diff options
Diffstat (limited to 'drivers/block/rbd.c')
| -rw-r--r-- | drivers/block/rbd.c | 935 |
1 files changed, 549 insertions, 386 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index ca63104136e..d6d314027b5 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -55,6 +55,39 @@ #define SECTOR_SHIFT 9 #define SECTOR_SIZE (1ULL << SECTOR_SHIFT) +/* + * Increment the given counter and return its updated value. + * If the counter is already 0 it will not be incremented. + * If the counter is already at its maximum value returns + * -EINVAL without updating it. + */ +static int atomic_inc_return_safe(atomic_t *v) +{ + unsigned int counter; + + counter = (unsigned int)__atomic_add_unless(v, 1, 0); + if (counter <= (unsigned int)INT_MAX) + return (int)counter; + + atomic_dec(v); + + return -EINVAL; +} + +/* Decrement the counter. Return the resulting value, or -EINVAL */ +static int atomic_dec_return_safe(atomic_t *v) +{ + int counter; + + counter = atomic_dec_return(v); + if (counter >= 0) + return counter; + + atomic_inc(v); + + return -EINVAL; +} + #define RBD_DRV_NAME "rbd" #define RBD_DRV_NAME_LONG "rbd (rados block device)" @@ -100,21 +133,20 @@ * block device image metadata (in-memory version) */ struct rbd_image_header { - /* These four fields never change for a given rbd image */ + /* These six fields never change for a given rbd image */ char *object_prefix; - u64 features; __u8 obj_order; __u8 crypt_type; __u8 comp_type; + u64 stripe_unit; + u64 stripe_count; + u64 features; /* Might be changeable someday? */ /* The remaining fields need to be updated occasionally */ u64 image_size; struct ceph_snap_context *snapc; - char *snap_names; - u64 *snap_sizes; - - u64 stripe_unit; - u64 stripe_count; + char *snap_names; /* format 1 only */ + u64 *snap_sizes; /* format 1 only */ }; /* @@ -225,6 +257,7 @@ struct rbd_obj_request { }; }; struct page **copyup_pages; + u32 copyup_page_count; struct ceph_osd_request *osd_req; @@ -257,6 +290,7 @@ struct rbd_img_request { struct rbd_obj_request *obj_request; /* obj req initiator */ }; struct page **copyup_pages; + u32 copyup_page_count; spinlock_t completion_lock;/* protects next_completion */ u32 next_completion; rbd_img_callback_t callback; @@ -311,6 +345,7 @@ struct rbd_device { struct rbd_spec *parent_spec; u64 parent_overlap; + atomic_t parent_ref; struct rbd_device *parent; /* protects updating the header */ @@ -359,7 +394,8 @@ static ssize_t rbd_add(struct bus_type *bus, const char *buf, size_t count); static ssize_t rbd_remove(struct bus_type *bus, const char *buf, size_t count); -static int rbd_dev_image_probe(struct rbd_device *rbd_dev); +static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool mapping); +static void rbd_spec_put(struct rbd_spec *spec); static struct bus_attribute rbd_bus_attrs[] = { __ATTR(add, S_IWUSR, NULL, rbd_add), @@ -426,7 +462,8 @@ static void rbd_img_parent_read(struct rbd_obj_request *obj_request); static void rbd_dev_remove_parent(struct rbd_device *rbd_dev); static int rbd_dev_refresh(struct rbd_device *rbd_dev); -static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev); +static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev); +static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev); static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev, u64 snap_id); static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id, @@ -726,88 +763,123 @@ static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk) } /* - * Create a new header structure, translate header format from the on-disk - * header. + * Fill an rbd image header with information from the given format 1 + * on-disk header. */ -static int rbd_header_from_disk(struct rbd_image_header *header, +static int rbd_header_from_disk(struct rbd_device *rbd_dev, struct rbd_image_header_ondisk *ondisk) { + struct rbd_image_header *header = &rbd_dev->header; + bool first_time = header->object_prefix == NULL; + struct ceph_snap_context *snapc; + char *object_prefix = NULL; + char *snap_names = NULL; + u64 *snap_sizes = NULL; u32 snap_count; - size_t len; size_t size; + int ret = -ENOMEM; u32 i; - memset(header, 0, sizeof (*header)); + /* Allocate this now to avoid having to handle failure below */ - snap_count = le32_to_cpu(ondisk->snap_count); + if (first_time) { + size_t len; - len = strnlen(ondisk->object_prefix, sizeof (ondisk->object_prefix)); - header->object_prefix = kmalloc(len + 1, GFP_KERNEL); - if (!header->object_prefix) - return -ENOMEM; - memcpy(header->object_prefix, ondisk->object_prefix, len); - header->object_prefix[len] = '\0'; + len = strnlen(ondisk->object_prefix, + sizeof (ondisk->object_prefix)); + object_prefix = kmalloc(len + 1, GFP_KERNEL); + if (!object_prefix) + return -ENOMEM; + memcpy(object_prefix, ondisk->object_prefix, len); + object_prefix[len] = '\0'; + } + /* Allocate the snapshot context and fill it in */ + + snap_count = le32_to_cpu(ondisk->snap_count); + snapc = ceph_create_snap_context(snap_count, GFP_KERNEL); + if (!snapc) + goto out_err; + snapc->seq = le64_to_cpu(ondisk->snap_seq); if (snap_count) { + struct rbd_image_snap_ondisk *snaps; u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len); - /* Save a copy of the snapshot names */ + /* We'll keep a copy of the snapshot names... */ - if (snap_names_len > (u64) SIZE_MAX) - return -EIO; - header->snap_names = kmalloc(snap_names_len, GFP_KERNEL); - if (!header->snap_names) + if (snap_names_len > (u64)SIZE_MAX) + goto out_2big; + snap_names = kmalloc(snap_names_len, GFP_KERNEL); + if (!snap_names) goto out_err; + + /* ...as well as the array of their sizes. */ + + size = snap_count * sizeof (*header->snap_sizes); + snap_sizes = kmalloc(size, GFP_KERNEL); + if (!snap_sizes) + goto out_err; + /* - * Note that rbd_dev_v1_header_read() guarantees - * the ondisk buffer we're working with has + * Copy the names, and fill in each