| /* |
| * linux/fs/fat/inode.c |
| * |
| * Written 1992,1993 by Werner Almesberger |
| * VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner |
| * Rewritten for the constant inumbers support by Al Viro |
| * |
| * Fixes: |
| * |
| * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0 |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/time.h> |
| #include <linux/slab.h> |
| #include <linux/smp_lock.h> |
| #include <linux/seq_file.h> |
| #include <linux/pagemap.h> |
| #include <linux/mpage.h> |
| #include <linux/buffer_head.h> |
| #include <linux/exportfs.h> |
| #include <linux/mount.h> |
| #include <linux/vfs.h> |
| #include <linux/parser.h> |
| #include <linux/uio.h> |
| #include <linux/writeback.h> |
| #include <linux/log2.h> |
| #include <linux/hash.h> |
| #include <asm/unaligned.h> |
| #include "fat.h" |
| |
| #ifndef CONFIG_FAT_DEFAULT_IOCHARSET |
| /* if user don't select VFAT, this is undefined. */ |
| #define CONFIG_FAT_DEFAULT_IOCHARSET "" |
| #endif |
| |
| static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE; |
| static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET; |
| |
| |
| static int fat_add_cluster(struct inode *inode) |
| { |
| int err, cluster; |
| |
| err = fat_alloc_clusters(inode, &cluster, 1); |
| if (err) |
| return err; |
| /* FIXME: this cluster should be added after data of this |
| * cluster is writed */ |
| err = fat_chain_add(inode, cluster, 1); |
| if (err) |
| fat_free_clusters(inode, cluster); |
| return err; |
| } |
| |
| static inline int __fat_get_block(struct inode *inode, sector_t iblock, |
| unsigned long *max_blocks, |
| struct buffer_head *bh_result, int create) |
| { |
| struct super_block *sb = inode->i_sb; |
| struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| unsigned long mapped_blocks; |
| sector_t phys; |
| int err, offset; |
| |
| err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create); |
| if (err) |
| return err; |
| if (phys) { |
| map_bh(bh_result, sb, phys); |
| *max_blocks = min(mapped_blocks, *max_blocks); |
| return 0; |
| } |
| if (!create) |
| return 0; |
| |
| if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) { |
| fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)", |
| MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private); |
| return -EIO; |
| } |
| |
| offset = (unsigned long)iblock & (sbi->sec_per_clus - 1); |
| if (!offset) { |
| /* TODO: multiple cluster allocation would be desirable. */ |
| err = fat_add_cluster(inode); |
| if (err) |
| return err; |
| } |
| /* available blocks on this cluster */ |
| mapped_blocks = sbi->sec_per_clus - offset; |
| |
| *max_blocks = min(mapped_blocks, *max_blocks); |
| MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits; |
| |
| err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create); |
| if (err) |
| return err; |
| |
| BUG_ON(!phys); |
| BUG_ON(*max_blocks != mapped_blocks); |
| set_buffer_new(bh_result); |
| map_bh(bh_result, sb, phys); |
| |
| return 0; |
| } |
| |
| static int fat_get_block(struct inode *inode, sector_t iblock, |
| struct buffer_head *bh_result, int create) |
| { |
| struct super_block *sb = inode->i_sb; |
| unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; |
| int err; |
| |
| err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create); |
| if (err) |
| return err; |
| bh_result->b_size = max_blocks << sb->s_blocksize_bits; |
| return 0; |
| } |
| |
| static int fat_writepage(struct page *page, struct writeback_control *wbc) |
| { |
| return block_write_full_page(page, fat_get_block, wbc); |
| } |
| |
| static int fat_writepages(struct address_space *mapping, |
| struct writeback_control *wbc) |
| { |
| return mpage_writepages(mapping, wbc, fat_get_block); |
| } |
| |
| static int fat_readpage(struct file *file, struct page *page) |
| { |
| return mpage_readpage(page, fat_get_block); |
| } |
| |
| static int fat_readpages(struct file *file, struct address_space *mapping, |
| struct list_head *pages, unsigned nr_pages) |
| { |
| return mpage_readpages(mapping, pages, nr_pages, fat_get_block); |
| } |
| |
| static int fat_write_begin(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned flags, |
| struct page **pagep, void **fsdata) |
| { |
| *pagep = NULL; |
| return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, |
| fat_get_block, |
| &MSDOS_I(mapping->host)->mmu_private); |
| } |
| |
| static int fat_write_end(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned copied, |
| struct page *pagep, void *fsdata) |
| { |
| struct inode *inode = mapping->host; |
| int err; |
| err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); |
| if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { |
| inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; |
| MSDOS_I(inode)->i_attrs |= ATTR_ARCH; |
| mark_inode_dirty(inode); |
| } |
| return err; |
| } |
| |
| static ssize_t fat_direct_IO(int rw, struct kiocb *iocb, |
| const struct iovec *iov, |
| loff_t offset, unsigned long nr_segs) |
| { |
| struct file *file = iocb->ki_filp; |
| struct inode *inode = file->f_mapping->host; |
| |
| if (rw == WRITE) { |
| /* |
| * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), |
| * so we need to update the ->mmu_private to block boundary. |
| * |
| * But we must fill the remaining area or hole by nul for |
| * updating ->mmu_private. |
| * |
| * Return 0, and fallback to normal buffered write. |
| */ |
