diff options
Diffstat (limited to 'fs/fat/inode.c')
-rw-r--r-- | fs/fat/inode.c | 1351 |
1 files changed, 1351 insertions, 0 deletions
diff --git a/fs/fat/inode.c b/fs/fat/inode.c new file mode 100644 index 0000000..8ccee84 --- /dev/null +++ b/fs/fat/inode.c @@ -0,0 +1,1351 @@ +/* + * 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/msdos_fs.h> +#include <linux/pagemap.h> +#include <linux/buffer_head.h> +#include <linux/mount.h> +#include <linux/vfs.h> +#include <linux/parser.h> +#include <asm/unaligned.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 int fat_get_block(struct inode *inode, sector_t iblock, + struct buffer_head *bh_result, int create) +{ + struct super_block *sb = inode->i_sb; + sector_t phys; + int err; + + err = fat_bmap(inode, iblock, &phys); + if (err) + return err; + if (phys) { + map_bh(bh_result, sb, phys); + 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; + } + if (!((unsigned long)iblock & (MSDOS_SB(sb)->sec_per_clus - 1))) { + err = fat_add_cluster(inode); + if (err) + return err; + } + MSDOS_I(inode)->mmu_private += sb->s_blocksize; + err = fat_bmap(inode, iblock, &phys); + if (err) + return err; + if (!phys) + BUG(); + set_buffer_new(bh_result); + map_bh(bh_result, sb, phys); + 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_readpage(struct file *file, struct page *page) +{ + return block_read_full_page(page, fat_get_block); +} + +static int fat_prepare_write(struct file *file, struct page *page, + unsigned from, unsigned to) +{ + return cont_prepare_write(page, from, to, fat_get_block, + &MSDOS_I(page->mapping->host)->mmu_private); +} + +static sector_t _fat_bmap(struct address_space *mapping, sector_t block) +{ + return generic_block_bmap(mapping, block, fat_get_block); +} + +static struct address_space_operations fat_aops = { + .readpage = fat_readpage, + .writepage = fat_writepage, + .sync_page = block_sync_page, + .prepare_write = fat_prepare_write, + .commit_write = generic_commit_write, + .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(struct super_block *sb, loff_t i_pos) +{ + unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb; + tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2); + return tmp & FAT_HASH_MASK; +} + +void fat_attach(struct inode *inode, loff_t i_pos) +{ + struct super_block *sb = inode->i_sb; + struct msdos_sb_info *sbi = MSDOS_SB(sb); + + spin_lock(&sbi->inode_hash_lock); + MSDOS_I(inode)->i_pos = i_pos; + hlist_add_head(&MSDOS_I(inode)->i_fat_hash, + sbi->inode_hashtable + fat_hash(sb, i_pos)); + spin_unlock(&sbi->inode_hash_lock); +} + +EXPORT_SYMBOL(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(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(sb, 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 = MSDOS_MKMODE(de->attr, + S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR; + 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 = MSDOS_MKMODE(de->attr, + ((sbi->options.showexec && + !is_exec(de->ext)) + ? S_IRUGO|S_IWUGO : S_IRWXUGO) + & ~sbi->options.fs_fmask) | S_IFREG; + 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; + } + MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED; + /* this is as close to the truth as we can get ... */ + inode->i_blksize = sbi->cluster_size; + inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) + & ~((loff_t)sbi->cluster_size - 1)) >> 9; + inode->i_mtime.tv_sec = inode->i_atime.tv_sec = + date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date)); + inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = 0; + if (sbi->options.isvfat) { + int secs = de->ctime_cs / 100; + int csecs = de->ctime_cs % 100; + inode->i_ctime.tv_sec = + date_dos2unix(le16_to_cpu(de->ctime), + le16_to_cpu(de->cdate)) + secs; + inode->i_ctime.tv_nsec = csecs * 10000000; + } else + inode->i_ctime = 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(fat_build_inode); + +static void fat_delete_inode(struct inode *inode) +{ + if (!is_bad_inode(inode)) { + inode->i_size = 0; + fat_truncate(inode); + } + clear_inode(inode); +} + +static void fat_clear_inode(struct inode *inode) +{ + struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); + + if (is_bad_inode(inode)) + return; + lock_kernel(); + spin_lock(&sbi->inode_hash_lock); + fat_cache_inval_inode(inode); + hlist_del_init(&MSDOS_I(inode)->i_fat_hash); + spin_unlock(&sbi->inode_hash_lock); + unlock_kernel(); +} + +static void fat_put_super(struct super_block *sb) +{ + struct msdos_sb_info *sbi = MSDOS_SB(sb); + + if (!