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-rw-r--r--drivers/md/dm-bufio.c69
-rw-r--r--include/linux/dm-bufio.h12
2 files changed, 76 insertions, 5 deletions
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index 2d519c223562..bf289be1ee3a 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -631,6 +631,19 @@ dmio:
submit_bio(bio);
}
+static inline sector_t block_to_sector(struct dm_bufio_client *c, sector_t block)
+{
+ sector_t sector;
+
+ if (likely(c->sectors_per_block_bits >= 0))
+ sector = block << c->sectors_per_block_bits;
+ else
+ sector = block * (c->block_size >> SECTOR_SHIFT);
+ sector += c->start;
+
+ return sector;
+}
+
static void submit_io(struct dm_buffer *b, int rw, void (*end_io)(struct dm_buffer *, blk_status_t))
{
unsigned n_sectors;
@@ -639,11 +652,7 @@ static void submit_io(struct dm_buffer *b, int rw, void (*end_io)(struct dm_buff
b->end_io = end_io;
- if (likely(b->c->sectors_per_block_bits >= 0))
- sector = b->block << b->c->sectors_per_block_bits;
- else
- sector = b->block * (b->c->block_size >> SECTOR_SHIFT);
- sector += b->c->start;
+ sector = block_to_sector(b->c, b->block);
if (rw != REQ_OP_WRITE) {
n_sectors = b->c->block_size >> SECTOR_SHIFT;
@@ -1326,6 +1335,56 @@ int dm_bufio_issue_flush(struct dm_bufio_client *c)
EXPORT_SYMBOL_GPL(dm_bufio_issue_flush);
/*
+ * Use dm-io to send a discard request to flush the device.
+ */
+int dm_bufio_issue_discard(struct dm_bufio_client *c, sector_t block, sector_t count)
+{
+ struct dm_io_request io_req = {
+ .bi_op = REQ_OP_DISCARD,
+ .bi_op_flags = REQ_SYNC,
+ .mem.type = DM_IO_KMEM,
+ .mem.ptr.addr = NULL,
+ .client = c->dm_io,
+ };
+ struct dm_io_region io_reg = {
+ .bdev = c->bdev,
+ .sector = block_to_sector(c, block),
+ .count = block_to_sector(c, count),
+ };
+
+ BUG_ON(dm_bufio_in_request());
+
+ return dm_io(&io_req, 1, &io_reg, NULL);
+}
+EXPORT_SYMBOL_GPL(dm_bufio_issue_discard);
+
+/*
+ * Free the specified range of buffers. If a buffer is held by other process, it
+ * is not freed. If a buffer is dirty, it is discarded without writeback.
+ * Finally, send the discard request to the device.
+ */
+int dm_bufio_discard_buffers(struct dm_bufio_client *c, sector_t block, sector_t count)
+{
+ sector_t i;
+
+ for (i = block; i < block + count; i++) {
+ struct dm_buffer *b;
+ dm_bufio_lock(c);
+ b = __find(c, i);
+ if (b && likely(!b->hold_count)) {
+ wait_on_bit_io(&b->state, B_READING, TASK_UNINTERRUPTIBLE);
+ wait_on_bit_io(&b->state, B_WRITING, TASK_UNINTERRUPTIBLE);
+ __unlink_buffer(b);
+ __free_buffer_wake(b);
+ }
+ dm_bufio_unlock(c);
+ }
+
+ return dm_bufio_issue_discard(c, block, count);
+}
+EXPORT_SYMBOL_GPL(dm_bufio_discard_buffers);
+
+/*
* We first delete any other buffer that may be at that new location.
*
* Then, we write the buffer to the original location if it was dirty.
diff --git a/include/linux/dm-bufio.h b/include/linux/dm-bufio.h
index 3c8b7d274bd9..07e1f163e299 100644
--- a/include/linux/dm-bufio.h
+++ b/include/linux/dm-bufio.h
@@ -119,6 +119,18 @@ int dm_bufio_write_dirty_buffers(struct dm_bufio_client *c);
int dm_bufio_issue_flush(struct dm_bufio_client *c);
/*
+ * Send a discard request to the underlying device.
+ */
+int dm_bufio_issue_discard(struct dm_bufio_client *c, sector_t block, sector_t count);
+
+/*
+ * Free the specified range of buffers. If a buffer is held by other process, it
+ * is not freed. If a buffer is dirty, it is discarded without writeback.
+ * Finally, send the discard request to the device.
+ */
+int dm_bufio_discard_buffers(struct dm_bufio_client *c, sector_t block, sector_t count);
+
+/*
* Like dm_bufio_release but also move the buffer to the new
* block. dm_bufio_write_dirty_buffers is needed to commit the new block.
*/