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/uio.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                atomic_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                atomic_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 (wbc->sync_mode == WB_SYNC_ALL)
 179                err = nilfs_construct_dsync_segment(inode->i_sb, inode,
 180                                                    wbc->range_start,
 181                                                    wbc->range_end);
 182        return err;
 183}
 184
 185static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
 186{
 187        struct inode *inode = page->mapping->host;
 188        int err;
 189
 190        redirty_page_for_writepage(wbc, page);
 191        unlock_page(page);
 192
 193        if (wbc->sync_mode == WB_SYNC_ALL) {
 194                err = nilfs_construct_segment(inode->i_sb);
 195                if (unlikely(err))
 196                        return err;
 197        } else if (wbc->for_reclaim)
 198                nilfs_flush_segment(inode->i_sb, inode->i_ino);
 199
 200        return 0;
 201}
 202
 203static int nilfs_set_page_dirty(struct page *page)
 204{
 205        int ret = __set_page_dirty_buffers(page);
 206
 207        if (ret) {
 208                struct inode *inode = page->mapping->host;
 209                unsigned nr_dirty = 1 << (PAGE_SHIFT - inode->i_blkbits);
 210
 211                nilfs_set_file_dirty(inode, nr_dirty);
 212        }
 213        return ret;
 214}
 215
 216void nilfs_write_failed(struct address_space *mapping, loff_t to)
 217{
 218        struct inode *inode = mapping->host;
 219
 220        if (to > inode->i_size) {
 221                truncate_pagecache(inode, to, inode->i_size);
 222                nilfs_truncate(inode);
 223        }
 224}
 225
 226static int nilfs_write_begin(struct file *file, struct address_space *mapping,
 227                             loff_t pos, unsigned len, unsigned flags,
 228                             struct page **pagep, void **fsdata)
 229
 230{
 231        struct inode *inode = mapping->host;
 232        int err = nilfs_transaction_begin(inode->i_sb, NULL, 1);
 233
 234        if (unlikely(err))
 235                return err;
 236
 237        err = block_write_begin(mapping, pos, len, flags, pagep,
 238                                nilfs_get_block);
 239        if (unlikely(err)) {
 240                nilfs_write_failed(mapping, pos + len);
 241                nilfs_transaction_abort(inode->i_sb);
 242        }
 243        return err;
 244}
 245
 246static int nilfs_write_end(struct file *file, struct address_space *mapping,
 247                           loff_t pos, unsigned len, unsigned copied,
 248                           struct page *page, void *fsdata)
 249{
 250        struct inode *inode = mapping->host;
 251        unsigned start = pos & (PAGE_CACHE_SIZE - 1);
 252        unsigned nr_dirty;
 253        int err;
 254
 255        nr_dirty = nilfs_page_count_clean_buffers(page, start,
 256                                                  start + copied);
 257        copied = generic_write_end(file, mapping, pos, len, copied, page,
 258                                   fsdata);
 259        nilfs_set_file_dirty(inode, nr_dirty);
 260        err = nilfs_transaction_commit(inode->i_sb);
 261        return err ? : copied;
 262}
 263
 264static ssize_t
 265nilfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
 266                loff_t offset, unsigned long nr_segs)
 267{
 268        struct file *file = iocb->ki_filp;
 269        struct address_space *mapping = file->f_mapping;
 270        struct inode *inode = file->f_mapping->host;
 271        ssize_t size;
 272
 273        if (rw == WRITE)
 274                return 0;
 275
 276        /* Needs synchronization with the cleaner */
 277        size = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
 278                                  nilfs_get_block);
 279
 280        /*
 281         * In case of error extending write may have instantiated a few
 282         * blocks outside i_size. Trim these off again.
