[PATCH 0/5] UBIFS: fix failure in dbg_check_space_info

[PATCH 0/5] UBIFS: fix failure in dbg_check_space_info

[Artem Bityutskiy]

This patch has to fix the failure in 'dbg_check_space_info()' which
I can reproduce myself with the 'integck' test and which has also been
reported here:

http://lists.infradead.org/pipermail/linux-mtd/2011-April/034647.html

The fix is in the last patch and it is quite trivial. It also describes
the reason for the failure.

Patches 1-4 mostly improve the debugging output which helps to diagnose
the problem quicker. So they are preparational patches.

Artem.

[PATCH 1/5] UBIFS: introduce a separate structure for budgeting info

[Artem Bityutskiy]

From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch separates out all the budgeting-related information
from 'struct ubifs_info' to 'struct ubifs_budg_info'. This way the
code looks a bit cleaner. However, the main driver for this is
that we want to save budgeting information and print it later,
so a separate data structure for this is helpful.

This patch is a preparation for the further debugging code
improvement.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 fs/ubifs/budget.c     |  104 ++++++++++++++++++++++++------------------------
 fs/ubifs/commit.c     |    2 +-
 fs/ubifs/debug.c      |   16 ++++----
 fs/ubifs/dir.c        |    4 +-
 fs/ubifs/file.c       |    4 +-
 fs/ubifs/find.c       |   10 ++--
 fs/ubifs/master.c     |    8 ++--
 fs/ubifs/replay.c     |    8 ++--
 fs/ubifs/super.c      |   25 ++++++------
 fs/ubifs/tnc_commit.c |   10 ++--
 fs/ubifs/ubifs.h      |   75 +++++++++++++++++++----------------
 11 files changed, 136 insertions(+), 130 deletions(-)

diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c
index c8ff0d1..02c73e7 100644
--- a/fs/ubifs/budget.c
+++ b/fs/ubifs/budget.c
@@ -106,7 +106,7 @@ static long long get_liability(struct ubifs_info *c)
 	long long liab;
 
 	spin_lock(&c->space_lock);
-	liab = c->budg_idx_growth + c->budg_data_growth + c->budg_dd_growth;
+	liab = c->bi.idx_growth + c->bi.data_growth + c->bi.dd_growth;
 	spin_unlock(&c->space_lock);
 	return liab;
 }
@@ -180,7 +180,7 @@ int ubifs_calc_min_idx_lebs(struct ubifs_info *c)
 	int idx_lebs;
 	long long idx_size;
 
-	idx_size = c->old_idx_sz + c->budg_idx_growth + c->budg_uncommitted_idx;
+	idx_size = c->bi.old_idx_sz + c->bi.idx_growth + c->bi.uncommitted_idx;
 	/* And make sure we have thrice the index size of space reserved */
 	idx_size += idx_size << 1;
 	/*
@@ -292,13 +292,13 @@ static int can_use_rp(struct ubifs_info *c)
  * budgeted index space to the size of the current index, multiplies this by 3,
  * and makes sure this does not exceed the amount of free LEBs.
  *
- * Notes about @c->min_idx_lebs and @c->lst.idx_lebs variables:
+ * Notes about @c->bi.min_idx_lebs and @c->lst.idx_lebs variables:
  * o @c->lst.idx_lebs is the number of LEBs the index currently uses. It might
  *    be large, because UBIFS does not do any index consolidation as long as
  *    there is free space. IOW, the index may take a lot of LEBs, but the LEBs
  *    will contain a lot of dirt.
- * o @c->min_idx_lebs is the number of LEBS the index presumably takes. IOW,
- *    the index may be consolidated to take up to @c->min_idx_lebs LEBs.
+ * o @c->bi.min_idx_lebs is the number of LEBS the index presumably takes. IOW,
+ *    the index may be consolidated to take up to @c->bi.min_idx_lebs LEBs.
  *
  * This function returns zero in case of success, and %-ENOSPC in case of
  * failure.
@@ -343,13 +343,13 @@ static int do_budget_space(struct ubifs_info *c)
 	       c->lst.taken_empty_lebs;
 	if (unlikely(rsvd_idx_lebs > lebs)) {
 		dbg_budg("out of indexing space: min_idx_lebs %d (old %d), "
-			 "rsvd_idx_lebs %d", min_idx_lebs, c->min_idx_lebs,
+			 "rsvd_idx_lebs %d", min_idx_lebs, c->bi.min_idx_lebs,
 			 rsvd_idx_lebs);
 		return -ENOSPC;
 	}
 
 	available = ubifs_calc_available(c, min_idx_lebs);
-	outstanding = c->budg_data_growth + c->budg_dd_growth;
+	outstanding = c->bi.data_growth + c->bi.dd_growth;
 
 	if (unlikely(available < outstanding)) {
 		dbg_budg("out of data space: available %lld, outstanding %lld",
@@ -360,7 +360,7 @@ static int do_budget_space(struct ubifs_info *c)
 	if (available - outstanding <= c->rp_size && !can_use_rp(c))
 		return -ENOSPC;
 
-	c->min_idx_lebs = min_idx_lebs;
+	c->bi.min_idx_lebs = min_idx_lebs;
 	return 0;
 }
 
@@ -393,11 +393,11 @@ static int calc_data_growth(const struct ubifs_info *c,
 {
 	int data_growth;
 
-	data_growth = req->new_ino  ? c->inode_budget : 0;
+	data_growth = req->new_ino  ? c->bi.inode_budget : 0;
 	if (req->new_page)
-		data_growth += c->page_budget;
+		data_growth += c->bi.page_budget;
 	if (req->new_dent)
-		data_growth += c->dent_budget;
+		data_growth += c->bi.dent_budget;
 	data_growth += req->new_ino_d;
 	return data_growth;
 }
@@ -413,12 +413,12 @@ static int calc_dd_growth(const struct ubifs_info *c,
 {
 	int dd_growth;
 
-	dd_growth = req->dirtied_page ? c->page_budget : 0;
+	dd_growth = req->dirtied_page ? c->bi.page_budget : 0;
 
 	if (req->dirtied_ino)
-		dd_growth += c->inode_budget << (req->dirtied_ino - 1);
+		dd_growth += c->bi.inode_budget << (req->dirtied_ino - 1);
 	if (req->mod_dent)
-		dd_growth += c->dent_budget;
+		dd_growth += c->bi.dent_budget;
 	dd_growth += req->dirtied_ino_d;
 	return dd_growth;
 }
@@ -460,19 +460,19 @@ int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req)
 
 again:
 	spin_lock(&c->space_lock);
-	ubifs_assert(c->budg_idx_growth >= 0);
-	ubifs_assert(c->budg_data_growth >= 0);
-	ubifs_assert(c->budg_dd_growth >= 0);
+	ubifs_assert(c->bi.idx_growth >= 0);
+	ubifs_assert(c->bi.data_growth >= 0);
+	ubifs_assert(c->bi.dd_growth >= 0);
 
-	if (unlikely(c->nospace) && (c->nospace_rp || !can_use_rp(c))) {
+	if (unlikely(c->bi.nospace) && (c->bi.nospace_rp || !can_use_rp(c))) {
 		dbg_budg("no space");
 		spin_unlock(&c->space_lock);
 		return -ENOSPC;
 	}
 
