// SPDX-License-Identifier: GPL-2.0 /* * 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 <linux/blkdev.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 void efs_kill_sb(struct super_block *s) { struct efs_sb_info *sbi = SUPER_INFO(s); kill_block_super(s); kfree(sbi); } static struct file_system_type efs_fs_type = { .owner = THIS_MODULE, .name = "efs", .mount = efs_mount, .kill_sb = efs_kill_sb, .fs_flags = FS_REQUIRES_DEV, }; MODULE_ALIAS_FS("efs"); 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 = kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL); if (!ei) return NULL; return &ei->vfs_inode; } static void efs_free_inode(struct inode *inode) { kmem_cache_free(efs_inode_cachep, INODE_INFO(inode)); } 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 init_inodecache(void) { efs_inode_cachep = kmem_cache_create("efs_inode_cache", sizeof(struct efs_inode_info), 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD| SLAB_ACCOUNT, init_once); if (efs_inode_cachep == NULL) return -ENOMEM; return 0; } static void destroy_inodecache(void) { /* * Make sure all delayed rcu free inodes are flushed before we * destroy cache. */ rcu_barrier(); kmem_cache_destroy(efs_inode_cachep); } static int efs_remount(struct super_block *sb, int *flags, char *data) { sync_filesystem(sb); *flags |= SB_RDONLY; return 0; } static const struct super_operations efs_superblock_operations = { .alloc_inode = efs_alloc_inode, .free_inode = efs_free_inode, .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; pr_info(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) { pr_warn("SGI disklabel: checksum bad, label corrupted\n"); return 0; } #ifdef DEBUG pr_debug("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]) { pr_debug("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)) { pr_debug("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) { pr_notice("partition table contained no EFS partitions\n"); #ifdef DEBUG } else { pr_info("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 = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL); if (!sb) return -ENOMEM; s->s_fs_info = sb; s->s_time_min = 0; s->s_time_max = U32_MAX; s->s_magic = EFS_SUPER_MAGIC; if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) { pr_err("device does not support %d byte blocks\n", EFS_BLOCKSIZE); return -EINVAL; } /* read the vh (volume header) block */ bh = sb_bread(s, 0); if (!bh) { pr_err("cannot read volume header\n"); return -EIO; } /* * 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) { return -EINVAL; } bh = sb_bread(s, sb->fs_start + EFS_SUPER); if (!bh) { pr_err("cannot read superblock\n"); return -EIO; } if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) { #ifdef DEBUG pr_warn("invalid superblock at block %u\n", sb->fs_start + EFS_SUPER); #endif brelse(bh); return -EINVAL; } brelse(bh); if (!sb_rdonly(s)) { #ifdef DEBUG pr_info("forcing read-only mode\n"); #endif s->s_flags |= SB_RDONLY; } s->s_op = &efs_superblock_operations; s->s_export_op = &efs_export_ops; root = efs_iget(s, EFS_ROOTINODE); if (IS_ERR(root)) { pr_err("get root inode failed\n"); return PTR_ERR(root); } s->s_root = d_make_root(root); if (!(s->s_root)) { pr_err("get root dentry failed\n"); return -ENOMEM; } return 0; } 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 = u64_to_fsid(id); buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */ return 0; }