[PATCH 1/5] f2fs: manipulate dirty file inodes when DATA_FLUSH is set

[PATCH 1/5] f2fs: manipulate dirty file inodes when DATA_FLUSH is set

[Jaegeuk Kim]

It needs to maintain dirty file inodes only if DATA_FLUSH is set.
Otherwise, let's avoid its overhead.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/checkpoint.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 3da6499..d04113b 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -785,9 +785,11 @@ void update_dirty_page(struct inode *inode, struct page *page)
 			!S_ISLNK(inode->i_mode))
 		return;
 
-	spin_lock(&sbi->inode_lock[type]);
-	__add_dirty_inode(inode, type);
-	spin_unlock(&sbi->inode_lock[type]);
+	if (type != FILE_INODE || test_opt(sbi, DATA_FLUSH)) {
+		spin_lock(&sbi->inode_lock[type]);
+		__add_dirty_inode(inode, type);
+		spin_unlock(&sbi->inode_lock[type]);
+	}
 
 	inode_inc_dirty_pages(inode);
 	SetPagePrivate(page);
@@ -803,6 +805,9 @@ void remove_dirty_inode(struct inode *inode)
 			!S_ISLNK(inode->i_mode))
 		return;
 
+	if (type == FILE_INODE && !test_opt(sbi, DATA_FLUSH))
+		return;
+
 	spin_lock(&sbi->inode_lock[type]);
 	__remove_dirty_inode(inode, type);
 	spin_unlock(&sbi->inode_lock[type]);
-- 
2.6.3


------------------------------------------------------------------------------
Mobile security can be enabling, not merely restricting. Employees who
bring their own devices (BYOD) to work are irked by the imposition of MDM
restrictions. Mobile Device Manager Plus allows you to control only the
apps on BYO-devices by containerizing them, leaving personal data untouched!
https://ad.doubleclick.net/ddm/clk/304595813;131938128;j

[PATCH 2/5] f2fs: use percpu_counter for page counters

[Jaegeuk Kim]

This patch substitutes percpu_counter for atomic_counter when counting
various types of pages.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/debug.c |  1 +
 fs/f2fs/f2fs.h  | 12 +++++++-----
 fs/f2fs/super.c | 31 +++++++++++++++++++++++++++----
 3 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index 37615b2..2210c7c 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -144,6 +144,7 @@ static void update_mem_info(struct f2fs_sb_info *sbi)
 	si->base_mem = sizeof(struct f2fs_sb_info) + sbi->sb->s_blocksize;
 	si->base_mem += 2 * sizeof(struct f2fs_inode_info);
 	si->base_mem += sizeof(*sbi->ckpt);
+	si->base_mem += sizeof(struct percpu_counter) * NR_COUNT_TYPE;
 
 	/* build sm */
 	si->base_mem += sizeof(struct f2fs_sm_info);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 24f8170..2851078 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -833,7 +833,9 @@ struct f2fs_sb_info {
 	block_t discard_blks;			/* discard command candidats */
 	block_t last_valid_block_count;		/* for recovery */
 	u32 s_next_generation;			/* for NFS support */
-	atomic_t nr_pages[NR_COUNT_TYPE];	/* # of pages, see count_type */
+
+	/* # of pages, see count_type */
+	struct percpu_counter nr_pages[NR_COUNT_TYPE];
 
 	struct f2fs_mount_info mount_opt;	/* mount options */
 
@@ -1178,7 +1180,7 @@ static inline void dec_valid_block_count(struct f2fs_sb_info *sbi,
 
 static inline void inc_page_count(struct f2fs_sb_info *sbi, int count_type)
 {
-	atomic_inc(&sbi->nr_pages[count_type]);
+	percpu_counter_inc(&sbi->nr_pages[count_type]);
 	set_sbi_flag(sbi, SBI_IS_DIRTY);
 }
 
@@ -1191,7 +1193,7 @@ static inline void inode_inc_dirty_pages(struct inode *inode)
 
 static inline void dec_page_count(struct f2fs_sb_info *sbi, int count_type)
 {
-	atomic_dec(&sbi->nr_pages[count_type]);
+	percpu_counter_dec(&sbi->nr_pages[count_type]);
 }
 
 static inline void inode_dec_dirty_pages(struct inode *inode)
@@ -1205,9 +1207,9 @@ static inline void inode_dec_dirty_pages(struct inode *inode)
 				F2FS_DIRTY_DENTS : F2FS_DIRTY_DATA);
 }
 
