[PATCH 1/2] quota: Provide interface for readding allocated space into reserved space

[PATCH 1/2] quota: Provide interface for readding allocated space into reserved space

[Jan Kara]

ext4 needs to convert allocated (metadata) blocks back into blocks
reserved for delayed allocation. Add functions into quota code for
supporting such operation.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/quota/dquot.c         | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 fs/stat.c                | 11 +++++++++--
 include/linux/fs.h       |  1 +
 include/linux/quotaops.h | 15 +++++++++++++++
 4 files changed, 71 insertions(+), 2 deletions(-)

 The ext4 patch depends on this so Ted please take it via ext4 tree. Thanks.

diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index fbad622..9a702e1 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -1094,6 +1094,14 @@ static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number)
 	dquot->dq_dqb.dqb_rsvspace -= number;
 }
 
+static void dquot_reclaim_reserved_space(struct dquot *dquot, qsize_t number)
+{
+	if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number))
+		number = dquot->dq_dqb.dqb_curspace;
+	dquot->dq_dqb.dqb_rsvspace += number;
+	dquot->dq_dqb.dqb_curspace -= number;
+}
+
 static inline
 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number)
 {
@@ -1528,6 +1536,15 @@ void inode_claim_rsv_space(struct inode *inode, qsize_t number)
 }
 EXPORT_SYMBOL(inode_claim_rsv_space);
 
+void inode_reclaim_rsv_space(struct inode *inode, qsize_t number)
+{
+	spin_lock(&inode->i_lock);
+	*inode_reserved_space(inode) += number;
+	__inode_sub_bytes(inode, number);
+	spin_unlock(&inode->i_lock);
+}
+EXPORT_SYMBOL(inode_reclaim_rsv_space);
+
 void inode_sub_rsv_space(struct inode *inode, qsize_t number)
 {
 	spin_lock(&inode->i_lock);
@@ -1702,6 +1719,35 @@ int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
 EXPORT_SYMBOL(dquot_claim_space_nodirty);
 
 /*
+ * Convert allocated space back to in-memory reserved quotas
+ */
+void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number)
+{
+	int cnt;
+
+	if (!dquot_active(inode)) {
+		inode_reclaim_rsv_space(inode, number);
+		return;
+	}
+
+	down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	spin_lock(&dq_data_lock);
+	/* Claim reserved quotas to allocated quotas */
+	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+		if (inode->i_dquot[cnt])
+			dquot_reclaim_reserved_space(inode->i_dquot[cnt],
+						     number);
+	}
+	/* Update inode bytes */
+	inode_reclaim_rsv_space(inode, number);
+	spin_unlock(&dq_data_lock);
+	mark_all_dquot_dirty(inode->i_dquot);
+	up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
+	return;
+}
+EXPORT_SYMBOL(dquot_reclaim_space_nodirty);
+
+/*
  * This operation can block, but only after everything is updated
  */
 void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
diff --git a/fs/stat.c b/fs/stat.c
index 04ce1ac..d0ea7ef 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -447,9 +447,8 @@ void inode_add_bytes(struct inode *inode, loff_t bytes)
 
 EXPORT_SYMBOL(inode_add_bytes);
 
-void inode_sub_bytes(struct inode *inode, loff_t bytes)
+void __inode_sub_bytes(struct inode *inode, loff_t bytes)
 {
-	spin_lock(&inode->i_lock);
 	inode->i_blocks -= bytes >> 9;
 	bytes &= 511;
 	if (inode->i_bytes < bytes) {
@@ -457,6 +456,14 @@ void inode_sub_bytes(struct inode *inode, loff_t bytes)
 		inode->i_bytes += 512;
 	}
 	inode->i_bytes -= bytes;
+}
+
+EXPORT_SYMBOL(__inode_sub_bytes);
+
+void inode_sub_bytes(struct inode *inode, loff_t bytes)
+{
+	spin_lock(&inode->i_lock);
+	__inode_sub_bytes(inode, bytes);
 	spin_unlock(&inode->i_lock);
 }
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9818747..e789352 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2503,6 +2503,7 @@ extern void generic_fillattr(struct inode *, struct kstat *);
 extern int vfs_getattr(struct path *, struct kstat *);
 void __inode_add_bytes(struct inode *inode, loff_t bytes);
 void inode_add_bytes(struct inode *inode, loff_t bytes);
+void __inode_sub_bytes(struct inode *inode, loff_t bytes);
 void inode_sub_bytes(struct inode *inode, loff_t bytes);
 loff_t inode_get_bytes(struct inode *inode);
 void inode_set_bytes(struct inode *inode, loff_t bytes);
diff --git a/include/linux/quotaops.h b/include/linux/quotaops.h
index 1c50093..6965fe3 100644
--- a/include/linux/quotaops.h
+++ b/include/linux/quotaops.h
@@ -41,6 +41,7 @@ void __quota_error(struct super_block *sb, const char *func,
 void inode_add_rsv_space(struct inode *inode, qsize_t number);
 void inode_claim_rsv_space(struct inode *inode, qsize_t number);
 void inode_sub_rsv_space(struct inode *inode, qsize_t number);
+void inode_reclaim_rsv_space(struct inode *inode, qsize_t number);
 
 void dquot_initialize(struct inode *inode);
 void dquot_drop(struct inode *inode);
@@ -59,6 +60,7 @@ int dquot_alloc_inode(const struct inode *inode);
 
