linux/fs/nilfs2/inode.c
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   1/*
   2 * inode.c - NILFS inode operations.
   3 *
   4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19 *
  20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
  21 *
  22 */
  23
  24#include <linux/buffer_head.h>
  25#include <linux/gfp.h>
  26#include <linux/mpage.h>
  27#include <linux/writeback.h>
  28#include <linux/aio.h>
  29#include "nilfs.h"
  30#include "btnode.h"
  31#include "segment.h"
  32#include "page.h"
  33#include "mdt.h"
  34#include "cpfile.h"
  35#include "ifile.h"
  36
  37/**
  38 * struct nilfs_iget_args - arguments used during comparison between inodes
  39 * @ino: inode number
  40 * @cno: checkpoint number
  41 * @root: pointer on NILFS root object (mounted checkpoint)
  42 * @for_gc: inode for GC flag
  43 */
  44struct nilfs_iget_args {
  45        u64 ino;
  46        __u64 cno;
  47        struct nilfs_root *root;
  48        int for_gc;
  49};
  50
  51void nilfs_inode_add_blocks(struct inode *inode, int n)
  52{
  53        struct nilfs_root *root = NILFS_I(inode)->i_root;
  54
  55        inode_add_bytes(inode, (1 << inode->i_blkbits) * n);
  56        if (root)
  57                atomic64_add(n, &root->blocks_count);
  58}
  59
  60void nilfs_inode_sub_blocks(struct inode *inode, int n)
  61{
  62        struct nilfs_root *root = NILFS_I(inode)->i_root;
  63
  64        inode_sub_bytes(inode, (1 << inode->i_blkbits) * n);
  65        if (root)
  66                atomic64_sub(n, &root->blocks_count);
  67}
  68
  69/**
  70 * nilfs_get_block() - get a file block on the filesystem (callback function)
  71 * @inode - inode struct of the target file
  72 * @blkoff - file block number
  73 * @bh_result - buffer head to be mapped on
  74 * @create - indicate whether allocating the block or not when it has not
  75 *      been allocated yet.
  76 *
  77 * This function does not issue actual read request of the specified data
  78 * block. It is done by VFS.
  79 */
  80int nilfs_get_block(struct inode *inode, sector_t blkoff,
  81                    struct buffer_head *bh_result, int create)
  82{
  83        struct nilfs_inode_info *ii = NILFS_I(inode);
  84        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
  85        __u64 blknum = 0;
  86        int err = 0, ret;
  87        unsigned maxblocks = bh_result->b_size >> inode->i_blkbits;
  88
  89        down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  90        ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
  91        up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  92        if (ret >= 0) { /* found */
  93                map_bh(bh_result, inode->i_sb, blknum);
  94                if (ret > 0)
  95                        bh_result->b_size = (ret << inode->i_blkbits);
  96                goto out;
  97        }
  98        /* data block was not found */
  99        if (ret == -ENOENT && create) {
 100                struct nilfs_transaction_info ti;
 101
 102                bh_result->b_blocknr = 0;
 103                err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
 104                if (unlikely(err))
 105                        goto out;
 106                err = nilfs_bmap_insert(ii->i_bmap, (unsigned long)blkoff,
 107                                        (unsigned long)bh_result);
 108                if (unlikely(err != 0)) {
 109                        if (err == -EEXIST) {
 110                                /*
 111                                 * The get_block() function could be called
 112                                 * from multiple callers for an inode.
 113                                 * However, the page having this block must
 114                                 * be locked in this case.
 115                                 */
 116                                printk(KERN_WARNING
 117                                       "nilfs_get_block: a race condition "
 118                                       "while inserting a data block. "
 119                                       "(inode number=%lu, file block "
 120                                       "offset=%llu)\n",
 121                                       inode->i_ino,
 122                                       (unsigned long long)blkoff);
 123                                err = 0;
 124                        }
 125                        nilfs_transaction_abort(inode->i_sb);
 126                        goto out;
 127                }
 128                nilfs_mark_inode_dirty(inode);
 129                nilfs_transaction_commit(inode->i_sb); /* never fails */
 130                /* Error handling should be detailed */
 131                set_buffer_new(bh_result);
 132                set_buffer_delay(bh_result);
 133                map_bh(bh_result, inode->i_sb, 0); /* dbn must be changed
 134                                                      to proper value */
 135        } else if (ret == -ENOENT) {
 136                /* not found is not error (e.g. hole); must return without
 137                   the mapped state flag. */
 138                ;
 139        } else {
 140                err = ret;
 141        }
 142
 143 out:
 144        return err;
 145}
 146
 147/**
 148 * nilfs_readpage() - implement readpage() method of nilfs_aops {}
 149 * address_space_operations.
