diff --git a/Cargo.lock b/Cargo.lock index 0ca6d78..d42d598 100644 --- a/Cargo.lock +++ b/Cargo.lock @@ -21,6 +21,11 @@ dependencies = [ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)", ] +[[package]] +name = "anyhow" +version = "1.0.31" +source = "registry+https://github.com/rust-lang/crates.io-index" + [[package]] name = "arrayvec" version = "0.4.12" @@ -100,6 +105,11 @@ dependencies = [ "regex 1.3.9 (registry+https://github.com/rust-lang/crates.io-index)", ] +[[package]] +name = "fixedbitset" +version = "0.3.0" +source = "registry+https://github.com/rust-lang/crates.io-index" + [[package]] name = "flate2" version = "1.0.14" @@ -240,6 +250,14 @@ dependencies = [ "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)", ] +[[package]] +name = "quick-xml" +version = "0.18.1" +source = "registry+https://github.com/rust-lang/crates.io-index" +dependencies = [ + "memchr 2.3.3 (registry+https://github.com/rust-lang/crates.io-index)", +] + [[package]] name = "quickcheck" version = "0.9.2" @@ -306,6 +324,11 @@ dependencies = [ "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)", ] +[[package]] +name = "redox_syscall" +version = "0.1.56" +source = "registry+https://github.com/rust-lang/crates.io-index" + [[package]] name = "regex" version = "1.3.9" @@ -322,6 +345,14 @@ name = "regex-syntax" version = "0.6.18" source = "registry+https://github.com/rust-lang/crates.io-index" +[[package]] +name = "remove_dir_all" +version = "0.5.3" +source = "registry+https://github.com/rust-lang/crates.io-index" +dependencies = [ + "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)", +] + [[package]] name = "rustc_version" version = "0.2.3" @@ -368,6 +399,19 @@ dependencies = [ "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)", ] +[[package]] +name = "tempfile" +version = "3.1.0" +source = "registry+https://github.com/rust-lang/crates.io-index" +dependencies = [ + "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)", + "libc 0.2.71 (registry+https://github.com/rust-lang/crates.io-index)", + "rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)", + "redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)", + "remove_dir_all 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)", + "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)", +] + [[package]] name = "textwrap" version = "0.11.0" @@ -380,9 +424,11 @@ dependencies = [ name = "thinp" version = "0.1.0" dependencies = [ + "anyhow 1.0.31 (registry+https://github.com/rust-lang/crates.io-index)", "byteorder 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)", "clap 2.33.1 (registry+https://github.com/rust-lang/crates.io-index)", "crc32c 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)", + "fixedbitset 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)", "flate2 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)", "libc 0.2.71 (registry+https://github.com/rust-lang/crates.io-index)", "nix 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)", @@ -390,9 +436,11 @@ dependencies = [ "num-derive 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)", "num-traits 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)", "num_cpus 1.13.0 (registry+https://github.com/rust-lang/crates.io-index)", + "quick-xml 0.18.1 (registry+https://github.com/rust-lang/crates.io-index)", "quickcheck 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)", "quickcheck_macros 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)", "rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)", + "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)", ] [[package]] @@ -456,6 +504,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index" "checksum adler32 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "5d2e7343e7fc9de883d1b0341e0b13970f764c14101234857d2ddafa1cb1cac2" "checksum aho-corasick 0.7.10 (registry+https://github.com/rust-lang/crates.io-index)" = "8716408b8bc624ed7f65d223ddb9ac2d044c0547b6fa4b0d554f3a9540496ada" "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b" +"checksum anyhow 1.0.31 (registry+https://github.com/rust-lang/crates.io-index)" = "85bb70cc08ec97ca5450e6eba421deeea5f172c0fc61f78b5357b2a8e8be195f" "checksum arrayvec 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)" = "cd9fd44efafa8690358b7408d253adf110036b88f55672a933f01d616ad9b1b9" "checksum atty 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)" = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8" "checksum autocfg 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f8aac770f1885fd7e387acedd76065302551364496e46b3dd00860b2f8359b9d" @@ -467,6 +516,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index" "checksum crc32c 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "77ba37ef26c12988c1cee882d522d65e1d5d2ad8c3864665b88ee92767ed84c5" "checksum crc32fast 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ba125de2af0df55319f41944744ad91c71113bf74a4646efff39afe1f6842db1" "checksum env_logger 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "44533bbbb3bb3c1fa17d9f2e4e38bbbaf8396ba82193c4cb1b6445d711445d36" +"checksum fixedbitset 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "2fc4fcacf5cd3681968f6524ea159383132937739c6c40dabab9e37ed515911b" "checksum flate2 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)" = "2cfff41391129e0a856d6d822600b8d71179d46879e310417eb9c762eb178b42" "checksum getrandom 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)" = "7abc8dd8451921606d809ba32e95b6111925cd2906060d2dcc29c070220503eb" "checksum hermit-abi 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "91780f809e750b0a89f5544be56617ff6b1227ee485bcb06ebe10cdf89bd3b71" @@ -484,6 +534,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index" "checksum num_cpus 1.13.0 (registry+https://github.com/rust-lang/crates.io-index)" = "05499f3756671c15885fee9034446956fff3f243d6077b91e5767df161f766b3" "checksum ppv-lite86 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "237a5ed80e274dbc66f86bd59c1e25edc039660be53194b5fe0a482e0f2612ea" "checksum proc-macro2 1.0.18 (registry+https://github.com/rust-lang/crates.io-index)" = "beae6331a816b1f65d04c45b078fd8e6c93e8071771f41b8163255bbd8d7c8fa" +"checksum quick-xml 0.18.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3cc440ee4802a86e357165021e3e255a9143724da31db1e2ea540214c96a0f82" "checksum quickcheck 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a44883e74aa97ad63db83c4bf8ca490f02b2fc02f92575e720c8551e843c945f" "checksum quickcheck_macros 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "608c156fd8e97febc07dc9c2e2c80bf74cfc6ef26893eae3daf8bc2bc94a4b7f" "checksum quote 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "54a21852a652ad6f610c9510194f398ff6f8692e334fd1145fed931f7fbe44ea" @@ -491,8 +542,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index" "checksum rand_chacha 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f4c8ed856279c9737206bf725bf36935d8666ead7aa69b52be55af369d193402" "checksum rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19" "checksum rand_hc 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c" +"checksum redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)" = "2439c63f3f6139d1b57529d16bc3b8bb855230c8efcc5d3a896c8bea7c3b1e84" "checksum regex 1.