/* * linux/fs/ext2/super.c * * Copyright (C) 1992, 1993, 1994, 1995 * Remy Card (card@masi.ibp.fr) * Laboratoire MASI - Institut Blaise Pascal * Universite Pierre et Marie Curie (Paris VI) * * from * * linux/fs/minix/inode.c * * Copyright (C) 1991, 1992 Linus Torvalds * * Big-endian to little-endian byte-swapping/bitmaps by * David S. Miller (davem@caip.rutgers.edu), 1995 */ #include <linux/config.h> #include <linux/module.h> #include <linux/string.h> #include <linux/fs.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/blkdev.h> #include <linux/parser.h> #include <linux/random.h> #include <linux/buffer_head.h> #include <linux/smp_lock.h> #include <linux/vfs.h> #include <linux/seq_file.h> #include <linux/mount.h> #include <asm/uaccess.h> #include "ext2.h" #include "xattr.h" #include "acl.h" #include "xip.h" static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es); static int ext2_remount (struct super_block * sb, int * flags, char * data); static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf); void ext2_error (struct super_block * sb, const char * function, const char * fmt, ...) { va_list args; struct ext2_sb_info *sbi = EXT2_SB(sb); struct ext2_super_block *es = sbi->s_es; if (!(sb->s_flags & MS_RDONLY)) { sbi->s_mount_state |= EXT2_ERROR_FS; es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS); ext2_sync_super(sb, es); } va_start(args, fmt); printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function); vprintk(fmt, args); printk("\n"); va_end(args); if (test_opt(sb, ERRORS_PANIC)) panic("EXT2-fs panic from previous error\n"); if (test_opt(sb, ERRORS_RO)) { printk("Remounting filesystem read-only\n"); sb->s_flags |= MS_RDONLY; } } void ext2_warning (struct super_block * sb, const char * function, const char * fmt, ...) { va_list args; va_start(args, fmt); printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ", sb->s_id, function); vprintk(fmt, args); printk("\n"); va_end(args); } void ext2_update_dynamic_rev(struct super_block *sb) { struct ext2_super_block *es = EXT2_SB(sb)->s_es; if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV) return; ext2_warning(sb, __FUNCTION__, "updating to rev %d because of new feature flag, " "running e2fsck is recommended", EXT2_DYNAMIC_REV); es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO); es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE); es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV); /* leave es->s_feature_*compat flags alone */ /* es->s_uuid will be set by e2fsck if empty */ /* * The rest of the superblock fields should be zero, and if not it * means they are likely already in use, so leave them alone. We * can leave it up to e2fsck to clean up any inconsistencies there. */ } static void ext2_put_super (struct super_block * sb) { int db_count; int i; struct ext2_sb_info *sbi = EXT2_SB(sb); ext2_xattr_put_super(sb); if (!(sb->s_flags & MS_RDONLY)) { struct ext2_super_block *es = sbi->s_es; es->s_state = cpu_to_le16(sbi->s_mount_state); ext2_sync_super(sb, es); } db_count = sbi->s_gdb_count; for (i = 0; i < db_count; i++) if (sbi->s_group_desc[i]) brelse (sbi->s_group_desc[i]); kfree(sbi->s_group_desc); kfree(sbi->s_debts); percpu_counter_destroy(&sbi->s_freeblocks_counter); percpu_counter_destroy(&sbi->s_freeinodes_counter); percpu_counter_destroy(&sbi->s_dirs_counter); brelse (sbi->s_sbh); sb->s_fs_info = NULL; kfree(sbi); return; } static kmem_cache_t * ext2_inode_cachep; static struct inode *ext2_alloc_inode(struct super_block *sb) { struct ext2_inode_info *ei; ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, SLAB_KERNEL); if (!ei) return NULL; #ifdef CONFIG_EXT2_FS_POSIX_ACL ei->i_acl = EXT2_ACL_NOT_CACHED; ei->i_default_acl = EXT2_ACL_NOT_CACHED; #endif ei->vfs_inode.i_version = 1; return &ei->vfs_inode; } static void ext2_destroy_inode(struct inode *inode) { kmem_cache_free(ext2_inode_cachep, EXT2_I(inode)); } static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) { struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == SLAB_CTOR_CONSTRUCTOR) { rwlock_init(&ei->i_meta_lock); #ifdef CONFIG_EXT2_FS_XATTR init_rwsem(&ei->xattr_sem); #endif inode_init_once(&ei->vfs_inode); } } static int init_inodecache(void) { ext2_inode_cachep = kmem_cache_create("ext2_inode_cache", sizeof(struct ext2_inode_info), 0, (SLAB_RECLAIM_ACCOUNT| SLAB_MEM_SPREAD), init_once, NULL); if (ext2_inode_cachep == NULL) return -ENOMEM; return 0; } static void destroy_inodecache(void) { if (kmem_cache_destroy(ext2_inode_cachep)) printk(KERN_INFO "ext2_inode_cache: not all structures were freed\n"); } static void ext2_clear_inode(struct inode *inode) { #ifdef CONFIG_EXT2_FS_POSIX_ACL struct ext2_inode_info *ei = EXT2_I(inode); if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) { posix_acl_release(ei->i_acl); ei->i_acl = EXT2_ACL_NOT_CACHED; } if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) { posix_acl_release(ei->i_default_acl); ei->i_default_acl = EXT2_ACL_NOT_CACHED; } #endif } static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) { struct ext2_sb_info *sbi = EXT2_SB(vfs->mnt_sb); if (sbi->s_mount_opt & EXT2_MOUNT_GRPID) seq_puts(seq, ",grpid"); #if defined(CONFIG_QUOTA) if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA) seq_puts(seq, ",usrquota"); if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA) seq_puts(seq, ",grpquota"); #endif #if defined(CONFIG_EXT2_FS_XIP) if (sbi->s_mount_opt & EXT2_MOUNT_XIP) seq_puts(seq, ",xip"); #endif return 0; } #ifdef CONFIG_QUOTA static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off); static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off); #endif static struct super_operations ext2_sops = { .alloc_inode = ext2_alloc_inode, .destroy_inode = ext2_destroy_inode, .read_inode = ext2_read_inode, .write_inode = ext2_write_inode, .put_inode = ext2_put_inode, .delete_inode = ext2_delete_inode, .put_super = ext2_put_super, .write_super = ext2_write_super, .statfs = ext2_statfs, .remount_fs = ext2_remount, .clear_inode = ext2_clear_inode, .show_options = ext2_show_options, #ifdef CONFIG_QUOTA .quota_read = ext2_quota_read, .quota_write = ext2_quota_write, #endif }; /* Yes, most of these are left as NULL!! * A NULL value implies the default, which works with ext2-like file * systems, but can be improved upon. * Currently only get_parent is required. */ static struct export_operations ext2_export_ops = { .get_parent = ext2_get_parent, }; static unsigned long get_sb_block(void **data) { unsigned long sb_block; char *options = (char *) *data; if (!options || strncmp(options, "sb=", 3) != 0) return 1; /* Default location */ options += 3; sb_block = simple_strtoul(options, &options, 0); if (*options && *options != ',') { printk("EXT2-fs: Invalid sb specification: %s\n", (char *) *data); return 1; } if (*options == ',') options++; *data = (void *) options; return sb_block; } enum { Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, Opt_usrquota, Opt_grpquota }; static match_table_t tokens = { {Opt_bsd_df, "bsddf"}, {Opt_minix_df, "minixdf"}, {Opt_grpid, "grpid"}, {Opt_grpid, "bsdgroups"}, {Opt_nogrpid, "nogrpid"}, {Opt_nogrpid, "sysvgroups"}, {Opt_resgid, "resgid=%u"}, {Opt_resuid, "resuid=%u"}, {Opt_sb, "sb=%u"}, {Opt_err_cont, "errors=continue"}, {Opt_err_panic, "errors=panic"}, {Opt_err_ro, "errors=remount-ro"}, {Opt_nouid32, "nouid32"}, {Opt_nocheck, "check=none"}, {Opt_nocheck, "nocheck"}, {Opt_debug, "debug"}, {Opt_oldalloc, "oldalloc"}, {Opt_orlov, "orlov"}, {Opt_nobh, "nobh"}, {Opt_user_xattr, "user_xattr"}, {Opt_nouser_xattr, "nouser_xattr"}, {Opt_acl, "acl"}, {Opt_noacl, "noacl"}, {Opt_xip, "xip"}, {Opt_grpquota, "grpquota"}, {Opt_ignore, "noquota"}, {Opt_quota, "quota"}, {Opt_usrquota, "usrquota"}, {Opt_err, NULL} }; static int parse_options (char * options, struct ext2_sb_info *sbi) { char * p; substring_t args[MAX_OPT_ARGS]; unsigned long kind = EXT2_MOUNT_ERRORS_CONT; int option; if (!options) return 1; while ((p = strsep (&options, ",")) != NULL) { int token; if (!