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-rw-r--r--drivers/block/rbd.c7457
1 files changed, 7457 insertions, 0 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
new file mode 100644
index 0000000000..1e2596c5ef
--- /dev/null
+++ b/drivers/block/rbd.c
@@ -0,0 +1,7457 @@
+
+/*
+ rbd.c -- Export ceph rados objects as a Linux block device
+
+
+ based on drivers/block/osdblk.c:
+
+ Copyright 2009 Red Hat, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; see the file COPYING. If not, write to
+ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+
+
+ For usage instructions, please refer to:
+
+ Documentation/ABI/testing/sysfs-bus-rbd
+
+ */
+
+#include <linux/ceph/libceph.h>
+#include <linux/ceph/osd_client.h>
+#include <linux/ceph/mon_client.h>
+#include <linux/ceph/cls_lock_client.h>
+#include <linux/ceph/striper.h>
+#include <linux/ceph/decode.h>
+#include <linux/fs_parser.h>
+#include <linux/bsearch.h>
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/blk-mq.h>
+#include <linux/fs.h>
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+#include <linux/idr.h>
+#include <linux/workqueue.h>
+
+#include "rbd_types.h"
+
+#define RBD_DEBUG /* Activate rbd_assert() calls */
+
+/*
+ * 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_fetch_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_MINORS_PER_MAJOR 256
+#define RBD_SINGLE_MAJOR_PART_SHIFT 4
+
+#define RBD_MAX_PARENT_CHAIN_LEN 16
+
+#define RBD_SNAP_DEV_NAME_PREFIX "snap_"
+#define RBD_MAX_SNAP_NAME_LEN \
+ (NAME_MAX - (sizeof (RBD_SNAP_DEV_NAME_PREFIX) - 1))
+
+#define RBD_MAX_SNAP_COUNT 510 /* allows max snapc to fit in 4KB */
+
+#define RBD_SNAP_HEAD_NAME "-"
+
+#define BAD_SNAP_INDEX U32_MAX /* invalid index into snap array */
+
+/* This allows a single page to hold an image name sent by OSD */
+#define RBD_IMAGE_NAME_LEN_MAX (PAGE_SIZE - sizeof (__le32) - 1)
+#define RBD_IMAGE_ID_LEN_MAX 64
+
+#define RBD_OBJ_PREFIX_LEN_MAX 64
+
+#define RBD_NOTIFY_TIMEOUT 5 /* seconds */
+#define RBD_RETRY_DELAY msecs_to_jiffies(1000)
+
+/* Feature bits */
+
+#define RBD_FEATURE_LAYERING (1ULL<<0)
+#define RBD_FEATURE_STRIPINGV2 (1ULL<<1)
+#define RBD_FEATURE_EXCLUSIVE_LOCK (1ULL<<2)
+#define RBD_FEATURE_OBJECT_MAP (1ULL<<3)
+#define RBD_FEATURE_FAST_DIFF (1ULL<<4)
+#define RBD_FEATURE_DEEP_FLATTEN (1ULL<<5)
+#define RBD_FEATURE_DATA_POOL (1ULL<<7)
+#define RBD_FEATURE_OPERATIONS (1ULL<<8)
+
+#define RBD_FEATURES_ALL (RBD_FEATURE_LAYERING | \
+ RBD_FEATURE_STRIPINGV2 | \
+ RBD_FEATURE_EXCLUSIVE_LOCK | \
+ RBD_FEATURE_OBJECT_MAP | \
+ RBD_FEATURE_FAST_DIFF | \
+ RBD_FEATURE_DEEP_FLATTEN | \
+ RBD_FEATURE_DATA_POOL | \
+ RBD_FEATURE_OPERATIONS)
+
+/* Features supported by this (client software) implementation. */
+
+#define RBD_FEATURES_SUPPORTED (RBD_FEATURES_ALL)
+
+/*
+ * An RBD device name will be "rbd#", where the "rbd" comes from
+ * RBD_DRV_NAME above, and # is a unique integer identifier.
+ */
+#define DEV_NAME_LEN 32
+
+/*
+ * block device image metadata (in-memory version)
+ */
+struct rbd_image_header {
+ /* These six fields never change for a given rbd image */
+ char *object_prefix;
+ __u8 obj_order;
+ u64 stripe_unit;
+ u64 stripe_count;
+ s64 data_pool_id;
+ 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; /* format 1 only */
+ u64 *snap_sizes; /* format 1 only */
+};
+
+/*
+ * An rbd image specification.
+ *
+ * The tuple (pool_id, image_id, snap_id) is sufficient to uniquely
+ * identify an image. Each rbd_dev structure includes a pointer to
+ * an rbd_spec structure that encapsulates this identity.
