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350 lines
8.1 KiB
350 lines
8.1 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* super.c |
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* |
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* Copyright (c) 1999 Al Smith |
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* |
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* Portions derived from work (c) 1995,1996 Christian Vogelgsang. |
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*/ |
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#include <linux/init.h> |
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#include <linux/module.h> |
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#include <linux/exportfs.h> |
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#include <linux/slab.h> |
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#include <linux/buffer_head.h> |
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#include <linux/vfs.h> |
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#include <linux/blkdev.h> |
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#include "efs.h" |
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#include <linux/efs_vh.h> |
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#include <linux/efs_fs_sb.h> |
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static int efs_statfs(struct dentry *dentry, struct kstatfs *buf); |
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static int efs_fill_super(struct super_block *s, void *d, int silent); |
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static struct dentry *efs_mount(struct file_system_type *fs_type, |
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int flags, const char *dev_name, void *data) |
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{ |
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return mount_bdev(fs_type, flags, dev_name, data, efs_fill_super); |
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} |
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static void efs_kill_sb(struct super_block *s) |
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{ |
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struct efs_sb_info *sbi = SUPER_INFO(s); |
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kill_block_super(s); |
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kfree(sbi); |
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} |
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static struct file_system_type efs_fs_type = { |
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.owner = THIS_MODULE, |
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.name = "efs", |
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.mount = efs_mount, |
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.kill_sb = efs_kill_sb, |
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.fs_flags = FS_REQUIRES_DEV, |
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}; |
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MODULE_ALIAS_FS("efs"); |
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static struct pt_types sgi_pt_types[] = { |
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{0x00, "SGI vh"}, |
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{0x01, "SGI trkrepl"}, |
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{0x02, "SGI secrepl"}, |
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{0x03, "SGI raw"}, |
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{0x04, "SGI bsd"}, |
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{SGI_SYSV, "SGI sysv"}, |
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{0x06, "SGI vol"}, |
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{SGI_EFS, "SGI efs"}, |
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{0x08, "SGI lv"}, |
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{0x09, "SGI rlv"}, |
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{0x0A, "SGI xfs"}, |
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{0x0B, "SGI xfslog"}, |
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{0x0C, "SGI xlv"}, |
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{0x82, "Linux swap"}, |
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{0x83, "Linux native"}, |
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{0, NULL} |
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}; |
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static struct kmem_cache * efs_inode_cachep; |
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static struct inode *efs_alloc_inode(struct super_block *sb) |
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{ |
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struct efs_inode_info *ei; |
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ei = alloc_inode_sb(sb, efs_inode_cachep, GFP_KERNEL); |
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if (!ei) |
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return NULL; |
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return &ei->vfs_inode; |
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} |
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static void efs_free_inode(struct inode *inode) |
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{ |
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kmem_cache_free(efs_inode_cachep, INODE_INFO(inode)); |
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} |
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static void init_once(void *foo) |
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{ |
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struct efs_inode_info *ei = (struct efs_inode_info *) foo; |
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inode_init_once(&ei->vfs_inode); |
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} |
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static int __init init_inodecache(void) |
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{ |
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efs_inode_cachep = kmem_cache_create("efs_inode_cache", |
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sizeof(struct efs_inode_info), 0, |
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SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD| |
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SLAB_ACCOUNT, init_once); |
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if (efs_inode_cachep == NULL) |
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return -ENOMEM; |
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return 0; |
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} |
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static void destroy_inodecache(void) |
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{ |
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/* |
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* Make sure all delayed rcu free inodes are flushed before we |
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* destroy cache. |
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*/ |
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rcu_barrier(); |
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kmem_cache_destroy(efs_inode_cachep); |
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} |
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static int efs_remount(struct super_block *sb, int *flags, char *data) |
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{ |
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sync_filesystem(sb); |
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*flags |= SB_RDONLY; |
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return 0; |
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} |
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static const struct super_operations efs_superblock_operations = { |
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.alloc_inode = efs_alloc_inode, |
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.free_inode = efs_free_inode, |
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.statfs = efs_statfs, |
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.remount_fs = efs_remount, |
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}; |
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static const struct export_operations efs_export_ops = { |
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.fh_to_dentry = efs_fh_to_dentry, |
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.fh_to_parent = efs_fh_to_parent, |
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.get_parent = efs_get_parent, |
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}; |
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static int __init init_efs_fs(void) { |
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int err; |
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pr_info(EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n"); |
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err = init_inodecache(); |
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if (err) |
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goto out1; |
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err = register_filesystem(&efs_fs_type); |
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if (err) |
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goto out; |
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return 0; |
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out: |
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destroy_inodecache(); |
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out1: |
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return err; |
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} |
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static void __exit exit_efs_fs(void) { |
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unregister_filesystem(&efs_fs_type); |
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destroy_inodecache(); |
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} |
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module_init(init_efs_fs) |
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module_exit(exit_efs_fs) |
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static efs_block_t efs_validate_vh(struct volume_header *vh) { |
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int i; |
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__be32 cs, *ui; |
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int csum; |
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efs_block_t sblock = 0; /* shuts up gcc */ |
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struct pt_types *pt_entry; |
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int pt_type, slice = -1; |
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if (be32_to_cpu(vh->vh_magic) != VHMAGIC) { |
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/* |
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* assume that we're dealing with a partition and allow |
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* read_super() to try and detect a valid superblock |
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* on the next block. |
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*/ |
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return 0; |
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} |
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ui = ((__be32 *) (vh + 1)) - 1; |
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for(csum = 0; ui >= ((__be32 *) vh);) { |
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cs = *ui--; |
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csum += be32_to_cpu(cs); |
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} |
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if (csum) { |
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pr_warn("SGI disklabel: checksum bad, label corrupted\n"); |
