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GFS2: Log the reason for log flushes in every log header

PATCH New Bob Peterson 3 participants 7 messages Dec 1, 2017 – Dec 11, 2017 1 message not in the archive GFS2 file system

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Bob Peterson

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#1 lore raw

PATCH 1/1 GFS2: Log the reason for log flushes in every log header

Hi,

This patch just adds the capability for GFS2 to track which function called gfs2_log_flush. This should make it easier to diagnose problems based on the sequence of events found in the journals.

Signed-off-by Bob Peterson <[email protected]>
---
 fs/gfs2/aops.c       |  2 +-
 fs/gfs2/file.c       |  3 ++-
 fs/gfs2/glops.c      | 13 +++++++------
 fs/gfs2/incore.h     | 22 ++++++++++++++++++++++
 fs/gfs2/log.c        | 19 +++++++++++--------
 fs/gfs2/log.h        |  3 ++-
 fs/gfs2/ops_fstype.c |  2 +-
 fs/gfs2/quota.c      |  3 ++-
 fs/gfs2/rgrp.c       |  3 ++-
 fs/gfs2/super.c      |  9 +++++----
 fs/gfs2/trans.c      |  2 +-
 11 files changed, 56 insertions(+), 25 deletions(-)
fs/gfs2/aops.c +1 -1
index 658ca027cab9..10fa52321a73 100644
@@ -445,7 +445,7 @@ static int gfs2_jdata_writepages(struct address_space *mapping,
 
 	ret = gfs2_write_cache_jdata(mapping, wbc);
 	if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
-		gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH);
+		gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH, LGF_JDATA_WPAGES);
 		ret = gfs2_write_cache_jdata(mapping, wbc);
 	}
 	return ret;
fs/gfs2/file.c +2 -1
index 58705ef8643a..e180df15e107 100644
@@ -246,7 +246,8 @@ static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
 	}
 	if ((flags ^ new_flags) & GFS2_DIF_JDATA) {
 		if (new_flags & GFS2_DIF_JDATA)
-			gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH);
+			gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH,
+				       LGF_SET_FLAGS);
 		error = filemap_fdatawrite(inode->i_mapping);
 		if (error)
 			goto out;
fs/gfs2/glops.c +7 -6
index cdd1c5f06f45..f661fbec259c 100644
@@ -107,7 +107,7 @@ static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
 	__gfs2_ail_flush(gl, 0, tr.tr_revokes);
 
 	gfs2_trans_end(sdp);
-	gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
+	gfs2_log_flush(sdp, NULL, NORMAL_FLUSH, LGF_AIL_EMPTY_GL);
 }
 
 void gfs2_ail_flush(struct gfs2_glock *gl, bool fsync)

@@ -128,7 +128,7 @@ void gfs2_ail_flush(struct gfs2_glock *gl, bool fsync)
 		return;
 	__gfs2_ail_flush(gl, fsync, max_revokes);
 	gfs2_trans_end(sdp);
-	gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
+	gfs2_log_flush(sdp, NULL, NORMAL_FLUSH, LGF_AIL_FLUSH);
 }
 
 /**

@@ -157,7 +157,7 @@ static void rgrp_go_sync(struct gfs2_glock *gl)
 		return;
 	GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_EXCLUSIVE);
 
-	gfs2_log_flush(sdp, gl, NORMAL_FLUSH);
+	gfs2_log_flush(sdp, gl, NORMAL_FLUSH, LGF_RGRP_GO_SYNC);
 	filemap_fdatawrite_range(mapping, gl->gl_vm.start, gl->gl_vm.end);
 	error = filemap_fdatawait_range(mapping, gl->gl_vm.start, gl->gl_vm.end);
 	mapping_set_error(mapping, error);

@@ -252,7 +252,7 @@ static void inode_go_sync(struct gfs2_glock *gl)
 
 	GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_EXCLUSIVE);
 
-	gfs2_log_flush(gl->gl_name.ln_sbd, gl, NORMAL_FLUSH);
+	gfs2_log_flush(gl->gl_name.ln_sbd, gl, NORMAL_FLUSH, LGF_INODE_GO_SYNC);
 	filemap_fdatawrite(metamapping);
 	if (isreg) {
 		struct address_space *mapping = ip->i_inode.i_mapping;

@@ -303,7 +303,8 @@ static void inode_go_inval(struct gfs2_glock *gl, int flags)
 	}
 
 	if (ip == GFS2_I(gl->gl_name.ln_sbd->sd_rindex)) {
-		gfs2_log_flush(gl->gl_name.ln_sbd, NULL, NORMAL_FLUSH);
+		gfs2_log_flush(gl->gl_name.ln_sbd, NULL, NORMAL_FLUSH,
+			       LGF_INODE_GO_INVAL);
 		gl->gl_name.ln_sbd->sd_rindex_uptodate = 0;
 	}
 	if (ip && S_ISREG(ip->i_inode.i_mode))

@@ -495,7 +496,7 @@ static void freeze_go_sync(struct gfs2_glock *gl)
 			gfs2_assert_withdraw(sdp, 0);
 		}
 		queue_work(gfs2_freeze_wq, &sdp->sd_freeze_work);
-		gfs2_log_flush(sdp, NULL, FREEZE_FLUSH);
+		gfs2_log_flush(sdp, NULL, FREEZE_FLUSH, LGF_FREEZE_GO_SYNC);
 	}
 }
fs/gfs2/incore.h +22 -0
index 6e18e9793ec4..1e07fa2468f9 100644
@@ -134,6 +134,28 @@ enum gfs2_state_bits {
 	BH_Zeronew = BH_PrivateStart + 2,
 };
 
