--- /dev/null
+/*
+ * super.c
+ *
+ * Copyright (c) 1999 Al Smith
+ *
+ * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/exportfs.h>
+#include <linux/slab.h>
+#include <linux/buffer_head.h>
+#include <linux/vfs.h>
+
+#include "efs.h"
+#include <linux/efs_vh.h>
+#include <linux/efs_fs_sb.h>
+
+static int efs_statfs(struct dentry *dentry, struct kstatfs *buf);
+static int efs_fill_super(struct super_block *s, void *d, int silent);
+
+static struct dentry *efs_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return mount_bdev(fs_type, flags, dev_name, data, efs_fill_super);
+}
+
+static void efs_kill_sb(struct super_block *s)
+{
+ struct efs_sb_info *sbi = SUPER_INFO(s);
+ kill_block_super(s);
+ kfree(sbi);
+}
+
+static struct file_system_type efs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "efs",
+ .mount = efs_mount,
+ .kill_sb = efs_kill_sb,
+ .fs_flags = FS_REQUIRES_DEV,
+};
+MODULE_ALIAS_FS("efs");
+
+static struct pt_types sgi_pt_types[] = {
+ {0x00, "SGI vh"},
+ {0x01, "SGI trkrepl"},
+ {0x02, "SGI secrepl"},
+ {0x03, "SGI raw"},
+ {0x04, "SGI bsd"},
+ {SGI_SYSV, "SGI sysv"},
+ {0x06, "SGI vol"},
+ {SGI_EFS, "SGI efs"},
+ {0x08, "SGI lv"},
+ {0x09, "SGI rlv"},
+ {0x0A, "SGI xfs"},
+ {0x0B, "SGI xfslog"},
+ {0x0C, "SGI xlv"},
+ {0x82, "Linux swap"},
+ {0x83, "Linux native"},
+ {0, NULL}
+};
+
+
+static struct kmem_cache * efs_inode_cachep;
+
+static struct inode *efs_alloc_inode(struct super_block *sb)
+{
+ struct efs_inode_info *ei;
+ ei = (struct efs_inode_info *)kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL);
+ if (!ei)
+ return NULL;
+ return &ei->vfs_inode;
+}
+
+static void efs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ kmem_cache_free(efs_inode_cachep, INODE_INFO(inode));
+}
+
+static void efs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, efs_i_callback);
+}
+
+static void init_once(void *foo)
+{
+ struct efs_inode_info *ei = (struct efs_inode_info *) foo;
+
+ inode_init_once(&ei->vfs_inode);
+}
+
+static int __init init_inodecache(void)
+{
+ efs_inode_cachep = kmem_cache_create("efs_inode_cache",
+ sizeof(struct efs_inode_info),
+ 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
+ init_once);
+ if (efs_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(efs_inode_cachep);
+}
+
+static int efs_remount(struct super_block *sb, int *flags, char *data)
+{
+ sync_filesystem(sb);
+ *flags |= MS_RDONLY;
+ return 0;
+}
+
+static const struct super_operations efs_superblock_operations = {
+ .alloc_inode = efs_alloc_inode,
+ .destroy_inode = efs_destroy_inode,
+ .statfs = efs_statfs,
+ .remount_fs = efs_remount,
+};
+
+static const struct export_operations efs_export_ops = {
+ .fh_to_dentry = efs_fh_to_dentry,
+ .fh_to_parent = efs_fh_to_parent,
+ .get_parent = efs_get_parent,
+};
+
+static int __init init_efs_fs(void) {
+ int err;
+ pr_info(EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n");
+ err = init_inodecache();
+ if (err)
+ goto out1;
+ err = register_filesystem(&efs_fs_type);
+ if (err)
+ goto out;
+ return 0;
+out:
+ destroy_inodecache();
+out1:
+ return err;
+}
+
+static void __exit exit_efs_fs(void) {
+ unregister_filesystem(&efs_fs_type);
+ destroy_inodecache();
+}
+
+module_init(init_efs_fs)
+module_exit(exit_efs_fs)
+
+static efs_block_t efs_validate_vh(struct volume_header *vh) {
+ int i;
+ __be32 cs, *ui;
+ int csum;
+ efs_block_t sblock = 0; /* shuts up gcc */
+ struct pt_types *pt_entry;
+ int pt_type, slice = -1;
+
+ if (be32_to_cpu(vh->vh_magic) != VHMAGIC) {
+ /*
+ * assume that we're dealing with a partition and allow
+ * read_super() to try and detect a valid superblock
+ * on the next block.
