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Diffstat (limited to 'fs/hfs/super.c')
-rw-r--r-- | fs/hfs/super.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/fs/hfs/super.c b/fs/hfs/super.c new file mode 100644 index 0000000..1e2c193 --- /dev/null +++ b/fs/hfs/super.c @@ -0,0 +1,395 @@ +/* + * linux/fs/hfs/super.c + * + * Copyright (C) 1995-1997 Paul H. Hargrove + * (C) 2003 Ardis Technologies <roman@ardistech.com> + * This file may be distributed under the terms of the GNU General Public License. + * + * This file contains hfs_read_super(), some of the super_ops and + * init_module() and cleanup_module(). The remaining super_ops are in + * inode.c since they deal with inodes. + * + * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/blkdev.h> +#include <linux/init.h> +#include <linux/parser.h> +#include <linux/vfs.h> + +#include "hfs_fs.h" +#include "btree.h" + +static kmem_cache_t *hfs_inode_cachep; + +MODULE_LICENSE("GPL"); + +/* + * hfs_write_super() + * + * Description: + * This function is called by the VFS only. When the filesystem + * is mounted r/w it updates the MDB on disk. + * Input Variable(s): + * struct super_block *sb: Pointer to the hfs superblock + * Output Variable(s): + * NONE + * Returns: + * void + * Preconditions: + * 'sb' points to a "valid" (struct super_block). + * Postconditions: + * The MDB is marked 'unsuccessfully unmounted' by clearing bit 8 of drAtrb + * (hfs_put_super() must set this flag!). Some MDB fields are updated + * and the MDB buffer is written to disk by calling hfs_mdb_commit(). + */ +static void hfs_write_super(struct super_block *sb) +{ + sb->s_dirt = 0; + if (sb->s_flags & MS_RDONLY) + return; + /* sync everything to the buffers */ + hfs_mdb_commit(sb); +} + +/* + * hfs_put_super() + * + * This is the put_super() entry in the super_operations structure for + * HFS filesystems. The purpose is to release the resources + * associated with the superblock sb. + */ +static void hfs_put_super(struct super_block *sb) +{ + hfs_mdb_close(sb); + /* release the MDB's resources */ + hfs_mdb_put(sb); +} + +/* + * hfs_statfs() + * + * This is the statfs() entry in the super_operations structure for + * HFS filesystems. The purpose is to return various data about the + * filesystem. + * + * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks. + */ +static int hfs_statfs(struct super_block *sb, struct kstatfs *buf) +{ + buf->f_type = HFS_SUPER_MAGIC; + buf->f_bsize = sb->s_blocksize; + buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div; + buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div; + buf->f_bavail = buf->f_bfree; + buf->f_files = HFS_SB(sb)->fs_ablocks; + buf->f_ffree = HFS_SB(sb)->free_ablocks; + buf->f_namelen = HFS_NAMELEN; + + return 0; +} + +static int hfs_remount(struct super_block *sb, int *flags, char *data) +{ + *flags |= MS_NODIRATIME; + if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) + return 0; + if (!(*flags & MS_RDONLY)) { + if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) { + printk("HFS-fs warning: Filesystem was not cleanly unmounted, " + "running fsck.hfs is recommended. leaving read-only.\n"); + sb->s_flags |= MS_RDONLY; + *flags |= MS_RDONLY; + } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) { + printk("HFS-fs: Filesystem is marked locked, leaving read-only.\n"); + sb->s_flags |= MS_RDONLY; + *flags |= MS_RDONLY; + } + } + return 0; +} + +static struct inode *hfs_alloc_inode(struct super_block *sb) +{ + struct hfs_inode_info *i; + + i = kmem_cache_alloc(hfs_inode_cachep, SLAB_KERNEL); + return i ? &i->vfs_inode : NULL; +} + +static void hfs_destroy_inode(struct inode *inode) +{ + kmem_cache_free(hfs_inode_cachep, HFS_I(inode)); +} + +static struct super_operations hfs_super_operations = { + .alloc_inode = hfs_alloc_inode, + .destroy_inode = hfs_destroy_inode, + .write_inode = hfs_write_inode, + .clear_inode = hfs_clear_inode, + .put_super = hfs_put_super, + .write_super = hfs_write_super, + .statfs = hfs_statfs, + .remount_fs = hfs_remount, +}; + +enum { + opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask, + opt_part, opt_session, opt_type, opt_creator, opt_quiet, + opt_err +}; + +static match_table_t tokens = { + { opt_uid, "uid=%u" }, + { opt_gid, "gid=%u" }, + { opt_umask, "umask=%o" }, + { opt_file_umask, "file_umask=%o" }, + { opt_dir_umask, "dir_umask=%o" }, + { opt_part, "part=%u" }, + { opt_session, "session=%u" }, + { opt_type, "type=%s" }, + { opt_creator, "creator=%s" }, + { opt_quiet, "quiet" }, + { opt_err, NULL } +}; + +static inline int match_fourchar(substring_t *arg, u32 *result) +{ + if (arg->to - arg->from != 4) + return -EINVAL; + memcpy(result, arg->from, 4); + return 0; +} + +/* + * parse_options() + * + * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger + * This function is called by hfs_read_super() to parse the mount options. + */ +static int parse_options(char *options, struct hfs_sb_info *hsb) +{ + char *p; + substring_t args[MAX_OPT_ARGS]; + int tmp, token; + + /* initialize the sb with defaults */ + hsb->s_uid = current->uid; + hsb->s_gid = current->gid; + hsb->s_file_umask = 0133; + hsb->s_dir_umask = 0022; + hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */ + hsb->s_quiet = 0; + hsb->part = -1; + hsb->session = -1; + + if (!options) + return 1; + + while ((p = strsep(&options, ",")) != NULL) { + if (!