| loff_t size = offset + iov_length(iov, nr_segs); |
| if (MSDOS_I(inode)->mmu_private < size) |
| return 0; |
| } |
| |
| /* |
| * FAT need to use the DIO_LOCKING for avoiding the race |
| * condition of fat_get_block() and ->truncate(). |
| */ |
| return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, |
| offset, nr_segs, fat_get_block, NULL); |
| } |
| |
| static sector_t _fat_bmap(struct address_space *mapping, sector_t block) |
| { |
| sector_t blocknr; |
| |
| /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ |
| mutex_lock(&mapping->host->i_mutex); |
| blocknr = generic_block_bmap(mapping, block, fat_get_block); |
| mutex_unlock(&mapping->host->i_mutex); |
| |
| return blocknr; |
| } |
| |
| static const struct address_space_operations fat_aops = { |
| .readpage = fat_readpage, |
| .readpages = fat_readpages, |
| .writepage = fat_writepage, |
| .writepages = fat_writepages, |
| .sync_page = block_sync_page, |
| .write_begin = fat_write_begin, |
| .write_end = fat_write_end, |
| .direct_IO = fat_direct_IO, |
| .bmap = _fat_bmap |
| }; |
| |
| /* |
| * New FAT inode stuff. We do the following: |
| * a) i_ino is constant and has nothing with on-disk location. |
| * b) FAT manages its own cache of directory entries. |
| * c) *This* cache is indexed by on-disk location. |
| * d) inode has an associated directory entry, all right, but |
| * it may be unhashed. |
| * e) currently entries are stored within struct inode. That should |
| * change. |
| * f) we deal with races in the following way: |
| * 1. readdir() and lookup() do FAT-dir-cache lookup. |
| * 2. rename() unhashes the F-d-c entry and rehashes it in |
| * a new place. |
| * 3. unlink() and rmdir() unhash F-d-c entry. |
| * 4. fat_write_inode() checks whether the thing is unhashed. |
| * If it is we silently return. If it isn't we do bread(), |
| * check if the location is still valid and retry if it |
| * isn't. Otherwise we do changes. |
| * 5. Spinlock is used to protect hash/unhash/location check/lookup |
| * 6. fat_clear_inode() unhashes the F-d-c entry. |
| * 7. lookup() and readdir() do igrab() if they find a F-d-c entry |
| * and consider negative result as cache miss. |
| */ |
| |
| static void fat_hash_init(struct super_block *sb) |
| { |
| struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| int i; |
| |
| spin_lock_init(&sbi->inode_hash_lock); |
| for (i = 0; i < FAT_HASH_SIZE; i++) |
| INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); |
| } |
| |
| static inline unsigned long fat_hash(loff_t i_pos) |
| { |
| return hash_32(i_pos, FAT_HASH_BITS); |
| } |
| |
| void fat_attach(struct inode *inode, loff_t i_pos) |
| { |
| struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); |
| struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); |
| |
| spin_lock(&sbi->inode_hash_lock); |
| MSDOS_I(inode)->i_pos = i_pos; |
| hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); |
| spin_unlock(&sbi->inode_hash_lock); |
| } |
| EXPORT_SYMBOL_GPL(fat_attach); |
| |
| void fat_detach(struct inode *inode) |
| { |
| struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); |
| spin_lock(&sbi->inode_hash_lock); |
| MSDOS_I(inode)->i_pos = 0; |
| hlist_del_init(&MSDOS_I(inode)->i_fat_hash); |
| spin_unlock(&sbi->inode_hash_lock); |
| } |
| EXPORT_SYMBOL_GPL(fat_detach); |
| |
| struct inode *fat_iget(struct super_block *sb, loff_t i_pos) |
| { |
| struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); |
| struct hlist_node *_p; |
| struct msdos_inode_info *i; |
| struct inode *inode = NULL; |
| |
| spin_lock(&sbi->inode_hash_lock); |
| hlist_for_each_entry(i, _p, head, i_fat_hash) { |
| BUG_ON(i->vfs_inode.i_sb != sb); |
| if (i->i_pos != i_pos) |
| continue; |
| inode = igrab(&i->vfs_inode); |
| if (inode) |
| break; |
| } |
| spin_unlock(&sbi->inode_hash_lock); |
| return inode; |
| } |
| |
| static int is_exec(unsigned char *extension) |
| { |
| unsigned char *exe_extensions = "EXECOMBAT", *walk; |
| |
| for (walk = exe_extensions; *walk; walk += 3) |
| if (!strncmp(extension, walk, 3)) |
| return 1; |
| return 0; |
| } |
| |
| static int fat_calc_dir_size(struct inode *inode) |
| { |
| struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); |
| int ret, fclus, dclus; |
| |
| inode->i_size = 0; |
| if (MSDOS_I(inode)->i_start == 0) |
| return 0; |
| |
| ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); |
| if (ret < 0) |
| return ret; |
| inode->i_size = (fclus + 1) << sbi->cluster_bits; |
| |
| return 0; |
| } |
| |
| /* doesn't deal with root inode */ |
| static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) |
| { |
| struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); |
| int error; |
| |
| MSDOS_I(inode)->i_pos = 0; |
| inode->i_uid = sbi->options.fs_uid; |
| inode->i_gid = sbi->options.fs_gid; |
| inode->i_version++; |
| inode->i_generation = get_seconds(); |
| |
| if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { |
| inode->i_generation &= ~1; |
| inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO); |
| inode->i_op = sbi->dir_ops; |
| inode->i_fop = &fat_dir_operations; |
| |
| MSDOS_I(inode)->i_start = le16_to_cpu(de->start); |
| if (sbi->fat_bits == 32) |
| MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16); |
| |
| MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; |
| error = fat_calc_dir_size(inode); |
| if (error < 0) |
| return error; |
| MSDOS_I(inode)->mmu_private = inode->i_size; |
| |