+ *
+ * Each of the id's in an rbd_spec has an associated name. For a
+ * user-mapped image, the names are supplied and the id's associated
+ * with them are looked up. For a layered image, a parent image is
+ * defined by the tuple, and the names are looked up.
+ *
+ * An rbd_dev structure contains a parent_spec pointer which is
+ * non-null if the image it represents is a child in a layered
+ * image. This pointer will refer to the rbd_spec structure used
+ * by the parent rbd_dev for its own identity (i.e., the structure
+ * is shared between the parent and child).
+ *
+ * Since these structures are populated once, during the discovery
+ * phase of image construction, they are effectively immutable so
+ * we make no effort to synchronize access to them.
+ *
+ * Note that code herein does not assume the image name is known (it
+ * could be a null pointer).
+ */
+struct rbd_spec {
+ u64 pool_id;
+ const char *pool_name;
+ const char *pool_ns; /* NULL if default, never "" */
+
+ const char *image_id;
+ const char *image_name;
+
+ u64 snap_id;
+ const char *snap_name;
+
+ struct kref kref;
+};
+
+/*
+ * an instance of the client. multiple devices may share an rbd client.
+ */
+struct rbd_client {
+ struct ceph_client *client;
+ struct kref kref;
+ struct list_head node;
+};
+
+struct pending_result {
+ int result; /* first nonzero result */
+ int num_pending;
+};
+
+struct rbd_img_request;
+
+enum obj_request_type {
+ OBJ_REQUEST_NODATA = 1,
+ OBJ_REQUEST_BIO, /* pointer into provided bio (list) */
+ OBJ_REQUEST_BVECS, /* pointer into provided bio_vec array */
+ OBJ_REQUEST_OWN_BVECS, /* private bio_vec array, doesn't own pages */
+};
+
+enum obj_operation_type {
+ OBJ_OP_READ = 1,
+ OBJ_OP_WRITE,
+ OBJ_OP_DISCARD,
+ OBJ_OP_ZEROOUT,
+};
+
+#define RBD_OBJ_FLAG_DELETION (1U << 0)
+#define RBD_OBJ_FLAG_COPYUP_ENABLED (1U << 1)
+#define RBD_OBJ_FLAG_COPYUP_ZEROS (1U << 2)
+#define RBD_OBJ_FLAG_MAY_EXIST (1U << 3)
+#define RBD_OBJ_FLAG_NOOP_FOR_NONEXISTENT (1U << 4)
+
+enum rbd_obj_read_state {
+ RBD_OBJ_READ_START = 1,
+ RBD_OBJ_READ_OBJECT,
+ RBD_OBJ_READ_PARENT,
+};
+
+/*
+ * Writes go through the following state machine to deal with
+ * layering:
+ *
+ * . . . . . RBD_OBJ_WRITE_GUARD. . . . . . . . . . . . . .
+ * . | .
+ * . v .
+ * . RBD_OBJ_WRITE_READ_FROM_PARENT. . . .
+ * . | . .
+ * . v v (deep-copyup .
+ * (image . RBD_OBJ_WRITE_COPYUP_EMPTY_SNAPC . not needed) .
+ * flattened) v | . .
+ * . v . .
+ * . . . .RBD_OBJ_WRITE_COPYUP_OPS. . . . . (copyup .
+ * | not needed) v
+ * v .
+ * done . . . . . . . . . . . . . . . . . .
+ * ^
+ * |
+ * RBD_OBJ_WRITE_FLAT
+ *
+ * Writes start in RBD_OBJ_WRITE_GUARD or _FLAT, depending on whether
+ * assert_exists guard is needed or not (in some cases it's not needed
+ * even if there is a parent).