 283         */
 284        if (unlikely((rw & WRITE) && size < 0)) {
 285                loff_t isize = i_size_read(inode);
 286                loff_t end = offset + iov_length(iov, nr_segs);
 287
 288                if (end > isize)
 289                        nilfs_write_failed(mapping, end);
 290        }
 291
 292        return size;
 293}
 294
 295const struct address_space_operations nilfs_aops = {
 296        .writepage              = nilfs_writepage,
 297        .readpage               = nilfs_readpage,
 298        .writepages             = nilfs_writepages,
 299        .set_page_dirty         = nilfs_set_page_dirty,
 300        .readpages              = nilfs_readpages,
 301        .write_begin            = nilfs_write_begin,
 302        .write_end              = nilfs_write_end,
 303        /* .releasepage         = nilfs_releasepage, */
 304        .invalidatepage         = block_invalidatepage,
 305        .direct_IO              = nilfs_direct_IO,
 306        .is_partially_uptodate  = block_is_partially_uptodate,
 307};
 308
 309struct inode *nilfs_new_inode(struct inode *dir, umode_t mode)
 310{
 311        struct super_block *sb = dir->i_sb;
 312        struct the_nilfs *nilfs = sb->s_fs_info;
 313        struct inode *inode;
 314        struct nilfs_inode_info *ii;
 315        struct nilfs_root *root;
 316        int err = -ENOMEM;
 317        ino_t ino;
 318
 319        inode = new_inode(sb);
 320        if (unlikely(!inode))
 321                goto failed;
 322
 323        mapping_set_gfp_mask(inode->i_mapping,
 324                             mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
 325
 326        root = NILFS_I(dir)->i_root;
 327        ii = NILFS_I(inode);
 328        ii->i_state = 1 << NILFS_I_NEW;
 329        ii->i_root = root;
 330
 331        err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh);
 332        if (unlikely(err))
 333                goto failed_ifile_create_inode;
 334        /* reference count of i_bh inherits from nilfs_mdt_read_block() */
 335
 336        atomic_inc(&root->inodes_count);
 337        inode_init_owner(inode, dir, mode);
 338        inode->i_ino = ino;
 339        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
 340
 341        if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
 342                err = nilfs_bmap_read(ii->i_bmap, NULL);
 343                if (err < 0)
 344                        goto failed_bmap;
 345
 346                set_bit(NILFS_I_BMAP, &ii->i_state);
 347                /* No lock is needed; iget() ensures it. */
 348        }
 349
 350        ii->i_flags = nilfs_mask_flags(
 351                mode, NILFS_I(dir)->i_flags & NILFS_FL_INHERITED);
 352
 353        /* ii->i_file_acl = 0; */
 354        /* ii->i_dir_acl = 0; */
 355        ii->i_dir_start_lookup = 0;
 356        nilfs_set_inode_flags(inode);
 357        spin_lock(&nilfs->ns_next_gen_lock);
 358        inode->i_generation = nilfs->ns_next_generation++;
 359        spin_unlock(&nilfs->ns_next_gen_lock);
 360        insert_inode_hash(inode);
 361
 362        err = nilfs_init_acl(inode, dir);
 363        if (unlikely(err))
 364                goto failed_acl; /* never occur. When supporting
 365                                    nilfs_init_acl(), proper cancellation of
 366                                    above jobs should be considered */
 367
 368        return inode;
 369
 370 failed_acl:
 371 failed_bmap:
 372        clear_nlink(inode);
 373        iput(inode);  /* raw_inode will be deleted through
 374                         generic_delete_inode() */
 375        goto failed;
 376
 377 failed_ifile_create_inode:
 378        make_bad_inode(inode);
 379        iput(inode);  /* if i_nlink == 1, generic_forget_inode() will be
 380                         called */
 381 failed:
 382        return ERR_PTR(err);
 383}
 384
 385void nilfs_set_inode_flags(struct inode *inode)
 386{
 387        unsigned int flags = NILFS_I(inode)->i_flags;
 388
 389        inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME |
 390                            S_DIRSYNC);
 391        if (flags & FS_SYNC_FL)
 392                inode->i_flags |= S_SYNC;
 393        if (flags & FS_APPEND_FL)
 394                inode->i_flags |= S_APPEND;
 395        if (flags & FS_IMMUTABLE_FL)
 396                inode->i_flags |= S_IMMUTABLE;
