[Devel] [PATCH rh7 30/30] ploop: Introduce possibility to use kaio engine for ext4

[Kirill Tkhai]

This is temporary module param for test time.

Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
---
 drivers/block/ploop/dev.c        |    4 ++++
 drivers/block/ploop/fmt_ploop1.c |    2 +-
 drivers/block/ploop/io_direct.c  |    4 +++-
 drivers/block/ploop/io_kaio.c    |    9 ++++++---
 include/linux/ploop/ploop.h      |    1 +
 5 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
index da124fa50250..f9d3eb2067aa 100644
--- a/drivers/block/ploop/dev.c
+++ b/drivers/block/ploop/dev.c
@@ -61,6 +61,8 @@ static long user_threshold __read_mostly = 4L * 1024 * 1024; /* 4GB in KB */
 
 static int large_disk_support __read_mostly = 1; /* true */
 static int native_discard_support __read_mostly = 1;
+int kaio_backed_ext4 __read_mostly = 0;
+EXPORT_SYMBOL(kaio_backed_ext4);
 
 static struct rb_root ploop_devices_tree = RB_ROOT;
 static DEFINE_MUTEX(ploop_devices_mutex);
@@ -5831,6 +5833,8 @@ module_param(large_disk_support, int, 0444);
 MODULE_PARM_DESC(ploop_large_disk_support, "Support of large disks (>2TB)");
 module_param(native_discard_support, int, 0644);
 MODULE_PARM_DESC(native_discard_support, "Native discard support");
+module_param(kaio_backed_ext4, int, 0644);
+MODULE_PARM_DESC(kaio_backed_ext4, "kaio-backed ext4");
 
 static int __init ploop_mod_init(void)
 {
diff --git a/drivers/block/ploop/fmt_ploop1.c b/drivers/block/ploop/fmt_ploop1.c
index 326862a2fd07..2180dfcb3580 100644
--- a/drivers/block/ploop/fmt_ploop1.c
+++ b/drivers/block/ploop/fmt_ploop1.c
@@ -333,7 +333,7 @@ ploop1_open(struct ploop_delta * delta)
 	    ((u64)ph->bd_size + ph->l1_off) << 9)
 		delta->flags |= PLOOP_FMT_PREALLOCATED;
 
-	if (delta->io.ops->id != PLOOP_IO_DIRECT)
+	if (delta->io.ops->id != PLOOP_IO_DIRECT || kaio_backed_ext4)
 		set_bit(PLOOP_S_NO_FALLOC_DISCARD, &delta->plo->state);
 
 	return 0;
diff --git a/drivers/block/ploop/io_direct.c b/drivers/block/ploop/io_direct.c
index 75edf5583e8e..54c995411c45 100644
--- a/drivers/block/ploop/io_direct.c
+++ b/drivers/block/ploop/io_direct.c
@@ -1720,7 +1720,9 @@ static int dio_autodetect(struct ploop_io * io)
 	int err;
 	mm_segment_t fs;
 	unsigned int flags;
-	
+
+	if (kaio_backed_ext4)
+		return -1;
 	if (inode->i_sb->s_magic != EXT4_SUPER_MAGIC)
 		return -1; /* not mine */
 
diff --git a/drivers/block/ploop/io_kaio.c b/drivers/block/ploop/io_kaio.c
index c4e64b42a657..7ca3374cce3b 100644
--- a/drivers/block/ploop/io_kaio.c
+++ b/drivers/block/ploop/io_kaio.c
@@ -185,9 +185,11 @@ static int kaio_kernel_submit(struct file *file, struct kaio_req *kreq,
 	if (!iocb)
 		return -ENOMEM;
 
-	if (rw & REQ_DISCARD)
+	if (rw & REQ_DISCARD) {
 		op = IOCB_CMD_UNMAP_ITER;
-	else if (rw & REQ_WRITE)
+		if (file_inode(file)->i_sb->s_magic == EXT4_SUPER_MAGIC)
+			return -ENOTSUPP;
+	} else if (rw & REQ_WRITE)
 		op = IOCB_CMD_WRITE_ITER;
 	else
 		op = IOCB_CMD_READ_ITER;
@@ -1155,7 +1157,8 @@ static int kaio_autodetect(struct ploop_io * io)
 	struct file  * file  = io->files.file;
 	struct inode * inode = file->f_mapping->host;
 
-	if (inode->i_sb->s_magic != FUSE_SUPER_MAGIC)
+	if (inode->i_sb->s_magic != FUSE_SUPER_MAGIC &&
+	    (inode->i_sb->s_magic != EXT4_SUPER_MAGIC || !kaio_backed_ext4))
 		return -1; /* not mine */
 
 	if (!(file->f_flags & O_DIRECT)) {
diff --git a/include/linux/ploop/ploop.h b/include/linux/ploop/ploop.h
index cdf3c3694516..24f748530f54 100644
--- a/include/linux/ploop/ploop.h
+++ b/include/linux/ploop/ploop.h
@@ -935,6 +935,7 @@ void ploop_queue_zero_request(struct ploop_device *plo, struct ploop_request *or
 int ploop_maintenance_wait(struct ploop_device * plo);
 
 extern int max_map_pages;
+extern int kaio_backed_ext4;
 
 extern void ploop_msg_once(struct ploop_device *plo, const char *, ...)
 	__attribute__ ((format (printf, 2, 3)));