![Dmitri Vorobiev](/assets/img/avatar_default.png)
I found a few bugs in the BFS driver. Detailed description of the bugs as well as the steps to reproduce the errors are given in the kernel bugzilla. Please follow these links for more information: http://bugzilla.kernel.org/show_bug.cgi?id=9363 http://bugzilla.kernel.org/show_bug.cgi?id=9364 http://bugzilla.kernel.org/show_bug.cgi?id=9365 http://bugzilla.kernel.org/show_bug.cgi?id=9366 This patch fixes the bugs described above. Besides, the patch introduces coding style changes to make the BFS driver conform to the requirements specified for Linux kernel code. Finally, I made a few cosmetic changes such as removal of trivial debug output. Also, the patch removes the fields `si_lf_ioff' and `si_lf_sblk' of the in-core superblock structure. These fields are initialized but never actually used. If you are wondering why I need BFS, here is the answer: I am using this driver in the context of Linux kernel classes I am teaching in the Moscow State University and in the International Institute of Information Technology in Pune, India. Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com> Cc: Tigran Aivazian <tigran@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
446 lines
11 KiB
C
446 lines
11 KiB
C
/*
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* fs/bfs/inode.c
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* BFS superblock and inode operations.
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* Copyright (C) 1999-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
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* From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
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*
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* Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.
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*/
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/fs.h>
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#include <linux/smp_lock.h>
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#include <linux/buffer_head.h>
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#include <linux/vfs.h>
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#include <asm/uaccess.h>
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#include "bfs.h"
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MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
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MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
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MODULE_LICENSE("GPL");
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#undef DEBUG
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#ifdef DEBUG
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#define dprintf(x...) printf(x)
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#else
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#define dprintf(x...)
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#endif
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void dump_imap(const char *prefix, struct super_block *s);
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static void bfs_read_inode(struct inode *inode)
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{
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unsigned long ino = inode->i_ino;
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struct bfs_inode *di;
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struct buffer_head *bh;
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int block, off;
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if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
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printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
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make_bad_inode(inode);
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return;
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}
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block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
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bh = sb_bread(inode->i_sb, block);
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if (!bh) {
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printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
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ino);
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make_bad_inode(inode);
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return;
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}
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off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
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di = (struct bfs_inode *)bh->b_data + off;
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inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
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if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
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inode->i_mode |= S_IFDIR;
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inode->i_op = &bfs_dir_inops;
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inode->i_fop = &bfs_dir_operations;
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} else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
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inode->i_mode |= S_IFREG;
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inode->i_op = &bfs_file_inops;
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inode->i_fop = &bfs_file_operations;
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inode->i_mapping->a_ops = &bfs_aops;
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}
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BFS_I(inode)->i_sblock = le32_to_cpu(di->i_sblock);
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BFS_I(inode)->i_eblock = le32_to_cpu(di->i_eblock);
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BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
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inode->i_uid = le32_to_cpu(di->i_uid);
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inode->i_gid = le32_to_cpu(di->i_gid);
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inode->i_nlink = le32_to_cpu(di->i_nlink);
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inode->i_size = BFS_FILESIZE(di);
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inode->i_blocks = BFS_FILEBLOCKS(di);
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inode->i_atime.tv_sec = le32_to_cpu(di->i_atime);
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inode->i_mtime.tv_sec = le32_to_cpu(di->i_mtime);
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inode->i_ctime.tv_sec = le32_to_cpu(di->i_ctime);
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inode->i_atime.tv_nsec = 0;
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inode->i_mtime.tv_nsec = 0;
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inode->i_ctime.tv_nsec = 0;
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brelse(bh);
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}
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static int bfs_write_inode(struct inode *inode, int unused)
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{
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unsigned int ino = (u16)inode->i_ino;
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unsigned long i_sblock;
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struct bfs_inode *di;
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struct buffer_head *bh;
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int block, off;
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dprintf("ino=%08x\n", ino);
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if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
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printf("Bad inode number %s:%08x\n", inode->i_sb->s_id, ino);
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return -EIO;
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}
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lock_kernel();
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block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
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bh = sb_bread(inode->i_sb, block);
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if (!bh) {
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printf("Unable to read inode %s:%08x\n",
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inode->i_sb->s_id, ino);
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unlock_kernel();
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return -EIO;
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}
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off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
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di = (struct bfs_inode *)bh->b_data + off;
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if (ino == BFS_ROOT_INO)
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di->i_vtype = cpu_to_le32(BFS_VDIR);
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else
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di->i_vtype = cpu_to_le32(BFS_VREG);
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di->i_ino = cpu_to_le16(ino);
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di->i_mode = cpu_to_le32(inode->i_mode);
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di->i_uid = cpu_to_le32(inode->i_uid);
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di->i_gid = cpu_to_le32(inode->i_gid);
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di->i_nlink = cpu_to_le32(inode->i_nlink);
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di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
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di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
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di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