+enum gfs2_log_flushers {
+	LGF_SHUTDOWN		= 0x701,
+	LGF_JDATA_WPAGES	= 0x702,
+	LGF_SET_FLAGS		= 0x703,
+	LGF_AIL_EMPTY_GL	= 0x704,
+	LGF_AIL_FLUSH		= 0x705,
+	LGF_RGRP_GO_SYNC	= 0x706,
+	LGF_INODE_GO_SYNC	= 0x707,
+	LGF_INODE_GO_INVAL	= 0x708,
+	LGF_FREEZE_GO_SYNC	= 0x709,
+	LGF_KILL_SB		= 0x70a,
+	LGF_DO_SYNC		= 0x70b,
+	LGF_INPLACE_RESERVE	= 0x70c,
+	LGF_WRITE_INODE		= 0x70d,
+	LGF_MAKE_FS_RO		= 0x70e,
+	LGF_SYNC_FS		= 0x70f,
+	LGF_EVICT_INODE		= 0x710,
+	LGF_TRANS_END		= 0x711,
+	LGF_LOGD_JFLUSH_REQD	= 0x712,
+	LGF_LOGD_AIL_FLUSH_REQD	= 0x712,
+};
+
 BUFFER_FNS(Pinned, pinned)
 TAS_BUFFER_FNS(Pinned, pinned)
 BUFFER_FNS(Escaped, escaped)
fs/gfs2/log.c +11 -8
index 311e22ec6716..b62f866220ee 100644
@@ -654,7 +654,7 @@ void gfs2_write_revokes(struct gfs2_sbd *sdp)
  * Returns: the initialized log buffer descriptor
  */
 
-static void log_write_header(struct gfs2_sbd *sdp, u32 flags)
+static void log_write_header(struct gfs2_sbd *sdp, u32 flags, u32 flusher)
 {
 	struct gfs2_log_header_v2 *lh2;
 	struct gfs2_log_header *lh;

@@ -692,6 +692,7 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags)
 	lh2->lh_jinode = cpu_to_be64(GFS2_I(sdp->sd_jdesc->jd_inode)->i_no_addr);
 	lh2->lh_statfs_addr = cpu_to_be64(GFS2_I(sdp->sd_sc_inode)->i_no_addr);
 	lh2->lh_quota_addr = cpu_to_be64(GFS2_I(sdp->sd_qc_inode)->i_no_addr);
+	lh2->lh_log_flusher = cpu_to_be32(flusher);
 
 	spin_lock(&sdp->sd_statfs_spin);
 	lh2->lh_local_total = cpu_to_be64(l_sc->sc_total);

@@ -722,7 +723,7 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags)
  */
 
 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl,
-		    enum gfs2_flush_type type)
+		    enum gfs2_flush_type type, enum gfs2_log_flushers lgf)
 {
 	struct gfs2_trans *tr;
 	enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);

@@ -761,11 +762,11 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl,
 
 	if (sdp->sd_log_head != sdp->sd_log_flush_head) {
 		log_flush_wait(sdp);
-		log_write_header(sdp, 0);
+		log_write_header(sdp, 0, lgf);
 	} else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
 		atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
 		trace_gfs2_log_blocks(sdp, -1);
-		log_write_header(sdp, 0);
+		log_write_header(sdp, 0, lgf);
 	}
 	lops_after_commit(sdp, tr);
 

@@ -792,7 +793,7 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl,
 			}
 			atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
 			trace_gfs2_log_blocks(sdp, -1);
-			log_write_header(sdp, 0);
+			log_write_header(sdp, 0, lgf);
 			sdp->sd_log_head = sdp->sd_log_flush_head;
 		}
 		if (type == SHUTDOWN_FLUSH || type == FREEZE_FLUSH)

@@ -897,7 +898,7 @@ void gfs2_log_shutdown(struct gfs2_sbd *sdp)
 
 	sdp->sd_log_flush_head = sdp->sd_log_head;
 
-	log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT);
+	log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT, LGF_SHUTDOWN);
 
 	gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
 	gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));

@@ -953,7 +954,8 @@ int gfs2_logd(void *data)
 		did_flush = false;
 		if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
 			gfs2_ail1_empty(sdp);
-			gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
+			gfs2_log_flush(sdp, NULL, NORMAL_FLUSH,
+				       LGF_LOGD_JFLUSH_REQD);
 			did_flush = true;
 		}
 

@@ -961,7 +963,8 @@ int gfs2_logd(void *data)
 			gfs2_ail1_start(sdp);
 			gfs2_ail1_wait(sdp);
 			gfs2_ail1_empty(sdp);
-			gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
+			gfs2_log_flush(sdp, NULL, NORMAL_FLUSH,
+				       LGF_LOGD_AIL_FLUSH_REQD);
 			did_flush = true;
 		}
fs/gfs2/log.h +2 -1
index 9499a6049212..32779b1e8fb5 100644
@@ -72,7 +72,8 @@ enum gfs2_flush_type {
 	FREEZE_FLUSH
 };
 extern void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl,
-			   enum gfs2_flush_type type);
+			   enum gfs2_flush_type type,
+			   enum gfs2_log_flushers lgf);
 extern void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *trans);
 extern void gfs2_remove_from_ail(struct gfs2_bufdata *bd);
 extern void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc);
fs/gfs2/ops_fstype.c +1 -1
index a3711f543405..d9795d2e54ea 100644
@@ -1382,7 +1382,7 @@ static void gfs2_kill_sb(struct super_block *sb)
 		return;
 	}
 
