diff options
Diffstat (limited to 'fs/affs/super.c')
| -rw-r--r-- | fs/affs/super.c | 684 |
1 files changed, 684 insertions, 0 deletions
diff --git a/fs/affs/super.c b/fs/affs/super.c new file mode 100644 index 000000000..ed8225b3c --- /dev/null +++ b/fs/affs/super.c @@ -0,0 +1,684 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/fs/affs/inode.c + * + * (c) 1996 Hans-Joachim Widmaier - Rewritten + * + * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem. + * + * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. + * + * (C) 1991 Linus Torvalds - minix filesystem + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/statfs.h> +#include <linux/fs_parser.h> +#include <linux/fs_context.h> +#include <linux/magic.h> +#include <linux/sched.h> +#include <linux/cred.h> +#include <linux/slab.h> +#include <linux/writeback.h> +#include <linux/blkdev.h> +#include <linux/seq_file.h> +#include <linux/iversion.h> +#include "affs.h" + +static int affs_statfs(struct dentry *dentry, struct kstatfs *buf); +static int affs_show_options(struct seq_file *m, struct dentry *root); + +static void +affs_commit_super(struct super_block *sb, int wait) +{ + struct affs_sb_info *sbi = AFFS_SB(sb); + struct buffer_head *bh = sbi->s_root_bh; + struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh); + + lock_buffer(bh); + affs_secs_to_datestamp(ktime_get_real_seconds(), &tail->disk_change); + affs_fix_checksum(sb, bh); + unlock_buffer(bh); + + mark_buffer_dirty(bh); + if (wait) + sync_dirty_buffer(bh); +} + +static void +affs_put_super(struct super_block *sb) +{ + struct affs_sb_info *sbi = AFFS_SB(sb); + pr_debug("%s()\n", __func__); + + cancel_delayed_work_sync(&sbi->sb_work); +} + +static int +affs_sync_fs(struct super_block *sb, int wait) +{ + affs_commit_super(sb, wait); + return 0; +} + +static void flush_superblock(struct work_struct *work) +{ + struct affs_sb_info *sbi; + struct super_block *sb; + + sbi = container_of(work, struct affs_sb_info, sb_work.work); + sb = sbi->sb; + + spin_lock(&sbi->work_lock); + sbi->work_queued = 0; + spin_unlock(&sbi->work_lock); + + affs_commit_super(sb, 1); +} + +void affs_mark_sb_dirty(struct super_block *sb) +{ + struct affs_sb_info *sbi = AFFS_SB(sb); + unsigned long delay; + + if (sb_rdonly(sb)) + return; + + spin_lock(&sbi->work_lock); + if (!sbi->work_queued) { + delay = msecs_to_jiffies(dirty_writeback_interval * 10); + queue_delayed_work(system_dfl_long_wq, &sbi->sb_work, delay); + sbi->work_queued = 1; + } + spin_unlock(&sbi->work_lock); +} + +static struct kmem_cache * affs_inode_cachep; + +static struct inode *affs_alloc_inode(struct super_block *sb) +{ + struct affs_inode_info *i; + + i = alloc_inode_sb(sb, affs_inode_cachep, GFP_KERNEL); + if (!i) + return NULL; + + inode_set_iversion(&i->vfs_inode, 1); + i->i_lc = NULL; + i->i_ext_bh = NULL; + i->i_pa_cnt = 0; + + return &i->vfs_inode; +} + +static void affs_free_inode(struct inode *inode) +{ + kmem_cache_free(affs_inode_cachep, AFFS_I(inode)); +} + +static void init_once(void *foo) +{ + struct affs_inode_info *ei = (struct affs_inode_info *) foo; + + mutex_init(&ei->i_link_lock); + mutex_init(&ei->i_ext_lock); + inode_init_once(&ei->vfs_inode); +} + +static int __init init_inodecache(void) +{ + affs_inode_cachep = kmem_cache_create("affs_inode_cache", + sizeof(struct affs_inode_info), + 0, (SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT), + init_once); + if (affs_inode_cachep == NULL) + return -ENOMEM; + return 0; +} + +static void destroy_inodecache(void) +{ + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); + kmem_cache_destroy(affs_inode_cachep); +} + +static