kernel/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/uio.h>
  26 #include <linux/writeback.h>
  27 #include "jfs_incore.h"
  28 #include "jfs_inode.h"
  29 #include "jfs_filsys.h"
  30 #include "jfs_imap.h"
  31 #include "jfs_extent.h"
  32 #include "jfs_unicode.h"
  33 #include "jfs_debug.h"
  34
  35
  36 struct inode *jfs_iget(struct super_block *sb, unsigned long ino)
  37 {
  38         struct inode *inode;
  39         int ret;
  40
  41         inode = iget_locked(sb, ino);
  42         if (!inode)
  43                 return ERR_PTR(-ENOMEM);
  44         if (!(inode->i_state & I_NEW))
  45                 return inode;
  46
  47         ret = diRead(inode);
  48         if (ret < 0) {
  49                 iget_failed(inode);
  50                 return ERR_PTR(ret);
  51         }
  52
  53         if (S_ISREG(inode->i_mode)) {
  54                 inode->i_op = &jfs_file_inode_operations;
  55                 inode->i_fop = &jfs_file_operations;
  56                 inode->i_mapping->a_ops = &jfs_aops;
  57         } else if (S_ISDIR(inode->i_mode)) {
  58                 inode->i_op = &jfs_dir_inode_operations;
  59                 inode->i_fop = &jfs_dir_operations;
  60         } else if (S_ISLNK(inode->i_mode)) {
  61                 if (inode->i_size >= IDATASIZE) {
  62                         inode->i_op = &page_symlink_inode_operations;
  63                         inode->i_mapping->a_ops = &jfs_aops;
  64                 } else {
  65                         inode->i_op = &jfs_fast_symlink_inode_operations;
  66                         /*
  67                          * The inline data should be null-terminated, but
  68                          * don't let on-disk corruption crash the kernel
  69                          */
  70                         JFS_IP(inode)->i_inline[inode->i_size] = '\0';
  71                 }
  72         } else {
  73                 inode->i_op = &jfs_file_inode_operations;
  74                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
  75         }
  76         unlock_new_inode(inode);
  77         return inode;
  78 }
  79
  80 /*
  81  * Workhorse of both fsync & write_inode
  82  */
  83 int jfs_commit_inode(struct inode *inode, int wait)
  84 {
  85         int rc = 0;
  86         tid_t tid;
  87         static int noisy = 5;
  88
  89         jfs_info("In jfs_commit_inode, inode = 0x%p", inode);
  90
  91         /*
  92          * Don't commit if inode has been committed since last being
  93          * marked dirty, or if it has been deleted.
  94          */
  95         if (inode->i_nlink == 0 || !test_cflag(COMMIT_Dirty, inode))
  96                 return 0;
  97
  98         if (isReadOnly(inode)) {
  99                 /* kernel allows writes to devices on read-only
 100                  * partitions and may think inode is dirty
 101                  */
 102                 if (!special_file(inode->i_mode) && noisy) {
 103                         jfs_err("jfs_commit_inode(0x%p) called on "
 104                                    "read-only volume", inode);
 105                         jfs_err("Is remount racy?");
 106                         noisy--;
 107                 }
 108                 return 0;
 109         }
 110
 111         tid = txBegin(inode->i_sb, COMMIT_INODE);
 112         mutex_lock(&JFS_IP(inode)->commit_mutex);
 113
 114         /*
 115          * Retest inode state after taking commit_mutex
 116          */
 117         if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
 118                 rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
 119
 120         txEnd(tid);
 121         mutex_unlock(&JFS_IP(inode)->commit_mutex);
 122         return rc;
 123 }
 124
 125 int jfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 126 {
 127         int wait = wbc->sync_mode == WB_SYNC_ALL;
 128
 129         if (inode->i_nlink == 0)
 130                 return 0;
 131         /*
 132          * If COMMIT_DIRTY is not set, the inode isn't really dirty.
 133          * It has been committed since the last change, but was still
 134          * on the dirty inode list.