snapshot's id + * and size. + * + * Note that rbd_dev_v1_header_info() guarantees the + * ondisk buffer we're working with has * snap_names_len bytes beyond the end of the * snapshot id array, this memcpy() is safe. */ - memcpy(header->snap_names, &ondisk->snaps[snap_count], - snap_names_len); + memcpy(snap_names, &ondisk->snaps[snap_count], snap_names_len); + snaps = ondisk->snaps; + for (i = 0; i < snap_count; i++) { + snapc->snaps[i] = le64_to_cpu(snaps[i].id); + snap_sizes[i] = le64_to_cpu(snaps[i].image_size); + } + } - /* Record each snapshot's size */ + /* We won't fail any more, fill in the header */ - size = snap_count * sizeof (*header->snap_sizes); - header->snap_sizes = kmalloc(size, GFP_KERNEL); - if (!header->snap_sizes) - goto out_err; - for (i = 0; i < snap_count; i++) - header->snap_sizes[i] = - le64_to_cpu(ondisk->snaps[i].image_size); + down_write(&rbd_dev->header_rwsem); + if (first_time) { + header->object_prefix = object_prefix; + header->obj_order = ondisk->options.order; + header->crypt_type = ondisk->options.crypt_type; + header->comp_type = ondisk->options.comp_type; + /* The rest aren't used for format 1 images */ + header->stripe_unit = 0; + header->stripe_count = 0; + header->features = 0; } else { - header->snap_names = NULL; - header->snap_sizes = NULL; + ceph_put_snap_context(header->snapc); + kfree(header->snap_names); + kfree(header->snap_sizes); } - header->features = 0; /* No features support in v1 images */ - header->obj_order = ondisk->options.order; - header->crypt_type = ondisk->options.crypt_type; - header->comp_type = ondisk->options.comp_type; - - /* Allocate and fill in the snapshot context */ + /* The remaining fields always get updated (when we refresh) */ header->image_size = le64_to_cpu(ondisk->image_size); + header->snapc = snapc; + header->snap_names = snap_names; + header->snap_sizes = snap_sizes; - header->snapc = ceph_create_snap_context(snap_count, GFP_KERNEL); - if (!header->snapc) - goto out_err; - header->snapc->seq = le64_to_cpu(ondisk->snap_seq); - for (i = 0; i < snap_count; i++) - header->snapc->snaps[i] = le64_to_cpu(ondisk->snaps[i].id); + /* Make sure mapping size is consistent with header info */ - return 0; + if (rbd_dev->spec->snap_id == CEPH_NOSNAP || first_time) + if (rbd_dev->mapping.size != header->image_size) + rbd_dev->mapping.size = header->image_size; + + up_write(&rbd_dev->header_rwsem); + return 0; +out_2big: + ret = -EIO; out_err: - kfree(header->snap_sizes); - header->snap_sizes = NULL; - kfree(header->snap_names); - header->snap_names = NULL; - kfree(header->object_prefix); - header->object_prefix = NULL; + kfree(snap_sizes); + kfree(snap_names); + ceph_put_snap_context(snapc); + kfree(object_prefix); - return -ENOMEM; + return ret; } static const char *_rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u32 which) @@ -934,20 +1006,11 @@ static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id, static int rbd_dev_mapping_set(struct rbd_device *rbd_dev) { - const char *snap_name = rbd_dev->spec->snap_name; - u64 snap_id; + u64 snap_id = rbd_dev->spec->snap_id; u64 size = 0; u64 features = 0; int ret; - if (strcmp(snap_name, RBD_SNAP_HEAD_NAME)) { - snap_id = rbd_snap_id_by_name(rbd_dev, snap_name); - if (snap_id == CEPH_NOSNAP) - return -ENOENT; - } else { - snap_id = CEPH_NOSNAP; - } - ret = rbd_snap_size(rbd_dev, snap_id, &size); if (ret) return ret; @@ -958,11 +1021,6 @@ static int rbd_dev_mapping_set(struct rbd_device *rbd_dev) rbd_dev->mapping.size = size; rbd_dev->mapping.features = features; - /* If we are mapping a snapshot it must be marked read-only */ - - if (snap_id != CEPH_NOSNAP) - rbd_dev->mapping.read_only = true; - return 0; } @@ -970,14 +1028,6 @@ static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev) { rbd_dev->mapping.size = 0; rbd_dev->mapping.features = 0; - rbd_dev->mapping.read_only = true; -} - -static void rbd_dev_clear_mapping(struct rbd_device *rbd_dev) -{ - rbd_dev->mapping.size = 0; - rbd_dev->mapping.features = 0; - rbd_dev->mapping.read_only = true; } static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset) @@ -1342,20 +1392,18 @@ static void rbd_obj_request_put(struct rbd_obj_request *obj_request) kref_put(&obj_request->kref, rbd_obj_request_destroy); } -static void rbd_img_request_get(struct rbd_img_request *img_request) -{ - dout("%s: img %p (was %d)\n", __func__, img_request, - atomic_read(&img_request->kref.refcount)); - kref_get(&img_request->kref); -} - +static bool img_request_child_test(struct rbd_img_request *img_request); +static void rbd_parent_request_destroy(struct kref *kref); static void rbd_img_request_destroy(struct kref *kref); static void rbd_img_request_put(struct rbd_img_request *img_request) { rbd_assert(img_request != NULL); dout("%s: img %p (was %d)\n", __func__, img_request, atomic_read(&img_request->kref.refcount)); - kref_put(&img_request->kref, rbd_img_request_destroy); + if (img_request_child_test(img_request)) + kref_put(&img_request->kref, rbd_parent_request_destroy); + else + kref_put(&img_request->kref, rbd_img_request_destroy); } static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request, @@ -1472,6 +1520,12 @@ static void img_request_child_set(struct rbd_img_request *img_request) smp_mb(); } +static void img_request_child_clear(struct rbd_img_request *img_request) +{ + clear_bit(IMG_REQ_CHILD, &img_request->flags); + smp_mb(); +} + static bool img_request_child_test(struct rbd_img_request *img_request) { smp_mb(); @@ -1484,6 +1538,12 @@ static void img_request_layered_set(struct rbd_img_request *img_request) smp_mb(); } +static void img_request_layered_clear(struct rbd_img_request *img_request) +{ + clear_bit(IMG_REQ_LAYERED, &img_request->flags); + smp_mb(); +} + static bool img_request_layered_test(struct rbd_img_request *img_request) { smp_mb(); @@ -1827,6 +1887,74 @@ static void rbd_obj_request_destroy(struct