+ */
+enum rbd_obj_write_state {
+ RBD_OBJ_WRITE_START = 1,
+ RBD_OBJ_WRITE_PRE_OBJECT_MAP,
+ RBD_OBJ_WRITE_OBJECT,
+ __RBD_OBJ_WRITE_COPYUP,
+ RBD_OBJ_WRITE_COPYUP,
+ RBD_OBJ_WRITE_POST_OBJECT_MAP,
+};
+
+enum rbd_obj_copyup_state {
+ RBD_OBJ_COPYUP_START = 1,
+ RBD_OBJ_COPYUP_READ_PARENT,
+ __RBD_OBJ_COPYUP_OBJECT_MAPS,
+ RBD_OBJ_COPYUP_OBJECT_MAPS,
+ __RBD_OBJ_COPYUP_WRITE_OBJECT,
+ RBD_OBJ_COPYUP_WRITE_OBJECT,
+};
+
+struct rbd_obj_request {
+ struct ceph_object_extent ex;
+ unsigned int flags; /* RBD_OBJ_FLAG_* */
+ union {
+ enum rbd_obj_read_state read_state; /* for reads */
+ enum rbd_obj_write_state write_state; /* for writes */
+ };
+
+ struct rbd_img_request *img_request;
+ struct ceph_file_extent *img_extents;
+ u32 num_img_extents;
+
+ union {
+ struct ceph_bio_iter bio_pos;
+ struct {
+ struct ceph_bvec_iter bvec_pos;
+ u32 bvec_count;
+ u32 bvec_idx;
+ };
+ };
+
+ enum rbd_obj_copyup_state copyup_state;
+ struct bio_vec *copyup_bvecs;
+ u32 copyup_bvec_count;
+
+ struct list_head osd_reqs; /* w/ r_private_item */
+
+ struct mutex state_mutex;
+ struct pending_result pending;
+ struct kref kref;
+};
+
+enum img_req_flags {
+ IMG_REQ_CHILD, /* initiator: block = 0, child image = 1 */
+ IMG_REQ_LAYERED, /* ENOENT handling: normal = 0, layered = 1 */
+};
+
+enum rbd_img_state {
+ RBD_IMG_START = 1,
+ RBD_IMG_EXCLUSIVE_LOCK,
+ __RBD_IMG_OBJECT_REQUESTS,
+ RBD_IMG_OBJECT_REQUESTS,
+};
+
+struct rbd_img_request {
+ struct rbd_device *rbd_dev;
+ enum obj_operation_type op_type;
+ enum obj_request_type data_type;
+ unsigned long flags;
+ enum rbd_img_state state;
+ union {
+ u64 snap_id; /* for reads */
+ struct ceph_snap_context *snapc; /* for writes */
+ };
+ struct rbd_obj_request *obj_request; /* obj req initiator */
+
+ struct list_head lock_item;
+ struct list_head object_extents; /* obj_req.ex structs */
+
+ struct mutex state_mutex;
+ struct pending_result pending;
+ struct work_struct work;
+ int work_result;
+};
+
+#define for_each_obj_request(ireq, oreq) \
+ list_for_each_entry(oreq, &(ireq)->object_extents, ex.oe_item)
+#define for_each_obj_request_safe(ireq, oreq, n) \
+ list_for_each_entry_safe(oreq, n, &(ireq)->object_extents, ex.oe_item)
+
+enum rbd_watch_state {
+ RBD_WATCH_STATE_UNREGISTERED,
+ RBD_WATCH_STATE_REGISTERED,
+ RBD_WATCH_STATE_ERROR,
+};
+
+enum rbd_lock_state {
+ RBD_LOCK_STATE_UNLOCKED,
+ RBD_LOCK_STATE_LOCKED,
+ RBD_LOCK_STATE_RELEASING,
+};
+
+/* WatchNotify::ClientId */
+struct rbd_client_id {
+ u64 gid;
+ u64 handle;
+};
+
+struct rbd_mapping {
+ u64 size;
+};
+
+/*
+ * a single device
+ */
+struct rbd_device {
+ int dev_id; /* blkdev unique id */
+
+ int major; /* blkdev assigned major */
+ int minor;
+ struct gendisk *disk; /* blkdev's gendisk and rq */
+
+ u32 image_format; /* Either 1 or 2 */
+ struct rbd_client *rbd_client;
+
+ char name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */
+
+ spinlock_t lock; /* queue, flags, open_count */
+
+ struct rbd_image_header header;
+ unsigned long flags; /* possibly lock protected */
+ struct rbd_spec *spec;
+ struct rbd_options *opts;
+ char *config_info; /* add{,_single_major} string */
+
+ struct ceph_object_id header_oid;
+ struct ceph_object_locator header_oloc;
+
+ struct ceph_file_layout layout; /* used for all rbd requests */
+
+ struct mutex watch_mutex;
+ enum rbd_watch_state watch_state;
+ struct ceph_osd_linger_request *watch_handle;
+ u64 watch_cookie;
+ struct delayed_work watch_dwork;
+
+ struct rw_semaphore lock_rwsem;
+ enum rbd_lock_state lock_state;
+ char lock_cookie[32];
+ struct rbd_client_id owner_cid;
+ struct work_struct acquired_lock_work;
+ struct work_struct released_lock_work;
+ struct delayed_work lock_dwork;
+ struct work_struct unlock_work;
+ spinlock_t lock_lists_lock;
+ struct list_head acquiring_list;
+ struct list_head running_list;
+ struct completion acquire_wait;
+ int acquire_err;
+ struct completion releasing_wait;
+
+ spinlock_t object_map_lock;
+ u8 *object_map;
+ u64 object_map_size; /* in objects */
+ u64 object_map_flags;
+
+ struct workqueue_struct *task_wq;
+
+ struct rbd_spec *parent_spec;