 135          */
 136          if (!test_cflag(COMMIT_Dirty, inode)) {
 137                 /* Make sure committed changes hit the disk */
 138                 jfs_flush_journal(JFS_SBI(inode->i_sb)->log, wait);
 139                 return 0;
 140          }
 141
 142         if (jfs_commit_inode(inode, wait)) {
 143                 jfs_err("jfs_write_inode: jfs_commit_inode failed!");
 144                 return -EIO;
 145         } else
 146                 return 0;
 147 }
 148
 149 void jfs_evict_inode(struct inode *inode)
 150 {
 151         jfs_info("In jfs_evict_inode, inode = 0x%p", inode);
 152
 153         if (!inode->i_nlink && !is_bad_inode(inode)) {
 154                 dquot_initialize(inode);
 155
 156                 if (JFS_IP(inode)->fileset == FILESYSTEM_I) {
 157                         truncate_inode_pages_final(&inode->i_data);
 158
 159                         if (test_cflag(COMMIT_Freewmap, inode))
 160                                 jfs_free_zero_link(inode);
 161
 162                         diFree(inode);
 163
 164                         /*
 165                          * Free the inode from the quota allocation.
 166                          */
 167                         dquot_initialize(inode);
 168                         dquot_free_inode(inode);
 169                 }
 170         } else {
 171                 truncate_inode_pages_final(&inode->i_data);
 172         }
 173         clear_inode(inode);
 174         dquot_drop(inode);
 175 }
 176
 177 void jfs_dirty_inode(struct inode *inode, int flags)
 178 {
 179         static int noisy = 5;
 180
 181         if (isReadOnly(inode)) {
 182                 if (!special_file(inode->i_mode) && noisy) {
 183                         /* kernel allows writes to devices on read-only
 184                          * partitions and may try to mark inode dirty
 185                          */
 186                         jfs_err("jfs_dirty_inode called on read-only volume");
 187                         jfs_err("Is remount racy?");
 188                         noisy--;
 189                 }
 190                 return;
 191         }
 192
 193         set_cflag(COMMIT_Dirty, inode);
 194 }
 195
 196 int jfs_get_block(struct inode *ip, sector_t lblock,
 197                   struct buffer_head *bh_result, int create)
 198 {
 199         s64 lblock64 = lblock;
 200         int rc = 0;
 201         xad_t xad;
 202         s64 xaddr;
 203         int xflag;
 204         s32 xlen = bh_result->b_size >> ip->i_blkbits;
 205
 206         /*
 207          * Take appropriate lock on inode
 208          */
 209         if (create)
 210                 IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
 211         else
 212                 IREAD_LOCK(ip, RDWRLOCK_NORMAL);
 213
 214         if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
 215             (!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
 216             xaddr) {
 217                 if (xflag & XAD_NOTRECORDED) {
 218                         if (!create)
 219                                 /*
 220                                  * Allocated but not recorded, read treats
 221                                  * this as a hole
 222                                  */
 223                                 goto unlock;
 224 #ifdef _JFS_4K
 225                         XADoffset(&xad, lblock64);
 226                         XADlength(&xad, xlen);
 227                         XADaddress(&xad, xaddr);
 228 #else                           /* _JFS_4K */
 229                         /*
 230                          * As long as block size = 4K, this isn't a problem.
 231                          * We should mark the whole page not ABNR, but how
 232                          * will we know to mark the other blocks BH_New?
 233                          */
 234                         BUG();
 235 #endif                          /* _JFS_4K */
 236                         rc = extRecord(ip, &xad);
 237                         if (rc)
 238                                 goto unlock;
 239                         set_buffer_new(bh_result);
 240                 }
 241
 242                 map_bh(bh_result, ip->i_sb, xaddr);
 243                 bh_result->b_size = xlen << ip->i_blkbits;
 244                 goto unlock;
 245         }
 246         if (!create)
 247                 goto unlock;
 248
 249         /*
 250          * Allocate a new block
 251          */
 252 #ifdef _JFS_4K
 253         if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
 254                 goto unlock;
 255         rc = extAlloc(ip, xlen, lblock64, &xad, false);
 256         if (rc)
 257                 goto unlock;
 258
 259         set_buffer_new(bh_result);
 260         map_bh(bh_result, ip->i_sb, addressXAD(&xad));
 261         bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
 262
 263 #else                           /* _JFS_4K */
 264         /*
 265          * We need to do whatever it takes to keep all but the last buffers
 266          * in 4K pages - see jfs_write.c
 267          */
 268         BUG();
 269 #endif                          /* _JFS_4K */
 270
 271       unlock:
 272         /*
 273          * Release lock on inode
 274          */