kref *kref) kmem_cache_free(rbd_obj_request_cache, obj_request); } +/* It's OK to call this for a device with no parent */ + +static void rbd_spec_put(struct rbd_spec *spec); +static void rbd_dev_unparent(struct rbd_device *rbd_dev) +{ + rbd_dev_remove_parent(rbd_dev); + rbd_spec_put(rbd_dev->parent_spec); + rbd_dev->parent_spec = NULL; + rbd_dev->parent_overlap = 0; +} + +/* + * Parent image reference counting is used to determine when an + * image's parent fields can be safely torn down--after there are no + * more in-flight requests to the parent image. When the last + * reference is dropped, cleaning them up is safe. + */ +static void rbd_dev_parent_put(struct rbd_device *rbd_dev) +{ + int counter; + + if (!rbd_dev->parent_spec) + return; + + counter = atomic_dec_return_safe(&rbd_dev->parent_ref); + if (counter > 0) + return; + + /* Last reference; clean up parent data structures */ + + if (!counter) + rbd_dev_unparent(rbd_dev); + else + rbd_warn(rbd_dev, "parent reference underflow\n"); +} + +/* + * If an image has a non-zero parent overlap, get a reference to its + * parent. + * + * We must get the reference before checking for the overlap to + * coordinate properly with zeroing the parent overlap in + * rbd_dev_v2_parent_info() when an image gets flattened. We + * drop it again if there is no overlap. + * + * Returns true if the rbd device has a parent with a non-zero + * overlap and a reference for it was successfully taken, or + * false otherwise. + */ +static bool rbd_dev_parent_get(struct rbd_device *rbd_dev) +{ + int counter; + + if (!rbd_dev->parent_spec) + return false; + + counter = atomic_inc_return_safe(&rbd_dev->parent_ref); + if (counter > 0 && rbd_dev->parent_overlap) + return true; + + /* Image was flattened, but parent is not yet torn down */ + + if (counter < 0) + rbd_warn(rbd_dev, "parent reference overflow\n"); + + return false; +} + /* * Caller is responsible for filling in the list of object requests * that comprises the image request, and the Linux request pointer @@ -1835,8 +1963,7 @@ static void rbd_obj_request_destroy(struct kref *kref) static struct rbd_img_request *rbd_img_request_create( struct rbd_device *rbd_dev, u64 offset, u64 length, - bool write_request, - bool child_request) + bool write_request) { struct rbd_img_request *img_request; @@ -1861,9 +1988,7 @@ static struct rbd_img_request *rbd_img_request_create( } else { img_request->snap_id = rbd_dev->spec->snap_id; } - if (child_request) - img_request_child_set(img_request); - if (rbd_dev->parent_spec) + if (rbd_dev_parent_get(rbd_dev)) img_request_layered_set(img_request); spin_lock_init(&img_request->completion_lock); img_request->next_completion = 0; @@ -1873,9 +1998,6 @@ static struct rbd_img_request *rbd_img_request_create( INIT_LIST_HEAD(&img_request->obj_requests); kref_init(&img_request->kref); - rbd_img_request_get(img_request); /* Avoid a warning */ - rbd_img_request_put(img_request); /* TEMPORARY */ - dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev, write_request ? "write" : "read", offset, length, img_request); @@ -1897,15 +2019,54 @@ static void rbd_img_request_destroy(struct kref *kref) rbd_img_obj_request_del(img_request, obj_request); rbd_assert(img_request->obj_request_count == 0); + if (img_request_layered_test(img_request)) { + img_request_layered_clear(img_request); + rbd_dev_parent_put(img_request->rbd_dev); + } + if (img_request_write_test(img_request)) ceph_put_snap_context(img_request->snapc); - if (img_request_child_test(img_request)) - rbd_obj_request_put(img_request->obj_request); - kmem_cache_free(rbd_img_request_cache, img_request); } +static struct rbd_img_request *rbd_parent_request_create( + struct rbd_obj_request *obj_request, + u64 img_offset, u64 length) +{ + struct rbd_img_request *parent_request; + struct rbd_device *rbd_dev; + + rbd_assert(obj_request->img_request); + rbd_dev = obj_request->img_request->rbd_dev; + + parent_request = rbd_img_request_create(rbd_dev->parent, + img_offset, length, false); + if (!parent_request) + return NULL; + + img_request_child_set(parent_request); + rbd_obj_request_get(obj_request); + parent_request->obj_request = obj_request; + + return parent_request; +} + +static void rbd_parent_request_destroy(struct kref *kref) +{ + struct rbd_img_request *parent_request; + struct rbd_obj_request *orig_request; + + parent_request = container_of(kref, struct rbd_img_request, kref); + orig_request = parent_request->obj_request; + + parent_request->obj_request = NULL; + rbd_obj_request_put(orig_request); + img_request_child_clear(parent_request); + + rbd_img_request_destroy(kref); +} + static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request) { struct rbd_img_request *img_request; @@ -2114,7 +2275,7 @@ rbd_img_obj_copyup_callback(struct rbd_obj_request *obj_request) { struct rbd_img_request *img_request; struct rbd_device *rbd_dev; - u64 length; + struct page **pages; u32 page_count; rbd_assert(obj_request->type == OBJ_REQUEST_BIO); @@ -2124,12 +2285,14 @@ rbd_img_obj_copyup_callback(struct rbd_obj_request *obj_request) rbd_dev = img_request->rbd_dev; rbd_assert(rbd_dev); - length = (u64)1 << rbd_dev->header.obj_order; - page_count = (u32)calc_pages_for(0, length); - rbd_assert(obj_request->copyup_pages); - ceph_release_page_vector(obj_request->copyup_pages, page_count); + pages = obj_request->copyup_pages; + rbd_assert(pages != NULL); obj_request->copyup_pages = NULL; + page_count = obj_request->copyup_page_count; + rbd_assert(page_count); + obj_request->copyup_page_count = 0; + ceph_release_page_vector(pages, page_count); /* * We want the transfer count to reflect the size of the @@ -2153,9 +2316,11 @@ rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request) struct ceph_osd_client *osdc; struct rbd_device *rbd_dev; struct page **pages; - int result; - u64 obj_size; - u64 xferred; + u32 