diff options
Diffstat (limited to 'fs/ext2/super.c')
| -rw-r--r-- | fs/ext2/super.c | 1161 |
1 files changed, 1161 insertions, 0 deletions
diff --git a/fs/ext2/super.c b/fs/ext2/super.c new file mode 100644 index 0000000..37ca77a --- /dev/null +++ b/fs/ext2/super.c @@ -0,0 +1,1161 @@ +/* + * 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/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 <asm/uaccess.h> +#include "ext2.h" +#include "xattr.h" +#include "acl.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 super_block * sb, 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, + 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 + if (!is_bad_inode(inode)) + ext2_discard_prealloc(inode); +} + + +#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, + .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, +#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. + */ +struct dentry *ext2_get_parent(struct dentry *child); +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_check, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov, Opt_nobh, + Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl, + Opt_ignore, Opt_err, +}; + +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_check, "check"}, + {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_ignore, "grpquota"}, + {Opt_ignore, "noquota"}, + {Opt_ignore, "quota"}, + {Opt_ignore, "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_check: +#ifdef CONFIG_EXT2_CHECK + set_opt (sbi->s_mount_opt, CHECK); +#else + printk("EXT2 Check option not supported\n"); +#endif + 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_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); +#ifdef CONFIG_EXT2_CHECK + if (test_opt (sb, CHECK)) { + ext2_check_blocks_bitmap (sb); + ext2_check_inodes_bitmap (sb); + } +#endif + 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); + + 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 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; + } + percpu_counter_init(&sbi->s_freeblocks_counter); + percpu_counter_init(&sbi->s_freeinodes_counter); + percpu_counter_init(&sbi->s_dirs_counter); + 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); + /* + * 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_mount2; + } + 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_mount2; + } + if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) + ext2_warning(sb, __FUNCTION__, + "mounting ext3 filesystem as ext2\n"); + ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY); + percpu_counter_mod(&sbi->s_freeblocks_counter, + ext2_count_free_blocks(sb)); + percpu_counter_mod(&sbi->s_freeinodes_counter, + ext2_count_free_inodes(sb)); + percpu_counter_mod(&sbi->s_dirs_counter, + ext2_count_dirs(sb)); + 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_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; + + /* + * Allow the "check" option to be passed as a remount option. + */ + if (!parse_options (data, sbi)) + return -EINVAL; + + sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | + ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0); + + es = sbi->s_es; + 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)); + return -EROFS; + } + /* + * 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; +} + +static int ext2_statfs (struct super_block * sb, struct kstatfs * buf) +{ + 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 struct super_block *ext2_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data) +{ + return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super); +} + +#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; + + down(&inode->i_sem); + 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); + up(&inode->i_sem); + 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) |
