[PATCH] OCFS2: The Second Oracle Cluster Filesystem

The OCFS2 file system module.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>

1 files changed, 618 insertions, 0 deletions

diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
new file mode 100644
index 00000000000..856e20ae826
--- /dev/null
+++ b/fs/ocfs2/dir.c
@@ -0,0 +1,618 @@
+/* -*- 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=%"MLFu64"\n", 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 #%"MLFu64" contains a hole "
+				       "at offset %lld\n",
+			     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_sem 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=%"MLFu64", name='%.*s', blkno=%p, "
+		   "inode=%p)\n",
+		   osb, 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_sem + 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 %"MLFu64", name '%.*s'\n", 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 #%"MLFu64") - "
+			       "no data block\n",
+		     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 #%"MLFu64") - "
+			       "no `.' or `..'\n",
+		     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, "directory #%"MLFu64" contains "
+					       "a hole at offset %lu\n",
+				     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 %"MLFu64" (i_size = %lld)\n",
+	     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 %"MLFu64"\n",
+	     namelen, 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;
+}