mirror of
https://github.com/torvalds/linux.git
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7cb74be6fd
Pages looked up by __hfs_bnode_create() (called by hfs_bnode_create() and
hfs_bnode_find() for finding or creating pages corresponding to an inode)
are immediately kmap()'ed and used (both read and write) and kunmap()'ed,
and should not be page_cache_release()'ed until hfs_bnode_free().
This patch fixes a problem I first saw in July 2012: merely running "du"
on a large hfsplus-mounted directory a few times on a reasonably loaded
system would get the hfsplus driver all confused and complaining about
B-tree inconsistencies, and generates a "BUG: Bad page state". Most
recently, I can generate this problem on up-to-date Fedora 22 with shipped
kernel 4.0.5, by running "du /" (="/" + "/home" + "/mnt" + other smaller
mounts) and "du /mnt" simultaneously on two windows, where /mnt is a
lightly-used QEMU VM image of the full Mac OS X 10.9:
$ df -i / /home /mnt
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/mapper/fedora-root 3276800 551665 2725135 17% /
/dev/mapper/fedora-home 52879360 716221 52163139 2% /home
/dev/nbd0p2 4294967295 1387818 4293579477 1% /mnt
After applying the patch, I was able to run "du /" (60+ times) and "du
/mnt" (150+ times) continuously and simultaneously for 6+ hours.
There are many reports of the hfsplus driver getting confused under load
and generating "BUG: Bad page state" or other similar issues over the
years. [1]
The unpatched code [2] has always been wrong since it entered the kernel
tree. The only reason why it gets away with it is that the
kmap/memcpy/kunmap follow very quickly after the page_cache_release() so
the kernel has not had a chance to reuse the memory for something else,
most of the time.
The current RW driver appears to have followed the design and development
of the earlier read-only hfsplus driver [3], where-by version 0.1 (Dec
2001) had a B-tree node-centric approach to
read_cache_page()/page_cache_release() per bnode_get()/bnode_put(),
migrating towards version 0.2 (June 2002) of caching and releasing pages
per inode extents. When the current RW code first entered the kernel [2]
in 2005, there was an REF_PAGES conditional (and "//" commented out code)
to switch between B-node centric paging to inode-centric paging. There
was a mistake with the direction of one of the REF_PAGES conditionals in
__hfs_bnode_create(). In a subsequent "remove debug code" commit [4], the
read_cache_page()/page_cache_release() per bnode_get()/bnode_put() were
removed, but a page_cache_release() was mistakenly left in (propagating
the "REF_PAGES <-> !REF_PAGE" mistake), and the commented-out
page_cache_release() in bnode_release() (which should be spanned by
!REF_PAGES) was never enabled.
References:
[1]:
Michael Fox, Apr 2013
http://www.spinics.net/lists/linux-fsdevel/msg63807.html
("hfsplus volume suddenly inaccessable after 'hfs: recoff %d too large'")
Sasha Levin, Feb 2015
http://lkml.org/lkml/2015/2/20/85 ("use after free")
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/740814
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1027887
https://bugzilla.kernel.org/show_bug.cgi?id=42342
https://bugzilla.kernel.org/show_bug.cgi?id=63841
https://bugzilla.kernel.org/show_bug.cgi?id=78761
[2]:
http://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/\
fs/hfs/bnode.c?id=d1081202f1d0ee35ab0beb490da4b65d4bc763db
commit d1081202f1d0ee35ab0beb490da4b65d4bc763db
Author: Andrew Morton <akpm@osdl.org>
Date: Wed Feb 25 16:17:36 2004 -0800
[PATCH] HFS rewrite
http://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/\
fs/hfsplus/bnode.c?id=91556682e0bf004d98a529bf829d339abb98bbbd
commit 91556682e0bf004d98a529bf829d339abb98bbbd
Author: Andrew Morton <akpm@osdl.org>
Date: Wed Feb 25 16:17:48 2004 -0800
[PATCH] HFS+ support
[3]:
http://sourceforge.net/projects/linux-hfsplus/
http://sourceforge.net/projects/linux-hfsplus/files/Linux%202.4.x%20patch/hfsplus%200.1/
http://sourceforge.net/projects/linux-hfsplus/files/Linux%202.4.x%20patch/hfsplus%200.2/
http://linux-hfsplus.cvs.sourceforge.net/viewvc/linux-hfsplus/linux/\
fs/hfsplus/bnode.c?r1=1.4&r2=1.5
Date: Thu Jun 6 09:45:14 2002 +0000
Use buffer cache instead of page cache in bnode.c. Cache inode extents.