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "9c3780fcf44b193bc4d09f36d2a3c87b251da4a046c87795a0d35f4f927ad8e6" "checksum regex-syntax 0.6.18 (registry+https://github.com/rust-lang/crates.io-index)" = "26412eb97c6b088a6997e05f69403a802a92d520de2f8e63c2b65f9e0f47c4e8" +"checksum remove_dir_all 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3acd125665422973a33ac9d3dd2df85edad0f4ae9b00dafb1a05e43a9f5ef8e7" "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a" "checksum ryu 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "71d301d4193d031abdd79ff7e3dd721168a9572ef3fe51a1517aba235bd8f86e" "checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403" @@ -500,6 +553,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index" "checksum static_assertions 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "7f3eb36b47e512f8f1c9e3d10c2c1965bc992bd9cdb024fa581e2194501c83d3" "checksum strsim 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a" "checksum syn 1.0.30 (registry+https://github.com/rust-lang/crates.io-index)" = "93a56fabc59dce20fe48b6c832cc249c713e7ed88fa28b0ee0a3bfcaae5fe4e2" +"checksum tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6e24d9338a0a5be79593e2fa15a648add6138caa803e2d5bc782c371732ca9" "checksum textwrap 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d326610f408c7a4eb6f51c37c330e496b08506c9457c9d34287ecc38809fb060" "checksum thread_local 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "d40c6d1b69745a6ec6fb1ca717914848da4b44ae29d9b3080cbee91d72a69b14" "checksum unicode-width 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "caaa9d531767d1ff2150b9332433f32a24622147e5ebb1f26409d5da67afd479" diff --git a/Cargo.toml b/Cargo.toml index e1e1c7c..892ea4c 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -6,15 +6,19 @@ edition = "2018" license = "GPL3" [dependencies] +anyhow = "1.0" byteorder = "1.3" clap = "2.33" crc32c = "0.4" flate2 = "1.0" +fixedbitset = "0.3" libc = "0.2.71" +quick-xml = "0.18" nix = "0.17" nom = "5.1" num_cpus = "1.13" rand = "0.7" +tempfile = "3.1" num-traits = "0.2" num-derive = "0.3" diff --git a/src/bin/thin_metadata_pack.rs b/src/bin/thin_metadata_pack.rs index ff3afa7..d4b731f 100644 --- a/src/bin/thin_metadata_pack.rs +++ b/src/bin/thin_metadata_pack.rs @@ -2,6 +2,7 @@ extern crate clap; extern crate thinp; use clap::{App, Arg}; +use std::path::Path; use std::process::exit; use thinp::file_utils; @@ -23,14 +24,14 @@ fn main() { .takes_value(true)); let matches = parser.get_matches(); - let input_file = matches.value_of("INPUT").unwrap(); - let output_file = matches.value_of("OUTPUT").unwrap(); + let input_file = Path::new(matches.value_of("INPUT").unwrap()); + let output_file = Path::new(matches.value_of("OUTPUT").unwrap()); - if !file_utils::file_exists(input_file) { - eprintln!("Couldn't find input file '{}'.", &input_file); + if !file_utils::file_exists(&input_file) { + eprintln!("Couldn't find input file '{}'.", &input_file.display()); exit(1); } - + if let Err(reason) = thinp::pack::toplevel::pack(&input_file, &output_file) { println!("Application error: {}\n", reason); exit(1); diff --git a/src/bin/thin_metadata_unpack.rs b/src/bin/thin_metadata_unpack.rs index a87dc8a..ca6403f 100644 --- a/src/bin/thin_metadata_unpack.rs +++ b/src/bin/thin_metadata_unpack.rs @@ -2,6 +2,7 @@ extern crate clap; extern crate thinp; use clap::{App, Arg}; +use std::path::Path; use std::process; use thinp::file_utils; @@ -9,30 +10,34 @@ use std::process::exit; fn main() { let parser = App::new("thin_metadata_unpack") - .version(thinp::version::TOOLS_VERSION) + .version(thinp::version::TOOLS_VERSION) .about("Unpack a compressed file of thin metadata.") - .arg(Arg::with_name("INPUT") - .help("Specify thinp metadata binary device/file") - .required(true) - .short("i") - .value_name("DEV") - .takes_value(true)) - .arg(Arg::with_name("OUTPUT") - .help("Specify packed output file") - .required(true) - .short("o") - .value_name("FILE") - .takes_value(true)); + .arg( + Arg::with_name("INPUT") + .help("Specify thinp metadata binary device/file") + .required(true) + .short("i") + .value_name("DEV") + .takes_value(true), + ) + .arg( + Arg::with_name("OUTPUT") + .help("Specify packed output file") + .required(true) + .short("o") + .value_name("FILE") + .takes_value(true), + ); let matches = parser.get_matches(); - let input_file = matches.value_of("INPUT").unwrap(); - let output_file = matches.value_of("OUTPUT").unwrap(); + let input_file = Path::new(matches.value_of("INPUT").unwrap()); + let output_file = Path::new(matches.value_of("OUTPUT").unwrap()); if !file_utils::file_exists(input_file) { - eprintln!("Couldn't find input file '{}'.", &input_file); + eprintln!("Couldn't find input file '{}'.", &input_file.display()); exit(1); } - + if let Err(reason) = thinp::pack::toplevel::unpack(&input_file, &output_file) { println!("Application error: {}", reason); process::exit(1); diff --git a/src/bin/thin_shrink.rs b/src/bin/thin_shrink.rs new file mode 100644 index 0000000..2e4e270 --- /dev/null +++ b/src/bin/thin_shrink.rs @@ -0,0 +1,74 @@ +extern crate clap; +extern crate thinp; + +use clap::{App, Arg}; +use std::path::Path; +use std::process::exit; +use thinp::file_utils; + +fn main() { + let parser = App::new("thin_shrink") + .version(thinp::version::TOOLS_VERSION) + .about("Rewrite xml metadata and move data in an inactive pool.") + .arg( + Arg::with_name("INPUT") + .help("Specify thinp metadata xml file") + .required(true) + .long("input") + .value_name("INPUT") + .takes_value(true), + ) + .arg( + Arg::with_name("OUTPUT") + .help("Specify output xml file") + .required(true) + .long("output") + .value_name("OUTPUT") + .takes_value(true), + ) + .arg( + Arg::with_name("DATA") + .help("Specify pool data device where data will be moved") + .required(true) + .long("data") + .value_name("DATA") + .takes_value(true), + ) + .arg( + Arg::with_name("NOCOPY") + .help("Skip the copying of data, useful for benchmarking") + .required(false) + .long("no-copy") + .value_name("NOCOPY") + .takes_value(false), + ) + .arg( + Arg::with_name("SIZE") + .help("Specify new size for the pool (in data blocks)") + .required(true) + .long("nr-blocks") + .value_name("SIZE") + .takes_value(true), + ); + + let matches = parser.get_matches(); + + // FIXME: check these look like xml + let input_file = Path::new(matches.value_of("INPUT").unwrap()); + let output_file = Path::new(matches.value_of("OUTPUT").unwrap()); + let size = matches.value_of("SIZE").unwrap().parse::().unwrap(); + let data_file = Path::new(matches.value_of("DATA").unwrap()); + let do_copy = !matches.is_present("NOCOPY"); + + if !file_utils::file_exists(input_file) { + eprintln!("Couldn't find input file '{}'.", input_file.display()); + exit(1); + } + + if let Err(reason) = + thinp::shrink::toplevel::shrink(&input_file, &output_file, &data_file, size, do_copy) + { + println!("Application error: {}\n", reason); + exit(1); + } +} diff --git a/src/file_utils.rs b/src/file_utils.rs index 3f5dce8..85f0714 100644 --- a/src/file_utils.rs +++ b/src/file_utils.rs @@ -1,8 +1,11 @@ use nix::sys::stat; use nix::sys::stat::{FileStat, SFlag}; +use std::fs::{File, OpenOptions}; use std::io; -use std::fs::File; +use std::io::{Seek, Write}; use std::os::unix::io::AsRawFd; +use std::path::Path; +use tempfile::tempfile; //--------------------------------------- @@ -11,15 +14,13 @@ fn check_bits(mode: u32, flag: &SFlag) -> bool { } pub fn is_file_or_blk(info: FileStat) -> bool { - check_bits(info.st_mode, &stat::SFlag::S_IFBLK) || - check_bits(info.st_mode, &stat::SFlag::S_IFREG) + check_bits(info.st_mode, &stat::SFlag::S_IFBLK) + || check_bits(info.st_mode, &stat::SFlag::S_IFREG) } -pub fn file_exists(path: &str) -> bool { +pub fn file_exists(path: &Path) -> bool { match stat::stat(path) { - Ok(info) => { - is_file_or_blk(info) - } + Ok(info) => is_file_or_blk(info), _ => { // FIXME: assuming all errors indicate the file doesn't // exist. @@ -39,19 +40,19 @@ pub fn fail(msg: &str) -> io::Result { Err(e) } -fn get_device_size(path: &str) -> io::Result { - let file = File::open(path)?; +fn get_device_size(path: &Path) -> io::Result { + let file = File::open(path)?; let fd = file.as_raw_fd(); let mut cap = 0u64; unsafe { - match ioctl_blkgetsize64(fd, &mut cap) { - Ok(_) => {Ok(cap)} - _ => {fail("BLKGETSIZE64 ioctl failed")} - } + match ioctl_blkgetsize64(fd, &mut cap) { + Ok(_) => Ok(cap), + _ => fail("BLKGETSIZE64 ioctl failed"), + } } } -pub fn file_size(path: &str) -> io::Result { +pub fn file_size(path: &Path) -> io::Result { match stat::stat(path) { Ok(info) => { if check_bits(info.st_mode, &SFlag::S_IFREG) { @@ -60,12 +61,40 @@ pub fn file_size(path: &str) -> io::Result { get_device_size(path) } else { fail("not a regular file or block device") - } + } } - _ => { - fail("stat failed") - } - } + _ => fail("stat failed"), + } +} + +//--------------------------------------- + +fn set_size(w: &mut W, nr_bytes: u64) -> io::Result<()> { + let zeroes: Vec = vec![0; 1]; + + if nr_bytes > 0 { + w.seek(io::SeekFrom::Start(nr_bytes - 1))?; + w.write_all(&zeroes)?; + } + + Ok(()) +} + +pub fn temp_file_sized(nr_bytes: u64) -> io::Result { + let mut file = tempfile()?; + set_size(&mut file, nr_bytes)?; + Ok(file) +} + +pub fn create_sized_file(path: &Path, nr_bytes: u64) -> io::Result { + let mut file = OpenOptions::new() + .read(false) + .write(true) + .create(true) + .truncate(true) + .open(path)?; + set_size(&mut file, nr_bytes)?; + Ok(file) } //--------------------------------------- diff --git a/src/lib.rs b/src/lib.rs index cf410c5..714c81c 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -1,3 +1,4 @@ +extern crate anyhow; extern crate byteorder; extern crate crc32c; extern crate flate2; @@ -18,4 +19,6 @@ pub mod block_manager; pub mod check; pub mod file_utils; pub mod pack; +pub mod shrink; +pub mod thin; pub mod version; diff --git a/src/pack/toplevel.rs b/src/pack/toplevel.rs index bd1757d..6179899 100644 --- a/src/pack/toplevel.rs +++ b/src/pack/toplevel.rs @@ -6,6 +6,7 @@ use std::os::unix::fs::OpenOptionsExt; use std::{ error::Error, fs::OpenOptions, + path::Path, io, io::prelude::*, io::Cursor, @@ -67,7 +68,7 @@ fn mk_chunk_vecs(nr_blocks: u64, nr_jobs: u64) -> Vec> { vs } -pub fn pack(input_file: &str, output_file: &str) -> Result<(), Box> { +pub fn pack(input_file: &Path, output_file: &Path) -> Result<(), Box> { let nr_blocks = get_nr_blocks(&input_file)?; let nr_jobs = std::cmp::max(1, std::cmp::min(num_cpus::get() as u64, nr_blocks / 128)); let chunk_vecs = mk_chunk_vecs(nr_blocks, nr_jobs); @@ -192,7 +193,7 @@ where r.read_u64::() } -fn get_nr_blocks(path: &str) -> io::Result { +fn get_nr_blocks(path: &Path) -> io::Result { let len = file_utils::file_size(path)?; Ok(len / (BLOCK_SIZE as u64)) } @@ -306,7 +307,7 @@ where Ok(()) } -pub fn unpack(input_file: &str, output_file: &str) -> Result<(), Box> { +pub fn unpack(input_file: &Path, output_file: &Path) -> Result<(), Box> { let mut input = OpenOptions::new() .read(true) .write(false) diff --git a/src/shrink/copier.rs b/src/shrink/copier.rs new file mode 100644 index 0000000..1be1f2a --- /dev/null +++ b/src/shrink/copier.rs @@ -0,0 +1,61 @@ +use anyhow::Result; +use std::fs::OpenOptions; +use std::path::Path; +use std::io::{Seek, SeekFrom, Write, Read}; +//use std::os::unix::fs::OpenOptionsExt; + +pub type Sector = u64; + +#[derive(Debug)] +pub struct Region { + pub src: Sector, + pub dest: Sector, + pub len: Sector, +} + + +fn copy_step(file: &mut W, src_byte: u64, dest_byte: u64, len: usize) -> Result<()> +where + W: Write + Seek + Read, +{ + let mut buf = vec![0; len]; + file.seek(SeekFrom::Start(src_byte))?; + file.read_exact(&mut buf)?; + file.seek(SeekFrom::Start(dest_byte))?; + file.write_all(&buf)?; + Ok(()) +} + +fn copy_region(file: &mut W, r: &Region) -> Result<()> +where + W: Write + Seek + Read, +{ + const MAX_BYTES: Sector = 1024 * 1024 * 64; + + let src_bytes = r.src * 512; + let dest_bytes = r.dest * 512; + let len_bytes = r.len * 512; + let mut written = 0; + while written != len_bytes { + let step = u64::min(len_bytes - written, MAX_BYTES); + copy_step(file, src_bytes + written, dest_bytes + written, step as usize)?; + written += step; + } + Ok(()) +} + +pub fn copy(path: &Path, regions: &[Region]) -> Result<()> { + let mut input = OpenOptions::new() + .read(true) + .write(true) + //.custom_flags(libc::O_DIRECT) + .open(path)?; + + for r in regions { + eprintln!("copying {:?}", r); + copy_region(&mut input, r)?; + } + input.flush()?; + + Ok(()) +} diff --git a/src/shrink/mod.rs b/src/shrink/mod.rs new file mode 100644 index 0000000..235bf23 --- /dev/null +++ b/src/shrink/mod.rs @@ -0,0 +1,3 @@ +pub mod toplevel; + +mod copier; diff --git a/src/shrink/toplevel.rs b/src/shrink/toplevel.rs new file mode 100644 index 0000000..38ffe82 --- /dev/null +++ b/src/shrink/toplevel.rs @@ -0,0 +1,528 @@ +use anyhow::{anyhow, Result}; +use fixedbitset::FixedBitSet; +use std::fs::OpenOptions; +use std::io::Write; +use std::os::unix::fs::OpenOptionsExt; +use std::path::Path; + +use crate::shrink::copier::{self, Region}; +use crate::thin::xml::{self, Visit}; + +//--------------------------------------- + +#[derive(Debug)] +struct Pass1 { + // FIXME: Inefficient, use a range_set of some description + allocated_blocks: FixedBitSet, + + nr_blocks: u64, + + /// High blocks are beyond the new, reduced end of the pool. These + /// will need to be moved. + nr_high_blocks: u64, + block_size: Option, +} + +impl Pass1 { + fn new(nr_blocks: u64) -> Pass1 { + Pass1 { + allocated_blocks: FixedBitSet::with_capacity(0), + nr_blocks, + nr_high_blocks: 0, + block_size: None, + } + } +} + +impl xml::MetadataVisitor for Pass1 { + fn superblock_b(&mut self, sb: &xml::Superblock) -> Result { + self.allocated_blocks.grow(sb.nr_data_blocks as usize); + self.block_size = Some(sb.data_block_size as u64); + Ok(Visit::Continue) + } + + fn superblock_e(&mut self) -> Result { + Ok(Visit::Continue) + } + + fn device_b(&mut self, _d: &xml::Device) -> Result { + Ok(Visit::Continue) + } + + fn device_e(&mut self) -> Result { + Ok(Visit::Continue) + } + + fn map(&mut self, m: &xml::Map) -> Result { + for i in m.data_begin..(m.data_begin + m.len) { + if i > self.nr_blocks { + self.nr_high_blocks += 1; + } + self.allocated_blocks.insert(i as usize); + } + Ok(Visit::Continue) + } + + fn eof(&mut self) -> Result { + Ok(Visit::Continue) + } +} + +//--------------------------------------- + +// Writes remapped xml +struct Pass2 { + writer: xml::XmlWriter, + nr_blocks: u64, + remaps: Vec<(BlockRange, BlockRange)>, +} + +impl Pass2 { + fn new(w: W, nr_blocks: u64, remaps: Vec<(BlockRange, BlockRange)>) -> Pass2 { + Pass2 { + writer: xml::XmlWriter::new(w), + nr_blocks, + remaps, + } + } +} + +impl xml::MetadataVisitor for Pass2 { + fn superblock_b(&mut self, sb: &xml::Superblock) -> Result { + self.writer.superblock_b(sb) + } + + fn superblock_e(&mut self) -> Result { + self.writer.superblock_e() + } + + fn device_b(&mut self, d: &xml::Device) -> Result { + self.writer.device_b(d) + } + + fn device_e(&mut self) -> Result { + self.writer.device_e() + } + + fn map(&mut self, m: &xml::Map) -> Result { + if m.data_begin + m.len < self.nr_blocks { + // no remapping needed. + self.writer.map(m)?; + } else { + let r = m.data_begin..(m.data_begin + m.len); + let remaps = remap(&r, &self.remaps); + let mut written = 0; + + for r in remaps { + self.writer.map(&xml::Map { + thin_begin: m.thin_begin + written, + data_begin: r.start, + time: m.time, + len: range_len(&r), + })?; + written += range_len(&r); + } + } + + Ok(Visit::Continue) + } + + fn eof(&mut self) -> Result { + self.writer.eof() + } +} + +//--------------------------------------- +type BlockRange = std::ops::Range; + +fn bits_to_ranges(bits: &FixedBitSet) -> Vec { + let mut ranges = Vec::new(); + let mut start = None; + + for i in 0..bits.len() { + match (bits[i], start) { + (false, None) => {} + (true, None) => { + start = Some((i as u64, 1)); + } + (false, Some((b, len))) => { + ranges.push(b..