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 inode *inode, __u32 *p, int *len, 32 struct inode *parent) 33 { 34 __be32 *fh = (__force __be32 *)p; 35 struct super_block *sb = inode->i_sb; 36 struct gfs2_inode *ip = GFS2_I(inode); 37 38 if (parent && (*len < GFS2_LARGE_FH_SIZE)) { 39 *len = GFS2_LARGE_FH_SIZE; 40 return 255; 41 } else if (*len < GFS2_SMALL_FH_SIZE) { 42 *len = GFS2_SMALL_FH_SIZE; 43 return 255; 44 } 45 46 fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32); 47 fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF); 48 fh[2] = cpu_to_be32(ip->i_no_addr >> 32); 49 fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF); 50 *len = GFS2_SMALL_FH_SIZE; 51 52 if (!parent || inode == sb->s_root->d_inode) 53 return *len; 54 55 ip = GFS2_I(parent); 56 57 fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32); 58 fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF); 59 fh[6] = cpu_to_be32(ip->i_no_addr >> 32); 60 fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF); 61 *len = GFS2_LARGE_FH_SIZE; 62 63 return *len; 64 } 65 66 struct get_name_filldir { 67 struct gfs2_inum_host inum; 68 char *name; 69 }; 70 71 static int get_name_filldir(void *opaque, const char *name, int length, 72 loff_t offset, u64 inum, unsigned int type) 73 { 74 struct get_name_filldir *gnfd = opaque; 75 76 if (inum != gnfd->inum.no_addr) 77 return 0; 78 79 memcpy(gnfd->name, name, length); 80 gnfd->name[length] = 0; 81 82 return 1; 83 } 84 85 static int gfs2_get_name(struct dentry *parent, char *name, 86 struct dentry *child) 87 { 88 struct inode *dir = parent->d_inode; 89 struct inode *inode = child->d_inode; 90 struct gfs2_inode *dip, *ip; 91 struct get_name_filldir gnfd; 92 struct gfs2_holder gh; 93 u64 offset = 0; 94 int error; 95 struct file_ra_state f_ra = { .start = 0 }; 96 97 if (!dir) 98 return -EINVAL; 99 100 if (!S_ISDIR(dir->i_mode) || !inode) 101 return -EINVAL; 102 103 dip = GFS2_I(dir); 104 ip = GFS2_I(inode); 105 106 *name = 0; 107 gnfd.inum.no_addr = ip->i_no_addr; 108 gnfd.inum.no_formal_ino = ip->i_no_formal_ino; 109 gnfd.name = name; 110 111 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh); 112 if (error) 113 return error; 114 115 error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir, &f_ra); 116 117 gfs2_glock_dq_uninit(&gh); 118 119 if (!error && !*name) 120 error = -ENOENT; 121 122 return error; 123 } 124 125 static struct dentry *gfs2_get_parent(struct dentry *child) 126 { 127 return d_obtain_alias(gfs2_lookupi(child->d_inode, &gfs2_qdotdot, 1)); 128 } 129 130 static struct dentry *gfs2_get_dentry(struct super_block *sb, 131 struct gfs2_inum_host *inum) 132 { 133 struct gfs2_sbd *sdp = sb->s_fs_info; 134 struct inode *inode; 135 136 inode = gfs2_ilookup(sb, inum->no_addr, 0); 137 if (inode) { 138 if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) { 139 iput(inode); 140 return ERR_PTR(-ESTALE); 141 } 142 goto out_inode; 143 } 144 145 inode = gfs2_lookup_by_inum(sdp, inum->no_addr, &inum->no_formal_ino, 146 GFS2_BLKST_DINODE); 147 if (IS_ERR(inode)) 148 return ERR_CAST(inode); 149 150 out_inode: 151 return d_obtain_alias(inode); 152 } 153 154 static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 155 int fh_len, int fh_type) 156 { 157 struct gfs2_inum_host this; 158 __be32 *fh = (__force __be32 *)fid->raw; 159 160 switch (fh_type) { 161 case GFS2_SMALL_FH_SIZE: 162 case GFS2_LARGE_FH_SIZE: 163 case GFS2_OLD_FH_SIZE: 164 if (fh_len < GFS2_SMALL_FH_SIZE) 165 return NULL; 166 this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32; 167 this.no_formal_ino |= be32_to_cpu(fh[1]); 168 this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32; 169 this.no_addr |= be32_to_cpu(fh[3]); 170 return gfs2_get_dentry(sb, &this); 171 default: 172 return NULL; 173 } 174 } 175 176 static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid, 177 int fh_len, int fh_type) 178 { 179 struct gfs2_inum_host parent; 180 __be32 *fh = (__force __be32 *)fid->raw; 181 182 switch (fh_type) { 183 case GFS2_LARGE_FH_SIZE: 184 case GFS2_OLD_FH_SIZE: 185 if (fh_len < GFS2_LARGE_FH_SIZE) 186 return NULL; 187 parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32; 188 parent.no_formal_ino |= be32_to_cpu(fh[5]); 189 parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32; 190 parent.no_addr |= be32_to_cpu(fh[7]); 191 return gfs2_get_dentry(sb, &parent); 192 default: 193 return NULL; 194 } 195 } 196 197 const struct export_operations gfs2_export_ops = { 198 .encode_fh = gfs2_encode_fh, 199 .fh_to_dentry = gfs2_fh_to_dentry, 200 .fh_to_parent = gfs2_fh_to_parent, 201 .get_name = gfs2_get_name, 202 .get_parent = gfs2_get_parent, 203 }; 204 205