*p) continue; token = match_token(p, tokens, args); switch (token) { case Opt_bsd_df: clear_opt (sbi->s_mount_opt, MINIX_DF); break; case Opt_minix_df: set_opt (sbi->s_mount_opt, MINIX_DF); break; case Opt_grpid: set_opt (sbi->s_mount_opt, GRPID); break; case Opt_nogrpid: clear_opt (sbi->s_mount_opt, GRPID); break; case Opt_resuid: if (match_int(&args[0], &option)) return 0; sbi->s_resuid = option; break; case Opt_resgid: if (match_int(&args[0], &option)) return 0; sbi->s_resgid = option; break; case Opt_sb: /* handled by get_sb_block() instead of here */ /* *sb_block = match_int(&args[0]); */ break; case Opt_err_panic: kind = EXT2_MOUNT_ERRORS_PANIC; break; case Opt_err_ro: kind = EXT2_MOUNT_ERRORS_RO; break; case Opt_err_cont: kind = EXT2_MOUNT_ERRORS_CONT; break; case Opt_nouid32: set_opt (sbi->s_mount_opt, NO_UID32); break; case Opt_nocheck: clear_opt (sbi->s_mount_opt, CHECK); break; case Opt_debug: set_opt (sbi->s_mount_opt, DEBUG); break; case Opt_oldalloc: set_opt (sbi->s_mount_opt, OLDALLOC); break; case Opt_orlov: clear_opt (sbi->s_mount_opt, OLDALLOC); break; case Opt_nobh: set_opt (sbi->s_mount_opt, NOBH); break; #ifdef CONFIG_EXT2_FS_XATTR case Opt_user_xattr: set_opt (sbi->s_mount_opt, XATTR_USER); break; case Opt_nouser_xattr: clear_opt (sbi->s_mount_opt, XATTR_USER); break; #else case Opt_user_xattr: case Opt_nouser_xattr: printk("EXT2 (no)user_xattr options not supported\n"); break; #endif #ifdef CONFIG_EXT2_FS_POSIX_ACL case Opt_acl: set_opt(sbi->s_mount_opt, POSIX_ACL); break; case Opt_noacl: clear_opt(sbi->s_mount_opt, POSIX_ACL); break; #else case Opt_acl: case Opt_noacl: printk("EXT2 (no)acl options not supported\n"); break; #endif case Opt_xip: #ifdef CONFIG_EXT2_FS_XIP set_opt (sbi->s_mount_opt, XIP); #else printk("EXT2 xip option not supported\n"); #endif break; #if defined(CONFIG_QUOTA) case Opt_quota: case Opt_usrquota: set_opt(sbi->s_mount_opt, USRQUOTA); break; case Opt_grpquota: set_opt(sbi->s_mount_opt, GRPQUOTA); break; #else case Opt_quota: case Opt_usrquota: case Opt_grpquota: printk(KERN_ERR "EXT2-fs: quota operations not supported.\n"); break; #endif case Opt_ignore: break; default: return 0; } } sbi->s_mount_opt |= kind; return 1; } static int ext2_setup_super (struct super_block * sb, struct ext2_super_block * es, int read_only) { int res = 0; struct ext2_sb_info *sbi = EXT2_SB(sb); if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) { printk ("EXT2-fs warning: revision level too high, " "forcing read-only mode\n"); res = MS_RDONLY; } if (read_only) return res; if (!(sbi->s_mount_state & EXT2_VALID_FS)) printk ("EXT2-fs warning: mounting unchecked fs, " "running e2fsck is recommended\n"); else if ((sbi->s_mount_state & EXT2_ERROR_FS)) printk ("EXT2-fs warning: mounting fs with errors, " "running e2fsck is recommended\n"); else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 && le16_to_cpu(es->s_mnt_count) >= (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) printk ("EXT2-fs warning: maximal mount count reached, " "running e2fsck is recommended\n"); else if (le32_to_cpu(es->s_checkinterval) && (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds())) printk ("EXT2-fs warning: checktime reached, " "running e2fsck is recommended\n"); if (!le16_to_cpu(es->s_max_mnt_count)) es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT); es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1); ext2_write_super(sb); if (test_opt (sb, DEBUG)) printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, " "bpg=%lu, ipg=%lu, mo=%04lx]\n", EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize, sbi->s_frag_size, sbi->s_groups_count, EXT2_BLOCKS_PER_GROUP(sb), EXT2_INODES_PER_GROUP(sb), sbi->s_mount_opt); return res; } static int