diff options
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_export.c')
| -rw-r--r-- | fs/xfs/linux-2.6/xfs_export.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/fs/xfs/linux-2.6/xfs_export.c b/fs/xfs/linux-2.6/xfs_export.c new file mode 100644 index 000000000000..f372a1a5e168 --- /dev/null +++ b/fs/xfs/linux-2.6/xfs_export.c @@ -0,0 +1,205 @@ +/* + * Copyright (c) 2004-2005 Silicon Graphics, Inc. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * + * Further, this software is distributed without any warranty that it is + * free of the rightful claim of any third person regarding infringement + * or the like. Any license provided herein, whether implied or + * otherwise, applies only to this software file. Patent licenses, if + * any, provided herein do not apply to combinations of this program with + * other software, or any other product whatsoever. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write the Free Software Foundation, Inc., 59 + * Temple Place - Suite 330, Boston MA 02111-1307, USA. + * + * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy, + * Mountain View, CA 94043, or: + * + * http://www.sgi.com + * + * For further information regarding this notice, see: + * + * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/ + */ + +#include "xfs.h" +#include "xfs_types.h" +#include "xfs_dmapi.h" +#include "xfs_log.h" +#include "xfs_trans.h" +#include "xfs_sb.h" +#include "xfs_dir.h" +#include "xfs_mount.h" +#include "xfs_export.h" + +/* + * XFS encode and decodes the fileid portion of NFS filehandles + * itself instead of letting the generic NFS code do it. This + * allows filesystems with 64 bit inode numbers to be exported. + * + * Note that a side effect is that xfs_vget() won't be passed a + * zero inode/generation pair under normal circumstances. As + * however a malicious client could send us such data, the check + * remains in that code. + */ + + +STATIC struct dentry * +linvfs_decode_fh( + struct super_block *sb, + __u32 *fh, + int fh_len, + int fileid_type, + int (*acceptable)( + void *context, + struct dentry *de), + void *context) +{ + xfs_fid2_t ifid; + xfs_fid2_t pfid; + void *parent = NULL; + int is64 = 0; + __u32 *p = fh; + +#if XFS_BIG_INUMS + is64 = (fileid_type & XFS_FILEID_TYPE_64FLAG); + fileid_type &= ~XFS_FILEID_TYPE_64FLAG; +#endif + + /* + * Note that we only accept fileids which are long enough + * rather than allow the parent generation number to default + * to zero. XFS considers zero a valid generation number not + * an invalid/wildcard value. There's little point printk'ing + * a warning here as we don't have the client information + * which would make such a warning useful. + */ + if (fileid_type > 2 || + fh_len < xfs_fileid_length((fileid_type == 2), is64)) + return NULL; + + p = xfs_fileid_decode_fid2(p, &ifid, is64); + + if (fileid_type == 2) { + p = xfs_fileid_decode_fid2(p, &pfid, is64); + parent = &pfid; + } + + fh = (__u32 *)&ifid; + return find_exported_dentry(sb, fh, parent, acceptable, context); +} + + +STATIC int +linvfs_encode_fh( + struct dentry *dentry, + __u32 *fh, + int *max_len, + int connectable) +{ + struct inode *inode = dentry->d_inode; + int type = 1; + __u32 *p = fh; + int len; + int is64 = 0; +#if XFS_BIG_INUMS + vfs_t *vfs = LINVFS_GET_VFS(inode->i_sb); + xfs_mount_t *mp = XFS_VFSTOM(vfs); + + if (!(mp->m_flags & XFS_MOUNT_32BITINOOPT)) { + /* filesystem may contain 64bit inode numbers */ + is64 = XFS_FILEID_TYPE_64FLAG; + } +#endif + + /* Directories don't need their parent encoded, they have ".." */ + if (S_ISDIR(inode->i_mode)) + connectable = 0; + + /* + * Only encode if there is enough space given. In practice + * this means we can't export a filesystem with 64bit inodes + * over NFSv2 with the subtree_check export option; the other + * seven combinations work. The real answer is "don't use v2". + */ + len = xfs_fileid_length(connectable, is64); + if (*max_len < len) + return 255; + *max_len = len; + + p = xfs_fileid_encode_inode(p, inode, is64); + if (connectable) { + spin_lock(&dentry->d_lock); + p = xfs_fileid_encode_inode(p, dentry->d_parent->d_inode, is64); + spin_unlock(&dentry->d_lock); + type = 2; + } + BUG_ON((p - fh) != len); + return type | is64; +} + +STATIC struct dentry * +linvfs_get_dentry( + struct super_block *sb, + void *data) +{ + vnode_t *vp; + struct inode *inode; + struct dentry *result; + vfs_t *vfsp = LINVFS_GET_VFS(sb); + int error; + + VFS_VGET(vfsp, &vp, (fid_t *)data, error); + if (error || vp == NULL) + return ERR_PTR(-ESTALE) ; + + inode = LINVFS_GET_IP(vp); + result = d_alloc_anon(inode); + if (!result) { + iput(inode); + return ERR_PTR(-ENOMEM); + } + return result; +} + +STATIC struct dentry * +linvfs_get_parent( + struct dentry *child) +{ + int error; + vnode_t *vp, *cvp; + struct dentry *parent; + struct dentry dotdot; + + dotdot.d_name.name = ".."; + dotdot.d_name.len = 2; + dotdot.d_inode = NULL; + + cvp = NULL; + vp = LINVFS_GET_VP(child->d_inode); + VOP_LOOKUP(vp, &dotdot, &cvp, 0, NULL, NULL, error); + if (unlikely(error)) + return ERR_PTR(-error); + + parent = d_alloc_anon(LINVFS_GET_IP(cvp)); + if (unlikely(!parent)) { + VN_RELE(cvp); + return ERR_PTR(-ENOMEM); + } + return parent; +} + +struct export_operations linvfs_export_ops = { + .decode_fh = linvfs_decode_fh, + .encode_fh = linvfs_encode_fh, + .get_parent = linvfs_get_parent, + .get_dentry = linvfs_get_dentry, +}; |