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 FILEID_INVALID; 41 } else if (*len < GFS2_SMALL_FH_SIZE) { 42 *len = GFS2_SMALL_FH_SIZE; 43 return FILEID_INVALID; 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 == d_inode(sb->s_root)) 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 dir_context ctx; 68 struct gfs2_inum_host inum; 69 char *name; 70 }; 71 72 static int get_name_filldir(struct dir_context *ctx, const char *name, 73 int length, loff_t offset, u64 inum, 74 unsigned int type) 75 { 76 struct get_name_filldir *gnfd = 77 container_of(ctx, struct get_name_filldir, ctx); 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 = d_inode(parent); 92 struct inode *inode = d_inode(child); 93 struct gfs2_inode *dip, *ip; 94 struct get_name_filldir gnfd = { 95 .ctx.actor = get_name_filldir, 96 .name = name 97 }; 98 struct gfs2_holder gh; 99 int error; 100 struct file_ra_state f_ra = { .start = 0 }; 101 102 if (!dir) 103 return -EINVAL; 104 105 if (!S_ISDIR(dir->i_mode) || !inode) 106 return -EINVAL; 107 108 dip = GFS2_I(dir); 109 ip = GFS2_I(inode); 110 111 *name = 0; 112 gnfd.inum.no_addr = ip->i_no_addr; 113 gnfd.inum.no_formal_ino = ip->i_no_formal_ino; 114 115 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh); 116 if (error) 117 return error; 118 119 error = gfs2_dir_read(dir, &gnfd.ctx, &f_ra); 120 121 gfs2_glock_dq_uninit(&gh); 122 123 if (!error && !*name) 124 error = -ENOENT; 125 126 return error; 127 } 128 129 static struct dentry *gfs2_get_parent(struct dentry *child) 130 { 131 return d_obtain_alias(gfs2_lookupi(d_inode(child), &gfs2_qdotdot, 1)); 132 } 133 134 static struct dentry *gfs2_get_dentry(struct super_block *sb, 135 struct gfs2_inum_host *inum) 136 { 137 struct gfs2_sbd *sdp = sb->s_fs_info; 138 struct inode *inode; 139 140 inode = gfs2_ilookup(sb, inum->no_addr, 0); 141 if (inode) { 142 if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) { 143 iput(inode); 144 return ERR_PTR(-ESTALE); 145 } 146 goto out_inode; 147 } 148 149 inode = gfs2_lookup_by_inum(sdp, inum->no_addr, &inum->no_formal_ino, 150 GFS2_BLKST_DINODE); 151 if (IS_ERR(inode)) 152 return ERR_CAST(inode); 153 154 out_inode: 155 return d_obtain_alias(inode); 156 } 157 158 static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 159 int fh_len, int fh_type) 160 { 161 struct gfs2_inum_host this; 162 __be32 *fh = (__force __be32 *)fid->raw; 163 164 switch (fh_type) { 165 case GFS2_SMALL_FH_SIZE: 166 case GFS2_LARGE_FH_SIZE: 167 case GFS2_OLD_FH_SIZE: 168 if (fh_len < GFS2_SMALL_FH_SIZE) 169 return NULL; 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 if (fh_len < GFS2_LARGE_FH_SIZE) 190 return NULL; 191 parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32; 192 parent.no_formal_ino |= be32_to_cpu(fh[5]); 193 parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32; 194 parent.no_addr |= be32_to_cpu(fh[7]); 195 return gfs2_get_dentry(sb, &parent); 196 default: 197 return NULL; 198 } 199 } 200 201 const struct export_operations gfs2_export_ops = { 202 .encode_fh = gfs2_encode_fh, 203 .fh_to_dentry = gfs2_fh_to_dentry, 204 .fh_to_parent = gfs2_fh_to_parent, 205 .get_name = gfs2_get_name, 206 .get_parent = gfs2_get_parent, 207 }; 208 209