ext2_check_descriptors (struct super_block * sb) { int i; int desc_block = 0; struct ext2_sb_info *sbi = EXT2_SB(sb); unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block); struct ext2_group_desc * gdp = NULL; ext2_debug ("Checking group descriptors"); for (i = 0; i < sbi->s_groups_count; i++) { if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0) gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data; if (le32_to_cpu(gdp->bg_block_bitmap) < block || le32_to_cpu(gdp->bg_block_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb)) { ext2_error (sb, "ext2_check_descriptors", "Block bitmap for group %d" " not in group (block %lu)!", i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); return 0; } if (le32_to_cpu(gdp->bg_inode_bitmap) < block || le32_to_cpu(gdp->bg_inode_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb)) { ext2_error (sb, "ext2_check_descriptors", "Inode bitmap for group %d" " not in group (block %lu)!", i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); return 0; } if (le32_to_cpu(gdp->bg_inode_table) < block || le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >= block + EXT2_BLOCKS_PER_GROUP(sb)) { ext2_error (sb, "ext2_check_descriptors", "Inode table for group %d" " not in group (block %lu)!", i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); return 0; } block += EXT2_BLOCKS_PER_GROUP(sb); gdp++; } return 1; } #define log2(n) ffz(~(n)) /* * Maximal file size. There is a direct, and {,double-,triple-}indirect * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. * We need to be 1 filesystem block less than the 2^32 sector limit. */ static loff_t ext2_max_size(int bits) { loff_t res = EXT2_NDIR_BLOCKS; /* This constant is calculated to be the largest file size for a * dense, 4k-blocksize file such that the total number of * sectors in the file, including data and all indirect blocks, * does not exceed 2^32. */ const loff_t upper_limit = 0x1ff7fffd000LL; res += 1LL << (bits-2); res += 1LL << (2*(bits-2)); res += 1LL << (3*(bits-2)); res <<= bits; if (res > upper_limit) res = upper_limit; return res; } static unsigned long descriptor_loc(struct super_block *sb, unsigned long logic_sb_block, int nr) { struct ext2_sb_info *sbi = EXT2_SB(sb); unsigned long bg, first_data_block, first_meta_bg; int has_super = 0; first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block); first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) || nr < first_meta_bg) return (logic_sb_block + nr + 1); bg = sbi->s_desc_per_block * nr; if (ext2_bg_has_super(sb, bg)) has_super = 1; return (first_data_block + has_super + (bg * sbi->s_blocks_per_group)); } static int ext2_fill_super(struct super_block *sb, void *data, int silent) { struct buffer_head * bh; struct ext2_sb_info * sbi; struct ext2_super_block * es; struct inode *root; unsigned long block; unsigned long sb_block = get_sb_block(&data); unsigned long logic_sb_block; unsigned long offset = 0; unsigned long def_mount_opts; int blocksize = BLOCK_SIZE; int db_count; int i, j; __le32 features; sbi = kmalloc(sizeof(*sbi), GFP_KERNEL); if (!sbi) return -ENOMEM; sb->s_fs_info = sbi; memset(sbi, 0, sizeof(*sbi)); /* * See what the current blocksize for the device is, and * use that as the blocksize. Otherwise (or if the blocksize * is smaller than the default) use the default. * This is important for devices that have a hardware * sectorsize that is larger than the default. */ blocksize = sb_min_blocksize(sb, BLOCK_SIZE); if (!blocksize) { printk ("EXT2-fs: unable to set blocksize\n"); goto failed_sbi; } /* * If the superblock doesn't start on a hardware sector boundary, * calculate the offset. */ if (blocksize != BLOCK_SIZE) { logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; offset = (sb_block*BLOCK_SIZE) % blocksize; } else { logic_sb_block = sb_block; } if (!