/* * 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 #include #include #include #include #include #include #include #include #include #include #include /* * 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. */ #define FAT_HASH_BITS 8 #define FAT_HASH_SIZE (1UL << FAT_HASH_BITS) #define FAT_HASH_MASK (FAT_HASH_SIZE-1) static struct list_head fat_inode_hashtable[FAT_HASH_SIZE]; spinlock_t fat_inode_lock = SPIN_LOCK_UNLOCKED; void fat_hash_init(void) { int i; for(i = 0; i < FAT_HASH_SIZE; i++) { INIT_LIST_HEAD(&fat_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) { spin_lock(&fat_inode_lock); MSDOS_I(inode)->i_pos = i_pos; list_add(&MSDOS_I(inode)->i_fat_hash, fat_inode_hashtable + fat_hash(inode->i_sb, i_pos)); spin_unlock(&fat_inode_lock); } void fat_detach(struct inode *inode) { spin_lock(&fat_inode_lock); MSDOS_I(inode)->i_pos = 0; list_del_init(&MSDOS_I(inode)->i_fat_hash); spin_unlock(&fat_inode_lock); } struct inode *fat_iget(struct super_block *sb, loff_t i_pos) { struct list_head *p = fat_inode_hashtable + fat_hash(sb, i_pos); struct list_head *walk; struct msdos_inode_info *i; struct inode *inode = NULL; spin_lock(&fat_inode_lock); list_for_each(walk, p) { i = list_entry(walk, struct msdos_inode_info, i_fat_hash); if (i->vfs_inode.i_sb != sb) continue; if (i->i_pos != i_pos) continue; inode = igrab(&i->vfs_inode); if (inode) break; } spin_unlock(&fat_inode_lock); return inode; } static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de); struct inode *fat_build_inode(struct super_block *sb, struct msdos_dir_entry *de, loff_t i_pos, int *res) { struct inode *inode; *res = 0; inode = fat_iget(sb, i_pos); if (inode) goto out; inode = new_inode(sb); *res = -ENOMEM; if (!inode) goto out; inode->i_ino = iunique(sb, MSDOS_ROOT_INO); inode->i_version = 1; *res = fat_fill_inode(inode, de); if (*res < 0) { iput(inode); inode = NULL; goto out; } fat_attach(inode, i_pos); insert_inode_hash(inode); out: return inode; } void fat_delete_inode(struct inode *inode) { if (!is_bad_inode(inode)) { inode->i_size = 0; fat_truncate(inode); } clear_inode(inode); } void fat_clear_inode(struct inode *inode) { if (is_bad_inode(inode)) return; lock_kernel(); spin_lock(&fat_inode_lock); fat_cache_inval_inode(inode); list_del_init(&MSDOS_I(inode)->i_fat_hash); spin_unlock(&fat_inode_lock); unlock_kernel(); } 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 = 0; } if (sbi->nls_io) { unload_nls(sbi->nls_io); sbi->nls_io = NULL; } /* * Note: the iocharset option might have been specified * without enabling nls_io, so check for it here. */ if (sbi->options.iocharset) { kfree(sbi->options.iocharset); sbi->options.iocharset = NULL; } sb->s_fs_info = NULL; kfree(sbi); } 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 && strcmp(sbi->nls_io->charset, CONFIG_NLS_DEFAULT)) 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; 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 = 0; opts->iocharset = NULL; 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 1; 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: kfree(opts->iocharset); opts->iocharset = match_strdup(&args[0]); if (!opts->iocharset) return 0; 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 0; } } if (opts->unicode_xlate) opts->utf8 = 0; return 1; } 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; } 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)->file_cluster = MSDOS_I(inode)->disk_cluster = 0; 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 = 0; 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; MSDOS_I(inode)->i_ctime_ms = 0; inode->i_nlink = fat_subdirs(inode)+2; return 0; } /* * 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. */ 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); } 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; } 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; } struct dentry *fat_get_parent(struct dentry *child) { struct buffer_head *bh=NULL; struct msdos_dir_entry *de = NULL; struct dentry *parent = NULL; int res; loff_t i_pos = 0; struct inode *inode; lock_kernel(); res = fat_scan(child->d_inode, MSDOS_DOTDOT, &bh, &de, &i_pos); if (res < 0) goto out; inode = fat_build_inode(child->d_sb, de, i_pos, &res); if (res) goto out; if (!inode) res = -EACCES; else { parent = d_alloc_anon(inode); if (!parent) { iput(inode); res = -ENOMEM; } } out: if(bh) brelse(bh); unlock_kernel(); if (res) return ERR_PTR(res); else return parent; } static kmem_cache_t *fat_inode_cachep; static struct inode *fat_alloc_inode(struct super_block *sb) { struct msdos_inode_info *ei; ei = (struct msdos_inode_info *)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) { INIT_LIST_HEAD(&ei->i_fat_hash); inode_init_once(&ei->vfs_inode); } } int __init fat_init_inodecache(void) { fat_inode_cachep = kmem_cache_create("fat_inode_cache", sizeof(struct msdos_inode_info), 0, SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT, init_once, NULL); if (fat_inode_cachep == NULL) return -ENOMEM; return 0; } 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) { *flags |= MS_NODIRATIME; return 0; } 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, }; 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, }; /* * 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, cp, first; 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 = -EINVAL; if (!parse_options(data, isvfat, &debug, &sbi->options)) goto out_fail; fat_cache_init(sb); /* set up enough so that it can read an inode */ init_MUTEX(&sbi->fat_lock); 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; } if (!b->secs_track) { if (!silent) printk(KERN_ERR "FAT: bogus sectors-per-track value\n"); brelse(bh); goto out_invalid; } if (!b->heads) { if (!silent) printk(KERN_ERR "FAT: bogus number-of-heads value\n"); brelse(bh); goto out_invalid; } 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 = CF_LE_W(get_unaligned((u16 *)&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 = CF_LE_W(b->reserved); sbi->fat_length = CF_LE_W(b->fat_length); sbi->root_cluster = 0; sbi->free_clusters = -1; /* Don't know yet */ sbi->prev_free = -1; 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 = CF_LE_L(b->fat32_length); sbi->root_cluster = CF_LE_L(b->root_cluster); sb->s_maxbytes = 0xffffffff; /* MC - if info_sector is 0, don't multiply by 0 */ sbi->fsinfo_sector = CF_LE_W(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", CF_LE_L(fsinfo->signature1), CF_LE_L(fsinfo->signature2), sbi->fsinfo_sector); } else { sbi->free_clusters = CF_LE_L(fsinfo->free_clusters); sbi->prev_free = CF_LE_L(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 = CF_LE_W(get_unaligned((u16 *)&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 = CF_LE_W(get_unaligned((u16 *)&b->sectors)); if (total_sectors == 0) total_sectors = CF_LE_L(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 - 2); 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->clusters = total_clusters; brelse(bh); /* validity check of FAT */ first = __fat_access(sb, 0, -1); if (first < 0) { error = first; goto out_fail; } if (FAT_FIRST_ENT(sb, media) == first) { /* all is as it should be */ } else if (media == 0xf8 && FAT_FIRST_ENT(sb, 0xfe) == first) { /* bad, reported on pc9800 */ } else if (media == 0xf0 && FAT_FIRST_ENT(sb, 0xf8) == first) { /* bad, reported with a MO disk on win95/me */ } else if (first == 0) { /* bad, reported with a SmartMedia card */ } else { if (!silent) printk(KERN_ERR "FAT: invalid first entry of FAT " "(0x%x != 0x%x)\n", FAT_FIRST_ENT(sb, media), first); goto out_invalid; } error = -EINVAL; cp = sbi->options.codepage ? sbi->options.codepage : 437; sprintf(buf, "cp%d", cp); sbi->nls_disk = load_nls(buf); if (!sbi->nls_disk) { /* Fail only if explicit charset specified */ if (sbi->options.codepage != 0) { printk(KERN_ERR "FAT: codepage %s not found\n", buf); goto out_fail; } sbi->options.codepage = 0; /* already 0?? */ sbi->nls_disk = load_nls_default(); } /* FIXME: utf8 is using iocharset for upper/lower conversion */ if (sbi->options.isvfat) { if (sbi->options.iocharset != NULL) { 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; } } else sbi->nls_io = load_nls_default(); } 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) kfree(sbi->options.iocharset); sb->s_fs_info = NULL; kfree(sbi); return error; } int fat_statfs(struct super_block *sb, struct kstatfs *buf) { int free, nr, ret; if (MSDOS_SB(sb)->free_clusters != -1) free = MSDOS_SB(sb)->free_clusters; else { lock_fat(sb); if (MSDOS_SB(sb)->free_clusters != -1) free = MSDOS_SB(sb)->free_clusters; else { free = 0; for (nr = 2; nr < MSDOS_SB(sb)->clusters + 2; nr++) { ret = fat_access(sb, nr, -1); if (ret < 0) { unlock_fat(sb); return ret; } else if (ret == FAT_ENT_FREE) free++; } MSDOS_SB(sb)->free_clusters = free; } unlock_fat(sb); } buf->f_type = sb->s_magic; buf->f_bsize = MSDOS_SB(sb)->cluster_size; buf->f_blocks = MSDOS_SB(sb)->clusters; buf->f_bfree = free; buf->f_bavail = free; buf->f_namelen = MSDOS_SB(sb)->options.isvfat ? 