 397        if (flags & FS_NOATIME_FL)
 398                inode->i_flags |= S_NOATIME;
 399        if (flags & FS_DIRSYNC_FL)
 400                inode->i_flags |= S_DIRSYNC;
 401        mapping_set_gfp_mask(inode->i_mapping,
 402                             mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
 403}
 404
 405int nilfs_read_inode_common(struct inode *inode,
 406                            struct nilfs_inode *raw_inode)
 407{
 408        struct nilfs_inode_info *ii = NILFS_I(inode);
 409        int err;
 410
 411        inode->i_mode = le16_to_cpu(raw_inode->i_mode);
 412        i_uid_write(inode, le32_to_cpu(raw_inode->i_uid));
 413        i_gid_write(inode, le32_to_cpu(raw_inode->i_gid));
 414        set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
 415        inode->i_size = le64_to_cpu(raw_inode->i_size);
 416        inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 417        inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
 418        inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 419        inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 420        inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
 421        inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 422        if (inode->i_nlink == 0 && inode->i_mode == 0)
 423                return -EINVAL; /* this inode is deleted */
 424
 425        inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
 426        ii->i_flags = le32_to_cpu(raw_inode->i_flags);
 427#if 0
 428        ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
 429        ii->i_dir_acl = S_ISREG(inode->i_mode) ?
 430                0 : le32_to_cpu(raw_inode->i_dir_acl);
 431#endif
 432        ii->i_dir_start_lookup = 0;
 433        inode->i_generation = le32_to_cpu(raw_inode->i_generation);
 434
 435        if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 436            S_ISLNK(inode->i_mode)) {
 437                err = nilfs_bmap_read(ii->i_bmap, raw_inode);
 438                if (err < 0)
 439                        return err;
 440                set_bit(NILFS_I_BMAP, &ii->i_state);
 441                /* No lock is needed; iget() ensures it. */
 442        }
 443        return 0;
 444}
 445
 446static int __nilfs_read_inode(struct super_block *sb,
 447                              struct nilfs_root *root, unsigned long ino,
 448                              struct inode *inode)
 449{
 450        struct the_nilfs *nilfs = sb->s_fs_info;
 451        struct buffer_head *bh;
 452        struct nilfs_inode *raw_inode;
 453        int err;
 454
 455        down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 456        err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
 457        if (unlikely(err))
 458                goto bad_inode;
 459
 460        raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
 461
 462        err = nilfs_read_inode_common(inode, raw_inode);
 463        if (err)
 464                goto failed_unmap;
 465
 466        if (S_ISREG(inode->i_mode)) {
 467                inode->i_op = &nilfs_file_inode_operations;
 468                inode->i_fop = &nilfs_file_operations;
 469                inode->i_mapping->a_ops = &nilfs_aops;
 470        } else if (S_ISDIR(inode->i_mode)) {
 471                inode->i_op = &nilfs_dir_inode_operations;
 472                inode->i_fop = &nilfs_dir_operations;
 473                inode->i_mapping->a_ops = &nilfs_aops;
 474        } else if (S_ISLNK(inode->i_mode)) {
 475                inode->i_op = &nilfs_symlink_inode_operations;
 476                inode->i_mapping->a_ops = &nilfs_aops;
 477        } else {
 478                inode->i_op = &nilfs_special_inode_operations;
 479                init_special_inode(
 480                        inode, inode->i_mode,
 481                        huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
 482        }
 483        nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 484        brelse(bh);
 485        up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 486        nilfs_set_inode_flags(inode);
 487        return 0;
 488
 489 failed_unmap:
 490        nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 491        brelse(bh);
 492
 493 bad_inode:
 494        up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 495        return err;
