// SPDX-License-Identifier: GPL-2.0-only /* * linux/fs/minix/inode.c * * Copyright (C) 1991, 1992 Linus Torvalds * * Copyright (C) 1996 Gertjan van Wingerde * Minix V2 fs support. * * Modified for 680x0 by Andreas Schwab * Updated to filesystem version 3 by Daniel Aragones */ #include #include "minix.h" #include #include #include #include #include #include #include #include static int minix_write_inode(struct inode *inode, struct writeback_control *wbc); static int minix_statfs(struct dentry *dentry, struct kstatfs *buf); static void minix_evict_inode(struct inode *inode) { truncate_inode_pages_final(&inode->i_data); if (!inode->i_nlink) { inode->i_size = 0; minix_truncate(inode); } invalidate_inode_buffers(inode); clear_inode(inode); if (!inode->i_nlink) minix_free_inode(inode); } static void minix_put_super(struct super_block *sb) { int i; struct minix_sb_info *sbi = minix_sb(sb); if (!sb_rdonly(sb)) { if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */ sbi->s_ms->s_state = sbi->s_mount_state; mark_buffer_dirty(sbi->s_sbh); } for (i = 0; i < sbi->s_imap_blocks; i++) brelse(sbi->s_imap[i]); for (i = 0; i < sbi->s_zmap_blocks; i++) brelse(sbi->s_zmap[i]); brelse (sbi->s_sbh); kfree(sbi->s_imap); sb->s_fs_info = NULL; kfree(sbi); } static struct kmem_cache * minix_inode_cachep; static struct inode *minix_alloc_inode(struct super_block *sb) { struct minix_inode_info *ei; ei = alloc_inode_sb(sb, minix_inode_cachep, GFP_KERNEL); if (!ei) return NULL; return &ei->vfs_inode; } static void minix_free_in_core_inode(struct inode *inode) { kmem_cache_free(minix_inode_cachep, minix_i(inode)); } static void init_once(void *foo) { struct minix_inode_info *ei = (struct minix_inode_info *) foo; inode_init_once(&ei->vfs_inode); } static int __init init_inodecache(void) { minix_inode_cachep = kmem_cache_create("minix_inode_cache", sizeof(struct minix_inode_info), 0, (SLAB_RECLAIM_ACCOUNT| SLAB_ACCOUNT), init_once); if (minix_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(minix_inode_cachep); } static const struct super_operations minix_sops = { .alloc_inode = minix_alloc_inode, .free_inode = minix_free_in_core_inode, .write_inode = minix_write_inode, .evict_inode = minix_evict_inode, .put_super = minix_put_super, .statfs = minix_statfs, }; static int minix_reconfigure(struct fs_context *fc) { struct minix_super_block * ms; struct super_block *sb = fc->root->d_sb; struct minix_sb_info * sbi = sb->s_fs_info; sync_filesystem(sb); ms = sbi->s_ms; if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb)) return 0; if (fc->sb_flags & SB_RDONLY) { if (ms->s_state & MINIX_VALID_FS || !(sbi->s_mount_state & MINIX_VALID_FS)) return 0; /* Mounting a rw partition read-only. */ if (sbi->s_version != MINIX_V3) ms->s_state = sbi->s_mount_state; mark_buffer_dirty(sbi->s_sbh); } else { /* Mount a partition which is read-only, read-write. */ if (sbi->s_version != MINIX_V3) { sbi->s_mount_state = ms->s_state; ms->s_state &= ~MINIX_VALID_FS; } else { sbi->s_mount_state = MINIX_VALID_FS; } mark_buffer_dirty(sbi->s_sbh); if (!(sbi->s_mount_state & MINIX_VALID_FS)) printk("MINIX-fs warning: remounting unchecked fs, " "running fsck is recommended\n"); else if ((sbi->s_mount_state & MINIX_ERROR_FS)) printk("MINIX-fs warning: remounting fs with errors, " "running fsck is recommended\n"); } return 0; } static bool minix_check_superblock(struct super_block *sb) { struct minix_sb_info *sbi = minix_sb(sb); if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0) return false; /* * s_max_size must not exceed the block mapping limitation. This check * is only needed for V1 filesystems, since V2/V3 support