inode.c

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/*
 *  linux/fs/hfsplus/inode.c
 *
 * Copyright (C) 2001
 * Brad Boyer ([email protected])
 * (C) 2003 Ardis Technologies <[email protected]>
 *
 * Inode handling routines
 */

#include <linux/blkdev.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/mpage.h>
#include <linux/sched.h>

#include "hfsplus_fs.h"
#include "hfsplus_raw.h"

static int hfsplus_readpage(struct file *file, struct page *page)
{
    return block_read_full_page(page, hfsplus_get_block);
}

static int hfsplus_writepage(struct page *page, struct writeback_control *wbc)
{
    return block_write_full_page(page, hfsplus_get_block, wbc);
}

static int hfsplus_write_begin(struct file *file, struct address_space *mapping,
            loff_t pos, unsigned len, unsigned flags,
            struct page **pagep, void **fsdata)
{
    int ret;

    *pagep = NULL;
    ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
                hfsplus_get_block,
                &HFSPLUS_I(mapping->host)->phys_size);
    if (unlikely(ret)) {
        loff_t isize = mapping->host->i_size;
        if (pos + len > isize)
            vmtruncate(mapping->host, isize);
    }

    return ret;
}

static sector_t hfsplus_bmap(struct address_space *mapping, sector_t block)
{
    return generic_block_bmap(mapping, block, hfsplus_get_block);
}

static int hfsplus_releasepage(struct page *page, gfp_t mask)
{
    struct inode *inode = page->mapping->host;
    struct super_block *sb = inode->i_sb;
    struct hfs_btree *tree;
    struct hfs_bnode *node;
    u32 nidx;
    int i, res = 1;

    switch (inode->i_ino) {
    case HFSPLUS_EXT_CNID:
        tree = HFSPLUS_SB(sb)->ext_tree;
        break;
    case HFSPLUS_CAT_CNID:
        tree = HFSPLUS_SB(sb)->cat_tree;
        break;
    case HFSPLUS_ATTR_CNID:
        tree = HFSPLUS_SB(sb)->attr_tree;
        break;
    default:
        BUG();
        return 0;
    }
    if (!tree)
        return 0;
    if (tree->node_size >= PAGE_CACHE_SIZE) {
        nidx = page->index >>
            (tree->node_size_shift - PAGE_CACHE_SHIFT);
        spin_lock(&tree->hash_lock);
        node = hfs_bnode_findhash(tree, nidx);
        if (!node)
            ;
        else if (atomic_read(&node->refcnt))
            res = 0;
        if (res && node) {
            hfs_bnode_unhash(node);
            hfs_bnode_free(node);
        }
        spin_unlock(&tree->hash_lock);
    } else {
        nidx = page->index <<
            (PAGE_CACHE_SHIFT - tree->node_size_shift);
        i = 1 << (PAGE_CACHE_SHIFT - tree->node_size_shift);
        spin_lock(&tree->hash_lock);
        do {
            node = hfs_bnode_findhash(tree, nidx++);
            if (!node)
                continue;
            if (atomic_read(&node->refcnt)) {
                res = 0;
                break;
            }
            hfs_bnode_unhash(node);
            hfs_bnode_free(node);
        } while (--i && nidx < tree->node_count);
        spin_unlock(&tree->hash_lock);
    }
    return res ? try_to_free_buffers(page) : 0;
}

static ssize_t hfsplus_direct_IO(int rw, struct kiocb *iocb,
        const struct iovec *iov, loff_t offset, unsigned long nr_segs)
{
    struct file *file = iocb->ki_filp;
    struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
    ssize_t ret;

    ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
                 hfsplus_get_block);

    /*
     * In case of error extending write may have instantiated a few
     * blocks outside i_size. Trim these off again.
     */
    if (unlikely((rw & WRITE) && ret < 0)) {
        loff_t isize = i_size_read(inode);
        loff_t end = offset + iov_length(iov, nr_segs);

        if (end > isize)
            vmtruncate(inode, isize);
    }

    return ret;
}

static int hfsplus_writepages(struct address_space *mapping,
                  struct writeback_control *wbc)
{
    return mpage_writepages(mapping, wbc, hfsplus_get_block);
}

const struct address_space_operations hfsplus_btree_aops = {
    .readpage   = hfsplus_readpage,
    .writepage  = hfsplus_writepage,
    .write_begin    = hfsplus_write_begin,
    .write_end  = generic_write_end,
    .bmap       = hfsplus_bmap,
    .releasepage    = hfsplus_releasepage,
};