 150 * @file - file struct of the file to be read
 151 * @page - the page to be read
 152 */
 153static int nilfs_readpage(struct file *file, struct page *page)
 154{
 155        return mpage_readpage(page, nilfs_get_block);
 156}
 157
 158/**
 159 * nilfs_readpages() - implement readpages() method of nilfs_aops {}
 160 * address_space_operations.
 161 * @file - file struct of the file to be read
 162 * @mapping - address_space struct used for reading multiple pages
 163 * @pages - the pages to be read
 164 * @nr_pages - number of pages to be read
 165 */
 166static int nilfs_readpages(struct file *file, struct address_space *mapping,
 167                           struct list_head *pages, unsigned nr_pages)
 168{
 169        return mpage_readpages(mapping, pages, nr_pages, nilfs_get_block);
 170}
 171
 172static int nilfs_writepages(struct address_space *mapping,
 173                            struct writeback_control *wbc)
 174{
 175        struct inode *inode = mapping->host;
 176        int err = 0;
 177
 178        if (inode->i_sb->s_flags & MS_RDONLY) {
 179                nilfs_clear_dirty_pages(mapping, false);
 180                return -EROFS;
 181        }
 182
 183        if (wbc->sync_mode == WB_SYNC_ALL)
 184                err = nilfs_construct_dsync_segment(inode->i_sb, inode,
 185                                                    wbc->range_start,
 186                                                    wbc->range_end);
 187        return err;
 188}
 189
 190static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
 191{
 192        struct inode *inode = page->mapping->host;
 193        int err;
 194
 195        if (inode->i_sb->s_flags & MS_RDONLY) {
 196                /*
 197                 * It means that filesystem was remounted in read-only
 198                 * mode because of error or metadata corruption. But we
 199                 * have dirty pages that try to be flushed in background.
 200                 * So, here we simply discard this dirty page.
 201                 */
 202                nilfs_clear_dirty_page(page, false);
 203                unlock_page(page);
 204                return -EROFS;
 205        }
 206
 207        redirty_page_for_writepage(wbc, page);
 208        unlock_page(page);
 209
 210        if (wbc->sync_mode == WB_SYNC_ALL) {
 211                err = nilfs_construct_segment(inode->i_sb);
 212                if (unlikely(err))
 213                        return err;
 214        } else if (wbc->for_reclaim)
 215                nilfs_flush_segment(inode->i_sb, inode->i_ino);
 216
 217        return 0;
 218}
 219
 220static int nilfs_set_page_dirty(struct page *page)
 221{
 222        int ret = __set_page_dirty_nobuffers(page);
 223
 224        if (page_has_buffers(page)) {
 225                struct inode *inode = page->mapping->host;
 226                unsigned nr_dirty = 0;
 227                struct buffer_head *bh, *head;
 228
 229                /*
 230                 * This page is locked by callers, and no other thread
 231                 * concurrently marks its buffers dirty since they are
 232                 * only dirtied through routines in fs/buffer.c in
 233                 * which call sites of mark_buffer_dirty are protected
 234                 * by page lock.
 235                 */
 236                bh = head = page_buffers(page);
 237                do {
 238                        /* Do not mark hole blocks dirty */
 239                        if (buffer_dirty(bh) || !buffer_mapped(bh))
 240                                continue;
 241
 242                        set_buffer_dirty(bh);
 243                        nr_dirty++;
 244                } while (bh = bh->b_this_page, bh != head);
 245
 246                if (nr_dirty)
 247                        nilfs_set_file_dirty(inode, nr_dirty);
 248        }
 249        return ret;
 250}
 251
 252void nilfs_write_failed(struct address_space *mapping, loff_t to)
 253{
 254        struct inode *inode = mapping->host;
 255
 256        if (to > inode->i_size) {
 257                truncate_pagecache(inode, to, inode->i_size);
 258                nilfs_truncate(inode);
 259        }
 260}
 261
 262static int nilfs_write_begin(struct file *file, struct address_space *mapping,
 263                             loff_t pos, unsigned len, unsigned flags,
 264                             struct page **pagep, void **fsdata)
 265
 266{
 267        struct inode *inode = mapping->host;
 268        int err = nilfs_transaction_begin(inode->i_sb, NULL, 1);
 269
 270        if (unlikely(err))
 271                return err;
 272
 273        err = block_write_begin(mapping, pos, len, flags, pagep,
 274                                nilfs_get_block);
 275        if (unlikely(err)) {
 276                nilfs_write_failed(mapping, pos + len);
 277                nilfs_transaction_abort(inode->i_sb);
 278        }
 279        return err;
 280}
 281
 282static int nilfs_write_end(struct file *file, struct address_space *mapping,
 283                           loff_t pos, unsigned len, unsigned copied,
 284                           struct page *page, void *fsdata)
 285{
 286        struct inode *inode = mapping->host;
 287        unsigned start = pos & (PAGE_CACHE_SIZE - 1);
 288        unsigned nr_dirty;
 289        int err;
 290
 291        nr_dirty = nilfs_page_count_clean_buffers(page, start,
 292                                                  start + copied);
 293        copied = generic_write_end(file, mapping, pos, len, copied, page,
 294                                   fsdata);
 295        nilfs_set_file_dirty(inode, nr_dirty);
 296        err = nilfs_transaction_commit(inode->i_sb);
 297        return err ? : copied;
 298}
 299
 300static ssize_t
 301nilfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
 302                loff_t offset, unsigned long nr_segs)
 303{
 304        struct file *file = iocb->ki_filp;
 305        struct address_space *mapping = file->f_mapping;
 306        struct inode *inode = file->f_mapping->host;
 307        ssize_t size;
 308
 309        if (rw == WRITE)
 310                return 0;
 311
 312        /* Needs synchronization with the cleaner */
 313        size = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
 314                                  nilfs_get_block);
 315
 316        /*
 317         * In case of error extending write may have instantiated a few
 318         * blocks outside i_size. Trim these off again.
