diff options
Diffstat (limited to 'fs/efs/super.c')
-rw-r--r-- | fs/efs/super.c | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/fs/efs/super.c b/fs/efs/super.c new file mode 100644 index 0000000..d8d5ea9 --- /dev/null +++ b/fs/efs/super.c @@ -0,0 +1,343 @@ +/* + * 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/efs_fs.h> +#include <linux/efs_vh.h> +#include <linux/efs_fs_sb.h> +#include <linux/slab.h> +#include <linux/buffer_head.h> +#include <linux/vfs.h> + +static int efs_statfs(struct super_block *s, struct kstatfs *buf); +static int efs_fill_super(struct super_block *s, void *d, int silent); + +static struct super_block *efs_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, efs_fill_super); +} + +static struct file_system_type efs_fs_type = { + .owner = THIS_MODULE, + .name = "efs", + .get_sb = efs_get_sb, + .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 kmem_cache_t * 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, SLAB_KERNEL); + if (!ei) + return NULL; + return &ei->vfs_inode; +} + +static void efs_destroy_inode(struct inode *inode) +{ + kmem_cache_free(efs_inode_cachep, INODE_INFO(inode)); +} + +static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) +{ + struct efs_inode_info *ei = (struct efs_inode_info *) foo; + + if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == + SLAB_CTOR_CONSTRUCTOR) + 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, + init_once, NULL); + if (efs_inode_cachep == NULL) + return -ENOMEM; + return 0; +} + +static void destroy_inodecache(void) +{ + if (kmem_cache_destroy(efs_inode_cachep)) + printk(KERN_INFO "efs_inode_cache: not all structures were freed\n"); +} + +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 struct super_operations efs_superblock_operations = { + .alloc_inode = efs_alloc_inode, + .destroy_inode = efs_destroy_inode, + .read_inode = efs_read_inode, + .put_super = efs_put_super, + .statfs = efs_statfs, + .remount_fs = efs_remount, +}; + +static struct export_operations efs_export_ops = { + .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; + + sb = kmalloc(sizeof(struct efs_sb_info), GFP_KERNEL); + if (!sb) + return -ENOMEM; + s->s_fs_info = sb; + memset(sb, 0, sizeof(struct efs_sb_info)); + + 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 = iget(s, EFS_ROOTINODE); + s->s_root = d_alloc_root(root); + + if (!(s->s_root)) { + printk(KERN_ERR "EFS: get root inode failed\n"); + iput(root); + goto out_no_fs; + } + + return 0; + +out_no_fs_ul: +out_no_fs: + s->s_fs_info = NULL; + kfree(sb); + return -EINVAL; +} + +static int efs_statfs(struct super_block *s, struct kstatfs *buf) { + struct efs_sb_info *sb = SUPER_INFO(s); + + buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */ + buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */ + buf->f_blocks = sb->total_groups * /* total data blocks */ + (sb->group_size - sb->inode_blocks); + buf->f_bfree = sb->data_free; /* free data blocks */ + buf->f_bavail = sb->data_free; /* free blocks for non-root */ + buf->f_files = sb->total_groups * /* total inodes */ + sb->inode_blocks * + (EFS_BLOCKSIZE / sizeof(struct efs_dinode)); + buf->f_ffree = sb->inode_free; /* free inodes */ + buf->f_fsid.val[0] = (sb->fs_magic >> 16) & 0xffff; /* fs ID */ + buf->f_fsid.val[1] = sb->fs_magic & 0xffff; /* fs ID */ + buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */ + + return 0; +} + |