page_count; + int img_result; + u64 parent_length; + u64 offset; + u64 length; rbd_assert(img_request_child_test(img_request)); @@ -2164,46 +2329,74 @@ rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request) pages = img_request->copyup_pages; rbd_assert(pages != NULL); img_request->copyup_pages = NULL; + page_count = img_request->copyup_page_count; + rbd_assert(page_count); + img_request->copyup_page_count = 0; orig_request = img_request->obj_request; rbd_assert(orig_request != NULL); - rbd_assert(orig_request->type == OBJ_REQUEST_BIO); - result = img_request->result; - obj_size = img_request->length; - xferred = img_request->xferred; + rbd_assert(obj_request_type_valid(orig_request->type)); + img_result = img_request->result; + parent_length = img_request->length; + rbd_assert(parent_length == img_request->xferred); + rbd_img_request_put(img_request); - rbd_dev = img_request->rbd_dev; + rbd_assert(orig_request->img_request); + rbd_dev = orig_request->img_request->rbd_dev; rbd_assert(rbd_dev); - rbd_assert(obj_size == (u64)1 << rbd_dev->header.obj_order); - rbd_img_request_put(img_request); + /* + * If the overlap has become 0 (most likely because the + * image has been flattened) we need to free the pages + * and re-submit the original write request. + */ + if (!rbd_dev->parent_overlap) { + struct ceph_osd_client *osdc; - if (result) - goto out_err; + ceph_release_page_vector(pages, page_count); + osdc = &rbd_dev->rbd_client->client->osdc; + img_result = rbd_obj_request_submit(osdc, orig_request); + if (!img_result) + return; + } - /* Allocate the new copyup osd request for the original request */ + if (img_result) + goto out_err; - result = -ENOMEM; - rbd_assert(!orig_request->osd_req); + /* + * The original osd request is of no use to use any more. + * We need a new one that can hold the two ops in a copyup + * request. Allocate the new copyup osd request for the + * original request, and release the old one. + */ + img_result = -ENOMEM; osd_req = rbd_osd_req_create_copyup(orig_request); if (!osd_req) goto out_err; + rbd_osd_req_destroy(orig_request->osd_req); orig_request->osd_req = osd_req; orig_request->copyup_pages = pages; + orig_request->copyup_page_count = page_count; /* Initialize the copyup op */ osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup"); - osd_req_op_cls_request_data_pages(osd_req, 0, pages, obj_size, 0, + osd_req_op_cls_request_data_pages(osd_req, 0, pages, parent_length, 0, false, false); /* Then the original write request op */ + offset = orig_request->offset; + length = orig_request->length; osd_req_op_extent_init(osd_req, 1, CEPH_OSD_OP_WRITE, - orig_request->offset, - orig_request->length, 0, 0); - osd_req_op_extent_osd_data_bio(osd_req, 1, orig_request->bio_list, - orig_request->length); + offset, length, 0, 0); + if (orig_request->type == OBJ_REQUEST_BIO) + osd_req_op_extent_osd_data_bio(osd_req, 1, + orig_request->bio_list, length); + else + osd_req_op_extent_osd_data_pages(osd_req, 1, + orig_request->pages, length, + offset & ~PAGE_MASK, false, false); rbd_osd_req_format_write(orig_request); @@ -2211,13 +2404,13 @@ rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request) orig_request->callback = rbd_img_obj_copyup_callback; osdc = &rbd_dev->rbd_client->client->osdc; - result = rbd_obj_request_submit(osdc, orig_request); - if (!result) + img_result = rbd_obj_request_submit(osdc, orig_request); + if (!img_result) return; out_err: /* Record the error code and complete the request */ - orig_request->result = result; + orig_request->result = img_result; orig_request->xferred = 0; obj_request_done_set(orig_request); rbd_obj_request_complete(orig_request); @@ -2249,7 +2442,7 @@ static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request) int result; rbd_assert(obj_request_img_data_test(obj_request)); - rbd_assert(obj_request->type == OBJ_REQUEST_BIO); + rbd_assert(obj_request_type_valid(obj_request->type)); img_request = obj_request->img_request; rbd_assert(img_request != NULL); @@ -2257,15 +2450,6 @@ static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request) rbd_assert(rbd_dev->parent != NULL); /* - * First things first. The original osd request is of no - * use to use any more, we'll need a new one that can hold - * the two ops in a copyup request. We'll get that later, - * but for now we can release the old one. - */ - rbd_osd_req_destroy(obj_request->osd_req); - obj_request->osd_req = NULL; - - /* * Determine the byte range covered by the object in the * child image to which the original request was to be sent. */ @@ -2295,18 +2479,16 @@ static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request) } result = -ENOMEM; - parent_request = rbd_img_request_create(rbd_dev->parent, - img_offset, length, - false, true); + parent_request = rbd_parent_request_create(obj_request, + img_offset, length); if (!parent_request) goto out_err; - rbd_obj_request_get(obj_request); - parent_request->obj_request = obj_request; result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages); if (result) goto out_err; parent_request->copyup_pages = pages; + parent_request->copyup_page_count = page_count; parent_request->callback = rbd_img_obj_parent_read_full_callback; result = rbd_img_request_submit(parent_request); @@ -2314,6 +2496,7 @@ static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request) return 0; parent_request->copyup_pages = NULL; + parent_request->copyup_page_count = 0; parent_request->obj_request = NULL; rbd_obj_request_put(obj_request); out_err: @@ -2331,6 +2514,7 @@ out_err: static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request) { struct rbd_obj_request *orig_request; + struct rbd_device *rbd_dev; int result; rbd_assert(!obj_request_img_data_test(obj_request)); @@ -2353,8 +2537,21 @@ static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request) obj_request->xferred, obj_request->length); rbd_obj_request_put(obj_request); - rbd_assert(orig_request); - rbd_assert(orig_request->img_request); + /* + * If the overlap has become 0 (most likely because the + * image has been flattened) we need to free the pages + * and re-submit the original write request. + */ + rbd_dev = orig_request->img_request->rbd_dev; + if (!rbd_dev->parent_overlap) { + struct ceph_osd_client *osdc; + + rbd_obj_request_put(orig_request); + osdc = &rbd_dev->rbd_client->client->osdc; + result = rbd_obj_request_submit(osdc, orig_request); + if (!result) + return; + } /* * Our only purpose here is to determine whether the object @@ -2512,14 +2709,36 @@ static void rbd_img_parent_read_callback(struct rbd_img_request *img_request) struct rbd_obj_request *obj_request; struct rbd_device *rbd_dev; u64 obj_end; + u64 img_xferred; + int img_result; rbd_assert(img_request_child_test(img_request)); + /* First get what we need from the image request and release it */ + obj_request = img_request->obj_request; + img_xferred = img_request->xferred; + img_result = img_request->result; + rbd_img_request_put(img_request); + + /* + * If the overlap has become 0 (most likely because the + * image has been flattened) we need to re-submit the + * original request. + */ rbd_assert(obj_request); rbd_assert(obj_request->img_request); + rbd_dev = obj_request->img_request->rbd_dev; + if (!rbd_dev->parent_overlap) { + struct ceph_osd_client *osdc; + + osdc = &rbd_dev->rbd_client->client->osdc; + img_result = rbd_obj_request_submit(osdc, obj_request); + if (!img_result) + return; + } - obj_request->result = img_request->result; + obj_request->result = img_result; if (obj_request->result) goto out; @@ -2532,7 +2751,6 @@ static void rbd_img_parent_read_callback(struct rbd_img_request *img_request) */ rbd_assert(obj_request->img_offset < U64_MAX - obj_request->length); obj_end = obj_request->img_offset + obj_request->length; - rbd_dev = obj_request->img_request->rbd_dev; if (obj_end > rbd_dev->parent_overlap) { u64 xferred = 0; @@ -2540,43 +2758,39 @@ static void rbd_img_parent_read_callback(struct rbd_img_request *img_request) xferred = rbd_dev->parent_overlap - obj_request->img_offset; - obj_request->xferred = min(img_request->xferred, xferred); + obj_request->xferred = min(img_xferred, xferred); } else { - obj_request->xferred = img_request->xferred; + obj_request->xferred = img_xferred; } out: - rbd_img_request_put(img_request); rbd_img_obj_request_read_callback(obj_request); rbd_obj_request_complete(obj_request); } static void rbd_img_parent_read(struct rbd_obj_request *obj_request) { - struct rbd_device *rbd_dev; struct rbd_img_request *img_request; int result; rbd_assert(obj_request_img_data_test(obj_request)); rbd_assert(obj_request->img_request != NULL); rbd_assert(obj_request->result == (s32) -ENOENT); - rbd_assert(obj_request->type == OBJ_REQUEST_BIO); + rbd_assert(obj_request_type_valid(obj_request->type)); - rbd_dev = obj_request->img_request->rbd_dev; - rbd_assert(rbd_dev->parent != NULL); /* rbd_read_finish(obj_request, obj_request->length); */ - img_request = rbd_img_request_create(rbd_dev->parent, + img_request = rbd_parent_request_create(obj_request, obj_request->img_offset, - obj_request->length, - false, true); + obj_request->length); result = -ENOMEM; if (!img_request) goto out_err; - rbd_obj_request_get(obj_request); - img_request->obj_request = obj_request; - - result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO, - obj_request->bio_list); + if (obj_request->type == OBJ_REQUEST_BIO) + result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO, + obj_request->bio_list); + else + result = rbd_img_request_fill(img_request, OBJ_REQUEST_PAGES, + obj_request->pages); if (result) goto out_err; @@ -2626,6 +2840,7 @@ out: static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data) { struct rbd_device *rbd_dev = (struct rbd_device *)data; + int ret; if (!rbd_dev) return; @@ -2633,7 +2848,9 @@ static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data) dout("%s: \"%s\" notify_id %llu opcode %u\n", __func__, rbd_dev->header_name, (unsigned long long)notify_id, (unsigned int)opcode); - (void)rbd_dev_refresh(rbd_dev); + ret = rbd_dev_refresh(rbd_dev); + if (ret) + rbd_warn(rbd_dev, ": header refresh error (%d)\n", ret); rbd_obj_notify_ack(rbd_dev, notify_id); } @@ -2642,7 +2859,7 @@ static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data) * Request sync osd watch/unwatch. The value of "start" determines * whether a watch request is being initiated or torn down. */ -static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, int start) +static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, bool start) { struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc; struct rbd_obj_request *obj_request; @@ -2676,7 +2893,7 @@ static int rbd_dev_header_watch_sync(struct rbd_device *rbd_dev, int start) rbd_dev->watch_request->osd_req); osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_WATCH, - rbd_dev->watch_event->cookie, 0, start); + rbd_dev->watch_event->cookie, 0, start ? 