+
+EXPORT_SYMBOL_GPL(fat_scan);
+
+static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
+{
+ struct super_block *sb = dir->i_sb;
+ struct buffer_head *bh;
+ struct msdos_dir_entry *de, *endp;
+ int err = 0, orig_slots;
+
+ while (nr_slots) {
+ bh = NULL;
+ if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
+ err = -EIO;
+ break;
+ }
+
+ orig_slots = nr_slots;
+ endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
+ while (nr_slots && de < endp) {
+ de->name[0] = DELETED_FLAG;
+ de++;
+ nr_slots--;
+ }
+ mark_buffer_dirty(bh);
+ if (IS_DIRSYNC(dir))
+ err = sync_dirty_buffer(bh);
+ brelse(bh);
+ if (err)
+ break;
+
+ /* pos is *next* de's position, so this does `- sizeof(de)' */
+ pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
+ }
+
+ return err;
+}
+
+int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
+{
+ struct msdos_dir_entry *de;
+ struct buffer_head *bh;
+ int err = 0, nr_slots;
+
+ /*
+ * First stage: Remove the shortname. By this, the directory
+ * entry is removed.
+ */
+ nr_slots = sinfo->nr_slots;
+ de = sinfo->de;
+ sinfo->de = NULL;
+ bh = sinfo->bh;
+ sinfo->bh = NULL;
+ while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
+ de->name[0] = DELETED_FLAG;
+ de--;
+ nr_slots--;
+ }
+ mark_buffer_dirty(bh);
+ if (IS_DIRSYNC(dir))
+ err = sync_dirty_buffer(bh);
+ brelse(bh);
+ if (err)
+ return err;
+ dir->i_version++;
+
+ if (nr_slots) {
+ /*
+ * Second stage: remove the remaining longname slots.
+ * (This directory entry is already removed, and so return
+ * the success)
+ */
+ err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
+ if (err) {
+ printk(KERN_WARNING
+ "FAT: Couldn't remove the long name slots\n");
+ }
+ }
+
+ dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
+ if (IS_DIRSYNC(dir))
+ (void)fat_sync_inode(dir);
+ else
+ mark_inode_dirty(dir);
+
+ return 0;
+}
+
+EXPORT_SYMBOL_GPL(fat_remove_entries);
+
+static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
+ struct buffer_head **bhs, int nr_bhs)
+{
+ struct super_block *sb = dir->i_sb;
+ sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
+ int err, i, n;
+
+ /* Zeroing the unused blocks on this cluster */
+ blknr += nr_used;
+ n = nr_used;
+ while (blknr < last_blknr) {
+ bhs[n] = sb_getblk(sb, blknr);
+ if (!bhs[n]) {
+ err = -ENOMEM;
+ goto error;
+ }
+ memset(bhs[n]->b_data, 0, sb->s_blocksize);
+ set_buffer_uptodate(bhs[n]);
+ mark_buffer_dirty(bhs[n]);
+
+ n++;
+ blknr++;
+ if (n == nr_bhs) {
+ if (IS_DIRSYNC(dir)) {
+ err = fat_sync_bhs(bhs, n);
+ if (err)
+ goto error;
+ }
+ for (i = 0; i < n; i++)
+ brelse(bhs[i]);
+ n = 0;
+ }
+ }
+ if (IS_DIRSYNC(dir)) {
+ err = fat_sync_bhs(bhs, n);
+ if (err)
+ goto error;
+ }
+ for (i = 0; i < n; i++)
+ brelse(bhs[i]);
+
+ return 0;
+
+error:
+ for (i = 0; i < n; i++)
+ bforget(bhs[i]);
+ return err;
+}
+
+int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
+{
+ struct super_block *sb = dir->i_sb;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ struct buffer_head *bhs[MAX_BUF_PER_PAGE];
+ struct msdos_dir_entry *de;
+ sector_t blknr;
+ __le16 date, time;
+ int err, cluster;
+
+ err = fat_alloc_clusters(dir, &cluster, 1);
+ if (err)
+ goto error;
+
+ blknr = fat_clus_to_blknr(sbi, cluster);
+ bhs[0] = sb_getblk(sb, blknr);
+ if (!bhs[0]) {
+ err = -ENOMEM;
+ goto error_free;
+ }
+
