From a159c1ac5f33c6cf0f5aa3c9d1ccdc82c907ee46 Mon Sep 17 00:00:00 2001 From: Jonathan Brassow Date: Tue, 6 Jan 2009 03:05:19 +0000 Subject: dm snapshot: extend exception store functions Supply dm_add_exception as a callback to the read_metadata function. Add a status function ready for a later patch and name the functions consistently. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon --- drivers/md/dm-exception-store.c | 1 - drivers/md/dm-exception-store.h | 13 ++++++++++--- drivers/md/dm-snap-persistent.c | 42 +++++++++++++++++++++++++---------------- drivers/md/dm-snap-transient.c | 21 ++++++++++++--------- drivers/md/dm-snap.c | 9 +++++++-- drivers/md/dm-snap.h | 6 ------ 6 files changed, 55 insertions(+), 37 deletions(-) diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c index 74777e0f80df..dccbfb0e010f 100644 --- a/drivers/md/dm-exception-store.c +++ b/drivers/md/dm-exception-store.c @@ -11,7 +11,6 @@ #include #include #include -#include #define DM_MSG_PREFIX "snapshot exception stores" diff --git a/drivers/md/dm-exception-store.h b/drivers/md/dm-exception-store.h index 78d1acec77e9..bb9f33d5daa2 100644 --- a/drivers/md/dm-exception-store.h +++ b/drivers/md/dm-exception-store.h @@ -11,6 +11,7 @@ #define _LINUX_DM_EXCEPTION_STORE #include +#include /* * The snapshot code deals with largish chunks of the disk at a @@ -37,7 +38,6 @@ struct dm_snap_exception { * COW device). */ struct dm_exception_store { - /* * Destroys this object when you've finished with it. */ @@ -45,9 +45,13 @@ struct dm_exception_store { /* * The target shouldn't read the COW device until this is - * called. + * called. As exceptions are read from the COW, they are + * reported back via the callback. */ - int (*read_metadata) (struct dm_exception_store *store); + int (*read_metadata) (struct dm_exception_store *store, + int (*callback)(void *callback_context, + chunk_t old, chunk_t new), + void *callback_context); /* * Find somewhere to store the next exception. @@ -68,6 +72,9 @@ struct dm_exception_store { */ void (*drop_snapshot) (struct dm_exception_store *store); + int (*status) (struct dm_exception_store *store, status_type_t status, + char *result, unsigned int maxlen); + /* * Return how full the snapshot is. */ diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c index 57c946c69ee7..936b34e0959f 100644 --- a/drivers/md/dm-snap-persistent.c +++ b/drivers/md/dm-snap-persistent.c @@ -395,7 +395,11 @@ static void write_exception(struct pstore *ps, * 'full' is filled in to indicate if the area has been * filled. */ -static int insert_exceptions(struct pstore *ps, int *full) +static int insert_exceptions(struct pstore *ps, + int (*callback)(void *callback_context, + chunk_t old, chunk_t new), + void *callback_context, + int *full) { int r; unsigned int i; @@ -428,7 +432,7 @@ static int insert_exceptions(struct pstore *ps, int *full) /* * Otherwise we add the exception to the snapshot. */ - r = dm_add_exception(ps->snap, de.old_chunk, de.new_chunk); + r = callback(callback_context, de.old_chunk, de.new_chunk); if (r) return r; } @@ -436,7 +440,10 @@ static int insert_exceptions(struct pstore *ps, int *full) return 0; } -static int read_exceptions(struct pstore *ps) +static int read_exceptions(struct pstore *ps, + int (*callback)(void *callback_context, chunk_t old, + chunk_t new), + void *callback_context) { int r, full = 1; @@ -449,7 +456,7 @@ static int read_exceptions(struct pstore *ps) if (r) return r; - r = insert_exceptions(ps, &full); + r = insert_exceptions(ps, callback, callback_context, &full); if (r) return r; } @@ -482,7 +489,10 @@ static void persistent_destroy(struct dm_exception_store *store) kfree(ps); } -static int persistent_read_metadata(struct dm_exception_store *store) +static int persistent_read_metadata(struct dm_exception_store *store, + int (*callback)(void *callback_context, + chunk_t old, chunk_t new), + void *callback_context) { int r, uninitialized_var(new_snapshot); struct pstore *ps = get_info(store); @@ -540,7 +550,7 @@ static int persistent_read_metadata(struct dm_exception_store *store) /* * Read the metadata. */ - r = read_exceptions(ps); + r = read_exceptions(ps, callback, callback_context); if (r) return r; } @@ -548,8 +558,8 @@ static int persistent_read_metadata(struct dm_exception_store *store) return 0; } -static int persistent_prepare(struct dm_exception_store *store, - struct dm_snap_exception *e) +static int persistent_prepare_exception(struct dm_exception_store *store, + struct dm_snap_exception *e) { struct pstore *ps = get_info(store); uint32_t stride; @@ -575,10 +585,10 @@ static int persistent_prepare(struct dm_exception_store *store, return 0; } -static void persistent_commit(struct dm_exception_store *store, - struct dm_snap_exception *e, - void (*callback) (void *, int success), - void *callback_context) +static void persistent_commit_exception(struct dm_exception_store *store, + struct dm_snap_exception *e, + void (*callback) (void *, int success), + void *callback_context) { unsigned int i; struct pstore *ps = get_info(store); @@ -637,7 +647,7 @@ static void persistent_commit(struct dm_exception_store *store, ps->callback_count = 0; } -static void persistent_drop(struct dm_exception_store *store) +static void persistent_drop_snapshot(struct dm_exception_store *store) { struct pstore *ps = get_info(store); @@ -675,9 +685,9 @@ int dm_create_persistent(struct dm_exception_store *store) store->destroy = persistent_destroy; store->read_metadata = persistent_read_metadata; - store->prepare_exception = persistent_prepare; - store->commit_exception = persistent_commit; - store->drop_snapshot = persistent_drop; + store->prepare_exception = persistent_prepare_exception; + store->commit_exception = persistent_commit_exception; + store->drop_snapshot = persistent_drop_snapshot; store->fraction_full = persistent_fraction_full; store->context = ps; diff --git a/drivers/md/dm-snap-transient.c b/drivers/md/dm-snap-transient.c index 2a781df57fef..7f6e2e6dcb0d 100644 --- a/drivers/md/dm-snap-transient.c +++ b/drivers/md/dm-snap-transient.c @@ -28,13 +28,16 @@ static void transient_destroy(struct dm_exception_store *store) kfree(store->context); } -static int transient_read_metadata(struct dm_exception_store *store) +static int transient_read_metadata(struct dm_exception_store *store, + int (*callback)(void *callback_context, + chunk_t old, chunk_t new), + void *callback_context) { return 0; } -static int transient_prepare(struct dm_exception_store *store, - struct dm_snap_exception *e) +static int transient_prepare_exception(struct dm_exception_store *store, + struct dm_snap_exception *e) { struct transient_c *tc = (struct transient_c *) store->context; sector_t size = get_dev_size(store->snap->cow->bdev); @@ -48,10 +51,10 @@ static int transient_prepare(struct dm_exception_store *store, return 0; } -static void transient_commit(struct dm_exception_store *store, - struct dm_snap_exception *e, - void (*callback) (void *, int success), - void *callback_context) +static void transient_commit_exception(struct dm_exception_store *store, + struct dm_snap_exception *e, + void (*callback) (void *, int success), + void *callback_context) { /* Just succeed */ callback(callback_context, 1); @@ -70,8 +73,8 @@ int dm_create_transient(struct dm_exception_store *store) store->destroy = transient_destroy; store->read_metadata = transient_read_metadata; - store->prepare_exception = transient_prepare; - store->commit_exception = transient_commit; + store->prepare_exception = transient_prepare_exception; + store->commit_exception = transient_commit_exception; store->drop_snapshot = NULL; store->fraction_full = transient_fraction_full; diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index 018b567fc758..65ff82ff124e 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -430,8 +430,13 @@ out: list_add(&new_e->hash_list, e ? &e->hash_list : l); } -int dm_add_exception(struct dm_snapshot *s, chunk_t old, chunk_t new) +/* + * Callback used by the exception stores to load exceptions when + * initialising. + */ +static int dm_add_exception(void *context, chunk_t old, chunk_t new) { + struct dm_snapshot *s = context; struct dm_snap_exception *e; e = alloc_exception(); @@ -660,7 +665,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) spin_lock_init(&s->tracked_chunk_lock); /* Metadata must only be loaded into one table at once */ - r = s->store.read_metadata(&s->store); + r = s->store.read_metadata(&s->store, dm_add_exception, (void *)s); if (r < 0) { ti->error = "Failed to read snapshot metadata"; goto bad_load_and_register; diff --git a/drivers/md/dm-snap.h b/drivers/md/dm-snap.h index 928123657024..d9e62b43cf85 100644 --- a/drivers/md/dm-snap.h +++ b/drivers/md/dm-snap.h @@ -75,12 +75,6 @@ struct dm_snapshot { struct hlist_head tracked_chunk_hash[DM_TRACKED_CHUNK_HASH_SIZE]; }; -/* - * Used by the exception stores to load exceptions hen - * initialising. - */ -int dm_add_exception(struct dm_snapshot *s, chunk_t old, chunk_t new); - /* * Return the number of sectors in the device. */ -- cgit v1.2.3