[RFCv1,21/72] e2fsck: add -m option for multithread

diff --git a/e2fsck/e2fsck.h b/e2fsck/e2fsck.h
index 252a17db..35428717 100644
--- a/e2fsck/e2fsck.h
+++ b/e2fsck/e2fsck.h
@@ -186,6 +186,7 @@  struct resource_track {
 #define E2F_OPT_UNSHARE_BLOCKS  0x40000
 #define E2F_OPT_CLEAR_UNINIT	0x80000 /* Hack to clear the uninit bit */
 #define E2F_OPT_CHECK_ENCODING  0x100000 /* Force verification of encoded filenames */
+#define E2F_OPT_MULTITHREAD	0x200000 /* Use multiple threads to speedup */
 
 /*
  * E2fsck flags
diff --git a/e2fsck/unix.c b/e2fsck/unix.c
index e5b672a2..1ee27f6a 100644
--- a/e2fsck/unix.c
+++ b/e2fsck/unix.c
@@ -76,13 +76,14 @@  int journal_enable_debug = -1;
 static void usage(e2fsck_t ctx)
 {
 	fprintf(stderr,
-		_("Usage: %s [-panyrcdfktvDFV] [-b superblock] [-B blocksize]\n"
+		_("Usage: %s [-pamnyrcdfktvDFV] [-b superblock] [-B blocksize]\n"
 		"\t\t[-l|-L bad_blocks_file] [-C fd] [-j external_journal]\n"
 		"\t\t[-E extended-options] [-z undo_file] device\n"),
 		ctx->program_name ? ctx->program_name : "e2fsck");
 
 	fprintf(stderr, "%s", _("\nEmergency help:\n"
 		" -p                   Automatic repair (no questions)\n"
+		" -m                   multiple threads to speedup fsck\n"
 		" -n                   Make no changes to the filesystem\n"
 		" -y                   Assume \"yes\" to all questions\n"
 		" -c                   Check for bad blocks and add them to the badblock list\n"
@@ -854,7 +855,8 @@  static errcode_t PRS(int argc, char *argv[], e2fsck_t *ret_ctx)
 
 	phys_mem_kb = get_memory_size() / 1024;
 	ctx->readahead_kb = ~0ULL;
-	while ((c = getopt(argc, argv, "panyrcC:B:dE:fvtFVM:b:I:j:P:l:L:N:SsDkz:")) != EOF)
+
+	while ((c = getopt(argc, argv, "pamnyrcC:B:dE:fvtFVM:b:I:j:P:l:L:N:SsDkz:")) != EOF)
 		switch (c) {
 		case 'C':
 			ctx->progress = e2fsck_update_progress;
@@ -895,6 +897,9 @@  static errcode_t PRS(int argc, char *argv[], e2fsck_t *ret_ctx)
 			}
 			ctx->options |= E2F_OPT_PREEN;
 			break;
+		case 'm':
+			ctx->options |= E2F_OPT_MULTITHREAD;
+			break;
 		case 'n':
 			if (ctx->options & (E2F_OPT_YES|E2F_OPT_PREEN))
 				goto conflict_opt;
@@ -1014,6 +1019,18 @@  static errcode_t PRS(int argc, char *argv[], e2fsck_t *ret_ctx)
 			_("The -n and -l/-L options are incompatible."));
 		fatal_error(ctx, 0);
 	}
+	if (ctx->options & E2F_OPT_MULTITHREAD) {
+		if ((ctx->options & (E2F_OPT_YES|E2F_OPT_NO|E2F_OPT_PREEN)) == 0) {
+			com_err(ctx->program_name, 0, "%s",
+				_("The -m option should be used together with one of -p/-y/-n options."));
+			fatal_error(ctx, 0);
+		}
+		if (ctx->progress) {
+			com_err(ctx->program_name, 0, "%s",
+				_("Only one of the options -C or -m may be specified."));
+			fatal_error(ctx, 0);
+		}
+	}
 	if (ctx->options & E2F_OPT_NO)
 		ctx->options |= E2F_OPT_READONLY;
 
@@ -1120,10 +1137,12 @@  static errcode_t PRS(int argc, char *argv[], e2fsck_t *ret_ctx)
 #ifdef SA_RESTART
 	sa.sa_flags = SA_RESTART;
 #endif
-	sa.sa_handler = signal_progress_on;
-	sigaction(SIGUSR1, &sa, 0);
-	sa.sa_handler = signal_progress_off;
-	sigaction(SIGUSR2, &sa, 0);
+	if ((ctx->options & E2F_OPT_MULTITHREAD) == 0) {
+		sa.sa_handler = signal_progress_on;
+		sigaction(SIGUSR1, &sa, 0);
+		sa.sa_handler = signal_progress_off;
+		sigaction(SIGUSR2, &sa, 0);
+	}
 #endif
 
 	/* Update our PATH to include /sbin if we need to run badblocks  */
diff --git a/tests/f_multithread/expect.1 b/tests/f_multithread/expect.1
new file mode 100644
index 00000000..e2b954d0
--- /dev/null
+++ b/tests/f_multithread/expect.1
@@ -0,0 +1,23 @@ 
+ext2fs_open2: Bad magic number in super-block
+../e2fsck/e2fsck: Superblock invalid, trying backup blocks...
