/* * 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 */ #include #include #include #include #include #include #include #include #include #include #include static char error_buf[1024]; void ext2_error (struct super_block * sb, const char * function, const char * fmt, ...) { 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; mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 1); sb->s_dirt = 1; } va_start (args, fmt); vsprintf (error_buf, fmt, args); va_end (args); if (test_opt (sb, ERRORS_PANIC) || (sb->u.ext2_sb.s_es->s_errors == EXT2_ERRORS_PANIC && !test_opt (sb, ERRORS_CONT) && !test_opt (sb, ERRORS_RO))) panic ("EXT2-fs panic (device %d/%d): %s: %s\n", MAJOR(sb->s_dev), MINOR(sb->s_dev), function, error_buf); printk (KERN_CRIT "EXT2-fs error (device %d/%d): %s: %s\n", MAJOR(sb->s_dev), MINOR(sb->s_dev), function, error_buf); if (test_opt (sb, ERRORS_RO) || (sb->u.ext2_sb.s_es->s_errors == EXT2_ERRORS_RO && !test_opt (sb, ERRORS_CONT) && !test_opt (sb, ERRORS_PANIC))) { printk ("Remounting filesystem read-only\n"); sb->s_flags |= MS_RDONLY; } } NORET_TYPE void ext2_panic (struct super_block * sb, const char * function, const char * fmt, ...) { 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; mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 1); sb->s_dirt = 1; } va_start (args, fmt); vsprintf (error_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, error_buf); } void ext2_warning (struct super_block * sb, const char * function, const char * fmt, ...) { va_list args; va_start (args, fmt); vsprintf (error_buf, fmt, args); va_end (args); printk (KERN_WARNING "EXT2-fs warning (device %d/%d): %s: %s\n", MAJOR(sb->s_dev), MINOR(sb->s_dev), function, error_buf); } void ext2_put_super (struct super_block * sb) { int db_count; 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; mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 1); } sb->s_dev = 0; db_count = sb->u.ext2_sb.s_db_per_group; for (i = 0; i < db_count; i++) if (sb->u.ext2_sb.s_group_desc[i]) brelse (sb->u.ext2_sb.s_group_desc[i]); kfree_s (sb->u.ext2_sb.s_group_desc, db_count * sizeof (struct buffer_head *)); 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; } mark_buffer_dirty(bh2, 1); brelse (bh2); es->s_magic = EXT2_SUPER_MAGIC; mark_buffer_dirty(bh, 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 short *resuid, unsigned short * resgid, 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, "bsddf")) clear_opt (*mount_options, MINIX_DF); else if (!strcmp (this_char, "check")) { if (!value || !*value) set_opt (*mount_options, CHECK_NORMAL); else if (!strcmp (value, "none")) { clear_opt (*mount_options, CHECK_NORMAL); clear_opt (*mount_options, CHECK_STRICT); } else if (strcmp (value, "normal")) set_opt (*mount_options, CHECK_NORMAL); else if (strcmp (value, "strict")) { set_opt (*mount_options, CHECK_NORMAL); set_opt (*mount_options, CHECK_STRICT); } else { printk ("EXT2-fs: Invalid check option: %s\n", value); return 0; } } else if (!strcmp (this_char, "debug")) set_opt (*mount_options, DEBUG); else if (!strcmp (this_char, "errors")) { if (!value || !