--- /dev/null
+/*[A[A
+ * Copyright (C) 2005-2009 Red Hat, Inc. All rights reserved.
+ *
+ * Module Author: Heinz Mauelshagen <heinzm@redhat.com>
+ *
+ * This file is released under the GPL.
+ *
+ *
+ * Linux 2.6 Device Mapper RAID4 and RAID5 target.
+ *
+ * Supports:
+ * o RAID4 with dedicated and selectable parity device
+ * o RAID5 with rotating parity (left+right, symmetric+asymmetric)
+ * o recovery of out of sync device for initial
+ * RAID set creation or after dead drive replacement
+ * o run time optimization of xor algorithm used to calculate parity
+ *
+ *
+ * Thanks to MD for:
+ * o the raid address calculation algorithm
+ * o the base of the biovec <-> page list copier.
+ *
+ *
+ * Uses region hash to keep track of how many writes are in flight to
+ * regions in order to use dirty log to keep state of regions to recover:
+ *
+ * o clean regions (those which are synchronized
+ * and don't have write io in flight)
+ * o dirty regions (those with write io in flight)
+ *
+ *
+ * On startup, any dirty regions are migrated to the
+ * 'nosync' state and are subject to recovery by the daemon.
+ *
+ * See raid_ctr() for table definition.
+ *
+ * FIXME: recovery bandwidth
+ */
+
+static const char *version = "v0.2594b";
+
+#include "dm.h"
+#include "dm-memcache.h"
+#include "dm-message.h"
+#include "dm-raid45.h"
+
+#include <linux/kernel.h>
+#include <linux/vmalloc.h>
+#include <linux/raid/xor.h>
+
+#include <linux/bio.h>
+#include <linux/dm-io.h>
+#include <linux/dm-dirty-log.h>
+#include "dm-region-hash.h"
+
+
+/*
+ * Configurable parameters
+ */
+
+/* Minimum/maximum and default # of selectable stripes. */
+#define STRIPES_MIN 8
+#define STRIPES_MAX 16384
+#define STRIPES_DEFAULT 80
+
+/* Maximum and default chunk size in sectors if not set in constructor. */
+#define CHUNK_SIZE_MIN 8
+#define CHUNK_SIZE_MAX 16384
+#define CHUNK_SIZE_DEFAULT 64
+
+/* Default io size in sectors if not set in constructor. */
+#define IO_SIZE_MIN CHUNK_SIZE_MIN
+#define IO_SIZE_DEFAULT IO_SIZE_MIN
+
+/* Recover io size default in sectors. */
+#define RECOVER_IO_SIZE_MIN 64
+#define RECOVER_IO_SIZE_DEFAULT 256
+
+/* Default, minimum and maximum percentage of recover io bandwidth. */
+#define BANDWIDTH_DEFAULT 10
+#define BANDWIDTH_MIN 1
+#define BANDWIDTH_MAX 100
+
+/* # of parallel recovered regions */
+#define RECOVERY_STRIPES_MIN 1
+#define RECOVERY_STRIPES_MAX 64
+#define RECOVERY_STRIPES_DEFAULT RECOVERY_STRIPES_MIN
+/*
+ * END Configurable parameters
+ */
+
+#define TARGET "dm-raid45"
+#define DAEMON "kraid45d"
+#define DM_MSG_PREFIX TARGET
+
+#define SECTORS_PER_PAGE (PAGE_SIZE >> SECTOR_SHIFT)
+
+/* Amount/size for __xor(). */
+#define XOR_SIZE PAGE_SIZE
+
+/* Check value in range. */
+#define range_ok(i, min, max) (i >= min && i <= max)
+
+/* Check argument is power of 2. */
+#define POWER_OF_2(a) (!(a & (a - 1)))
+
+/* Structure access macros. */
+/* Derive raid_set from stripe_cache pointer. */
+#define RS(x) container_of(x, struct raid_set, sc)
+
+/* Page reference. */
+#define PAGE(stripe, p) ((stripe)->obj[p].pl->page)
+
+/* Stripe chunk reference. */
+#define CHUNK(stripe, p) ((stripe)->chunk + p)
+
+/* Bio list reference. */
+#define BL(stripe, p, rw) (stripe->chunk[p].bl + rw)
+#define BL_CHUNK(chunk, rw) (chunk->bl + rw)
+
+/* Page list reference. */
+#define PL(stripe, p) (stripe->obj[p].pl)
+/* END: structure access macros. */
+
+/* Factor out to dm-bio-list.h */
+static inline void bio_list_push(struct bio_list *bl, struct bio *bio)
+{
+ bio->bi_next = bl->head;
+ bl->head = bio;
+
+ if (!bl->tail)
+ bl->tail = bio;
+}
+
+/* Factor out to dm.h */
+#define TI_ERR_RET(str, ret) \
+ do { ti->error = str; return ret; } while (0);
+#define TI_ERR(str) TI_ERR_RET(str, -EINVAL)
+
+/* Macro to define access IO flags access inline functions. */
+#define BITOPS(name, what, var, flag) \
+static inline int TestClear ## name ## what(struct var *v) \
+{ return test_and_clear_bit(flag, &v->io.flags); } \
+static inline int TestSet ## name ## what(struct var *v) \
+{ return test_and_set_bit(flag, &v->io.flags); } \
+static inline void Clear ## name ## what(struct var *v) \
+{ clear_bit(flag, &v->io.flags); } \
+static inline void Set ## name ## what(struct var *v) \
+{ set_bit(flag, &v->io.flags); } \
+static inline int name ## what(struct var *v) \
+{ return test_bit(flag, &v->io.flags); }
+
+/*-----------------------------------------------------------------
+ * Stripe cache
+ *
+ * Cache for all reads and writes to raid sets (operational or degraded)
+ *
+ * We need to run all data to and from a RAID set through this cache,
+ * because parity chunks need to get calculated from data chunks
+ * or, in the degraded/resynchronization case, missing chunks need
+ * to be reconstructed using the other chunks of the stripe.
+ *---------------------------------------------------------------*/
+/* A chunk within a stripe (holds bios hanging off). */
+/* IO status flags for chunks of a stripe. */
+enum chunk_flags {
+ CHUNK_DIRTY, /* Pages of chunk dirty; need writing. */
+ CHUNK_ERROR, /* IO error on any chunk page. */
+ CHUNK_IO, /* Allow/prohibit IO on chunk pages. */
+ CHUNK_LOCKED, /* Chunk pages locked during IO. */
+ CHUNK_MUST_IO, /* Chunk must io. */
+ CHUNK_UNLOCK, /* Enforce chunk unlock. */
+ CHUNK_UPTODATE, /* Chunk pages are uptodate. */
+};
+
+#if READ != 0 || WRITE != 1
+#error dm-raid45: READ/WRITE != 0/1 used as index!!!
+#endif
+
+enum bl_type {
+ WRITE_QUEUED = WRITE + 1,
+ WRITE_MERGED,
+ NR_BL_TYPES, /* Must be last one! */
+};
+struct stripe_chunk {
+ atomic_t cnt; /* Reference count. */
+ struct stripe *stripe; /* Backpointer to stripe for endio(). */
+ /* Bio lists for reads, writes, and writes merged. */
+ struct bio_list bl[NR_BL_TYPES];
+ struct {
+ unsigned long flags; /* IO status flags. */
+ } io;
+};
+
+/* Define chunk bit operations. */
+BITOPS(Chunk, Dirty, stripe_chunk, CHUNK_DIRTY)
+BITOPS(Chunk, Error, stripe_chunk, CHUNK_ERROR)
+BITOPS(Chunk, Io, stripe_chunk, CHUNK_IO)
+BITOPS(Chunk, Locked, stripe_chunk, CHUNK_LOCKED)
+BITOPS(Chunk, MustIo, stripe_chunk, CHUNK_MUST_IO)
+BITOPS(Chunk, Unlock, stripe_chunk, CHUNK_UNLOCK)
+BITOPS(Chunk, Uptodate, stripe_chunk, CHUNK_UPTODATE)
+
+/*
+ * Stripe linked list indexes. Keep order, because the stripe
+ * and the stripe cache rely on the first 3!
+ */
+enum list_types {
+ LIST_FLUSH, /* Stripes to flush for io. */
+ LIST_ENDIO, /* Stripes to endio. */
+ LIST_LRU, /* Least recently used stripes. */
+ SC_NR_LISTS, /* # of lists in stripe cache. */
+ LIST_HASH = SC_NR_LISTS, /* Hashed stripes. */
+ LIST_RECOVER = LIST_HASH, /* For recovery type stripes only. */
+ STRIPE_NR_LISTS,/* To size array in struct stripe. */
+};
+
+/* Adressing region recovery. */
+struct recover_addr {
+ struct dm_region *reg; /* Actual region to recover. */
+ sector_t pos; /* Position within region to recover. */
+ sector_t end; /* End of region to recover. */
+};
+
+/* A stripe: the io object to handle all reads and writes to a RAID set. */
+struct stripe {
+ atomic_t cnt; /* Reference count. */
+ struct stripe_cache *sc; /* Backpointer to stripe cache. */
+
+ /*
+ * 4 linked lists:
+ * o io list to flush io
+ * o endio list
+ * o LRU list to put stripes w/o reference count on
+ * o stripe cache hash
+ */
+ struct list_head lists[STRIPE_NR_LISTS];
+
+ sector_t key; /* Hash key. */
+ region_t region; /* Region stripe is mapped to. */
+
+ struct {
+ unsigned long flags; /* Stripe state flags (see below). */
+
+ /*
+ * Pending ios in flight:
+ *
+ * used to control move of stripe to endio list
+ */
+ atomic_t pending;
+
+ /* Sectors to read and write for multi page stripe sets. */
+ unsigned size;
+ } io;
+
+ /* Address region recovery. */
+ struct recover_addr *recover;
+
+ /* Lock on stripe (Future: for clustering). */
+ void *lock;
+
+ struct {
+ unsigned short parity; /* Parity chunk index. */
+ short recover; /* Recovery chunk index. */
+ } idx;
+
+ /*
+ * This stripe's memory cache object (dm-mem-cache);
+ * i.e. the io chunk pages.
+ */
+ struct dm_mem_cache_object *obj;
+
+ /* Array of stripe sets (dynamically allocated). */
+ struct stripe_chunk chunk[0];
+};
+
+/* States stripes can be in (flags field). */
+enum stripe_states {
+ STRIPE_ERROR, /* io error on stripe. */
+ STRIPE_MERGED, /* Writes got merged to be written. */
+ STRIPE_RBW, /* Read-before-write stripe. */
+ STRIPE_RECONSTRUCT, /* Reconstruct of a missing chunk required. */
+ STRIPE_RECONSTRUCTED, /* Reconstructed of a missing chunk. */
+ STRIPE_RECOVER, /* Stripe used for RAID set recovery. */
+};
+
+/* Define stripe bit operations. */
+BITOPS(Stripe, Error, stripe, STRIPE_ERROR)
+BITOPS(Stripe, Merged, stripe, STRIPE_MERGED)
+BITOPS(Stripe, RBW, stripe, STRIPE_RBW)
+BITOPS(Stripe, Reconstruct, stripe, STRIPE_RECONSTRUCT)
+BITOPS(Stripe, Reconstructed, stripe, STRIPE_RECONSTRUCTED)
+BITOPS(Stripe, Recover, stripe, STRIPE_RECOVER)
+
+/* A stripe hash. */
+struct stripe_hash {
+ struct list_head *hash;
+ unsigned buckets;
+ unsigned mask;
+ unsigned prime;
+ unsigned shift;
+};
+
+enum sc_lock_types {
+ LOCK_ENDIO, /* Protect endio list. */
+ LOCK_LRU, /* Protect LRU list. */
+ NR_LOCKS, /* To size array in struct stripe_cache. */
+};
+
+/* A stripe cache. */
+struct stripe_cache {
+ /* Stripe hash. */
+ struct stripe_hash hash;
+
+ spinlock_t locks[NR_LOCKS]; /* Locks to protect lists. */
+
+ /* Stripes with io to flush, stripes to endio and LRU lists. */
+ struct list_head lists[SC_NR_LISTS];
+
+ /* Slab cache to allocate stripes from. */
+ struct {
+ struct kmem_cache *cache; /* Cache itself. */
+ char name[32]; /* Unique name. */
+ } kc;
+
+ struct dm_io_client *dm_io_client; /* dm-io client resource context. */
+
+ /* dm-mem-cache client resource context. */
+ struct dm_mem_cache_client *mem_cache_client;
+
+ int stripes_parm; /* # stripes parameter from constructor. */
+ atomic_t stripes; /* actual # of stripes in cache. */
+ atomic_t stripes_to_set; /* # of stripes to resize cache to. */
+ atomic_t stripes_last; /* last # of stripes in cache. */
+ atomic_t active_stripes; /* actual # of active stripes in cache. */
+
+ /* REMOVEME: */
+ atomic_t active_stripes_max; /* actual # of active stripes in cache. */
+};
+
+/* Flag specs for raid_dev */ ;
+enum raid_dev_flags {
+ DEV_FAILED, /* Device failed. */
+ DEV_IO_QUEUED, /* Io got queued to device. */
+};
+
+/* The raid device in a set. */
+struct raid_dev {
+ struct dm_dev *dev;
+ sector_t start; /* Offset to map to. */
+ struct { /* Using struct to be able to BITOPS(). */
+ unsigned long flags; /* raid_dev_flags. */
+ } io;
+};
+
+BITOPS(Dev, Failed, raid_dev, DEV_FAILED)
+BITOPS(Dev, IoQueued, raid_dev, DEV_IO_QUEUED)
+
+/* Flags spec for raid_set. */
+enum raid_set_flags {
+ RS_CHECK_OVERWRITE, /* Check for chunk overwrites. */
+ RS_DEAD, /* RAID set inoperational. */
+ RS_DEGRADED, /* Io errors on RAID device. */
+ RS_DEVEL_STATS, /* REMOVEME: display status information. */
+ RS_RECOVER, /* Do recovery. */
+ RS_RECOVERY_BANDWIDTH, /* Allow recovery bandwidth (delayed bios). */
+ RS_SC_BUSY, /* Stripe cache busy -> send an event. */
+ RS_SUSPEND, /* Suspend RAID set. */
+};
+
+/* REMOVEME: devel stats counters. */
+enum stats_types {
+ S_BIOS_READ,
+ S_BIOS_ADDED_READ,
+ S_BIOS_ENDIO_READ,
+ S_BIOS_WRITE,
+ S_BIOS_ADDED_WRITE,
+ S_BIOS_ENDIO_WRITE,
+ S_CAN_MERGE,
+ S_CANT_MERGE,
+ S_CONGESTED,
+ S_DM_IO_READ,
+ S_DM_IO_WRITE,
+ S_BANDWIDTH,
+ S_BARRIER,
+ S_BIO_COPY_PL_NEXT,
+ S_DEGRADED,
+ S_DELAYED_BIOS,
+ S_FLUSHS,
+ S_HITS_1ST,
+ S_IOS_POST,
+ S_INSCACHE,
+ S_MAX_LOOKUP,
+ S_CHUNK_LOCKED,
+ S_NO_BANDWIDTH,
+ S_NOT_CONGESTED,
+ S_NO_RW,
+ S_NOSYNC,
+ S_OVERWRITE,
+ S_PROHIBITCHUNKIO,
+ S_RECONSTRUCT_EI,
+ S_RECONSTRUCT_DEV,
+ S_RECONSTRUCT_SET,
+ S_RECONSTRUCTED,
+ S_REQUEUE,
+ S_STRIPE_ERROR,
+ S_SUM_DELAYED_BIOS,
+ S_XORS,
+ S_NR_STATS, /* # of stats counters. Must be last! */
+};
+
+/* Status type -> string mappings. */
+struct stats_map {
+ const enum stats_types type;
+ const char *str;
+};
+
+static struct stats_map stats_map[] = {
+ { S_BIOS_READ, "r=" },
+ { S_BIOS_ADDED_READ, "/" },
+ { S_BIOS_ENDIO_READ, "/" },
+ { S_BIOS_WRITE, " w=" },
+ { S_BIOS_ADDED_WRITE, "/" },
+ { S_BIOS_ENDIO_WRITE, "/" },
+ { S_DM_IO_READ, " rc=" },
+ { S_DM_IO_WRITE, " wc=" },
+ { S_BANDWIDTH, "\nbw=" },
+ { S_NO_BANDWIDTH, " no_bw=" },
+ { S_BARRIER, "\nbarrier=" },
+ { S_BIO_COPY_PL_NEXT, "\nbio_cp_next=" },
+ { S_CAN_MERGE, "\nmerge=" },
+ { S_CANT_MERGE, "/no_merge=" },
+ { S_CHUNK_LOCKED, "\nchunk_locked=" },
+ { S_CONGESTED, "\ncgst=" },
+ { S_NOT_CONGESTED, "/not_cgst=" },
+ { S_DEGRADED, "\ndegraded=" },
+ { S_DELAYED_BIOS, "\ndel_bios=" },
+ { S_SUM_DELAYED_BIOS, "/sum_del_bios=" },
+ { S_FLUSHS, "\nflushs=" },
+ { S_HITS_1ST, "\nhits_1st=" },
+ { S_IOS_POST, " ios_post=" },
+ { S_INSCACHE, " inscache=" },
+ { S_MAX_LOOKUP, " maxlookup=" },
+ { S_NO_RW, "\nno_rw=" },
+ { S_NOSYNC, " nosync=" },
+ { S_OVERWRITE, " ovr=" },
+ { S_PROHIBITCHUNKIO, " prhbt_io=" },
+ { S_RECONSTRUCT_EI, "\nrec_ei=" },
+ { S_RECONSTRUCT_DEV, " rec_dev=" },
+ { S_RECONSTRUCT_SET, " rec_set=" },
+ { S_RECONSTRUCTED, " rec=" },
+ { S_REQUEUE, " requeue=" },
+ { S_STRIPE_ERROR, " stripe_err=" },
+ { S_XORS, " xors=" },
+};
+
+/*
+ * A RAID set.
