1 /* Blue Sky: File Systems in the Cloud
3 * Copyright (C) 2009 The Regents of the University of California
4 * Written by Michael Vrable <mvrable@cs.ucsd.edu>
14 #include "bluesky-private.h"
16 /* Serialization of in-memory filesystem data structures to bytestrings which
17 * can be written to persistent storage. All data is stored in little-endian
20 /* Magic signature and structure of serialized superblocks. */
22 #define SUPERBLOCK_MAGIC 0x65ca91e91b124234ULL
24 struct serialized_superblock {
25 uint64_t signature; /* SUPERBLOCK_MAGIC */
27 } __attribute__((packed));
29 /* Magic signature for serialized inodes. */
31 #define INODE_MAGIC 0xa6832100943d71e6ULL
33 struct serialized_inode {
34 uint64_t signature; /* INODE_MAGIC */
40 uint64_t change_count;
45 } __attribute__((packed));
47 void bluesky_serialize_superblock(GString *out, BlueSkyFS *fs)
49 struct serialized_superblock buf;
51 buf.signature = GUINT64_TO_LE(SUPERBLOCK_MAGIC);
52 buf.next_inum = GUINT64_TO_LE(fs->next_inum);
54 g_string_append_len(out, (gchar *)&buf, sizeof(buf));
57 BlueSkyFS *bluesky_deserialize_superblock(const gchar *buf)
59 struct serialized_superblock *raw = (struct serialized_superblock *)buf;
61 if (GUINT64_FROM_LE(raw->signature) != SUPERBLOCK_MAGIC)
64 BlueSkyFS *fs = bluesky_new_fs("deserialized");
65 fs->next_inum = GUINT64_FROM_LE(raw->next_inum);
70 BlueSkyCloudLog *bluesky_serialize_inode(BlueSkyInode *inode)
72 BlueSkyFS *fs = inode->fs;
73 GString *out = g_string_new("");
74 struct serialized_inode buf;
76 BlueSkyCloudLog *cloudlog = bluesky_cloudlog_new(fs);
77 cloudlog->type = LOGTYPE_INODE;
78 cloudlog->inum = inode->inum;
80 buf.signature = GUINT64_TO_LE(INODE_MAGIC);
81 buf.type = GUINT32_TO_LE(inode->type);
82 buf.mode = GUINT32_TO_LE(inode->mode);
83 buf.uid = GUINT32_TO_LE(inode->uid);
84 buf.gid = GUINT32_TO_LE(inode->gid);
85 buf.nlink = GUINT32_TO_LE(inode->nlink);
86 buf.inum = GUINT64_TO_LE(inode->inum);
87 buf.change_count = GUINT64_TO_LE(inode->change_count);
88 buf.atime = GINT64_TO_LE(inode->atime);
89 buf.ctime = GINT64_TO_LE(inode->ctime);
90 buf.mtime = GINT64_TO_LE(inode->mtime);
91 buf.ntime = GINT64_TO_LE(inode->ntime);
93 g_string_append_len(out, (gchar *)&buf, sizeof(buf));
95 switch (inode->type) {
98 uint64_t size = GUINT64_TO_LE(inode->size);
99 g_string_append_len(out, (gchar *)&size, sizeof(uint64_t));
100 for (int i = 0; i < inode->blocks->len; i++) {
101 BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock, i);
102 BlueSkyCloudLog *ref = NULL;
103 if (b->type == BLUESKY_BLOCK_REF)
105 bluesky_cloudlog_ref(ref);
106 g_array_append_val(cloudlog->links, ref);
111 case BLUESKY_DIRECTORY:
115 GSequenceIter *i = g_sequence_get_begin_iter(inode->dirents);
117 while (!g_sequence_iter_is_end(i)) {
118 BlueSkyDirent *d = g_sequence_get(i);
120 seq = GUINT32_TO_LE(d->cookie);
121 inum = GUINT64_TO_LE(d->inum);
122 g_string_append_len(out, (gchar *)&seq, sizeof(uint32_t));
123 g_string_append_len(out, (gchar *)&inum, sizeof(uint64_t));