 496}
 497
 498static int nilfs_iget_test(struct inode *inode, void *opaque)
 499{
 500        struct nilfs_iget_args *args = opaque;
 501        struct nilfs_inode_info *ii;
 502
 503        if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
 504                return 0;
 505
 506        ii = NILFS_I(inode);
 507        if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
 508                return !args->for_gc;
 509
 510        return args->for_gc && args->cno == ii->i_cno;
 511}
 512
 513static int nilfs_iget_set(struct inode *inode, void *opaque)
 514{
 515        struct nilfs_iget_args *args = opaque;
 516
 517        inode->i_ino = args->ino;
 518        if (args->for_gc) {
 519                NILFS_I(inode)->i_state = 1 << NILFS_I_GCINODE;
 520                NILFS_I(inode)->i_cno = args->cno;
 521                NILFS_I(inode)->i_root = NULL;
 522        } else {
 523                if (args->root && args->ino == NILFS_ROOT_INO)
 524                        nilfs_get_root(args->root);
 525                NILFS_I(inode)->i_root = args->root;
 526        }
 527        return 0;
 528}
 529
 530struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
 531                            unsigned long ino)
 532{
 533        struct nilfs_iget_args args = {
 534                .ino = ino, .root = root, .cno = 0, .for_gc = 0
 535        };
 536
 537        return ilookup5(sb, ino, nilfs_iget_test, &args);
 538}
 539
 540struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
 541                                unsigned long ino)
 542{
 543        struct nilfs_iget_args args = {
 544                .ino = ino, .root = root, .cno = 0, .for_gc = 0
 545        };
 546
 547        return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 548}
 549
 550struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
 551                         unsigned long ino)
 552{
 553        struct inode *inode;
 554        int err;
 555
 556        inode = nilfs_iget_locked(sb, root, ino);
 557        if (unlikely(!inode))
 558                return ERR_PTR(-ENOMEM);
 559        if (!(inode->i_state & I_NEW))
 560                return inode;
 561
 562        err = __nilfs_read_inode(sb, root, ino, inode);
 563        if (unlikely(err)) {
 564                iget_failed(inode);
 565                return ERR_PTR(err);
 566        }
 567        unlock_new_inode(inode);
 568        return inode;
 569}
 570
 571struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
 572                                __u64 cno)
 573{
 574        struct nilfs_iget_args args = {
 575                .ino = ino, .root = NULL, .cno = cno, .for_gc = 1
 576        };
 577        struct inode *inode;
 578        int err;
 579
 580        inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 581        if (unlikely(!inode))
 582                return ERR_PTR(-ENOMEM);
 583        if (!(inode->i_state & I_NEW))
 584                return inode;
 585
 586        err = nilfs_init_gcinode(inode);
 587        if (unlikely(err)) {
 588                iget_failed(inode);
 589                return ERR_PTR(err);
 590        }
 591        unlock_new_inode(inode);
 592        return inode;
 593}
 594
 595void nilfs_write_inode_common(struct inode *inode,
 596                              struct nilfs_inode *raw_inode, int has_bmap)
 597{
 598        struct nilfs_inode_info *ii = NILFS_I(inode);
 599
 600        raw_inode->i_mode = cpu_to_le16(inode->i_mode);
 601        raw_inode->i_uid = cpu_to_le32(i_uid_read(inode));
 602        raw_inode->i_gid = cpu_to_le32(i_gid_read(inode));
 603        raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
 604        raw_inode->i_size = cpu_to_le64(inode->i_size);
 605        raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 606        raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
 607        raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 608        raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
 609        raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
 610
 611        raw_inode->i_flags = cpu_to_le32(ii->i_flags);
 612        raw_inode->i_generation = cpu_to_le32(inode->i_generation);
 613
 614        if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