+ u64 parent_overlap;
+ atomic_t parent_ref;
+ struct rbd_device *parent;
+
+ /* Block layer tags. */
+ struct blk_mq_tag_set tag_set;
+
+ /* protects updating the header */
+ struct rw_semaphore header_rwsem;
+
+ struct rbd_mapping mapping;
+
+ struct list_head node;
+
+ /* sysfs related */
+ struct device dev;
+ unsigned long open_count; /* protected by lock */
+};
+
+/*
+ * Flag bits for rbd_dev->flags:
+ * - REMOVING (which is coupled with rbd_dev->open_count) is protected
+ * by rbd_dev->lock
+ */
+enum rbd_dev_flags {
+ RBD_DEV_FLAG_EXISTS, /* rbd_dev_device_setup() ran */
+ RBD_DEV_FLAG_REMOVING, /* this mapping is being removed */
+ RBD_DEV_FLAG_READONLY, /* -o ro or snapshot */
+};
+
+static DEFINE_MUTEX(client_mutex); /* Serialize client creation */
+
+static LIST_HEAD(rbd_dev_list); /* devices */
+static DEFINE_SPINLOCK(rbd_dev_list_lock);
+
+static LIST_HEAD(rbd_client_list); /* clients */
+static DEFINE_SPINLOCK(rbd_client_list_lock);
+
+/* Slab caches for frequently-allocated structures */
+
+static struct kmem_cache *rbd_img_request_cache;
+static struct kmem_cache *rbd_obj_request_cache;
+
+static int rbd_major;
+static DEFINE_IDA(rbd_dev_id_ida);
+
+static struct workqueue_struct *rbd_wq;
+
+static struct ceph_snap_context rbd_empty_snapc = {
+ .nref = REFCOUNT_INIT(1),
+};
+
+/*
+ * single-major requires >= 0.75 version of userspace rbd utility.
+ */
+static bool single_major = true;
+module_param(single_major, bool, 0444);
+MODULE_PARM_DESC(single_major, "Use a single major number for all rbd devices (default: true)");
+
+static ssize_t add_store(const struct bus_type *bus, const char *buf, size_t count);
+static ssize_t remove_store(const struct bus_type *bus, const char *buf,
+ size_t count);
+static ssize_t add_single_major_store(const struct bus_type *bus, const char *buf,
+ size_t count);
+static ssize_t remove_single_major_store(const struct bus_type *bus, const char *buf,
+ size_t count);
+static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth);
+
+static int rbd_dev_id_to_minor(int dev_id)
+{
+ return dev_id << RBD_SINGLE_MAJOR_PART_SHIFT;
+}
+
+static int minor_to_rbd_dev_id(int minor)
+{
+ return minor >> RBD_SINGLE_MAJOR_PART_SHIFT;
+}
+
+static bool rbd_is_ro(struct rbd_device *rbd_dev)
+{
+ return test_bit(RBD_DEV_FLAG_READONLY, &rbd_dev->flags);
+}
+
+static bool rbd_is_snap(struct rbd_device *rbd_dev)
+{
+ return rbd_dev->spec->snap_id != CEPH_NOSNAP;
+}
+
+static bool __rbd_is_lock_owner(struct rbd_device *rbd_dev)
+{
+ lockdep_assert_held(&rbd_dev->lock_rwsem);
+
+ return rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED ||
+ rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING;
+}
+
+static bool rbd_is_lock_owner(struct rbd_device *rbd_dev)
+{
+ bool is_lock_owner;
+
+ down_read(&rbd_dev->lock_rwsem);
+ is_lock_owner = __rbd_is_lock_owner(rbd_dev);
+ up_read(&rbd_dev->lock_rwsem);
+ return is_lock_owner;
+}
+
+static ssize_t supported_features_show(const struct bus_type *bus, char *buf)
+{
+ return sprintf(buf, "0x%llx\n", RBD_FEATURES_SUPPORTED);
+}
+
+static BUS_ATTR_WO(add);
+static BUS_ATTR_WO(remove);
+static BUS_ATTR_WO(add_single_major);
+static BUS_ATTR_WO(remove_single_major);
+static BUS_ATTR_RO(supported_features);
+
+static struct attribute *rbd_bus_attrs[] = {
+ &bus_attr_add.attr,
+ &bus_attr_remove.attr,
+ &bus_attr_add_single_major.attr,
+ &bus_attr_remove_single_major.attr,
+ &bus_attr_supported_features.attr,
+ NULL,
+};
+
+static umode_t rbd_bus_is_visible(struct kobject *kobj,
+ struct attribute *attr, int index)
+{
+ if (!single_major &&
+ (attr == &bus_attr_add_single_major.attr ||
+ attr == &bus_attr_remove_single_major.attr))
+ return 0;
+
+ return attr->mode;
+}
+
+static const struct attribute_group rbd_bus_group = {
+ .attrs = rbd_bus_attrs,
+ .is_visible = rbd_bus_is_visible,
+};
+__ATTRIBUTE_GROUPS(rbd_bus);
+
+static struct bus_type rbd_bus_type = {
+ .name = "rbd",
+ .bus_groups = rbd_bus_groups,
+};
+
+static void rbd_root_dev_release(struct device *dev)
+{
+}
+
+static struct device rbd_root_dev = {
+ .init_name = "rbd",
