[RFCv1 29/72] e2fsck: add start/end group for thread

["Ritesh Harjani (IBM)" <ritesh.list@gmail.com>]

From: Li Xi <lixi@ddn.com>

When multi-threads are used for check, each thread needs to jump
to different group in pass1 check. This patch adds the group
jumping support. But still, only one thread is used to check.

Signed-off-by: Li Xi <lixi@ddn.com>
Signed-off-by: Wang Shilong <wshilong@ddn.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
---
 e2fsck/e2fsck.h           | 23 ++++++++++++++++++--
 e2fsck/logfile.c          |  3 ++-
 e2fsck/pass1.c            | 44 ++++++++++++++++++++++++++++++++++++---
 e2fsck/problem.c          |  5 +++++
 e2fsck/problem.h          |  3 +++
 lib/ext2fs/ext2_err.et.in |  3 +++
 6 files changed, 75 insertions(+), 6 deletions(-)

diff --git a/e2fsck/e2fsck.h b/e2fsck/e2fsck.h
index 5bc24c3f..639f4e80 100644
--- a/e2fsck/e2fsck.h
+++ b/e2fsck/e2fsck.h
@@ -261,6 +261,22 @@ struct e2fsck_fc_replay_state {
 	__u16 fc_super_state;
 };
 
+#ifdef HAVE_PTHREAD
+/*
+ * Fields that used for multi-thread
+ */
+struct e2fsck_thread {
+	/* Thread index */
+	int		et_thread_index;
+	/* The start group number for this thread */
+	dgrp_t		et_group_start;
+	/* The end (not included) group number for this thread*/
+	dgrp_t		et_group_end;
+	/* The next group number to check */
+	dgrp_t		et_group_next;
+};
+#endif
+
 struct e2fsck_struct {
 	/* Global context to get the cancel flag */
 	e2fsck_t global_ctx;
@@ -344,8 +360,11 @@ struct e2fsck_struct {
 	 */
 	ext2_ino_t		stashed_ino;
 	struct ext2_inode	*stashed_inode;
-	/* Thread index, if global_ctx is null, this field is unused */
-	int			thread_index;
+
+	/* if @global_ctx is null, this field is unused */
+#ifdef HAVE_PTHREAD
+	struct e2fsck_thread	 thread_info;
+#endif
 
 	/*
 	 * Location of the lost and found directory
diff --git a/e2fsck/logfile.c b/e2fsck/logfile.c
index 74781f80..cc811d5a 100644
--- a/e2fsck/logfile.c
+++ b/e2fsck/logfile.c
@@ -315,7 +315,8 @@ static FILE *set_up_log_file(e2fsck_t ctx, const char *key, const char *fn)
 	expand_logfn(ctx, log_fn, &s);
 #ifdef HAVE_PTHREAD
 	if (ctx->global_ctx) {
-		sprintf(string_index, "%d", ctx->thread_index);
+		sprintf(string_index, "%d",
+			ctx->thread_info.et_thread_index);
 		append_string(&s, ".", 1);
 		append_string(&s, string_index, 0);
 	}
diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index ea432ff2..3bb87669 100644
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -1389,6 +1389,23 @@ void e2fsck_pass1_run(e2fsck_t ctx)
 	/* Set up ctx->lost_and_found if possible */
 	(void) e2fsck_get_lost_and_found(ctx, 0);
 
+#ifdef HAVE_PTHREAD
+	if (ctx->global_ctx) {
+		if (ctx->options & E2F_OPT_DEBUG &&
+		    ctx->options & E2F_OPT_MULTITHREAD)
+			fprintf(stderr, "thread %d jumping to group %d\n",
+					ctx->thread_info.et_thread_index,
+					ctx->thread_info.et_group_start);
+		pctx.errcode = ext2fs_inode_scan_goto_blockgroup(scan,
+					ctx->thread_info.et_group_start);
+		if (pctx.errcode) {
+			fix_problem(ctx, PR_1_PASS_HEADER, &pctx);
+			ctx->flags |= E2F_FLAG_ABORT;
+			goto endit;
+		}
+	}
+#endif
+
 	while (1) {
 		if (ino % (fs->super->s_inodes_per_group * 4) == 1) {
 			if (e2fsck_mmp_update(fs))
@@ -1432,6 +1449,8 @@ void e2fsck_pass1_run(e2fsck_t ctx)
 			ext2fs_mark_inode_bitmap2(ctx->inode_used_map, ino);
 			continue;
 		}
+		if (pctx.errcode == EXT2_ET_SCAN_FINISHED)
+			break;
 		if (pctx.errcode &&
 		    pctx.errcode != EXT2_ET_INODE_CSUM_INVALID &&
 		    pctx.errcode != EXT2_ET_INODE_IS_GARBAGE) {
@@ -2211,12 +2230,14 @@ static errcode_t e2fsck_open_channel_fs(ext2_filsys dest, e2fsck_t dest_context,
 	return 0;
 }
 