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+Free blocks count wrong for group #0 (7987, counted=7982).
+Fix? yes
+
+Free blocks count wrong (11602, counted=11597).
+Fix? yes
+
+Free inodes count wrong for group #0 (1493, counted=1488).
+Fix? yes
+
+Free inodes count wrong (2997, counted=2992).
+Fix? yes
+
+
+test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
+test_filesys: 16/3008 files (0.0% non-contiguous), 403/12000 blocks
+Exit status is 1
diff --git a/tests/f_multithread/expect.2 b/tests/f_multithread/expect.2
new file mode 100644
index 00000000..a833aefc
--- /dev/null
+++ b/tests/f_multithread/expect.2
@@ -0,0 +1,7 @@ 
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+test_filesys: 16/3008 files (0.0% non-contiguous), 403/12000 blocks
+Exit status is 0
diff --git a/tests/f_multithread/image.gz b/tests/f_multithread/image.gz
new file mode 120000
index 00000000..0fd40018
--- /dev/null
+++ b/tests/f_multithread/image.gz
@@ -0,0 +1 @@ 
+../f_zero_super/image.gz
\ No newline at end of file
diff --git a/tests/f_multithread/name b/tests/f_multithread/name
new file mode 100644
index 00000000..df838ea6
--- /dev/null
+++ b/tests/f_multithread/name
@@ -0,0 +1 @@ 
+test "e2fsck -m" option
\ No newline at end of file
diff --git a/tests/f_multithread/script b/tests/f_multithread/script
new file mode 100644
index 00000000..0fe96cd0
--- /dev/null
+++ b/tests/f_multithread/script
@@ -0,0 +1,4 @@ 
+FSCK_OPT="-fy -m"
+SECOND_FSCK_OPT=-yf
+
+. $cmd_dir/run_e2fsck
diff --git a/tests/f_multithread_completion/expect.1 b/tests/f_multithread_completion/expect.1
new file mode 100644
index 00000000..61cac9bb
--- /dev/null
+++ b/tests/f_multithread_completion/expect.1
@@ -0,0 +1,2 @@ 
+../e2fsck/e2fsck: Only one of the options -C or -m may be specified.
+Exit status is 8
diff --git a/tests/f_multithread_completion/expect.2 b/tests/f_multithread_completion/expect.2
new file mode 100644
index 00000000..e2b954d0
--- /dev/null
+++ b/tests/f_multithread_completion/expect.2
@@ -0,0 +1,23 @@ 
+ext2fs_open2: Bad magic number in super-block
+../e2fsck/e2fsck: Superblock invalid, trying backup blocks...
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+Free blocks count wrong for group #0 (7987, counted=7982).
+Fix? yes
+
+Free blocks count wrong (11602, counted=11597).
+Fix? yes
+
+Free inodes count wrong for group #0 (1493, counted=1488).
+Fix? yes
+
+Free inodes count wrong (2997, counted=2992).