-	c->budg_idx_growth += idx_growth;
-	c->budg_data_growth += data_growth;
-	c->budg_dd_growth += dd_growth;
+	c->bi.idx_growth += idx_growth;
+	c->bi.data_growth += data_growth;
+	c->bi.dd_growth += dd_growth;
 
 	err = do_budget_space(c);
 	if (likely(!err)) {
@@ -484,9 +484,9 @@ again:
 	}
 
 	/* Restore the old values */
-	c->budg_idx_growth -= idx_growth;
-	c->budg_data_growth -= data_growth;
-	c->budg_dd_growth -= dd_growth;
+	c->bi.idx_growth -= idx_growth;
+	c->bi.data_growth -= data_growth;
+	c->bi.dd_growth -= dd_growth;
 	spin_unlock(&c->space_lock);
 
 	if (req->fast) {
@@ -506,9 +506,9 @@ again:
 			goto again;
 		}
 		dbg_budg("FS is full, -ENOSPC");
-		c->nospace = 1;
+		c->bi.nospace = 1;
 		if (can_use_rp(c) || c->rp_size == 0)
-			c->nospace_rp = 1;
+			c->bi.nospace_rp = 1;
 		smp_wmb();
 	} else
 		ubifs_err("cannot budget space, error %d", err);
@@ -523,8 +523,8 @@ again:
  * This function releases the space budgeted by 'ubifs_budget_space()'. Note,
  * since the index changes (which were budgeted for in @req->idx_growth) will
  * only be written to the media on commit, this function moves the index budget
- * from @c->budg_idx_growth to @c->budg_uncommitted_idx. The latter will be
- * zeroed by the commit operation.
+ * from @c->bi.idx_growth to @c->bi.uncommitted_idx. The latter will be zeroed
+ * by the commit operation.
  */
 void ubifs_release_budget(struct ubifs_info *c, struct ubifs_budget_req *req)
 {
@@ -553,23 +553,23 @@ void ubifs_release_budget(struct ubifs_info *c, struct ubifs_budget_req *req)
 	if (!req->data_growth && !req->dd_growth)
 		return;
 
-	c->nospace = c->nospace_rp = 0;
+	c->bi.nospace = c->bi.nospace_rp = 0;
 	smp_wmb();
 
 	spin_lock(&c->space_lock);
-	c->budg_idx_growth -= req->idx_growth;
-	c->budg_uncommitted_idx += req->idx_growth;
-	c->budg_data_growth -= req->data_growth;
-	c->budg_dd_growth -= req->dd_growth;
-	c->min_idx_lebs = ubifs_calc_min_idx_lebs(c);
-
-	ubifs_assert(c->budg_idx_growth >= 0);
-	ubifs_assert(c->budg_data_growth >= 0);
-	ubifs_assert(c->budg_dd_growth >= 0);
-	ubifs_assert(c->min_idx_lebs < c->main_lebs);
-	ubifs_assert(!(c->budg_idx_growth & 7));
-	ubifs_assert(!(c->budg_data_growth & 7));
-	ubifs_assert(!(c->budg_dd_growth & 7));
+	c->bi.idx_growth -= req->idx_growth;
+	c->bi.uncommitted_idx += req->idx_growth;
+	c->bi.data_growth -= req->data_growth;
+	c->bi.dd_growth -= req->dd_growth;
+	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
+
+	ubifs_assert(c->bi.idx_growth >= 0);
+	ubifs_assert(c->bi.data_growth >= 0);
+	ubifs_assert(c->bi.dd_growth >= 0);
+	ubifs_assert(c->bi.min_idx_lebs < c->main_lebs);
+	ubifs_assert(!(c->bi.idx_growth & 7));
+	ubifs_assert(!(c->bi.data_growth & 7));
+	ubifs_assert(!(c->bi.dd_growth & 7));
 	spin_unlock(&c->space_lock);
 }
 
@@ -586,13 +586,13 @@ void ubifs_convert_page_budget(struct ubifs_info *c)
 {
 	spin_lock(&c->space_lock);
 	/* Release the index growth reservation */
-	c->budg_idx_growth -= c->max_idx_node_sz << UBIFS_BLOCKS_PER_PAGE_SHIFT;
+	c->bi.idx_growth -= c->max_idx_node_sz << UBIFS_BLOCKS_PER_PAGE_SHIFT;
 	/* Release the data growth reservation */
-	c->budg_data_growth -= c->page_budget;
+	c->bi.data_growth -= c->bi.page_budget;
 	/* Increase the dirty data growth reservation instead */
-	c->budg_dd_growth += c->page_budget;
+	c->bi.dd_growth += c->bi.page_budget;
 	/* And re-calculate the indexing space reservation */
-	c->min_idx_lebs = ubifs_calc_min_idx_lebs(c);
+	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
 	spin_unlock(&c->space_lock);
 }
 
@@ -612,7 +612,7 @@ void ubifs_release_dirty_inode_budget(struct ubifs_info *c,
 
 	memset(&req, 0, sizeof(struct ubifs_budget_req));
 	/* The "no space" flags will be cleared because dd_growth is > 0 */
-	req.dd_growth = c->inode_budget + ALIGN(ui->data_len, 8);
+	req.dd_growth = c->bi.inode_budget + ALIGN(ui->data_len, 8);
 	ubifs_release_budget(c, &req);
 }
 
@@ -682,9 +682,9 @@ long long ubifs_get_free_space_nolock(struct ubifs_info *c)
 	int rsvd_idx_lebs, lebs;
 	long long available, outstanding, free;
 
-	ubifs_assert(c->min_idx_lebs == ubifs_calc_min_idx_lebs(c));
-	outstanding = c->budg_data_growth + c->budg_dd_growth;
-	available = ubifs_calc_available(c, c->min_idx_lebs);
+	ubifs_assert(c->bi.min_idx_lebs == ubifs_calc_min_idx_lebs(c));
+	outstanding = c->bi.data_growth + c->bi.dd_growth;
+	available = ubifs_calc_available(c, c->bi.min_idx_lebs);
 