+ fat_date_unix2dos(ts->tv_sec, &time, &date);
+
+ de = (struct msdos_dir_entry *)bhs[0]->b_data;
+ /* filling the new directory slots ("." and ".." entries) */
+ memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
+ memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
+ de->attr = de[1].attr = ATTR_DIR;
+ de[0].lcase = de[1].lcase = 0;
+ de[0].time = de[1].time = time;
+ de[0].date = de[1].date = date;
+ de[0].ctime_cs = de[1].ctime_cs = 0;
+ if (sbi->options.isvfat) {
+ /* extra timestamps */
+ de[0].ctime = de[1].ctime = time;
+ de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
+ } else {
+ de[0].ctime = de[1].ctime = 0;
+ de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
+ }
+ de[0].start = cpu_to_le16(cluster);
+ de[0].starthi = cpu_to_le16(cluster >> 16);
+ de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart);
+ de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16);
+ de[0].size = de[1].size = 0;
+ memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
+ set_buffer_uptodate(bhs[0]);
+ mark_buffer_dirty(bhs[0]);
+
+ err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
+ if (err)
+ goto error_free;
+
+ return cluster;
+
+error_free:
+ fat_free_clusters(dir, cluster);
+error:
+ return err;
+}
+
+EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
+
+static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
+ int *nr_cluster, struct msdos_dir_entry **de,
+ struct buffer_head **bh, loff_t *i_pos)
+{
+ struct super_block *sb = dir->i_sb;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ struct buffer_head *bhs[MAX_BUF_PER_PAGE];
+ sector_t blknr, start_blknr, last_blknr;
+ unsigned long size, copy;
+ int err, i, n, offset, cluster[2];
+
+ /*
+ * The minimum cluster size is 512bytes, and maximum entry
+ * size is 32*slots (672bytes). So, iff the cluster size is
+ * 512bytes, we may need two clusters.
+ */
+ size = nr_slots * sizeof(struct msdos_dir_entry);
+ *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
+ BUG_ON(*nr_cluster > 2);
+
+ err = fat_alloc_clusters(dir, cluster, *nr_cluster);
+ if (err)
+ goto error;
+
+ /*
+ * First stage: Fill the directory entry. NOTE: This cluster
+ * is not referenced from any inode yet, so updates order is
+ * not important.
+ */
+ i = n = copy = 0;
+ do {
+ start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
+ last_blknr = start_blknr + sbi->sec_per_clus;
+ while (blknr < last_blknr) {
+ bhs[n] = sb_getblk(sb, blknr);
+ if (!bhs[n]) {
+ err = -ENOMEM;
+ goto error_nomem;
+ }
+
+ /* fill the directory entry */
+ copy = min(size, sb->s_blocksize);
+ memcpy(bhs[n]->b_data, slots, copy);
+ slots += copy;
+ size -= copy;
+ set_buffer_uptodate(bhs[n]);
+ mark_buffer_dirty(bhs[n]);
+ if (!size)
+ break;
+ n++;
+ blknr++;
+ }
+ } while (++i < *nr_cluster);
+
+ memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
+ offset = copy - sizeof(struct msdos_dir_entry);
+ get_bh(bhs[n]);
+ *bh = bhs[n];
+ *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
+ *i_pos = fat_make_i_pos(sb, *bh, *de);
+
+ /* Second stage: clear the rest of cluster, and write outs */
+ err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
+ if (err)
+ goto error_free;
+
+ return cluster[0];
+
+error_free:
+ brelse(*bh);
+ *bh = NULL;
+ n = 0;
+error_nomem:
+ for (i = 0; i < n; i++)
+ bforget(bhs[i]);
+ fat_free_clusters(dir, cluster[0]);