-static inline int get_pages(struct f2fs_sb_info *sbi, int count_type)
+static inline s64 get_pages(struct f2fs_sb_info *sbi, int count_type)
 {
-	return atomic_read(&sbi->nr_pages[count_type]);
+	return percpu_counter_sum_positive(&sbi->nr_pages[count_type]);
 }
 
 static inline int get_dirty_pages(struct inode *inode)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 9df6d72..b3030ed 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -606,6 +606,14 @@ static void f2fs_destroy_inode(struct inode *inode)
 	call_rcu(&inode->i_rcu, f2fs_i_callback);
 }
 
+static void destroy_percpu_info(struct f2fs_sb_info *sbi)
+{
+	int i;
+
+	for (i = 0; i < NR_COUNT_TYPE; i++)
+		percpu_counter_destroy(&sbi->nr_pages[i]);
+}
+
 static void f2fs_put_super(struct super_block *sb)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
@@ -667,6 +675,8 @@ static void f2fs_put_super(struct super_block *sb)
 	if (sbi->s_chksum_driver)
 		crypto_free_shash(sbi->s_chksum_driver);
 	kfree(sbi->raw_super);
+
+	destroy_percpu_info(sbi);
 	kfree(sbi);
 }
 
@@ -1325,7 +1335,6 @@ int sanity_check_ckpt(struct f2fs_sb_info *sbi)
 static void init_sb_info(struct f2fs_sb_info *sbi)
 {
 	struct f2fs_super_block *raw_super = sbi->raw_super;
-	int i;
 
 	sbi->log_sectors_per_block =
 		le32_to_cpu(raw_super->log_sectors_per_block);
@@ -1345,9 +1354,6 @@ static void init_sb_info(struct f2fs_sb_info *sbi)
 	sbi->cur_victim_sec = NULL_SECNO;
 	sbi->max_victim_search = DEF_MAX_VICTIM_SEARCH;
 
-	for (i = 0; i < NR_COUNT_TYPE; i++)
-		atomic_set(&sbi->nr_pages[i], 0);
-
 	sbi->dir_level = DEF_DIR_LEVEL;
 	sbi->interval_time[CP_TIME] = DEF_CP_INTERVAL;
 	sbi->interval_time[REQ_TIME] = DEF_IDLE_INTERVAL;
@@ -1363,6 +1369,18 @@ static void init_sb_info(struct f2fs_sb_info *sbi)
 #endif
 }
 
+static int init_percpu_info(struct f2fs_sb_info *sbi)
+{
+	int i, err;
+
+	for (i = 0; i < NR_COUNT_TYPE; i++) {
+		err = percpu_counter_init(&sbi->nr_pages[i], 0, GFP_KERNEL);
+		if (err)
+			return err;
+	}
+	return 0;
+}
+
 /*
  * Read f2fs raw super block.
  * Because we have two copies of super block, so read both of them
@@ -1553,6 +1571,10 @@ try_onemore:
 	init_waitqueue_head(&sbi->cp_wait);
 	init_sb_info(sbi);
 
+	err = init_percpu_info(sbi);
+	if (err)
+		goto free_options;
+
 	/* get an inode for meta space */
 	sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
 	if (IS_ERR(sbi->meta_inode)) {
@@ -1755,6 +1777,7 @@ free_meta_inode:
 	make_bad_inode(sbi->meta_inode);
 	iput(sbi->meta_inode);
 free_options:
+	destroy_percpu_info(sbi);
 	kfree(options);
 free_sb_buf:
 	kfree(raw_super);
-- 
2.6.3


------------------------------------------------------------------------------
Mobile security can be enabling, not merely restricting. Employees who
bring their own devices (BYOD) to work are irked by the imposition of MDM
restrictions. Mobile Device Manager Plus allows you to control only the
apps on BYO-devices by containerizing them, leaving personal data untouched!
https://ad.doubleclick.net/ddm/clk/304595813;131938128;j

[PATCH 3/5] f2fs: use percpu_counter for # of dirty pages in inode

[Jaegeuk Kim]