+ */
+#define dm_rh_client dm_region_hash
+enum count_type { IO_WORK = 0, IO_RECOVER, IO_NR_COUNT };
+typedef void (*xor_function_t)(unsigned count, unsigned long **data);
+struct raid_set {
+ struct dm_target *ti; /* Target pointer. */
+
+ struct {
+ unsigned long flags; /* State flags. */
+ struct mutex in_lock; /* Protects central input list below. */
+ struct bio_list in; /* Pending ios (central input list). */
+ struct bio_list work; /* ios work set. */
+ wait_queue_head_t suspendq; /* suspend synchronization. */
+ atomic_t in_process; /* counter of queued bios (suspendq). */
+ atomic_t in_process_max;/* counter of queued bios max. */
+
+ /* io work. */
+ struct workqueue_struct *wq;
+ struct delayed_work dws_do_raid; /* For main worker. */
+ struct work_struct ws_do_table_event; /* For event worker. */
+ } io;
+
+ /* Stripe locking abstraction. */
+ struct dm_raid45_locking_type *locking;
+
+ struct stripe_cache sc; /* Stripe cache for this set. */
+
+ /* Xor optimization. */
+ struct {
+ struct xor_func *f;
+ unsigned chunks;
+ unsigned speed;
+ } xor;
+
+ /* Recovery parameters. */
+ struct recover {
+ struct dm_dirty_log *dl; /* Dirty log. */
+ struct dm_rh_client *rh; /* Region hash. */
+
+ struct dm_io_client *dm_io_client; /* recovery dm-io client. */
+ /* dm-mem-cache client resource context for recovery stripes. */
+ struct dm_mem_cache_client *mem_cache_client;
+
+ struct list_head stripes; /* List of recovery stripes. */
+
+ region_t nr_regions;
+ region_t nr_regions_to_recover;
+ region_t nr_regions_recovered;
+ unsigned long start_jiffies;
+ unsigned long end_jiffies;
+
+ unsigned bandwidth; /* Recovery bandwidth [%]. */
+ unsigned bandwidth_work; /* Recovery bandwidth [factor]. */
+ unsigned bandwidth_parm; /* " constructor parm. */
+ unsigned io_size; /* recovery io size <= region size. */
+ unsigned io_size_parm; /* recovery io size ctr parameter. */
+ unsigned recovery; /* Recovery allowed/prohibited. */
+ unsigned recovery_stripes; /* # of parallel recovery stripes. */
+
+ /* recovery io throttling. */
+ atomic_t io_count[IO_NR_COUNT]; /* counter recover/regular io.*/
+ unsigned long last_jiffies;
+ } recover;
+
+ /* RAID set parameters. */
+ struct {
+ struct raid_type *raid_type; /* RAID type (eg, RAID4). */
+ unsigned raid_parms; /* # variable raid parameters. */
+
+ unsigned chunk_size; /* Sectors per chunk. */
+ unsigned chunk_size_parm;
+ unsigned chunk_shift; /* rsector chunk size shift. */
+
+ unsigned io_size; /* Sectors per io. */
+ unsigned io_size_parm;
+ unsigned io_mask; /* Mask for bio_copy_page_list(). */
+ unsigned io_inv_mask; /* Mask for raid_address(). */
+
+ sector_t sectors_per_dev; /* Sectors per device. */
+
+ atomic_t failed_devs; /* Amount of devices failed. */
+
+ /* Index of device to initialize. */
+ int dev_to_init;
+ int dev_to_init_parm;
+
+ /* Raid devices dynamically allocated. */
+ unsigned raid_devs; /* # of RAID devices below. */
+ unsigned data_devs; /* # of RAID data devices. */
+
+ int ei; /* index of failed RAID device. */
+
+ /* Index of dedicated parity device (i.e. RAID4). */
+ int pi;
+ int pi_parm; /* constructor parm for status output. */
+ } set;
+
+ /* REMOVEME: devel stats counters. */
+ atomic_t stats[S_NR_STATS];
+
+ /* Dynamically allocated temporary pointers for xor(). */
+ unsigned long **data;
+
+ /* Dynamically allocated RAID devices. Alignment? */
+ struct raid_dev dev[0];
+};
+
+/* Define RAID set bit operations. */
+BITOPS(RS, Bandwidth, raid_set, RS_RECOVERY_BANDWIDTH)
+BITOPS(RS, CheckOverwrite, raid_set, RS_CHECK_OVERWRITE)
+BITOPS(RS, Dead, raid_set, RS_DEAD)
+BITOPS(RS, Degraded, raid_set, RS_DEGRADED)
+BITOPS(RS, DevelStats, raid_set, RS_DEVEL_STATS)
+BITOPS(RS, Recover, raid_set, RS_RECOVER)
+BITOPS(RS, ScBusy, raid_set, RS_SC_BUSY)
+BITOPS(RS, Suspend, raid_set, RS_SUSPEND)
+#undef BITOPS
+
+/*-----------------------------------------------------------------
+ * Raid-4/5 set structures.
+ *---------------------------------------------------------------*/
+/* RAID level definitions. */
+enum raid_level {
+ raid4,
+ raid5,
+};
+
+/* Symmetric/Asymmetric, Left/Right parity rotating algorithms. */
+enum raid_algorithm {
+ none,
+ left_asym,
+ right_asym,
+ left_sym,
+ right_sym,
+};
+
+struct raid_type {
+ const char *name; /* RAID algorithm. */
+ const char *descr; /* Descriptor text for logging. */
+ const unsigned parity_devs; /* # of parity devices. */
+ const unsigned minimal_devs; /* minimal # of devices in set. */
+ const enum raid_level level; /* RAID level. */
+ const enum raid_algorithm algorithm; /* RAID algorithm. */
+};
+
+/* Supported raid types and properties. */
+static struct raid_type raid_types[] = {
+ {"raid4", "RAID4 (dedicated parity disk)", 1, 3, raid4, none},
+ {"raid5_la", "RAID5 (left asymmetric)", 1, 3, raid5, left_asym},
+ {"raid5_ra", "RAID5 (right asymmetric)", 1, 3, raid5, right_asym},
+ {"raid5_ls", "RAID5 (left symmetric)", 1, 3, raid5, left_sym},
+ {"raid5_rs", "RAID5 (right symmetric)", 1, 3, raid5, right_sym},
+};
+
+/* Address as calculated by raid_address(). */
+struct raid_address {
+ sector_t key; /* Hash key (address of stripe % chunk_size). */
+ unsigned di, pi; /* Data and parity disks index. */
+};
+
+/* REMOVEME: reset statistics counters. */
+static void stats_reset(struct raid_set *rs)
+{
+ unsigned s = S_NR_STATS;
+
+ while (s--)
+ atomic_set(rs->stats + s, 0);
+}
+
+/*----------------------------------------------------------------
+ * RAID set management routines.
+ *--------------------------------------------------------------*/
+/*
+ * Begin small helper functions.
+ */
+/* No need to be called from region hash indirectly at dm_rh_dec(). */
+static void wake_dummy(void *context) {}
+
+/* Return # of io reference. */
+static int io_ref(struct raid_set *rs)
+{
+ return atomic_read(&rs->io.in_process);
+}
+
+/* Get an io reference. */
+static void io_get(struct raid_set *rs)
+{
+ int p = atomic_inc_return(&rs->io.in_process);
+
+ if (p > atomic_read(&rs->io.in_process_max))
+ atomic_set(&rs->io.in_process_max, p); /* REMOVEME: max. */
+}
+
+/* Put the io reference and conditionally wake io waiters. */
+static void io_put(struct raid_set *rs)
+{
+ /* Intel: rebuild data corrupter? */
+ if (atomic_dec_and_test(&rs->io.in_process))
+ wake_up(&rs->io.suspendq);
+ else
+ BUG_ON(io_ref(rs) < 0);
+}
+
+/* Wait until all io has been processed. */
+static void wait_ios(struct raid_set *rs)
+{
+ wait_event(rs->io.suspendq, !io_ref(rs));
+}
+
+/* Queue (optionally delayed) io work. */
+static void wake_do_raid_delayed(struct raid_set *rs, unsigned long delay)
+{
+ queue_delayed_work(rs->io.wq, &rs->io.dws_do_raid, delay);
+}
+
+/* Queue io work immediately (called from region hash too). */
+static void wake_do_raid(void *context)
+{
+ struct raid_set *rs = context;
+
+ queue_work(rs->io.wq, &rs->io.dws_do_raid.work);
+}
+
+/* Calculate device sector offset. */
+static sector_t _sector(struct raid_set *rs, struct bio *bio)
+{
+ sector_t sector = bio->bi_sector;
+
+ sector_div(sector, rs->set.data_devs);
+ return sector;
+}
+
+/* Return # of active stripes in stripe cache. */
+static int sc_active(struct stripe_cache *sc)
+{
+ return atomic_read(&sc->active_stripes);
+}
+
+/* Stripe cache busy indicator. */
+static int sc_busy(struct raid_set *rs)
+{
+ return sc_active(&rs->sc) >
+ atomic_read(&rs->sc.stripes) - (STRIPES_MIN / 2);
+}
+
+/* Set chunks states. */
+enum chunk_dirty_type { CLEAN, DIRTY, ERROR };
+static void chunk_set(struct stripe_chunk *chunk, enum chunk_dirty_type type)
+{
+ switch (type) {
+ case CLEAN:
+ ClearChunkDirty(chunk);
+ break;
+ case DIRTY:
+ SetChunkDirty(chunk);
+ break;
+ case ERROR:
+ SetChunkError(chunk);
+ SetStripeError(chunk->stripe);
+ return;
+ default:
+ BUG();
+ }
+
+ SetChunkUptodate(chunk);
+ SetChunkIo(chunk);
+ ClearChunkError(chunk);
+}
+
+/* Return region state for a sector. */
+static int region_state(struct raid_set *rs, sector_t sector,
+ enum dm_rh_region_states state)
+{
+ struct dm_rh_client *rh = rs->recover.rh;
+ region_t region = dm_rh_sector_to_region(rh, sector);
+
+ return !!(dm_rh_get_state(rh, region, 1) & state);
+}
+
+/*
+ * Return true in case a chunk should be read/written
+ *
+ * Conditions to read/write:
+ * o chunk not uptodate
+ * o chunk dirty
+ *
+ * Conditios to avoid io:
+ * o io already ongoing on chunk
+ * o io explitely prohibited
+ */
+static int chunk_io(struct stripe_chunk *chunk)
+{
+ /* 2nd run optimization (flag set below on first run). */
+ if (TestClearChunkMustIo(chunk))
+ return 1;
+
+ /* Avoid io if prohibited or a locked chunk. */
+ if (!ChunkIo(chunk) || ChunkLocked(chunk))
+ return 0;
+
+ if (!ChunkUptodate(chunk) || ChunkDirty(chunk)) {
+ SetChunkMustIo(chunk); /* 2nd run optimization. */
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Call a function on each chunk needing io unless device failed. */
+static unsigned for_each_io_dev(struct stripe *stripe,
+ void (*f_io)(struct stripe *stripe, unsigned p))
+{
+ struct raid_set *rs = RS(stripe->sc);
+ unsigned p, r = 0;
+
+ for (p = 0; p < rs->set.raid_devs; p++) {
+ if (chunk_io(CHUNK(stripe, p)) && !DevFailed(rs->dev + p)) {
+ f_io(stripe, p);
+ r++;
+ }
+ }
+
+ return r;
+}
+
+/*
+ * Index of device to calculate parity on.
+ *
+ * Either the parity device index *or* the selected
+ * device to init after a spare replacement.
+ */
+static int dev_for_parity(struct stripe *stripe, int *sync)
+{
+ struct raid_set *rs = RS(stripe->sc);
+ int r = region_state(rs, stripe->key, DM_RH_NOSYNC | DM_RH_RECOVERING);
+
+ *sync = !r;
+
+ /* Reconstruct a particular device ?. */
+ if (r && rs->set.dev_to_init > -1)
+ return rs->set.dev_to_init;
+ else if (rs->set.raid_type->level == raid4)
+ return rs->set.pi;
+ else if (!StripeRecover(stripe))
+ return stripe->idx.parity;
+ else
+ return -1;
+}
+
+/* RAID set congested function. */
+static int rs_congested(void *congested_data, int bdi_bits)
+{
+ int r;
+ unsigned p;
+ struct raid_set *rs = congested_data;
+
+ if (sc_busy(rs) || RSSuspend(rs))
+ r = 1;
+ else for (r = 0, p = rs->set.raid_devs; !r && p--; ) {
+ /* If any of our component devices are overloaded. */
+ struct request_queue *q = bdev_get_queue(rs->dev[p].dev->bdev);
+
+ r |= bdi_congested(&q->backing_dev_info, bdi_bits);
+ }
+
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + (r ? S_CONGESTED : S_NOT_CONGESTED));
+ return r;
+}
+
+/* RAID device degrade check. */
+static void rs_check_degrade_dev(struct raid_set *rs,
+ struct stripe *stripe, unsigned p)
+{
+ if (TestSetDevFailed(rs->dev + p))
+ return;
+
+ /* Through an event in case of member device errors. */
+ if (atomic_inc_return(&rs->set.failed_devs) >
+ rs->set.raid_type->parity_devs &&
+ !TestSetRSDead(rs)) {
+ /* Display RAID set dead message once. */
+ unsigned p;
+ char buf[BDEVNAME_SIZE];
+
+ DMERR("FATAL: too many devices failed -> RAID set broken");
+ for (p = 0; p < rs->set.raid_devs; p++) {
+ if (DevFailed(rs->dev + p))
+ DMERR("device /dev/%s failed",
+ bdevname(rs->dev[p].dev->bdev, buf));
+ }
+ }
+
+ /* Only log the first member error. */
+ if (!TestSetRSDegraded(rs)) {
+ char buf[BDEVNAME_SIZE];
+
+ /* Store index for recovery. */
+ rs->set.ei = p;
+ DMERR("CRITICAL: %sio error on device /dev/%s "
+ "in region=%llu; DEGRADING RAID set\n",
+ stripe ? "" : "FAKED ",
+ bdevname(rs->dev[p].dev->bdev, buf),
+ (unsigned long long) (stripe ? stripe->key : 0));
+ DMERR("further device error messages suppressed");
+ }
+
+ schedule_work(&rs->io.ws_do_table_event);
+}
+
+/* RAID set degrade check. */
+static void rs_check_degrade(struct stripe *stripe)
+{
+ struct raid_set *rs = RS(stripe->sc);
+ unsigned p = rs->set.raid_devs;
+
+ while (p--) {
+ if (ChunkError(CHUNK(stripe, p)))
+ rs_check_degrade_dev(rs, stripe, p);
+ }
+}
+
+/* Lookup a RAID device by name or by major:minor number. */
+static int raid_dev_lookup(struct raid_set *rs, struct raid_dev *dev_lookup)
+{
+ unsigned p;
+ struct raid_dev *dev;
+
+ /*
+ * Must be an incremental loop, because the device array
+ * can have empty slots still on calls from raid_ctr()
+ */
+ for (dev = rs->dev, p = 0;
+ dev->dev && p < rs->set.raid_devs;
+ dev++, p++) {
+ if (dev_lookup->dev->bdev->bd_dev == dev->dev->bdev->bd_dev)
+ return p;
+ }
+
+ return -ENODEV;
+}
+/*
+ * End small helper functions.
+ */
+
+/*
+ * Stripe hash functions
+ */
+/* Initialize/destroy stripe hash. */
+static int hash_init(struct stripe_hash *hash, unsigned stripes)
+{
+ unsigned buckets = 2, max_buckets = stripes >> 1;
+ static unsigned hash_primes[] = {
+ /* Table of primes for hash_fn/table size optimization. */
+ 1, 2, 3, 7, 13, 27, 53, 97, 193, 389, 769,
+ 1543, 3079, 6151, 12289, 24593, 49157, 98317,
+ };
+
+ /* Calculate number of buckets (2^^n <= stripes / 2). */
+ while (buckets < max_buckets)
+ buckets <<= 1;
+
+ /* Allocate stripe hash buckets. */
+ hash->hash = vmalloc(buckets * sizeof(*hash->hash));
+ if (!hash->hash)
+ return -ENOMEM;
+
+ hash->buckets = buckets;
+ hash->mask = buckets - 1;
+ hash->shift = ffs(buckets);
+ if (hash->shift > ARRAY_SIZE(hash_primes))
+ hash->shift = ARRAY_SIZE(hash_primes) - 1;
+
+ BUG_ON(hash->shift < 2);
+ hash->prime = hash_primes[hash->shift];
+
+ /* Initialize buckets. */
+ while (buckets--)
+ INIT_LIST_HEAD(hash->hash + buckets);
+ return 0;
+}
+
+static void hash_exit(struct stripe_hash *hash)
+{
+ if (hash->hash) {
+ vfree(hash->hash);
+ hash->hash = NULL;
+ }
+}
+
+static unsigned hash_fn(struct stripe_hash *hash, sector_t key)
+{
+ return (unsigned) (((key * hash->prime) >> hash->shift) & hash->mask);
+}
+
+static struct list_head *hash_bucket(struct stripe_hash *hash, sector_t key)
+{
+ return hash->hash + hash_fn(hash, key);
+}
+
+/* Insert an entry into a hash. */
+static void stripe_insert(struct stripe_hash *hash, struct stripe *stripe)
+{
+ list_add(stripe->lists + LIST_HASH, hash_bucket(hash, stripe->key));
+}
+
+/* Lookup an entry in the stripe hash. */
+static struct stripe *stripe_lookup(struct stripe_cache *sc, sector_t key)
+{
+ unsigned look = 0;
+ struct stripe *stripe;
+ struct list_head *bucket = hash_bucket(&sc->hash, key);
+
+ list_for_each_entry(stripe, bucket, lists[LIST_HASH]) {
+ look++;
+
+ if (stripe->key == key) {
+ /* REMOVEME: statisics. */
+ if (look > atomic_read(RS(sc)->stats + S_MAX_LOOKUP))
+ atomic_set(RS(sc)->stats + S_MAX_LOOKUP, look);
+ return stripe;
+ }
+ }
+
+ return NULL;
+}
+
+/* Resize the stripe cache hash on size changes. */
+static int sc_hash_resize(struct stripe_cache *sc)
+{
+ /* Resize indicated ? */
+ if (atomic_read(&sc->stripes) != atomic_read(&sc->stripes_last)) {
+ int r;
+ struct stripe_hash hash;
+
+ r = hash_init(&hash, atomic_read(&sc->stripes));
+ if (r)
+ return r;
+
+ if (sc->hash.hash) {
+ unsigned b = sc->hash.buckets;
+ struct list_head *pos, *tmp;
+
+ /* Walk old buckets and insert into new. */
+ while (b--) {
+ list_for_each_safe(pos, tmp, sc->hash.hash + b)
+ stripe_insert(&hash,
+ list_entry(pos, struct stripe,
+ lists[LIST_HASH]));
+ }
+
+ }
+
+ hash_exit(&sc->hash);
+ memcpy(&sc->hash, &hash, sizeof(sc->hash));
+ atomic_set(&sc->stripes_last, atomic_read(&sc->stripes));
+ }
+
+ return 0;
+}
+/* End hash stripe hash function. */
+
+/* List add, delete, push and pop functions. */
+/* Add stripe to flush list. */
+#define DEL_LIST(lh) \
+ if (!list_empty(lh)) \
+ list_del_init(lh);
+
+/* Delete stripe from hash. */
+static void stripe_hash_del(struct stripe *stripe)
+{
+ DEL_LIST(stripe->lists + LIST_HASH);
+}
+
+/* Return stripe reference count. */
+static inline int stripe_ref(struct stripe *stripe)
+{
+ return atomic_read(&stripe->cnt);
+}
+
+static void stripe_flush_add(struct stripe *stripe)
+{
+ struct stripe_cache *sc = stripe->sc;
+ struct list_head *lh = stripe->lists + LIST_FLUSH;
+
+ if (!StripeReconstruct(stripe) && list_empty(lh))
+ list_add_tail(lh, sc->lists + LIST_FLUSH);
+}
+
+/*
+ * Add stripe to LRU (inactive) list.
+ *
+ * Need lock, because of concurrent access from message interface.