 	/*
 	 * When reporting free space to user-space, UBIFS guarantees that it is
@@ -697,8 +697,8 @@ long long ubifs_get_free_space_nolock(struct ubifs_info *c)
 	 * Note, the calculations below are similar to what we have in
 	 * 'do_budget_space()', so refer there for comments.
 	 */
-	if (c->min_idx_lebs > c->lst.idx_lebs)
-		rsvd_idx_lebs = c->min_idx_lebs - c->lst.idx_lebs;
+	if (c->bi.min_idx_lebs > c->lst.idx_lebs)
+		rsvd_idx_lebs = c->bi.min_idx_lebs - c->lst.idx_lebs;
 	else
 		rsvd_idx_lebs = 0;
 	lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt -
diff --git a/fs/ubifs/commit.c b/fs/ubifs/commit.c
index 1bd01de..87cd0ea 100644
--- a/fs/ubifs/commit.c
+++ b/fs/ubifs/commit.c
@@ -182,7 +182,7 @@ static int do_commit(struct ubifs_info *c)
 	c->mst_node->root_len    = cpu_to_le32(zroot.len);
 	c->mst_node->ihead_lnum  = cpu_to_le32(c->ihead_lnum);
 	c->mst_node->ihead_offs  = cpu_to_le32(c->ihead_offs);
-	c->mst_node->index_size  = cpu_to_le64(c->old_idx_sz);
+	c->mst_node->index_size  = cpu_to_le64(c->bi.old_idx_sz);
 	c->mst_node->lpt_lnum    = cpu_to_le32(c->lpt_lnum);
 	c->mst_node->lpt_offs    = cpu_to_le32(c->lpt_offs);
 	c->mst_node->nhead_lnum  = cpu_to_le32(c->nhead_lnum);
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index c04efa8..5e8d6d3 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -614,14 +614,14 @@ void dbg_dump_budg(struct ubifs_info *c)
 	spin_lock(&dbg_lock);
 	printk(KERN_DEBUG "(pid %d) Budgeting info: budg_data_growth %lld, "
 	       "budg_dd_growth %lld, budg_idx_growth %lld\n", current->pid,
-	       c->budg_data_growth, c->budg_dd_growth, c->budg_idx_growth);
+	       c->bi.data_growth, c->bi.dd_growth, c->bi.idx_growth);
 	printk(KERN_DEBUG "\tdata budget sum %lld, total budget sum %lld, "
-	       "freeable_cnt %d\n", c->budg_data_growth + c->budg_dd_growth,
-	       c->budg_data_growth + c->budg_dd_growth + c->budg_idx_growth,
+	       "freeable_cnt %d\n", c->bi.data_growth + c->bi.dd_growth,
+	       c->bi.data_growth + c->bi.dd_growth + c->bi.idx_growth,
 	       c->freeable_cnt);
 	printk(KERN_DEBUG "\tmin_idx_lebs %d, old_idx_sz %lld, "
-	       "calc_idx_sz %lld, idx_gc_cnt %d\n", c->min_idx_lebs,
-	       c->old_idx_sz, c->calc_idx_sz, c->idx_gc_cnt);
+	       "calc_idx_sz %lld, idx_gc_cnt %d\n", c->bi.min_idx_lebs,
+	       c->bi.old_idx_sz, c->calc_idx_sz, c->idx_gc_cnt);
 	printk(KERN_DEBUG "\tdirty_pg_cnt %ld, dirty_zn_cnt %ld, "
 	       "clean_zn_cnt %ld\n", atomic_long_read(&c->dirty_pg_cnt),
 	       atomic_long_read(&c->dirty_zn_cnt),
@@ -648,8 +648,8 @@ void dbg_dump_budg(struct ubifs_info *c)
 	printk(KERN_DEBUG "\tcommit state %d\n", c->cmt_state);
 
 	/* Print budgeting predictions */
-	available = ubifs_calc_available(c, c->min_idx_lebs);
-	outstanding = c->budg_data_growth + c->budg_dd_growth;
+	available = ubifs_calc_available(c, c->bi.min_idx_lebs);
+	outstanding = c->bi.data_growth + c->bi.dd_growth;
 	free = ubifs_get_free_space_nolock(c);
 	printk(KERN_DEBUG "Budgeting predictions:\n");
 	printk(KERN_DEBUG "\tavailable: %lld, outstanding %lld, free %lld\n",
@@ -996,7 +996,7 @@ int dbg_check_space_info(struct ubifs_info *c)
 	long long avail, free;
 
 	spin_lock(&c->space_lock);
-	avail = ubifs_calc_available(c, c->min_idx_lebs);
+	avail = ubifs_calc_available(c, c->bi.min_idx_lebs);
 	spin_unlock(&c->space_lock);
 	free = ubifs_get_free_space(c);
 
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index 7217d67..ef5abd3 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -603,7 +603,7 @@ static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
 		ubifs_release_budget(c, &req);
 	else {
 		/* We've deleted something - clean the "no space" flags */
-		c->nospace = c->nospace_rp = 0;
+		c->bi.nospace = c->bi.nospace_rp = 0;
 		smp_wmb();
 	}
 	return 0;
@@ -693,7 +693,7 @@ static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
 		ubifs_release_budget(c, &req);
 	else {
 		/* We've deleted something - clean the "no space" flags */
-		c->nospace = c->nospace_rp = 0;
+		c->bi.nospace = c->bi.nospace_rp = 0;
 		smp_wmb();
 	}
 	return 0;
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 0f20df5..a2b5012 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -212,7 +212,7 @@ static void release_new_page_budget(struct ubifs_info *c)
  */
 static void release_existing_page_budget(struct ubifs_info *c)
 {
-	struct ubifs_budget_req req = { .dd_growth = c->page_budget};
+	struct ubifs_budget_req req = { .dd_growth = c->bi.page_budget};
 
 	ubifs_release_budget(c, &req);
 }
@@ -1189,7 +1189,7 @@ out_budg:
 	if (budgeted)
 		ubifs_release_budget(c, &req);
 	else {
-		c->nospace = c->nospace_rp = 0;
+		c->bi.nospace = c->bi.nospace_rp = 0;
 		smp_wmb();
 	}
 	return err;
diff --git a/fs/ubifs/find.c b/fs/ubifs/find.c
index 1d54383..2559d17 100644
--- a/fs/ubifs/find.c
+++ b/fs/ubifs/find.c
@@ -252,8 +252,8 @@ int ubifs_find_dirty_leb(struct ubifs_info *c, struct ubifs_lprops *ret_lp,
 		 * But if the index takes fewer LEBs than it is reserved for it,
 		 * this function must avoid picking those reserved LEBs.
 		 */
-		if (c->min_idx_lebs >= c->lst.idx_lebs) {
-			rsvd_idx_lebs = c->min_idx_lebs -  c->lst.idx_lebs;
+		if (c->bi.min_idx_lebs >= c->lst.idx_lebs) {
+			rsvd_idx_lebs = c->bi.min_idx_lebs -  c->lst.idx_lebs;
 			exclude_index = 1;
 		}
 		spin_unlock(&c->space_lock);
@@ -276,7 +276,7 @@ int ubifs_find_dirty_leb(struct ubifs_info *c, struct ubifs_lprops *ret_lp,
 			pick_free = 0;
 	} else {
 		spin_lock(&c->space_lock);
-		exclude_index = (c->min_idx_lebs >= c->lst.idx_lebs);
+		exclude_index = (c->bi.min_idx_lebs >= c->lst.idx_lebs);
 		spin_unlock(&c->space_lock);
 	}
 
@@ -501,8 +501,8 @@ int ubifs_find_free_space(struct ubifs_info *c, int min_space, int *offs,
 
 	/* Check if there are enough empty LEBs for commit */
 	spin_lock(&c->space_lock);
-	if (c->min_idx_lebs > c->lst.idx_lebs)
-		rsvd_idx_lebs = c->min_idx_lebs -  c->lst.idx_lebs;
+	if (c->bi.min_idx_lebs > c->lst.idx_lebs)
+		rsvd_idx_lebs = c->bi.min_idx_lebs -  c->lst.idx_lebs;
 	else
 		rsvd_idx_lebs = 0;
 	lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt -
diff --git a/fs/ubifs/master.c b/fs/ubifs/master.c
index 21f47af..278c238 100644
--- a/fs/ubifs/master.c
+++ b/fs/ubifs/master.c
@@ -148,7 +148,7 @@ static int validate_master(const struct ubifs_info *c)
 	}
 
 	main_sz = (long long)c->main_lebs * c->leb_size;
-	if (c->old_idx_sz & 7 || c->old_idx_sz >= main_sz) {
+	if (c->bi.old_idx_sz & 7 || c->bi.old_idx_sz >= main_sz) {
 		err = 9;
 		goto out;
 	}
@@ -218,7 +218,7 @@ static int validate_master(const struct ubifs_info *c)
 	}
 
