From: "Darrick J. Wong" Subject: [PATCH 15/34] libext2fs: support BLKZEROOUT/FALLOC_FL_ZERO_RANGE in ext2fs_zero_blocks Date: Sat, 13 Sep 2014 15:12:53 -0700 Message-ID: <20140913221253.13646.7723.stgit@birch.djwong.org> References: <20140913221112.13646.3873.stgit@birch.djwong.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: linux-ext4@vger.kernel.org To: tytso@mit.edu, darrick.wong@oracle.com Return-path: Received: from userp1040.oracle.com ([156.151.31.81]:32277 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752307AbaIMWM5 (ORCPT ); Sat, 13 Sep 2014 18:12:57 -0400 In-Reply-To: <20140913221112.13646.3873.stgit@birch.djwong.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: Plumb a new call into the IO manager to support translating ext2fs_zero_blocks calls into the equivalent kernel-level BLKZEROOUT ioctl or FALLOC_FL_ZERO_RANGE fallocate flag primitives when possible. Signed-off-by: Darrick J. Wong --- contrib/fallocate.c | 14 +++++++++ lib/ext2fs/ext2_io.h | 7 ++++- lib/ext2fs/io_manager.c | 11 +++++++ lib/ext2fs/mkjournal.c | 6 ++++ lib/ext2fs/test_io.c | 21 ++++++++++++++ lib/ext2fs/unix_io.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++ 6 files changed, 128 insertions(+), 2 deletions(-) diff --git a/contrib/fallocate.c b/contrib/fallocate.c index 1f9b59a..01d4af7 100644 --- a/contrib/fallocate.c +++ b/contrib/fallocate.c @@ -36,6 +36,8 @@ // #include #define FALLOC_FL_KEEP_SIZE 0x01 #define FALLOC_FL_PUNCH_HOLE 0x02 /* de-allocates range */ +#define FALLOC_FL_COLLAPSE_RANGE 0x08 +#define FALLOC_FL_ZERO_RANGE 0x10 void usage(void) { @@ -95,7 +97,7 @@ int main(int argc, char **argv) int error; int tflag = 0; - while ((opt = getopt(argc, argv, "npl:o:t")) != -1) { + while ((opt = getopt(argc, argv, "npl:o:tzc")) != -1) { switch(opt) { case 'n': /* do not change filesize */ @@ -106,6 +108,16 @@ int main(int argc, char **argv) falloc_mode = (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE); break; + case 'c': + /* collapse range mode */ + falloc_mode = (FALLOC_FL_COLLAPSE_RANGE | + FALLOC_FL_KEEP_SIZE); + break; + case 'z': + /* zero range mode */ + falloc_mode = (FALLOC_FL_ZERO_RANGE | + FALLOC_FL_KEEP_SIZE); + break; case 'l': length = cvtnum(optarg); break; diff --git a/lib/ext2fs/ext2_io.h b/lib/ext2fs/ext2_io.h index 4c5a5c5..1faa720 100644 --- a/lib/ext2fs/ext2_io.h +++ b/lib/ext2fs/ext2_io.h @@ -93,7 +93,9 @@ struct struct_io_manager { errcode_t (*cache_readahead)(io_channel channel, unsigned long long block, unsigned long long count); - long reserved[15]; + errcode_t (*zeroout)(io_channel channel, unsigned long long block, + unsigned long long count); + long reserved[14]; }; #define IO_FLAG_RW 0x0001 @@ -125,6 +127,9 @@ extern errcode_t io_channel_write_blk64(io_channel channel, extern errcode_t io_channel_discard(io_channel channel, unsigned long long block, unsigned long long count); +extern errcode_t io_channel_zeroout(io_channel channel, + unsigned long long block, + unsigned long long count); extern errcode_t io_channel_alloc_buf(io_channel channel, int count, void *ptr); extern errcode_t io_channel_cache_readahead(io_channel io, diff --git a/lib/ext2fs/io_manager.c b/lib/ext2fs/io_manager.c index dc5888d..c395d61 100644 --- a/lib/ext2fs/io_manager.c +++ b/lib/ext2fs/io_manager.c @@ -112,6 +112,17 @@ errcode_t io_channel_discard(io_channel channel, unsigned long long block, return EXT2_ET_UNIMPLEMENTED; } +errcode_t io_channel_zeroout(io_channel channel, unsigned long long block, + unsigned long long count) +{ + EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL); + + if (channel->manager->zeroout) + return (channel->manager->zeroout)(channel, block, count); + + return EXT2_ET_UNIMPLEMENTED; +} + errcode_t io_channel_alloc_buf(io_channel io, int count, void *ptr) { size_t size; diff --git a/lib/ext2fs/mkjournal.c b/lib/ext2fs/mkjournal.c index 6f3a862..5be425c 100644 --- a/lib/ext2fs/mkjournal.c +++ b/lib/ext2fs/mkjournal.c @@ -164,6 +164,12 @@ errcode_t ext2fs_zero_blocks2(ext2_filsys fs, blk64_t blk, int