 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number);
 void dquot_free_inode(const struct inode *inode);
+void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number);
 
 int dquot_disable(struct super_block *sb, int type, unsigned int flags);
 /* Suspend quotas on remount RO */
@@ -238,6 +240,13 @@ static inline int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
 	return 0;
 }
 
+static inline int dquot_reclaim_space_nodirty(struct inode *inode,
+					      qsize_t number)
+{
+	inode_sub_bytes(inode, number);
+	return 0;
+}
+
 static inline int dquot_disable(struct super_block *sb, int type,
 		unsigned int flags)
 {
@@ -336,6 +345,12 @@ static inline int dquot_claim_block(struct inode *inode, qsize_t nr)
 	return ret;
 }
 
+static inline void dquot_reclaim_block(struct inode *inode, qsize_t nr)
+{
+	dquot_reclaim_space_nodirty(inode, nr << inode->i_blkbits);
+	mark_inode_dirty_sync(inode);
+}
+
 static inline void dquot_free_space_nodirty(struct inode *inode, qsize_t nr)
 {
 	__dquot_free_space(inode, nr, 0);
-- 
1.8.1.4

[PATCH 2/2] ext4: Fix warning in ext4_da_update_reserve_space()

[Jan Kara]

reaim workfile.dbase test easily triggers warning in
ext4_da_update_reserve_space():

EXT4-fs warning (device ram0): ext4_da_update_reserve_space:365:
ino 12, allocated 1 with only 0 reserved metadata blocks (releasing 1
blocks with reserved 9 data blocks)

The problem is that (one of) tests creates file and then randomly writes
to it with O_SYNC. That results in writing back pages of the file in
random order so we create extents for written blocks say 0, 2, 4, 6, 8
- this last allocation also allocates new block for extents. Then we
writeout block 1 so we have extents 0-2, 4, 6, 8 and we release
indirect extent block because extents fit in the inode again. Then we
writeout block 10 and we need to allocate indirect extent block again
which triggers the warning because we don't have the reservation
anymore.

Fix the problem by giving back freed metadata blocks resulting from
extent merging into inode's reservation pool.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/ext4.h    |  1 +
 fs/ext4/extents.c |  3 ++-
 fs/ext4/mballoc.c | 21 +++++++++++++++++----
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 78a0b30..7f49dc7 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -569,6 +569,7 @@ enum {
 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE	0x0008
 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
+#define EXT4_FREE_BLOCKS_RESERVE		0x0040
 
 /*
  * ioctl commands
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index a618738..324dfc6 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1705,7 +1705,8 @@ static void ext4_ext_try_to_merge_up(handle_t *handle,
 
 	brelse(path[1].p_bh);
 	ext4_free_blocks(handle, inode, NULL, blk, 1,
-			 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
+			 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET |
+			 EXT4_FREE_BLOCKS_RESERVE);
 }
 
 /*
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 4bbbf13b..aa7d058 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4585,6 +4585,7 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
 	struct buffer_head *gd_bh;
 	ext4_group_t block_group;
 	struct ext4_sb_info *sbi;
+	struct ext4_inode_info *ei = EXT4_I(inode);
 	struct ext4_buddy e4b;
 	unsigned int count_clusters;
 	int err = 0;
@@ -4784,7 +4785,6 @@ do_more:
 	ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh);
 	ext4_group_desc_csum_set(sb, block_group, gdp);
 	ext4_unlock_group(sb, block_group);
-	percpu_counter_add(&sbi->s_freeclusters_counter, count_clusters);
 
 	if (sbi->s_log_groups_per_flex) {
 		ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
@@ -4792,10 +4792,23 @@ do_more:
 			     &sbi->s_flex_groups[flex_group].free_clusters);
 	}
 
-	ext4_mb_unload_buddy(&e4b);

Re: [PATCH 2/2] ext4: Fix warning in ext4_da_update_reserve_space()

[Theodore Ts'o]

On Fri, Aug 09, 2013 at 03:07:00PM +0200, Jan Kara wrote:
> reaim workfile.dbase test easily triggers warning in
> ext4_da_update_reserve_space():
> 
> EXT4-fs warning (device ram0): ext4_da_update_reserve_space:365:
> ino 12, allocated 1 with only 0 reserved metadata blocks (releasing 1
> blocks with reserved 9 data blocks)
> 
> The problem is that (one of) tests creates file and then randomly writes
> to it with O_SYNC. That results in writing back pages of the file in
> random order so we create extents for written blocks say 0, 2, 4, 6, 8
> - this last allocation also allocates new block for extents. Then we
> writeout block 1 so we have extents 0-2, 4, 6, 8 and we release
> indirect extent block because extents fit in the inode again. Then we
> writeout block 10 and we need to allocate indirect extent block again
> which triggers the warning because we don't have the reservation
> anymore.
> 
> Fix the problem by giving back freed metadata blocks resulting from
> extent merging into inode's reservation pool.
> 
> Signed-off-by: Jan Kara <jack@suse.cz>

Thanks, applied.

						- Ted

Re: [PATCH 1/2] quota: Provide interface for readding allocated space into reserved space

[Theodore Ts'o]

On Fri, Aug 09, 2013 at 03:06:59PM +0200, Jan Kara wrote:
> ext4 needs to convert allocated (metadata) blocks back into blocks
> reserved for delayed allocation. Add functions into quota code for
> supporting such operation.
> 
> Signed-off-by: Jan Kara <jack@suse.cz>

Thanks, applied.

						- Ted