1 : 0); rbd_osd_req_format_write(obj_request); ret = rbd_obj_request_submit(osdc, obj_request); @@ -2869,9 +3086,16 @@ static void rbd_request_fn(struct request_queue *q) goto end_request; /* Shouldn't happen */ } + result = -EIO; + if (offset + length > rbd_dev->mapping.size) { + rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)\n", + offset, length, rbd_dev->mapping.size); + goto end_request; + } + result = -ENOMEM; img_request = rbd_img_request_create(rbd_dev, offset, length, - write_request, false); + write_request); if (!img_request) goto end_request; @@ -3022,17 +3246,11 @@ out: } /* - * Read the complete header for the given rbd device. - * - * Returns a pointer to a dynamically-allocated buffer containing - * the complete and validated header. Caller can pass the address - * of a variable that will be filled in with the version of the - * header object at the time it was read. - * - * Returns a pointer-coded errno if a failure occurs. + * Read the complete header for the given rbd device. On successful + * return, the rbd_dev->header field will contain up-to-date + * information about the image. */ -static struct rbd_image_header_ondisk * -rbd_dev_v1_header_read(struct rbd_device *rbd_dev) +static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev) { struct rbd_image_header_ondisk *ondisk = NULL; u32 snap_count = 0; @@ -3057,22 +3275,22 @@ rbd_dev_v1_header_read(struct rbd_device *rbd_dev) size += names_size; ondisk = kmalloc(size, GFP_KERNEL); if (!ondisk) - return ERR_PTR(-ENOMEM); + return -ENOMEM; ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_name, 0, size, ondisk); if (ret < 0) - goto out_err; + goto out; if ((size_t)ret < size) { ret = -ENXIO; rbd_warn(rbd_dev, "short header read (want %zd got %d)", size, ret); - goto out_err; + goto out; } if (!rbd_dev_ondisk_valid(ondisk)) { ret = -ENXIO; rbd_warn(rbd_dev, "invalid header"); - goto out_err; + goto out; } names_size = le64_to_cpu(ondisk->snap_names_len); @@ -3080,85 +3298,13 @@ rbd_dev_v1_header_read(struct rbd_device *rbd_dev) snap_count = le32_to_cpu(ondisk->snap_count); } while (snap_count != want_count); - return ondisk; - -out_err: - kfree(ondisk); - - return ERR_PTR(ret); -} - -/* - * reload the ondisk the header - */ -static int rbd_read_header(struct rbd_device *rbd_dev, - struct rbd_image_header *header) -{ - struct rbd_image_header_ondisk *ondisk; - int ret; - - ondisk = rbd_dev_v1_header_read(rbd_dev); - if (IS_ERR(ondisk)) - return PTR_ERR(ondisk); - ret = rbd_header_from_disk(header, ondisk); + ret = rbd_header_from_disk(rbd_dev, ondisk); +out: kfree(ondisk); return ret; } -static void rbd_update_mapping_size(struct rbd_device *rbd_dev) -{ - if (rbd_dev->spec->snap_id != CEPH_NOSNAP) - return; - - if (rbd_dev->mapping.size != rbd_dev->header.image_size) { - sector_t size; - - rbd_dev->mapping.size = rbd_dev->header.image_size; - size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE; - dout("setting size to %llu sectors", (unsigned long long)size); - set_capacity(rbd_dev->disk, size); - } -} - -/* - * only read the first part of the ondisk header, without the snaps info - */ -static int rbd_dev_v1_refresh(struct rbd_device *rbd_dev) -{ - int ret; - struct rbd_image_header h; - - ret = rbd_read_header(rbd_dev, &h); - if (ret < 0) - return ret; - - down_write(&rbd_dev->header_rwsem); - - /* Update image size, and check for resize of mapped image */ - rbd_dev->header.image_size = h.image_size; - rbd_update_mapping_size(rbd_dev); - - /* rbd_dev->header.object_prefix shouldn't change */ - kfree(rbd_dev->header.snap_sizes); - kfree(rbd_dev->header.snap_names); - /* osd requests may still refer to snapc */ - ceph_put_snap_context(rbd_dev->header.snapc); - - rbd_dev->header.image_size = h.image_size; - rbd_dev->header.snapc = h.snapc; - rbd_dev->header.snap_names = h.snap_names; - rbd_dev->header.snap_sizes = h.snap_sizes; - /* Free the extra copy of the object prefix */ - if (strcmp(rbd_dev->header.object_prefix, h.object_prefix)) - rbd_warn(rbd_dev, "object prefix changed (ignoring)"); - kfree(h.object_prefix); - - up_write(&rbd_dev->header_rwsem); - - return ret; -} - /* * Clear the rbd device's EXISTS flag if the snapshot it's mapped to * has disappeared from the (just updated) snapshot context. @@ -3180,26 +3326,29 @@ static void rbd_exists_validate(struct rbd_device *rbd_dev) static int rbd_dev_refresh(struct rbd_device *rbd_dev) { - u64 image_size; + u64 mapping_size; int ret; rbd_assert(rbd_image_format_valid(rbd_dev->image_format)); - image_size = rbd_dev->header.image_size; + mapping_size = rbd_dev->mapping.size; mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING); if (rbd_dev->image_format == 1) - ret = rbd_dev_v1_refresh(rbd_dev); + ret = rbd_dev_v1_header_info(rbd_dev); else - ret = rbd_dev_v2_refresh(rbd_dev); + ret = rbd_dev_v2_header_info(rbd_dev); /* If it's a mapped snapshot, validate its EXISTS flag */ rbd_exists_validate(rbd_dev); mutex_unlock(&ctl_mutex); - if (ret) - rbd_warn(rbd_dev, "got notification but failed to " - " update snaps: %d\n", ret); - if (image_size != rbd_dev->header.image_size) + if (mapping_size != rbd_dev->mapping.size) { + sector_t size; + + size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE; + dout("setting size to %llu sectors", (unsigned long long)size); + set_capacity(rbd_dev->disk, size); revalidate_disk(rbd_dev->disk); + } return ret; } @@ -3403,6 +3552,8 @@ static ssize_t rbd_image_refresh(struct device *dev, int ret; ret = rbd_dev_refresh(rbd_dev); + if (ret) + rbd_warn(rbd_dev, ": manual header refresh error (%d)\n", ret); return ret < 0 ? ret : size; } @@ -3501,6 +3652,7 @@ static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc, spin_lock_init(&rbd_dev->lock); rbd_dev->flags = 0; + atomic_set(&rbd_dev->parent_ref, 0); INIT_LIST_HEAD(&rbd_dev->node); init_rwsem(&rbd_dev->header_rwsem); @@ -3650,6 +3802,7 @@ static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev) __le64 snapid; void *p; void *end; + u64 pool_id; char *image_id; u64 overlap; int ret; @@ -3680,18 +3833,37 @@ static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev) p = reply_buf; end = reply_buf + ret; ret = -ERANGE; - ceph_decode_64_safe(&p, end, parent_spec->pool_id, out_err); - if (parent_spec->pool_id == CEPH_NOPOOL) + ceph_decode_64_safe(&p, end, pool_id, out_err); + if (pool_id == CEPH_NOPOOL) { + /* + * Either the parent never existed, or we have + * record of it but the image got flattened so it no + * longer has a parent. When the parent of a + * layered image disappears we immediately set the + * overlap to 0. The effect of this is that all new + * requests will be treated as if the image had no + * parent. + */ + if (rbd_dev->parent_overlap) { + rbd_dev->parent_overlap = 0; + smp_mb(); + rbd_dev_parent_put(rbd_dev); + pr_info("%s: clone image has been flattened\n", + rbd_dev->disk->disk_name); + } + goto out; /* No parent? No problem. */ + } /* The ceph file layout needs to fit pool id in 32 bits */ ret = -EIO; - if (parent_spec->pool_id > (u64)U32_MAX) { + if (pool_id > (u64)U32_MAX) { rbd_warn(NULL, "parent pool id too large (%llu > %u)\n", - (unsigned long long)parent_spec->pool_id, U32_MAX); + (unsigned long long)pool_id, U32_MAX); goto out_err; } + parent_spec->pool_id = pool_id; image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL); if (IS_ERR(image_id)) { @@ -3702,9 +3874,14 @@ static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev) ceph_decode_64_safe(&p, end, parent_spec->snap_id, out_err); ceph_decode_64_safe(&p, end, overlap, out_err); - rbd_dev->parent_overlap = overlap; - rbd_dev->parent_spec = parent_spec; - parent_spec = NULL; /* rbd_dev now owns this */ + if (overlap) { + rbd_spec_put(rbd_dev->parent_spec); + rbd_dev->parent_spec = parent_spec; + parent_spec = NULL; /* rbd_dev now owns this */ + rbd_dev->parent_overlap = overlap; + } else { + rbd_warn(rbd_dev, "ignoring parent of clone with overlap 0\n"); + } out: ret = 0; out_err: @@ -4002,6 +4179,7 @@ static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev) for (i = 0; i < snap_count; i++) snapc->snaps[i] = ceph_decode_64(&p); + ceph_put_snap_context(rbd_dev->header.snapc); rbd_dev->header.snapc = snapc; dout(" snap context seq = %llu, snap_count = %u\n", @@ -4053,21 +4231,56 @@ out: return snap_name; } -static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev) +static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev) { + bool first_time = rbd_dev->header.object_prefix == NULL; int ret; down_write(&rbd_dev->header_rwsem); + if (first_time) { + ret = rbd_dev_v2_header_onetime(rbd_dev); + if (ret) + goto out; + } + + /* + * If the image supports layering, get the parent info. We + * need to probe the first time regardless. Thereafter we + * only need to if there's a parent, to see if it has + * disappeared due to the mapped image getting flattened. + */ + if (rbd_dev->header.features & RBD_FEATURE_LAYERING && + (first_time || rbd_dev->parent_spec)) { + bool warn; + + ret = rbd_dev_v2_parent_info(rbd_dev); + if (ret) + goto out; + + /* + * Print a warning if this is the initial probe and + * the image has a parent. Don't print it if the + * image now being probed is itself a parent. We + * can tell at this point because we won't know its + * pool name yet (just its pool id). + */ + warn = rbd_dev->parent_spec && rbd_dev->spec->pool_name; + if (first_time && warn) + rbd_warn(rbd_dev, "WARNING: kernel layering " + "is EXPERIMENTAL!"); + } + ret = rbd_dev_v2_image_size(rbd_dev); if (ret) goto out; - rbd_update_mapping_size(rbd_dev); + + if (rbd_dev->spec->snap_id == CEPH_NOSNAP) + if (rbd_dev->mapping.size != rbd_dev->header.image_size) + rbd_dev->mapping.size = rbd_dev->header.image_size; ret = rbd_dev_v2_snap_context(rbd_dev); dout("rbd_dev_v2_snap_context returned %d\n", ret); - if (ret) - goto out; out: up_write(&rbd_dev->header_rwsem); @@ -4490,10 +4703,10 @@ static void rbd_dev_unprobe(struct rbd_device *rbd_dev) { struct rbd_image_header *header; - rbd_dev_remove_parent(rbd_dev); - rbd_spec_put(rbd_dev->parent_spec); - rbd_dev->parent_spec = NULL; - rbd_dev->parent_overlap = 0; + /* Drop parent reference unless it's already been done (or none) */ + + if (rbd_dev->parent_overlap) + rbd_dev_parent_put(rbd_dev); /* Free dynamic fields from the header, then zero it out */ @@ -4505,72 +4718,22 @@ static void rbd_dev_unprobe(struct rbd_device *rbd_dev) memset(header, 0, sizeof (*header)); } -static int rbd_dev_v1_probe(struct rbd_device *rbd_dev) +static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev) { int ret; - /* Populate rbd image metadata */ - - ret = rbd_read_header(rbd_dev, &rbd_dev->header); - if (ret < 0) - goto out_err; - - /* Version 1 images have no parent (no layering) */ - - rbd_dev->parent_spec = NULL; - rbd_dev->parent_overlap = 0; - - dout("discovered version 1 image, header name is %s\n", - rbd_dev->header_name); - - return 0; - -out_err: - kfree(rbd_dev->header_name); - rbd_dev->header_name = NULL; - kfree(rbd_dev->spec->image_id); - rbd_dev->spec->image_id = NULL; - - return ret; -} - -static int rbd_dev_v2_probe(struct rbd_device *rbd_dev) -{ - int ret; - - ret = rbd_dev_v2_image_size(rbd_dev); - if (ret) - goto out_err; - - /* Get the object prefix (a.k.a. block_name) for the image */ - ret = rbd_dev_v2_object_prefix(rbd_dev); if (ret) goto out_err; - /* Get the and check features for the image */ - + /* + * Get the and check features for the image. Currently the + * features are assumed to never change. + */ ret = rbd_dev_v2_features(rbd_dev); if (ret) goto out_err; - /* If the image supports layering, get the parent info */ - - if (rbd_dev->header.features & RBD_FEATURE_LAYERING) { - ret = rbd_dev_v2_parent_info(rbd_dev); - if (ret) - goto out_err; - - /* - * Don't print a warning for parent images. We can - * tell this point because we won't know its pool - * name yet (just its pool id). - */ - if (rbd_dev->spec->pool_name) - rbd_warn(rbd_dev, "WARNING: kernel layering " - "is EXPERIMENTAL!"); - } - /* If the image supports fancy striping, get its parameters */ if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) { @@ -4578,28 +4741,11 @@ static int rbd_dev_v2_probe(struct rbd_device *rbd_dev) if (ret < 0) goto out_err; } - - /* crypto and compression type aren't (yet) supported for v2 images */ - - rbd_dev->header.crypt_type = 0; - rbd_dev->header.comp_type = 0; - - /* Get the snapshot context, plus the header version */ - - ret = rbd_dev_v2_snap_context(rbd_dev); - if (ret) - goto out_err; - - dout("discovered version 2 image, header name is %s\n", - rbd_dev->header_name); + /* No