xref: /spdk/lib/blob/blobstore.h (revision b961d9cc12de49251d135307eaa05ec0fc9dd2fa)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
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10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
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18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #ifndef SPDK_BLOBSTORE_H
35 #define SPDK_BLOBSTORE_H
36 
37 #include "spdk/assert.h"
38 #include "spdk/blob.h"
39 #include "spdk/queue.h"
40 #include "spdk/util.h"
41 
42 /* In Memory Data Structures
43  *
44  * The following data structures exist only in memory.
45  */
46 
47 #define SPDK_BLOB_OPTS_CLUSTER_SZ (1024 * 1024)
48 #define SPDK_BLOB_OPTS_NUM_MD_PAGES UINT32_MAX
49 #define SPDK_BLOB_OPTS_MAX_MD_OPS 32
50 
51 struct spdk_xattr {
52 	/* TODO: reorder for best packing */
53 	uint32_t	index;
54 	char		*name;
55 	void		*value;
56 	uint16_t	value_len;
57 	TAILQ_ENTRY(spdk_xattr)	link;
58 };
59 
60 /* The mutable part of the blob data that is sync'd to
61  * disk. The data in here is both mutable and persistent.
62  */
63 struct spdk_blob_mut_data {
64 	/* Number of data clusters in the blob */
65 	uint64_t	num_clusters;
66 
67 	/* Array LBAs that are the beginning of a cluster, in
68 	 * the order they appear in the blob.
69 	 */
70 	uint64_t	*clusters;
71 
72 	/* The size of the clusters array. This is greater than or
73 	 * equal to 'num_clusters'.
74 	 */
75 	size_t		cluster_array_size;
76 
77 	/* Number of metadata pages */
78 	uint32_t	num_pages;
79 
80 	/* Array of page offsets into the metadata region, in
81 	 * the order of the metadata page sequence.
82 	 */
83 	uint32_t	*pages;
84 };
85 
86 enum spdk_blob_state {
87 	/* The blob in-memory version does not match the on-disk
88 	 * version.
89 	 */
90 	SPDK_BLOB_STATE_DIRTY,
91 
92 	/* The blob in memory version of the blob matches the on disk
93 	 * version.
94 	 */
95 	SPDK_BLOB_STATE_CLEAN,
96 
97 	/* The in-memory state being synchronized with the on-disk
98 	 * blob state. */
99 	SPDK_BLOB_STATE_LOADING,
100 
101 	/* The disk state is being synchronized with the current
102 	 * blob state.
103 	 */
104 	SPDK_BLOB_STATE_SYNCING,
105 };
106 
107 struct spdk_blob {
108 	struct spdk_blob_store *bs;
109 
110 	uint32_t	open_ref;
111 
112 	spdk_blob_id	id;
113 
114 	enum spdk_blob_state		state;
115 
116 	/* Two copies of the mutable data. One is a version
117 	 * that matches the last known data on disk (clean).
118 	 * The other (active) is the current data. Syncing
119 	 * a blob makes the clean match the active.
120 	 */
121 	struct spdk_blob_mut_data	clean;
122 	struct spdk_blob_mut_data	active;
123 
124 	/* TODO: The xattrs are mutable, but we don't want to be
125 	 * copying them unecessarily. Figure this out.
126 	 */
127 	TAILQ_HEAD(, spdk_xattr) xattrs;
128 
129 	TAILQ_ENTRY(spdk_blob) link;
130 };
131 
132 struct spdk_blob_store {
133 	uint64_t			md_start; /* Offset from beginning of disk, in pages */
134 	uint32_t			md_len; /* Count, in pages */
135 	struct spdk_io_channel		*md_channel;
136 
137 	struct spdk_bs_dev		*dev;
138 
139 	struct spdk_bit_array		*used_md_pages;
140 	struct spdk_bit_array		*used_clusters;
141 
142 	uint32_t			cluster_sz;
143 	uint64_t			total_clusters;
144 	uint64_t			num_free_clusters;
145 	uint32_t			pages_per_cluster;
146 
147 	uint32_t			max_md_ops;
148 
149 	spdk_blob_id			super_blob;
150 
151 	TAILQ_HEAD(, spdk_blob) 	blobs;
152 };
153 
154 struct spdk_bs_channel {
155 	struct spdk_bs_request_set	*req_mem;
156 	TAILQ_HEAD(, spdk_bs_request_set) reqs;
157 
158 	struct spdk_blob_store		*bs;
159 
160 	struct spdk_bs_dev		*dev;
161 	struct spdk_io_channel		*dev_channel;
162 };
163 
164 /* On-Disk Data Structures
165  *
166  * The following data structures exist on disk.