*value) { printk ("EXT2-fs: the errors option requires " "an argument"); return 0; } if (!strcmp (value, "continue")) { clear_opt (*mount_options, ERRORS_RO); clear_opt (*mount_options, ERRORS_PANIC); set_opt (*mount_options, ERRORS_CONT); } else if (!strcmp (value, "remount-ro")) { clear_opt (*mount_options, ERRORS_CONT); clear_opt (*mount_options, ERRORS_PANIC); set_opt (*mount_options, ERRORS_RO); } else if (!strcmp (value, "panic")) { clear_opt (*mount_options, ERRORS_CONT); clear_opt (*mount_options, ERRORS_RO); set_opt (*mount_options, ERRORS_PANIC); } else { printk ("EXT2-fs: Invalid errors option: %s\n", value); return 0; } } else if (!strcmp (this_char, "grpid") || !strcmp (this_char, "bsdgroups")) set_opt (*mount_options, GRPID); else if (!strcmp (this_char, "minixdf")) set_opt (*mount_options, MINIX_DF); else if (!strcmp (this_char, "nocheck")) { clear_opt (*mount_options, CHECK_NORMAL); clear_opt (*mount_options, CHECK_STRICT); } else if (!strcmp (this_char, "nogrpid") || !strcmp (this_char, "sysvgroups")) clear_opt (*mount_options, GRPID); else if (!strcmp (this_char, "resgid")) { if (!value || !*value) { printk ("EXT2-fs: the resgid option requires " "an argument"); return 0; } *resgid = simple_strtoul (value, &value, 0); if (*value) { printk ("EXT2-fs: Invalid resgid option: %s\n", value); return 0; } } else if (!strcmp (this_char, "resuid")) { if (!value || !*value) { printk ("EXT2-fs: the resuid option requires " "an argument"); return 0; } *resuid = simple_strtoul (value, &value, 0); if (*value) { printk ("EXT2-fs: Invalid resuid option: %s\n", value); return 0; } } else if (!strcmp (this_char, "sb")) { if (!value || !*value) { printk ("EXT2-fs: the sb option requires " "an argument"); return 0; } *sb_block = simple_strtoul (value, &value, 0); if (*value) { printk ("EXT2-fs: Invalid sb option: %s\n", value); return 0; } } else { printk ("EXT2-fs: Unrecognized mount option %s\n", this_char); return 0; } } return 1; } static void ext2_setup_super (struct super_block * sb, struct ext2_super_block * es) { if (es->s_rev_level > EXT2_CURRENT_REV) { printk ("EXT2-fs warning: revision level too high, " "forcing read/only mode\n"); sb->s_flags |= MS_RDONLY; } if (!(sb->s_flags & MS_RDONLY)) { if (!(sb->u.ext2_sb.s_mount_state & EXT2_VALID_FS)) printk ("EXT2-fs warning: mounting unchecked fs, " "running e2fsck is recommended\n"); else if ((sb->u.ext2_sb.s_mount_state & EXT2_ERROR_FS)) printk ("EXT2-fs warning: mounting fs with errors, " "running e2fsck is recommended\n"); else if (es->s_max_mnt_count >= 0 && es->s_mnt_count >= (unsigned short) es->s_max_mnt_count) printk ("EXT2-fs warning: maximal mount count reached, " "running e2fsck is recommended\n"); else if (es->s_checkinterval && (es->s_lastcheck + es->s_checkinterval <= CURRENT_TIME)) printk ("EXT2-fs warning: checktime reached, " "running e2fsck is recommended\n"); 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; mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 1); sb->s_dirt = 1; 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, sb->u.ext2_sb.s_frag_size, sb->u.ext2_sb.s_groups_count, EXT2_BLOCKS_PER_GROUP(sb), EXT2_INODES_PER_GROUP(sb), sb->u.ext2_sb.s_mount_opt); if (test_opt (sb, CHECK)) { ext2_check_blocks_bitmap (sb); ext2_check_inodes_bitmap (sb); } } } static int ext2_check_descriptors (struct super_block * sb) { int i; int desc_block = 0; unsigned long block = sb->u.ext2_sb.s_es->s_first_data_block; struct ext2_group_desc * gdp = NULL; ext2_debug ("Checking group descriptors"); for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) { if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0) gdp = (struct ext2_group_desc *) sb->u.ext2_sb.s_group_desc[desc_block++]->b_data; if (gdp->bg_block_bitmap < block || 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) gdp->bg_block_bitmap); return 0; } if (gdp->bg_inode_bitmap < block || 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) gdp->bg_inode_bitmap); return 0; } if (gdp->bg_inode_table < block || gdp->bg_inode_table + sb->u.ext2_sb.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) gdp->bg_inode_table); return 0; } block += EXT2_BLOCKS_PER_GROUP(sb); gdp++; } return 1; } struct super_block * ext2_read_super (struct super_block * sb, void * data, int silent) { struct buffer_head * bh; struct ext2_super_block * es; unsigned long sb_block = 1; unsigned short resuid = EXT2_DEF_RESUID; unsigned short resgid = EXT2_DEF_RESGID; unsigned long logic_sb_block = 1; int dev = sb->s_dev; int db_count; int i, j; #ifdef EXT2FS_PRE_02B_COMPAT int fs_converted = 0; #endif set_opt (sb->u.ext2_sb.s_mount_opt, CHECK_NORMAL); if (!parse_options ((char *) data, &sb_block, &resuid, &resgid, &sb->u.ext2_sb.s_mount_opt)) { sb->s_dev = 0; return NULL; } lock_super (sb); set_blocksize (dev, BLOCK_SIZE); if (!(bh = bread (dev, sb_block, BLOCK_SIZE))) { sb->s_dev = 0; unlock_super (sb); printk ("EXT2-fs: unable to read superblock\n"); return NULL; } /* * Note: s_es must be initialized s_es as soon as possible because * some ext2 macro-instructions depend on its value */ es = (struct ext2_super_block *) bh->b_data; sb->u.ext2_sb.s_es = es; sb->s_magic = es->s_magic; if (sb->s_magic != EXT2_SUPER_MAGIC #ifdef EXT2FS_PRE_02B_COMPAT && sb->s_magic != EXT2_PRE_02B_MAGIC #endif ) { sb->s_dev = 0; unlock_super (sb); brelse (bh); if (!silent) printk ("VFS: Can't find an ext2 filesystem on dev %d/%d.\n", MAJOR(dev), MINOR(dev)); return NULL; } sb->s_blocksize = EXT2_MIN_BLOCK_SIZE << es->s_log_block_size; sb->s_blocksize_bits = EXT2_BLOCK_SIZE_BITS(sb); if (sb->s_blocksize != BLOCK_SIZE && (sb->s_blocksize == 1024 || sb->s_blocksize == 2048 || sb->s_blocksize == 4096)) { unsigned long offset; brelse (bh); set_blocksize (dev, sb->s_blocksize); logic_sb_block = (sb_block*BLOCK_SIZE) / sb->s_blocksize; offset = (sb_block*BLOCK_SIZE) % sb->s_blocksize; bh = bread (dev, logic_sb_block, sb->s_blocksize); if(!bh) return NULL; es = (struct ext2_super_block *) (((char *)bh->b_data) + offset); sb->u.ext2_sb.s_es = es; if (es->s_magic != EXT2_SUPER_MAGIC) { sb->s_dev = 0; unlock_super (sb); brelse (bh); printk ("EXT2-fs: Magic mismatch, very weird !