/* * Optimized MPEG FS - inode and super operations. * Copyright (C) 2006 Bob Copeland <me@bobcopeland.com> * Released under GPL v2. */ #include <linux/module.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/fs.h> #include <linux/vfs.h> #include <linux/parser.h> #include <linux/buffer_head.h> #include <linux/vmalloc.h> #include <linux/writeback.h> #include <linux/crc-itu-t.h> #include "omfs.h" MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>"); MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux"); MODULE_LICENSE("GPL"); struct buffer_head *omfs_bread(struct super_block *sb, sector_t block) { struct omfs_sb_info *sbi = OMFS_SB(sb); if (block >= sbi->s_num_blocks) return NULL; return sb_bread(sb, clus_to_blk(sbi, block)); } struct inode *omfs_new_inode(struct inode *dir, umode_t mode) { struct inode *inode; u64 new_block; int err; int len; struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb); inode = new_inode(dir->i_sb); if (!inode) return ERR_PTR(-ENOMEM); err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors, &new_block, &len); if (err) goto fail; inode->i_ino = new_block; inode_init_owner(inode, NULL, mode); inode->i_mapping->a_ops = &omfs_aops; inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; switch (mode & S_IFMT) { case S_IFDIR: inode->i_op = &omfs_dir_inops; inode->i_fop = &omfs_dir_operations; inode->i_size = sbi->s_sys_blocksize; inc_nlink(inode); break; case S_IFREG: inode->i_op = &omfs_file_inops; inode->i_fop = &omfs_file_operations; inode->i_size = 0; break; } insert_inode_hash(inode); mark_inode_dirty(inode); return inode; fail: make_bad_inode(inode); iput(inode); return ERR_PTR(err); } /* * Update the header checksums for a dirty inode based on its contents. * Caller is expected to hold the buffer head underlying oi and mark it * dirty. */ static void omfs_update_checksums(struct omfs_inode *oi) { int xor, i, ofs = 0, count; u16 crc = 0; unsigned char *ptr = (unsigned char *) oi; count = be32_to_cpu(oi->i_head.h_body_size); ofs = sizeof(struct omfs_header); crc = crc_itu_t(crc, ptr + ofs, count); oi->i_head.h_crc = cpu_to_be16(crc); xor = ptr[0]; for (i = 1; i < OMFS_XOR_COUNT; i++) xor ^= ptr[i]; oi->i_head.h_check_xor = xor; } static int __omfs_write_inode(struct inode *inode, int wait) { struct omfs_inode *oi; struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb); struct buffer_head *bh, *bh2; u64 ctime; int i; int ret = -EIO; int sync_failed = 0; /* get current inode since we may have written sibling ptrs etc. */ bh = omfs_bread(inode->i_sb, inode->i_ino); if (!bh) goto out; oi = (struct omfs_inode *) bh->b_data; oi->i_head.h_self = cpu_to_be64(inode->i_ino); if (S_ISDIR(inode->i_mode)) oi->i_type = OMFS_DIR; else if (S_ISREG(inode->i_mode)) oi->i_type = OMFS_FILE; else { printk(KERN_WARNING "omfs: unknown file type: %d\n", inode->i_mode); goto out_brelse; } oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize - sizeof(struct omfs_header)); oi->i_head.h_version = 1; oi->i_head.h_type = OMFS_INODE_NORMAL; oi->i_head.h_magic = OMFS_IMAGIC; oi->i_size = cpu_to_be64(inode->i_size); ctime = inode->i_ctime.tv_sec * 1000LL + ((inode->i_ctime.tv_nsec + 999)/1000); oi->i_ctime = cpu_to_be64(ctime); omfs_update_checksums(oi); mark_buffer_dirty(bh); if (wait) { sync_dirty_buffer(bh); if (buffer_req(bh) && !buffer_uptodate(bh)) sync_failed = 1; } /* if mirroring writes, copy to next fsblock */ for (i = 1; i < sbi->s_mirrors; i++) { bh2 = omfs_bread(inode->i_sb, inode->i_ino + i); if (!bh2) goto out_brelse; memcpy(bh2->b_data, bh->b_data, bh->b_size); mark_buffer_dirty(bh2); if (wait) { sync_dirty_buffer(bh2); if (buffer_req(bh2) && !buffer_uptodate(bh2)) sync_failed = 1; } brelse(bh2); } ret = (sync_failed) ? -EIO : 0; out_brelse: brelse(bh); out: return ret; } static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc) { return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); } int omfs_sync_inode(struct inode *inode) { return __omfs_write_inode(inode, 1); } /* * called when an entry is deleted, need to clear the bits in the * bitmaps. */ static void omfs_evict_inode(struct inode *inode) { truncate_inode_pages(&inode->i_data, 0); clear_inode(inode); if (inode->i_nlink) return; if (S_ISREG(inode->i_mode)) { inode->i_size = 0; omfs_shrink_inode(inode); } omfs_clear_range(inode->i_sb, inode->i_ino, 2); } struct inode *omfs_iget(struct super_block *sb, ino_t ino) { struct omfs_sb_info *sbi = OMFS_SB(sb); struct omfs_inode *oi; struct buffer_head *bh; u64 ctime; unsigned long nsecs; struct inode *inode; inode = iget_locked(sb, ino); if (!inode) return ERR_PTR(-ENOMEM); if (!