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1// SPDX-License-Identifier: GPL-2.02/*3 * linux/fs/affs/amigaffs.c4 *5 * (c) 1996 Hans-Joachim Widmaier - Rewritten6 *7 * (C) 1993 Ray Burr - Amiga FFS filesystem.8 *9 * Please send bug reports to: hjw@zvw.de10 */11 12#include <linux/math64.h>13#include <linux/iversion.h>14#include "affs.h"15 16/*17 * Functions for accessing Amiga-FFS structures.18 */19 20 21/* Insert a header block bh into the directory dir22 * caller must hold AFFS_DIR->i_hash_lock!23 */24 25int26affs_insert_hash(struct inode *dir, struct buffer_head *bh)27{28 struct super_block *sb = dir->i_sb;29 struct buffer_head *dir_bh;30 u32 ino, hash_ino;31 int offset;32 33 ino = bh->b_blocknr;34 offset = affs_hash_name(sb, AFFS_TAIL(sb, bh)->name + 1, AFFS_TAIL(sb, bh)->name[0]);35 36 pr_debug("%s(dir=%lu, ino=%d)\n", __func__, dir->i_ino, ino);37 38 dir_bh = affs_bread(sb, dir->i_ino);39 if (!dir_bh)40 return -EIO;41 42 hash_ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[offset]);43 while (hash_ino) {44 affs_brelse(dir_bh);45 dir_bh = affs_bread(sb, hash_ino);46 if (!dir_bh)47 return -EIO;48 hash_ino = be32_to_cpu(AFFS_TAIL(sb, dir_bh)->hash_chain);49 }50 AFFS_TAIL(sb, bh)->parent = cpu_to_be32(dir->i_ino);51 AFFS_TAIL(sb, bh)->hash_chain = 0;52 affs_fix_checksum(sb, bh);53 54 if (dir->i_ino == dir_bh->b_blocknr)55 AFFS_HEAD(dir_bh)->table[offset] = cpu_to_be32(ino);56 else57 AFFS_TAIL(sb, dir_bh)->hash_chain = cpu_to_be32(ino);58 59 affs_adjust_checksum(dir_bh, ino);60 mark_buffer_dirty_inode(dir_bh, dir);61 affs_brelse(dir_bh);62 63 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));64 inode_inc_iversion(dir);65 mark_inode_dirty(dir);66 67 return 0;68}69 70/* Remove a header block from its directory.71 * caller must hold AFFS_DIR->i_hash_lock!72 */73 74int75affs_remove_hash(struct inode *dir, struct buffer_head *rem_bh)76{77 struct super_block *sb;78 struct buffer_head *bh;79 u32 rem_ino, hash_ino;80 __be32 ino;81 int offset, retval;82 83 sb = dir->i_sb;84 rem_ino = rem_bh->b_blocknr;85 offset = affs_hash_name(sb, AFFS_TAIL(sb, rem_bh)->name+1, AFFS_TAIL(sb, rem_bh)->name[0]);86 pr_debug("%s(dir=%lu, ino=%d, hashval=%d)\n", __func__, dir->i_ino,87 rem_ino, offset);88 89 bh = affs_bread(sb, dir->i_ino);90 if (!bh)91 return -EIO;92 93 retval = -ENOENT;94 hash_ino = be32_to_cpu(AFFS_HEAD(bh)->table[offset]);95 while (hash_ino) {96 if (hash_ino == rem_ino) {97 ino = AFFS_TAIL(sb, rem_bh)->hash_chain;98 if (dir->i_ino == bh->b_blocknr)99 AFFS_HEAD(bh)->table[offset] = ino;100 else101 AFFS_TAIL(sb, bh)->hash_chain = ino;102 affs_adjust_checksum(bh, be32_to_cpu(ino) - hash_ino);103 mark_buffer_dirty_inode(bh, dir);104 AFFS_TAIL(sb, rem_bh)->parent = 0;105 retval = 0;106 break;107 }108 affs_brelse(bh);109 bh = affs_bread(sb, hash_ino);110 if (!bh)111 return -EIO;112 hash_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);113 }114 115 affs_brelse(bh);116 117 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));118 inode_inc_iversion(dir);119 mark_inode_dirty(dir);120 121 return retval;122}123 124static void125affs_fix_dcache(struct inode *inode, u32 entry_ino)126{127 struct dentry *dentry;128 spin_lock(&inode->i_lock);129 hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) {130 if (entry_ino == (u32)(long)dentry->d_fsdata) {131 dentry->d_fsdata = (void *)inode->i_ino;132 break;133 }134 }135 spin_unlock(&inode->i_lock);136}137 138 139/* Remove header from link chain */140 141static int142affs_remove_link(struct dentry *dentry)143{144 struct inode *dir, *inode = d_inode(dentry);145 struct super_block *sb = inode->i_sb;146 struct buffer_head *bh, *link_bh = NULL;147 u32 link_ino, ino;148 int retval;149 150 pr_debug("%s(key=%ld)\n", __func__, inode->i_ino);151 retval = -EIO;152 bh = affs_bread(sb, inode->i_ino);153 if (!bh)154 goto done;155 156 link_ino = (u32)(long)dentry->d_fsdata;157 if (inode->i_ino == link_ino) {158 /* we can't remove the head of the link, as its blocknr is still used as ino,159 * so we remove the block of the first link instead.160 */ 161 link_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain);162 link_bh = affs_bread(sb, link_ino);163 if (!link_bh)164 goto done;165 166 dir = affs_iget(sb, be32_to_cpu(AFFS_TAIL(sb, link_bh)->parent));167 if (IS_ERR(dir)) {168 retval = PTR_ERR(dir);169 goto done;170 }171 172 affs_lock_dir(dir);173 /*174 * if there's a dentry for that block, make it175 * refer to inode itself.176 */177 affs_fix_dcache(inode, link_ino);178 retval = affs_remove_hash(dir, link_bh);179 if (retval) {180 affs_unlock_dir(dir);181 goto done;182 }183 mark_buffer_dirty_inode(link_bh, inode);184 185 memcpy(AFFS_TAIL(sb, bh)->name, AFFS_TAIL(sb, link_bh)->name, 32);186 retval = affs_insert_hash(dir, bh);187 if (retval) {188 affs_unlock_dir(dir);189 goto done;190 }191 mark_buffer_dirty_inode(bh, inode);192 193 affs_unlock_dir(dir);194 iput(dir);195 } else {196 link_bh = affs_bread(sb, link_ino);197 if (!link_bh)198 goto done;199 }200 201 while ((ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain)) != 0) {202 if (ino == link_ino) {203 __be32 ino2 = AFFS_TAIL(sb, link_bh)->link_chain;204 AFFS_TAIL(sb, bh)->link_chain = ino2;205 affs_adjust_checksum(bh, be32_to_cpu(ino2) - link_ino);206 mark_buffer_dirty_inode(bh, inode);207 retval = 0;208 /* Fix the link count, if bh is a normal header block without links */209 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {210 case ST_LINKDIR:211 case ST_LINKFILE:212 break;213 default:214 if (!AFFS_TAIL(sb, bh)->link_chain)215 set_nlink(inode, 1);216 }217 affs_free_block(sb, link_ino);218 goto done;219 }220 affs_brelse(bh);221 bh = affs_bread(sb, ino);222 if (!bh)223 goto done;224 }225 retval = -ENOENT;226done:227 affs_brelse(link_bh);228 affs_brelse(bh);229 return retval;230}231 232 233static int234affs_empty_dir(struct inode *inode)235{236 struct super_block *sb = inode->i_sb;237 struct buffer_head *bh;238 int retval, size;239 240 retval = -EIO;241 bh = affs_bread(sb, inode->i_ino);242 if (!bh)243 goto done;244 245 retval = -ENOTEMPTY;246 for (size = AFFS_SB(sb)->s_hashsize - 1; size >= 0; size--)247 if (AFFS_HEAD(bh)->table[size])248 goto not_empty;249 retval = 0;250not_empty:251 affs_brelse(bh);252done:253 return retval;254}255 256 257/* Remove a filesystem object. If the object to be removed has258 * links to it, one of the links must be changed to inherit259 * the file or directory. As above, any inode will do.260 * The buffer will not be freed. If the header is a link, the261 * block will be marked as free.262 * This function returns a negative error number in case of263 * an error, else 0 if the inode is to be deleted or 1 if not.264 */265 266int267affs_remove_header(struct dentry *dentry)268{269 struct super_block *sb;270 struct inode *inode, *dir;271 struct buffer_head *bh = NULL;272 int retval;273 274 dir = d_inode(dentry->d_parent);275 sb = dir->i_sb;276 277 retval = -ENOENT;278 inode = d_inode(dentry);279 if (!inode)280 goto done;281 282 pr_debug("%s(key=%ld)\n", __func__, inode->i_ino);283 retval = -EIO;284 bh = affs_bread(sb, (u32)(long)dentry->d_fsdata);285 if (!bh)286 goto done;287 288 affs_lock_link(inode);289 affs_lock_dir(dir);290 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {291 case ST_USERDIR:292 /* if we ever want to support links to dirs293 * i_hash_lock of the inode must only be294 * taken after some checks295 */296 affs_lock_dir(inode);297 retval = affs_empty_dir(inode);298 affs_unlock_dir(inode);299 if (retval)300 goto done_unlock;301 break;302 default:303 break;304 }305 306 retval = affs_remove_hash(dir, bh);307 if (retval)308 goto done_unlock;309 mark_buffer_dirty_inode(bh, inode);310 311 affs_unlock_dir(dir);312 313 if (inode->i_nlink > 1)314 retval = affs_remove_link(dentry);315 else316 clear_nlink(inode);317 affs_unlock_link(inode);318 inode_set_ctime_current(inode);319 mark_inode_dirty(inode);320 321done:322 affs_brelse(bh);323 return retval;324 325done_unlock:326 affs_unlock_dir(dir);327 affs_unlock_link(inode);328 goto done;329}330 331/* Checksum a block, do various consistency checks and optionally return332 the blocks type number. DATA points to the block. If their pointers333 are non-null, *PTYPE and *STYPE are set to the primary and secondary334 block types respectively, *HASHSIZE is set to the size of the hashtable335 (which lets us calculate the block size).336 Returns non-zero if the block is not consistent. */337 338u32339affs_checksum_block(struct super_block *sb, struct buffer_head *bh)340{341 __be32 *ptr = (__be32 *)bh->b_data;342 u32 sum;343 int bsize;344 345 sum = 0;346 for (bsize = sb->s_blocksize / sizeof(__be32); bsize > 0; bsize--)347 sum += be32_to_cpu(*ptr++);348 return sum;349}350 351/*352 * Calculate the checksum of a disk block and store it353 * at the indicated position.354 */355 356void357affs_fix_checksum(struct super_block *sb, struct buffer_head *bh)358{359 int cnt = sb->s_blocksize / sizeof(__be32);360 __be32 *ptr = (__be32 *)bh->b_data;361 u32 checksum;362 __be32 *checksumptr;363 364 checksumptr = ptr + 5;365 *checksumptr = 0;366 for (checksum = 0; cnt > 0; ptr++, cnt--)367 checksum += be32_to_cpu(*ptr);368 *checksumptr = cpu_to_be32(-checksum);369}370 371void372affs_secs_to_datestamp(time64_t secs, struct affs_date *ds)373{374 u32 days;375 u32 minute;376 s32 rem;377 378 secs -= sys_tz.tz_minuteswest * 60 + AFFS_EPOCH_DELTA;379 if (secs < 0)380 secs = 0;381 days = div_s64_rem(secs, 86400, &rem);382 minute = rem / 60;383 rem -= minute * 60;384 385 ds->days = cpu_to_be32(days);386 ds->mins = cpu_to_be32(minute);387 ds->ticks = cpu_to_be32(rem * 50);388}389 390umode_t391affs_prot_to_mode(u32 prot)392{393 umode_t mode = 0;394 395 if (!(prot & FIBF_NOWRITE))396 mode |= 0200;397 if (!(prot & FIBF_NOREAD))398 mode |= 0400;399 if (!