+Fix? yes
+
+
+test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
+test_filesys: 16/3008 files (0.0% non-contiguous), 403/12000 blocks
+Exit status is 1
diff --git a/tests/f_multithread_completion/image.gz b/tests/f_multithread_completion/image.gz
new file mode 120000
index 00000000..0fd40018
--- /dev/null
+++ b/tests/f_multithread_completion/image.gz
@@ -0,0 +1 @@ 
+../f_zero_super/image.gz
\ No newline at end of file
diff --git a/tests/f_multithread_completion/name b/tests/f_multithread_completion/name
new file mode 100644
index 00000000..a959045d
--- /dev/null
+++ b/tests/f_multithread_completion/name
@@ -0,0 +1 @@ 
+test "e2fsck -m" option conflicts with "-C"
\ No newline at end of file
diff --git a/tests/f_multithread_completion/script b/tests/f_multithread_completion/script
new file mode 100644
index 00000000..bf23cd61
--- /dev/null
+++ b/tests/f_multithread_completion/script
@@ -0,0 +1,4 @@ 
+FSCK_OPT="-fy -m -C 1"
+SECOND_FSCK_OPT=-yf
+
+. $cmd_dir/run_e2fsck
diff --git a/tests/f_multithread_no/expect.1 b/tests/f_multithread_no/expect.1
new file mode 100644
index 00000000..d14c4083
--- /dev/null
+++ b/tests/f_multithread_no/expect.1
@@ -0,0 +1,24 @@ 
+ext2fs_open2: Bad magic number in super-block
+../e2fsck/e2fsck: Superblock invalid, trying backup blocks...
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+Free blocks count wrong for group #0 (7987, counted=7982).
+Fix? no
+
+Free blocks count wrong (11602, counted=11597).
+Fix? no
+
+Free inodes count wrong for group #0 (1493, counted=1488).
+Fix? no
+
+Free inodes count wrong (2997, counted=2992).
+Fix? no
+
+
+test_filesys: ********** WARNING: Filesystem still has errors **********
+
+test_filesys: 11/3008 files (0.0% non-contiguous), 398/12000 blocks
+Exit status is 4
diff --git a/tests/f_multithread_no/expect.2 b/tests/f_multithread_no/expect.2
new file mode 100644
index 00000000..e2b954d0
--- /dev/null
+++ b/tests/f_multithread_no/expect.2
@@ -0,0 +1,23 @@ 
+ext2fs_open2: Bad magic number in super-block
+../e2fsck/e2fsck: Superblock invalid, trying backup blocks...
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+Free blocks count wrong for group #0 (7987, counted=7982).
+Fix? yes
+
+Free blocks count wrong (11602, counted=11597).
+Fix? yes
+
+Free inodes count wrong for group #0 (1493, counted=1488).
+Fix? yes
+
+Free inodes count wrong (2997, counted=2992).
+Fix? yes
+
+
+test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
+test_filesys: 16/3008 files (0.0% non-contiguous), 403/12000 blocks
+Exit status is 1
diff --git a/tests/f_multithread_no/image.gz b/tests/f_multithread_no/image.gz
new file mode 120000
index 00000000..0fd40018
--- /dev/null
+++ b/tests/f_multithread_no/image.gz
@@ -0,0 +1 @@ 
+../f_zero_super/image.gz
\ No newline at end of file
diff --git a/tests/f_multithread_no/name b/tests/f_multithread_no/name
new file mode 100644
index 00000000..fa49692e
--- /dev/null
+++ b/tests/f_multithread_no/name
@@ -0,0 +1 @@ 
+test "e2fsck -m" option works with "-n"
\ No newline at end of file
diff --git a/tests/f_multithread_no/script b/tests/f_multithread_no/script
new file mode 100644
index 00000000..b93deb3a
--- /dev/null
+++ b/tests/f_multithread_no/script
@@ -0,0 +1,4 @@ 
+FSCK_OPT="-fn -m"
+SECOND_FSCK_OPT=-yf
+
+. $cmd_dir/run_e2fsck
diff --git a/tests/f_multithread_preen/expect.1 b/tests/f_multithread_preen/expect.1
new file mode 100644
index 00000000..b4b0cd9a
--- /dev/null
+++ b/tests/f_multithread_preen/expect.1
@@ -0,0 +1,11 @@ 
+../e2fsck/e2fsck: Bad magic number in super-block while trying to open test.img
+test_filesys: 
+The superblock could not be read or does not describe a valid ext2/ext3/ext4
+filesystem.  If the device is valid and it really contains an ext2/ext3/ext4
+filesystem (and not swap or ufs or something else), then the superblock
+is corrupt, and you might try running e2fsck with an alternate superblock:
+    e2fsck -b 8193 <device>
+ or
+    e2fsck -b 32768 <device>
+
+Exit status is 8
diff --git a/tests/f_multithread_preen/expect.2 b/tests/f_multithread_preen/expect.2
new file mode 100644
index 00000000..e2b954d0
--- /dev/null
+++ b/tests/f_multithread_preen/expect.2
@@ -0,0 +1,23 @@ 
+ext2fs_open2: Bad magic number in super-block
+../e2fsck/e2fsck: Superblock invalid, trying backup blocks...