const struct super_operations affs_sops = { + .alloc_inode = affs_alloc_inode, + .free_inode = affs_free_inode, + .write_inode = affs_write_inode, + .evict_inode = affs_evict_inode, + .put_super = affs_put_super, + .sync_fs = affs_sync_fs, + .statfs = affs_statfs, + .show_options = affs_show_options, +}; + +enum { + Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect, + Opt_reserved, Opt_root, Opt_setgid, Opt_setuid, + Opt_verbose, Opt_volume, Opt_ignore, +}; + +struct affs_context { + kuid_t uid; /* uid to override */ + kgid_t gid; /* gid to override */ + unsigned int mode; /* mode to override */ + unsigned int reserved; /* Number of reserved blocks */ + int root_block; /* FFS root block number */ + int blocksize; /* Initial device blksize */ + char *prefix; /* Prefix for volumes and assigns */ + char volume[32]; /* Vol. prefix for absolute symlinks */ + unsigned long mount_flags; /* Options */ +}; + +static const struct fs_parameter_spec affs_param_spec[] = { + fsparam_u32 ("bs", Opt_bs), + fsparam_u32oct ("mode", Opt_mode), + fsparam_flag ("mufs", Opt_mufs), + fsparam_flag ("nofilenametruncate", Opt_notruncate), + fsparam_string ("prefix", Opt_prefix), + fsparam_flag ("protect", Opt_protect), + fsparam_u32 ("reserved", Opt_reserved), + fsparam_u32 ("root", Opt_root), + fsparam_gid ("setgid", Opt_setgid), + fsparam_uid ("setuid", Opt_setuid), + fsparam_flag ("verbose", Opt_verbose), + fsparam_string ("volume", Opt_volume), + fsparam_flag ("grpquota", Opt_ignore), + fsparam_flag ("noquota", Opt_ignore), + fsparam_flag ("quota", Opt_ignore), + fsparam_flag ("usrquota", Opt_ignore), + {}, +}; + +static int affs_parse_param(struct fs_context *fc, struct fs_parameter *param) +{ + struct affs_context *ctx = fc->fs_private; + struct fs_parse_result result; + int n; + int opt; + + opt = fs_parse(fc, affs_param_spec, param, &result); + if (opt < 0) + return opt; + + switch (opt) { + case Opt_bs: + n = result.uint_32; + if (n != 512 && n != 1024 && n != 2048 + && n != 4096) { + pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n"); + return -EINVAL; + } + ctx->blocksize = n; + break; + case Opt_mode: + ctx->mode = result.uint_32 & 0777; + affs_set_opt(ctx->mount_flags, SF_SETMODE); + break; + case Opt_mufs: + affs_set_opt(ctx->mount_flags, SF_MUFS); + break; + case Opt_notruncate: + affs_set_opt(ctx->mount_flags, SF_NO_TRUNCATE); + break; + case Opt_prefix: + kfree(ctx->prefix); + ctx->prefix = param->string; + param->string = NULL; + affs_set_opt(ctx->mount_flags, SF_PREFIX); + break; + case Opt_protect: + affs_set_opt(ctx->mount_flags, SF_IMMUTABLE); + break; + case Opt_reserved: + ctx->reserved = result.uint_32; + break; + case Opt_root: + ctx->root_block = result.uint_32; + break; + case Opt_setgid: + ctx->gid = result.gid; + affs_set_opt(ctx->mount_flags, SF_SETGID); + break; + case Opt_setuid: + ctx->uid = result.uid; + affs_set_opt(ctx->mount_flags, SF_SETUID); + break; + case Opt_verbose: + affs_set_opt(ctx->mount_flags, SF_VERBOSE); + break; + case Opt_volume: + strscpy(ctx->volume, param->string, 32); + break; + case Opt_ignore: + /* Silently ignore the quota options */ + break; + default: + return -EINVAL; + } + return 0; +} + +static int affs_show_options(struct seq_file *m, struct dentry *root) +{ + struct super_block *sb = root->d_sb; + struct affs_sb_info *sbi = AFFS_SB(sb); + + if (sb->s_blocksize) + seq_printf(m, ",bs=%lu", sb->s_blocksize); + if (affs_test_opt(sbi->s_flags, SF_SETMODE)) + seq_printf(m, ",mode=%o", sbi->s_mode); + if (affs_test_opt(sbi->s_flags, SF_MUFS)) + seq_puts(m, ",mufs"); + if (affs_test_opt(sbi->s_flags, SF_NO_TRUNCATE)) + seq_puts(m, ",nofilenametruncate"); + if (affs_test_opt(sbi->s_flags, SF_PREFIX)) + seq_printf(m, ",prefix=%s", sbi->s_prefix); + if (affs_test_opt(sbi->s_flags, SF_IMMUTABLE)) + seq_puts(m, ",protect"); + if (sbi->s_reserved != 2) + seq_printf(m, ",reserved=%u", sbi->s_reserved); + if (sbi->s_root_block != (sbi->s_reserved + sbi->s_partition_size - 1) / 2) + seq_printf(m, ",root=%u", sbi->s_root_block); + if (affs_test_opt(sbi->s_flags, SF_SETGID)) + seq_printf(m, ",setgid=%u", + from_kgid_munged(&init_user_ns, sbi->s_gid)); + if (affs_test_opt(sbi->s_flags, SF_SETUID)) + seq_printf(m, ",setuid=%u", + from_kuid_munged(&init_user_ns, sbi->s_uid)); + if (affs_test_opt(sbi->s_flags, SF_VERBOSE)) + seq_puts(m, ",verbose"); + if (sbi->s_volume[0]) + seq_printf(m, ",volume=%s", sbi->s_volume); + return 0; +} + +/* This function definitely needs to be split up. Some fine day I'll + * hopefully have the guts to do so. Until then: sorry for the mess. + */ + +static int affs_fill_super(struct super_block *sb, struct fs_context *fc) +{ + struct affs_sb_info *sbi; + struct affs_context *ctx = fc->fs_private; + struct buffer_head *root_bh = NULL; + struct buffer_head *boot_bh; + struct inode *root_inode = NULL; + int silent = fc->sb_flags & SB_SILENT; + int size, blocksize; + u32 chksum; + int num_bm; + int i, j; + int tmp_flags; /* fix remount prototype... */ + u8 sig[4]; + int ret; + + sb->s_magic = AFFS_SUPER_MAGIC; + sb->s_op = &affs_sops; + sb->s_flags |= SB_NODIRATIME; + + sb->s_time_gran = NSEC_PER_SEC; + sb->s_time_min = sys_tz.tz_minuteswest * 60 + AFFS_EPOCH_DELTA; + sb->s_time_max = 86400LL * U32_MAX + 86400 + sb->s_time_min; + + sbi = kzalloc_obj(struct affs_sb_info); + if (!sbi) + return -ENOMEM; + + sb->s_fs_info = sbi; + sbi->sb = sb; + mutex_init(&sbi->s_bmlock); + spin_lock_init(&sbi->symlink_lock); + spin_lock_init(&sbi->work_lock); + INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock); + + sbi->s_flags = ctx->mount_flags; + sbi->s_mode = ctx->mode; + sbi->s_uid = ctx->uid; + sbi->s_gid = ctx->gid; + sbi->s_reserved = ctx->reserved; + sbi->s_prefix = ctx->prefix; + ctx->prefix = NULL; + memcpy(sbi->s_volume, ctx->volume, 32); + + /* N.B. after this point s_prefix must be released */ + + /* Get the size of the device in 512-byte blocks. + * If we later see that the partition uses bigger + * blocks, we will have to change it. + */ + + size = bdev_nr_sectors(sb->s_bdev); + pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size); + + if (!sb_set_blocksize(sb, PAGE_SIZE)) + return -EINVAL; + /* Try to find root block. Its location depends on the block size. */ + + i = bdev_logical_block_size(sb->s_bdev); + j = PAGE_SIZE; + blocksize = ctx->blocksize; + if (blocksize > 0) { + i = j = blocksize; + size = size / (blocksize / 512); + } + + for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) { + sbi->s_root_block = ctx->root_block; + if (ctx->root_block < 0) + sbi->s_root_block = (ctx->reserved + size - 1) / 2; + pr_debug("setting blocksize to %d\n", blocksize); + if (!sb_set_blocksize(sb, blocksize)) + return -EINVAL; + sbi->s_partition_size = size; + + /* The root block location that was calculated above is not + * correct if the partition size is an odd number of 512- + * byte blocks, which will be rounded down to a number of + * 1024-byte blocks, and if there were an even number of + * reserved blocks. Ideally, all partition checkers should + * report the real number of blocks of the real blocksize, + * but since this just cannot be done, we have to try to + * find the root block anyways. In the above