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return 0; |
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} |
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#ifdef DEBUG |
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pr_debug("bf: \"%16s\"\n", vh->vh_bootfile); |
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for(i = 0; i < NVDIR; i++) { |
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int j; |
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char name[VDNAMESIZE+1]; |
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for(j = 0; j < VDNAMESIZE; j++) { |
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name[j] = vh->vh_vd[i].vd_name[j]; |
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} |
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name[j] = (char) 0; |
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if (name[0]) { |
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pr_debug("vh: %8s block: 0x%08x size: 0x%08x\n", |
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name, (int) be32_to_cpu(vh->vh_vd[i].vd_lbn), |
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(int) be32_to_cpu(vh->vh_vd[i].vd_nbytes)); |
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} |
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} |
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#endif |
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for(i = 0; i < NPARTAB; i++) { |
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pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type); |
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for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) { |
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if (pt_type == pt_entry->pt_type) break; |
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} |
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#ifdef DEBUG |
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if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) { |
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pr_debug("pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n", |
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i, (int)be32_to_cpu(vh->vh_pt[i].pt_firstlbn), |
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(int)be32_to_cpu(vh->vh_pt[i].pt_nblks), |
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pt_type, (pt_entry->pt_name) ? |
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pt_entry->pt_name : "unknown"); |
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} |
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#endif |
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if (IS_EFS(pt_type)) { |
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sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn); |
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slice = i; |
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} |
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} |
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if (slice == -1) { |
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pr_notice("partition table contained no EFS partitions\n"); |
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#ifdef DEBUG |
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} else { |
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pr_info("using slice %d (type %s, offset 0x%x)\n", slice, |
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(pt_entry->pt_name) ? pt_entry->pt_name : "unknown", |
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sblock); |
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#endif |
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} |
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return sblock; |
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} |
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static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) { |
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if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic))) |
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return -1; |
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sb->fs_magic = be32_to_cpu(super->fs_magic); |
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sb->total_blocks = be32_to_cpu(super->fs_size); |
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sb->first_block = be32_to_cpu(super->fs_firstcg); |
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sb->group_size = be32_to_cpu(super->fs_cgfsize); |
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sb->data_free = be32_to_cpu(super->fs_tfree); |
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sb->inode_free = be32_to_cpu(super->fs_tinode); |
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sb->inode_blocks = be16_to_cpu(super->fs_cgisize); |
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sb->total_groups = be16_to_cpu(super->fs_ncg); |
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return 0; |
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} |
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static int efs_fill_super(struct super_block *s, void *d, int silent) |
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{ |
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struct efs_sb_info *sb; |
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struct buffer_head *bh; |
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struct inode *root; |
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sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL); |
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if (!sb) |
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return -ENOMEM; |
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s->s_fs_info = sb; |
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s->s_time_min = 0; |
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s->s_time_max = U32_MAX; |
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s->s_magic = EFS_SUPER_MAGIC; |
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if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) { |
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pr_err("device does not support %d byte blocks\n", |
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EFS_BLOCKSIZE); |
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return -EINVAL; |
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} |
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/* read the vh (volume header) block */ |
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bh = sb_bread(s, 0); |
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if (!bh) { |
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pr_err("cannot read volume header\n"); |
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return -EIO; |
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} |
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/* |
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* if this returns zero then we didn't find any partition table. |
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* this isn't (yet) an error - just assume for the moment that |
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* the device is valid and go on to search for a superblock. |
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*/ |
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sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data); |
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brelse(bh); |
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if (sb->fs_start == -1) { |
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return -EINVAL; |
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} |
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bh = sb_bread(s, sb->fs_start + EFS_SUPER); |
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if (!bh) { |
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pr_err("cannot read superblock\n"); |
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return -EIO; |
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} |
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if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) { |
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#ifdef DEBUG |
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pr_warn("invalid superblock at block %u\n", |
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sb->fs_start + EFS_SUPER); |
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#endif |
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brelse(bh); |
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return -EINVAL; |
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} |
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brelse(bh); |
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if (!sb_rdonly(s)) { |
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#ifdef DEBUG |
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pr_info("forcing read-only mode\n"); |
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#endif |
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s->s_flags |= SB_RDONLY; |
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} |
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s->s_op = &efs_superblock_operations; |
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s->s_export_op = &efs_export_ops; |
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root = efs_iget(s, EFS_ROOTINODE); |
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if (IS_ERR(root)) { |
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pr_err("get root inode failed\n"); |
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return PTR_ERR(root); |
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} |
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s->s_root = d_make_root(root); |
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if (!(s->s_root)) { |
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pr_err("get root dentry failed\n"); |
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return -ENOMEM; |
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} |
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return 0; |
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} |
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static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) { |
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struct super_block *sb = dentry->d_sb; |
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struct efs_sb_info *sbi = SUPER_INFO(sb); |
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u64 id = huge_encode_dev(sb->s_bdev->bd_dev); |
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buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */ |
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buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */ |
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buf->f_blocks = sbi->total_groups * /* total data blocks */ |
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(sbi->group_size - sbi->inode_blocks); |
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buf->f_bfree = sbi->data_free; /* free data blocks */ |
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buf->f_bavail = sbi->data_free; /* free blocks for non-root */ |
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buf->f_files = sbi->total_groups * /* total inodes */ |
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sbi->inode_blocks * |
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(EFS_BLOCKSIZE / sizeof(struct efs_dinode)); |
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buf->f_ffree = sbi->inode_free; /* free inodes */ |
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buf->f_fsid = u64_to_fsid(id); |
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buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */ |
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return 0; |
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} |
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