 	if (c->lst.total_dead + c->lst.total_dark +
-	    c->lst.total_used + c->old_idx_sz > main_sz) {
+	    c->lst.total_used + c->bi.old_idx_sz > main_sz) {
 		err = 21;
 		goto out;
 	}
@@ -286,7 +286,7 @@ int ubifs_read_master(struct ubifs_info *c)
 	c->gc_lnum         = le32_to_cpu(c->mst_node->gc_lnum);
 	c->ihead_lnum      = le32_to_cpu(c->mst_node->ihead_lnum);
 	c->ihead_offs      = le32_to_cpu(c->mst_node->ihead_offs);
-	c->old_idx_sz      = le64_to_cpu(c->mst_node->index_size);
+	c->bi.old_idx_sz   = le64_to_cpu(c->mst_node->index_size);
 	c->lpt_lnum        = le32_to_cpu(c->mst_node->lpt_lnum);
 	c->lpt_offs        = le32_to_cpu(c->mst_node->lpt_offs);
 	c->nhead_lnum      = le32_to_cpu(c->mst_node->nhead_lnum);
@@ -305,7 +305,7 @@ int ubifs_read_master(struct ubifs_info *c)
 	c->lst.total_dead  = le64_to_cpu(c->mst_node->total_dead);
 	c->lst.total_dark  = le64_to_cpu(c->mst_node->total_dark);
 
-	c->calc_idx_sz = c->old_idx_sz;
+	c->calc_idx_sz = c->bi.old_idx_sz;
 
 	if (c->mst_node->flags & cpu_to_le32(UBIFS_MST_NO_ORPHS))
 		c->no_orphs = 1;
diff --git a/fs/ubifs/replay.c b/fs/ubifs/replay.c
index eed0fcf..b716a18 100644
--- a/fs/ubifs/replay.c
+++ b/fs/ubifs/replay.c
@@ -1059,13 +1059,13 @@ int ubifs_replay_journal(struct ubifs_info *c)
 		goto out;
 
 	/*
-	 * UBIFS budgeting calculations use @c->budg_uncommitted_idx variable
-	 * to roughly estimate index growth. Things like @c->min_idx_lebs
+	 * UBIFS budgeting calculations use @c->bi.uncommitted_idx variable
+	 * to roughly estimate index growth. Things like @c->bi.min_idx_lebs
 	 * depend on it. This means we have to initialize it to make sure
 	 * budgeting works properly.
 	 */
-	c->budg_uncommitted_idx = atomic_long_read(&c->dirty_zn_cnt);
-	c->budg_uncommitted_idx *= c->max_idx_node_sz;
+	c->bi.uncommitted_idx = atomic_long_read(&c->dirty_zn_cnt);
+	c->bi.uncommitted_idx *= c->max_idx_node_sz;
 
 	ubifs_assert(c->bud_bytes <= c->max_bud_bytes || c->need_recovery);
 	dbg_mnt("finished, log head LEB %d:%d, max_sqnum %llu, "
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index e0fb6b8..b9dc373 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -375,7 +375,7 @@ out:
 		ubifs_release_dirty_inode_budget(c, ui);
 	else {
 		/* We've deleted something - clean the "no space" flags */
-		c->nospace = c->nospace_rp = 0;
+		c->bi.nospace = c->bi.nospace_rp = 0;
 		smp_wmb();
 	}
 done:
@@ -694,11 +694,11 @@ static int init_constants_sb(struct ubifs_info *c)
 	 * be compressed and direntries are of the maximum size.
 	 *
 	 * Note, data, which may be stored in inodes is budgeted separately, so
-	 * it is not included into 'c->inode_budget'.
+	 * it is not included into 'c->bi.inode_budget'.
 	 */
-	c->page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
-	c->inode_budget = UBIFS_INO_NODE_SZ;
-	c->dent_budget = UBIFS_MAX_DENT_NODE_SZ;
+	c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
+	c->bi.inode_budget = UBIFS_INO_NODE_SZ;
+	c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ;
 
 	/*
 	 * When the amount of flash space used by buds becomes
@@ -742,7 +742,7 @@ static void init_constants_master(struct ubifs_info *c)
 {
 	long long tmp64;
 
-	c->min_idx_lebs = ubifs_calc_min_idx_lebs(c);
+	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
 	c->report_rp_size = ubifs_reported_space(c, c->rp_size);
 
 	/*
@@ -1304,7 +1304,7 @@ static int mount_ubifs(struct ubifs_info *c)
 	if (err)
 		goto out_lpt;
 
-	err = dbg_check_idx_size(c, c->old_idx_sz);
+	err = dbg_check_idx_size(c, c->bi.old_idx_sz);
 	if (err)
 		goto out_lpt;
 
@@ -1313,7 +1313,7 @@ static int mount_ubifs(struct ubifs_info *c)
 		goto out_journal;
 
 	/* Calculate 'min_idx_lebs' after journal replay */
-	c->min_idx_lebs = ubifs_calc_min_idx_lebs(c);
+	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
 
 	err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
 	if (err)
@@ -1442,7 +1442,8 @@ static int mount_ubifs(struct ubifs_info *c)
 		c->main_lebs, c->main_first, c->leb_cnt - 1);
 	dbg_msg("index LEBs:          %d", c->lst.idx_lebs);
 	dbg_msg("total index bytes:   %lld (%lld KiB, %lld MiB)",
-		c->old_idx_sz, c->old_idx_sz >> 10, c->old_idx_sz >> 20);
+		c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
+		c->bi.old_idx_sz >> 20);
 	dbg_msg("key hash type:       %d", c->key_hash_type);
 	dbg_msg("tree fanout:         %d", c->fanout);
 	dbg_msg("reserved GC LEB:     %d", c->gc_lnum);
@@ -1762,9 +1763,9 @@ static void ubifs_put_super(struct super_block *sb)
 	 * to write them back because of I/O errors.
 	 */
 	ubifs_assert(atomic_long_read(&c->dirty_pg_cnt) == 0);
-	ubifs_assert(c->budg_idx_growth == 0);
-	ubifs_assert(c->budg_dd_growth == 0);
-	ubifs_assert(c->budg_data_growth == 0);
+	ubifs_assert(c->bi.idx_growth == 0);
+	ubifs_assert(c->bi.dd_growth == 0);
+	ubifs_assert(c->bi.data_growth == 0);
 
 	/*
 	 * The 'c->umount_lock' prevents races between UBIFS memory shrinker
diff --git a/fs/ubifs/tnc_commit.c b/fs/ubifs/tnc_commit.c
index 53288e5..9c376b9 100644
--- a/fs/ubifs/tnc_commit.c
+++ b/fs/ubifs/tnc_commit.c
@@ -796,16 +796,16 @@ int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot)
 	spin_lock(&c->space_lock);
 	/*
 	 * Although we have not finished committing yet, update size of the
-	 * committed index ('c->old_idx_sz') and zero out the index growth
+	 * committed index ('c->bi.old_idx_sz') and zero out the index growth
 	 * budget. It is OK to do this now, because we've reserved all the
 	 * space which is needed to commit the index, and it is save for the
 	 * budgeting subsystem to assume the index is already committed,
 	 * even though it is not.
 	 */
-	ubifs_assert(c->min_idx_lebs == ubifs_calc_min_idx_lebs(c));
-	c->old_idx_sz = c->calc_idx_sz;
-	c->budg_uncommitted_idx = 0;
-	c->min_idx_lebs = ubifs_calc_min_idx_lebs(c);
+	ubifs_assert(c->bi.min_idx_lebs == ubifs_calc_min_idx_lebs(c));
+	c->bi.old_idx_sz = c->calc_idx_sz;
+	c->bi.uncommitted_idx = 0;
+	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
 	spin_unlock(&c->space_lock);
 	mutex_unlock(&c->tnc_mutex);
 
