aboutsummaryrefslogtreecommitdiffstats
path: root/fs/ceph/ceph_fs.c
blob: b3ecf1b075213c04b57175d1b14e2cecbecc2d43 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
/*
 * Some non-inline ceph helpers
 */
#include "types.h"

/*
 * return true if @layout appears to be valid
 */
int ceph_file_layout_is_valid(const struct ceph_file_layout *layout)
{
	__u32 su = le32_to_cpu(layout->fl_stripe_unit);
	__u32 sc = le32_to_cpu(layout->fl_stripe_count);
	__u32 os = le32_to_cpu(layout->fl_object_size);

	/* stripe unit, object size must be non-zero, 64k increment */
	if (!su || (su & (CEPH_MIN_STRIPE_UNIT-1)))
		return 0;
	if (!os || (os & (CEPH_MIN_STRIPE_UNIT-1)))
		return 0;
	/* object size must be a multiple of stripe unit */
	if (os < su || os % su)
		return 0;
	/* stripe count must be non-zero */
	if (!sc)
		return 0;
	return 1;
}


int ceph_flags_to_mode(int flags)
{
#ifdef O_DIRECTORY  /* fixme */
	if ((flags & O_DIRECTORY) == O_DIRECTORY)
		return CEPH_FILE_MODE_PIN;
#endif
#ifdef O_LAZY
	if (flags & O_LAZY)
		return CEPH_FILE_MODE_LAZY;
#endif
	if ((flags & O_APPEND) == O_APPEND)
		flags |= O_WRONLY;

	flags &= O_ACCMODE;
	if ((flags & O_RDWR) == O_RDWR)
		return CEPH_FILE_MODE_RDWR;
	if ((flags & O_WRONLY) == O_WRONLY)
		return CEPH_FILE_MODE_WR;
	return CEPH_FILE_MODE_RD;
}

int ceph_caps_for_mode(int mode)
{
	switch (mode) {
	case CEPH_FILE_MODE_PIN:
		return CEPH_CAP_PIN;
	case CEPH_FILE_MODE_RD:
		return CEPH_CAP_PIN | CEPH_CAP_FILE_SHARED |
			CEPH_CAP_FILE_RD | CEPH_CAP_FILE_CACHE;
	case CEPH_FILE_MODE_RDWR:
		return CEPH_CAP_PIN | CEPH_CAP_FILE_SHARED |
			CEPH_CAP_FILE_EXCL |
			CEPH_CAP_FILE_RD | CEPH_CAP_FILE_CACHE |
			CEPH_CAP_FILE_WR | CEPH_CAP_FILE_BUFFER |
			CEPH_CAP_AUTH_SHARED | CEPH_CAP_AUTH_EXCL |
			CEPH_CAP_XATTR_SHARED | CEPH_CAP_XATTR_EXCL;
	case CEPH_FILE_MODE_WR:
		return CEPH_CAP_PIN | CEPH_CAP_FILE_SHARED |
			CEPH_CAP_FILE_EXCL |
			CEPH_CAP_FILE_WR | CEPH_CAP_FILE_BUFFER |
			CEPH_CAP_AUTH_SHARED | CEPH_CAP_AUTH_EXCL |
			CEPH_CAP_XATTR_SHARED | CEPH_CAP_XATTR_EXCL;
	}
	return 0;
}

/*
 * Robert Jenkin's hash function.
 * http://burtleburtle.net/bob/hash/evahash.html
 * This is in the public domain.
 */
#define mix(a, b, c)						\
	do {							\
		a = a - b;  a = a - c;  a = a ^ (c >> 13);	\
		b = b - c;  b = b - a;  b = b ^ (a << 8);	\
		c = c - a;  c = c - b;  c = c ^ (b >> 13);	\
		a = a - b;  a = a - c;  a = a ^ (c >> 12);	\
		b = b - c;  b = b - a;  b = b ^ (a << 16);	\
		c = c - a;  c = c - b;  c = c ^ (b >> 5);	\
		a = a - b;  a = a - c;  a = a ^ (c >> 3);	\
		b = b - c;  b = b - a;  b = b ^ (a << 10);	\
		c = c - a;  c = c - b;  c = c ^ (b >> 15);	\
	} while (0)

unsigned int ceph_full_name_hash(const char *str, unsigned int length)
{
	const unsigned char *k = (const unsigned char *)str;
	__u32 a, b, c;  /* the internal state */
	__u32 len;      /* how many key bytes still need mixing */

	/* Set up the internal state */
	len = length;
	a = 0x9e3779b9;      /* the golden ratio; an arbitrary value */
	b = a;
	c = 0;               /* variable initialization of internal state */

	/* handle most of the key */
	while (len >= 12) {
		a = a + (k[0] + ((__u32)k[1] << 8) + ((__u32)k[2] << 16) +
			 ((__u32)k[3] << 24));
		b = b + (k[4] + ((__u32)k[5] << 8) + ((__u32)k[6] << 16) +
			 ((__u32)k[7] << 24));
		c = c + (k[8] + ((__u32)k[9] << 8) + ((__u32)k[10] << 16) +
			 ((__u32)k[11] << 24));
		mix(a, b, c);
		k = k + 12;
		len = len - 12;
	}

	/* handle the last 11 bytes */
	c = c + length;
	switch (len) {            /* all the case statements fall through */
	case 11:
		c = c + ((__u32)k[10] << 24);
	case 10:
		c = c + ((__u32)k[9] << 16);
	case 9:
		c = c + ((__u32)k[8] << 8);
		/* the first byte of c is reserved for the length */
	case 8:
		b = b + ((__u32)k[7] << 24);
	case 7:
		b = b + ((__u32)k[6] << 16);
	case 6:
		b = b + ((__u32)k[5] << 8);
	case 5:
		b = b + k[4];
	case 4:
		a = a + ((__u32)k[3] << 24);
	case 3:
		a = a + ((__u32)k[2] << 16);
	case 2:
		a = a + ((__u32)k[1] << 8);
	case 1:
		a = a + k[0];
		/* case 0: nothing left to add */
	}
	mix(a, b, c);

	return c;
}