diff options
Diffstat (limited to 'fs/bfs/dir.c')
| -rw-r--r-- | fs/bfs/dir.c | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/fs/bfs/dir.c b/fs/bfs/dir.c new file mode 100644 index 000000000000..5a1e5ce057ff --- /dev/null +++ b/fs/bfs/dir.c @@ -0,0 +1,362 @@ +/* + * fs/bfs/dir.c + * BFS directory operations. + * Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com> + */ + +#include <linux/time.h> +#include <linux/string.h> +#include <linux/fs.h> +#include <linux/smp_lock.h> +#include <linux/buffer_head.h> +#include <linux/sched.h> +#include "bfs.h" + +#undef DEBUG + +#ifdef DEBUG +#define dprintf(x...) printf(x) +#else +#define dprintf(x...) +#endif + +static int bfs_add_entry(struct inode * dir, const char * name, int namelen, int ino); +static struct buffer_head * bfs_find_entry(struct inode * dir, + const char * name, int namelen, struct bfs_dirent ** res_dir); + +static int bfs_readdir(struct file * f, void * dirent, filldir_t filldir) +{ + struct inode * dir = f->f_dentry->d_inode; + struct buffer_head * bh; + struct bfs_dirent * de; + unsigned int offset; + int block; + + lock_kernel(); + + if (f->f_pos & (BFS_DIRENT_SIZE-1)) { + printf("Bad f_pos=%08lx for %s:%08lx\n", (unsigned long)f->f_pos, + dir->i_sb->s_id, dir->i_ino); + unlock_kernel(); + return -EBADF; + } + + while (f->f_pos < dir->i_size) { + offset = f->f_pos & (BFS_BSIZE-1); + block = BFS_I(dir)->i_sblock + (f->f_pos >> BFS_BSIZE_BITS); + bh = sb_bread(dir->i_sb, block); + if (!bh) { + f->f_pos += BFS_BSIZE - offset; + continue; + } + do { + de = (struct bfs_dirent *)(bh->b_data + offset); + if (de->ino) { + int size = strnlen(de->name, BFS_NAMELEN); + if (filldir(dirent, de->name, size, f->f_pos, de->ino, DT_UNKNOWN) < 0) { + brelse(bh); + unlock_kernel(); + return 0; + } + } + offset += BFS_DIRENT_SIZE; + f->f_pos += BFS_DIRENT_SIZE; + } while (offset < BFS_BSIZE && f->f_pos < dir->i_size); + brelse(bh); + } + + unlock_kernel(); + return 0; +} + +struct file_operations bfs_dir_operations = { + .read = generic_read_dir, + .readdir = bfs_readdir, + .fsync = file_fsync, +}; + +extern void dump_imap(const char *, struct super_block *); + +static int bfs_create(struct inode * dir, struct dentry * dentry, int mode, + struct nameidata *nd) +{ + int err; + struct inode * inode; + struct super_block * s = dir->i_sb; + struct bfs_sb_info * info = BFS_SB(s); + unsigned long ino; + + inode = new_inode(s); + if (!inode) + return -ENOSPC; + lock_kernel(); + ino = find_first_zero_bit(info->si_imap, info->si_lasti); + if (ino > info->si_lasti) { + unlock_kernel(); + iput(inode); + return -ENOSPC; + } + set_bit(ino, info->si_imap); + info->si_freei--; + inode->i_uid = current->fsuid; + inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid; + inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC; + inode->i_blocks = inode->i_blksize = 0; + inode->i_op = &bfs_file_inops; + inode->i_fop = &bfs_file_operations; + inode->i_mapping->a_ops = &bfs_aops; + inode->i_mode = mode; + inode->i_ino = ino; + BFS_I(inode)->i_dsk_ino = ino; + BFS_I(inode)->i_sblock = 0; + BFS_I(inode)->i_eblock = 0; + insert_inode_hash(inode); + mark_inode_dirty(inode); + dump_imap("create",s); + + err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len, inode->i_ino); + if (err) { + inode->i_nlink--; + mark_inode_dirty(inode); + iput(inode); + unlock_kernel(); + return err; + } + unlock_kernel(); + d_instantiate(dentry, inode); + return 0; +} + +static struct dentry * bfs_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd) +{ + struct inode * inode = NULL; + struct buffer_head * bh; + struct bfs_dirent * de; + + if (dentry->d_name.len > BFS_NAMELEN) + return ERR_PTR(-ENAMETOOLONG); + + lock_kernel(); + bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de); + if (bh) { + unsigned long ino = le32_to_cpu(de->ino); + brelse(bh); + inode = iget(dir->i_sb, ino); + if (!inode) { + unlock_kernel(); + return ERR_PTR(-EACCES); + } + } + unlock_kernel(); + d_add(dentry, inode); + return NULL; +} + +static int bfs_link(struct dentry * old, struct inode * dir, struct dentry * new) +{ + struct inode * inode = old->d_inode; + int err; + + lock_kernel(); + err = bfs_add_entry(dir, new->d_name.name, new->d_name.len, inode->i_ino); + if (err) { + unlock_kernel(); + return err; + } + inode->i_nlink++; + inode->i_ctime = CURRENT_TIME_SEC; + mark_inode_dirty(inode); + atomic_inc(&inode->i_count); + d_instantiate(new, inode); + unlock_kernel(); + return 