, bh, offset)) {
                        /* On error, skip the f_pos to the
                           next block. */
                        *f_pos = ((*f_pos) | (sb->s_blocksize - 1)) + 1;
                        brelse(bh);
                        goto out;
                  }
                  offset += le16_to_cpu(de->rec_len);
                  if (le64_to_cpu(de->inode)) {
                        /* We might block in the next section
                         * if the data destination is
                         * currently swapped out.  So, use a
                         * version stamp to detect whether or
                         * not the directory has been modified
                         * during the copy operation.
                         */
                        unsigned long version = *f_version;
                        unsigned char d_type = DT_UNKNOWN;

                        if (de->file_type < OCFS2_FT_MAX)
                              d_type = ocfs2_filetype_table[de->file_type];
                        error = filldir(priv, de->name,
                                    de->name_len,
                                    *f_pos,
                                    le64_to_cpu(de->inode),
                                    d_type);
                        if (error) {
                              if (filldir_err)
                                    *filldir_err = error;
                              break;
                        }
                        if (version != *f_version)
                              goto revalidate;
                        stored ++;
                  }
                  *f_pos += le16_to_cpu(de->rec_len);
            }
            offset = 0;
            brelse(bh);
      }

      stored = 0;
out:
      return stored;
}

static int ocfs2_dir_foreach_blk(struct inode *inode, u64 *f_version,
                         loff_t *f_pos, void *priv, filldir_t filldir,
                         int *filldir_err)
{
      if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
            return ocfs2_dir_foreach_blk_id(inode, f_version, f_pos, priv,
                                    filldir, filldir_err);

      return ocfs2_dir_foreach_blk_el(inode, f_version, f_pos, priv, filldir,
                              filldir_err);
}

/*
 * This is intended to be called from inside other kernel functions,
 * so we fake some arguments.
 */
int ocfs2_dir_foreach(struct inode *inode, loff_t *f_pos, void *priv,
                  filldir_t filldir)
{
      int ret = 0, filldir_err = 0;
      u64 version = inode->i_version;

      while (*f_pos < i_size_read(inode)) {
            ret = ocfs2_dir_foreach_blk(inode, &version, f_pos, priv,
                                  filldir, &filldir_err);
            if (ret || filldir_err)
                  break;
      }

      if (ret > 0)
            ret = -EIO;

      return 0;
}

/*
 * ocfs2_readdir()
 *
 */
int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
      int error = 0;
      struct inode *inode = filp->f_path.dentry->d_inode;
      int lock_level = 0;

      mlog_entry("dirino=%llu\n",
               (unsigned long long)OCFS2_I(inode)->ip_blkno);

      error = ocfs2_meta_lock_atime(inode, filp->f_vfsmnt, &lock_level);
      if (lock_level && error >= 0) {
            /* We release EX lock which used to update atime
             * and get PR lock again to reduce contention
             * on commonly accessed directories. */
            ocfs2_meta_unlock(inode, 1);
            lock_level = 0;
            error = ocfs2_meta_lock(inode, NULL, 0);
      }
      if (error < 0) {
            if (error != -ENOENT)
                  mlog_errno(error);
            /* we haven't got any yet, so propagate the error. */
            goto bail_nolock;
      }

      error = ocfs2_dir_foreach_blk(inode, &filp->f_version, &filp->f_pos,
                              dirent, filldir, NULL);

      ocfs2_meta_unlock(inode, lock_level);

bail_nolock:
      mlog_exit(error);

      return error;
}

/*
 * NOTE: this should always be called with parent dir i_mutex taken.
 */
int ocfs2_find_files_on_disk(const char *name,
                       int namelen,
                       u64 *blkno,
                       struct inode *inode,
                       struct buffer_head **dirent_bh,
                       struct ocfs2_dir_entry **dirent)
{
      int status = -ENOENT;

      mlog_entry("(name=%.*s, blkno=%p, inode=%p, dirent_bh=%p, dirent=%p)\n",
               namelen, name, blkno, inode, dirent_bh, dirent);

      *dirent_bh = ocfs2_find_entry(name, namelen, inode, dirent);
      if (!*dirent_bh || !*dirent) {
            status = -ENOENT;
            goto leave;
      }

