1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) International Business Machines Corp., 2000-2004
4 */
5
6/*
7 * Module: jfs_mount.c
8 *
9 * note: file system in transition to aggregate/fileset:
10 *
11 * file system mount is interpreted as the mount of aggregate,
12 * if not already mounted, and mount of the single/only fileset in
13 * the aggregate;
14 *
15 * a file system/aggregate is represented by an internal inode
16 * (aka mount inode) initialized with aggregate superblock;
17 * each vfs represents a fileset, and points to its "fileset inode
18 * allocation map inode" (aka fileset inode):
19 * (an aggregate itself is structured recursively as a filset:
20 * an internal vfs is constructed and points to its "fileset inode
21 * allocation map inode" (aka aggregate inode) where each inode
22 * represents a fileset inode) so that inode number is mapped to
23 * on-disk inode in uniform way at both aggregate and fileset level;
24 *
25 * each vnode/inode of a fileset is linked to its vfs (to facilitate
26 * per fileset inode operations, e.g., unmount of a fileset, etc.);
27 * each inode points to the mount inode (to facilitate access to
28 * per aggregate information, e.g., block size, etc.) as well as
29 * its file set inode.
30 *
31 * aggregate
32 * ipmnt
33 * mntvfs -> fileset ipimap+ -> aggregate ipbmap -> aggregate ipaimap;
34 * fileset vfs -> vp(1) <-> ... <-> vp(n) <->vproot;
35 */
36
37#include <linux/fs.h>
38#include <linux/buffer_head.h>
39#include <linux/blkdev.h>
40#include <linux/log2.h>
41
42#include "jfs_incore.h"
43#include "jfs_filsys.h"
44#include "jfs_superblock.h"
45#include "jfs_dmap.h"
46#include "jfs_imap.h"
47#include "jfs_metapage.h"
48#include "jfs_debug.h"
49
50
51/*
52 * forward references
53 */
54static int chkSuper(struct super_block *);
55static int logMOUNT(struct super_block *sb);
56
57/*
58 * NAME: jfs_mount(sb)
59 *
60 * FUNCTION: vfs_mount()
61 *
62 * PARAMETER: sb - super block
63 *
64 * RETURN: -EBUSY - device already mounted or open for write
65 * -EBUSY - cvrdvp already mounted;
66 * -EBUSY - mount table full
67 * -ENOTDIR- cvrdvp not directory on a device mount
68 * -ENXIO - device open failure
69 */
70int jfs_mount(struct super_block *sb)
71{
72 int rc = 0; /* Return code */
73 struct jfs_sb_info *sbi = JFS_SBI(sb);
74 struct inode *ipaimap = NULL;
75 struct inode *ipaimap2 = NULL;
76 struct inode *ipimap = NULL;
77 struct inode *ipbmap = NULL;
78
79 /*
80 * read/validate superblock
81 * (initialize mount inode from the superblock)
82 */
83 if ((rc = chkSuper(sb))) {
84 goto out;
85 }
86
87 ipaimap = diReadSpecial(sb, AGGREGATE_I, 0);
88 if (ipaimap == NULL) {
89 jfs_err("jfs_mount: Failed to read AGGREGATE_I");
90 rc = -EIO;
91 goto out;
92 }
93 sbi->ipaimap = ipaimap;
94
95 jfs_info("jfs_mount: ipaimap:0x%p", ipaimap);
96
97 /*
98 * initialize aggregate inode allocation map
99 */
100 if ((rc = diMount(ipaimap))) {
101 jfs_err("jfs_mount: diMount(ipaimap) failed w/rc = %d", rc);
102 goto err_ipaimap;
103 }
104
105 /*
106 * open aggregate block allocation map
107 */
108 ipbmap = diReadSpecial(sb, BMAP_I, 0);
109 if (ipbmap == NULL) {
110 rc = -EIO;
111 goto err_umount_ipaimap;
112 }
113
114 jfs_info("jfs_mount: ipbmap:0x%p", ipbmap);
115
116 sbi->ipbmap = ipbmap;
117
118 /*
119 * initialize aggregate block allocation map
120 */
121 if ((rc = dbMount(ipbmap))) {
122 jfs_err("jfs_mount: dbMount failed w/rc = %d", rc);
123 goto err_ipbmap;
124 }
125
126 /*
127 * open the secondary aggregate inode allocation map
128 *
129 * This is a duplicate of the aggregate inode allocation map.
130 *
131 * hand craft a vfs in the same fashion as we did to read ipaimap.
132 * By adding INOSPEREXT (32) to the inode number, we are telling
133 * diReadSpecial that we are reading from the secondary aggregate
134 * inode table. This also creates a unique entry in the inode hash
135 * table.
