Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ]
Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  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  */
 65 static int chkSuper(struct super_block *);
 66 static 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  */
 81 int 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: Faild 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 == 0) {
151                         jfs_err("jfs_mount: Faild 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  */
239 int 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         /*
289          * Set page cache allocation policy
290          */
291         mapping_set_gfp_mask(sb->s_bdev->bd_inode->i_mapping, GFP_NOFS);
292 
293         return rc;
294 }
295 
296 /*
297  *      chkSuper()
298  *
299  * validate the superblock of the file system to be mounted and 
300  * get the file system parameters.
301  *
302  * returns
303  *      0 with fragsize set if check successful
304  *      error code if not successful
305  */
306 static int chkSuper(struct super_block *sb)
307 {
308         int rc = 0;
309         struct jfs_sb_info *sbi = JFS_SBI(sb);
310         struct jfs_superblock *j_sb;
311         struct buffer_head *bh;
312         int AIM_bytesize, AIT_bytesize;
313         int expected_AIM_bytesize, expected_AIT_bytesize;
314         s64 AIM_byte_addr, AIT_byte_addr, fsckwsp_addr;
315         s64 byte_addr_diff0, byte_addr_diff1;
316         s32 bsize;
317 
318         if ((rc = readSuper(sb, &bh)))
319                 return rc;
320         j_sb = (struct jfs_superblock *)bh->b_data;
321 
322         /*
323          * validate superblock
324          */
325         /* validate fs signature */
326         if (strncmp(j_sb->s_magic, JFS_MAGIC, 4) ||
327             le32_to_cpu(j_sb->s_version) > JFS_VERSION) {
328                 rc = -EINVAL;
329                 goto out;
330         }
331 
332         bsize = le32_to_cpu(j_sb->s_bsize);
333 #ifdef _JFS_4K
334         if (bsize != PSIZE) {
335                 jfs_err("Currently only 4K block size supported!");
336                 rc = -EINVAL;
337                 goto out;
338         }
339 #endif                          /* _JFS_4K */
340 
341         jfs_info("superblock: flag:0x%08x state:0x%08x size:0x%Lx",
342                  le32_to_cpu(j_sb->s_flag), le32_to_cpu(j_sb->s_state),
343                  (unsigned long long) le64_to_cpu(j_sb->s_size));
344 
345         /* validate the descriptors for Secondary AIM and AIT */
346         if ((j_sb->s_flag & cpu_to_le32(JFS_BAD_SAIT)) !=
347             cpu_to_le32(JFS_BAD_SAIT)) {
348                 expected_AIM_bytesize = 2 * PSIZE;
349                 AIM_bytesize = lengthPXD(&(j_sb->s_aim2)) * bsize;
350                 expected_AIT_bytesize = 4 * PSIZE;
351                 AIT_bytesize = lengthPXD(&(j_sb->s_ait2)) * bsize;
352                 AIM_byte_addr = addressPXD(&(j_sb->s_aim2)) * bsize;
353                 AIT_byte_addr = addressPXD(&(j_sb->s_ait2)) * bsize;
354                 byte_addr_diff0 = AIT_byte_addr - AIM_byte_addr;
355                 fsckwsp_addr = addressPXD(&(j_sb->s_fsckpxd)) * bsize;
356                 byte_addr_diff1 = fsckwsp_addr - AIT_byte_addr;
357                 if ((AIM_bytesize != expected_AIM_bytesize) ||
358                     (AIT_bytesize != expected_AIT_bytesize) ||
359                     (byte_addr_diff0 != AIM_bytesize) ||
360                     (byte_addr_diff1 <= AIT_bytesize))
361                         j_sb->s_flag |= cpu_to_le32(JFS_BAD_SAIT);
362         }
363 
364         if ((j_sb->s_flag & cpu_to_le32(JFS_GROUPCOMMIT)) !=
365             cpu_to_le32(JFS_GROUPCOMMIT))
366                 j_sb->s_flag |= cpu_to_le32(JFS_GROUPCOMMIT);
367 
368         /* validate fs state */
369         if (j_sb->s_state != cpu_to_le32(FM_CLEAN) &&
370             !(sb->s_flags & MS_RDONLY)) {
371                 jfs_err("jfs_mount: Mount Failure: File System Dirty.");
372                 rc = -EINVAL;
373                 goto out;
374         }
375 
376         sbi->state = le32_to_cpu(j_sb->s_state);
377         sbi->mntflag = le32_to_cpu(j_sb->s_flag);
378 
379         /*
380          * JFS always does I/O by 4K pages.  Don't tell the buffer cache
381          * that we use anything else (leave s_blocksize alone).
382          */
383         sbi->bsize = bsize;
384         sbi->l2bsize = le16_to_cpu(j_sb->s_l2bsize);
385 
386         /*
387          * For now, ignore s_pbsize, l2bfactor.  All I/O going through buffer
388          * cache.