[4]:
http://git.kernel.org/cgit/linux/kernel/git/\
stable/linux-stable.git/commit/?id=a5e3985fa014029eb6795664c704953720cc7f7d
commit a5e3985fa0
Author: Roman Zippel <zippel@linux-m68k.org>
Date: Tue Sep 6 15:18:47 2005 -0700
[PATCH] hfs: remove debug code
Signed-off-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: Sergei Antonov <saproj@gmail.com>
Reviewed-by: Anton Altaparmakov <anton@tuxera.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Sougata Santra <sougata@tuxera.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
669 lines
16 KiB
C
669 lines
16 KiB
C
/*
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* linux/fs/hfsplus/bnode.c
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*
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* Copyright (C) 2001
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* Brad Boyer (flar@allandria.com)
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* (C) 2003 Ardis Technologies <roman@ardistech.com>
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*
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* Handle basic btree node operations
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*/
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#include <linux/string.h>
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#include <linux/slab.h>
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#include <linux/pagemap.h>
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#include <linux/fs.h>
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#include <linux/swap.h>
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#include "hfsplus_fs.h"
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#include "hfsplus_raw.h"
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/* Copy a specified range of bytes from the raw data of a node */
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void hfs_bnode_read(struct hfs_bnode *node, void *buf, int off, int len)
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{
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struct page **pagep;
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int l;
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off += node->page_offset;
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pagep = node->page + (off >> PAGE_CACHE_SHIFT);
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off &= ~PAGE_CACHE_MASK;
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l = min_t(int, len, PAGE_CACHE_SIZE - off);
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memcpy(buf, kmap(*pagep) + off, l);
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kunmap(*pagep);
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while ((len -= l) != 0) {
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buf += l;
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l = min_t(int, len, PAGE_CACHE_SIZE);
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memcpy(buf, kmap(*++pagep), l);
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kunmap(*pagep);
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}
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}
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u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
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{
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__be16 data;
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/* TODO: optimize later... */
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hfs_bnode_read(node, &data, off, 2);
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return be16_to_cpu(data);
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}
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u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)
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{
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u8 data;
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/* TODO: optimize later... */
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hfs_bnode_read(node, &data, off, 1);
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return data;
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}
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void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off)
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{
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struct hfs_btree *tree;
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int key_len;
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tree = node->tree;
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if (node->type == HFS_NODE_LEAF ||
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tree->attributes & HFS_TREE_VARIDXKEYS ||
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node->tree->cnid == HFSPLUS_ATTR_CNID)
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key_len = hfs_bnode_read_u16(node, off) + 2;
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else
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key_len = tree->max_key_len + 2;
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hfs_bnode_read(node, key, off, key_len);
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}
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void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len)
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{
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struct page **pagep;
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int l;
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off += node->page_offset;
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pagep = node->page + (off >> PAGE_CACHE_SHIFT);