support for crypto and compression type format 2 images */ return 0; out_err: - rbd_dev->parent_overlap = 0; - rbd_spec_put(rbd_dev->parent_spec); - rbd_dev->parent_spec = NULL; - kfree(rbd_dev->header_name); - rbd_dev->header_name = NULL; + rbd_dev->header.features = 0; kfree(rbd_dev->header.object_prefix); rbd_dev->header.object_prefix = NULL; @@ -4628,15 +4774,16 @@ static int rbd_dev_probe_parent(struct rbd_device *rbd_dev) if (!parent) goto out_err; - ret = rbd_dev_image_probe(parent); + ret = rbd_dev_image_probe(parent, false); if (ret < 0) goto out_err; rbd_dev->parent = parent; + atomic_set(&rbd_dev->parent_ref, 1); return 0; out_err: if (parent) { - rbd_spec_put(rbd_dev->parent_spec); + rbd_dev_unparent(rbd_dev); kfree(rbd_dev->header_name); rbd_dev_destroy(parent); } else { @@ -4651,10 +4798,6 @@ static int rbd_dev_device_setup(struct rbd_device *rbd_dev) { int ret; - ret = rbd_dev_mapping_set(rbd_dev); - if (ret) - return ret; - /* generate unique id: find highest unique id, add one */ rbd_dev_id_get(rbd_dev); @@ -4676,13 +4819,17 @@ static int rbd_dev_device_setup(struct rbd_device *rbd_dev) if (ret) goto err_out_blkdev; - ret = rbd_bus_add_dev(rbd_dev); + ret = rbd_dev_mapping_set(rbd_dev); if (ret) goto err_out_disk; + set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE); + + ret = rbd_bus_add_dev(rbd_dev); + if (ret) + goto err_out_mapping; /* Everything's ready. Announce the disk to the world. */ - set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE); set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags); add_disk(rbd_dev->disk); @@ -4691,6 +4838,8 @@ static int rbd_dev_device_setup(struct rbd_device *rbd_dev) return ret; +err_out_mapping: + rbd_dev_mapping_clear(rbd_dev); err_out_disk: rbd_free_disk(rbd_dev); err_out_blkdev: @@ -4731,12 +4880,7 @@ static int rbd_dev_header_name(struct rbd_device *rbd_dev) static void rbd_dev_image_release(struct rbd_device *rbd_dev) { - int ret; - rbd_dev_unprobe(rbd_dev); - ret = rbd_dev_header_watch_sync(rbd_dev, 0); - if (ret) - rbd_warn(rbd_dev, "failed to cancel watch event (%d)\n", ret); kfree(rbd_dev->header_name); rbd_dev->header_name = NULL; rbd_dev->image_format = 0; @@ -4748,10 +4892,11 @@ static void rbd_dev_image_release(struct rbd_device *rbd_dev) /* * Probe for the existence of the header object for the given rbd - * device. For format 2 images this includes determining the image - * id. + * device. If this image is the one being mapped (i.e., not a + * parent), initiate a watch on its header object before using that + * object to get detailed information about the rbd image. */ -static int rbd_dev_image_probe(struct rbd_device *rbd_dev) +static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool mapping) { int ret; int tmp; @@ -4771,14 +4916,16 @@ static int rbd_dev_image_probe(struct rbd_device *rbd_dev) if (ret) goto err_out_format; - ret = rbd_dev_header_watch_sync(rbd_dev, 1); - if (ret) - goto out_header_name; + if (mapping) { + ret = rbd_dev_header_watch_sync(rbd_dev, true); + if (ret) + goto out_header_name; + } if (rbd_dev->image_format == 1) - ret = rbd_dev_v1_probe(rbd_dev); + ret = rbd_dev_v1_header_info(rbd_dev); else - ret = rbd_dev_v2_probe(rbd_dev); + ret = rbd_dev_v2_header_info(rbd_dev); if (ret) goto err_out_watch; @@ -4787,15 +4934,22 @@ static int rbd_dev_image_probe(struct rbd_device *rbd_dev) goto err_out_probe; ret = rbd_dev_probe_parent(rbd_dev); - if (!ret) - return 0; + if (ret) + goto err_out_probe; + + dout("discovered format %u image, header name is %s\n", + rbd_dev->image_format, rbd_dev->header_name); + return 0; err_out_probe: rbd_dev_unprobe(rbd_dev); err_out_watch: - tmp = rbd_dev_header_watch_sync(rbd_dev, 0); - if (tmp) - rbd_warn(rbd_dev, "unable to tear down watch request\n"); + if (mapping) { + tmp = rbd_dev_header_watch_sync(rbd_dev, false); + if (tmp) + rbd_warn(rbd_dev, "unable to tear down " + "watch request (%d)\n", tmp); + } out_header_name: kfree(rbd_dev->header_name); rbd_dev->header_name = NULL; @@ -4819,6 +4973,7 @@ static ssize_t rbd_add(struct bus_type *bus, struct rbd_spec *spec = NULL; struct rbd_client *rbdc; struct ceph_osd_client *osdc; + bool read_only; int rc = -ENOMEM; if (!try_module_get(THIS_MODULE)) @@ -4828,6 +4983,9 @@ static ssize_t rbd_add(struct bus_type *bus, rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec); if (rc < 0) goto err_out_module; + read_only = rbd_opts->read_only; + kfree(rbd_opts); + rbd_opts = NULL; /* done with this */ rbdc = rbd_get_client(ceph_opts); if (IS_ERR(rbdc)) { @@ -4858,14 +5016,16 @@ static ssize_t rbd_add(struct bus_type *bus, rbdc = NULL; /* rbd_dev now owns this */ spec = NULL; /* rbd_dev now owns this */ - rbd_dev->mapping.read_only = rbd_opts->read_only; - kfree(rbd_opts); - rbd_opts = NULL; /* done with this */ - - rc = rbd_dev_image_probe(rbd_dev); + rc = rbd_dev_image_probe(rbd_dev, true); if (rc < 0) goto err_out_rbd_dev; + /* If we are mapping a snapshot it must be marked read-only */ + + if (rbd_dev->spec->snap_id != CEPH_NOSNAP) + read_only = true; + rbd_dev->mapping.read_only = read_only; + rc = rbd_dev_device_setup(rbd_dev); if (!rc) return count; @@ -4911,7 +5071,7 @@ static void rbd_dev_device_release(struct device *dev) rbd_free_disk(rbd_dev); clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags); - rbd_dev_clear_mapping(rbd_dev); + rbd_dev_mapping_clear(rbd_dev); unregister_blkdev(rbd_dev->major, rbd_dev->name); rbd_dev->major = 0; rbd_dev_id_put(rbd_dev); @@ -4978,10 +5138,13 @@ static ssize_t rbd_remove(struct bus_type *bus, spin_unlock_irq(&rbd_dev->lock); if (ret < 0) goto done; - ret = count; rbd_bus_del_dev(rbd_dev); + ret = rbd_dev_header_watch_sync(rbd_dev, false); + if (ret) + rbd_warn(rbd_dev, "failed to cancel watch event (%d)\n", ret); rbd_dev_image_release(rbd_dev); module_put(THIS_MODULE); + ret = count; done: mutex_unlock(&ctl_mutex); |