/* * 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 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. 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 the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include "xfs.h" #include "xfs_format.h" #include "xfs_log_format.h" #include "xfs_trans_resv.h" #include "xfs_mount.h" #include "xfs_da_format.h" #include "xfs_dir2.h" #include "xfs_export.h" #include "xfs_inode.h" #include "xfs_trans.h" #include "xfs_inode_item.h" #include "xfs_trace.h" #include "xfs_icache.h" #include "xfs_log.h" /* * 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. */ static int xfs_fileid_length(int fileid_type) { switch (fileid_type) { case FILEID_INO32_GEN: return 2; case FILEID_INO32_GEN_PARENT: return 4; case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG: return 3; case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: return 6; } return FILEID_INVALID; } STATIC int xfs_fs_encode_fh( struct inode *inode, __u32 *fh, int *max_len, struct inode *parent) { struct fid *fid = (struct fid *)fh; struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fh; int fileid_type; int len; /* Directories don't need their parent encoded, they have ".." */ if (!parent) fileid_type = FILEID_INO32_GEN; else fileid_type = FILEID_INO32_GEN_PARENT; /* * If the the filesystem may contain 64bit inode numbers, we need * to use larger file handles that can represent them. * * While we only allocate inodes that do not fit into 32 bits any * large enough filesystem may contain them, thus the slightly * confusing looking conditional below. */ if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS) || (XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_32BITINODES)) fileid_type |= XFS_FILEID_TYPE_64FLAG; /* * 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(fileid_type); if (*max_len < len) { *max_len = len; return FILEID_INVALID; } *max_len = len; switch (fileid_type) { case FILEID_INO32_GEN_PARENT: fid->i32.parent_ino = XFS_I(parent)->i_ino; fid->i32.parent_gen = parent->i_generation; /*FALLTHRU*/ case FILEID_INO32_GEN: fid->i32.ino = XFS_I(inode)->i_ino; fid->i32.gen = inode->i_generation; break; case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: fid64->parent_ino = XFS_I(parent)->i_ino; fid64->parent_gen = parent->i_generation; /*FALLTHRU*/ case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG: fid64->ino = XFS_I(inode)->i_ino; fid64->gen = inode->i_generation; break; } return fileid_type; } STATIC struct inode * xfs_nfs_get_inode( struct super_block *sb, u64 ino, u32 generation) { xfs_mount_t *mp = XFS_M(sb); xfs_inode_t *ip; int error; /* * NFS can sometimes send requests for ino 0. Fail them gracefully. */ if (ino == 0) return ERR_PTR(-ESTALE); /* * The XFS_IGET_UNTRUSTED means that an invalid inode number is just * fine and not an indication of a corrupted filesystem as clients can * send invalid file handles and we have to handle it gracefully.. */ error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip); if (error) { /* * EINVAL means the inode cluster doesn't exist anymore. * This implies the filehandle is stale, so we should * translate it here. * We don't use ESTALE directly down the chain to not * confuse applications using bulkstat that expect EINVAL. */ if (error == -EINVAL || error == -ENOENT) error = -ESTALE; return ERR_PTR(error); } if (ip->i_d.di_gen != generation) { IRELE(ip); return ERR_PTR(-ESTALE); } return VFS_I(ip); } STATIC struct dentry * xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, int fileid_type) { struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid; struct inode *inode = NULL; if (fh_len < xfs_fileid_length(fileid_type)) return NULL; switch (fileid_type) { case FILEID_INO32_GEN_PARENT: case FILEID_INO32_GEN: inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen); break; case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG: inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen); break; } return d_obtain_alias(inode); } STATIC struct dentry * xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len, int fileid_type) { struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid; struct inode *inode = NULL; if (fh_len < xfs_fileid_length(fileid_type)) return NULL; switch (fileid_type) { case FILEID_INO32_GEN_PARENT: inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino, fid->i32.parent_gen); break; case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: inode = xfs_nfs_get_inode(sb, fid64->parent_ino, fid64->parent_gen); break; } return d_obtain_alias(inode); } STATIC struct dentry * xfs_fs_get_parent( struct dentry *child) { int error; struct xfs_inode *cip; error = xfs_lookup(XFS_I(child->d_inode), &xfs_name_dotdot, &cip, NULL); if (unlikely(error)) return ERR_PTR(error); return d_obtain_alias(VFS_I(cip)); } STATIC int xfs_fs_nfs_commit_metadata( struct inode *inode) { struct xfs_inode *ip = XFS_I(inode); struct xfs_mount *mp = ip->i_mount; xfs_lsn_t lsn = 0; xfs_ilock(ip, XFS_ILOCK_SHARED); if (xfs_ipincount(ip)) lsn = ip->i_itemp->ili_last_lsn; xfs_iunlock(ip, XFS_ILOCK_SHARED); if (!lsn) return 0; return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL); } const struct export_operations xfs_export_operations = { .encode_fh = xfs_fs_encode_fh, .fh_to_dentry = xfs_fs_fh_to_dentry, .fh_to_parent = xfs_fs_fh_to_parent, .get_parent = xfs_fs_get_parent, .commit_metadata = xfs_fs_nfs_commit_metadata, };