      *blkno = le64_to_cpu((*dirent)->inode);

      status = 0;
leave:
      if (status < 0) {
            *dirent = NULL;
            if (*dirent_bh) {
                  brelse(*dirent_bh);
                  *dirent_bh = NULL;
            }
      }

      mlog_exit(status);
      return status;
}

/*
 * Convenience function for callers which just want the block number
 * mapped to a name and don't require the full dirent info, etc.
 */
int ocfs2_lookup_ino_from_name(struct inode *dir, const char *name,
                         int namelen, u64 *blkno)
{
      int ret;
      struct buffer_head *bh = NULL;
      struct ocfs2_dir_entry *dirent = NULL;

      ret = ocfs2_find_files_on_disk(name, namelen, blkno, dir, &bh, &dirent);
      brelse(bh);

      return ret;
}

/* Check for a name within a directory.
 *
 * Return 0 if the name does not exist
 * Return -EEXIST if the directory contains the name
 *
 * Callers should have i_mutex + a cluster lock on dir
 */
int ocfs2_check_dir_for_entry(struct inode *dir,
                        const char *name,
                        int namelen)
{
      int ret;
      struct buffer_head *dirent_bh = NULL;
      struct ocfs2_dir_entry *dirent = NULL;

      mlog_entry("dir %llu, name '%.*s'\n",
               (unsigned long long)OCFS2_I(dir)->ip_blkno, namelen, name);

      ret = -EEXIST;
      dirent_bh = ocfs2_find_entry(name, namelen, dir, &dirent);
      if (dirent_bh)
            goto bail;

      ret = 0;
bail:
      if (dirent_bh)
            brelse(dirent_bh);

      mlog_exit(ret);
      return ret;
}

struct ocfs2_empty_dir_priv {
      unsigned seen_dot;
      unsigned seen_dot_dot;
      unsigned seen_other;
};
static int ocfs2_empty_dir_filldir(void *priv, const char *name, int name_len,
                           loff_t pos, u64 ino, unsigned type)
{
      struct ocfs2_empty_dir_priv *p = priv;

      /*
       * Check the positions of "." and ".." records to be sure
       * they're in the correct place.
       */
      if (name_len == 1 && !strncmp(".", name, 1) && pos == 0) {
            p->seen_dot = 1;
            return 0;
      }

      if (name_len == 2 && !strncmp("..", name, 2) &&
          pos == OCFS2_DIR_REC_LEN(1)) {
            p->seen_dot_dot = 1;
            return 0;
      }

      p->seen_other = 1;
      return 1;
}
/*
 * routine to check that the specified directory is empty (for rmdir)
 *
 * Returns 1 if dir is empty, zero otherwise.
 */
int ocfs2_empty_dir(struct inode *inode)
{
      int ret;
      loff_t start = 0;
      struct ocfs2_empty_dir_priv priv;

      memset(&priv, 0, sizeof(priv));

      ret = ocfs2_dir_foreach(inode, &start, &priv, ocfs2_empty_dir_filldir);
      if (ret)
            mlog_errno(ret);

      if (!priv.seen_dot || !priv.seen_dot_dot) {
            mlog(ML_ERROR, "bad directory (dir #%llu) - no `.' or `..'\n",
                 (unsigned long long)OCFS2_I(inode)->ip_blkno);
            /*
             * XXX: Is it really safe to allow an unlink to continue?
             */
            return 1;
      }

      return !priv.seen_other;
}

static void ocfs2_fill_initial_dirents(struct inode *inode,
                               struct inode *parent,
                               char *start, unsigned int size)
{
      struct ocfs2_dir_entry *de = (struct ocfs2_dir_entry *)start;

      de->inode = cpu_to_le64(OCFS2_I(inode)->ip_blkno);
      de->name_len = 1;
      de->rec_len =
            cpu_to_le16(OCFS2_DIR_REC_LEN(de->name_len));
      strcpy(de->name, ".");
      ocfs2_set_de_type(de, S_IFDIR);

      de = (struct ocfs2_dir_entry *) ((char *)de + le16_to_cpu(de->rec_len));
      de->inode = cpu_to_le64(OCFS2_I(parent)->ip_blkno);
      de->rec_len = cpu_to_le16(size - OCFS2_DIR_REC_LEN(1));
      de->name_len = 2;
      strcpy(de->name, "..");
      ocfs2_set_de_type(de, S_IFDIR);
}