const struct address_space_operations hfsplus_aops = {
    .readpage   = hfsplus_readpage,
    .writepage  = hfsplus_writepage,
    .write_begin    = hfsplus_write_begin,
    .write_end  = generic_write_end,
    .bmap       = hfsplus_bmap,
    .direct_IO  = hfsplus_direct_IO,
    .writepages = hfsplus_writepages,
};

const struct dentry_operations hfsplus_dentry_operations = {
    .d_hash       = hfsplus_hash_dentry,
    .d_compare    = hfsplus_compare_dentry,
};

static struct dentry *hfsplus_file_lookup(struct inode *dir,
        struct dentry *dentry, unsigned int flags)
{
    struct hfs_find_data fd;
    struct super_block *sb = dir->i_sb;
    struct inode *inode = NULL;
    struct hfsplus_inode_info *hip;
    int err;

    if (HFSPLUS_IS_RSRC(dir) || strcmp(dentry->d_name.name, "rsrc"))
        goto out;

    inode = HFSPLUS_I(dir)->rsrc_inode;
    if (inode)
        goto out;

    inode = new_inode(sb);
    if (!inode)
        return ERR_PTR(-ENOMEM);

    hip = HFSPLUS_I(inode);
    inode->i_ino = dir->i_ino;
    INIT_LIST_HEAD(&hip->open_dir_list);
    mutex_init(&hip->extents_lock);
    hip->extent_state = 0;
    hip->flags = 0;
    hip->userflags = 0;
    set_bit(HFSPLUS_I_RSRC, &hip->flags);

    err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
    if (!err) {
        err = hfsplus_find_cat(sb, dir->i_ino, &fd);
        if (!err)
            err = hfsplus_cat_read_inode(inode, &fd);
        hfs_find_exit(&fd);
    }
    if (err) {
        iput(inode);
        return ERR_PTR(err);
    }
    hip->rsrc_inode = dir;
    HFSPLUS_I(dir)->rsrc_inode = inode;
    igrab(dir);

    /*
     * __mark_inode_dirty expects inodes to be hashed.  Since we don't
     * want resource fork inodes in the regular inode space, we make them
     * appear hashed, but do not put on any lists.  hlist_del()
     * will work fine and require no locking.
     */
    hlist_add_fake(&inode->i_hash);

    mark_inode_dirty(inode);
out:
    d_add(dentry, inode);
    return NULL;
}

static void hfsplus_get_perms(struct inode *inode,
        struct hfsplus_perm *perms, int dir)
{
    struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
    u16 mode;

    mode = be16_to_cpu(perms->mode);

    i_uid_write(inode, be32_to_cpu(perms->owner));
    if (!i_uid_read(inode) && !mode)
        inode->i_uid = sbi->uid;

    i_gid_write(inode, be32_to_cpu(perms->group));
    if (!i_gid_read(inode) && !mode)
        inode->i_gid = sbi->gid;

    if (dir) {
        mode = mode ? (mode & S_IALLUGO) : (S_IRWXUGO & ~(sbi->umask));
        mode |= S_IFDIR;
    } else if (!mode)
        mode = S_IFREG | ((S_IRUGO|S_IWUGO) & ~(sbi->umask));
    inode->i_mode = mode;

    HFSPLUS_I(inode)->userflags = perms->userflags;
    if (perms->rootflags & HFSPLUS_FLG_IMMUTABLE)
        inode->i_flags |= S_IMMUTABLE;
    else
        inode->i_flags &= ~S_IMMUTABLE;
    if (perms->rootflags & HFSPLUS_FLG_APPEND)
        inode->i_flags |= S_APPEND;
    else
        inode->i_flags &= ~S_APPEND;
}

static int hfsplus_file_open(struct inode *inode, struct file *file)
{
    if (HFSPLUS_IS_RSRC(inode))
        inode = HFSPLUS_I(inode)->rsrc_inode;
    if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
        return -EOVERFLOW;
    atomic_inc(&HFSPLUS_I(inode)->opencnt);
    return 0;
}

static int hfsplus_file_release(struct inode *inode, struct file *file)
{
    struct super_block *sb = inode->i_sb;

    if (HFSPLUS_IS_RSRC(inode))
        inode = HFSPLUS_I(inode)->rsrc_inode;
    if (atomic_dec_and_test(&HFSPLUS_I(inode)->opencnt)) {
        mutex_lock(&inode->i_mutex);
        hfsplus_file_truncate(inode);
        if (inode->i_flags & S_DEAD) {
            hfsplus_delete_cat(inode->i_ino,
                       HFSPLUS_SB(sb)->hidden_dir, NULL);
            hfsplus_delete_inode(inode);
        }
        mutex_unlock(&inode->i_mutex);
    }
    return 0;
}

