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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * QNX4 file system, Linux implementation.4 *5 * Version : 0.2.16 *7 * Using parts of the xiafs filesystem.8 *9 * History :10 *11 * 01-06-1998 by Richard Frowijn : first release.12 * 20-06-1998 by Frank Denis : Linux 2.1.99+ support, boot signature, misc.13 * 30-06-1998 by Frank Denis : first step to write inodes.14 */15 16#include <linux/module.h>17#include <linux/init.h>18#include <linux/slab.h>19#include <linux/highuid.h>20#include <linux/pagemap.h>21#include <linux/buffer_head.h>22#include <linux/writeback.h>23#include <linux/statfs.h>24#include <linux/fs_context.h>25#include "qnx4.h"26 27#define QNX4_VERSION 428#define QNX4_BMNAME ".bitmap"29 30static const struct super_operations qnx4_sops;31 32static struct inode *qnx4_alloc_inode(struct super_block *sb);33static void qnx4_free_inode(struct inode *inode);34static int qnx4_statfs(struct dentry *, struct kstatfs *);35static int qnx4_get_tree(struct fs_context *fc);36 37static const struct super_operations qnx4_sops =38{39 .alloc_inode = qnx4_alloc_inode,40 .free_inode = qnx4_free_inode,41 .statfs = qnx4_statfs,42};43 44static int qnx4_reconfigure(struct fs_context *fc)45{46 struct super_block *sb = fc->root->d_sb;47 struct qnx4_sb_info *qs;48 49 sync_filesystem(sb);50 qs = qnx4_sb(sb);51 qs->Version = QNX4_VERSION;52 fc->sb_flags |= SB_RDONLY;53 return 0;54}55 56static const struct fs_context_operations qnx4_context_opts = {57 .get_tree = qnx4_get_tree,58 .reconfigure = qnx4_reconfigure,59};60 61static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create )62{63 unsigned long phys;64 65 QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock));66 67 phys = qnx4_block_map( inode, iblock );68 if ( phys ) {69 // logical block is before EOF70 map_bh(bh, inode->i_sb, phys);71 }72 return 0;73}74 75static inline u32 try_extent(qnx4_xtnt_t *extent, u32 *offset)76{77 u32 size = le32_to_cpu(extent->xtnt_size);78 if (*offset < size)79 return le32_to_cpu(extent->xtnt_blk) + *offset - 1;80 *offset -= size;81 return 0;82}83 84unsigned long qnx4_block_map( struct inode *inode, long iblock )85{86 int ix;87 long i_xblk;88 struct buffer_head *bh = NULL;89 struct qnx4_xblk *xblk = NULL;90 struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode);91 u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts);92 u32 offset = iblock;93 u32 block = try_extent(&qnx4_inode->di_first_xtnt, &offset);94 95 if (block) {96 // iblock is in the first extent. This is easy.97 } else {98 // iblock is beyond first extent. We have to follow the extent chain.99 i_xblk = le32_to_cpu(qnx4_inode->di_xblk);100 ix = 0;101 while ( --nxtnt > 0 ) {102 if ( ix == 0 ) {103 // read next xtnt block.104 bh = sb_bread(inode->i_sb, i_xblk - 1);105 if ( !bh ) {106 QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));107 return -EIO;108 }109 xblk = (struct qnx4_xblk*)bh->b_data;110 if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {111 QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));112 return -EIO;113 }114 }115 block = try_extent(&xblk->xblk_xtnts[ix], &offset);116 if (block) {117 // got it!118 break;119 }120 if ( ++ix >= xblk->xblk_num_xtnts ) {121 i_xblk = le32_to_cpu(xblk->xblk_next_xblk);122 ix = 0;123 brelse( bh );124 bh = NULL;125 }126 }127 if ( bh )128 brelse( bh );129 }130 131 QNX4DEBUG((KERN_INFO "qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block));132 return block;133}134 135static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf)136{137 struct super_block *sb = dentry->d_sb;138 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);139 140 buf->f_type = sb->s_magic;141 buf->f_bsize = sb->s_blocksize;142 buf->f_blocks = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8;143 buf->f_bfree = qnx4_count_free_blocks(sb);144 buf->f_bavail = buf->f_bfree;145 