[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/drivers/md/dm-linear.c b/ap/os/linux/linux-3.4.x/drivers/md/dm-linear.c
new file mode 100644
index 0000000..5a5e9c8
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/md/dm-linear.c
@@ -0,0 +1,181 @@
+/*
+ * Copyright (C) 2001-2003 Sistina Software (UK) Limited.
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dm.h"
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/bio.h>
+#include <linux/slab.h>
+#include <linux/device-mapper.h>
+
+#define DM_MSG_PREFIX "linear"
+
+/*
+ * Linear: maps a linear range of a device.
+ */
+struct linear_c {
+ struct dm_dev *dev;
+ sector_t start;
+};
+
+/*
+ * Construct a linear mapping: <dev_path> <offset>
+ */
+static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
+{
+ struct linear_c *lc;
+ unsigned long long tmp;
+ char dummy;
+
+ if (argc != 2) {
+ ti->error = "Invalid argument count";
+ return -EINVAL;
+ }
+
+ lc = kmalloc(sizeof(*lc), GFP_KERNEL);
+ if (lc == NULL) {
+ ti->error = "dm-linear: Cannot allocate linear context";
+ return -ENOMEM;
+ }
+
+ if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1) {
+ ti->error = "dm-linear: Invalid device sector";
+ goto bad;
+ }
+ lc->start = tmp;
+
+ if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev)) {
+ ti->error = "dm-linear: Device lookup failed";
+ goto bad;
+ }
+
+ ti->num_flush_requests = 1;
+ ti->num_discard_requests = 1;
+ ti->private = lc;
+ return 0;
+
+ bad:
+ kfree(lc);
+ return -EINVAL;
+}
+
+static void linear_dtr(struct dm_target *ti)
+{
+ struct linear_c *lc = (struct linear_c *) ti->private;
+
+ dm_put_device(ti, lc->dev);
+ kfree(lc);
+}
+
+static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
+{
+ struct linear_c *lc = ti->private;
+
+ return lc->start + dm_target_offset(ti, bi_sector);
+}
+
+static void linear_map_bio(struct dm_target *ti, struct bio *bio)
+{
+ struct linear_c *lc = ti->private;
+
+ bio->bi_bdev = lc->dev->bdev;
+ if (bio_sectors(bio))
+ bio->bi_sector = linear_map_sector(ti, bio->bi_sector);
+}
+
+static int linear_map(struct dm_target *ti, struct bio *bio,
+ union map_info *map_context)
+{
+ linear_map_bio(ti, bio);
+
+ return DM_MAPIO_REMAPPED;
+}
+
+static void linear_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned int maxlen)
+{
+ struct linear_c *lc = (struct linear_c *) ti->private;
+
+ switch (type) {
+ case STATUSTYPE_INFO:
+ result[0] = '\0';
+ break;
+
+ case STATUSTYPE_TABLE:
+ snprintf(result, maxlen, "%s %llu", lc->dev->name,
+ (unsigned long long)lc->start);
+ break;
+ }
+}
+
+static int linear_ioctl(struct dm_target *ti, unsigned int cmd,
+ unsigned long arg)
+{
+ struct linear_c *lc = (struct linear_c *) ti->private;
+ struct dm_dev *dev = lc->dev;
+ int r = 0;
+
+ /*
+ * Only pass ioctls through if the device sizes match exactly.
+ */
+ if (lc->start ||
+ ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
+ r = scsi_verify_blk_ioctl(NULL, cmd);
+
+ return r ? : __blkdev_driver_ioctl(dev->bdev, dev->mode, cmd, arg);
+}
+
+static int linear_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
+ struct bio_vec *biovec, int max_size)
+{
+ struct linear_c *lc = ti->private;
+ struct request_queue *q = bdev_get_queue(lc->dev->bdev);
+
+ if (!q->merge_bvec_fn)
+ return max_size;
+
+ bvm->bi_bdev = lc->dev->bdev;
+ bvm->bi_sector = linear_map_sector(ti, bvm->bi_sector);
+
+ return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
+}
+
+static int linear_iterate_devices(struct dm_target *ti,
+ iterate_devices_callout_fn fn, void *data)
+{
+ struct linear_c *lc = ti->private;
+
+ return fn(ti, lc->dev, lc->start, ti->len, data);
+}
+
+static struct target_type linear_target = {
+ .name = "linear",
+ .version = {1, 1, 0},
+ .module = THIS_MODULE,
+ .ctr = linear_ctr,
+ .dtr = linear_dtr,
+ .map = linear_map,
+ .status = linear_status,
+ .ioctl = linear_ioctl,
+ .merge = linear_merge,
+ .iterate_devices = linear_iterate_devices,
+};
+
+int __init dm_linear_init(void)
+{
+ int r = dm_register_target(&linear_target);
+
+ if (r < 0)
+ DMERR("register failed %d", r);
+
+ return r;
+}
+
+void dm_linear_exit(void)
+{
+ dm_unregister_target(&linear_target);
+}