-	gfs2_log_flush(sdp, NULL, SYNC_FLUSH);
+	gfs2_log_flush(sdp, NULL, SYNC_FLUSH, LGF_KILL_SB);
 	dput(sdp->sd_root_dir);
 	dput(sdp->sd_master_dir);
 	sdp->sd_root_dir = NULL;
fs/gfs2/quota.c +2 -1
index e700fb162664..e70d9b0d848f 100644
@@ -955,7 +955,8 @@ static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
 		gfs2_glock_dq_uninit(&ghs[qx]);
 	inode_unlock(&ip->i_inode);
 	kfree(ghs);
-	gfs2_log_flush(ip->i_gl->gl_name.ln_sbd, ip->i_gl, NORMAL_FLUSH);
+	gfs2_log_flush(ip->i_gl->gl_name.ln_sbd, ip->i_gl, NORMAL_FLUSH,
+		       LGF_DO_SYNC);
 	return error;
 }
fs/gfs2/rgrp.c +2 -1
index b52c5c3ac445..a122181cee81 100644
@@ -2072,7 +2072,8 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
 		}
 		/* Flushing the log may release space */
 		if (loops == 2)
-			gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
+			gfs2_log_flush(sdp, NULL, NORMAL_FLUSH,
+				       LGF_INPLACE_RESERVE);
 	}
 
 	return -ENOSPC;
fs/gfs2/super.c +5 -4
index 9cb5c9a97d69..d4af64d4551b 100644
@@ -757,7 +757,8 @@ static int gfs2_write_inode(struct inode *inode, struct writeback_control *wbc)
 	bool flush_all = (wbc->sync_mode == WB_SYNC_ALL || gfs2_is_jdata(ip));
 
 	if (flush_all)
-		gfs2_log_flush(GFS2_SB(inode), ip->i_gl, NORMAL_FLUSH);
+		gfs2_log_flush(GFS2_SB(inode), ip->i_gl, NORMAL_FLUSH,
+			       LGF_WRITE_INODE);
 	if (bdi->wb.dirty_exceeded)
 		gfs2_ail1_flush(sdp, wbc);
 	else

@@ -853,7 +854,7 @@ static int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
 	gfs2_quota_sync(sdp->sd_vfs, 0);
 	gfs2_statfs_sync(sdp->sd_vfs, 0);
 
-	gfs2_log_flush(sdp, NULL, SHUTDOWN_FLUSH);
+	gfs2_log_flush(sdp, NULL, SHUTDOWN_FLUSH, LGF_MAKE_FS_RO);
 	wait_event(sdp->sd_reserving_log_wait, atomic_read(&sdp->sd_reserving_log) == 0);
 	gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks);
 

@@ -946,7 +947,7 @@ static int gfs2_sync_fs(struct super_block *sb, int wait)
 
 	gfs2_quota_sync(sb, -1);
 	if (wait)
-		gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
+		gfs2_log_flush(sdp, NULL, NORMAL_FLUSH, LGF_SYNC_FS);
 	return sdp->sd_log_error;
 }
 

@@ -1650,7 +1651,7 @@ static void gfs2_evict_inode(struct inode *inode)
 	goto out_unlock;
 
 out_truncate:
-	gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH);
+	gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH, LGF_EVICT_INODE);
 	metamapping = gfs2_glock2aspace(ip->i_gl);
 	if (test_bit(GLF_DIRTY, &ip->i_gl->gl_flags)) {
 		filemap_fdatawrite(metamapping);
fs/gfs2/trans.c +1 -1
index a85ca8b2c9ba..1f06dd9e4ff4 100644
@@ -118,7 +118,7 @@ void gfs2_trans_end(struct gfs2_sbd *sdp)
 	up_read(&sdp->sd_log_flush_lock);
 
 	if (sdp->sd_vfs->s_flags & MS_SYNCHRONOUS)
-		gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
+		gfs2_log_flush(sdp, NULL, NORMAL_FLUSH, LGF_TRANS_END);
 	if (alloced)
 		sb_end_intwrite(sdp->sd_vfs);
 }
#2 lore raw

PATCH 1/1 GFS2: Log the reason for log flushes in every log header

Hi,

Quoted 26 lines · Bob Peterson

Hi,

This patch just adds the capability for GFS2 to track which function called gfs2_log_flush. This should make it easier to diagnose problems based on the sequence of events found in the journals.

Signed-off-by Bob Peterson <[email protected]>
---
  fs/gfs2/aops.c       |  2 +-
  fs/gfs2/file.c       |  3 ++-
  fs/gfs2/glops.c      | 13 +++++++------
  fs/gfs2/incore.h     | 22 ++++++++++++++++++++++
  fs/gfs2/log.c        | 19 +++++++++++--------
  fs/gfs2/log.h        |  3 ++-
  fs/gfs2/ops_fstype.c |  2 +-
  fs/gfs2/quota.c      |  3 ++-
  fs/gfs2/rgrp.c       |  3 ++-
  fs/gfs2/super.c      |  9 +++++----
  fs/gfs2/trans.c      |  2 +-
  11 files changed, 56 insertions(+), 25 deletions(-)
fs/gfs2/aops.c +0 -0
index 658ca027cab9..10fa52321a73 100644

fs/gfs2/aops.c static int gfs2_jdata_writepages(struct address_space *mapping, · line 451

Quoted 8 lines
fs/gfs2/aops.c +1 -1
@@ -445,7 +445,7 @@ static int gfs2_jdata_writepages(struct address_space *mapping,
 
  	ret = gfs2_write_cache_jdata(mapping, wbc);
  	if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
-		gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH);
+		gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH, LGF_JDATA_WPAGES);
  		ret = gfs2_write_cache_jdata(mapping, wbc);
  	}
  	return ret;

Since we already have a flags field for gfs2_log_flush, lets make these the same field to avoid having to send two sets of flags.

