42 static void fat12_ent_set_ptr(struct fat_entry *fatent, int offset)  in fat12_ent_set_ptr()  argument
44 	struct buffer_head **bhs = fatent->bhs;  in fat12_ent_set_ptr()
45 	if (fatent->nr_bhs == 1) {  in fat12_ent_set_ptr()
47 		fatent->u.ent12_p[0] = bhs[0]->b_data + offset;  in fat12_ent_set_ptr()
48 		fatent->u.ent12_p[1] = bhs[0]->b_data + (offset + 1);  in fat12_ent_set_ptr()
51 		fatent->u.ent12_p[0] = bhs[0]->b_data + offset;  in fat12_ent_set_ptr()
52 		fatent->u.ent12_p[1] = bhs[1]->b_data;  in fat12_ent_set_ptr()
56 static void fat16_ent_set_ptr(struct fat_entry *fatent, int offset)  in fat16_ent_set_ptr()  argument
59 	fatent->u.ent16_p = (__le16 *)(fatent->bhs[0]->b_data + offset);  in fat16_ent_set_ptr()
62 static void fat32_ent_set_ptr(struct fat_entry *fatent, int offset)  in fat32_ent_set_ptr()  argument
65 	fatent->u.ent32_p = (__le32 *)(fatent->bhs[0]->b_data + offset);  in fat32_ent_set_ptr()
68 static int fat12_ent_bread(struct super_block *sb, struct fat_entry *fatent,  in fat12_ent_bread()  argument
71 	struct buffer_head **bhs = fatent->bhs;  in fat12_ent_bread()
74 	fatent->fat_inode = MSDOS_SB(sb)->fat_inode;  in fat12_ent_bread()
81 		fatent->nr_bhs = 1;  in fat12_ent_bread()
88 		fatent->nr_bhs = 2;  in fat12_ent_bread()
90 	fat12_ent_set_ptr(fatent, offset);  in fat12_ent_bread()
100 static int fat_ent_bread(struct super_block *sb, struct fat_entry *fatent,  in fat_ent_bread()  argument
106 	fatent->fat_inode = MSDOS_SB(sb)->fat_inode;  in fat_ent_bread()
107 	fatent->bhs[0] = sb_bread(sb, blocknr);  in fat_ent_bread()
108 	if (!fatent->bhs[0]) {  in fat_ent_bread()
113 	fatent->nr_bhs = 1;  in fat_ent_bread()
114 	ops->ent_set_ptr(fatent, offset);  in fat_ent_bread()
118 static int fat12_ent_get(struct fat_entry *fatent)  in fat12_ent_get()  argument
120 	u8 **ent12_p = fatent->u.ent12_p;  in fat12_ent_get()
124 	if (fatent->entry & 1)  in fat12_ent_get()
136 static int fat16_ent_get(struct fat_entry *fatent)  in fat16_ent_get()  argument
138 	int next = le16_to_cpu(*fatent->u.ent16_p);  in fat16_ent_get()
139 	WARN_ON((unsigned long)fatent->u.ent16_p & (2 - 1));  in fat16_ent_get()
145 static int fat32_ent_get(struct fat_entry *fatent)  in fat32_ent_get()  argument
147 	int next = le32_to_cpu(*fatent->u.ent32_p) & 0x0fffffff;  in fat32_ent_get()
148 	WARN_ON((unsigned long)fatent->u.ent32_p & (4 - 1));  in fat32_ent_get()
154 static void fat12_ent_put(struct fat_entry *fatent, int new)  in fat12_ent_put()  argument
156 	u8 **ent12_p = fatent->u.ent12_p;  in fat12_ent_put()
162 	if (fatent->entry & 1) {  in fat12_ent_put()
171 	mark_buffer_dirty_inode(fatent->bhs[0], fatent->fat_inode);  in fat12_ent_put()
172 	if (fatent->nr_bhs == 2)  in fat12_ent_put()
173 		mark_buffer_dirty_inode(fatent->bhs[1], fatent->fat_inode);  in fat12_ent_put()
176 static void fat16_ent_put(struct fat_entry *fatent, int new)  in fat16_ent_put()  argument
181 	*fatent->u.ent16_p = cpu_to_le16(new);  in fat16_ent_put()
182 	mark_buffer_dirty_inode(fatent->bhs[0], fatent->fat_inode);  in fat16_ent_put()
185 static void fat32_ent_put(struct fat_entry *fatent, int new)  in fat32_ent_put()  argument
188 	new |= le32_to_cpu(*fatent->u.ent32_p) & ~0x0fffffff;  in fat32_ent_put()
