home *** CD-ROM | disk | FTP | other *** search
- /*
- * linux/fs/ext2/super.c
- *
- * Copyright (C) 1992, 1993 Remy Card (card@masi.ibp.fr)
- *
- * from
- *
- * linux/fs/minix/inode.c
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- */
-
- #include <stdarg.h>
-
- #include <asm/segment.h>
- #include <asm/system.h>
-
- #include <linux/errno.h>
- #include <linux/fs.h>
- #include <linux/ext2_fs.h>
- #include <linux/kernel.h>
- #include <linux/sched.h>
- #include <linux/stat.h>
- #include <linux/string.h>
- #include <linux/locks.h>
-
- extern int vsprintf (char *, const char *, va_list);
-
- void ext2_error (struct super_block * sb, const char * function,
- const char * fmt, ...)
- {
- char buf[1024];
- va_list args;
-
- if (!(sb->s_flags & MS_RDONLY)) {
- sb->u.ext2_sb.s_mount_state |= EXT2_ERROR_FS;
- sb->u.ext2_sb.s_es->s_state |= EXT2_ERROR_FS;
- sb->u.ext2_sb.s_sbh->b_dirt = 1;
- sb->s_dirt = 1;
- }
- va_start (args, fmt);
- vsprintf (buf, fmt, args);
- va_end (args);
- printk (
- #ifdef KERN_ERR
- KERN_ERR
- #endif
- "EXT2-fs error (device %d/%d): %s: %s\n",
- MAJOR(sb->s_dev), MINOR(sb->s_dev), function, buf);
- }
-
- volatile void ext2_panic (struct super_block * sb, const char * function,
- const char * fmt, ...)
- {
- char buf[1024];
- va_list args;
-
- if (!(sb->s_flags & MS_RDONLY)) {
- sb->u.ext2_sb.s_mount_state |= EXT2_ERROR_FS;
- sb->u.ext2_sb.s_es->s_state |= EXT2_ERROR_FS;
- sb->u.ext2_sb.s_sbh->b_dirt = 1;
- sb->s_dirt = 1;
- }
- va_start (args, fmt);
- vsprintf (buf, fmt, args);
- va_end (args);
- panic ("EXT2-fs panic (device %d/%d): %s: %s\n",
- MAJOR(sb->s_dev), MINOR(sb->s_dev), function, buf);
- }
-
- void ext2_warning (struct super_block * sb, const char * function,
- const char * fmt, ...)
- {
- char buf[1024];
- va_list args;
-
- va_start (args, fmt);
- vsprintf (buf, fmt, args);
- va_end (args);
- printk (
- #ifdef KERN_WARNING
- KERN_WARNING
- #endif
- "EXT2-fs warning (device %d/%d): %s: %s\n",
- MAJOR(sb->s_dev), MINOR(sb->s_dev), function, buf);
- }
-
- void ext2_put_super (struct super_block * sb)
- {
- int i;
-
- lock_super (sb);
- if (!(sb->s_flags & MS_RDONLY)) {
- sb->u.ext2_sb.s_es->s_state = sb->u.ext2_sb.s_mount_state;
- sb->u.ext2_sb.s_sbh->b_dirt = 1;
- }
- #ifndef DONT_USE_DCACHE
- ext2_dcache_invalidate (sb->s_dev);
- #endif
- sb->s_dev = 0;
- for (i = 0; i < EXT2_MAX_GROUP_DESC; i++)
- if (sb->u.ext2_sb.s_group_desc[i])
- brelse (sb->u.ext2_sb.s_group_desc[i]);
- for (i = 0; i < EXT2_MAX_GROUP_LOADED; i++)
- if (sb->u.ext2_sb.s_inode_bitmap[i])
- brelse (sb->u.ext2_sb.s_inode_bitmap[i]);
- for (i = 0; i < EXT2_MAX_GROUP_LOADED; i++)
- if (sb->u.ext2_sb.s_block_bitmap[i])
- brelse (sb->u.ext2_sb.s_block_bitmap[i]);
- brelse (sb->u.ext2_sb.s_sbh);
- unlock_super (sb);
- return;
- }
-
- static struct super_operations ext2_sops = {
- ext2_read_inode,
- NULL,
- ext2_write_inode,
