This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / fs / ocfs2 / dir.c
diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
new file mode 100644 (file)
index 0000000..ae47f45
--- /dev/null
@@ -0,0 +1,616 @@
+/* -*- 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 "uptodate.h"
+
+#include "buffer_head_io.h"
+
+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,
+                           struct buffer_head **new_de_bh);
+/*
+ * ocfs2_readdir()
+ *
+ */
+int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir)
+{
+       int error = 0;
+       unsigned long offset, blk;
+       int i, num, stored;
+       struct buffer_head * bh, * tmp;
+       struct ocfs2_dir_entry * de;
+       int err;
+       struct inode *inode = filp->f_dentry->d_inode;
+       struct super_block * sb = inode->i_sb;
+       int have_disk_lock = 0;
+
+       mlog_entry("dirino=%llu\n",
+                  (unsigned long long)OCFS2_I(inode)->ip_blkno);
+
+       stored = 0;
+       bh = NULL;
+
+       error = ocfs2_meta_lock(inode, NULL, NULL, 0);
+       if (error < 0) {
+               if (error != -ENOENT)
+                       mlog_errno(error);
+               /* we haven't got any yet, so propagate the error. */
+               stored = error;
+               goto bail;
+       }
+       have_disk_lock = 1;
+
+       offset = filp->f_pos & (sb->s_blocksize - 1);
+
+       while (!error && !stored && filp->f_pos < i_size_read(inode)) {
+               blk = (filp->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,
+                            filp->f_pos);
+                       filp->f_pos += sb->s_blocksize - offset;
+                       continue;
+               }
+
+               /*
+                * Do the readahead (8k)
+                */
+               if (!offset) {
+                       for (i = 16 >> (sb->s_blocksize_bits - 9), num = 0;
+                            i > 0; i--) {
+                               tmp = ocfs2_bread(inode, ++blk, &err, 1);
+                               if (tmp)
+                                       brelse(tmp);
+                       }
+               }
+
+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 (filp->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;
+                       filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
+                               | offset;
+                       filp->f_version = inode->i_version;
+               }
+
+               while (!error && filp->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. */
+                               filp->f_pos = (filp->f_pos |
+                                              (sb->s_blocksize - 1)) + 1;
+                               brelse(bh);
+                               goto bail;
+                       }
+                       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 = filp->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(dirent, de->name,
+                                               de->name_len,
+                                               filp->f_pos,
+                                               ino_from_blkno(sb, le64_to_cpu(de->inode)),
+                                               d_type);
+                               if (error)
+                                       break;
+                               if (version != filp->f_version)
+                                       goto revalidate;
+                               stored ++;
+                       }
+                       filp->f_pos += le16_to_cpu(de->rec_len);
+               }
+               offset = 0;
+               brelse(bh);
+       }
+
+       stored = 0;
+bail:
+       if (have_disk_lock)
+               ocfs2_meta_unlock(inode, 0);
+
+       mlog_exit(stored);
+
+       return stored;
+}
+
+/*
+ * 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;
+       struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+       mlog_entry("(osb=%p, parent=%llu, name='%.*s', blkno=%p, inode=%p)\n",
+                  osb, (unsigned long long)OCFS2_I(inode)->ip_blkno,
+                  namelen, name, blkno, inode);
+
+       *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;
+}
+
+/* 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;
+}
+
+/*
+ * routine to check that the specified directory is empty (for rmdir)
+ */
+int ocfs2_empty_dir(struct inode *inode)
+{
+       unsigned long offset;
+       struct buffer_head * bh;
+       struct ocfs2_dir_entry * de, * de1;
+       struct super_block * sb;
+       int err;
+
+       sb = inode->i_sb;
+       if ((i_size_read(inode) <
+            (OCFS2_DIR_REC_LEN(1) + OCFS2_DIR_REC_LEN(2))) ||
+           !(bh = ocfs2_bread(inode, 0, &err, 0))) {
+               mlog(ML_ERROR, "bad directory (dir #%llu) - no data block\n",
+                    (unsigned long long)OCFS2_I(inode)->ip_blkno);
+               return 1;
+       }
+
+       de = (struct ocfs2_dir_entry *) bh->b_data;
+       de1 = (struct ocfs2_dir_entry *)
+                       ((char *)de + le16_to_cpu(de->rec_len));
+       if ((le64_to_cpu(de->inode) != OCFS2_I(inode)->ip_blkno) ||
+                       !le64_to_cpu(de1->inode) ||
+                       strcmp(".", de->name) ||
+                       strcmp("..", de1->name)) {
+               mlog(ML_ERROR, "bad directory (dir #%llu) - no `.' or `..'\n",
+                    (unsigned long long)OCFS2_I(inode)->ip_blkno);
+               brelse(bh);
+               return 1;
+       }
+       offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len);
+       de = (struct ocfs2_dir_entry *)((char *)de1 + le16_to_cpu(de1->rec_len));
+       while (offset < i_size_read(inode) ) {
+               if (!bh || (void *)de >= (void *)(bh->b_data + sb->s_blocksize)) {