Quoted 93 lines
fs/gfs2/file.c +2 -1
index 58705ef8643a..e180df15e107 100644
@@ -246,7 +246,8 @@ static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
  	}
  	if ((flags ^ new_flags) & GFS2_DIF_JDATA) {
  		if (new_flags & GFS2_DIF_JDATA)
-			gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH);
+			gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH,
+				       LGF_SET_FLAGS);
  		error = filemap_fdatawrite(inode->i_mapping);
  		if (error)
  			goto out;
fs/gfs2/glops.c +7 -6
index cdd1c5f06f45..f661fbec259c 100644
@@ -107,7 +107,7 @@ static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
  	__gfs2_ail_flush(gl, 0, tr.tr_revokes);
 
  	gfs2_trans_end(sdp);
-	gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
+	gfs2_log_flush(sdp, NULL, NORMAL_FLUSH, LGF_AIL_EMPTY_GL);
  }
 
  void gfs2_ail_flush(struct gfs2_glock *gl, bool fsync)

@@ -128,7 +128,7 @@ void gfs2_ail_flush(struct gfs2_glock *gl, bool fsync)
  		return;
  	__gfs2_ail_flush(gl, fsync, max_revokes);
  	gfs2_trans_end(sdp);
-	gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
+	gfs2_log_flush(sdp, NULL, NORMAL_FLUSH, LGF_AIL_FLUSH);
  }
 
  /**

@@ -157,7 +157,7 @@ static void rgrp_go_sync(struct gfs2_glock *gl)
  		return;
  	GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_EXCLUSIVE);
 
-	gfs2_log_flush(sdp, gl, NORMAL_FLUSH);
+	gfs2_log_flush(sdp, gl, NORMAL_FLUSH, LGF_RGRP_GO_SYNC);
  	filemap_fdatawrite_range(mapping, gl->gl_vm.start, gl->gl_vm.end);
  	error = filemap_fdatawait_range(mapping, gl->gl_vm.start, gl->gl_vm.end);
  	mapping_set_error(mapping, error);

@@ -252,7 +252,7 @@ static void inode_go_sync(struct gfs2_glock *gl)
 
  	GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_EXCLUSIVE);
 
-	gfs2_log_flush(gl->gl_name.ln_sbd, gl, NORMAL_FLUSH);
+	gfs2_log_flush(gl->gl_name.ln_sbd, gl, NORMAL_FLUSH, LGF_INODE_GO_SYNC);
  	filemap_fdatawrite(metamapping);
  	if (isreg) {
  		struct address_space *mapping = ip->i_inode.i_mapping;

@@ -303,7 +303,8 @@ static void inode_go_inval(struct gfs2_glock *gl, int flags)
  	}
 
  	if (ip == GFS2_I(gl->gl_name.ln_sbd->sd_rindex)) {
-		gfs2_log_flush(gl->gl_name.ln_sbd, NULL, NORMAL_FLUSH);
+		gfs2_log_flush(gl->gl_name.ln_sbd, NULL, NORMAL_FLUSH,
+			       LGF_INODE_GO_INVAL);
  		gl->gl_name.ln_sbd->sd_rindex_uptodate = 0;
  	}
  	if (ip && S_ISREG(ip->i_inode.i_mode))

@@ -495,7 +496,7 @@ static void freeze_go_sync(struct gfs2_glock *gl)
  			gfs2_assert_withdraw(sdp, 0);
  		}
  		queue_work(gfs2_freeze_wq, &sdp->sd_freeze_work);
-		gfs2_log_flush(sdp, NULL, FREEZE_FLUSH);
+		gfs2_log_flush(sdp, NULL, FREEZE_FLUSH, LGF_FREEZE_GO_SYNC);
  	}
  }
fs/gfs2/incore.h +12 -0
index 6e18e9793ec4..1e07fa2468f9 100644
@@ -134,6 +134,28 @@ enum gfs2_state_bits {
  	BH_Zeronew = BH_PrivateStart + 2,
  };
 
+enum gfs2_log_flushers {
+	LGF_SHUTDOWN		= 0x701,
+	LGF_JDATA_WPAGES	= 0x702,
+	LGF_SET_FLAGS		= 0x703,
+	LGF_AIL_EMPTY_GL	= 0x704,
+	LGF_AIL_FLUSH		= 0x705,
+	LGF_RGRP_GO_SYNC	= 0x706,
+	LGF_INODE_GO_SYNC	= 0x707,
+	LGF_INODE_GO_INVAL	= 0x708,
+	LGF_FREEZE_GO_SYNC	= 0x709,
+	LGF_KILL_SB		= 0x70a,
+	LGF_DO_SYNC		= 0x70b,

fs/gfs2/incore.h enum gfs2_state_bits { · line 158

Quoted 10 lines
fs/gfs2/incore.h +10 -0
+	LGF_INPLACE_RESERVE	= 0x70c,
+	LGF_WRITE_INODE		= 0x70d,
+	LGF_MAKE_FS_RO		= 0x70e,
+	LGF_SYNC_FS		= 0x70f,
+	LGF_EVICT_INODE		= 0x710,
+	LGF_TRANS_END		= 0x711,
+	LGF_LOGD_JFLUSH_REQD	= 0x712,
+	LGF_LOGD_AIL_FLUSH_REQD	= 0x712,
+};
+

These constants are written to disk, so they need to be in the ondisk header file in order that the utils can access them.

Steve.

author
#3 lore raw

PATCH 1/1 GFS2: Log the reason for log flushes in every log header

In reply to Bob Peterson

Hi,

This is a version 2 replacement for this patch, with some improvements.
---
This patch just adds the capability for GFS2 to track which function called gfs2_log_flush. This should make it easier to diagnose problems based on the sequence of events found in the journals.

