|  | /* | 
|  | * super.c | 
|  | * | 
|  | * Copyright (c) 1999 Al Smith | 
|  | * | 
|  | * Portions derived from work (c) 1995,1996 Christian Vogelgsang. | 
|  | */ | 
|  |  | 
|  | #include <linux/init.h> | 
|  | #include <linux/module.h> | 
|  | #include <linux/exportfs.h> | 
|  | #include <linux/slab.h> | 
|  | #include <linux/buffer_head.h> | 
|  | #include <linux/vfs.h> | 
|  |  | 
|  | #include "efs.h" | 
|  | #include <linux/efs_vh.h> | 
|  | #include <linux/efs_fs_sb.h> | 
|  |  | 
|  | static int efs_statfs(struct dentry *dentry, struct kstatfs *buf); | 
|  | static int efs_fill_super(struct super_block *s, void *d, int silent); | 
|  |  | 
|  | static struct dentry *efs_mount(struct file_system_type *fs_type, | 
|  | int flags, const char *dev_name, void *data) | 
|  | { | 
|  | return mount_bdev(fs_type, flags, dev_name, data, efs_fill_super); | 
|  | } | 
|  |  | 
|  | static struct file_system_type efs_fs_type = { | 
|  | .owner		= THIS_MODULE, | 
|  | .name		= "efs", | 
|  | .mount		= efs_mount, | 
|  | .kill_sb	= kill_block_super, | 
|  | .fs_flags	= FS_REQUIRES_DEV, | 
|  | }; | 
|  |  | 
|  | static struct pt_types sgi_pt_types[] = { | 
|  | {0x00,		"SGI vh"}, | 
|  | {0x01,		"SGI trkrepl"}, | 
|  | {0x02,		"SGI secrepl"}, | 
|  | {0x03,		"SGI raw"}, | 
|  | {0x04,		"SGI bsd"}, | 
|  | {SGI_SYSV,	"SGI sysv"}, | 
|  | {0x06,		"SGI vol"}, | 
|  | {SGI_EFS,	"SGI efs"}, | 
|  | {0x08,		"SGI lv"}, | 
|  | {0x09,		"SGI rlv"}, | 
|  | {0x0A,		"SGI xfs"}, | 
|  | {0x0B,		"SGI xfslog"}, | 
|  | {0x0C,		"SGI xlv"}, | 
|  | {0x82,		"Linux swap"}, | 
|  | {0x83,		"Linux native"}, | 
|  | {0,		NULL} | 
|  | }; | 
|  |  | 
|  |  | 
|  | static struct kmem_cache * efs_inode_cachep; | 
|  |  | 
|  | static struct inode *efs_alloc_inode(struct super_block *sb) | 
|  | { | 
|  | struct efs_inode_info *ei; | 
|  | ei = (struct efs_inode_info *)kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL); | 
|  | if (!ei) | 
|  | return NULL; | 
|  | return &ei->vfs_inode; | 
|  | } | 
|  |  | 
|  | static void efs_i_callback(struct rcu_head *head) | 
|  | { | 
|  | struct inode *inode = container_of(head, struct inode, i_rcu); | 
|  | kmem_cache_free(efs_inode_cachep, INODE_INFO(inode)); | 
|  | } | 
|  |  | 
|  | static void efs_destroy_inode(struct inode *inode) | 
|  | { | 
|  | call_rcu(&inode->i_rcu, efs_i_callback); | 
|  | } | 
|  |  | 
|  | static void init_once(void *foo) | 
|  | { | 
|  | struct efs_inode_info *ei = (struct efs_inode_info *) foo; | 
|  |  | 
|  | inode_init_once(&ei->vfs_inode); | 
|  | } | 
|  |  | 
|  | static int init_inodecache(void) | 
|  | { | 
|  | efs_inode_cachep = kmem_cache_create("efs_inode_cache", | 
|  | sizeof(struct efs_inode_info), | 
|  | 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, | 
|  | init_once); | 
|  | if (efs_inode_cachep == NULL) | 
|  | return -ENOMEM; | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static void destroy_inodecache(void) | 
|  | { | 
|  | kmem_cache_destroy(efs_inode_cachep); | 
|  | } | 
|  |  | 
|  | static void efs_put_super(struct super_block *s) | 
|  | { | 
|  | kfree(s->s_fs_info); | 
|  | s->s_fs_info = NULL; | 
|  | } | 
|  |  | 
|  | static int efs_remount(struct super_block *sb, int *flags, char *data) | 
|  | { | 
|  | *flags |= MS_RDONLY; | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static const struct super_operations efs_superblock_operations = { | 
|  | .alloc_inode	= efs_alloc_inode, | 
|  | .destroy_inode	= efs_destroy_inode, | 
|  | .put_super	= efs_put_super, | 
|  | .statfs		= efs_statfs, | 
|  | .remount_fs	= efs_remount, | 
|  | }; | 
|  |  | 
|  | static const struct export_operations efs_export_ops = { | 
|  | .fh_to_dentry	= efs_fh_to_dentry, | 
