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      1 /*
      2  * Implementation of new quotafile format
      3  *
      4  * Jan Kara <jack (at) suse.cz> - sponsored by SuSE CR
      5  */
      6 
      7 #include "config.h"
      8 #include <sys/types.h>
      9 #include <errno.h>
     10 #include <stdio.h>
     11 #include <stdlib.h>
     12 #include <string.h>
     13 #include <unistd.h>
     14 
     15 #include "common.h"
     16 #include "quotaio_tree.h"
     17 #include "quotaio.h"
     18 
     19 typedef char *dqbuf_t;
     20 
     21 #define freedqbuf(buf)		ext2fs_free_mem(&buf)
     22 
     23 static inline dqbuf_t getdqbuf(void)
     24 {
     25 	dqbuf_t buf;
     26 	if (ext2fs_get_memzero(QT_BLKSIZE, &buf)) {
     27 		log_err("Failed to allocate dqbuf");
     28 		return NULL;
     29 	}
     30 
     31 	return buf;
     32 }
     33 
     34 /* Is given dquot empty? */
     35 int qtree_entry_unused(struct qtree_mem_dqinfo *info, char *disk)
     36 {
     37 	unsigned int i;
     38 
     39 	for (i = 0; i < info->dqi_entry_size; i++)
     40 		if (disk[i])
     41 			return 0;
     42 	return 1;
     43 }
     44 
     45 int qtree_dqstr_in_blk(struct qtree_mem_dqinfo *info)
     46 {
     47 	return (QT_BLKSIZE - sizeof(struct qt_disk_dqdbheader)) /
     48 		info->dqi_entry_size;
     49 }
     50 
     51 static int get_index(qid_t id, int depth)
     52 {
     53 	return (id >> ((QT_TREEDEPTH - depth - 1) * 8)) & 0xff;
     54 }
     55 
     56 static inline void mark_quotafile_info_dirty(struct quota_handle *h)
     57 {
     58 	h->qh_io_flags |= IOFL_INFODIRTY;
     59 }
     60 
     61 /* Read given block */
     62 static void read_blk(struct quota_handle *h, unsigned int blk, dqbuf_t buf)
     63 {
     64 	int err;
     65 
     66 	err = h->e2fs_read(&h->qh_qf, blk << QT_BLKSIZE_BITS, buf,
     67 			QT_BLKSIZE);
     68 	if (err < 0)
     69 		log_err("Cannot read block %u: %s", blk, strerror(errno));
     70 	else if (err != QT_BLKSIZE)
     71 		memset(buf + err, 0, QT_BLKSIZE - err);
     72 }
     73 
     74 /* Write block */
     75 static int write_blk(struct quota_handle *h, unsigned int blk, dqbuf_t buf)
     76 {
     77 	int err;
     78 
     79 	err = h->e2fs_write(&h->qh_qf, blk << QT_BLKSIZE_BITS, buf,
     80 			QT_BLKSIZE);
     81 	if (err < 0 && errno != ENOSPC)
     82 		log_err("Cannot write block (%u): %s", blk, strerror(errno));
     83 	if (err != QT_BLKSIZE)
     84 		return -ENOSPC;
     85 	return 0;
     86 }
     87 
     88 /* Get free block in file (either from free list or create new one) */
     89 static int get_free_dqblk(struct quota_handle *h)
     90 {
     91 	dqbuf_t buf = getdqbuf();
     92 	struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
     93 	struct qtree_mem_dqinfo *info = &h->qh_info.u.v2_mdqi.dqi_qtree;
     94 	int blk;
     95 
     96 	if (!buf)
     97 		return -ENOMEM;
     98 
     99 	if (info->dqi_free_blk) {
    100 		blk = info->dqi_free_blk;
    101 		read_blk(h, blk, buf);
    102 		info->dqi_free_blk = ext2fs_le32_to_cpu(dh->dqdh_next_free);
    103 	} else {
    104 		memset(buf, 0, QT_BLKSIZE);
    105 		/* Assure block allocation... */
    106 		if (write_blk(h, info->dqi_blocks, buf) < 0) {
    107 			freedqbuf(buf);
    108 			log_err("Cannot allocate new quota block "
    109 				"(out of disk space).");