Signed-off-by Bob Peterson <[email protected]>
---
 fs/gfs2/aops.c                   |  2 +-
 fs/gfs2/file.c                   |  2 +-
 fs/gfs2/glops.c                  | 12 ++++----
 fs/gfs2/incore.h                 |  1 +
 fs/gfs2/log.c                    | 61 +++++++++++++++++++++++++++++++++-------
 fs/gfs2/log.h                    |  8 +-----
 fs/gfs2/ops_fstype.c             |  2 +-
 fs/gfs2/quota.c                  |  2 +-
 fs/gfs2/rgrp.c                   |  2 +-
 fs/gfs2/super.c                  |  8 +++---
 fs/gfs2/trace_gfs2.h             | 11 +++++---
 fs/gfs2/trans.c                  |  2 +-
 include/uapi/linux/gfs2_ondisk.h | 36 ++++++++++++++++++++++++
 13 files changed, 112 insertions(+), 37 deletions(-)
fs/gfs2/aops.c +1 -1
index 658ca027cab9..4ef09ad463d4 100644
@@ -445,7 +445,7 @@ static int gfs2_jdata_writepages(struct address_space *mapping,
 
 	ret = gfs2_write_cache_jdata(mapping, wbc);
 	if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
-		gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH);
+		gfs2_log_flush(sdp, ip->i_gl, LHF_JDATA_WPAGES);
 		ret = gfs2_write_cache_jdata(mapping, wbc);
 	}
 	return ret;
fs/gfs2/file.c +1 -1
index 58705ef8643a..68fee09efdf2 100644
@@ -246,7 +246,7 @@ static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
 	}
 	if ((flags ^ new_flags) & GFS2_DIF_JDATA) {
 		if (new_flags & GFS2_DIF_JDATA)
-			gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH);
+			gfs2_log_flush(sdp, ip->i_gl, LHF_SET_FLAGS);
 		error = filemap_fdatawrite(inode->i_mapping);
 		if (error)
 			goto out;
fs/gfs2/glops.c +6 -6
index cdd1c5f06f45..1e95c0bdbc3b 100644
@@ -107,7 +107,7 @@ static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
 	__gfs2_ail_flush(gl, 0, tr.tr_revokes);
 
 	gfs2_trans_end(sdp);
-	gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
+	gfs2_log_flush(sdp, NULL, LHF_AIL_EMPTY_GL);
 }
 
 void gfs2_ail_flush(struct gfs2_glock *gl, bool fsync)

@@ -128,7 +128,7 @@ void gfs2_ail_flush(struct gfs2_glock *gl, bool fsync)
 		return;
 	__gfs2_ail_flush(gl, fsync, max_revokes);
 	gfs2_trans_end(sdp);
-	gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
+	gfs2_log_flush(sdp, NULL, LHF_AIL_FLUSH);
 }
 
 /**

@@ -157,7 +157,7 @@ static void rgrp_go_sync(struct gfs2_glock *gl)
 		return;
 	GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_EXCLUSIVE);
 
-	gfs2_log_flush(sdp, gl, NORMAL_FLUSH);
+	gfs2_log_flush(sdp, gl, LHF_RGRP_GO_SYNC);
 	filemap_fdatawrite_range(mapping, gl->gl_vm.start, gl->gl_vm.end);
 	error = filemap_fdatawait_range(mapping, gl->gl_vm.start, gl->gl_vm.end);
 	mapping_set_error(mapping, error);

@@ -252,7 +252,7 @@ static void inode_go_sync(struct gfs2_glock *gl)
 
 	GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_EXCLUSIVE);
 
-	gfs2_log_flush(gl->gl_name.ln_sbd, gl, NORMAL_FLUSH);
+	gfs2_log_flush(gl->gl_name.ln_sbd, gl, LHF_INODE_GO_SYNC);
 	filemap_fdatawrite(metamapping);
 	if (isreg) {
 		struct address_space *mapping = ip->i_inode.i_mapping;

@@ -303,7 +303,7 @@ static void inode_go_inval(struct gfs2_glock *gl, int flags)
 	}
 
 	if (ip == GFS2_I(gl->gl_name.ln_sbd->sd_rindex)) {
-		gfs2_log_flush(gl->gl_name.ln_sbd, NULL, NORMAL_FLUSH);
+		gfs2_log_flush(gl->gl_name.ln_sbd, NULL, LHF_INODE_GO_INVAL);
 		gl->gl_name.ln_sbd->sd_rindex_uptodate = 0;
 	}
 	if (ip && S_ISREG(ip->i_inode.i_mode))

@@ -495,7 +495,7 @@ static void freeze_go_sync(struct gfs2_glock *gl)
 			gfs2_assert_withdraw(sdp, 0);
 		}
 		queue_work(gfs2_freeze_wq, &sdp->sd_freeze_work);
-		gfs2_log_flush(sdp, NULL, FREEZE_FLUSH);
+		gfs2_log_flush(sdp, NULL, LHF_FREEZE_GO_SYNC);
 	}
 }
fs/gfs2/incore.h +1 -0
index 6e18e9793ec4..4a45c2590b1b 100644
@@ -844,6 +844,7 @@ struct gfs2_sbd {
 	struct dentry *debugfs_dentry_glocks;
 	struct dentry *debugfs_dentry_glstats;
 	struct dentry *debugfs_dentry_sbstats;
+	unsigned long sd_log_flushers;
 };
 
 static inline void gfs2_glstats_inc(struct gfs2_glock *gl, int which)
fs/gfs2/log.c +51 -10

139 lines not on this page · raw message

fs/gfs2/log.h +1 -7
index 9499a6049212..aad2b2c69d54 100644
@@ -65,14 +65,8 @@ extern unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
 
 extern void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks);
 extern int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks);
-enum gfs2_flush_type {
-	NORMAL_FLUSH = 0,
-	SYNC_FLUSH,
-	SHUTDOWN_FLUSH,
-	FREEZE_FLUSH
-};
 extern void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl,
-			   enum gfs2_flush_type type);
+			   enum gfs2_log_flushers flusher);
 extern void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *trans);
 extern void gfs2_remove_from_ail(struct gfs2_bufdata *bd);
 extern void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc);
fs/gfs2/ops_fstype.c +1 -1
index a3711f543405..b53cf3e111e1 100644
@@ -1382,7 +1382,7 @@ static void gfs2_kill_sb(struct super_block *sb)
 		return;
 	}
 
