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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /fs/befs/linuxvfs.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/befs/linuxvfs.c')
-rw-r--r-- | fs/befs/linuxvfs.c | 1027 |
1 files changed, 1027 insertions, 0 deletions
diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c new file mode 100644 index 000000000..32749fcee --- /dev/null +++ b/fs/befs/linuxvfs.c @@ -0,0 +1,1027 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/fs/befs/linuxvfs.c + * + * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com + * + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/errno.h> +#include <linux/stat.h> +#include <linux/nls.h> +#include <linux/buffer_head.h> +#include <linux/vfs.h> +#include <linux/parser.h> +#include <linux/namei.h> +#include <linux/sched.h> +#include <linux/cred.h> +#include <linux/exportfs.h> +#include <linux/seq_file.h> +#include <linux/blkdev.h> + +#include "befs.h" +#include "btree.h" +#include "inode.h" +#include "datastream.h" +#include "super.h" +#include "io.h" + +MODULE_DESCRIPTION("BeOS File System (BeFS) driver"); +MODULE_AUTHOR("Will Dyson"); +MODULE_LICENSE("GPL"); + +/* The units the vfs expects inode->i_blocks to be in */ +#define VFS_BLOCK_SIZE 512 + +static int befs_readdir(struct file *, struct dir_context *); +static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int); +static int befs_read_folio(struct file *file, struct folio *folio); +static sector_t befs_bmap(struct address_space *mapping, sector_t block); +static struct dentry *befs_lookup(struct inode *, struct dentry *, + unsigned int); +static struct inode *befs_iget(struct super_block *, unsigned long); +static struct inode *befs_alloc_inode(struct super_block *sb); +static void befs_free_inode(struct inode *inode); +static void befs_destroy_inodecache(void); +static int befs_symlink_read_folio(struct file *, struct folio *); +static int befs_utf2nls(struct super_block *sb, const char *in, int in_len, + char **out, int *out_len); +static int befs_nls2utf(struct super_block *sb, const char *in, int in_len, + char **out, int *out_len); +static void befs_put_super(struct super_block *); +static int befs_remount(struct super_block *, int *, char *); +static int befs_statfs(struct dentry *, struct kstatfs *); +static int befs_show_options(struct seq_file *, struct dentry *); +static int parse_options(char *, struct befs_mount_options *); +static struct dentry *befs_fh_to_dentry(struct super_block *sb, + struct fid *fid, int fh_len, int fh_type); +static struct dentry *befs_fh_to_parent(struct super_block *sb, + struct fid *fid, int fh_len, int fh_type); +static struct dentry *befs_get_parent(struct dentry *child); + +static const struct super_operations befs_sops = { + .alloc_inode = befs_alloc_inode, /* allocate a new inode */ + .free_inode = befs_free_inode, /* deallocate an inode */ + .put_super = befs_put_super, /* uninit super */ + .statfs = befs_statfs, /* statfs */ + .remount_fs = befs_remount, + .show_options = befs_show_options, +}; + +/* slab cache for befs_inode_info objects */ +static struct kmem_cache *befs_inode_cachep; + +static const struct file_operations befs_dir_operations = { + .read = generic_read_dir, + .iterate_shared = befs_readdir, + .llseek = generic_file_llseek, +}; + +static const struct inode_operations befs_dir_inode_operations = { + .lookup = befs_lookup, +}; + +static const struct address_space_operations befs_aops = { + .read_folio = befs_read_folio, + .bmap = befs_bmap, +}; + +static const struct address_space_operations befs_symlink_aops = { + .read_folio = befs_symlink_read_folio, +}; + +static const struct export_operations befs_export_operations = { + .fh_to_dentry = befs_fh_to_dentry, + .fh_to_parent = befs_fh_to_parent, + .get_parent = befs_get_parent, +}; + +/* + * Called by generic_file_read() to read a folio of data + * + * In turn, simply calls a generic block read function and + * passes it the address of befs_get_block, for mapping file + * positions to disk blocks. + */ +static int befs_read_folio(struct file *file, struct folio *folio) +{ + return block_read_full_folio(folio, befs_get_block); +} + +static sector_t +befs_bmap(struct address_space *mapping, sector_t block) +{ + return generic_block_bmap(mapping, block, befs_get_block); +} + +/* + * Generic function to map a file position (block) to a + * disk offset (passed back in bh_result). + * + * Used by many higher level functions. + * + * Calls befs_fblock2brun() in datastream.c to do the real work. + */ + +static int +befs_get_block(struct inode *inode, sector_t block, + struct buffer_head *bh_result, int create) +{ + struct super_block *sb = inode->i_sb; + befs_data_stream *ds = &BEFS_I(inode)->i_data.ds; + befs_block_run run = BAD_IADDR; + int res; + ulong disk_off; + + befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld", + (unsigned long)inode->i_ino, (long)block); + if (create) { + befs_error(sb, "befs_get_block() was asked to write to " + "block %ld in inode %lu", (long)block, + (unsigned long)inode->i_ino); + return -EPERM; + } + + res = befs_fblock2brun(sb, ds, block, &run); + if (res != BEFS_OK) { + befs_error(sb, + "<--- %s for inode %lu, block %ld ERROR", + __func__, (unsigned long)inode->i_ino, + (long)block); + return -EFBIG; + } + + disk_off = (ulong) iaddr2blockno(sb, &run); + + map_bh(bh_result, inode->i_sb, disk_off); + + befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu", + __func__, (unsigned long)inode->i_ino, (long)block, + (unsigned long)disk_off); + + return 0; +} + +static struct dentry * +befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) +{ + struct inode *inode; + struct super_block *sb = dir->i_sb; + const befs_data_stream *ds = &BEFS_I(dir)->i_data.ds; + befs_off_t offset; + int ret; + int utfnamelen; + char *utfname; + const char *name = dentry->d_name.name; + + befs_debug(sb, "---> %s name %pd inode %ld", __func__, + dentry, dir->i_ino); + + /* Convert to UTF-8 */ + if (BEFS_SB(sb)->nls) { + ret = + befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen); + if (ret < 0) { + befs_debug(sb, "<--- %s ERROR", __func__); + return ERR_PTR(ret); + } + ret = befs_btree_find(sb, ds, utfname, &offset); + kfree(utfname); + + } else { + ret = befs_btree_find(sb, ds, name, &offset); + } + + if (ret == BEFS_BT_NOT_FOUND) { + befs_debug(sb, "<--- %s %pd not found", __func__, dentry); + inode = NULL; + } else if (ret != BEFS_OK || offset == 0) { + befs_error(sb, "<--- %s Error", __func__); + inode = ERR_PTR(-ENODATA); + } else { + inode = befs_iget(dir->i_sb, (ino_t) offset); + } + befs_debug(sb, "<--- %s", __func__); + + return d_splice_alias(inode, dentry); +} + +static int +befs_readdir(struct file *file, struct dir_context *ctx) +{ + struct inode *inode = file_inode(file); + struct super_block *sb = inode->i_sb; + const befs_data_stream *ds = &BEFS_I(inode)->i_data.ds; + befs_off_t value; + int result; + size_t keysize; + char keybuf[BEFS_NAME_LEN + 1]; + + befs_debug(sb, "---> %s name %pD, inode %ld, ctx->pos %lld", + __func__, file, inode->i_ino, ctx->pos); + + while (1) { + result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1, + keybuf, &keysize, &value); + + if (result == BEFS_ERR) { + befs_debug(sb, "<--- %s ERROR", __func__); + befs_error(sb, "IO error reading %pD (inode %lu)", + file, inode->i_ino); + return -EIO; + + } else if (result == BEFS_BT_END) { + befs_debug(sb, "<--- %s END", __func__); + return 0; + + } else if (result == BEFS_BT_EMPTY) { + befs_debug(sb, "<--- %s Empty directory", __func__); + return 0; + } + + /* Convert to NLS */ + if (BEFS_SB(sb)->nls) { + char *nlsname; + int nlsnamelen; + + result = + befs_utf2nls(sb, keybuf, keysize, &nlsname, + &nlsnamelen); + if (result < 0) { + befs_debug(sb, "<--- %s ERROR", __func__); + return result; + } + if (!dir_emit(ctx, nlsname, nlsnamelen, + (ino_t) value, DT_UNKNOWN)) { + kfree(nlsname); + return 0; + } + kfree(nlsname); + } else { + if (!dir_emit(ctx, keybuf, keysize, + (ino_t) value, DT_UNKNOWN)) + return 0; + } + ctx->pos++; + } +} + +static struct inode * +befs_alloc_inode(struct super_block *sb) +{ + struct befs_inode_info *bi; + + bi = alloc_inode_sb(sb, befs_inode_cachep, GFP_KERNEL); + if (!bi) + return NULL; + return &bi->vfs_inode; +} + +static void befs_free_inode(struct inode *inode) +{ + kmem_cache_free(befs_inode_cachep, BEFS_I(inode)); +} + +static void init_once(void *foo) +{ + struct befs_inode_info *bi = (struct befs_inode_info *) foo; + + inode_init_once(&bi->vfs_inode); +} + +static struct inode *befs_iget(struct super_block *sb, unsigned long ino) +{ + struct buffer_head *bh; + befs_inode *raw_inode; + struct befs_sb_info *befs_sb = BEFS_SB(sb); + struct befs_inode_info *befs_ino; + struct inode *inode; + + befs_debug(sb, "---> %s inode = %lu", __func__, ino); + + inode = iget_locked(sb, ino); + if (!inode) + return ERR_PTR(-ENOMEM); + if (!(inode->i_state & I_NEW)) + return inode; + + befs_ino = BEFS_I(inode); + + /* convert from vfs's inode number to befs's inode number */ + befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino); + + befs_debug(sb, " real inode number [%u, %hu, %hu]", + befs_ino->i_inode_num.allocation_group, + befs_ino->i_inode_num.start, befs_ino->i_inode_num.len); + + bh = sb_bread(sb, inode->i_ino); + if (!bh) { + befs_error(sb, "unable to read inode block - " + "inode = %lu", inode->i_ino); + goto unacquire_none; + } + + raw_inode = (befs_inode *) bh->b_data; + + befs_dump_inode(sb, raw_inode); + + if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) { + befs_error(sb, "Bad inode: %lu", inode->i_ino); + goto unacquire_bh; + } + + inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode); + + /* + * set uid and gid. But since current BeOS is single user OS, so + * you can change by "uid" or "gid" options. + */ + + inode->i_uid = befs_sb->mount_opts.use_uid ? + befs_sb->mount_opts.uid : + make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid)); + inode->i_gid = befs_sb->mount_opts.use_gid ? + befs_sb->mount_opts.gid : + make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid)); + + set_nlink(inode, 1); + + /* + * BEFS's time is 64 bits, but current VFS is 32 bits... + * BEFS don't have access time. Nor inode change time. VFS + * doesn't have creation time. + * Also, the lower 16 bits of the last_modified_time and + * create_time are just a counter to help ensure uniqueness + * for indexing purposes. (PFD, page 54) + */ + + inode->i_mtime.tv_sec = + fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16; + inode->i_mtime.tv_nsec = 0; /* lower 16 bits are not a time */ + inode->i_ctime = inode->i_mtime; + inode->i_atime = inode->i_mtime; + + befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num); + befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent); + befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes); + befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags); + + if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){ + inode->i_size = 0; + inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE; + strlcpy(befs_ino->i_data.symlink, raw_inode->data.symlink, + BEFS_SYMLINK_LEN); + } else { + int num_blks; + + befs_ino->i_data.ds = + fsds_to_cpu(sb, &raw_inode->data.datastream); + + num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds); + inode->i_blocks = + num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE); + inode->i_size = befs_ino->i_data.ds.size; + } + + inode->i_mapping->a_ops = &befs_aops; + + if (S_ISREG(inode->i_mode)) { + inode->i_fop = &generic_ro_fops; + } else if (S_ISDIR(inode->i_mode)) { + inode->i_op = &befs_dir_inode_operations; + inode->i_fop = &befs_dir_operations; + } else if (S_ISLNK(inode->i_mode)) { + if (befs_ino->i_flags & BEFS_LONG_SYMLINK) { + inode->i_op = &page_symlink_inode_operations; + inode_nohighmem(inode); + inode->i_mapping->a_ops = &befs_symlink_aops; + } else { + inode->i_link = befs_ino->i_data.symlink; + inode->i_op = &simple_symlink_inode_operations; + } + } else { + befs_error(sb, "Inode %lu is not a regular file, " + "directory or symlink. THAT IS WRONG! BeFS has no " + "on disk special files", inode->i_ino); + goto unacquire_bh; + } + + brelse(bh); + befs_debug(sb, "<--- %s", __func__); + unlock_new_inode(inode); + return inode; + +unacquire_bh: + brelse(bh); + +unacquire_none: + iget_failed(inode); + befs_debug(sb, "<--- %s - Bad inode", __func__); + return ERR_PTR(-EIO); +} + +/* Initialize the inode cache. Called at fs setup. + * + * Taken from NFS implementation by Al Viro. + */ +static int __init +befs_init_inodecache(void) +{ + befs_inode_cachep = kmem_cache_create_usercopy("befs_inode_cache", + sizeof(struct befs_inode_info), 0, + (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD| + SLAB_ACCOUNT), + offsetof(struct befs_inode_info, + i_data.symlink), + sizeof_field(struct befs_inode_info, + i_data.symlink), + init_once); + if (befs_inode_cachep == NULL) + return -ENOMEM; + + return 0; +} + +/* Called at fs teardown. + * + * Taken from NFS implementation by Al Viro. + */ +static void +befs_destroy_inodecache(void) +{ + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); + kmem_cache_destroy(befs_inode_cachep); +} + +/* + * The inode of symbolic link is different to data stream. + * The data stream become link name. Unless the LONG_SYMLINK + * flag is set. + */ +static int befs_symlink_read_folio(struct file *unused, struct folio *folio) +{ + struct inode *inode = folio->mapping->host; + struct super_block *sb = inode->i_sb; + struct befs_inode_info *befs_ino = BEFS_I(inode); + befs_data_stream *data = &befs_ino->i_data.ds; + befs_off_t len = data->size; + char *link = folio_address(folio); + + if (len == 0 || len > PAGE_SIZE) { + befs_error(sb, "Long symlink with illegal length"); + goto fail; + } + befs_debug(sb, "Follow long symlink"); + + if (befs_read_lsymlink(sb, data, link, len) != len) { + befs_error(sb, "Failed to read entire long symlink"); + goto fail; + } + link[len - 1] = '\0'; + folio_mark_uptodate(folio); + folio_unlock(folio); + return 0; +fail: + folio_set_error(folio); + folio_unlock(folio); + return -EIO; +} + +/* + * UTF-8 to NLS charset convert routine + * + * Uses uni2char() / char2uni() rather than the nls tables directly + */ +static int +befs_utf2nls(struct super_block *sb, const char *in, + int in_len, char **out, int *out_len) +{ + struct nls_table *nls = BEFS_SB(sb)->nls; + int i, o; + unicode_t uni; + int unilen, utflen; + char *result; + /* The utf8->nls conversion won't make the final nls string bigger + * than the utf one, but if the string is pure ascii they'll have the + * same width and an extra char is needed to save the additional \0 + */ + int maxlen = in_len + 1; + + befs_debug(sb, "---> %s", __func__); + + if (!nls) { + befs_error(sb, "%s called with no NLS table loaded", __func__); + return -EINVAL; + } + + *out = result = kmalloc(maxlen, GFP_NOFS); + if (!