- ext2_put_inode,
- ext2_put_super,
- ext2_write_super,
- ext2_statfs,
- ext2_remount
- };
-
- #ifdef EXT2FS_PRE_02B_COMPAT
-
- static int convert_pre_02b_fs (struct super_block * sb,
- struct buffer_head * bh)
- {
- struct ext2_super_block * es;
- struct ext2_old_group_desc old_group_desc [BLOCK_SIZE / sizeof (struct ext2_old_group_desc)];
- struct ext2_group_desc * gdp;
- struct buffer_head * bh2;
- int groups_count;
- int i;
-
- es = (struct ext2_super_block *) bh->b_data;
- bh2 = bread (sb->s_dev, 2, BLOCK_SIZE);
- if (!bh2) {
- printk ("Cannot read descriptor blocks while converting !\n");
- return 0;
- }
- memcpy (old_group_desc, bh2->b_data, BLOCK_SIZE);
- groups_count = (sb->u.ext2_sb.s_blocks_count -
- sb->u.ext2_sb.s_first_data_block +
- (EXT2_BLOCK_SIZE(sb) * 8) - 1) /
- (EXT2_BLOCK_SIZE(sb) * 8);
- memset (bh2->b_data, 0, BLOCK_SIZE);
- gdp = (struct ext2_group_desc *) bh2->b_data;
- for (i = 0; i < groups_count; i++) {
- gdp[i].bg_block_bitmap = old_group_desc[i].bg_block_bitmap;
- gdp[i].bg_inode_bitmap = old_group_desc[i].bg_inode_bitmap;
- gdp[i].bg_inode_table = old_group_desc[i].bg_inode_table;
- gdp[i].bg_free_blocks_count = old_group_desc[i].bg_free_blocks_count;
- gdp[i].bg_free_inodes_count = old_group_desc[i].bg_free_inodes_count;
- }
- bh2->b_dirt = 1;
- brelse (bh2);
- es->s_magic = EXT2_SUPER_MAGIC;
- bh->b_dirt = 1;
- sb->s_magic = EXT2_SUPER_MAGIC;
- return 1;
- }
-
- #endif
-
- /*
- * This function has been shamelessly adapted from the msdos fs
- */
- static int parse_options (char * options, unsigned long * sb_block,
- unsigned long * mount_options)
- {
- char * this_char;
- char * value;
-
- if (!options)
- return 1;
- for (this_char = strtok (options, ",");
- this_char != NULL;
- this_char = strtok (NULL, ",")) {
- if ((value = strchr (this_char, '=')) != NULL)
- *value++ = 0;
- if (!strcmp (this_char, "check"))
- *mount_options |= EXT2_MOUNT_CHECK;
- else if (!strcmp (this_char, "sb")) {
- if (!value || !*value)
- return 0;
- *sb_block = simple_strtoul (value, &value, 0);
- if (*value)
- return 0;
- }
- else {
- printk ("EXT2-fs: Unrecognized mount option %s\n", this_char);
- return 0;
- }
- }
- return 1;
- }
-
- struct super_block * ext2_read_super (struct super_block * s, void * data,
- int silent)
- {
- struct buffer_head * bh;
- struct ext2_super_block * es;
- unsigned long sb_block = 1;
- unsigned long logic_sb_block = 1;
- int dev = s->s_dev;
- int bh_count;
- int i, j;
- #ifdef EXT2FS_PRE_02B_COMPAT
- int fs_converted = 0;
- #endif
-
- s->u.ext2_sb.s_mount_opt = 0;
- if (!parse_options ((char *) data, &sb_block,
- &s->u.ext2_sb.s_mount_opt)) {
- s->s_dev = 0;
- return NULL;
- }
-
- lock_super (s);
- set_blocksize (dev, BLOCK_SIZE);
- if (!(bh = bread (dev, sb_block, BLOCK_SIZE))) {
- s->s_dev = 0;
- unlock_super (s);
- printk ("EXT2-fs: unable to read superblock\n");
- return NULL;
- }
