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