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off &= ~PAGE_CACHE_MASK;
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l = min_t(int, len, PAGE_CACHE_SIZE - off);
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memcpy(kmap(*pagep) + off, buf, l);
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set_page_dirty(*pagep);
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kunmap(*pagep);
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while ((len -= l) != 0) {
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buf += l;
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l = min_t(int, len, PAGE_CACHE_SIZE);
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memcpy(kmap(*++pagep), buf, l);
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set_page_dirty(*pagep);
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kunmap(*pagep);
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}
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}
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void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
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{
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__be16 v = cpu_to_be16(data);
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/* TODO: optimize later... */
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hfs_bnode_write(node, &v, off, 2);
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}
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void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
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{
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struct page **pagep;
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int l;
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off += node->page_offset;
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pagep = node->page + (off >> PAGE_CACHE_SHIFT);
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off &= ~PAGE_CACHE_MASK;
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l = min_t(int, len, PAGE_CACHE_SIZE - off);
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memset(kmap(*pagep) + off, 0, l);
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set_page_dirty(*pagep);
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kunmap(*pagep);
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while ((len -= l) != 0) {
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l = min_t(int, len, PAGE_CACHE_SIZE);
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memset(kmap(*++pagep), 0, l);
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set_page_dirty(*pagep);
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kunmap(*pagep);
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}
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}
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void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
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struct hfs_bnode *src_node, int src, int len)
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{
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struct hfs_btree *tree;
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struct page **src_page, **dst_page;
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int l;
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hfs_dbg(BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
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if (!len)
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return;
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tree = src_node->tree;
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src += src_node->page_offset;
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dst += dst_node->page_offset;
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src_page = src_node->page + (src >> PAGE_CACHE_SHIFT);
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src &= ~PAGE_CACHE_MASK;
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dst_page = dst_node->page + (dst >> PAGE_CACHE_SHIFT);
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dst &= ~PAGE_CACHE_MASK;
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if (src == dst) {
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l = min_t(int, len, PAGE_CACHE_SIZE - src);
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memcpy(kmap(*dst_page) + src, kmap(*src_page) + src, l);
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kunmap(*src_page);
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set_page_dirty(*dst_page);
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kunmap(*dst_page);
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while ((len -= l) != 0) {
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l = min_t(int, len, PAGE_CACHE_SIZE);
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memcpy(kmap(*++dst_page), kmap(*++src_page), l);
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kunmap(*src_page);
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set_page_dirty(*dst_page);
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kunmap(*dst_page);
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}
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} else {
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void *src_ptr, *dst_ptr;
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do {
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src_ptr = kmap(*src_page) + src;
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dst_ptr = kmap(*dst_page) + dst;
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if (PAGE_CACHE_SIZE - src < PAGE_CACHE_SIZE - dst) {