+ */
+static void stripe_lru_add(struct stripe *stripe)
+{
+ if (!StripeRecover(stripe)) {
+ unsigned long flags;
+ struct list_head *lh = stripe->lists + LIST_LRU;
+ spinlock_t *lock = stripe->sc->locks + LOCK_LRU;
+
+ spin_lock_irqsave(lock, flags);
+ if (list_empty(lh))
+ list_add_tail(lh, stripe->sc->lists + LIST_LRU);
+ spin_unlock_irqrestore(lock, flags);
+ }
+}
+
+#define POP_LIST(list) \
+ do { \
+ if (list_empty(sc->lists + (list))) \
+ stripe = NULL; \
+ else { \
+ stripe = list_first_entry(sc->lists + (list), \
+ struct stripe, \
+ lists[(list)]); \
+ list_del_init(stripe->lists + (list)); \
+ } \
+ } while (0);
+
+/* Pop an available stripe off the LRU list. */
+static struct stripe *stripe_lru_pop(struct stripe_cache *sc)
+{
+ struct stripe *stripe;
+ spinlock_t *lock = sc->locks + LOCK_LRU;
+
+ spin_lock_irq(lock);
+ POP_LIST(LIST_LRU);
+ spin_unlock_irq(lock);
+
+ return stripe;
+}
+
+/* Pop an available stripe off the io list. */
+static struct stripe *stripe_io_pop(struct stripe_cache *sc)
+{
+ struct stripe *stripe;
+
+ POP_LIST(LIST_FLUSH);
+ return stripe;
+}
+
+/* Push a stripe safely onto the endio list to be handled by do_endios(). */
+static void stripe_endio_push(struct stripe *stripe)
+{
+ unsigned long flags;
+ struct stripe_cache *sc = stripe->sc;
+ struct list_head *stripe_list = stripe->lists + LIST_ENDIO,
+ *sc_list = sc->lists + LIST_ENDIO;
+ spinlock_t *lock = sc->locks + LOCK_ENDIO;
+
+ /* This runs in parallel with do_endios(). */
+ spin_lock_irqsave(lock, flags);
+ if (list_empty(stripe_list))
+ list_add_tail(stripe_list, sc_list);
+ spin_unlock_irqrestore(lock, flags);
+
+ wake_do_raid(RS(sc)); /* Wake myself. */
+}
+
+/* Pop a stripe off safely off the endio list. */
+static struct stripe *stripe_endio_pop(struct stripe_cache *sc)
+{
+ struct stripe *stripe;
+ spinlock_t *lock = sc->locks + LOCK_ENDIO;
+
+ /* This runs in parallel with endio(). */
+ spin_lock_irq(lock);
+ POP_LIST(LIST_ENDIO)
+ spin_unlock_irq(lock);
+ return stripe;
+}
+#undef POP_LIST
+
+/*
+ * Stripe cache locking functions
+ */
+/* Dummy lock function for single host RAID4+5. */
+static void *no_lock(sector_t key, enum dm_lock_type type)
+{
+ return &no_lock;
+}
+
+/* Dummy unlock function for single host RAID4+5. */
+static void no_unlock(void *lock_handle)
+{
+}
+
+/* No locking (for single host RAID 4+5). */
+static struct dm_raid45_locking_type locking_none = {
+ .lock = no_lock,
+ .unlock = no_unlock,
+};
+
+/* Lock a stripe (for clustering). */
+static int
+stripe_lock(struct stripe *stripe, int rw, sector_t key)
+{
+ stripe->lock = RS(stripe->sc)->locking->lock(key, rw == READ ? DM_RAID45_SHARED : DM_RAID45_EX);
+ return stripe->lock ? 0 : -EPERM;
+}
+
+/* Unlock a stripe (for clustering). */
+static void stripe_unlock(struct stripe *stripe)
+{
+ RS(stripe->sc)->locking->unlock(stripe->lock);
+ stripe->lock = NULL;
+}
+
+/* Test io pending on stripe. */
+static int stripe_io_ref(struct stripe *stripe)
+{
+ return atomic_read(&stripe->io.pending);
+}
+
+static void stripe_io_get(struct stripe *stripe)
+{
+ if (atomic_inc_return(&stripe->io.pending) == 1)
+ /* REMOVEME: statistics */
+ atomic_inc(&stripe->sc->active_stripes);
+ else
+ BUG_ON(stripe_io_ref(stripe) < 0);
+}
+
+static void stripe_io_put(struct stripe *stripe)
+{
+ if (atomic_dec_and_test(&stripe->io.pending)) {
+ if (unlikely(StripeRecover(stripe)))
+ /* Don't put recovery stripe on endio list. */
+ wake_do_raid(RS(stripe->sc));
+ else
+ /* Add regular stripe to endio list and wake daemon. */
+ stripe_endio_push(stripe);
+
+ /* REMOVEME: statistics */
+ atomic_dec(&stripe->sc->active_stripes);
+ } else
+ BUG_ON(stripe_io_ref(stripe) < 0);
+}
+
+/* Take stripe reference out. */
+static int stripe_get(struct stripe *stripe)
+{
+ int r;
+ struct list_head *lh = stripe->lists + LIST_LRU;
+ spinlock_t *lock = stripe->sc->locks + LOCK_LRU;
+
+ /* Delete stripe from LRU (inactive) list if on. */
+ spin_lock_irq(lock);
+ DEL_LIST(lh);
+ spin_unlock_irq(lock);
+
+ BUG_ON(stripe_ref(stripe) < 0);
+
+ /* Lock stripe on first reference */
+ r = (atomic_inc_return(&stripe->cnt) == 1) ?
+ stripe_lock(stripe, WRITE, stripe->key) : 0;
+
+ return r;
+}
+#undef DEL_LIST
+
+/* Return references on a chunk. */
+static int chunk_ref(struct stripe_chunk *chunk)
+{
+ return atomic_read(&chunk->cnt);
+}
+
+/* Take out reference on a chunk. */
+static int chunk_get(struct stripe_chunk *chunk)
+{
+ return atomic_inc_return(&chunk->cnt);
+}
+
+/* Drop reference on a chunk. */
+static void chunk_put(struct stripe_chunk *chunk)
+{
+ BUG_ON(atomic_dec_return(&chunk->cnt) < 0);
+}
+
+/*
+ * Drop reference on a stripe.
+ *
+ * Move it to list of LRU stripes if zero.
+ */
+static void stripe_put(struct stripe *stripe)
+{
+ if (atomic_dec_and_test(&stripe->cnt)) {
+ BUG_ON(stripe_io_ref(stripe));
+ stripe_unlock(stripe);
+ } else
+ BUG_ON(stripe_ref(stripe) < 0);
+}
+
+/* Helper needed by for_each_io_dev(). */
+static void stripe_get_references(struct stripe *stripe, unsigned p)
+{
+
+ /*
+ * Another one to reference the stripe in
+ * order to protect vs. LRU list moves.
+ */
+ io_get(RS(stripe->sc)); /* Global io references. */
+ stripe_get(stripe);
+ stripe_io_get(stripe); /* One for each chunk io. */
+}
+
+/* Helper for endio() to put all take references. */
+static void stripe_put_references(struct stripe *stripe)
+{
+ stripe_io_put(stripe); /* One for each chunk io. */
+ stripe_put(stripe);
+ io_put(RS(stripe->sc));
+}
+
+/*
+ * Stripe cache functions.
+ */
+/*
+ * Invalidate all chunks (i.e. their pages) of a stripe.
+ *
+ * I only keep state for the whole chunk.
+ */
+static inline void stripe_chunk_invalidate(struct stripe_chunk *chunk)
+{
+ chunk->io.flags = 0;
+}
+
+static void
+stripe_chunks_invalidate(struct stripe *stripe)
+{
+ unsigned p = RS(stripe->sc)->set.raid_devs;
+
+ while (p--)
+ stripe_chunk_invalidate(CHUNK(stripe, p));
+}
+
+/* Prepare stripe for (re)use. */
+static void stripe_invalidate(struct stripe *stripe)
+{
+ stripe->io.flags = 0;
+ stripe->idx.parity = stripe->idx.recover = -1;
+ stripe_chunks_invalidate(stripe);
+}
+
+/*
+ * Allow io on all chunks of a stripe.
+ * If not set, IO will not occur; i.e. it's prohibited.
+ *
+ * Actual IO submission for allowed chunks depends
+ * on their !uptodate or dirty state.
+ */
+static void stripe_allow_io(struct stripe *stripe)
+{
+ unsigned p = RS(stripe->sc)->set.raid_devs;
+
+ while (p--)
+ SetChunkIo(CHUNK(stripe, p));
+}
+
+/* Initialize a stripe. */
+static void stripe_init(struct stripe_cache *sc, struct stripe *stripe)
+{
+ unsigned i, p = RS(sc)->set.raid_devs;
+
+ /* Work all io chunks. */
+ while (p--) {
+ struct stripe_chunk *chunk = CHUNK(stripe, p);
+
+ atomic_set(&chunk->cnt, 0);
+ chunk->stripe = stripe;
+ i = ARRAY_SIZE(chunk->bl);
+ while (i--)
+ bio_list_init(chunk->bl + i);
+ }
+
+ stripe->sc = sc;
+
+
+ i = ARRAY_SIZE(stripe->lists);
+ while (i--)
+ INIT_LIST_HEAD(stripe->lists + i);
+
+ stripe->io.size = RS(sc)->set.io_size;
+ atomic_set(&stripe->cnt, 0);
+ atomic_set(&stripe->io.pending, 0);
+ stripe_invalidate(stripe);
+}
+
+/* Number of pages per chunk. */
+static inline unsigned chunk_pages(unsigned sectors)
+{
+ return dm_div_up(sectors, SECTORS_PER_PAGE);
+}
+
+/* Number of pages per stripe. */
+static inline unsigned stripe_pages(struct raid_set *rs, unsigned io_size)
+{
+ return chunk_pages(io_size) * rs->set.raid_devs;
+}
+
+/* Initialize part of page_list (recovery). */
+static void stripe_zero_pl_part(struct stripe *stripe, int p,
+ unsigned start, unsigned count)
+{
+ unsigned o = start / SECTORS_PER_PAGE, pages = chunk_pages(count);
+ /* Get offset into the page_list. */
+ struct page_list *pl = pl_elem(PL(stripe, p), o);
+
+ BUG_ON(!pl);
+ while (pl && pages--) {
+ BUG_ON(!pl->page);
+ memset(page_address(pl->page), 0, PAGE_SIZE);
+ pl = pl->next;
+ }
+}
+
+/* Initialize parity chunk of stripe. */
+static void stripe_zero_chunk(struct stripe *stripe, int p)
+{
+ if (p > -1)
+ stripe_zero_pl_part(stripe, p, 0, stripe->io.size);
+}
+
+/* Return dynamic stripe structure size. */
+static size_t stripe_size(struct raid_set *rs)
+{
+ return sizeof(struct stripe) +
+ rs->set.raid_devs * sizeof(struct stripe_chunk);
+}
+
+/* Allocate a stripe and its memory object. */
+/* XXX adjust to cope with stripe cache and recovery stripe caches. */
+enum grow { SC_GROW, SC_KEEP };
+static struct stripe *stripe_alloc(struct stripe_cache *sc,
+ struct dm_mem_cache_client *mc,
+ enum grow grow)
+{
+ int r;
+ struct stripe *stripe;
+
+ stripe = kmem_cache_zalloc(sc->kc.cache, GFP_KERNEL);
+ if (stripe) {
+ /* Grow the dm-mem-cache by one object. */
+ if (grow == SC_GROW) {
+ r = dm_mem_cache_grow(mc, 1);
+ if (r)
+ goto err_free;
+ }
+
+ stripe->obj = dm_mem_cache_alloc(mc);
+ if (!stripe->obj)
+ goto err_shrink;
+
+ stripe_init(sc, stripe);
+ }
+
+ return stripe;
+
+err_shrink:
+ if (grow == SC_GROW)
+ dm_mem_cache_shrink(mc, 1);
+err_free:
+ kmem_cache_free(sc->kc.cache, stripe);
+ return NULL;
+}
+
+/*
+ * Free a stripes memory object, shrink the
+ * memory cache and free the stripe itself.
+ */
+static void stripe_free(struct stripe *stripe, struct dm_mem_cache_client *mc)
+{
+ dm_mem_cache_free(mc, stripe->obj);
+ dm_mem_cache_shrink(mc, 1);
+ kmem_cache_free(stripe->sc->kc.cache, stripe);
+}
+
+/* Free the recovery stripe. */
+static void stripe_recover_free(struct raid_set *rs)
+{
+ struct recover *rec = &rs->recover;
+ struct dm_mem_cache_client *mc;
+
+ mc = rec->mem_cache_client;
+ rec->mem_cache_client = NULL;
+ if (mc) {
+ struct stripe *stripe;
+
+ while (!list_empty(&rec->stripes)) {
+ stripe = list_first_entry(&rec->stripes, struct stripe,
+ lists[LIST_RECOVER]);
+ list_del(stripe->lists + LIST_RECOVER);
+ kfree(stripe->recover);
+ stripe_free(stripe, mc);
+ }
+
+ dm_mem_cache_client_destroy(mc);
+ dm_io_client_destroy(rec->dm_io_client);
+ rec->dm_io_client = NULL;
+ }
+}
+
+/* Grow stripe cache. */
+static int sc_grow(struct stripe_cache *sc, unsigned stripes, enum grow grow)
+{
+ int r = 0;
+
+ /* Try to allocate this many (additional) stripes. */
+ while (stripes--) {
+ struct stripe *stripe =
+ stripe_alloc(sc, sc->mem_cache_client, grow);
+
+ if (likely(stripe)) {
+ stripe_lru_add(stripe);
+ atomic_inc(&sc->stripes);
+ } else {
+ r = -ENOMEM;
+ break;
+ }
+ }
+
+ return r ? r : sc_hash_resize(sc);
+}
+
+/* Shrink stripe cache. */
+static int sc_shrink(struct stripe_cache *sc, unsigned stripes)
+{
+ int r = 0;
+
+ /* Try to get unused stripe from LRU list. */
+ while (stripes--) {
+ struct stripe *stripe;
+
+ stripe = stripe_lru_pop(sc);
+ if (stripe) {
+ /* An LRU stripe may never have ios pending! */
+ BUG_ON(stripe_io_ref(stripe));
+ BUG_ON(stripe_ref(stripe));
+ atomic_dec(&sc->stripes);
+ /* Remove from hash if on before deletion. */
+ stripe_hash_del(stripe);
+ stripe_free(stripe, sc->mem_cache_client);
+ } else {
+ r = -ENOENT;
+ break;
+ }
+ }
+
+ /* Check if stats are still sane. */
+ if (atomic_read(&sc->active_stripes_max) >
+ atomic_read(&sc->stripes))
+ atomic_set(&sc->active_stripes_max, 0);
+
+ if (r)
+ return r;
+
+ return atomic_read(&sc->stripes) ? sc_hash_resize(sc) : 0;
+}
+
+/* Create stripe cache and recovery. */
+static int sc_init(struct raid_set *rs, unsigned stripes)
+{
+ unsigned i, r, rstripes;
+ struct stripe_cache *sc = &rs->sc;
+ struct stripe *stripe;
+ struct recover *rec = &rs->recover;
+ struct mapped_device *md;
+ struct gendisk *disk;
+
+ /* Initialize lists and locks. */
+ i = ARRAY_SIZE(sc->lists);
+ while (i--)
+ INIT_LIST_HEAD(sc->lists + i);
+
+ INIT_LIST_HEAD(&rec->stripes);
+
+ /* Initialize endio and LRU list locks. */
+ i = NR_LOCKS;
+ while (i--)
+ spin_lock_init(sc->locks + i);
+
+ /* Initialize atomic variables. */
+ atomic_set(&sc->stripes, 0);
+ atomic_set(&sc->stripes_to_set, 0);
+ atomic_set(&sc->active_stripes, 0);
+ atomic_set(&sc->active_stripes_max, 0); /* REMOVEME: statistics. */
+
+ /*
+ * We need a runtime unique # to suffix the kmem cache name
+ * because we'll have one for each active RAID set.
+ */
+ md = dm_table_get_md(rs->ti->table);
+ disk = dm_disk(md);
+ sprintf(sc->kc.name, "%s-%d", TARGET, disk->first_minor);
+ dm_put(md);
+ sc->kc.cache = kmem_cache_create(sc->kc.name, stripe_size(rs),
+ 0, 0, NULL);
+ if (!sc->kc.cache)
+ return -ENOMEM;
+
+ /* Create memory cache client context for RAID stripe cache. */
+ sc->mem_cache_client =
+ dm_mem_cache_client_create(stripes, rs->set.raid_devs,
+ chunk_pages(rs->set.io_size));
+ if (IS_ERR(sc->mem_cache_client))
+ return PTR_ERR(sc->mem_cache_client);
+
+ /* Create memory cache client context for RAID recovery stripe(s). */
+ rstripes = rec->recovery_stripes;
+ rec->mem_cache_client =
+ dm_mem_cache_client_create(rstripes, rs->set.raid_devs,
+ chunk_pages(rec->io_size));
+ if (IS_ERR(rec->mem_cache_client))
+ return PTR_ERR(rec->mem_cache_client);
+
+ /* Create dm-io client context for IO stripes. */
+ sc->dm_io_client =
+ dm_io_client_create((stripes > 32 ? 32 : stripes) *
+ rs->set.raid_devs *
+ chunk_pages(rs->set.io_size));
+ if (IS_ERR(sc->dm_io_client))
+ return PTR_ERR(sc->dm_io_client);
+
+ /* FIXME: intermingeled with stripe cache initialization. */
+ /* Create dm-io client context for recovery stripes. */
+ rec->dm_io_client =
+ dm_io_client_create(rstripes * rs->set.raid_devs *
+ chunk_pages(rec->io_size));
+ if (IS_ERR(rec->dm_io_client))
+ return PTR_ERR(rec->dm_io_client);
+
+ /* Allocate stripes for set recovery. */
+ while (rstripes--) {
+ stripe = stripe_alloc(sc, rec->mem_cache_client, SC_KEEP);
+ if (!stripe)
+ return -ENOMEM;
+
+ stripe->recover = kzalloc(sizeof(*stripe->recover), GFP_KERNEL);
+ if (!stripe->recover) {
+ stripe_free(stripe, rec->mem_cache_client);
+ return -ENOMEM;
+ }
+
+ SetStripeRecover(stripe);
+ stripe->io.size = rec->io_size;
+ list_add_tail(stripe->lists + LIST_RECOVER, &rec->stripes);
+ /* Don't add recovery stripes to LRU list! */
+ }
+
+ /*
+ * Allocate the stripe objetcs from the
+ * cache and add them to the LRU list.
+ */
+ r = sc_grow(sc, stripes, SC_KEEP);
+ if (!r)
+ atomic_set(&sc->stripes_last, stripes);
+
+ return r;
+}
+
+/* Destroy the stripe cache. */
+static void sc_exit(struct stripe_cache *sc)
+{
+ struct raid_set *rs = RS(sc);
+
+ if (sc->kc.cache) {
+ stripe_recover_free(rs);
+ BUG_ON(sc_shrink(sc, atomic_read(&sc->stripes)));
+ kmem_cache_destroy(sc->kc.cache);
+ sc->kc.cache = NULL;
+
+ if (sc->mem_cache_client && !IS_ERR(sc->mem_cache_client))
+ dm_mem_cache_client_destroy(sc->mem_cache_client);
+
+ if (sc->dm_io_client && !IS_ERR(sc->dm_io_client))
+ dm_io_client_destroy(sc->dm_io_client);
+
+ hash_exit(&sc->hash);
+ }
+}
+
+/*
+ * Calculate RAID address
+ *
+ * Delivers tuple with the index of the data disk holding the chunk
+ * in the set, the parity disks index and the start of the stripe
+ * within the address space of the set (used as the stripe cache hash key).
+ */
+/* thx MD. */
+static struct raid_address *raid_address(struct raid_set *rs, sector_t sector,
+ struct raid_address *addr)
+{
+ sector_t stripe, tmp;
+
+ /*
+ * chunk_number = sector / chunk_size
+ * stripe_number = chunk_number / data_devs
+ * di = stripe % data_devs;
+ */
+ stripe = sector >> rs->set.chunk_shift;
+ addr->di = sector_div(stripe, rs->set.data_devs);
+
+ switch (rs->set.raid_type->level) {
+ case raid4:
+ addr->pi = rs->set.pi;
+ goto check_shift_di;
+ case raid5:
+ tmp = stripe;
+ addr->pi = sector_div(tmp, rs->set.raid_devs);
+
+ switch (rs->set.raid_type->algorithm) {
+ case left_asym: /* Left asymmetric. */
+ addr->pi = rs->set.data_devs - addr->pi;
+ case right_asym: /* Right asymmetric. */
+check_shift_di:
+ if (addr->di >= addr->pi)
+ addr->di++;
+ break;
+ case left_sym: /* Left symmetric. */
+ addr->pi = rs->set.data_devs - addr->pi;
+ case right_sym: /* Right symmetric. */
+ addr->di = (addr->pi + addr->di + 1) %
+ rs->set.raid_devs;
+ break;
+ case none: /* Ain't happen: RAID4 algorithm placeholder. */
+ BUG();
+ }
+ }
+
+ /*
+ * Start offset of the stripes chunk on any single device of the RAID
+ * set, adjusted in case io size differs from chunk size.
+ */
+ addr->key = (stripe << rs->set.chunk_shift) +
+ (sector & rs->set.io_inv_mask);
+ return addr;
+}
+
+/*
+ * Copy data across between stripe pages and bio vectors.
+ *
+ * Pay attention to data alignment in stripe and bio pages.