136 */
137 if ((sbi->mntflag & JFS_BAD_SAIT) == 0) {
138 ipaimap2 = diReadSpecial(sb, AGGREGATE_I, 1);
139 if (!ipaimap2) {
140 jfs_err("jfs_mount: Failed to read AGGREGATE_I");
141 rc = -EIO;
142 goto err_umount_ipbmap;
143 }
144 sbi->ipaimap2 = ipaimap2;
145
146 jfs_info("jfs_mount: ipaimap2:0x%p", ipaimap2);
147
148 /*
149 * initialize secondary aggregate inode allocation map
150 */
151 if ((rc = diMount(ipaimap2))) {
152 jfs_err("jfs_mount: diMount(ipaimap2) failed, rc = %d",
153 rc);
154 goto err_ipaimap2;
155 }
156 } else
157 /* Secondary aggregate inode table is not valid */
158 sbi->ipaimap2 = NULL;
159
160 /*
161 * mount (the only/single) fileset
162 */
163 /*
164 * open fileset inode allocation map (aka fileset inode)
165 */
166 ipimap = diReadSpecial(sb, FILESYSTEM_I, 0);
167 if (ipimap == NULL) {
168 jfs_err("jfs_mount: Failed to read FILESYSTEM_I");
169 /* open fileset secondary inode allocation map */
170 rc = -EIO;
171 goto err_umount_ipaimap2;
172 }
173 jfs_info("jfs_mount: ipimap:0x%p", ipimap);
174
175 /* initialize fileset inode allocation map */
176 if ((rc = diMount(ipimap))) {
177 jfs_err("jfs_mount: diMount failed w/rc = %d", rc);
178 goto err_ipimap;
179 }
180
181 /* map further access of per fileset inodes by the fileset inode */
182 sbi->ipimap = ipimap;
183
184 return rc;
185
186 /*
187 * unwind on error
188 */
189err_ipimap:
190 /* close fileset inode allocation map inode */
191 diFreeSpecial(ipimap);
192err_umount_ipaimap2:
193 /* close secondary aggregate inode allocation map */
194 if (ipaimap2)
195 diUnmount(ipaimap2, 1);
196err_ipaimap2:
197 /* close aggregate inodes */
198 if (ipaimap2)
199 diFreeSpecial(ipaimap2);
200err_umount_ipbmap: /* close aggregate block allocation map */
201 dbUnmount(ipbmap, mounterror: 1);
202err_ipbmap: /* close aggregate inodes */
203 diFreeSpecial(ipbmap);
204err_umount_ipaimap: /* close aggregate inode allocation map */
205 diUnmount(ipaimap, 1);
206err_ipaimap: /* close aggregate inodes */
207 diFreeSpecial(ipaimap);
208out:
209 if (rc)
210 jfs_err("Mount JFS Failure: %d", rc);
211
212 return rc;
213}
214
215/*
216 * NAME: jfs_mount_rw(sb, remount)
217 *
218 * FUNCTION: Completes read-write mount, or remounts read-only volume
219 * as read-write
220 */
221int jfs_mount_rw(struct super_block *sb, int remount)
222{
223 struct jfs_sb_info *sbi = JFS_SBI(sb);
224 int rc;
225
226 /*
227 * If we are re-mounting a previously read-only volume, we want to
228 * re-read the inode and block maps, since fsck.jfs may have updated
229 * them.
230 */
231 if (remount) {
232 if (chkSuper(sb) || (sbi->state != FM_CLEAN))
233 return -EINVAL;
234
235 truncate_inode_pages(mapping: sbi->ipimap->i_mapping, lstart: 0);
236 truncate_inode_pages(mapping: sbi->ipbmap->i_mapping, lstart: 0);
237
238 IWRITE_LOCK(sbi->ipimap, RDWRLOCK_IMAP);
239 diUnmount(sbi->ipimap, 1);
240 if ((rc = diMount(sbi->ipimap))) {
241 IWRITE_UNLOCK(sbi->ipimap);
242 jfs_err("jfs_mount_rw: diMount failed!");
243 return rc;
244 }
245 IWRITE_UNLOCK(sbi->ipimap);
246
247 dbUnmount(ipbmap: sbi->ipbmap, mounterror: 1);
248 if ((rc = dbMount(ipbmap: sbi->ipbmap))) {
249 jfs_err("jfs_mount_rw: dbMount failed!");
250 return rc;
251 }
252 }
253
254 /*
255 * open/initialize log
256 */
257 if ((rc = lmLogOpen(sb)))
258 return rc;
259
260 /*
261 * update file system superblock;
262 */
263 if ((rc = updateSuper(sb, FM_MOUNT))) {
264 jfs_err("jfs_mount: updateSuper failed w/rc = %d", rc);
265 lmLogClose(sb);
266 return rc;
267 }
268
269 /*
270 * write MOUNT log record of the file system
271 */
272 logMOUNT(sb);
273
274 return rc;
275}
276
277/*
278 * chkSuper()
279 *
280 * validate the superblock of the file system to be mounted and
281 * get the file system parameters.