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index d4c07a9..26a7ebe 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -937,6 +937,40 @@ struct ubifs_mount_opts {
 	unsigned int compr_type:2;
 };
 
+/**
+ * struct ubifs_budg_info - UBIFS budgeting information.
+ * @idx_growth: amount of bytes budgeted for index growth
+ * @data_growth: amount of bytes budgeted for cached data
+ * @dd_growth: amount of bytes budgeted for cached data that will make
+ *             other data dirty
+ * @uncommitted_idx: amount of bytes were budgeted for growth of the index, but
+ *                   which still have to be taken into account because the index
+ *                   has not been committed so far
+ * @old_idx_sz: size of index on flash
+ * @min_idx_lebs: minimum number of LEBs required for the index
+ * @nospace: non-zero if the file-system does not have flash space (used as
+ *           optimization)
+ * @nospace_rp: the same as @nospace, but additionally means that even reserved
+ *              pool is full
+ * @page_budget: budget for a page (constant, nenver changed after mount)
+ * @inode_budget: budget for an inode (constant, nenver changed after mount)
+ * @dent_budget: budget for a directory entry (constant, nenver changed after
+ *               mount)
+ */
+struct ubifs_budg_info {
+	long long idx_growth;
+	long long data_growth;
+	long long dd_growth;
+	long long uncommitted_idx;
+	unsigned long long old_idx_sz;
+	int min_idx_lebs;
+	unsigned int nospace:1;
+	unsigned int nospace_rp:1;
+	int page_budget;
+	int inode_budget;
+	int dent_budget;
+};
+
 struct ubifs_debug_info;
 
 /**
@@ -1057,32 +1091,14 @@ struct ubifs_debug_info;
  * @dirty_zn_cnt: number of dirty znodes
  * @clean_zn_cnt: number of clean znodes
  *
- * @budg_idx_growth: amount of bytes budgeted for index growth
- * @budg_data_growth: amount of bytes budgeted for cached data
- * @budg_dd_growth: amount of bytes budgeted for cached data that will make
- *                  other data dirty
- * @budg_uncommitted_idx: amount of bytes were budgeted for growth of the index,
- *                        but which still have to be taken into account because
- *                        the index has not been committed so far
- * @space_lock: protects @budg_idx_growth, @budg_data_growth, @budg_dd_growth,
- *              @budg_uncommited_idx, @min_idx_lebs, @old_idx_sz, @lst,
- *              @nospace, and @nospace_rp;
- * @min_idx_lebs: minimum number of LEBs required for the index
- * @old_idx_sz: size of index on flash
+ * @space_lock: protects @bi and @lst
+ * @lst: lprops statistics
+ * @bi: budgeting information
  * @calc_idx_sz: temporary variable which is used to calculate new index size
  *               (contains accurate new index size at end of TNC commit start)
- * @lst: lprops statistics
- * @nospace: non-zero if the file-system does not have flash space (used as
- *           optimization)
- * @nospace_rp: the same as @nospace, but additionally means that even reserved
- *              pool is full
- *
- * @page_budget: budget for a page
- * @inode_budget: budget for an inode
- * @dent_budget: budget for a directory entry
  *
  * @ref_node_alsz: size of the LEB reference node aligned to the min. flash
- * I/O unit
+ *                 I/O unit
  * @mst_node_alsz: master node aligned size
  * @min_idx_node_sz: minimum indexing node aligned on 8-bytes boundary
  * @max_idx_node_sz: maximum indexing node aligned on 8-bytes boundary
@@ -1308,21 +1324,10 @@ struct ubifs_info {
 	atomic_long_t dirty_zn_cnt;
 	atomic_long_t clean_zn_cnt;
 
-	long long budg_idx_growth;
-	long long budg_data_growth;
-	long long budg_dd_growth;
-	long long budg_uncommitted_idx;
 	spinlock_t space_lock;
-	int min_idx_lebs;
-	unsigned long long old_idx_sz;
-	unsigned long long calc_idx_sz;
 	struct ubifs_lp_stats lst;
-	unsigned int nospace:1;
-	unsigned int nospace_rp:1;
-
-	int page_budget;
-	int inode_budget;
-	int dent_budget;
+	struct ubifs_budg_info bi;
+	unsigned long long calc_idx_sz;
 
 	int ref_node_alsz;
 	int mst_node_alsz;
-- 
1.7.2.3

[PATCH 2/5] UBIFS: simplify dbg_dump_budg calling conventions

[Artem Bityutskiy]

From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

The current 'dbg_dump_budg()' calling convention is that the
'c->space_lock' spinlock is held. However, none of the callers
actually use it from contects which have 'c->space_lock' locked,
so all callers have to explicitely lock and unlock the spinlock.
This is not very sensible convention. This patch changes it and
makes 'dbg_dump_budg()' lock the spinlock instead of imposing this
to the callers. This simplifies the code a little.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 fs/ubifs/debug.c      |   12 ++++--------
 fs/ubifs/journal.c    |    2 --
 fs/ubifs/tnc_commit.c |    2 --
 3 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index 5e8d6d3..68014aa 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -610,7 +610,7 @@ void dbg_dump_budg(struct ubifs_info *c)
 	struct ubifs_gced_idx_leb *idx_gc;
 	long long available, outstanding, free;
 
-	ubifs_assert(spin_is_locked(&c->space_lock));
+	spin_lock(&c->space_lock);
 	spin_lock(&dbg_lock);
 	printk(KERN_DEBUG "(pid %d) Budgeting info: budg_data_growth %lld, "
 	       "budg_dd_growth %lld, budg_idx_growth %lld\n", current->pid,
@@ -655,6 +655,7 @@ void dbg_dump_budg(struct ubifs_info *c)
 	printk(KERN_DEBUG "\tavailable: %lld, outstanding %lld, free %lld\n",
 	       available, outstanding, free);
 	spin_unlock(&dbg_lock);
+	spin_unlock(&c->space_lock);
 }
 
 void dbg_dump_lprop(const struct ubifs_info *c, const struct ubifs_lprops *lp)
@@ -1015,10 +1016,7 @@ out:
 
 	ubifs_msg("current lprops statistics dump");
 	dbg_dump_lstats(&lst);
-
-	spin_lock(&c->space_lock);
 	dbg_dump_budg(c);
-	spin_unlock(&c->space_lock);
 	dump_stack();
 	return -EINVAL;
 }
@@ -2765,11 +2763,9 @@ static ssize_t write_debugfs_file(struct file *file, const char __user *buf,
 