/*
 * This works together with code in ocfs2_mknod_locked() which sets
 * the inline-data flag and initializes the inline-data section.
 */
static int ocfs2_fill_new_dir_id(struct ocfs2_super *osb,
                         handle_t *handle,
                         struct inode *parent,
                         struct inode *inode,
                         struct buffer_head *di_bh)
{
      int ret;
      struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
      struct ocfs2_inline_data *data = &di->id2.i_data;
      unsigned int size = le16_to_cpu(data->id_count);

      ret = ocfs2_journal_access(handle, inode, di_bh,
                           OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      ocfs2_fill_initial_dirents(inode, parent, data->id_data, size);

      ocfs2_journal_dirty(handle, di_bh);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      i_size_write(inode, size);
      inode->i_nlink = 2;
      inode->i_blocks = ocfs2_inode_sector_count(inode);

      ret = ocfs2_mark_inode_dirty(handle, inode, di_bh);
      if (ret < 0)
            mlog_errno(ret);

out:
      return ret;
}

static int ocfs2_fill_new_dir_el(struct ocfs2_super *osb,
                         handle_t *handle,
                         struct inode *parent,
                         struct inode *inode,
                         struct buffer_head *fe_bh,
                         struct ocfs2_alloc_context *data_ac)
{
      int status;
      struct buffer_head *new_bh = NULL;

      mlog_entry_void();

      status = ocfs2_do_extend_dir(osb->sb, handle, inode, fe_bh,
                             data_ac, NULL, &new_bh);
      if (status < 0) {
            mlog_errno(status);
            goto bail;
      }

      ocfs2_set_new_buffer_uptodate(inode, new_bh);

      status = ocfs2_journal_access(handle, inode, new_bh,
                              OCFS2_JOURNAL_ACCESS_CREATE);
      if (status < 0) {
            mlog_errno(status);
            goto bail;
      }
      memset(new_bh->b_data, 0, osb->sb->s_blocksize);

      ocfs2_fill_initial_dirents(inode, parent, new_bh->b_data,
                           osb->sb->s_blocksize);

      status = ocfs2_journal_dirty(handle, new_bh);
      if (status < 0) {
            mlog_errno(status);
            goto bail;
      }

      i_size_write(inode, inode->i_sb->s_blocksize);
      inode->i_nlink = 2;
      inode->i_blocks = ocfs2_inode_sector_count(inode);
      status = ocfs2_mark_inode_dirty(handle, inode, fe_bh);
      if (status < 0) {
            mlog_errno(status);
            goto bail;
      }

      status = 0;
bail:
      if (new_bh)
            brelse(new_bh);

      mlog_exit(status);
      return status;
}

int ocfs2_fill_new_dir(struct ocfs2_super *osb,
                   handle_t *handle,
                   struct inode *parent,
                   struct inode *inode,
                   struct buffer_head *fe_bh,
                   struct ocfs2_alloc_context *data_ac)
{
      BUG_ON(!ocfs2_supports_inline_data(osb) && data_ac == NULL);

      if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
            return ocfs2_fill_new_dir_id(osb, handle, parent, inode, fe_bh);

      return ocfs2_fill_new_dir_el(osb, handle, parent, inode, fe_bh,
                             data_ac);
}

static void ocfs2_expand_last_dirent(char *start, unsigned int old_size,
                             unsigned int new_size)
{
      struct ocfs2_dir_entry *de;
      struct ocfs2_dir_entry *prev_de;
      char *de_buf, *limit;
      unsigned int bytes = new_size - old_size;

      limit = start + old_size;
      de_buf = start;
      de = (struct ocfs2_dir_entry *)de_buf;
      do {
            prev_de = de;
            de_buf += le16_to_cpu(de->rec_len);
            de = (struct ocfs2_dir_entry *)de_buf;
      } while (de_buf < limit);

      le16_add_cpu(&prev_de->rec_len, bytes);
}

/*
 * We allocate enough clusters to fulfill "blocks_wanted", but set
 * i_size to exactly one block. Ocfs2_extend_dir() will handle the
 * rest automatically for us.
 *
 * *first_block_bh is a pointer to the 1st data block allocated to the
 *  directory.
 */
static int ocfs2_expand_inline_dir(struct inode *dir, struct buffer_head *di_bh,
                           unsigned int blocks_wanted,
                           struct buffer_head **first_block_bh)
{
      int ret, credits = OCFS2_INLINE_TO_EXTENTS_CREDITS;
      u32 alloc, bit_off, len;
      struct super_block *sb = dir->i_sb;
      u64 blkno, bytes = blocks_wanted << sb->s_blocksize_bits;
      struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
      struct ocfs2_inode_info *oi = OCFS2_I(dir);
      struct ocfs2_alloc_context *data_ac;
      struct buffer_head *dirdata_bh = NULL;
      struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
      handle_t *handle;

      alloc = ocfs2_clusters_for_bytes(sb, bytes);

