Root/fs/jfs/jfs_mount.c

1/*
2 * Copyright (C) International Business Machines Corp., 2000-2004
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12 * the GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18
19/*
20 * Module: jfs_mount.c
21 *
22 * note: file system in transition to aggregate/fileset:
23 *
24 * file system mount is interpreted as the mount of aggregate,
25 * if not already mounted, and mount of the single/only fileset in
26 * the aggregate;
27 *
28 * a file system/aggregate is represented by an internal inode
29 * (aka mount inode) initialized with aggregate superblock;
30 * each vfs represents a fileset, and points to its "fileset inode
31 * allocation map inode" (aka fileset inode):
32 * (an aggregate itself is structured recursively as a filset:
33 * an internal vfs is constructed and points to its "fileset inode
34 * allocation map inode" (aka aggregate inode) where each inode
35 * represents a fileset inode) so that inode number is mapped to
36 * on-disk inode in uniform way at both aggregate and fileset level;
37 *
38 * each vnode/inode of a fileset is linked to its vfs (to facilitate
39 * per fileset inode operations, e.g., unmount of a fileset, etc.);
40 * each inode points to the mount inode (to facilitate access to
41 * per aggregate information, e.g., block size, etc.) as well as
42 * its file set inode.
43 *
44 * aggregate
45 * ipmnt
46 * mntvfs -> fileset ipimap+ -> aggregate ipbmap -> aggregate ipaimap;
47 * fileset vfs -> vp(1) <-> ... <-> vp(n) <->vproot;
48 */
49
50#include <linux/fs.h>
51#include <linux/buffer_head.h>
52
53#include "jfs_incore.h"
54#include "jfs_filsys.h"
55#include "jfs_superblock.h"
56#include "jfs_dmap.h"
57#include "jfs_imap.h"
58#include "jfs_metapage.h"
59#include "jfs_debug.h"
60
61
62/*
63 * forward references
64 */
65static int chkSuper(struct super_block *);
66static int logMOUNT(struct super_block *sb);
67
68/*
69 * NAME: jfs_mount(sb)
70 *
71 * FUNCTION: vfs_mount()
72 *
73 * PARAMETER: sb - super block
74 *
75 * RETURN: -EBUSY - device already mounted or open for write
76 * -EBUSY - cvrdvp already mounted;
77 * -EBUSY - mount table full
78 * -ENOTDIR- cvrdvp not directory on a device mount
79 * -ENXIO - device open failure
80 */
81int jfs_mount(struct super_block *sb)
82{
83    int rc = 0; /* Return code */
84    struct jfs_sb_info *sbi = JFS_SBI(sb);
85    struct inode *ipaimap = NULL;
86    struct inode *ipaimap2 = NULL;
87    struct inode *ipimap = NULL;
88    struct inode *ipbmap = NULL;
89
90    /*
91     * read/validate superblock
92     * (initialize mount inode from the superblock)
93     */
94    if ((rc = chkSuper(sb))) {
95        goto errout20;
96    }
97
98    ipaimap = diReadSpecial(sb, AGGREGATE_I, 0);
99    if (ipaimap == NULL) {
100        jfs_err("jfs_mount: Failed to read AGGREGATE_I");
101        rc = -EIO;
102        goto errout20;
103    }
104    sbi->ipaimap = ipaimap;
105
106    jfs_info("jfs_mount: ipaimap:0x%p", ipaimap);
107
108    /*
109     * initialize aggregate inode allocation map
110     */
111    if ((rc = diMount(ipaimap))) {
112        jfs_err("jfs_mount: diMount(ipaimap) failed w/rc = %d", rc);
113        goto errout21;
114    }
115
116    /*
117     * open aggregate block allocation map
118     */
119    ipbmap = diReadSpecial(sb, BMAP_I, 0);
120    if (ipbmap == NULL) {
121        rc = -EIO;
122        goto errout22;
123    }
124
125    jfs_info("jfs_mount: ipbmap:0x%p", ipbmap);
126
127    sbi->ipbmap = ipbmap;
128
129    /*
130     * initialize aggregate block allocation map
131     */
132    if ((rc = dbMount(ipbmap))) {
133        jfs_err("jfs_mount: dbMount failed w/rc = %d", rc);
134        goto errout22;
135    }
136
137    /*
138     * open the secondary aggregate inode allocation map
139     *
140     * This is a duplicate of the aggregate inode allocation map.
141     *
142     * hand craft a vfs in the same fashion as we did to read ipaimap.
