Commit 00c14a09 authored by Viacheslav Dubeyko's avatar Viacheslav Dubeyko
Browse files

hfs/hfsplus: prevent getting negative values of offset/length 



The syzbot reported KASAN out-of-bounds issue in
hfs_bnode_move():

[   45.588165][ T9821] hfs: dst 14, src 65536, len -65536
[   45.588895][ T9821] ==================================================================
[   45.590114][ T9821] BUG: KASAN: out-of-bounds in hfs_bnode_move+0xfd/0x140
[   45.591127][ T9821] Read of size 18446744073709486080 at addr ffff888035935400 by task repro/9821
[   45.592207][ T9821]
[   45.592420][ T9821] CPU: 0 UID: 0 PID: 9821 Comm: repro Not tainted 6.16.0-rc7-dirty #42 PREEMPT(full)
[   45.592428][ T9821] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[   45.592431][ T9821] Call Trace:
[   45.592434][ T9821]  <TASK>
[   45.592437][ T9821]  dump_stack_lvl+0x1c1/0x2a0
[   45.592446][ T9821]  ? __virt_addr_valid+0x1c8/0x5c0
[   45.592454][ T9821]  ? __pfx_dump_stack_lvl+0x10/0x10
[   45.592461][ T9821]  ? rcu_is_watching+0x15/0xb0
[   45.592469][ T9821]  ? lock_release+0x4b/0x3e0
[   45.592476][ T9821]  ? __virt_addr_valid+0x1c8/0x5c0
[   45.592483][ T9821]  ? __virt_addr_valid+0x4a5/0x5c0
[   45.592491][ T9821]  print_report+0x17e/0x7c0
[   45.592497][ T9821]  ? __virt_addr_valid+0x1c8/0x5c0
[   45.592504][ T9821]  ? __virt_addr_valid+0x4a5/0x5c0
[   45.592511][ T9821]  ? __phys_addr+0xd3/0x180
[   45.592519][ T9821]  ? hfs_bnode_move+0xfd/0x140
[   45.592526][ T9821]  kasan_report+0x147/0x180
[   45.592531][ T9821]  ? _printk+0xcf/0x120
[   45.592537][ T9821]  ? hfs_bnode_move+0xfd/0x140
[   45.592544][ T9821]  ? hfs_bnode_move+0xfd/0x140
[   45.592552][ T9821]  kasan_check_range+0x2b0/0x2c0
[   45.592557][ T9821]  ? hfs_bnode_move+0xfd/0x140
[   45.592565][ T9821]  __asan_memmove+0x29/0x70
[   45.592572][ T9821]  hfs_bnode_move+0xfd/0x140
[   45.592580][ T9821]  hfs_brec_remove+0x473/0x560
[   45.592589][ T9821]  hfs_cat_move+0x6fb/0x960
[   45.592598][ T9821]  ? __pfx_hfs_cat_move+0x10/0x10
[   45.592607][ T9821]  ? seqcount_lockdep_reader_access+0x122/0x1c0
[   45.592614][ T9821]  ? lockdep_hardirqs_on+0x9c/0x150
[   45.592631][ T9821]  ? __lock_acquire+0xaec/0xd80
[   45.592641][ T9821]  hfs_rename+0x1dc/0x2d0
[   45.592649][ T9821]  ? __pfx_hfs_rename+0x10/0x10
[   45.592657][ T9821]  vfs_rename+0xac6/0xed0
[   45.592664][ T9821]  ? __pfx_vfs_rename+0x10/0x10
[   45.592670][ T9821]  ? d_alloc+0x144/0x190
[   45.592677][ T9821]  ? bpf_lsm_path_rename+0x9/0x20
[   45.592683][ T9821]  ? security_path_rename+0x17d/0x490
[   45.592691][ T9821]  do_renameat2+0x890/0xc50
[   45.592699][ T9821]  ? __pfx_do_renameat2+0x10/0x10
[   45.592707][ T9821]  ? getname_flags+0x1e5/0x540
[   45.592714][ T9821]  __x64_sys_rename+0x82/0x90
[   45.592720][ T9821]  ? entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   45.592725][ T9821]  do_syscall_64+0xf3/0x3a0
[   45.592741][ T9821]  ? exc_page_fault+0x9f/0xf0
[   45.592748][ T9821]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   45.592754][ T9821] RIP: 0033:0x7f7f73fe3fc9
[   45.592760][ T9821] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 48
[   45.592765][ T9821] RSP: 002b:00007ffc7e116cf8 EFLAGS: 00000283 ORIG_RAX: 0000000000000052
[   45.592772][ T9821] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7f73fe3fc9