389          */
390         sbi->nbperpage = PSIZE >> sbi->l2bsize;
391         sbi->l2nbperpage = L2PSIZE - sbi->l2bsize;
392         sbi->l2niperblk = sbi->l2bsize - L2DISIZE;
393         if (sbi->mntflag & JFS_INLINELOG)
394                 sbi->logpxd = j_sb->s_logpxd;
395         else {
396                 sbi->logdev = new_decode_dev(le32_to_cpu(j_sb->s_logdev));
397                 memcpy(sbi->uuid, j_sb->s_uuid, sizeof(sbi->uuid));
398                 memcpy(sbi->loguuid, j_sb->s_loguuid, sizeof(sbi->uuid));
399         }
400         sbi->fsckpxd = j_sb->s_fsckpxd;
401         sbi->ait2 = j_sb->s_ait2;
402 
403       out:
404         brelse(bh);
405         return rc;
406 }
407 
408 
409 /*
410  *      updateSuper()
411  *
412  * update synchronously superblock if it is mounted read-write.
413  */
414 int updateSuper(struct super_block *sb, uint state)
415 {
416         struct jfs_superblock *j_sb;
417         struct jfs_sb_info *sbi = JFS_SBI(sb);
418         struct buffer_head *bh;
419         int rc;
420 
421         if (sbi->flag & JFS_NOINTEGRITY) {
422                 if (state == FM_DIRTY) {
423                         sbi->p_state = state;
424                         return 0;
425                 } else if (state == FM_MOUNT) {
426                         sbi->p_state = sbi->state;
427                         state = FM_DIRTY;
428                 } else if (state == FM_CLEAN) {
429                         state = sbi->p_state;
430                 } else
431                         jfs_err("updateSuper: bad state");
432         } else if (sbi->state == FM_DIRTY)
433                 return 0;
434         
435         if ((rc = readSuper(sb, &bh)))
436                 return rc;
437 
438         j_sb = (struct jfs_superblock *)bh->b_data;
439 
440         j_sb->s_state = cpu_to_le32(state);
441         sbi->state = state;
442 
443         if (state == FM_MOUNT) {
444                 /* record log's dev_t and mount serial number */
445                 j_sb->s_logdev = cpu_to_le32(new_encode_dev(sbi->log->bdev->bd_dev));
446                 j_sb->s_logserial = cpu_to_le32(sbi->log->serial);
447         } else if (state == FM_CLEAN) {
448                 /*
449                  * If this volume is shared with OS/2, OS/2 will need to
450                  * recalculate DASD usage, since we don't deal with it.
451                  */
452                 if (j_sb->s_flag & cpu_to_le32(JFS_DASD_ENABLED))
453                         j_sb->s_flag |= cpu_to_le32(JFS_DASD_PRIME);
454         }
455 
456         mark_buffer_dirty(bh);
457         sync_dirty_buffer(bh);
458         brelse(bh);
459 
460         return 0;
461 }
462 
463 
464 /*
465  *      readSuper()
466  *
467  * read superblock by raw sector address
468  */
469 int readSuper(struct super_block *sb, struct buffer_head **bpp)
470 {
471         /* read in primary superblock */
472         *bpp = sb_bread(sb, SUPER1_OFF >> sb->s_blocksize_bits);
473         if (*bpp)
474                 return 0;
475 
476         /* read in secondary/replicated superblock */
477         *bpp = sb_bread(sb, SUPER2_OFF >> sb->s_blocksize_bits);
478         if (*bpp)
479                 return 0;
480 
481         return -EIO;
482 }
483 
484 
485 /*
486  *      logMOUNT()
487  *
488  * function: write a MOUNT log record for file system.
489  *
490  * MOUNT record keeps logredo() from processing log records
491  * for this file system past this point in log.
492  * it is harmless if mount fails.
493  *
494  * note: MOUNT record is at aggregate level, not at fileset level, 
495  * since log records of previous mounts of a fileset
496  * (e.g., AFTER record of extent allocation) have to be processed 
497  * to update block allocation map at aggregate level.
498  */
499 static int logMOUNT(struct super_block *sb)
500 {
501         struct jfs_log *log = JFS_SBI(sb)->log;
502         struct lrd lrd;
503 
504         lrd.logtid = 0;
505         lrd.backchain = 0;
506         lrd.type = cpu_to_le16(LOG_MOUNT);
507         lrd.length = 0;
508         lrd.aggregate = cpu_to_le32(new_encode_dev(sb->s_bdev->bd_dev));
509         lmLog(log, NULL, &lrd, NULL);
510 
511         return 0;
512 }
513 
  This page was automatically generated by the LXR engine.