+ .release = rbd_root_dev_release,
+};
+
+static __printf(2, 3)
+void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
+{
+ struct va_format vaf;
+ va_list args;
+
+ va_start(args, fmt);
+ vaf.fmt = fmt;
+ vaf.va = &args;
+
+ if (!rbd_dev)
+ printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
+ else if (rbd_dev->disk)
+ printk(KERN_WARNING "%s: %s: %pV\n",
+ RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
+ else if (rbd_dev->spec && rbd_dev->spec->image_name)
+ printk(KERN_WARNING "%s: image %s: %pV\n",
+ RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
+ else if (rbd_dev->spec && rbd_dev->spec->image_id)
+ printk(KERN_WARNING "%s: id %s: %pV\n",
+ RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
+ else /* punt */
+ printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
+ RBD_DRV_NAME, rbd_dev, &vaf);
+ va_end(args);
+}
+
+#ifdef RBD_DEBUG
+#define rbd_assert(expr) \
+ if (unlikely(!(expr))) { \
+ printk(KERN_ERR "\nAssertion failure in %s() " \
+ "at line %d:\n\n" \
+ "\trbd_assert(%s);\n\n", \
+ __func__, __LINE__, #expr); \
+ BUG(); \
+ }
+#else /* !RBD_DEBUG */
+# define rbd_assert(expr) ((void) 0)
+#endif /* !RBD_DEBUG */
+
+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_header_onetime(struct rbd_device *rbd_dev,
+ struct rbd_image_header *header);
+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,
+ u8 *order, u64 *snap_size);
+static int rbd_dev_v2_get_flags(struct rbd_device *rbd_dev);
+
+static void rbd_obj_handle_request(struct rbd_obj_request *obj_req, int result);
+static void rbd_img_handle_request(struct rbd_img_request *img_req, int result);
+
+/*
+ * Return true if nothing else is pending.
+ */
+static bool pending_result_dec(struct pending_result *pending, int *result)
+{
+ rbd_assert(pending->num_pending > 0);
+
+ if (*result && !pending->result)
+ pending->result = *result;
+ if (--pending->num_pending)
+ return false;
+
+ *result = pending->result;
+ return true;
+}
+
+static int rbd_open(struct gendisk *disk, blk_mode_t mode)
+{
+ struct rbd_device *rbd_dev = disk->private_data;
+ bool removing = false;
+
+ spin_lock_irq(&rbd_dev->lock);
+ if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
+ removing = true;
+ else
+ rbd_dev->open_count++;
+ spin_unlock_irq(&rbd_dev->lock);
+ if (removing)
+ return -ENOENT;
+
+ (void) get_device(&rbd_dev->dev);
+
+ return 0;
+}
+
+static void rbd_release(struct gendisk *disk)
+{
+ struct rbd_device *rbd_dev = disk->private_data;
+ unsigned long open_count_before;
+
+ spin_lock_irq(&rbd_dev->lock);
+ open_count_before = rbd_dev->open_count--;
+ spin_unlock_irq(&rbd_dev->lock);
+ rbd_assert(open_count_before > 0);
+
+ put_device(&rbd_dev->dev);
+}
+
+static const struct block_device_operations rbd_bd_ops = {
+ .owner = THIS_MODULE,
+ .open = rbd_open,
+ .release = rbd_release,
+};
+
+/*
+ * Initialize an rbd client instance. Success or not, this function
+ * consumes ceph_opts. Caller holds client_mutex.
+ */
+static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
+{
+ struct rbd_client *rbdc;
+ int ret = -ENOMEM;
+
+ dout("%s:\n", __func__);
+ rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
+ if (!rbdc)
+ goto out_opt;
+
+ kref_init(&rbdc->kref);
+ INIT_LIST_HEAD(&rbdc->node);
+
+ rbdc->client = ceph_create_client(ceph_opts, rbdc);
+ if (IS_ERR(rbdc->client))
+ goto out_rbdc;
+ ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
+
+ ret = ceph_open_session(rbdc->client);
+ if (ret < 0)
+ goto out_client;
+
+ spin_lock(&rbd_client_list_lock);
+ list_add_tail(&rbdc->node, &rbd_client_list);
+ spin_unlock(&rbd_client_list_lock);
+
+ dout("%s: rbdc %p\n", __func__, rbdc);
+
+ return rbdc;
+out_client:
+ ceph_destroy_client(rbdc->client);
+out_rbdc:
+ kfree(rbdc);
+out_opt:
+ if (ceph_opts)
+ ceph_destroy_options(ceph_opts);
+ dout("%s: error %d\n", __func__, ret);
+
+ return ERR_PTR(ret);
+}
+
+static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
+{
+ kref_get(&rbdc->kref);
+
+ return rbdc;
+}
+
+/*
+ * Find a ceph client with specific addr and configuration. If
+ * found, bump its reference count.