 319         */
 320        if (unlikely((rw & WRITE) && size < 0)) {
 321                loff_t isize = i_size_read(inode);
 322                loff_t end = offset + iov_length(iov, nr_segs);
 323
 324                if (end > isize)
 325                        nilfs_write_failed(mapping, end);
 326        }
 327
 328        return size;
 329}
 330
 331const struct address_space_operations nilfs_aops = {
 332        .writepage              = nilfs_writepage,
 333        .readpage               = nilfs_readpage,
 334        .writepages             = nilfs_writepages,
 335        .set_page_dirty         = nilfs_set_page_dirty,
 336        .readpages              = nilfs_readpages,
 337        .write_begin            = nilfs_write_begin,
 338        .write_end              = nilfs_write_end,
 339        /* .releasepage         = nilfs_releasepage, */
 340        .invalidatepage         = block_invalidatepage,
 341        .direct_IO              = nilfs_direct_IO,
 342        .is_partially_uptodate  = block_is_partially_uptodate,
 343};
 344
 345struct inode *nilfs_new_inode(struct inode *dir, umode_t mode)
 346{
 347        struct super_block *sb = dir->i_sb;
 348        struct the_nilfs *nilfs = sb->s_fs_info;
 349        struct inode *inode;
 350        struct nilfs_inode_info *ii;
 351        struct nilfs_root *root;
 352        int err = -ENOMEM;
 353        ino_t ino;
 354
 355        inode = new_inode(sb);
 356        if (unlikely(!inode))
 357                goto failed;
 358
 359        mapping_set_gfp_mask(inode->i_mapping,
 360                             mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
 361
 362        root = NILFS_I(dir)->i_root;
 363        ii = NILFS_I(inode);
 364        ii->i_state = 1 << NILFS_I_NEW;
 365        ii->i_root = root;
 366
 367        err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh);
 368        if (unlikely(err))
 369                goto failed_ifile_create_inode;
 370        /* reference count of i_bh inherits from nilfs_mdt_read_block() */
 371
 372        atomic64_inc(&root->inodes_count);
 373        inode_init_owner(inode, dir, mode);
 374        inode->i_ino = ino;
 375        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
 376
 377        if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
 378                err = nilfs_bmap_read(ii->i_bmap, NULL);
 379                if (err < 0)
 380                        goto failed_bmap;
 381
 382                set_bit(NILFS_I_BMAP, &ii->i_state);
 383                /* No lock is needed; iget() ensures it. */
 384        }
 385
 386        ii->i_flags = nilfs_mask_flags(
 387                mode, NILFS_I(dir)->i_flags & NILFS_FL_INHERITED);
 388
 389        /* ii->i_file_acl = 0; */
 390        /* ii->i_dir_acl = 0; */
 391        ii->i_dir_start_lookup = 0;
 392        nilfs_set_inode_flags(inode);
 393        spin_lock(&nilfs->ns_next_gen_lock);
 394        inode->i_generation = nilfs->ns_next_generation++;
 395        spin_unlock(&nilfs->ns_next_gen_lock);
 396        insert_inode_hash(inode);
 397
 398        err = nilfs_init_acl(inode, dir);
 399        if (unlikely(err))
 400                goto failed_acl; /* never occur. When supporting
 401                                    nilfs_init_acl(), proper cancellation of
 402                                    above jobs should be considered */
 403
 404        return inode;
 405
 406 failed_acl:
 407 failed_bmap:
 408        clear_nlink(inode);
 409        iput(inode);  /* raw_inode will be deleted through
 410                         generic_delete_inode() */
 411        goto failed;
 412
 413 failed_ifile_create_inode:
 414        make_bad_inode(inode);
 415        iput(inode);  /* if i_nlink == 1, generic_forget_inode() will be
 416                         called */
 417 failed:
 418        return ERR_PTR(err);
 419}
 420
 421void nilfs_set_inode_flags(struct inode *inode)
 422{
 423        unsigned int flags = NILFS_I(inode)->i_flags;
 424
 425        inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME |
 426                            S_DIRSYNC);
 427        if (flags & FS_SYNC_FL)
 428                inode->i_flags |= S_SYNC;
 429        if (flags & FS_APPEND_FL)
 430                inode->i_flags |= S_APPEND;
 431        if (flags & FS_IMMUTABLE_FL)
 432                inode->i_flags |= S_IMMUTABLE;
 433        if (flags & FS_NOATIME_FL)
 434                inode->i_flags |= S_NOATIME;
 435        if (flags & FS_DIRSYNC_FL)
 436                inode->i_flags |= S_DIRSYNC;
 437        mapping_set_gfp_mask(inode->i_mapping,
 438                             mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
 439}
 440
 441int nilfs_read_inode_common(struct inode *inode,
 442                            struct nilfs_inode *raw_inode)