      /*
       * We should never need more than 2 clusters for this -
       * maximum dirent size is far less than one block. In fact,
       * the only time we'd need more than one cluster is if
       * blocksize == clustersize and the dirent won't fit in the
       * extra space that the expansion to a single block gives. As
       * of today, that only happens on 4k/4k file systems.
       */
      BUG_ON(alloc > 2);

      ret = ocfs2_reserve_clusters(osb, alloc, &data_ac);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      down_write(&oi->ip_alloc_sem);

      /*
       * Prepare for worst case allocation scenario of two seperate
       * extents.
       */
      if (alloc == 2)
            credits += OCFS2_SUBALLOC_ALLOC;

      handle = ocfs2_start_trans(osb, credits);
      if (IS_ERR(handle)) {
            ret = PTR_ERR(handle);
            mlog_errno(ret);
            goto out_sem;
      }

      /*
       * Try to claim as many clusters as the bitmap can give though
       * if we only get one now, that's enough to continue. The rest
       * will be claimed after the conversion to extents.
       */
      ret = ocfs2_claim_clusters(osb, handle, data_ac, 1, &bit_off, &len);
      if (ret) {
            mlog_errno(ret);
            goto out_commit;
      }

      /*
       * Operations are carefully ordered so that we set up the new
       * data block first. The conversion from inline data to
       * extents follows.
       */
      blkno = ocfs2_clusters_to_blocks(dir->i_sb, bit_off);
      dirdata_bh = sb_getblk(sb, blkno);
      if (!dirdata_bh) {
            ret = -EIO;
            mlog_errno(ret);
            goto out_commit;
      }

      ocfs2_set_new_buffer_uptodate(dir, dirdata_bh);

      ret = ocfs2_journal_access(handle, dir, dirdata_bh,
                           OCFS2_JOURNAL_ACCESS_CREATE);
      if (ret) {
            mlog_errno(ret);
            goto out_commit;
      }

      memcpy(dirdata_bh->b_data, di->id2.i_data.id_data, i_size_read(dir));
      memset(dirdata_bh->b_data + i_size_read(dir), 0,
             sb->s_blocksize - i_size_read(dir));
      ocfs2_expand_last_dirent(dirdata_bh->b_data, i_size_read(dir),
                         sb->s_blocksize);

      ret = ocfs2_journal_dirty(handle, dirdata_bh);
      if (ret) {
            mlog_errno(ret);
            goto out_commit;
      }

      /*
       * Set extent, i_size, etc on the directory. After this, the
       * inode should contain the same exact dirents as before and
       * be fully accessible from system calls.
       *
       * We let the later dirent insert modify c/mtime - to the user
       * the data hasn't changed.
       */
      ret = ocfs2_journal_access(handle, dir, di_bh,
                           OCFS2_JOURNAL_ACCESS_CREATE);
      if (ret) {
            mlog_errno(ret);
            goto out_commit;
      }

      spin_lock(&oi->ip_lock);
      oi->ip_dyn_features &= ~OCFS2_INLINE_DATA_FL;
      di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
      spin_unlock(&oi->ip_lock);

      ocfs2_dinode_new_extent_list(dir, di);

      i_size_write(dir, sb->s_blocksize);
      dir->i_mtime = dir->i_ctime = CURRENT_TIME;

      di->i_size = cpu_to_le64(sb->s_blocksize);
      di->i_ctime = di->i_mtime = cpu_to_le64(dir->i_ctime.tv_sec);
      di->i_ctime_nsec = di->i_mtime_nsec = cpu_to_le32(dir->i_ctime.tv_nsec);
      dir->i_blocks = ocfs2_inode_sector_count(dir);

      /*
       * This should never fail as our extent list is empty and all
       * related blocks have been journaled already.
       */
      ret = ocfs2_insert_extent(osb, handle, dir, di_bh, 0, blkno, len, 0,
                          NULL);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_journal_dirty(handle, di_bh);
      if (ret) {
            mlog_errno(ret);
            goto out_commit;
      }

