#include <stdint.h>
#include <glib.h>
#include <string.h>
+#include <inttypes.h>
#include "bluesky-private.h"
/* Core filesystem: handling of regular files and caching of file data. */
/* Mark a given block dirty and make sure that data is faulted in so that it
- * can be written to. */
-void bluesky_block_touch(BlueSkyInode *inode, uint64_t i)
+ * can be written to.
+ *
+ * If preserve is set to false, this is a hint that the block is about to be
+ * entirely overwritten. In this case, a dirty block is made available but any
+ * prior contents might be lost. A value of preserve = TRUE is always safe. */
+void bluesky_block_touch(BlueSkyInode *inode, uint64_t i, gboolean preserve)
{
g_return_if_fail(i < inode->blocks->len);
BlueSkyBlock *block = &g_array_index(inode->blocks, BlueSkyBlock, i);
+ gsize block_len;
+ if (i < inode->blocks->len - 1) {
+ block_len = BLUESKY_BLOCK_SIZE;
+ } else {
+ block_len = inode->size - i * BLUESKY_BLOCK_SIZE;
+ }
+
switch (block->type) {
case BLUESKY_BLOCK_ZERO:
- block->data = bluesky_string_new(g_malloc0(BLUESKY_BLOCK_SIZE),
- BLUESKY_BLOCK_SIZE);
+ block->dirty = bluesky_string_new(g_malloc0(block_len), block_len);
break;
case BLUESKY_BLOCK_REF:
- bluesky_block_fetch(inode->fs, block);
- g_assert(block->type == BLUESKY_BLOCK_CACHED);
- /* Fall through */
- case BLUESKY_BLOCK_CACHED:
+ if (preserve) {
+ // FIXME: locking on the cloudlog?
+ bluesky_block_fetch(inode, block, NULL);
+ bluesky_string_ref(block->ref->data);
+ block->dirty = bluesky_string_dup(block->ref->data);
+ } else {
+ block->dirty = bluesky_string_new(g_malloc0(block_len), block_len);
+ }
+ break;
case BLUESKY_BLOCK_DIRTY:
- block->data = bluesky_string_dup(block->data);
+ block->dirty = bluesky_string_dup(block->dirty);
break;
}
+ if (block->type != BLUESKY_BLOCK_DIRTY)
+ g_atomic_int_add(&inode->fs->cache_dirty, 1);
+
block->type = BLUESKY_BLOCK_DIRTY;
+ bluesky_cloudlog_unref(block->ref);
+ block->ref = NULL;
}
/* Set the size of a file. This will truncate or extend the file as needed.
* Newly-allocated bytes are zeroed. */
+// FIXME
void bluesky_file_truncate(BlueSkyInode *inode, uint64_t size)
{
g_return_if_fail(size <= BLUESKY_MAX_FILE_SIZE);
if (size == inode->size)
return;
+ if (bluesky_verbose) {
+ g_log("bluesky/file", G_LOG_LEVEL_DEBUG,
+ "Truncating file to %"PRIi64" bytes", size);
+ }
+
uint64_t blocks = (size + BLUESKY_BLOCK_SIZE - 1) / BLUESKY_BLOCK_SIZE;
+ /* Calculate number of bytes in the last block of the file */
+ int lastblock_old, lastblock_new;
+ lastblock_old = inode->size % BLUESKY_BLOCK_SIZE;
+ if (lastblock_old == 0 && inode->size > 0)
+ lastblock_old = BLUESKY_BLOCK_SIZE;
+ lastblock_new = size % BLUESKY_BLOCK_SIZE;
+ if (lastblock_new == 0 && size > 0)
+ lastblock_new = BLUESKY_BLOCK_SIZE;
+
if (blocks > inode->blocks->len) {
/* Need to add new blocks to the end of a file. New block structures
* are automatically zeroed, which initializes them to be pointers to
- * zero blocks so we don't need to do any more work. */
+ * zero blocks so we don't need to do any more work. If the
+ * previously-last block in the file is smaller than
+ * BLUESKY_BLOCK_SIZE, extend it to full size. */
+ if (inode->blocks->len > 0) {
+ BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock,
+ inode->blocks->len - 1);
+
+ if (b->type != BLUESKY_BLOCK_ZERO
+ && lastblock_old < BLUESKY_BLOCK_SIZE) {
+ bluesky_block_touch(inode, inode->blocks->len - 1, TRUE);
+ gsize old_size = b->dirty->len;
+ if (lastblock_old != old_size) {
+ fprintf(stderr,
+ "Warning: last block size = %zd, expected %d\n",
+ old_size, lastblock_old);
+ }
+ bluesky_string_resize(b->dirty, BLUESKY_BLOCK_SIZE);