- es = (struct ext2_super_block *) bh->b_data;
- /* Note: s_es must be initialized s_es as soon as possible because
- some ext2 macro-instructions depend on its value */
- s->u.ext2_sb.s_es = es;
- s->s_magic = es->s_magic;
- if (s->s_magic != EXT2_SUPER_MAGIC
- #ifdef EXT2FS_PRE_02B_COMPAT
- && s->s_magic != EXT2_PRE_02B_MAGIC
- #endif
- ) {
- s->s_dev = 0;
- unlock_super (s);
- brelse (bh);
- if (!silent)
- printk ("VFS: Can't find an ext2 filesystem on dev 0x%04x.\n",
- dev);
- return NULL;
- }
- s->s_blocksize = EXT2_MIN_BLOCK_SIZE << es->s_log_block_size;
- s->s_blocksize_bits = EXT2_BLOCK_SIZE_BITS(s);
- if (s->s_blocksize != BLOCK_SIZE &&
- (s->s_blocksize == 1024 || s->s_blocksize == 2048 ||
- s->s_blocksize == 4096)) {
- unsigned long offset;
-
- brelse (bh);
- set_blocksize (dev, s->s_blocksize);
- logic_sb_block = sb_block / s->s_blocksize;
- offset = sb_block % s->s_blocksize;
- bh = bread (dev, logic_sb_block, s->s_blocksize);
- if(!bh)
- return NULL;
- es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
- s->u.ext2_sb.s_es = es;
- if (es->s_magic != EXT2_SUPER_MAGIC) {
- s->s_dev = 0;
- unlock_super (s);
- brelse (bh);
- printk ("EXT2-fs: Magic mismatch, very weird !\n");
- return NULL;
- }
- }
- s->u.ext2_sb.s_frag_size = EXT2_MIN_FRAG_SIZE <<
- es->s_log_frag_size;
- if (s->u.ext2_sb.s_frag_size)
- s->u.ext2_sb.s_frags_per_block = s->s_blocksize /
- s->u.ext2_sb.s_frag_size;
- else
- s->s_magic = 0;
- s->u.ext2_sb.s_blocks_per_group = es->s_blocks_per_group;
- s->u.ext2_sb.s_frags_per_group = es->s_frags_per_group;
- s->u.ext2_sb.s_inodes_per_group = es->s_inodes_per_group;
- s->u.ext2_sb.s_inodes_per_block = s->s_blocksize /
- sizeof (struct ext2_inode);
- s->u.ext2_sb.s_desc_per_block = s->s_blocksize /
- sizeof (struct ext2_group_desc);
- s->u.ext2_sb.s_sbh = bh;
- s->u.ext2_sb.s_es = es;
- s->u.ext2_sb.s_mount_state = es->s_state;
- s->u.ext2_sb.s_rename_lock = 0;
- s->u.ext2_sb.s_rename_wait = NULL;
- #ifdef EXT2FS_PRE_02B_COMPAT
- if (s->s_magic == EXT2_PRE_02B_MAGIC) {
- if (es->s_blocks_count > 262144) {
- /* fs > 256 MB can't be converted */
- s->s_dev = 0;
- unlock_super (s);
- brelse (bh);
- printk ("EXT2-fs: trying to mount a pre-0.2b file"
- "system which cannot be converted\n");
- return NULL;
- }
- printk ("EXT2-fs: mounting a pre 0.2b file system, "
- "will try to convert the structure\n");
- if (!(s->s_flags & MS_RDONLY)) {
- s->s_dev = 0;
- unlock_super (s);
- brelse (bh);
- printk ("EXT2-fs: cannot convert a read-only fs\n");
- return NULL;
- }
- if (!convert_pre_02b_fs (s, bh)) {
- s->s_dev = 0;
- unlock_super (s);
- brelse (bh);
- printk ("EXT2-fs: conversion failed !!!\n");
- return NULL;
- }
- printk ("EXT2-fs: conversion succeeded !!!\n");
- fs_converted = 1;
- }
- #endif
- if (s->s_magic != EXT2_SUPER_MAGIC) {
- s->s_dev = 0;
- unlock_super (s);
- brelse (bh);
- if (!silent)