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l = PAGE_CACHE_SIZE - src;
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src = 0;
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dst += l;
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} else {
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l = PAGE_CACHE_SIZE - dst;
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src += l;
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dst = 0;
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}
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l = min(len, l);
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memcpy(dst_ptr, src_ptr, l);
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kunmap(*src_page);
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set_page_dirty(*dst_page);
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kunmap(*dst_page);
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if (!dst)
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dst_page++;
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else
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src_page++;
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} while ((len -= l));
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}
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}
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void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
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{
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struct page **src_page, **dst_page;
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int l;
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hfs_dbg(BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
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if (!len)
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return;
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src += node->page_offset;
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dst += node->page_offset;
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if (dst > src) {
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src += len - 1;
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src_page = node->page + (src >> PAGE_CACHE_SHIFT);
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src = (src & ~PAGE_CACHE_MASK) + 1;
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dst += len - 1;
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dst_page = node->page + (dst >> PAGE_CACHE_SHIFT);
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dst = (dst & ~PAGE_CACHE_MASK) + 1;
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if (src == dst) {
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while (src < len) {
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memmove(kmap(*dst_page), kmap(*src_page), src);
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kunmap(*src_page);
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set_page_dirty(*dst_page);
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kunmap(*dst_page);
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len -= src;
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src = PAGE_CACHE_SIZE;
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src_page--;
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dst_page--;
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}
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src -= len;
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memmove(kmap(*dst_page) + src,
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kmap(*src_page) + src, len);
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kunmap(*src_page);
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set_page_dirty(*dst_page);
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kunmap(*dst_page);
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} else {
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void *src_ptr, *dst_ptr;
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do {
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src_ptr = kmap(*src_page) + src;
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dst_ptr = kmap(*dst_page) + dst;
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if (src < dst) {
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l = src;
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src = PAGE_CACHE_SIZE;
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dst -= l;
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} else {
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l = dst;
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src -= l;
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dst = PAGE_CACHE_SIZE;
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}
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l = min(len, l);
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memmove(dst_ptr - l, src_ptr - l, l);
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kunmap(*src_page);
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set_page_dirty(*dst_page);
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kunmap(*dst_page);
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if (dst == PAGE_CACHE_SIZE)
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dst_page--;
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else
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src_page--;
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} while ((len -= l));
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}
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} else {
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src_page = node->page + (src >> PAGE_CACHE_SHIFT);
