Merge branch 'akpm' (patches from Andrew)

Merge second patch-bomb from Andrew Morton:

 - most of the rest of MM

 - procfs

 - lib/ updates

 - printk updates

 - bitops infrastructure tweaks

 - checkpatch updates

 - nilfs2 update

 - signals

 - various other misc bits: coredump, seqfile, kexec, pidns, zlib, ipc,
   dma-debug, dma-mapping, ...

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (102 commits)
  ipc,msg: drop dst nil validation in copy_msg
  include/linux/zutil.h: fix usage example of zlib_adler32()
  panic: release stale console lock to always get the logbuf printed out
  dma-debug: check nents in dma_sync_sg*
  dma-mapping: tidy up dma_parms default handling
  pidns: fix set/getpriority and ioprio_set/get in PRIO_USER mode
  kexec: use file name as the output message prefix
  fs, seqfile: always allow oom killer
  seq_file: reuse string_escape_str()
  fs/seq_file: use seq_* helpers in seq_hex_dump()
  coredump: change zap_threads() and zap_process() to use for_each_thread()
  coredump: ensure all coredumping tasks have SIGNAL_GROUP_COREDUMP
  signal: remove jffs2_garbage_collect_thread()->allow_signal(SIGCONT)
  signal: introduce kernel_signal_stop() to fix jffs2_garbage_collect_thread()
  signal: turn dequeue_signal_lock() into kernel_dequeue_signal()
  signals: kill block_all_signals() and unblock_all_signals()
  nilfs2: fix gcc uninitialized-variable warnings in powerpc build
  nilfs2: fix gcc unused-but-set-variable warnings
  MAINTAINERS: nilfs2: add header file for tracing
  nilfs2: add tracepoints for analyzing reading and writing metadata files
  ...

1 files changed, 84 insertions, 23 deletions

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index c6abbad9b8e3..3b65adaae7e4 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -77,6 +77,36 @@ enum {
 	NILFS_ST_DONE,
 };
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/nilfs2.h>
+
+/*
+ * nilfs_sc_cstage_inc(), nilfs_sc_cstage_set(), nilfs_sc_cstage_get() are
+ * wrapper functions of stage count (nilfs_sc_info->sc_stage.scnt). Users of
+ * the variable must use them because transition of stage count must involve
+ * trace events (trace_nilfs2_collection_stage_transition).
+ *
+ * nilfs_sc_cstage_get() isn't required for the above purpose because it doesn't
+ * produce tracepoint events. It is provided just for making the intention
+ * clear.
+ */
+static inline void nilfs_sc_cstage_inc(struct nilfs_sc_info *sci)
+{
+	sci->sc_stage.scnt++;
+	trace_nilfs2_collection_stage_transition(sci);
+}
+
+static inline void nilfs_sc_cstage_set(struct nilfs_sc_info *sci, int next_scnt)
+{
+	sci->sc_stage.scnt = next_scnt;
+	trace_nilfs2_collection_stage_transition(sci);
+}
+
+static inline int nilfs_sc_cstage_get(struct nilfs_sc_info *sci)
+{
+	return sci->sc_stage.scnt;
+}
+
 /* State flags of collection */
 #define NILFS_CF_NODE		0x0001	/* Collecting node blocks */
 #define NILFS_CF_IFILE_STARTED	0x0002	/* IFILE stage has started */
@@ -184,11 +214,18 @@ int nilfs_transaction_begin(struct super_block *sb,
 {
 	struct the_nilfs *nilfs;
 	int ret = nilfs_prepare_segment_lock(ti);
+	struct nilfs_transaction_info *trace_ti;
 
 	if (unlikely(ret < 0))
 		return ret;
-	if (ret > 0)
+	if (ret > 0) {
+		trace_ti = current->journal_info;
+
+		trace_nilfs2_transaction_transition(sb, trace_ti,
+				    trace_ti->ti_count, trace_ti->ti_flags,
+				    TRACE_NILFS2_TRANSACTION_BEGIN);
 		return 0;
+	}
 
 	sb_start_intwrite(sb);
 