(inode->i_state & I_NEW)) return inode; bh = omfs_bread(inode->i_sb, ino); if (!bh) goto iget_failed; oi = (struct omfs_inode *)bh->b_data; /* check self */ if (ino != be64_to_cpu(oi->i_head.h_self)) goto fail_bh; inode->i_uid = sbi->s_uid; inode->i_gid = sbi->s_gid; ctime = be64_to_cpu(oi->i_ctime); nsecs = do_div(ctime, 1000) * 1000L; inode->i_atime.tv_sec = ctime; inode->i_mtime.tv_sec = ctime; inode->i_ctime.tv_sec = ctime; inode->i_atime.tv_nsec = nsecs; inode->i_mtime.tv_nsec = nsecs; inode->i_ctime.tv_nsec = nsecs; inode->i_mapping->a_ops = &omfs_aops; switch (oi->i_type) { case OMFS_DIR: inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask); inode->i_op = &omfs_dir_inops; inode->i_fop = &omfs_dir_operations; inode->i_size = sbi->s_sys_blocksize; inc_nlink(inode); break; case OMFS_FILE: inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask); inode->i_fop = &omfs_file_operations; inode->i_size = be64_to_cpu(oi->i_size); break; } brelse(bh); unlock_new_inode(inode); return inode; fail_bh: brelse(bh); iget_failed: iget_failed(inode); return ERR_PTR(-EIO); } static void omfs_put_super(struct super_block *sb) { struct omfs_sb_info *sbi = OMFS_SB(sb); kfree(sbi->s_imap); kfree(sbi); sb->s_fs_info = NULL; } static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf) { struct super_block *s = dentry->d_sb; struct omfs_sb_info *sbi = OMFS_SB(s); u64 id = huge_encode_dev(s->s_bdev->bd_dev); buf->f_type = OMFS_MAGIC; buf->f_bsize = sbi->s_blocksize; buf->f_blocks = sbi->s_num_blocks; buf->f_files = sbi->s_num_blocks; buf->f_namelen = OMFS_NAMELEN; buf->f_fsid.val[0] = (u32)id; buf->f_fsid.val[1] = (u32)(id >> 32); buf->f_bfree = buf->f_bavail = buf->f_ffree = omfs_count_free(s); return 0; } static const struct super_operations omfs_sops = { .write_inode = omfs_write_inode, .evict_inode = omfs_evict_inode, .put_super = omfs_put_super, .statfs = omfs_statfs, .show_options = generic_show_options, }; /* * For Rio Karma, there is an on-disk free bitmap whose location is * stored in the root block. For ReplayTV, there is no such free bitmap * so we have to walk the tree. Both inodes and file data are allocated * from the same map. This array can be big (300k) so we allocate * in units of the blocksize. */ static int omfs_get_imap(struct super_block *sb) { int bitmap_size; int array_size; int count; struct omfs_sb_info *sbi = OMFS_SB(sb); struct buffer_head *bh; unsigned long **ptr; sector_t block; bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8); array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize); if (sbi->s_bitmap_ino == ~0ULL) goto out; sbi->s_imap_size = array_size; sbi->s_imap = kzalloc(array_size * sizeof(unsigned long *), GFP_KERNEL); if (!sbi->s_imap) goto nomem; block = clus_to_blk(sbi, sbi->s_bitmap_ino); if (block >= sbi->s_num_blocks) goto nomem; ptr = sbi->s_imap; for (count = bitmap_size; count > 0; count -= sb->s_blocksize) { bh = sb_bread(sb, block++); if (!bh) goto nomem_free; *ptr = kmalloc(sb->s_blocksize, GFP_KERNEL); if (!*ptr) { brelse(bh); goto nomem_free; } memcpy(*ptr, bh->b_data, sb->s_blocksize); if (count < sb->s_blocksize) memset((void *)*ptr + count, 0xff, sb->s_blocksize - count); brelse(bh); ptr++; } out: return 0; nomem_free: for (count = 0; count < array_size; count++) kfree(sbi->s_imap[count]); kfree(sbi->s_imap); nomem: sbi->s_imap = NULL; sbi->s_imap_size = 0; return -ENOMEM; } enum { Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask }; static const match_table_t tokens = { {Opt_uid, "uid=%u"}, {Opt_gid, "gid=%u"}, {Opt_umask, "umask=%o"}, {Opt_dmask, "dmask=%o"}, {Opt_fmask, "fmask=%o"}, }; static int parse_options(char *options, struct omfs_sb_info *sbi) { char *p; substring_t args[MAX_OPT_ARGS]; int option; if (!options) return 1; while ((p = strsep(&options, ",")) != NULL) { int token; if (!