+ */
+static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
+{
+ struct rbd_client *rbdc = NULL, *iter;
+
+ if (ceph_opts->flags & CEPH_OPT_NOSHARE)
+ return NULL;
+
+ spin_lock(&rbd_client_list_lock);
+ list_for_each_entry(iter, &rbd_client_list, node) {
+ if (!ceph_compare_options(ceph_opts, iter->client)) {
+ __rbd_get_client(iter);
+
+ rbdc = iter;
+ break;
+ }
+ }
+ spin_unlock(&rbd_client_list_lock);
+
+ return rbdc;
+}
+
+/*
+ * (Per device) rbd map options
+ */
+enum {
+ Opt_queue_depth,
+ Opt_alloc_size,
+ Opt_lock_timeout,
+ /* int args above */
+ Opt_pool_ns,
+ Opt_compression_hint,
+ /* string args above */
+ Opt_read_only,
+ Opt_read_write,
+ Opt_lock_on_read,
+ Opt_exclusive,
+ Opt_notrim,
+};
+
+enum {
+ Opt_compression_hint_none,
+ Opt_compression_hint_compressible,
+ Opt_compression_hint_incompressible,
+};
+
+static const struct constant_table rbd_param_compression_hint[] = {
+ {"none", Opt_compression_hint_none},
+ {"compressible", Opt_compression_hint_compressible},
+ {"incompressible", Opt_compression_hint_incompressible},
+ {}
+};
+
+static const struct fs_parameter_spec rbd_parameters[] = {
+ fsparam_u32 ("alloc_size", Opt_alloc_size),
+ fsparam_enum ("compression_hint", Opt_compression_hint,
+ rbd_param_compression_hint),
+ fsparam_flag ("exclusive", Opt_exclusive),
+ fsparam_flag ("lock_on_read", Opt_lock_on_read),
+ fsparam_u32 ("lock_timeout", Opt_lock_timeout),
+ fsparam_flag ("notrim", Opt_notrim),
+ fsparam_string ("_pool_ns", Opt_pool_ns),
+ fsparam_u32 ("queue_depth", Opt_queue_depth),
+ fsparam_flag ("read_only", Opt_read_only),
+ fsparam_flag ("read_write", Opt_read_write),
+ fsparam_flag ("ro", Opt_read_only),
+ fsparam_flag ("rw", Opt_read_write),
+ {}
+};
+
+struct rbd_options {
+ int queue_depth;
+ int alloc_size;
+ unsigned long lock_timeout;
+ bool read_only;
+ bool lock_on_read;
+ bool exclusive;
+ bool trim;
+
+ u32 alloc_hint_flags; /* CEPH_OSD_OP_ALLOC_HINT_FLAG_* */
+};
+
+#define RBD_QUEUE_DEPTH_DEFAULT BLKDEV_DEFAULT_RQ
+#define RBD_ALLOC_SIZE_DEFAULT (64 * 1024)
+#define RBD_LOCK_TIMEOUT_DEFAULT 0 /* no timeout */
+#define RBD_READ_ONLY_DEFAULT false
+#define RBD_LOCK_ON_READ_DEFAULT false
+#define RBD_EXCLUSIVE_DEFAULT false
+#define RBD_TRIM_DEFAULT true
+
+struct rbd_parse_opts_ctx {
+ struct rbd_spec *spec;
+ struct ceph_options *copts;
+ struct rbd_options *opts;
+};
+
+static char* obj_op_name(enum obj_operation_type op_type)
+{
+ switch (op_type) {
+ case OBJ_OP_READ:
+ return "read";
+ case OBJ_OP_WRITE:
+ return "write";
+ case OBJ_OP_DISCARD:
+ return "discard";
+ case OBJ_OP_ZEROOUT:
+ return "zeroout";
+ default:
+ return "???";
+ }
+}
+
+/*
+ * Destroy ceph client
+ *
+ * Caller must hold rbd_client_list_lock.
+ */
+static void rbd_client_release(struct kref *kref)
+{
+ struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref);
+
+ dout("%s: rbdc %p\n", __func__, rbdc);
+ spin_lock(&rbd_client_list_lock);
+ list_del(&rbdc->node);
+ spin_unlock(&rbd_client_list_lock);
+
+ ceph_destroy_client(rbdc->client);
+ kfree(rbdc);
+}
+
+/*
+ * Drop reference to ceph client node. If it's not referenced anymore, release
+ * it.