 	if (file->f_path.dentry == d->dfs_dump_lprops)
 		dbg_dump_lprops(c);
-	else if (file->f_path.dentry == d->dfs_dump_budg) {
-		spin_lock(&c->space_lock);
+	else if (file->f_path.dentry == d->dfs_dump_budg)
 		dbg_dump_budg(c);
-		spin_unlock(&c->space_lock);
-	} else if (file->f_path.dentry == d->dfs_dump_tnc) {
+	else if (file->f_path.dentry == d->dfs_dump_tnc) {
 		mutex_lock(&c->tnc_mutex);
 		dbg_dump_tnc(c);
 		mutex_unlock(&c->tnc_mutex);
diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
index aed25e8..65d485f 100644
--- a/fs/ubifs/journal.c
+++ b/fs/ubifs/journal.c
@@ -380,10 +380,8 @@ out:
 	if (err == -ENOSPC) {
 		/* This are some budgeting problems, print useful information */
 		down_write(&c->commit_sem);
-		spin_lock(&c->space_lock);
 		dbg_dump_stack();
 		dbg_dump_budg(c);
-		spin_unlock(&c->space_lock);
 		dbg_dump_lprops(c);
 		cmt_retries = dbg_check_lprops(c);
 		up_write(&c->commit_sem);
diff --git a/fs/ubifs/tnc_commit.c b/fs/ubifs/tnc_commit.c
index 9c376b9..66f066d 100644
--- a/fs/ubifs/tnc_commit.c
+++ b/fs/ubifs/tnc_commit.c
@@ -383,9 +383,7 @@ static int layout_in_gaps(struct ubifs_info *c, int cnt)
 				 * option which forces in-the-gaps is enabled.
 				 */
 				ubifs_err("out of space");
-				spin_lock(&c->space_lock);
 				dbg_dump_budg(c);
-				spin_unlock(&c->space_lock);
 				dbg_dump_lprops(c);
 			}
 			/* Try to commit anyway */
-- 
1.7.2.3

[PATCH 3/5] UBIFS: rearrange the budget dump

[Artem Bityutskiy]

From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

Re-arrange the budget dump and make sure we first dump all
the 'struct ubifs_budg_info' fields, and then the other information.
Additionally, print the 'uncommitted_idx' variable.

This change is required for to the following dumping function
enhancement where it will be possible to dump saved
'struct ubifs_budg_info' objects, not only the current one.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 fs/ubifs/debug.c |   30 ++++++++++++++++++------------
 1 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index 68014aa..6646009 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -612,22 +612,28 @@ void dbg_dump_budg(struct ubifs_info *c)
 
 	spin_lock(&c->space_lock);
 	spin_lock(&dbg_lock);
-	printk(KERN_DEBUG "(pid %d) Budgeting info: budg_data_growth %lld, "
-	       "budg_dd_growth %lld, budg_idx_growth %lld\n", current->pid,
-	       c->bi.data_growth, c->bi.dd_growth, c->bi.idx_growth);
-	printk(KERN_DEBUG "\tdata budget sum %lld, total budget sum %lld, "
-	       "freeable_cnt %d\n", c->bi.data_growth + c->bi.dd_growth,
-	       c->bi.data_growth + c->bi.dd_growth + c->bi.idx_growth,
-	       c->freeable_cnt);
-	printk(KERN_DEBUG "\tmin_idx_lebs %d, old_idx_sz %lld, "
-	       "calc_idx_sz %lld, idx_gc_cnt %d\n", c->bi.min_idx_lebs,
-	       c->bi.old_idx_sz, c->calc_idx_sz, c->idx_gc_cnt);
+	printk(KERN_DEBUG "(pid %d) Budgeting info: data budget sum %lld, "
+	       "total budget sum %lld\n", current->pid,
+	       c->bi.data_growth + c->bi.dd_growth,
+	       c->bi.data_growth + c->bi.dd_growth + c->bi.idx_growth);
+	printk(KERN_DEBUG "\tbudg_data_growth %lld, budg_dd_growth %lld, "
+	       "budg_idx_growth %lld\n", c->bi.data_growth, c->bi.dd_growth,
+	       c->bi.idx_growth);
+	printk(KERN_DEBUG "\tmin_idx_lebs %d, old_idx_sz %llu, "
+	       "uncommitted_idx %lld\n", c->bi.min_idx_lebs, c->bi.old_idx_sz,
+	       c->bi.uncommitted_idx);
+	printk(KERN_DEBUG "\tpage_budget %d, inode_budget %d, dent_budget %d\n",
+	       c->bi.page_budget, c->bi.inode_budget, c->bi.dent_budget);
+	printk(KERN_DEBUG "\tnospace %u, nospace_rp %u\n",
+	       c->bi.nospace, c->bi.nospace_rp);
+	printk(KERN_DEBUG "\tdark_wm %d, dead_wm %d, max_idx_node_sz %d\n",
+	       c->dark_wm, c->dead_wm, c->max_idx_node_sz);
+	printk(KERN_DEBUG "freeable_cnt %d, calc_idx_sz %lld, idx_gc_cnt %d\n",
+	       c->freeable_cnt, c->calc_idx_sz, c->idx_gc_cnt);
 	printk(KERN_DEBUG "\tdirty_pg_cnt %ld, dirty_zn_cnt %ld, "
 	       "clean_zn_cnt %ld\n", atomic_long_read(&c->dirty_pg_cnt),
 	       atomic_long_read(&c->dirty_zn_cnt),
 	       atomic_long_read(&c->clean_zn_cnt));
-	printk(KERN_DEBUG "\tdark_wm %d, dead_wm %d, max_idx_node_sz %d\n",
-	       c->dark_wm, c->dead_wm, c->max_idx_node_sz);
 	printk(KERN_DEBUG "\tgc_lnum %d, ihead_lnum %d\n",
 	       c->gc_lnum, c->ihead_lnum);
 	/* If we are in R/O mode, journal heads do not exist */
-- 
1.7.2.3

[PATCH 4/5] UBIFS: improve space checking debugging feature

[Artem Bityutskiy]

From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch improves the 'dbg_check_space_info()' function which checks
whether the amount of space before re-mounting and after re-mounting
is the same (remounting from R/O to R/W modes and vice-versa).

The problem is that 'dbg_check_space_info()' does not save the budgeting
information before re-mounting, so when an error is reported, we do not
know why the amount of free space changed.

This patches makes the following changes:

1. Teaches 'dbg_dump_budg()' function to accept a 'struct ubifs_budg_info'
   argument and print out the this argument. This way we may ask it to
   print any saved budgeting info, no only the current one.
2. Accordingly changes all the callers of 'dbg_dump_budg()' to comply with
   the changed interface.
3. Introduce a 'saved_bi' (saved budgeting info) field to
   'struct ubifs_debug_info' and save the budgeting info before re-mounting
   there.
4. Change 'dbg_check_space_info()' and make it print both old and new
   budgeting information.
5. Additionally, save 'c->freeable_cnt' and 'c->igx_gc_cnt' and print them
   if and error happens. These values contribute to the amount of free space,
   so we have to print them.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 fs/ubifs/debug.c      |   49 +++++++++++++++++++++++++++++++++----------------
 fs/ubifs/debug.h      |   12 +++++++++---
 fs/ubifs/journal.c    |    2 +-
 fs/ubifs/super.c      |    2 +-
 fs/ubifs/tnc_commit.c |    2 +-
 5 files changed, 45 insertions(+), 22 deletions(-)

diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index 6646009..92b4709 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -602,7 +602,7 @@ void dbg_dump_lstats(const struct ubifs_lp_stats *lst)
 	spin_unlock(&dbg_lock);
 }
 