+ */
+static void bio_copy_page_list(int rw, struct stripe *stripe,
+ struct page_list *pl, struct bio *bio)
+{
+ unsigned i, page_offset;
+ void *page_addr;
+ struct raid_set *rs = RS(stripe->sc);
+ struct bio_vec *bv;
+
+ /* Get start page in page list for this sector. */
+ i = (bio->bi_sector & rs->set.io_mask) / SECTORS_PER_PAGE;
+ pl = pl_elem(pl, i);
+ BUG_ON(!pl);
+ BUG_ON(!pl->page);
+
+ page_addr = page_address(pl->page);
+ page_offset = to_bytes(bio->bi_sector & (SECTORS_PER_PAGE - 1));
+
+ /* Walk all segments and copy data across between bio_vecs and pages. */
+ bio_for_each_segment(bv, bio, i) {
+ int len = bv->bv_len, size;
+ unsigned bio_offset = 0;
+ void *bio_addr = __bio_kmap_atomic(bio, i, KM_USER0);
+redo:
+ size = (page_offset + len > PAGE_SIZE) ?
+ PAGE_SIZE - page_offset : len;
+
+ if (rw == READ)
+ memcpy(bio_addr + bio_offset,
+ page_addr + page_offset, size);
+ else
+ memcpy(page_addr + page_offset,
+ bio_addr + bio_offset, size);
+
+ page_offset += size;
+ if (page_offset == PAGE_SIZE) {
+ /*
+ * We reached the end of the chunk page ->
+ * need to refer to the next one to copy more data.
+ */
+ len -= size;
+ if (len) {
+ /* Get next page. */
+ pl = pl->next;
+ BUG_ON(!pl);
+ BUG_ON(!pl->page);
+ page_addr = page_address(pl->page);
+ page_offset = 0;
+ bio_offset += size;
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + S_BIO_COPY_PL_NEXT);
+ goto redo;
+ }
+ }
+
+ __bio_kunmap_atomic(bio_addr, KM_USER0);
+ }
+}
+
+/*
+ * Xor optimization macros.
+ */
+/* Xor data pointer declaration and initialization macros. */
+#define DECLARE_2 unsigned long *d0 = data[0], *d1 = data[1]
+#define DECLARE_3 DECLARE_2, *d2 = data[2]
+#define DECLARE_4 DECLARE_3, *d3 = data[3]
+#define DECLARE_5 DECLARE_4, *d4 = data[4]
+#define DECLARE_6 DECLARE_5, *d5 = data[5]
+#define DECLARE_7 DECLARE_6, *d6 = data[6]
+#define DECLARE_8 DECLARE_7, *d7 = data[7]
+
+/* Xor unrole macros. */
+#define D2(n) d0[n] = d0[n] ^ d1[n]
+#define D3(n) D2(n) ^ d2[n]
+#define D4(n) D3(n) ^ d3[n]
+#define D5(n) D4(n) ^ d4[n]
+#define D6(n) D5(n) ^ d5[n]
+#define D7(n) D6(n) ^ d6[n]
+#define D8(n) D7(n) ^ d7[n]
+
+#define X_2(macro, offset) macro(offset); macro(offset + 1);
+#define X_4(macro, offset) X_2(macro, offset); X_2(macro, offset + 2);
+#define X_8(macro, offset) X_4(macro, offset); X_4(macro, offset + 4);
+#define X_16(macro, offset) X_8(macro, offset); X_8(macro, offset + 8);
+#define X_32(macro, offset) X_16(macro, offset); X_16(macro, offset + 16);
+#define X_64(macro, offset) X_32(macro, offset); X_32(macro, offset + 32);
+
+/* Define a _xor_#chunks_#xors_per_run() function. */
+#define _XOR(chunks, xors_per_run) \
+static void _xor ## chunks ## _ ## xors_per_run(unsigned long **data) \
+{ \
+ unsigned end = XOR_SIZE / sizeof(data[0]), i; \
+ DECLARE_ ## chunks; \
+\
+ for (i = 0; i < end; i += xors_per_run) { \
+ X_ ## xors_per_run(D ## chunks, i); \
+ } \
+}
+
+/* Define xor functions for 2 - 8 chunks and xors per run. */
+#define MAKE_XOR_PER_RUN(xors_per_run) \
+ _XOR(2, xors_per_run); _XOR(3, xors_per_run); \
+ _XOR(4, xors_per_run); _XOR(5, xors_per_run); \
+ _XOR(6, xors_per_run); _XOR(7, xors_per_run); \
+ _XOR(8, xors_per_run);
+
+MAKE_XOR_PER_RUN(8) /* Define _xor_*_8() functions. */
+MAKE_XOR_PER_RUN(16) /* Define _xor_*_16() functions. */
+MAKE_XOR_PER_RUN(32) /* Define _xor_*_32() functions. */
+MAKE_XOR_PER_RUN(64) /* Define _xor_*_64() functions. */
+
+#define MAKE_XOR(xors_per_run) \
+struct { \
+ void (*f)(unsigned long **); \
+} static xor_funcs ## xors_per_run[] = { \
+ { NULL }, /* NULL pointers to optimize indexing in xor(). */ \
+ { NULL }, \
+ { _xor2_ ## xors_per_run }, \
+ { _xor3_ ## xors_per_run }, \
+ { _xor4_ ## xors_per_run }, \
+ { _xor5_ ## xors_per_run }, \
+ { _xor6_ ## xors_per_run }, \
+ { _xor7_ ## xors_per_run }, \
+ { _xor8_ ## xors_per_run }, \
+}; \
+\
+static void xor_ ## xors_per_run(unsigned n, unsigned long **data) \
+{ \
+ /* Call respective function for amount of chunks. */ \
+ xor_funcs ## xors_per_run[n].f(data); \
+}
+
+/* Define xor_8() - xor_64 functions. */
+MAKE_XOR(8)
+MAKE_XOR(16)
+MAKE_XOR(32)
+MAKE_XOR(64)
+
+/* Maximum number of chunks, which can be xor'ed in one go. */
+#define XOR_CHUNKS_MAX (ARRAY_SIZE(xor_funcs8) - 1)
+
+static void xor_blocks_wrapper(unsigned n, unsigned long **data)
+{
+ BUG_ON(n < 2 || n > MAX_XOR_BLOCKS + 1);
+ xor_blocks(n - 1, XOR_SIZE, (void *) data[0], (void **) data + 1);
+}
+
+struct xor_func {
+ xor_function_t f;
+ const char *name;
+} static xor_funcs[] = {
+ { xor_8, "xor_8" },
+ { xor_16, "xor_16" },
+ { xor_32, "xor_32" },
+ { xor_64, "xor_64" },
+ { xor_blocks_wrapper, "xor_blocks" },
+};
+
+/*
+ * Check, if chunk has to be xored in/out:
+ *
+ * o if writes are queued
+ * o if writes are merged
+ * o if stripe is to be reconstructed
+ * o if recovery stripe
+ */
+static inline int chunk_must_xor(struct stripe_chunk *chunk)
+{
+ if (ChunkUptodate(chunk)) {
+ BUG_ON(!bio_list_empty(BL_CHUNK(chunk, WRITE_QUEUED)) &&
+ !bio_list_empty(BL_CHUNK(chunk, WRITE_MERGED)));
+
+ if (!bio_list_empty(BL_CHUNK(chunk, WRITE_QUEUED)) ||
+ !bio_list_empty(BL_CHUNK(chunk, WRITE_MERGED)))
+ return 1;
+
+ if (StripeReconstruct(chunk->stripe) ||
+ StripeRecover(chunk->stripe))
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * Calculate crc.
+ *
+ * This indexes into the chunks of a stripe and their pages.
+ *
+ * All chunks will be xored into the indexed (@pi)
+ * chunk in maximum groups of xor.chunks.
+ *
+ */
+static void xor(struct stripe *stripe, unsigned pi, unsigned sector)
+{
+ struct raid_set *rs = RS(stripe->sc);
+ unsigned max_chunks = rs->xor.chunks, n = 1,
+ o = sector / SECTORS_PER_PAGE, /* Offset into the page_list. */
+ p = rs->set.raid_devs;
+ unsigned long **d = rs->data;
+ xor_function_t xor_f = rs->xor.f->f;
+
+ BUG_ON(sector > stripe->io.size);
+
+ /* Address of parity page to xor into. */
+ d[0] = page_address(pl_elem(PL(stripe, pi), o)->page);
+
+ while (p--) {
+ /* Preset pointers to data pages. */
+ if (p != pi && chunk_must_xor(CHUNK(stripe, p)))
+ d[n++] = page_address(pl_elem(PL(stripe, p), o)->page);
+
+ /* If max chunks -> xor. */
+ if (n == max_chunks) {
+ xor_f(n, d);
+ n = 1;
+ }
+ }
+
+ /* If chunks -> xor. */
+ if (n > 1)
+ xor_f(n, d);
+}
+
+/* Common xor loop through all stripe page lists. */
+static void common_xor(struct stripe *stripe, sector_t count,
+ unsigned off, unsigned pi)
+{
+ unsigned sector;
+
+ BUG_ON(!count);
+ for (sector = off; sector < count; sector += SECTORS_PER_PAGE)
+ xor(stripe, pi, sector);
+
+ /* Set parity page uptodate and clean. */
+ chunk_set(CHUNK(stripe, pi), CLEAN);
+ atomic_inc(RS(stripe->sc)->stats + S_XORS); /* REMOVEME: statistics. */
+}
+
+/*
+ * Calculate parity sectors on intact stripes.
+ *
+ * Need to calculate raid address for recover stripe, because its
+ * chunk sizes differs and is typically larger than io chunk size.
+ */
+static void parity_xor(struct stripe *stripe)
+{
+ struct raid_set *rs = RS(stripe->sc);
+ unsigned chunk_size = rs->set.chunk_size, io_size = stripe->io.size,
+ xor_size = chunk_size > io_size ? io_size : chunk_size;
+ sector_t off;
+
+ /* This can be the recover stripe with a larger io size. */
+ for (off = 0; off < io_size; off += xor_size) {
+ /*
+ * Recover stripe is likely bigger than regular io
+ * ones and has no precalculated parity disk index ->
+ * need to calculate RAID address.
+ */
+ if (unlikely(StripeRecover(stripe))) {
+ struct raid_address addr;
+
+ raid_address(rs,
+ (stripe->key + off) * rs->set.data_devs,
+ &addr);
+ stripe->idx.parity = addr.pi;
+ stripe_zero_pl_part(stripe, addr.pi, off, xor_size);
+ }
+
+ common_xor(stripe, xor_size, off, stripe->idx.parity);
+ chunk_set(CHUNK(stripe, stripe->idx.parity), DIRTY);
+ }
+}
+
+/* Reconstruct missing chunk. */
+static void stripe_reconstruct(struct stripe *stripe)
+{
+ struct raid_set *rs = RS(stripe->sc);
+ int p = rs->set.raid_devs, pr = stripe->idx.recover;
+
+ BUG_ON(pr < 0);
+
+ /* Check if all but the chunk to be reconstructed are uptodate. */
+ while (p--)
+ BUG_ON(p != pr && !ChunkUptodate(CHUNK(stripe, p)));
+
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + (RSDegraded(rs) ? S_RECONSTRUCT_EI :
+ S_RECONSTRUCT_DEV));
+ /* Zero chunk to be reconstructed. */
+ stripe_zero_chunk(stripe, pr);
+ common_xor(stripe, stripe->io.size, 0, pr);
+ stripe->idx.recover = -1;
+}
+
+/*
+ * Recovery io throttling
+ */
+/* Conditionally reset io counters. */
+static int recover_io_reset(struct raid_set *rs)
+{
+ unsigned long j = jiffies;
+
+ /* Pay attention to jiffies overflows. */
+ if (j > rs->recover.last_jiffies + HZ / 20 ||
+ j < rs->recover.last_jiffies) {
+ atomic_set(rs->recover.io_count + IO_WORK, 0);
+ atomic_set(rs->recover.io_count + IO_RECOVER, 0);
+ rs->recover.last_jiffies = j;
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Count ios. */
+static void recover_io_count(struct stripe *stripe)
+{
+ struct raid_set *rs = RS(stripe->sc);
+
+ recover_io_reset(rs);
+ atomic_inc(rs->recover.io_count +
+ (StripeRecover(stripe) ? IO_RECOVER : IO_WORK));
+}
+
+/* Try getting a stripe either from the hash or from the LRU list. */
+static struct stripe *stripe_find(struct raid_set *rs,
+ struct raid_address *addr)
+{
+ int r;
+ struct stripe_cache *sc = &rs->sc;
+ struct stripe *stripe;
+
+ /* Try stripe from hash. */
+ stripe = stripe_lookup(sc, addr->key);
+ if (stripe) {
+ r = stripe_get(stripe);
+ if (r)
+ goto get_lock_failed;
+
+ atomic_inc(rs->stats + S_HITS_1ST); /* REMOVEME: statistics. */
+ } else {
+ /* Not in hash -> try to get an LRU stripe. */
+ stripe = stripe_lru_pop(sc);
+ if (stripe) {
+ /*
+ * An LRU stripe may not be referenced
+ * and may never have ios pending!
+ */
+ BUG_ON(stripe_ref(stripe));
+ BUG_ON(stripe_io_ref(stripe));
+
+ /* Remove from hash if on before reuse. */
+ stripe_hash_del(stripe);
+
+ /* Invalidate before reinserting with changed key. */
+ stripe_invalidate(stripe);
+
+ stripe->key = addr->key;
+ stripe->region = dm_rh_sector_to_region(rs->recover.rh,
+ addr->key);
+ stripe->idx.parity = addr->pi;
+ r = stripe_get(stripe);
+ if (r)
+ goto get_lock_failed;
+
+ /* Insert stripe into the stripe hash. */
+ stripe_insert(&sc->hash, stripe);
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + S_INSCACHE);
+ }
+ }
+
+ return stripe;
+
+get_lock_failed:
+ stripe_put(stripe);
+ return NULL;
+}
+
+/*
+ * Process end io
+ *
+ * I need to do it here because I can't in interrupt
+ */
+/* End io all bios on a bio list. */
+static void bio_list_endio(struct stripe *stripe, struct bio_list *bl,
+ int p, int error)
+{
+ struct raid_set *rs = RS(stripe->sc);
+ struct bio *bio;
+ struct page_list *pl = PL(stripe, p);
+ struct stripe_chunk *chunk = CHUNK(stripe, p);
+
+ /* Update region counters. */
+ while ((bio = bio_list_pop(bl))) {
+ if (bio_data_dir(bio) == WRITE)
+ /* Drop io pending count for any writes. */
+ dm_rh_dec(rs->recover.rh, stripe->region);
+ else if (!error)
+ /* Copy data accross. */
+ bio_copy_page_list(READ, stripe, pl, bio);
+
+ bio_endio(bio, error);
+
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + (bio_data_dir(bio) == READ ?
+ S_BIOS_ENDIO_READ : S_BIOS_ENDIO_WRITE));
+
+ chunk_put(chunk);
+ stripe_put(stripe);
+ io_put(rs); /* Wake any suspend waiters on last bio. */
+ }
+}
+
+/*
+ * End io all reads/writes on a stripe copying
+ * read data accross from stripe to bios and
+ * decrementing region counters for writes.
+ *
+ * Processing of ios depeding on state:
+ * o no chunk error -> endio ok
+ * o degraded:
+ * - chunk error and read -> ignore to be requeued
+ * - chunk error and write -> endio ok
+ * o dead (more than parity_devs failed) and chunk_error-> endio failed
+ */
+static void stripe_endio(int rw, struct stripe *stripe)
+{
+ struct raid_set *rs = RS(stripe->sc);
+ unsigned p = rs->set.raid_devs;
+ int write = (rw != READ);
+
+ while (p--) {
+ struct stripe_chunk *chunk = CHUNK(stripe, p);
+ struct bio_list *bl;
+
+ BUG_ON(ChunkLocked(chunk));
+
+ bl = BL_CHUNK(chunk, rw);
+ if (bio_list_empty(bl))
+ continue;
+
+ if (unlikely(ChunkError(chunk) || !ChunkUptodate(chunk))) {
+ /* RAID set dead. */
+ if (unlikely(RSDead(rs)))
+ bio_list_endio(stripe, bl, p, -EIO);
+ /* RAID set degraded. */
+ else if (write)
+ bio_list_endio(stripe, bl, p, 0);
+ } else {
+ BUG_ON(!RSDegraded(rs) && ChunkDirty(chunk));
+ bio_list_endio(stripe, bl, p, 0);
+ }
+ }
+}
+
+/* Fail all ios hanging off all bio lists of a stripe. */
+static void stripe_fail_io(struct stripe *stripe)
+{
+ struct raid_set *rs = RS(stripe->sc);
+ unsigned p = rs->set.raid_devs;
+
+ while (p--) {
+ struct stripe_chunk *chunk = CHUNK(stripe, p);
+ int i = ARRAY_SIZE(chunk->bl);
+
+ /* Fail all bios on all bio lists of the stripe. */
+ while (i--) {
+ struct bio_list *bl = chunk->bl + i;
+
+ if (!bio_list_empty(bl))
+ bio_list_endio(stripe, bl, p, -EIO);
+ }
+ }
+
+ /* Put stripe on LRU list. */
+ BUG_ON(stripe_io_ref(stripe));
+ BUG_ON(stripe_ref(stripe));
+}
+
+/* Unlock all required chunks. */
+static void stripe_chunks_unlock(struct stripe *stripe)
+{
+ unsigned p = RS(stripe->sc)->set.raid_devs;
+ struct stripe_chunk *chunk;
+
+ while (p--) {
+ chunk = CHUNK(stripe, p);
+
+ if (TestClearChunkUnlock(chunk))
+ ClearChunkLocked(chunk);
+ }
+}
+
+/*
+ * Queue reads and writes to a stripe by hanging
+ * their bios off the stripesets read/write lists.
+ */
+static int stripe_queue_bio(struct raid_set *rs, struct bio *bio,
+ struct bio_list *reject)
+{
+ struct raid_address addr;
+ struct stripe *stripe;
+
+ stripe = stripe_find(rs, raid_address(rs, bio->bi_sector, &addr));
+ if (stripe) {
+ int r = 0, rw = bio_data_dir(bio);
+
+ /* Distinguish reads and writes. */
+ bio_list_add(BL(stripe, addr.di, rw), bio);
+
+ if (rw == READ)
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + S_BIOS_ADDED_READ);
+ else {
+ /* Inrement pending write count on region. */
+ dm_rh_inc(rs->recover.rh, stripe->region);
+ r = 1;
+
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + S_BIOS_ADDED_WRITE);
+ }
+
+ /*
+ * Put on io (flush) list in case of
+ * initial bio queued to chunk.
+ */
+ if (chunk_get(CHUNK(stripe, addr.di)) == 1)
+ stripe_flush_add(stripe);
+
+ return r;
+ }
+
+ /* Got no stripe from cache or failed to lock it -> reject bio. */
+ bio_list_add(reject, bio);
+ atomic_inc(rs->stats + S_IOS_POST); /* REMOVEME: statistics. */
+ return 0;
+}
+
+/*
+ * Handle all stripes by handing them to the daemon, because we can't
+ * map their chunk pages to copy the data in interrupt context.
+ *
+ * We don't want to handle them here either, while interrupts are disabled.
+ */
+
+/* Read/write endio function for dm-io (interrupt context). */
+static void endio(unsigned long error, void *context)
+{
+ struct stripe_chunk *chunk = context;
+
+ if (unlikely(error)) {
+ chunk_set(chunk, ERROR);
+ /* REMOVEME: statistics. */
+ atomic_inc(RS(chunk->stripe->sc)->stats + S_STRIPE_ERROR);
+ } else
+ chunk_set(chunk, CLEAN);
+
+ /*
+ * For recovery stripes, I need to reset locked locked
+ * here, because those aren't processed in do_endios().