This patch adds percpu_counter for # of dirty pages in inode.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/f2fs.h  | 10 +++++-----
 fs/f2fs/file.c  |  2 +-
 fs/f2fs/super.c |  8 +++++++-
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 2851078..ae978a1 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -456,7 +456,7 @@ struct f2fs_inode_info {
 	/* Use below internally in f2fs*/
 	unsigned long flags;		/* use to pass per-file flags */
 	struct rw_semaphore i_sem;	/* protect fi info */
-	atomic_t dirty_pages;		/* # of dirty pages */
+	struct percpu_counter dirty_pages;	/* # of dirty pages */
 	f2fs_hash_t chash;		/* hash value of given file name */
 	unsigned int clevel;		/* maximum level of given file name */
 	nid_t i_xattr_nid;		/* node id that contains xattrs */
@@ -1186,7 +1186,7 @@ static inline void inc_page_count(struct f2fs_sb_info *sbi, int count_type)
 
 static inline void inode_inc_dirty_pages(struct inode *inode)
 {
-	atomic_inc(&F2FS_I(inode)->dirty_pages);
+	percpu_counter_inc(&F2FS_I(inode)->dirty_pages);
 	inc_page_count(F2FS_I_SB(inode), S_ISDIR(inode->i_mode) ?
 				F2FS_DIRTY_DENTS : F2FS_DIRTY_DATA);
 }
@@ -1202,7 +1202,7 @@ static inline void inode_dec_dirty_pages(struct inode *inode)
 			!S_ISLNK(inode->i_mode))
 		return;
 
-	atomic_dec(&F2FS_I(inode)->dirty_pages);
+	percpu_counter_dec(&F2FS_I(inode)->dirty_pages);
 	dec_page_count(F2FS_I_SB(inode), S_ISDIR(inode->i_mode) ?
 				F2FS_DIRTY_DENTS : F2FS_DIRTY_DATA);
 }
@@ -1212,9 +1212,9 @@ static inline s64 get_pages(struct f2fs_sb_info *sbi, int count_type)
 	return percpu_counter_sum_positive(&sbi->nr_pages[count_type]);
 }
 
-static inline int get_dirty_pages(struct inode *inode)
+static inline s64 get_dirty_pages(struct inode *inode)
 {
-	return atomic_read(&F2FS_I(inode)->dirty_pages);
+	return percpu_counter_sum_positive(&F2FS_I(inode)->dirty_pages);
 }
 
 static inline int get_blocktype_secs(struct f2fs_sb_info *sbi, int block_type)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index b5e3999..69451b83 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1457,7 +1457,7 @@ static int f2fs_ioc_start_atomic_write(struct file *filp)
 		goto out;
 
 	f2fs_msg(F2FS_I_SB(inode)->sb, KERN_WARNING,
-		"Unexpected flush for atomic writes: ino=%lu, npages=%u",
+		"Unexpected flush for atomic writes: ino=%lu, npages=%lld",
 					inode->i_ino, get_dirty_pages(inode));
 	ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
 	if (ret)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index b3030ed..56f177b 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -526,9 +526,13 @@ static struct inode *f2fs_alloc_inode(struct super_block *sb)
 
 	init_once((void *) fi);
 
+	if (percpu_counter_init(&fi->dirty_pages, 0, GFP_NOFS)) {
+		kmem_cache_free(f2fs_inode_cachep, fi);
+		return NULL;
+	}
+
 	/* Initialize f2fs-specific inode info */
 	fi->vfs_inode.i_version = 1;
-	atomic_set(&fi->dirty_pages, 0);
 	fi->i_current_depth = 1;
 	fi->i_advise = 0;
 	init_rwsem(&fi->i_sem);
@@ -598,6 +602,8 @@ static void f2fs_dirty_inode(struct inode *inode, int flags)
 static void f2fs_i_callback(struct rcu_head *head)
 {
 	struct inode *inode = container_of(head, struct inode, i_rcu);
+
+	percpu_counter_destroy(&F2FS_I(inode)->dirty_pages);
 	kmem_cache_free(f2fs_inode_cachep, F2FS_I(inode));
 }
 
-- 
2.6.3


------------------------------------------------------------------------------
Mobile security can be enabling, not merely restricting. Employees who
bring their own devices (BYOD) to work are irked by the imposition of MDM
restrictions. Mobile Device Manager Plus allows you to control only the
apps on BYO-devices by containerizing them, leaving personal data untouched!
https://ad.doubleclick.net/ddm/clk/304595813;131938128;j

[PATCH 4/5] f2fs: use percpu_counter for alloc_valid_block_count

[Jaegeuk Kim]