*out) + return -ENOMEM; + + for (i = o = 0; i < in_len; i += utflen, o += unilen) { + + /* convert from UTF-8 to Unicode */ + utflen = utf8_to_utf32(&in[i], in_len - i, &uni); + if (utflen < 0) + goto conv_err; + + /* convert from Unicode to nls */ + if (uni > MAX_WCHAR_T) + goto conv_err; + unilen = nls->uni2char(uni, &result[o], in_len - o); + if (unilen < 0) + goto conv_err; + } + result[o] = '\0'; + *out_len = o; + + befs_debug(sb, "<--- %s", __func__); + + return o; + +conv_err: + befs_error(sb, "Name using character set %s contains a character that " + "cannot be converted to unicode.", nls->charset); + befs_debug(sb, "<--- %s", __func__); + kfree(result); + return -EILSEQ; +} + +/** + * befs_nls2utf - Convert NLS string to utf8 encodeing + * @sb: Superblock + * @in: Input string buffer in NLS format + * @in_len: Length of input string in bytes + * @out: The output string in UTF-8 format + * @out_len: Length of the output buffer + * + * Converts input string @in, which is in the format of the loaded NLS map, + * into a utf8 string. + * + * The destination string @out is allocated by this function and the caller is + * responsible for freeing it with kfree() + * + * On return, *@out_len is the length of @out in bytes. + * + * On success, the return value is the number of utf8 characters written to + * the output buffer @out. + * + * On Failure, a negative number coresponding to the error code is returned. + */ + +static int +befs_nls2utf(struct super_block *sb, const char *in, + int in_len, char **out, int *out_len) +{ + struct nls_table *nls = BEFS_SB(sb)->nls; + int i, o; + wchar_t uni; + int unilen, utflen; + char *result; + /* + * There are nls characters that will translate to 3-chars-wide UTF-8 + * characters, an additional byte is needed to save the final \0 + * in special cases + */ + int maxlen = (3 * in_len) + 1; + + befs_debug(sb, "---> %s\n", __func__); + + if (!nls) { + befs_error(sb, "%s called with no NLS table loaded.", + __func__); + return -EINVAL; + } + + *out = result = kmalloc(maxlen, GFP_NOFS); + if (!*out) { + *out_len = 0; + return -ENOMEM; + } + + for (i = o = 0; i < in_len; i += unilen, o += utflen) { + + /* convert from nls to unicode */ + unilen = nls->char2uni(&in[i], in_len - i, &uni); + if (unilen < 0) + goto conv_err; + + /* convert from unicode to UTF-8 */ + utflen = utf32_to_utf8(uni, &result[o], 3); + if (utflen <= 0) + goto conv_err; + } + + result[o] = '\0'; + *out_len = o; + + befs_debug(sb, "<--- %s", __func__); + + return i; + +conv_err: + befs_error(sb, "Name using character set %s contains a character that " + "cannot be converted to unicode.", nls->charset); + befs_debug(sb, "<--- %s", __func__); + kfree(result); + return -EILSEQ; +} + +static struct inode *befs_nfs_get_inode(struct super_block *sb, uint64_t ino, + uint32_t generation) +{ + /* No need to handle i_generation */ + return befs_iget(sb, ino); +} + +/* + * Map a NFS file handle to a corresponding dentry + */ +static struct dentry *befs_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, + befs_nfs_get_inode); +} + +/* + * Find the parent for a file specified by NFS handle + */ +static struct dentry *befs_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, + befs_nfs_get_inode); +} + +static struct dentry *befs_get_parent(struct dentry *child) +{ + struct inode *parent; + struct befs_inode_info *befs_ino = BEFS_I(d_inode(child)); + + parent = befs_iget(child->d_sb, + (unsigned long)befs_ino->i_parent.start); + if (IS_ERR(parent)) + return ERR_CAST(parent); + + return d_obtain_alias(parent); +} + +enum { + Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err, +}; + +static const match_table_t befs_tokens = { + {Opt_uid, "uid=%d"}, + {Opt_gid, "gid=%d"}, + {Opt_charset, "iocharset=%s"}, + {Opt_debug, "debug"}, + {Opt_err, NULL} +}; + +static int +parse_options(char *options, struct befs_mount_options *opts) +{ + char *p; + substring_t args[MAX_OPT_ARGS]; + int option; + kuid_t uid; + kgid_t gid; + + /* Initialize options */ + opts->uid = GLOBAL_ROOT_UID; + opts->gid = GLOBAL_ROOT_GID; + opts->use_uid = 0; + opts->use_gid = 0; + opts->iocharset = NULL; + opts->debug = 0; + + if (!options) + return 1; + + while ((p = strsep(&options, ",")) != NULL) { + int token; + + if (!