an extra level * of indirect blocks which places the limit well above U32_MAX. */ if (sbi->s_version == MINIX_V1 && sb->s_maxbytes > (7 + 512 + 512*512) * BLOCK_SIZE) return false; return true; } static int minix_fill_super(struct super_block *s, struct fs_context *fc) { struct buffer_head *bh; struct buffer_head **map; struct minix_super_block *ms; struct minix3_super_block *m3s = NULL; unsigned long i, block; struct inode *root_inode; struct minix_sb_info *sbi; int ret = -EINVAL; int silent = fc->sb_flags & SB_SILENT; sbi = kzalloc(sizeof(struct minix_sb_info), GFP_KERNEL); if (!sbi) return -ENOMEM; s->s_fs_info = sbi; BUILD_BUG_ON(32 != sizeof (struct minix_inode)); BUILD_BUG_ON(64 != sizeof(struct minix2_inode)); if (!sb_set_blocksize(s, BLOCK_SIZE)) goto out_bad_hblock; if (!(bh = sb_bread(s, 1))) goto out_bad_sb; ms = (struct minix_super_block *) bh->b_data; sbi->s_ms = ms; sbi->s_sbh = bh; sbi->s_mount_state = ms->s_state; sbi->s_ninodes = ms->s_ninodes; sbi->s_nzones = ms->s_nzones; sbi->s_imap_blocks = ms->s_imap_blocks; sbi->s_zmap_blocks = ms->s_zmap_blocks; sbi->s_firstdatazone = ms->s_firstdatazone; sbi->s_log_zone_size = ms->s_log_zone_size; s->s_maxbytes = ms->s_max_size; s->s_magic = ms->s_magic; if (s->s_magic == MINIX_SUPER_MAGIC) { sbi->s_version = MINIX_V1; sbi->s_dirsize = 16; sbi->s_namelen = 14; s->s_max_links = MINIX_LINK_MAX; } else if (s->s_magic == MINIX_SUPER_MAGIC2) { sbi->s_version = MINIX_V1; sbi->s_dirsize = 32; sbi->s_namelen = 30; s->s_max_links = MINIX_LINK_MAX; } else if (s->s_magic == MINIX2_SUPER_MAGIC) { sbi->s_version = MINIX_V2; sbi->s_nzones = ms->s_zones; sbi->s_dirsize = 16; sbi->s_namelen = 14; s->s_max_links = MINIX2_LINK_MAX; } else if (s->s_magic == MINIX2_SUPER_MAGIC2) { sbi->s_version = MINIX_V2; sbi->s_nzones = ms->s_zones; sbi->s_dirsize = 32; sbi->s_namelen = 30; s->s_max_links = MINIX2_LINK_MAX; } else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) { m3s = (struct minix3_super_block *) bh->b_data; s->s_magic = m3s->s_magic; sbi->s_imap_blocks = m3s->s_imap_blocks; sbi->s_zmap_blocks = m3s->s_zmap_blocks; sbi->s_firstdatazone = m3s->s_firstdatazone; sbi->s_log_zone_size = m3s->s_log_zone_size; s->s_maxbytes = m3s->s_max_size; sbi->s_ninodes = m3s->s_ninodes; sbi->s_nzones = m3s->s_zones; sbi->s_dirsize = 64; sbi->s_namelen = 60; sbi->s_version = MINIX_V3; sbi->s_mount_state = MINIX_VALID_FS; sb_set_blocksize(s, m3s->s_blocksize); s->s_max_links = MINIX2_LINK_MAX; } else goto out_no_fs; if (!minix_check_superblock(s)) goto out_illegal_sb; /* * Allocate the buffer map to keep the superblock small. */ i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh); map = kzalloc(i, GFP_KERNEL); if (!map) goto out_no_map; sbi->s_imap = &map[0]; sbi->s_zmap = &map[sbi->s_imap_blocks]; block=2; for (i=0 ; i < sbi->s_imap_blocks ; i++) { if (!(sbi->s_imap[i]=sb_bread(s, block))) goto out_no_bitmap; block++; } for (i=0 ; i < sbi->s_zmap_blocks ; i++) { if (!(sbi->s_zmap[i]=sb_bread(s, block))) goto out_no_bitmap; block++; } minix_set_bit(0,sbi->s_imap[0]->b_data); minix_set_bit(0,sbi->s_zmap[0]->b_data); /* Apparently minix can create filesystems that allocate more blocks for * the bitmaps than needed. We simply ignore that, but verify it didn't * create one with not enough blocks and bail out if so. */ block = minix_blocks_needed(sbi->s_ninodes, s->s_blocksize); if (sbi->s_imap_blocks < block) { printk("MINIX-fs: file system does not have enough " "imap blocks allocated. Refusing to mount.\n"); goto out_no_bitmap; } block = minix_blocks_needed( (sbi->s_nzones - sbi->s_firstdatazone + 1), s->s_blocksize); if (sbi->s_zmap_blocks < block) { printk("MINIX-fs: file system does not have enough " "zmap blocks allocated. Refusing to mount.