diff options
Diffstat (limited to 'fs/efs')
| -rw-r--r-- | fs/efs/Kconfig | 14 | ||||
| -rw-r--r-- | fs/efs/Makefile | 7 | ||||
| -rw-r--r-- | fs/efs/dir.c | 103 | ||||
| -rw-r--r-- | fs/efs/efs.h | 147 | ||||
| -rw-r--r-- | fs/efs/file.c | 57 | ||||
| -rw-r--r-- | fs/efs/inode.c | 312 | ||||
| -rw-r--r-- | fs/efs/namei.c | 120 | ||||
| -rw-r--r-- | fs/efs/super.c | 354 | ||||
| -rw-r--r-- | fs/efs/symlink.c | 53 |
9 files changed, 1167 insertions, 0 deletions
diff --git a/fs/efs/Kconfig b/fs/efs/Kconfig new file mode 100644 index 000000000..d020e3c30 --- /dev/null +++ b/fs/efs/Kconfig @@ -0,0 +1,14 @@ +config EFS_FS + tristate "EFS file system support (read only)" + depends on BLOCK + help + EFS is an older file system used for non-ISO9660 CD-ROMs and hard + disk partitions by SGI's IRIX operating system (IRIX 6.0 and newer + uses the XFS file system for hard disk partitions however). + + This implementation only offers read-only access. If you don't know + what all this is about, it's safe to say N. For more information + about EFS see its home page at <http://aeschi.ch.eu.org/efs/>. + + To compile the EFS file system support as a module, choose M here: the + module will be called efs. diff --git a/fs/efs/Makefile b/fs/efs/Makefile new file mode 100644 index 000000000..963543d46 --- /dev/null +++ b/fs/efs/Makefile @@ -0,0 +1,7 @@ +# +# Makefile for the linux efs-filesystem routines. +# + +obj-$(CONFIG_EFS_FS) += efs.o + +efs-objs := super.o inode.o namei.o dir.o file.o symlink.o diff --git a/fs/efs/dir.c b/fs/efs/dir.c new file mode 100644 index 000000000..f892ac7c2 --- /dev/null +++ b/fs/efs/dir.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * dir.c + * + * Copyright (c) 1999 Al Smith + */ + +#include <linux/buffer_head.h> +#include "efs.h" + +static int efs_readdir(struct file *, struct dir_context *); + +const struct file_operations efs_dir_operations = { + .llseek = generic_file_llseek, + .read = generic_read_dir, + .iterate_shared = efs_readdir, +}; + +const struct inode_operations efs_dir_inode_operations = { + .lookup = efs_lookup, +}; + +static int efs_readdir(struct file *file, struct dir_context *ctx) +{ + struct inode *inode = file_inode(file); + efs_block_t block; + int slot; + + if (inode->i_size & (EFS_DIRBSIZE-1)) + pr_warn("%s(): directory size not a multiple of EFS_DIRBSIZE\n", + __func__); + + /* work out where this entry can be found */ + block = ctx->pos >> EFS_DIRBSIZE_BITS; + + /* each block contains at most 256 slots */ + slot = ctx->pos & 0xff; + + /* look at all blocks */ + while (block < inode->i_blocks) { + struct efs_dir *dirblock; + struct buffer_head *bh; + + /* read the dir block */ + bh = sb_bread(inode->i_sb, efs_bmap(inode, block)); + + if (!bh) { + pr_err("%s(): failed to read dir block %d\n", + __func__, block); + break; + } + + dirblock = (struct efs_dir *) bh->b_data; + + if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) { + pr_err("%s(): invalid directory block\n", __func__); + brelse(bh); + break; + } + + for (; slot < dirblock->slots; slot++) { + struct efs_dentry *dirslot; + efs_ino_t inodenum; + const char *nameptr; + int namelen; + + if (dirblock->space[slot] == 0) + continue; + + dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot)); + + inodenum = be32_to_cpu(dirslot->inode); + namelen = dirslot->namelen; + nameptr = dirslot->name; + pr_debug("%s(): block %d slot %d/%d: inode %u, name \"%s\", namelen %u\n", + __func__, block, slot, dirblock->slots-1, + inodenum, nameptr, namelen); + if (!namelen) + continue; + /* found the next entry */ + ctx->pos = (block << EFS_DIRBSIZE_BITS) | slot; + + /* sanity check */ + if (nameptr - (char *) dirblock + namelen > EFS_DIRBSIZE) { + pr_warn("directory entry %d exceeds directory block\n", + slot); + continue; + } + + /* copy filename and data in dirslot */ + if (!dir_emit(ctx, nameptr, namelen, inodenum, DT_UNKNOWN)) { + brelse(bh); + return 0; + } + } + brelse(bh); + + slot = 0; + block++; + } + ctx->pos = (block << EFS_DIRBSIZE_BITS) | slot; + return 0; +} diff --git a/fs/efs/efs.h b/fs/efs/efs.h new file mode 100644 index 000000000..13a4d9622 --- /dev/null +++ b/fs/efs/efs.h @@ -0,0 +1,147 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 1999 Al Smith + * + * Portions derived from work (c) 1995,1996 Christian Vogelgsang. + * Portions derived from IRIX header files (c) 1988 Silicon Graphics + */ +#ifndef _EFS_EFS_H_ +#define _EFS_EFS_H_ + +#ifdef pr_fmt +#undef pr_fmt +#endif + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/fs.h> +#include <linux/uaccess.h> + +#define EFS_VERSION "1.0a" + +static const char cprt[] = "EFS: "EFS_VERSION" - (c) 1999 Al Smith <Al.Smith@aeschi.ch.eu.org>"; + + +/* 1 block is 512 bytes */ +#define EFS_BLOCKSIZE_BITS 9 +#define EFS_BLOCKSIZE (1 << EFS_BLOCKSIZE_BITS) + +typedef int32_t efs_block_t; +typedef uint32_t efs_ino_t; + +#define EFS_DIRECTEXTENTS 12 + +/* + * layout of an extent, in memory and on disk. 8 bytes exactly. + */ +typedef union extent_u { + unsigned char raw[8]; + struct extent_s { + unsigned int ex_magic:8; /* magic # (zero) */ + unsigned int ex_bn:24; /* basic block */ + unsigned int ex_length:8; /* numblocks in this extent */ + unsigned int ex_offset:24; /* logical offset into file */ + } cooked; +} efs_extent; + +typedef struct edevs { + __be16 odev; + __be32 ndev; +} efs_devs; + +/* + * extent based filesystem inode as it appears on disk. The efs inode + * is exactly 128 bytes long. + */ +struct efs_dinode { + __be16 di_mode; /* mode and type of file */ + __be16 di_nlink; /* number of links to file */ + __be16 di_uid; /* owner's user id */ + __be16 di_gid; /* owner's group id */ + __be32 di_size; /* number of bytes in file */ + __be32 di_atime; /* time last accessed */ + __be32 di_mtime; /* time last modified */ + __be32 di_ctime; /* time created */ + __be32 di_gen; /* generation number */ + __be16 di_numextents; /* # of extents */ + u_char di_version; /* version of inode */ + u_char di_spare; /* spare - used by AFS */ + union di_addr { + efs_extent di_extents[EFS_DIRECTEXTENTS]; + efs_devs di_dev; /* device for IFCHR/IFBLK */ + } di_u; +}; + +/* efs inode storage in memory */ +struct efs_inode_info { + int numextents; + int lastextent; + + efs_extent extents[EFS_DIRECTEXTENTS]; + struct inode vfs_inode; +}; + +#include <linux/efs_fs_sb.h> + +#define EFS_DIRBSIZE_BITS EFS_BLOCKSIZE_BITS +#define EFS_DIRBSIZE (1 << EFS_DIRBSIZE_BITS) + +struct efs_dentry { + __be32 inode; + unsigned char namelen; + char name[3]; +}; + +#define EFS_DENTSIZE (sizeof(struct efs_dentry) - 3 + 1) +#define EFS_MAXNAMELEN ((1 << (sizeof(char) * 