 615                struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 616
 617                /* zero-fill unused portion in the case of super root block */
 618                raw_inode->i_xattr = 0;
 619                raw_inode->i_pad = 0;
 620                memset((void *)raw_inode + sizeof(*raw_inode), 0,
 621                       nilfs->ns_inode_size - sizeof(*raw_inode));
 622        }
 623
 624        if (has_bmap)
 625                nilfs_bmap_write(ii->i_bmap, raw_inode);
 626        else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 627                raw_inode->i_device_code =
 628                        cpu_to_le64(huge_encode_dev(inode->i_rdev));
 629        /* When extending inode, nilfs->ns_inode_size should be checked
 630           for substitutions of appended fields */
 631}
 632
 633void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh)
 634{
 635        ino_t ino = inode->i_ino;
 636        struct nilfs_inode_info *ii = NILFS_I(inode);
 637        struct inode *ifile = ii->i_root->ifile;
 638        struct nilfs_inode *raw_inode;
 639
 640        raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
 641
 642        if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
 643                memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
 644        set_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
 645
 646        nilfs_write_inode_common(inode, raw_inode, 0);
 647                /* XXX: call with has_bmap = 0 is a workaround to avoid
 648                   deadlock of bmap. This delays update of i_bmap to just
 649                   before writing */
 650        nilfs_ifile_unmap_inode(ifile, ino, ibh);
 651}
 652
 653#define NILFS_MAX_TRUNCATE_BLOCKS       16384  /* 64MB for 4KB block */
 654
 655static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
 656                                unsigned long from)
 657{
 658        unsigned long b;
 659        int ret;
 660
 661        if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 662                return;
 663repeat:
 664        ret = nilfs_bmap_last_key(ii->i_bmap, &b);
 665        if (ret == -ENOENT)
 666                return;
 667        else if (ret < 0)
 668                goto failed;
 669
 670        if (b < from)
 671                return;
 672
 673        b -= min_t(unsigned long, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
 674        ret = nilfs_bmap_truncate(ii->i_bmap, b);
 675        nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
 676        if (!ret || (ret == -ENOMEM &&
 677                     nilfs_bmap_truncate(ii->i_bmap, b) == 0))
 678                goto repeat;
 679
 680failed:
 681        nilfs_warning(ii->vfs_inode.i_sb, __func__,
 682                      "failed to truncate bmap (ino=%lu, err=%d)",
 683                      ii->vfs_inode.i_ino, ret);
 684}
 685
 686void nilfs_truncate(struct inode *inode)
 687{
 688        unsigned long blkoff;
 689        unsigned int blocksize;
 690        struct nilfs_transaction_info ti;
 691        struct super_block *sb = inode->i_sb;
 692        struct nilfs_inode_info *ii = NILFS_I(inode);
 693
 694        if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 695                return;
 696        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 697                return;
 698
 699        blocksize = sb->s_blocksize;
 700        blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
 701        nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 702
 703        block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
 704
 705        nilfs_truncate_bmap(ii, blkoff);
 706
 707        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 708        if (IS_SYNC(inode))
 709                nilfs_set_transaction_flag(NILFS_TI_SYNC);
 710
 711        nilfs_mark_inode_dirty(inode);
 712        nilfs_set_file_dirty(inode, 0);
 713        nilfs_transaction_commit(sb);
 714        /* May construct a logical segment and may fail in sync mode.
 715           But truncate has no return value. */
 716}
 717
 718static void nilfs_clear_inode(struct inode *inode)
 719{
 720        struct nilfs_inode_info *ii = NILFS_I(inode);
 721        struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 722
 723        /*
 724         * Free resources allocated in nilfs_read_inode(), here.