-	gfs2_log_flush(sdp, NULL, SYNC_FLUSH);
+	gfs2_log_flush(sdp, NULL, LHF_KILL_SB);
 	dput(sdp->sd_root_dir);
 	dput(sdp->sd_master_dir);
 	sdp->sd_root_dir = NULL;
fs/gfs2/quota.c +1 -1
index e700fb162664..a90ccd8855aa 100644
@@ -955,7 +955,7 @@ static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
 		gfs2_glock_dq_uninit(&ghs[qx]);
 	inode_unlock(&ip->i_inode);
 	kfree(ghs);
-	gfs2_log_flush(ip->i_gl->gl_name.ln_sbd, ip->i_gl, NORMAL_FLUSH);
+	gfs2_log_flush(ip->i_gl->gl_name.ln_sbd, ip->i_gl, LHF_DO_SYNC);
 	return error;
 }
fs/gfs2/rgrp.c +1 -1
index b52c5c3ac445..f9b00836ce1a 100644
@@ -2072,7 +2072,7 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
 		}
 		/* Flushing the log may release space */
 		if (loops == 2)
-			gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
+			gfs2_log_flush(sdp, NULL, LHF_INPLACE_RESERVE);
 	}
 
 	return -ENOSPC;
fs/gfs2/super.c +4 -4
index 9cb5c9a97d69..5bf53ac15ab3 100644
@@ -757,7 +757,7 @@ static int gfs2_write_inode(struct inode *inode, struct writeback_control *wbc)
 	bool flush_all = (wbc->sync_mode == WB_SYNC_ALL || gfs2_is_jdata(ip));
 
 	if (flush_all)
-		gfs2_log_flush(GFS2_SB(inode), ip->i_gl, NORMAL_FLUSH);
+		gfs2_log_flush(GFS2_SB(inode), ip->i_gl, LHF_WRITE_INODE);
 	if (bdi->wb.dirty_exceeded)
 		gfs2_ail1_flush(sdp, wbc);
 	else

@@ -853,7 +853,7 @@ static int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
 	gfs2_quota_sync(sdp->sd_vfs, 0);
 	gfs2_statfs_sync(sdp->sd_vfs, 0);
 
-	gfs2_log_flush(sdp, NULL, SHUTDOWN_FLUSH);
+	gfs2_log_flush(sdp, NULL, LHF_MAKE_FS_RO);
 	wait_event(sdp->sd_reserving_log_wait, atomic_read(&sdp->sd_reserving_log) == 0);
 	gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks);
 

@@ -946,7 +946,7 @@ static int gfs2_sync_fs(struct super_block *sb, int wait)
 
 	gfs2_quota_sync(sb, -1);
 	if (wait)
-		gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
+		gfs2_log_flush(sdp, NULL, LHF_SYNC_FS);
 	return sdp->sd_log_error;
 }
 

@@ -1650,7 +1650,7 @@ static void gfs2_evict_inode(struct inode *inode)
 	goto out_unlock;
 
 out_truncate:
-	gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH);
+	gfs2_log_flush(sdp, ip->i_gl, LHF_EVICT_INODE);
 	metamapping = gfs2_glock2aspace(ip->i_gl);
 	if (test_bit(GLF_DIRTY, &ip->i_gl->gl_flags)) {
 		filemap_fdatawrite(metamapping);
fs/gfs2/trace_gfs2.h +7 -4
index f67a709589d3..62ada4847250 100644
@@ -353,26 +353,29 @@ TRACE_EVENT(gfs2_pin,
 /* Flushing the log */
 TRACE_EVENT(gfs2_log_flush,
 
-	TP_PROTO(const struct gfs2_sbd *sdp, int start),
+	TP_PROTO(const struct gfs2_sbd *sdp, int start, u32 flusher),
 
-	TP_ARGS(sdp, start),
+	TP_ARGS(sdp, start, flusher),
 
 	TP_STRUCT__entry(
 		__field(        dev_t,  dev                     )
 		__field(	int,	start			)
 		__field(	u64,	log_seq			)
+		__field(	u32,	flusher			)
 	),
 
 	TP_fast_assign(
 		__entry->dev            = sdp->sd_vfs->s_dev;
 		__entry->start		= start;
 		__entry->log_seq	= sdp->sd_log_sequence;
+		__entry->flusher	= flusher;
 	),
 
-	TP_printk("%u,%u log flush %s %llu",
+	TP_printk("%u,%u log flush %s %llu %llx",
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  __entry->start ? "start" : "end",
-		  (unsigned long long)__entry->log_seq)
+		  (unsigned long long)__entry->log_seq,
+		  (unsigned long long)__entry->flusher)
 );
 
 /* Reserving/releasing blocks in the log */
fs/gfs2/trans.c +1 -1
index a85ca8b2c9ba..9842778e32d1 100644
@@ -118,7 +118,7 @@ void gfs2_trans_end(struct gfs2_sbd *sdp)
 	up_read(&sdp->sd_log_flush_lock);
 
 	if (sdp->sd_vfs->s_flags & MS_SYNCHRONOUS)
-		gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
+		gfs2_log_flush(sdp, NULL, LHF_TRANS_END);
 	if (alloced)
 		sb_end_intwrite(sdp->sd_vfs);
 }
include/uapi/linux/gfs2_ondisk.h +36 -0
index 96d9676ac354..cf867896436d 100644
@@ -406,6 +406,42 @@ struct gfs2_log_header {
 	__be32 lh_hash;
 };
 