(b + len)); + start = None; + } + (true, Some((b, len))) => { + start = Some((b, len + 1)); + } + } + } + + if let Some((b, len)) = start { + ranges.push(b..(b + len)); + } + + ranges +} + +// Splits the ranges into those below threshold, and those equal or +// above threshold below threshold, and those equal or above threshold +fn ranges_split(ranges: &[BlockRange], threshold: u64) -> (Vec, Vec) { + use std::ops::Range; + + let mut below = Vec::new(); + let mut above = Vec::new(); + for r in ranges { + match r { + Range { start, end } if *end <= threshold => below.push(*start..*end), + Range { start, end } if *start < threshold => { + below.push(*start..threshold); + above.push(threshold..*end); + } + Range { start, end } => above.push(*start..*end), + } + } + (below, above) +} + +fn negate_ranges(ranges: &[BlockRange], upper_limit: u64) -> Vec { + use std::ops::Range; + + let mut result = Vec::new(); + let mut cursor = 0; + + for r in ranges { + match r { + Range { start, end } if cursor < *start => { + result.push(cursor..*start); + cursor = *end; + } + Range { start: _, end } => { + cursor = *end; + } + } + } + + if cursor < upper_limit { + result.push(cursor..upper_limit); + } + + result +} + +fn range_len(r: &BlockRange) -> u64 { + r.end - r.start +} + +fn ranges_total(rs: &[BlockRange]) -> u64 { + rs.iter().fold(0, |sum, r| sum + range_len(r)) +} + +// Assumes there is enough space to remap. +fn build_remaps(ranges: Vec, free: Vec) -> Vec<(BlockRange, BlockRange)> { + use std::cmp::Ordering; + + let mut remap = Vec::new(); + let mut range_iter = ranges.into_iter(); + let mut free_iter = free.into_iter(); + + let mut r_ = range_iter.next(); + let mut f_ = free_iter.next(); + + while let (Some(r), Some(f)) = (r_, f_) { + let rlen = range_len(&r); + let flen = range_len(&f); + + match rlen.cmp(&flen) { + Ordering::Less => { + // range fits into the free chunk + remap.push((r, f.start..(f.start + rlen))); + f_ = Some((f.start + rlen)..f.end); + r_ = range_iter.next(); + } + Ordering::Equal => { + remap.push((r, f)); + r_ = range_iter.next(); + f_ = free_iter.next(); + } + Ordering::Greater => { + remap.push((r.start..(r.start + flen), f)); + r_ = Some((r.start + flen)..r.end); + f_ = free_iter.next(); + } + } + } + + remap +} + +#[test] +fn test_build_remaps() { + struct Test { + ranges: Vec, + free: Vec, + result: Vec<(BlockRange, BlockRange)>, + } + + let tests = vec![ + Test { + ranges: vec![], + free: vec![], + result: vec![], + }, + Test { + ranges: vec![], + free: vec![0..100], + result: vec![], + }, + Test { + ranges: vec![1000..1002], + free: vec![0..100], + result: vec![(1000..1002, 0..2)], + }, + Test { + ranges: vec![1000..1002, 1100..1110], + free: vec![0..100], + result: vec![(1000..1002, 0..2), (1100..1110, 2..12)], + }, + Test { + ranges: vec![100..120], + free: vec![0..5, 20..23, 30..50], + result: vec![(100..105, 0..5), (105..108, 20..23), (108..120, 30..42)], + }, + ]; + + for t in tests { + assert_eq!(build_remaps(t.ranges, t.free), t.result); + } +} + +fn overlaps(r1: &BlockRange, r2: &BlockRange, index: usize) -> Option { + if r1.start >= r2.end { + return None; + } + + if r2.start >= r1.end { + return None; + } + + Some(index) +} + +// Finds the index of the first entry that overlaps r. +fn find_first(r: &BlockRange, remaps: &[(BlockRange, BlockRange)]) -> Option { + if remaps.is_empty() { + return None; + } + + match remaps.binary_search_by_key(&r.start, |(from, _)| from.start) { + Ok(n) => Some(n), + Err(n) => { + if n == 0 { + let (from, _) = &remaps[n]; + overlaps(&r, &from, n) + } else if n == remaps.len() { + let (from, _) = &remaps[n - 1]; + overlaps(&r, from, n - 1) + } else { + // Need to check the previous entry + let (from, _) = &remaps[n - 1]; + overlaps(&r, &from, n - 1).or_else(|| { + let (from, _) = &remaps[n]; + overlaps(&r, &from, n) + }) + } + } + } +} + +fn is_empty(r: &BlockRange) -> bool { + r.start == r.end +} + +// remaps must be in sorted order by from.start. +fn remap(r: &BlockRange, remaps: &[(BlockRange, BlockRange)]) -> Vec { + let mut remap = Vec::new(); + let mut r = r.start..r.end; + + if let Some(index) = find_first(&r, &remaps) { + let mut index = index; + loop { + let (from, to) = &remaps[index]; + + // There may be a prefix that doesn't overlap with 'from' + if r.start < from.start { + let len = u64::min(range_len(&r), from.start - r.start); + remap.push(r.start..(r.start + len)); + r = (r.start + len)..r.end; + + if is_empty(&r) { + break; + } + } + + let to = (to.start + (r.start - from.start))..to.end; + let from = r.start..from.end; + let rlen = range_len(&r); + let flen = range_len(&from); + + let len = u64::min(rlen, flen); + remap.push(to.start..(to.start + len)); + + r = (r.start + len)..r.end; + if is_empty(&r) { + break; + } + + if len == flen { + index += 1; + } + + if index == remaps.len() { + remap.push(r.start..r.end); + break; + } + } + } else { + remap.push(r.start..r.end); + } + + remap +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn remap_test() { + struct Test { + remaps: Vec<(BlockRange, BlockRange)>, + input: BlockRange, + output: Vec, + } + + let tests = [ + Test { + remaps: vec![], + input: 0..1, + output: vec![0..1], + }, + Test { + remaps: vec![], + input: 100..1000, + output: vec![100..1000], + }, + Test { + remaps: vec![(10..20, 110..120)], + input: 0..5, + output: vec![0..5], + }, + Test { + remaps: vec![(10..20, 110..120)], + input: 10..20, + output: vec![110..120], + }, + Test { + remaps: vec![(10..20, 110..120)], + input: 5..15, + output: vec![5..10, 110..115], + }, + Test { + remaps: vec![(10..20, 110..120)], + input: 5..25, + output: vec![5..10, 110..120, 20..25], + }, + Test { + remaps: vec![(10..20, 110..120)], + input: 15..25, + output: vec![115..120, 20..25], + }, + Test { + remaps: vec![(10..20, 110..120)], + input: 25..35, + output: vec![25..35], + }, + Test { + remaps: vec![(10..20, 110..120), (30..40, 230..240)], + input: 0..50, + output: vec![0..10, 110..120, 20..30, 230..240, 40..50], + }, + ]; + + for t in &tests { + let rs = remap(&t.input, &t.remaps); + assert_eq!(rs, t.output); + } + } +} + +fn build_copy_regions(remaps: &[(BlockRange, BlockRange)], block_size: u64) -> Vec { + let mut rs = Vec::new(); + + for (from, to) in remaps { + rs.push(Region { + src: from.start * block_size, + dest: to.start * block_size, + len: range_len(&from) * block_size, + }); + } + + rs +} + +fn process_xml(input_path: &Path, pass: &mut MV) -> Result<()> { + let input = OpenOptions::new() + .read(true) + .write(false) + .custom_flags(libc::O_EXCL) + .open(input_path)?; + + xml::read(input, pass)?; + Ok(()) +} + +pub fn shrink( + input_path: &Path, + output_path: &Path, + data_path: &Path, + nr_blocks: u64, + do_copy: bool, +) -> Result<()> { + let mut pass1 = Pass1::new(nr_blocks); + eprint!("Reading xml..."); + process_xml(input_path, &mut pass1)?; + eprintln!("done"); + eprintln!("{} blocks need moving", pass1.nr_high_blocks); + + let ranges = bits_to_ranges(&pass1.allocated_blocks); + let (below, above) = ranges_split(&ranges, nr_blocks); + + let free = negate_ranges(&below, nr_blocks); + let free_blocks = ranges_total(&free); + eprintln!("{} free blocks.", free_blocks); + + if free_blocks < pass1.nr_high_blocks { + return Err(anyhow!("Insufficient space")); + } + + let remaps = build_remaps(above, free); + + if do_copy { + let regions = build_copy_regions(&remaps, pass1.block_size.unwrap() as u64); + copier::copy(data_path, ®ions)?; + } else { + eprintln!