8)) - 1) + +#define EFS_DIRBLK_HEADERSIZE 4 +#define EFS_DIRBLK_MAGIC 0xbeef /* moo */ + +struct efs_dir { + __be16 magic; + unsigned char firstused; + unsigned char slots; + + unsigned char space[EFS_DIRBSIZE - EFS_DIRBLK_HEADERSIZE]; +}; + +#define EFS_MAXENTS \ + ((EFS_DIRBSIZE - EFS_DIRBLK_HEADERSIZE) / \ + (EFS_DENTSIZE + sizeof(char))) + +#define EFS_SLOTAT(dir, slot) EFS_REALOFF((dir)->space[slot]) + +#define EFS_REALOFF(offset) ((offset << 1)) + + +static inline struct efs_inode_info *INODE_INFO(struct inode *inode) +{ + return container_of(inode, struct efs_inode_info, vfs_inode); +} + +static inline struct efs_sb_info *SUPER_INFO(struct super_block *sb) +{ + return sb->s_fs_info; +} + +struct statfs; +struct fid; + +extern const struct inode_operations efs_dir_inode_operations; +extern const struct file_operations efs_dir_operations; +extern const struct address_space_operations efs_symlink_aops; + +extern struct inode *efs_iget(struct super_block *, unsigned long); +extern efs_block_t efs_map_block(struct inode *, efs_block_t); +extern int efs_get_block(struct inode *, sector_t, struct buffer_head *, int); + +extern struct dentry *efs_lookup(struct inode *, struct dentry *, unsigned int); +extern struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid, + int fh_len, int fh_type); +extern struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid, + int fh_len, int fh_type); +extern struct dentry *efs_get_parent(struct dentry *); +extern int efs_bmap(struct inode *, int); + +#endif /* _EFS_EFS_H_ */ diff --git a/fs/efs/file.c b/fs/efs/file.c new file mode 100644 index 000000000..9e641da6f --- /dev/null +++ b/fs/efs/file.c @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * file.c + * + * Copyright (c) 1999 Al Smith + * + * Portions derived from work (c) 1995,1996 Christian Vogelgsang. + */ + +#include <linux/buffer_head.h> +#include "efs.h" + +int efs_get_block(struct inode *inode, sector_t iblock, + struct buffer_head *bh_result, int create) +{ + int error = -EROFS; + long phys; + + if (create) + return error; + if (iblock >= inode->i_blocks) { +#ifdef DEBUG + /* + * i have no idea why this happens as often as it does + */ + pr_warn("%s(): block %d >= %ld (filesize %ld)\n", + __func__, block, inode->i_blocks, inode->i_size); +#endif + return 0; + } + phys = efs_map_block(inode, iblock); + if (phys) + map_bh(bh_result, inode->i_sb, phys); + return 0; +} + +int efs_bmap(struct inode *inode, efs_block_t block) { + + if (block < 0) { + pr_warn("%s(): block < 0\n", __func__); + return 0; + } + + /* are we about to read past the end of a file ? */ + if (!(block < inode->i_blocks)) { +#ifdef DEBUG + /* + * i have no idea why this happens as often as it does + */ + pr_warn("%s(): block %d >= %ld (filesize %ld)\n", + __func__, block, inode->i_blocks, inode->i_size); +#endif + return 0; + } + + return efs_map_block(inode, block); +} diff --git a/fs/efs/inode.c b/fs/efs/inode.c new file mode 100644 index 000000000..cdf087238 --- /dev/null +++ b/fs/efs/inode.c @@ -0,0 +1,312 @@ +/* + * inode.c + * + * Copyright (c) 1999 Al Smith + * + * Portions derived from work (c) 1995,1996 Christian Vogelgsang, + * and from work (c) 1998 Mike Shaver. + */ + +#include <linux/buffer_head.h> +#include <linux/module.h> +#include <linux/fs.h> +#include "efs.h" +#include <linux/efs_fs_sb.h> + +static int efs_readpage(struct file *file, struct page *page) +{ + return block_read_full_page(page,efs_get_block); +} +static sector_t _efs_bmap(struct address_space *mapping, sector_t block) +{ + return generic_block_bmap(mapping,block,efs_get_block); +} +static const struct address_space_operations efs_aops = { + .readpage = efs_readpage, + .bmap = _efs_bmap +}; + +static inline void extent_copy(efs_extent *src, efs_extent *dst) { + /* + * this is slightly evil. it doesn't just copy + * efs_extent from src to dst, it also mangles + * the bits so that dst ends up in cpu byte-order. + */ + + dst->cooked.ex_magic = (unsigned int) src->raw[0]; + dst->cooked.ex_bn = ((unsigned int) src->raw[1] << 16) | + ((unsigned int) src->raw[2] << 8) | + ((unsigned int) src->raw[3] << 0); + dst->cooked.ex_length = (unsigned int) src->raw[4]; + dst->cooked.ex_offset = ((unsigned int) src->raw[5] << 16) | + ((unsigned int) src->raw[6] << 8) | + ((unsigned int) src->raw[7] << 0); + return; +} + +struct inode *efs_iget(struct super_block *super, unsigned long ino) +{ + int i, inode_index; + dev_t device; + u32 rdev; + struct buffer_head *bh; + struct efs_sb_info *sb = SUPER_INFO(super); + struct efs_inode_info *in; + efs_block_t block, offset; + struct efs_dinode *efs_inode; + struct inode *inode; + + inode = iget_locked(super, ino); + if (!inode) + return ERR_PTR(-ENOMEM); + if (!(inode->i_state & I_NEW)) + return inode; + + in = INODE_INFO(inode); + + /* + ** EFS layout: + ** + ** | cylinder group | cylinder group | cylinder group ..etc + ** |inodes|data |inodes|data |inodes|data ..etc + ** + ** work out the inode block index, (considering initially that the + ** inodes are stored as consecutive blocks). then work out the block + ** number of that inode given the above layout, and finally the + ** offset of the inode within that block. + */ + + inode_index = inode->i_ino / + (EFS_BLOCKSIZE / sizeof(struct efs_dinode)); + + block = sb->fs_start + sb->first_block + + (sb->group_size * (inode_index / sb->inode_blocks)) + + (inode_index % sb->inode_blocks); + + offset = (inode->i_ino % + (EFS_BLOCKSIZE / sizeof(struct efs_dinode))) * + sizeof(struct efs_dinode); + + bh = sb_bread(inode->i_sb, block); + if (!bh) { + pr_warn("%s() failed at block %d\n", __func__, block); + goto read_inode_error; + } + + efs_inode = (struct efs_dinode *) (bh->b_data + offset); + + inode->i_mode = be16_to_cpu(efs_inode->di_mode); + set_nlink(inode, be16_to_cpu(efs_inode->di_nlink)); + i_uid_write(inode, (uid_t)be16_to_cpu(efs_inode->di_uid)); + i_gid_write(inode, (gid_t)be16_to_cpu(efs_inode->di_gid)); + inode->i_size = be32_to_cpu(efs_inode->di_size); + inode->i_atime.tv_sec = be32_to_cpu(efs_inode->di_atime); + inode->i_mtime.tv_sec = be32_to_cpu(efs_inode->di_mtime); + inode->i_ctime.tv_sec = be32_to_cpu(efs_inode->di_ctime); + inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; + + /* this is the number of blocks in the file */ + if (inode->i_size == 0) { + inode->i_blocks = 0; + } else { + inode->i_blocks = ((inode->i_size - 1) >> EFS_BLOCKSIZE_BITS) + 1; + } + + rdev = be16_to_cpu(efs_inode->di_u.di_dev.odev); + if (rdev == 0xffff) { + rdev = be32_to_cpu(efs_inode->di_u.di_dev.ndev); + if (sysv_major(rdev) > 0xfff) + device = 