1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or https://opensource.org/licenses/CDDL-1.0. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2011 Gunnar Beutner 23 * Copyright (c) 2012 Cyril Plisko. All rights reserved. 24 */ 25 26 27 #include <sys/file.h> 28 #include <sys/zfs_znode.h> 29 #include <sys/zfs_vnops.h> 30 #include <sys/zfs_ctldir.h> 31 #include <sys/zpl.h> 32 33 34 static int 35 zpl_encode_fh(struct inode *ip, __u32 *fh, int *max_len, struct inode *parent) 36 { 37 fstrans_cookie_t cookie; 38 ushort_t empty_fid = 0; 39 fid_t *fid; 40 int len_bytes, rc; 41 42 len_bytes = *max_len * sizeof (__u32); 43 44 if (len_bytes < offsetof(fid_t, fid_data)) { 45 fid = (fid_t *)&empty_fid; 46 } else { 47 fid = (fid_t *)fh; 48 fid->fid_len = len_bytes - offsetof(fid_t, fid_data); 49 } 50 51 cookie = spl_fstrans_mark(); 52 53 if (zfsctl_is_node(ip)) 54 rc = zfsctl_fid(ip, fid); 55 else 56 rc = zfs_fid(ip, fid); 57 58 spl_fstrans_unmark(cookie); 59 len_bytes = offsetof(fid_t, fid_data) + fid->fid_len; 60 *max_len = roundup(len_bytes, sizeof (__u32)) / sizeof (__u32); 61 62 return (rc == 0 ? FILEID_INO32_GEN : 255); 63 } 64 65 static struct dentry * 66 zpl_fh_to_dentry(struct super_block *sb, struct fid *fh, 67 int fh_len, int fh_type) 68 { 69 fid_t *fid = (fid_t *)fh; 70 fstrans_cookie_t cookie; 71 struct inode *ip; 72 int len_bytes, rc; 73 74 len_bytes = fh_len * sizeof (__u32); 75 76 if (fh_type != FILEID_INO32_GEN || 77 len_bytes < offsetof(fid_t, fid_data) || 78 len_bytes < offsetof(fid_t, fid_data) + fid->fid_len) 79 return (ERR_PTR(-EINVAL)); 80 81 cookie = spl_fstrans_mark(); 82 rc = zfs_vget(sb, &ip, fid); 83 spl_fstrans_unmark(cookie); 84 85 if (rc) { 86 /* 87 * If we see ENOENT it might mean that an NFSv4 * client 88 * is using a cached inode value in a file handle and 89 * that the sought after file has had its inode changed 90 * by a third party. So change the error to ESTALE 91 * which will trigger a full lookup by the client and 92 * will find the new filename/inode pair if it still 93 * exists. 94 */ 95 if (rc == ENOENT) 96 rc = ESTALE; 97 98 return (ERR_PTR(-rc)); 99 } 100 101 ASSERT((ip != NULL) && !IS_ERR(ip)); 102 103 return (d_obtain_alias(ip)); 104 } 105 106 /* 107 * In case the filesystem contains name longer than 255, we need to override 108 * the default get_name so we don't get buffer overflow. Unfortunately, since 109 * the buffer size is hardcoded in Linux, we will get ESTALE error in this 110 * case. 111 */ 112 static int 113 zpl_get_name(struct dentry *parent, char *name, struct dentry *child) 114 { 115 cred_t *cr = CRED(); 116 fstrans_cookie_t cookie; 117 struct inode *dir = parent->d_inode; 118 struct inode *ip = child->d_inode; 119 int error; 120 121 if (!dir || !S_ISDIR(dir->i_mode)) 122 return (-ENOTDIR); 123 124 crhold(cr); 125 cookie = spl_fstrans_mark(); 126 spl_inode_lock_shared(dir); 127 error = -zfs_get_name(ITOZ(dir), name, ITOZ(ip)); 128 spl_inode_unlock_shared(dir); 129 spl_fstrans_unmark(cookie); 130 crfree(cr); 131 132 return (error); 133 } 134 135 static struct dentry * 136 zpl_get_parent(struct dentry *child) 137 { 138 cred_t *cr = CRED(); 139 fstrans_cookie_t cookie; 140 znode_t *zp; 141 int error; 142 143 crhold(cr); 144 cookie = spl_fstrans_mark(); 145 error = -zfs_lookup(ITOZ(child->d_inode), "..", &zp, 0, cr, NULL, NULL); 146 spl_fstrans_unmark(cookie); 147 crfree(cr); 148 ASSERT3S(error, <=, 0); 149 150 if (error) 151 return (ERR_PTR(error)); 152 153 return (d_obtain_alias(ZTOI(zp))); 154 } 155 156 static int 157 zpl_commit_metadata(struct inode *inode) 158 { 159 cred_t *cr = CRED(); 160 fstrans_cookie_t cookie; 161 int error; 162 163 if (zfsctl_is_node(inode)) 164 return (0); 165 166 crhold(cr); 167 cookie = spl_fstrans_mark(); 168 error = -zfs_fsync(ITOZ(inode), 0, cr); 169 spl_fstrans_unmark(cookie); 170 crfree(cr); 171 ASSERT3S(error, <=, 0); 172 173 return (error); 174 } 175 176 const struct export_operations zpl_export_operations = { 177 .encode_fh = zpl_encode_fh, 178 .fh_to_dentry = zpl_fh_to_dentry, 179 .get_name = zpl_get_name, 180 .get_parent = zpl_get_parent, 181 .commit_metadata = zpl_commit_metadata, 182 }; 183