282 *
283 * returns
284 * 0 with fragsize set if check successful
285 * error code if not successful
286 */
287static int chkSuper(struct super_block *sb)
288{
289 int rc = 0;
290 struct jfs_sb_info *sbi = JFS_SBI(sb);
291 struct jfs_superblock *j_sb;
292 struct buffer_head *bh;
293 int AIM_bytesize, AIT_bytesize;
294 int expected_AIM_bytesize, expected_AIT_bytesize;
295 s64 AIM_byte_addr, AIT_byte_addr, fsckwsp_addr;
296 s64 byte_addr_diff0, byte_addr_diff1;
297 s32 bsize;
298
299 if ((rc = readSuper(sb, &bh)))
300 return rc;
301 j_sb = (struct jfs_superblock *)bh->b_data;
302
303 /*
304 * validate superblock
305 */
306 /* validate fs signature */
307 if (strncmp(j_sb->s_magic, JFS_MAGIC, 4) ||
308 le32_to_cpu(j_sb->s_version) > JFS_VERSION) {
309 rc = -EINVAL;
310 goto out;
311 }
312
313 bsize = le32_to_cpu(j_sb->s_bsize);
314 if (bsize != PSIZE) {
315 jfs_err("Only 4K block size supported!");
316 rc = -EINVAL;
317 goto out;
318 }
319
320 jfs_info("superblock: flag:0x%08x state:0x%08x size:0x%Lx",
321 le32_to_cpu(j_sb->s_flag), le32_to_cpu(j_sb->s_state),
322 (unsigned long long) le64_to_cpu(j_sb->s_size));
323
324 /* validate the descriptors for Secondary AIM and AIT */
325 if ((j_sb->s_flag & cpu_to_le32(JFS_BAD_SAIT)) !=
326 cpu_to_le32(JFS_BAD_SAIT)) {
327 expected_AIM_bytesize = 2 * PSIZE;
328 AIM_bytesize = lengthPXD(pxd: &j_sb->s_aim2) * bsize;
329 expected_AIT_bytesize = 4 * PSIZE;
330 AIT_bytesize = lengthPXD(pxd: &j_sb->s_ait2) * bsize;
331 AIM_byte_addr = addressPXD(pxd: &j_sb->s_aim2) * bsize;
332 AIT_byte_addr = addressPXD(pxd: &j_sb->s_ait2) * bsize;
333 byte_addr_diff0 = AIT_byte_addr - AIM_byte_addr;
334 fsckwsp_addr = addressPXD(pxd: &j_sb->s_fsckpxd) * bsize;
335 byte_addr_diff1 = fsckwsp_addr - AIT_byte_addr;
336 if ((AIM_bytesize != expected_AIM_bytesize) ||
337 (AIT_bytesize != expected_AIT_bytesize) ||
338 (byte_addr_diff0 != AIM_bytesize) ||
339 (byte_addr_diff1 <= AIT_bytesize))
340 j_sb->s_flag |= cpu_to_le32(JFS_BAD_SAIT);
341 }
342
343 if ((j_sb->s_flag & cpu_to_le32(JFS_GROUPCOMMIT)) !=
344 cpu_to_le32(JFS_GROUPCOMMIT))
345 j_sb->s_flag |= cpu_to_le32(JFS_GROUPCOMMIT);
346
347 /* validate fs state */
348 if (j_sb->s_state != cpu_to_le32(FM_CLEAN) &&
349 !sb_rdonly(sb)) {
350 jfs_err("jfs_mount: Mount Failure: File System Dirty.");
351 rc = -EINVAL;
352 goto out;
353 }
354
355 sbi->state = le32_to_cpu(j_sb->s_state);
356 sbi->mntflag = le32_to_cpu(j_sb->s_flag);
357
358 /*
359 * JFS always does I/O by 4K pages. Don't tell the buffer cache
360 * that we use anything else (leave s_blocksize alone).
361 */
362 sbi->bsize = bsize;
363 sbi->l2bsize = le16_to_cpu(j_sb->s_l2bsize);
364
365 /* check some fields for possible corruption */
366 if (sbi->l2bsize != ilog2((u32)bsize) ||
367 j_sb->pad != 0 ||
368 le32_to_cpu(j_sb->s_state) > FM_STATE_MAX) {
369 rc = -EINVAL;
370 jfs_err("jfs_mount: Mount Failure: superblock is corrupt!");
371 goto out;
372 }
373
374 /*
375 * For now, ignore s_pbsize, l2bfactor. All I/O going through buffer
376 * cache.