    110 			return -ENOSPC;
    111 		}
    112 		blk = info->dqi_blocks++;
    113 	}
    114 	mark_quotafile_info_dirty(h);
    115 	freedqbuf(buf);
    116 	return blk;
    117 }
    118 
    119 /* Put given block to free list */
    120 static void put_free_dqblk(struct quota_handle *h, dqbuf_t buf,
    121 			   unsigned int blk)
    122 {
    123 	struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
    124 	struct qtree_mem_dqinfo *info = &h->qh_info.u.v2_mdqi.dqi_qtree;
    125 
    126 	dh->dqdh_next_free = ext2fs_cpu_to_le32(info->dqi_free_blk);
    127 	dh->dqdh_prev_free = ext2fs_cpu_to_le32(0);
    128 	dh->dqdh_entries = ext2fs_cpu_to_le16(0);
    129 	info->dqi_free_blk = blk;
    130 	mark_quotafile_info_dirty(h);
    131 	write_blk(h, blk, buf);
    132 }
    133 
    134 /* Remove given block from the list of blocks with free entries */
    135 static void remove_free_dqentry(struct quota_handle *h, dqbuf_t buf,
    136 				unsigned int blk)
    137 {
    138 	dqbuf_t tmpbuf = getdqbuf();
    139 	struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
    140 	unsigned int nextblk = ext2fs_le32_to_cpu(dh->dqdh_next_free), prevblk =
    141 
    142 		ext2fs_le32_to_cpu(dh->dqdh_prev_free);
    143 
    144 	if (!tmpbuf)
    145 		return;
    146 
    147 	if (nextblk) {
    148 		read_blk(h, nextblk, tmpbuf);
    149 		((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
    150 				dh->dqdh_prev_free;
    151 		write_blk(h, nextblk, tmpbuf);
    152 	}
    153 	if (prevblk) {
    154 		read_blk(h, prevblk, tmpbuf);
    155 		((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_next_free =
    156 				dh->dqdh_next_free;
    157 		write_blk(h, prevblk, tmpbuf);
    158 	} else {
    159 		h->qh_info.u.v2_mdqi.dqi_qtree.dqi_free_entry = nextblk;
    160 		mark_quotafile_info_dirty(h);
    161 	}
    162 	freedqbuf(tmpbuf);
    163 	dh->dqdh_next_free = dh->dqdh_prev_free = ext2fs_cpu_to_le32(0);
    164 	write_blk(h, blk, buf);	/* No matter whether write succeeds
    165 				 * block is out of list */
    166 }
    167 
    168 /* Insert given block to the beginning of list with free entries */
    169 static void insert_free_dqentry(struct quota_handle *h, dqbuf_t buf,
    170 				unsigned int blk)
    171 {
    172 	dqbuf_t tmpbuf = getdqbuf();
    173 	struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
    174 	struct qtree_mem_dqinfo *info = &h->qh_info.u.v2_mdqi.dqi_qtree;
    175 
    176 	if (!tmpbuf)
    177 		return;
    178 
    179 	dh->dqdh_next_free = ext2fs_cpu_to_le32(info->dqi_free_entry);
    180 	dh->dqdh_prev_free = ext2fs_cpu_to_le32(0);
    181 	write_blk(h, blk, buf);
    182 	if (info->dqi_free_entry) {
    183 		read_blk(h, info->dqi_free_entry, tmpbuf);
    184 		((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
    185 				ext2fs_cpu_to_le32(blk);
    186 		write_blk(h, info->dqi_free_entry, tmpbuf);
    187 	}
    188 	freedqbuf(tmpbuf);
    189 	info->dqi_free_entry = blk;
    190 	mark_quotafile_info_dirty(h);
    191 }
    192 
    193 /* Find space for dquot */
    194 static unsigned int find_free_dqentry(struct quota_handle *h,
    195 				      struct dquot *dquot, int *err)
    196 {
    197 	int blk, i;
    198 	struct qt_disk_dqdbheader *dh;
    199 	struct qtree_mem_dqinfo *info = &h->qh_info.u.v2_mdqi.dqi_qtree;