case, it is one + * block behind the calculated one. So we check this one, too. + */ + for (num_bm = 0; num_bm < 2; num_bm++) { + pr_debug("Dev %s, trying root=%u, bs=%d, " + "size=%d, reserved=%d\n", + sb->s_id, + sbi->s_root_block + num_bm, + ctx->blocksize, size, ctx->reserved); + root_bh = affs_bread(sb, sbi->s_root_block + num_bm); + if (!root_bh) + continue; + if (!affs_checksum_block(sb, root_bh) && + be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT && + be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) { + sbi->s_hashsize = blocksize / 4 - 56; + sbi->s_root_block += num_bm; + goto got_root; + } + affs_brelse(root_bh); + root_bh = NULL; + } + } + if (!silent) + pr_err("No valid root block on device %s\n", sb->s_id); + return -EINVAL; + + /* N.B. after this point bh must be released */ +got_root: + /* Keep super block in cache */ + sbi->s_root_bh = root_bh; + ctx->root_block = sbi->s_root_block; + + /* Find out which kind of FS we have */ + boot_bh = sb_bread(sb, 0); + if (!boot_bh) { + pr_err("Cannot read boot block\n"); + return -EINVAL; + } + memcpy(sig, boot_bh->b_data, 4); + brelse(boot_bh); + chksum = be32_to_cpu(*(__be32 *)sig); + + /* Dircache filesystems are compatible with non-dircache ones + * when reading. As long as they aren't supported, writing is + * not recommended. + */ + if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS + || chksum == MUFS_DCOFS) && !sb_rdonly(sb)) { + pr_notice("Dircache FS - mounting %s read only\n", sb->s_id); + sb->s_flags |= SB_RDONLY; + } + switch (chksum) { + case MUFS_FS: + case MUFS_INTLFFS: + case MUFS_DCFFS: + affs_set_opt(sbi->s_flags, SF_MUFS); + fallthrough; + case FS_INTLFFS: + case FS_DCFFS: + affs_set_opt(sbi->s_flags, SF_INTL); + break; + case MUFS_FFS: + affs_set_opt(sbi->s_flags, SF_MUFS); + break; + case FS_FFS: + break; + case MUFS_OFS: + affs_set_opt(sbi->s_flags, SF_MUFS); + fallthrough; + case FS_OFS: + affs_set_opt(sbi->s_flags, SF_OFS); + sb->s_flags |= SB_NOEXEC; + break; + case MUFS_DCOFS: + case MUFS_INTLOFS: + affs_set_opt(sbi->s_flags, SF_MUFS); + fallthrough; + case FS_DCOFS: + case FS_INTLOFS: + affs_set_opt(sbi->s_flags, SF_INTL); + affs_set_opt(sbi->s_flags, SF_OFS); + sb->s_flags |= SB_NOEXEC; + break; + default: + pr_err("Unknown filesystem on device %s: %08X\n", + sb->s_id, chksum); + return -EINVAL; + } + + if (affs_test_opt(ctx->mount_flags, SF_VERBOSE)) { + u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0]; + pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n", + len > 31 ? 31 : len, + AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1, + sig, sig[3] + '0', blocksize); + } + + sb->s_flags |= SB_NODEV | SB_NOSUID; + + sbi->s_data_blksize = sb->s_blocksize; + if (affs_test_opt(sbi->s_flags, SF_OFS)) + sbi->s_data_blksize -= 24; + + tmp_flags = sb->s_flags; + ret = affs_init_bitmap(sb, &tmp_flags); + if (ret) + return ret; + sb->s_flags = tmp_flags; + + /* set up enough so that it can read an inode */ + + root_inode = affs_iget(sb, ctx->root_block); + if (IS_ERR(root_inode)) + return PTR_ERR(root_inode); + + if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL)) + set_default_d_op(sb, &affs_intl_dentry_operations); + else + set_default_d_op(sb, &affs_dentry_operations); + + sb->s_root = d_make_root(root_inode); + if (!sb->s_root) { + pr_err("AFFS: Get root inode failed\n"); + return -ENOMEM; + } + + sb->s_export_op = &affs_export_ops; + pr_debug("s_flags=%lX\n", sb->s_flags); + return 0; +} + +static int affs_reconfigure(struct fs_context *fc) +{ + struct super_block *sb = fc->root->d_sb; + struct affs_context *ctx = fc->fs_private; + struct affs_sb_info *sbi = AFFS_SB(sb); + int res = 0; + + sync_filesystem(sb); + fc->sb_flags |= SB_NODIRATIME; + + flush_delayed_work(&sbi->sb_work); + + /* + * NB: Historically, only mount_flags, mode, uid, gic, prefix, + * and volume are accepted during remount. + */ + sbi->s_flags = ctx->mount_flags; + sbi->s_mode = ctx->mode; + sbi->s_uid = ctx->uid; + sbi->s_gid = ctx->gid; + /* protect against readers */ + spin_lock(&sbi->symlink_lock); + if (ctx->prefix) { + kfree(sbi->s_prefix); + sbi->s_prefix = ctx->prefix; + ctx->prefix = NULL; + } + memcpy(sbi->s_volume, ctx->volume, 32); + spin_unlock(&sbi->symlink_lock); + + if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb)) + return 0; + + if (fc->sb_flags & SB_RDONLY) + affs_free_bitmap(sb); + else + res = affs_init_bitmap(sb, &fc->sb_flags); + + return res; +} + +static int +affs_statfs(struct dentry *dentry, struct kstatfs *buf) +{ + struct super_block *sb = dentry->d_sb; + int free; + u64 id = huge_encode_dev(sb->s_bdev->bd_dev); + + pr_debug("%s() partsize=%d, reserved=%d\n", + __func__, AFFS_SB(sb)->s_partition_size, + AFFS_SB(sb)->s_reserved); + + free = affs_count_free_blocks(sb); + buf->f_type = AFFS_SUPER_MAGIC; + buf->f_bsize = sb->s_blocksize; + buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved; + buf->f_bfree = free; + buf->f_bavail = free; + buf->f_fsid = u64_to_fsid(id); + buf->f_namelen = AFFSNAMEMAX; + return 0; +} + +static int affs_get_tree(struct fs_context *fc) +{ + return get_tree_bdev(fc, affs_fill_super); +} + +static void affs_kill_sb(struct super_block *sb) +{ + struct affs_sb_info *sbi = AFFS_SB(sb); + kill_block_super(sb); + if (sbi) { + affs_free_bitmap(sb); + affs_brelse(sbi->s_root_bh); + kfree(sbi->s_prefix); + mutex_destroy(&sbi->s_bmlock); + kfree_rcu(sbi, rcu); + } +} + +static void affs_free_fc(struct fs_context *fc) +{ + struct affs_context *ctx = fc->fs_private; + + kfree(ctx->prefix); + kfree(ctx); +} + +static const struct fs_context_operations affs_context_ops = { + .parse_param = affs_parse_param, + .get_tree = affs_get_tree, + .reconfigure = affs_reconfigure, + .free = affs_free_fc, +}; + +static int affs_init_fs_context(struct fs_context *fc) +{ + struct affs_context *ctx; + + ctx = kzalloc_obj(struct affs_context); + if (!ctx) + return -ENOMEM; + + if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) { + struct super_block *sb = fc->root->d_sb; + struct affs_sb_info *sbi = AFFS_SB(sb); + + /* + * NB: historically, no options other than volume were + * preserved across a remount unless they were explicitly + * passed in. + */ + memcpy(ctx->volume, sbi->s_volume, 32); + } else { + ctx->uid = current_uid(); + ctx->gid = current_gid(); + ctx->reserved = 2; + ctx->root_block = -1; + ctx->blocksize = -1; + ctx->volume[0] = ':'; + } + + fc->ops = &affs_context_ops; + fc->fs_private = ctx; + + return 0; +} + +static struct file_system_type affs_fs_type = { + .owner = THIS_MODULE, + .name = "affs", + .kill_sb = affs_kill_sb, + .fs_flags = FS_REQUIRES_DEV, + .init_fs_context = affs_init_fs_context, + .parameters = affs_param_spec, +}; +MODULE_ALIAS_FS("affs"); + +static int __init init_affs_fs(void) +{ + int err = init_inodecache(); + if (err) + goto out1; + err = register_filesystem(&affs_fs_type); + if (err) + goto out; + return 0; +out: + destroy_inodecache(); +out1: + return err; +} + +static void __exit exit_affs_fs(void) +{ + unregister_filesystem(&affs_fs_type); + destroy_inodecache(); +} + +MODULE_DESCRIPTION("Amiga filesystem support for Linux"); +MODULE_LICENSE("GPL"); + +module_init(init_affs_fs) +module_exit(exit_affs_fs) |