*p) + continue; + + token = match_token(p, tokens, args); + switch (token) { + case opt_uid: + if (match_int(&args[0], &tmp)) { + printk("HFS: uid requires an argument\n"); + return 0; + } + hsb->s_uid = (uid_t)tmp; + break; + case opt_gid: + if (match_int(&args[0], &tmp)) { + printk("HFS: gid requires an argument\n"); + return 0; + } + hsb->s_gid = (gid_t)tmp; + break; + case opt_umask: + if (match_octal(&args[0], &tmp)) { + printk("HFS: umask requires a value\n"); + return 0; + } + hsb->s_file_umask = (umode_t)tmp; + hsb->s_dir_umask = (umode_t)tmp; + break; + case opt_file_umask: + if (match_octal(&args[0], &tmp)) { + printk("HFS: file_umask requires a value\n"); + return 0; + } + hsb->s_file_umask = (umode_t)tmp; + break; + case opt_dir_umask: + if (match_octal(&args[0], &tmp)) { + printk("HFS: dir_umask requires a value\n"); + return 0; + } + hsb->s_dir_umask = (umode_t)tmp; + break; + case opt_part: + if (match_int(&args[0], &hsb->part)) { + printk("HFS: part requires an argument\n"); + return 0; + } + break; + case opt_session: + if (match_int(&args[0], &hsb->session)) { + printk("HFS: session requires an argument\n"); + return 0; + } + break; + case opt_type: + if (match_fourchar(&args[0], &hsb->s_type)) { + printk("HFS+-fs: type requires a 4 character value\n"); + return 0; + } + break; + case opt_creator: + if (match_fourchar(&args[0], &hsb->s_creator)) { + printk("HFS+-fs: creator requires a 4 character value\n"); + return 0; + } + break; + case opt_quiet: + hsb->s_quiet = 1; + break; + default: + return 0; + } + } + + hsb->s_dir_umask &= 0777; + hsb->s_file_umask &= 0577; + + return 1; +} + +/* + * hfs_read_super() + * + * This is the function that is responsible for mounting an HFS + * filesystem. It performs all the tasks necessary to get enough data + * from the disk to read the root inode. This includes parsing the + * mount options, dealing with Macintosh partitions, reading the + * superblock and the allocation bitmap blocks, calling + * hfs_btree_init() to get the necessary data about the extents and + * catalog B-trees and, finally, reading the root inode into memory. + */ +static int hfs_fill_super(struct super_block *sb, void *data, int silent) +{ + struct hfs_sb_info *sbi; + struct hfs_find_data fd; + hfs_cat_rec rec; + struct inode *root_inode; + int res; + + sbi = kmalloc(sizeof(struct hfs_sb_info), GFP_KERNEL); + if (!sbi) + return -ENOMEM; + sb->s_fs_info = sbi; + memset(sbi, 0, sizeof(struct hfs_sb_info)); + INIT_HLIST_HEAD(&sbi->rsrc_inodes); + + res = -EINVAL; + if (!parse_options((char *)data, sbi)) { + hfs_warn("hfs_fs: unable to parse mount options.\n"); + goto bail3; + } + + sb->s_op = &hfs_super_operations; + sb->s_flags |= MS_NODIRATIME; + init_MUTEX(&sbi->bitmap_lock); + + res = hfs_mdb_get(sb); + if (res) { + if (!silent) + hfs_warn("VFS: Can't find a HFS filesystem on dev %s.\n", + hfs_mdb_name(sb)); + res = -EINVAL; + goto bail2; + } + + /* try to get the root inode */ + hfs_find_init(HFS_SB(sb)->cat_tree, &fd); + res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd); + if (!res) + hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength); + if (res) { + hfs_find_exit(&fd); + goto bail_no_root; + } + root_inode = hfs_iget(sb, &fd.search_key->cat, &rec); + hfs_find_exit(&fd); + if (!root_inode) + goto bail_no_root; + + sb->s_root = d_alloc_root(root_inode); + if (!sb->s_root) + goto bail_iput; + + sb->s_root->d_op = &hfs_dentry_operations; + + /* everything's okay */ + return 0; + +bail_iput: + iput(root_inode); +bail_no_root: + hfs_warn("hfs_fs: get root inode failed.\n"); + hfs_mdb_put(sb); +bail2: +bail3: + kfree(sbi); + return res; +} + +static struct super_block *hfs_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data) +{ + return get_sb_bdev(fs_type, flags, dev_name, data, hfs_fill_super); +} + +static struct file_system_type hfs_fs_type = { + .owner = THIS_MODULE, + .name = "hfs", + .get_sb = hfs_get_sb, + .kill_sb = kill_block_super, + .fs_flags = FS_REQUIRES_DEV, +}; + +static void hfs_init_once(void *p, kmem_cache_t *cachep, unsigned long flags) +{ + struct hfs_inode_info *i = p; + + if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == SLAB_CTOR_CONSTRUCTOR) + inode_init_once(&i->vfs_inode); +} + +static int __init init_hfs_fs(void) +{ + int err; + + hfs_inode_cachep = kmem_cache_create("hfs_inode_cache", + sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN, + hfs_init_once, NULL); + if (!hfs_inode_cachep) + return -ENOMEM; + err = register_filesystem(&hfs_fs_type); + if (err) + kmem_cache_destroy(hfs_inode_cachep); + return err; +} + +static void __exit exit_hfs_fs(void) +{ + unregister_filesystem(&hfs_fs_type); + if (kmem_cache_destroy(hfs_inode_cachep)) + printk(KERN_INFO "hfs_inode_cache: not all structures were freed\n"); +} + +module_init(init_hfs_fs) +module_exit(exit_hfs_fs) |