260 : 12; return 0; } 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_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) { kmap(page); return cont_prepare_write(page,from,to,fat_get_block, &MSDOS_I(page->mapping->host)->mmu_private); } static int fat_commit_write(struct file *file, struct page *page, unsigned from, unsigned to) { kunmap(page); return generic_commit_write(file, page, from, to); } 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 = fat_commit_write, .bmap = _fat_bmap }; /* doesn't deal with root inode */ static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) { struct super_block *sb = inode->i_sb; struct msdos_sb_info *sbi = MSDOS_SB(sb); int error; MSDOS_I(inode)->file_cluster = MSDOS_I(inode)->disk_cluster = 0; 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 = CF_LE_W(de->start); if (sbi->fat_bits == 32) MSDOS_I(inode)->i_start |= (CF_LE_W(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 = CF_LE_W(de->start); if (sbi->fat_bits == 32) MSDOS_I(inode)->i_start |= (CF_LE_W(de->starthi) << 16); MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; inode->i_size = CF_LE_L(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(CF_LE_W(de->time),CF_LE_W(de->date)); inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = 0; inode->i_ctime.tv_sec = MSDOS_SB(sb)->options.isvfat ? date_dos2unix(CF_LE_W(de->ctime),CF_LE_W(de->cdate)) : inode->i_mtime.tv_sec; inode->i_ctime.tv_nsec = de->ctime_ms * 1000000; MSDOS_I(inode)->i_ctime_ms = de->ctime_ms; return 0; } void fat_write_inode(struct inode *inode, int wait) { struct super_block *sb = inode->i_sb; struct buffer_head *bh; struct msdos_dir_entry *raw_entry; loff_t i_pos; retry: i_pos = MSDOS_I(inode)->i_pos; if (inode->i_ino == MSDOS_ROOT_INO || !i_pos) { return; } lock_kernel(); if (!(bh = sb_bread(sb, i_pos >> MSDOS_SB(sb)->dir_per_block_bits))) { printk(KERN_ERR "FAT: unable to read inode block " "for updating (i_pos %lld)\n", i_pos); unlock_kernel(); return /* -EIO */; } spin_lock(&fat_inode_lock); if (i_pos != MSDOS_I(inode)->i_pos) { spin_unlock(&fat_inode_lock); brelse(bh); unlock_kernel(); goto retry; } raw_entry = &((struct msdos_dir_entry *) (bh->b_data)) [i_pos & (MSDOS_SB(sb)->dir_per_block - 1)]; if (S_ISDIR(inode->i_mode)) { raw_entry->attr = ATTR_DIR; raw_entry->size = 0; } else { raw_entry->attr = ATTR_NONE; raw_entry->size = CT_LE_L(inode->i_size); } raw_entry->attr |= MSDOS_MKATTR(inode->i_mode) | MSDOS_I(inode)->i_attrs; raw_entry->start = CT_LE_W(MSDOS_I(inode)->i_logstart); raw_entry->starthi = CT_LE_W(MSDOS_I(inode)->i_logstart >> 16); fat_date_unix2dos(inode->i_mtime.tv_sec,&raw_entry->time,&raw_entry->date); raw_entry->time = CT_LE_W(raw_entry->time); raw_entry->date = CT_LE_W(raw_entry->date); if (MSDOS_SB(sb)->options.isvfat) { fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate); raw_entry->ctime_ms = MSDOS_I(inode)->i_ctime_ms; /* use i_ctime.tv_nsec? */ raw_entry->ctime = CT_LE_W(raw_entry->ctime); raw_entry->cdate = CT_LE_W(raw_entry->cdate); } spin_unlock(&fat_inode_lock); mark_buffer_dirty(bh); brelse(bh); unlock_kernel(); } int fat_notify_change(struct dentry * dentry, struct iattr * attr) { struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb); struct inode *inode = dentry->d_inode; int mask, error = 0; lock_kernel(); /* FAT cannot truncate to a longer file */ if (attr->ia_valid & ATTR_SIZE) { if (attr->ia_size > inode->i_size) { error = -EPERM; goto out; } } error = inode_change_ok(inode, attr); if (error) { if (sbi->options.quiet) error = 0; goto out; } if (((attr->ia_valid & ATTR_UID) && (attr->ia_uid != sbi->options.fs_uid)) || ((attr->ia_valid & ATTR_GID) && (attr->ia_gid != sbi->options.fs_gid)) || ((attr->ia_valid & ATTR_MODE) && (attr->ia_mode & ~MSDOS_VALID_MODE))) error = -EPERM; if (error) { if (sbi->options.quiet) error = 0; goto out; } error = inode_setattr(inode, attr); if (error) goto out; if (S_ISDIR(inode->i_mode)) mask = sbi->options.fs_dmask; else mask = sbi->options.fs_fmask; inode->i_mode &= S_IFMT | (S_IRWXUGO & ~mask); out: unlock_kernel(); return error; } MODULE_LICENSE("GPL");