 443{
 444        struct nilfs_inode_info *ii = NILFS_I(inode);
 445        int err;
 446
 447        inode->i_mode = le16_to_cpu(raw_inode->i_mode);
 448        i_uid_write(inode, le32_to_cpu(raw_inode->i_uid));
 449        i_gid_write(inode, le32_to_cpu(raw_inode->i_gid));
 450        set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
 451        inode->i_size = le64_to_cpu(raw_inode->i_size);
 452        inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 453        inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
 454        inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 455        inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 456        inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
 457        inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 458        if (inode->i_nlink == 0 && inode->i_mode == 0)
 459                return -EINVAL; /* this inode is deleted */
 460
 461        inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
 462        ii->i_flags = le32_to_cpu(raw_inode->i_flags);
 463#if 0
 464        ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
 465        ii->i_dir_acl = S_ISREG(inode->i_mode) ?
 466                0 : le32_to_cpu(raw_inode->i_dir_acl);
 467#endif
 468        ii->i_dir_start_lookup = 0;
 469        inode->i_generation = le32_to_cpu(raw_inode->i_generation);
 470
 471        if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 472            S_ISLNK(inode->i_mode)) {
 473                err = nilfs_bmap_read(ii->i_bmap, raw_inode);
 474                if (err < 0)
 475                        return err;
 476                set_bit(NILFS_I_BMAP, &ii->i_state);
 477                /* No lock is needed; iget() ensures it. */
 478        }
 479        return 0;
 480}
 481
 482static int __nilfs_read_inode(struct super_block *sb,
 483                              struct nilfs_root *root, unsigned long ino,
 484                              struct inode *inode)
 485{
 486        struct the_nilfs *nilfs = sb->s_fs_info;
 487        struct buffer_head *bh;
 488        struct nilfs_inode *raw_inode;
 489        int err;
 490
 491        down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 492        err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
 493        if (unlikely(err))
 494                goto bad_inode;
 495
 496        raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
 497
 498        err = nilfs_read_inode_common(inode, raw_inode);
 499        if (err)
 500                goto failed_unmap;
 501
 502        if (S_ISREG(inode->i_mode)) {
 503                inode->i_op = &nilfs_file_inode_operations;
 504                inode->i_fop = &nilfs_file_operations;
 505                inode->i_mapping->a_ops = &nilfs_aops;
 506        } else if (S_ISDIR(inode->i_mode)) {
 507                inode->i_op = &nilfs_dir_inode_operations;
 508                inode->i_fop = &nilfs_dir_operations;
 509                inode->i_mapping->a_ops = &nilfs_aops;
 510        } else if (S_ISLNK(inode->i_mode)) {
 511                inode->i_op = &nilfs_symlink_inode_operations;
 512                inode->i_mapping->a_ops = &nilfs_aops;
 513        } else {
 514                inode->i_op = &nilfs_special_inode_operations;
 515                init_special_inode(
 516                        inode, inode->i_mode,
 517                        huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
 518        }
 519        nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 520        brelse(bh);
 521        up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 522        nilfs_set_inode_flags(inode);
 523        return 0;
 524
 525 failed_unmap:
 526        nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 527        brelse(bh);
 528
 529 bad_inode:
 530        up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 531        return err;
 532}
 533
 534static int nilfs_iget_test(struct inode *inode, void *opaque)
 535{
 536        struct nilfs_iget_args *args = opaque;
 537        struct nilfs_inode_info *ii;
 538
 539        if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
 540                return 0;
 541
 542        ii = NILFS_I(inode);
 543        if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
 544                return !args->for_gc;
 545
 546        return args->for_gc && args->cno == ii->i_cno;
 547}
 548
 549static int nilfs_iget_set(struct inode *inode, void *opaque)
 550{
 551        struct nilfs_iget_args *args = opaque;
 552
 553        inode->i_ino = args->ino;
 554        if (args->for_gc) {
 555                NILFS_I(inode)->i_state = 1 << NILFS_I_GCINODE;
 556                NILFS_I(inode)->i_cno = args->cno;
 557                NILFS_I(inode)->i_root = NULL;
 558        } else {