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i_sblock = BFS_I(inode)->i_sblock;
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di->i_sblock = cpu_to_le32(i_sblock);
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di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
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di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
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mark_buffer_dirty(bh);
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brelse(bh);
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unlock_kernel();
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return 0;
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}
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static void bfs_delete_inode(struct inode *inode)
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{
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unsigned long ino = inode->i_ino;
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struct bfs_inode *di;
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struct buffer_head *bh;
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int block, off;
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struct super_block *s = inode->i_sb;
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struct bfs_sb_info *info = BFS_SB(s);
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struct bfs_inode_info *bi = BFS_I(inode);
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dprintf("ino=%08lx\n", ino);
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truncate_inode_pages(&inode->i_data, 0);
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if ((ino < BFS_ROOT_INO) || (ino > info->si_lasti)) {
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printf("invalid ino=%08lx\n", ino);
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return;
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}
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inode->i_size = 0;
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inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
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lock_kernel();
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mark_inode_dirty(inode);
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block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
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bh = sb_bread(s, block);
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if (!bh) {
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printf("Unable to read inode %s:%08lx\n",
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inode->i_sb->s_id, ino);
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unlock_kernel();
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return;
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}
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off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
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di = (struct bfs_inode *)bh->b_data + off;
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memset((void *)di, 0, sizeof(struct bfs_inode));
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mark_buffer_dirty(bh);
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brelse(bh);
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if (bi->i_dsk_ino) {
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info->si_freeb += BFS_FILEBLOCKS(bi);
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info->si_freei++;
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clear_bit(ino, info->si_imap);
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dump_imap("delete_inode", s);
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}
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/*
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* If this was the last file, make the previous block
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* "last block of the last file" even if there is no
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* real file there, saves us 1 gap.
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*/
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if (info->si_lf_eblk == bi->i_eblock) {
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info->si_lf_eblk = bi->i_sblock - 1;
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mark_buffer_dirty(info->si_sbh);
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}
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unlock_kernel();
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clear_inode(inode);
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}
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static void bfs_put_super(struct super_block *s)
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{
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struct bfs_sb_info *info = BFS_SB(s);
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brelse(info->si_sbh);
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kfree(info->si_imap);
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kfree(info);
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s->s_fs_info = NULL;
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}
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static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
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{
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struct super_block *s = dentry->d_sb;
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struct bfs_sb_info *info = BFS_SB(s);
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u64 id = huge_encode_dev(s->s_bdev->bd_dev);
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buf->f_type = BFS_MAGIC;
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buf->f_bsize = s->s_blocksize;
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buf->f_blocks = info->si_blocks;
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buf->f_bfree = buf->f_bavail = info->si_freeb;
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buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
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buf->f_ffree = info->si_freei;
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buf->f_fsid.val[0] = (u32)id;
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buf->f_fsid.val[1] = (u32)(id >> 32);
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buf->f_namelen = BFS_NAMELEN;
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return 0;
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}
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static void bfs_write_super(struct super_block *s)
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{
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lock_kernel();
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if (!(s->s_flags & MS_RDONLY))
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mark_buffer_dirty(BFS_SB(s)->si_sbh);
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s->s_dirt = 0;
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unlock_kernel();
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}
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static struct kmem_cache *bfs_inode_cachep;
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static struct inode *bfs_alloc_inode(struct super_block *sb)
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{
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struct bfs_inode_info *bi;
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bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
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if (!bi)
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return NULL;
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return &bi->vfs_inode;
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}
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static void bfs_destroy_inode(struct inode *inode)
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{
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kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
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}
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static void init_once(struct kmem_cache *cachep, void *foo)
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{
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struct bfs_inode_info *bi = foo;
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inode_init_once(&bi->vfs_inode);
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}
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static int init_inodecache(void)
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{
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bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
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sizeof(struct bfs_inode_info),
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0, (SLAB_RECLAIM_ACCOUNT|
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SLAB_MEM_SPREAD),
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init_once);
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if (bfs_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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kmem_cache_destroy(bfs_inode_cachep);
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}
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static const struct super_operations bfs_sops = {
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.alloc_inode = bfs_alloc_inode,
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.destroy_inode = bfs_destroy_inode,
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.read_inode = bfs_read_inode,
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.write_inode = bfs_write_inode,
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.delete_inode = bfs_delete_inode,
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.put_super = bfs_put_super,
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.write_super = bfs_write_super,
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.statfs = bfs_statfs,
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};