("skipping copy"); + } + + let output = OpenOptions::new() + .read(false) + .write(true) + .create(true) + .open(output_path)?; + let mut pass2 = Pass2::new(output, nr_blocks, remaps); + eprint!("writing new xml..."); + process_xml(input_path, &mut pass2)?; + eprintln!("done."); + + Ok(()) +} + +//--------------------------------------- diff --git a/src/thin/mod.rs b/src/thin/mod.rs new file mode 100644 index 0000000..2910ec6 --- /dev/null +++ b/src/thin/mod.rs @@ -0,0 +1 @@ +pub mod xml; diff --git a/src/thin/xml.rs b/src/thin/xml.rs new file mode 100644 index 0000000..7da0fe2 --- /dev/null +++ b/src/thin/xml.rs @@ -0,0 +1,413 @@ +use anyhow::Result; +use std::{borrow::Cow, fmt::Display, io::prelude::*, io::BufReader, io::Write}; + +use quick_xml::events::attributes::Attribute; +use quick_xml::events::{BytesEnd, BytesStart, Event}; +use quick_xml::{Reader, Writer}; + +//--------------------------------------- + +#[derive(Clone)] +pub struct Superblock { + pub uuid: String, + pub time: u64, + pub transaction: u64, + pub flags: Option, + pub version: Option, + pub data_block_size: u32, + pub nr_data_blocks: u64, + pub metadata_snap: Option, +} + +#[derive(Clone)] +pub struct Device { + pub dev_id: u32, + pub mapped_blocks: u64, + pub transaction: u64, + pub creation_time: u64, + pub snap_time: u64, +} + +#[derive(Clone)] +pub struct Map { + pub thin_begin: u64, + pub data_begin: u64, + pub time: u32, + pub len: u64, +} + +#[derive(Clone)] +pub enum Visit { + Continue, + Stop, +} + +pub trait MetadataVisitor { + fn superblock_b(&mut self, sb: &Superblock) -> Result; + fn superblock_e(&mut self) -> Result; + + fn device_b(&mut self, d: &Device) -> Result; + fn device_e(&mut self) -> Result; + + fn map(&mut self, m: &Map) -> Result; + + fn eof(&mut self) -> Result; +} + +pub struct XmlWriter { + w: Writer, +} + +impl XmlWriter { + pub fn new(w: W) -> XmlWriter { + XmlWriter { + w: Writer::new_with_indent(w, 0x20, 2), + } + } +} + +fn mk_attr_<'a, T: Display>(n: T) -> Cow<'a, [u8]> { + let str = format!("{}", n); + Cow::Owned(str.into_bytes()) +} + +fn mk_attr(key: &[u8], value: T) -> Attribute { + Attribute { + key, + value: mk_attr_(value), + } +} + +const XML_VERSION: u32 = 2; + +impl MetadataVisitor for XmlWriter { + fn superblock_b(&mut self, sb: &Superblock) -> Result { + let tag = b"superblock"; + let mut elem = BytesStart::owned(tag.to_vec(), tag.len()); + elem.push_attribute(mk_attr(b"uuid", sb.uuid.clone())); + elem.push_attribute(mk_attr(b"time", sb.time)); + elem.push_attribute(mk_attr(b"transaction", sb.transaction)); + if let Some(flags) = sb.flags { + // FIXME: is this really a nr? + elem.push_attribute(mk_attr(b"flags", flags)); + } + + elem.push_attribute(mk_attr(b"version", XML_VERSION)); + elem.push_attribute(mk_attr(b"data_block_size", sb.data_block_size)); + elem.push_attribute(mk_attr(b"nr_data_blocks", sb.nr_data_blocks)); + + if let Some(snap) = sb.metadata_snap { + elem.push_attribute(mk_attr(b"metadata_snap", snap)); + } + + self.w.write_event(Event::Start(elem))?; + Ok(Visit::Continue) + } + + fn superblock_e(&mut self) -> Result { + self.w + .write_event(Event::End(BytesEnd::borrowed(b"superblock")))?; + Ok(Visit::Continue) + } + + fn device_b(&mut self, d: &Device) -> Result { + let tag = b"device"; + let mut elem = BytesStart::owned(tag.to_vec(), tag.len()); + elem.push_attribute(mk_attr(b"dev_id", d.dev_id)); + elem.push_attribute(mk_attr(b"mapped_blocks", d.mapped_blocks)); + elem.push_attribute(mk_attr(b"transaction", d.transaction)); + elem.push_attribute(mk_attr(b"creation_time", d.creation_time)); + elem.push_attribute(mk_attr(b"snap_time", d.snap_time)); + self.w.write_event(Event::Start(elem))?; + Ok(Visit::Continue) + } + + fn device_e(&mut self) -> Result { + self.w + .write_event(Event::End(BytesEnd::borrowed(b"device")))?; + Ok(Visit::Continue) + } + + fn map(&mut self, m: &Map) -> Result { + match m.len { + 1 => { + let tag = b"single_mapping"; + let mut elem = BytesStart::owned(tag.to_vec(), tag.len()); + elem.push_attribute(mk_attr(b"origin_block", m.thin_begin)); + elem.push_attribute(mk_attr(b"data_block", m.data_begin)); + elem.push_attribute(mk_attr(b"time", m.time)); + self.w.write_event(Event::Empty(elem))?; + } + _ => { + let tag = b"range_mapping"; + let mut elem = BytesStart::owned(tag.to_vec(), tag.len()); + elem.push_attribute(mk_attr(b"origin_begin", m.thin_begin)); + elem.push_attribute(mk_attr(b"data_begin", m.data_begin)); + elem.push_attribute(mk_attr(b"length", m.len)); + elem.push_attribute(mk_attr(b"time", m.time)); + self.w.write_event(Event::Empty(elem))?; + } + } + Ok(Visit::Continue) + } + + fn eof(&mut self) -> Result { + let w = self.w.inner(); + w.flush()?; + Ok(Visit::Continue) + } +} + +//--------------------------------------- + +// FIXME: nasty unwraps +fn string_val(kv: &Attribute) -> String { + let v = kv.unescaped_value().unwrap(); + let bytes = v.to_vec(); + String::from_utf8(bytes).unwrap() +} + +// FIXME: there's got to be a way of doing this without copying the string +fn u64_val(kv: &Attribute) -> Result { + let n = string_val(kv).parse::()?; + Ok(n) +} + +fn u32_val(kv: &Attribute) -> Result { + let n = string_val(kv).parse::()?; + Ok(n) +} + +fn bad_attr(_tag: &str, _attr: &[u8]) -> Result { + todo!(); +} + +fn missing_attr(_tag: &str, _attr: &str) -> Result { + todo!(); +} + +fn check_attr(tag: &str, name: &str, maybe_v: Option) -> Result { + match maybe_v { + None => missing_attr(tag, name), + Some(v) => Ok(v), + } +} + +fn parse_superblock(e: &BytesStart) -> Result { + let mut uuid: Option = None; + let mut time: Option = None; + let mut transaction: Option = None; + let mut flags: Option = None; + let mut version: Option = None; + let mut data_block_size: Option = None; + let mut nr_data_blocks: Option = None; + let mut metadata_snap: Option = None; + + for a in e.attributes() { + let kv = a.unwrap(); + match kv.key { + b"uuid" => uuid = Some(string_val(&kv)), + b"time" => time = Some(u64_val(&kv)?), + b"transaction" => transaction = Some(u64_val(&kv)?), + b"flags" => flags = Some(u32_val(&kv)?), + b"version" => version = Some(u32_val(&kv)?), + b"data_block_size" => data_block_size = Some(u32_val(&kv)?), + b"nr_data_blocks" => nr_data_blocks = Some(u64_val(&kv)?), + b"metadata_snap" => metadata_snap = Some(u64_val(&kv)?), + _ => return bad_attr("superblock", kv.key), + } + } + + let tag = "superblock"; + + Ok(Superblock { + uuid: check_attr(tag, "uuid", uuid)?, + time: check_attr(tag, "time", time)?, + transaction: check_attr(tag, "transaction", transaction)?, + flags, + version, + data_block_size: check_attr(tag, "data_block_size", data_block_size)?, + nr_data_blocks: check_attr(tag, "nr_data_blocks", nr_data_blocks)?, + metadata_snap, + }) +} + +fn parse_device(e: &BytesStart) -> Result { + let mut dev_id: Option = None; + let mut mapped_blocks: Option = None; + let mut transaction: Option = None; + let mut creation_time: Option = None; + let mut snap_time: Option = None; + + for a in e.attributes() { + let kv = a.unwrap(); + match kv.key { + b"dev_id" => dev_id = Some(u32_val(&kv)?), + b"mapped_blocks" => mapped_blocks = Some(u64_val(&kv)?), + b"transaction" => transaction = Some(u64_val(&kv)?), + b"creation_time" => creation_time = Some(u64_val(&kv)?), + b"snap_time" => snap_time = Some(u64_val(&kv)?), + _ => return bad_attr("device", kv.key), + } + } + + let tag = "device"; + + Ok(Device { + dev_id: check_attr(tag, "dev_id", dev_id)?, + mapped_blocks: check_attr(tag, "mapped_blocks", mapped_blocks)?, + transaction: check_attr(tag, "transaction", transaction)?, + creation_time: check_attr(tag, "creation_time", creation_time)?, + snap_time: check_attr(tag, "snap_time", snap_time)?, + }) +} + +fn parse_single_map(e: &BytesStart) -> Result { + let mut thin_begin: Option = None; + let mut data_begin: Option = None; + let mut time: Option = None; + + for a in e.attributes() { + let kv = a.unwrap(); + match kv.key { + b"origin_block" => thin_begin = Some(u64_val(&kv)?), + b"data_block" => data_begin = Some(u64_val(&kv)?), + b"time" => time = Some(u32_val(&kv)?), + _ => return bad_attr("single_mapping", kv.key), + } + } + + let tag = "single_mapping"; + + Ok(Map { + thin_begin: check_attr(tag, "origin_block", thin_begin)?, + data_begin: check_attr(tag, "data_block", data_begin)?, + time: check_attr(tag, "time", time)?, + len: 1, + }) +} + +fn parse_range_map(e: &BytesStart) -> Result { + let mut thin_begin: Option = None; + let mut data_begin: Option = None; + let mut time: Option = None; + let mut length: Option = None; + + for a in e.attributes() { + let kv = a.unwrap(); + match kv.key { + b"origin_begin" => thin_begin = Some(u64_val(&kv)?), + b"data_begin" => data_begin = Some(u64_val(&kv)?), + b"time" => time = Some(u32_val(&kv)?), + b"length" => length = Some(u64_val(&kv)?), + _ => return bad_attr("range_mapping", kv.key), + } + } + + let tag = "range_mapping"; + + Ok(Map { + thin_begin: check_attr(tag, "origin_begin", thin_begin)?, + data_begin: check_attr(tag, "data_begin", data_begin)?, + time: check_attr(tag, "time", time)?, + len: check_attr(tag, "length", length)?, + }) +} + +fn handle_event(reader: &mut Reader, buf: &mut Vec, visitor: &mut M) -> Result +where + R: Read + BufRead, + M: MetadataVisitor, +{ + match reader.read_event(buf) { + Ok(Event::Start(ref e)) => match e.name() { + b"superblock" => visitor.superblock_b(&parse_superblock(e)?), + b"device" => visitor.device_b(&parse_device(e)?), + _ => todo!(), + }, + Ok(Event::End(ref e)) => match e.name() { + b"superblock" => visitor.superblock_e(), + b"device" => visitor.device_e(), + _ => todo!(), + }, + Ok(Event::Empty(ref e)) => match e.name() { + b"single_mapping" => visitor.map(&parse_single_map(e)?), + b"range_mapping" => visitor.map(&parse_range_map(e)?), + _ => todo!(), + }, + Ok(Event::Text(_)) => Ok(Visit::Continue), + Ok(Event::Comment(_)) => Ok(Visit::Continue), + Ok(Event::Eof) => { + visitor.eof()?; + Ok(Visit::Stop) + } + Ok(_) => todo!(), + + // FIXME: don't panic! + Err(e) => panic!("error parsing xml {:?}", e), + } +} + +pub fn read(input: R, visitor: &mut M) -> Result<()> +where + R: Read, + M: MetadataVisitor, +{ + let input = BufReader::new(input); + let mut reader = Reader::from_reader(input); + + reader.trim_text(true); + let mut buf = Vec::new(); + + loop { + match handle_event(&mut reader, &mut buf, visitor)? { + Visit::Continue => {} + Visit::Stop => break, + } + } + + Ok(()) +} + +//--------------------------------------- + +struct SBVisitor { + superblock: Option, +} + +impl MetadataVisitor for SBVisitor { + fn superblock_b(&mut self, sb: &Superblock) -> Result { + self.superblock = Some(sb.clone()); + Ok(Visit::Stop) + } + + fn superblock_e(&mut self) -> Result { + Ok(Visit::Continue) + } + + fn device_b(&mut self, _d: &Device) -> Result { + Ok(Visit::Continue) + } + fn device_e(&mut self) -> Result { + Ok(Visit::Continue) + } + + fn map(&mut self, _m: &Map) -> Result { + Ok(Visit::Continue) + } + + fn eof(&mut self) -> Result { + Ok(Visit::Stop) + } +} + +pub fn read_superblock(input: R) -> Result +where + R: Read, +{ + let mut v = SBVisitor {superblock: None}; + read(input, &mut v)?; + Ok(v.superblock.unwrap()) +} + +//--------------------------------------- diff --git a/tests/thin_shrink.rs b/tests/thin_shrink.rs new file mode 100644 index 0000000..0291340 --- /dev/null +++ b/tests/thin_shrink.rs @@ -0,0 +1,934 @@ +use anyhow::{anyhow, Result}; +use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt}; +use rand::prelude::*; +use std::collections::VecDeque; +use std::fs::OpenOptions; +use std::io::{Cursor, Read, Seek, SeekFrom, Write}; +use std::ops::Range; +use std::path::{Path, PathBuf}; +use tempfile::tempdir; + +use thinp::file_utils; +use thinp::thin::xml::{self, Visit}; + +//------------------------------------ + +#[derive(Debug)] +struct ThinBlock { + thin_id: u32, + thin_block: u64, + data_block: u64, + block_size: usize, +} + +struct ThinReadRef { + pub data: Vec, +} + +struct ThinWriteRef<'a, W: Write + Seek> { + file: &'a mut W, + block_byte: u64, + pub data: Vec, +} + +impl ThinBlock { + fn read_ref(&self, r: &mut R) -> Result { + let mut rr = ThinReadRef { + data: vec![0; self.block_size * 512], + }; + let byte = self.data_block * (self.block_size as u64) * 512; + r.seek(SeekFrom::Start(byte))?; + r.read_exact(&mut rr.data)?; + Ok(rr) + } + + fn zero_ref<'a, W: Write + Seek>(&self, w: &'a mut W) -> ThinWriteRef<'a, W> { + ThinWriteRef { + file: w, + block_byte: self.data_block * (self.block_size as u64) * 512, + data: vec![0; self.block_size * 512], + } + } + + //fn write_ref<'a, W>(&self, w: &'a mut W) -> Result> + //where + //W: Read + Write + Seek, + //{ + //let mut data = vec![0; self.block_size]; + //w.seek(SeekFrom::Start(self.data_block * (self.block_size as u64)))?; + //w.read_exact(&mut data[0..])?; + // + //let wr = ThinWriteRef { + //file: w, + //block_byte: self.data_block * (self.block_size as u64), + //data: vec![0; self.block_size], + //}; + // + //Ok(wr) + //} +} + +impl<'a, W: Write + Seek> Drop for ThinWriteRef<'a, W> { + fn drop(&mut self) { + // FIXME: We shouldn't panic in a drop function, so any IO + // errors will have to make their way back to the user + // another way (eg, via a flush() method). + self.file.seek(SeekFrom::Start(self.block_byte)).unwrap(); + self.file.write_all(&self.data).unwrap(); + } +} + +//------------------------------------ + +trait ThinVisitor { + fn thin_block(&mut self, tb: &ThinBlock) -> Result<()>; +} + +struct ThinXmlVisitor<'a, V: ThinVisitor> { + inner: &'a mut V, + block_size: Option, + thin_id: Option, +} + +impl<'a, V: ThinVisitor> xml::MetadataVisitor for ThinXmlVisitor<'a, V> { + fn superblock_b(&mut self, sb: &xml::Superblock) -> Result { + self.block_size = Some(sb.data_block_size); + Ok(Visit::Continue) + } + + fn superblock_e(&mut self) -> Result { + Ok(Visit::Continue) + } + + fn device_b(&mut self, d: &xml::Device) -> Result { + self.thin_id = Some(d.dev_id); + Ok(Visit::Continue) + } + + fn device_e(&mut self) -> Result { + Ok(Visit::Continue) + } + + fn map(&mut self, m: &xml::Map) -> Result { + for i in 0..m.len { + let block = ThinBlock { + thin_id: self.thin_id.unwrap(), + thin_block: m.thin_begin + i, + data_block: m.data_begin + i, + block_size: self.block_size.unwrap() as usize, + }; + self.inner.thin_block(&block)?; + } + Ok(Visit::Continue) + } + + fn eof(&mut self) -> Result { + Ok(Visit::Stop) + } +} + +fn thin_visit(input: R, visitor: &mut M) -> Result<()> +where + R: Read, + M: ThinVisitor, +{ + let mut xml_visitor = ThinXmlVisitor { + inner: visitor, + block_size: None, + thin_id: None, + }; + + xml::read(input, &mut xml_visitor) +} + +//------------------------------------ + +// To test thin_shrink we'd like to stamp a known pattern across the +// provisioned areas of the thins in the pool, do the shrink, verify +// the patterns. + +// A simple linear congruence generator used to create the data to +// go into the thin blocks. +struct Generator { + x: u64, + a: u64, + c: u64, +} + +impl Generator { + fn new() -> Generator { + Generator { + x: 0, + a: 6364136223846793005, + c: 1442695040888963407, + } + } + + fn step(&mut self) { + self.x = self.a.wrapping_mul(self.x).wrapping_add(self.c) + } + + fn fill_buffer(&mut self, seed: u64, bytes: &mut [u8]) -> Result<()> { + self.x = seed; + + assert!