0; + else + device = MKDEV(sysv_major(rdev), sysv_minor(rdev)); + } else + device = old_decode_dev(rdev); + + /* get the number of extents for this object */ + in->numextents = be16_to_cpu(efs_inode->di_numextents); + in->lastextent = 0; + + /* copy the extents contained within the inode to memory */ + for(i = 0; i < EFS_DIRECTEXTENTS; i++) { + extent_copy(&(efs_inode->di_u.di_extents[i]), &(in->extents[i])); + if (i < in->numextents && in->extents[i].cooked.ex_magic != 0) { + pr_warn("extent %d has bad magic number in inode %lu\n", + i, inode->i_ino); + brelse(bh); + goto read_inode_error; + } + } + + brelse(bh); + pr_debug("efs_iget(): inode %lu, extents %d, mode %o\n", + inode->i_ino, in->numextents, inode->i_mode); + switch (inode->i_mode & S_IFMT) { + case S_IFDIR: + inode->i_op = &efs_dir_inode_operations; + inode->i_fop = &efs_dir_operations; + break; + case S_IFREG: + inode->i_fop = &generic_ro_fops; + inode->i_data.a_ops = &efs_aops; + break; + case S_IFLNK: + inode->i_op = &page_symlink_inode_operations; + inode_nohighmem(inode); + inode->i_data.a_ops = &efs_symlink_aops; + break; + case S_IFCHR: + case S_IFBLK: + case S_IFIFO: + init_special_inode(inode, inode->i_mode, device); + break; + default: + pr_warn("unsupported inode mode %o\n", inode->i_mode); + goto read_inode_error; + break; + } + + unlock_new_inode(inode); + return inode; + +read_inode_error: + pr_warn("failed to read inode %lu\n", inode->i_ino); + iget_failed(inode); + return ERR_PTR(-EIO); +} + +static inline efs_block_t +efs_extent_check(efs_extent *ptr, efs_block_t block, struct efs_sb_info *sb) { + efs_block_t start; + efs_block_t length; + efs_block_t offset; + + /* + * given an extent and a logical block within a file, + * can this block be found within this extent ? + */ + start = ptr->cooked.ex_bn; + length = ptr->cooked.ex_length; + offset = ptr->cooked.ex_offset; + + if ((block >= offset) && (block < offset+length)) { + return(sb->fs_start + start + block - offset); + } else { + return 0; + } +} + +efs_block_t efs_map_block(struct inode *inode, efs_block_t block) { + struct efs_sb_info *sb = SUPER_INFO(inode->i_sb); + struct efs_inode_info *in = INODE_INFO(inode); + struct buffer_head *bh = NULL; + + int cur, last, first = 1; + int ibase, ioffset, dirext, direxts, indext, indexts; + efs_block_t iblock, result = 0, lastblock = 0; + efs_extent ext, *exts; + + last = in->lastextent; + + if (in->numextents <= EFS_DIRECTEXTENTS) { + /* first check the last extent we returned */ + if ((result = efs_extent_check(&in->extents[last], block, sb))) + return result; + + /* if we only have one extent then nothing can be found */ + if (in->numextents == 1) { + pr_err("%s() failed to map (1 extent)\n", __func__); + return 0; + } + + direxts = in->numextents; + + /* + * check the stored extents in the inode + * start with next extent and check forwards + */ + for(dirext = 1; dirext < direxts; dirext++) { + cur = (last + dirext) % in->numextents; + if ((result = efs_extent_check(&in->extents[cur], block, sb))) { + in->lastextent = cur; + return result; + } + } + + pr_err("%s() failed to map block %u (dir)\n", __func__, block); + return 0; + } + + pr_debug("%s(): indirect search for logical block %u\n", + __func__, block); + direxts = in->extents[0].cooked.ex_offset; + indexts = in->numextents; + + for(indext = 0; indext < indexts; indext++) { + cur = (last + indext) % indexts; + + /* + * work out which direct extent contains `cur'. + * + * also compute ibase: i.e. the number of the first + * indirect extent contained within direct extent `cur'. + * + */ + ibase = 0; + for(dirext = 0; cur < ibase && dirext < direxts; dirext++) { + ibase += in->extents[dirext].cooked.ex_length * + (EFS_BLOCKSIZE / sizeof(efs_extent)); + } + + if (dirext == direxts) { + /* should never happen */ + pr_err("couldn't find direct extent for indirect extent %d (block %u)\n", + cur, block); + if (bh) brelse(bh); + return 0; + } + + /* work out block number and offset of this indirect extent */ + iblock = sb->fs_start + in->extents[dirext].cooked.ex_bn + + (cur - ibase) / + (EFS_BLOCKSIZE / sizeof(efs_extent)); + ioffset = (cur - ibase) % + (EFS_BLOCKSIZE / sizeof(efs_extent)); + + if (first || lastblock != iblock) { + if (bh) brelse(bh); + + bh = sb_bread(inode->i_sb, iblock); + if (!bh) { + pr_err("%s() failed at block %d\n", + __func__, iblock); + return 0; + } + pr_debug("%s(): read indirect extent block %d\n", + __func__, iblock); + first = 0; + lastblock = iblock; + } + + exts = (efs_extent *) bh->b_data; + + extent_copy(&(exts[ioffset]), &ext); + + if (ext.cooked.ex_magic != 0) { + pr_err("extent %d has bad magic number in block %d\n", + cur, iblock); + if (bh) brelse(bh); + return 0; + } + + if ((result = efs_extent_check(&ext, block, sb))) { + if (bh) brelse(bh); + in->lastextent = cur; + return result; + } + } + if (bh) brelse(bh); + pr_err("%s() failed to map block %u (indir)\n", __func__, block); + return 0; +} + +MODULE_LICENSE("GPL"); diff --git a/fs/efs/namei.c b/fs/efs/namei.c new file mode 100644 index 000000000..38961ee1d --- /dev/null +++ b/fs/efs/namei.c @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * namei.c + * + * Copyright (c) 1999 Al Smith + * + * Portions derived from work (c) 1995,1996 Christian Vogelgsang. + */ + +#include <linux/buffer_head.h> +#include <linux/string.h> +#include <linux/exportfs.h> +#include "efs.h" + + +static efs_ino_t efs_find_entry(struct inode *inode, const char *name, int len) +{ + struct buffer_head *bh; + + int slot, namelen; + char *nameptr; + struct efs_dir *dirblock; + struct efs_dentry *dirslot; + efs_ino_t inodenum; + efs_block_t block; + + if (inode->i_size & (EFS_DIRBSIZE-1)) + pr_warn("%s(): directory size not a multiple of EFS_DIRBSIZE\n", + __func__); + + for(block = 0; block < inode->i_blocks; block++) { + + bh = sb_bread(inode->i_sb, efs_bmap(inode, block)); + if (!bh) { + pr_err("%s(): failed to read dir block %d\n", + __func__, block); + return 0; + } + + dirblock = (struct efs_dir *) bh->b_data; + + if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) { + pr_err("%s(): invalid directory block\n", __func__); + brelse(bh); + return 0; + } + + for (slot = 0; slot < dirblock->slots; slot++) { + dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot)); + + namelen = dirslot->namelen; + nameptr = dirslot->name; + + if ((namelen == len) && (!memcmp(name, nameptr, len))) { + inodenum = be32_to_cpu(dirslot->inode); + brelse(bh); + return inodenum; + } + } + brelse(bh); + } + return 0; +} + +struct dentry *efs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) +{ + efs_ino_t