1 /* 2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. 4 * 5 * This copyrighted material is made available to anyone wishing to use, 6 * modify, copy, or redistribute it subject to the terms and conditions 7 * of the GNU General Public License version 2. 8 */ 9 10 #include <linux/spinlock.h> 11 #include <linux/completion.h> 12 #include <linux/buffer_head.h> 13 #include <linux/exportfs.h> 14 #include <linux/gfs2_ondisk.h> 15 #include <linux/crc32.h> 16 17 #include "gfs2.h" 18 #include "incore.h" 19 #include "dir.h" 20 #include "glock.h" 21 #include "glops.h" 22 #include "inode.h" 23 #include "super.h" 24 #include "rgrp.h" 25 #include "util.h" 26 27 #define GFS2_SMALL_FH_SIZE 4 28 #define GFS2_LARGE_FH_SIZE 8 29 #define GFS2_OLD_FH_SIZE 10 30 31 static int gfs2_encode_fh(struct dentry *dentry, __u32 *p, int *len, 32 int connectable) 33 { 34 __be32 *fh = (__force __be32 *)p; 35 struct inode *inode = dentry->d_inode; 36 struct super_block *sb = inode->i_sb; 37 struct gfs2_inode *ip = GFS2_I(inode); 38 39 if (connectable && (*len < GFS2_LARGE_FH_SIZE)) { 40 *len = GFS2_LARGE_FH_SIZE; 41 return 255; 42 } else if (*len < GFS2_SMALL_FH_SIZE) { 43 *len = GFS2_SMALL_FH_SIZE; 44 return 255; 45 } 46 47 fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32); 48 fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF); 49 fh[2] = cpu_to_be32(ip->i_no_addr >> 32); 50 fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF); 51 *len = GFS2_SMALL_FH_SIZE; 52 53 if (!connectable || inode == sb->s_root->d_inode) 54 return *len; 55 56 spin_lock(&dentry->d_lock); 57 inode = dentry->d_parent->d_inode; 58 ip = GFS2_I(inode); 59 igrab(inode); 60 spin_unlock(&dentry->d_lock); 61 62 fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32); 63 fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF); 64 fh[6] = cpu_to_be32(ip->i_no_addr >> 32); 65 fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF); 66 *len = GFS2_LARGE_FH_SIZE; 67 68 iput(inode); 69 70 return *len; 71 } 72 73 struct get_name_filldir { 74 struct gfs2_inum_host inum; 75 char *name; 76 }; 77 78 static int get_name_filldir(void *opaque, const char *name, int length, 79 loff_t offset, u64 inum, unsigned int type) 80 { 81 struct get_name_filldir *gnfd = opaque; 82 83 if (inum != gnfd->inum.no_addr) 84 return 0; 85 86 memcpy(gnfd->name, name, length); 87 gnfd->name[length] = 0; 88 89 return 1; 90 } 91 92 static int gfs2_get_name(struct dentry *parent, char *name, 93 struct dentry *child) 94 { 95 struct inode *dir = parent->d_inode; 96 struct inode *inode = child->d_inode; 97 struct gfs2_inode *dip, *ip; 98 struct get_name_filldir gnfd; 99 struct gfs2_holder gh; 100 u64 offset = 0; 101 int error; 102 103 if (!dir) 104 return -EINVAL; 105 106 if (!S_ISDIR(dir->i_mode) || !inode) 107 return -EINVAL; 108 109 dip = GFS2_I(dir); 110 ip = GFS2_I(inode); 111 112 *name = 0; 113 gnfd.inum.no_addr = ip->i_no_addr; 114 gnfd.inum.no_formal_ino = ip->i_no_formal_ino; 115 gnfd.name = name; 116 117 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh); 118 if (error) 119 return error; 120 121 error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir); 122 123 gfs2_glock_dq_uninit(&gh); 124 125 if (!error && !*name) 126 error = -ENOENT; 127 128 return error; 129 } 130 131 static struct dentry *gfs2_get_parent(struct dentry *child) 132 { 133 return d_obtain_alias(gfs2_lookupi(child->d_inode, &gfs2_qdotdot, 1)); 134 } 135 136 static struct dentry *gfs2_get_dentry(struct super_block *sb, 137 struct gfs2_inum_host *inum) 138 { 139 struct gfs2_sbd *sdp = sb->s_fs_info; 140 struct inode *inode; 141 142 inode = gfs2_ilookup(sb, inum->no_addr); 143 if (inode) { 144 if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) { 145 iput(inode); 146 return ERR_PTR(-ESTALE); 147 } 148 goto out_inode; 149 } 150 151 inode = gfs2_lookup_by_inum(sdp, inum->no_addr, &inum->no_formal_ino, 152 GFS2_BLKST_DINODE); 153 if (IS_ERR(inode)) 154 return ERR_CAST(inode); 155 156 out_inode: 157 return d_obtain_alias(inode); 158 } 159 160 static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 161 int fh_len, int fh_type) 162 { 163 struct gfs2_inum_host this; 164 __be32 *fh = (__force __be32 *)fid->raw; 165 166 switch (fh_type) { 167 case GFS2_SMALL_FH_SIZE: 168 case GFS2_LARGE_FH_SIZE: 169 case GFS2_OLD_FH_SIZE: 170 this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32; 171 this.no_formal_ino |= be32_to_cpu(fh[1]); 172 this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32; 173 this.no_addr |= be32_to_cpu(fh[3]); 174 return gfs2_get_dentry(sb, &this); 175 default: 176 return NULL; 177 } 178 } 179 180 static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid, 181 int fh_len, int fh_type) 182 { 183 struct gfs2_inum_host parent; 184 __be32 *fh = (__force __be32 *)fid->raw; 185 186 switch (fh_type) { 187 case GFS2_LARGE_FH_SIZE: 188 case GFS2_OLD_FH_SIZE: 189 parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32; 190 parent.no_formal_ino |= be32_to_cpu(fh[5]); 191 parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32; 192 parent.no_addr |= be32_to_cpu(fh[7]); 193 return gfs2_get_dentry(sb, &parent); 194 default: 195 return NULL; 196 } 197 } 198 199 const struct export_operations gfs2_export_ops = { 200 .encode_fh = gfs2_encode_fh, 201 .fh_to_dentry = gfs2_fh_to_dentry, 202 .fh_to_parent = gfs2_fh_to_parent, 203 .get_name = gfs2_get_name, 204 .get_parent = gfs2_get_parent, 205 }; 206 207