    200 	char *ddquot;
    201 	dqbuf_t buf;
    202 
    203 	*err = 0;
    204 	buf = getdqbuf();
    205 	if (!buf) {
    206 		*err = -ENOMEM;
    207 		return 0;
    208 	}
    209 
    210 	dh = (struct qt_disk_dqdbheader *)buf;
    211 	if (info->dqi_free_entry) {
    212 		blk = info->dqi_free_entry;
    213 		read_blk(h, blk, buf);
    214 	} else {
    215 		blk = get_free_dqblk(h);
    216 		if (blk < 0) {
    217 			freedqbuf(buf);
    218 			*err = blk;
    219 			return 0;
    220 		}
    221 		memset(buf, 0, QT_BLKSIZE);
    222 		info->dqi_free_entry = blk;
    223 		mark_quotafile_info_dirty(h);
    224 	}
    225 
    226 	/* Block will be full? */
    227 	if (ext2fs_le16_to_cpu(dh->dqdh_entries) + 1 >=
    228 	    qtree_dqstr_in_blk(info))
    229 		remove_free_dqentry(h, buf, blk);
    230 
    231 	dh->dqdh_entries =
    232 		ext2fs_cpu_to_le16(ext2fs_le16_to_cpu(dh->dqdh_entries) + 1);
    233 	/* Find free structure in block */
    234 	ddquot = buf + sizeof(struct qt_disk_dqdbheader);
    235 	for (i = 0;
    236 	     i < qtree_dqstr_in_blk(info) && !qtree_entry_unused(info, ddquot);
    237 	     i++)
    238 		ddquot += info->dqi_entry_size;
    239 
    240 	if (i == qtree_dqstr_in_blk(info))
    241 		log_err("find_free_dqentry(): Data block full unexpectedly.");
    242 
    243 	write_blk(h, blk, buf);
    244 	dquot->dq_dqb.u.v2_mdqb.dqb_off =
    245 		(blk << QT_BLKSIZE_BITS) + sizeof(struct qt_disk_dqdbheader) +
    246 		i * info->dqi_entry_size;
    247 	freedqbuf(buf);
    248 	return blk;
    249 }
    250 
    251 /* Insert reference to structure into the trie */
    252 static int do_insert_tree(struct quota_handle *h, struct dquot *dquot,
    253 			  unsigned int * treeblk, int depth)
    254 {
    255 	dqbuf_t buf;
    256 	int newson = 0, newact = 0;
    257 	__le32 *ref;
    258 	unsigned int newblk;
    259 	int ret = 0;
    260 
    261 	log_debug("inserting in tree: treeblk=%u, depth=%d", *treeblk, depth);
    262 	buf = getdqbuf();
    263 	if (!buf)
    264 		return -ENOMEM;
    265 
    266 	if (!*treeblk) {
    267 		ret = get_free_dqblk(h);
    268 		if (ret < 0)
    269 			goto out_buf;
    270 		*treeblk = ret;
    271 		memset(buf, 0, QT_BLKSIZE);
    272 		newact = 1;
    273 	} else {
    274 		read_blk(h, *treeblk, buf);
    275 	}
    276 
    277 	ref = (__le32 *) buf;
    278 	newblk = ext2fs_le32_to_cpu(ref[get_index(dquot->dq_id, depth)]);
    279 	if (!newblk)
    280 		newson = 1;
    281 	if (depth == QT_TREEDEPTH - 1) {
    282 		if (newblk)
    283 			log_err("Inserting already present quota entry "
    284 				"(block %u).",
    285 				ref[get_index(dquot->dq_id, depth)]);
    286 		newblk = find_free_dqentry(h, dquot, &ret);
    287 	} else {
    288 		ret = do_insert_tree(h, dquot, &newblk, depth + 1);
    289 	}
    290 
    291 	if (newson && ret >= 0) {
    292 		ref[get_index(dquot->dq_id, depth)] =
    293 			ext2fs_cpu_to_le32(newblk);
    294 		write_blk(h, *treeblk, buf);
    295 	} else if (newact && ret < 0) {
    296 		put_free_dqblk(h, buf, *treeblk);
    297 	}
    298 
    299 out_buf:
    300 	freedqbuf(buf);
    301 	return ret;
    302 }
    303 
    304 /* Wrapper for inserting quota structure into tree */
    305 static void dq_insert_tree(struct quota_handle *h, struct dquot *dquot)
    306 {
    307 	unsigned int tmp = QT_TREEOFF;