@@ -199,6 +236,11 @@ int nilfs_transaction_begin(struct super_block *sb,
 		ret = -ENOSPC;
 		goto failed;
 	}
+
+	trace_ti = current->journal_info;
+	trace_nilfs2_transaction_transition(sb, trace_ti, trace_ti->ti_count,
+					    trace_ti->ti_flags,
+					    TRACE_NILFS2_TRANSACTION_BEGIN);
 	return 0;
 
  failed:
@@ -231,6 +273,8 @@ int nilfs_transaction_commit(struct super_block *sb)
 	ti->ti_flags |= NILFS_TI_COMMIT;
 	if (ti->ti_count > 0) {
 		ti->ti_count--;
+		trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
+			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_COMMIT);
 		return 0;
 	}
 	if (nilfs->ns_writer) {
@@ -242,6 +286,9 @@ int nilfs_transaction_commit(struct super_block *sb)
 			nilfs_segctor_do_flush(sci, 0);
 	}
 	up_read(&nilfs->ns_segctor_sem);
+	trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
+			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_COMMIT);
+
 	current->journal_info = ti->ti_save;
 
 	if (ti->ti_flags & NILFS_TI_SYNC)
@@ -260,10 +307,15 @@ void nilfs_transaction_abort(struct super_block *sb)
 	BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
 	if (ti->ti_count > 0) {
 		ti->ti_count--;
+		trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
+			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_ABORT);
 		return;
 	}
 	up_read(&nilfs->ns_segctor_sem);
 
+	trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
+		    ti->ti_flags, TRACE_NILFS2_TRANSACTION_ABORT);
+
 	current->journal_info = ti->ti_save;
 	if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
 		kmem_cache_free(nilfs_transaction_cachep, ti);
@@ -309,6 +361,9 @@ static void nilfs_transaction_lock(struct super_block *sb,
 	current->journal_info = ti;
 
 	for (;;) {
+		trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
+			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_TRYLOCK);
+
 		down_write(&nilfs->ns_segctor_sem);
 		if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags))
 			break;
@@ -320,6 +375,9 @@ static void nilfs_transaction_lock(struct super_block *sb,
 	}
 	if (gcflag)
 		ti->ti_flags |= NILFS_TI_GC;
+
+	trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
+			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_LOCK);
 }
 
 static void nilfs_transaction_unlock(struct super_block *sb)
@@ -332,6 +390,9 @@ static void nilfs_transaction_unlock(struct super_block *sb)
 
 	up_write(&nilfs->ns_segctor_sem);
 	current->journal_info = ti->ti_save;
+
+	trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
+			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_UNLOCK);
 }
 
 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
@@ -1062,7 +1123,7 @@ static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
 	size_t ndone;
 	int err = 0;
 
-	switch (sci->sc_stage.scnt) {
+	switch (nilfs_sc_cstage_get(sci)) {
 	case NILFS_ST_INIT:
 		/* Pre-processes */
 		sci->sc_stage.flags = 0;
@@ -1071,7 +1132,7 @@ static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
 			sci->sc_nblk_inc = 0;
 			sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
 			if (mode == SC_LSEG_DSYNC) {
-				sci->sc_stage.scnt = NILFS_ST_DSYNC;
+				nilfs_sc_cstage_set(sci, NILFS_ST_DSYNC);
 				goto dsync_mode;
 			}
 		}
@@ -1079,10 +1140,10 @@ static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
 		sci->sc_stage.dirty_file_ptr = NULL;
 		sci->sc_stage.gc_inode_ptr = NULL;
 		if (mode == SC_FLUSH_DAT) {
-			sci->sc_stage.scnt = NILFS_ST_DAT;
+			nilfs_sc_cstage_set(sci, NILFS_ST_DAT);
 			goto dat_stage;
 		}
-		sci->sc_stage.scnt++;  /* Fall through */
+		nilfs_sc_cstage_inc(sci);  /* Fall through */
 	case NILFS_ST_GC:
 		if (nilfs_doing_gc()) {
 			head = &sci->sc_gc_inodes;
@@ -1103,7 +1164,7 @@ static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
 			}
 			sci->sc_stage.gc_inode_ptr = NULL;
 		}
-		sci->sc_stage.scnt++;  /* Fall through */
+		nilfs_sc_cstage_inc(sci);  /* Fall through */
 	case NILFS_ST_FILE:
 		head = &sci->sc_dirty_files;
 		ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
@@ -1125,10 +1186,10 @@ static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
 		}
 		sci->sc_stage.dirty_file_ptr = NULL;
 		if (mode == SC_FLUSH_FILE) {
-			sci->sc_stage.scnt = NILFS_ST_DONE;
+			nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
 			return 0;
 		}
-		sci->sc_stage.scnt++;
+		nilfs_sc_cstage_inc(sci);
 		sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
 		/* Fall through */
 	case NILFS_ST_IFILE:
@@ -1136,7 +1197,7 @@ static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
 					      &nilfs_sc_file_ops);
 		if (unlikely(err))
 			break;
-		sci->sc_stage.scnt++;
+		nilfs_sc_cstage_inc(sci);
 		/* Creating a checkpoint */
 		err = nilfs_segctor_create_checkpoint(sci);
 		if (unlikely(err))
@@ -1147,7 +1208,7 @@ static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
 					      &nilfs_sc_file_ops);
 		if (unlikely(err))
 			break;
-		sci->sc_stage.scnt++;  /* Fall through */
+		nilfs_sc_cstage_inc(sci);  /* Fall through */
 	case NILFS_ST_SUFILE:
 		err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
 					 sci->sc_nfreesegs, &ndone);
@@ -1163,7 +1224,7 @@ static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
 					      &nilfs_sc_file_ops);
 		if (unlikely(err))
 			break;
-		sci->sc_stage.scnt++;  /* Fall through */
+		nilfs_sc_cstage_inc(sci);  /* Fall through */
 	case NILFS_ST_DAT:
  dat_stage:
 		err = nilfs_segctor_scan_file(sci, nilfs->ns_dat,
@@ -1171,10 +1232,10 @@ static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
 		if (unlikely(err))
 			break;
 		if (mode == SC_FLUSH_DAT) {
-			sci->sc_stage.scnt = NILFS_ST_DONE;
+			nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
 			return 0;
 		}
-		sci->sc_stage.scnt++;  /* Fall through */
+		nilfs_sc_cstage_inc(sci);  /* Fall through */
 	case NILFS_ST_SR:
 		if (mode == SC_LSEG_SR) {
 			/* Appending a super root */
@@ -1184,7 +1245,7 @@ static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
 		}
 		/* End of a logical segment */
 		sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
-		sci->sc_stage.scnt = NILFS_ST_DONE;
+		nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
 		return 0;
 	case NILFS_ST_DSYNC:
  dsync_mode:
@@ -1197,7 +1258,7 @@ static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
 		if (unlikely(err))
 			break;
 		sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
-		sci->sc_stage.scnt = NILFS_ST_DONE;
+		nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
 		return 0;
 	case NILFS_ST_DONE:
 		return 0;
@@ -1442,7 +1503,8 @@ static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
 			goto failed;
 