124 g_string_append(out, d->name);
125 g_string_append_c(out, '\0');
127 i = g_sequence_iter_next(i);
130 seq = GUINT32_TO_LE(0);
131 g_string_append_len(out, (gchar *)&seq, sizeof(uint32_t));
136 case BLUESKY_SYMLINK:
138 g_string_append(out, inode->symlink_contents);
139 g_string_append_c(out, '\0');
144 g_warning("Serialization for inode type %d not implemented!\n",
148 cloudlog->data = bluesky_string_new_from_gstring(out);
149 bluesky_cloudlog_insert(cloudlog);
150 bluesky_cloudlog_stats_update(cloudlog, 1);
155 /* Deserialize an inode into an in-memory representation. Returns a boolean
156 * indicating whether the deserialization was successful. */
157 gboolean bluesky_deserialize_inode(BlueSkyInode *inode, const gchar *buf)
159 if (bluesky_verbose) {
160 g_log("bluesky/serialize", G_LOG_LEVEL_DEBUG,
161 "Deserializing inode %lld...", (long long)inode->inum);
164 struct serialized_inode *raw = (struct serialized_inode *)buf;
166 if (GUINT64_FROM_LE(raw->signature) != INODE_MAGIC)
169 if (inode->inum != GUINT64_FROM_LE(raw->inum))
172 bluesky_init_inode(inode, GUINT32_FROM_LE(raw->type));
174 inode->mode = GUINT32_FROM_LE(raw->mode);
175 inode->uid = GUINT32_FROM_LE(raw->uid);
176 inode->gid = GUINT32_FROM_LE(raw->gid);
177 inode->nlink = GUINT32_FROM_LE(raw->nlink);
178 inode->change_count = GUINT64_FROM_LE(raw->change_count);
179 inode->change_commit = inode->change_count;
180 inode->atime = GINT64_FROM_LE(raw->atime);
181 inode->ctime = GINT64_FROM_LE(raw->ctime);
182 inode->mtime = GINT64_FROM_LE(raw->mtime);
183 inode->ntime = GINT64_FROM_LE(raw->ntime);
185 buf += sizeof(struct serialized_inode);
187 /* TODO: Bounds checking */
188 switch (inode->type) {
189 case BLUESKY_REGULAR:
190 inode->size = GINT64_FROM_LE(*(uint64_t *)buf);
191 buf += sizeof(uint64_t);
192 g_array_set_size(inode->blocks,
193 (inode->size + BLUESKY_BLOCK_SIZE - 1)
194 / BLUESKY_BLOCK_SIZE);
197 for (int i = 0; i < inode->blocks->len; i++) {
198 BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock, i);
199 b->type = BLUESKY_BLOCK_REF;
200 b->ref = g_strdup(buf);
201 buf += strlen(b->ref) + 1;
206 case BLUESKY_DIRECTORY:
208 struct serialized_dirent {
212 } __attribute__((packed));
214 struct serialized_dirent *d = (struct serialized_dirent *)buf;
215 while (GUINT32_FROM_LE(d->seq) != 0) {
216 BlueSkyDirent *dirent = g_new(BlueSkyDirent, 1);
217 dirent->cookie = GUINT64_FROM_LE(d->seq);
218 dirent->inum = GUINT64_FROM_LE(d->inum);
219 dirent->name = g_strdup(d->name);
220 dirent->name_folded = bluesky_lowercase(d->name);
222 g_sequence_insert_sorted(inode->dirents, dirent,
223 bluesky_dirent_compare, NULL);
224 g_hash_table_insert(inode->dirhash, dirent->name, dirent);
225 g_hash_table_insert(inode->dirhash_folded, dirent->name_folded,
228 buf = strchr(d->name, '\0') + 1;
229 d = (struct serialized_dirent *)buf;
234 case BLUESKY_SYMLINK:
236 inode->symlink_contents = g_strdup(buf);
241 g_warning("Deserialization for inode type %d not implemented!\n",