(bh = sb_bread(sb, logic_sb_block))) { printk ("EXT2-fs: unable to read superblock\n"); goto failed_sbi; } /* * Note: s_es must be initialized as soon as possible because * some ext2 macro-instructions depend on its value */ es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); sbi->s_es = es; sb->s_magic = le16_to_cpu(es->s_magic); if (sb->s_magic != EXT2_SUPER_MAGIC) goto cantfind_ext2; /* Set defaults before we parse the mount options */ def_mount_opts = le32_to_cpu(es->s_default_mount_opts); if (def_mount_opts & EXT2_DEFM_DEBUG) set_opt(sbi->s_mount_opt, DEBUG); if (def_mount_opts & EXT2_DEFM_BSDGROUPS) set_opt(sbi->s_mount_opt, GRPID); if (def_mount_opts & EXT2_DEFM_UID16) set_opt(sbi->s_mount_opt, NO_UID32); if (def_mount_opts & EXT2_DEFM_XATTR_USER) set_opt(sbi->s_mount_opt, XATTR_USER); if (def_mount_opts & EXT2_DEFM_ACL) set_opt(sbi->s_mount_opt, POSIX_ACL); if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC) set_opt(sbi->s_mount_opt, ERRORS_PANIC); else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO) set_opt(sbi->s_mount_opt, ERRORS_RO); sbi->s_resuid = le16_to_cpu(es->s_def_resuid); sbi->s_resgid = le16_to_cpu(es->s_def_resgid); if (!parse_options ((char *) data, sbi)) goto failed_mount; sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset EXT2_MOUNT_XIP if not */ if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV && (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) || EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) || EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U))) printk("EXT2-fs warning: feature flags set on rev 0 fs, " "running e2fsck is recommended\n"); /* * Check feature flags regardless of the revision level, since we * previously didn't change the revision level when setting the flags, * so there is a chance incompat flags are set on a rev 0 filesystem. */ features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP); if (features) { printk("EXT2-fs: %s: couldn't mount because of " "unsupported optional features (%x).\n", sb->s_id, le32_to_cpu(features)); goto failed_mount; } if (!(sb->s_flags & MS_RDONLY) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){ printk("EXT2-fs: %s: couldn't mount RDWR because of " "unsupported optional features (%x).\n", sb->s_id, le32_to_cpu(features)); goto failed_mount; } blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) || (sb->s_blocksize != blocksize))) { if (!silent) printk("XIP: Unsupported blocksize\n"); goto failed_mount; } /* If the blocksize doesn't match, re-read the thing.. */ if (sb->s_blocksize != blocksize) { brelse(bh); if (!sb_set_blocksize(sb, blocksize)) { printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n"); goto failed_sbi; } logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; offset = (sb_block*BLOCK_SIZE) % blocksize; bh = sb_bread(sb, logic_sb_block); if(!bh) { printk("EXT2-fs: Couldn't read superblock on " "2nd try.\n"); goto failed_sbi; } es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); sbi->s_es = es; if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) { printk ("EXT2-fs: Magic mismatch, very weird !\n"); goto failed_mount; } } sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits); if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) { sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE; sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; } else { sbi->s_inode_size = le16_to_cpu(es->s_inode_size); sbi->s_first_ino = le32_to_cpu(es->s_first_ino); if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) || (sbi->s_inode_size & (sbi->s_inode_size - 1)) || (sbi->s_inode_size > blocksize)) { printk ("EXT2-fs: unsupported inode size: %d\n", sbi->s_inode_size); goto failed_mount; } } sbi->s_frag_size = EXT2_MIN_FRAG_SIZE << le32_to_cpu(es->s_log_frag_size); if (sbi->s_frag_size == 0) goto cantfind_ext2; sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size; sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); if (EXT2_INODE_SIZE(sb) == 0) goto