|  | .fh_to_parent	= efs_fh_to_parent, | 
|  | .get_parent	= efs_get_parent, | 
|  | }; | 
|  |  | 
|  | static int __init init_efs_fs(void) { | 
|  | int err; | 
|  | printk("EFS: "EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n"); | 
|  | err = init_inodecache(); | 
|  | if (err) | 
|  | goto out1; | 
|  | err = register_filesystem(&efs_fs_type); | 
|  | if (err) | 
|  | goto out; | 
|  | return 0; | 
|  | out: | 
|  | destroy_inodecache(); | 
|  | out1: | 
|  | return err; | 
|  | } | 
|  |  | 
|  | static void __exit exit_efs_fs(void) { | 
|  | unregister_filesystem(&efs_fs_type); | 
|  | destroy_inodecache(); | 
|  | } | 
|  |  | 
|  | module_init(init_efs_fs) | 
|  | module_exit(exit_efs_fs) | 
|  |  | 
|  | static efs_block_t efs_validate_vh(struct volume_header *vh) { | 
|  | int		i; | 
|  | __be32		cs, *ui; | 
|  | int		csum; | 
|  | efs_block_t	sblock = 0; /* shuts up gcc */ | 
|  | struct pt_types	*pt_entry; | 
|  | int		pt_type, slice = -1; | 
|  |  | 
|  | if (be32_to_cpu(vh->vh_magic) != VHMAGIC) { | 
|  | /* | 
|  | * assume that we're dealing with a partition and allow | 
|  | * read_super() to try and detect a valid superblock | 
|  | * on the next block. | 
|  | */ | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | ui = ((__be32 *) (vh + 1)) - 1; | 
|  | for(csum = 0; ui >= ((__be32 *) vh);) { | 
|  | cs = *ui--; | 
|  | csum += be32_to_cpu(cs); | 
|  | } | 
|  | if (csum) { | 
|  | printk(KERN_INFO "EFS: SGI disklabel: checksum bad, label corrupted\n"); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | #ifdef DEBUG | 
|  | printk(KERN_DEBUG "EFS: bf: \"%16s\"\n", vh->vh_bootfile); | 
|  |  | 
|  | for(i = 0; i < NVDIR; i++) { | 
|  | int	j; | 
|  | char	name[VDNAMESIZE+1]; | 
|  |  | 
|  | for(j = 0; j < VDNAMESIZE; j++) { | 
|  | name[j] = vh->vh_vd[i].vd_name[j]; | 
|  | } | 
|  | name[j] = (char) 0; | 
|  |  | 
|  | if (name[0]) { | 
|  | printk(KERN_DEBUG "EFS: vh: %8s block: 0x%08x size: 0x%08x\n", | 
|  | name, | 
|  | (int) be32_to_cpu(vh->vh_vd[i].vd_lbn), | 
|  | (int) be32_to_cpu(vh->vh_vd[i].vd_nbytes)); | 
|  | } | 
|  | } | 
|  | #endif | 
|  |  | 
|  | for(i = 0; i < NPARTAB; i++) { | 
|  | pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type); | 
|  | for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) { | 
|  | if (pt_type == pt_entry->pt_type) break; | 
|  | } | 
|  | #ifdef DEBUG | 
|  | if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) { | 
|  | printk(KERN_DEBUG "EFS: pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n", | 
|  | i, | 
|  | (int) be32_to_cpu(vh->vh_pt[i].pt_firstlbn), | 
|  | (int) be32_to_cpu(vh->vh_pt[i].pt_nblks), | 
|  | pt_type, | 
|  | (pt_entry->pt_name) ? pt_entry->pt_name : "unknown"); | 
|  | } | 
|  | #endif | 
|  | if (IS_EFS(pt_type)) { | 
|  | sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn); | 
|  | slice = i; | 
|  | } | 
|  | } | 
|  |  | 
|  | if (slice == -1) { | 
|  | printk(KERN_NOTICE "EFS: partition table contained no EFS partitions\n"); | 
|  | #ifdef DEBUG | 
|  | } else { | 
|  | printk(KERN_INFO "EFS: using slice %d (type %s, offset 0x%x)\n", | 
|  | slice, | 
|  | (pt_entry->pt_name) ? pt_entry->pt_name : "unknown", | 
|  | sblock); | 
|  | #endif | 
|  | } | 
|  | return sblock; | 
|  | } | 
|  |  | 
|  | static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) { | 
|  |  | 
|  | if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic))) | 
|  | return -1; | 
|  |  | 
|  | sb->fs_magic     = be32_to_cpu(super->fs_magic); | 
|  | sb->total_blocks = be32_to_cpu(super->fs_size); | 
|  | sb->first_block  = be32_to_cpu(super->fs_firstcg); | 
|  | sb->group_size   = be32_to_cpu(super->fs_cgfsize); | 
|  | sb->data_free    = be32_to_cpu(super->fs_tfree); | 