143     * By adding INOSPEREXT (32) to the inode number, we are telling
144     * diReadSpecial that we are reading from the secondary aggregate
145     * inode table. This also creates a unique entry in the inode hash
146     * table.
147     */
148    if ((sbi->mntflag & JFS_BAD_SAIT) == 0) {
149        ipaimap2 = diReadSpecial(sb, AGGREGATE_I, 1);
150        if (!ipaimap2) {
151            jfs_err("jfs_mount: Failed to read AGGREGATE_I");
152            rc = -EIO;
153            goto errout35;
154        }
155        sbi->ipaimap2 = ipaimap2;
156
157        jfs_info("jfs_mount: ipaimap2:0x%p", ipaimap2);
158
159        /*
160         * initialize secondary aggregate inode allocation map
161         */
162        if ((rc = diMount(ipaimap2))) {
163            jfs_err("jfs_mount: diMount(ipaimap2) failed, rc = %d",
164                rc);
165            goto errout35;
166        }
167    } else
168        /* Secondary aggregate inode table is not valid */
169        sbi->ipaimap2 = NULL;
170
171    /*
172     * mount (the only/single) fileset
173     */
174    /*
175     * open fileset inode allocation map (aka fileset inode)
176     */
177    ipimap = diReadSpecial(sb, FILESYSTEM_I, 0);
178    if (ipimap == NULL) {
179        jfs_err("jfs_mount: Failed to read FILESYSTEM_I");
180        /* open fileset secondary inode allocation map */
181        rc = -EIO;
182        goto errout40;
183    }
184    jfs_info("jfs_mount: ipimap:0x%p", ipimap);
185
186    /* map further access of per fileset inodes by the fileset inode */
187    sbi->ipimap = ipimap;
188
189    /* initialize fileset inode allocation map */
190    if ((rc = diMount(ipimap))) {
191        jfs_err("jfs_mount: diMount failed w/rc = %d", rc);
192        goto errout41;
193    }
194
195    goto out;
196
197    /*
198     * unwind on error
199     */
200      errout41: /* close fileset inode allocation map inode */
201    diFreeSpecial(ipimap);
202
203      errout40: /* fileset closed */
204
205    /* close secondary aggregate inode allocation map */
206    if (ipaimap2) {
207        diUnmount(ipaimap2, 1);
208        diFreeSpecial(ipaimap2);
209    }
210
211      errout35:
212
213    /* close aggregate block allocation map */
214    dbUnmount(ipbmap, 1);
215    diFreeSpecial(ipbmap);
216
217      errout22: /* close aggregate inode allocation map */
218
219    diUnmount(ipaimap, 1);
220
221      errout21: /* close aggregate inodes */
222    diFreeSpecial(ipaimap);
223      errout20: /* aggregate closed */
224
225      out:
226
227    if (rc)
228        jfs_err("Mount JFS Failure: %d", rc);
229
230    return rc;
231}
232
233/*
234 * NAME: jfs_mount_rw(sb, remount)
235 *
236 * FUNCTION: Completes read-write mount, or remounts read-only volume
237 * as read-write
238 */
239int jfs_mount_rw(struct super_block *sb, int remount)
240{
241    struct jfs_sb_info *sbi = JFS_SBI(sb);
242    int rc;
243
244    /*
245     * If we are re-mounting a previously read-only volume, we want to
246     * re-read the inode and block maps, since fsck.jfs may have updated
247     * them.
248     */
249    if (remount) {
250        if (chkSuper(sb) || (sbi->state != FM_CLEAN))
251            return -EINVAL;
252
253        truncate_inode_pages(sbi->ipimap->i_mapping, 0);
254        truncate_inode_pages(sbi->ipbmap->i_mapping, 0);
255        diUnmount(sbi->ipimap, 1);
256        if ((rc = diMount(sbi->ipimap))) {
257            jfs_err("jfs_mount_rw: diMount failed!");
258            return rc;
259        }
260
261        dbUnmount(sbi->ipbmap, 1);
262        if ((rc = dbMount(sbi->ipbmap))) {
263            jfs_err("jfs_mount_rw: dbMount failed!");
264            return rc;
265        }
266    }
267
268    /*
269     * open/initialize log
270     */
271    if ((rc = lmLogOpen(sb)))
272        return rc;
273
274    /*
275     * update file system superblock;
276     */
277    if ((rc = updateSuper(sb, FM_MOUNT))) {
278        jfs_err("jfs_mount: updateSuper failed w/rc = %d", rc);
279        lmLogClose(sb);
280        return rc;
281    }
282
283    /*
284     * write MOUNT log record of the file system
285     */
286    logMOUNT(sb);
287
288    return rc;
289}
290
291/*
292 * chkSuper()
293 *
294 * validate the superblock of the file system to be mounted and
295 * get the file system parameters.
