linux/fs/f2fs/hash.c
Linus Torvalds 42612e7763 f2fs-for-5.8-rc1
In this round, we've added some knobs to enhance compression feature and harden
 testing environment. In addition, we've fixed several bugs reported from Android
 devices such as long discarding latency, device hanging during quota_sync, etc.
 
 Enhancement:
 - support lzo-rle algorithm
 - add two ioctls to release and reserve blocks for compression
 - support partial truncation/fiemap on compressed file
 - introduce sysfs entries to attach IO flags explicitly
 - add iostat trace point along with read io stat
 
 Bug fix:
 - fix long discard latency
 - flush quota data by f2fs_quota_sync correctly
 - fix to recover parent inode number for power-cut recovery
 - fix lz4/zstd output buffer budget
 - parse checkpoint mount option correctly
 - avoid inifinite loop to wait for flushing node/meta pages
 - manage discard space correctly
 
 And some refactoring and clean up patches were added.
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Merge tag 'f2fs-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've added some knobs to enhance compression feature
  and harden testing environment. In addition, we've fixed several bugs
  reported from Android devices such as long discarding latency, device
  hanging during quota_sync, etc.

  Enhancements:
   - support lzo-rle algorithm
   - add two ioctls to release and reserve blocks for compression
   - support partial truncation/fiemap on compressed file
   - introduce sysfs entries to attach IO flags explicitly
   - add iostat trace point along with read io stat

  Bug fixes:
   - fix long discard latency
   - flush quota data by f2fs_quota_sync correctly
   - fix to recover parent inode number for power-cut recovery
   - fix lz4/zstd output buffer budget
   - parse checkpoint mount option correctly
   - avoid inifinite loop to wait for flushing node/meta pages
   - manage discard space correctly

  And some refactoring and clean up patches were added"

* tag 'f2fs-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (51 commits)
  f2fs: attach IO flags to the missing cases
  f2fs: add node_io_flag for bio flags likewise data_io_flag
  f2fs: remove unused parameter of f2fs_put_rpages_mapping()
  f2fs: handle readonly filesystem in f2fs_ioc_shutdown()
  f2fs: avoid utf8_strncasecmp() with unstable name
  f2fs: don't return vmalloc() memory from f2fs_kmalloc()
  f2fs: fix retry logic in f2fs_write_cache_pages()
  f2fs: fix wrong discard space
  f2fs: compress: don't compress any datas after cp stop
  f2fs: remove unneeded return value of __insert_discard_tree()
  f2fs: fix wrong value of tracepoint parameter
  f2fs: protect new segment allocation in expand_inode_data
  f2fs: code cleanup by removing ifdef macro surrounding
  f2fs: avoid inifinite loop to wait for flushing node pages at cp_error
  f2fs: flush dirty meta pages when flushing them
  f2fs: fix checkpoint=disable:%u%%
  f2fs: compress: fix zstd data corruption
  f2fs: add compressed/gc data read IO stat
  f2fs: fix potential use-after-free issue
  f2fs: compress: don't handle non-compressed data in workqueue
  ...
2020-06-09 11:28:59 -07:00

128 lines
2.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* fs/f2fs/hash.c
*
* Copyright (c) 2012 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* Portions of this code from linux/fs/ext3/hash.c
*
* Copyright (C) 2002 by Theodore Ts'o
*/
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/f2fs_fs.h>
#include <linux/pagemap.h>
#include <linux/unicode.h>
#include "f2fs.h"
/*
* Hashing code copied from ext3
*/
#define DELTA 0x9E3779B9
static void TEA_transform(unsigned int buf[4], unsigned int const in[])
{
__u32 sum = 0;
__u32 b0 = buf[0], b1 = buf[1];
__u32 a = in[0], b = in[1], c = in[2], d = in[3];
int n = 16;
do {
sum += DELTA;
b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b);
b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d);
} while (--n);
buf[0] += b0;
buf[1] += b1;
}
static void str2hashbuf(const unsigned char *msg, size_t len,
unsigned int *buf, int num)
{
unsigned pad, val;
int i;
pad = (__u32)len | ((__u32)len << 8);
pad |= pad << 16;
val = pad;
if (len > num * 4)
len = num * 4;
for (i = 0; i < len; i++) {
if ((i % 4) == 0)
val = pad;
val = msg[i] + (val << 8);
if ((i % 4) == 3) {
*buf++ = val;
val = pad;
num--;
}
}
if (--num >= 0)
*buf++ = val;
while (--num >= 0)
*buf++ = pad;
}
static u32 TEA_hash_name(const u8 *p, size_t len)
{
__u32 in[8], buf[4];
/* Initialize the default seed for the hash checksum functions */
buf[0] = 0x67452301;
buf[1] = 0xefcdab89;
buf[2] = 0x98badcfe;
buf[3] = 0x10325476;
while (1) {
str2hashbuf(p, len, in, 4);
TEA_transform(buf, in);
p += 16;
if (len <= 16)
break;
len -= 16;
}
return buf[0] & ~F2FS_HASH_COL_BIT;
}
/*
* Compute @fname->hash. For all directories, @fname->disk_name must be set.
* For casefolded directories, @fname->usr_fname must be set, and also
* @fname->cf_name if the filename is valid Unicode.
*/
void f2fs_hash_filename(const struct inode *dir, struct f2fs_filename *fname)
{
const u8 *name = fname->disk_name.name;
size_t len = fname->disk_name.len;
WARN_ON_ONCE(!name);
if (is_dot_dotdot(name, len)) {
fname->hash = 0;
return;
}
#ifdef CONFIG_UNICODE
if (IS_CASEFOLDED(dir)) {
/*
* If the casefolded name is provided, hash it instead of the
* on-disk name. If the casefolded name is *not* provided, that
* should only be because the name wasn't valid Unicode, so fall
* back to treating the name as an opaque byte sequence.
*/
WARN_ON_ONCE(!fname->usr_fname->name);
if (fname->cf_name.name) {
name = fname->cf_name.name;
len = fname->cf_name.len;
} else {
name = fname->usr_fname->name;
len = fname->usr_fname->len;
}
}
#endif
fname->hash = cpu_to_le32(TEA_hash_name(name, len));
}