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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 | /* * linux/fs/adfs/inode.c * * Copyright (C) 1997-1999 Russell King * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/buffer_head.h> #include <linux/writeback.h> #include "adfs.h" /* * Lookup/Create a block at offset 'block' into 'inode'. We currently do * not support creation of new blocks, so we return -EIO for this case. */ static int adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh, int create) { if (!create) { if (block >= inode->i_blocks) goto abort_toobig; block = __adfs_block_map(inode->i_sb, inode->i_ino, block); if (block) map_bh(bh, inode->i_sb, block); return 0; } /* don't support allocation of blocks yet */ return -EIO; abort_toobig: return 0; } static int adfs_writepage(struct page *page, struct writeback_control *wbc) { return block_write_full_page(page, adfs_get_block, wbc); } static int adfs_readpage(struct file *file, struct page *page) { return block_read_full_page(page, adfs_get_block); } static void adfs_write_failed(struct address_space *mapping, loff_t to) { struct inode *inode = mapping->host; if (to > inode->i_size) truncate_pagecache(inode, to, inode->i_size); } static int adfs_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata) { int ret; *pagep = NULL; ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, adfs_get_block, &ADFS_I(mapping->host)->mmu_private); if (unlikely(ret)) adfs_write_failed(mapping, pos + len); return ret; } static sector_t _adfs_bmap(struct address_space *mapping, sector_t block) { return generic_block_bmap(mapping, block, adfs_get_block); } static const struct address_space_operations adfs_aops = { .readpage = adfs_readpage, .writepage = adfs_writepage, .write_begin = adfs_write_begin, .write_end = generic_write_end, .bmap = _adfs_bmap }; /* * Convert ADFS attributes and filetype to Linux permission. */ static umode_t adfs_atts2mode(struct super_block *sb, struct inode *inode) { unsigned int attr = ADFS_I(inode)->attr; umode_t mode, rmask; struct adfs_sb_info *asb = ADFS_SB(sb); if (attr & ADFS_NDA_DIRECTORY) { mode = S_IRUGO & asb->s_owner_mask; return S_IFDIR | S_IXUGO | mode; } switch (ADFS_I(inode)->filetype) { case 0xfc0: /* LinkFS */ return S_IFLNK|S_IRWXUGO; case 0xfe6: /* UnixExec */ rmask = S_IRUGO | S_IXUGO; break; default: rmask = S_IRUGO; } mode = S_IFREG; if (attr & ADFS_NDA_OWNER_READ) mode |= rmask & asb->s_owner_mask; if (attr & ADFS_NDA_OWNER_WRITE) mode |= S_IWUGO & asb->s_owner_mask; if (attr & ADFS_NDA_PUBLIC_READ) mode |= rmask & asb->s_other_mask; if (attr & ADFS_NDA_PUBLIC_WRITE) mode |= S_IWUGO & asb->s_other_mask; return mode; } /* * Convert Linux permission to ADFS attribute. We try to do the reverse * of atts2mode, but there is not a 1:1 translation. */ static int adfs_mode2atts(struct super_block *sb, struct inode *inode) { umode_t mode; int attr; struct adfs_sb_info *asb = ADFS_SB(sb); /* FIXME: should we be able to alter a link? */ if (S_ISLNK(inode->i_mode)) return ADFS_I(inode)->attr; if (S_ISDIR(inode->i_mode)) attr = ADFS_NDA_DIRECTORY; else attr = 0; mode = inode->i_mode & asb->s_owner_mask; if (mode & S_IRUGO) attr |= ADFS_NDA_OWNER_READ; if (mode & S_IWUGO) attr |= ADFS_NDA_OWNER_WRITE; mode = inode->i_mode & asb->s_other_mask; mode &= ~asb->s_owner_mask; if (mode & S_IRUGO) attr |= ADFS_NDA_PUBLIC_READ; if (mode & S_IWUGO) attr |= ADFS_NDA_PUBLIC_WRITE; return attr; } /* * Convert an ADFS time to Unix time. ADFS has a 40-bit centi-second time * referenced to 1 Jan 1900 (til 2248) so we need to discard 2208988800 seconds * of time to convert from RISC OS epoch to Unix epoch. */ static void adfs_adfs2unix_time(struct timespec *tv, struct inode *inode) { unsigned int high, low; /* 01 Jan 1970 00:00:00 (Unix epoch) as nanoseconds since * 01 Jan 1900 00:00:00 (RISC OS epoch) */ static const s64 nsec_unix_epoch_diff_risc_os_epoch = 2208988800000000000LL; s64 nsec; if (ADFS_I(inode)->stamped == 0) goto cur_time; high = ADFS_I(inode)->loadaddr & 0xFF; /* top 8 bits of timestamp */ low = ADFS_I(inode)->execaddr; /* bottom 32 bits of timestamp */ /* convert 40-bit centi-seconds to 32-bit seconds * going via nanoseconds to retain precision */ nsec = (((s64) high << 32) | (s64) low) * 10000000; /* cs to ns */ /* Files dated pre 01 Jan 1970 00:00:00. */ if (nsec < nsec_unix_epoch_diff_risc_os_epoch) goto too_early; /* convert from RISC OS to Unix epoch */ nsec -= nsec_unix_epoch_diff_risc_os_epoch; *tv = ns_to_timespec(nsec); return; cur_time: *tv = CURRENT_TIME; return; too_early: tv->tv_sec = tv->tv_nsec = 0; return; } /* * Convert an Unix time to ADFS time. We only do this if the entry has a * time/date stamp already. */ static void adfs_unix2adfs_time(struct inode *inode, unsigned int secs) { unsigned int high, low; if (ADFS_I(inode)->stamped) { /* convert 32-bit seconds to 40-bit centi-seconds */ low = (secs & 255) * 100; high = (secs / 256) * 100 + (low >> 8) + 0x336e996a; ADFS_I(inode)->loadaddr = (high >> 24) | (ADFS_I(inode)->loadaddr & ~0xff); ADFS_I(inode)->execaddr = (low & 255) | (high << 8); } } /* * Fill in the inode information from the object information. * * Note that this is an inode-less filesystem, so we can't use the inode * number to reference the metadata on the media. Instead, we use the * inode number to hold the object ID, which in turn will tell us where * the data is held. We also save the parent object ID, and with these * two, we can locate the metadata. * * This does mean that we rely on an objects parent remaining the same at * all times - we cannot cope with a cross-directory rename (yet). */ struct inode * adfs_iget(struct super_block *sb, struct object_info *obj) { struct inode *inode; inode = new_inode(sb); if (!inode) goto out; inode->i_uid = ADFS_SB(sb)->s_uid; inode->i_gid = ADFS_SB(sb)->s_gid; inode->i_ino = obj->file_id; inode->i_size = obj->size; set_nlink(inode, 2); inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits; /* * we need to save the parent directory ID so that * write_inode can update the directory information * for this file. This will need special handling * for cross-directory renames. */ ADFS_I(inode)->parent_id = obj->parent_id; ADFS_I(inode)->loadaddr = obj->loadaddr; ADFS_I(inode)->execaddr = obj->execaddr; ADFS_I(inode)->attr = obj->attr; ADFS_I(inode)->filetype = obj->filetype; ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000); inode->i_mode = adfs_atts2mode(sb, inode); adfs_adfs2unix_time(&inode->i_mtime, inode); inode->i_atime = inode->i_mtime; inode->i_ctime = inode->i_mtime; if (S_ISDIR(inode->i_mode)) { inode->i_op = &adfs_dir_inode_operations; inode->i_fop = &adfs_dir_operations; } else if (S_ISREG(inode->i_mode)) { inode->i_op = &adfs_file_inode_operations; inode->i_fop = &adfs_file_operations; inode->i_mapping->a_ops = &adfs_aops; ADFS_I(inode)->mmu_private = inode->i_size; } insert_inode_hash(inode); out: return inode; } /* * Validate and convert a changed access mode/time to their ADFS equivalents. * adfs_write_inode will actually write the information back to the directory * later. */ int adfs_notify_change(struct dentry *dentry, struct iattr *attr) { struct inode *inode = dentry->d_inode; struct super_block *sb = inode->i_sb; unsigned int ia_valid = attr->ia_valid; int error; error = inode_change_ok(inode, attr); /* * we can't change the UID or GID of any file - * we have a global UID/GID in the superblock */ if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, ADFS_SB(sb)->s_uid)) || (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, ADFS_SB(sb)->s_gid))) error = -EPERM; if (error) goto out; /* XXX: this is missing some actual on-disk truncation.. */ if (ia_valid & ATTR_SIZE) truncate_setsize(inode, attr->ia_size); if (ia_valid & ATTR_MTIME) { inode->i_mtime = attr->ia_mtime; adfs_unix2adfs_time(inode, attr->ia_mtime.tv_sec); } /* * FIXME: should we make these == to i_mtime since we don't * have the ability to represent them in our filesystem? */ if (ia_valid & ATTR_ATIME) inode->i_atime = attr->ia_atime; if (ia_valid & ATTR_CTIME) inode->i_ctime = attr->ia_ctime; if (ia_valid & ATTR_MODE) { ADFS_I(inode)->attr = adfs_mode2atts(sb, inode); inode->i_mode = adfs_atts2mode(sb, inode); } /* * FIXME: should we be marking this inode dirty even if * we don't have any metadata to write back? */ if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE)) mark_inode_dirty(inode); out: return error; } /* * write an existing inode back to the directory, and therefore the disk. * The adfs-specific inode data has already been updated by * adfs_notify_change() */ int adfs_write_inode(struct inode *inode, struct writeback_control *wbc) { struct super_block *sb = inode->i_sb; struct object_info obj; int ret; obj.file_id = inode->i_ino; obj.name_len = 0; obj.parent_id = ADFS_I(inode)->parent_id; obj.loadaddr = ADFS_I(inode)->loadaddr; obj.execaddr = ADFS_I(inode)->execaddr; obj.attr = ADFS_I(inode)->attr; obj.size = inode->i_size; ret = adfs_dir_update(sb, &obj, wbc->sync_mode == WB_SYNC_ALL); return ret; } |