(bytes.len() % 8 == 0); + let nr_words = bytes.len() / 8; + let mut out = Cursor::new(bytes); + + for _ in 0..nr_words { + out.write_u64::(self.x)?; + self.step(); + } + + Ok(()) + } + + fn verify_buffer(&mut self, seed: u64, bytes: &[u8]) -> Result { + self.x = seed; + + assert!(bytes.len() % 8 == 0); + let nr_words = bytes.len() / 8; + let mut input = Cursor::new(bytes); + + for _ in 0..nr_words { + let w = input.read_u64::()?; + if w != self.x { + eprintln!("{} != {}", w, self.x); + return Ok(false); + } + self.step(); + } + + Ok(true) + } +} + +//------------------------------------ + +struct Stamper<'a, W: Write + Seek> { + data_file: &'a mut W, + seed: u64, +} + +impl<'a, W: Write + Seek> Stamper<'a, W> { + fn new(w: &'a mut W, seed: u64) -> Stamper<'a, W> { + Stamper { data_file: w, seed } + } +} + +impl<'a, W: Write + Seek> ThinVisitor for Stamper<'a, W> { + fn thin_block(&mut self, b: &ThinBlock) -> Result<()> { + let mut wr = b.zero_ref(self.data_file); + let mut gen = Generator::new(); + gen.fill_buffer(self.seed ^ (b.thin_id as u64) ^ b.thin_block, &mut wr.data)?; + Ok(()) + } +} + +//------------------------------------ + +struct Verifier<'a, R: Read + Seek> { + data_file: &'a mut R, + seed: u64, +} + +impl<'a, R: Read + Seek> Verifier<'a, R> { + fn new(r: &'a mut R, seed: u64) -> Verifier<'a, R> { + Verifier { data_file: r, seed } + } +} + +impl<'a, R: Read + Seek> ThinVisitor for Verifier<'a, R> { + fn thin_block(&mut self, b: &ThinBlock) -> Result<()> { + let rr = b.read_ref(self.data_file)?; + let mut gen = Generator::new(); + if !gen.verify_buffer(self.seed ^ (b.thin_id as u64) ^ b.thin_block, &rr.data)? { + return Err(anyhow!("data verify failed for {:?}", b)); + } + Ok(()) + } +} + +//------------------------------------ + +fn mk_path(dir: &Path, file: &str) -> PathBuf { + let mut p = PathBuf::new(); + p.push(dir); + p.push(PathBuf::from(file)); + p +} + +fn generate_xml(path: &Path, g: &mut dyn Scenario) -> Result<()> { + let xml_out = OpenOptions::new() + .read(false) + .write(true) + .create(true) + .truncate(true) + .open(path)?; + let mut w = xml::XmlWriter::new(xml_out); + + g.generate_xml(&mut w) +} + +fn create_data_file(data_path: &Path, xml_path: &Path) -> Result<()> { + let input = OpenOptions::new().read(true).write(false).open(xml_path)?; + + let sb = xml::read_superblock(input)?; + let nr_blocks = sb.nr_data_blocks as u64; + let block_size = sb.data_block_size as u64 * 512; + + let _file = file_utils::create_sized_file(data_path, nr_blocks * block_size)?; + Ok(()) +} + +fn stamp(xml_path: &Path, data_path: &Path, seed: u64) -> Result<()> { + let mut data = OpenOptions::new() + .read(false) + .write(true) + .open(&data_path)?; + let xml = OpenOptions::new().read(true).write(false).open(&xml_path)?; + + let mut stamper = Stamper::new(&mut data, seed); + thin_visit(xml, &mut stamper) +} + +fn verify(xml_path: &Path, data_path: &Path, seed: u64) -> Result<()> { + let mut data = OpenOptions::new() + .read(true) + .write(false) + .open(&data_path)?; + let xml = OpenOptions::new().read(true).write(false).open(&xml_path)?; + + let mut verifier = Verifier::new(&mut data, seed); + thin_visit(xml, &mut verifier) +} + +trait Scenario { + fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()>; + fn get_new_nr_blocks(&self) -> u64; +} + +fn test_shrink(scenario: &mut dyn Scenario) -> Result<()> { + let dir = tempdir()?; + let xml_before = mk_path(dir.path(), "before.xml"); + let xml_after = mk_path(dir.path(), "after.xml"); + let data_path = mk_path(dir.path(), "metadata.bin"); + + generate_xml(&xml_before, scenario)?; + create_data_file(&data_path, &xml_before)?; + + let mut rng = rand::thread_rng(); + let seed = rng.gen::(); + + stamp(&xml_before, &data_path, seed)?; + verify(&xml_before, &data_path, seed)?; + + let new_nr_blocks = scenario.get_new_nr_blocks(); + thinp::shrink::toplevel::shrink(&xml_before, &xml_after, &data_path, new_nr_blocks, true)?; + + verify(&xml_after, &data_path, seed)?; + Ok(()) +} + +//------------------------------------ + +fn common_sb(nr_blocks: u64) -> xml::Superblock { + xml::Superblock { + uuid: "".to_string(), + time: 0, + transaction: 0, + flags: None, + version: None, + data_block_size: 32, + nr_data_blocks: nr_blocks, + metadata_snap: None, + } +} + +struct EmptyPoolS {} + +impl Scenario for EmptyPoolS { + fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()> { + v.superblock_b(&common_sb(1024))?; + v.superblock_e()?; + Ok(()) + } + + fn get_new_nr_blocks(&self) -> u64 { + 512 + } +} + +#[test] +fn shrink_empty_pool() -> Result<()> { + let mut s = EmptyPoolS {}; + test_shrink(&mut s) +} + +//------------------------------------ + +struct SingleThinS { + offset: u64, + len: u64, + old_nr_data_blocks: u64, + new_nr_data_blocks: u64, +} + +impl SingleThinS { + fn new(offset: u64, len: u64, old_nr_data_blocks: u64, new_nr_data_blocks: u64) -> Self { + SingleThinS { + offset, + len, + old_nr_data_blocks, + new_nr_data_blocks, + } + } +} + +impl Scenario for SingleThinS { + fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()> { + v.superblock_b(&common_sb(self.old_nr_data_blocks))?; + v.device_b(&xml::Device { + dev_id: 0, + mapped_blocks: self.len, + transaction: 0, + creation_time: 0, + snap_time: 0, + })?; + v.map(&xml::Map { + thin_begin: 0, + data_begin: self.offset, + time: 0, + len: self.len, + })?; + v.device_e()?; + v.superblock_e()?; + Ok(()) + } + + fn get_new_nr_blocks(&self) -> u64 { + self.new_nr_data_blocks + } +} + +#[test] +fn shrink_single_no_move_1() -> Result<()> { + let mut s = SingleThinS::new(0, 1024, 2048, 1280); + test_shrink(&mut s) +} + +#[test] +fn shrink_single_no_move_2() -> Result<()> { + let mut s = SingleThinS::new(100, 1024, 2048, 1280); + test_shrink(&mut s) +} + +#[test] +fn shrink_single_no_move_3() -> Result<()> { + let mut s = SingleThinS::new(1024, 1024, 2048, 2048); + test_shrink(&mut s) +} + +#[test] +fn shrink_single_partial_move() -> Result<()> { + let mut s = SingleThinS::new(1024, 1024, 2048, 1280); + test_shrink(&mut s) +} + +#[test] +fn shrink_single_total_move() -> Result<()> { + let mut s = SingleThinS::new(2048, 1024, 1024 + 2048, 1280); + test_shrink(&mut s) +} + +#[test] +fn shrink_insufficient_space() -> Result<()> { + let mut s = SingleThinS::new(0, 2048, 3000, 1280); + match test_shrink(&mut s) { + Ok(_) => Err(anyhow!("Shrink unexpectedly succeeded")), + Err(_) => Ok(()), + } +} + +//------------------------------------ + +struct FragmentedS { + nr_thins: u32, + thin_size: u64, + old_nr_data_blocks: u64, + new_nr_data_blocks: u64, +} + +impl FragmentedS { + fn new(nr_thins: u32, thin_size: u64) -> Self { + let old_size = (nr_thins as u64) * thin_size; + FragmentedS { + nr_thins, + thin_size, + old_nr_data_blocks: (nr_thins as u64) * thin_size, + new_nr_data_blocks: old_size * 3 / 4, + } + } +} + +#[derive(Clone)] +struct ThinRun { + thin_id: u32, + thin_begin: u64, + len: u64, +} + +#[derive(Clone, Debug, Copy)] +struct MappedRun { + thin_id: u32, + thin_begin: u64, + data_begin: u64, + len: u64, +} + +fn mk_runs(thin_id: u32, total_len: u64, run_len: std::ops::Range) -> Vec { + let mut runs = Vec::new(); + let mut b = 0u64; + while b < total_len { + let len = u64::min( + total_len - b, + thread_rng().gen_range(run_len.start, run_len.end), + ); + runs.push(ThinRun { + thin_id: thin_id, + thin_begin: b, + len, + }); + b += len; + } + runs +} + +impl Scenario for FragmentedS { + fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()> { + // Allocate each thin fully, in runs between 1 and 16. + let mut runs = Vec::new(); + for thin in 0..self.nr_thins { + runs.append(&mut mk_runs(thin, self.thin_size, 1..17)); + } + + // Shuffle + runs.shuffle(&mut rand::thread_rng()); + + // map across the data + let mut maps = Vec::new(); + let mut b = 