num, } return 0; } + + /* Try a zero out command, if supported */ + retval = io_channel_zeroout(fs->io, blk, num); + if (retval == 0) + return 0; + /* Allocate the zeroizing buffer if necessary */ if (!buf) { buf = malloc(fs->blocksize * STRIDE_LENGTH); diff --git a/lib/ext2fs/test_io.c b/lib/ext2fs/test_io.c index b03a939..f7c50d1 100644 --- a/lib/ext2fs/test_io.c +++ b/lib/ext2fs/test_io.c @@ -86,6 +86,7 @@ void (*test_io_cb_write_byte) #define TEST_FLAG_SET_OPTION 0x20 #define TEST_FLAG_DISCARD 0x40 #define TEST_FLAG_READAHEAD 0x80 +#define TEST_FLAG_ZEROOUT 0x100 static void test_dump_block(io_channel channel, struct test_private_data *data, @@ -507,6 +508,25 @@ static errcode_t test_cache_readahead(io_channel channel, return retval; } +static errcode_t test_zeroout(io_channel channel, unsigned long long block, + unsigned long long count) +{ + struct test_private_data *data; + errcode_t retval = 0; + + EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL); + data = (struct test_private_data *) channel->private_data; + EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL); + + if (data->real) + retval = io_channel_zeroout(data->real, block, count); + if (data->flags & TEST_FLAG_ZEROOUT) + fprintf(data->outfile, + "Test_io: zeroout(%llu, %llu) returned %s\n", + block, count, retval ? error_message(retval) : "OK"); + return retval; +} + static struct struct_io_manager struct_test_manager = { .magic = EXT2_ET_MAGIC_IO_MANAGER, .name = "Test I/O Manager", @@ -523,6 +543,7 @@ static struct struct_io_manager struct_test_manager = { .write_blk64 = test_write_blk64, .discard = test_discard, .cache_readahead = test_cache_readahead, + .zeroout = test_zeroout, }; io_manager test_io_manager = &struct_test_manager; diff --git a/lib/ext2fs/unix_io.c b/lib/ext2fs/unix_io.c index 189adce..20e5b64 100644 --- a/lib/ext2fs/unix_io.c +++ b/lib/ext2fs/unix_io.c @@ -986,6 +986,76 @@ unimplemented: return EXT2_ET_UNIMPLEMENTED; } +#if defined(__linux__) && !defined(BLKZEROOUT) +#define BLKZEROOUT _IO(0x12, 127) +#endif + +#if defined(__linux__) && !defined(FALLOC_FL_ZERO_RANGE) +#define FALLOC_FL_ZERO_RANGE 0x10 +#endif + +static errcode_t unix_zeroout(io_channel channel, unsigned long long block, + unsigned long long count) +{ + struct unix_private_data *data; + int ret; + + EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL); + data = (struct unix_private_data *) channel->private_data; + EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL); + + if (getenv("UNIX_IO_NOZEROOUT")) + goto unimplemented; + + if (channel->flags & CHANNEL_FLAGS_BLOCK_DEVICE) { +#ifdef BLKZEROOUT + __u64 range[2]; + + range[0] = (__u64)(block) * channel->block_size; + range[1] = (__u64)(count) * channel->block_size; + + ret = ioctl(data->dev, BLKZEROOUT, &range); +#else + goto unimplemented; +#endif + } else { +#if defined(HAVE_FALLOCATE) && defined(FALLOC_FL_ZERO_RANGE) + int flag = FALLOC_FL_ZERO_RANGE; + struct stat statbuf; + + /* + * If we're trying to zero a range past the end of the file, + * just use regular fallocate to get there, because zeroing + * a range past EOF does not extend the file. + */ + ret = fstat(data->dev, &statbuf); + if (ret) + goto err; + if (statbuf.st_size < (block + count) * channel->block_size) + flag = 0; + /* + * If we are not on block device, try to use the zero out + * primitive. + */ + ret = fallocate(data->dev, + flag, + (off_t)(block) * channel->block_size, + (off_t)(count) * channel->block_size); +#else + goto unimplemented; +#endif + } +err: + if (ret < 0) { + if (errno == EOPNOTSUPP) + goto unimplemented; + return errno; + } + return 0; +unimplemented: + return EXT2_ET_UNIMPLEMENTED; +} + static struct struct_io_manager struct_unix_manager = { .magic = EXT2_ET_MAGIC_IO_MANAGER, .name = "Unix I/O Manager", @@ -1002,6 +1072,7 @@ static struct struct_io_manager struct_unix_manager = { .write_blk64 = unix_write_blk64, .discard = unix_discard, .cache_readahead = unix_cache_readahead, + .zeroout = unix_zeroout, }; io_manager unix_io_manager = &struct_unix_manager;