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src &= ~PAGE_CACHE_MASK;
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dst_page = node->page + (dst >> PAGE_CACHE_SHIFT);
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dst &= ~PAGE_CACHE_MASK;
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if (src == dst) {
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l = min_t(int, len, PAGE_CACHE_SIZE - src);
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memmove(kmap(*dst_page) + src,
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kmap(*src_page) + src, l);
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kunmap(*src_page);
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set_page_dirty(*dst_page);
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kunmap(*dst_page);
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while ((len -= l) != 0) {
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l = min_t(int, len, PAGE_CACHE_SIZE);
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memmove(kmap(*++dst_page),
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kmap(*++src_page), l);
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kunmap(*src_page);
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set_page_dirty(*dst_page);
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kunmap(*dst_page);
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}
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} else {
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void *src_ptr, *dst_ptr;
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do {
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src_ptr = kmap(*src_page) + src;
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dst_ptr = kmap(*dst_page) + dst;
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if (PAGE_CACHE_SIZE - src <
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PAGE_CACHE_SIZE - dst) {
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l = PAGE_CACHE_SIZE - src;
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src = 0;
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dst += l;
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} else {
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l = PAGE_CACHE_SIZE - dst;
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src += l;
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dst = 0;
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}
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l = min(len, l);
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memmove(dst_ptr, src_ptr, l);
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kunmap(*src_page);
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set_page_dirty(*dst_page);
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kunmap(*dst_page);
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if (!dst)
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dst_page++;
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else
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src_page++;
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} while ((len -= l));
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}
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}
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}
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void hfs_bnode_dump(struct hfs_bnode *node)
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{
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struct hfs_bnode_desc desc;
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__be32 cnid;
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int i, off, key_off;
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hfs_dbg(BNODE_MOD, "bnode: %d\n", node->this);
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hfs_bnode_read(node, &desc, 0, sizeof(desc));
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hfs_dbg(BNODE_MOD, "%d, %d, %d, %d, %d\n",
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be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
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desc.type, desc.height, be16_to_cpu(desc.num_recs));
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off = node->tree->node_size - 2;
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for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
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key_off = hfs_bnode_read_u16(node, off);
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hfs_dbg(BNODE_MOD, " %d", key_off);
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if (i && node->type == HFS_NODE_INDEX) {
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int tmp;
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if (node->tree->attributes & HFS_TREE_VARIDXKEYS ||
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node->tree->cnid == HFSPLUS_ATTR_CNID)
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tmp = hfs_bnode_read_u16(node, key_off) + 2;
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else
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tmp = node->tree->max_key_len + 2;
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hfs_dbg_cont(BNODE_MOD, " (%d", tmp);
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hfs_bnode_read(node, &cnid, key_off + tmp, 4);
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hfs_dbg_cont(BNODE_MOD, ",%d)", be32_to_cpu(cnid));
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} else if (i && node->type == HFS_NODE_LEAF) {
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int tmp;
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tmp = hfs_bnode_read_u16(node, key_off);
