super.c

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

#include <linux/module.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/blkdev.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/vfs.h>
#include <linux/nls.h>

static struct inode *hfsplus_alloc_inode(struct super_block *sb);
static void hfsplus_destroy_inode(struct inode *inode);

#include "hfsplus_fs.h"

static int hfsplus_system_read_inode(struct inode *inode)
{
    struct hfsplus_vh *vhdr = HFSPLUS_SB(inode->i_sb)->s_vhdr;

    switch (inode->i_ino) {
    case HFSPLUS_EXT_CNID:
        hfsplus_inode_read_fork(inode, &vhdr->ext_file);
        inode->i_mapping->a_ops = &hfsplus_btree_aops;
        break;
    case HFSPLUS_CAT_CNID:
        hfsplus_inode_read_fork(inode, &vhdr->cat_file);
        inode->i_mapping->a_ops = &hfsplus_btree_aops;
        break;
    case HFSPLUS_ALLOC_CNID:
        hfsplus_inode_read_fork(inode, &vhdr->alloc_file);
        inode->i_mapping->a_ops = &hfsplus_aops;
        break;
    case HFSPLUS_START_CNID:
        hfsplus_inode_read_fork(inode, &vhdr->start_file);
        break;
    case HFSPLUS_ATTR_CNID:
        hfsplus_inode_read_fork(inode, &vhdr->attr_file);
        inode->i_mapping->a_ops = &hfsplus_btree_aops;
        break;
    default:
        return -EIO;
    }

    return 0;
}

struct inode *hfsplus_iget(struct super_block *sb, unsigned long ino)
{
    struct hfs_find_data fd;
    struct inode *inode;
    int err;

    inode = iget_locked(sb, ino);
    if (!inode)
        return ERR_PTR(-ENOMEM);
    if (!(inode->i_state & I_NEW))
        return inode;

    INIT_LIST_HEAD(&HFSPLUS_I(inode)->open_dir_list);
    mutex_init(&HFSPLUS_I(inode)->extents_lock);
    HFSPLUS_I(inode)->flags = 0;
    HFSPLUS_I(inode)->extent_state = 0;
    HFSPLUS_I(inode)->rsrc_inode = NULL;
    atomic_set(&HFSPLUS_I(inode)->opencnt, 0);

    if (inode->i_ino >= HFSPLUS_FIRSTUSER_CNID ||
        inode->i_ino == HFSPLUS_ROOT_CNID) {
        err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
        if (!err) {
            err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
            if (!err)
                err = hfsplus_cat_read_inode(inode, &fd);
            hfs_find_exit(&fd);
        }
    } else {
        err = hfsplus_system_read_inode(inode);
    }

    if (err) {
        iget_failed(inode);
        return ERR_PTR(err);
    }

    unlock_new_inode(inode);
    return inode;
}

static int hfsplus_system_write_inode(struct inode *inode)
{
    struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
    struct hfsplus_vh *vhdr = sbi->s_vhdr;
    struct hfsplus_fork_raw *fork;
    struct hfs_btree *tree = NULL;

    switch (inode->i_ino) {
    case HFSPLUS_EXT_CNID:
        fork = &vhdr->ext_file;
        tree = sbi->ext_tree;
        break;
    case HFSPLUS_CAT_CNID:
        fork = &vhdr->cat_file;
        tree = sbi->cat_tree;
        break;
    case HFSPLUS_ALLOC_CNID:
        fork = &vhdr->alloc_file;
        break;
    case HFSPLUS_START_CNID:
        fork = &vhdr->start_file;
        break;
    case HFSPLUS_ATTR_CNID:
        fork = &vhdr->attr_file;
        tree = sbi->attr_tree;
    default:
        return -EIO;
    }

    if (fork->total_size != cpu_to_be64(inode->i_size)) {
        set_bit(HFSPLUS_SB_WRITEBACKUP, &sbi->flags);
        hfsplus_mark_mdb_dirty(inode->i_sb);
    }
    hfsplus_inode_write_fork(inode, fork);
    if (tree)
        hfs_btree_write(tree);
    return 0;
}