189 	*fatent->u.ent32_p = cpu_to_le32(new);  in fat32_ent_put()
190 	mark_buffer_dirty_inode(fatent->bhs[0], fatent->fat_inode);  in fat32_ent_put()
193 static int fat12_ent_next(struct fat_entry *fatent)  in fat12_ent_next()  argument
195 	u8 **ent12_p = fatent->u.ent12_p;  in fat12_ent_next()
196 	struct buffer_head **bhs = fatent->bhs;  in fat12_ent_next()
197 	u8 *nextp = ent12_p[1] + 1 + (fatent->entry & 1);  in fat12_ent_next()
199 	fatent->entry++;  in fat12_ent_next()
200 	if (fatent->nr_bhs == 1) {  in fat12_ent_next()
218 		fatent->nr_bhs = 1;  in fat12_ent_next()
226 static int fat16_ent_next(struct fat_entry *fatent)  in fat16_ent_next()  argument
228 	const struct buffer_head *bh = fatent->bhs[0];  in fat16_ent_next()
229 	fatent->entry++;  in fat16_ent_next()
230 	if (fatent->u.ent16_p < (__le16 *)(bh->b_data + (bh->b_size - 2))) {  in fat16_ent_next()
231 		fatent->u.ent16_p++;  in fat16_ent_next()
234 	fatent->u.ent16_p = NULL;  in fat16_ent_next()
238 static int fat32_ent_next(struct fat_entry *fatent)  in fat32_ent_next()  argument
240 	const struct buffer_head *bh = fatent->bhs[0];  in fat32_ent_next()
241 	fatent->entry++;  in fat32_ent_next()
242 	if (fatent->u.ent32_p < (__le32 *)(bh->b_data + (bh->b_size - 4))) {  in fat32_ent_next()
243 		fatent->u.ent32_p++;  in fat32_ent_next()
246 	fatent->u.ent32_p = NULL;  in fat32_ent_next()
320 				     struct fat_entry *fatent,  in fat_ent_update_ptr()  argument
325 	struct buffer_head **bhs = fatent->bhs;  in fat_ent_update_ptr()
328 	if (!fatent->nr_bhs || bhs[0]->b_blocknr != blocknr)  in fat_ent_update_ptr()
333 			if (fatent->nr_bhs == 2) {  in fat_ent_update_ptr()
335 				fatent->nr_bhs = 1;  in fat_ent_update_ptr()
339 			if (fatent->nr_bhs != 2)  in fat_ent_update_ptr()
345 	ops->ent_set_ptr(fatent, offset);  in fat_ent_update_ptr()
349 int fat_ent_read(struct inode *inode, struct fat_entry *fatent, int entry)  in fat_ent_read()  argument
358 		fatent_brelse(fatent);  in fat_ent_read()
363 	fatent_set_entry(fatent, entry);  in fat_ent_read()
366 	if (!fat_ent_update_ptr(sb, fatent, offset, blocknr)) {  in fat_ent_read()
367 		fatent_brelse(fatent);  in fat_ent_read()
368 		err = ops->ent_bread(sb, fatent, offset, blocknr);  in fat_ent_read()
372 	return ops->ent_get(fatent);  in fat_ent_read()
407 int fat_ent_write(struct inode *inode, struct fat_entry *fatent,  in fat_ent_write()  argument
414 	ops->ent_put(fatent, new);  in fat_ent_write()
416 		err = fat_sync_bhs(fatent->bhs, fatent->nr_bhs);  in fat_ent_write()
420 	return fat_mirror_bhs(sb, fatent->bhs, fatent->nr_bhs);  in fat_ent_write()
424 			       struct fat_entry *fatent)  in fat_ent_next()  argument
426 	if (sbi->fatent_ops->ent_next(fatent)) {  in fat_ent_next()
427 		if (fatent->entry < sbi->max_cluster)  in fat_ent_next()
434 				     struct fat_entry *fatent)  in fat_ent_read_block()  argument
440 	fatent_brelse(fatent);  in fat_ent_read_block()
441 	ops->ent_blocknr(sb, fatent->entry, &offset, &blocknr);  in fat_ent_read_block()
442 	return ops->ent_bread(sb, fatent, offset, blocknr);  in fat_ent_read_block()
446 			    struct fat_entry *fatent)  in fat_collect_bhs()  argument
450 	for (n = 0; n < fatent->nr_bhs; n++) {  in fat_collect_bhs()