+ */
+ if (unlikely(StripeRecover(chunk->stripe)))
+ ClearChunkLocked(chunk);
+ else
+ SetChunkUnlock(chunk);
+
+ /* Indirectly puts stripe on cache's endio list via stripe_io_put(). */
+ stripe_put_references(chunk->stripe);
+}
+
+/* Read/Write a chunk asynchronously. */
+static void stripe_chunk_rw(struct stripe *stripe, unsigned p)
+{
+ struct stripe_cache *sc = stripe->sc;
+ struct raid_set *rs = RS(sc);
+ struct dm_mem_cache_object *obj = stripe->obj + p;
+ struct page_list *pl = obj->pl;
+ struct stripe_chunk *chunk = CHUNK(stripe, p);
+ struct raid_dev *dev = rs->dev + p;
+ struct dm_io_region io = {
+ .bdev = dev->dev->bdev,
+ .sector = stripe->key,
+ .count = stripe->io.size,
+ };
+ struct dm_io_request control = {
+ .bi_rw = ChunkDirty(chunk) ? WRITE : READ,
+ .mem = {
+ .type = DM_IO_PAGE_LIST,
+ .ptr.pl = pl,
+ .offset = 0,
+ },
+ .notify = {
+ .fn = endio,
+ .context = chunk,
+ },
+ .client = StripeRecover(stripe) ? rs->recover.dm_io_client :
+ sc->dm_io_client,
+ };
+
+ BUG_ON(ChunkLocked(chunk));
+ BUG_ON(!ChunkUptodate(chunk) && ChunkDirty(chunk));
+ BUG_ON(ChunkUptodate(chunk) && !ChunkDirty(chunk));
+
+ /*
+ * Don't rw past end of device, which can happen, because
+ * typically sectors_per_dev isn't divisible by io_size.
+ */
+ if (unlikely(io.sector + io.count > rs->set.sectors_per_dev))
+ io.count = rs->set.sectors_per_dev - io.sector;
+
+ BUG_ON(!io.count);
+ io.sector += dev->start; /* Add <offset>. */
+ if (RSRecover(rs))
+ recover_io_count(stripe); /* Recovery io accounting. */
+
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + (ChunkDirty(chunk) ? S_DM_IO_WRITE :
+ S_DM_IO_READ));
+ SetChunkLocked(chunk);
+ SetDevIoQueued(dev);
+ BUG_ON(dm_io(&control, 1, &io, NULL));
+}
+
+/*
+ * Write dirty or read not uptodate page lists of a stripe.
+ */
+static int stripe_chunks_rw(struct stripe *stripe)
+{
+ int r;
+ struct raid_set *rs = RS(stripe->sc);
+
+ /*
+ * Increment the pending count on the stripe
+ * first, so that we don't race in endio().
+ *
+ * An inc (IO) is needed for any chunk unless !ChunkIo(chunk):
+ *
+ * o not uptodate
+ * o dirtied by writes merged
+ * o dirtied by parity calculations
+ */
+ r = for_each_io_dev(stripe, stripe_get_references);
+ if (r) {
+ /* Io needed: chunks are either not uptodate or dirty. */
+ int max; /* REMOVEME: */
+ struct stripe_cache *sc = &rs->sc;
+
+ /* Submit actual io. */
+ for_each_io_dev(stripe, stripe_chunk_rw);
+
+ /* REMOVEME: statistics */
+ max = sc_active(sc);
+ if (atomic_read(&sc->active_stripes_max) < max)
+ atomic_set(&sc->active_stripes_max, max);
+
+ atomic_inc(rs->stats + S_FLUSHS);
+ /* END REMOVEME: statistics */
+ }
+
+ return r;
+}
+
+/* Merge in all writes hence dirtying respective chunks. */
+static void stripe_merge_writes(struct stripe *stripe)
+{
+ unsigned p = RS(stripe->sc)->set.raid_devs;
+
+ while (p--) {
+ struct stripe_chunk *chunk = CHUNK(stripe, p);
+ struct bio_list *write = BL_CHUNK(chunk, WRITE_QUEUED);
+
+ if (!bio_list_empty(write)) {
+ struct bio *bio;
+ struct page_list *pl = stripe->obj[p].pl;
+
+ /*
+ * We can play with the lists without holding a lock,
+ * because it is just us accessing them anyway.
+ */
+ bio_list_for_each(bio, write)
+ bio_copy_page_list(WRITE, stripe, pl, bio);
+
+ bio_list_merge(BL_CHUNK(chunk, WRITE_MERGED), write);
+ bio_list_init(write);
+ chunk_set(chunk, DIRTY);
+ }
+ }
+}
+
+/* Queue all writes to get merged. */
+static int stripe_queue_writes(struct stripe *stripe)
+{
+ int r = 0;
+ unsigned p = RS(stripe->sc)->set.raid_devs;
+
+ while (p--) {
+ struct stripe_chunk *chunk = CHUNK(stripe, p);
+ struct bio_list *write = BL_CHUNK(chunk, WRITE);
+
+ if (!bio_list_empty(write)) {
+ bio_list_merge(BL_CHUNK(chunk, WRITE_QUEUED), write);
+ bio_list_init(write);
+SetChunkIo(chunk);
+ r = 1;
+ }
+ }
+
+ return r;
+}
+
+
+/* Check, if a chunk gets completely overwritten. */
+static int stripe_check_chunk_overwrite(struct stripe *stripe, unsigned p)
+{
+ unsigned sectors = 0;
+ struct bio *bio;
+ struct bio_list *bl = BL(stripe, p, WRITE_QUEUED);
+
+ bio_list_for_each(bio, bl)
+ sectors += bio_sectors(bio);
+
+ BUG_ON(sectors > RS(stripe->sc)->set.io_size);
+ return sectors == RS(stripe->sc)->set.io_size;
+}
+
+/*
+ * Avoid io on broken/reconstructed drive in order to
+ * reconstruct date on endio.
+ *
+ * (*1*) We set StripeReconstruct() in here, so that _do_endios()
+ * will trigger a reconstruct call before resetting it.
+ */
+static int stripe_chunk_set_io_flags(struct stripe *stripe, int pr)
+{
+ struct stripe_chunk *chunk = CHUNK(stripe, pr);
+
+ /*
+ * Allow io on all chunks but the indexed one,
+ * because we're either degraded or prohibit it
+ * on the one for later reconstruction.
+ */
+ /* Includes ClearChunkIo(), ClearChunkUptodate(). */
+ stripe_chunk_invalidate(chunk);
+ stripe->idx.recover = pr;
+ SetStripeReconstruct(stripe);
+
+ /* REMOVEME: statistics. */
+ atomic_inc(RS(stripe->sc)->stats + S_PROHIBITCHUNKIO);
+ return -EPERM;
+}
+
+/* Chunk locked/uptodate and device failed tests. */
+static struct stripe_chunk *
+stripe_chunk_check(struct stripe *stripe, unsigned p, unsigned *chunks_uptodate)
+{
+ struct raid_set *rs = RS(stripe->sc);
+ struct stripe_chunk *chunk = CHUNK(stripe, p);
+
+ /* Can't access active chunks. */
+ if (ChunkLocked(chunk)) {
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + S_CHUNK_LOCKED);
+ return NULL;
+ }
+
+ /* Can't access broken devive. */
+ if (ChunkError(chunk) || DevFailed(rs->dev + p))
+ return NULL;
+
+ /* Can access uptodate chunks. */
+ if (ChunkUptodate(chunk)) {
+ (*chunks_uptodate)++;
+ return NULL;
+ }
+
+ return chunk;
+}
+
+/*
+ * Degraded/reconstruction mode.
+ *
+ * Check stripe state to figure which chunks don't need IO.
+ *
+ * Returns 0 for fully operational, -EPERM for degraded/resynchronizing.
+ */
+static int stripe_check_reconstruct(struct stripe *stripe)
+{
+ struct raid_set *rs = RS(stripe->sc);
+
+ if (RSDead(rs)) {
+ ClearStripeReconstruct(stripe);
+ ClearStripeReconstructed(stripe);
+ stripe_allow_io(stripe);
+ return 0;
+ }
+
+ /* Avoid further reconstruction setting, when already set. */
+ if (StripeReconstruct(stripe)) {
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + S_RECONSTRUCT_SET);
+ return -EBUSY;
+ }
+
+ /* Initially allow io on all chunks. */
+ stripe_allow_io(stripe);
+
+ /* Return if stripe is already reconstructed. */
+ if (StripeReconstructed(stripe)) {
+ atomic_inc(rs->stats + S_RECONSTRUCTED);
+ return 0;
+ }
+
+ /*
+ * Degraded/reconstruction mode (device failed) ->
+ * avoid io on the failed device.
+ */
+ if (unlikely(RSDegraded(rs))) {
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + S_DEGRADED);
+ /* Allow IO on all devices but the dead one. */
+ BUG_ON(rs->set.ei < 0);
+ return stripe_chunk_set_io_flags(stripe, rs->set.ei);
+ } else {
+ int sync, pi = dev_for_parity(stripe, &sync);
+
+ /*
+ * Reconstruction mode (ie. a particular (replaced) device or
+ * some (rotating) parity chunk is being resynchronized) ->
+ * o make sure all needed chunks are read in
+ * o writes are allowed to go through
+ */
+ if (!sync) {
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + S_NOSYNC);
+ /* Allow IO on all devs but the one to reconstruct. */
+ return stripe_chunk_set_io_flags(stripe, pi);
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Check, if stripe is ready to merge writes.
+ * I.e. if all chunks present to allow to merge bios.
+ *
+ * We prohibit io on:
+ *
+ * o chunks without bios
+ * o chunks which get completely written over
+ */
+static int stripe_merge_possible(struct stripe *stripe, int nosync)
+{
+ struct raid_set *rs = RS(stripe->sc);
+ unsigned chunks_overwrite = 0, chunks_prohibited = 0,
+ chunks_uptodate = 0, p = rs->set.raid_devs;
+
+ /* Walk all chunks. */
+ while (p--) {
+ struct stripe_chunk *chunk;
+
+ /* Prohibit io on broken devices. */
+ if (DevFailed(rs->dev + p)) {
+ chunk = CHUNK(stripe, p);
+ goto prohibit_io;
+ }
+
+ /* We can't optimize any further if no chunk. */
+ chunk = stripe_chunk_check(stripe, p, &chunks_uptodate);
+ if (!chunk || nosync)
+ continue;
+
+ /*
+ * We have a chunk, which is not uptodate.
+ *
+ * If this is not parity and we don't have
+ * reads queued, we can optimize further.
+ */
+ if (p != stripe->idx.parity &&
+ bio_list_empty(BL_CHUNK(chunk, READ)) &&
+ bio_list_empty(BL_CHUNK(chunk, WRITE_MERGED))) {
+ if (bio_list_empty(BL_CHUNK(chunk, WRITE_QUEUED)))
+ goto prohibit_io;
+ else if (RSCheckOverwrite(rs) &&
+ stripe_check_chunk_overwrite(stripe, p))
+ /* Completely overwritten chunk. */
+ chunks_overwrite++;
+ }
+
+ /* Allow io for chunks with bios and overwritten ones. */
+ SetChunkIo(chunk);
+ continue;
+
+prohibit_io:
+ /* No io for broken devices or for chunks w/o bios. */
+ ClearChunkIo(chunk);
+ chunks_prohibited++;
+ /* REMOVEME: statistics. */
+ atomic_inc(RS(stripe->sc)->stats + S_PROHIBITCHUNKIO);
+ }
+
+ /* All data chunks will get written over. */
+ if (chunks_overwrite == rs->set.data_devs)
+ atomic_inc(rs->stats + S_OVERWRITE); /* REMOVEME: statistics.*/
+ else if (chunks_uptodate + chunks_prohibited < rs->set.raid_devs) {
+ /* We don't have enough chunks to merge. */
+ atomic_inc(rs->stats + S_CANT_MERGE); /* REMOVEME: statistics.*/
+ return -EPERM;
+ }
+
+ /*
+ * If we have all chunks up to date or overwrite them, we
+ * just zero the parity chunk and let stripe_rw() recreate it.
+ */
+ if (chunks_uptodate == rs->set.raid_devs ||
+ chunks_overwrite == rs->set.data_devs) {
+ stripe_zero_chunk(stripe, stripe->idx.parity);
+ BUG_ON(StripeReconstruct(stripe));
+ SetStripeReconstruct(stripe); /* Enforce xor in caller. */
+ } else {
+ /*
+ * With less chunks, we xor parity out.
+ *
+ * (*4*) We rely on !StripeReconstruct() in chunk_must_xor(),
+ * so that only chunks with queued or merged writes
+ * are being xored.
+ */
+ parity_xor(stripe);
+ }
+
+ /*
+ * We do have enough chunks to merge.
+ * All chunks are uptodate or get written over.
+ */
+ atomic_inc(rs->stats + S_CAN_MERGE); /* REMOVEME: statistics. */
+ return 0;
+}
+
+/*
+ * Avoid reading chunks in case we're fully operational.
+ *
+ * We prohibit io on any chunks without bios but the parity chunk.
+ */
+static void stripe_avoid_reads(struct stripe *stripe)
+{
+ struct raid_set *rs = RS(stripe->sc);
+ unsigned dummy = 0, p = rs->set.raid_devs;
+
+ /* Walk all chunks. */
+ while (p--) {
+ struct stripe_chunk *chunk =
+ stripe_chunk_check(stripe, p, &dummy);
+
+ if (!chunk)
+ continue;
+
+ /* If parity or any bios pending -> allow io. */
+ if (chunk_ref(chunk) || p == stripe->idx.parity)
+ SetChunkIo(chunk);
+ else {
+ ClearChunkIo(chunk);
+ /* REMOVEME: statistics. */
+ atomic_inc(RS(stripe->sc)->stats + S_PROHIBITCHUNKIO);
+ }
+ }
+}
+
+/*
+ * Read/write a stripe.
+ *
+ * All stripe read/write activity goes through this function
+ * unless recovery, which has to call stripe_chunk_rw() directly.
+ *
+ * Make sure we don't try already merged stripes in order
+ * to avoid data corruption.
+ *
+ * Check the state of the RAID set and if degraded (or
+ * resynchronizing for reads), read in all other chunks but
+ * the one on the dead/resynchronizing device in order to be
+ * able to reconstruct the missing one in _do_endios().
+ *
+ * Can be called on active stripes in order
+ * to dispatch new io on inactive chunks.
+ *
+ * States to cover:
+ * o stripe to read and/or write
+ * o stripe with error to reconstruct
+ */
+static void stripe_rw(struct stripe *stripe)
+{
+ int nosync, r;
+ struct raid_set *rs = RS(stripe->sc);
+
+ /*
+ * Check, if a chunk needs to be reconstructed
+ * because of a degraded set or a region out of sync.
+ */
+ nosync = stripe_check_reconstruct(stripe);
+ switch (nosync) {
+ case -EBUSY:
+ return; /* Wait for stripe reconstruction to finish. */
+ case -EPERM:
+ goto io;
+ }
+
+ /*
+ * If we don't have merged writes pending, we can schedule
+ * queued writes to be merged next without corrupting data.
+ */
+ if (!StripeMerged(stripe)) {
+ r = stripe_queue_writes(stripe);
+ if (r)
+ /* Writes got queued -> flag RBW. */
+ SetStripeRBW(stripe);
+ }
+
+ /*
+ * Merge all writes hanging off uptodate/overwritten
+ * chunks of the stripe.
+ */
+ if (StripeRBW(stripe)) {
+ r = stripe_merge_possible(stripe, nosync);
+ if (!r) { /* Merge possible. */
+ struct stripe_chunk *chunk;
+
+ /*
+ * I rely on valid parity in order
+ * to xor a fraction of chunks out
+ * of parity and back in.
+ */
+ stripe_merge_writes(stripe); /* Merge writes in. */
+ parity_xor(stripe); /* Update parity. */
+ ClearStripeReconstruct(stripe); /* Reset xor enforce. */
+ SetStripeMerged(stripe); /* Writes merged. */
+ ClearStripeRBW(stripe); /* Disable RBW. */
+
+ /*
+ * REMOVEME: sanity check on parity chunk
+ * states after writes got merged.
+ */
+ chunk = CHUNK(stripe, stripe->idx.parity);
+ BUG_ON(ChunkLocked(chunk));
+ BUG_ON(!ChunkUptodate(chunk));
+ BUG_ON(!ChunkDirty(chunk));
+ BUG_ON(!ChunkIo(chunk));
+ }
+ } else if (!nosync && !StripeMerged(stripe))
+ /* Read avoidance if not degraded/resynchronizing/merged. */
+ stripe_avoid_reads(stripe);
+
+io:
+ /* Now submit any reads/writes for non-uptodate or dirty chunks. */
+ r = stripe_chunks_rw(stripe);
+ if (!r) {
+ /*
+ * No io submitted because of chunk io
+ * prohibited or locked chunks/failed devices
+ * -> push to end io list for processing.
+ */
+ stripe_endio_push(stripe);
+ atomic_inc(rs->stats + S_NO_RW); /* REMOVEME: statistics. */
+ }
+}
+
+/*
+ * Recovery functions
+ */
+/* Read a stripe off a raid set for recovery. */
+static int stripe_recover_read(struct stripe *stripe, int pi)
+{
+ BUG_ON(stripe_io_ref(stripe));
+
+ /* Invalidate all chunks so that they get read in. */
+ stripe_chunks_invalidate(stripe);
+ stripe_allow_io(stripe); /* Allow io on all recovery chunks. */
+
+ /*
+ * If we are reconstructing a perticular device, we can avoid
+ * reading the respective chunk in, because we're going to
+ * reconstruct it anyway.
+ *
+ * We can't do that for resynchronization of rotating parity,
+ * because the recovery stripe chunk size is typically larger
+ * than the sets chunk size.
+ */
+ if (pi > -1)
+ ClearChunkIo(CHUNK(stripe, pi));
+
+ return stripe_chunks_rw(stripe);
+}
+
+/* Write a stripe to a raid set for recovery. */
+static int stripe_recover_write(struct stripe *stripe, int pi)
+{
+ BUG_ON(stripe_io_ref(stripe));
+
+ /*
+ * If this is a reconstruct of a particular device, then
+ * reconstruct the respective chunk, else create parity chunk.
+ */
+ if (pi > -1) {
+ stripe_zero_chunk(stripe, pi);
+ common_xor(stripe, stripe->io.size, 0, pi);
+ chunk_set(CHUNK(stripe, pi), DIRTY);
+ } else
+ parity_xor(stripe);
+
+ return stripe_chunks_rw(stripe);
+}
+
+/* Read/write a recovery stripe. */
+static int stripe_recover_rw(struct stripe *stripe)
+{
+ int r = 0, sync = 0;
+
+ /* Read/write flip-flop. */
+ if (TestClearStripeRBW(stripe)) {
+ SetStripeMerged(stripe);
+ stripe->key = stripe->recover->pos;
+ r = stripe_recover_read(stripe, dev_for_parity(stripe, &sync));
+ BUG_ON(!r);
+ } else if (TestClearStripeMerged(stripe)) {
+ r = stripe_recover_write(stripe, dev_for_parity(stripe, &sync));
+ BUG_ON(!r);
+ }
+
+ BUG_ON(sync);
+ return r;
+}
+
+/* Recover bandwidth available ?. */
+static int recover_bandwidth(struct raid_set *rs)
+{
+ int r, work;
+
+ /* On reset or when bios delayed -> allow recovery. */
+ r = recover_io_reset(rs);
+ if (r || RSBandwidth(rs))
+ goto out;
+
+ work = atomic_read(rs->recover.io_count + IO_WORK);
+ if (work) {
+ /* Pay attention to larger recover stripe size. */
+ int recover = atomic_read(rs->recover.io_count + IO_RECOVER) *
+ rs->recover.io_size / rs->set.io_size;
+
+ /*
+ * Don't use more than given bandwidth
+ * of the work io for recovery.
