[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-stripe.c b/ap/os/linux/linux-3.4.x/drivers/md/dm-stripe.c
new file mode 100644
index 0000000..58ffcda
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/md/dm-stripe.c
@@ -0,0 +1,449 @@
+/*
+ * Copyright (C) 2001-2003 Sistina Software (UK) Limited.
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/device-mapper.h>
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/bio.h>
+#include <linux/slab.h>
+#include <linux/log2.h>
+
+#define DM_MSG_PREFIX "striped"
+#define DM_IO_ERROR_THRESHOLD 15
+
+struct stripe {
+ struct dm_dev *dev;
+ sector_t physical_start;
+
+ atomic_t error_count;
+};
+
+struct stripe_c {
+ uint32_t stripes;
+ int stripes_shift;
+ sector_t stripes_mask;
+
+ /* The size of this target / num. stripes */
+ sector_t stripe_width;
+
+ /* stripe chunk size */
+ uint32_t chunk_shift;
+ sector_t chunk_mask;
+
+ /* Needed for handling events */
+ struct dm_target *ti;
+
+ /* Work struct used for triggering events*/
+ struct work_struct trigger_event;
+
+ struct stripe stripe[0];
+};
+
+/*
+ * An event is triggered whenever a drive
+ * drops out of a stripe volume.
+ */
+static void trigger_event(struct work_struct *work)
+{
+ struct stripe_c *sc = container_of(work, struct stripe_c,
+ trigger_event);
+ dm_table_event(sc->ti->table);
+}
+
+static inline struct stripe_c *alloc_context(unsigned int stripes)
+{
+ size_t len;
+
+ if (dm_array_too_big(sizeof(struct stripe_c), sizeof(struct stripe),
+ stripes))
+ return NULL;
+
+ len = sizeof(struct stripe_c) + (sizeof(struct stripe) * stripes);
+
+ return kmalloc(len, GFP_KERNEL);
+}
+
+/*
+ * Parse a single <dev> <sector> pair
+ */
+static int get_stripe(struct dm_target *ti, struct stripe_c *sc,
+ unsigned int stripe, char **argv)
+{
+ unsigned long long start;
+ char dummy;
+
+ if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1)
+ return -EINVAL;
+
+ if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
+ &sc->stripe[stripe].dev))
+ return -ENXIO;
+
+ sc->stripe[stripe].physical_start = start;
+
+ return 0;
+}
+
+/*
+ * Construct a striped mapping.
+ * <number of stripes> <chunk size (2^^n)> [<dev_path> <offset>]+
+ */
+static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
+{
+ struct stripe_c *sc;
+ sector_t width;
+ uint32_t stripes;
+ uint32_t chunk_size;
+ char *end;
+ int r;
+ unsigned int i;
+
+ if (argc < 2) {
+ ti->error = "Not enough arguments";
+ return -EINVAL;
+ }
+
+ stripes = simple_strtoul(argv[0], &end, 10);
+ if (!stripes || *end) {
+ ti->error = "Invalid stripe count";
+ return -EINVAL;
+ }
+
+ chunk_size = simple_strtoul(argv[1], &end, 10);
+ if (*end) {
+ ti->error = "Invalid chunk_size";
+ return -EINVAL;
+ }
+
+ /*
+ * chunk_size is a power of two
+ */
+ if (!is_power_of_2(chunk_size) ||
+ (chunk_size < (PAGE_SIZE >> SECTOR_SHIFT))) {
+ ti->error = "Invalid chunk size";
+ return -EINVAL;
+ }
+
+ if (ti->len & (chunk_size - 1)) {
+ ti->error = "Target length not divisible by "
+ "chunk size";
+ return -EINVAL;
+ }
+
+ width = ti->len;
+ if (sector_div(width, stripes)) {
+ ti->error = "Target length not divisible by "
+ "number of stripes";
+ return -EINVAL;
+ }
+
+ /*
+ * Do we have enough arguments for that many stripes ?
+ */
+ if (argc != (2 + 2 * stripes)) {
+ ti->error = "Not enough destinations "
+ "specified";
+ return -EINVAL;
+ }
+
+ sc = alloc_context(stripes);
+ if (!sc) {
+ ti->error = "Memory allocation for striped context "
+ "failed";
+ return -ENOMEM;
+ }
+
+ INIT_WORK(&sc->trigger_event, trigger_event);
+
+ /* Set pointer to dm target; used in trigger_event */
+ sc->ti = ti;
+ sc->stripes = stripes;
+ sc->stripe_width = width;
+
+ if (stripes & (stripes - 1))
+ sc->stripes_shift = -1;
+ else {
+ sc->stripes_shift = ffs(stripes) - 1;
+ sc->stripes_mask = ((sector_t) stripes) - 1;
+ }
+
+ ti->split_io = chunk_size;
+ ti->num_flush_requests = stripes;
+ ti->num_discard_requests = stripes;
+
+ sc->chunk_shift = ffs(chunk_size) - 1;
+ sc->chunk_mask = ((sector_t) chunk_size) - 1;
+
+ /*
+ * Get the stripe destinations.