    308 
    309 	if (do_insert_tree(h, dquot, &tmp, 0) < 0)
    310 		log_err("Cannot write quota (id %u): %s",
    311 			(unsigned int) dquot->dq_id, strerror(errno));
    312 }
    313 
    314 /* Write dquot to file */
    315 void qtree_write_dquot(struct dquot *dquot)
    316 {
    317 	errcode_t retval;
    318 	unsigned int ret;
    319 	char *ddquot;
    320 	struct quota_handle *h = dquot->dq_h;
    321 	struct qtree_mem_dqinfo *info =
    322 			&dquot->dq_h->qh_info.u.v2_mdqi.dqi_qtree;
    323 	log_debug("writing ddquot 1: off=%llu, info->dqi_entry_size=%u",
    324 			dquot->dq_dqb.u.v2_mdqb.dqb_off,
    325 			info->dqi_entry_size);
    326 	retval = ext2fs_get_mem(info->dqi_entry_size, &ddquot);
    327 	if (retval) {
    328 		errno = ENOMEM;
    329 		log_err("Quota write failed (id %u): %s",
    330 			(unsigned int)dquot->dq_id, strerror(errno));
    331 		return;
    332 	}
    333 	memset(ddquot, 0, info->dqi_entry_size);
    334 
    335 	if (!dquot->dq_dqb.u.v2_mdqb.dqb_off)
    336 		dq_insert_tree(dquot->dq_h, dquot);
    337 	info->dqi_ops->mem2disk_dqblk(ddquot, dquot);
    338 	log_debug("writing ddquot 2: off=%llu, info->dqi_entry_size=%u",
    339 			dquot->dq_dqb.u.v2_mdqb.dqb_off,
    340 			info->dqi_entry_size);
    341 	ret = h->e2fs_write(&h->qh_qf, dquot->dq_dqb.u.v2_mdqb.dqb_off, ddquot,
    342 			info->dqi_entry_size);
    343 
    344 	if (ret != info->dqi_entry_size) {
    345 		if (ret > 0)
    346 			errno = ENOSPC;
    347 		log_err("Quota write failed (id %u): %s",
    348 			(unsigned int)dquot->dq_id, strerror(errno));
    349 	}
    350 	ext2fs_free_mem(&ddquot);
    351 }
    352 
    353 /* Free dquot entry in data block */
    354 static void free_dqentry(struct quota_handle *h, struct dquot *dquot,
    355 			 unsigned int blk)
    356 {
    357 	struct qt_disk_dqdbheader *dh;
    358 	struct qtree_mem_dqinfo *info = &h->qh_info.u.v2_mdqi.dqi_qtree;
    359 	dqbuf_t buf = getdqbuf();
    360 
    361 	if (!buf)
    362 		return;
    363 
    364 	if (dquot->dq_dqb.u.v2_mdqb.dqb_off >> QT_BLKSIZE_BITS != blk)
    365 		log_err("Quota structure has offset to other block (%u) "
    366 			"than it should (%u).", blk,
    367 			  (unsigned int) (dquot->dq_dqb.u.v2_mdqb.dqb_off >>
    368 				  QT_BLKSIZE_BITS));
    369 
    370 	read_blk(h, blk, buf);
    371 	dh = (struct qt_disk_dqdbheader *)buf;
    372 	dh->dqdh_entries =
    373 		ext2fs_cpu_to_le16(ext2fs_le16_to_cpu(dh->dqdh_entries) - 1);
    374 
    375 	if (!ext2fs_le16_to_cpu(dh->dqdh_entries)) {	/* Block got free? */
    376 		remove_free_dqentry(h, buf, blk);
    377 		put_free_dqblk(h, buf, blk);
    378 	} else {
    379 		memset(buf + (dquot->dq_dqb.u.v2_mdqb.dqb_off &
    380 			      ((1 << QT_BLKSIZE_BITS) - 1)),
    381 		       0, info->dqi_entry_size);
    382 
    383 		/* First free entry? */
    384 		if (ext2fs_le16_to_cpu(dh->dqdh_entries) ==
    385 				qtree_dqstr_in_blk(info) - 1)
    386 			/* This will also write data block */
    387 			insert_free_dqentry(h, buf, blk);
    388 		else
    389 			write_blk(h, blk, buf);
    390 	}
    391 	dquot->dq_dqb.u.v2_mdqb.dqb_off = 0;
    392 	freedqbuf(buf);
    393 }
    394 
    395 /* Remove reference to dquot from tree */
    396 static void remove_tree(struct quota_handle *h, struct dquot *dquot,
    397 			unsigned int * blk, int depth)