167  */
168 #define SPDK_BS_VERSION 1
169 
170 #pragma pack(push, 1)
171 
172 #define SPDK_MD_MASK_TYPE_USED_PAGES 0
173 #define SPDK_MD_MASK_TYPE_USED_CLUSTERS 1
174 
175 struct spdk_bs_md_mask {
176 	uint8_t		type;
177 	uint32_t	length; /* In bits */
178 	uint8_t		mask[0];
179 };
180 
181 #define SPDK_MD_DESCRIPTOR_TYPE_PADDING 0
182 #define SPDK_MD_DESCRIPTOR_TYPE_EXTENT 1
183 #define SPDK_MD_DESCRIPTOR_TYPE_XATTR 2
184 
185 struct spdk_blob_md_descriptor_xattr {
186 	uint8_t		type;
187 	uint32_t	length;
188 
189 	uint16_t	name_length;
190 	uint16_t	value_length;
191 
192 	char		name[0];
193 	/* String name immediately followed by string value. */
194 };
195 
196 struct spdk_blob_md_descriptor_extent {
197 	uint8_t		type;
198 	uint32_t	length;
199 
200 	struct {
201 		uint32_t        cluster_idx;
202 		uint32_t        length; /* In units of clusters */
203 	} extents[0];
204 };
205 
206 struct spdk_blob_md_descriptor {
207 	uint8_t		type;
208 	uint32_t	length;
209 };
210 
211 #define SPDK_INVALID_MD_PAGE UINT32_MAX
212 
213 struct spdk_blob_md_page {
214 	spdk_blob_id     id;
215 
216 	uint32_t        sequence_num;
217 	uint32_t	reserved0;
218 
219 	/* Descriptors here */
220 	uint8_t		descriptors[4072];
221 
222 	uint32_t	next;
223 	uint32_t	crc;
224 };
225 SPDK_STATIC_ASSERT(sizeof(struct spdk_blob_md_page) == 0x1000, "Invalid md page size");
226 
227 #define SPDK_BS_SUPER_BLOCK_SIG "SPDKBLOB"
228 
229 struct spdk_bs_super_block {
230 	uint8_t		signature[8];
231 	uint32_t        version;
232 	uint32_t        length;
233 	uint32_t	clean; /* If there was a clean shutdown, this is 1. */
234 	spdk_blob_id	super_blob;
235 
236 	uint32_t	cluster_size; /* In bytes */
237 
238 	uint32_t	used_page_mask_start; /* Offset from beginning of disk, in pages */
239 	uint32_t	used_page_mask_len; /* Count, in pages */
240 
241 	uint32_t	used_cluster_mask_start; /* Offset from beginning of disk, in pages */
242 	uint32_t	used_cluster_mask_len; /* Count, in pages */
243 
244 	uint32_t	md_start; /* Offset from beginning of disk, in pages */
245 	uint32_t	md_len; /* Count, in pages */
246 
247 	uint8_t		reserved[4040];
248 };
249 SPDK_STATIC_ASSERT(sizeof(struct spdk_bs_super_block) == 0x1000, "Invalid super block size");
250 
251 #pragma pack(pop)
252 
253 /* Unit Conversions
254  *
255  * The blobstore works with several different units:
256  * - Byte: Self explanatory
257  * - LBA: The logical blocks on the backing storage device.
258  * - Page: The read/write units of blobs and metadata. This is
259  *         an offset into a blob in units of 4KiB.