 725         */
 726        BUG_ON(!list_empty(&ii->i_dirty));
 727        brelse(ii->i_bh);
 728        ii->i_bh = NULL;
 729
 730        if (mdi && mdi->mi_palloc_cache)
 731                nilfs_palloc_destroy_cache(inode);
 732
 733        if (test_bit(NILFS_I_BMAP, &ii->i_state))
 734                nilfs_bmap_clear(ii->i_bmap);
 735
 736        nilfs_btnode_cache_clear(&ii->i_btnode_cache);
 737
 738        if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
 739                nilfs_put_root(ii->i_root);
 740}
 741
 742void nilfs_evict_inode(struct inode *inode)
 743{
 744        struct nilfs_transaction_info ti;
 745        struct super_block *sb = inode->i_sb;
 746        struct nilfs_inode_info *ii = NILFS_I(inode);
 747        int ret;
 748
 749        if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
 750                if (inode->i_data.nrpages)
 751                        truncate_inode_pages(&inode->i_data, 0);
 752                clear_inode(inode);
 753                nilfs_clear_inode(inode);
 754                return;
 755        }
 756        nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 757
 758        if (inode->i_data.nrpages)
 759                truncate_inode_pages(&inode->i_data, 0);
 760
 761        /* TODO: some of the following operations may fail.  */
 762        nilfs_truncate_bmap(ii, 0);
 763        nilfs_mark_inode_dirty(inode);
 764        clear_inode(inode);
 765
 766        ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
 767        if (!ret)
 768                atomic_dec(&ii->i_root->inodes_count);
 769
 770        nilfs_clear_inode(inode);
 771
 772        if (IS_SYNC(inode))
 773                nilfs_set_transaction_flag(NILFS_TI_SYNC);
 774        nilfs_transaction_commit(sb);
 775        /* May construct a logical segment and may fail in sync mode.
 776           But delete_inode has no return value. */
 777}
 778
 779int nilfs_setattr(struct dentry *dentry, struct iattr *iattr)
 780{
 781        struct nilfs_transaction_info ti;
 782        struct inode *inode = dentry->d_inode;
 783        struct super_block *sb = inode->i_sb;
 784        int err;
 785
 786        err = inode_change_ok(inode, iattr);
 787        if (err)
 788                return err;
 789
 790        err = nilfs_transaction_begin(sb, &ti, 0);
 791        if (unlikely(err))
 792                return err;
 793
 794        if ((iattr->ia_valid & ATTR_SIZE) &&
 795            iattr->ia_size != i_size_read(inode)) {
 796                inode_dio_wait(inode);
 797                truncate_setsize(inode, iattr->ia_size);
 798                nilfs_truncate(inode);
 799        }
 800
 801        setattr_copy(inode, iattr);
 802        mark_inode_dirty(inode);
 803
 804        if (iattr->ia_valid & ATTR_MODE) {
 805                err = nilfs_acl_chmod(inode);
 806                if (unlikely(err))
 807                        goto out_err;
 808        }
 809
 810        return nilfs_transaction_commit(sb);
 811
 812out_err:
 813        nilfs_transaction_abort(sb);
 814        return err;
 815}
 816
 817int nilfs_permission(struct inode *inode, int mask)
 818{
 819        struct nilfs_root *root = NILFS_I(inode)->i_root;
 820        if ((mask & MAY_WRITE) && root &&
 821            root->cno != NILFS_CPTREE_CURRENT_CNO)
 822                return -EROFS; /* snapshot is not writable */
 823
 824        return generic_permission(inode, mask);
 825}
 826
 827int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
 828{
 829        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 830        struct nilfs_inode_info *ii = NILFS_I(inode);
 831        int err;
 832
 833        spin_lock(&nilfs->ns_inode_lock);
 834        if (ii->i_bh == NULL) {
 835                spin_unlock(&nilfs->ns_inode_lock);