+/*
+ * Log Header version 2 constants - actor who wrote a log header
+ */
+
+enum gfs2_log_flushers {
+	/* Constants reserved for kernel space */
+	LHF_SHUTDOWN		= 0,
+	LHF_JDATA_WPAGES	= 1,
+	LHF_SET_FLAGS		= 2,
+	LHF_AIL_EMPTY_GL	= 3,
+	LHF_AIL_FLUSH		= 4,
+	LHF_RGRP_GO_SYNC	= 5,
+	LHF_INODE_GO_SYNC	= 6,
+	LHF_INODE_GO_INVAL	= 7,
+	LHF_FREEZE_GO_SYNC	= 8,
+	LHF_KILL_SB		= 9,
+	LHF_DO_SYNC		= 10,
+	LHF_INPLACE_RESERVE	= 11,
+	LHF_WRITE_INODE		= 12,
+	LHF_MAKE_FS_RO		= 13,
+	LHF_SYNC_FS		= 14,
+	LHF_EVICT_INODE		= 15,
+	LHF_TRANS_END		= 16,
+	LHF_LOGD_JFLUSH_REQD	= 17,
+	LHF_LOGD_AIL_FLUSH_REQD	= 18,
+	LHF_LOG_FLUSHERS	= 19, /* number of kernel log flushers */
+
+	/* Constants reserved for user space / gfs2-utils */
+	LHF_GFS2_CONVERT       	= 26,
+	LHF_GFS2_EDIT		= 27,
+	LHF_GFS2_FSCK		= 28,
+	LHF_GFS2_FSCK_JREPLAY	= 29,
+	LHF_GFS2_MKFS		= 30,
+	LHF_GFS2_JADD		= 31
+};
+
 struct gfs2_log_header_v2 {
 	struct gfs2_log_header lhv1;
#4 lore raw

PATCH 1/1 GFS2: Log the reason for log flushes in every log header

Quoted 9 lines · Bob Peterson

Hi,

This is a version 2 replacement for this patch, with some improvements.
---
This patch just adds the capability for GFS2 to track which function called gfs2_log_flush. This should make it easier to diagnose problems based on the sequence of events found in the journals.

Signed-off-by Bob Peterson <[email protected]>

<snip>

include/uapi/linux/gfs2_ondisk.h struct gfs2_log_header { · line 415

Quoted 13 lines
include/uapi/linux/gfs2_ondisk.h +7 -0
@@ -406,6 +406,42 @@ struct gfs2_log_header {
  	__be32 lh_hash;
  };
 
+/*
+ * Log Header version 2 constants - actor who wrote a log header
+ */
+
+enum gfs2_log_flushers {
+	/* Constants reserved for kernel space */
+	LHF_SHUTDOWN		= 0,

Should 0 be used for "unknown"?

Quoted 17 lines
include/uapi/linux/gfs2_ondisk.h +17 -0
+	LHF_JDATA_WPAGES	= 1,
+	LHF_SET_FLAGS		= 2,
+	LHF_AIL_EMPTY_GL	= 3,
+	LHF_AIL_FLUSH		= 4,
+	LHF_RGRP_GO_SYNC	= 5,
+	LHF_INODE_GO_SYNC	= 6,
+	LHF_INODE_GO_INVAL	= 7,
+	LHF_FREEZE_GO_SYNC	= 8,
+	LHF_KILL_SB		= 9,
+	LHF_DO_SYNC		= 10,
+	LHF_INPLACE_RESERVE	= 11,
+	LHF_WRITE_INODE		= 12,
+	LHF_MAKE_FS_RO		= 13,
+	LHF_SYNC_FS		= 14,
+	LHF_EVICT_INODE		= 15,
+	LHF_TRANS_END		= 16,
+	LHF_LOGD_JFLUSH_REQD	= 17,

include/uapi/linux/gfs2_ondisk.h struct gfs2_log_header { · line 442

Quoted 10 lines
include/uapi/linux/gfs2_ondisk.h +10 -0
+	LHF_LOGD_AIL_FLUSH_REQD	= 18,
+	LHF_LOG_FLUSHERS	= 19, /* number of kernel log flushers */
+
+	/* Constants reserved for user space / gfs2-utils */
+	LHF_GFS2_CONVERT       	= 26,
+	LHF_GFS2_EDIT		= 27,
+	LHF_GFS2_FSCK		= 28,
+	LHF_GFS2_FSCK_JREPLAY	= 29,
+	LHF_GFS2_MKFS		= 30,
+	LHF_GFS2_JADD		= 31

Would it be better to have values for the purposes that the utils would need to touch the log header, e.g. LHF_UTIL_REPLAY, LHF_UTIL_FIX or LHF_UTIL_CREATE. That way, if a util is renamed or a new util is written (even some third party tool that we don't know about) they would still have a sensible value to use.

Cheers,
Andy

#5 lore raw

PATCH 1/1 GFS2: Log the reason for log flushes in every log header

Hi,

Quoted 11 lines · Andrew Price
Quoted 9 lines · Bob Peterson

Hi,

This is a version 2 replacement for this patch, with some improvements.
---
This patch just adds the capability for GFS2 to track which function called gfs2_log_flush. This should make it easier to diagnose problems based on the sequence of events found in the journals.

Signed-off-by Bob Peterson <[email protected]>

<snip>

Quoted 15 lines

include/uapi/linux/gfs2_ondisk.h struct gfs2_log_header {

Quoted 12 lines
include/uapi/linux/gfs2_ondisk.h +0 -0
@@ -406,6 +406,42 @@ struct gfs2_log_header {
 ????? __be32 lh_hash;
 ? };

? +/*
+ * Log Header version 2 constants - actor who wrote a log header
+ */

include/uapi/linux/gfs2_ondisk.h +4 -0
+
+enum gfs2_log_flushers {
+??? /* Constants reserved for kernel space */
+??? LHF_SHUTDOWN??????? = 0,

Should 0 be used for "unknown"?