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+Free blocks count wrong for group #0 (7987, counted=7982).
+Fix? yes
+
+Free blocks count wrong (11602, counted=11597).
+Fix? yes
+
+Free inodes count wrong for group #0 (1493, counted=1488).
+Fix? yes
+
+Free inodes count wrong (2997, counted=2992).
+Fix? yes
+
+
+test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
+test_filesys: 16/3008 files (0.0% non-contiguous), 403/12000 blocks
+Exit status is 1
diff --git a/tests/f_multithread_preen/image.gz b/tests/f_multithread_preen/image.gz
new file mode 120000
index 00000000..0fd40018
--- /dev/null
+++ b/tests/f_multithread_preen/image.gz
@@ -0,0 +1 @@ 
+../f_zero_super/image.gz
\ No newline at end of file
diff --git a/tests/f_multithread_preen/name b/tests/f_multithread_preen/name
new file mode 100644
index 00000000..90d199df
--- /dev/null
+++ b/tests/f_multithread_preen/name
@@ -0,0 +1 @@ 
+test "e2fsck -m" option works with "-p"
\ No newline at end of file
diff --git a/tests/f_multithread_preen/script b/tests/f_multithread_preen/script
new file mode 100644
index 00000000..ecb79cd6
--- /dev/null
+++ b/tests/f_multithread_preen/script
@@ -0,0 +1,4 @@ 
+FSCK_OPT="-fp -m"
+SECOND_FSCK_OPT=-yf
+
+. $cmd_dir/run_e2fsck
diff --git a/tests/f_multithread_yes/expect.1 b/tests/f_multithread_yes/expect.1
new file mode 100644
index 00000000..8b780ecf
--- /dev/null
+++ b/tests/f_multithread_yes/expect.1
@@ -0,0 +1,2 @@ 
+../e2fsck/e2fsck: The -m option should be used together with one of -p/-y/-n options.
+Exit status is 8
diff --git a/tests/f_multithread_yes/expect.2 b/tests/f_multithread_yes/expect.2
new file mode 100644
index 00000000..e2b954d0
--- /dev/null
+++ b/tests/f_multithread_yes/expect.2
@@ -0,0 +1,23 @@ 
+ext2fs_open2: Bad magic number in super-block
+../e2fsck/e2fsck: Superblock invalid, trying backup blocks...
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+Free blocks count wrong for group #0 (7987, counted=7982).
+Fix? yes
+
+Free blocks count wrong (11602, counted=11597).
+Fix? yes
+
+Free inodes count wrong for group #0 (1493, counted=1488).
+Fix? yes
+
+Free inodes count wrong (2997, counted=2992).
+Fix? yes
+
+
+test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
+test_filesys: 16/3008 files (0.0% non-contiguous), 403/12000 blocks
+Exit status is 1
diff --git a/tests/f_multithread_yes/image.gz b/tests/f_multithread_yes/image.gz
new file mode 120000
index 00000000..0fd40018
--- /dev/null
+++ b/tests/f_multithread_yes/image.gz
@@ -0,0 +1 @@ 
+../f_zero_super/image.gz
\ No newline at end of file
diff --git a/tests/f_multithread_yes/name b/tests/f_multithread_yes/name
new file mode 100644
index 00000000..3a703195
--- /dev/null
+++ b/tests/f_multithread_yes/name
@@ -0,0 +1 @@ 
+test "e2fsck -m" option works with "-y"
\ No newline at end of file
diff --git a/tests/f_multithread_yes/script b/tests/f_multithread_yes/script
new file mode 100644
index 00000000..38891f6a
--- /dev/null
+++ b/tests/f_multithread_yes/script
@@ -0,0 +1,4 @@ 
+FSCK_OPT="-f -m"
+SECOND_FSCK_OPT=-yf
+
+. $cmd_dir/run_e2fsck