377 */
378 sbi->nbperpage = PSIZE >> sbi->l2bsize;
379 sbi->l2nbperpage = L2PSIZE - sbi->l2bsize;
380 sbi->l2niperblk = sbi->l2bsize - L2DISIZE;
381 if (sbi->mntflag & JFS_INLINELOG)
382 sbi->logpxd = j_sb->s_logpxd;
383 else {
384 sbi->logdev = new_decode_dev(le32_to_cpu(j_sb->s_logdev));
385 uuid_copy(dst: &sbi->uuid, src: &j_sb->s_uuid);
386 uuid_copy(dst: &sbi->loguuid, src: &j_sb->s_loguuid);
387 }
388 sbi->fsckpxd = j_sb->s_fsckpxd;
389 sbi->ait2 = j_sb->s_ait2;
390
391 out:
392 brelse(bh);
393 return rc;
394}
395
396
397/*
398 * updateSuper()
399 *
400 * update synchronously superblock if it is mounted read-write.
401 */
402int updateSuper(struct super_block *sb, uint state)
403{
404 struct jfs_superblock *j_sb;
405 struct jfs_sb_info *sbi = JFS_SBI(sb);
406 struct buffer_head *bh;
407 int rc;
408
409 if (sbi->flag & JFS_NOINTEGRITY) {
410 if (state == FM_DIRTY) {
411 sbi->p_state = state;
412 return 0;
413 } else if (state == FM_MOUNT) {
414 sbi->p_state = sbi->state;
415 state = FM_DIRTY;
416 } else if (state == FM_CLEAN) {
417 state = sbi->p_state;
418 } else
419 jfs_err("updateSuper: bad state");
420 } else if (sbi->state == FM_DIRTY)
421 return 0;
422
423 if ((rc = readSuper(sb, &bh)))
424 return rc;
425
426 j_sb = (struct jfs_superblock *)bh->b_data;
427
428 j_sb->s_state = cpu_to_le32(state);
429 sbi->state = state;
430
431 if (state == FM_MOUNT) {
432 /* record log's dev_t and mount serial number */
433 j_sb->s_logdev = cpu_to_le32(
434 new_encode_dev(file_bdev(sbi->log->bdev_file)->bd_dev));
435 j_sb->s_logserial = cpu_to_le32(sbi->log->serial);
436 } else if (state == FM_CLEAN) {
437 /*
438 * If this volume is shared with OS/2, OS/2 will need to
439 * recalculate DASD usage, since we don't deal with it.
440 */
441 if (j_sb->s_flag & cpu_to_le32(JFS_DASD_ENABLED))
442 j_sb->s_flag |= cpu_to_le32(JFS_DASD_PRIME);
443 }
444
445 mark_buffer_dirty(bh);
446 sync_dirty_buffer(bh);
447 brelse(bh);
448
449 return 0;
450}
451
452
453/*
454 * readSuper()
455 *
456 * read superblock by raw sector address
457 */
458int readSuper(struct super_block *sb, struct buffer_head **bpp)
459{
460 /* read in primary superblock */
461 *bpp = sb_bread(sb, SUPER1_OFF >> sb->s_blocksize_bits);
462 if (*bpp)
463 return 0;
464
465 /* read in secondary/replicated superblock */
466 *bpp = sb_bread(sb, SUPER2_OFF >> sb->s_blocksize_bits);
467 if (*bpp)
468 return 0;
469
470 return -EIO;
471}
472
473
474/*
475 * logMOUNT()
476 *
477 * function: write a MOUNT log record for file system.
478 *
479 * MOUNT record keeps logredo() from processing log records
480 * for this file system past this point in log.
481 * it is harmless if mount fails.
482 *
483 * note: MOUNT record is at aggregate level, not at fileset level,
484 * since log records of previous mounts of a fileset
485 * (e.g., AFTER record of extent allocation) have to be processed
486 * to update block allocation map at aggregate level.
487 */
488static int logMOUNT(struct super_block *sb)
489{
490 struct jfs_log *log = JFS_SBI(sb)->log;
491 struct lrd lrd;
492
493 lrd.logtid = 0;
494 lrd.backchain = 0;
495 lrd.type = cpu_to_le16(LOG_MOUNT);
496 lrd.length = 0;
497 lrd.aggregate = cpu_to_le32(new_encode_dev(sb->s_bdev->bd_dev));
498 lmLog(log, NULL, &lrd, NULL);
499
500 return 0;
501}
502

source code of linux/fs/jfs/jfs_mount.c