+ memset(&b->dirty->data[old_size], 0,
+ BLUESKY_BLOCK_SIZE - old_size);
+ }
+ }
+
g_array_set_size(inode->blocks, blocks);
} else if (blocks < inode->blocks->len) {
/* Delete blocks from a file. Must reclaim memory. */
- for (guint i = inode->blocks->len; i < blocks; i++) {
+ for (guint i = blocks; i < inode->blocks->len; i++) {
BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock, i);
- g_free(b->ref);
- bluesky_string_unref(b->data);
+ if (b->type == BLUESKY_BLOCK_DIRTY)
+ g_atomic_int_add(&inode->fs->cache_dirty, -1);
+ bluesky_string_unref(b->dirty);
+ bluesky_cloudlog_unref(b->ref);
}
g_array_set_size(inode->blocks, blocks);
}
- /* If the file size is being decreased, ensure that any trailing data in
- * the last block is zeroed. */
- if (size < inode->size) {
+ /* Ensure the new last block of the file is properly sized. If the block
+ * is extended, newly-added bytes must be zeroed. */
+ if (blocks > 0) {
BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock,
blocks - 1);
- if (b->type != BLUESKY_BLOCK_ZERO) {
- bluesky_block_touch(inode, blocks - 1);
- int end_offset = size % BLUESKY_BLOCK_SIZE;
- if (end_offset > 0) {
- memset(&b->data->data[end_offset], 0,
- BLUESKY_BLOCK_SIZE - end_offset);
+
+ gboolean need_resize = TRUE;
+ if (b->type == BLUESKY_BLOCK_ZERO)
+ need_resize = FALSE;
+ else if (size < inode->size && lastblock_new == BLUESKY_BLOCK_SIZE)
+ need_resize = FALSE;
+
+ if (need_resize) {
+ bluesky_block_touch(inode, blocks - 1, TRUE);
+ gsize old_size = b->dirty->len;
+ gsize new_size = size - (blocks - 1) * BLUESKY_BLOCK_SIZE;
+
+ bluesky_string_resize(b->dirty, new_size);
+
+ if (new_size > old_size) {
+ memset(&b->dirty->data[old_size], 0, new_size - old_size);
}
}
}
gint block_offset = offset % BLUESKY_BLOCK_SIZE;
gint bytes = MIN(BLUESKY_BLOCK_SIZE - block_offset, len);
- bluesky_block_touch(inode, block_num);
+ gboolean preserve = TRUE;
+ gsize block_size = BLUESKY_BLOCK_SIZE;
+ if (block_num == inode->blocks->len - 1) {
+ block_size = inode->size - block_num * BLUESKY_BLOCK_SIZE;
+ }
+ if (block_offset == 0 && bytes == block_size) {
+ preserve = FALSE;
+ }
+ bluesky_block_touch(inode, block_num, preserve);
BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock,
block_num);
- memcpy(&b->data->data[block_offset], data, bytes);
- bluesky_block_flush(inode->fs, b);
+ memcpy(&b->dirty->data[block_offset], data, bytes);
offset += bytes;
data += bytes;
}
bluesky_inode_update_ctime(inode, 1);
- bluesky_inode_flush(inode->fs, inode);
}
void bluesky_file_read(BlueSkyInode *inode, uint64_t offset,
char *buf, gint len)
{
+ if (len == 0 && offset <= inode->size)
+ return;
+
g_return_if_fail(inode->type == BLUESKY_REGULAR);
g_return_if_fail(offset < inode->size);
g_return_if_fail(len <= inode->size - offset);
+ BlueSkyProfile *profile = bluesky_profile_get();
+
+ bluesky_profile_add_event(profile,
+ g_strdup_printf("Start file read prefetch"));
+ uint64_t start_block, end_block;
+ start_block = offset / BLUESKY_BLOCK_SIZE;
+ end_block = (offset + len - 1) / BLUESKY_BLOCK_SIZE;
+ for (uint64_t i = start_block; i <= end_block; i++) {
+ BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock,
+ i);
+ if (b->type == BLUESKY_BLOCK_REF)
+ bluesky_cloudlog_prefetch(b->ref);
+ }
+
+ bluesky_profile_add_event(profile,
+ g_strdup_printf("End file read prefetch"));
+
while (len > 0) {
uint64_t block_num = offset / BLUESKY_BLOCK_SIZE;
gint block_offset = offset % BLUESKY_BLOCK_SIZE;
BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock,
block_num);
- switch (b->type) {
- case BLUESKY_BLOCK_ZERO:
+ if (b->type == BLUESKY_BLOCK_ZERO) {
memset(buf, 0, bytes);
- break;
- case BLUESKY_BLOCK_REF:
- bluesky_block_fetch(inode->fs, b);
- /* Fall through */
- case BLUESKY_BLOCK_CACHED:
- case BLUESKY_BLOCK_DIRTY:
- memcpy(buf, &b->data->data[block_offset], bytes);
- break;
+ } else {
+ BlueSkyRCStr *data = NULL;
+ if (b->type == BLUESKY_BLOCK_REF) {
+ bluesky_block_fetch(inode, b, NULL);
+ data = b->ref->data;
+ } else if (b->type == BLUESKY_BLOCK_DIRTY) {
+ data = b->dirty;
+ }
+ memcpy(buf, &data->data[block_offset], bytes);
}
offset += bytes;
buf += bytes;
len -= bytes;
}
+
+ bluesky_profile_add_event(profile,
+ g_strdup_printf("BlueSky read complete"));
}
-/* Read the given block from cloud-backed storage if the data is not already
- * cached. */
-void bluesky_block_fetch(BlueSkyFS *fs, BlueSkyBlock *block)
+void bluesky_block_fetch(BlueSkyInode *inode, BlueSkyBlock *block,
+ BlueSkyStoreAsync *barrier)
{
if (block->type != BLUESKY_BLOCK_REF)
return;
- BlueSkyRCStr *string = bluesky_store_get(fs->store, block->ref);
-
- bluesky_string_unref(block->data);
- block->data = bluesky_crypt_decrypt(string, fs->encryption_key);
- block->type = BLUESKY_BLOCK_CACHED;
- bluesky_string_unref(string);
+ g_mutex_lock(block->ref->lock);
+ bluesky_cloudlog_fetch(block->ref);
+ g_mutex_unlock(block->ref->lock);
+ block->type = BLUESKY_BLOCK_REF;
}
/* Write the given block to cloud-backed storage and mark it clean. */
-void bluesky_block_flush(BlueSkyFS *fs, BlueSkyBlock *block)
+void bluesky_block_flush(BlueSkyInode *inode, BlueSkyBlock *block,
+ GList **log_items)
{
+ BlueSkyFS *fs = inode->fs;
+
if (block->type != BLUESKY_BLOCK_DIRTY)
return;
- BlueSkyRCStr *data = block->data;
- data = bluesky_crypt_encrypt(data, fs->encryption_key);
+ g_assert(block->ref == NULL);
- GChecksum *csum = g_checksum_new(G_CHECKSUM_SHA256);
- g_checksum_update(csum, data->data, data->len);
- gchar *name = g_strdup(g_checksum_get_string(csum));
+ BlueSkyCloudLog *cloudlog = bluesky_cloudlog_new(fs, NULL);
+ cloudlog->type = LOGTYPE_DATA;
+ cloudlog->inum = inode->inum;
+ cloudlog->data = block->dirty; // String ownership is transferred
+ bluesky_cloudlog_stats_update(cloudlog, 1);
+ bluesky_cloudlog_sync(cloudlog);
+ bluesky_cloudlog_ref(cloudlog); // Reference for log_items list
+ *log_items = g_list_prepend(*log_items, cloudlog);
+ bluesky_cloudlog_insert(cloudlog);
- bluesky_store_put(fs->store, name, data);
- g_free(block->ref);
- block->ref = name;
+ block->ref = cloudlog; // Uses initial reference from _new()
- /* block->type = BLUESKY_BLOCK_CACHED; */
- bluesky_string_unref(block->data);
- block->data = NULL;
block->type = BLUESKY_BLOCK_REF;
+ block->dirty = NULL;
+ g_atomic_int_add(&fs->cache_dirty, -1);
+}
+
+/* Flush all blocks in a file to stable storage. */
+void bluesky_file_flush(BlueSkyInode *inode, GList **log_items)
+{
+ g_return_if_fail(inode->type == BLUESKY_REGULAR);
+
+ for (int i = 0; i < inode->blocks->len; i++) {
+ BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock, i);
+ bluesky_block_flush(inode, b, log_items);
+ }
+}
- g_checksum_free(csum);
- bluesky_string_unref(data);
+/* Drop clean data blocks for a file from cache. */
+void bluesky_file_drop_cached(BlueSkyInode *inode)
+{
+ g_return_if_fail(inode->type == BLUESKY_REGULAR);
+
+ for (int i = 0; i < inode->blocks->len; i++) {
+ BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock, i);
+ if (b->type == BLUESKY_BLOCK_REF) {
+ g_mutex_lock(b->ref->lock);
+ if (b->ref->data != NULL
+ && g_atomic_int_get(&b->ref->data_lock_count) == 0
+ && (b->ref->location_flags != 0))
+ {
+ bluesky_cloudlog_stats_update(b->ref, -1);
+ bluesky_string_unref(b->ref->data);
+ b->ref->data = NULL;
+ bluesky_cloudlog_stats_update(b->ref, 1);
+ }
+ g_mutex_unlock(b->ref->lock);
+ }
+ }
}