452 			if (fatent->bhs[n] == bhs[i])  in fat_collect_bhs()
456 			get_bh(fatent->bhs[n]);  in fat_collect_bhs()
457 			bhs[i] = fatent->bhs[n];  in fat_collect_bhs()
468 	struct fat_entry fatent, prev_ent;  in fat_alloc_clusters()  local
484 	fatent_init(&fatent);  in fat_alloc_clusters()
485 	fatent_set_entry(&fatent, sbi->prev_free + 1);  in fat_alloc_clusters()
487 		if (fatent.entry >= sbi->max_cluster)  in fat_alloc_clusters()
488 			fatent.entry = FAT_START_ENT;  in fat_alloc_clusters()
489 		fatent_set_entry(&fatent, fatent.entry);  in fat_alloc_clusters()
490 		err = fat_ent_read_block(sb, &fatent);  in fat_alloc_clusters()
496 			if (ops->ent_get(&fatent) == FAT_ENT_FREE) {  in fat_alloc_clusters()
497 				int entry = fatent.entry;  in fat_alloc_clusters()
500 				ops->ent_put(&fatent, FAT_ENT_EOF);  in fat_alloc_clusters()
504 				fat_collect_bhs(bhs, &nr_bhs, &fatent);  in fat_alloc_clusters()
519 				prev_ent = fatent;  in fat_alloc_clusters()
524 		} while (fat_ent_next(sbi, &fatent));  in fat_alloc_clusters()
535 	fatent_brelse(&fatent);  in fat_alloc_clusters()
556 	struct fat_entry fatent;  in fat_free_clusters()  local
562 	fatent_init(&fatent);  in fat_free_clusters()
565 		cluster = fat_ent_read(inode, &fatent, cluster);  in fat_free_clusters()
582 			if (cluster != fatent.entry + 1) {  in fat_free_clusters()
583 				int nr_clus = fatent.entry - first_cl + 1;  in fat_free_clusters()
594 		ops->ent_put(&fatent, FAT_ENT_FREE);  in fat_free_clusters()
600 		if (nr_bhs + fatent.nr_bhs > MAX_BUF_PER_PAGE) {  in fat_free_clusters()
613 		fat_collect_bhs(bhs, &nr_bhs, &fatent);  in fat_free_clusters()
623 	fatent_brelse(&fatent);  in fat_free_clusters()
637 static void fat_ent_reada(struct super_block *sb, struct fat_entry *fatent,  in fat_ent_reada()  argument
644 	ops->ent_blocknr(sb, fatent->entry, &offset, &blocknr);  in fat_ent_reada()
654 	struct fat_entry fatent;  in fat_count_free_clusters()  local
667 	fatent_init(&fatent);  in fat_count_free_clusters()
668 	fatent_set_entry(&fatent, FAT_START_ENT);  in fat_count_free_clusters()
669 	while (fatent.entry < sbi->max_cluster) {  in fat_count_free_clusters()
673 			fat_ent_reada(sb, &fatent, min(reada_blocks, rest));  in fat_count_free_clusters()
677 		err = fat_ent_read_block(sb, &fatent);  in fat_count_free_clusters()
682 			if (ops->ent_get(&fatent) == FAT_ENT_FREE)  in fat_count_free_clusters()
684 		} while (fat_ent_next(sbi, &fatent));  in fat_count_free_clusters()
690 	fatent_brelse(&fatent);  in fat_count_free_clusters()
708 	struct fat_entry fatent;  in fat_trim_fs()  local
732 	fatent_init(&fatent);  in fat_trim_fs()
734 	fatent_set_entry(&fatent, ent_start);  in fat_trim_fs()
735 	while (fatent.entry <= ent_end) {  in fat_trim_fs()
739 			fat_ent_reada(sb, &fatent, min(reada_blocks, rest));  in fat_trim_fs()
743 		err = fat_ent_read_block(sb, &fatent);  in fat_trim_fs()
747 			if (ops->ent_get(&fatent) == FAT_ENT_FREE) {  in fat_trim_fs()
751 					u32 clus = fatent.entry - free;  in fat_trim_fs()
762 		} while (fat_ent_next(sbi, &fatent) && fatent.entry <= ent_end);  in fat_trim_fs()
770 			fatent_brelse(&fatent);  in fat_trim_fs()
778 		u32 clus = fatent.entry - free;  in fat_trim_fs()
789 	fatent_brelse(&fatent);  in fat_trim_fs()