| inode->i_nlink = fat_subdirs(inode); |
| } else { /* not a directory */ |
| inode->i_generation |= 1; |
| inode->i_mode = fat_make_mode(sbi, de->attr, |
| ((sbi->options.showexec && !is_exec(de->name + 8)) |
| ? S_IRUGO|S_IWUGO : S_IRWXUGO)); |
| MSDOS_I(inode)->i_start = le16_to_cpu(de->start); |
| if (sbi->fat_bits == 32) |
| MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16); |
| |
| MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; |
| inode->i_size = le32_to_cpu(de->size); |
| inode->i_op = &fat_file_inode_operations; |
| inode->i_fop = &fat_file_operations; |
| inode->i_mapping->a_ops = &fat_aops; |
| MSDOS_I(inode)->mmu_private = inode->i_size; |
| } |
| if (de->attr & ATTR_SYS) { |
| if (sbi->options.sys_immutable) |
| inode->i_flags |= S_IMMUTABLE; |
| } |
| fat_save_attrs(inode, de->attr); |
| |
| inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) |
| & ~((loff_t)sbi->cluster_size - 1)) >> 9; |
| |
| fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0); |
| if (sbi->options.isvfat) { |
| fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime, |
| de->cdate, de->ctime_cs); |
| fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0); |
| } else |
| inode->i_ctime = inode->i_atime = inode->i_mtime; |
| |
| return 0; |
| } |
| |
| struct inode *fat_build_inode(struct super_block *sb, |
| struct msdos_dir_entry *de, loff_t i_pos) |
| { |
| struct inode *inode; |
| int err; |
| |
| inode = fat_iget(sb, i_pos); |
| if (inode) |
| goto out; |
| inode = new_inode(sb); |
| if (!inode) { |
| inode = ERR_PTR(-ENOMEM); |
| goto out; |
| } |
| inode->i_ino = iunique(sb, MSDOS_ROOT_INO); |
| inode->i_version = 1; |
| err = fat_fill_inode(inode, de); |
| if (err) { |
| iput(inode); |
| inode = ERR_PTR(err); |
| goto out; |
| } |
| fat_attach(inode, i_pos); |
| insert_inode_hash(inode); |
| out: |
| return inode; |
| } |
| |
| EXPORT_SYMBOL_GPL(fat_build_inode); |
| |
| static void fat_delete_inode(struct inode *inode) |
| { |
| truncate_inode_pages(&inode->i_data, 0); |
| inode->i_size = 0; |
| fat_truncate(inode); |
| clear_inode(inode); |
| } |
| |
| static void fat_clear_inode(struct inode *inode) |
| { |
| fat_cache_inval_inode(inode); |
| fat_detach(inode); |
| } |
| |
| static void fat_write_super(struct super_block *sb) |
| { |
| sb->s_dirt = 0; |
| |
| if (!(sb->s_flags & MS_RDONLY)) |
| fat_clusters_flush(sb); |
| } |
| |
| static void fat_put_super(struct super_block *sb) |
| { |
| struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| |
| if (sbi->nls_disk) { |
| unload_nls(sbi->nls_disk); |
| sbi->nls_disk = NULL; |
| sbi->options.codepage = fat_default_codepage; |
| } |
| if (sbi->nls_io) { |
| unload_nls(sbi->nls_io); |
| sbi->nls_io = NULL; |
| } |
| if (sbi->options.iocharset != fat_default_iocharset) { |
| kfree(sbi->options.iocharset); |
| sbi->options.iocharset = fat_default_iocharset; |
| } |
| |
| sb->s_fs_info = NULL; |
| kfree(sbi); |
| } |
| |
| static struct kmem_cache *fat_inode_cachep; |
| |
| static struct inode *fat_alloc_inode(struct super_block *sb) |
| { |
| struct msdos_inode_info *ei; |
| ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS); |
| if (!ei) |
| return NULL; |
| return &ei->vfs_inode; |
| } |
| |
| static void fat_destroy_inode(struct inode *inode) |
| { |
| kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); |
| } |
| |
| static void init_once(void *foo) |
| { |
| struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; |
| |
| spin_lock_init(&ei->cache_lru_lock); |
| ei->nr_caches = 0; |
| ei->cache_valid_id = FAT_CACHE_VALID + 1; |
| INIT_LIST_HEAD(&ei->cache_lru); |
| INIT_HLIST_NODE(&ei->i_fat_hash); |
| inode_init_once(&ei->vfs_inode); |
| } |
| |
| static int __init fat_init_inodecache(void) |
| { |
| fat_inode_cachep = kmem_cache_create("fat_inode_cache", |
| sizeof(struct msdos_inode_info), |
| 0, (SLAB_RECLAIM_ACCOUNT| |
| SLAB_MEM_SPREAD), |
| init_once); |
| if (fat_inode_cachep == NULL) |
| return -ENOMEM; |
| return 0; |
| } |
| |
| static void __exit fat_destroy_inodecache(void) |
| { |
| kmem_cache_destroy(fat_inode_cachep); |
| } |
| |
| static int fat_remount(struct super_block *sb, int *flags, char *data) |
| { |
| struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME); |
| return 0; |
| } |
| |
| static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) |
| { |
| struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb); |
| |
| /* If the count of free cluster is still unknown, counts it here. */ |
| if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { |
| int err = fat_count_free_clusters(dentry->d_sb); |
| if (err) |
| return err; |
| } |
| |
| buf->f_type = dentry->d_sb->s_magic; |
| buf->f_bsize = sbi->cluster_size; |
| buf->f_blocks = sbi->max_cluster - FAT_START_ENT; |
| buf->f_bfree = sbi->free_clusters; |
| buf->f_bavail = sbi->free_clusters; |
| buf->f_namelen = sbi->options.isvfat ? 260 : 12; |
| |
| return 0; |
| } |
| |
| static int fat_write_inode(struct inode *inode, int wait) |
| { |
| struct super_block *sb = inode->i_sb; |
| struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| struct buffer_head *bh; |
| struct msdos_dir_entry *raw_entry; |
| loff_t i_pos; |
| int err; |
| |
| retry: |
| i_pos = MSDOS_I(inode)->i_pos; |
| if (inode->i_ino == MSDOS_ROOT_INO || !i_pos) |
| return 0; |
| |
| bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits); |
| if (!bh) { |
| printk(KERN_ERR "FAT: unable to read inode block " |