+ */
+static void rbd_put_client(struct rbd_client *rbdc)
+{
+ if (rbdc)
+ kref_put(&rbdc->kref, rbd_client_release);
+}
+
+/*
+ * Get a ceph client with specific addr and configuration, if one does
+ * not exist create it. Either way, ceph_opts is consumed by this
+ * function.
+ */
+static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
+{
+ struct rbd_client *rbdc;
+ int ret;
+
+ mutex_lock(&client_mutex);
+ rbdc = rbd_client_find(ceph_opts);
+ if (rbdc) {
+ ceph_destroy_options(ceph_opts);
+
+ /*
+ * Using an existing client. Make sure ->pg_pools is up to
+ * date before we look up the pool id in do_rbd_add().
+ */
+ ret = ceph_wait_for_latest_osdmap(rbdc->client,
+ rbdc->client->options->mount_timeout);
+ if (ret) {
+ rbd_warn(NULL, "failed to get latest osdmap: %d", ret);
+ rbd_put_client(rbdc);
+ rbdc = ERR_PTR(ret);
+ }
+ } else {
+ rbdc = rbd_client_create(ceph_opts);
+ }
+ mutex_unlock(&client_mutex);
+
+ return rbdc;
+}
+
+static bool rbd_image_format_valid(u32 image_format)
+{
+ return image_format == 1 || image_format == 2;
+}
+
+static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
+{
+ size_t size;
+ u32 snap_count;
+
+ /* The header has to start with the magic rbd header text */
+ if (memcmp(&ondisk->text, RBD_HEADER_TEXT, sizeof (RBD_HEADER_TEXT)))
+ return false;
+
+ /* The bio layer requires at least sector-sized I/O */
+
+ if (ondisk->options.order < SECTOR_SHIFT)
+ return false;
+
+ /* If we use u64 in a few spots we may be able to loosen this */
+
+ if (ondisk->options.order > 8 * sizeof (int) - 1)
+ return false;
+
+ /*
+ * The size of a snapshot header has to fit in a size_t, and
+ * that limits the number of snapshots.
+ */
+ snap_count = le32_to_cpu(ondisk->snap_count);
+ size = SIZE_MAX - sizeof (struct ceph_snap_context);
+ if (snap_count > size / sizeof (__le64))
+ return false;
+
+ /*
+ * Not only that, but the size of the entire the snapshot
+ * header must also be representable in a size_t.
+ */
+ size -= snap_count * sizeof (__le64);
+ if ((u64) size < le64_to_cpu(ondisk->snap_names_len))
+ return false;
+
+ return true;
+}
+
+/*
+ * returns the size of an object in the image
+ */
+static u32 rbd_obj_bytes(struct rbd_image_header *header)
+{
+ return 1U << header->obj_order;
+}
+
+static void rbd_init_layout(struct rbd_device *rbd_dev)
+{
+ if (rbd_dev->header.stripe_unit == 0 ||
+ rbd_dev->header.stripe_count == 0) {
+ rbd_dev->header.stripe_unit = rbd_obj_bytes(&rbd_dev->header);
+ rbd_dev->header.stripe_count = 1;
+ }
+
+ rbd_dev->layout.stripe_unit = rbd_dev->header.stripe_unit;
+ rbd_dev->layout.stripe_count = rbd_dev->header.stripe_count;
+ rbd_dev->layout.object_size = rbd_obj_bytes(&rbd_dev->header);
+ rbd_dev->layout.pool_id = rbd_dev->header.data_pool_id == CEPH_NOPOOL ?
+ rbd_dev->spec->pool_id : rbd_dev->header.data_pool_id;
+ RCU_INIT_POINTER(rbd_dev->layout.pool_ns, NULL);
+}
+
+static void rbd_image_header_cleanup(struct rbd_image_header *header)
+{
+ kfree(header->object_prefix);
+ ceph_put_snap_context(header->snapc);
+ kfree(header->snap_sizes);
+ kfree(header->snap_names);
+
+ memset(header, 0, sizeof(*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,
+ struct rbd_image_header_ondisk *ondisk,
+ bool first_time)
+{
+ struct ceph_snap_context *snapc;
+ char *object_prefix = NULL;
+ char *snap_names = NULL;
+ u64 *snap_sizes = NULL;
+ u32 snap_count;
+ int ret = -ENOMEM;
+ u32 i;
+
+ /* Allocate this now to avoid having to handle failure below */
+
+ if (first_time) {
+ object_prefix = kstrndup(ondisk->object_prefix,
+ sizeof(ondisk->object_prefix),
+ GFP_KERNEL);
+ if (!object_prefix)
+ return -ENOMEM;
+ }
+
+ /* 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);
+
+ /* We'll keep a copy of the snapshot 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. */
+ snap_sizes = kmalloc_array(snap_count,
+ sizeof(*header->snap_sizes),
+ GFP_KERNEL);
+ if (!snap_sizes)
+ goto out_err;
+
+ /*
+ * 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(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);
+ }
+ }
+
+ /* We won't fail any more, fill in the header */
+
+ if (first_time) {
+ header->object_prefix = object_prefix;
+ header->obj_order = ondisk->options.order;
+ }
+
+ /* 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;
+
+ return 0;
+out_2big:
+ ret = -EIO;
+out_err:
+ kfree(snap_sizes);
+ kfree(snap_names);
+ ceph_put_snap_context(snapc);
+ kfree(object_prefix);
+
+ return ret;
+}
+
+static const char *_rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u32 which)
+{
+ const char *snap_name;
+
+ rbd_assert(which < rbd_dev->header.snapc->num_snaps);
+
+ /* Skip over names until we find the one we are looking for */
+
+ snap_name = rbd_dev->header.snap_names;
+ while (which--)
+ snap_name += strlen(snap_name) + 1;
+
+ return kstrdup(snap_name, GFP_KERNEL);
+}
+
+/*
+ * Snapshot id comparison function for use with qsort()/bsearch().