    398 {
    399 	dqbuf_t buf = getdqbuf();
    400 	unsigned int newblk;
    401 	__le32 *ref = (__le32 *) buf;
    402 
    403 	if (!buf)
    404 		return;
    405 
    406 	read_blk(h, *blk, buf);
    407 	newblk = ext2fs_le32_to_cpu(ref[get_index(dquot->dq_id, depth)]);
    408 	if (depth == QT_TREEDEPTH - 1) {
    409 		free_dqentry(h, dquot, newblk);
    410 		newblk = 0;
    411 	} else {
    412 		remove_tree(h, dquot, &newblk, depth + 1);
    413 	}
    414 
    415 	if (!newblk) {
    416 		int i;
    417 
    418 		ref[get_index(dquot->dq_id, depth)] = ext2fs_cpu_to_le32(0);
    419 
    420 		/* Block got empty? */
    421 		for (i = 0; i < QT_BLKSIZE && !buf[i]; i++);
    422 
    423 		/* Don't put the root block into the free block list */
    424 		if (i == QT_BLKSIZE && *blk != QT_TREEOFF) {
    425 			put_free_dqblk(h, buf, *blk);
    426 			*blk = 0;
    427 		} else {
    428 			write_blk(h, *blk, buf);
    429 		}
    430 	}
    431 	freedqbuf(buf);
    432 }
    433 
    434 /* Delete dquot from tree */
    435 void qtree_delete_dquot(struct dquot *dquot)
    436 {
    437 	unsigned int tmp = QT_TREEOFF;
    438 
    439 	if (!dquot->dq_dqb.u.v2_mdqb.dqb_off)	/* Even not allocated? */
    440 		return;
    441 	remove_tree(dquot->dq_h, dquot, &tmp, 0);
    442 }
    443 
    444 /* Find entry in block */
    445 static ext2_loff_t find_block_dqentry(struct quota_handle *h,
    446 				      struct dquot *dquot, unsigned int blk)
    447 {
    448 	struct qtree_mem_dqinfo *info = &h->qh_info.u.v2_mdqi.dqi_qtree;
    449 	dqbuf_t buf = getdqbuf();
    450 	int i;
    451 	char *ddquot = buf + sizeof(struct qt_disk_dqdbheader);
    452 
    453 	if (!buf)
    454 		return -ENOMEM;
    455 
    456 	read_blk(h, blk, buf);
    457 	for (i = 0;
    458 	     i < qtree_dqstr_in_blk(info) && !info->dqi_ops->is_id(ddquot, dquot);
    459 	     i++)
    460 		ddquot += info->dqi_entry_size;
    461 
    462 	if (i == qtree_dqstr_in_blk(info))
    463 		log_err("Quota for id %u referenced but not present.",
    464 			dquot->dq_id);
    465 	freedqbuf(buf);
    466 	return (blk << QT_BLKSIZE_BITS) + sizeof(struct qt_disk_dqdbheader) +
    467 		i * info->dqi_entry_size;
    468 }
    469 
    470 /* Find entry for given id in the tree */
    471 static ext2_loff_t find_tree_dqentry(struct quota_handle *h,
    472 				     struct dquot *dquot,
    473 				     unsigned int blk, int depth)
    474 {
    475 	dqbuf_t buf = getdqbuf();
    476 	ext2_loff_t ret = 0;
    477 	__le32 *ref = (__le32 *) buf;
    478 
    479 	if (!buf)
    480 		return -ENOMEM;
    481 
    482 	read_blk(h, blk, buf);
    483 	ret = 0;
    484 	blk = ext2fs_le32_to_cpu(ref[get_index(dquot->dq_id, depth)]);
    485 	if (!blk)	/* No reference? */
    486 		goto out_buf;
    487 	if (depth < QT_TREEDEPTH - 1)
    488 		ret = find_tree_dqentry(h, dquot, blk, depth + 1);
    489 	else
    490 		ret = find_block_dqentry(h, dquot, blk);
    491 out_buf:
    492 	freedqbuf(buf);
    493 	return ret;
    494 }
    495 
    496 /* Find entry for given id in the tree - wrapper function */
    497 static inline ext2_loff_t find_dqentry(struct quota_handle *h,
    498 				       struct dquot *dquot)
    499 {
    500 	return find_tree_dqentry(h, dquot, QT_TREEOFF, 0);
    501 }
    502 
    503 /*
    504  *  Read dquot from disk.
