From patchwork Fri May 1 14:18:53 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonthan Brassow X-Patchwork-Id: 21433 X-Patchwork-Delegate: agk@redhat.com Received: from hormel.redhat.com (hormel1.redhat.com [209.132.177.33]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n41EIvC6016346 for ; Fri, 1 May 2009 14:18:58 GMT Received: from listman.util.phx.redhat.com (listman.util.phx.redhat.com [10.8.4.110]) by hormel.redhat.com (Postfix) with ESMTP id DC70361A6A5; Fri, 1 May 2009 10:18:56 -0400 (EDT) Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by listman.util.phx.redhat.com (8.13.1/8.13.1) with ESMTP id n41EItu2010271 for ; Fri, 1 May 2009 10:18:55 -0400 Received: from hydrogen.msp.redhat.com (hydrogen.msp.redhat.com [10.15.80.1]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id n41EIr52006680 for ; Fri, 1 May 2009 10:18:54 -0400 Received: from hydrogen.msp.redhat.com (localhost.localdomain [127.0.0.1]) by hydrogen.msp.redhat.com (8.14.1/8.14.1) with ESMTP id n41EIr6H029574 for ; Fri, 1 May 2009 09:18:53 -0500 Received: (from jbrassow@localhost) by hydrogen.msp.redhat.com (8.14.1/8.14.1/Submit) id n41EIrsR029573 for dm-devel@redhat.com; Fri, 1 May 2009 09:18:53 -0500 Date: Fri, 1 May 2009 09:18:53 -0500 From: Jonathan Brassow Message-Id: <200905011418.n41EIrsR029573@hydrogen.msp.redhat.com> To: dm-devel@redhat.com X-Scanned-By: MIMEDefang 2.58 on 172.16.52.254 X-loop: dm-devel@redhat.com Subject: [dm-devel] [PATCH 15 of 33] DM Snapshot: move exception code to new file X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.5 Precedence: junk Reply-To: device-mapper development List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com Patch name: dm-snap-move-exception-code-to-new-file.patch Extract exception table/cache code from dm-snap.c so that it can be used elsewhere. I've created the new files, dm-exception.[ch]. I chose against including this code in this dm-exception-store.[ch] files. Signed-off-by: Jonathan Brassow --- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel Index: linux-2.6/drivers/md/dm-exception-store.h =================================================================== --- linux-2.6.orig/drivers/md/dm-exception-store.h +++ linux-2.6/drivers/md/dm-exception-store.h @@ -12,26 +12,7 @@ #include #include - -/* - * The snapshot code deals with largish chunks of the disk at a - * time. Typically 32k - 512k. - */ -typedef sector_t chunk_t; - -/* - * An exception is used where an old chunk of data has been - * replaced by a new one. - * If chunk_t is 64 bits in size, the top 8 bits of new_chunk hold the number - * of chunks that follow contiguously. Remaining bits hold the number of the - * chunk within the device. - */ -struct dm_exception { - struct list_head hash_list; - - chunk_t old_chunk; - chunk_t new_chunk; -}; +#include "dm-exception.h" /* * Abstraction to handle the meta/layout of exception stores (the @@ -109,49 +90,6 @@ struct dm_exception_store { }; /* - * Funtions to manipulate consecutive chunks - */ -# if defined(CONFIG_LBD) || (BITS_PER_LONG == 64) -# define DM_CHUNK_CONSECUTIVE_BITS 8 -# define DM_CHUNK_NUMBER_BITS 56 - -static inline chunk_t dm_chunk_number(chunk_t chunk) -{ - return chunk & (chunk_t)((1ULL << DM_CHUNK_NUMBER_BITS) - 1ULL); -} - -static inline unsigned dm_consecutive_chunk_count(struct dm_exception *e) -{ - return e->new_chunk >> DM_CHUNK_NUMBER_BITS; -} - -static inline void dm_consecutive_chunk_count_inc(struct dm_exception *e) -{ - e->new_chunk += (1ULL << DM_CHUNK_NUMBER_BITS); - - BUG_ON(!dm_consecutive_chunk_count(e)); -} - -# else -# define DM_CHUNK_CONSECUTIVE_BITS 0 - -static inline chunk_t dm_chunk_number(chunk_t chunk) -{ - return chunk; -} - -static inline unsigned dm_consecutive_chunk_count(struct dm_exception *e) -{ - return 0; -} - -static inline void dm_consecutive_chunk_count_inc(struct dm_exception *e) -{ -} - -# endif - -/* * Return the number of sectors in the device. */ static inline sector_t get_dev_size(struct block_device *bdev) Index: linux-2.6/drivers/md/dm-exception.c =================================================================== --- /dev/null +++ linux-2.6/drivers/md/dm-exception.c @@ -0,0 +1,163 @@ +#include +#include "dm-exception.h" + +struct dm_exception_table_internal { + struct dm_exception_table et; + + struct dm_exception *(*alloc_exception)(void *context); + void *alloc_context; + + void (*free_exception)(struct dm_exception *e, void *context); + void *free_context; +}; + +/* + * Implementation of the exception hash tables. + * The lowest hash_shift bits of the chunk number are ignored, allowing + * some consecutive chunks to be grouped together. + */ +struct dm_exception_table * +dm_exception_table_create(uint32_t size, unsigned hash_shift, + struct dm_exception *(*alloc_exception)(void *), + void *alloc_context, + void (*free_exception)(struct dm_exception *e, void *), + void *free_context) +{ + unsigned int i; + struct dm_exception_table_internal *eti; + struct dm_exception_table *et; + + eti = kmalloc(sizeof(*eti), GFP_KERNEL); + if (!eti) + return NULL; + + et = &eti->et; + + et->hash_shift = hash_shift; + et->hash_mask = size - 1; + et->table = dm_vcalloc(size, sizeof(struct list_head)); + if (!et->table) { + kfree(et); + return NULL; + } + + eti->alloc_exception = alloc_exception; + eti->alloc_context = alloc_context; + eti->free_exception = free_exception; + eti->free_context = free_context; + + for (i = 0; i < size; i++) + INIT_LIST_HEAD(et->table + i); + + return et; +} + +void dm_exception_table_destroy(struct dm_exception_table *et) +{ + struct dm_exception_table_internal *eti; + struct list_head *slot; + struct dm_exception *ex, *next; + int i, size; + + eti = container_of(et, struct dm_exception_table_internal, et); + + size = et->hash_mask + 1; + for (i = 0; i < size; i++) { + slot = et->table + i; + + list_for_each_entry_safe(ex, next, slot, hash_list) + eti->free_exception(ex, eti->free_context); + } + + vfree(et->table); + kfree(eti); +} + +static uint32_t exception_hash(struct dm_exception_table *et, chunk_t chunk) +{ + return (chunk >> et->hash_shift) & et->hash_mask; +} + +void dm_insert_exception(struct dm_exception_table *eh, + struct dm_exception *new_e) +{ + struct list_head *l; + struct dm_exception *e = NULL; + + l = &eh->table[exception_hash(eh, new_e->old_chunk)]; + + /* Add immediately if this table doesn't support consecutive chunks */ + if (!eh->hash_shift) + goto out; + + /* List is ordered by old_chunk */ + list_for_each_entry_reverse(e, l, hash_list) { + /* Insert after an existing chunk? */ + if (new_e->old_chunk == (e->old_chunk + + dm_consecutive_chunk_count(e) + 1) && + new_e->new_chunk == (dm_chunk_number(e->new_chunk) + + dm_consecutive_chunk_count(e) + 1)) { + dm_consecutive_chunk_count_inc(e); + dm_free_exception(eh, new_e); + return; + } + + /* Insert before an existing chunk? */ + if (new_e->old_chunk == (e->old_chunk - 1) && + new_e->new_chunk == (dm_chunk_number(e->new_chunk) - 1)) { + dm_consecutive_chunk_count_inc(e); + e->old_chunk--; + e->new_chunk--; + dm_free_exception(eh, new_e); + return; + } + + if (new_e->old_chunk > e->old_chunk) + break; + } + +out: + list_add(&new_e->hash_list, e ? &e->hash_list : l); +} + +void dm_remove_exception(struct dm_exception *e) +{ + list_del(&e->hash_list); +} + +/* + * Return the exception data for a sector, or NULL if not + * remapped. + */ +struct dm_exception *dm_lookup_exception(struct dm_exception_table *et, + chunk_t chunk) +{ + struct list_head *slot; + struct dm_exception *e; + + slot = &et->table[exception_hash(et, chunk)]; + list_for_each_entry(e, slot, hash_list) + if (chunk >= e->old_chunk && + chunk <= e->old_chunk + dm_consecutive_chunk_count(e)) + return e; + + return NULL; +} + +struct dm_exception *dm_alloc_exception(struct dm_exception_table *et) +{ + struct dm_exception_table_internal *eti; + + eti = container_of(et, struct dm_exception_table_internal, et); + + return eti->alloc_exception(eti->alloc_context); +} + +void dm_free_exception(struct dm_exception_table *et, struct dm_exception *e) +{ + struct dm_exception_table_internal *eti; + + eti = container_of(et, struct dm_exception_table_internal, et); + + return eti->free_exception(e, eti->free_context); +} Index: linux-2.6/drivers/md/dm-exception.h =================================================================== --- /dev/null +++ linux-2.6/drivers/md/dm-exception.h @@ -0,0 +1,104 @@ +/* + * Copyright (C) 2009 Red Hat, Inc. All rights reserved. + * + * Device-mapper exception structure and associated functions. + * + * This file is released under the GPL. + */ + +#ifndef __LINUX_DM_EXCEPTION__ +#define __LINUX_DM_EXCEPTION__ + +#include + +/* + * The snapshot code deals with largish chunks of the disk at a + * time. Typically 32k - 512k. + */ +typedef sector_t chunk_t; + +/* + * An exception is used where an old chunk of data has been + * replaced by a new one. + * If chunk_t is 64 bits in size, the top 8 bits of new_chunk hold the number + * of chunks that follow contiguously. Remaining bits hold the number of the + * chunk within the device. + */ +struct dm_exception { + struct list_head hash_list; + + chunk_t old_chunk; + chunk_t new_chunk; +}; + +struct dm_exception_table { + uint32_t hash_mask; + unsigned hash_shift; + struct list_head *table; +}; + +/* + * Funtions to manipulate consecutive chunks + */ +# if defined(CONFIG_LBD) || (BITS_PER_LONG == 64) +# define DM_CHUNK_CONSECUTIVE_BITS 8 +# define DM_CHUNK_NUMBER_BITS 56 + +static inline chunk_t dm_chunk_number(chunk_t chunk) +{ + return chunk & (chunk_t)((1ULL << DM_CHUNK_NUMBER_BITS) - 1ULL); +} + +static inline unsigned dm_consecutive_chunk_count(struct dm_exception *e) +{ + return e->new_chunk >> DM_CHUNK_NUMBER_BITS; +} + +static inline void dm_consecutive_chunk_count_inc(struct dm_exception *e) +{ + e->new_chunk += (1ULL << DM_CHUNK_NUMBER_BITS); + + BUG_ON(!dm_consecutive_chunk_count(e)); +} + +# else +# define DM_CHUNK_CONSECUTIVE_BITS 0 + +static inline chunk_t dm_chunk_number(chunk_t chunk) +{ + return chunk; +} + +static inline unsigned dm_consecutive_chunk_count(struct dm_exception *e) +{ + return 0; +} + +static inline void dm_consecutive_chunk_count_inc(struct dm_exception *e) +{ +} + +# endif + +struct dm_exception_table * +dm_exception_table_create(uint32_t size, unsigned hash_shift, + struct dm_exception *(*alloc_exception)(void *), + void *alloc_context, + void (*free_exception)(struct dm_exception *e, void *), + void *free_context); + +void dm_exception_table_destroy(struct dm_exception_table *et); + +void dm_insert_exception(struct dm_exception_table *eh, + struct dm_exception *e); + +void dm_remove_exception(struct dm_exception *e); + +struct dm_exception *dm_lookup_exception(struct dm_exception_table *et, + chunk_t chunk); + +struct dm_exception *dm_alloc_exception(struct dm_exception_table *et); + +void dm_free_exception(struct dm_exception_table *et, struct dm_exception *e); + +#endif /* __LINUX_DM_EXCEPTION__ */ Index: linux-2.6/drivers/md/dm-snap.c =================================================================== --- linux-2.6.orig/drivers/md/dm-snap.c +++ linux-2.6/drivers/md/dm-snap.c @@ -50,12 +50,6 @@ #define DM_TRACKED_CHUNK_HASH(x) ((unsigned long)(x) & \ (DM_TRACKED_CHUNK_HASH_SIZE - 1)) -struct dm_exception_table { - uint32_t hash_mask; - unsigned hash_shift; - struct list_head *table; -}; - struct dm_snapshot { struct rw_semaphore lock; @@ -342,126 +336,6 @@ static void unregister_snapshot(struct d up_write(&_origins_lock); } -struct dm_exception_table_internal { - struct dm_exception_table et; - - struct dm_exception *(*alloc_exception)(void *context); - void *alloc_context; - - void (*free_exception)(struct dm_exception *e, void *context); - void *free_context; -}; - -/* - * Implementation of the exception hash tables. - * The lowest hash_shift bits of the chunk number are ignored, allowing - * some consecutive chunks to be grouped together. - */ -static struct dm_exception_table * -dm_exception_table_create(uint32_t size, unsigned hash_shift, - struct dm_exception *(*alloc_exception)(void *), - void *alloc_context, - void (*free_exception)(struct dm_exception *e, void *), - void *free_context) -{ - unsigned int i; - struct dm_exception_table_internal *eti; - struct dm_exception_table *et; - - eti = kmalloc(sizeof(*eti), GFP_KERNEL); - if (!eti) - return