| "for updating (i_pos %lld)\n", i_pos); |
| return -EIO; |
| } |
| spin_lock(&sbi->inode_hash_lock); |
| if (i_pos != MSDOS_I(inode)->i_pos) { |
| spin_unlock(&sbi->inode_hash_lock); |
| brelse(bh); |
| goto retry; |
| } |
| |
| raw_entry = &((struct msdos_dir_entry *) (bh->b_data)) |
| [i_pos & (sbi->dir_per_block - 1)]; |
| if (S_ISDIR(inode->i_mode)) |
| raw_entry->size = 0; |
| else |
| raw_entry->size = cpu_to_le32(inode->i_size); |
| raw_entry->attr = fat_make_attrs(inode); |
| raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart); |
| raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16); |
| fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, |
| &raw_entry->date, NULL); |
| if (sbi->options.isvfat) { |
| __le16 atime; |
| fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime, |
| &raw_entry->cdate, &raw_entry->ctime_cs); |
| fat_time_unix2fat(sbi, &inode->i_atime, &atime, |
| &raw_entry->adate, NULL); |
| } |
| spin_unlock(&sbi->inode_hash_lock); |
| mark_buffer_dirty(bh); |
| err = 0; |
| if (wait) |
| err = sync_dirty_buffer(bh); |
| brelse(bh); |
| return err; |
| } |
| |
| int fat_sync_inode(struct inode *inode) |
| { |
| return fat_write_inode(inode, 1); |
| } |
| |
| EXPORT_SYMBOL_GPL(fat_sync_inode); |
| |
| static int fat_show_options(struct seq_file *m, struct vfsmount *mnt); |
| static const struct super_operations fat_sops = { |
| .alloc_inode = fat_alloc_inode, |
| .destroy_inode = fat_destroy_inode, |
| .write_inode = fat_write_inode, |
| .delete_inode = fat_delete_inode, |
| .put_super = fat_put_super, |
| .write_super = fat_write_super, |
| .statfs = fat_statfs, |
| .clear_inode = fat_clear_inode, |
| .remount_fs = fat_remount, |
| |
| .show_options = fat_show_options, |
| }; |
| |
| /* |
| * a FAT file handle with fhtype 3 is |
| * 0/ i_ino - for fast, reliable lookup if still in the cache |
| * 1/ i_generation - to see if i_ino is still valid |
| * bit 0 == 0 iff directory |
| * 2/ i_pos(8-39) - if ino has changed, but still in cache |
| * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos |
| * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc |
| * |
| * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum |
| * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits |
| * of i_logstart is used to store the directory entry offset. |
| */ |
| |
| static struct dentry *fat_fh_to_dentry(struct super_block *sb, |
| struct fid *fid, int fh_len, int fh_type) |
| { |
| struct inode *inode = NULL; |
| struct dentry *result; |
| u32 *fh = fid->raw; |
| |
| if (fh_len < 5 || fh_type != 3) |
| return NULL; |
| |
| inode = ilookup(sb, fh[0]); |
| if (!inode || inode->i_generation != fh[1]) { |
| if (inode) |
| iput(inode); |
| inode = NULL; |
| } |
| if (!inode) { |
| loff_t i_pos; |
| int i_logstart = fh[3] & 0x0fffffff; |
| |
| i_pos = (loff_t)fh[2] << 8; |
| i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28); |
| |
| /* try 2 - see if i_pos is in F-d-c |
| * require i_logstart to be the same |
| * Will fail if you truncate and then re-write |
| */ |
| |
| inode = fat_iget(sb, i_pos); |
| if (inode && MSDOS_I(inode)->i_logstart != i_logstart) { |
| iput(inode); |
| inode = NULL; |
| } |
| } |
| |
| /* |
| * For now, do nothing if the inode is not found. |
| * |
| * What we could do is: |
| * |
| * - follow the file starting at fh[4], and record the ".." entry, |
| * and the name of the fh[2] entry. |
| * - then follow the ".." file finding the next step up. |
| * |
| * This way we build a path to the root of the tree. If this works, we |
| * lookup the path and so get this inode into the cache. Finally try |
| * the fat_iget lookup again. If that fails, then we are totally out |
| * of luck. But all that is for another day |
| */ |
| result = d_obtain_alias(inode); |
| if (!IS_ERR(result)) |
| result->d_op = sb->s_root->d_op; |
| return result; |
| } |
| |
| static int |
| fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable) |
| { |
| int len = *lenp; |
| struct inode *inode = de->d_inode; |
| u32 ipos_h, ipos_m, ipos_l; |
| |
| if (len < 5) |
| return 255; /* no room */ |
| |
| ipos_h = MSDOS_I(inode)->i_pos >> 8; |
| ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24; |
| ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28; |
| *lenp = 5; |
| fh[0] = inode->i_ino; |
| fh[1] = inode->i_generation; |
| fh[2] = ipos_h; |
| fh[3] = ipos_m | MSDOS_I(inode)->i_logstart; |
| spin_lock(&de->d_lock); |
| fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart; |
| spin_unlock(&de->d_lock); |
| return 3; |
| } |
| |
| static struct dentry *fat_get_parent(struct dentry *child) |
| { |
| struct super_block *sb = child->d_sb; |
| struct buffer_head *bh; |
| struct msdos_dir_entry *de; |
| loff_t i_pos; |
| struct dentry *parent; |
| struct inode *inode; |
| int err; |
| |
| lock_super(sb); |
| |
| err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos); |
| if (err) { |
| parent = ERR_PTR(err); |
| goto out; |
| } |
| inode = fat_build_inode(sb, de, i_pos); |
| brelse(bh); |
| |
| parent = d_obtain_alias(inode); |
| out: |
| unlock_super(sb); |
| |
| return parent; |
| } |
| |
| static const struct export_operations fat_export_ops = { |
| .encode_fh = fat_encode_fh, |
| .fh_to_dentry = fat_fh_to_dentry, |
| .get_parent = fat_get_parent, |
| }; |
| |
| static int fat_show_options(struct seq_file *m, struct vfsmount *mnt) |
| { |
| struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb); |
| struct fat_mount_options *opts = &sbi->options; |
| int isvfat = opts->isvfat; |
| |
| if (opts->fs_uid != 0) |
| seq_printf(m, ",uid=%u", opts->fs_uid); |
| if (opts->fs_gid != 0) |
| seq_printf(m, ",gid=%u", opts->fs_gid); |
| seq_printf(m, ",fmask=%04o", opts->fs_fmask); |
| seq_printf(m, ",dmask=%04o", opts->fs_dmask); |
| if (opts->allow_utime) |
| seq_printf(m, ",allow_utime=%04o", opts->allow_utime); |
| if (sbi->nls_disk) |
| seq_printf(m, ",codepage=%s", sbi->nls_disk->charset); |
| if (isvfat) { |
| if (sbi->nls_io) |
| seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); |
| |
| switch (opts->shortname) { |
| case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: |
| seq_puts(m, ",shortname=win95"); |
| break; |
| case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: |
| seq_puts(m, ",shortname=winnt"); |
| break; |
| case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: |
| seq_puts(m, ",shortname=mixed"); |
| break; |
| case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: |
| /* seq_puts(m, ",shortname=lower"); */ |
| break; |
| default: |
| seq_puts(m, ",shortname=unknown"); |
| break; |
| } |
| } |
| if (opts->name_check != 'n') |
| seq_printf(m, ",check=%c", opts->name_check); |
| if (opts->usefree) |
| seq_puts(m, ",usefree"); |
| if (opts->quiet) |
| seq_puts(m, ",quiet"); |
| if (opts->showexec) |
| seq_puts(m, ",showexec"); |
| if (opts->sys_immutable) |
| seq_puts(m, ",sys_immutable"); |
| if (!isvfat) { |
| if (opts->dotsOK) |
| seq_puts(m, ",dotsOK=yes"); |
| if (opts->nocase) |
| seq_puts(m, ",nocase"); |
| } else { |
| if (opts->utf8) |
| seq_puts(m, ",utf8"); |
| if (opts->unicode_xlate) |
| seq_puts(m, ",uni_xlate"); |
| if (!opts->numtail) |
| seq_puts(m, ",nonumtail"); |
| if (opts->rodir) |
| seq_puts(m, ",rodir"); |
| } |
| if (opts->flush) |
| seq_puts(m, ",flush"); |
| if (opts->tz_utc) |
| seq_puts(m, ",tz=UTC"); |
| |
| return 0; |
| } |
| |
| enum { |
| Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, |
| Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, |
| Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, |
| Opt_immutable, Opt_dots, Opt_nodots, |
| Opt_charset, Opt_shortname_lower, Opt_shortname_win95, |
| Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, |
| Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, |
| Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err, |
| }; |
| |
| static const match_table_t fat_tokens = { |
| {Opt_check_r, "check=relaxed"}, |
| {Opt_check_s, "check=strict"}, |
| {Opt_check_n, "check=normal"}, |
| {Opt_check_r, "check=r"}, |
| {Opt_check_s, "check=s"}, |
| {Opt_check_n, "check=n"}, |
| {Opt_uid, "uid=%u"}, |
| {Opt_gid, "gid=%u"}, |
| {Opt_umask, "umask=%o"}, |
| {Opt_dmask, "dmask=%o"}, |
| {Opt_fmask, "fmask=%o"}, |
| {Opt_allow_utime, "allow_utime=%o"}, |
| {Opt_codepage, "codepage=%u"}, |
| {Opt_usefree, "usefree"}, |
| {Opt_nocase, "nocase"}, |
| {Opt_quiet, "quiet"}, |
| {Opt_showexec, "showexec"}, |
| {Opt_debug, "debug"}, |
| {Opt_immutable, "sys_immutable"}, |
| {Opt_obsolate, "conv=binary"}, |
| {Opt_obsolate, "conv=text"}, |
| {Opt_obsolate, "conv=auto"}, |
| {Opt_obsolate, "conv=b"}, |
| {Opt_obsolate, "conv=t"}, |
| {Opt_obsolate, "conv=a"}, |
| {Opt_obsolate, "fat=%u"}, |
| {Opt_obsolate, "blocksize=%u"}, |
| {Opt_obsolate, "cvf_format=%20s"}, |
| {Opt_obsolate, "cvf_options=%100s"}, |
| {Opt_obsolate, "posix"}, |
| {Opt_flush, "flush"}, |
| {Opt_tz_utc, "tz=UTC"}, |
| {Opt_err, NULL}, |
| }; |
| static const match_table_t msdos_tokens = { |
| {Opt_nodots, "nodots"}, |
| {Opt_nodots, "dotsOK=no"}, |
| {Opt_dots, "dots"}, |
| {Opt_dots, "dotsOK=yes"}, |
| {Opt_err, NULL} |
| }; |
| static const match_table_t vfat_tokens = { |
| {Opt_charset, "iocharset=%s"}, |
| {Opt_shortname_lower, "shortname=lower"}, |
| {Opt_shortname_win95, "shortname=win95"}, |
| {Opt_shortname_winnt, "shortname=winnt"}, |
| {Opt_shortname_mixed, "shortname=mixed"}, |
| {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ |
| {Opt_utf8_no, "utf8=no"}, |
| {Opt_utf8_no, "utf8=false"}, |
| {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ |
| {Opt_utf8_yes, "utf8=yes"}, |
| {Opt_utf8_yes, "utf8=true"}, |
| {Opt_utf8_yes, "utf8"}, |
| {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ |
| {Opt_uni_xl_no, "uni_xlate=no"}, |
| {Opt_uni_xl_no, "uni_xlate=false"}, |
| {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ |
| {Opt_uni_xl_yes, "uni_xlate=yes"}, |
| {Opt_uni_xl_yes, "uni_xlate=true"}, |
| {Opt_uni_xl_yes, "uni_xlate"}, |
| {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ |
| {Opt_nonumtail_no, "nonumtail=no"}, |
| {Opt_nonumtail_no, "nonumtail=false"}, |
| {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ |
| {Opt_nonumtail_yes, "nonumtail=yes"}, |
| {Opt_nonumtail_yes, "nonumtail=true"}, |
| {Opt_nonumtail_yes, "nonumtail"}, |
| {Opt_rodir, "rodir"}, |
| {Opt_err, NULL} |
| }; |
| |
| static int parse_options(char *options, int is_vfat, int silent, int *debug, |
| struct fat_mount_options *opts) |
| { |
| char *p; |
| substring_t args[MAX_OPT_ARGS]; |
| int option; |
| char *iocharset; |
| |
| opts->isvfat = is_vfat; |
| |
| opts->fs_uid = current->uid; |
| opts->fs_gid = current->gid; |
| opts->fs_fmask = opts->fs_dmask = current->fs->umask; |
| opts->allow_utime = -1; |
| opts->codepage = fat_default_codepage; |
| opts->iocharset = fat_default_iocharset; |