[   45.592776][ T9821] RDX: 0000200000000871 RSI: 0000200000000780 RDI: 00002000000003c0
[   45.592781][ T9821] RBP: 00007ffc7e116d00 R08: 0000000000000000 R09: 00007ffc7e116d30
[   45.592784][ T9821] R10: fffffffffffffff0 R11: 0000000000000283 R12: 00005557e81f8250
[   45.592788][ T9821] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   45.592795][ T9821]  </TASK>
[   45.592797][ T9821]
[   45.619721][ T9821] The buggy address belongs to the physical page:
[   45.620300][ T9821] page: refcount:1 mapcount:1 mapping:0000000000000000 index:0x559a88174 pfn:0x35935
[   45.621150][ T9821] memcg:ffff88810a1d5b00
[   45.621531][ T9821] anon flags: 0xfff60000020838(uptodate|dirty|lru|owner_2|swapbacked|node=0|zone=1|lastcpupid=0x7ff)
[   45.622496][ T9821] raw: 00fff60000020838 ffffea0000d64d88 ffff888021753e10 ffff888029da0771
[   45.623260][ T9821] raw: 0000000559a88174 0000000000000000 0000000100000000 ffff88810a1d5b00
[   45.624030][ T9821] page dumped because: kasan: bad access detected
[   45.624602][ T9821] page_owner tracks the page as allocated
[   45.625115][ T9821] page last allocated via order 0, migratetype Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO0
[   45.626685][ T9821]  post_alloc_hook+0x240/0x2a0
[   45.627127][ T9821]  get_page_from_freelist+0x2101/0x21e0
[   45.627628][ T9821]  __alloc_frozen_pages_noprof+0x274/0x380
[   45.628154][ T9821]  alloc_pages_mpol+0x241/0x4b0
[   45.628593][ T9821]  vma_alloc_folio_noprof+0xe4/0x210
[   45.629066][ T9821]  folio_prealloc+0x30/0x180
[   45.629487][ T9821]  __handle_mm_fault+0x34bd/0x5640
[   45.629957][ T9821]  handle_mm_fault+0x40e/0x8e0
[   45.630392][ T9821]  do_user_addr_fault+0xa81/0x1390
[   45.630862][ T9821]  exc_page_fault+0x76/0xf0
[   45.631273][ T9821]  asm_exc_page_fault+0x26/0x30
[   45.631712][ T9821] page last free pid 5269 tgid 5269 stack trace:
[   45.632281][ T9821]  free_unref_folios+0xc73/0x14c0
[   45.632740][ T9821]  folios_put_refs+0x55b/0x640
[   45.633177][ T9821]  free_pages_and_swap_cache+0x26d/0x510
[   45.633685][ T9821]  tlb_flush_mmu+0x3a0/0x680
[   45.634105][ T9821]  tlb_finish_mmu+0xd4/0x200
[   45.634525][ T9821]  exit_mmap+0x44c/0xb70
[   45.634914][ T9821]  __mmput+0x118/0x420
[   45.635286][ T9821]  exit_mm+0x1da/0x2c0
[   45.635659][ T9821]  do_exit+0x652/0x2330
[   45.636039][ T9821]  do_group_exit+0x21c/0x2d0
[   45.636457][ T9821]  __x64_sys_exit_group+0x3f/0x40
[   45.636915][ T9821]  x64_sys_call+0x21ba/0x21c0
[   45.637342][ T9821]  do_syscall_64+0xf3/0x3a0
[   45.637756][ T9821]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[   45.638290][ T9821] page has been migrated, last migrate reason: numa_misplaced
[   45.638956][ T9821]
[   45.639173][ T9821] Memory state around the buggy address:
[   45.639677][ T9821]  ffff888035935300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   45.640397][ T9821]  ffff888035935380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   45.641117][ T9821] >ffff888035935400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   45.641837][ T9821]                    ^
[   45.642207][ T9821]  ffff888035935480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   45.642929][ T9821]  ffff888035935500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   45.643650][ T9821] ==================================================================