\n"); goto out_no_bitmap; } /* set up enough so that it can read an inode */ s->s_op = &minix_sops; s->s_time_min = 0; s->s_time_max = U32_MAX; root_inode = minix_iget(s, MINIX_ROOT_INO); if (IS_ERR(root_inode)) { ret = PTR_ERR(root_inode); goto out_no_root; } ret = -ENOMEM; s->s_root = d_make_root(root_inode); if (!s->s_root) goto out_no_root; if (!sb_rdonly(s)) { if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */ ms->s_state &= ~MINIX_VALID_FS; mark_buffer_dirty(bh); } if (!(sbi->s_mount_state & MINIX_VALID_FS)) printk("MINIX-fs: mounting unchecked file system, " "running fsck is recommended\n"); else if (sbi->s_mount_state & MINIX_ERROR_FS) printk("MINIX-fs: mounting file system with errors, " "running fsck is recommended\n"); return 0; out_no_root: if (!silent) printk("MINIX-fs: get root inode failed\n"); goto out_freemap; out_no_bitmap: printk("MINIX-fs: bad superblock or unable to read bitmaps\n"); out_freemap: for (i = 0; i < sbi->s_imap_blocks; i++) brelse(sbi->s_imap[i]); for (i = 0; i < sbi->s_zmap_blocks; i++) brelse(sbi->s_zmap[i]); kfree(sbi->s_imap); goto out_release; out_no_map: ret = -ENOMEM; if (!silent) printk("MINIX-fs: can't allocate map\n"); goto out_release; out_illegal_sb: if (!silent) printk("MINIX-fs: bad superblock\n"); goto out_release; out_no_fs: if (!silent) printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 " "on device %s.\n", s->s_id); out_release: brelse(bh); goto out; out_bad_hblock: printk("MINIX-fs: blocksize too small for device\n"); goto out; out_bad_sb: printk("MINIX-fs: unable to read superblock\n"); out: s->s_fs_info = NULL; kfree(sbi); return ret; } static int minix_get_tree(struct fs_context *fc) { return get_tree_bdev(fc, minix_fill_super); } static const struct fs_context_operations minix_context_ops = { .get_tree = minix_get_tree, .reconfigure = minix_reconfigure, }; static int minix_init_fs_context(struct fs_context *fc) { fc->ops = &minix_context_ops; return 0; } static int minix_statfs(struct dentry *dentry, struct kstatfs *buf) { struct super_block *sb = dentry->d_sb; struct minix_sb_info *sbi = minix_sb(sb); u64 id = huge_encode_dev(sb->s_bdev->bd_dev); buf->f_type = sb->s_magic; buf->f_bsize = sb->s_blocksize; buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size; buf->f_bfree = minix_count_free_blocks(sb); buf->f_bavail = buf->f_bfree; buf->f_files = sbi->s_ninodes; buf->f_ffree = minix_count_free_inodes(sb); buf->f_namelen = sbi->s_namelen; buf->f_fsid = u64_to_fsid(id); return 0; } static int minix_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create) { if (INODE_VERSION(inode) == MINIX_V1) return V1_minix_get_block(inode, block, bh_result, create); else return V2_minix_get_block(inode, block, bh_result, create); } static int minix_writepages(struct address_space *mapping, struct writeback_control *wbc) { return mpage_writepages(mapping, wbc, minix_get_block); } static int minix_read_folio(struct file *file, struct folio *folio) { return block_read_full_folio(folio, minix_get_block); } int minix_prepare_chunk(struct folio *folio, loff_t pos, unsigned len) { return __block_write_begin(folio, pos, len, minix_get_block); } static void minix_write_failed(struct address_space *mapping, loff_t to) { struct inode *inode = mapping->host; if (to > inode->i_size) { truncate_pagecache(inode, inode->i_size); minix_truncate(inode); } } static int minix_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, struct folio **foliop, void **fsdata) { int ret; ret = block_write_begin(mapping, pos, len, foliop, minix_get_block); if (unlikely(ret)) minix_write_failed(mapping, pos + len); return ret; } static sector_t minix_bmap(struct address_space *mapping, sector_t block) { return generic_block_bmap(mapping,block,minix_get_block); } static const struct address_space_operations minix_aops = { .dirty_folio = block_dirty_folio, .invalidate_folio = block_invalidate_folio, .read_folio = minix_read_folio, .writepages = minix_writepages, .write_begin = minix_write_begin, .write_end = generic_write_end, .migrate_folio = buffer_migrate_folio, .bmap = minix_bmap, .direct_IO = noop_direct_IO }; static const struct inode_operations minix_symlink_inode_operations = { .get_link = page_get_link, .getattr = minix_getattr, }; void minix_set_inode(struct inode *inode, dev_t rdev) { if (S_ISREG(inode->i_mode)) { inode->i_op = &minix_file_inode_operations; inode->i_fop = &minix_file_operations; inode->i_mapping->a_ops = &minix_aops; } else if (S_ISDIR(inode->i_mode)) { inode->i_op = &minix_dir_inode_operations; inode->i_fop = &minix_dir_operations; inode->i_mapping->a_ops = &minix_aops; } else if (S_ISLNK(inode->i_mode)) { inode->i_op = &minix_symlink_inode_operations; inode_nohighmem(inode); inode->i_mapping->a_ops = &minix_aops; } else init_special_inode(inode, inode->i_mode, rdev); } /* * The minix V1 function to read an inode. */ static struct inode *V1_minix_iget(struct inode *inode) { struct buffer_head * bh; struct minix_inode * raw_inode; struct minix_inode_info *minix_inode = minix_i(inode); int i; raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh); if (!raw_inode) { iget_failed(inode); return ERR_PTR(-EIO); } if (raw_inode->i_nlinks == 0) { printk("MINIX-fs: deleted inode referenced: %lu\n", inode->i_ino); brelse(bh); iget_failed(inode); return ERR_PTR(-ESTALE); } inode->i_mode = raw_inode->i_mode; i_uid_write(inode, raw_inode->i_uid); i_gid_write(inode, raw_inode->i_gid); set_nlink(inode, raw_inode->i_nlinks); inode->i_size = raw_inode->i_size; inode_set_mtime_to_ts(inode, inode_set_atime_to_ts(inode, inode_set_ctime(inode, raw_inode->i_time, 0))); inode->i_blocks = 0; for (i = 0; i < 9; i++) minix_inode->u.i1_data[i] = raw_inode->i_zone[i]; minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0])); brelse(bh); unlock_new_inode(inode); return inode; } /* * The minix V2 function to read an inode. */ static struct inode *V2_minix_iget(struct inode *inode) { struct buffer_head * bh; struct minix2_inode * raw_inode; struct minix_inode_info *minix_inode = minix_i(inode); int i; raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh); if (!raw_inode) { iget_failed(inode); return ERR_PTR(-EIO); } if (raw_inode->i_nlinks == 0) { printk("MINIX-fs: deleted inode referenced: %lu\n", inode->i_ino); brelse(bh); iget_failed(inode); return ERR_PTR(-ESTALE); } inode->i_mode = raw_inode->i_mode; i_uid_write(inode, raw_inode->i_uid); i_gid_write(inode, raw_inode->i_gid); set_nlink(inode, raw_inode->i_nlinks); inode->i_size = raw_inode->i_size; inode_set_mtime(inode, raw_inode->i_mtime, 0); inode_set_atime(inode, raw_inode->i_atime, 0); inode_set_ctime(inode, raw_inode->i_ctime, 0); inode->i_blocks = 0; for (i = 0; i < 10; i++) minix_inode->u.i2_data[i] = raw_inode->i_zone[i]; minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0])); brelse(bh); unlock_new_inode(inode); return inode; } /* * The global function to read an inode. */ struct inode *minix_iget(struct super_block *sb, unsigned long ino) { struct inode *inode; inode = iget_locked(sb, ino); if (!inode) return ERR_PTR(-ENOMEM); if (!