 559                if (args->root && args->ino == NILFS_ROOT_INO)
 560                        nilfs_get_root(args->root);
 561                NILFS_I(inode)->i_root = args->root;
 562        }
 563        return 0;
 564}
 565
 566struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
 567                            unsigned long ino)
 568{
 569        struct nilfs_iget_args args = {
 570                .ino = ino, .root = root, .cno = 0, .for_gc = 0
 571        };
 572
 573        return ilookup5(sb, ino, nilfs_iget_test, &args);
 574}
 575
 576struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
 577                                unsigned long ino)
 578{
 579        struct nilfs_iget_args args = {
 580                .ino = ino, .root = root, .cno = 0, .for_gc = 0
 581        };
 582
 583        return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 584}
 585
 586struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
 587                         unsigned long ino)
 588{
 589        struct inode *inode;
 590        int err;
 591
 592        inode = nilfs_iget_locked(sb, root, ino);
 593        if (unlikely(!inode))
 594                return ERR_PTR(-ENOMEM);
 595        if (!(inode->i_state & I_NEW))
 596                return inode;
 597
 598        err = __nilfs_read_inode(sb, root, ino, inode);
 599        if (unlikely(err)) {
 600                iget_failed(inode);
 601                return ERR_PTR(err);
 602        }
 603        unlock_new_inode(inode);
 604        return inode;
 605}
 606
 607struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
 608                                __u64 cno)
 609{
 610        struct nilfs_iget_args args = {
 611                .ino = ino, .root = NULL, .cno = cno, .for_gc = 1
 612        };
 613        struct inode *inode;
 614        int err;
 615
 616        inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 617        if (unlikely(!inode))
 618                return ERR_PTR(-ENOMEM);
 619        if (!(inode->i_state & I_NEW))
 620                return inode;
 621
 622        err = nilfs_init_gcinode(inode);
 623        if (unlikely(err)) {
 624                iget_failed(inode);
 625                return ERR_PTR(err);
 626        }
 627        unlock_new_inode(inode);
 628        return inode;
 629}
 630
 631void nilfs_write_inode_common(struct inode *inode,
 632                              struct nilfs_inode *raw_inode, int has_bmap)
 633{
 634        struct nilfs_inode_info *ii = NILFS_I(inode);
 635
 636        raw_inode->i_mode = cpu_to_le16(inode->i_mode);
 637        raw_inode->i_uid = cpu_to_le32(i_uid_read(inode));
 638        raw_inode->i_gid = cpu_to_le32(i_gid_read(inode));
 639        raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
 640        raw_inode->i_size = cpu_to_le64(inode->i_size);
 641        raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 642        raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
 643        raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 644        raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
 645        raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
 646
 647        raw_inode->i_flags = cpu_to_le32(ii->i_flags);
 648        raw_inode->i_generation = cpu_to_le32(inode->i_generation);
 649
 650        if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
 651                struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 652
 653                /* zero-fill unused portion in the case of super root block */
 654                raw_inode->i_xattr = 0;
 655                raw_inode->i_pad = 0;
 656                memset((void *)raw_inode + sizeof(*raw_inode), 0,
 657                       nilfs->ns_inode_size - sizeof(*raw_inode));
 658        }
 659
 660        if (has_bmap)
 661                nilfs_bmap_write(ii->i_bmap, raw_inode);
 662        else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 663                raw_inode->i_device_code =
 664                        cpu_to_le64(huge_encode_dev(inode->i_rdev));
 665        /* When extending inode, nilfs->ns_inode_size should be checked
 666           for substitutions of appended fields */
 667}
 668
 669void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh)
 670{
 671        ino_t ino = inode->i_ino;
 672        struct nilfs_inode_info *ii = NILFS_I(inode);
 673        struct inode *ifile = ii->i_root->ifile;
 674        struct nilfs_inode *raw_inode;
 675
 676        raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
 677
 678        if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
 679                memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
 680        set_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
 681