This patch uses percpu_count for sbi->alloc_valid_block_count.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/checkpoint.c | 2 +-
 fs/f2fs/f2fs.h       | 8 +++++---
 fs/f2fs/recovery.c   | 5 +++--
 fs/f2fs/super.c      | 7 +++++--
 4 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index d04113b..140643d 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1079,7 +1079,7 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 
 	/* update user_block_counts */
 	sbi->last_valid_block_count = sbi->total_valid_block_count;
-	sbi->alloc_valid_block_count = 0;
+	percpu_counter_set(&sbi->alloc_valid_block_count, 0);
 
 	/* Here, we only have one bio having CP pack */
 	sync_meta_pages(sbi, META_FLUSH, LONG_MAX);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index ae978a1..43aa692 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -829,13 +829,14 @@ struct f2fs_sb_info {
 
 	block_t user_block_count;		/* # of user blocks */
 	block_t total_valid_block_count;	/* # of valid blocks */
-	block_t alloc_valid_block_count;	/* # of allocated blocks */
 	block_t discard_blks;			/* discard command candidats */
 	block_t last_valid_block_count;		/* for recovery */
 	u32 s_next_generation;			/* for NFS support */
 
 	/* # of pages, see count_type */
 	struct percpu_counter nr_pages[NR_COUNT_TYPE];
+	/* # of allocated blocks */
+	struct percpu_counter alloc_valid_block_count;
 
 	struct f2fs_mount_info mount_opt;	/* mount options */
 
@@ -1161,8 +1162,9 @@ static inline bool inc_valid_block_count(struct f2fs_sb_info *sbi,
 	inode->i_blocks += *count;
 	sbi->total_valid_block_count =
 		sbi->total_valid_block_count + (block_t)(*count);
-	sbi->alloc_valid_block_count += (block_t)(*count);
 	spin_unlock(&sbi->stat_lock);
+
+	percpu_counter_add(&sbi->alloc_valid_block_count, (*count));
 	return true;
 }
 
@@ -1310,11 +1312,11 @@ static inline bool inc_valid_node_count(struct f2fs_sb_info *sbi,
 	if (inode)
 		inode->i_blocks++;
 
-	sbi->alloc_valid_block_count++;
 	sbi->total_valid_node_count++;
 	sbi->total_valid_block_count++;
 	spin_unlock(&sbi->stat_lock);
 
+	percpu_counter_inc(&sbi->alloc_valid_block_count);
 	return true;
 }
 
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index 6303b2a..f89b70e 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -49,8 +49,9 @@ static struct kmem_cache *fsync_entry_slab;
 
 bool space_for_roll_forward(struct f2fs_sb_info *sbi)
 {
-	if (sbi->last_valid_block_count + sbi->alloc_valid_block_count
-			> sbi->user_block_count)
+	s64 nalloc = percpu_counter_sum_positive(&sbi->alloc_valid_block_count);
+
+	if (sbi->last_valid_block_count + nalloc > sbi->user_block_count)
 		return false;
 	return true;
 }
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 56f177b..c0fd075 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -618,6 +618,7 @@ static void destroy_percpu_info(struct f2fs_sb_info *sbi)
 
 	for (i = 0; i < NR_COUNT_TYPE; i++)
 		percpu_counter_destroy(&sbi->nr_pages[i]);
+	percpu_counter_destroy(&sbi->alloc_valid_block_count);
 }
 
 static void f2fs_put_super(struct super_block *sb)
@@ -1384,7 +1385,9 @@ static int init_percpu_info(struct f2fs_sb_info *sbi)
 		if (err)
 			return err;
 	}
-	return 0;
+
+	return percpu_counter_init(&sbi->alloc_valid_block_count, 0,
+								GFP_KERNEL);
 }
 
 /*
@@ -1603,7 +1606,7 @@ try_onemore:
 	sbi->total_valid_block_count =
 				le64_to_cpu(sbi->ckpt->valid_block_count);
 	sbi->last_valid_block_count = sbi->total_valid_block_count;
-	sbi->alloc_valid_block_count = 0;
+
 	for (i = 0; i < NR_INODE_TYPE; i++) {
 		INIT_LIST_HEAD(&sbi->inode_list[i]);
 		spin_lock_init(&sbi->inode_lock[i]);
-- 
2.6.3


------------------------------------------------------------------------------
Mobile security can be enabling, not merely restricting. Employees who
bring their own devices (BYOD) to work are irked by the imposition of MDM
restrictions. Mobile Device Manager Plus allows you to control only the
apps on BYO-devices by containerizing them, leaving personal data untouched!
https://ad.doubleclick.net/ddm/clk/304595813;131938128;j