static int hfsplus_write_inode(struct inode *inode,
        struct writeback_control *wbc)
{
    int err;

    dprint(DBG_INODE, "hfsplus_write_inode: %lu\n", inode->i_ino);

    err = hfsplus_ext_write_extent(inode);
    if (err)
        return err;

    if (inode->i_ino >= HFSPLUS_FIRSTUSER_CNID ||
        inode->i_ino == HFSPLUS_ROOT_CNID)
        return hfsplus_cat_write_inode(inode);
    else
        return hfsplus_system_write_inode(inode);
}

static void hfsplus_evict_inode(struct inode *inode)
{
    dprint(DBG_INODE, "hfsplus_evict_inode: %lu\n", inode->i_ino);
    truncate_inode_pages(&inode->i_data, 0);
    clear_inode(inode);
    if (HFSPLUS_IS_RSRC(inode)) {
        HFSPLUS_I(HFSPLUS_I(inode)->rsrc_inode)->rsrc_inode = NULL;
        iput(HFSPLUS_I(inode)->rsrc_inode);
    }
}

static int hfsplus_sync_fs(struct super_block *sb, int wait)
{
    struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
    struct hfsplus_vh *vhdr = sbi->s_vhdr;
    int write_backup = 0;
    int error, error2;

    if (!wait)
        return 0;

    dprint(DBG_SUPER, "hfsplus_sync_fs\n");

    /*
     * Explicitly write out the special metadata inodes.
     *
     * While these special inodes are marked as hashed and written
     * out peridocically by the flusher threads we redirty them
     * during writeout of normal inodes, and thus the life lock
     * prevents us from getting the latest state to disk.
     */
    error = filemap_write_and_wait(sbi->cat_tree->inode->i_mapping);
    error2 = filemap_write_and_wait(sbi->ext_tree->inode->i_mapping);
    if (!error)
        error = error2;
    error2 = filemap_write_and_wait(sbi->alloc_file->i_mapping);
    if (!error)
        error = error2;

    mutex_lock(&sbi->vh_mutex);
    mutex_lock(&sbi->alloc_mutex);
    vhdr->free_blocks = cpu_to_be32(sbi->free_blocks);
    vhdr->next_cnid = cpu_to_be32(sbi->next_cnid);
    vhdr->folder_count = cpu_to_be32(sbi->folder_count);
    vhdr->file_count = cpu_to_be32(sbi->file_count);

    if (test_and_clear_bit(HFSPLUS_SB_WRITEBACKUP, &sbi->flags)) {
        memcpy(sbi->s_backup_vhdr, sbi->s_vhdr, sizeof(*sbi->s_vhdr));
        write_backup = 1;
    }

    error2 = hfsplus_submit_bio(sb,
                   sbi->part_start + HFSPLUS_VOLHEAD_SECTOR,
                   sbi->s_vhdr_buf, NULL, WRITE_SYNC);
    if (!error)
        error = error2;
    if (!write_backup)
        goto out;

    error2 = hfsplus_submit_bio(sb,
                  sbi->part_start + sbi->sect_count - 2,
                  sbi->s_backup_vhdr_buf, NULL, WRITE_SYNC);
    if (!error)
        error2 = error;
out:
    mutex_unlock(&sbi->alloc_mutex);
    mutex_unlock(&sbi->vh_mutex);

