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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /fs/bfs/dir.c
Initial import
Diffstat (limited to 'fs/bfs/dir.c')
-rw-r--r--fs/bfs/dir.c365
1 files changed, 365 insertions, 0 deletions
diff --git a/fs/bfs/dir.c b/fs/bfs/dir.c
new file mode 100644
index 000000000..3ec611314
--- /dev/null
+++ b/fs/bfs/dir.c
@@ -0,0 +1,365 @@
+/*
+ * fs/bfs/dir.c
+ * BFS directory operations.
+ * Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com>
+ * Made endianness-clean by Andrew Stribblehill <ads@wompom.org> 2005
+ */
+
+#include <linux/time.h>
+#include <linux/string.h>
+#include <linux/fs.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 unsigned char *name,
+ int namelen, int ino);
+static struct buffer_head *bfs_find_entry(struct inode *dir,
+ const unsigned char *name, int namelen,
+ struct bfs_dirent **res_dir);
+
+static int bfs_readdir(struct file *f, struct dir_context *ctx)
+{
+ struct inode *dir = file_inode(f);
+ struct buffer_head *bh;
+ struct bfs_dirent *de;
+ unsigned int offset;
+ int block;
+
+ if (ctx->pos & (BFS_DIRENT_SIZE - 1)) {
+ printf("Bad f_pos=%08lx for %s:%08lx\n",
+ (unsigned long)ctx->pos,
+ dir->i_sb->s_id, dir->i_ino);
+ return -EINVAL;
+ }
+
+ while (ctx->pos < dir->i_size) {
+ offset = ctx->pos & (BFS_BSIZE - 1);
+ block = BFS_I(dir)->i_sblock + (ctx->pos >> BFS_BSIZE_BITS);
+ bh = sb_bread(dir->i_sb, block);
+ if (!bh) {
+ ctx->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 (!dir_emit(ctx, de->name, size,
+ le16_to_cpu(de->ino),
+ DT_UNKNOWN)) {
+ brelse(bh);
+ return 0;
+ }
+ }
+ offset += BFS_DIRENT_SIZE;
+ ctx->pos += BFS_DIRENT_SIZE;
+ } while ((offset < BFS_BSIZE) && (ctx->pos < dir->i_size));
+ brelse(bh);
+ }
+ return 0;
+}
+
+const struct file_operations bfs_dir_operations = {
+ .read = generic_read_dir,
+ .iterate = bfs_readdir,
+ .fsync = generic_file_fsync,
+ .llseek = generic_file_llseek,
+};
+
+static int bfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
+ bool excl)
+{
+ 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 -ENOMEM;
+ mutex_lock(&info->bfs_lock);
+ ino = find_first_zero_bit(info->si_imap, info->si_lasti + 1);
+ if (ino > info->si_lasti) {
+ mutex_unlock(&info->bfs_lock);
+ iput(inode);
+ return -ENOSPC;
+ }
+ set_bit(ino, info->si_imap);
+ info->si_freei--;
+ inode_init_owner(inode, dir, mode);
+ inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
+ inode->i_blocks = 0;
+ inode->i_op = &bfs_file_inops;
+ inode->i_fop = &bfs_file_operations;
+ inode->i_mapping->a_ops = &bfs_aops;
+ 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);
+ bfs_dump_imap("create", s);
+
+ err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len,
+ inode->i_ino);
+ if (err) {
+ inode_dec_link_count(inode);
+ mutex_unlock(&info->bfs_lock);
+ iput(inode);
+ return err;
+ }
+ mutex_unlock(&info->bfs_lock);
+ d_instantiate(dentry, inode);
+ return 0;
+}
+
+static struct dentry *bfs_lookup(struct inode *dir, struct dentry *dentry,
+ unsigned int flags)
+{
+ struct inode *inode = NULL;
+ struct buffer_head *bh;
+ struct bfs_dirent *de;
+ struct bfs_sb_info *info = BFS_SB(dir->i_sb);
+
+ if (dentry->d_name.len > BFS_NAMELEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ mutex_lock(&info->bfs_lock);
+ bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
+ if (bh) {
+ unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
+ brelse(bh);
+ inode = bfs_iget(dir->i_sb, ino);
+ if (IS_ERR(inode)) {