      /*
       * We asked for two clusters, but only got one in the 1st
       * pass. Claim the 2nd cluster as a separate extent.
       */
      if (alloc > len) {
            ret = ocfs2_claim_clusters(osb, handle, data_ac, 1, &bit_off,
                                 &len);
            if (ret) {
                  mlog_errno(ret);
                  goto out_commit;
            }
            blkno = ocfs2_clusters_to_blocks(dir->i_sb, bit_off);

            ret = ocfs2_insert_extent(osb, handle, dir, di_bh, 1, blkno,
                                len, 0, NULL);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }
      }

      *first_block_bh = dirdata_bh;
      dirdata_bh = NULL;

out_commit:
      ocfs2_commit_trans(osb, handle);

out_sem:
      up_write(&oi->ip_alloc_sem);

out:
      if (data_ac)
            ocfs2_free_alloc_context(data_ac);

      brelse(dirdata_bh);

      return ret;
}

/* returns a bh of the 1st new block in the allocation. */
static int ocfs2_do_extend_dir(struct super_block *sb,
                         handle_t *handle,
                         struct inode *dir,
                         struct buffer_head *parent_fe_bh,
                         struct ocfs2_alloc_context *data_ac,
                         struct ocfs2_alloc_context *meta_ac,
                         struct buffer_head **new_bh)
{
      int status;
      int extend;
      u64 p_blkno, v_blkno;

      spin_lock(&OCFS2_I(dir)->ip_lock);
      extend = (i_size_read(dir) == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters));
      spin_unlock(&OCFS2_I(dir)->ip_lock);

      if (extend) {
            u32 offset = OCFS2_I(dir)->ip_clusters;

            status = ocfs2_do_extend_allocation(OCFS2_SB(sb), dir, &offset,
                                        1, 0, parent_fe_bh, handle,
                                        data_ac, meta_ac, NULL);
            BUG_ON(status == -EAGAIN);
            if (status < 0) {
                  mlog_errno(status);
                  goto bail;
            }
      }

      v_blkno = ocfs2_blocks_for_bytes(sb, i_size_read(dir));
      status = ocfs2_extent_map_get_blocks(dir, v_blkno, &p_blkno, NULL, NULL);
      if (status < 0) {
            mlog_errno(status);
            goto bail;
      }

      *new_bh = sb_getblk(sb, p_blkno);
      if (!*new_bh) {
            status = -EIO;
            mlog_errno(status);
            goto bail;
      }
      status = 0;
bail:
      mlog_exit(status);
      return status;
}

/*
 * Assumes you already have a cluster lock on the directory.
 *
 * 'blocks_wanted' is only used if we have an inline directory which
 * is to be turned into an extent based one. The size of the dirent to
 * insert might be larger than the space gained by growing to just one
 * block, so we may have to grow the inode by two blocks in that case.
 */
static int ocfs2_extend_dir(struct ocfs2_super *osb,
                      struct inode *dir,
                      struct buffer_head *parent_fe_bh,
                      unsigned int blocks_wanted,
                      struct buffer_head **new_de_bh)
{
      int status = 0;
      int credits, num_free_extents, drop_alloc_sem = 0;
      loff_t dir_i_size;
      struct ocfs2_dinode *fe = (struct ocfs2_dinode *) parent_fe_bh->b_data;
      struct ocfs2_alloc_context *data_ac = NULL;
      struct ocfs2_alloc_context *meta_ac = NULL;
      handle_t *handle = NULL;
      struct buffer_head *new_bh = NULL;
      struct ocfs2_dir_entry * de;
      struct super_block *sb = osb->sb;

      mlog_entry_void();

      if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
            status = ocfs2_expand_inline_dir(dir, parent_fe_bh,
                                     blocks_wanted, &new_bh);
            if (status) {
                  mlog_errno(status);
                  goto bail;
            }

            if (blocks_wanted == 1) {
                  /*
                   * If the new dirent will fit inside the space
                   * created by pushing out to one block, then
                   * we can complete the operation
                   * here. Otherwise we have to expand i_size
                   * and format the 2nd block below.
                   */
                  BUG_ON(new_bh == NULL);
                  goto bail_bh;
            }

            /*
             * Get rid of 'new_bh' - we want to format the 2nd
             * data block and return that instead.
             */
            brelse(new_bh);
            new_bh = NULL;

            dir_i_size = i_size_read(dir);
            credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS;
            goto do_extend;
      }

      dir_i_size = i_size_read(dir);
      mlog(0, "extending dir %llu (i_size = %lld)\n",
           (unsigned long long)OCFS2_I(dir)->ip_blkno, dir_i_size);