static int hfsplus_setattr(struct dentry *dentry, struct iattr *attr)
{
    struct inode *inode = dentry->d_inode;
    int error;

    error = inode_change_ok(inode, attr);
    if (error)
        return error;

    if ((attr->ia_valid & ATTR_SIZE) &&
        attr->ia_size != i_size_read(inode)) {
        inode_dio_wait(inode);

        error = vmtruncate(inode, attr->ia_size);
        if (error)
            return error;
    }

    setattr_copy(inode, attr);
    mark_inode_dirty(inode);
    return 0;
}

int hfsplus_file_fsync(struct file *file, loff_t start, loff_t end,
               int datasync)
{
    struct inode *inode = file->f_mapping->host;
    struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
    struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
    int error = 0, error2;

    error = filemap_write_and_wait_range(inode->i_mapping, start, end);
    if (error)
        return error;
    mutex_lock(&inode->i_mutex);

    /*
     * Sync inode metadata into the catalog and extent trees.
     */
    sync_inode_metadata(inode, 1);

    /*
     * And explicitly write out the btrees.
     */
    if (test_and_clear_bit(HFSPLUS_I_CAT_DIRTY, &hip->flags))
        error = filemap_write_and_wait(sbi->cat_tree->inode->i_mapping);

    if (test_and_clear_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags)) {
        error2 =
            filemap_write_and_wait(sbi->ext_tree->inode->i_mapping);
        if (!error)
            error = error2;
    }

    if (test_and_clear_bit(HFSPLUS_I_ALLOC_DIRTY, &hip->flags)) {
        error2 = filemap_write_and_wait(sbi->alloc_file->i_mapping);
        if (!error)
            error = error2;
    }

    if (!test_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags))
        blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);

    mutex_unlock(&inode->i_mutex);

    return error;
}

static const struct inode_operations hfsplus_file_inode_operations = {
    .lookup     = hfsplus_file_lookup,
    .truncate   = hfsplus_file_truncate,
    .setattr    = hfsplus_setattr,
    .setxattr   = hfsplus_setxattr,
    .getxattr   = hfsplus_getxattr,
    .listxattr  = hfsplus_listxattr,
};

static const struct file_operations hfsplus_file_operations = {
    .llseek     = generic_file_llseek,
    .read       = do_sync_read,
    .aio_read   = generic_file_aio_read,
    .write      = do_sync_write,
    .aio_write  = generic_file_aio_write,
    .mmap       = generic_file_mmap,
    .splice_read    = generic_file_splice_read,
    .fsync      = hfsplus_file_fsync,
    .open       = hfsplus_file_open,
    .release    = hfsplus_file_release,
    .unlocked_ioctl = hfsplus_ioctl,
};

struct inode *hfsplus_new_inode(struct super_block *sb, umode_t mode)
{
    struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
    struct inode *inode = new_inode(sb);
    struct hfsplus_inode_info *hip;

    if (!inode)
        return NULL;

    inode->i_ino = sbi->next_cnid++;
    inode->i_mode = mode;
    inode->i_uid = current_fsuid();
    inode->i_gid = current_fsgid();
    set_nlink(inode, 1);
    inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;

    hip = HFSPLUS_I(inode);
    INIT_LIST_HEAD(&hip->open_dir_list);
    mutex_init(&hip->extents_lock);
    atomic_set(&hip->opencnt, 0);
    hip->extent_state = 0;
    hip->flags = 0;
    hip->userflags = 0;
    memset(hip->first_extents, 0, sizeof(hfsplus_extent_rec));
    memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
    hip->alloc_blocks = 0;
    hip->first_blocks = 0;
    hip->cached_start = 0;
    hip->cached_blocks = 0;
    hip->phys_size = 0;
    hip->fs_blocks = 0;
    hip->rsrc_inode = NULL;
    if (S_ISDIR(inode->i_mode)) {
        inode->i_size = 2;
        sbi->folder_count++;
        inode->i_op = &hfsplus_dir_inode_operations;
        inode->i_fop = &hfsplus_dir_operations;
    } else if (S_ISREG(inode->i_mode)) {
        sbi->file_count++;
        inode->i_op = &hfsplus_file_inode_operations;
        inode->i_fop = &hfsplus_file_operations;
        inode->i_mapping->a_ops = &hfsplus_aops;
        hip->clump_blocks = sbi->data_clump_blocks;
    } else if (S_ISLNK(inode->i_mode)) {
        sbi->file_count++;
        inode->i_op = &page_symlink_inode_operations;
        inode->i_mapping->a_ops = &hfsplus_aops;
        hip->clump_blocks = 1;
    } else
        sbi->file_count++;
    insert_inode_hash(inode);
    mark_inode_dirty(inode);
    hfsplus_mark_mdb_dirty(sb);

