From 0468c150fea1a3f0941b786c67bc27e797dade40 Mon Sep 17 00:00:00 2001 From: Luke Shumaker Date: Fri, 18 May 2018 18:27:16 -0400 Subject: fix dedupe-range --- lib/dedupe-range.c | 58 +++++++++++++++++++++++++++++++++++------------------- 1 file changed, 38 insertions(+), 20 deletions(-) (limited to 'lib/dedupe-range.c') diff --git a/lib/dedupe-range.c b/lib/dedupe-range.c index cdb5044..c9e9bb0 100644 --- a/lib/dedupe-range.c +++ b/lib/dedupe-range.c @@ -13,17 +13,23 @@ #define MIN(a, b) ((a) < (b) ? (a) : (b)) -void dedupe_range(struct range src, struct range *dsts) { +void dedupe_range(uint64_t src_length, struct filepos src, struct filepos *dsts) { + // Count how many destination ranges we have size_t dst_count; for (dst_count = 0; dsts[dst_count].filename; dst_count++); + // Figure the maximum number of destination ranges we can fit + // in 1 ioctl const size_t max_dst_count = (sysconf(_SC_PAGESIZE) - sizeof(struct file_dedupe_range)) / sizeof(struct file_dedupe_range_info); + assert(max_dst_count > 0); + // Open the source file int src_fd = open(src.filename, src.flags); if (src_fd < 0) error(EXIT_FAILURE, errno, "open src: %s", src.filename); + // Open the destination files struct file_dedupe_range_info *range_info = calloc(dst_count, sizeof(struct file_dedupe_range_info)); if (!range_info) @@ -36,27 +42,36 @@ void dedupe_range(struct range src, struct range *dsts) { range_info[i].dest_offset = dsts[i].offset; } + // Do the work + struct file_dedupe_range *range = malloc(sysconf(_SC_PAGESIZE)); + if (!range) + error(EXIT_FAILURE, errno, "malloc"); for (size_t files_deduped = 0; files_deduped < dst_count; ) { - uint16_t dest_count = MIN(dst_count - files_deduped, max_dst_count); - struct file_dedupe_range *range = malloc(sizeof(struct file_dedupe_range) + dest_count * sizeof(struct file_dedupe_range_info)); - if (!range) - error(EXIT_FAILURE, errno, "malloc"); - *range = (struct file_dedupe_range){ - .src_offset = src.offset, - .src_length = src.length, - .dest_count = dest_count, - .reserved1 = 0, - .reserved2 = 0, - }; - for (size_t i = 0; i < dest_count; i++) + // initialize the range structure + *range = (struct file_dedupe_range){0}; + range->dest_count = MIN(dst_count - files_deduped, max_dst_count); + assert(range->dest_count > 0); + for (size_t i = 0;i < range->dest_count; i++) range->info[i] = range_info[files_deduped+i]; - bool erred = false; - while (range->src_length > 0) { - if (ioctl(src_fd, FIDEDUPERANGE, &range) < 0) - error(EXIT_FAILURE, errno, "ioctl (FIDEDUPERANGE)"); + // call FIDEDUPERANGE repeatedly to dedupe all of src_length + uint64_t bytes_todo = src_length; + uint64_t bytes_done = 0; + while (bytes_todo > 0) { + range->src_offset = src.offset + bytes_done; + range->src_length = MIN(bytes_todo, 16*1024*1024/*16MiB*/); // XXX "silently ignore"? + + if (ioctl(src_fd, FIDEDUPERANGE, range) < 0) + error(EXIT_FAILURE, errno, "FIDEDUPERANGE"); + + // how much actually got done? uint64_t bytes_deduped = range->info[0].bytes_deduped; assert(bytes_deduped <= range->src_length); + bytes_done += bytes_deduped; + bytes_todo -= bytes_deduped; + + // verify that dedupe for each dst went ok + bool erred = false; for (size_t i = 0; i < range->dest_count; i ++) { if (range->info[i].bytes_deduped != bytes_deduped) { error(0, errno, "dedupe: %"PRIu64" != %"PRIu64": %s", @@ -79,11 +94,14 @@ void dedupe_range(struct range src, struct range *dsts) { } if (erred == true) exit(EXIT_FAILURE); - range->src_offset += bytes_deduped; - range->src_length -= bytes_deduped; } files_deduped += range->dest_count; - free(range); } + free(range); + + for (size_t i = 0; i < dst_count; i++) + close(range_info[i].dest_fd); free(range_info); + + close(src_fd); } -- cgit v1.2.3