-static errcode_t e2fsck_pass1_thread_prepare(e2fsck_t global_ctx, e2fsck_t *thread_ctx)
+static errcode_t e2fsck_pass1_thread_prepare(e2fsck_t global_ctx, e2fsck_t *thread_ctx,
+					     int thread_index)
 {
 	errcode_t retval;
 	e2fsck_t thread_context;
 	ext2_filsys thread_fs;
 	ext2_filsys global_fs = global_ctx->fs;
+	struct e2fsck_thread *tinfo;
 
 	assert(global_ctx->inode_used_map == NULL);
 	assert(global_ctx->inode_dir_map == NULL);
@@ -2252,8 +2273,15 @@ static errcode_t e2fsck_pass1_thread_prepare(e2fsck_t global_ctx, e2fsck_t *thre
 		goto out_fs;
 	}
 
-	thread_context->thread_index = 0;
+	thread_context->thread_info.et_thread_index = thread_index;
 	set_up_logging(thread_context);
+
+	assert(thread_index == 0);
+	tinfo = &thread_context->thread_info;
+	tinfo->et_group_start = 0;
+	tinfo->et_group_next = 0;
+	tinfo->et_group_end = thread_fs->group_desc_count;
+
 	*thread_ctx = thread_context;
 	return 0;
 out_fs:
@@ -2495,7 +2523,7 @@ static int e2fsck_pass1_threads_start(struct e2fsck_thread_info **pinfo,
 	for (i = 0; i < num_threads; i++) {
 		tmp_pinfo = &infos[i];
 		tmp_pinfo->eti_thread_index = i;
-		retval = e2fsck_pass1_thread_prepare(global_ctx, &thread_ctx);
+		retval = e2fsck_pass1_thread_prepare(global_ctx, &thread_ctx, i);
 		if (retval) {
 			com_err(global_ctx->program_name, retval,
 				_("while preparing pass1 thread\n"));
@@ -2580,6 +2608,7 @@ static errcode_t scan_callback(ext2_filsys fs,
 {
 	struct scan_callback_struct *scan_struct;
 	e2fsck_t ctx;
+	struct e2fsck_thread *tinfo;
 
 	scan_struct = (struct scan_callback_struct *) priv_data;
 	ctx = scan_struct->ctx;
@@ -2591,6 +2620,15 @@ static errcode_t scan_callback(ext2_filsys fs,
 				    ctx->fs->group_desc_count))
 			return EXT2_ET_CANCEL_REQUESTED;
 
+#ifdef HAVE_PTHREAD
+	if (ctx->global_ctx) {
+		tinfo = &ctx->thread_info;
+		tinfo->et_group_next++;
+		if (tinfo->et_group_next >= tinfo->et_group_end)
+			return EXT2_ET_SCAN_FINISHED;
+	}
+#endif
+
 	return 0;
 }
 
diff --git a/e2fsck/problem.c b/e2fsck/problem.c
index 6ad6fb84..d5452441 100644
--- a/e2fsck/problem.c
+++ b/e2fsck/problem.c
@@ -1309,6 +1309,11 @@ static struct e2fsck_problem problem_table[] = {
 	  N_("Orphan file @i %i is not in use, but contains data.  "),
 	  PROMPT_CLEAR, PR_PREEN_OK },
 
+	/* Failed to goto block group */
+	{ PR_1_SCAN_GOTO,
+	  N_("failed to goto block group"),
+          PROMPT_NONE, PR_FATAL, 0, 0, 0 },
+
 	/* Pass 1b errors */
 
 	/* Pass 1B: Rescan for duplicate/bad blocks */
diff --git a/e2fsck/problem.h b/e2fsck/problem.h
index b47b0c63..a6207428 100644
--- a/e2fsck/problem.h
+++ b/e2fsck/problem.h
@@ -734,6 +734,9 @@ struct problem_context {
 /* Orphan file inode is not in use, but contains data */
 #define PR_1_ORPHAN_FILE_NOT_CLEAR		0x010090
 
+/* Failed to goto block group */
+#define PR_1_SCAN_GOTO				0x0100A0
+
 /*
  * Pass 1b errors
  */
diff --git a/lib/ext2fs/ext2_err.et.in b/lib/ext2fs/ext2_err.et.in
index de140198..b8f45ae2 100644
--- a/lib/ext2fs/ext2_err.et.in
+++ b/lib/ext2fs/ext2_err.et.in
@@ -557,4 +557,7 @@ ec	EXT2_ET_EXTENT_CYCLE,
 ec	EXT2_ET_EXTERNAL_JOURNAL_NOSUPP,
 	"Operation not supported on an external journal"
 
+ec	EXT2_ET_SCAN_FINISHED,
+	"Scanning finished"
+
 	end
-- 
2.37.3