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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /ANDROID_3.4.5/drivers/md/dm-stripe.c | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
download | FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.gz FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.bz2 FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.zip |
Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'ANDROID_3.4.5/drivers/md/dm-stripe.c')
-rw-r--r-- | ANDROID_3.4.5/drivers/md/dm-stripe.c | 450 |
1 files changed, 0 insertions, 450 deletions
diff --git a/ANDROID_3.4.5/drivers/md/dm-stripe.c b/ANDROID_3.4.5/drivers/md/dm-stripe.c deleted file mode 100644 index 35c94ff2..00000000 --- a/ANDROID_3.4.5/drivers/md/dm-stripe.c +++ /dev/null @@ -1,450 +0,0 @@ -/* - * 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 int 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; - } - return 0; -} - -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); -} |