fs/jfs/inode.c

   1 /*
   2  *   Copyright (C) International Business Machines Corp., 2000-2004
   3  *   Portions Copyright (C) Christoph Hellwig, 2001-2002
   4  *
   5  *   This program is free software;  you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation; either version 2 of the License, or
   8  *   (at your option) any later version.
   9  *
  10  *   This program is distributed in the hope that it will be useful,
  11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  13  *   the GNU General Public License for more details.
  14  *
  15  *   You should have received a copy of the GNU General Public License
  16  *   along with this program;  if not, write to the Free Software
  17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18  */
  19
  20 #include <linux/fs.h>
  21 #include <linux/mpage.h>
  22 #include <linux/buffer_head.h>
  23 #include <linux/pagemap.h>
  24 #include <linux/quotaops.h>
  25 #include <linux/writeback.h>
  26 #include "jfs_incore.h"
  27 #include "jfs_inode.h"
  28 #include "jfs_filsys.h"
  29 #include "jfs_imap.h"
  30 #include "jfs_extent.h"
  31 #include "jfs_unicode.h"
  32 #include "jfs_debug.h"
  33
  34
  35 struct inode *jfs_iget(struct super_block *sb, unsigned long ino)
  36 {
  37         struct inode *inode;
  38         int ret;
  39
  40         inode = iget_locked(sb, ino);
  41         if (!inode)
  42                 return ERR_PTR(-ENOMEM);
  43         if (!(inode->i_state & I_NEW))
  44                 return inode;
  45
  46         ret = diRead(inode);
  47         if (ret < 0) {
  48                 iget_failed(inode);
  49                 return ERR_PTR(ret);
  50         }
  51
  52         if (S_ISREG(inode->i_mode)) {
  53                 inode->i_op = &jfs_file_inode_operations;
  54                 inode->i_fop = &jfs_file_operations;
  55                 inode->i_mapping->a_ops = &jfs_aops;
  56         } else if (S_ISDIR(inode->i_mode)) {
  57                 inode->i_op = &jfs_dir_inode_operations;
  58                 inode->i_fop = &jfs_dir_operations;
  59         } else if (S_ISLNK(inode->i_mode)) {
  60                 if (inode->i_size >= IDATASIZE) {
  61                         inode->i_op = &page_symlink_inode_operations;
  62                         inode->i_mapping->a_ops = &jfs_aops;
  63                 } else {
  64                         inode->i_op = &jfs_fast_symlink_inode_operations;
  65                         /*
  66                          * The inline data should be null-terminated, but
  67                          * don't let on-disk corruption crash the kernel
  68                          */
  69                         JFS_IP(inode)->i_inline[inode->i_size] = '\0';
  70                 }
  71         } else {
  72                 inode->i_op = &jfs_file_inode_operations;
  73                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
  74         }
  75         unlock_new_inode(inode);
  76         return inode;
  77 }
  78
  79 /*
  80  * Workhorse of both fsync & write_inode
  81  */
  82 int jfs_commit_inode(struct inode *inode, int wait)
  83 {
  84         int rc = 0;
  85         tid_t tid;
  86         static int noisy = 5;
  87
  88         jfs_info("In jfs_commit_inode, inode = 0x%p", inode);
  89
  90         /*
  91          * Don't commit if inode has been committed since last being
  92          * marked dirty, or if it has been deleted.
  93          */
  94         if (inode->i_nlink == 0 || !test_cflag(COMMIT_Dirty, inode))
  95                 return 0;
  96
  97         if (isReadOnly(inode)) {
  98                 /* kernel allows writes to devices on read-only
  99                  * partitions and may think inode is dirty
 100                  */
 101                 if (!special_file(inode->i_mode) && noisy) {
 102                         jfs_err("jfs_commit_inode(0x%p) called on "
 103                                    "read-only volume", inode);
 104                         jfs_err("Is remount racy?");
 105                         noisy--;
 106                 }
 107                 return 0;
 108         }
 109
 110         tid = txBegin(inode->i_sb, COMMIT_INODE);
 111         mutex_lock(&JFS_IP(inode)->commit_mutex);
 112
 113         /*
 114          * Retest inode state after taking commit_mutex
 115          */
 116         if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
 117                 rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
 118
 119         txEnd(tid);
 120         mutex_unlock(&JFS_IP(inode)->commit_mutex);
 121         return rc;
 122 }
 123
 124 int jfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 125 {
 126         int wait = wbc->sync_mode == WB_SYNC_ALL;
 127
 128         if (test_cflag(COMMIT_Nolink, inode))
 129                 return 0;
 130         /*
 131          * If COMMIT_DIRTY is not set, the inode isn't really dirty.
 132          * It has been committed since the last change, but was still
 133          * on the dirty inode list.
