From: Saugata Das <saugata.das@xxxxxxxxxx>
Today, storage devices like eMMC has special features like data tagging
(introduced in MMC-4.5 version) in order to improve performance of some
specific writes. On MMC stack, data tagging is used for all writes which
has REQ_META flag set. This patch adds the capability to add REQ_META flag
during meta data write.
Signed-off-by: Saugata Das <saugata.das@xxxxxxxxxx>
---
fs/buffer.c | 10 ++++++++--
include/linux/buffer_head.h | 2 ++
2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/fs/buffer.c b/fs/buffer.c
index 36d6665..688b38b 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1685,7 +1685,10 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
do {
struct buffer_head *next = bh->b_this_page;
if (buffer_async_write(bh)) {
- submit_bh(write_op, bh);
+ if (buffer_meta(bh))
+ submit_bh(write_op | REQ_META, bh);
+ else
+ submit_bh(write_op, bh);
nr_underway++;
}
bh = next;
@@ -1739,7 +1742,10 @@ recover:
struct buffer_head *next = bh->b_this_page;
if (buffer_async_write(bh)) {
clear_buffer_dirty(bh);
- submit_bh(write_op, bh);
+ if (buffer_meta(bh))
+ submit_bh(write_op | REQ_META, bh);
+ else
+ submit_bh(write_op, bh);
nr_underway++;
}
bh = next;
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index ef26043..0776564 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -34,6 +34,7 @@ enum bh_state_bits {
BH_Write_EIO, /* I/O error on write */
BH_Unwritten, /* Buffer is allocated on disk but not written */
BH_Quiet, /* Buffer Error Prinks to be quiet */
+ BH_Meta, /* Is meta */
BH_PrivateStart,/* not a state bit, but the first bit available
* for private allocation by other entities
@@ -126,6 +127,7 @@ BUFFER_FNS(Delay, delay)
BUFFER_FNS(Boundary, boundary)
BUFFER_FNS(Write_EIO, write_io_error)
BUFFER_FNS(Unwritten, unwritten)
+BUFFER_FNS(Meta, meta)
#define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK)
#define touch_buffer(bh) mark_page_accessed(bh->b_page)
--
1.7.4.3
--
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