\n"); return NULL; } } sb->u.ext2_sb.s_frag_size = EXT2_MIN_FRAG_SIZE << es->s_log_frag_size; if (sb->u.ext2_sb.s_frag_size) sb->u.ext2_sb.s_frags_per_block = sb->s_blocksize / sb->u.ext2_sb.s_frag_size; else sb->s_magic = 0; sb->u.ext2_sb.s_blocks_per_group = es->s_blocks_per_group; sb->u.ext2_sb.s_frags_per_group = es->s_frags_per_group; sb->u.ext2_sb.s_inodes_per_group = es->s_inodes_per_group; sb->u.ext2_sb.s_inodes_per_block = sb->s_blocksize / sizeof (struct ext2_inode); sb->u.ext2_sb.s_itb_per_group = sb->u.ext2_sb.s_inodes_per_group / sb->u.ext2_sb.s_inodes_per_block; sb->u.ext2_sb.s_desc_per_block = sb->s_blocksize / sizeof (struct ext2_group_desc); sb->u.ext2_sb.s_sbh = bh; sb->u.ext2_sb.s_es = es; if (resuid != EXT2_DEF_RESUID) sb->u.ext2_sb.s_resuid = resuid; else sb->u.ext2_sb.s_resuid = es->s_def_resuid; if (resgid != EXT2_DEF_RESGID) sb->u.ext2_sb.s_resgid = resgid; else sb->u.ext2_sb.s_resgid = es->s_def_resgid; sb->u.ext2_sb.s_mount_state = es->s_state; sb->u.ext2_sb.s_rename_lock = 0; sb->u.ext2_sb.s_rename_wait = NULL; #ifdef EXT2FS_PRE_02B_COMPAT if (sb->s_magic == EXT2_PRE_02B_MAGIC) { if (es->s_blocks_count > 262144) { /* * fs > 256 MB can't be converted */ sb->s_dev = 0; unlock_super (sb); 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 (!(sb->s_flags & MS_RDONLY)) { sb->s_dev = 0; unlock_super (sb); brelse (bh); printk ("EXT2-fs: cannot convert a read-only fs\n"); return NULL; } if (!convert_pre_02b_fs (sb, bh)) { sb->s_dev = 0; unlock_super (sb); brelse (bh); printk ("EXT2-fs: conversion failed !!!\n"); return NULL; } printk ("EXT2-fs: conversion succeeded !!!\n"); fs_converted = 1; } #endif if (sb->s_magic != EXT2_SUPER_MAGIC) { sb->s_dev = 0; unlock_super (sb); brelse (bh); if (!silent) printk ("VFS: Can't find an ext2 filesystem on dev %d/%d.\n", MAJOR(dev), MINOR(dev)); return NULL; } if (sb->s_blocksize != bh->b_size) { sb->s_dev = 0; unlock_super (sb); brelse (bh); if (!silent) printk ("VFS: Unsupported blocksize on dev 0x%04x.\n", dev); return NULL; } if (sb->s_blocksize != sb->u.ext2_sb.s_frag_size) { sb->s_dev = 0; unlock_super (sb); brelse (bh); printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n", sb->u.ext2_sb.s_frag_size, sb->s_blocksize); return NULL; } if (sb->u.ext2_sb.s_blocks_per_group > sb->s_blocksize * 8) { sb->s_dev = 0; unlock_super (sb); brelse (bh); printk ("EXT2-fs: #blocks per group too big: %lu\n", sb->u.ext2_sb.s_blocks_per_group); return NULL; } if (sb->u.ext2_sb.s_frags_per_group > sb->s_blocksize * 8) { sb->s_dev = 0; unlock_super (sb); brelse (bh); printk ("EXT2-fs: #fragments per group too big: %lu\n", sb->u.ext2_sb.s_frags_per_group); return NULL; } if (sb->u.ext2_sb.s_inodes_per_group > sb->s_blocksize * 8) { sb->s_dev = 0; unlock_super (sb); brelse (bh); printk ("EXT2-fs: #inodes per group too big: %lu\n", sb->u.ext2_sb.s_inodes_per_group); return NULL; } sb->u.ext2_sb.s_groups_count = (es->s_blocks_count - es->s_first_data_block + EXT2_BLOCKS_PER_GROUP(sb) - 1) / EXT2_BLOCKS_PER_GROUP(sb); db_count = (sb->u.ext2_sb.s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / EXT2_DESC_PER_BLOCK(sb); sb->u.ext2_sb.s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); if (sb->u.ext2_sb.s_group_desc == NULL) { sb->s_dev = 0; unlock_super (sb); brelse (bh); printk ("EXT2-fs: not enough memory\n"); return NULL; } for (i = 0; i < db_count; i++) { sb->u.ext2_sb.s_group_desc[i] = bread (dev, logic_sb_block + i + 1, sb->s_blocksize); if (!sb->u.ext2_sb.s_group_desc[i]) { sb->s_dev = 0; unlock_super (sb); for (j = 0; j < i; j++) brelse (sb->u.ext2_sb.s_group_desc[j]); kfree_s (sb->u.ext2_sb.s_group_desc, db_count * sizeof (struct buffer_head *)); brelse (bh); printk ("EXT2-fs: unable to read group descriptors\n"); return NULL; } } if (!ext2_check_descriptors (sb)) { sb->s_dev = 0; unlock_super (sb); for (j = 0; j < db_count; j++) brelse (sb->u.ext2_sb.s_group_desc[j]); kfree_s (sb->u.ext2_sb.s_group_desc, db_count * sizeof (struct buffer_head *)); brelse (bh); printk ("EXT2-fs: group descriptors corrupted !\n"); return NULL; } for (i = 0; i < EXT2_MAX_GROUP_LOADED; i++) { sb->u.ext2_sb.s_inode_bitmap_number[i] = 0; sb->u.ext2_sb.s_inode_bitmap[i] = NULL; sb->u.ext2_sb.s_block_bitmap_number[i] = 0; sb->u.ext2_sb.s_block_bitmap[i] = NULL; } sb->u.ext2_sb.s_loaded_inode_bitmaps = 0; sb->u.ext2_sb.s_loaded_block_bitmaps = 0; sb->u.ext2_sb.s_db_per_group = db_count; unlock_super (sb); /* * set up enough so that it can read an inode */ sb->s_dev = dev; sb->s_op = &ext2_sops; if (!(sb->s_mounted = iget (sb, EXT2_ROOT_INO))) { sb->s_dev = 0; for (i = 0; i < db_count; i++) if (sb->u.ext2_sb.s_group_desc[i]) brelse (sb->u.ext2_sb.s_group_desc[i]); kfree_s (sb->u.ext2_sb.s_group_desc, db_count * sizeof (struct buffer_head *)); brelse (bh); printk ("EXT2-fs: get root inode failed\n"); return NULL; } #ifdef EXT2FS_PRE_02B_COMPAT if (fs_converted) { for (i = 0; i < db_count; i++) mark_buffer_dirty(sb->u.ext2_sb.s_group_desc[i], 1); sb->s_dirt = 1; } #endif ext2_setup_super (sb, es); return sb; } static void ext2_commit_super (struct super_block * sb, struct ext2_super_block * es) { es->s_wtime = CURRENT_TIME; mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 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, char * data) { struct ext2_super_block * es; unsigned short resuid = sb->u.ext2_sb.s_resuid; unsigned short resgid = sb->u.ext2_sb.s_resgid; unsigned long new_mount_opt; unsigned long tmp; /* * Allow the "check" option to be passed as a remount option. */ set_opt (sb->u.ext2_sb.s_mount_opt, CHECK_NORMAL); if (!parse_options (data, &tmp, &resuid, &resgid, &new_mount_opt)) return -EINVAL; sb->u.ext2_sb.s_mount_opt = new_mount_opt; sb->u.ext2_sb.s_resuid = resuid; sb->u.ext2_sb.s_resgid = resgid; 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; mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 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; sb->s_flags &= ~MS_RDONLY; ext2_setup_super (sb, es); } return 0; } void ext2_statfs (struct super_block * sb, struct statfs * buf) { long tmp; unsigned long overhead; unsigned long overhead_per_group; if (test_opt (sb, MINIX_DF)) overhead = 0; else { /* * Compute the overhead (FS structures) */ overhead_per_group = 1 /* super block */ + sb->u.ext2_sb.s_db_per_group /* descriptors */ + 1 /* block bitmap */ + 1 /* inode bitmap */ + sb->u.ext2_sb.s_itb_per_group /* inode table */; overhead = sb->u.ext2_sb.s_es->s_first_data_block + sb->u.ext2_sb.s_groups_count * overhead_per_group; } 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 - overhead, &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 */ }