 275         if (create)
 276                 IWRITE_UNLOCK(ip);
 277         else
 278                 IREAD_UNLOCK(ip);
 279         return rc;
 280 }
 281
 282 static int jfs_writepage(struct page *page, struct writeback_control *wbc)
 283 {
 284         return block_write_full_page(page, jfs_get_block, wbc);
 285 }
 286
 287 static int jfs_writepages(struct address_space *mapping,
 288                         struct writeback_control *wbc)
 289 {
 290         return mpage_writepages(mapping, wbc, jfs_get_block);
 291 }
 292
 293 static int jfs_readpage(struct file *file, struct page *page)
 294 {
 295         return mpage_readpage(page, jfs_get_block);
 296 }
 297
 298 static int jfs_readpages(struct file *file, struct address_space *mapping,
 299                 struct list_head *pages, unsigned nr_pages)
 300 {
 301         return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
 302 }
 303
 304 static void jfs_write_failed(struct address_space *mapping, loff_t to)
 305 {
 306         struct inode *inode = mapping->host;
 307
 308         if (to > inode->i_size) {
 309                 truncate_pagecache(inode, inode->i_size);
 310                 jfs_truncate(inode);
 311         }
 312 }
 313
 314 static int jfs_write_begin(struct file *file, struct address_space *mapping,
 315                                 loff_t pos, unsigned len, unsigned flags,
 316                                 struct page **pagep, void **fsdata)
 317 {
 318         int ret;
 319
 320         ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata,
 321                                 jfs_get_block);
 322         if (unlikely(ret))
 323                 jfs_write_failed(mapping, pos + len);
 324
 325         return ret;
 326 }
 327
 328 static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
 329 {
 330         return generic_block_bmap(mapping, block, jfs_get_block);
 331 }
 332
 333 static ssize_t jfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 334                              loff_t offset)
 335 {
 336         struct file *file = iocb->ki_filp;
 337         struct address_space *mapping = file->f_mapping;
 338         struct inode *inode = file->f_mapping->host;
 339         size_t count = iov_iter_count(iter);
 340         ssize_t ret;
 341
 342         ret = blockdev_direct_IO(iocb, inode, iter, offset, jfs_get_block);
 343
 344         /*
 345          * In case of error extending write may have instantiated a few
 346          * blocks outside i_size. Trim these off again.
 347          */
 348         if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
 349                 loff_t isize = i_size_read(inode);
 350                 loff_t end = offset + count;
 351
 352                 if (end > isize)
 353                         jfs_write_failed(mapping, end);
 354         }
 355
 356         return ret;
 357 }
 358
 359 const struct address_space_operations jfs_aops = {
 360         .readpage       = jfs_readpage,
 361         .readpages      = jfs_readpages,
 362         .writepage      = jfs_writepage,
 363         .writepages     = jfs_writepages,
 364         .write_begin    = jfs_write_begin,
 365         .write_end      = nobh_write_end,
 366         .bmap           = jfs_bmap,
 367         .direct_IO      = jfs_direct_IO,
 368 };
 369
 370 /*
 371  * Guts of jfs_truncate.  Called with locks already held.  Can be called
 372  * with directory for truncating directory index table.
 373  */
 374 void jfs_truncate_nolock(struct inode *ip, loff_t length)
 375 {
 376         loff_t newsize;
 377         tid_t tid;
 378
 379         ASSERT(length >= 0);
 380
 381         if (test_cflag(COMMIT_Nolink, ip)) {
 382                 xtTruncate(0, ip, length, COMMIT_WMAP);
 383                 return;
 384         }
 385
 386         do {
 387                 tid = txBegin(ip->i_sb, 0);
 388
 389                 /*
 390                  * The commit_mutex cannot be taken before txBegin.
 391                  * txBegin may block and there is a chance the inode
 392                  * could be marked dirty and need to be committed
 393                  * before txBegin unblocks
 394                  */
 395                 mutex_lock(&JFS_IP(ip)->commit_mutex);
 396
 397                 newsize = xtTruncate(tid, ip, length,
 398                                      COMMIT_TRUNCATE | COMMIT_PWMAP);
 399                 if (newsize < 0) {
 400                         txEnd(tid);
 401                         mutex_unlock(&JFS_IP(ip)->commit_mutex);
 402                         break;
 403                 }
 404
 405                 ip->i_mtime = ip->i_ctime = CURRENT_TIME;
 406                 mark_inode_dirty(ip);
 407
 408                 txCommit(tid, 1, &ip, 0);
 409                 txEnd(tid);
 410                 mutex_unlock(&JFS_IP(ip)->commit_mutex);
 411         } while (newsize > length);     /* Truncate isn't always atomic */
 412 }
 413
 414 void jfs_truncate(struct inode *ip)
 415 {
 416         jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
 417
 418         nobh_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
 419
 420         IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
 421         jfs_truncate_nolock(ip, ip->i_size);
 422         IWRITE_UNLOCK(ip);
 423 }