This commit [1] fixes the issue if an offset inside of b-tree node
or length of the request is bigger than b-tree node. However,
this fix is still not ready for negative values
of the offset or length. Moreover, negative values of
the offset or length doesn't make sense for b-tree's
operations. Because we could try to access the memory address
outside of the beginning of memory page's addresses range.
Also, using of negative values make logic very complicated,
unpredictable, and we could access the wrong item(s)
in the b-tree node.

This patch changes b-tree interface by means of converting
signed integer arguments of offset and length on u32 type.
Such conversion has goal to prevent of using negative values
unintentionally or by mistake in b-tree operations.

[1] 'commit a431930c ("hfs: fix slab-out-of-bounds in hfs_bnode_read()")'

Signed-off-by: default avatarViacheslav Dubeyko <slava@dubeyko.com>
cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
cc: Yangtao Li <frank.li@vivo.com>
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20251002200020.2578311-1-slava@dubeyko.com


Signed-off-by: default avatarViacheslav Dubeyko <slava@dubeyko.com>
parent 152af114

fs/hfs/bfind.c

+1 −1
Original line number Diff line number Diff line
@@ -167,7 +167,7 @@ int hfs_brec_find(struct hfs_find_data *fd) 
	return res;

}



int hfs_brec_read(struct hfs_find_data *fd, void *rec, int rec_len)

int hfs_brec_read(struct hfs_find_data *fd, void *rec, u32 rec_len)

{

	int res;

fs/hfs/bnode.c

+26 −26
Original line number Diff line number Diff line
@@ -16,14 +16,14 @@ 
#include "btree.h"



static inline

bool is_bnode_offset_valid(struct hfs_bnode *node, int off)

bool is_bnode_offset_valid(struct hfs_bnode *node, u32 off)

{

	bool is_valid = off < node->tree->node_size;



	if (!is_valid) {

		pr_err("requested invalid offset: "

		       "NODE: id %u, type %#x, height %u, "

		       "node_size %u, offset %d\n",

		       "node_size %u, offset %u\n",

		       node->this, node->type, node->height,

		       node->tree->node_size, off);

	}
@@ -32,7 +32,7 @@ bool is_bnode_offset_valid(struct hfs_bnode *node, int off) 
}



static inline

int check_and_correct_requested_length(struct hfs_bnode *node, int off, int len)

u32 check_and_correct_requested_length(struct hfs_bnode *node, u32 off, u32 len)

{

	unsigned int node_size;
@@ -42,12 +42,12 @@ int check_and_correct_requested_length(struct hfs_bnode *node, int off, int len) 
	node_size = node->tree->node_size;



	if ((off + len) > node_size) {

		int new_len = (int)node_size - off;

		u32 new_len = node_size - off;



		pr_err("requested length has been corrected: "

		       "NODE: id %u, type %#x, height %u, "

		       "node_size %u, offset %d, "

		       "requested_len %d, corrected_len %d\n",

		       "node_size %u, offset %u, "

		       "requested_len %u, corrected_len %u\n",

		       node->this, node->type, node->height,

		       node->tree->node_size, off, len, new_len);
@@ -57,12 +57,12 @@ int check_and_correct_requested_length(struct hfs_bnode *node, int off, int len) 
	return len;

}



void hfs_bnode_read(struct hfs_bnode *node, void *buf, int off, int len)

void hfs_bnode_read(struct hfs_bnode *node, void *buf, u32 off, u32 len)

{

	struct page *page;

	int pagenum;

	int bytes_read;

	int bytes_to_read;

	u32 pagenum;

	u32 bytes_read;

	u32 bytes_to_read;



	if (!is_bnode_offset_valid(node, off))

		return;
@@ -70,7 +70,7 @@ void hfs_bnode_read(struct hfs_bnode *node, void *buf, int off, int len) 
	if (len == 0) {

		pr_err("requested zero length: "

		       "NODE: id %u, type %#x, height %u, "

		       "node_size %u, offset %d, len %d\n",

		       "node_size %u, offset %u, len %u\n",

		       node->this, node->type, node->height,

		       node->tree->node_size, off, len);

		return;
@@ -86,7 +86,7 @@ void hfs_bnode_read(struct hfs_bnode *node, void *buf, int off, int len) 
		if (pagenum >= node->tree->pages_per_bnode)

			break;

		page = node->page[pagenum];

		bytes_to_read = min_t(int, len - bytes_read, PAGE_SIZE - off);

		bytes_to_read = min_t(u32, len - bytes_read, PAGE_SIZE - off);



		memcpy_from_page(buf + bytes_read, page, off, bytes_to_read);
@@ -95,7 +95,7 @@ void hfs_bnode_read(struct hfs_bnode *node, void *buf, int off, int len) 
	}

}



u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)

u16 hfs_bnode_read_u16(struct hfs_bnode *node, u32 off)

{

	__be16 data;

	// optimize later...
@@ -103,7 +103,7 @@ u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off) 
	return be16_to_cpu(data);

}



u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)

u8 hfs_bnode_read_u8(struct hfs_bnode *node, u32 off)

{

	u8 data;