 836                err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
 837                                                  inode->i_ino, pbh);
 838                if (unlikely(err))
 839                        return err;
 840                spin_lock(&nilfs->ns_inode_lock);
 841                if (ii->i_bh == NULL)
 842                        ii->i_bh = *pbh;
 843                else {
 844                        brelse(*pbh);
 845                        *pbh = ii->i_bh;
 846                }
 847        } else
 848                *pbh = ii->i_bh;
 849
 850        get_bh(*pbh);
 851        spin_unlock(&nilfs->ns_inode_lock);
 852        return 0;
 853}
 854
 855int nilfs_inode_dirty(struct inode *inode)
 856{
 857        struct nilfs_inode_info *ii = NILFS_I(inode);
 858        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 859        int ret = 0;
 860
 861        if (!list_empty(&ii->i_dirty)) {
 862                spin_lock(&nilfs->ns_inode_lock);
 863                ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
 864                        test_bit(NILFS_I_BUSY, &ii->i_state);
 865                spin_unlock(&nilfs->ns_inode_lock);
 866        }
 867        return ret;
 868}
 869
 870int nilfs_set_file_dirty(struct inode *inode, unsigned nr_dirty)
 871{
 872        struct nilfs_inode_info *ii = NILFS_I(inode);
 873        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 874
 875        atomic_add(nr_dirty, &nilfs->ns_ndirtyblks);
 876
 877        if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
 878                return 0;
 879
 880        spin_lock(&nilfs->ns_inode_lock);
 881        if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
 882            !test_bit(NILFS_I_BUSY, &ii->i_state)) {
 883                /* Because this routine may race with nilfs_dispose_list(),
 884                   we have to check NILFS_I_QUEUED here, too. */
 885                if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
 886                        /* This will happen when somebody is freeing
 887                           this inode. */
 888                        nilfs_warning(inode->i_sb, __func__,
 889                                      "cannot get inode (ino=%lu)\n",
 890                                      inode->i_ino);
 891                        spin_unlock(&nilfs->ns_inode_lock);
 892                        return -EINVAL; /* NILFS_I_DIRTY may remain for
 893                                           freeing inode */
 894                }
 895                list_move_tail(&ii->i_dirty, &nilfs->ns_dirty_files);
 896                set_bit(NILFS_I_QUEUED, &ii->i_state);
 897        }
 898        spin_unlock(&nilfs->ns_inode_lock);
 899        return 0;
 900}
 901
 902int nilfs_mark_inode_dirty(struct inode *inode)
 903{
 904        struct buffer_head *ibh;
 905        int err;
 906
 907        err = nilfs_load_inode_block(inode, &ibh);
 908        if (unlikely(err)) {
 909                nilfs_warning(inode->i_sb, __func__,
 910                              "failed to reget inode block.\n");
 911                return err;
 912        }
 913        nilfs_update_inode(inode, ibh);
 914        mark_buffer_dirty(ibh);
 915        nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
 916        brelse(ibh);
 917        return 0;
 918}
 919
 920/**
 921 * nilfs_dirty_inode - reflect changes on given inode to an inode block.
 922 * @inode: inode of the file to be registered.
 923 *
 924 * nilfs_dirty_inode() loads a inode block containing the specified
 925 * @inode and copies data from a nilfs_inode to a corresponding inode
 926 * entry in the inode block. This operation is excluded from the segment
 927 * construction. This function can be called both as a single operation
 928 * and as a part of indivisible file operations.