    505  */
    506 struct dquot *qtree_read_dquot(struct quota_handle *h, qid_t id)
    507 {
    508 	struct qtree_mem_dqinfo *info = &h->qh_info.u.v2_mdqi.dqi_qtree;
    509 	ext2_loff_t offset;
    510 	unsigned int ret;
    511 	char *ddquot;
    512 	struct dquot *dquot = get_empty_dquot();
    513 
    514 	if (!dquot)
    515 		return NULL;
    516 	if (ext2fs_get_mem(info->dqi_entry_size, &ddquot)) {
    517 		ext2fs_free_mem(&dquot);
    518 		return NULL;
    519 	}
    520 
    521 	dquot->dq_id = id;
    522 	dquot->dq_h = h;
    523 	dquot->dq_dqb.u.v2_mdqb.dqb_off = 0;
    524 	memset(&dquot->dq_dqb, 0, sizeof(struct util_dqblk));
    525 
    526 	offset = find_dqentry(h, dquot);
    527 	if (offset > 0) {
    528 		dquot->dq_dqb.u.v2_mdqb.dqb_off = offset;
    529 		ret = h->e2fs_read(&h->qh_qf, offset, ddquot,
    530 			info->dqi_entry_size);
    531 		if (ret != info->dqi_entry_size) {
    532 			if (ret > 0)
    533 				errno = EIO;
    534 			log_err("Cannot read quota structure for id %u: %s",
    535 				dquot->dq_id, strerror(errno));
    536 		}
    537 		info->dqi_ops->disk2mem_dqblk(dquot, ddquot);
    538 	}
    539 	ext2fs_free_mem(&ddquot);
    540 	return dquot;
    541 }
    542 
    543 /*
    544  * Scan all dquots in file and call callback on each
    545  */
    546 #define set_bit(bmp, ind) ((bmp)[(ind) >> 3] |= (1 << ((ind) & 7)))
    547 #define get_bit(bmp, ind) ((bmp)[(ind) >> 3] & (1 << ((ind) & 7)))
    548 
    549 static int report_block(struct dquot *dquot, unsigned int blk, char *bitmap,
    550 			int (*process_dquot) (struct dquot *, void *),
    551 			void *data)
    552 {
    553 	struct qtree_mem_dqinfo *info =
    554 			&dquot->dq_h->qh_info.u.v2_mdqi.dqi_qtree;
    555 	dqbuf_t buf = getdqbuf();
    556 	struct qt_disk_dqdbheader *dh;
    557 	char *ddata;
    558 	int entries, i;
    559 
    560 	if (!buf)
    561 		return 0;
    562 
    563 	set_bit(bitmap, blk);
    564 	read_blk(dquot->dq_h, blk, buf);
    565 	dh = (struct qt_disk_dqdbheader *)buf;
    566 	ddata = buf + sizeof(struct qt_disk_dqdbheader);
    567 	entries = ext2fs_le16_to_cpu(dh->dqdh_entries);
    568 	for (i = 0; i < qtree_dqstr_in_blk(info);
    569 			i++, ddata += info->dqi_entry_size)
    570 		if (!qtree_entry_unused(info, ddata)) {
    571 			dquot->dq_dqb.u.v2_mdqb.dqb_off =
    572 				(blk << QT_BLKSIZE_BITS) +
    573 				sizeof(struct qt_disk_dqdbheader) +
    574 				i * info->dqi_entry_size;
    575 			info->dqi_ops->disk2mem_dqblk(dquot, ddata);
    576 			if (process_dquot(dquot, data) < 0)
    577 				break;
    578 		}
    579 	freedqbuf(buf);
    580 	return entries;
    581 }
    582 