*p) + continue; + + token = match_token(p, befs_tokens, args); + switch (token) { + case Opt_uid: + if (match_int(&args[0], &option)) + return 0; + uid = INVALID_UID; + if (option >= 0) + uid = make_kuid(current_user_ns(), option); + if (!uid_valid(uid)) { + pr_err("Invalid uid %d, " + "using default\n", option); + break; + } + opts->uid = uid; + opts->use_uid = 1; + break; + case Opt_gid: + if (match_int(&args[0], &option)) + return 0; + gid = INVALID_GID; + if (option >= 0) + gid = make_kgid(current_user_ns(), option); + if (!gid_valid(gid)) { + pr_err("Invalid gid %d, " + "using default\n", option); + break; + } + opts->gid = gid; + opts->use_gid = 1; + break; + case Opt_charset: + kfree(opts->iocharset); + opts->iocharset = match_strdup(&args[0]); + if (!opts->iocharset) { + pr_err("allocation failure for " + "iocharset string\n"); + return 0; + } + break; + case Opt_debug: + opts->debug = 1; + break; + default: + pr_err("Unrecognized mount option \"%s\" " + "or missing value\n", p); + return 0; + } + } + return 1; +} + +static int befs_show_options(struct seq_file *m, struct dentry *root) +{ + struct befs_sb_info *befs_sb = BEFS_SB(root->d_sb); + struct befs_mount_options *opts = &befs_sb->mount_opts; + + if (!uid_eq(opts->uid, GLOBAL_ROOT_UID)) + seq_printf(m, ",uid=%u", + from_kuid_munged(&init_user_ns, opts->uid)); + if (!gid_eq(opts->gid, GLOBAL_ROOT_GID)) + seq_printf(m, ",gid=%u", + from_kgid_munged(&init_user_ns, opts->gid)); + if (opts->iocharset) + seq_printf(m, ",charset=%s", opts->iocharset); + if (opts->debug) + seq_puts(m, ",debug"); + return 0; +} + +/* This function has the responsibiltiy of getting the + * filesystem ready for unmounting. + * Basically, we free everything that we allocated in + * befs_read_inode + */ +static void +befs_put_super(struct super_block *sb) +{ + kfree(BEFS_SB(sb)->mount_opts.iocharset); + BEFS_SB(sb)->mount_opts.iocharset = NULL; + unload_nls(BEFS_SB(sb)->nls); + kfree(sb->s_fs_info); + sb->s_fs_info = NULL; +} + +/* Allocate private field of the superblock, fill it. + * + * Finish filling the public superblock fields + * Make the root directory + * Load a set of NLS translations if needed. + */ +static int +befs_fill_super(struct super_block *sb, void *data, int silent) +{ + struct buffer_head *bh; + struct befs_sb_info *befs_sb; + befs_super_block *disk_sb; + struct inode *root; + long ret = -EINVAL; + const unsigned long sb_block = 0; + const off_t x86_sb_off = 512; + int blocksize; + + sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL); + if (sb->s_fs_info == NULL) + goto unacquire_none; + + befs_sb = BEFS_SB(sb); + + if (!parse_options((char *) data, &befs_sb->mount_opts)) { + if (!silent) + befs_error(sb, "cannot parse mount options"); + goto unacquire_priv_sbp; + } + + befs_debug(sb, "---> %s", __func__); + + if (!sb_rdonly(sb)) { + befs_warning(sb, + "No write support. Marking filesystem read-only"); + sb->s_flags |= SB_RDONLY; + } + + /* + * Set dummy blocksize to read super block. + * Will be set to real fs blocksize later. + * + * Linux 2.4.10 and later refuse to read blocks smaller than + * the logical block size for the device. But we also need to read at + * least 1k to get the second 512 bytes of the volume. + */ + blocksize = sb_min_blocksize(sb, 1024); + if (!blocksize) { + if (!silent) + befs_error(sb, "unable to set blocksize"); + goto unacquire_priv_sbp; + } + + bh = sb_bread(sb, sb_block); + if (!bh) { + if (!silent) + befs_error(sb, "unable to read superblock"); + goto unacquire_priv_sbp; + } + + /* account for offset of super block on x86 */ + disk_sb = (befs_super_block *) bh->b_data; + if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) || + (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) { + befs_debug(sb, "Using PPC superblock location"); + } else { + befs_debug(sb, "Using x86 superblock location"); + disk_sb = + (befs_super_block *) ((void *) bh->b_data + x86_sb_off); + } + + if ((befs_load_sb(sb, disk_sb) != BEFS_OK) || + (befs_check_sb(sb) != BEFS_OK)) + goto unacquire_bh; + + befs_dump_super_block(sb, disk_sb); + + brelse(bh); + + if (befs_sb->num_blocks > ~((sector_t)0)) { + if (!silent) + befs_error(sb, "blocks count: %llu is larger than the host can use", + befs_sb->num_blocks); + goto unacquire_priv_sbp; + } + + /* + * set up enough so that it can read an inode + * Fill in kernel superblock fields from private sb + */ + sb->s_magic = BEFS_SUPER_MAGIC; + /* Set real blocksize of fs */ + sb_set_blocksize(sb, (ulong) befs_sb->block_size); + sb->s_op = &befs_sops; + sb->s_export_op = &befs_export_operations; + sb->s_time_min = 0; + sb->s_time_max = 0xffffffffffffll; + root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir))); + if (IS_ERR(root)) { + ret = PTR_ERR(root); + goto unacquire_priv_sbp; + } + sb->s_root = d_make_root(root); + if (!sb->s_root) { + if (!silent) + befs_error(sb, "get root inode failed"); + goto unacquire_priv_sbp; + } + + /* load nls library */ + if (befs_sb->mount_opts.iocharset) { + befs_debug(sb, "Loading nls: %s", + befs_sb->mount_opts.iocharset); + befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset); + if (!befs_sb->nls) { + befs_warning(sb, "Cannot load nls %s" + " loading default nls", + befs_sb->mount_opts.iocharset); + befs_sb->nls = load_nls_default(); + } + /* load default nls if none is specified in mount options */ + } else { + befs_debug(sb, "Loading default nls"); + befs_sb->nls = load_nls_default(); + } + + return 0; + +unacquire_bh: + brelse(bh); + +unacquire_priv_sbp: + kfree(befs_sb->mount_opts.iocharset); + kfree(sb->s_fs_info); + sb->s_fs_info = NULL; + +unacquire_none: + return ret; +} + +static int +befs_remount(struct super_block *sb, int *flags, char *data) +{ + sync_filesystem(sb); + if (!(*flags & SB_RDONLY)) + return -EINVAL; + return 0; +} + +static int +befs_statfs(struct dentry *dentry, struct kstatfs *buf) +{ + struct super_block *sb = dentry->d_sb; + u64 id = huge_encode_dev(sb->s_bdev->bd_dev); + + befs_debug(sb, "---> %s", __func__); + + buf->f_type = BEFS_SUPER_MAGIC; + buf->f_bsize = sb->s_blocksize; + buf->f_blocks = BEFS_SB(sb)->num_blocks; + buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks; + buf->f_bavail = buf->f_bfree; + buf->f_files = 0; /* UNKNOWN */ + buf->f_ffree = 0; /* UNKNOWN */ + buf->f_fsid = u64_to_fsid(id); + buf->f_namelen = BEFS_NAME_LEN; + + befs_debug(sb, "<--- %s", __func__); + + return 0; +} + +static struct dentry * +befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, + void *data) +{ + return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super); +} + +static struct file_system_type befs_fs_type = { + .owner = THIS_MODULE, + .name = "befs", + .mount = befs_mount, + .kill_sb = kill_block_super, + .fs_flags = FS_REQUIRES_DEV, +}; +MODULE_ALIAS_FS("befs"); + +static int __init +init_befs_fs(void) +{ + int err; + + pr_info("version: %s\n", BEFS_VERSION); + + err = befs_init_inodecache(); + if (err) + goto unacquire_none; + + err = register_filesystem(&befs_fs_type); + if (err) + goto unacquire_inodecache; + + return 0; + +unacquire_inodecache: + befs_destroy_inodecache(); + +unacquire_none: + return err; +} + +static void __exit +exit_befs_fs(void) +{ + befs_destroy_inodecache(); + + unregister_filesystem(&befs_fs_type); +} + +/* + * Macros that typecheck the init and exit functions, + * ensures that they are called at init and cleanup, + * and eliminates warnings about unused functions. + */ +module_init(init_befs_fs) +module_exit(exit_befs_fs) |