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) 2023, Klara Inc. 23 */ 24 25 #ifdef CONFIG_COMPAT 26 #include <linux/compat.h> 27 #endif 28 #include <linux/fs.h> 29 #include <sys/file.h> 30 #include <sys/zfs_znode.h> 31 #include <sys/zfs_vnops.h> 32 #include <sys/zfeature.h> 33 34 /* 35 * Clone part of a file via block cloning. 36 * 37 * Note that we are not required to update file offsets; the kernel will take 38 * care of that depending on how it was called. 39 */ 40 static ssize_t 41 zpl_clone_file_range_impl(struct file *src_file, loff_t src_off, 42 struct file *dst_file, loff_t dst_off, size_t len) 43 { 44 struct inode *src_i = file_inode(src_file); 45 struct inode *dst_i = file_inode(dst_file); 46 uint64_t src_off_o = (uint64_t)src_off; 47 uint64_t dst_off_o = (uint64_t)dst_off; 48 uint64_t len_o = (uint64_t)len; 49 cred_t *cr = CRED(); 50 fstrans_cookie_t cookie; 51 int err; 52 53 if (!zfs_bclone_enabled) 54 return (-EOPNOTSUPP); 55 56 if (!spa_feature_is_enabled( 57 dmu_objset_spa(ITOZSB(dst_i)->z_os), SPA_FEATURE_BLOCK_CLONING)) 58 return (-EOPNOTSUPP); 59 60 if (src_i != dst_i) 61 spl_inode_lock_shared(src_i); 62 spl_inode_lock(dst_i); 63 64 crhold(cr); 65 cookie = spl_fstrans_mark(); 66 67 err = -zfs_clone_range(ITOZ(src_i), &src_off_o, ITOZ(dst_i), 68 &dst_off_o, &len_o, cr); 69 70 spl_fstrans_unmark(cookie); 71 crfree(cr); 72 73 spl_inode_unlock(dst_i); 74 if (src_i != dst_i) 75 spl_inode_unlock_shared(src_i); 76 77 if (err < 0) 78 return (err); 79 80 return ((ssize_t)len_o); 81 } 82 83 #if defined(HAVE_VFS_COPY_FILE_RANGE) || \ 84 defined(HAVE_VFS_FILE_OPERATIONS_EXTEND) 85 /* 86 * Entry point for copy_file_range(). Copy len bytes from src_off in src_file 87 * to dst_off in dst_file. We are permitted to do this however we like, so we 88 * try to just clone the blocks, and if we can't support it, fall back to the 89 * kernel's generic byte copy function. 90 */ 91 ssize_t 92 zpl_copy_file_range(struct file *src_file, loff_t src_off, 93 struct file *dst_file, loff_t dst_off, size_t len, unsigned int flags) 94 { 95 ssize_t ret; 96 97 /* Flags is reserved for future extensions and must be zero. */ 98 if (flags != 0) 99 return (-EINVAL); 100 101 /* Try to do it via zfs_clone_range() and allow shortening. */ 102 ret = zpl_clone_file_range_impl(src_file, src_off, 103 dst_file, dst_off, len); 104 105 #ifdef HAVE_VFS_GENERIC_COPY_FILE_RANGE 106 /* 107 * Since Linux 5.3 the filesystem driver is responsible for executing 108 * an appropriate fallback, and a generic fallback function is provided. 109 */ 110 if (ret == -EOPNOTSUPP || ret == -EINVAL || ret == -EXDEV || 111 ret == -EAGAIN) 112 ret = generic_copy_file_range(src_file, src_off, dst_file, 113 dst_off, len, flags); 114 #else 115 /* 116 * Before Linux 5.3 the filesystem has to return -EOPNOTSUPP to signal 117 * to the kernel that it should fallback to a content copy. 118 */ 119 if (ret == -EINVAL || ret == -EXDEV || ret == -EAGAIN) 120 ret = -EOPNOTSUPP; 121 #endif /* HAVE_VFS_GENERIC_COPY_FILE_RANGE */ 122 123 return (ret); 124 } 125 #endif /* HAVE_VFS_COPY_FILE_RANGE || HAVE_VFS_FILE_OPERATIONS_EXTEND */ 126 127 #ifdef HAVE_VFS_REMAP_FILE_RANGE 128 /* 129 * Entry point for FICLONE/FICLONERANGE/FIDEDUPERANGE. 130 * 131 * FICLONE and FICLONERANGE are basically the same as copy_file_range(), except 132 * that they must clone - they cannot fall back to copying. FICLONE is exactly 133 * FICLONERANGE, for the entire file. We don't need to try to tell them apart; 134 * the kernel will sort that out for us. 135 * 136 * FIDEDUPERANGE is for turning a non-clone into a clone, that is, compare the 137 * range in both files and if they're the same, arrange for them to be backed 138 * by the same storage. 