+                       brelse(bh);
+                       bh = ocfs2_bread(inode,
+                                        offset >> sb->s_blocksize_bits, &err, 0);
+                       if (!bh) {
+                               mlog(ML_ERROR, "dir %llu has a hole at %lu\n",
+                                    (unsigned long long)OCFS2_I(inode)->ip_blkno, offset);
+                               offset += sb->s_blocksize;
+                               continue;
+                       }
+                       de = (struct ocfs2_dir_entry *) bh->b_data;
+               }
+               if (!ocfs2_check_dir_entry(inode, de, bh, offset)) {
+                       brelse(bh);
+                       return 1;
+               }
+               if (le64_to_cpu(de->inode)) {
+                       brelse(bh);
+                       return 0;
+               }
+               offset += le16_to_cpu(de->rec_len);
+               de = (struct ocfs2_dir_entry *)
+                       ((char *)de + le16_to_cpu(de->rec_len));
+       }
+       brelse(bh);
+       return 1;
+}
+
+/* returns a bh of the 1st new block in the allocation. */
+int ocfs2_do_extend_dir(struct super_block *sb,
+                       struct ocfs2_journal_handle *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;
+
+       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) {
+               status = ocfs2_do_extend_allocation(OCFS2_SB(sb), dir, 1,
+                                                   parent_fe_bh, handle,
+                                                   data_ac, meta_ac, NULL);
+               BUG_ON(status == -EAGAIN);
+               if (status < 0) {
+                       mlog_errno(status);
+                       goto bail;
+               }
+       }
+
+       status = ocfs2_extent_map_get_blocks(dir, (dir->i_blocks >>
+                                                  (sb->s_blocksize_bits - 9)),
+                                            1, &p_blkno, 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. */
+static int ocfs2_extend_dir(struct ocfs2_super *osb,
+                           struct inode *dir,
+                           struct buffer_head *parent_fe_bh,
+                           struct buffer_head **new_de_bh)
+{
+       int status = 0;
+       int credits, num_free_extents;
+       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;
+       struct ocfs2_journal_handle *handle = NULL;
+       struct buffer_head *new_bh = NULL;
+       struct ocfs2_dir_entry * de;
+       struct super_block *sb = osb->sb;
+
+       mlog_entry_void();
+
+       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);
+
+       handle = ocfs2_alloc_handle(osb);
+       if (handle == NULL) {
+               status = -ENOMEM;
+               mlog_errno(status);
+               goto bail;
+       }
+
+       /* 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, handle,
+                                                           fe, &meta_ac);
+                       if (status < 0) {
+                               if (status != -ENOSPC)
+                                       mlog_errno(status);
+                               goto bail;
+                       }
+               }
+
+               status = ocfs2_reserve_clusters(osb, handle, 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;
+       }
+
+       handle = ocfs2_start_trans(osb, handle, 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_align_bytes_to_sectors(dir_i_size);
+       status = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh);
+       if (status < 0) {
+               mlog_errno(status);
+               goto bail;
+       }
+
+       *new_de_bh = new_bh;
+       get_bh(*new_de_bh);
+bail:
+       if (handle)
+               ocfs2_commit_trans(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;
+}
+
+/*
+ * Search the dir for a good spot, extending it if necessary. The
+ * block containing an appropriate record is returned in ret_de_bh.
+ */
+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)
+{
+       unsigned long offset;
+       struct buffer_head * bh = NULL;
+       unsigned short rec_len;
+       struct ocfs2_dinode *fe;
+       struct ocfs2_dir_entry *de;
+       struct super_block *sb;
+       int status;
+
+       mlog_entry_void();
+
+       mlog(0, "getting ready to insert namelen %d into dir %llu\n",
+            namelen, (unsigned long long)OCFS2_I(dir)->ip_blkno);
+
+       BUG_ON(!S_ISDIR(dir->i_mode));
+       fe = (struct ocfs2_dinode *) parent_fe_bh->b_data;
+       BUG_ON(le64_to_cpu(fe->i_size) != i_size_read(dir));
+
+       sb = dir->i_sb;
+
+       if (!namelen) {
+               status = -EINVAL;
+               mlog_errno(status);
+               goto bail;
+       }
+
+       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) {
+                               status = ocfs2_extend_dir(osb,
+                                                         dir,
+                                                         parent_fe_bh,
+                                                         &bh);
+                               if (status < 0) {
+                                       mlog_errno(status);
+                                       goto bail;
+                               }
+                               BUG_ON(!bh);
+                               *ret_de_bh = bh;
+                               get_bh(*ret_de_bh);
+                               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 (((le64_to_cpu(de->inode) == 0) &&
+                    (le16_to_cpu(de->rec_len) >= rec_len)) ||
+                   (le16_to_cpu(de->rec_len) >=
+                    (OCFS2_DIR_REC_LEN(de->name_len) + 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;
+}