	// optimize later...
@@ -111,10 +111,10 @@ u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off) 
	return data;

}



void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off)

void hfs_bnode_read_key(struct hfs_bnode *node, void *key, u32 off)

{

	struct hfs_btree *tree;

	int key_len;

	u32 key_len;



	tree = node->tree;

	if (node->type == HFS_NODE_LEAF ||
@@ -125,14 +125,14 @@ void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off) 


	if (key_len > sizeof(hfs_btree_key) || key_len < 1) {

		memset(key, 0, sizeof(hfs_btree_key));

		pr_err("hfs: Invalid key length: %d\n", key_len);

		pr_err("hfs: Invalid key length: %u\n", key_len);

		return;

	}



	hfs_bnode_read(node, key, off, key_len);

}



void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len)

void hfs_bnode_write(struct hfs_bnode *node, void *buf, u32 off, u32 len)

{

	struct page *page;
@@ -142,7 +142,7 @@ void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len) 
	if (len == 0) {

		pr_err("requested zero length: "

		       "NODE: id %u, type %#x, height %u, "

		       "node_size %u, offset %d, len %d\n",

		       "node_size %u, offset %u, len %u\n",

		       node->this, node->type, node->height,

		       node->tree->node_size, off, len);

		return;
@@ -157,20 +157,20 @@ void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len) 
	set_page_dirty(page);

}



void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)

void hfs_bnode_write_u16(struct hfs_bnode *node, u32 off, u16 data)

{

	__be16 v = cpu_to_be16(data);

	// optimize later...

	hfs_bnode_write(node, &v, off, 2);

}



void hfs_bnode_write_u8(struct hfs_bnode *node, int off, u8 data)

void hfs_bnode_write_u8(struct hfs_bnode *node, u32 off, u8 data)

{

	// optimize later...

	hfs_bnode_write(node, &data, off, 1);

}



void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)

void hfs_bnode_clear(struct hfs_bnode *node, u32 off, u32 len)

{

	struct page *page;
@@ -180,7 +180,7 @@ void hfs_bnode_clear(struct hfs_bnode *node, int off, int len) 
	if (len == 0) {

		pr_err("requested zero length: "

		       "NODE: id %u, type %#x, height %u, "

		       "node_size %u, offset %d, len %d\n",

		       "node_size %u, offset %u, len %u\n",

		       node->this, node->type, node->height,

		       node->tree->node_size, off, len);

		return;
@@ -195,8 +195,8 @@ void hfs_bnode_clear(struct hfs_bnode *node, int off, int len) 
	set_page_dirty(page);

}



void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,

		struct hfs_bnode *src_node, int src, int len)

void hfs_bnode_copy(struct hfs_bnode *dst_node, u32 dst,

		    struct hfs_bnode *src_node, u32 src, u32 len)

{

	struct page *src_page, *dst_page;
@@ -216,7 +216,7 @@ void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst, 
	set_page_dirty(dst_page);

}



void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)

void hfs_bnode_move(struct hfs_bnode *node, u32 dst, u32 src, u32 len)

{

	struct page *page;

	void *ptr;

fs/hfs/brec.c

+1 −1
Original line number Diff line number Diff line
@@ -62,7 +62,7 @@ u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec) 
	return retval;

}



int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len)

int hfs_brec_insert(struct hfs_find_data *fd, void *entry, u32 entry_len)

{

	struct hfs_btree *tree;

	struct hfs_bnode *node, *new_node;

fs/hfs/btree.c

+1 −1
Original line number Diff line number Diff line
@@ -259,7 +259,7 @@ static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx) 
}



/* Make sure @tree has enough space for the @rsvd_nodes */

int hfs_bmap_reserve(struct hfs_btree *tree, int rsvd_nodes)

int hfs_bmap_reserve(struct hfs_btree *tree, u32 rsvd_nodes)

{

	struct inode *inode = tree->inode;

	u32 count;

fs/hfs/btree.h

+36 −35
Original line number Diff line number Diff line
@@ -86,48 +86,49 @@ struct hfs_find_data { 




/* btree.c */

extern struct hfs_btree *hfs_btree_open(struct super_block *, u32, btree_keycmp);

extern void hfs_btree_close(struct hfs_btree *);

extern void hfs_btree_write(struct hfs_btree *);

extern int hfs_bmap_reserve(struct hfs_btree *, int);

extern struct hfs_bnode * hfs_bmap_alloc(struct hfs_btree *);

extern struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id,

					btree_keycmp keycmp);

extern void hfs_btree_close(struct hfs_btree *tree);

extern void hfs_btree_write(struct hfs_btree *tree);

extern int hfs_bmap_reserve(struct hfs_btree *tree, u32 rsvd_nodes);

extern struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree);

extern void hfs_bmap_free(struct hfs_bnode *node);