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

    return error;
}

static void delayed_sync_fs(struct work_struct *work)
{
    struct hfsplus_sb_info *sbi;

    sbi = container_of(work, struct hfsplus_sb_info, sync_work.work);

    spin_lock(&sbi->work_lock);
    sbi->work_queued = 0;
    spin_unlock(&sbi->work_lock);

    hfsplus_sync_fs(sbi->alloc_file->i_sb, 1);
}

void hfsplus_mark_mdb_dirty(struct super_block *sb)
{
    struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
    unsigned long delay;

    if (sb->s_flags & MS_RDONLY)
        return;

    spin_lock(&sbi->work_lock);
    if (!sbi->work_queued) {
        delay = msecs_to_jiffies(dirty_writeback_interval * 10);
        queue_delayed_work(system_long_wq, &sbi->sync_work, delay);
        sbi->work_queued = 1;
    }
    spin_unlock(&sbi->work_lock);
}

static void hfsplus_put_super(struct super_block *sb)
{
    struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);

    dprint(DBG_SUPER, "hfsplus_put_super\n");

    cancel_delayed_work_sync(&sbi->sync_work);

    if (!(sb->s_flags & MS_RDONLY) && sbi->s_vhdr) {
        struct hfsplus_vh *vhdr = sbi->s_vhdr;

        vhdr->modify_date = hfsp_now2mt();
        vhdr->attributes |= cpu_to_be32(HFSPLUS_VOL_UNMNT);
        vhdr->attributes &= cpu_to_be32(~HFSPLUS_VOL_INCNSTNT);

        hfsplus_sync_fs(sb, 1);
    }

    hfs_btree_close(sbi->cat_tree);
    hfs_btree_close(sbi->ext_tree);
    iput(sbi->alloc_file);
    iput(sbi->hidden_dir);
    kfree(sbi->s_vhdr_buf);
    kfree(sbi->s_backup_vhdr_buf);
    unload_nls(sbi->nls);
    kfree(sb->s_fs_info);
    sb->s_fs_info = NULL;
}

static int hfsplus_statfs(struct dentry *dentry, struct kstatfs *buf)
{
    struct super_block *sb = dentry->d_sb;
    struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
    u64 id = huge_encode_dev(sb->s_bdev->bd_dev);

    buf->f_type = HFSPLUS_SUPER_MAGIC;
    buf->f_bsize = sb->s_blocksize;
    buf->f_blocks = sbi->total_blocks << sbi->fs_shift;
    buf->f_bfree = sbi->free_blocks << sbi->fs_shift;
    buf->f_bavail = buf->f_bfree;
    buf->f_files = 0xFFFFFFFF;
    buf->f_ffree = 0xFFFFFFFF - sbi->next_cnid;
    buf->f_fsid.val[0] = (u32)id;
    buf->f_fsid.val[1] = (u32)(id >> 32);
    buf->f_namelen = HFSPLUS_MAX_STRLEN;

    return 0;
}

static int hfsplus_remount(struct super_block *sb, int *flags, char *data)
{
    if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
        return 0;
    if (!(*flags & MS_RDONLY)) {
        struct hfsplus_vh *vhdr = HFSPLUS_SB(sb)->s_vhdr;
        int force = 0;

        if (!hfsplus_parse_options_remount(data, &force))
            return -EINVAL;

        if (!(vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_UNMNT))) {
            printk(KERN_WARNING "hfs: filesystem was "
                    "not cleanly unmounted, "
                    "running fsck.hfsplus is recommended.  "
                    "leaving read-only.\n");
            sb->s_flags |= MS_RDONLY;
            *flags |= MS_RDONLY;
        } else if (force) {
            /* nothing */
        } else if (vhdr->attributes &
                cpu_to_be32(HFSPLUS_VOL_SOFTLOCK)) {
            printk(KERN_WARNING "hfs: filesystem is marked locked, "
                    "leaving read-only.\n");
            sb->s_flags |= MS_RDONLY;
            *flags |= MS_RDONLY;
        } else if (vhdr->attributes &
                cpu_to_be32(HFSPLUS_VOL_JOURNALED)) {
            printk(KERN_WARNING "hfs: filesystem is "
                    "marked journaled, "
                    "leaving read-only.\n");
            sb->s_flags |= MS_RDONLY;
            *flags |= MS_RDONLY;
        }
    }
    return 0;
}