-void dbg_dump_budg(struct ubifs_info *c)
+void dbg_dump_budg(struct ubifs_info *c, const struct ubifs_budg_info *bi)
 {
 	int i;
 	struct rb_node *rb;
@@ -614,21 +614,30 @@ void dbg_dump_budg(struct ubifs_info *c)
 	spin_lock(&dbg_lock);
 	printk(KERN_DEBUG "(pid %d) Budgeting info: data budget sum %lld, "
 	       "total budget sum %lld\n", current->pid,
-	       c->bi.data_growth + c->bi.dd_growth,
-	       c->bi.data_growth + c->bi.dd_growth + c->bi.idx_growth);
+	       bi->data_growth + bi->dd_growth,
+	       bi->data_growth + bi->dd_growth + bi->idx_growth);
 	printk(KERN_DEBUG "\tbudg_data_growth %lld, budg_dd_growth %lld, "
-	       "budg_idx_growth %lld\n", c->bi.data_growth, c->bi.dd_growth,
-	       c->bi.idx_growth);
+	       "budg_idx_growth %lld\n", bi->data_growth, bi->dd_growth,
+	       bi->idx_growth);
 	printk(KERN_DEBUG "\tmin_idx_lebs %d, old_idx_sz %llu, "
-	       "uncommitted_idx %lld\n", c->bi.min_idx_lebs, c->bi.old_idx_sz,
-	       c->bi.uncommitted_idx);
+	       "uncommitted_idx %lld\n", bi->min_idx_lebs, bi->old_idx_sz,
+	       bi->uncommitted_idx);
 	printk(KERN_DEBUG "\tpage_budget %d, inode_budget %d, dent_budget %d\n",
-	       c->bi.page_budget, c->bi.inode_budget, c->bi.dent_budget);
+	       bi->page_budget, bi->inode_budget, bi->dent_budget);
 	printk(KERN_DEBUG "\tnospace %u, nospace_rp %u\n",
-	       c->bi.nospace, c->bi.nospace_rp);
+	       bi->nospace, bi->nospace_rp);
 	printk(KERN_DEBUG "\tdark_wm %d, dead_wm %d, max_idx_node_sz %d\n",
 	       c->dark_wm, c->dead_wm, c->max_idx_node_sz);
-	printk(KERN_DEBUG "freeable_cnt %d, calc_idx_sz %lld, idx_gc_cnt %d\n",
+
+	if (bi != &c->bi)
+		/*
+		 * If we are dumping saved budgeting data, do not print
+		 * additional information which is about the current state, not
+		 * the old one which corresponded to the saved budgeting data.
+		 */
+		goto out_unlock;
+
+	printk(KERN_DEBUG "\nfreeable_cnt %d, calc_idx_sz %lld, idx_gc_cnt %d\n",
 	       c->freeable_cnt, c->calc_idx_sz, c->idx_gc_cnt);
 	printk(KERN_DEBUG "\tdirty_pg_cnt %ld, dirty_zn_cnt %ld, "
 	       "clean_zn_cnt %ld\n", atomic_long_read(&c->dirty_pg_cnt),
@@ -636,6 +645,7 @@ void dbg_dump_budg(struct ubifs_info *c)
 	       atomic_long_read(&c->clean_zn_cnt));
 	printk(KERN_DEBUG "\tgc_lnum %d, ihead_lnum %d\n",
 	       c->gc_lnum, c->ihead_lnum);
+
 	/* If we are in R/O mode, journal heads do not exist */
 	if (c->jheads)
 		for (i = 0; i < c->jhead_cnt; i++)
@@ -660,6 +670,7 @@ void dbg_dump_budg(struct ubifs_info *c)
 	printk(KERN_DEBUG "Budgeting predictions:\n");
 	printk(KERN_DEBUG "\tavailable: %lld, outstanding %lld, free %lld\n",
 	       available, outstanding, free);
+out_unlock:
 	spin_unlock(&dbg_lock);
 	spin_unlock(&c->space_lock);
 }
@@ -980,10 +991,12 @@ void dbg_save_space_info(struct ubifs_info *c)
 {
 	struct ubifs_debug_info *d = c->dbg;
 
-	ubifs_get_lp_stats(c, &d->saved_lst);
-
 	spin_lock(&c->space_lock);
+	memcpy(&d->saved_lst, &c->lst, sizeof(struct ubifs_lp_stats));
+	memcpy(&d->saved_bi, &c->bi, sizeof(struct ubifs_budg_info));
 	d->saved_free = ubifs_get_free_space_nolock(c);
+	d->saved_freeable_cnt = c->freeable_cnt;
+	d->saved_idx_gc_cnt = c->idx_gc_cnt;
 	spin_unlock(&c->space_lock);
 }
 
@@ -1018,11 +1031,15 @@ int dbg_check_space_info(struct ubifs_info *c)
 out:
 	ubifs_msg("saved lprops statistics dump");
 	dbg_dump_lstats(&d->saved_lst);
-	ubifs_get_lp_stats(c, &lst);
-
+	ubifs_msg("saved budgeting info dump");
+	dbg_dump_budg(c, &d->saved_bi);
+	ubifs_msg("saved freeable_cnt %d, saved idx_gc_cnt %d",
+		  d->saved_freeable_cnt, d->saved_idx_gc_cnt);
 	ubifs_msg("current lprops statistics dump");
+	ubifs_get_lp_stats(c, &lst);
 	dbg_dump_lstats(&lst);
-	dbg_dump_budg(c);
+	ubifs_msg("current budgeting info dump");
+	dbg_dump_budg(c, &c->bi);
 	dump_stack();
 	return -EINVAL;
 }
@@ -2770,7 +2787,7 @@ static ssize_t write_debugfs_file(struct file *file, const char __user *buf,
 	if (file->f_path.dentry == d->dfs_dump_lprops)
 		dbg_dump_lprops(c);
 	else if (file->f_path.dentry == d->dfs_dump_budg)
-		dbg_dump_budg(c);
+		dbg_dump_budg(c, &c->bi);
 	else if (file->f_path.dentry == d->dfs_dump_tnc) {
 		mutex_lock(&c->tnc_mutex);
 		dbg_dump_tnc(c);
diff --git a/fs/ubifs/debug.h b/fs/ubifs/debug.h
index 919f0de..c217ae9 100644
--- a/fs/ubifs/debug.h
+++ b/fs/ubifs/debug.h
@@ -44,7 +44,10 @@
  * @new_ihead_offs: used by debugging to check @c->ihead_offs
  *
  * @saved_lst: saved lprops statistics (used by 'dbg_save_space_info()')
- * @saved_free: saved free space (used by 'dbg_save_space_info()')
+ * @saved_bi: saved budgeting information
+ * @saved_free: saved amount of free space
+ * @saved_freeable_cnt: saved value of @c->freeable_cnt
+ * @saved_idx_gc_cnt: saved value of @c->idx_gc_cnt
  *
  * dfs_dir_name: name of debugfs directory containing this file-system's files
  * dfs_dir: direntry object of the file-system debugfs directory
@@ -70,7 +73,10 @@ struct ubifs_debug_info {
 	int new_ihead_offs;
 
 	struct ubifs_lp_stats saved_lst;
+	struct ubifs_budg_info saved_bi;
 	long long saved_free;
+	int saved_freeable_cnt;
+	int saved_idx_gc_cnt;
 