0; +} + + +static int bfs_unlink(struct inode * dir, struct dentry * dentry) +{ + int error = -ENOENT; + struct inode * inode; + struct buffer_head * bh; + struct bfs_dirent * de; + + inode = dentry->d_inode; + lock_kernel(); + bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de); + if (!bh || de->ino != inode->i_ino) + goto out_brelse; + + if (!inode->i_nlink) { + printf("unlinking non-existent file %s:%lu (nlink=%d)\n", inode->i_sb->s_id, + inode->i_ino, inode->i_nlink); + inode->i_nlink = 1; + } + de->ino = 0; + mark_buffer_dirty(bh); + dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC; + mark_inode_dirty(dir); + inode->i_nlink--; + inode->i_ctime = dir->i_ctime; + mark_inode_dirty(inode); + error = 0; + +out_brelse: + brelse(bh); + unlock_kernel(); + return error; +} + +static int bfs_rename(struct inode * old_dir, struct dentry * old_dentry, + struct inode * new_dir, struct dentry * new_dentry) +{ + struct inode * old_inode, * new_inode; + struct buffer_head * old_bh, * new_bh; + struct bfs_dirent * old_de, * new_de; + int error = -ENOENT; + + old_bh = new_bh = NULL; + old_inode = old_dentry->d_inode; + if (S_ISDIR(old_inode->i_mode)) + return -EINVAL; + + lock_kernel(); + old_bh = bfs_find_entry(old_dir, + old_dentry->d_name.name, + old_dentry->d_name.len, &old_de); + + if (!old_bh || old_de->ino != old_inode->i_ino) + goto end_rename; + + error = -EPERM; + new_inode = new_dentry->d_inode; + new_bh = bfs_find_entry(new_dir, + new_dentry->d_name.name, + new_dentry->d_name.len, &new_de); + + if (new_bh && !new_inode) { + brelse(new_bh); + new_bh = NULL; + } + if (!new_bh) { + error = bfs_add_entry(new_dir, + new_dentry->d_name.name, + new_dentry->d_name.len, old_inode->i_ino); + if (error) + goto end_rename; + } + old_de->ino = 0; + old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC; + mark_inode_dirty(old_dir); + if (new_inode) { + new_inode->i_nlink--; + new_inode->i_ctime = CURRENT_TIME_SEC; + mark_inode_dirty(new_inode); + } + mark_buffer_dirty(old_bh); + error = 0; + +end_rename: + unlock_kernel(); + brelse(old_bh); + brelse(new_bh); + return error; +} + +struct inode_operations bfs_dir_inops = { + .create = bfs_create, + .lookup = bfs_lookup, + .link = bfs_link, + .unlink = bfs_unlink, + .rename = bfs_rename, +}; + +static int bfs_add_entry(struct inode * dir, const char * name, int namelen, int ino) +{ + struct buffer_head * bh; + struct bfs_dirent * de; + int block, sblock, eblock, off, eoff; + int i; + + dprintf("name=%s, namelen=%d\n", name, namelen); + + if (!namelen) + return -ENOENT; + if (namelen > BFS_NAMELEN) + return -ENAMETOOLONG; + + sblock = BFS_I(dir)->i_sblock; + eblock = BFS_I(dir)->i_eblock; + eoff = dir->i_size % BFS_BSIZE; + for (block=sblock; block<=eblock; block++) { + bh = sb_bread(dir->i_sb, block); + if(!bh) + return -ENOSPC; + for (off=0; off<BFS_BSIZE; off+=BFS_DIRENT_SIZE) { + de = (struct bfs_dirent *)(bh->b_data + off); + if (block==eblock && off>=eoff) { + /* Do not read/interpret the garbage in the end of eblock. */ + de->ino = 0; + } + if (!de->ino) { + if ((block-sblock)*BFS_BSIZE + off >= dir->i_size) { + dir->i_size += BFS_DIRENT_SIZE; + dir->i_ctime = CURRENT_TIME_SEC; + } + dir->i_mtime = CURRENT_TIME_SEC; + mark_inode_dirty(dir); + de->ino = ino; + for (i=0; i<BFS_NAMELEN; i++) + de->name[i] = (i < namelen) ? name[i] : 0; + mark_buffer_dirty(bh); + brelse(bh); + return 0; + } + } + brelse(bh); + } + return -ENOSPC; +} + +static inline int bfs_namecmp(int len, const char * name, const char * buffer) +{ + if (len < BFS_NAMELEN && buffer[len]) + return 0; + return !memcmp(name, buffer, len); +} + +static struct buffer_head * bfs_find_entry(struct inode * dir, + const char * name, int namelen, struct bfs_dirent ** res_dir) +{ + unsigned long block, offset; + struct buffer_head * bh; + struct bfs_dirent * de; + + *res_dir = NULL; + if (namelen > BFS_NAMELEN) + return NULL; + bh = NULL; + block = offset = 0; + while (block * BFS_BSIZE + offset < dir->i_size) { + if (!bh) { + bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block); + if (!bh) { + block++; + continue; + } + } + de = (struct bfs_dirent *)(bh->b_data + offset); + offset += BFS_DIRENT_SIZE; + if (de->ino && bfs_namecmp(namelen, name, de->name)) { + *res_dir = de; + return bh; + } + if (offset < bh->b_size) + continue; + brelse(bh); + bh = NULL; + offset = 0; + block++; + } + brelse(bh); + return NULL; +} |