NULL; - - et = &eti->et; - - et->hash_shift = hash_shift; - et->hash_mask = size - 1; - et->table = dm_vcalloc(size, sizeof(struct list_head)); - if (!et->table) { - kfree(et); - return NULL; - } - - eti->alloc_exception = alloc_exception; - eti->alloc_context = alloc_context; - eti->free_exception = free_exception; - eti->free_context = free_context; - - for (i = 0; i < size; i++) - INIT_LIST_HEAD(et->table + i); - - return et; -} - -static void dm_exception_table_destroy(struct dm_exception_table *et) -{ - struct dm_exception_table_internal *eti; - struct list_head *slot; - struct dm_exception *ex, *next; - int i, size; - - eti = container_of(et, struct dm_exception_table_internal, et); - - size = et->hash_mask + 1; - for (i = 0; i < size; i++) { - slot = et->table + i; - - list_for_each_entry_safe (ex, next, slot, hash_list) - eti->free_exception(ex, eti->free_context); - } - - vfree(et->table); - kfree(eti); -} - -static uint32_t exception_hash(struct dm_exception_table *et, chunk_t chunk) -{ - return (chunk >> et->hash_shift) & et->hash_mask; -} - -static void dm_remove_exception(struct dm_exception *e) -{ - list_del(&e->hash_list); -} - -/* - * Return the exception data for a sector, or NULL if not - * remapped. - */ -static struct dm_exception *dm_lookup_exception(struct dm_exception_table *et, - chunk_t chunk) -{ - struct list_head *slot; - struct dm_exception *e; - - slot = &et->table[exception_hash(et, chunk)]; - list_for_each_entry (e, slot, hash_list) - if (chunk >= e->old_chunk && - chunk <= e->old_chunk + dm_consecutive_chunk_count(e)) - return e; - - return NULL; -} - -static struct dm_exception *dm_alloc_exception(struct dm_exception_table *et) -{ - struct dm_exception_table_internal *eti; - - eti = container_of(et, struct dm_exception_table_internal, et); - - return eti->alloc_exception(eti->alloc_context); -} - -static void dm_free_exception(struct dm_exception_table *et, - struct dm_exception *e) -{ - struct dm_exception_table_internal *eti; - - eti = container_of(et, struct dm_exception_table_internal, et); - - return eti->free_exception(e, eti->free_context); -} - static struct dm_exception *alloc_completed_exception(void *unused) { struct dm_exception *e; @@ -503,48 +377,6 @@ static void free_pending_exception(struc atomic_dec(&s->pending_exceptions_count); } -static void dm_insert_exception(struct dm_exception_table *eh, - struct dm_exception *new_e) -{ - struct list_head *l; - struct dm_exception *e = NULL; - - l = &eh->table[exception_hash(eh, new_e->old_chunk)]; - - /* Add immediately if this table doesn't support consecutive chunks */ - if (!eh->hash_shift) - goto out; - - /* List is ordered by old_chunk */ - list_for_each_entry_reverse(e, l, hash_list) { - /* Insert after an existing chunk? */ - if (new_e->old_chunk == (e->old_chunk + - dm_consecutive_chunk_count(e) + 1) && - new_e->new_chunk == (dm_chunk_number(e->new_chunk) + - dm_consecutive_chunk_count(e) + 1)) { - dm_consecutive_chunk_count_inc(e); - dm_free_exception(eh, new_e); - return; - } - - /* Insert before an existing chunk? */ - if (new_e->old_chunk == (e->old_chunk - 1) && - new_e->new_chunk == (dm_chunk_number(e->new_chunk) - 1)) { - dm_consecutive_chunk_count_inc(e); - e->old_chunk--; - e->new_chunk--; - dm_free_exception(eh, new_e); - return; - } - - if (new_e->old_chunk > e->old_chunk) - break; - } - -out: - list_add(&new_e->hash_list, e ? &e->hash_list : l); -} - /* * Callback used by the exception stores to load exceptions when * initialising. Index: linux-2.6/drivers/md/Makefile =================================================================== --- linux-2.6.orig/drivers/md/Makefile +++ linux-2.6/drivers/md/Makefile @@ -5,8 +5,8 @@ dm-mod-y += dm.o dm-table.o dm-target.o dm-linear.o dm-stripe.o \ dm-ioctl.o dm-io.o dm-kcopyd.o dm-sysfs.o dm-multipath-y += dm-path-selector.o dm-mpath.o -dm-snapshot-y += dm-snap.o dm-exception-store.o dm-snap-transient.o \ - dm-snap-persistent.o +dm-snapshot-y += dm-snap.o dm-exception.o dm-exception-store.o \ + dm-snap-transient.o dm-snap-persistent.o dm-mirror-y += dm-raid1.o md-mod-y += md.o bitmap.o raid456-y += raid5.o