 134          */
 135          if (!test_cflag(COMMIT_Dirty, inode)) {
 136                 /* Make sure committed changes hit the disk */
 137                 jfs_flush_journal(JFS_SBI(inode->i_sb)->log, wait);
 138                 return 0;
 139          }
 140
 141         if (jfs_commit_inode(inode, wait)) {
 142                 jfs_err("jfs_write_inode: jfs_commit_inode failed!");
 143                 return -EIO;
 144         } else
 145                 return 0;
 146 }
 147
 148 void jfs_evict_inode(struct inode *inode)
 149 {
 150         jfs_info("In jfs_evict_inode, inode = 0x%p", inode);
 151
 152         if (!inode->i_nlink && !is_bad_inode(inode)) {
 153                 dquot_initialize(inode);
 154
 155                 if (JFS_IP(inode)->fileset == FILESYSTEM_I) {
 156                         truncate_inode_pages(&inode->i_data, 0);
 157
 158                         if (test_cflag(COMMIT_Freewmap, inode))
 159                                 jfs_free_zero_link(inode);
 160
 161                         diFree(inode);
 162
 163                         /*
 164                          * Free the inode from the quota allocation.
 165                          */
 166                         dquot_initialize(inode);
 167                         dquot_free_inode(inode);
 168                 }
 169         } else {
 170                 truncate_inode_pages(&inode->i_data, 0);
 171         }
 172         clear_inode(inode);
 173         dquot_drop(inode);
 174 }
 175
 176 void jfs_dirty_inode(struct inode *inode, int flags)
 177 {
 178         static int noisy = 5;
 179
 180         if (isReadOnly(inode)) {
 181                 if (!special_file(inode->i_mode) && noisy) {
 182                         /* kernel allows writes to devices on read-only
 183                          * partitions and may try to mark inode dirty
 184                          */
 185                         jfs_err("jfs_dirty_inode called on read-only volume");
 186                         jfs_err("Is remount racy?");
 187                         noisy--;
 188                 }
 189                 return;
 190         }
 191
 192         set_cflag(COMMIT_Dirty, inode);
 193 }
 194
 195 int jfs_get_block(struct inode *ip, sector_t lblock,
 196                   struct buffer_head *bh_result, int create)
 197 {
 198         s64 lblock64 = lblock;
 199         int rc = 0;
 200         xad_t xad;
 201         s64 xaddr;
 202         int xflag;
 203         s32 xlen = bh_result->b_size >> ip->i_blkbits;
 204
 205         /*
 206          * Take appropriate lock on inode
 207          */
 208         if (create)
 209                 IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
 210         else
 211                 IREAD_LOCK(ip, RDWRLOCK_NORMAL);
 212
 213         if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
 214             (!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
 215             xaddr) {
 216                 if (xflag & XAD_NOTRECORDED) {
 217                         if (!create)
 218                                 /*
 219                                  * Allocated but not recorded, read treats
 220                                  * this as a hole
 221                                  */
 222                                 goto unlock;
 223 #ifdef _JFS_4K
 224                         XADoffset(&xad, lblock64);
 225                         XADlength(&xad, xlen);
 226                         XADaddress(&xad, xaddr);
 227 #else                           /* _JFS_4K */
 228                         /*
 229                          * As long as block size = 4K, this isn't a problem.
 230                          * We should mark the whole page not ABNR, but how
 231                          * will we know to mark the other blocks BH_New?
 232                          */
 233                         BUG();
 234 #endif                          /* _JFS_4K */
 235                         rc = extRecord(ip, &xad);
 236                         if (rc)
 237                                 goto unlock;
 238                         set_buffer_new(bh_result);
 239                 }
 240
 241                 map_bh(bh_result, ip->i_sb, xaddr);
 242                 bh_result->b_size = xlen << ip->i_blkbits;
 243                 goto unlock;
 244         }
 245         if (!create)
 246                 goto unlock;
 247
 248         /*
 249          * Allocate a new block
 250          */
 251 #ifdef _JFS_4K
 252         if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
 253                 goto unlock;
 254         rc = extAlloc(ip, xlen, lblock64, &xad, false);
 255         if (rc)
 256                 goto unlock;
 257
 258         set_buffer_new(bh_result);
 259         map_bh(bh_result, ip->i_sb, addressXAD(&xad));
 260         bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
 261
 262 #else                           /* _JFS_4K */
 263         /*
 264          * We need to do whatever it takes to keep all but the last buffers
 265          * in 4K pages - see jfs_write.c
 266          */
 267         BUG();
 268 #endif                          /* _JFS_4K */
 269
 270       unlock:
 271         /*
 272          * Release lock on inode
 273          */
 274         if (create)