*p) continue; token = match_token(p, tokens, args); switch (token) { case Opt_uid: if (match_int(&args[0], &option)) return 0; sbi->s_uid = make_kuid(current_user_ns(), option); if (!uid_valid(sbi->s_uid)) return 0; break; case Opt_gid: if (match_int(&args[0], &option)) return 0; sbi->s_gid = make_kgid(current_user_ns(), option); if (!gid_valid(sbi->s_gid)) return 0; break; case Opt_umask: if (match_octal(&args[0], &option)) return 0; sbi->s_fmask = sbi->s_dmask = option; break; case Opt_dmask: if (match_octal(&args[0], &option)) return 0; sbi->s_dmask = option; break; case Opt_fmask: if (match_octal(&args[0], &option)) return 0; sbi->s_fmask = option; break; default: return 0; } } return 1; } static int omfs_fill_super(struct super_block *sb, void *data, int silent) { struct buffer_head *bh, *bh2; struct omfs_super_block *omfs_sb; struct omfs_root_block *omfs_rb; struct omfs_sb_info *sbi; struct inode *root; int ret = -EINVAL; save_mount_options(sb, (char *) data); sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL); if (!sbi) return -ENOMEM; sb->s_fs_info = sbi; sbi->s_uid = current_uid(); sbi->s_gid = current_gid(); sbi->s_dmask = sbi->s_fmask = current_umask(); if (!parse_options((char *) data, sbi)) goto end; sb->s_maxbytes = 0xffffffff; sb_set_blocksize(sb, 0x200); bh = sb_bread(sb, 0); if (!bh) goto end; omfs_sb = (struct omfs_super_block *)bh->b_data; if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) { if (!silent) printk(KERN_ERR "omfs: Invalid superblock (%x)\n", omfs_sb->s_magic); goto out_brelse_bh; } sb->s_magic = OMFS_MAGIC; sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks); sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize); sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors); sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block); sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize); mutex_init(&sbi->s_bitmap_lock); if (sbi->s_sys_blocksize > PAGE_SIZE) { printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n", sbi->s_sys_blocksize); goto out_brelse_bh; } if (sbi->s_blocksize < sbi->s_sys_blocksize || sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) { printk(KERN_ERR "omfs: block size (%d) is out of range\n", sbi->s_blocksize); goto out_brelse_bh; } /* * Use sys_blocksize as the fs block since it is smaller than a * page while the fs blocksize can be larger. */ sb_set_blocksize(sb, sbi->s_sys_blocksize); /* * ...and the difference goes into a shift. sys_blocksize is always * a power of two factor of blocksize. */ sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) - get_bitmask_order(sbi->s_sys_blocksize); bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block)); if (!bh2) goto out_brelse_bh; omfs_rb = (struct omfs_root_block *)bh2->b_data; sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap); sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize); if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) { printk(KERN_ERR "omfs: block count discrepancy between " "super and root blocks (%llx, %llx)\n", (unsigned long long)sbi->s_num_blocks, (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks)); goto out_brelse_bh2; } if (sbi->s_bitmap_ino != ~0ULL && sbi->s_bitmap_ino > sbi->s_num_blocks) { printk(KERN_ERR "omfs: free space bitmap location is corrupt " "(%llx, total blocks %llx)\n", (unsigned long long) sbi->s_bitmap_ino, (unsigned long long) sbi->s_num_blocks); goto out_brelse_bh2; } if (sbi->s_clustersize < 1 || sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) { printk(KERN_ERR "omfs: cluster size out of range (%d)", sbi->s_clustersize); goto out_brelse_bh2; } ret = omfs_get_imap(sb); if (ret) goto out_brelse_bh2; sb->s_op = &omfs_sops; root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir)); if (IS_ERR(root)) { ret = PTR_ERR(root); goto out_brelse_bh2; } sb->s_root = d_make_root(root); if (!sb->s_root) goto out_brelse_bh2; printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name); ret = 0; out_brelse_bh2: brelse(bh2); out_brelse_bh: brelse(bh); end: if (ret) kfree(sbi); return ret; } static struct dentry *omfs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { return mount_bdev(fs_type, flags, dev_name, data, omfs_fill_super); } static struct file_system_type omfs_fs_type = { .owner = THIS_MODULE, .name = "omfs", .mount = omfs_mount, .kill_sb = kill_block_super, .fs_flags = FS_REQUIRES_DEV, }; static int __init init_omfs_fs(void) { return register_filesystem(&omfs_fs_type); } static void __exit exit_omfs_fs(void) { unregister_filesystem(&omfs_fs_type); } module_init(init_omfs_fs); module_exit(exit_omfs_fs);