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 (*len < GFS2_SMALL_FH_SIZE || 40 (connectable && *len < GFS2_LARGE_FH_SIZE)) 41 return 255; 42 43 fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32); 44 fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF); 45 fh[2] = cpu_to_be32(ip->i_no_addr >> 32); 46 fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF); 47 *len = GFS2_SMALL_FH_SIZE; 48 49 if (!connectable || inode == sb->s_root->d_inode) 50 return *len; 51 52 spin_lock(&dentry->d_lock); 53 inode = dentry->d_parent->d_inode; 54 ip = GFS2_I(inode); 55 igrab(inode); 56 spin_unlock(&dentry->d_lock); 57 58 fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32); 59 fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF); 60 fh[6] = cpu_to_be32(ip->i_no_addr >> 32); 61 fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF); 62 *len = GFS2_LARGE_FH_SIZE; 63 64 iput(inode); 65 66 return *len; 67 } 68 69 struct get_name_filldir { 70 struct gfs2_inum_host inum; 71 char *name; 72 }; 73 74 static int get_name_filldir(void *opaque, const char *name, int length, 75 loff_t offset, u64 inum, unsigned int type) 76 { 77 struct get_name_filldir *gnfd = opaque; 78 79 if (inum != gnfd->inum.no_addr) 80 return 0; 81 82 memcpy(gnfd->name, name, length); 83 gnfd->name[length] = 0; 84 85 return 1; 86 } 87 88 static int gfs2_get_name(struct dentry *parent, char *name, 89 struct dentry *child) 90 { 91 struct inode *dir = parent->d_inode; 92 struct inode *inode = child->d_inode; 93 struct gfs2_inode *dip, *ip; 94 struct get_name_filldir gnfd; 95 struct gfs2_holder gh; 96 u64 offset = 0; 97 int error; 98 99 if (!dir) 100 return -EINVAL; 101 102 if (!S_ISDIR(dir->i_mode) || !inode) 103 return -EINVAL; 104 105 dip = GFS2_I(dir); 106 ip = GFS2_I(inode); 107 108 *name = 0; 109 gnfd.inum.no_addr = ip->i_no_addr; 110 gnfd.inum.no_formal_ino = ip->i_no_formal_ino; 111 gnfd.name = name; 112 113 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh); 114 if (error) 115 return error; 116 117 error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir); 118 119 gfs2_glock_dq_uninit(&gh); 120 121 if (!error && !*name) 122 error = -ENOENT; 123 124 return error; 125 } 126 127 static struct dentry *gfs2_get_parent(struct dentry *child) 128 { 129 struct qstr dotdot; 130 struct dentry *dentry; 131 132 /* 133 * XXX(hch): it would be a good idea to keep this around as a 134 * static variable. 135 */ 136 gfs2_str2qstr(&dotdot, ".."); 137 138 dentry = d_obtain_alias(gfs2_lookupi(child->d_inode, &dotdot, 1)); 139 if (!IS_ERR(dentry)) 140 dentry->d_op = &gfs2_dops; 141 return dentry; 142 } 143 144 static struct dentry *gfs2_get_dentry(struct super_block *sb, 145 struct gfs2_inum_host *inum) 146 { 147 struct gfs2_sbd *sdp = sb->s_fs_info; 148 struct gfs2_holder i_gh; 149 struct inode *inode; 150 struct dentry *dentry; 151 int error; 152 153 inode = gfs2_ilookup(sb, inum->no_addr); 154 if (inode) { 155 if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) { 156 iput(inode); 157 return ERR_PTR(-ESTALE); 158 } 159 goto out_inode; 160 } 161 162 error = gfs2_glock_nq_num(sdp, inum->no_addr, &gfs2_inode_glops, 163 LM_ST_SHARED, LM_FLAG_ANY, &i_gh); 164 if (error) 165 return ERR_PTR(error); 166 167 error = gfs2_check_blk_type(sdp, inum->no_addr, GFS2_BLKST_DINODE); 168 if (error) 169 goto fail; 170 171 inode = gfs2_inode_lookup(sb, DT_UNKNOWN, inum->no_addr, 0); 172 if (IS_ERR(inode)) { 173 error = PTR_ERR(inode); 174 goto fail; 175 } 176 177 error = gfs2_inode_refresh(GFS2_I(inode)); 178 if (error) { 179 iput(inode); 180 goto fail; 181 } 182 183 /* Pick up the works we bypass in gfs2_inode_lookup */ 184 if (inode->i_state & I_NEW) 185 gfs2_set_iop(inode); 186 187 if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) { 188 iput(inode); 189 goto fail; 190 } 191 192 error = -EIO; 193 if (GFS2_I(inode)->i_diskflags & GFS2_DIF_SYSTEM) { 194 iput(inode); 195 goto fail; 196 } 197 198 gfs2_glock_dq_uninit(&i_gh); 199 200 out_inode: 201 dentry = d_obtain_alias(inode); 202 if (!IS_ERR(dentry)) 203 dentry->d_op = &gfs2_dops; 204 return dentry; 205 fail: 206 gfs2_glock_dq_uninit(&i_gh); 207 return ERR_PTR(error); 208 } 209 210 static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 211 int fh_len, int fh_type) 212 { 213 struct gfs2_inum_host this; 214 __be32 *fh = (__force __be32 *)fid->raw; 215 216 switch (fh_type) { 217 case GFS2_SMALL_FH_SIZE: 218 case GFS2_LARGE_FH_SIZE: 219 case GFS2_OLD_FH_SIZE: 220 this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32; 221 this.no_formal_ino |= be32_to_cpu(fh[1]); 222 this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32; 223 this.no_addr |= be32_to_cpu(fh[3]); 224 return gfs2_get_dentry(sb, &this); 225 default: 226 return NULL; 227 } 228 } 229 230 static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid, 231 int fh_len, int fh_type) 232 { 233 struct gfs2_inum_host parent; 234 __be32 *fh = (__force __be32 *)fid->raw; 235 236 switch (fh_type) { 237 case GFS2_LARGE_FH_SIZE: 238 case GFS2_OLD_FH_SIZE: 239 parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32; 240 parent.no_formal_ino |= be32_to_cpu(fh[5]); 241 parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32; 242 parent.no_addr |= be32_to_cpu(fh[7]); 243 return gfs2_get_dentry(sb, &parent); 244 default: 245 return NULL; 246 } 247 } 248 249 const struct export_operations gfs2_export_ops = { 250 .encode_fh = gfs2_encode_fh, 251 .fh_to_dentry = gfs2_fh_to_dentry, 252 .fh_to_parent = gfs2_fh_to_parent, 253 .get_name = gfs2_get_name, 254 .get_parent = gfs2_get_parent, 255 }; 256 257