(inode->i_state & I_NEW)) return inode; if (INODE_VERSION(inode) == MINIX_V1) return V1_minix_iget(inode); else return V2_minix_iget(inode); } /* * The minix V1 function to synchronize an inode. */ static struct buffer_head * V1_minix_update_inode(struct inode * inode) { struct buffer_head * bh; struct minix_inode * raw_inode; struct minix_inode_info *minix_inode = minix_i(inode); int i; raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh); if (!raw_inode) return NULL; raw_inode->i_mode = inode->i_mode; raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode)); raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode)); raw_inode->i_nlinks = inode->i_nlink; raw_inode->i_size = inode->i_size; raw_inode->i_time = inode_get_mtime_sec(inode); if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev); else for (i = 0; i < 9; i++) raw_inode->i_zone[i] = minix_inode->u.i1_data[i]; mark_buffer_dirty(bh); return bh; } /* * The minix V2 function to synchronize an inode. */ static struct buffer_head * V2_minix_update_inode(struct inode * inode) { struct buffer_head * bh; struct minix2_inode * raw_inode; struct minix_inode_info *minix_inode = minix_i(inode); int i; raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh); if (!raw_inode) return NULL; raw_inode->i_mode = inode->i_mode; raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode)); raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode)); raw_inode->i_nlinks = inode->i_nlink; raw_inode->i_size = inode->i_size; raw_inode->i_mtime = inode_get_mtime_sec(inode); raw_inode->i_atime = inode_get_atime_sec(inode); raw_inode->i_ctime = inode_get_ctime_sec(inode); if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev); else for (i = 0; i < 10; i++) raw_inode->i_zone[i] = minix_inode->u.i2_data[i]; mark_buffer_dirty(bh); return bh; } static int minix_write_inode(struct inode *inode, struct writeback_control *wbc) { int err = 0; struct buffer_head *bh; if (INODE_VERSION(inode) == MINIX_V1) bh = V1_minix_update_inode(inode); else bh = V2_minix_update_inode(inode); if (!bh) return -EIO; if (wbc->sync_mode == WB_SYNC_ALL && buffer_dirty(bh)) { sync_dirty_buffer(bh); if (buffer_req(bh) && !buffer_uptodate(bh)) { printk("IO error syncing minix inode [%s:%08lx]\n", inode->i_sb->s_id, inode->i_ino); err = -EIO; } } brelse (bh); return err; } int minix_getattr(struct mnt_idmap *idmap, const struct path *path, struct kstat *stat, u32 request_mask, unsigned int flags) { struct super_block *sb = path->dentry->d_sb; struct inode *inode = d_inode(path->dentry); generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat); if (INODE_VERSION(inode) == MINIX_V1) stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb); else stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb); stat->blksize = sb->s_blocksize; return 0; } /* * The function that is called for file truncation. */ void minix_truncate(struct inode * inode) { if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))) return; if (INODE_VERSION(inode) == MINIX_V1) V1_minix_truncate(inode); else V2_minix_truncate(inode); } static struct file_system_type minix_fs_type = { .owner = THIS_MODULE, .name = "minix", .kill_sb = kill_block_super, .fs_flags = FS_REQUIRES_DEV, .init_fs_context = minix_init_fs_context, }; MODULE_ALIAS_FS("minix"); static int __init init_minix_fs(void) { int err = init_inodecache(); if (err) goto out1; err = register_filesystem(&minix_fs_type); if (err) goto out; return 0; out: destroy_inodecache(); out1: return err; } static void __exit exit_minix_fs(void) { unregister_filesystem(&minix_fs_type); destroy_inodecache(); } module_init(init_minix_fs) module_exit(exit_minix_fs) MODULE_DESCRIPTION("Minix file system"); MODULE_LICENSE("GPL");