[PATCH 5/5] f2fs: use percpu_counter for total_valid_inode_count

[Jaegeuk Kim]

This patch uses percpu_counter to avoid stat_lock.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/f2fs.h  | 18 +++++++-----------
 fs/f2fs/super.c | 11 ++++++++---
 2 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 43aa692..c965897 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -822,7 +822,6 @@ struct f2fs_sb_info {
 	unsigned int total_sections;		/* total section count */
 	unsigned int total_node_count;		/* total node block count */
 	unsigned int total_valid_node_count;	/* valid node block count */
-	unsigned int total_valid_inode_count;	/* valid inode count */
 	loff_t max_file_blocks;			/* max block index of file */
 	int active_logs;			/* # of active logs */
 	int dir_level;				/* directory level */
@@ -838,6 +837,9 @@ struct f2fs_sb_info {
 	/* # of allocated blocks */
 	struct percpu_counter alloc_valid_block_count;
 
+	/* valid inode count */
+	struct percpu_counter total_valid_inode_count;
+
 	struct f2fs_mount_info mount_opt;	/* mount options */
 
 	/* for cleaning operations */
@@ -1343,23 +1345,17 @@ static inline unsigned int valid_node_count(struct f2fs_sb_info *sbi)
 
 static inline void inc_valid_inode_count(struct f2fs_sb_info *sbi)
 {
-	spin_lock(&sbi->stat_lock);
-	f2fs_bug_on(sbi, sbi->total_valid_inode_count == sbi->total_node_count);
-	sbi->total_valid_inode_count++;
-	spin_unlock(&sbi->stat_lock);
+	percpu_counter_inc(&sbi->total_valid_inode_count);
 }
 
 static inline void dec_valid_inode_count(struct f2fs_sb_info *sbi)
 {
-	spin_lock(&sbi->stat_lock);
-	f2fs_bug_on(sbi, !sbi->total_valid_inode_count);
-	sbi->total_valid_inode_count--;
-	spin_unlock(&sbi->stat_lock);
+	percpu_counter_dec(&sbi->total_valid_inode_count);
 }
 
-static inline unsigned int valid_inode_count(struct f2fs_sb_info *sbi)
+static inline s64 valid_inode_count(struct f2fs_sb_info *sbi)
 {
-	return sbi->total_valid_inode_count;
+	return percpu_counter_sum_positive(&sbi->total_valid_inode_count);
 }
 
 static inline struct page *f2fs_grab_cache_page(struct address_space *mapping,
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index c0fd075..bbfeb6a 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -619,6 +619,7 @@ static void destroy_percpu_info(struct f2fs_sb_info *sbi)
 	for (i = 0; i < NR_COUNT_TYPE; i++)
 		percpu_counter_destroy(&sbi->nr_pages[i]);
 	percpu_counter_destroy(&sbi->alloc_valid_block_count);
+	percpu_counter_destroy(&sbi->total_valid_inode_count);
 }
 
 static void f2fs_put_super(struct super_block *sb)
@@ -1386,7 +1387,11 @@ static int init_percpu_info(struct f2fs_sb_info *sbi)
 			return err;
 	}
 
-	return percpu_counter_init(&sbi->alloc_valid_block_count, 0,
+	err = percpu_counter_init(&sbi->alloc_valid_block_count, 0, GFP_KERNEL);
+	if (err)
+		return err;
+
+	return percpu_counter_init(&sbi->total_valid_inode_count, 0,
 								GFP_KERNEL);
 }
 
@@ -1600,8 +1605,8 @@ try_onemore:
 
 	sbi->total_valid_node_count =
 				le32_to_cpu(sbi->ckpt->valid_node_count);
-	sbi->total_valid_inode_count =
-				le32_to_cpu(sbi->ckpt->valid_inode_count);
+	percpu_counter_set(&sbi->total_valid_inode_count,
+				le32_to_cpu(sbi->ckpt->valid_inode_count));
 	sbi->user_block_count = le64_to_cpu(sbi->ckpt->user_block_count);
 	sbi->total_valid_block_count =
 				le64_to_cpu(sbi->ckpt->valid_block_count);
-- 
2.6.3


------------------------------------------------------------------------------
Mobile security can be enabling, not merely restricting. Employees who
bring their own devices (BYOD) to work are irked by the imposition of MDM
restrictions. Mobile Device Manager Plus allows you to control only the
apps on BYO-devices by containerizing them, leaving personal data untouched!
https://ad.doubleclick.net/ddm/clk/304595813;131938128;j