 275                 IWRITE_UNLOCK(ip);
 276         else
 277                 IREAD_UNLOCK(ip);
 278         return rc;
 279 }
 280
 281 static int jfs_writepage(struct page *page, struct writeback_control *wbc)
 282 {
 283         return block_write_full_page(page, jfs_get_block, wbc);
 284 }
 285
 286 static int jfs_writepages(struct address_space *mapping,
 287                         struct writeback_control *wbc)
 288 {
 289         return mpage_writepages(mapping, wbc, jfs_get_block);
 290 }
 291
 292 static int jfs_readpage(struct file *file, struct page *page)
 293 {
 294         return mpage_readpage(page, jfs_get_block);
 295 }
 296
 297 static int jfs_readpages(struct file *file, struct address_space *mapping,
 298                 struct list_head *pages, unsigned nr_pages)
 299 {
 300         return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
 301 }
 302
 303 static void jfs_write_failed(struct address_space *mapping, loff_t to)
 304 {
 305         struct inode *inode = mapping->host;
 306
 307         if (to > inode->i_size) {
 308                 truncate_pagecache(inode, to, inode->i_size);
 309                 jfs_truncate(inode);
 310         }
 311 }
 312
 313 static int jfs_write_begin(struct file *file, struct address_space *mapping,
 314                                 loff_t pos, unsigned len, unsigned flags,
 315                                 struct page **pagep, void **fsdata)
 316 {
 317         int ret;
 318
 319         ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata,
 320                                 jfs_get_block);
 321         if (unlikely(ret))
 322                 jfs_write_failed(mapping, pos + len);
 323
 324         return ret;
 325 }
 326
 327 static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
 328 {
 329         return generic_block_bmap(mapping, block, jfs_get_block);
 330 }
 331
 332 static ssize_t jfs_direct_IO(int rw, struct kiocb *iocb,
 333         const struct iovec *iov, loff_t offset, unsigned long nr_segs)
 334 {
 335         struct file *file = iocb->ki_filp;
 336         struct address_space *mapping = file->f_mapping;
 337         struct inode *inode = file->f_mapping->host;
 338         ssize_t ret;
 339
 340         ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
 341                                  jfs_get_block);
 342
 343         /*
 344          * In case of error extending write may have instantiated a few
 345          * blocks outside i_size. Trim these off again.
 346          */
 347         if (unlikely((rw & WRITE) && ret < 0)) {
 348                 loff_t isize = i_size_read(inode);
 349                 loff_t end = offset + iov_length(iov, nr_segs);
 350
 351                 if (end > isize)
 352                         jfs_write_failed(mapping, end);
 353         }
 354
 355         return ret;
 356 }
 357
 358 const struct address_space_operations jfs_aops = {
 359         .readpage       = jfs_readpage,
 360         .readpages      = jfs_readpages,
 361         .writepage      = jfs_writepage,
 362         .writepages     = jfs_writepages,
 363         .write_begin    = jfs_write_begin,
 364         .write_end      = nobh_write_end,
 365         .bmap           = jfs_bmap,
 366         .direct_IO      = jfs_direct_IO,
 367 };
 368
 369 /*
 370  * Guts of jfs_truncate.  Called with locks already held.  Can be called
 371  * with directory for truncating directory index table.
 372  */
 373 void jfs_truncate_nolock(struct inode *ip, loff_t length)
 374 {
 375         loff_t newsize;
 376         tid_t tid;
 377
 378         ASSERT(length >= 0);
 379
 380         if (test_cflag(COMMIT_Nolink, ip)) {
 381                 xtTruncate(0, ip, length, COMMIT_WMAP);
 382                 return;
 383         }
 384
 385         do {
 386                 tid = txBegin(ip->i_sb, 0);
 387
 388                 /*
 389                  * The commit_mutex cannot be taken before txBegin.
 390                  * txBegin may block and there is a chance the inode
 391                  * could be marked dirty and need to be committed
 392                  * before txBegin unblocks
 393                  */
 394                 mutex_lock(&JFS_IP(ip)->commit_mutex);
 395
 396                 newsize = xtTruncate(tid, ip, length,
 397                                      COMMIT_TRUNCATE | COMMIT_PWMAP);
 398                 if (newsize < 0) {
 399                         txEnd(tid);
 400                         mutex_unlock(&JFS_IP(ip)->commit_mutex);
 401                         break;
 402                 }
 403
 404                 ip->i_mtime = ip->i_ctime = CURRENT_TIME;
 405                 mark_inode_dirty(ip);
 406
 407                 txCommit(tid, 1, &ip, 0);
 408                 txEnd(tid);
 409                 mutex_unlock(&JFS_IP(ip)->commit_mutex);
 410         } while (newsize > length);     /* Truncate isn't always atomic */
 411 }
 412
 413 void jfs_truncate(struct inode *ip)
 414 {
 415         jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
 416
 417         nobh_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
 418
 419         IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
 420         jfs_truncate_nolock(ip, ip->i_size);
 421         IWRITE_UNLOCK(ip);
 422 }