(prot & FIBF_NOEXECUTE))400 mode |= 0100;401 if (prot & FIBF_GRP_WRITE)402 mode |= 0020;403 if (prot & FIBF_GRP_READ)404 mode |= 0040;405 if (prot & FIBF_GRP_EXECUTE)406 mode |= 0010;407 if (prot & FIBF_OTR_WRITE)408 mode |= 0002;409 if (prot & FIBF_OTR_READ)410 mode |= 0004;411 if (prot & FIBF_OTR_EXECUTE)412 mode |= 0001;413 414 return mode;415}416 417void418affs_mode_to_prot(struct inode *inode)419{420 u32 prot = AFFS_I(inode)->i_protect;421 umode_t mode = inode->i_mode;422 423 /*424 * First, clear all RWED bits for owner, group, other.425 * Then, recalculate them afresh.426 *427 * We'll always clear the delete-inhibit bit for the owner, as that is428 * the classic single-user mode AmigaOS protection bit and we need to429 * stay compatible with all scenarios.430 *431 * Since multi-user AmigaOS is an extension, we'll only set the432 * delete-allow bit if any of the other bits in the same user class433 * (group/other) are used.434 */435 prot &= ~(FIBF_NOEXECUTE | FIBF_NOREAD436 | FIBF_NOWRITE | FIBF_NODELETE437 | FIBF_GRP_EXECUTE | FIBF_GRP_READ438 | FIBF_GRP_WRITE | FIBF_GRP_DELETE439 | FIBF_OTR_EXECUTE | FIBF_OTR_READ440 | FIBF_OTR_WRITE | FIBF_OTR_DELETE);441 442 /* Classic single-user AmigaOS flags. These are inverted. */443 if (!(mode & 0100))444 prot |= FIBF_NOEXECUTE;445 if (!(mode & 0400))446 prot |= FIBF_NOREAD;447 if (!(mode & 0200))448 prot |= FIBF_NOWRITE;449 450 /* Multi-user extended flags. Not inverted. */451 if (mode & 0010)452 prot |= FIBF_GRP_EXECUTE;453 if (mode & 0040)454 prot |= FIBF_GRP_READ;455 if (mode & 0020)456 prot |= FIBF_GRP_WRITE;457 if (mode & 0070)458 prot |= FIBF_GRP_DELETE;459 460 if (mode & 0001)461 prot |= FIBF_OTR_EXECUTE;462 if (mode & 0004)463 prot |= FIBF_OTR_READ;464 if (mode & 0002)465 prot |= FIBF_OTR_WRITE;466 if (mode & 0007)467 prot |= FIBF_OTR_DELETE;468 469 AFFS_I(inode)->i_protect = prot;470}471 472void473affs_error(struct super_block *sb, const char *function, const char *fmt, ...)474{475 struct va_format vaf;476 va_list args;477 478 va_start(args, fmt);479 vaf.fmt = fmt;480 vaf.va = &args;481 pr_crit("error (device %s): %s(): %pV\n", sb->s_id, function, &vaf);482 if (!sb_rdonly(sb))483 pr_warn("Remounting filesystem read-only\n");484 sb->s_flags |= SB_RDONLY;485 va_end(args);486}487 488void489affs_warning(struct super_block *sb, const char *function, const char *fmt, ...)490{491 struct va_format vaf;492 va_list args;493 494 va_start(args, fmt);495 vaf.fmt = fmt;496 vaf.va = &args;497 pr_warn("(device %s): %s(): %pV\n", sb->s_id, function, &vaf);498 va_end(args);499}500 501bool502affs_nofilenametruncate(const struct dentry *dentry)503{504 return affs_test_opt(AFFS_SB(dentry->d_sb)->s_flags, SF_NO_TRUNCATE);505}506 507/* Check if the name is valid for a affs object. */508 509int510affs_check_name(const unsigned char *name, int len, bool notruncate)511{512 int i;513 514 if (len > AFFSNAMEMAX) {515 if (notruncate)516 return -ENAMETOOLONG;517 len = AFFSNAMEMAX;518 }519 for (i = 0; i < len; i++) {520 if (name[i] < ' ' || name[i] == ':'521 || (name[i] > 0x7e && name[i] < 0xa0))522 return -EINVAL;523 }524 525 return 0;526}527 528/* This function copies name to bstr, with at most 30529 * characters length. The bstr will be prepended by530 * a length byte.531 * NOTE: The name will must be already checked by532 * affs_check_name()!533 */534 535int536affs_copy_name(unsigned char *bstr, struct dentry *dentry)537{538 u32 len = min(dentry->d_name.len, AFFSNAMEMAX);539 540 *bstr++ = len;541 memcpy(bstr, dentry->d_name.name, len);542 return len;543}544