|  | sb->inode_free   = be32_to_cpu(super->fs_tinode); | 
|  | sb->inode_blocks = be16_to_cpu(super->fs_cgisize); | 
|  | sb->total_groups = be16_to_cpu(super->fs_ncg); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int efs_fill_super(struct super_block *s, void *d, int silent) | 
|  | { | 
|  | struct efs_sb_info *sb; | 
|  | struct buffer_head *bh; | 
|  | struct inode *root; | 
|  | int ret = -EINVAL; | 
|  |  | 
|  | sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL); | 
|  | if (!sb) | 
|  | return -ENOMEM; | 
|  | s->s_fs_info = sb; | 
|  |  | 
|  | s->s_magic		= EFS_SUPER_MAGIC; | 
|  | if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) { | 
|  | printk(KERN_ERR "EFS: device does not support %d byte blocks\n", | 
|  | EFS_BLOCKSIZE); | 
|  | goto out_no_fs_ul; | 
|  | } | 
|  |  | 
|  | /* read the vh (volume header) block */ | 
|  | bh = sb_bread(s, 0); | 
|  |  | 
|  | if (!bh) { | 
|  | printk(KERN_ERR "EFS: cannot read volume header\n"); | 
|  | goto out_no_fs_ul; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * if this returns zero then we didn't find any partition table. | 
|  | * this isn't (yet) an error - just assume for the moment that | 
|  | * the device is valid and go on to search for a superblock. | 
|  | */ | 
|  | sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data); | 
|  | brelse(bh); | 
|  |  | 
|  | if (sb->fs_start == -1) { | 
|  | goto out_no_fs_ul; | 
|  | } | 
|  |  | 
|  | bh = sb_bread(s, sb->fs_start + EFS_SUPER); | 
|  | if (!bh) { | 
|  | printk(KERN_ERR "EFS: cannot read superblock\n"); | 
|  | goto out_no_fs_ul; | 
|  | } | 
|  |  | 
|  | if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) { | 
|  | #ifdef DEBUG | 
|  | printk(KERN_WARNING "EFS: invalid superblock at block %u\n", sb->fs_start + EFS_SUPER); | 
|  | #endif | 
|  | brelse(bh); | 
|  | goto out_no_fs_ul; | 
|  | } | 
|  | brelse(bh); | 
|  |  | 
|  | if (!(s->s_flags & MS_RDONLY)) { | 
|  | #ifdef DEBUG | 
|  | printk(KERN_INFO "EFS: forcing read-only mode\n"); | 
|  | #endif | 
|  | s->s_flags |= MS_RDONLY; | 
|  | } | 
|  | s->s_op   = &efs_superblock_operations; | 
|  | s->s_export_op = &efs_export_ops; | 
|  | root = efs_iget(s, EFS_ROOTINODE); | 
|  | if (IS_ERR(root)) { | 
|  | printk(KERN_ERR "EFS: get root inode failed\n"); | 
|  | ret = PTR_ERR(root); | 
|  | goto out_no_fs; | 
|  | } | 
|  |  | 
|  | s->s_root = d_alloc_root(root); | 
|  | if (!(s->s_root)) { | 
|  | printk(KERN_ERR "EFS: get root dentry failed\n"); | 
|  | iput(root); | 
|  | ret = -ENOMEM; | 
|  | goto out_no_fs; | 
|  | } | 
|  |  | 
|  | return 0; | 
|  |  | 
|  | out_no_fs_ul: | 
|  | out_no_fs: | 
|  | s->s_fs_info = NULL; | 
|  | kfree(sb); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) { | 
|  | struct super_block *sb = dentry->d_sb; | 
|  | struct efs_sb_info *sbi = SUPER_INFO(sb); | 
|  | u64 id = huge_encode_dev(sb->s_bdev->bd_dev); | 
|  |  | 
|  | buf->f_type    = EFS_SUPER_MAGIC;	/* efs magic number */ | 
|  | buf->f_bsize   = EFS_BLOCKSIZE;		/* blocksize */ | 
|  | buf->f_blocks  = sbi->total_groups *	/* total data blocks */ | 
|  | (sbi->group_size - sbi->inode_blocks); | 
|  | buf->f_bfree   = sbi->data_free;	/* free data blocks */ | 
|  | buf->f_bavail  = sbi->data_free;	/* free blocks for non-root */ | 
|  | buf->f_files   = sbi->total_groups *	/* total inodes */ | 
|  | sbi->inode_blocks * | 
|  | (EFS_BLOCKSIZE / sizeof(struct efs_dinode)); | 
|  | buf->f_ffree   = sbi->inode_free;	/* free inodes */ | 
|  | buf->f_fsid.val[0] = (u32)id; | 
|  | buf->f_fsid.val[1] = (u32)(id >> 32); | 
|  | buf->f_namelen = EFS_MAXNAMELEN;	/* max filename length */ | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  |