(sb->s_flags & MS_RDONLY)) + fat_clusters_flush(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 kmem_cache_t *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, SLAB_KERNEL); + 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, kmem_cache_t * cachep, unsigned long flags) +{ + struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; + + if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == + SLAB_CTOR_CONSTRUCTOR) { + 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, + init_once, NULL); + if (fat_inode_cachep == NULL) + return -ENOMEM; + return 0; +} + +static void __exit fat_destroy_inodecache(void) +{ + if (kmem_cache_destroy(fat_inode_cachep)) + printk(KERN_INFO "fat_inode_cache: not all structures were freed\n"); +} + +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 super_block *sb, struct kstatfs *buf) +{ + struct msdos_sb_info *sbi = MSDOS_SB(sb); + + /* If the count of free cluster is still unknown, counts it here. */ + if (sbi->free_clusters == -1) { + int err = fat_count_free_clusters(sb); + if (err) + return err; + } + + buf->f_type = 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 = 0; + +retry: + i_pos = MSDOS_I(inode)->i_pos; + if (inode->i_ino == MSDOS_ROOT_INO || !i_pos) + return 0; + + lock_kernel(); + 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); + err = -EIO; + goto out; + } + spin_lock(&sbi->inode_hash_lock); + if (i_pos != MSDOS_I(inode)->i_pos) { + spin_unlock(&sbi->inode_hash_lock); + brelse(bh); + unlock_kernel(); + 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_attr(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_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date); + if (sbi->options.isvfat) { + fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate); + raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 + + inode->i_ctime.tv_nsec / 10000000; + } + spin_unlock(&sbi->inode_hash_lock); + mark_buffer_dirty(bh); + if (wait) + err = sync_dirty_buffer(bh); + brelse(bh); +out: + unlock_kernel(); + return err; +} + +int fat_sync_inode(struct inode *inode) +{ + return fat_write_inode(inode, 1); +} + +EXPORT_SYMBOL(fat_sync_inode); + +static int fat_show_options(struct seq_file *m, struct vfsmount *mnt); +static 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, + .statfs = fat_statfs, + .clear_inode = fat_clear_inode, + .remount_fs = fat_remount, + + .read_inode = make_bad_inode, + + .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_decode_fh(struct super_block *sb, __u32 *fh, int len, int fhtype, + int (*acceptable)(void *context, struct dentry *de), + void *context) +{ + if (fhtype != 3) + return ERR_PTR(-ESTALE); + if (len < 5) + return ERR_PTR(-ESTALE); + + return sb->s_export_op->find_exported_dentry(sb, fh, NULL, acceptable, context); +} + +static struct dentry *fat_get_dentry(struct super_block *sb, void *inump) +{ + struct inode *inode = NULL; + struct dentry *result; + __u32 *fh = inump; + + inode = iget(sb, fh[0]); + if (!inode || is_bad_inode(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; + } + } + if (!inode) { + /* For now, do nothing + * What we could do is: + * follow the file starting at fh[4], and record + * the ".." entry, and the name of the fh[2] entry. + * The 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 weare totally out of luck + * But all that is for another day + */ + } + if (!inode) + return ERR_PTR(-ESTALE); + + + /* now to find a dentry. + * If possible, get a well-connected one + */ + result = d_alloc_anon(inode); + if (result == NULL) { + iput(inode); + return ERR_PTR(-ENOMEM); + } + 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 buffer_head *bh; + struct msdos_dir_entry *de; + loff_t i_pos; + struct dentry *parent; + struct inode *inode; + int err; + + lock_kernel(); + + err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos); + if (err) { + parent = ERR_PTR(err); + goto