+ mutex_unlock(&info->bfs_lock);
+ return ERR_CAST(inode);
+ }
+ }
+ mutex_unlock(&info->bfs_lock);
+ d_add(dentry, inode);
+ return NULL;
+}
+
+static int bfs_link(struct dentry *old, struct inode *dir,
+ struct dentry *new)
+{
+ struct inode *inode = d_inode(old);
+ struct bfs_sb_info *info = BFS_SB(inode->i_sb);
+ int err;
+
+ mutex_lock(&info->bfs_lock);
+ err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
+ inode->i_ino);
+ if (err) {
+ mutex_unlock(&info->bfs_lock);
+ return err;
+ }
+ inc_nlink(inode);
+ inode->i_ctime = CURRENT_TIME_SEC;
+ mark_inode_dirty(inode);
+ ihold(inode);
+ d_instantiate(new, inode);
+ mutex_unlock(&info->bfs_lock);
+ return 0;
+}
+
+static int bfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ int error = -ENOENT;
+ struct inode *inode = d_inode(dentry);
+ struct buffer_head *bh;
+ struct bfs_dirent *de;
+ struct bfs_sb_info *info = BFS_SB(inode->i_sb);
+
+ mutex_lock(&info->bfs_lock);
+ bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
+ if (!bh || (le16_to_cpu(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);
+ set_nlink(inode, 1);
+ }
+ de->ino = 0;
+ mark_buffer_dirty_inode(bh, dir);
+ dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
+ mark_inode_dirty(dir);
+ inode->i_ctime = dir->i_ctime;
+ inode_dec_link_count(inode);
+ error = 0;
+
+out_brelse:
+ brelse(bh);
+ mutex_unlock(&info->bfs_lock);
+ 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;
+ struct bfs_sb_info *info;
+ int error = -ENOENT;
+
+ old_bh = new_bh = NULL;
+ old_inode = d_inode(old_dentry);
+ if (S_ISDIR(old_inode->i_mode))
+ return -EINVAL;
+
+ info = BFS_SB(old_inode->i_sb);
+
+ mutex_lock(&info->bfs_lock);
+ old_bh = bfs_find_entry(old_dir,
+ old_dentry->d_name.name,
+ old_dentry->d_name.len, &old_de);
+
+ if (!old_bh || (le16_to_cpu(old_de->ino) != old_inode->i_ino))
+ goto end_rename;
+
+ error = -EPERM;
+ new_inode = d_inode(new_dentry);
+ 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_ctime = CURRENT_TIME_SEC;
+ inode_dec_link_count(new_inode);
+ }
+ mark_buffer_dirty_inode(old_bh, old_dir);
+ error = 0;
+
+end_rename:
+ mutex_unlock(&info->bfs_lock);
+ brelse(old_bh);
+ brelse(new_bh);
+ return error;
+}
+
+const 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 unsigned char *name,
+ int namelen, int ino)
+{
+ struct buffer_head *bh;
+ struct bfs_dirent *de;
+ int block, sblock, eblock, off, pos;
+ 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;
+ for (block = sblock; block <= eblock; block++) {
+ bh = sb_bread(dir->i_sb, block);
+ if (!bh)
+ return -EIO;
+ for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) {
+ de = (struct bfs_dirent *)(bh->b_data + off);
+ if (!de->ino) {
+ pos = (block - sblock) * BFS_BSIZE + off;
+ if (pos >= 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 = cpu_to_le16((u16)ino);
+ for (i = 0; i < BFS_NAMELEN; i++)
+ de->name[i] =
+ (i < namelen) ? name[i] : 0;
+ mark_buffer_dirty_inode(bh, dir);
+ brelse(bh);
+ return 0;
+ }
+ }
+ brelse(bh);
+ }
+ return -ENOSPC;
+}
+
+static inline int bfs_namecmp(int len, const unsigned 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 unsigned char *name, int namelen,
+ struct bfs_dirent **res_dir)
+{
+ unsigned long block = 0, offset = 0;
+ struct buffer_head *bh = NULL;
+ struct bfs_dirent *de;
+
+ *res_dir = NULL;
+ if (namelen > BFS_NAMELEN)
+ return NULL;
+
+ 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 (le16_to_cpu(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;
+}