139 * 140 * REMAP_FILE_CAN_SHORTEN lets us know we can clone less than the given range 141 * if we want. It's designed for filesystems that may need to shorten the 142 * length for alignment, EOF, or any other requirement. ZFS may shorten the 143 * request when there is outstanding dirty data which hasn't been written. 144 */ 145 loff_t 146 zpl_remap_file_range(struct file *src_file, loff_t src_off, 147 struct file *dst_file, loff_t dst_off, loff_t len, unsigned int flags) 148 { 149 if (flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_CAN_SHORTEN)) 150 return (-EINVAL); 151 152 /* No support for dedup yet */ 153 if (flags & REMAP_FILE_DEDUP) 154 return (-EOPNOTSUPP); 155 156 /* Zero length means to clone everything to the end of the file */ 157 if (len == 0) 158 len = i_size_read(file_inode(src_file)) - src_off; 159 160 ssize_t ret = zpl_clone_file_range_impl(src_file, src_off, 161 dst_file, dst_off, len); 162 163 if (!(flags & REMAP_FILE_CAN_SHORTEN) && ret >= 0 && ret != len) 164 ret = -EINVAL; 165 166 return (ret); 167 } 168 #endif /* HAVE_VFS_REMAP_FILE_RANGE */ 169 170 #if defined(HAVE_VFS_CLONE_FILE_RANGE) || \ 171 defined(HAVE_VFS_FILE_OPERATIONS_EXTEND) 172 /* 173 * Entry point for FICLONE and FICLONERANGE, before Linux 4.20. 174 */ 175 int 176 zpl_clone_file_range(struct file *src_file, loff_t src_off, 177 struct file *dst_file, loff_t dst_off, uint64_t len) 178 { 179 /* Zero length means to clone everything to the end of the file */ 180 if (len == 0) 181 len = i_size_read(file_inode(src_file)) - src_off; 182 183 /* The entire length must be cloned or this is an error. */ 184 ssize_t ret = zpl_clone_file_range_impl(src_file, src_off, 185 dst_file, dst_off, len); 186 187 if (ret >= 0 && ret != len) 188 ret = -EINVAL; 189 190 return (ret); 191 } 192 #endif /* HAVE_VFS_CLONE_FILE_RANGE || HAVE_VFS_FILE_OPERATIONS_EXTEND */ 193 194 #ifdef HAVE_VFS_DEDUPE_FILE_RANGE 195 /* 196 * Entry point for FIDEDUPERANGE, before Linux 4.20. 197 */ 198 int 199 zpl_dedupe_file_range(struct file *src_file, loff_t src_off, 200 struct file *dst_file, loff_t dst_off, uint64_t len) 201 { 202 /* No support for dedup yet */ 203 return (-EOPNOTSUPP); 204 } 205 #endif /* HAVE_VFS_DEDUPE_FILE_RANGE */ 206 207 /* Entry point for FICLONE, before Linux 4.5. */ 208 long 209 zpl_ioctl_ficlone(struct file *dst_file, void *arg) 210 { 211 unsigned long sfd = (unsigned long)arg; 212 213 struct file *src_file = fget(sfd); 214 if (src_file == NULL) 215 return (-EBADF); 216 217 if (dst_file->f_op != src_file->f_op) { 218 fput(src_file); 219 return (-EXDEV); 220 } 221 222 size_t len = i_size_read(file_inode(src_file)); 223 224 ssize_t ret = zpl_clone_file_range_impl(src_file, 0, dst_file, 0, len); 225 226 fput(src_file); 227 228 if (ret < 0) { 229 if (ret == -EOPNOTSUPP) 230 return (-ENOTTY); 231 return (ret); 232 } 233 234 if (ret != len) 235 return (-EINVAL); 236 237 return (0); 238 } 239 240 /* Entry point for FICLONERANGE, before Linux 4.5. */ 241 long 242 zpl_ioctl_ficlonerange(struct file *dst_file, void __user *arg) 243 { 244 zfs_ioc_compat_file_clone_range_t fcr; 245 246 if (copy_from_user(&fcr, arg, sizeof (fcr))) 247 return (-EFAULT); 248 249 struct file *src_file = fget(fcr.fcr_src_fd); 250 if (src_file == NULL) 251 return (-EBADF); 252 253 if (dst_file->f_op != src_file->f_op) { 254 fput(src_file); 255 return (-EXDEV); 256 } 257 258 size_t len = fcr.fcr_src_length; 259 if (len == 0) 260 len = i_size_read(file_inode(src_file)) - fcr.fcr_src_offset; 261 262 ssize_t ret = zpl_clone_file_range_impl(src_file, fcr.fcr_src_offset, 263 dst_file, fcr.fcr_dest_offset, len); 264 265 fput(src_file); 266 267 if (ret < 0) { 268 if (ret == -EOPNOTSUPP) 269 return (-ENOTTY); 270 return (ret); 271 } 272 273 if (ret != len) 274 return (-EINVAL); 275 276 return (0); 277 } 278 279 /* Entry point for FIDEDUPERANGE, before Linux 4.5. */ 280 long 281 zpl_ioctl_fideduperange(struct file *filp, void *arg) 282 { 283 (void) arg; 284 285 /* No support for dedup yet */ 286 return (-ENOTTY); 287 } 288