    return inode;
}

void hfsplus_delete_inode(struct inode *inode)
{
    struct super_block *sb = inode->i_sb;

    if (S_ISDIR(inode->i_mode)) {
        HFSPLUS_SB(sb)->folder_count--;
        hfsplus_mark_mdb_dirty(sb);
        return;
    }
    HFSPLUS_SB(sb)->file_count--;
    if (S_ISREG(inode->i_mode)) {
        if (!inode->i_nlink) {
            inode->i_size = 0;
            hfsplus_file_truncate(inode);
        }
    } else if (S_ISLNK(inode->i_mode)) {
        inode->i_size = 0;
        hfsplus_file_truncate(inode);
    }
    hfsplus_mark_mdb_dirty(sb);
}

void hfsplus_inode_read_fork(struct inode *inode, struct hfsplus_fork_raw *fork)
{
    struct super_block *sb = inode->i_sb;
    struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
    struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
    u32 count;
    int i;

    memcpy(&hip->first_extents, &fork->extents, sizeof(hfsplus_extent_rec));
    for (count = 0, i = 0; i < 8; i++)
        count += be32_to_cpu(fork->extents[i].block_count);
    hip->first_blocks = count;
    memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
    hip->cached_start = 0;
    hip->cached_blocks = 0;

    hip->alloc_blocks = be32_to_cpu(fork->total_blocks);
    hip->phys_size = inode->i_size = be64_to_cpu(fork->total_size);
    hip->fs_blocks =
        (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
    inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
    hip->clump_blocks =
        be32_to_cpu(fork->clump_size) >> sbi->alloc_blksz_shift;
    if (!hip->clump_blocks) {
        hip->clump_blocks = HFSPLUS_IS_RSRC(inode) ?
            sbi->rsrc_clump_blocks :
            sbi->data_clump_blocks;
    }
}

void hfsplus_inode_write_fork(struct inode *inode,
        struct hfsplus_fork_raw *fork)
{
    memcpy(&fork->extents, &HFSPLUS_I(inode)->first_extents,
           sizeof(hfsplus_extent_rec));
    fork->total_size = cpu_to_be64(inode->i_size);
    fork->total_blocks = cpu_to_be32(HFSPLUS_I(inode)->alloc_blocks);
}

int hfsplus_cat_read_inode(struct inode *inode, struct hfs_find_data *fd)
{
    hfsplus_cat_entry entry;
    int res = 0;
    u16 type;

    type = hfs_bnode_read_u16(fd->bnode, fd->entryoffset);

    HFSPLUS_I(inode)->linkid = 0;
    if (type == HFSPLUS_FOLDER) {
        struct hfsplus_cat_folder *folder = &entry.folder;

        if (fd->entrylength < sizeof(struct hfsplus_cat_folder))
            /* panic? */;
        hfs_bnode_read(fd->bnode, &entry, fd->entryoffset,
                    sizeof(struct hfsplus_cat_folder));
        hfsplus_get_perms(inode, &folder->permissions, 1);
        set_nlink(inode, 1);
        inode->i_size = 2 + be32_to_cpu(folder->valence);
        inode->i_atime = hfsp_mt2ut(folder->access_date);
        inode->i_mtime = hfsp_mt2ut(folder->content_mod_date);
        inode->i_ctime = hfsp_mt2ut(folder->attribute_mod_date);
        HFSPLUS_I(inode)->create_date = folder->create_date;
        HFSPLUS_I(inode)->fs_blocks = 0;
        inode->i_op = &hfsplus_dir_inode_operations;
        inode->i_fop = &hfsplus_dir_operations;
    } else if (type == HFSPLUS_FILE) {
        struct hfsplus_cat_file *file = &entry.file;

        if (fd->entrylength < sizeof(struct hfsplus_cat_file))
            /* panic? */;
        hfs_bnode_read(fd->bnode, &entry, fd->entryoffset,
                    sizeof(struct hfsplus_cat_file));