cantfind_ext2; sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb); if (sbi->s_inodes_per_block == 0) goto cantfind_ext2; sbi->s_itb_per_group = sbi->s_inodes_per_group / sbi->s_inodes_per_block; sbi->s_desc_per_block = sb->s_blocksize / sizeof (struct ext2_group_desc); sbi->s_sbh = bh; sbi->s_mount_state = le16_to_cpu(es->s_state); sbi->s_addr_per_block_bits = log2 (EXT2_ADDR_PER_BLOCK(sb)); sbi->s_desc_per_block_bits = log2 (EXT2_DESC_PER_BLOCK(sb)); if (sb->s_magic != EXT2_SUPER_MAGIC) goto cantfind_ext2; if (sb->s_blocksize != bh->b_size) { if (!silent) printk ("VFS: Unsupported blocksize on dev " "%s.\n", sb->s_id); goto failed_mount; } if (sb->s_blocksize != sbi->s_frag_size) { printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n", sbi->s_frag_size, sb->s_blocksize); goto failed_mount; } if (sbi->s_blocks_per_group > sb->s_blocksize * 8) { printk ("EXT2-fs: #blocks per group too big: %lu\n", sbi->s_blocks_per_group); goto failed_mount; } if (sbi->s_frags_per_group > sb->s_blocksize * 8) { printk ("EXT2-fs: #fragments per group too big: %lu\n", sbi->s_frags_per_group); goto failed_mount; } if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { printk ("EXT2-fs: #inodes per group too big: %lu\n", sbi->s_inodes_per_group); goto failed_mount; } if (EXT2_BLOCKS_PER_GROUP(sb) == 0) goto cantfind_ext2; sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) - le32_to_cpu(es->s_first_data_block) + EXT2_BLOCKS_PER_GROUP(sb) - 1) / EXT2_BLOCKS_PER_GROUP(sb); db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / EXT2_DESC_PER_BLOCK(sb); sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); if (sbi->s_group_desc == NULL) { printk ("EXT2-fs: not enough memory\n"); goto failed_mount; } bgl_lock_init(&sbi->s_blockgroup_lock); sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts), GFP_KERNEL); if (!sbi->s_debts) { printk ("EXT2-fs: not enough memory\n"); goto failed_mount_group_desc; } memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts)); for (i = 0; i < db_count; i++) { block = descriptor_loc(sb, logic_sb_block, i); sbi->s_group_desc[i] = sb_bread(sb, block); if (!sbi->s_group_desc[i]) { for (j = 0; j < i; j++) brelse (sbi->s_group_desc[j]); printk ("EXT2-fs: unable to read group descriptors\n"); goto failed_mount_group_desc; } } if (!ext2_check_descriptors (sb)) { printk ("EXT2-fs: group descriptors corrupted!\n"); db_count = i; goto failed_mount2; } sbi->s_gdb_count = db_count; get_random_bytes(&sbi->s_next_generation, sizeof(u32)); spin_lock_init(&sbi->s_next_gen_lock); percpu_counter_init(&sbi->s_freeblocks_counter, ext2_count_free_blocks(sb)); percpu_counter_init(&sbi->s_freeinodes_counter, ext2_count_free_inodes(sb)); percpu_counter_init(&sbi->s_dirs_counter, ext2_count_dirs(sb)); /* * set up enough so that it can read an inode */ sb->s_op = &ext2_sops; sb->s_export_op = &ext2_export_ops; sb->s_xattr = ext2_xattr_handlers; root = iget(sb, EXT2_ROOT_INO); sb->s_root = d_alloc_root(root); if (!sb->s_root) { iput(root); printk(KERN_ERR "EXT2-fs: get root inode failed\n"); goto failed_mount3; } if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) { dput(sb->s_root); sb->s_root = NULL; printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n"); goto failed_mount3; } if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) ext2_warning(sb, __FUNCTION__, "mounting ext3 filesystem as ext2"); ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY); return 0; cantfind_ext2: if (!silent) printk("VFS: Can't find an ext2 filesystem on dev %s.