 929 */
 930void nilfs_dirty_inode(struct inode *inode, int flags)
 931{
 932        struct nilfs_transaction_info ti;
 933        struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 934
 935        if (is_bad_inode(inode)) {
 936                nilfs_warning(inode->i_sb, __func__,
 937                              "tried to mark bad_inode dirty. ignored.\n");
 938                dump_stack();
 939                return;
 940        }
 941        if (mdi) {
 942                nilfs_mdt_mark_dirty(inode);
 943                return;
 944        }
 945        nilfs_transaction_begin(inode->i_sb, &ti, 0);
 946        nilfs_mark_inode_dirty(inode);
 947        nilfs_transaction_commit(inode->i_sb); /* never fails */
 948}
 949
 950int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 951                 __u64 start, __u64 len)
 952{
 953        struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 954        __u64 logical = 0, phys = 0, size = 0;
 955        __u32 flags = 0;
 956        loff_t isize;
 957        sector_t blkoff, end_blkoff;
 958        sector_t delalloc_blkoff;
 959        unsigned long delalloc_blklen;
 960        unsigned int blkbits = inode->i_blkbits;
 961        int ret, n;
 962
 963        ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
 964        if (ret)
 965                return ret;
 966
 967        mutex_lock(&inode->i_mutex);
 968
 969        isize = i_size_read(inode);
 970
 971        blkoff = start >> blkbits;
 972        end_blkoff = (start + len - 1) >> blkbits;
 973
 974        delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
 975                                                        &delalloc_blkoff);
 976
 977        do {
 978                __u64 blkphy;
 979                unsigned int maxblocks;
 980
 981                if (delalloc_blklen && blkoff == delalloc_blkoff) {
 982                        if (size) {
 983                                /* End of the current extent */
 984                                ret = fiemap_fill_next_extent(
 985                                        fieinfo, logical, phys, size, flags);
 986                                if (ret)
 987                                        break;
 988                        }
 989                        if (blkoff > end_blkoff)
 990                                break;
 991
 992                        flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
 993                        logical = blkoff << blkbits;
 994                        phys = 0;
 995                        size = delalloc_blklen << blkbits;
 996
 997                        blkoff = delalloc_blkoff + delalloc_blklen;
 998                        delalloc_blklen = nilfs_find_uncommitted_extent(
 999                                inode, blkoff, &delalloc_blkoff);
1000                        continue;
1001                }
1002
1003                /*
1004                 * Limit the number of blocks that we look up so as
1005                 * not to get into the next delayed allocation extent.
1006                 */
1007                maxblocks = INT_MAX;
1008                if (delalloc_blklen)
1009                        maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
1010                                          maxblocks);
1011                blkphy = 0;
1012
1013                down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1014                n = nilfs_bmap_lookup_contig(
1015                        NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
1016                up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1017
1018                if (n < 0) {
1019                        int past_eof;
1020
1021                        if (unlikely(n != -ENOENT))
1022                                break; /* error */
1023
1024                        /* HOLE */
1025                        blkoff++;
1026                        past_eof = ((blkoff << blkbits) >= isize);
1027
1028                        if (size) {
1029                                /* End of the current extent */
1030
1031                                if (past_eof)
1032                                        flags |= FIEMAP_EXTENT_LAST;
1033
1034                                ret = fiemap_fill_next_extent(
1035                                        fieinfo, logical, phys, size, flags);
1036                                if (ret)
1037                                        break;
1038                                size = 0;
1039                        }
1040                        if (blkoff > end_blkoff || past_eof)
1041                                break;
1042                } else {
1043                        if (size) {
1044                                if (phys && blkphy << blkbits == phys + size) {
1045                                        /* The current extent goes on */
1046                                        size += n << blkbits;
1047                                } else {
1048                                        /* Terminate the current extent */
1049                                        ret = fiemap_fill_next_extent(
1050                                                fieinfo, logical, phys, size,
1051                                                flags);
1052                                        if (ret || blkoff > end_blkoff)
1053                                                break;
1054
1055                                        /* Start another extent */
1056                                        flags = FIEMAP_EXTENT_MERGED;
1057                                        logical = blkoff << blkbits;
1058                                        phys = blkphy << blkbits;
1059                                        size = n << blkbits;
1060                                }
1061                        } else {
1062                                /* Start a new extent */
1063                                flags = FIEMAP_EXTENT_MERGED;
1064                                logical = blkoff << blkbits;
1065                                phys = blkphy << blkbits;
1066                                size = n << blkbits;
1067                        }
1068                        blkoff += n;
1069                }
1070                cond_resched();
1071        } while (true);
1072
1073        /* If ret is 1 then we just hit the end of the extent array */
1074        if (ret == 1)
1075                ret = 0;
1076
1077        mutex_unlock(&inode->i_mutex);
1078        return ret;
1079}
1080
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