 682        nilfs_write_inode_common(inode, raw_inode, 0);
 683                /* XXX: call with has_bmap = 0 is a workaround to avoid
 684                   deadlock of bmap. This delays update of i_bmap to just
 685                   before writing */
 686        nilfs_ifile_unmap_inode(ifile, ino, ibh);
 687}
 688
 689#define NILFS_MAX_TRUNCATE_BLOCKS       16384  /* 64MB for 4KB block */
 690
 691static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
 692                                unsigned long from)
 693{
 694        unsigned long b;
 695        int ret;
 696
 697        if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 698                return;
 699repeat:
 700        ret = nilfs_bmap_last_key(ii->i_bmap, &b);
 701        if (ret == -ENOENT)
 702                return;
 703        else if (ret < 0)
 704                goto failed;
 705
 706        if (b < from)
 707                return;
 708
 709        b -= min_t(unsigned long, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
 710        ret = nilfs_bmap_truncate(ii->i_bmap, b);
 711        nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
 712        if (!ret || (ret == -ENOMEM &&
 713                     nilfs_bmap_truncate(ii->i_bmap, b) == 0))
 714                goto repeat;
 715
 716failed:
 717        nilfs_warning(ii->vfs_inode.i_sb, __func__,
 718                      "failed to truncate bmap (ino=%lu, err=%d)",
 719                      ii->vfs_inode.i_ino, ret);
 720}
 721
 722void nilfs_truncate(struct inode *inode)
 723{
 724        unsigned long blkoff;
 725        unsigned int blocksize;
 726        struct nilfs_transaction_info ti;
 727        struct super_block *sb = inode->i_sb;
 728        struct nilfs_inode_info *ii = NILFS_I(inode);
 729
 730        if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 731                return;
 732        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 733                return;
 734
 735        blocksize = sb->s_blocksize;
 736        blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
 737        nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 738
 739        block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
 740
 741        nilfs_truncate_bmap(ii, blkoff);
 742
 743        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 744        if (IS_SYNC(inode))
 745                nilfs_set_transaction_flag(NILFS_TI_SYNC);
 746
 747        nilfs_mark_inode_dirty(inode);
 748        nilfs_set_file_dirty(inode, 0);
 749        nilfs_transaction_commit(sb);
 750        /* May construct a logical segment and may fail in sync mode.
 751           But truncate has no return value. */
 752}
 753
 754static void nilfs_clear_inode(struct inode *inode)
 755{
 756        struct nilfs_inode_info *ii = NILFS_I(inode);
 757        struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 758
 759        /*
 760         * Free resources allocated in nilfs_read_inode(), here.
 761         */
 762        BUG_ON(!list_empty(&ii->i_dirty));
 763        brelse(ii->i_bh);
 764        ii->i_bh = NULL;
 765
 766        if (mdi && mdi->mi_palloc_cache)
 767                nilfs_palloc_destroy_cache(inode);
 768
 769        if (test_bit(NILFS_I_BMAP, &ii->i_state))
 770                nilfs_bmap_clear(ii->i_bmap);
 771
 772        nilfs_btnode_cache_clear(&ii->i_btnode_cache);
 773
 774        if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
 775                nilfs_put_root(ii->i_root);
 776}
 777
 778void nilfs_evict_inode(struct inode *inode)
 779{
 780        struct nilfs_transaction_info ti;
 781        struct super_block *sb = inode->i_sb;
 782        struct nilfs_inode_info *ii = NILFS_I(inode);
 783        int ret;
 784
 785        if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
 786                if (inode->i_data.nrpages)
 787                        truncate_inode_pages(&inode->i_data, 0);
 788                clear_inode(inode);
 789                nilfs_clear_inode(inode);
 790                return;
 791        }
 792        nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 793
 794        if (inode->i_data.nrpages)
 795                truncate_inode_pages(&inode->i_data, 0);
 796
 797        /* TODO: some of the following operations may fail.  */
 798        nilfs_truncate_bmap(ii, 0);
 799        nilfs_mark_inode_dirty(inode);
 800        clear_inode(inode);
 801
 802        ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
 803        if (!ret)
 804                atomic64_dec(&ii->i_root->inodes_count);
 805
 806        nilfs_clear_inode(inode);
 807
 808        if (IS_SYNC(inode))
 809                nilfs_set_transaction_flag(NILFS_TI_SYNC);
 810        nilfs_transaction_commit(sb);
 811        /* May construct a logical segment and may fail in sync mode.