        hfsplus_inode_read_fork(inode, HFSPLUS_IS_RSRC(inode) ?
                    &file->rsrc_fork : &file->data_fork);
        hfsplus_get_perms(inode, &file->permissions, 0);
        set_nlink(inode, 1);
        if (S_ISREG(inode->i_mode)) {
            if (file->permissions.dev)
                set_nlink(inode,
                      be32_to_cpu(file->permissions.dev));
            inode->i_op = &hfsplus_file_inode_operations;
            inode->i_fop = &hfsplus_file_operations;
            inode->i_mapping->a_ops = &hfsplus_aops;
        } else if (S_ISLNK(inode->i_mode)) {
            inode->i_op = &page_symlink_inode_operations;
            inode->i_mapping->a_ops = &hfsplus_aops;
        } else {
            init_special_inode(inode, inode->i_mode,
                       be32_to_cpu(file->permissions.dev));
        }
        inode->i_atime = hfsp_mt2ut(file->access_date);
        inode->i_mtime = hfsp_mt2ut(file->content_mod_date);
        inode->i_ctime = hfsp_mt2ut(file->attribute_mod_date);
        HFSPLUS_I(inode)->create_date = file->create_date;
    } else {
        printk(KERN_ERR "hfs: bad catalog entry used to create inode\n");
        res = -EIO;
    }
    return res;
}

int hfsplus_cat_write_inode(struct inode *inode)
{
    struct inode *main_inode = inode;
    struct hfs_find_data fd;
    hfsplus_cat_entry entry;

    if (HFSPLUS_IS_RSRC(inode))
        main_inode = HFSPLUS_I(inode)->rsrc_inode;

    if (!main_inode->i_nlink)
        return 0;

    if (hfs_find_init(HFSPLUS_SB(main_inode->i_sb)->cat_tree, &fd))
        /* panic? */
        return -EIO;

    if (hfsplus_find_cat(main_inode->i_sb, main_inode->i_ino, &fd))
        /* panic? */
        goto out;

    if (S_ISDIR(main_inode->i_mode)) {
        struct hfsplus_cat_folder *folder = &entry.folder;

        if (fd.entrylength < sizeof(struct hfsplus_cat_folder))
            /* panic? */;
        hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
                    sizeof(struct hfsplus_cat_folder));
        /* simple node checks? */
        hfsplus_cat_set_perms(inode, &folder->permissions);
        folder->access_date = hfsp_ut2mt(inode->i_atime);
        folder->content_mod_date = hfsp_ut2mt(inode->i_mtime);
        folder->attribute_mod_date = hfsp_ut2mt(inode->i_ctime);
        folder->valence = cpu_to_be32(inode->i_size - 2);
        hfs_bnode_write(fd.bnode, &entry, fd.entryoffset,
                     sizeof(struct hfsplus_cat_folder));
    } else if (HFSPLUS_IS_RSRC(inode)) {
        struct hfsplus_cat_file *file = &entry.file;
        hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
                   sizeof(struct hfsplus_cat_file));
        hfsplus_inode_write_fork(inode, &file->rsrc_fork);
        hfs_bnode_write(fd.bnode, &entry, fd.entryoffset,
                sizeof(struct hfsplus_cat_file));
    } else {
        struct hfsplus_cat_file *file = &entry.file;

        if (fd.entrylength < sizeof(struct hfsplus_cat_file))
            /* panic? */;
        hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
                    sizeof(struct hfsplus_cat_file));
        hfsplus_inode_write_fork(inode, &file->data_fork);
        hfsplus_cat_set_perms(inode, &file->permissions);
        if (HFSPLUS_FLG_IMMUTABLE &
                (file->permissions.rootflags |
                    file->permissions.userflags))
            file->flags |= cpu_to_be16(HFSPLUS_FILE_LOCKED);
        else
            file->flags &= cpu_to_be16(~HFSPLUS_FILE_LOCKED);
        file->access_date = hfsp_ut2mt(inode->i_atime);
        file->content_mod_date = hfsp_ut2mt(inode->i_mtime);
        file->attribute_mod_date = hfsp_ut2mt(inode->i_ctime);
        hfs_bnode_write(fd.bnode, &entry, fd.entryoffset,
                     sizeof(struct hfsplus_cat_file));
    }

    set_bit(HFSPLUS_I_CAT_DIRTY, &HFSPLUS_I(inode)->flags);
out:
    hfs_find_exit(&fd);
    return 0;
}