Yes

Quoted 28 lines
Quoted 19 lines

+??? LHF_JDATA_WPAGES??? = 1,
+??? LHF_SET_FLAGS??????? = 2,
+??? LHF_AIL_EMPTY_GL??? = 3,
+??? LHF_AIL_FLUSH??????? = 4,
+??? LHF_RGRP_GO_SYNC??? = 5,
+??? LHF_INODE_GO_SYNC??? = 6,
+??? LHF_INODE_GO_INVAL??? = 7,
+??? LHF_FREEZE_GO_SYNC??? = 8,
+??? LHF_KILL_SB??????? = 9,
+??? LHF_DO_SYNC??????? = 10,
+??? LHF_INPLACE_RESERVE??? = 11,
+??? LHF_WRITE_INODE??????? = 12,
+??? LHF_MAKE_FS_RO??????? = 13,
+??? LHF_SYNC_FS??????? = 14,
+??? LHF_EVICT_INODE??????? = 15,
+??? LHF_TRANS_END??????? = 16,
+??? LHF_LOGD_JFLUSH_REQD??? = 17,
+??? LHF_LOGD_AIL_FLUSH_REQD??? = 18,
+??? LHF_LOG_FLUSHERS??? = 19, /* number of kernel log flushers */

Quoted 8 lines

+
+??? /* Constants reserved for user space / gfs2-utils */ +??? LHF_GFS2_CONVERT?????????? = 26,
+??? LHF_GFS2_EDIT??????? = 27,
+??? LHF_GFS2_FSCK??????? = 28,
+??? LHF_GFS2_FSCK_JREPLAY??? = 29,
+??? LHF_GFS2_MKFS??????? = 30,
+??? LHF_GFS2_JADD??????? = 31

Quoted 9 lines

Would it be better to have values for the purposes that the utils would need to touch the log header, e.g. LHF_UTIL_REPLAY, LHF_UTIL_FIX or LHF_UTIL_CREATE. That way, if a util is renamed or a new util is written (even some third party tool that we don't know about) they would still have a sensible value to use.

Cheers,
Andy

Yes. Also lets not make this an enum. It would make more sense to have it as a set of flags. That way we can have a single field but containing two different meanings. One set would give us the reason for the log header (normal log flush, recovery, freeze, or whatever) and another single bit flag telling us whether it is userspace or kernel space. We can then have an origin, which can be numbered independently in userspace and kernel space which indicates which function it was called from.

That also gets rid of that big log_flush_types array. So a typical call to gfs2_log_flush() would look like:

gfs2_log_flush(sdp, NULL, GFS2_LF_SYNC|GFS2_LO_KILLSB);

in this case assuming it is called from gfs2_kill_sb(). The flag for the kernel would be added automatically in log_write_header(), since it would be needed for everything. That would make the code rather easier to understand, since the two independent fields would be declared separately. There are 32 bits to use, so no issue to divide it into two 16 bit sub fields for example,

Steve.

author
#6 lore raw

PATCH 1/1 GFS2: Log the reason for log flushes in every log header

In reply to Andrew Price

Hi,

----- Original Message -----
| > + LHF_SHUTDOWN = 0,
| Should 0 be used for "unknown"?

Good idea. I'll add that.
(snip)

| > +	/* Constants reserved for user space / gfs2-utils */
| > +	LHF_GFS2_CONVERT       	= 26,
| > +	LHF_GFS2_EDIT		= 27,
| > +	LHF_GFS2_FSCK		= 28,
| > +	LHF_GFS2_FSCK_JREPLAY	= 29,
| > +	LHF_GFS2_MKFS		= 30,
| > +	LHF_GFS2_JADD		= 31
| 
| Would it be better to have values for the purposes that the utils would
| need to touch the log header, e.g. LHF_UTIL_REPLAY, LHF_UTIL_FIX or
| LHF_UTIL_CREATE. That way, if a util is renamed or a new util is written
| (even some third party tool that we don't know about) they would still
| have a sensible value to use.
| 
| Cheers,
| Andy

Actually, yes, I was kind of hoping you would suggest some useful values for user space. I didn't go over how gfs2-utils works with log headers because I didn't want to delay posting a prototype further.

I only allocated one 32-bit set of flags, with some space in the middle carved out for user space, but it seems a bit confining. Obviously this is still just a prototype, so we can add another 32-bit flag (one for kernel space and one for user space?) or improve it any other way that would be useful. I'm open to suggestions.

Regards,

Bob Peterson
Red Hat File Systems

#7 lore raw

PATCH 1/1 GFS2: Log the reason for log flushes in every log header

Quoted 29 lines · Bob Peterson

Hi,

----- Original Message -----
| > + LHF_SHUTDOWN = 0,
| Should 0 be used for "unknown"?

Good idea. I'll add that.
(snip)

| > +	/* Constants reserved for user space / gfs2-utils */
| > +	LHF_GFS2_CONVERT       	= 26,
| > +	LHF_GFS2_EDIT		= 27,
| > +	LHF_GFS2_FSCK		= 28,
| > +	LHF_GFS2_FSCK_JREPLAY	= 29,
| > +	LHF_GFS2_MKFS		= 30,
| > +	LHF_GFS2_JADD		= 31
|
| Would it be better to have values for the purposes that the utils would
| need to touch the log header, e.g. LHF_UTIL_REPLAY, LHF_UTIL_FIX or
| LHF_UTIL_CREATE. That way, if a util is renamed or a new util is written
| (even some third party tool that we don't know about) they would still
| have a sensible value to use.
|
| Cheers,
| Andy

Actually, yes, I was kind of hoping you would suggest some useful values for user space. I didn't go over how gfs2-utils works with log headers because I didn't want to delay posting a prototype further.

Quoted 5 lines

I only allocated one 32-bit set of flags, with some space in the middle carved out for user space, but it seems a bit confining. Obviously this is still just a prototype, so we can add another 32-bit flag (one for kernel space and one for user space?) or improve it any other way that would be useful. I'm open to suggestions.

Well I like Steve's suggestion of switching to bit flags assuming it's generally practical.

It might be useful to move the definitions of the values/flags into the same patch as the new log header struct is defined.

Cheers,
Andy