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-rw-r--r--fs/bfs/dir.c362
1 files changed, 362 insertions, 0 deletions
diff --git a/fs/bfs/dir.c b/fs/bfs/dir.c
new file mode 100644
index 0000000..5a1e5ce
--- /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;
+}
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