 812           But delete_inode has no return value. */
 813}
 814
 815int nilfs_setattr(struct dentry *dentry, struct iattr *iattr)
 816{
 817        struct nilfs_transaction_info ti;
 818        struct inode *inode = dentry->d_inode;
 819        struct super_block *sb = inode->i_sb;
 820        int err;
 821
 822        err = inode_change_ok(inode, iattr);
 823        if (err)
 824                return err;
 825
 826        err = nilfs_transaction_begin(sb, &ti, 0);
 827        if (unlikely(err))
 828                return err;
 829
 830        if ((iattr->ia_valid & ATTR_SIZE) &&
 831            iattr->ia_size != i_size_read(inode)) {
 832                inode_dio_wait(inode);
 833                truncate_setsize(inode, iattr->ia_size);
 834                nilfs_truncate(inode);
 835        }
 836
 837        setattr_copy(inode, iattr);
 838        mark_inode_dirty(inode);
 839
 840        if (iattr->ia_valid & ATTR_MODE) {
 841                err = nilfs_acl_chmod(inode);
 842                if (unlikely(err))
 843                        goto out_err;
 844        }
 845
 846        return nilfs_transaction_commit(sb);
 847
 848out_err:
 849        nilfs_transaction_abort(sb);
 850        return err;
 851}
 852
 853int nilfs_permission(struct inode *inode, int mask)
 854{
 855        struct nilfs_root *root = NILFS_I(inode)->i_root;
 856        if ((mask & MAY_WRITE) && root &&
 857            root->cno != NILFS_CPTREE_CURRENT_CNO)
 858                return -EROFS; /* snapshot is not writable */
 859
 860        return generic_permission(inode, mask);
 861}
 862
 863int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
 864{
 865        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 866        struct nilfs_inode_info *ii = NILFS_I(inode);
 867        int err;
 868
 869        spin_lock(&nilfs->ns_inode_lock);
 870        if (ii->i_bh == NULL) {
 871                spin_unlock(&nilfs->ns_inode_lock);
 872                err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
 873                                                  inode->i_ino, pbh);
 874                if (unlikely(err))
 875                        return err;
 876                spin_lock(&nilfs->ns_inode_lock);
 877                if (ii->i_bh == NULL)
 878                        ii->i_bh = *pbh;
 879                else {
 880                        brelse(*pbh);
 881                        *pbh = ii->i_bh;
 882                }
 883        } else
 884                *pbh = ii->i_bh;
 885
 886        get_bh(*pbh);
 887        spin_unlock(&nilfs->ns_inode_lock);
 888        return 0;
 889}
 890
 891int nilfs_inode_dirty(struct inode *inode)
 892{
 893        struct nilfs_inode_info *ii = NILFS_I(inode);
 894        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 895        int ret = 0;
 896
 897        if (!list_empty(&ii->i_dirty)) {
 898                spin_lock(&nilfs->ns_inode_lock);
 899                ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
 900                        test_bit(NILFS_I_BUSY, &ii->i_state);
 901                spin_unlock(&nilfs->ns_inode_lock);
 902        }
 903        return ret;
 904}
 905
 906int nilfs_set_file_dirty(struct inode *inode, unsigned nr_dirty)
 907{
 908        struct nilfs_inode_info *ii = NILFS_I(inode);
 909        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 910
 911        atomic_add(nr_dirty, &nilfs->ns_ndirtyblks);
 912
 913        if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
 914                return 0;
 915
 916        spin_lock(&nilfs->ns_inode_lock);
 917        if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
 918            !test_bit(NILFS_I_BUSY, &ii->i_state)) {
 919                /* Because this routine may race with nilfs_dispose_list(),
 920                   we have to check NILFS_I_QUEUED here, too. */
 921                if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
 922                        /* This will happen when somebody is freeing
 923                           this inode. */
 924                        nilfs_warning(inode->i_sb, __func__,
 925                                      "cannot get inode (ino=%lu)\n",
 926                                      inode->i_ino);
 927                        spin_unlock(&nilfs->ns_inode_lock);
 928                        return -EINVAL; /* NILFS_I_DIRTY may remain for
 929                                           freeing inode */
 930                }
 931                list_move_tail(&ii->i_dirty, &nilfs->ns_dirty_files);
 932                set_bit(NILFS_I_QUEUED, &ii->i_state);
 933        }
 934        spin_unlock(&nilfs->ns_inode_lock);
 935        return 0;
 936}
 937
 938int nilfs_mark_inode_dirty(struct inode *inode)
 939{
 940        struct buffer_head *ibh;
 941        int err;
 942
 943        err = nilfs_load_inode_block(inode, &ibh);
 944        if (unlikely(err)) {
 945                nilfs_warning(inode->i_sb, __func__,
 946                              "failed to reget inode block.\n");
 947                return err;
 948        }
 949        nilfs_update_inode(inode, ibh);
 950        mark_buffer_dirty(ibh);
 951        nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
 952        brelse(ibh);
 953        return 0;
 954}
 955
 956/**
 957 * nilfs_dirty_inode - reflect changes on given inode to an inode block.
 958 * @inode: inode of the file to be registered.
 959 *
 960 * nilfs_dirty_inode() loads a inode block containing the specified
 961 * @inode and copies data from a nilfs_inode to a corresponding inode
 962 * entry in the inode block. This operation is excluded from the segment
 963 * construction. This function can be called both as a single operation
 964 * and as a part of indivisible file operations.