inodenum; + struct inode *inode = NULL; + + inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len); + if (inodenum) + inode = efs_iget(dir->i_sb, inodenum); + + return d_splice_alias(inode, dentry); +} + +static struct inode *efs_nfs_get_inode(struct super_block *sb, u64 ino, + u32 generation) +{ + struct inode *inode; + + if (ino == 0) + return ERR_PTR(-ESTALE); + inode = efs_iget(sb, ino); + if (IS_ERR(inode)) + return ERR_CAST(inode); + + if (generation && inode->i_generation != generation) { + iput(inode); + return ERR_PTR(-ESTALE); + } + + return inode; +} + +struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid, + int fh_len, int fh_type) +{ + return generic_fh_to_dentry(sb, fid, fh_len, fh_type, + efs_nfs_get_inode); +} + +struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid, + int fh_len, int fh_type) +{ + return generic_fh_to_parent(sb, fid, fh_len, fh_type, + efs_nfs_get_inode); +} + +struct dentry *efs_get_parent(struct dentry *child) +{ + struct dentry *parent = ERR_PTR(-ENOENT); + efs_ino_t ino; + + ino = efs_find_entry(d_inode(child), "..", 2); + if (ino) + parent = d_obtain_alias(efs_iget(child->d_sb, ino)); + + return parent; +} diff --git a/fs/efs/super.c b/fs/efs/super.c new file mode 100644 index 000000000..6ffb7ba15 --- /dev/null +++ b/fs/efs/super.c @@ -0,0 +1,354 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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 = 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| + SLAB_ACCOUNT, 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 |= SB_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 -EIO; + } + + /* + * 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 -EIO; + } + + 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 (!sb_rdonly(s)) { +#ifdef DEBUG + pr_info("forcing read-only mode\n"); +#endif + s->s_flags |= SB_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; +} + diff --git a/fs/efs/symlink.c b/fs/efs/symlink.c new file mode 100644 index 000000000..923eb9165 --- /dev/null +++ b/fs/efs/symlink.c @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * symlink.c + * + * Copyright (c) 1999 Al Smith + * + * Portions derived from work (c) 1995,1996 Christian Vogelgsang. + */ + +#include <linux/string.h> +#include <linux/pagemap.h> +#include <linux/buffer_head.h> +#include "efs.h" + +static int efs_symlink_readpage(struct file *file, struct page *page) +{ + char *link = page_address(page); + struct buffer_head * bh; + struct inode * inode = page->mapping->host; + efs_block_t size = inode->i_size; + int err; + + err = -ENAMETOOLONG; + if (size > 2 * EFS_BLOCKSIZE) + goto fail; + + /* read first 512 bytes of link target */ + err = -EIO; + bh = sb_bread(inode->i_sb, efs_bmap(inode, 0)); + if (!bh) + goto fail; + memcpy(link, bh->b_data, (size > EFS_BLOCKSIZE) ? EFS_BLOCKSIZE : size); + brelse(bh); + if (size > EFS_BLOCKSIZE) { + bh = sb_bread(inode->i_sb, efs_bmap(inode, 1)); + if (!bh) + goto fail; + memcpy(link + EFS_BLOCKSIZE, bh->b_data, size - EFS_BLOCKSIZE); + brelse(bh); + } + link[size] = '\0'; + SetPageUptodate(page); + unlock_page(page); + return 0; +fail: + SetPageError(page); + unlock_page(page); + return err; +} + +const struct address_space_operations efs_symlink_aops = { + .readpage = efs_symlink_readpage +}; |