296 *
297 * returns
298 * 0 with fragsize set if check successful
299 * error code if not successful
300 */
301static int chkSuper(struct super_block *sb)
302{
303    int rc = 0;
304    struct jfs_sb_info *sbi = JFS_SBI(sb);
305    struct jfs_superblock *j_sb;
306    struct buffer_head *bh;
307    int AIM_bytesize, AIT_bytesize;
308    int expected_AIM_bytesize, expected_AIT_bytesize;
309    s64 AIM_byte_addr, AIT_byte_addr, fsckwsp_addr;
310    s64 byte_addr_diff0, byte_addr_diff1;
311    s32 bsize;
312
313    if ((rc = readSuper(sb, &bh)))
314        return rc;
315    j_sb = (struct jfs_superblock *)bh->b_data;
316
317    /*
318     * validate superblock
319     */
320    /* validate fs signature */
321    if (strncmp(j_sb->s_magic, JFS_MAGIC, 4) ||
322        le32_to_cpu(j_sb->s_version) > JFS_VERSION) {
323        rc = -EINVAL;
324        goto out;
325    }
326
327    bsize = le32_to_cpu(j_sb->s_bsize);
328#ifdef _JFS_4K
329    if (bsize != PSIZE) {
330        jfs_err("Currently only 4K block size supported!");
331        rc = -EINVAL;
332        goto out;
333    }
334#endif /* _JFS_4K */
335
336    jfs_info("superblock: flag:0x%08x state:0x%08x size:0x%Lx",
337         le32_to_cpu(j_sb->s_flag), le32_to_cpu(j_sb->s_state),
338         (unsigned long long) le64_to_cpu(j_sb->s_size));
339
340    /* validate the descriptors for Secondary AIM and AIT */
341    if ((j_sb->s_flag & cpu_to_le32(JFS_BAD_SAIT)) !=
342        cpu_to_le32(JFS_BAD_SAIT)) {
343        expected_AIM_bytesize = 2 * PSIZE;
344        AIM_bytesize = lengthPXD(&(j_sb->s_aim2)) * bsize;
345        expected_AIT_bytesize = 4 * PSIZE;
346        AIT_bytesize = lengthPXD(&(j_sb->s_ait2)) * bsize;
347        AIM_byte_addr = addressPXD(&(j_sb->s_aim2)) * bsize;
348        AIT_byte_addr = addressPXD(&(j_sb->s_ait2)) * bsize;
349        byte_addr_diff0 = AIT_byte_addr - AIM_byte_addr;
350        fsckwsp_addr = addressPXD(&(j_sb->s_fsckpxd)) * bsize;
351        byte_addr_diff1 = fsckwsp_addr - AIT_byte_addr;
352        if ((AIM_bytesize != expected_AIM_bytesize) ||
353            (AIT_bytesize != expected_AIT_bytesize) ||
354            (byte_addr_diff0 != AIM_bytesize) ||
355            (byte_addr_diff1 <= AIT_bytesize))
356            j_sb->s_flag |= cpu_to_le32(JFS_BAD_SAIT);
357    }
358
359    if ((j_sb->s_flag & cpu_to_le32(JFS_GROUPCOMMIT)) !=
360        cpu_to_le32(JFS_GROUPCOMMIT))
361        j_sb->s_flag |= cpu_to_le32(JFS_GROUPCOMMIT);
362
363    /* validate fs state */
364    if (j_sb->s_state != cpu_to_le32(FM_CLEAN) &&
365        !(sb->s_flags & MS_RDONLY)) {
366        jfs_err("jfs_mount: Mount Failure: File System Dirty.");
367        rc = -EINVAL;
368        goto out;
369    }
370
371    sbi->state = le32_to_cpu(j_sb->s_state);
372    sbi->mntflag = le32_to_cpu(j_sb->s_flag);
373
374    /*
375     * JFS always does I/O by 4K pages. Don't tell the buffer cache
376     * that we use anything else (leave s_blocksize alone).
377     */
378    sbi->bsize = bsize;
379    sbi->l2bsize = le16_to_cpu(j_sb->s_l2bsize);
380
381    /*
382     * For now, ignore s_pbsize, l2bfactor. All I/O going through buffer
383     * cache.