- printk ("VFS: Can't find an ext2 filesystem on dev 0x%04x.\n",
- dev);
- return NULL;
- }
- if (s->s_blocksize != bh->b_size) {
- s->s_dev = 0;
- unlock_super (s);
- brelse (bh);
- if (!silent)
- printk ("VFS: Unsupported blocksize on dev 0x%04x.\n",
- dev);
- return NULL;
- }
-
- if (s->s_blocksize != s->u.ext2_sb.s_frag_size) {
- s->s_dev = 0;
- unlock_super (s);
- brelse (bh);
- printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
- s->u.ext2_sb.s_frag_size, s->s_blocksize);
- return NULL;
- }
-
- s->u.ext2_sb.s_groups_count = (es->s_blocks_count -
- es->s_first_data_block +
- EXT2_BLOCKS_PER_GROUP(s) - 1) /
- EXT2_BLOCKS_PER_GROUP(s);
- for (i = 0; i < EXT2_MAX_GROUP_DESC; i++)
- s->u.ext2_sb.s_group_desc[i] = NULL;
- bh_count = (s->u.ext2_sb.s_groups_count + EXT2_DESC_PER_BLOCK(s) - 1) /
- EXT2_DESC_PER_BLOCK(s);
- if (bh_count > EXT2_MAX_GROUP_DESC) {
- s->s_dev = 0;
- unlock_super (s);
- brelse (bh);
- printk ("EXT2-fs: file system is too big\n");
- return NULL;
- }
- for (i = 0; i < bh_count; i++) {
- s->u.ext2_sb.s_group_desc[i] = bread (dev, logic_sb_block + i + 1,
- s->s_blocksize);
- if (!s->u.ext2_sb.s_group_desc[i]) {
- s->s_dev = 0;
- unlock_super (s);
- for (j = 0; j < i; j++)
- brelse (s->u.ext2_sb.s_group_desc[i]);
- brelse (bh);
- printk ("EXT2-fs: unable to read group descriptors\n");
- return NULL;
- }
- }
- for (i = 0; i < EXT2_MAX_GROUP_LOADED; i++) {
- s->u.ext2_sb.s_inode_bitmap_number[i] = 0;
- s->u.ext2_sb.s_inode_bitmap[i] = NULL;
- s->u.ext2_sb.s_block_bitmap_number[i] = 0;
- s->u.ext2_sb.s_block_bitmap[i] = NULL;
- }
- s->u.ext2_sb.s_loaded_inode_bitmaps = 0;
- s->u.ext2_sb.s_loaded_block_bitmaps = 0;
- unlock_super (s);
- /* set up enough so that it can read an inode */
- s->s_dev = dev;
- s->s_op = &ext2_sops;
- if (!(s->s_mounted = iget (s, EXT2_ROOT_INO))) {
- s->s_dev = 0;
- for (i = 0; i < EXT2_MAX_GROUP_DESC; i++)
- if (s->u.ext2_sb.s_group_desc[i])
- brelse (s->u.ext2_sb.s_group_desc[i]);
- brelse (bh);
- printk ("EXT2-fs: get root inode failed\n");
- return NULL;
- }
- if (!(s->s_flags & MS_RDONLY)) {
- es->s_state &= ~EXT2_VALID_FS;
- if (!es->s_max_mnt_count)
- es->s_max_mnt_count = EXT2_DFL_MAX_MNT_COUNT;
- es->s_mnt_count++;
- es->s_mtime = CURRENT_TIME;
- bh->b_dirt = 1;
- s->s_dirt = 1;
- }
- #ifdef EXT2FS_PRE_02B_COMPAT
- if (fs_converted) {
- for (i = 0; i < bh_count; i++)
- s->u.ext2_sb.s_group_desc[i]->b_dirt = 1;
- s->s_dirt = 1;
- }
- #endif
- if (!(s->u.ext2_sb.s_mount_state & EXT2_VALID_FS))
- printk ("EXT2-fs warning: mounting unchecked file system, "
- "running e2fsck is recommended\n");
- else if (s->u.ext2_sb.s_mount_state & EXT2_ERROR_FS)
- printk ("EXT2-fs warning: mounting file system with errors, "
- "running e2fsck is recommended\n");
- else if (es->s_mnt_count >= es->s_max_mnt_count)
- printk ("EXT2-fs warning: maximal mount count reached, "
- "running e2fsck is recommended\n");