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hfs_dbg_cont(BNODE_MOD, " (%d)", tmp);
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}
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}
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hfs_dbg_cont(BNODE_MOD, "\n");
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}
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void hfs_bnode_unlink(struct hfs_bnode *node)
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{
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struct hfs_btree *tree;
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struct hfs_bnode *tmp;
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__be32 cnid;
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tree = node->tree;
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if (node->prev) {
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tmp = hfs_bnode_find(tree, node->prev);
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if (IS_ERR(tmp))
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return;
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tmp->next = node->next;
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cnid = cpu_to_be32(tmp->next);
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hfs_bnode_write(tmp, &cnid,
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offsetof(struct hfs_bnode_desc, next), 4);
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hfs_bnode_put(tmp);
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} else if (node->type == HFS_NODE_LEAF)
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tree->leaf_head = node->next;
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if (node->next) {
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tmp = hfs_bnode_find(tree, node->next);
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if (IS_ERR(tmp))
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return;
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tmp->prev = node->prev;
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cnid = cpu_to_be32(tmp->prev);
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hfs_bnode_write(tmp, &cnid,
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offsetof(struct hfs_bnode_desc, prev), 4);
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hfs_bnode_put(tmp);
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} else if (node->type == HFS_NODE_LEAF)
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tree->leaf_tail = node->prev;
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/* move down? */
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if (!node->prev && !node->next)
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hfs_dbg(BNODE_MOD, "hfs_btree_del_level\n");
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if (!node->parent) {
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tree->root = 0;
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tree->depth = 0;
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}
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set_bit(HFS_BNODE_DELETED, &node->flags);
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}
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static inline int hfs_bnode_hash(u32 num)
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{
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num = (num >> 16) + num;
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num += num >> 8;
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return num & (NODE_HASH_SIZE - 1);
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}
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|
|
struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid)
|
|
{
|
|
struct hfs_bnode *node;
|
|
|
|
if (cnid >= tree->node_count) {
|
|
pr_err("request for non-existent node %d in B*Tree\n",
|
|
cnid);
|
|
return NULL;
|
|
}
|
|
|
|
for (node = tree->node_hash[hfs_bnode_hash(cnid)];
|
|
node; node = node->next_hash)
|
|
if (node->this == cnid)
|
|
return node;
|
|
return NULL;
|
|
}
|
|
|
|
static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
|
|
{
|
|
struct super_block *sb;
|
|
struct hfs_bnode *node, *node2;
|
|
struct address_space *mapping;
|
|
struct page *page;
|
|
int size, block, i, hash;
|
|
loff_t off;
|
|
|
|
if (cnid >= tree->node_count) {
|
|
pr_err("request for non-existent node %d in B*Tree\n",
|
|
cnid);
|
|
return NULL;
|
|
}
|
|
|
|
sb = tree->inode->i_sb;
|
|
size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
|
|
sizeof(struct page *);
|
|
node = kzalloc(size, GFP_KERNEL);
|
|
if (!node)
|
|
return NULL;
|
|
node->tree = tree;
|
|
node->this = cnid;
|
|
set_bit(HFS_BNODE_NEW, &node->flags);
|
|
atomic_set(&node->refcnt, 1);
|
|
hfs_dbg(BNODE_REFS, "new_node(%d:%d): 1\n",
|
|
node->tree->cnid, node->this);
|
|
init_waitqueue_head(&node->lock_wq);
|
|
spin_lock(&tree->hash_lock);
|
|
node2 = hfs_bnode_findhash(tree, cnid);
|
|
if (!node2) {
|
|
hash = hfs_bnode_hash(cnid);
|
|
node->next_hash = tree->node_hash[hash];
|
|
tree->node_hash[hash] = node;
|
|
tree->node_hash_cnt++;
|
|
} else {
|
|
spin_unlock(&tree->hash_lock);
|
|
kfree(node);
|
|
wait_event(node2->lock_wq,
|
|
!test_bit(HFS_BNODE_NEW, &node2->flags));
|
|
return node2;
|
|
}
|
|
spin_unlock(&tree->hash_lock);
|
|
|
|
mapping = tree->inode->i_mapping;
|
|
off = (loff_t)cnid << tree->node_size_shift;
|
|
block = off >> PAGE_CACHE_SHIFT;
|
|
node->page_offset = off & ~PAGE_CACHE_MASK;
|
|
for (i = 0; i < tree->pages_per_bnode; block++, i++) {
|
|
page = read_mapping_page(mapping, block, NULL);
|
|
if (IS_ERR(page))
|
|
goto fail;
|
|
if (PageError(page)) {
|
|
page_cache_release(page);
|
|
goto fail;
|
|
}
|
|