0; + for r in &runs { + maps.push(MappedRun { + thin_id: r.thin_id, + thin_begin: r.thin_begin, + data_begin: b, + len: r.len, + }); + b += r.len; + } + + // drop half the mappings, which leaves us free runs + let mut dropped = Vec::new(); + for i in 0..maps.len() { + if i % 2 == 0 { + dropped.push(maps[i].clone()); + } + } + + // Unshuffle. This isn't strictly necc. but makes the xml + // more readable. + use std::cmp::Ordering; + maps.sort_by(|&l, &r| match l.thin_id.cmp(&r.thin_id) { + Ordering::Equal => l.thin_begin.cmp(&r.thin_begin), + o => o, + }); + + // write the xml + v.superblock_b(&common_sb(self.old_nr_data_blocks))?; + for thin in 0..self.nr_thins { + v.device_b(&xml::Device { + dev_id: thin, + mapped_blocks: self.thin_size, + transaction: 0, + creation_time: 0, + snap_time: 0, + })?; + + for m in &dropped { + if m.thin_id != thin { + continue; + } + + v.map(&xml::Map { + thin_begin: m.thin_begin, + data_begin: m.data_begin, + time: 0, + len: m.len, + })?; + } + + v.device_e()?; + } + v.superblock_e()?; + Ok(()) + } + + fn get_new_nr_blocks(&self) -> u64 { + self.new_nr_data_blocks + } +} + +#[test] +fn shrink_fragmented_thin_1() -> Result<()> { + let mut s = FragmentedS::new(1, 2048); + test_shrink(&mut s) +} + +#[test] +fn shrink_fragmented_thin_2() -> Result<()> { + let mut s = FragmentedS::new(2, 2048); + test_shrink(&mut s) +} + +#[test] +fn shrink_fragmented_thin_8() -> Result<()> { + let mut s = FragmentedS::new(2, 2048); + test_shrink(&mut s) +} + +#[test] +fn shrink_fragmented_thin_64() -> Result<()> { + let mut s = FragmentedS::new(2, 2048); + test_shrink(&mut s) +} + +//------------------------------------ + +struct Allocator { + runs: VecDeque>, +} + +impl Allocator { + fn new_shuffled(total_len: u64, run_len: Range) -> Allocator { + let mut runs = Vec::new(); + + let mut b = 0u64; + while b < total_len { + let len = u64::min( + total_len - b, + thread_rng().gen_range(run_len.start, run_len.end), + ); + runs.push(b..(b + len)); + b += len; + } + + runs.shuffle(&mut thread_rng()); + let runs: VecDeque> = runs.iter().map(|r| r.clone()).collect(); + Allocator { runs } + } + + fn is_empty(&self) -> bool { + self.runs.is_empty() + } + + fn alloc(&mut self, len: u64) -> Result>> { + let mut len = len; + let mut runs = Vec::new(); + + while len > 0 { + let r = self.runs.pop_front(); + + if r.is_none() { + return Err(anyhow!("could not allocate; out of space")); + } + + let mut r = r.unwrap(); + let rlen = r.end - r.start; + if len < rlen { + runs.push(r.start..(r.start + len)); + + // We need to push something back. + self.runs.push_front((r.start + len)..r.end); + len = 0; + } else { + runs.push(r.start..r.end); + len -= rlen; + } + } + + Ok(runs) + } +} + +// Having explicitly unmapped regions makes it easier to +// apply snapshots. +#[derive(Clone)] +enum Run { + Mapped { data_begin: u64, len: u64 }, + UnMapped { len: u64 }, +} + +impl Run { + fn len(&self) -> u64 { + match self { + Run::Mapped { + data_begin: _data_begin, + len, + } => *len, + Run::UnMapped { len } => *len, + } + } + + fn split(&self, n: u64) -> (Option, Option) { + if n == 0 { + return (None, Some(self.clone())); + } else { + if self.len() <= n { + return (Some(self.clone()), None); + } else { + match self { + Run::Mapped { data_begin, len } => ( + Some(Run::Mapped { + data_begin: *data_begin, + len: n, + }), + Some(Run::Mapped { + data_begin: data_begin + n, + len: len - n, + }), + ), + Run::UnMapped { len } => ( + Some(Run::UnMapped { len: n }), + Some(Run::UnMapped { len: len - n }), + ), + } + } + } + } +} + +#[derive(Clone)] +struct ThinDev { + thin_id: u32, + dev_size: u64, + runs: Vec, +} + +impl ThinDev { + fn emit(&self, v: &mut dyn xml::MetadataVisitor) -> Result<()> { + v.device_b(&xml::Device { + dev_id: self.thin_id, + mapped_blocks: self.dev_size, + transaction: 0, + creation_time: 0, + snap_time: 0, + })?; + + let mut b = 0; + for r in &self.runs { + match r { + Run::Mapped { data_begin, len } => { + v.map(&xml::Map { + thin_begin: b, + data_begin: *data_begin, + time: 0, + len: *len, + })?; + b += len; + } + Run::UnMapped { len } => { + b += len; + } + } + } + + v.device_e()?; + Ok(()) + } +} + +#[derive(Clone)] +enum SnapRunType { + Same, + Diff, + Hole, +} + +#[derive(Clone)] +struct SnapRun(SnapRunType, u64); + +fn mk_origin(thin_id: u32, total_len: u64, allocator: &mut Allocator) -> Result { + let mut runs = Vec::new(); + let mut b = 0; + while b < total_len { + let len = u64::min(thread_rng().gen_range(16, 64), total_len - b); + match thread_rng().gen_range(0, 2) { + 0 => { + for data in allocator.alloc(len)? { + assert!(data.end >= data.start); + runs.push(Run::Mapped { + data_begin: data.start, + len: data.end - data.start, + }); + } + } + 1 => { + runs.push(Run::UnMapped { len }); + } + _ => { + return Err(anyhow!("bad value returned from rng")); + } + }; + + b += len; + } + + Ok(ThinDev { + thin_id, + dev_size: total_len, + runs, + }) +} + +fn mk_snap_mapping( + total_len: u64, + run_len: Range, + same_percent: usize, + diff_percent: usize, +) -> Vec { + let mut runs = Vec::new(); + + let mut b = 0u64; + while b < total_len { + let len = u64::min( + total_len - b, + thread_rng().gen_range(run_len.start, run_len.end), + ); + + let n = thread_rng().gen_range(0, 100); + + if n < same_percent { + runs.push(SnapRun(SnapRunType::Same, len)); + } else if n < diff_percent { + runs.push(SnapRun(SnapRunType::Diff, len)); + } else { + runs.push(SnapRun(SnapRunType::Hole, len)); + } + + b += len; + } + + runs +} + +fn split_runs(mut n: u64, runs: &Vec) -> (Vec, Vec) { + let mut before = Vec::new(); + let mut after = Vec::new(); + + for r in runs { + match r.split(n) { + (Some(lhs), None) => { + before.push(lhs); + } + (Some(lhs), Some(rhs)) => { + before.push(lhs); + after.push(rhs); + } + (None, Some(rhs)) => { + after.push(rhs); + } + (None, None) => {} + } + n -= r.len(); + } + + (before, after) +} + +fn apply_snap_runs( + origin: &Vec, + snap: &Vec, + allocator: &mut Allocator, +) -> Result> { + let mut origin = origin.clone(); + let mut runs = Vec::new(); + + for SnapRun(st, slen) in snap { + let (os, rest) = split_runs(*slen, &origin); + match st { + SnapRunType::Same => { + for o in os { + runs.push(o); + } + } + SnapRunType::Diff => { + for data in allocator.alloc(*slen)? { + runs.push(Run::Mapped { + data_begin: data.start, + len: data.end - data.start, + }); + } + } + SnapRunType::Hole => { + runs.push(Run::UnMapped { len: *slen }); + } + } + + origin = rest; + } + + Ok(runs) +} + +// Snapshots share mappings, not neccessarily the entire ranges. +struct SnapS { + len: u64, + nr_snaps: u32, + + // Snaps will differ from the origin by this percentage + percent_change: usize, + old_nr_data_blocks: u64, + new_nr_data_blocks: u64, +} + +impl SnapS { + fn new(len: u64, nr_snaps: u32, percent_change: usize) -> Self { + let delta = len * (nr_snaps as u64) * (percent_change as u64) / 100; + let old_nr_data_blocks = len + 3 * delta; + let new_nr_data_blocks = len + 2 * delta; + + SnapS { + len, + nr_snaps, + percent_change, + old_nr_data_blocks, + new_nr_data_blocks, + } + } +} + +impl Scenario for SnapS { + fn generate_xml(&mut self, v: &mut dyn xml::MetadataVisitor) -> Result<()> { + let mut allocator = Allocator::new_shuffled(self.old_nr_data_blocks, 64..512); + let origin = mk_origin(0, self.len, &mut allocator)?; + + v.superblock_b(&common_sb(self.old_nr_data_blocks))?; + origin.emit(v)?; + v.superblock_e()?; + + Ok(()) + } + + fn get_new_nr_blocks(&self) -> u64 { + self.new_nr_data_blocks + } +} + +#[test] +fn shrink_identical_snap() -> Result<()> { + let mut s = SnapS::new(1024, 1, 0); + test_shrink(&mut s) +} + +//------------------------------------