- if (s->u.ext2_sb.s_mount_opt & EXT2_MOUNT_CHECK) {
- printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, bpg=%lu, ipg=%lu]\n",
- EXT2FS_VERSION, EXT2FS_DATE, s->s_blocksize,
- s->u.ext2_sb.s_frag_size, s->u.ext2_sb.s_groups_count,
- EXT2_BLOCKS_PER_GROUP(s), EXT2_INODES_PER_GROUP(s));
- ext2_check_blocks_bitmap (s);
- ext2_check_inodes_bitmap (s);
- }
- return s;
- }
-
- static void ext2_commit_super (struct super_block * sb,
- struct ext2_super_block * es)
- {
- es->s_wtime = CURRENT_TIME;
- sb->u.ext2_sb.s_sbh->b_dirt = 1;
- 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;
-
- if (!(sb->s_flags & MS_RDONLY)) {
- es = sb->u.ext2_sb.s_es;
-
- ext2_debug ("setting valid to 0\n");
-
- if (es->s_state & EXT2_VALID_FS) {
- es->s_state &= ~EXT2_VALID_FS;
- es->s_mtime = CURRENT_TIME;
- }
- ext2_commit_super (sb, es);
- }
- sb->s_dirt = 0;
- }
-
- int ext2_remount (struct super_block * sb, int * flags)
- {
- struct ext2_super_block * es;
-
- es = sb->u.ext2_sb.s_es;
- if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
- return 0;
- if (*flags & MS_RDONLY) {
- if (es->s_state & EXT2_VALID_FS ||
- !(sb->u.ext2_sb.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 = sb->u.ext2_sb.s_mount_state;
- es->s_mtime = CURRENT_TIME;
- sb->u.ext2_sb.s_sbh->b_dirt = 1;
- sb->s_dirt = 1;
- ext2_commit_super (sb, es);
- }
- else {
- /* 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.) */
- sb->u.ext2_sb.s_mount_state = es->s_state;
- es->s_state &= ~EXT2_VALID_FS;
- if (!es->s_max_mnt_count)
- es->s_max_mnt_count = EXT2_DFL_MAX_MNT_COUNT;
- es->s_mnt_count++;
- es->s_mtime = CURRENT_TIME;
- sb->u.ext2_sb.s_sbh->b_dirt = 1;
- sb->s_dirt = 1;
- if (!(sb->u.ext2_sb.s_mount_state & EXT2_VALID_FS))
- printk ("EXT2-fs warning: remounting unchecked fs, "
- "running e2fsck is recommended\n");
- else if ((sb->u.ext2_sb.s_mount_state & EXT2_ERROR_FS))
- printk ("EXT2-fs warning: remounting fs with errors, "
- "running e2fsck is recommended\n");
- else if (es->s_mnt_count >= es->s_max_mnt_count)
- printk ("EXT2-fs warning: maximal mount count reached, "
- "running e2fsck is recommended\n");
- }
- return 0;
- }
-
- void ext2_statfs (struct super_block * sb, struct statfs * buf)
- {
- long tmp;
-
- put_fs_long (EXT2_SUPER_MAGIC, &buf->f_type);
- put_fs_long (sb->s_blocksize, &buf->f_bsize);
- put_fs_long (sb->u.ext2_sb.s_es->s_blocks_count, &buf->f_blocks);
- tmp = ext2_count_free_blocks (sb);
- put_fs_long (tmp, &buf->f_bfree);
- if (tmp >= sb->u.ext2_sb.s_es->s_r_blocks_count)
- put_fs_long (tmp - sb->u.ext2_sb.s_es->s_r_blocks_count,
- &buf->f_bavail);
- else
- put_fs_long (0, &buf->f_bavail);
- put_fs_long (sb->u.ext2_sb.s_es->s_inodes_count, &buf->f_files);
- put_fs_long (ext2_count_free_inodes (sb), &buf->f_ffree);
- put_fs_long (EXT2_NAME_LEN, &buf->f_namelen);
- /* Don't know what value to put in buf->f_fsid */
- }
-