| if (is_vfat) { |
| opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95; |
| opts->rodir = 0; |
| } else { |
| opts->shortname = 0; |
| opts->rodir = 1; |
| } |
| opts->name_check = 'n'; |
| opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; |
| opts->utf8 = opts->unicode_xlate = 0; |
| opts->numtail = 1; |
| opts->usefree = opts->nocase = 0; |
| opts->tz_utc = 0; |
| *debug = 0; |
| |
| if (!options) |
| goto out; |
| |
| while ((p = strsep(&options, ",")) != NULL) { |
| int token; |
| if (!*p) |
| continue; |
| |
| token = match_token(p, fat_tokens, args); |
| if (token == Opt_err) { |
| if (is_vfat) |
| token = match_token(p, vfat_tokens, args); |
| else |
| token = match_token(p, msdos_tokens, args); |
| } |
| switch (token) { |
| case Opt_check_s: |
| opts->name_check = 's'; |
| break; |
| case Opt_check_r: |
| opts->name_check = 'r'; |
| break; |
| case Opt_check_n: |
| opts->name_check = 'n'; |
| break; |
| case Opt_usefree: |
| opts->usefree = 1; |
| break; |
| case Opt_nocase: |
| if (!is_vfat) |
| opts->nocase = 1; |
| else { |
| /* for backward compatibility */ |
| opts->shortname = VFAT_SFN_DISPLAY_WIN95 |
| | VFAT_SFN_CREATE_WIN95; |
| } |
| break; |
| case Opt_quiet: |
| opts->quiet = 1; |
| break; |
| case Opt_showexec: |
| opts->showexec = 1; |
| break; |
| case Opt_debug: |
| *debug = 1; |
| break; |
| case Opt_immutable: |
| opts->sys_immutable = 1; |
| break; |
| case Opt_uid: |
| if (match_int(&args[0], &option)) |
| return 0; |
| opts->fs_uid = option; |
| break; |
| case Opt_gid: |
| if (match_int(&args[0], &option)) |
| return 0; |
| opts->fs_gid = option; |
| break; |
| case Opt_umask: |
| if (match_octal(&args[0], &option)) |
| return 0; |
| opts->fs_fmask = opts->fs_dmask = option; |
| break; |
| case Opt_dmask: |
| if (match_octal(&args[0], &option)) |
| return 0; |
| opts->fs_dmask = option; |
| break; |
| case Opt_fmask: |
| if (match_octal(&args[0], &option)) |
| return 0; |
| opts->fs_fmask = option; |
| break; |
| case Opt_allow_utime: |
| if (match_octal(&args[0], &option)) |
| return 0; |
| opts->allow_utime = option & (S_IWGRP | S_IWOTH); |
| break; |
| case Opt_codepage: |
| if (match_int(&args[0], &option)) |
| return 0; |
| opts->codepage = option; |
| break; |
| case Opt_flush: |
| opts->flush = 1; |
| break; |
| case Opt_tz_utc: |
| opts->tz_utc = 1; |
| break; |
| |
| /* msdos specific */ |
| case Opt_dots: |
| opts->dotsOK = 1; |
| break; |
| case Opt_nodots: |
| opts->dotsOK = 0; |
| break; |
| |
| /* vfat specific */ |
| case Opt_charset: |
| if (opts->iocharset != fat_default_iocharset) |
| kfree(opts->iocharset); |
| iocharset = match_strdup(&args[0]); |
| if (!iocharset) |
| return -ENOMEM; |
| opts->iocharset = iocharset; |
| break; |
| case Opt_shortname_lower: |
| opts->shortname = VFAT_SFN_DISPLAY_LOWER |
| | VFAT_SFN_CREATE_WIN95; |
| break; |
| case Opt_shortname_win95: |
| opts->shortname = VFAT_SFN_DISPLAY_WIN95 |
| | VFAT_SFN_CREATE_WIN95; |
| break; |
| case Opt_shortname_winnt: |
| opts->shortname = VFAT_SFN_DISPLAY_WINNT |
| | VFAT_SFN_CREATE_WINNT; |
| break; |
| case Opt_shortname_mixed: |
| opts->shortname = VFAT_SFN_DISPLAY_WINNT |
| | VFAT_SFN_CREATE_WIN95; |
| break; |
| case Opt_utf8_no: /* 0 or no or false */ |
| opts->utf8 = 0; |
| break; |
| case Opt_utf8_yes: /* empty or 1 or yes or true */ |
| opts->utf8 = 1; |
| break; |
| case Opt_uni_xl_no: /* 0 or no or false */ |
| opts->unicode_xlate = 0; |
| break; |
| case Opt_uni_xl_yes: /* empty or 1 or yes or true */ |
| opts->unicode_xlate = 1; |
| break; |
| case Opt_nonumtail_no: /* 0 or no or false */ |
| opts->numtail = 1; /* negated option */ |
| break; |
| case Opt_nonumtail_yes: /* empty or 1 or yes or true */ |
| opts->numtail = 0; /* negated option */ |
| break; |
| case Opt_rodir: |
| opts->rodir = 1; |
| break; |
| |
| /* obsolete mount options */ |
| case Opt_obsolate: |
| printk(KERN_INFO "FAT: \"%s\" option is obsolete, " |
| "not supported now\n", p); |
| break; |
| /* unknown option */ |
| default: |
| if (!silent) { |
| printk(KERN_ERR |
| "FAT: Unrecognized mount option \"%s\" " |
| "or missing value\n", p); |
| } |
| return -EINVAL; |
| } |
| } |
| |
| out: |
| /* UTF-8 doesn't provide FAT semantics */ |
| if (!strcmp(opts->iocharset, "utf8")) { |
| printk(KERN_ERR "FAT: utf8 is not a recommended IO charset" |
| " for FAT filesystems, filesystem will be " |
| "case sensitive!\n"); |
| } |
| |
| /* If user doesn't specify allow_utime, it's initialized from dmask. */ |
| if (opts->allow_utime == (unsigned short)-1) |
| opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); |
| if (opts->unicode_xlate) |
| opts->utf8 = 0; |
| |
| return 0; |
| } |
| |
| static int fat_read_root(struct inode *inode) |
| { |
| struct super_block *sb = inode->i_sb; |
| struct msdos_sb_info *sbi = MSDOS_SB(sb); |
| int error; |
| |
| MSDOS_I(inode)->i_pos = 0; |
| inode->i_uid = sbi->options.fs_uid; |
| inode->i_gid = sbi->options.fs_gid; |
| inode->i_version++; |
| inode->i_generation = 0; |
| inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); |
| inode->i_op = sbi->dir_ops; |
| inode->i_fop = &fat_dir_operations; |
| if (sbi->fat_bits == 32) { |
| MSDOS_I(inode)->i_start = sbi->root_cluster; |
| error = fat_calc_dir_size(inode); |
| if (error < 0) |
| return error; |
| } else { |
| MSDOS_I(inode)->i_start = 0; |
| inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); |
| } |
| inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) |
| & ~((loff_t)sbi->cluster_size - 1)) >> 9; |
| MSDOS_I(inode)->i_logstart = 0; |
| MSDOS_I(inode)->mmu_private = inode->i_size; |
| |
| fat_save_attrs(inode, ATTR_DIR); |
| inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; |
| inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; |
| inode->i_nlink = fat_subdirs(inode)+2; |
| |
| return 0; |
| } |
| |
| /* |
| * Read the super block of an MS-DOS FS. |
| */ |
| int fat_fill_super(struct super_block *sb, void *data, int silent, |
| const struct inode_operations *fs_dir_inode_ops, int isvfat) |
| { |
| struct inode *root_inode = NULL; |
| struct buffer_head *bh; |
| struct fat_boot_sector *b; |
| struct msdos_sb_info *sbi; |
| u16 logical_sector_size; |
| u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; |
| int debug; |
| unsigned int media; |
| long error; |
| char buf[50]; |
| |
| /* |
| * GFP_KERNEL is ok here, because while we do hold the |
| * supeblock lock, memory pressure can't call back into |
| * the filesystem, since we're only just about to mount |
| * it and have no inodes etc active! |
| */ |
| sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); |
| if (!sbi) |
| return -ENOMEM; |
| sb->s_fs_info = sbi; |
| |
| sb->s_flags |= MS_NODIRATIME; |
| sb->s_magic = MSDOS_SUPER_MAGIC; |
| sb->s_op = &fat_sops; |
| sb->s_export_op = &fat_export_ops; |
| sbi->dir_ops = fs_dir_inode_ops; |
| |
| error = parse_options(data, isvfat, silent, &debug, &sbi->options); |
| if (error) |
| goto out_fail; |
| |
| error = -EIO; |
| sb_min_blocksize(sb, 512); |
| bh = sb_bread(sb, 0); |
| if (bh == NULL) { |
| printk(KERN_ERR "FAT: unable to read boot sector\n"); |
| goto out_fail; |
| } |
| |
| b = (struct fat_boot_sector *) bh->b_data; |
| if (!b->reserved) { |
| if (!silent) |
| printk(KERN_ERR "FAT: bogus number of reserved sectors\n"); |
| brelse(bh); |
| goto out_invalid; |
| } |
| if (!b->fats) { |
| if (!silent) |
| printk(KERN_ERR "FAT: bogus number of FAT structure\n"); |
| brelse(bh); |
| goto out_invalid; |
| } |
| |
| /* |
| * Earlier we checked here that b->secs_track and b->head are nonzero, |
| * but it turns out valid FAT filesystems can have zero there. |
| */ |
| |
| media = b->media; |
| if (!fat_valid_media(media)) { |
| if (!silent) |
| printk(KERN_ERR "FAT: invalid media value (0x%02x)\n", |
| media); |
| brelse(bh); |
| goto out_invalid; |
| } |
| logical_sector_size = get_unaligned_le16(&b->sector_size); |
| if (!is_power_of_2(logical_sector_size) |
| || (logical_sector_size < 512) |
| || (logical_sector_size > 4096)) { |
| if (!silent) |
| printk(KERN_ERR "FAT: bogus logical sector size %u\n", |
| logical_sector_size); |
| brelse(bh); |
| goto out_invalid; |
| } |
| sbi->sec_per_clus = b->sec_per_clus; |
| if (!is_power_of_2(sbi->sec_per_clus)) { |
| if (!silent) |
| printk(KERN_ERR "FAT: bogus sectors per cluster %u\n", |
| sbi->sec_per_clus); |
| brelse(bh); |
| goto out_invalid; |
| } |
| |
| if (logical_sector_size < sb->s_blocksize) { |
| printk(KERN_ERR "FAT: logical sector size too small for device" |
| " (logical sector size = %u)\n", logical_sector_size); |
| brelse(bh); |
| goto out_fail; |
| } |
| if (logical_sector_size > sb->s_blocksize) { |
| brelse(bh); |
| |
| if (!sb_set_blocksize(sb, logical_sector_size)) { |
| printk(KERN_ERR "FAT: unable to set blocksize %u\n", |
| logical_sector_size); |
| goto out_fail; |
| } |
| bh = sb_bread(sb, 0); |
| if (bh == NULL) { |
| printk(KERN_ERR "FAT: unable to read boot sector" |
| " (logical sector size = %lu)\n", |
| sb->s_blocksize); |
| goto out_fail; |
| } |
| b = (struct fat_boot_sector *) bh->b_data; |
| } |
| |
| sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; |
| sbi->cluster_bits = ffs(sbi->cluster_size) - 1; |
| sbi->fats = b->fats; |
| sbi->fat_bits = 0; /* Don't know yet */ |
| sbi->fat_start = le16_to_cpu(b->reserved); |
| sbi->fat_length = le16_to_cpu(b->fat_length); |
| sbi->root_cluster = 0; |
| sbi->free_clusters = -1; /* Don't know yet */ |
| sbi->free_clus_valid = 0; |
| sbi->prev_free = FAT_START_ENT; |
| |
| if (!sbi->fat_length && b->fat32_length) { |
| struct fat_boot_fsinfo *fsinfo; |
| struct buffer_head *fsinfo_bh; |
| |
| /* Must be FAT32 */ |
| sbi->fat_bits = 32; |
| sbi->fat_length = le32_to_cpu(b->fat32_length); |
| sbi->root_cluster = le32_to_cpu(b->root_cluster); |
| |
| sb->s_maxbytes = 0xffffffff; |
| |
| /* MC - if info_sector is 0, don't multiply by 0 */ |
| sbi->fsinfo_sector = le16_to_cpu(b->info_sector); |
| if (sbi->fsinfo_sector == 0) |
| sbi->fsinfo_sector = 1; |
| |
| fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); |
| if (fsinfo_bh == NULL) { |
| printk(KERN_ERR "FAT: bread failed, FSINFO block" |
| " (sector = %lu)\n", sbi->fsinfo_sector); |
| brelse(bh); |
| goto out_fail; |
| } |
| |
| fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; |
| if (!IS_FSINFO(fsinfo)) { |
| printk(KERN_WARNING "FAT: Invalid FSINFO signature: " |
| "0x%08x, 0x%08x (sector = %lu)\n", |
| le32_to_cpu(fsinfo->signature1), |
| le32_to_cpu(fsinfo->signature2), |
| sbi->fsinfo_sector); |
| } else { |
| if (sbi->options.usefree) |
| sbi->free_clus_valid = 1; |
| sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); |
| sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); |
| } |
| |
| brelse(fsinfo_bh); |
| } |
| |
| sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); |
| sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; |
| |
| sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; |
| sbi->dir_entries = get_unaligned_le16(&b->dir_entries); |
| if (sbi->dir_entries & (sbi->dir_per_block - 1)) { |
| if (!silent) |
| printk(KERN_ERR "FAT: bogus directroy-entries per block" |
| " (%u)\n", sbi->dir_entries); |
| brelse(bh); |
| goto out_invalid; |
| } |
| |
| rootdir_sectors = sbi->dir_entries |
| * sizeof(struct msdos_dir_entry) / sb->s_blocksize; |
| sbi->data_start = sbi->dir_start + rootdir_sectors; |
| total_sectors = get_unaligned_le16(&b->sectors); |
| if (total_sectors == 0) |
| total_sectors = le32_to_cpu(b->total_sect); |
| |
| total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; |
| |
| if (sbi->fat_bits != 32) |
| sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; |
| |
| /* check that FAT table does not overflow */ |
| fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; |
| total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); |
| if (total_clusters > MAX_FAT(sb)) { |
| if (!silent) |
| printk(KERN_ERR "FAT: count of clusters too big (%u)\n", |
| total_clusters); |
| brelse(bh); |
| goto out_invalid; |
| } |
| |
| sbi->max_cluster = total_clusters + FAT_START_ENT; |
| /* check the free_clusters, it's not necessarily correct */ |
| if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) |
| sbi->free_clusters = -1; |
| /* check the prev_free, it's not necessarily correct */ |
| sbi->prev_free %= sbi->max_cluster; |
| if (sbi->prev_free < FAT_START_ENT) |
| sbi->prev_free = FAT_START_ENT; |
| |
| brelse(bh); |
| |
| /* set up enough so that it can read an inode */ |
| fat_hash_init(sb); |
| fat_ent_access_init(sb); |
| |
| /* |
| * The low byte of FAT's first entry must have same value with |
| * media-field. But in real world, too many devices is |
| * writing wrong value. So, removed that validity check. |
| * |
| * if (FAT_FIRST_ENT(sb, media) != first) |
| */ |
| |
| error = -EINVAL; |
| sprintf(buf, "cp%d", sbi->options.codepage); |
| sbi->nls_disk = load_nls(buf); |
| if (!sbi->nls_disk) { |
| printk(KERN_ERR "FAT: codepage %s not found\n", buf); |
| goto out_fail; |
| } |
| |
| /* FIXME: utf8 is using iocharset for upper/lower conversion */ |
| if (sbi->options.isvfat) { |
| sbi->nls_io = load_nls(sbi->options.iocharset); |
| if (!sbi->nls_io) { |
| printk(KERN_ERR "FAT: IO charset %s not found\n", |
| sbi->options.iocharset); |
| goto out_fail; |
| } |
| } |
| |
| error = -ENOMEM; |
| root_inode = new_inode(sb); |
| if (!root_inode) |
| goto out_fail; |
| root_inode->i_ino = MSDOS_ROOT_INO; |
| root_inode->i_version = 1; |
| error = fat_read_root(root_inode); |
| if (error < 0) |
| goto out_fail; |
| error = -ENOMEM; |
| insert_inode_hash(root_inode); |
| sb->s_root = d_alloc_root(root_inode); |
| if (!sb->s_root) { |
| printk(KERN_ERR "FAT: get root inode failed\n"); |
| goto out_fail; |
| } |
| |
| return 0; |
| |
| out_invalid: |
| error = -EINVAL; |
| if (!silent) |
| printk(KERN_INFO "VFS: Can't find a valid FAT filesystem" |
| " on dev %s.\n", sb->s_id); |
| |
| out_fail: |
| if (root_inode) |
| iput(root_inode); |
| if (sbi->nls_io) |
| unload_nls(sbi->nls_io); |
| if (sbi->nls_disk) |
| unload_nls(sbi->nls_disk); |
| if (sbi->options.iocharset != fat_default_iocharset) |
| kfree(sbi->options.iocharset); |
| sb->s_fs_info = NULL; |
| kfree(sbi); |
| return error; |
| } |
| |
| EXPORT_SYMBOL_GPL(fat_fill_super); |
| |
| /* |
| * helper function for fat_flush_inodes. This writes both the inode |
| * and the file data blocks, waiting for in flight data blocks before |
| * the start of the call. It does not wait for any io started |
| * during the call |
| */ |
| static int writeback_inode(struct inode *inode) |
| { |
| |
| int ret; |
| struct address_space *mapping = inode->i_mapping; |
| struct writeback_control wbc = { |
| .sync_mode = WB_SYNC_NONE, |
| .nr_to_write = 0, |
| }; |
| /* if we used WB_SYNC_ALL, sync_inode waits for the io for the |
| * inode to finish. So WB_SYNC_NONE is sent down to sync_inode |
| * and filemap_fdatawrite is used for the data blocks |
| */ |
| ret = sync_inode(inode, &wbc); |
| if (!ret) |
| ret = filemap_fdatawrite(mapping); |
| return ret; |
| } |
| |
| /* |
| * write data and metadata corresponding to i1 and i2. The io is |
| * started but we do not wait for any of it to finish. |
| * |
| * filemap_flush is used for the block device, so if there is a dirty |
| * page for a block already in flight, we will not wait and start the |
| * io over again |
| */ |
| int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) |
| { |
| int ret = 0; |
| if (!MSDOS_SB(sb)->options.flush) |
| return 0; |
| if (i1) |
| ret = writeback_inode(i1); |
| if (!ret && i2) |
| ret = writeback_inode(i2); |
| if (!ret) { |
| struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; |
| ret = filemap_flush(mapping); |
| } |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(fat_flush_inodes); |
| |
| static int __init init_fat_fs(void) |
| { |
| int err; |
| |
| err = fat_cache_init(); |
| if (err) |
| return err; |
| |
| err = fat_init_inodecache(); |
| if (err) |
| goto failed; |
| |
| return 0; |
| |
| failed: |
| fat_cache_destroy(); |
| return err; |
| } |
| |
| static void __exit exit_fat_fs(void) |
| { |
| fat_cache_destroy(); |
| fat_destroy_inodecache(); |
| } |
| |
| module_init(init_fat_fs) |
| module_exit(exit_fat_fs) |
| |
| MODULE_LICENSE("GPL"); |