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>
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 void bluesky_serialize_inode(GString *out, BlueSkyInode *inode)
72 struct serialized_inode buf;
74 buf.signature = GUINT64_TO_LE(INODE_MAGIC);
75 buf.type = GUINT32_TO_LE(inode->type);
76 buf.mode = GUINT32_TO_LE(inode->mode);
77 buf.uid = GUINT32_TO_LE(inode->uid);
78 buf.gid = GUINT32_TO_LE(inode->gid);
79 buf.nlink = GUINT32_TO_LE(inode->nlink);
80 buf.inum = GUINT64_TO_LE(inode->inum);
81 buf.change_count = GUINT64_TO_LE(inode->change_count);
82 buf.atime = GINT64_TO_LE(inode->atime);
83 buf.ctime = GINT64_TO_LE(inode->ctime);
84 buf.mtime = GINT64_TO_LE(inode->mtime);
85 buf.ntime = GINT64_TO_LE(inode->ntime);
87 g_string_append_len(out, (gchar *)&buf, sizeof(buf));
89 switch (inode->type) {
92 uint64_t size = GUINT64_TO_LE(inode->size);
93 g_string_append_len(out, (gchar *)&size, sizeof(uint64_t));
94 for (int i = 0; i < inode->blocks->len; i++) {
95 BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock, i);
97 g_string_append(out, b->ref);
98 g_string_append_c(out, '\0');
103 case BLUESKY_DIRECTORY:
107 GSequenceIter *i = g_sequence_get_begin_iter(inode->dirents);
109 while (!g_sequence_iter_is_end(i)) {
110 BlueSkyDirent *d = g_sequence_get(i);
112 seq = GUINT32_TO_LE(d->cookie);
113 inum = GUINT64_TO_LE(d->inum);
114 g_string_append_len(out, (gchar *)&seq, sizeof(uint32_t));
115 g_string_append_len(out, (gchar *)&inum, sizeof(uint64_t));
116 g_string_append(out, d->name);
117 g_string_append_c(out, '\0');
119 i = g_sequence_iter_next(i);
122 seq = GUINT32_TO_LE(0);
123 g_string_append_len(out, (gchar *)&seq, sizeof(uint32_t));
128 g_warning("Serialization for inode type %d not implemented!\n",
133 BlueSkyInode *bluesky_deserialize_inode(BlueSkyFS *fs, const gchar *buf)
135 struct serialized_inode *raw = (struct serialized_inode *)buf;
137 if (GUINT64_FROM_LE(raw->signature) != INODE_MAGIC)
140 BlueSkyInode *inode = bluesky_new_inode(GUINT64_FROM_LE(raw->inum),
141 fs, GUINT32_FROM_LE(raw->type));
143 inode->mode = GUINT32_FROM_LE(raw->mode);
144 inode->uid = GUINT32_FROM_LE(raw->uid);
145 inode->gid = GUINT32_FROM_LE(raw->gid);
146 inode->nlink = GUINT32_FROM_LE(raw->nlink);
147 inode->change_count = GUINT64_FROM_LE(raw->change_count);
148 inode->atime = GINT64_FROM_LE(raw->atime);
149 inode->ctime = GINT64_FROM_LE(raw->ctime);
150 inode->mtime = GINT64_FROM_LE(raw->mtime);
151 inode->ntime = GINT64_FROM_LE(raw->ntime);
153 buf += sizeof(struct serialized_inode);
155 g_print("Deserializing inode %lld...\n", (long long)inode->inum);
157 /* TODO: Bounds checking */
158 switch (inode->type) {
159 case BLUESKY_REGULAR:
160 inode->size = GINT64_FROM_LE(*(uint64_t *)buf);
161 buf += sizeof(uint64_t);
162 g_array_set_size(inode->blocks,
163 (inode->size + BLUESKY_BLOCK_SIZE - 1)
164 / BLUESKY_BLOCK_SIZE);
165 for (int i = 0; i < inode->blocks->len; i++) {
166 BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock, i);
167 b->type = BLUESKY_BLOCK_REF;
168 b->ref = g_strdup(buf);
169 buf += strlen(b->ref) + 1;
173 case BLUESKY_DIRECTORY:
175 struct serialized_dirent {
179 } __attribute__((packed));
181 struct serialized_dirent *d = (struct serialized_dirent *)buf;
182 while (GUINT32_FROM_LE(d->seq) != 0) {
183 BlueSkyDirent *dirent = g_new(BlueSkyDirent, 1);
184 dirent->cookie = GUINT64_FROM_LE(d->seq);
185 dirent->inum = GUINT64_FROM_LE(d->inum);
186 dirent->name = g_strdup(d->name);
187 dirent->name_folded = bluesky_lowercase(d->name);
189 g_sequence_insert_sorted(inode->dirents, dirent,
190 bluesky_dirent_compare, NULL);
191 g_hash_table_insert(inode->dirhash, dirent->name, dirent);
192 g_hash_table_insert(inode->dirhash_folded, dirent->name_folded,
195 g_print(" dirent[%08x]: %s -> %"PRIu64"\n",
196 dirent->cookie, dirent->name, dirent->inum);
198 buf = strchr(d->name, '\0') + 1;
199 d = (struct serialized_dirent *)buf;
204 g_warning("Deserialization for inode type %d not implemented!\n",