+ */
+ if (recover > work / rs->recover.bandwidth_work) {
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + S_NO_BANDWIDTH);
+ return 0;
+ }
+ }
+
+out:
+ atomic_inc(rs->stats + S_BANDWIDTH); /* REMOVEME: statistics. */
+ return 1;
+}
+
+/* Try to get a region to recover. */
+static int stripe_recover_get_region(struct stripe *stripe)
+{
+ struct raid_set *rs = RS(stripe->sc);
+ struct recover *rec = &rs->recover;
+ struct recover_addr *addr = stripe->recover;
+ struct dm_dirty_log *dl = rec->dl;
+ struct dm_rh_client *rh = rec->rh;
+
+ BUG_ON(!dl);
+ BUG_ON(!rh);
+
+ /* Return, that we have region first to finish it during suspension. */
+ if (addr->reg)
+ return 1;
+
+ if (RSSuspend(rs))
+ return -EPERM;
+
+ if (dl->type->get_sync_count(dl) >= rec->nr_regions)
+ return -ENOENT;
+
+ /* If we don't have enough bandwidth, we don't proceed recovering. */
+ if (!recover_bandwidth(rs))
+ return -EAGAIN;
+
+ /* Start quiescing a region. */
+ dm_rh_recovery_prepare(rh);
+ addr->reg = dm_rh_recovery_start(rh);
+ if (!addr->reg)
+ return -EAGAIN;
+
+ addr->pos = dm_rh_region_to_sector(rh, dm_rh_get_region_key(addr->reg));
+ addr->end = addr->pos + dm_rh_get_region_size(rh);
+
+ /*
+ * Take one global io reference out for the
+ * whole region, which is going to be released
+ * when the region is completely done with.
+ */
+ io_get(rs);
+ return 0;
+}
+
+/* Update region hash state. */
+enum recover_type { REC_FAILURE = 0, REC_SUCCESS = 1 };
+static void recover_rh_update(struct stripe *stripe, enum recover_type success)
+{
+ struct recover_addr *addr = stripe->recover;
+ struct raid_set *rs = RS(stripe->sc);
+ struct recover *rec = &rs->recover;
+
+ if (!addr->reg) {
+ DMERR("%s- Called w/o region", __func__);
+ return;
+ }
+
+ dm_rh_recovery_end(addr->reg, success);
+ if (success)
+ rec->nr_regions_recovered++;
+
+ addr->reg = NULL;
+
+ /*
+ * Completely done with this region ->
+ * release the 1st io reference.
+ */
+ io_put(rs);
+}
+
+/* Set start of recovery state. */
+static void set_start_recovery(struct raid_set *rs)
+{
+ /* Initialize recovery. */
+ rs->recover.start_jiffies = jiffies;
+ rs->recover.end_jiffies = 0;
+}
+
+/* Set end of recovery state. */
+static void set_end_recovery(struct raid_set *rs)
+{
+ ClearRSRecover(rs);
+ rs->set.dev_to_init = -1;
+
+ /* Check for jiffies overrun. */
+ rs->recover.end_jiffies = jiffies;
+ if (rs->recover.end_jiffies < rs->recover.start_jiffies)
+ rs->recover.end_jiffies = ~0;
+}
+
+/* Handle recovery on one recovery stripe. */
+static int _do_recovery(struct stripe *stripe)
+{
+ int r;
+ struct raid_set *rs = RS(stripe->sc);
+ struct recover_addr *addr = stripe->recover;
+
+ /* If recovery is active -> return. */
+ if (stripe_io_ref(stripe))
+ return 1;
+
+ /* IO error is fatal for recovery -> stop it. */
+ if (unlikely(StripeError(stripe)))
+ goto err;
+
+ /* Recovery end required. */
+ if (!RSRecover(rs))
+ goto err;
+
+ /* Get a region to recover. */
+ r = stripe_recover_get_region(stripe);
+ switch (r) {
+ case 0: /* Got a new region: flag initial read before write. */
+ SetStripeRBW(stripe);
+ case 1: /* Have a region in the works. */
+ break;
+ case -EAGAIN:
+ /* No bandwidth/quiesced region yet, try later. */
+ if (!io_ref(rs))
+ wake_do_raid_delayed(rs, HZ / 4);
+ case -EPERM:
+ /* Suspend. */
+ return 1;
+ case -ENOENT: /* No more regions to recover. */
+ schedule_work(&rs->io.ws_do_table_event);
+ return 0;
+ default:
+ BUG();
+ }
+
+ /* Read/write a recover stripe. */
+ r = stripe_recover_rw(stripe);
+ if (r)
+ /* IO initiated. */
+ return 1;
+
+ /* Read and write finished-> update recovery position within region. */
+ addr->pos += stripe->io.size;
+
+ /* If we're at end of region, update region hash. */
+ if (addr->pos >= addr->end ||
+ addr->pos >= rs->set.sectors_per_dev)
+ recover_rh_update(stripe, REC_SUCCESS);
+ else
+ /* Prepare to read next region segment. */
+ SetStripeRBW(stripe);
+
+ /* Schedule myself for another round... */
+ wake_do_raid(rs);
+ return 1;
+
+err:
+ /* FIXME: rather try recovering other regions on error? */
+ rs_check_degrade(stripe);
+ recover_rh_update(stripe, REC_FAILURE);
+
+ /* Check state of partially recovered array. */
+ if (RSDegraded(rs) && !RSDead(rs) &&
+ rs->set.dev_to_init != -1 &&
+ rs->set.ei != rs->set.dev_to_init)
+ /* Broken drive != drive to recover -> FATAL. */
+ SetRSDead(rs);
+
+ if (StripeError(stripe)) {
+ char buf[BDEVNAME_SIZE];
+
+ DMERR("stopping recovery due to "
+ "ERROR on /dev/%s, stripe at offset %llu",
+ bdevname(rs->dev[rs->set.ei].dev->bdev, buf),
+ (unsigned long long) stripe->key);
+
+ }
+
+ /* Make sure, that all quiesced regions get released. */
+ while (addr->reg) {
+ dm_rh_recovery_end(addr->reg, -EIO);
+ addr->reg = dm_rh_recovery_start(rs->recover.rh);
+ }
+
+ return 0;
+}
+
+/* Called by main io daemon to recover regions. */
+static void do_recovery(struct raid_set *rs)
+{
+ if (RSRecover(rs)) {
+ int r = 0;
+ struct stripe *stripe;
+
+ list_for_each_entry(stripe, &rs->recover.stripes,
+ lists[LIST_RECOVER])
+ r += _do_recovery(stripe);
+
+ if (!r) {
+ set_end_recovery(rs);
+ stripe_recover_free(rs);
+ }
+ }
+}
+
+/*
+ * END recovery functions
+ */
+
+/* End io process all stripes handed in by endio() callback. */
+static void _do_endios(struct raid_set *rs, struct stripe *stripe,
+ struct list_head *flush_list)
+{
+ /* First unlock all required chunks. */
+ stripe_chunks_unlock(stripe);
+
+ /*
+ * If an io error on a stripe occured, degrade the RAID set
+ * and try to endio as many bios as possible. If any bios can't
+ * be endio processed, requeue the stripe (stripe_ref() != 0).
+ */
+ if (TestClearStripeError(stripe)) {
+ /*
+ * FIXME: if read, rewrite the failed chunk after reconstruction
+ * in order to trigger disk bad sector relocation.
+ */
+ rs_check_degrade(stripe); /* Resets ChunkError(). */
+ ClearStripeReconstruct(stripe);
+ ClearStripeReconstructed(stripe);
+ }
+
+ /* Got to reconstruct a missing chunk. */
+ if (StripeReconstruct(stripe)) {
+ /*
+ * (*2*) We use StripeReconstruct() to allow for
+ * all chunks to be xored into the reconstructed
+ * one (see chunk_must_xor()).
+ */
+ stripe_reconstruct(stripe);
+
+ /*
+ * (*3*) Now we reset StripeReconstruct() and flag
+ * StripeReconstructed() to show to stripe_rw(),
+ * that we have reconstructed a missing chunk.
+ */
+ ClearStripeReconstruct(stripe);
+ SetStripeReconstructed(stripe);
+
+ /* FIXME: reschedule to be written in case of read. */
+ // if (!StripeRBW(stripe)) {
+ // chunk_set(CHUNK(stripe, pr), DIRTY);
+ // stripe_chunks_rw(stripe);
+ // }
+ }
+
+ /*
+ * Now that we eventually got a complete stripe, we
+ * can process the rest of the end ios on reads.
+ */
+ stripe_endio(READ, stripe);
+
+ /* End io all merged writes. */
+ if (TestClearStripeMerged(stripe))
+ stripe_endio(WRITE_MERGED, stripe);
+
+ /* If RAID set is dead -> fail any ios to dead drives. */
+ if (RSDead(rs)) {
+ DMERR_LIMIT("RAID set dead: failing ios to dead devices");
+ stripe_fail_io(stripe);
+ }
+
+ /*
+ * We have stripe references still,
+ * beacuse of read befeore writes or IO errors ->
+ * got to put on flush list for processing.
+ */
+ if (stripe_ref(stripe)) {
+ BUG_ON(!list_empty(stripe->lists + LIST_LRU));
+ list_add_tail(stripe->lists + LIST_FLUSH, flush_list);
+ atomic_inc(rs->stats + S_REQUEUE); /* REMOVEME: statistics. */
+ } else
+ stripe_lru_add(stripe);
+}
+
+/* Pop any endio stripes off of the endio list and belabour them. */
+static void do_endios(struct raid_set *rs)
+{
+ struct stripe_cache *sc = &rs->sc;
+ struct stripe *stripe;
+ /* IO flush list for sorted requeued stripes. */
+ struct list_head flush_list;
+
+ INIT_LIST_HEAD(&flush_list);
+
+ while ((stripe = stripe_endio_pop(sc))) {
+ /* Avoid endio on stripes with newly io'ed chunks. */
+ if (!stripe_io_ref(stripe))
+ _do_endios(rs, stripe, &flush_list);
+ }
+
+ /*
+ * Insert any requeued stripes in the proper
+ * order at the beginning of the io (flush) list.
+ */
+ list_splice(&flush_list, sc->lists + LIST_FLUSH);
+}
+
+/* Flush any stripes on the io list. */
+static void do_flush(struct raid_set *rs)
+{
+ struct stripe *stripe;
+
+ while ((stripe = stripe_io_pop(&rs->sc)))
+ stripe_rw(stripe); /* Read/write stripe. */
+}
+
+/* Stripe cache resizing. */
+static void do_sc_resize(struct raid_set *rs)
+{
+ unsigned set = atomic_read(&rs->sc.stripes_to_set);
+
+ if (set) {
+ unsigned cur = atomic_read(&rs->sc.stripes);
+ int r = (set > cur) ? sc_grow(&rs->sc, set - cur, SC_GROW) :
+ sc_shrink(&rs->sc, cur - set);
+
+ /* Flag end of resizeing if ok. */
+ if (!r)
+ atomic_set(&rs->sc.stripes_to_set, 0);
+ }
+}
+
+/*
+ * Process all ios
+ *
+ * We do different things with the io depending
+ * on the state of the region that it is in:
+ *
+ * o reads: hang off stripe cache or postpone if full
+ *
+ * o writes:
+ *
+ * CLEAN/DIRTY/NOSYNC: increment pending and hang io off stripe's stripe set.
+ * In case stripe cache is full or busy, postpone the io.
+ *
+ * RECOVERING: delay the io until recovery of the region completes.
+ *
+ */
+static void do_ios(struct raid_set *rs, struct bio_list *ios)
+{
+ int r;
+ unsigned flush = 0, delay = 0;
+ sector_t sector;
+ struct dm_rh_client *rh = rs->recover.rh;
+ struct bio *bio;
+ struct bio_list reject;
+
+ bio_list_init(&reject);
+
+ /*
+ * Classify each io:
+ * o delay writes to recovering regions (let reads go through)
+ * o queue io to all other regions
+ */
+ while ((bio = bio_list_pop(ios))) {
+ /*
+ * In case we get a barrier bio, push it back onto
+ * the input queue unless all work queues are empty
+ * and the stripe cache is inactive.
+ */
+ if (unlikely(bio_barrier(bio))) {
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + S_BARRIER);
+ if (delay ||
+ !list_empty(rs->sc.lists + LIST_FLUSH) ||
+ !bio_list_empty(&reject) ||
+ sc_active(&rs->sc)) {
+ bio_list_push(ios, bio);
+ break;
+ }
+ }
+
+ /* Check for recovering regions. */
+ sector = _sector(rs, bio);
+ r = region_state(rs, sector, DM_RH_RECOVERING);
+ if (unlikely(r && bio_data_dir(bio) == WRITE)) {
+ delay++;
+ /* Wait writing to recovering regions. */
+ dm_rh_delay_by_region(rh, bio,
+ dm_rh_sector_to_region(rh,
+ sector));
+ /* REMOVEME: statistics.*/
+ atomic_inc(rs->stats + S_DELAYED_BIOS);
+ atomic_inc(rs->stats + S_SUM_DELAYED_BIOS);
+
+ /* Force bandwidth tests in recovery. */
+ SetRSBandwidth(rs);
+ } else {
+ /*
+ * Process ios to non-recovering regions by queueing
+ * them to stripes (does dm_rh_inc()) for writes).
+ */
+ flush += stripe_queue_bio(rs, bio, &reject);
+ }
+ }
+
+ if (flush) {
+ /* FIXME: better error handling. */
+ r = dm_rh_flush(rh); /* Writes got queued -> flush dirty log. */
+ if (r)
+ DMERR_LIMIT("dirty log flush");
+ }
+
+ /* Merge any rejected bios back to the head of the input list. */
+ bio_list_merge_head(ios, &reject);
+}
+
+/* Unplug: let any queued io role on the sets devices. */
+static void do_unplug(struct raid_set *rs)
+{
+ struct raid_dev *dev = rs->dev + rs->set.raid_devs;
+
+ while (dev-- > rs->dev) {
+ /* Only call any device unplug function, if io got queued. */
+ if (TestClearDevIoQueued(dev))
+ blk_unplug(bdev_get_queue(dev->dev->bdev));
+ }
+}
+
+/* Send an event in case we're getting too busy. */
+static void do_busy_event(struct raid_set *rs)
+{
+ if (sc_busy(rs)) {
+ if (!TestSetRSScBusy(rs))
+ schedule_work(&rs->io.ws_do_table_event);
+ }
+
+ ClearRSScBusy(rs);
+}
+
+/* Throw an event. */
+static void do_table_event(struct work_struct *ws)
+{
+ struct raid_set *rs = container_of(ws, struct raid_set,
+ io.ws_do_table_event);
+ dm_table_event(rs->ti->table);
+}
+
+
+/*-----------------------------------------------------------------
+ * RAID daemon
+ *---------------------------------------------------------------*/
+/*
+ * o belabour all end ios
+ * o update the region hash states
+ * o optionally shrink the stripe cache
+ * o optionally do recovery
+ * o unplug any component raid devices with queued bios
+ * o grab the input queue
+ * o work an all requeued or new ios and perform stripe cache flushs
+ * o unplug any component raid devices with queued bios
+ * o check, if the stripe cache gets too busy and throw an event if so
+ */
+static void do_raid(struct work_struct *ws)
+{
+ struct raid_set *rs = container_of(ws, struct raid_set,
+ io.dws_do_raid.work);
+ struct bio_list *ios = &rs->io.work, *ios_in = &rs->io.in;
+
+ /*
+ * We always need to end io, so that ios can get errored in
+ * case the set failed and the region counters get decremented
+ * before we update region hash states and go any further.
+ */
+ do_endios(rs);
+ dm_rh_update_states(rs->recover.rh, 1);
+
+ /*
+ * Now that we've end io'd, which may have put stripes on the LRU list
+ * to allow for shrinking, we resize the stripe cache if requested.
+ */
+ do_sc_resize(rs);
+
+ /* Try to recover regions. */
+ do_recovery(rs);
+ do_unplug(rs); /* Unplug the sets device queues. */
+
+ /* Quickly grab all new ios queued and add them to the work list. */
+ mutex_lock(&rs->io.in_lock);
+ bio_list_merge(ios, ios_in);
+ bio_list_init(ios_in);
+ mutex_unlock(&rs->io.in_lock);
+
+ if (!bio_list_empty(ios))
+ do_ios(rs, ios); /* Got ios to work into the cache. */
+
+ do_flush(rs); /* Flush any stripes on io list. */
+ do_unplug(rs); /* Unplug the sets device queues. */
+ do_busy_event(rs); /* Check if we got too busy. */
+}
+
+/*
+ * Callback for region hash to dispatch
+ * delayed bios queued to recovered regions
+ * (gets called via dm_rh_update_states()).
+ */
+static void dispatch_delayed_bios(void *context, struct bio_list *bl)
+{
+ struct raid_set *rs = context;
+ struct bio *bio;
+
+ /* REMOVEME: statistics; decrement pending delayed bios counter. */
+ bio_list_for_each(bio, bl)
+ atomic_dec(rs->stats + S_DELAYED_BIOS);
+
+ /* Merge region hash private list to work list. */
+ bio_list_merge_head(&rs->io.work, bl);
+ bio_list_init(bl);
+ ClearRSBandwidth(rs);
+}
+
+/*************************************************************
+ * Constructor helpers
+ *************************************************************/
+/* Calculate MB/sec. */
+static unsigned mbpers(struct raid_set *rs, unsigned speed)
+{
+ return to_bytes(speed * rs->set.data_devs *
+ rs->recover.io_size * HZ >> 10) >> 10;
+}
+
+/*
+ * Discover fastest xor algorithm and # of chunks combination.
+ */
+/* Calculate speed for algorithm and # of chunks. */
+static unsigned xor_speed(struct stripe *stripe)
+{
+ unsigned r = 0;
+ unsigned long j;
+
+ /* Wait for next tick. */
+ for (j = jiffies; j == jiffies; )
+ ;
+
+ /* Do xors for a full tick. */
+ for (j = jiffies; j == jiffies; ) {
+ mb();
+ common_xor(stripe, stripe->io.size, 0, 0);
+ mb();
+ r++;
+ }
+
+ return r;
+}
+
+/* Optimize xor algorithm for this RAID set. */
+static unsigned xor_optimize(struct raid_set *rs)
+{
+ unsigned chunks_max = 2, p = rs->set.raid_devs, speed_max = 0;
+ struct xor_func *f = ARRAY_END(xor_funcs), *f_max = NULL;
+ struct stripe *stripe;
+
+ BUG_ON(list_empty(&rs->recover.stripes));
+ stripe = list_first_entry(&rs->recover.stripes, struct stripe,
+ lists[LIST_RECOVER]);
+
+ /* Must set uptodate so that xor() will belabour chunks. */
+ while (p--)
+ SetChunkUptodate(CHUNK(stripe, p));
+
+ /* Try all xor functions. */
+ while (f-- > xor_funcs) {
+ unsigned speed;
+
+ /* Set actual xor function for common_xor(). */
+ rs->xor.f = f;
+ rs->xor.chunks = (f->f == xor_blocks_wrapper ?
