linux/fs/jfs/inode.c
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   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
  35struct 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 */
  82int 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
 124int 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
 148void 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
 176void 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
 195int 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
 281static int jfs_writepage(struct page *page, struct writeback_control *wbc)
 282{
 283        return block_write_full_page(page, jfs_get_block, wbc);
 284}
 285
 286static int jfs_writepages(struct address_space *mapping,
 287                        struct writeback_control *wbc)
 288{
 289        return mpage_writepages(mapping, wbc, jfs_get_block);
 290}
 291
 292static int jfs_readpage(struct file *file, struct page *page)
 293{
 294        return mpage_readpage(page, jfs_get_block);
 295}
 296
 297static 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
 303static int jfs_write_begin(struct file *file, struct address_space *mapping,
 304                                loff_t pos, unsigned len, unsigned flags,
 305                                struct page **pagep, void **fsdata)
 306{
 307        int ret;
 308
 309        ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata,
 310                                jfs_get_block);
 311        if (unlikely(ret)) {
 312                loff_t isize = mapping->host->i_size;
 313                if (pos + len > isize)
 314                        vmtruncate(mapping->host, isize);
 315        }
 316
 317        return ret;
 318}
 319
 320static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
 321{
 322        return generic_block_bmap(mapping, block, jfs_get_block);
 323}
 324
 325static ssize_t jfs_direct_IO(int rw, struct kiocb *iocb,
 326        const struct iovec *iov, loff_t offset, unsigned long nr_segs)
 327{
 328        struct file *file = iocb->ki_filp;
 329        struct inode *inode = file->f_mapping->host;
 330        ssize_t ret;
 331
 332        ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
 333                                 jfs_get_block);
 334
 335        /*
 336         * In case of error extending write may have instantiated a few
 337         * blocks outside i_size. Trim these off again.
 338         */
 339        if (unlikely((rw & WRITE) && ret < 0)) {
 340                loff_t isize = i_size_read(inode);
 341                loff_t end = offset + iov_length(iov, nr_segs);
 342
 343                if (end > isize)
 344                        vmtruncate(inode, isize);
 345        }
 346
 347        return ret;
 348}
 349
 350const struct address_space_operations jfs_aops = {
 351        .readpage       = jfs_readpage,
 352        .readpages      = jfs_readpages,
 353        .writepage      = jfs_writepage,
 354        .writepages     = jfs_writepages,
 355        .write_begin    = jfs_write_begin,
 356        .write_end      = nobh_write_end,
 357        .bmap           = jfs_bmap,
 358        .direct_IO      = jfs_direct_IO,
 359};
 360
 361/*
 362 * Guts of jfs_truncate.  Called with locks already held.  Can be called
 363 * with directory for truncating directory index table.
 364 */
 365void jfs_truncate_nolock(struct inode *ip, loff_t length)
 366{
 367        loff_t newsize;
 368        tid_t tid;
 369
 370        ASSERT(length >= 0);
 371
 372        if (test_cflag(COMMIT_Nolink, ip)) {
 373                xtTruncate(0, ip, length, COMMIT_WMAP);
 374                return;
 375        }
 376
 377        do {
 378                tid = txBegin(ip->i_sb, 0);
 379
 380                /*
 381                 * The commit_mutex cannot be taken before txBegin.
 382                 * txBegin may block and there is a chance the inode
 383                 * could be marked dirty and need to be committed
 384                 * before txBegin unblocks
 385                 */
 386                mutex_lock(&JFS_IP(ip)->commit_mutex);
 387
 388                newsize = xtTruncate(tid, ip, length,
 389                                     COMMIT_TRUNCATE | COMMIT_PWMAP);
 390                if (newsize < 0) {
 391                        txEnd(tid);
 392                        mutex_unlock(&JFS_IP(ip)->commit_mutex);
 393                        break;
 394                }
 395
 396                ip->i_mtime = ip->i_ctime = CURRENT_TIME;
 397                mark_inode_dirty(ip);
 398
 399                txCommit(tid, 1, &ip, 0);
 400                txEnd(tid);
 401                mutex_unlock(&JFS_IP(ip)->commit_mutex);
 402        } while (newsize > length);     /* Truncate isn't always atomic */
 403}
 404
 405void jfs_truncate(struct inode *ip)
 406{
 407        jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
 408
 409        nobh_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
 410
 411        IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
 412        jfs_truncate_nolock(ip, ip->i_size);
 413        IWRITE_UNLOCK(ip);
 414}
 415
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