+error:
+ return err;
+}
+
+int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
+ struct fat_slot_info *sinfo)
+{
+ struct super_block *sb = dir->i_sb;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
+ struct msdos_dir_entry *de;
+ int err, free_slots, i, nr_bhs;
+ loff_t pos, i_pos;
+
+ sinfo->nr_slots = nr_slots;
+
+ /* First stage: search free direcotry entries */
+ free_slots = nr_bhs = 0;
+ bh = prev = NULL;
+ pos = 0;
+ err = -ENOSPC;
+ while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
+ /* check the maximum size of directory */
+ if (pos >= FAT_MAX_DIR_SIZE)
+ goto error;
+
+ if (IS_FREE(de->name)) {
+ if (prev != bh) {
+ get_bh(bh);
+ bhs[nr_bhs] = prev = bh;
+ nr_bhs++;
+ }
+ free_slots++;
+ if (free_slots == nr_slots)
+ goto found;
+ } else {
+ for (i = 0; i < nr_bhs; i++)
+ brelse(bhs[i]);
+ prev = NULL;
+ free_slots = nr_bhs = 0;
+ }
+ }
+ if (dir->i_ino == MSDOS_ROOT_INO) {
+ if (sbi->fat_bits != 32)
+ goto error;
+ } else if (MSDOS_I(dir)->i_start == 0) {
+ printk(KERN_ERR "FAT: Corrupted directory (i_pos %lld)\n",
+ MSDOS_I(dir)->i_pos);
+ err = -EIO;
+ goto error;
+ }
+
+found:
+ err = 0;
+ pos -= free_slots * sizeof(*de);
+ nr_slots -= free_slots;
+ if (free_slots) {
+ /*
+ * Second stage: filling the free entries with new entries.
+ * NOTE: If this slots has shortname, first, we write
+ * the long name slots, then write the short name.
+ */
+ int size = free_slots * sizeof(*de);
+ int offset = pos & (sb->s_blocksize - 1);
+ int long_bhs = nr_bhs - (nr_slots == 0);
+
+ /* Fill the long name slots. */
+ for (i = 0; i < long_bhs; i++) {
+ int copy = min_t(int, sb->s_blocksize - offset, size);
+ memcpy(bhs[i]->b_data + offset, slots, copy);
+ mark_buffer_dirty(bhs[i]);
+ offset = 0;
+ slots += copy;
+ size -= copy;
+ }
+ if (long_bhs && IS_DIRSYNC(dir))
+ err = fat_sync_bhs(bhs, long_bhs);
+ if (!err && i < nr_bhs) {
+ /* Fill the short name slot. */
+ int copy = min_t(int, sb->s_blocksize - offset, size);
+ memcpy(bhs[i]->b_data + offset, slots, copy);
+ mark_buffer_dirty(bhs[i]);
+ if (IS_DIRSYNC(dir))
+ err = sync_dirty_buffer(bhs[i]);
+ }
+ for (i = 0; i < nr_bhs; i++)
+ brelse(bhs[i]);
+ if (err)
+ goto error_remove;
+ }
+
+ if (nr_slots) {
+ int cluster, nr_cluster;
+
+ /*
+ * Third stage: allocate the cluster for new entries.
+ * And initialize the cluster with new entries, then
+ * add the cluster to dir.
+ */
+ cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
+ &de, &bh, &i_pos);
+ if (cluster < 0) {
+ err = cluster;
+ goto error_remove;
+ }
+ err = fat_chain_add(dir, cluster, nr_cluster);
+ if (err) {
+ fat_free_clusters(dir, cluster);
+ goto error_remove;
+ }
+ if (dir->i_size & (sbi->cluster_size - 1)) {
+ fat_fs_panic(sb, "Odd directory size");
+ dir->i_size = (dir->i_size + sbi->cluster_size - 1)
+ & ~((loff_t)sbi->cluster_size - 1);
+ }
+ dir->i_size += nr_cluster << sbi->cluster_bits;
+ MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
+ }
+ sinfo->slot_off = pos;
+ sinfo->de = de;
+ sinfo->bh = bh;
+ sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
+
+ return 0;
+
+error:
+ brelse(bh);
+ for (i = 0; i < nr_bhs; i++)
+ brelse(bhs[i]);
+ return err;
+
+error_remove:
+ brelse(bh);
+ if (free_slots)
+ __fat_remove_entries(dir, pos, free_slots);
+ return err;
+}
+
+EXPORT_SYMBOL_GPL(fat_add_entries);