      /* dir->i_size is always block aligned. */
      spin_lock(&OCFS2_I(dir)->ip_lock);
      if (dir_i_size == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)) {
            spin_unlock(&OCFS2_I(dir)->ip_lock);
            num_free_extents = ocfs2_num_free_extents(osb, dir, fe);
            if (num_free_extents < 0) {
                  status = num_free_extents;
                  mlog_errno(status);
                  goto bail;
            }

            if (!num_free_extents) {
                  status = ocfs2_reserve_new_metadata(osb, fe, &meta_ac);
                  if (status < 0) {
                        if (status != -ENOSPC)
                              mlog_errno(status);
                        goto bail;
                  }
            }

            status = ocfs2_reserve_clusters(osb, 1, &data_ac);
            if (status < 0) {
                  if (status != -ENOSPC)
                        mlog_errno(status);
                  goto bail;
            }

            credits = ocfs2_calc_extend_credits(sb, fe, 1);
      } else {
            spin_unlock(&OCFS2_I(dir)->ip_lock);
            credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS;
      }

do_extend:
      down_write(&OCFS2_I(dir)->ip_alloc_sem);
      drop_alloc_sem = 1;

      handle = ocfs2_start_trans(osb, credits);
      if (IS_ERR(handle)) {
            status = PTR_ERR(handle);
            handle = NULL;
            mlog_errno(status);
            goto bail;
      }

      status = ocfs2_do_extend_dir(osb->sb, handle, dir, parent_fe_bh,
                             data_ac, meta_ac, &new_bh);
      if (status < 0) {
            mlog_errno(status);
            goto bail;
      }

      ocfs2_set_new_buffer_uptodate(dir, new_bh);

      status = ocfs2_journal_access(handle, dir, new_bh,
                              OCFS2_JOURNAL_ACCESS_CREATE);
      if (status < 0) {
            mlog_errno(status);
            goto bail;
      }
      memset(new_bh->b_data, 0, sb->s_blocksize);
      de = (struct ocfs2_dir_entry *) new_bh->b_data;
      de->inode = 0;
      de->rec_len = cpu_to_le16(sb->s_blocksize);
      status = ocfs2_journal_dirty(handle, new_bh);
      if (status < 0) {
            mlog_errno(status);
            goto bail;
      }

      dir_i_size += dir->i_sb->s_blocksize;
      i_size_write(dir, dir_i_size);
      dir->i_blocks = ocfs2_inode_sector_count(dir);
      status = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh);
      if (status < 0) {
            mlog_errno(status);
            goto bail;
      }

bail_bh:
      *new_de_bh = new_bh;
      get_bh(*new_de_bh);
bail:
      if (drop_alloc_sem)
            up_write(&OCFS2_I(dir)->ip_alloc_sem);
      if (handle)
            ocfs2_commit_trans(osb, handle);

      if (data_ac)
            ocfs2_free_alloc_context(data_ac);
      if (meta_ac)
            ocfs2_free_alloc_context(meta_ac);

      if (new_bh)
            brelse(new_bh);

      mlog_exit(status);
      return status;
}

static int ocfs2_find_dir_space_id(struct inode *dir, struct buffer_head *di_bh,
                           const char *name, int namelen,
                           struct buffer_head **ret_de_bh,
                           unsigned int *blocks_wanted)
{
      int ret;
      struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
      struct ocfs2_dir_entry *de, *last_de = NULL;
      char *de_buf, *limit;
      unsigned long offset = 0;
      unsigned int rec_len, new_rec_len;

      de_buf = di->id2.i_data.id_data;
      limit = de_buf + i_size_read(dir);
      rec_len = OCFS2_DIR_REC_LEN(namelen);

      while (de_buf < limit) {
            de = (struct ocfs2_dir_entry *)de_buf;

            if (!ocfs2_check_dir_entry(dir, de, di_bh, offset)) {
                  ret = -ENOENT;
                  goto out;
            }
            if (ocfs2_match(namelen, name, de)) {
                  ret = -EEXIST;
                  goto out;
            }
            if (ocfs2_dirent_would_fit(de, rec_len)) {
                  /* Ok, we found a spot. Return this bh and let
                   * the caller actually fill it in. */
                  *ret_de_bh = di_bh;
                  get_bh(*ret_de_bh);
                  ret = 0;
                  goto out;
            }

            last_de = de;
            de_buf += le16_to_cpu(de->rec_len);
            offset += le16_to_cpu(de->rec_len);
      }