+ (MAX_XOR_BLOCKS + 1) : XOR_CHUNKS_MAX) + 1;
+
+ while (rs->xor.chunks-- > 2) {
+ speed = xor_speed(stripe);
+ if (speed > speed_max) {
+ speed_max = speed;
+ chunks_max = rs->xor.chunks;
+ f_max = f;
+ }
+ }
+ }
+
+ /* Memorize optimum parameters. */
+ rs->xor.f = f_max;
+ rs->xor.chunks = chunks_max;
+ return speed_max;
+}
+
+/*
+ * Allocate a RAID context (a RAID set)
+ */
+/* Structure for variable RAID parameters. */
+struct variable_parms {
+ int bandwidth;
+ int bandwidth_parm;
+ int chunk_size;
+ int chunk_size_parm;
+ int io_size;
+ int io_size_parm;
+ int stripes;
+ int stripes_parm;
+ int recover_io_size;
+ int recover_io_size_parm;
+ int raid_parms;
+ int recovery;
+ int recovery_stripes;
+ int recovery_stripes_parm;
+};
+
+static struct raid_set *
+context_alloc(struct raid_type *raid_type, struct variable_parms *p,
+ unsigned raid_devs, sector_t sectors_per_dev,
+ struct dm_target *ti, unsigned dl_parms, char **argv)
+{
+ int r;
+ size_t len;
+ sector_t region_size, ti_len;
+ struct raid_set *rs = NULL;
+ struct dm_dirty_log *dl;
+ struct recover *rec;
+
+ /*
+ * Create the dirty log
+ *
+ * We need to change length for the dirty log constructor,
+ * because we want an amount of regions for all stripes derived
+ * from the single device size, so that we can keep region
+ * size = 2^^n independant of the number of devices
+ */
+ ti_len = ti->len;
+ ti->len = sectors_per_dev;
+ dl = dm_dirty_log_create(argv[0], ti, dl_parms, argv + 2);
+ ti->len = ti_len;
+ if (!dl)
+ goto bad_dirty_log;
+
+ /* Chunk size *must* be smaller than region size. */
+ region_size = dl->type->get_region_size(dl);
+ if (p->chunk_size > region_size)
+ goto bad_chunk_size;
+
+ /* Recover io size *must* be smaller than region size as well. */
+ if (p->recover_io_size > region_size)
+ goto bad_recover_io_size;
+
+ /* Size and allocate the RAID set structure. */
+ len = sizeof(*rs->data) + sizeof(*rs->dev);
+ if (dm_array_too_big(sizeof(*rs), len, raid_devs))
+ goto bad_array;
+
+ len = sizeof(*rs) + raid_devs * len;
+ rs = kzalloc(len, GFP_KERNEL);
+ if (!rs)
+ goto bad_alloc;
+
+ rec = &rs->recover;
+ atomic_set(&rs->io.in_process, 0);
+ atomic_set(&rs->io.in_process_max, 0);
+ rec->io_size = p->recover_io_size;
+
+ /* Pointer to data array. */
+ rs->data = (unsigned long **)
+ ((void *) rs->dev + raid_devs * sizeof(*rs->dev));
+ rec->dl = dl;
+ rs->set.raid_devs = raid_devs;
+ rs->set.data_devs = raid_devs - raid_type->parity_devs;
+ rs->set.raid_type = raid_type;
+
+ rs->set.raid_parms = p->raid_parms;
+ rs->set.chunk_size_parm = p->chunk_size_parm;
+ rs->set.io_size_parm = p->io_size_parm;
+ rs->sc.stripes_parm = p->stripes_parm;
+ rec->io_size_parm = p->recover_io_size_parm;
+ rec->bandwidth_parm = p->bandwidth_parm;
+ rec->recovery = p->recovery;
+ rec->recovery_stripes = p->recovery_stripes;
+
+ /*
+ * Set chunk and io size and respective shifts
+ * (used to avoid divisions)
+ */
+ rs->set.chunk_size = p->chunk_size;
+ rs->set.chunk_shift = ffs(p->chunk_size) - 1;
+
+ rs->set.io_size = p->io_size;
+ rs->set.io_mask = p->io_size - 1;
+ /* Mask to adjust address key in case io_size != chunk_size. */
+ rs->set.io_inv_mask = (p->chunk_size - 1) & ~rs->set.io_mask;
+
+ rs->set.sectors_per_dev = sectors_per_dev;
+
+ rs->set.ei = -1; /* Indicate no failed device. */
+ atomic_set(&rs->set.failed_devs, 0);
+
+ rs->ti = ti;
+
+ atomic_set(rec->io_count + IO_WORK, 0);
+ atomic_set(rec->io_count + IO_RECOVER, 0);
+
+ /* Initialize io lock and queues. */
+ mutex_init(&rs->io.in_lock);
+ bio_list_init(&rs->io.in);
+ bio_list_init(&rs->io.work);
+
+ init_waitqueue_head(&rs->io.suspendq); /* Suspend waiters (dm-io). */
+
+ rec->nr_regions = dm_sector_div_up(sectors_per_dev, region_size);
+ rec->rh = dm_region_hash_create(rs, dispatch_delayed_bios,
+ wake_dummy, wake_do_raid, 0, p->recovery_stripes,
+ dl, region_size, rec->nr_regions);
+ if (IS_ERR(rec->rh))
+ goto bad_rh;
+
+ /* Initialize stripe cache. */
+ r = sc_init(rs, p->stripes);
+ if (r)
+ goto bad_sc;
+
+ /* REMOVEME: statistics. */
+ stats_reset(rs);
+ ClearRSDevelStats(rs); /* Disnable development status. */
+ return rs;
+
+bad_dirty_log:
+ TI_ERR_RET("Error creating dirty log", ERR_PTR(-ENOMEM));
+
+bad_chunk_size:
+ dm_dirty_log_destroy(dl);
+ TI_ERR_RET("Chunk size larger than region size", ERR_PTR(-EINVAL));
+
+bad_recover_io_size:
+ dm_dirty_log_destroy(dl);
+ TI_ERR_RET("Recover stripe io size larger than region size",
+ ERR_PTR(-EINVAL));
+
+bad_array:
+ dm_dirty_log_destroy(dl);
+ TI_ERR_RET("Arry too big", ERR_PTR(-EINVAL));
+
+bad_alloc:
+ dm_dirty_log_destroy(dl);
+ TI_ERR_RET("Cannot allocate raid context", ERR_PTR(-ENOMEM));
+
+bad_rh:
+ dm_dirty_log_destroy(dl);
+ ti->error = DM_MSG_PREFIX "Error creating dirty region hash";
+ goto free_rs;
+
+bad_sc:
+ dm_region_hash_destroy(rec->rh); /* Destroys dirty log too. */
+ sc_exit(&rs->sc);
+ ti->error = DM_MSG_PREFIX "Error creating stripe cache";
+free_rs:
+ kfree(rs);
+ return ERR_PTR(-ENOMEM);
+}
+
+/* Free a RAID context (a RAID set). */
+static void context_free(struct raid_set *rs, unsigned p)
+{
+ while (p--)
+ dm_put_device(rs->ti, rs->dev[p].dev);
+
+ sc_exit(&rs->sc);
+ dm_region_hash_destroy(rs->recover.rh); /* Destroys dirty log too. */
+ kfree(rs);
+}
+
+/* Create work queue and initialize delayed work. */
+static int rs_workqueue_init(struct raid_set *rs)
+{
+ struct dm_target *ti = rs->ti;
+
+ rs->io.wq = create_singlethread_workqueue(DAEMON);
+ if (!rs->io.wq)
+ TI_ERR_RET("failed to create " DAEMON, -ENOMEM);
+
+ INIT_DELAYED_WORK(&rs->io.dws_do_raid, do_raid);
+ INIT_WORK(&rs->io.ws_do_table_event, do_table_event);
+ return 0;
+}
+
+/* Return pointer to raid_type structure for raid name. */
+static struct raid_type *get_raid_type(char *name)
+{
+ struct raid_type *r = ARRAY_END(raid_types);
+
+ while (r-- > raid_types) {
+ if (!strcmp(r->name, name))
+ return r;
+ }
+
+ return NULL;
+}
+
+/* FIXME: factor out to dm core. */
+static int multiple(sector_t a, sector_t b, sector_t *n)
+{
+ sector_t r = a;
+
+ sector_div(r, b);
+ *n = r;
+ return a == r * b;
+}
+
+/* Log RAID set information to kernel log. */
+static void rs_log(struct raid_set *rs, unsigned speed)
+{
+ unsigned p;
+ char buf[BDEVNAME_SIZE];
+
+ for (p = 0; p < rs->set.raid_devs; p++)
+ DMINFO("/dev/%s is raid disk %u%s",
+ bdevname(rs->dev[p].dev->bdev, buf), p,
+ (p == rs->set.pi) ? " (parity)" : "");
+
+ DMINFO("%d/%d/%d sectors chunk/io/recovery size, %u stripes\n"
+ "algorithm \"%s\", %u chunks with %uMB/s\n"
+ "%s set with net %u/%u devices",
+ rs->set.chunk_size, rs->set.io_size, rs->recover.io_size,
+ atomic_read(&rs->sc.stripes),
+ rs->xor.f->name, rs->xor.chunks, mbpers(rs, speed),
+ rs->set.raid_type->descr, rs->set.data_devs, rs->set.raid_devs);
+}
+
+/* Get all devices and offsets. */
+static int dev_parms(struct raid_set *rs, char **argv, int *p)
+{
+ struct dm_target *ti = rs->ti;
+
+ for (*p = 0; *p < rs->set.raid_devs; (*p)++, argv += 2) {
+ int r;
+ unsigned long long tmp;
+ struct raid_dev *dev = rs->dev + *p;
+
+ /* Get offset and device. */
+ if (sscanf(argv[1], "%llu", &tmp) != 1 ||
+ tmp > rs->set.sectors_per_dev)
+ TI_ERR("Invalid RAID device offset parameter");
+
+ dev->start = tmp;
+ r = dm_get_device(ti, *argv, dev->start,
+ rs->set.sectors_per_dev,
+ dm_table_get_mode(ti->table), &dev->dev);
+ if (r)
+ TI_ERR_RET("RAID device lookup failure", r);
+
+ r = raid_dev_lookup(rs, dev);
+ if (r != -ENODEV && r < *p) {
+ (*p)++; /* Ensure dm_put_device() on actual device. */
+ TI_ERR_RET("Duplicate RAID device", -ENXIO);
+ }
+ }
+
+ return 0;
+}
+
+/* Set recovery bandwidth. */
+static void
+recover_set_bandwidth(struct raid_set *rs, unsigned bandwidth)
+{
+ rs->recover.bandwidth = bandwidth;
+ rs->recover.bandwidth_work = 100 / bandwidth;
+}
+
+/* Handle variable number of RAID parameters. */
+static int get_raid_variable_parms(struct dm_target *ti, char **argv,
+ struct variable_parms *vp)
+{
+ int p, value;
+ struct {
+ int action; /* -1: skip, 0: no pwer2 check, 1: power2 check */
+ char *errmsg;
+ int min, max;
+ int *var, *var2, *var3;
+ } argctr[] = {
+ { 1,
+ "Invalid chunk size; must be -1 or 2^^n and <= 16384",
+ IO_SIZE_MIN, CHUNK_SIZE_MAX,
+ &vp->chunk_size_parm, &vp->chunk_size, &vp->io_size },
+ { 0,
+ "Invalid number of stripes: must be -1 or >= 8 and <= 16384",
+ STRIPES_MIN, STRIPES_MAX,
+ &vp->stripes_parm, &vp->stripes, NULL },
+ { 1,
+ "Invalid io size; must -1 or >= 8, 2^^n and less equal "
+ "min(BIO_MAX_SECTORS/2, chunk size)",
+ IO_SIZE_MIN, 0, /* Needs to be updated in loop below. */
+ &vp->io_size_parm, &vp->io_size, NULL },
+ { 1,
+ "Invalid recovery io size; must be -1 or "
+ "2^^n and less equal BIO_MAX_SECTORS/2",
+ RECOVER_IO_SIZE_MIN, BIO_MAX_SECTORS / 2,
+ &vp->recover_io_size_parm, &vp->recover_io_size, NULL },
+ { 0,
+ "Invalid recovery bandwidth percentage; "
+ "must be -1 or > 0 and <= 100",
+ BANDWIDTH_MIN, BANDWIDTH_MAX,
+ &vp->bandwidth_parm, &vp->bandwidth, NULL },
+ /* Handle sync argument seperately in loop. */
+ { -1,
+ "Invalid recovery switch; must be \"sync\" or \"nosync\"" },
+ { 0,
+ "Invalid number of recovery stripes;"
+ "must be -1, > 0 and <= 16384",
+ RECOVERY_STRIPES_MIN, RECOVERY_STRIPES_MAX,
+ &vp->recovery_stripes_parm, &vp->recovery_stripes, NULL },
+ }, *varp;
+
+ /* Fetch # of variable raid parameters. */
+ if (sscanf(*(argv++), "%d", &vp->raid_parms) != 1 ||
+ !range_ok(vp->raid_parms, 0, 7))
+ TI_ERR("Bad variable raid parameters number");
+
+ /* Preset variable RAID parameters. */
+ vp->chunk_size = CHUNK_SIZE_DEFAULT;
+ vp->io_size = IO_SIZE_DEFAULT;
+ vp->stripes = STRIPES_DEFAULT;
+ vp->recover_io_size = RECOVER_IO_SIZE_DEFAULT;
+ vp->bandwidth = BANDWIDTH_DEFAULT;
+ vp->recovery = 1;
+ vp->recovery_stripes = RECOVERY_STRIPES_DEFAULT;
+
+ /* Walk the array of argument constraints for all given ones. */
+ for (p = 0, varp = argctr; p < vp->raid_parms; p++, varp++) {
+ BUG_ON(varp >= ARRAY_END(argctr));
+
+ /* Special case for "[no]sync" string argument. */
+ if (varp->action < 0) {
+ if (!strcmp(*argv, "sync"))
+ ;
+ else if (!strcmp(*argv, "nosync"))
+ vp->recovery = 0;
+ else
+ TI_ERR(varp->errmsg);
+
+ argv++;
+ continue;
+ }
+
+ /*
+ * Special case for io_size depending
+ * on previously set chunk size.
+ */
+ if (p == 2)
+ varp->max = min(BIO_MAX_SECTORS / 2, vp->chunk_size);
+
+ if (sscanf(*(argv++), "%d", &value) != 1 ||
+ (value != -1 &&
+ ((varp->action && !POWER_OF_2(value)) ||
+ !range_ok(value, varp->min, varp->max))))
+ TI_ERR(varp->errmsg);
+
+ *varp->var = value;
+ if (value != -1) {
+ if (varp->var2)
+ *varp->var2 = value;
+ if (varp->var3)
+ *varp->var3 = value;
+ }
+ }
+
+ return 0;
+}
+
+/* Parse optional locking parameters. */
+static int get_raid_locking_parms(struct dm_target *ti, char **argv,
+ int *locking_parms,
+ struct dm_raid45_locking_type **locking_type)
+{
+ if (!strnicmp(argv[0], "locking", strlen(argv[0]))) {
+ char *lckstr = argv[1];
+ size_t lcksz = strlen(lckstr);
+
+ if (!strnicmp(lckstr, "none", lcksz)) {
+ *locking_type = &locking_none;
+ *locking_parms = 2;
+ } else if (!strnicmp(lckstr, "cluster", lcksz)) {
+ DMERR("locking type \"%s\" not yet implemented",
+ lckstr);
+ return -EINVAL;
+ } else {
+ DMERR("unknown locking type \"%s\"", lckstr);
+ return -EINVAL;
+ }
+ }
+
+ *locking_parms = 0;
+ *locking_type = &locking_none;
+ return 0;
+}
+
+/* Set backing device read ahead properties of RAID set. */
+static void rs_set_read_ahead(struct raid_set *rs,
+ unsigned sectors, unsigned stripes)
+{
+ unsigned ra_pages = dm_div_up(sectors, SECTORS_PER_PAGE);
+ struct mapped_device *md = dm_table_get_md(rs->ti->table);
+ struct backing_dev_info *bdi = &dm_disk(md)->queue->backing_dev_info;
+
+ /* Set read-ahead for the RAID set and the component devices. */
+ if (ra_pages) {
+ unsigned p = rs->set.raid_devs;
+
+ bdi->ra_pages = stripes * ra_pages * rs->set.data_devs;
+
+ while (p--) {
+ struct request_queue *q =
+ bdev_get_queue(rs->dev[p].dev->bdev);
+
+ q->backing_dev_info.ra_pages = ra_pages;
+ }
+ }
+
+ dm_put(md);
+}
+
+/* Set congested function. */
+static void rs_set_congested_fn(struct raid_set *rs)
+{
+ struct mapped_device *md = dm_table_get_md(rs->ti->table);
+ struct backing_dev_info *bdi = &dm_disk(md)->queue->backing_dev_info;
+
+ /* Set congested function and data. */
+ bdi->congested_fn = rs_congested;
+ bdi->congested_data = rs;
+ dm_put(md);
+}
+
+/*
+ * Construct a RAID4/5 mapping:
+ *
+ * log_type #log_params <log_params> \
+ * raid_type [#parity_dev] #raid_variable_params <raid_params> \
+ * [locking "none"/"cluster"]
+ * #raid_devs #dev_to_initialize [<dev_path> <offset>]{3,}
+ *
+ * log_type = "core"/"disk",
+ * #log_params = 1-3 (1-2 for core dirty log type, 3 for disk dirty log only)
+ * log_params = [dirty_log_path] region_size [[no]sync])
+ *
+ * raid_type = "raid4", "raid5_la", "raid5_ra", "raid5_ls", "raid5_rs"
+ *
+ * #parity_dev = N if raid_type = "raid4"
+ * o N = -1: pick default = last device
+ * o N >= 0 and < #raid_devs: parity device index
+ *
+ * #raid_variable_params = 0-7; raid_params (-1 = default):
+ * [chunk_size [#stripes [io_size [recover_io_size \
+ * [%recovery_bandwidth [recovery_switch [#recovery_stripes]]]]]]]
+ * o chunk_size (unit to calculate drive addresses; must be 2^^n, > 8
+ * and <= CHUNK_SIZE_MAX)
+ * o #stripes is number of stripes allocated to stripe cache
+ * (must be > 1 and < STRIPES_MAX)
+ * o io_size (io unit size per device in sectors; must be 2^^n and > 8)
+ * o recover_io_size (io unit size per device for recovery in sectors;
+ must be 2^^n, > SECTORS_PER_PAGE and <= region_size)
+ * o %recovery_bandwith is the maximum amount spend for recovery during
+ * application io (1-100%)
+ * o recovery switch = [sync|nosync]
+ * o #recovery_stripes is the number of recovery stripes used for
+ * parallel recovery of the RAID set
+ * If raid_variable_params = 0, defaults will be used.