260  * - Cluster Index: The disk is broken into a sequential list of
261  *		    clusters. This is the offset from the beginning.
262  *
263  * NOTE: These conversions all act on simple magnitudes, not with any sort
264  *        of knowledge about the blobs themselves. For instance, converting
265  *        a page to an lba with the conversion function below simply converts
266  *        a number of pages to an equivalent number of lbas, but that
267  *        lba certainly isn't the right lba that corresponds to a page offset
268  *        for a particular blob.
269  */
270 static inline uint64_t
271 _spdk_bs_byte_to_lba(struct spdk_blob_store *bs, uint64_t length)
272 {
273 	assert(length % bs->dev->blocklen == 0);
274 
275 	return length / bs->dev->blocklen;
276 }
277 
278 static inline uint64_t
279 _spdk_bs_lba_to_byte(struct spdk_blob_store *bs, uint64_t lba)
280 {
281 	return lba * bs->dev->blocklen;
282 }
283 
284 static inline uint64_t
285 _spdk_bs_page_to_lba(struct spdk_blob_store *bs, uint64_t page)
286 {
287 	return page * sizeof(struct spdk_blob_md_page) / bs->dev->blocklen;
288 }
289 
290 static inline uint32_t
291 _spdk_bs_lba_to_page(struct spdk_blob_store *bs, uint64_t lba)
292 {
293 	uint64_t	lbas_per_page;
294 
295 	lbas_per_page = sizeof(struct spdk_blob_md_page) / bs->dev->blocklen;
296 
297 	assert(lba % lbas_per_page == 0);
298 
299 	return lba / lbas_per_page;
300 }
301 
302 static inline uint64_t
303 _spdk_bs_cluster_to_page(struct spdk_blob_store *bs, uint32_t cluster)
304 {
305 	return cluster * bs->pages_per_cluster;
306 }
307 
308 static inline uint32_t
309 _spdk_bs_page_to_cluster(struct spdk_blob_store *bs, uint64_t page)
310 {
311 	assert(page % bs->pages_per_cluster == 0);
312 
313 	return page / bs->pages_per_cluster;
314 }
315 
316 static inline uint64_t
317 _spdk_bs_cluster_to_lba(struct spdk_blob_store *bs, uint32_t cluster)
318 {
319 	return cluster * (bs->cluster_sz / bs->dev->blocklen);
320 }
321 
322 static inline uint32_t
323 _spdk_bs_lba_to_cluster(struct spdk_blob_store *bs, uint64_t lba)
324 {
325 	assert(lba % (bs->cluster_sz / bs->dev->blocklen) == 0);
326 
327 	return lba / (bs->cluster_sz / bs->dev->blocklen);
328 }
329 
330 /* End basic conversions */
331 
332 static inline uint32_t
333 _spdk_bs_blobid_to_page(spdk_blob_id id)
334 {
335 	return id & 0xFFFFFFFF;
336 }
337 
338 /* Given a page offset into a blob, look up the LBA for the
339  * start of that page.
340  */
341 static inline uint64_t
342 _spdk_bs_blob_page_to_lba(struct spdk_blob *blob, uint32_t page)
343 {
344 	uint64_t	lba;
345 	uint32_t	pages_per_cluster;
346 
347 	pages_per_cluster = blob->bs->pages_per_cluster;
348 
349 	assert(page < blob->active.num_clusters * pages_per_cluster);
350 
351 	lba = blob->active.clusters[page / pages_per_cluster];
352 	lba += _spdk_bs_page_to_lba(blob->bs, page % pages_per_cluster);
353 
354 	return lba;
355 }
356 
357 /* Given a page offset into a blob, look up the number of pages until the
358  * next cluster boundary.
359  */
360 static inline uint32_t
361 _spdk_bs_num_pages_to_cluster_boundary(struct spdk_blob *blob, uint32_t page)
362 {
363 	uint32_t	pages_per_cluster;
364 
365 	pages_per_cluster = blob->bs->pages_per_cluster;
366 
367 	return pages_per_cluster - (page % pages_per_cluster);
368 }
369 
370 #endif
371