384     */
385    sbi->nbperpage = PSIZE >> sbi->l2bsize;
386    sbi->l2nbperpage = L2PSIZE - sbi->l2bsize;
387    sbi->l2niperblk = sbi->l2bsize - L2DISIZE;
388    if (sbi->mntflag & JFS_INLINELOG)
389        sbi->logpxd = j_sb->s_logpxd;
390    else {
391        sbi->logdev = new_decode_dev(le32_to_cpu(j_sb->s_logdev));
392        memcpy(sbi->uuid, j_sb->s_uuid, sizeof(sbi->uuid));
393        memcpy(sbi->loguuid, j_sb->s_loguuid, sizeof(sbi->uuid));
394    }
395    sbi->fsckpxd = j_sb->s_fsckpxd;
396    sbi->ait2 = j_sb->s_ait2;
397
398      out:
399    brelse(bh);
400    return rc;
401}
402
403
404/*
405 * updateSuper()
406 *
407 * update synchronously superblock if it is mounted read-write.
408 */
409int updateSuper(struct super_block *sb, uint state)
410{
411    struct jfs_superblock *j_sb;
412    struct jfs_sb_info *sbi = JFS_SBI(sb);
413    struct buffer_head *bh;
414    int rc;
415
416    if (sbi->flag & JFS_NOINTEGRITY) {
417        if (state == FM_DIRTY) {
418            sbi->p_state = state;
419            return 0;
420        } else if (state == FM_MOUNT) {
421            sbi->p_state = sbi->state;
422            state = FM_DIRTY;
423        } else if (state == FM_CLEAN) {
424            state = sbi->p_state;
425        } else
426            jfs_err("updateSuper: bad state");
427    } else if (sbi->state == FM_DIRTY)
428        return 0;
429
430    if ((rc = readSuper(sb, &bh)))
431        return rc;
432
433    j_sb = (struct jfs_superblock *)bh->b_data;
434
435    j_sb->s_state = cpu_to_le32(state);
436    sbi->state = state;
437
438    if (state == FM_MOUNT) {
439        /* record log's dev_t and mount serial number */
440        j_sb->s_logdev = cpu_to_le32(new_encode_dev(sbi->log->bdev->bd_dev));
441        j_sb->s_logserial = cpu_to_le32(sbi->log->serial);
442    } else if (state == FM_CLEAN) {
443        /*
444         * If this volume is shared with OS/2, OS/2 will need to
445         * recalculate DASD usage, since we don't deal with it.
446         */
447        if (j_sb->s_flag & cpu_to_le32(JFS_DASD_ENABLED))
448            j_sb->s_flag |= cpu_to_le32(JFS_DASD_PRIME);
449    }
450
451    mark_buffer_dirty(bh);
452    sync_dirty_buffer(bh);
453    brelse(bh);
454
455    return 0;
456}
457
458
459/*
460 * readSuper()
461 *
462 * read superblock by raw sector address
463 */
464int readSuper(struct super_block *sb, struct buffer_head **bpp)
465{
466    /* read in primary superblock */
467    *bpp = sb_bread(sb, SUPER1_OFF >> sb->s_blocksize_bits);
468    if (*bpp)
469        return 0;
470
471    /* read in secondary/replicated superblock */
472    *bpp = sb_bread(sb, SUPER2_OFF >> sb->s_blocksize_bits);
473    if (*bpp)
474        return 0;
475
476    return -EIO;
477}
478
479
480/*
481 * logMOUNT()
482 *
483 * function: write a MOUNT log record for file system.
484 *
485 * MOUNT record keeps logredo() from processing log records
486 * for this file system past this point in log.
487 * it is harmless if mount fails.
488 *
489 * note: MOUNT record is at aggregate level, not at fileset level,
490 * since log records of previous mounts of a fileset
491 * (e.g., AFTER record of extent allocation) have to be processed
492 * to update block allocation map at aggregate level.
493 */
494static int logMOUNT(struct super_block *sb)
495{
496    struct jfs_log *log = JFS_SBI(sb)->log;
497    struct lrd lrd;
498
499    lrd.logtid = 0;
500    lrd.backchain = 0;
501    lrd.type = cpu_to_le16(LOG_MOUNT);
502    lrd.length = 0;
503    lrd.aggregate = cpu_to_le32(new_encode_dev(sb->s_bdev->bd_dev));
504    lmLog(log, NULL, &lrd, NULL);
505
506    return 0;
507}
508

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