static const struct super_operations hfsplus_sops = {
    .alloc_inode    = hfsplus_alloc_inode,
    .destroy_inode  = hfsplus_destroy_inode,
    .write_inode    = hfsplus_write_inode,
    .evict_inode    = hfsplus_evict_inode,
    .put_super  = hfsplus_put_super,
    .sync_fs    = hfsplus_sync_fs,
    .statfs     = hfsplus_statfs,
    .remount_fs = hfsplus_remount,
    .show_options   = hfsplus_show_options,
};

static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
{
    struct hfsplus_vh *vhdr;
    struct hfsplus_sb_info *sbi;
    hfsplus_cat_entry entry;
    struct hfs_find_data fd;
    struct inode *root, *inode;
    struct qstr str;
    struct nls_table *nls = NULL;
    u64 last_fs_block, last_fs_page;
    int err;

    err = -ENOMEM;
    sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
    if (!sbi)
        goto out;

    sb->s_fs_info = sbi;
    mutex_init(&sbi->alloc_mutex);
    mutex_init(&sbi->vh_mutex);
    spin_lock_init(&sbi->work_lock);
    INIT_DELAYED_WORK(&sbi->sync_work, delayed_sync_fs);
    hfsplus_fill_defaults(sbi);

    err = -EINVAL;
    if (!hfsplus_parse_options(data, sbi)) {
        printk(KERN_ERR "hfs: unable to parse mount options\n");
        goto out_unload_nls;
    }

    /* temporarily use utf8 to correctly find the hidden dir below */
    nls = sbi->nls;
    sbi->nls = load_nls("utf8");
    if (!sbi->nls) {
        printk(KERN_ERR "hfs: unable to load nls for utf8\n");
        goto out_unload_nls;
    }

    /* Grab the volume header */
    if (hfsplus_read_wrapper(sb)) {
        if (!silent)
            printk(KERN_WARNING "hfs: unable to find HFS+ superblock\n");
        goto out_unload_nls;
    }
    vhdr = sbi->s_vhdr;

    /* Copy parts of the volume header into the superblock */
    sb->s_magic = HFSPLUS_VOLHEAD_SIG;
    if (be16_to_cpu(vhdr->version) < HFSPLUS_MIN_VERSION ||
        be16_to_cpu(vhdr->version) > HFSPLUS_CURRENT_VERSION) {
        printk(KERN_ERR "hfs: wrong filesystem version\n");
        goto out_free_vhdr;
    }
    sbi->total_blocks = be32_to_cpu(vhdr->total_blocks);
    sbi->free_blocks = be32_to_cpu(vhdr->free_blocks);
    sbi->next_cnid = be32_to_cpu(vhdr->next_cnid);
    sbi->file_count = be32_to_cpu(vhdr->file_count);
    sbi->folder_count = be32_to_cpu(vhdr->folder_count);
    sbi->data_clump_blocks =
        be32_to_cpu(vhdr->data_clump_sz) >> sbi->alloc_blksz_shift;
    if (!sbi->data_clump_blocks)
        sbi->data_clump_blocks = 1;
    sbi->rsrc_clump_blocks =
        be32_to_cpu(vhdr->rsrc_clump_sz) >> sbi->alloc_blksz_shift;
    if (!sbi->rsrc_clump_blocks)
        sbi->rsrc_clump_blocks = 1;

    err = -EFBIG;
    last_fs_block = sbi->total_blocks - 1;
    last_fs_page = (last_fs_block << sbi->alloc_blksz_shift) >>
            PAGE_CACHE_SHIFT;

    if ((last_fs_block > (sector_t)(~0ULL) >> (sbi->alloc_blksz_shift - 9)) ||
        (last_fs_page > (pgoff_t)(~0ULL))) {
        printk(KERN_ERR "hfs: filesystem size too large.\n");
        goto out_free_vhdr;
    }