buf->f_namelen = QNX4_NAME_MAX;146 buf->f_fsid = u64_to_fsid(id);147 148 return 0;149}150 151/*152 * Check the root directory of the filesystem to make sure153 * it really _is_ a qnx4 filesystem, and to check the size154 * of the directory entry.155 */156static const char *qnx4_checkroot(struct super_block *sb,157 struct qnx4_super_block *s)158{159 struct buffer_head *bh;160 struct qnx4_inode_entry *rootdir;161 int rd, rl;162 int i, j;163 164 if (s->RootDir.di_fname[0] != '/' || s->RootDir.di_fname[1] != '\0')165 return "no qnx4 filesystem (no root dir).";166 QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id));167 rd = le32_to_cpu(s->RootDir.di_first_xtnt.xtnt_blk) - 1;168 rl = le32_to_cpu(s->RootDir.di_first_xtnt.xtnt_size);169 for (j = 0; j < rl; j++) {170 bh = sb_bread(sb, rd + j); /* root dir, first block */171 if (bh == NULL)172 return "unable to read root entry.";173 rootdir = (struct qnx4_inode_entry *) bh->b_data;174 for (i = 0; i < QNX4_INODES_PER_BLOCK; i++, rootdir++) {175 QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname));176 if (strcmp(rootdir->di_fname, QNX4_BMNAME) != 0)177 continue;178 qnx4_sb(sb)->BitMap = kmemdup(rootdir,179 sizeof(struct qnx4_inode_entry),180 GFP_KERNEL);181 brelse(bh);182 if (!qnx4_sb(sb)->BitMap)183 return "not enough memory for bitmap inode";184 /* keep bitmap inode known */185 return NULL;186 }187 brelse(bh);188 }189 return "bitmap file not found.";190}191 192static int qnx4_fill_super(struct super_block *s, struct fs_context *fc)193{194 struct buffer_head *bh;195 struct inode *root;196 const char *errmsg;197 struct qnx4_sb_info *qs;198 int silent = fc->sb_flags & SB_SILENT;199 200 qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL);201 if (!qs)202 return -ENOMEM;203 s->s_fs_info = qs;204 205 sb_set_blocksize(s, QNX4_BLOCK_SIZE);206 207 s->s_op = &qnx4_sops;208 s->s_magic = QNX4_SUPER_MAGIC;209 s->s_flags |= SB_RDONLY; /* Yup, read-only yet */210 s->s_time_min = 0;211 s->s_time_max = U32_MAX;212 213 /* Check the superblock signature. Since the qnx4 code is214 dangerous, we should leave as quickly as possible215 if we don't belong here... */216 bh = sb_bread(s, 1);217 if (!bh) {218 printk(KERN_ERR "qnx4: unable to read the superblock\n");219 return -EINVAL;220 }221 222 /* check before allocating dentries, inodes, .. */223 errmsg = qnx4_checkroot(s, (struct qnx4_super_block *) bh->b_data);224 brelse(bh);225 if (errmsg != NULL) {226 if (!silent)227 printk(KERN_ERR "qnx4: %s\n", errmsg);228 return -EINVAL;229 }230 231 /* does root not have inode number QNX4_ROOT_INO ?? */232 root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK);233 if (IS_ERR(root)) {234 printk(KERN_ERR "qnx4: get inode failed\n");235 return PTR_ERR(root);236 }237 238 s->s_root = d_make_root(root);239 if (s->s_root == NULL)240 return -ENOMEM;241 242 return 0;243}244 245static int qnx4_get_tree(struct fs_context *fc)246{247 return get_tree_bdev(fc, qnx4_fill_super);248}249 250static int qnx4_init_fs_context(struct fs_context *fc)251{252 fc->ops = &qnx4_context_opts;253 254 return 0;255}256 257static void qnx4_kill_sb(struct super_block *sb)258{259 struct qnx4_sb_info *qs = qnx4_sb(sb);260 kill_block_super(sb);261 if (qs) {262 kfree(qs->BitMap);263 kfree(qs);264 }265}266 267static int qnx4_read_folio(struct file *file, struct folio *folio)268{269 return block_read_full_folio(folio, qnx4_get_block);270}271 272static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)273{274 return generic_block_bmap(mapping,block,qnx4_get_block);275}276 277static const struct address_space_operations qnx4_aops = {278 .read_folio = qnx4_read_folio,279 .bmap = qnx4_bmap280};281 282struct inode *qnx4_iget(struct super_block *sb, unsigned long ino)283{284 struct buffer_head *bh;285 struct qnx4_inode_entry *raw_inode;286 int block;287 struct qnx4_inode_entry *qnx4_inode;288 struct inode *inode;289 290 inode = iget_locked(sb, ino);291 if (!inode)292 return ERR_PTR(-ENOMEM);293 if (!