    583 static void check_reference(struct quota_handle *h, unsigned int blk)
    584 {
    585 	if (blk >= h->qh_info.u.v2_mdqi.dqi_qtree.dqi_blocks)
    586 		log_err("Illegal reference (%u >= %u) in %s quota file. "
    587 			"Quota file is probably corrupted.\n"
    588 			"Please run e2fsck (8) to fix it.",
    589 			blk,
    590 			h->qh_info.u.v2_mdqi.dqi_qtree.dqi_blocks,
    591 			quota_type2name(h->qh_type));
    592 }
    593 
    594 static int report_tree(struct dquot *dquot, unsigned int blk, int depth,
    595 		       char *bitmap,
    596 		       int (*process_dquot) (struct dquot *, void *),
    597 		       void *data)
    598 {
    599 	int entries = 0, i;
    600 	dqbuf_t buf = getdqbuf();
    601 	__le32 *ref = (__le32 *) buf;
    602 
    603 	if (!buf)
    604 		return 0;
    605 
    606 	read_blk(dquot->dq_h, blk, buf);
    607 	if (depth == QT_TREEDEPTH - 1) {
    608 		for (i = 0; i < QT_BLKSIZE >> 2; i++) {
    609 			blk = ext2fs_le32_to_cpu(ref[i]);
    610 			check_reference(dquot->dq_h, blk);
    611 			if (blk && !get_bit(bitmap, blk))
    612 				entries += report_block(dquot, blk, bitmap,
    613 							process_dquot, data);
    614 		}
    615 	} else {
    616 		for (i = 0; i < QT_BLKSIZE >> 2; i++) {
    617 			blk = ext2fs_le32_to_cpu(ref[i]);
    618 			if (blk) {
    619 				check_reference(dquot->dq_h, blk);
    620 				entries += report_tree(dquot, blk, depth + 1,
    621 						       bitmap, process_dquot,
    622 						       data);
    623 			}
    624 		}
    625 	}
    626 	freedqbuf(buf);
    627 	return entries;
    628 }
    629 
    630 static unsigned int find_set_bits(char *bmp, int blocks)
    631 {
    632 	unsigned int	used = 0;
    633 	int		i;
    634 
    635 	for (i = 0; i < blocks; i++)
    636 		if (get_bit(bmp, i))
    637 			used++;
    638 	return used;
    639 }
    640 
    641 int qtree_scan_dquots(struct quota_handle *h,
    642 		      int (*process_dquot) (struct dquot *, void *),
    643 		      void *data)
    644 {
    645 	char *bitmap;
    646 	struct v2_mem_dqinfo *v2info = &h->qh_info.u.v2_mdqi;
    647 	struct qtree_mem_dqinfo *info = &v2info->dqi_qtree;
    648 	struct dquot *dquot = get_empty_dquot();
    649 
    650 	if (!dquot)
    651 		return -1;
    652 
    653 	dquot->dq_h = h;
    654 	if (ext2fs_get_memzero((info->dqi_blocks + 7) >> 3, &bitmap)) {
    655 		ext2fs_free_mem(&dquot);
    656 		return -1;
    657 	}
    658 	v2info->dqi_used_entries = report_tree(dquot, QT_TREEOFF, 0, bitmap,
    659 					       process_dquot, data);
    660 	v2info->dqi_data_blocks = find_set_bits(bitmap, info->dqi_blocks);
    661 	ext2fs_free_mem(&bitmap);
    662 	ext2fs_free_mem(&dquot);
    663 	return 0;
    664 }
    665