From e8cc53ad5fbac2cb2f578091125dc506f136bfde Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Mon, 22 Mar 2021 16:20:39 +0100 Subject: block processor: simplify backlog accounting Simply count the number of blocks we hand out (malloc'ed or recycled) and decrease the counter when we put blocks back for recycling. The sync() part becomes a little more complicated, because we can get stuck with a backlog of 1 or 2 because we have a fragment or current block buffer in use. We also need to accout for this when creating the processor, because we need to be able to request at least 2 blocks without stalling. Signed-off-by: David Oberhollenzer --- lib/sqfs/block_processor/backend.c | 9 ++++----- lib/sqfs/block_processor/block_processor.c | 19 ++++++++++++++++++- lib/sqfs/block_processor/frontend.c | 6 ++++-- 3 files changed, 26 insertions(+), 8 deletions(-) diff --git a/lib/sqfs/block_processor/backend.c b/lib/sqfs/block_processor/backend.c index ff142c9..68e299e 100644 --- a/lib/sqfs/block_processor/backend.c +++ b/lib/sqfs/block_processor/backend.c @@ -48,6 +48,8 @@ static void release_old_block(sqfs_block_processor_t *proc, sqfs_block_t *blk) { blk->next = proc->free_list; proc->free_list = blk; + + proc->backlog -= 1; } static int process_completed_block(sqfs_block_processor_t *proc, sqfs_block_t *blk) @@ -216,7 +218,8 @@ static int process_completed_fragment(sqfs_block_processor_t *proc, return 0; fail: free(chunk); - free(frag); + if (frag != NULL) + release_old_block(proc, frag); return err; } @@ -236,7 +239,6 @@ static void store_io_block(sqfs_block_processor_t *proc, sqfs_block_t *blk) } blk->next = it; - proc->backlog += 1; } int dequeue_block(sqfs_block_processor_t *proc) @@ -253,7 +255,6 @@ int dequeue_block(sqfs_block_processor_t *proc) blk = proc->io_queue; proc->io_queue = blk->next; proc->io_deq_seq_num += 1; - proc->backlog -= 1; status = process_completed_block(proc, blk); if (status != 0) @@ -270,8 +271,6 @@ int dequeue_block(sqfs_block_processor_t *proc) return status ? status : SQFS_ERROR_INTERNAL; } - proc->backlog -= 1; - if (blk->flags & SQFS_BLK_IS_FRAGMENT) { status = process_completed_fragment(proc, blk); if (status != 0) diff --git a/lib/sqfs/block_processor/block_processor.c b/lib/sqfs/block_processor/block_processor.c index f9313db..29496f9 100644 --- a/lib/sqfs/block_processor/block_processor.c +++ b/lib/sqfs/block_processor/block_processor.c @@ -98,7 +98,20 @@ int sqfs_block_processor_sync(sqfs_block_processor_t *proc) { int ret; - while (proc->backlog > 0) { + for (;;) { + if (proc->backlog == 0) + break; + + if ((proc->backlog == 1) && + (proc->frag_block != NULL || proc->blk_current != NULL)) { + break; + } + + if ((proc->backlog == 2) && + proc->frag_block != NULL && proc->blk_current != NULL) { + break; + } + ret = dequeue_block(proc); if (ret != 0) return ret; @@ -162,6 +175,10 @@ int sqfs_block_processor_create_ex(const sqfs_block_processor_desc_t *desc, proc->stats.size = sizeof(proc->stats); ((sqfs_object_t *)proc)->destroy = block_processor_destroy; + /* we need at least one current data block + one fragment block */ + if (proc->max_backlog < 2) + proc->max_backlog = 2; + /* create the thread pool */ proc->pool = thread_pool_create(desc->num_workers, process_block); if (proc->pool == NULL) { diff --git a/lib/sqfs/block_processor/frontend.c b/lib/sqfs/block_processor/frontend.c index ccf54c0..a4a38e9 100644 --- a/lib/sqfs/block_processor/frontend.c +++ b/lib/sqfs/block_processor/frontend.c @@ -28,6 +28,8 @@ static int get_new_block(sqfs_block_processor_t *proc, sqfs_block_t **out) memset(blk, 0, sizeof(*blk)); *out = blk; + + proc->backlog += 1; return 0; } @@ -56,11 +58,11 @@ int enqueue_block(sqfs_block_processor_t *proc, sqfs_block_t *blk) if (status == 0) status = SQFS_ERROR_ALLOC; - free(blk); + blk->next = proc->free_list; + proc->free_list = blk; return status; } - proc->backlog += 1; return 0; } -- cgit v1.2.3