 	char dfs_dir_name[100];
 	struct dentry *dfs_dir;
@@ -256,7 +262,7 @@ void dbg_dump_lpt_node(const struct ubifs_info *c, void *node, int lnum,
 		       int offs);
 void dbg_dump_budget_req(const struct ubifs_budget_req *req);
 void dbg_dump_lstats(const struct ubifs_lp_stats *lst);
-void dbg_dump_budg(struct ubifs_info *c);
+void dbg_dump_budg(struct ubifs_info *c, const struct ubifs_budg_info *bi);
 void dbg_dump_lprop(const struct ubifs_info *c, const struct ubifs_lprops *lp);
 void dbg_dump_lprops(struct ubifs_info *c);
 void dbg_dump_lpt_info(struct ubifs_info *c);
@@ -413,7 +419,7 @@ void dbg_debugfs_exit_fs(struct ubifs_info *c);
 #define dbg_dump_lpt_node(c, node, lnum, offs) ({})
 #define dbg_dump_budget_req(req)               ({})
 #define dbg_dump_lstats(lst)                   ({})
-#define dbg_dump_budg(c)                       ({})
+#define dbg_dump_budg(c, bi)                   ({})
 #define dbg_dump_lprop(c, lp)                  ({})
 #define dbg_dump_lprops(c)                     ({})
 #define dbg_dump_lpt_info(c)                   ({})
diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
index 65d485f..ce55a48 100644
--- a/fs/ubifs/journal.c
+++ b/fs/ubifs/journal.c
@@ -381,7 +381,7 @@ out:
 		/* This are some budgeting problems, print useful information */
 		down_write(&c->commit_sem);
 		dbg_dump_stack();
-		dbg_dump_budg(c);
+		dbg_dump_budg(c, &c->bi);
 		dbg_dump_lprops(c);
 		cmt_retries = dbg_check_lprops(c);
 		up_write(&c->commit_sem);
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index b9dc373..66c12cd 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1145,7 +1145,7 @@ static int check_free_space(struct ubifs_info *c)
 	ubifs_assert(c->dark_wm > 0);
 	if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
 		ubifs_err("insufficient free space to mount in R/W mode");
-		dbg_dump_budg(c);
+		dbg_dump_budg(c, &c->bi);
 		dbg_dump_lprops(c);
 		return -ENOSPC;
 	}
diff --git a/fs/ubifs/tnc_commit.c b/fs/ubifs/tnc_commit.c
index 66f066d..c471b06 100644
--- a/fs/ubifs/tnc_commit.c
+++ b/fs/ubifs/tnc_commit.c
@@ -383,7 +383,7 @@ static int layout_in_gaps(struct ubifs_info *c, int cnt)
 				 * option which forces in-the-gaps is enabled.
 				 */
 				ubifs_err("out of space");
-				dbg_dump_budg(c);
+				dbg_dump_budg(c, &c->bi);
 				dbg_dump_lprops(c);
 			}
 			/* Try to commit anyway */
-- 
1.7.2.3

[PATCH 5/5] UBIFS: fix debugging failure in dbg_check_space_info

[Artem Bityutskiy]

From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch fixes a debugging failure with which looks like this:
UBIFS error (pid 32313): dbg_check_space_info: free space changed from 6019344 to 6022654

The reason for this failure is described in the comment this patch adds
to the code. But in short - 'c->freeable_cnt' may be different before
and after re-mounting, and this is normal. So the debugging code should
make sure that free space calculations do not depend on 'c->freeable_cnt'.

A similar issue has been reported here:
http://lists.infradead.org/pipermail/linux-mtd/2011-April/034647.html

This patch should fix it.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 fs/ubifs/debug.c |   41 ++++++++++++++++++++++++++++++++++++-----
 1 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index 92b4709..12c000b 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -990,13 +990,41 @@ void dbg_dump_index(struct ubifs_info *c)
 void dbg_save_space_info(struct ubifs_info *c)
 {
 	struct ubifs_debug_info *d = c->dbg;
+	int freeable_cnt;
 
 	spin_lock(&c->space_lock);
 	memcpy(&d->saved_lst, &c->lst, sizeof(struct ubifs_lp_stats));
 	memcpy(&d->saved_bi, &c->bi, sizeof(struct ubifs_budg_info));
-	d->saved_free = ubifs_get_free_space_nolock(c);
-	d->saved_freeable_cnt = c->freeable_cnt;
 	d->saved_idx_gc_cnt = c->idx_gc_cnt;
+
+	/*
+	 * We use a dirty hack here and zero out @c->freeable_cnt, because it
+	 * affects the free space calculations, and UBIFS might not know about
+	 * all freeable eraseblocks. Indeed, we know about freeable eraseblocks
+	 * only when we read their lprops, and we do this only lazily, upon the
+	 * need. So at any given point of time @c->freeable_cnt might be not
+	 * exactly accurate.
+	 *
+	 * Just one example about the issue we hit when we did not zero
+	 * @c->freeable_cnt.
+	 * 1. The file-system is mounted R/O, c->freeable_cnt is %0. We save the
+	 *    amount of free space in @d->saved_free
+	 * 2. We re-mount R/W, which makes UBIFS to read the "lsave"
+	 *    information from flash, where we cache LEBs from various
+	 *    categories ('ubifs_remount_fs()' -> 'ubifs_lpt_init()'
+	 *    -> 'lpt_init_wr()' -> 'read_lsave()' -> 'ubifs_lpt_lookup()'
+	 *    -> 'ubifs_get_pnode()' -> 'update_cats()'
+	 *    -> 'ubifs_add_to_cat()').
+	 * 3. Lsave contains a freeable eraseblock, and @c->freeable_cnt
+	 *    becomes %1.
+	 * 4. We calculate the amount of free space when the re-mount is
+	 *    finished in 'dbg_check_space_info()' and it does not match
+	 *    @d->saved_free.
+	 */
+	freeable_cnt = c->freeable_cnt;
+	c->freeable_cnt = 0;
+	d->saved_free = ubifs_get_free_space_nolock(c);
+	c->freeable_cnt = freeable_cnt;
 	spin_unlock(&c->space_lock);
 }
 
@@ -1013,12 +1041,15 @@ int dbg_check_space_info(struct ubifs_info *c)
 {
 	struct ubifs_debug_info *d = c->dbg;
 	struct ubifs_lp_stats lst;
-	long long avail, free;
+	long long free;
+	int freeable_cnt;
 
 	spin_lock(&c->space_lock);
-	avail = ubifs_calc_available(c, c->bi.min_idx_lebs);
+	freeable_cnt = c->freeable_cnt;
+	c->freeable_cnt = 0;
+	free = ubifs_get_free_space_nolock(c);
+	c->freeable_cnt = freeable_cnt;
 	spin_unlock(&c->space_lock);
-	free = ubifs_get_free_space(c);
 
 	if (free != d->saved_free) {
 		ubifs_err("free space changed from %lld to %lld",
-- 
1.7.2.3

Re: [PATCH 0/5] UBIFS: fix failure in dbg_check_space_info

[Artem Bityutskiy]

On Mon, 2011-04-04 at 17:44 +0300, Artem Bityutskiy wrote:
> This patch has to fix the failure in 'dbg_check_space_info()' which
> I can reproduce myself with the 'integck' test and which has also been
> reported here:
> 
> http://lists.infradead.org/pipermail/linux-mtd/2011-April/034647.html
> 
> The fix is in the last patch and it is quite trivial. It also describes
> the reason for the failure.
> 
> Patches 1-4 mostly improve the debugging output which helps to diagnose
> the problem quicker. So they are preparational patches.

Actually, I think this is bad arrangement. I'll re-arrange patches so
that the first patch is the fix, and then the debugging output
improvements. So you can pick only the fix, and I'll also send it to
-stable. I'll send you the fix shortly.

-- 
Best Regards,
Artem Bityutskiy (Артём Битюцкий)