    /* Set up operations so we can load metadata */
    sb->s_op = &hfsplus_sops;
    sb->s_maxbytes = MAX_LFS_FILESIZE;

    if (!(vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_UNMNT))) {
        printk(KERN_WARNING "hfs: Filesystem was "
                "not cleanly unmounted, "
                "running fsck.hfsplus is recommended.  "
                "mounting read-only.\n");
        sb->s_flags |= MS_RDONLY;
    } else if (test_and_clear_bit(HFSPLUS_SB_FORCE, &sbi->flags)) {
        /* nothing */
    } else if (vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_SOFTLOCK)) {
        printk(KERN_WARNING "hfs: Filesystem is marked locked, mounting read-only.\n");
        sb->s_flags |= MS_RDONLY;
    } else if ((vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_JOURNALED)) &&
            !(sb->s_flags & MS_RDONLY)) {
        printk(KERN_WARNING "hfs: write access to "
                "a journaled filesystem is not supported, "
                "use the force option at your own risk, "
                "mounting read-only.\n");
        sb->s_flags |= MS_RDONLY;
    }

    err = -EINVAL;

    /* Load metadata objects (B*Trees) */
    sbi->ext_tree = hfs_btree_open(sb, HFSPLUS_EXT_CNID);
    if (!sbi->ext_tree) {
        printk(KERN_ERR "hfs: failed to load extents file\n");
        goto out_free_vhdr;
    }
    sbi->cat_tree = hfs_btree_open(sb, HFSPLUS_CAT_CNID);
    if (!sbi->cat_tree) {
        printk(KERN_ERR "hfs: failed to load catalog file\n");
        goto out_close_ext_tree;
    }

    inode = hfsplus_iget(sb, HFSPLUS_ALLOC_CNID);
    if (IS_ERR(inode)) {
        printk(KERN_ERR "hfs: failed to load allocation file\n");
        err = PTR_ERR(inode);
        goto out_close_cat_tree;
    }
    sbi->alloc_file = inode;

    /* Load the root directory */
    root = hfsplus_iget(sb, HFSPLUS_ROOT_CNID);
    if (IS_ERR(root)) {
        printk(KERN_ERR "hfs: failed to load root directory\n");
        err = PTR_ERR(root);
        goto out_put_alloc_file;
    }

    sb->s_d_op = &hfsplus_dentry_operations;
    sb->s_root = d_make_root(root);
    if (!sb->s_root) {
        err = -ENOMEM;
        goto out_put_alloc_file;
    }

    str.len = sizeof(HFSP_HIDDENDIR_NAME) - 1;
    str.name = HFSP_HIDDENDIR_NAME;
    err = hfs_find_init(sbi->cat_tree, &fd);
    if (err)
        goto out_put_root;
    hfsplus_cat_build_key(sb, fd.search_key, HFSPLUS_ROOT_CNID, &str);
    if (!hfs_brec_read(&fd, &entry, sizeof(entry))) {
        hfs_find_exit(&fd);
        if (entry.type != cpu_to_be16(HFSPLUS_FOLDER))
            goto out_put_root;
        inode = hfsplus_iget(sb, be32_to_cpu(entry.folder.id));
        if (IS_ERR(inode)) {
            err = PTR_ERR(inode);
            goto out_put_root;
        }
        sbi->hidden_dir = inode;
    } else
        hfs_find_exit(&fd);

    if (!(sb->s_flags & MS_RDONLY)) {
        /*
         * H+LX == hfsplusutils, H+Lx == this driver, H+lx is unused
         * all three are registered with Apple for our use
         */
        vhdr->last_mount_vers = cpu_to_be32(HFSP_MOUNT_VERSION);
        vhdr->modify_date = hfsp_now2mt();
        be32_add_cpu(&vhdr->write_count, 1);
        vhdr->attributes &= cpu_to_be32(~HFSPLUS_VOL_UNMNT);
        vhdr->attributes |= cpu_to_be32(HFSPLUS_VOL_INCNSTNT);
        hfsplus_sync_fs(sb, 1);

