X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=drivers%2Fmd%2Fdm-exception-store.c;h=99cdffa7fbfe0a4522330099dd80ca810f3dc796;hb=e52e15d3c153b88c4536cf18214fac18481c888a;hp=cc07bbebbb1688156db22c88d746ae54a18b41ee;hpb=d7f6884ae0ae6e406ec3500fcde16e8f51642460;p=powerpc.git diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c index cc07bbebbb..99cdffa7fb 100644 --- a/drivers/md/dm-exception-store.c +++ b/drivers/md/dm-exception-store.c @@ -16,6 +16,9 @@ #include #include +#define DM_MSG_PREFIX "snapshots" +#define DM_CHUNK_SIZE_DEFAULT_SECTORS 32 /* 16KB */ + /*----------------------------------------------------------------- * Persistent snapshots, by persistent we mean that the snapshot * will survive a reboot. @@ -91,7 +94,6 @@ struct pstore { struct dm_snapshot *snap; /* up pointer to my snapshot */ int version; int valid; - uint32_t chunk_size; uint32_t exceptions_per_area; /* @@ -133,7 +135,7 @@ static int alloc_area(struct pstore *ps) int r = -ENOMEM; size_t len; - len = ps->chunk_size << SECTOR_SHIFT; + len = ps->snap->chunk_size << SECTOR_SHIFT; /* * Allocate the chunk_size block of memory that will hold @@ -149,6 +151,7 @@ static int alloc_area(struct pstore *ps) static void free_area(struct pstore *ps) { vfree(ps->area); + ps->area = NULL; } /* @@ -160,8 +163,8 @@ static int chunk_io(struct pstore *ps, uint32_t chunk, int rw) unsigned long bits; where.bdev = ps->snap->cow->bdev; - where.sector = ps->chunk_size * chunk; - where.count = ps->chunk_size; + where.sector = ps->snap->chunk_size * chunk; + where.count = ps->snap->chunk_size; return dm_io_sync_vm(1, &where, rw, ps->area, &bits); } @@ -188,7 +191,7 @@ static int area_io(struct pstore *ps, uint32_t area, int rw) static int zero_area(struct pstore *ps, uint32_t area) { - memset(ps->area, 0, ps->chunk_size << SECTOR_SHIFT); + memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT); return area_io(ps, area, WRITE); } @@ -196,27 +199,80 @@ static int read_header(struct pstore *ps, int *new_snapshot) { int r; struct disk_header *dh; + chunk_t chunk_size; + int chunk_size_supplied = 1; - r = chunk_io(ps, 0, READ); + /* + * Use default chunk size (or hardsect_size, if larger) if none supplied + */ + if (!ps->snap->chunk_size) { + ps->snap->chunk_size = max(DM_CHUNK_SIZE_DEFAULT_SECTORS, + bdev_hardsect_size(ps->snap->cow->bdev) >> 9); + ps->snap->chunk_mask = ps->snap->chunk_size - 1; + ps->snap->chunk_shift = ffs(ps->snap->chunk_size) - 1; + chunk_size_supplied = 0; + } + + r = dm_io_get(sectors_to_pages(ps->snap->chunk_size)); if (r) return r; + r = alloc_area(ps); + if (r) + goto bad1; + + r = chunk_io(ps, 0, READ); + if (r) + goto bad2; + dh = (struct disk_header *) ps->area; if (le32_to_cpu(dh->magic) == 0) { *new_snapshot = 1; + return 0; + } - } else if (le32_to_cpu(dh->magic) == SNAP_MAGIC) { - *new_snapshot = 0; - ps->valid = le32_to_cpu(dh->valid); - ps->version = le32_to_cpu(dh->version); - ps->chunk_size = le32_to_cpu(dh->chunk_size); - - } else { - DMWARN("Invalid/corrupt snapshot"); + if (le32_to_cpu(dh->magic) != SNAP_MAGIC) { + DMWARN("Invalid or corrupt snapshot"); r = -ENXIO; + goto bad2; } + *new_snapshot = 0; + ps->valid = le32_to_cpu(dh->valid); + ps->version = le32_to_cpu(dh->version); + chunk_size = le32_to_cpu(dh->chunk_size); + + if (!chunk_size_supplied || ps->snap->chunk_size == chunk_size) + return 0; + + DMWARN("chunk size %llu in device metadata overrides " + "table chunk size of %llu.", + (unsigned long long)chunk_size, + (unsigned long long)ps->snap->chunk_size); + + /* We had a bogus chunk_size. Fix stuff up. */ + dm_io_put(sectors_to_pages(ps->snap->chunk_size)); + free_area(ps); + + ps->snap->chunk_size = chunk_size; + ps->snap->chunk_mask = chunk_size - 1; + ps->snap->chunk_shift = ffs(chunk_size) - 1; + + r = dm_io_get(sectors_to_pages(chunk_size)); + if (r) + return r; + + r = alloc_area(ps); + if (r) + goto bad1; + + return 0; + +bad2: + free_area(ps); +bad1: + dm_io_put(sectors_to_pages(ps->snap->chunk_size)); return r; } @@ -224,13 +280,13 @@ static int write_header(struct pstore *ps) { struct disk_header *dh; - memset(ps->area, 0, ps->chunk_size << SECTOR_SHIFT); + memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT); dh = (struct disk_header *) ps->area; dh->magic = cpu_to_le32(SNAP_MAGIC); dh->valid = cpu_to_le32(ps->valid); dh->version = cpu_to_le32(ps->version); - dh->chunk_size = cpu_to_le32(ps->chunk_size); + dh->chunk_size = cpu_to_le32(ps->snap->chunk_size); return chunk_io(ps, 0, WRITE); } @@ -240,42 +296,29 @@ static int write_header(struct pstore *ps) */ static struct disk_exception *get_exception(struct pstore *ps, uint32_t index) { - if (index >= ps->exceptions_per_area) - return NULL; + BUG_ON(index >= ps->exceptions_per_area); return ((struct disk_exception *) ps->area) + index; } -static int read_exception(struct pstore *ps, - uint32_t index, struct disk_exception *result) +static void read_exception(struct pstore *ps, + uint32_t index, struct disk_exception *result) { - struct disk_exception *e; - - e = get_exception(ps, index); - if (!e) - return -EINVAL; + struct disk_exception *e = get_exception(ps, index); /* copy it */ result->old_chunk = le64_to_cpu(e->old_chunk); result->new_chunk = le64_to_cpu(e->new_chunk); - - return 0; } -static int write_exception(struct pstore *ps, - uint32_t index, struct disk_exception *de) +static void write_exception(struct pstore *ps, + uint32_t index, struct disk_exception *de) { - struct disk_exception *e; - - e = get_exception(ps, index); - if (!e) - return -EINVAL; + struct disk_exception *e = get_exception(ps, index); /* copy it */ e->old_chunk = cpu_to_le64(de->old_chunk); e->new_chunk = cpu_to_le64(de->new_chunk); - - return 0; } /* @@ -293,10 +336,7 @@ static int insert_exceptions(struct pstore *ps, int *full) *full = 1; for (i = 0; i < ps->exceptions_per_area; i++) { - r = read_exception(ps, i, &de); - - if (r) - return r; + read_exception(ps, i, &de); /* * If the new_chunk is pointing at the start of @@ -365,7 +405,7 @@ static void persistent_destroy(struct exception_store *store) { struct pstore *ps = get_info(store); - dm_io_put(sectors_to_pages(ps->chunk_size)); + dm_io_put(sectors_to_pages(ps->snap->chunk_size)); vfree(ps->callbacks); free_area(ps); kfree(ps); @@ -383,6 +423,16 @@ static int persistent_read_metadata(struct exception_store *store) if (r) return r; + /* + * Now we know correct chunk_size, complete the initialisation. + */ + ps->exceptions_per_area = (ps->snap->chunk_size << SECTOR_SHIFT) / + sizeof(struct disk_exception); + ps->callbacks = dm_vcalloc(ps->exceptions_per_area, + sizeof(*ps->callbacks)); + if (!ps->callbacks) + return -ENOMEM; + /* * Do we need to setup a new snapshot ? */ @@ -486,6 +536,16 @@ static void persistent_commit(struct exception_store *store, if (r) ps->valid = 0; + /* + * Have we completely filled the current area ? + */ + if (ps->current_committed == ps->exceptions_per_area) { + ps->current_committed = 0; + r = zero_area(ps, ps->current_area + 1); + if (r) + ps->valid = 0; + } + for (i = 0; i < ps->callback_count; i++) { cb = ps->callbacks + i; cb->callback(cb->context, r == 0 ? 1 : 0); @@ -493,16 +553,6 @@ static void persistent_commit(struct exception_store *store, ps->callback_count = 0; } - - /* - * Have we completely filled the current area ? - */ - if (ps->current_committed == ps->exceptions_per_area) { - ps->current_committed = 0; - r = zero_area(ps, ps->current_area + 1); - if (r) - ps->valid = 0; - } } static void persistent_drop(struct exception_store *store) @@ -514,47 +564,25 @@ static void persistent_drop(struct exception_store *store) DMWARN("write header failed"); } -int dm_create_persistent(struct exception_store *store, uint32_t chunk_size) +int dm_create_persistent(struct exception_store *store) { - int r; struct pstore *ps; - r = dm_io_get(sectors_to_pages(chunk_size)); - if (r) - return r; - /* allocate the pstore */ ps = kmalloc(sizeof(*ps), GFP_KERNEL); - if (!ps) { - r = -ENOMEM; - goto bad; - } + if (!ps) + return -ENOMEM; ps->snap = store->snap; ps->valid = 1; ps->version = SNAPSHOT_DISK_VERSION; - ps->chunk_size = chunk_size; - ps->exceptions_per_area = (chunk_size << SECTOR_SHIFT) / - sizeof(struct disk_exception); + ps->area = NULL; ps->next_free = 2; /* skipping the header and first area */ ps->current_committed = 0; - r = alloc_area(ps); - if (r) - goto bad; - - /* - * Allocate space for all the callbacks. - */ ps->callback_count = 0; atomic_set(&ps->pending_count, 0); - ps->callbacks = dm_vcalloc(ps->exceptions_per_area, - sizeof(*ps->callbacks)); - - if (!ps->callbacks) { - r = -ENOMEM; - goto bad; - } + ps->callbacks = NULL; store->destroy = persistent_destroy; store->read_metadata = persistent_read_metadata; @@ -565,13 +593,6 @@ int dm_create_persistent(struct exception_store *store, uint32_t chunk_size) store->context = ps; return 0; - - bad: - dm_io_put(sectors_to_pages(chunk_size)); - if (ps && ps->area) - free_area(ps); - kfree(ps); - return r; } /*----------------------------------------------------------------- @@ -621,18 +642,16 @@ static void transient_fraction_full(struct exception_store *store, *denominator = get_dev_size(store->snap->cow->bdev); } -int dm_create_transient(struct exception_store *store, - struct dm_snapshot *s, int blocksize) +int dm_create_transient(struct exception_store *store) { struct transient_c *tc; - memset(store, 0, sizeof(*store)); store->destroy = transient_destroy; store->read_metadata = transient_read_metadata; store->prepare_exception = transient_prepare; store->commit_exception = transient_commit; + store->drop_snapshot = NULL; store->fraction_full = transient_fraction_full; - store->snap = s; tc = kmalloc(sizeof(struct transient_c), GFP_KERNEL); if (!tc)