(inode->i_state & I_NEW))294 return inode;295 296 qnx4_inode = qnx4_raw_inode(inode);297 inode->i_mode = 0;298 299 QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino));300 if (!ino) {301 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is "302 "out of range\n",303 sb->s_id, ino);304 iget_failed(inode);305 return ERR_PTR(-EIO);306 }307 block = ino / QNX4_INODES_PER_BLOCK;308 309 if (!(bh = sb_bread(sb, block))) {310 printk(KERN_ERR "qnx4: major problem: unable to read inode from dev "311 "%s\n", sb->s_id);312 iget_failed(inode);313 return ERR_PTR(-EIO);314 }315 raw_inode = ((struct qnx4_inode_entry *) bh->b_data) +316 (ino % QNX4_INODES_PER_BLOCK);317 318 inode->i_mode = le16_to_cpu(raw_inode->di_mode);319 i_uid_write(inode, (uid_t)le16_to_cpu(raw_inode->di_uid));320 i_gid_write(inode, (gid_t)le16_to_cpu(raw_inode->di_gid));321 set_nlink(inode, le16_to_cpu(raw_inode->di_nlink));322 inode->i_size = le32_to_cpu(raw_inode->di_size);323 inode_set_mtime(inode, le32_to_cpu(raw_inode->di_mtime), 0);324 inode_set_atime(inode, le32_to_cpu(raw_inode->di_atime), 0);325 inode_set_ctime(inode, le32_to_cpu(raw_inode->di_ctime), 0);326 inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size);327 328 memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE);329 if (S_ISREG(inode->i_mode)) {330 inode->i_fop = &generic_ro_fops;331 inode->i_mapping->a_ops = &qnx4_aops;332 qnx4_i(inode)->mmu_private = inode->i_size;333 } else if (S_ISDIR(inode->i_mode)) {334 inode->i_op = &qnx4_dir_inode_operations;335 inode->i_fop = &qnx4_dir_operations;336 } else if (S_ISLNK(inode->i_mode)) {337 inode->i_op = &page_symlink_inode_operations;338 inode_nohighmem(inode);339 inode->i_mapping->a_ops = &qnx4_aops;340 qnx4_i(inode)->mmu_private = inode->i_size;341 } else {342 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n",343 ino, sb->s_id);344 iget_failed(inode);345 brelse(bh);346 return ERR_PTR(-EIO);347 }348 brelse(bh);349 unlock_new_inode(inode);350 return inode;351}352 353static struct kmem_cache *qnx4_inode_cachep;354 355static struct inode *qnx4_alloc_inode(struct super_block *sb)356{357 struct qnx4_inode_info *ei;358 ei = alloc_inode_sb(sb, qnx4_inode_cachep, GFP_KERNEL);359 if (!ei)360 return NULL;361 return &ei->vfs_inode;362}363 364static void qnx4_free_inode(struct inode *inode)365{366 kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode));367}368 369static void init_once(void *foo)370{371 struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo;372 373 inode_init_once(&ei->vfs_inode);374}375 376static int init_inodecache(void)377{378 qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache",379 sizeof(struct qnx4_inode_info),380 0, (SLAB_RECLAIM_ACCOUNT|381 SLAB_ACCOUNT),382 init_once);383 if (qnx4_inode_cachep == NULL)384 return -ENOMEM;385 return 0;386}387 388static void destroy_inodecache(void)389{390 /*391 * Make sure all delayed rcu free inodes are flushed before we392 * destroy cache.393 */394 rcu_barrier();395 kmem_cache_destroy(qnx4_inode_cachep);396}397 398static struct file_system_type qnx4_fs_type = {399 .owner = THIS_MODULE,400 .name = "qnx4",401 .kill_sb = qnx4_kill_sb,402 .fs_flags = FS_REQUIRES_DEV,403 .init_fs_context = qnx4_init_fs_context,404};405MODULE_ALIAS_FS("qnx4");406 407static int __init init_qnx4_fs(void)408{409 int err;410 411 err = init_inodecache();412 if (err)413 return err;414 415 err = register_filesystem(&qnx4_fs_type);416 if (err) {417 destroy_inodecache();418 return err;419 }420 421 printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n");422 return 0;423}424 425static void __exit exit_qnx4_fs(void)426{427 unregister_filesystem(&qnx4_fs_type);428 destroy_inodecache();429}430 431module_init(init_qnx4_fs)432module_exit(exit_qnx4_fs)433MODULE_DESCRIPTION("QNX4 file system");434MODULE_LICENSE("GPL");435 436