diff options
Diffstat (limited to 'fs/ocfs2/export.c')
| -rw-r--r-- | fs/ocfs2/export.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/fs/ocfs2/export.c b/fs/ocfs2/export.c new file mode 100644 index 00000000000..5810160d92a --- /dev/null +++ b/fs/ocfs2/export.c @@ -0,0 +1,248 @@ +/* -*- mode: c; c-basic-offset: 8; -*- + * vim: noexpandtab sw=8 ts=8 sts=0: + * + * export.c + * + * Functions to facilitate NFS exporting + * + * Copyright (C) 2002, 2005 Oracle. All rights reserved. + * + * 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> + +#define MLOG_MASK_PREFIX ML_EXPORT +#include <cluster/masklog.h> + +#include "ocfs2.h" + +#include "dir.h" +#include "dlmglue.h" +#include "export.h" +#include "inode.h" + +#include "buffer_head_io.h" + +struct ocfs2_inode_handle +{ + u64 ih_blkno; + u32 ih_generation; +}; + +static struct dentry *ocfs2_get_dentry(struct super_block *sb, void *vobjp) +{ + struct ocfs2_inode_handle *handle = vobjp; + struct inode *inode; + struct dentry *result; + + mlog_entry("(0x%p, 0x%p)\n", sb, handle); + + if (handle->ih_blkno == 0) { + mlog_errno(-ESTALE); + return ERR_PTR(-ESTALE); + } + + inode = ocfs2_iget(OCFS2_SB(sb), handle->ih_blkno); + + if (IS_ERR(inode)) { + mlog_errno(PTR_ERR(inode)); + return (void *)inode; + } + + if (handle->ih_generation != inode->i_generation) { + iput(inode); + mlog_errno(-ESTALE); + return ERR_PTR(-ESTALE); + } + + result = d_alloc_anon(inode); + + if (!result) { + iput(inode); + mlog_errno(-ENOMEM); + return ERR_PTR(-ENOMEM); + } + + mlog_exit_ptr(result); + return result; +} + +static struct dentry *ocfs2_get_parent(struct dentry *child) +{ + int status; + u64 blkno; + struct dentry *parent; + struct inode *inode; + struct inode *dir = child->d_inode; + struct buffer_head *dirent_bh = NULL; + struct ocfs2_dir_entry *dirent; + + mlog_entry("(0x%p, '%.*s')\n", child, + child->d_name.len, child->d_name.name); + + mlog(0, "find parent of directory %"MLFu64"\n", + OCFS2_I(dir)->ip_blkno); + + status = ocfs2_meta_lock(dir, NULL, NULL, 0); + if (status < 0) { + if (status != -ENOENT) + mlog_errno(status); + parent = ERR_PTR(status); + goto bail; + } + + status = ocfs2_find_files_on_disk("..", 2, &blkno, dir, &dirent_bh, + &dirent); + if (status < 0) { + parent = ERR_PTR(-ENOENT); + goto bail_unlock; + } + + inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno); + if (IS_ERR(inode)) { + mlog(ML_ERROR, "Unable to create inode %"MLFu64"\n", blkno); + parent = ERR_PTR(-EACCES); + goto bail_unlock; + } + + parent = d_alloc_anon(inode); + if (!parent) { + iput(inode); + parent = ERR_PTR(-ENOMEM); + } + +bail_unlock: + ocfs2_meta_unlock(dir, 0); + + if (dirent_bh) + brelse(dirent_bh); + +bail: + mlog_exit_ptr(parent); + + return parent; +} + +static int ocfs2_encode_fh(struct dentry *dentry, __be32 *fh, int *max_len, + int connectable) +{ + struct inode *inode = dentry->d_inode; + int len = *max_len; + int type = 1; + u64 blkno; + u32 generation; + + mlog_entry("(0x%p, '%.*s', 0x%p, %d, %d)\n", dentry, + dentry->d_name.len, dentry->d_name.name, + fh, len, connectable); + + if (len < 3 || (connectable && len < 6)) { + mlog(ML_ERROR, "fh buffer is too small for encoding\n"); + type = 255; + goto bail; + } + + blkno = OCFS2_I(inode)->ip_blkno; + generation = inode->i_generation; + + mlog(0, "Encoding fh: blkno: %"MLFu64", generation: %u\n", + blkno, generation); + + len = 3; + fh[0] = cpu_to_le32((u32)(blkno >> 32)); + fh[1] = cpu_to_le32((u32)(blkno & 0xffffffff)); + fh[2] = cpu_to_le32(generation); + + if (connectable && !S_ISDIR(inode->i_mode)) { + struct inode *parent; + + spin_lock(&dentry->d_lock); + + parent = dentry->d_parent->d_inode; + blkno = OCFS2_I(parent)->ip_blkno; + generation = parent->i_generation; + + fh[3] = cpu_to_le32((u32)(blkno >> 32)); + fh[4] = cpu_to_le32((u32)(blkno & 0xffffffff)); + fh[5] = cpu_to_le32(generation); + + spin_unlock(&dentry->d_lock); + + len = 6; + type = 2; + + mlog(0, "Encoding parent: blkno: %"MLFu64", generation: %u\n", + blkno, generation); + } + + *max_len = len; + +bail: + mlog_exit(type); + return type; +} + +static struct dentry *ocfs2_decode_fh(struct super_block *sb, __be32 *fh, + int fh_len, int fileid_type, + int (*acceptable)(void *context, + struct dentry *de), + void *context) +{ + struct ocfs2_inode_handle handle, parent; + struct dentry *ret = NULL; + + mlog_entry("(0x%p, 0x%p, %d, %d, 0x%p, 0x%p)\n", + sb, fh, fh_len, fileid_type, acceptable, context); + + if (fh_len < 3 || fileid_type > 2) + goto bail; + + if (fileid_type == 2) { + if (fh_len < 6) + goto bail; + + parent.ih_blkno = (u64)le32_to_cpu(fh[3]) << 32; + parent.ih_blkno |= (u64)le32_to_cpu(fh[4]); + parent.ih_generation = le32_to_cpu(fh[5]); + + mlog(0, "Decoding parent: blkno: %"MLFu64", generation: %u\n", + parent.ih_blkno, parent.ih_generation); + } + + handle.ih_blkno = (u64)le32_to_cpu(fh[0]) << 32; + handle.ih_blkno |= (u64)le32_to_cpu(fh[1]); + handle.ih_generation = le32_to_cpu(fh[2]); + + mlog(0, "Encoding fh: blkno: %"MLFu64", generation: %u\n", + handle.ih_blkno, handle.ih_generation); + + ret = ocfs2_export_ops.find_exported_dentry(sb, &handle, &parent, + acceptable, context); + +bail: + mlog_exit_ptr(ret); + return ret; +} + +struct export_operations ocfs2_export_ops = { + .decode_fh = ocfs2_decode_fh, + .encode_fh = ocfs2_encode_fh, + + .get_parent = ocfs2_get_parent, + .get_dentry = ocfs2_get_dentry, +}; 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