X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=bluesky%2Ffile.c;h=5fb19479149db76ed4100e90b6520554644edfef;hb=8ff0fd08d6e1cc97cdb7e94b7cd97dc28c29e674;hp=7b11e70e4512d0ef169d465aa13557e8da6e3012;hpb=6732e9143e2c773a8c94947713bc8fc22613f702;p=bluesky.git diff --git a/bluesky/file.c b/bluesky/file.c index 7b11e70..5fb1947 100644 --- a/bluesky/file.c +++ b/bluesky/file.c @@ -3,7 +3,29 @@ * Copyright (C) 2009 The Regents of the University of California * Written by Michael Vrable * - * TODO: Licensing + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. */ #include @@ -16,8 +38,12 @@ /* 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); @@ -34,10 +60,14 @@ void bluesky_block_touch(BlueSkyInode *inode, uint64_t i) block->dirty = bluesky_string_new(g_malloc0(block_len), block_len); break; case BLUESKY_BLOCK_REF: - // 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); + 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->dirty = bluesky_string_dup(block->dirty); @@ -69,6 +99,15 @@ void bluesky_file_truncate(BlueSkyInode *inode, uint64_t 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 @@ -80,10 +119,14 @@ void bluesky_file_truncate(BlueSkyInode *inode, uint64_t size) inode->blocks->len - 1); if (b->type != BLUESKY_BLOCK_ZERO - && (b->type == BLUESKY_BLOCK_REF - || b->dirty->len < BLUESKY_BLOCK_SIZE)) { - bluesky_block_touch(inode, inode->blocks->len - 1); + && 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); @@ -109,8 +152,14 @@ void bluesky_file_truncate(BlueSkyInode *inode, uint64_t size) BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock, blocks - 1); - if (b->type != BLUESKY_BLOCK_ZERO) { - bluesky_block_touch(inode, blocks - 1); + 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; @@ -136,14 +185,20 @@ void bluesky_file_write(BlueSkyInode *inode, uint64_t offset, if (len == 0) return; - // TODO: Optimization: If we are entirely overwriting a block we don't need - // to fetch it frm storage first. while (len > 0) { uint64_t block_num = offset / BLUESKY_BLOCK_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->dirty->data[block_offset], data, bytes); @@ -166,31 +221,22 @@ void bluesky_file_read(BlueSkyInode *inode, uint64_t offset, g_return_if_fail(offset < inode->size); g_return_if_fail(len <= inode->size - offset); -#if 0 - /* Start fetches on any data blocks that we will need for this read. */ - BlueSkyStoreAsync *barrier = bluesky_store_async_new(inode->fs->store); - barrier->op = STORE_OP_BARRIER; + 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; - if (bluesky_verbose) { - g_log("bluesky/file", G_LOG_LEVEL_DEBUG, - "Start prefetch on blocks %"PRIi64" .. %"PRIi64, - start_block, end_block); - } 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_block_fetch(inode, b, barrier); + bluesky_cloudlog_prefetch(b->ref); } - bluesky_store_async_submit(barrier); - bluesky_store_async_wait(barrier); - bluesky_store_async_unref(barrier); - if (bluesky_verbose) { - g_log("bluesky/file", G_LOG_LEVEL_DEBUG, "Prefetch complete."); - } -#endif + + bluesky_profile_add_event(profile, + g_strdup_printf("End file read prefetch")); while (len > 0) { uint64_t block_num = offset / BLUESKY_BLOCK_SIZE; @@ -216,6 +262,9 @@ void bluesky_file_read(BlueSkyInode *inode, uint64_t offset, buf += bytes; len -= bytes; } + + bluesky_profile_add_event(profile, + g_strdup_printf("BlueSky read complete")); } void bluesky_block_fetch(BlueSkyInode *inode, BlueSkyBlock *block,