/* bnode.c */

extern void hfs_bnode_read(struct hfs_bnode *, void *, int, int);

extern u16 hfs_bnode_read_u16(struct hfs_bnode *, int);

extern u8 hfs_bnode_read_u8(struct hfs_bnode *, int);

extern void hfs_bnode_read_key(struct hfs_bnode *, void *, int);

extern void hfs_bnode_write(struct hfs_bnode *, void *, int, int);

extern void hfs_bnode_write_u16(struct hfs_bnode *, int, u16);

extern void hfs_bnode_write_u8(struct hfs_bnode *, int, u8);

extern void hfs_bnode_clear(struct hfs_bnode *, int, int);

extern void hfs_bnode_copy(struct hfs_bnode *, int,

			   struct hfs_bnode *, int, int);

extern void hfs_bnode_move(struct hfs_bnode *, int, int, int);

extern void hfs_bnode_dump(struct hfs_bnode *);

extern void hfs_bnode_unlink(struct hfs_bnode *);

extern struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *, u32);

extern struct hfs_bnode *hfs_bnode_find(struct hfs_btree *, u32);

extern void hfs_bnode_unhash(struct hfs_bnode *);

extern void hfs_bnode_free(struct hfs_bnode *);

extern struct hfs_bnode *hfs_bnode_create(struct hfs_btree *, u32);

extern void hfs_bnode_get(struct hfs_bnode *);

extern void hfs_bnode_put(struct hfs_bnode *);

extern void hfs_bnode_read(struct hfs_bnode *node, void *buf, u32 off, u32 len);

extern u16 hfs_bnode_read_u16(struct hfs_bnode *node, u32 off);

extern u8 hfs_bnode_read_u8(struct hfs_bnode *node, u32 off);

extern void hfs_bnode_read_key(struct hfs_bnode *node, void *key, u32 off);

extern void hfs_bnode_write(struct hfs_bnode *node, void *buf, u32 off, u32 len);

extern void hfs_bnode_write_u16(struct hfs_bnode *node, u32 off, u16 data);

extern void hfs_bnode_write_u8(struct hfs_bnode *node, u32 off, u8 data);

extern void hfs_bnode_clear(struct hfs_bnode *node, u32 off, u32 len);

extern void hfs_bnode_copy(struct hfs_bnode *dst_node, u32 dst,

			   struct hfs_bnode *src_node, u32 src, u32 len);

extern void hfs_bnode_move(struct hfs_bnode *node, u32 dst, u32 src, u32 len);

extern void hfs_bnode_dump(struct hfs_bnode *node);

extern void hfs_bnode_unlink(struct hfs_bnode *node);

extern struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid);

extern struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num);

extern void hfs_bnode_unhash(struct hfs_bnode *node);

extern void hfs_bnode_free(struct hfs_bnode *node);

extern struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num);

extern void hfs_bnode_get(struct hfs_bnode *node);

extern void hfs_bnode_put(struct hfs_bnode *node);



/* brec.c */

extern u16 hfs_brec_lenoff(struct hfs_bnode *, u16, u16 *);

extern u16 hfs_brec_keylen(struct hfs_bnode *, u16);

extern int hfs_brec_insert(struct hfs_find_data *, void *, int);

extern int hfs_brec_remove(struct hfs_find_data *);

extern u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off);

extern u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec);

extern int hfs_brec_insert(struct hfs_find_data *fd, void *entry, u32 entry_len);

extern int hfs_brec_remove(struct hfs_find_data *fd);



/* bfind.c */

extern int hfs_find_init(struct hfs_btree *, struct hfs_find_data *);

extern void hfs_find_exit(struct hfs_find_data *);

extern int __hfs_brec_find(struct hfs_bnode *, struct hfs_find_data *);

extern int hfs_brec_find(struct hfs_find_data *);

extern int hfs_brec_read(struct hfs_find_data *, void *, int);

extern int hfs_brec_goto(struct hfs_find_data *, int);

extern int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd);

extern void hfs_find_exit(struct hfs_find_data *fd);

extern int __hfs_brec_find(struct hfs_bnode *bnode, struct hfs_find_data *fd);

extern int hfs_brec_find(struct hfs_find_data *fd);

extern int hfs_brec_read(struct hfs_find_data *fd, void *rec, u32 rec_len);

extern int hfs_brec_goto(struct hfs_find_data *fd, int cnt);





struct hfs_bnode_desc {