 		/* The current segment is filled up */
-		if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
+		if (mode != SC_LSEG_SR ||
+		    nilfs_sc_cstage_get(sci) < NILFS_ST_CPFILE)
 			break;
 
 		nilfs_clear_logs(&sci->sc_segbufs);
@@ -1946,7 +2008,7 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
 	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 	int err;
 
-	sci->sc_stage.scnt = NILFS_ST_INIT;
+	nilfs_sc_cstage_set(sci, NILFS_ST_INIT);
 	sci->sc_cno = nilfs->ns_cno;
 
 	err = nilfs_segctor_collect_dirty_files(sci, nilfs);
@@ -1974,7 +2036,7 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
 			goto failed;
 
 		/* Avoid empty segment */
-		if (sci->sc_stage.scnt == NILFS_ST_DONE &&
+		if (nilfs_sc_cstage_get(sci) == NILFS_ST_DONE &&
 		    nilfs_segbuf_empty(sci->sc_curseg)) {
 			nilfs_segctor_abort_construction(sci, nilfs, 1);
 			goto out;
@@ -1988,7 +2050,7 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
 			nilfs_segctor_fill_in_file_bmap(sci);
 
 		if (mode == SC_LSEG_SR &&
-		    sci->sc_stage.scnt >= NILFS_ST_CPFILE) {
+		    nilfs_sc_cstage_get(sci) >= NILFS_ST_CPFILE) {
 			err = nilfs_segctor_fill_in_checkpoint(sci);
 			if (unlikely(err))
 				goto failed_to_write;
@@ -2007,7 +2069,7 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
 		if (unlikely(err))
 			goto failed_to_write;
 
-		if (sci->sc_stage.scnt == NILFS_ST_DONE ||
+		if (nilfs_sc_cstage_get(sci) == NILFS_ST_DONE ||
 		    nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) {
 			/*
 			 * At this point, we avoid double buffering
@@ -2020,7 +2082,7 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
 			if (err)
 				goto failed_to_write;
 		}
-	} while (sci->sc_stage.scnt != NILFS_ST_DONE);
+	} while (nilfs_sc_cstage_get(sci) != NILFS_ST_DONE);
 
  out:
 	nilfs_segctor_drop_written_files(sci, nilfs);
@@ -2430,7 +2492,6 @@ static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
 {
 	int mode = 0;
-	int err;
 
 	spin_lock(&sci->sc_state_lock);
 	mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
@@ -2438,7 +2499,7 @@ static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
 	spin_unlock(&sci->sc_state_lock);
 
 	if (mode) {
-		err = nilfs_segctor_do_construct(sci, mode);
+		nilfs_segctor_do_construct(sci, mode);
 
 		spin_lock(&sci->sc_state_lock);
 		sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?