+ */
+ return 0;
+ }
+
+ ui = ((__be32 *) (vh + 1)) - 1;
+ for(csum = 0; ui >= ((__be32 *) vh);) {
+ cs = *ui--;
+ csum += be32_to_cpu(cs);
+ }
+ if (csum) {
+ pr_warn("SGI disklabel: checksum bad, label corrupted\n");
+ return 0;
+ }
+
+#ifdef DEBUG
+ pr_debug("bf: \"%16s\"\n", vh->vh_bootfile);
+
+ for(i = 0; i < NVDIR; i++) {
+ int j;
+ char name[VDNAMESIZE+1];
+
+ for(j = 0; j < VDNAMESIZE; j++) {
+ name[j] = vh->vh_vd[i].vd_name[j];
+ }
+ name[j] = (char) 0;
+
+ if (name[0]) {
+ pr_debug("vh: %8s block: 0x%08x size: 0x%08x\n",
+ name, (int) be32_to_cpu(vh->vh_vd[i].vd_lbn),
+ (int) be32_to_cpu(vh->vh_vd[i].vd_nbytes));
+ }
+ }
+#endif
+
+ for(i = 0; i < NPARTAB; i++) {
+ pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type);
+ for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) {
+ if (pt_type == pt_entry->pt_type) break;
+ }
+#ifdef DEBUG
+ if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) {
+ pr_debug("pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n",
+ i, (int)be32_to_cpu(vh->vh_pt[i].pt_firstlbn),
+ (int)be32_to_cpu(vh->vh_pt[i].pt_nblks),
+ pt_type, (pt_entry->pt_name) ?
+ pt_entry->pt_name : "unknown");
+ }
+#endif
+ if (IS_EFS(pt_type)) {
+ sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn);
+ slice = i;
+ }
+ }
+
+ if (slice == -1) {
+ pr_notice("partition table contained no EFS partitions\n");
+#ifdef DEBUG
+ } else {
+ pr_info("using slice %d (type %s, offset 0x%x)\n", slice,
+ (pt_entry->pt_name) ? pt_entry->pt_name : "unknown",
+ sblock);
+#endif
+ }
+ return sblock;
+}
+
+static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) {
+
+ if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic)))
+ return -1;
+
+ sb->fs_magic = be32_to_cpu(super->fs_magic);
+ sb->total_blocks = be32_to_cpu(super->fs_size);
+ sb->first_block = be32_to_cpu(super->fs_firstcg);
+ sb->group_size = be32_to_cpu(super->fs_cgfsize);
+ sb->data_free = be32_to_cpu(super->fs_tfree);
+ sb->inode_free = be32_to_cpu(super->fs_tinode);
+ sb->inode_blocks = be16_to_cpu(super->fs_cgisize);
+ sb->total_groups = be16_to_cpu(super->fs_ncg);
+
+ return 0;
+}
+
+static int efs_fill_super(struct super_block *s, void *d, int silent)
+{
+ struct efs_sb_info *sb;
+ struct buffer_head *bh;
+ struct inode *root;
+
+ sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL);
+ if (!sb)
+ return -ENOMEM;
+ s->s_fs_info = sb;
+
+ s->s_magic = EFS_SUPER_MAGIC;
+ if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) {
+ pr_err("device does not support %d byte blocks\n",
+ EFS_BLOCKSIZE);
+ return -EINVAL;
+ }
+
+ /* read the vh (volume header) block */
+ bh = sb_bread(s, 0);
+
+ if (!bh) {
+ pr_err("cannot read volume header\n");
+ return -EINVAL;
+ }
+
+ /*
+ * if this returns zero then we didn't find any partition table.
+ * this isn't (yet) an error - just assume for the moment that
+ * the device is valid and go on to search for a superblock.
+ */
+ sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data);
+ brelse(bh);
+
+ if (sb->fs_start == -1) {
+ return -EINVAL;
+ }
+
+ bh = sb_bread(s, sb->fs_start + EFS_SUPER);
+ if (!bh) {
+ pr_err("cannot read superblock\n");
+ return -EINVAL;
+ }
+
+ if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) {
+#ifdef DEBUG
+ pr_warn("invalid superblock at block %u\n",
+ sb->fs_start + EFS_SUPER);
+#endif
+ brelse(bh);
+ return -EINVAL;
+ }
+ brelse(bh);
+
+ if (!(s->s_flags & MS_RDONLY)) {
+#ifdef DEBUG
+ pr_info("forcing read-only mode\n");
+#endif
+ s->s_flags |= MS_RDONLY;
+ }
+ s->s_op = &efs_superblock_operations;
+ s->s_export_op = &efs_export_ops;
+ root = efs_iget(s, EFS_ROOTINODE);
+ if (IS_ERR(root)) {
+ pr_err("get root inode failed\n");
+ return PTR_ERR(root);
+ }
+
+ s->s_root = d_make_root(root);
+ if (!(s->s_root)) {
+ pr_err("get root dentry failed\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) {
+ struct super_block *sb = dentry->d_sb;
+ struct efs_sb_info *sbi = SUPER_INFO(sb);
+ u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+
+ buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */
+ buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */
+ buf->f_blocks = sbi->total_groups * /* total data blocks */
+ (sbi->group_size - sbi->inode_blocks);
+ buf->f_bfree = sbi->data_free; /* free data blocks */
+ buf->f_bavail = sbi->data_free; /* free blocks for non-root */
+ buf->f_files = sbi->total_groups * /* total inodes */
+ sbi->inode_blocks *
+ (EFS_BLOCKSIZE / sizeof(struct efs_dinode));
+ buf->f_ffree = sbi->inode_free; /* free inodes */
+ buf->f_fsid.val[0] = (u32)id;
+ buf->f_fsid.val[1] = (u32)(id >> 32);
+ buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */
+
+ return 0;
+}
+
Code Review / kvmfornfv.git / blobdiff