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void dump_imap(const char *prefix, struct super_block *s)
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{
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#ifdef DEBUG
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int i;
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char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
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if (!tmpbuf)
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return;
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for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
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if (i > PAGE_SIZE - 100) break;
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if (test_bit(i, BFS_SB(s)->si_imap))
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strcat(tmpbuf, "1");
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else
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strcat(tmpbuf, "0");
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}
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printf("BFS-fs: %s: lasti=%08lx <%s>\n",
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prefix, BFS_SB(s)->si_lasti, tmpbuf);
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free_page((unsigned long)tmpbuf);
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#endif
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}
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static int bfs_fill_super(struct super_block *s, void *data, int silent)
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{
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struct buffer_head *bh;
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struct bfs_super_block *bfs_sb;
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struct inode *inode;
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unsigned i, imap_len;
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struct bfs_sb_info *info;
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info = kzalloc(sizeof(*info), GFP_KERNEL);
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if (!info)
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return -ENOMEM;
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s->s_fs_info = info;
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sb_set_blocksize(s, BFS_BSIZE);
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bh = sb_bread(s, 0);
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if(!bh)
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goto out;
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bfs_sb = (struct bfs_super_block *)bh->b_data;
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if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
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if (!silent)
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printf("No BFS filesystem on %s (magic=%08x)\n",
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s->s_id, le32_to_cpu(bfs_sb->s_magic));
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goto out;
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}
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if (BFS_UNCLEAN(bfs_sb, s) && !silent)
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printf("%s is unclean, continuing\n", s->s_id);
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s->s_magic = BFS_MAGIC;
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info->si_sbh = bh;
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info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
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sizeof(struct bfs_inode)
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+ BFS_ROOT_INO - 1;
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imap_len = (info->si_lasti / 8) + 1;
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info->si_imap = kzalloc(imap_len, GFP_KERNEL);
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if (!info->si_imap)
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goto out;
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for (i = 0; i < BFS_ROOT_INO; i++)
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set_bit(i, info->si_imap);
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s->s_op = &bfs_sops;
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inode = iget(s, BFS_ROOT_INO);
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if (!inode) {
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kfree(info->si_imap);
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goto out;
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}
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s->s_root = d_alloc_root(inode);
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if (!s->s_root) {
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iput(inode);
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kfree(info->si_imap);
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goto out;
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}
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info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
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info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
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- le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
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info->si_freei = 0;
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info->si_lf_eblk = 0;
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bh = NULL;
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for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
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struct bfs_inode *di;
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int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
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int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
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unsigned long sblock, eblock;
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if (!off) {
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brelse(bh);
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bh = sb_bread(s, block);
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}
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if (!bh)
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continue;
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di = (struct bfs_inode *)bh->b_data + off;
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if (!di->i_ino) {
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info->si_freei++;
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continue;
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}
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set_bit(i, info->si_imap);
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info->si_freeb -= BFS_FILEBLOCKS(di);
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sblock = le32_to_cpu(di->i_sblock);
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eblock = le32_to_cpu(di->i_eblock);
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if (eblock > info->si_lf_eblk)
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info->si_lf_eblk = eblock;
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}
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brelse(bh);
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if (!(s->s_flags & MS_RDONLY)) {
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mark_buffer_dirty(info->si_sbh);
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s->s_dirt = 1;
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}
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dump_imap("read_super", s);
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return 0;
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out:
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brelse(bh);
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kfree(info);
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s->s_fs_info = NULL;
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return -EINVAL;
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}
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static int bfs_get_sb(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data, struct vfsmount *mnt)
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{
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return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
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}
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static struct file_system_type bfs_fs_type = {
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.owner = THIS_MODULE,
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.name = "bfs",
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.get_sb = bfs_get_sb,
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.kill_sb = kill_block_super,
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.fs_flags = FS_REQUIRES_DEV,
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};
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static int __init init_bfs_fs(void)
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{
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int err = init_inodecache();
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if (err)
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goto out1;
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err = register_filesystem(&bfs_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_bfs_fs(void)
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{
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unregister_filesystem(&bfs_fs_type);
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destroy_inodecache();
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}
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module_init(init_bfs_fs)
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module_exit(exit_bfs_fs)
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