+ */
+ for (i = 0; i < stripes; i++) {
+ argv += 2;
+
+ r = get_stripe(ti, sc, i, argv);
+ if (r < 0) {
+ ti->error = "Couldn't parse stripe destination";
+ while (i--)
+ dm_put_device(ti, sc->stripe[i].dev);
+ kfree(sc);
+ return r;
+ }
+ atomic_set(&(sc->stripe[i].error_count), 0);
+ }
+
+ ti->private = sc;
+
+ return 0;
+}
+
+static void stripe_dtr(struct dm_target *ti)
+{
+ unsigned int i;
+ struct stripe_c *sc = (struct stripe_c *) ti->private;
+
+ for (i = 0; i < sc->stripes; i++)
+ dm_put_device(ti, sc->stripe[i].dev);
+
+ flush_work_sync(&sc->trigger_event);
+ kfree(sc);
+}
+
+static void stripe_map_sector(struct stripe_c *sc, sector_t sector,
+ uint32_t *stripe, sector_t *result)
+{
+ sector_t offset = dm_target_offset(sc->ti, sector);
+ sector_t chunk = offset >> sc->chunk_shift;
+
+ if (sc->stripes_shift < 0)
+ *stripe = sector_div(chunk, sc->stripes);
+ else {
+ *stripe = chunk & sc->stripes_mask;
+ chunk >>= sc->stripes_shift;
+ }
+
+ *result = (chunk << sc->chunk_shift) | (offset & sc->chunk_mask);
+}
+
+static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector,
+ uint32_t target_stripe, sector_t *result)
+{
+ uint32_t stripe;
+
+ stripe_map_sector(sc, sector, &stripe, result);
+ if (stripe == target_stripe)
+ return;
+ *result &= ~sc->chunk_mask; /* round down */
+ if (target_stripe < stripe)
+ *result += sc->chunk_mask + 1; /* next chunk */
+}
+
+static int stripe_map_discard(struct stripe_c *sc, struct bio *bio,
+ uint32_t target_stripe)
+{
+ sector_t begin, end;
+
+ stripe_map_range_sector(sc, bio->bi_sector, target_stripe, &begin);
+ stripe_map_range_sector(sc, bio->bi_sector + bio_sectors(bio),
+ target_stripe, &end);
+ if (begin < end) {
+ bio->bi_bdev = sc->stripe[target_stripe].dev->bdev;
+ bio->bi_sector = begin + sc->stripe[target_stripe].physical_start;
+ bio->bi_size = to_bytes(end - begin);
+ return DM_MAPIO_REMAPPED;
+ } else {
+ /* The range doesn't map to the target stripe */
+ bio_endio(bio, 0);
+ return DM_MAPIO_SUBMITTED;
+ }
+}
+
+static int stripe_map(struct dm_target *ti, struct bio *bio,
+ union map_info *map_context)
+{
+ struct stripe_c *sc = ti->private;
+ uint32_t stripe;
+ unsigned target_request_nr;
+
+ if (bio->bi_rw & REQ_FLUSH) {
+ target_request_nr = map_context->target_request_nr;
+ BUG_ON(target_request_nr >= sc->stripes);
+ bio->bi_bdev = sc->stripe[target_request_nr].dev->bdev;
+ return DM_MAPIO_REMAPPED;
+ }
+ if (unlikely(bio->bi_rw & REQ_DISCARD)) {
+ target_request_nr = map_context->target_request_nr;
+ BUG_ON(target_request_nr >= sc->stripes);
+ return stripe_map_discard(sc, bio, target_request_nr);
+ }
+
+ stripe_map_sector(sc, bio->bi_sector, &stripe, &bio->bi_sector);
+
+ bio->bi_sector += sc->stripe[stripe].physical_start;
+ bio->bi_bdev = sc->stripe[stripe].dev->bdev;
+
+ return DM_MAPIO_REMAPPED;
+}
+
+/*
+ * Stripe status:
+ *
+ * INFO
+ * #stripes [stripe_name <stripe_name>] [group word count]
+ * [error count 'A|D' <error count 'A|D'>]
+ *
+ * TABLE
+ * #stripes [stripe chunk size]
+ * [stripe_name physical_start <stripe_name physical_start>]
+ *
+ */
+
+static void stripe_status(struct dm_target *ti,
+ status_type_t type, char *result, unsigned int maxlen)
+{
+ struct stripe_c *sc = (struct stripe_c *) ti->private;
+ char buffer[sc->stripes + 1];
+ unsigned int sz = 0;
+ unsigned int i;
+
+ switch (type) {
+ case STATUSTYPE_INFO:
+ DMEMIT("%d ", sc->stripes);
+ for (i = 0; i < sc->stripes; i++) {
+ DMEMIT("%s ", sc->stripe[i].dev->name);
+ buffer[i] = atomic_read(&(sc->stripe[i].error_count)) ?