node->page[i] = page;
|
|
}
|
|
|
|
return node;
|
|
fail:
|
|
set_bit(HFS_BNODE_ERROR, &node->flags);
|
|
return node;
|
|
}
|
|
|
|
void hfs_bnode_unhash(struct hfs_bnode *node)
|
|
{
|
|
struct hfs_bnode **p;
|
|
|
|
hfs_dbg(BNODE_REFS, "remove_node(%d:%d): %d\n",
|
|
node->tree->cnid, node->this, atomic_read(&node->refcnt));
|
|
for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
|
|
*p && *p != node; p = &(*p)->next_hash)
|
|
;
|
|
BUG_ON(!*p);
|
|
*p = node->next_hash;
|
|
node->tree->node_hash_cnt--;
|
|
}
|
|
|
|
/* Load a particular node out of a tree */
|
|
struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num)
|
|
{
|
|
struct hfs_bnode *node;
|
|
struct hfs_bnode_desc *desc;
|
|
int i, rec_off, off, next_off;
|
|
int entry_size, key_size;
|
|
|
|
spin_lock(&tree->hash_lock);
|
|
node = hfs_bnode_findhash(tree, num);
|
|
if (node) {
|
|
hfs_bnode_get(node);
|
|
spin_unlock(&tree->hash_lock);
|
|
wait_event(node->lock_wq,
|
|
!test_bit(HFS_BNODE_NEW, &node->flags));
|
|
if (test_bit(HFS_BNODE_ERROR, &node->flags))
|
|
goto node_error;
|
|
return node;
|
|
}
|
|
spin_unlock(&tree->hash_lock);
|
|
node = __hfs_bnode_create(tree, num);
|
|
if (!node)
|
|
return ERR_PTR(-ENOMEM);
|
|
if (test_bit(HFS_BNODE_ERROR, &node->flags))
|
|
goto node_error;
|
|
if (!test_bit(HFS_BNODE_NEW, &node->flags))
|
|
return node;
|
|
|
|
desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) +
|
|
node->page_offset);
|
|
node->prev = be32_to_cpu(desc->prev);
|
|
node->next = be32_to_cpu(desc->next);
|
|
node->num_recs = be16_to_cpu(desc->num_recs);
|
|
node->type = desc->type;
|
|
node->height = desc->height;
|
|
kunmap(node->page[0]);
|
|
|
|
switch (node->type) {
|
|
case HFS_NODE_HEADER:
|
|
case HFS_NODE_MAP:
|
|
if (node->height != 0)
|
|
goto node_error;
|
|
break;
|
|
case HFS_NODE_LEAF:
|
|
if (node->height != 1)
|
|
goto node_error;
|
|
break;
|
|
case HFS_NODE_INDEX:
|
|
if (node->height <= 1 || node->height > tree->depth)
|
|
goto node_error;
|
|
break;
|
|
default:
|
|
goto node_error;
|
|
}
|
|
|
|
rec_off = tree->node_size - 2;
|
|
off = hfs_bnode_read_u16(node, rec_off);
|
|
if (off != sizeof(struct hfs_bnode_desc))
|
|
goto node_error;
|
|
for (i = 1; i <= node->num_recs; off = next_off, i++) {
|
|
rec_off -= 2;
|
|
next_off = hfs_bnode_read_u16(node, rec_off);
|
|
if (next_off <= off ||
|
|
next_off > tree->node_size ||
|
|
next_off & 1)
|
|
goto node_error;
|
|
entry_size = next_off - off;
|
|
if (node->type != HFS_NODE_INDEX &&
|
|
node->type != HFS_NODE_LEAF)
|
|
continue;
|
|
key_size = hfs_bnode_read_u16(node, off) + 2;
|
|
if (key_size >= entry_size || key_size & 1)
|
|
goto node_error;
|
|
}
|
|
clear_bit(HFS_BNODE_NEW, &node->flags);
|
|
wake_up(&node->lock_wq);
|
|
return node;
|
|
|
|
node_error:
|
|
set_bit(HFS_BNODE_ERROR, &node->flags);
|
|
clear_bit(HFS_BNODE_NEW, &node->flags);
|
|
wake_up(&node->lock_wq);
|
|
hfs_bnode_put(node);
|
|
return ERR_PTR(-EIO);
|
|
}
|
|
|
|
void hfs_bnode_free(struct hfs_bnode *node)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < node->tree->pages_per_bnode; i++)
|
|
if (node->page[i])
|
|
page_cache_release(node->page[i]);
|
|
kfree(node);
|
|
}
|
|
|
|
struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num)
|
|
{
|
|
struct hfs_bnode *node;
|
|
struct page **pagep;
|
|
int i;
|
|
|
|
spin_lock(&tree->hash_lock);
|
|
node = hfs_bnode_findhash(tree, num);
|
|
spin_unlock(&tree->hash_lock);
|
|
if (node) {
|
|
pr_crit("new node %u already hashed?\n", num);
|
|
WARN_ON(1);
|
|
return node;
|
|
}
|
|
node = __hfs_bnode_create(tree, num);
|
|
if (!node)
|
|
return ERR_PTR(-ENOMEM);
|
|
if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
|
|
hfs_bnode_put(node);
|
|
return ERR_PTR(-EIO);
|
|
}
|
|
|
|
pagep = node->page;
|
|
memset(kmap(*pagep) + node->page_offset, 0,
|
|
min_t(int, PAGE_CACHE_SIZE, tree->node_size));
|
|
set_page_dirty(*pagep);
|
|
kunmap(*pagep);
|
|
for (i = 1; i < tree->pages_per_bnode; i++) {
|
|
memset(kmap(*++pagep), 0, PAGE_CACHE_SIZE);
|
|
set_page_dirty(*pagep);
|
|
kunmap(*pagep);
|
|
}
|
|
clear_bit(HFS_BNODE_NEW, &node->flags);
|
|
wake_up(&node->lock_wq);
|
|
|
|
return node;
|
|
}
|
|
|
|
void hfs_bnode_get(struct hfs_bnode *node)
|
|
{
|
|
if (node) {
|
|
atomic_inc(&node->refcnt);
|
|
hfs_dbg(BNODE_REFS, "get_node(%d:%d): %d\n",
|
|
node->tree->cnid, node->this,
|
|
atomic_read(&node->refcnt));
|
|
}
|
|
}
|
|
|
|
/* Dispose of resources used by a node */
|
|
void hfs_bnode_put(struct hfs_bnode *node)
|
|
{
|
|
if (node) {
|
|
struct hfs_btree *tree = node->tree;
|
|
int i;
|
|
|
|
hfs_dbg(BNODE_REFS, "put_node(%d:%d): %d\n",
|
|
node->tree->cnid, node->this,
|
|
atomic_read(&node->refcnt));
|
|
BUG_ON(!atomic_read(&node->refcnt));
|
|
if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock))
|
|
return;
|
|
for (i = 0; i < tree->pages_per_bnode; i++) {
|
|
if (!node->page[i])
|
|
continue;
|
|
mark_page_accessed(node->page[i]);
|
|
}
|
|
|
|
if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
|
|
hfs_bnode_unhash(node);
|
|
spin_unlock(&tree->hash_lock);
|
|
if (hfs_bnode_need_zeroout(tree))
|
|
hfs_bnode_clear(node, 0, tree->node_size);
|
|
hfs_bmap_free(node);
|
|
hfs_bnode_free(node);
|
|
return;
|
|
}
|
|
spin_unlock(&tree->hash_lock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Unused nodes have to be zeroed if this is the catalog tree and
|
|
* a corresponding flag in the volume header is set.
|
|
*/
|
|
bool hfs_bnode_need_zeroout(struct hfs_btree *tree)
|
|
{
|
|
struct super_block *sb = tree->inode->i_sb;
|
|
struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
|
|
const u32 volume_attr = be32_to_cpu(sbi->s_vhdr->attributes);
|
|
|
|
return tree->cnid == HFSPLUS_CAT_CNID &&
|
|
volume_attr & HFSPLUS_VOL_UNUSED_NODE_FIX;
|
|
}
|