out; + } + inode = fat_build_inode(child->d_sb, de, i_pos); + brelse(bh); + if (IS_ERR(inode)) { + parent = ERR_PTR(PTR_ERR(inode)); + goto out; + } + parent = d_alloc_anon(inode); + if (!parent) { + iput(inode); + parent = ERR_PTR(-ENOMEM); + } +out: + unlock_kernel(); + + return parent; +} + +static struct export_operations fat_export_ops = { + .decode_fh = fat_decode_fh, + .encode_fh = fat_encode_fh, + .get_dentry = fat_get_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 (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->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"); + } + + return 0; +} + +enum { + Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, + Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, 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_err, +}; + +static 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_codepage, "codepage=%u"}, + {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_err, NULL} +}; +static match_table_t msdos_tokens = { + {Opt_nodots, "nodots"}, + {Opt_nodots, "dotsOK=no"}, + {Opt_dots, "dots"}, + {Opt_dots, "dotsOK=yes"}, + {Opt_err, NULL} +}; +static 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_err, NULL} +}; + +static int parse_options(char *options, int is_vfat, 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->codepage = fat_default_codepage; + opts->iocharset = fat_default_iocharset; + if (is_vfat) + opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95; + else + opts->shortname = 0; + opts->name_check = 'n'; + opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; + opts->utf8 = opts->unicode_xlate = 0; + opts->numtail = 1; + opts->nocase = 0; + *debug = 0; + + if (!options) + return 0; + + 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_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_codepage: + if (match_int(&args[0], &option)) + return 0; + opts->codepage = option; + 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; + + /* obsolete mount options */ + case Opt_obsolate: + printk(KERN_INFO "FAT: \"%s\" option is obsolete, " + "not supported now\n", p); + break; + /* unknown option */ + default: + printk(KERN_ERR "FAT: Unrecognized mount option \"%s\" " + "or missing value\n", p); + return -EINVAL; + } + } + /* UTF8 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 (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 = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR; + 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_blksize = sbi->cluster_size; + 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; + + MSDOS_I(inode)->i_attrs = ATTR_NONE; + 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, + 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]; + + sbi = kmalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); + if (!sbi) + return -ENOMEM; + sb->s_fs_info = sbi; + memset(sbi, 0, sizeof(struct msdos_sb_info)); + + 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, &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 = + le16_to_cpu(get_unaligned((__le16 *)&b->sector_size)); + if (!logical_sector_size + || (logical_sector_size & (logical_sector_size - 1)) + || (logical_sector_size < 512) + || (PAGE_CACHE_SIZE < logical_sector_size)) { + 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 (!sbi->sec_per_clus + || (sbi->sec_per_clus & (sbi->sec_per_clus - 1))) { + 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->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: Did not find valid FSINFO signature.\n" + " Found signature1 0x%08x signature2 0x%08x" + " (sector = %lu)\n", + le32_to_cpu(fsinfo->signature1), + le32_to_cpu(fsinfo->signature2), + sbi->fsinfo_sector); + } else { + 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 = + le16_to_cpu(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 = le16_to_cpu(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(fat_fill_super); + +int __init fat_cache_init(void); +void __exit fat_cache_destroy(void); + +static int __init init_fat_fs(void) +{ + int ret; + + ret = fat_cache_init(); + if (ret < 0) + return ret; + return fat_init_inodecache(); +} + +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"); |