      /*
       * We're going to require expansion of the directory - figure
       * out how many blocks we'll need so that a place for the
       * dirent can be found.
       */
      *blocks_wanted = 1;
      new_rec_len = le16_to_cpu(last_de->rec_len) + (dir->i_sb->s_blocksize - i_size_read(dir));
      if (new_rec_len < (rec_len + OCFS2_DIR_REC_LEN(last_de->name_len)))
            *blocks_wanted = 2;

      ret = -ENOSPC;
out:
      return ret;
}

static int ocfs2_find_dir_space_el(struct inode *dir, const char *name,
                           int namelen, struct buffer_head **ret_de_bh)
{
      unsigned long offset;
      struct buffer_head *bh = NULL;
      unsigned short rec_len;
      struct ocfs2_dir_entry *de;
      struct super_block *sb = dir->i_sb;
      int status;

      bh = ocfs2_bread(dir, 0, &status, 0);
      if (!bh) {
            mlog_errno(status);
            goto bail;
      }

      rec_len = OCFS2_DIR_REC_LEN(namelen);
      offset = 0;
      de = (struct ocfs2_dir_entry *) bh->b_data;
      while (1) {
            if ((char *)de >= sb->s_blocksize + bh->b_data) {
                  brelse(bh);
                  bh = NULL;

                  if (i_size_read(dir) <= offset) {
                        /*
                         * Caller will have to expand this
                         * directory.
                         */
                        status = -ENOSPC;
                        goto bail;
                  }
                  bh = ocfs2_bread(dir,
                               offset >> sb->s_blocksize_bits,
                               &status,
                               0);
                  if (!bh) {
                        mlog_errno(status);
                        goto bail;
                  }
                  /* move to next block */
                  de = (struct ocfs2_dir_entry *) bh->b_data;
            }
            if (!ocfs2_check_dir_entry(dir, de, bh, offset)) {
                  status = -ENOENT;
                  goto bail;
            }
            if (ocfs2_match(namelen, name, de)) {
                  status = -EEXIST;
                  goto bail;
            }
            if (ocfs2_dirent_would_fit(de, rec_len)) {
                  /* Ok, we found a spot. Return this bh and let
                   * the caller actually fill it in. */
                  *ret_de_bh = bh;
                  get_bh(*ret_de_bh);
                  status = 0;
                  goto bail;
            }
            offset += le16_to_cpu(de->rec_len);
            de = (struct ocfs2_dir_entry *)((char *) de + le16_to_cpu(de->rec_len));
      }

      status = 0;
bail:
      if (bh)
            brelse(bh);

      mlog_exit(status);
      return status;
}

int ocfs2_prepare_dir_for_insert(struct ocfs2_super *osb,
                         struct inode *dir,
                         struct buffer_head *parent_fe_bh,
                         const char *name,
                         int namelen,
                         struct buffer_head **ret_de_bh)
{
      int ret;
      unsigned int blocks_wanted = 1;
      struct buffer_head *bh = NULL;

      mlog(0, "getting ready to insert namelen %d into dir %llu\n",
           namelen, (unsigned long long)OCFS2_I(dir)->ip_blkno);

      *ret_de_bh = NULL;

      if (!namelen) {
            ret = -EINVAL;
            mlog_errno(ret);
            goto out;
      }

      if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
            ret = ocfs2_find_dir_space_id(dir, parent_fe_bh, name,
                                    namelen, &bh, &blocks_wanted);
      } else
            ret = ocfs2_find_dir_space_el(dir, name, namelen, &bh);

      if (ret && ret != -ENOSPC) {
            mlog_errno(ret);
            goto out;
      }

      if (ret == -ENOSPC) {
            /*
             * We have to expand the directory to add this name.
             */
            BUG_ON(bh);

            ret = ocfs2_extend_dir(osb, dir, parent_fe_bh, blocks_wanted,
                               &bh);
            if (ret) {
                  if (ret != -ENOSPC)
                        mlog_errno(ret);
                  goto out;
            }

            BUG_ON(!bh);
      }

      *ret_de_bh = bh;
      bh = NULL;
out:
      if (bh)
            brelse(bh);
      return ret;
}

Generated by  Doxygen 1.6.0   Back to index