 965 */
 966void nilfs_dirty_inode(struct inode *inode, int flags)
 967{
 968        struct nilfs_transaction_info ti;
 969        struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 970
 971        if (is_bad_inode(inode)) {
 972                nilfs_warning(inode->i_sb, __func__,
 973                              "tried to mark bad_inode dirty. ignored.\n");
 974                dump_stack();
 975                return;
 976        }
 977        if (mdi) {
 978                nilfs_mdt_mark_dirty(inode);
 979                return;
 980        }
 981        nilfs_transaction_begin(inode->i_sb, &ti, 0);
 982        nilfs_mark_inode_dirty(inode);
 983        nilfs_transaction_commit(inode->i_sb); /* never fails */
 984}
 985
 986int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 987                 __u64 start, __u64 len)
 988{
 989        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 990        __u64 logical = 0, phys = 0, size = 0;
 991        __u32 flags = 0;
 992        loff_t isize;
 993        sector_t blkoff, end_blkoff;
 994        sector_t delalloc_blkoff;
 995        unsigned long delalloc_blklen;
 996        unsigned int blkbits = inode->i_blkbits;
 997        int ret, n;
 998
 999        ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
1000        if (ret)
1001                return ret;
1002
1003        mutex_lock(&inode->i_mutex);
1004
1005        isize = i_size_read(inode);
1006
1007        blkoff = start >> blkbits;
1008        end_blkoff = (start + len - 1) >> blkbits;
1009
1010        delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
1011                                                        &delalloc_blkoff);
1012
1013        do {
1014                __u64 blkphy;
1015                unsigned int maxblocks;
1016
1017                if (delalloc_blklen && blkoff == delalloc_blkoff) {
1018                        if (size) {
1019                                /* End of the current extent */
1020                                ret = fiemap_fill_next_extent(
1021                                        fieinfo, logical, phys, size, flags);
1022                                if (ret)
1023                                        break;
1024                        }
1025                        if (blkoff > end_blkoff)
1026                                break;
1027
1028                        flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
1029                        logical = blkoff << blkbits;
1030                        phys = 0;
1031                        size = delalloc_blklen << blkbits;
1032
1033                        blkoff = delalloc_blkoff + delalloc_blklen;
1034                        delalloc_blklen = nilfs_find_uncommitted_extent(
1035                                inode, blkoff, &delalloc_blkoff);
1036                        continue;
1037                }
1038
1039                /*
1040                 * Limit the number of blocks that we look up so as
1041                 * not to get into the next delayed allocation extent.
1042                 */
1043                maxblocks = INT_MAX;
1044                if (delalloc_blklen)
1045                        maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
1046                                          maxblocks);
1047                blkphy = 0;
1048
1049                down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1050                n = nilfs_bmap_lookup_contig(
1051                        NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
1052                up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1053
1054                if (n < 0) {
1055                        int past_eof;
1056
1057                        if (unlikely(n != -ENOENT))
1058                                break; /* error */
1059
1060                        /* HOLE */
1061                        blkoff++;
1062                        past_eof = ((blkoff << blkbits) >= isize);
1063
1064                        if (size) {
1065                                /* End of the current extent */
1066
1067                                if (past_eof)
1068                                        flags |= FIEMAP_EXTENT_LAST;
1069
1070                                ret = fiemap_fill_next_extent(
1071                                        fieinfo, logical, phys, size, flags);
1072                                if (ret)
1073                                        break;
1074                                size = 0;
1075                        }
1076                        if (blkoff > end_blkoff || past_eof)
1077                                break;
1078                } else {
1079                        if (size) {
1080                                if (phys && blkphy << blkbits == phys + size) {
1081                                        /* The current extent goes on */
1082                                        size += n << blkbits;
1083                                } else {
1084                                        /* Terminate the current extent */
1085                                        ret = fiemap_fill_next_extent(
1086                                                fieinfo, logical, phys, size,
1087                                                flags);
1088                                        if (ret || blkoff > end_blkoff)
1089                                                break;
1090
1091                                        /* Start another extent */
1092                                        flags = FIEMAP_EXTENT_MERGED;
1093                                        logical = blkoff << blkbits;
1094                                        phys = blkphy << blkbits;
1095                                        size = n << blkbits;
1096                                }
1097                        } else {
1098                                /* Start a new extent */
1099                                flags = FIEMAP_EXTENT_MERGED;
1100                                logical = blkoff << blkbits;
1101                                phys = blkphy << blkbits;
1102                                size = n << blkbits;
1103                        }
1104                        blkoff += n;
1105                }
1106                cond_resched();
1107        } while (true);
1108
1109        /* If ret is 1 then we just hit the end of the extent array */
1110        if (ret == 1)
1111                ret = 0;
1112
1113        mutex_unlock(&inode->i_mutex);
1114        return ret;
1115}
1116
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