\n", sb->s_id); goto failed_mount; failed_mount3: percpu_counter_destroy(&sbi->s_freeblocks_counter); percpu_counter_destroy(&sbi->s_freeinodes_counter); percpu_counter_destroy(&sbi->s_dirs_counter); failed_mount2: for (i = 0; i < db_count; i++) brelse(sbi->s_group_desc[i]); failed_mount_group_desc: kfree(sbi->s_group_desc); kfree(sbi->s_debts); failed_mount: brelse(bh); failed_sbi: sb->s_fs_info = NULL; kfree(sbi); return -EINVAL; } static void ext2_commit_super (struct super_block * sb, struct ext2_super_block * es) { es->s_wtime = cpu_to_le32(get_seconds()); mark_buffer_dirty(EXT2_SB(sb)->s_sbh); sb->s_dirt = 0; } static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es) { es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); es->s_wtime = cpu_to_le32(get_seconds()); mark_buffer_dirty(EXT2_SB(sb)->s_sbh); sync_dirty_buffer(EXT2_SB(sb)->s_sbh); sb->s_dirt = 0; } /* * In the second extended file system, it is not necessary to * write the super block since we use a mapping of the * disk super block in a buffer. * * However, this function is still used to set the fs valid * flags to 0. We need to set this flag to 0 since the fs * may have been checked while mounted and e2fsck may have * set s_state to EXT2_VALID_FS after some corrections. */ void ext2_write_super (struct super_block * sb) { struct ext2_super_block * es; lock_kernel(); if (!(sb->s_flags & MS_RDONLY)) { es = EXT2_SB(sb)->s_es; if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) { ext2_debug ("setting valid to 0\n"); es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT2_VALID_FS); es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); es->s_mtime = cpu_to_le32(get_seconds()); ext2_sync_super(sb, es); } else ext2_commit_super (sb, es); } sb->s_dirt = 0; unlock_kernel(); } static int ext2_remount (struct super_block * sb, int * flags, char * data) { struct ext2_sb_info * sbi = EXT2_SB(sb); struct ext2_super_block * es; unsigned long old_mount_opt = sbi->s_mount_opt; struct ext2_mount_options old_opts; unsigned long old_sb_flags; int err; /* Store the old options */ old_sb_flags = sb->s_flags; old_opts.s_mount_opt = sbi->s_mount_opt; old_opts.s_resuid = sbi->s_resuid; old_opts.s_resgid = sbi->s_resgid; /* * Allow the "check" option to be passed as a remount option. */ if (!parse_options (data, sbi)) { err = -EINVAL; goto restore_opts; } sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); es = sbi->s_es; if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) != (old_mount_opt & EXT2_MOUNT_XIP)) && invalidate_inodes(sb)) ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\ "xip remain in cache (no functional problem)"); if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) return 0; if (*flags & MS_RDONLY) { if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || !(sbi->s_mount_state & EXT2_VALID_FS)) return 0; /* * OK, we are remounting a valid rw partition rdonly, so set * the rdonly flag and then mark the partition as valid again. */ es->s_state = cpu_to_le16(sbi->s_mount_state); es->s_mtime = cpu_to_le32(get_seconds()); } else { __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP); if (ret) { printk("EXT2-fs: %s: couldn't remount RDWR because of " "unsupported optional features (%x).\n", sb->s_id, le32_to_cpu(ret)); err = -EROFS; goto restore_opts; } /* * Mounting a RDONLY partition read-write, so reread and * store the current valid flag. (It may have been changed * by e2fsck since we originally mounted the partition.) */ sbi->s_mount_state = le16_to_cpu(es->s_state); if (!ext2_setup_super (sb, es, 0)) sb->s_flags &= ~MS_RDONLY; } ext2_sync_super(sb, es); return 0; restore_opts: sbi->s_mount_opt = old_opts.s_mount_opt; sbi->s_resuid = old_opts.s_resuid; sbi->s_resgid = old_opts.s_resgid; sb->s_flags = old_sb_flags; return err; } static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) { struct super_block *sb = dentry->d_sb; struct ext2_sb_info *sbi = EXT2_SB(sb); unsigned long overhead; int i; if (test_opt (sb, MINIX_DF)) overhead = 0; else { /* * Compute the overhead (FS structures) */ /* * All of the blocks before first_data_block are * overhead */ overhead = le32_to_cpu(sbi->s_es->s_first_data_block); /* * Add the overhead attributed to the superblock and * block group descriptors. If the sparse superblocks * feature