+ 'D' : 'A';
+ }
+ buffer[i] = '\0';
+ DMEMIT("1 %s", buffer);
+ break;
+
+ case STATUSTYPE_TABLE:
+ DMEMIT("%d %llu", sc->stripes,
+ (unsigned long long)sc->chunk_mask + 1);
+ for (i = 0; i < sc->stripes; i++)
+ DMEMIT(" %s %llu", sc->stripe[i].dev->name,
+ (unsigned long long)sc->stripe[i].physical_start);
+ break;
+ }
+}
+
+static int stripe_end_io(struct dm_target *ti, struct bio *bio,
+ int error, union map_info *map_context)
+{
+ unsigned i;
+ char major_minor[16];
+ struct stripe_c *sc = ti->private;
+
+ if (!error)
+ return 0; /* I/O complete */
+
+ if ((error == -EWOULDBLOCK) && (bio->bi_rw & REQ_RAHEAD))
+ return error;
+
+ if (error == -EOPNOTSUPP)
+ return error;
+
+ memset(major_minor, 0, sizeof(major_minor));
+ sprintf(major_minor, "%d:%d",
+ MAJOR(disk_devt(bio->bi_bdev->bd_disk)),
+ MINOR(disk_devt(bio->bi_bdev->bd_disk)));
+
+ /*
+ * Test to see which stripe drive triggered the event
+ * and increment error count for all stripes on that device.
+ * If the error count for a given device exceeds the threshold
+ * value we will no longer trigger any further events.
+ */
+ for (i = 0; i < sc->stripes; i++)
+ if (!strcmp(sc->stripe[i].dev->name, major_minor)) {
+ atomic_inc(&(sc->stripe[i].error_count));
+ if (atomic_read(&(sc->stripe[i].error_count)) <
+ DM_IO_ERROR_THRESHOLD)
+ schedule_work(&sc->trigger_event);
+ }
+
+ return error;
+}
+
+static int stripe_iterate_devices(struct dm_target *ti,
+ iterate_devices_callout_fn fn, void *data)
+{
+ struct stripe_c *sc = ti->private;
+ int ret = 0;
+ unsigned i = 0;
+
+ do {
+ ret = fn(ti, sc->stripe[i].dev,
+ sc->stripe[i].physical_start,
+ sc->stripe_width, data);
+ } while (!ret && ++i < sc->stripes);
+
+ return ret;
+}
+
+static void stripe_io_hints(struct dm_target *ti,
+ struct queue_limits *limits)
+{
+ struct stripe_c *sc = ti->private;
+ unsigned chunk_size = (sc->chunk_mask + 1) << 9;
+
+ blk_limits_io_min(limits, chunk_size);
+ blk_limits_io_opt(limits, chunk_size * sc->stripes);
+}
+
+static int stripe_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
+ struct bio_vec *biovec, int max_size)
+{
+ struct stripe_c *sc = ti->private;
+ sector_t bvm_sector = bvm->bi_sector;
+ uint32_t stripe;
+ struct request_queue *q;
+
+ stripe_map_sector(sc, bvm_sector, &stripe, &bvm_sector);
+
+ q = bdev_get_queue(sc->stripe[stripe].dev->bdev);
+ if (!q->merge_bvec_fn)
+ return max_size;
+
+ bvm->bi_bdev = sc->stripe[stripe].dev->bdev;
+ bvm->bi_sector = sc->stripe[stripe].physical_start + bvm_sector;
+
+ return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
+}
+
+static struct target_type stripe_target = {
+ .name = "striped",
+ .version = {1, 4, 0},
+ .module = THIS_MODULE,
+ .ctr = stripe_ctr,
+ .dtr = stripe_dtr,
+ .map = stripe_map,
+ .end_io = stripe_end_io,
+ .status = stripe_status,
+ .iterate_devices = stripe_iterate_devices,
+ .io_hints = stripe_io_hints,
+ .merge = stripe_merge,
+};
+
+int __init dm_stripe_init(void)
+{
+ int r;
+
+ r = dm_register_target(&stripe_target);
+ if (r < 0) {
+ DMWARN("target registration failed");
+ return r;
+ }
+
+ return r;
+}
+
+void dm_stripe_exit(void)
+{
+ dm_unregister_target(&stripe_target);
+}