        if (!sbi->hidden_dir) {
            mutex_lock(&sbi->vh_mutex);
            sbi->hidden_dir = hfsplus_new_inode(sb, S_IFDIR);
            if (!sbi->hidden_dir) {
                mutex_unlock(&sbi->vh_mutex);
                err = -ENOMEM;
                goto out_put_root;
            }
            err = hfsplus_create_cat(sbi->hidden_dir->i_ino, root,
                         &str, sbi->hidden_dir);
            mutex_unlock(&sbi->vh_mutex);
            if (err)
                goto out_put_hidden_dir;

            hfsplus_mark_inode_dirty(sbi->hidden_dir,
                         HFSPLUS_I_CAT_DIRTY);
        }
    }

    unload_nls(sbi->nls);
    sbi->nls = nls;
    return 0;

out_put_hidden_dir:
    iput(sbi->hidden_dir);
out_put_root:
    dput(sb->s_root);
    sb->s_root = NULL;
out_put_alloc_file:
    iput(sbi->alloc_file);
out_close_cat_tree:
    hfs_btree_close(sbi->cat_tree);
out_close_ext_tree:
    hfs_btree_close(sbi->ext_tree);
out_free_vhdr:
    kfree(sbi->s_vhdr_buf);
    kfree(sbi->s_backup_vhdr_buf);
out_unload_nls:
    unload_nls(sbi->nls);
    unload_nls(nls);
    kfree(sbi);
out:
    return err;
}

MODULE_AUTHOR("Brad Boyer");
MODULE_DESCRIPTION("Extended Macintosh Filesystem");
MODULE_LICENSE("GPL");

static struct kmem_cache *hfsplus_inode_cachep;

static struct inode *hfsplus_alloc_inode(struct super_block *sb)
{
    struct hfsplus_inode_info *i;

    i = kmem_cache_alloc(hfsplus_inode_cachep, GFP_KERNEL);
    return i ? &i->vfs_inode : NULL;
}

static void hfsplus_i_callback(struct rcu_head *head)
{
    struct inode *inode = container_of(head, struct inode, i_rcu);

    kmem_cache_free(hfsplus_inode_cachep, HFSPLUS_I(inode));
}

static void hfsplus_destroy_inode(struct inode *inode)
{
    call_rcu(&inode->i_rcu, hfsplus_i_callback);
}

#define HFSPLUS_INODE_SIZE  sizeof(struct hfsplus_inode_info)

static struct dentry *hfsplus_mount(struct file_system_type *fs_type,
              int flags, const char *dev_name, void *data)
{
    return mount_bdev(fs_type, flags, dev_name, data, hfsplus_fill_super);
}

static struct file_system_type hfsplus_fs_type = {
    .owner      = THIS_MODULE,
    .name       = "hfsplus",
    .mount      = hfsplus_mount,
    .kill_sb    = kill_block_super,
    .fs_flags   = FS_REQUIRES_DEV,
};

static void hfsplus_init_once(void *p)
{
    struct hfsplus_inode_info *i = p;

    inode_init_once(&i->vfs_inode);
}

static int __init init_hfsplus_fs(void)
{
    int err;

    hfsplus_inode_cachep = kmem_cache_create("hfsplus_icache",
        HFSPLUS_INODE_SIZE, 0, SLAB_HWCACHE_ALIGN,
        hfsplus_init_once);
    if (!hfsplus_inode_cachep)
        return -ENOMEM;
    err = register_filesystem(&hfsplus_fs_type);
    if (err)
        kmem_cache_destroy(hfsplus_inode_cachep);
    return err;
}

static void __exit exit_hfsplus_fs(void)
{
    unregister_filesystem(&hfsplus_fs_type);

    /*
     * Make sure all delayed rcu free inodes are flushed before we
     * destroy cache.
     */
    rcu_barrier();
    kmem_cache_destroy(hfsplus_inode_cachep);
}

module_init(init_hfsplus_fs)
module_exit(exit_hfsplus_fs)