is turned on, then not all groups have this. */ for (i = 0; i < sbi->s_groups_count; i++) overhead += ext2_bg_has_super(sb, i) + ext2_bg_num_gdb(sb, i); /* * Every block group has an inode bitmap, a block * bitmap, and an inode table. */ overhead += (sbi->s_groups_count * (2 + sbi->s_itb_per_group)); } buf->f_type = EXT2_SUPER_MAGIC; buf->f_bsize = sb->s_blocksize; buf->f_blocks = le32_to_cpu(sbi->s_es->s_blocks_count) - overhead; buf->f_bfree = ext2_count_free_blocks(sb); buf->f_bavail = buf->f_bfree - le32_to_cpu(sbi->s_es->s_r_blocks_count); if (buf->f_bfree < le32_to_cpu(sbi->s_es->s_r_blocks_count)) buf->f_bavail = 0; buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count); buf->f_ffree = ext2_count_free_inodes (sb); buf->f_namelen = EXT2_NAME_LEN; return 0; } static int ext2_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt) { return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt); } #ifdef CONFIG_QUOTA /* Read data from quotafile - avoid pagecache and such because we cannot afford * acquiring the locks... As quota files are never truncated and quota code * itself serializes the operations (and noone else should touch the files) * we don't have to be afraid of races */ static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off) { struct inode *inode = sb_dqopt(sb)->files[type]; sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); int err = 0; int offset = off & (sb->s_blocksize - 1); int tocopy; size_t toread; struct buffer_head tmp_bh; struct buffer_head *bh; loff_t i_size = i_size_read(inode); if (off > i_size) return 0; if (off+len > i_size) len = i_size-off; toread = len; while (toread > 0) { tocopy = sb->s_blocksize - offset < toread ? sb->s_blocksize - offset : toread; tmp_bh.b_state = 0; err = ext2_get_block(inode, blk, &tmp_bh, 0); if (err) return err; if (!buffer_mapped(&tmp_bh)) /* A hole? */ memset(data, 0, tocopy); else { bh = sb_bread(sb, tmp_bh.b_blocknr); if (!bh) return -EIO; memcpy(data, bh->b_data+offset, tocopy); brelse(bh); } offset = 0; toread -= tocopy; data += tocopy; blk++; } return len; } /* Write to quotafile */ static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off) { struct inode *inode = sb_dqopt(sb)->files[type]; sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb); int err = 0; int offset = off & (sb->s_blocksize - 1); int tocopy; size_t towrite = len; struct buffer_head tmp_bh; struct buffer_head *bh; mutex_lock(&inode->i_mutex); while (towrite > 0) { tocopy = sb->s_blocksize - offset < towrite ? sb->s_blocksize - offset : towrite; tmp_bh.b_state = 0; err = ext2_get_block(inode, blk, &tmp_bh, 1); if (err) goto out; if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) bh = sb_bread(sb, tmp_bh.b_blocknr); else bh = sb_getblk(sb, tmp_bh.b_blocknr); if (!bh) { err = -EIO; goto out; } lock_buffer(bh); memcpy(bh->b_data+offset, data, tocopy); flush_dcache_page(bh->b_page); set_buffer_uptodate(bh); mark_buffer_dirty(bh); unlock_buffer(bh); brelse(bh); offset = 0; towrite -= tocopy; data += tocopy; blk++; } out: if (len == towrite) return err; if (inode->i_size < off+len-towrite) i_size_write(inode, off+len-towrite); inode->i_version++; inode->i_mtime = inode->i_ctime = CURRENT_TIME; mark_inode_dirty(inode); mutex_unlock(&inode->i_mutex); return len - towrite; } #endif static struct file_system_type ext2_fs_type = { .owner = THIS_MODULE, .name = "ext2", .get_sb = ext2_get_sb, .kill_sb = kill_block_super, .fs_flags = FS_REQUIRES_DEV, }; static int __init init_ext2_fs(void) { int err = init_ext2_xattr(); if (err) return err; err = init_inodecache(); if (err) goto out1; err = register_filesystem(&ext2_fs_type); if (err) goto out; return 0; out: destroy_inodecache(); out1: exit_ext2_xattr(); return err; } static void __exit exit_ext2_fs(void) { unregister_filesystem(&ext2_fs_type); destroy_inodecache(); exit_ext2_xattr(); } module_init(init_ext2_fs) module_exit(exit_ext2_fs)