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38e0abdcfb
Test Case: [NFS Client] ls -lR . [NFS Server] while [ 1 ] do echo 3 > /proc/sys/vm/drop_caches done Error on NFS Client: "No such file or directory" When cache is dropped at the server, it results in lookup failure at the NFS client due to non-connection with the parent. The default path is it initiates a lookup by calculating the hash value for the name, even though the hash values stored on the disk for "." and ".." is maintained as zero, which results in failure from find_in_block due to not matching HASH values. Fix up, by using the correct hashing values for these entries. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
102 lines
2.0 KiB
C
102 lines
2.0 KiB
C
/*
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* fs/f2fs/hash.c
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*
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* Copyright (c) 2012 Samsung Electronics Co., Ltd.
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* http://www.samsung.com/
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*
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* Portions of this code from linux/fs/ext3/hash.c
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*
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* Copyright (C) 2002 by Theodore Ts'o
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/types.h>
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#include <linux/fs.h>
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#include <linux/f2fs_fs.h>
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#include <linux/cryptohash.h>
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#include <linux/pagemap.h>
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#include "f2fs.h"
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/*
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* Hashing code copied from ext3
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*/
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#define DELTA 0x9E3779B9
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static void TEA_transform(unsigned int buf[4], unsigned int const in[])
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{
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__u32 sum = 0;
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__u32 b0 = buf[0], b1 = buf[1];
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__u32 a = in[0], b = in[1], c = in[2], d = in[3];
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int n = 16;
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do {
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sum += DELTA;
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b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b);
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b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d);
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} while (--n);
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buf[0] += b0;
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buf[1] += b1;
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}
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static void str2hashbuf(const char *msg, int len, unsigned int *buf, int num)
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{
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unsigned pad, val;
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int i;
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pad = (__u32)len | ((__u32)len << 8);
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pad |= pad << 16;
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val = pad;
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if (len > num * 4)
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len = num * 4;
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for (i = 0; i < len; i++) {
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if ((i % 4) == 0)
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val = pad;
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val = msg[i] + (val << 8);
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if ((i % 4) == 3) {
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*buf++ = val;
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val = pad;
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num--;
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}
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}
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if (--num >= 0)
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*buf++ = val;
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while (--num >= 0)
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*buf++ = pad;
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}
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f2fs_hash_t f2fs_dentry_hash(const char *name, int len)
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{
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__u32 hash, minor_hash;
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f2fs_hash_t f2fs_hash;
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const char *p;
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__u32 in[8], buf[4];
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if ((len <= 2) && (name[0] == '.') &&
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(name[1] == '.' || name[1] == '\0'))
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return 0;
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/* Initialize the default seed for the hash checksum functions */
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buf[0] = 0x67452301;
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buf[1] = 0xefcdab89;
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buf[2] = 0x98badcfe;
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buf[3] = 0x10325476;
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p = name;
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while (len > 0) {
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str2hashbuf(p, len, in, 4);
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TEA_transform(buf, in);
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len -= 16;
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p += 16;
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}
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hash = buf[0];
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minor_hash = buf[1];
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f2fs_hash = cpu_to_le32(hash & ~F2FS_HASH_COL_BIT);
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return f2fs_hash;
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}
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