+ * Any raid_variable_param can be set to -1 to apply a default
+ *
+ * #raid_devs = N (N >= 3)
+ *
+ * #dev_to_initialize = N
+ * -1: initialize parity on all devices
+ * >= 0 and < #raid_devs: initialize raid_path; used to force reconstruction
+ * of a failed devices content after replacement
+ *
+ * <dev_path> = device_path (eg, /dev/sdd1)
+ * <offset> = begin at offset on <dev_path>
+ *
+ */
+#define MIN_PARMS 13
+static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
+{
+ int dev_to_init, dl_parms, i, locking_parms,
+ parity_parm, pi = -1, r, raid_devs;
+ unsigned speed;
+ sector_t tmp, sectors_per_dev;
+ struct dm_raid45_locking_type *locking;
+ struct raid_set *rs;
+ struct raid_type *raid_type;
+ struct variable_parms parms;
+
+ /* Ensure minimum number of parameters. */
+ if (argc < MIN_PARMS)
+ TI_ERR("Not enough parameters");
+
+ /* Fetch # of dirty log parameters. */
+ if (sscanf(argv[1], "%d", &dl_parms) != 1 ||
+ !range_ok(dl_parms, 1, 4711)) /* ;-) */
+ TI_ERR("Bad dirty log parameters number");
+
+ /* Check raid_type. */
+ raid_type = get_raid_type(argv[dl_parms + 2]);
+ if (!raid_type)
+ TI_ERR("Bad raid type");
+
+ /* In case of RAID4, parity drive is selectable. */
+ parity_parm = !!(raid_type->level == raid4);
+
+ /* Handle variable number of RAID parameters. */
+ r = get_raid_variable_parms(ti, argv + dl_parms + parity_parm + 3,
+ &parms);
+ if (r)
+ return r;
+
+ /* Handle any locking parameters. */
+ r = get_raid_locking_parms(ti,
+ argv + dl_parms + parity_parm +
+ parms.raid_parms + 4,
+ &locking_parms, &locking);
+ if (r)
+ return r;
+
+ /* # of raid devices. */
+ i = dl_parms + parity_parm + parms.raid_parms + locking_parms + 4;
+ if (sscanf(argv[i], "%d", &raid_devs) != 1 ||
+ raid_devs < raid_type->minimal_devs)
+ TI_ERR("Invalid number of raid devices");
+
+ /* In case of RAID4, check parity drive index is in limits. */
+ if (raid_type->level == raid4) {
+ /* Fetch index of parity device. */
+ if (sscanf(argv[dl_parms + 3], "%d", &pi) != 1 ||
+ (pi != -1 && !range_ok(pi, 0, raid_devs - 1)))
+ TI_ERR("Invalid RAID4 parity device index");
+ }
+
+ /*
+ * Index of device to initialize starts at 0
+ *
+ * o -1 -> don't initialize a selected device;
+ * initialize parity conforming to algorithm
+ * o 0..raid_devs-1 -> initialize respective device
+ * (used for reconstruction of a replaced device)
+ */
+ if (sscanf(argv[dl_parms + parity_parm + parms.raid_parms +
+ locking_parms + 5], "%d", &dev_to_init) != 1 ||
+ !range_ok(dev_to_init, -1, raid_devs - 1))
+ TI_ERR("Invalid number for raid device to initialize");
+
+ /* Check # of raid device arguments. */
+ if (argc - dl_parms - parity_parm - parms.raid_parms - 6 !=
+ 2 * raid_devs)
+ TI_ERR("Wrong number of raid device/offset arguments");
+
+ /*
+ * Check that the table length is devisable
+ * w/o rest by (raid_devs - parity_devs)
+ */
+ if (!multiple(ti->len, raid_devs - raid_type->parity_devs,
+ §ors_per_dev))
+ TI_ERR("Target length not divisible by number of data devices");
+
+ /*
+ * Check that the device size is
+ * devisable w/o rest by chunk size
+ */
+ if (!multiple(sectors_per_dev, parms.chunk_size, &tmp))
+ TI_ERR("Device length not divisible by chunk_size");
+
+ /****************************************************************
+ * Now that we checked the constructor arguments ->
+ * let's allocate the RAID set
+ ****************************************************************/
+ rs = context_alloc(raid_type, &parms, raid_devs, sectors_per_dev,
+ ti, dl_parms, argv);
+ if (IS_ERR(rs))
+ return PTR_ERR(rs);
+
+
+ rs->set.dev_to_init = rs->set.dev_to_init_parm = dev_to_init;
+ rs->set.pi = rs->set.pi_parm = pi;
+
+ /* Set RAID4 parity drive index. */
+ if (raid_type->level == raid4)
+ rs->set.pi = (pi == -1) ? rs->set.data_devs : pi;
+
+ recover_set_bandwidth(rs, parms.bandwidth);
+
+ /* Use locking type to lock stripe access. */
+ rs->locking = locking;
+
+ /* Get the device/offset tupels. */
+ argv += dl_parms + 6 + parity_parm + parms.raid_parms;
+ r = dev_parms(rs, argv, &i);
+ if (r)
+ goto err;
+
+ /* Set backing device information (eg. read ahead). */
+ rs_set_read_ahead(rs, 2 * rs->set.chunk_size, 4 /* stripes */);
+ rs_set_congested_fn(rs); /* Set congested function. */
+ SetRSCheckOverwrite(rs); /* Allow chunk overwrite checks. */
+ speed = xor_optimize(rs); /* Select best xor algorithm. */
+
+ /* Set for recovery of any nosync regions. */
+ if (parms.recovery)
+ SetRSRecover(rs);
+ else {
+ /*
+ * Need to free recovery stripe(s) here in case
+ * of nosync, because xor_optimize uses one.
+ */
+ set_start_recovery(rs);
+ set_end_recovery(rs);
+ stripe_recover_free(rs);
+ }
+
+ /*
+ * Make sure that dm core only hands maximum io size
+ * length down and pays attention to io boundaries.
+ */
+ ti->split_io = rs->set.io_size;
+ ti->private = rs;
+
+ /* Initialize work queue to handle this RAID set's io. */
+ r = rs_workqueue_init(rs);
+ if (r)
+ goto err;
+
+ rs_log(rs, speed); /* Log information about RAID set. */
+ return 0;
+
+err:
+ context_free(rs, i);
+ return r;
+}
+
+/*
+ * Destruct a raid mapping
+ */
+static void raid_dtr(struct dm_target *ti)
+{
+ struct raid_set *rs = ti->private;
+
+ destroy_workqueue(rs->io.wq);
+ context_free(rs, rs->set.raid_devs);
+}
+
+/* Raid mapping function. */
+static int raid_map(struct dm_target *ti, struct bio *bio,
+ union map_info *map_context)
+{
+ /* I don't want to waste stripe cache capacity. */
+ if (bio_rw(bio) == READA)
+ return -EIO;
+ else {
+ struct raid_set *rs = ti->private;
+
+ /*
+ * Get io reference to be waiting for to drop
+ * to zero on device suspension/destruction.
+ */
+ io_get(rs);
+ bio->bi_sector -= ti->begin; /* Remap sector. */
+
+ /* Queue io to RAID set. */
+ mutex_lock(&rs->io.in_lock);
+ bio_list_add(&rs->io.in, bio);
+ mutex_unlock(&rs->io.in_lock);
+
+ /* Wake daemon to process input list. */
+ wake_do_raid(rs);
+
+ /* REMOVEME: statistics. */
+ atomic_inc(rs->stats + (bio_data_dir(bio) == READ ?
+ S_BIOS_READ : S_BIOS_WRITE));
+ return DM_MAPIO_SUBMITTED; /* Handle later. */
+ }
+}
+
+/* Device suspend. */
+static void raid_presuspend(struct dm_target *ti)
+{
+ struct raid_set *rs = ti->private;
+ struct dm_dirty_log *dl = rs->recover.dl;
+
+ SetRSSuspend(rs);
+
+ if (RSRecover(rs))
+ dm_rh_stop_recovery(rs->recover.rh);
+
+ cancel_delayed_work(&rs->io.dws_do_raid);
+ flush_workqueue(rs->io.wq);
+ wait_ios(rs); /* Wait for completion of all ios being processed. */
+
+ if (dl->type->presuspend && dl->type->presuspend(dl))
+ /* FIXME: need better error handling. */
+ DMWARN("log presuspend failed");
+}
+
+static void raid_postsuspend(struct dm_target *ti)
+{
+ struct raid_set *rs = ti->private;
+ struct dm_dirty_log *dl = rs->recover.dl;
+
+ if (dl->type->postsuspend && dl->type->postsuspend(dl))
+ /* FIXME: need better error handling. */
+ DMWARN("log postsuspend failed");
+
+}
+
+/* Device resume. */
+static void raid_resume(struct dm_target *ti)
+{
+ struct raid_set *rs = ti->private;
+ struct recover *rec = &rs->recover;
+ struct dm_dirty_log *dl = rec->dl;
+
+ if (dl->type->resume && dl->type->resume(dl))
+ /* Resume dirty log. */
+ /* FIXME: need better error handling. */
+ DMWARN("log resume failed");
+
+ rec->nr_regions_to_recover =
+ rec->nr_regions - dl->type->get_sync_count(dl);
+
+ /* Restart any unfinished recovery. */
+ if (RSRecover(rs)) {
+ set_start_recovery(rs);
+ dm_rh_start_recovery(rec->rh);
+ }
+
+ ClearRSSuspend(rs);
+ wake_do_raid(rs);
+}
+
+/* Return stripe cache size. */
+static unsigned sc_size(struct raid_set *rs)
+{
+ return to_sector(atomic_read(&rs->sc.stripes) *
+ (sizeof(struct stripe) +
+ (sizeof(struct stripe_chunk) +
+ (sizeof(struct page_list) +
+ to_bytes(rs->set.io_size) *
+ rs->set.raid_devs)) +
+ (rs->recover.end_jiffies ?
+ 0 : rs->recover.recovery_stripes *
+ to_bytes(rs->set.raid_devs * rs->recover.io_size))));
+}
+
+/* REMOVEME: status output for development. */
+static void raid_devel_stats(struct dm_target *ti, char *result,
+ unsigned *size, unsigned maxlen)
+{
+ unsigned sz = *size;
+ unsigned long j;
+ char buf[BDEVNAME_SIZE], *p;
+ struct stats_map *sm;
+ struct raid_set *rs = ti->private;
+ struct recover *rec = &rs->recover;
+ struct timespec ts;
+
+ DMEMIT("%s %s %u\n", version, rs->xor.f->name, rs->xor.chunks);
+ DMEMIT("act_ios=%d ", io_ref(rs));
+ DMEMIT("act_ios_max=%d\n", atomic_read(&rs->io.in_process_max));
+ DMEMIT("act_stripes=%d ", sc_active(&rs->sc));
+ DMEMIT("act_stripes_max=%d\n",
+ atomic_read(&rs->sc.active_stripes_max));
+
+ for (sm = stats_map; sm < ARRAY_END(stats_map); sm++)
+ DMEMIT("%s%d", sm->str, atomic_read(rs->stats + sm->type));
+
+ DMEMIT(" checkovr=%s\n", RSCheckOverwrite(rs) ? "on" : "off");
+ DMEMIT("sc=%u/%u/%u/%u/%u/%u/%u\n", rs->set.chunk_size,
+ atomic_read(&rs->sc.stripes), rs->set.io_size,
+ rec->recovery_stripes, rec->io_size, rs->sc.hash.buckets,
+ sc_size(rs));
+
+ j = (rec->end_jiffies ? rec->end_jiffies : jiffies) -
+ rec->start_jiffies;
+ jiffies_to_timespec(j, &ts);
+ sprintf(buf, "%ld.%ld", ts.tv_sec, ts.tv_nsec);
+ p = strchr(buf, '.');
+ p[3] = 0;
+
+ DMEMIT("rg=%llu/%llu/%llu/%u %s\n",
+ (unsigned long long) rec->nr_regions_recovered,
+ (unsigned long long) rec->nr_regions_to_recover,
+ (unsigned long long) rec->nr_regions, rec->bandwidth, buf);
+
+ *size = sz;
+}
+
+static int raid_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned maxlen)
+{
+ unsigned p, sz = 0;
+ char buf[BDEVNAME_SIZE];
+ struct raid_set *rs = ti->private;
+ int raid_parms[] = {
+ rs->set.chunk_size_parm,
+ rs->sc.stripes_parm,
+ rs->set.io_size_parm,
+ rs->recover.io_size_parm,
+ rs->recover.bandwidth_parm,
+ -2,
+ rs->recover.recovery_stripes,
+ };
+
+ switch (type) {
+ case STATUSTYPE_INFO:
+ /* REMOVEME: statistics. */
+ if (RSDevelStats(rs))
+ raid_devel_stats(ti, result, &sz, maxlen);
+
+ DMEMIT("%u ", rs->set.raid_devs);
+
+ for (p = 0; p < rs->set.raid_devs; p++)
+ DMEMIT("%s ",
+ format_dev_t(buf, rs->dev[p].dev->bdev->bd_dev));
+
+ DMEMIT("1 ");
+ for (p = 0; p < rs->set.raid_devs; p++) {
+ DMEMIT("%c", !DevFailed(rs->dev + p) ? 'A' : 'D');
+
+ if (p == rs->set.pi)
+ DMEMIT("p");
+
+ if (rs->set.dev_to_init == p)
+ DMEMIT("i");
+ }
+
+ break;
+ case STATUSTYPE_TABLE:
+ sz = rs->recover.dl->type->status(rs->recover.dl, type,
+ result, maxlen);
+ DMEMIT("%s %u ", rs->set.raid_type->name,
+ rs->set.raid_parms);
+
+ for (p = 0; p < rs->set.raid_parms; p++) {
+ if (raid_parms[p] > -2)
+ DMEMIT("%d ", raid_parms[p]);
+ else
+ DMEMIT("%s ", rs->recover.recovery ?
+ "sync" : "nosync");
+ }
+
+ DMEMIT("%u %d ", rs->set.raid_devs, rs->set.dev_to_init);
+
+ for (p = 0; p < rs->set.raid_devs; p++)
+ DMEMIT("%s %llu ",
+ format_dev_t(buf, rs->dev[p].dev->bdev->bd_dev),
+ (unsigned long long) rs->dev[p].start);
+ }
+
+ return 0;
+}
+
+/*
+ * Message interface
+ */
+enum raid_msg_actions {
+ act_bw, /* Recovery bandwidth switch. */
+ act_dev, /* Device failure switch. */
+ act_overwrite, /* Stripe overwrite check. */
+ act_stats, /* Development statistics switch. */
+ act_sc, /* Stripe cache switch. */
+
+ act_on, /* Set entity on. */
+ act_off, /* Set entity off. */
+ act_reset, /* Reset entity. */
+
+ act_set = act_on, /* Set # absolute. */
+ act_grow = act_off, /* Grow # by an amount. */
+ act_shrink = act_reset, /* Shrink # by an amount. */
+};
+
+/* Turn a delta into an absolute value. */
+static int _absolute(unsigned long action, int act, int r)
+{
+ /* Make delta absolute. */
+ if (test_bit(act_set, &action))
+ ;
+ else if (test_bit(act_grow, &action))
+ r += act;
+ else if (test_bit(act_shrink, &action))
+ r = act - r;
+ else
+ r = -EINVAL;
+
+ return r;
+}
+
+ /* Change recovery io bandwidth. */
+static int bandwidth_change(struct dm_msg *msg, void *context)
+{
+ struct raid_set *rs = context;
+ int act = rs->recover.bandwidth;
+ int bandwidth = DM_MSG_INT_ARG(msg);
+
+ if (range_ok(bandwidth, BANDWIDTH_MIN, BANDWIDTH_MAX)) {
+ /* Make delta bandwidth absolute. */
+ bandwidth = _absolute(msg->action, act, bandwidth);
+
+ /* Check range. */
+ if (range_ok(bandwidth, BANDWIDTH_MIN, BANDWIDTH_MAX)) {
+ recover_set_bandwidth(rs, bandwidth);
+ return 0;
+ }
+ }
+
+ set_bit(dm_msg_ret_arg, &msg->ret);
+ set_bit(dm_msg_ret_inval, &msg->ret);
+ return -EINVAL;
+}
+
+/* Set/reset development feature flags. */
+static int devel_flags(struct dm_msg *msg, void *context)
+{
+ struct raid_set *rs = context;
+
+ if (test_bit(act_on, &msg->action))
+ return test_and_set_bit(msg->spec->parm,
+ &rs->io.flags) ? -EPERM : 0;
+ else if (test_bit(act_off, &msg->action))
+ return test_and_clear_bit(msg->spec->parm,
+ &rs->io.flags) ? 0 : -EPERM;
+ else if (test_bit(act_reset, &msg->action)) {
+ if (test_bit(act_stats, &msg->action)) {
+ stats_reset(rs);
+ goto on;
+ } else if (test_bit(act_overwrite, &msg->action)) {
+on:
+ set_bit(msg->spec->parm, &rs->io.flags);
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+
+/* Resize the stripe cache. */
+static int sc_resize(struct dm_msg *msg, void *context)
+{
+ int act, stripes;
+ struct raid_set *rs = context;
+
+ /* Deny permission in case the daemon is still resizing!. */
+ if (atomic_read(&rs->sc.stripes_to_set))
+ return -EPERM;
+
+ stripes = DM_MSG_INT_ARG(msg);
+ if (stripes > 0) {
+ act = atomic_read(&rs->sc.stripes);
+
+ /* Make delta stripes absolute. */
+ stripes = _absolute(msg->action, act, stripes);
+
+ /*
+ * Check range and that the # of stripes changes.
+ * We leave the resizing to the wroker.
+ */
+ if (range_ok(stripes, STRIPES_MIN, STRIPES_MAX) &&
+ stripes != atomic_read(&rs->sc.stripes)) {
+ atomic_set(&rs->sc.stripes_to_set, stripes);
+ wake_do_raid(rs);
+ return 0;
+ }
+ }
+
+ set_bit(dm_msg_ret_arg, &msg->ret);
+ set_bit(dm_msg_ret_inval, &msg->ret);
+ return -EINVAL;
+}
+
+/* Parse the RAID message action. */
+/*
+ * 'ba[ndwidth] {se[t],g[row],sh[rink]} #' # e.g 'ba se 50'
+ * "o[verwrite] {on,of[f],r[eset]}' # e.g. 'o of'
+ * 'sta[tistics] {on,of[f],r[eset]}' # e.g. 'stat of'
+ * 'str[ipecache] {se[t],g[row],sh[rink]} #' # e.g. 'stripe set 1024'
+ *
+ */
+static int raid_message(struct dm_target *ti, unsigned argc, char **argv)
+{
+ /* Variables to store the parsed parameters im. */
+ static int i[2];
+ static unsigned long *i_arg[] = {
+ (unsigned long *) i + 0,
+ (unsigned long *) i + 1,
+ };
+
+ /* Declare all message option strings. */
+ static char *str_sgs[] = { "set", "grow", "shrink" };
+ static char *str_oor[] = { "on", "off", "reset" };
+
+ /* Declare all actions. */
+ static unsigned long act_sgs[] = { act_set, act_grow, act_shrink };
+ static unsigned long act_oor[] = { act_on, act_off, act_reset };
+
+ /* Bandwidth option. */
+ static struct dm_message_option bw_opt = { 3, str_sgs, act_sgs };
+ static struct dm_message_argument bw_args = {
+ 1, i_arg, { dm_msg_int_t }
+ };
+
+ static struct dm_message_argument null_args = {
+ 0, NULL, { dm_msg_int_t }
+ };
+
+ /* Overwrite and statistics option. */
+ static struct dm_message_option ovr_stats_opt = { 3, str_oor, act_oor };
+
+ /* Sripecache option. */
+ static struct dm_message_option stripe_opt = { 3, str_sgs, act_sgs };
+
+ /* Declare messages. */
+ static struct dm_msg_spec specs[] = {
+ { "bandwidth", act_bw, &bw_opt, &bw_args,
+ 0, bandwidth_change },
+ { "overwrite", act_overwrite, &ovr_stats_opt, &null_args,
+ RS_CHECK_OVERWRITE, devel_flags },
+ { "statistics", act_stats, &ovr_stats_opt, &null_args,
+ RS_DEVEL_STATS, devel_flags },
+ { "stripecache", act_sc, &stripe_opt, &bw_args,
+ 0, sc_resize },
+ };
+
+ /* The message for the parser. */
+ struct dm_msg msg = {
+ .num_specs = ARRAY_SIZE(specs),
+ .specs = specs,
+ };
+
+ return dm_message_parse(TARGET, &msg, ti->private, argc, argv);
+}
+/*
+ * END message interface
+ */
+
+static struct target_type raid_target = {
+ .name = "raid45",
+ .version = {1, 0, 0},
+ .module = THIS_MODULE,
+ .ctr = raid_ctr,
+ .dtr = raid_dtr,
+ .map = raid_map,
+ .presuspend = raid_presuspend,
+ .postsuspend = raid_postsuspend,
+ .resume = raid_resume,
+ .status = raid_status,
+ .message = raid_message,
+};
+
+static void init_exit(const char *bad_msg, const char *good_msg, int r)
+{
+ if (r)
+ DMERR("Failed to %sregister target [%d]", bad_msg, r);
+ else
+ DMINFO("%s %s", good_msg, version);
+}
+
+static int __init dm_raid_init(void)
+{
+ int r = dm_register_target(&raid_target);
+
+ init_exit("", "initialized", r);
+ return r;
+}
+
+static void __exit dm_raid_exit(void)
+{
+ dm_unregister_target(&raid_target);
+ init_exit("un", "exit", 0);
+}
+
+/* Module hooks. */
+module_init(dm_raid_init);
+module_exit(dm_raid_exit);
+
+MODULE_DESCRIPTION(DM_NAME " raid4/5 target");
+MODULE_AUTHOR("Heinz Mauelshagen <hjm@redhat.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("dm-raid4");
+MODULE_ALIAS("dm-raid5");
projects / linux-flexiantxendom0-natty.git / commitdiff