+ * Note that result is for snapshots in *descending* order.
+ */
+static int snapid_compare_reverse(const void *s1, const void *s2)
+{
+ u64 snap_id1 = *(u64 *)s1;
+ u64 snap_id2 = *(u64 *)s2;
+
+ if (snap_id1 < snap_id2)
+ return 1;
+ return snap_id1 == snap_id2 ? 0 : -1;
+}
+
+/*
+ * Search a snapshot context to see if the given snapshot id is
+ * present.
+ *
+ * Returns the position of the snapshot id in the array if it's found,
+ * or BAD_SNAP_INDEX otherwise.
+ *
+ * Note: The snapshot array is in kept sorted (by the osd) in
+ * reverse order, highest snapshot id first.
+ */
+static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
+{
+ struct ceph_snap_context *snapc = rbd_dev->header.snapc;
+ u64 *found;
+
+ found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
+ sizeof (snap_id), snapid_compare_reverse);
+
+ return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
+}
+
+static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
+ u64 snap_id)
+{
+ u32 which;
+ const char *snap_name;
+
+ which = rbd_dev_snap_index(rbd_dev, snap_id);
+ if (which == BAD_SNAP_INDEX)
+ return ERR_PTR(-ENOENT);
+
+ snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
+ return snap_name ? snap_name : ERR_PTR(-ENOMEM);
+}
+
+static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
+{
+ if (snap_id == CEPH_NOSNAP)
+ return RBD_SNAP_HEAD_NAME;
+
+ rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
+ if (rbd_dev->image_format == 1)
+ return rbd_dev_v1_snap_name(rbd_dev, snap_id);
+
+ return rbd_dev_v2_snap_name(rbd_dev, snap_id);
+}
+
+static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
+ u64 *snap_size)
+{
+ rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
+ if (snap_id == CEPH_NOSNAP) {
+ *snap_size = rbd_dev->header.image_size;
+ } else if (rbd_dev->image_format == 1) {
+ u32 which;
+
+ which = rbd_dev_snap_index(rbd_dev, snap_id);
+ if (which == BAD_SNAP_INDEX)
+ return -ENOENT;
+
+ *snap_size = rbd_dev->header.snap_sizes[which];
+ } else {
+ u64 size = 0;
+ int ret;
+
+ ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, NULL, &size);
+ if (ret)
+ return ret;
+
+ *snap_size = size;
+ }
+ return 0;
+}
+
+static int rbd_dev_mapping_set(struct rbd_device *rbd_dev)
+{
+ u64 snap_id = rbd_dev->spec->snap_id;
+ u64 size = 0;
+ int ret;
+
+ ret = rbd_snap_size(rbd_dev, snap_id, &size);
+ if (ret)
+ return ret;
+
+ rbd_dev->mapping.size = size;
+ return 0;
+}
+
+static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
+{
+ rbd_dev->mapping.size = 0;
+}
+
+static void zero_bios(struct ceph_bio_iter *bio_pos, u32 off, u32 bytes)
+{
+ struct ceph_bio_iter it = *bio_pos;
+
+ ceph_bio_iter_advance(&it, off);
+ ceph_bio_iter_advance_step(&it, bytes, ({
+ memzero_bvec(&bv);
+ }));
+}
+
+static void zero_bvecs(struct ceph_bvec_iter *bvec_pos, u32 off, u32 bytes)
+{
+ struct ceph_bvec_iter it = *bvec_pos;
+
+ ceph_bvec_iter_advance(&it, off);
+ ceph_bvec_iter_advance_step(&it, bytes, ({
+ memzero_bvec(&bv);
+ }));
+}
+
+/*
+ * Zero a range in @obj_req data buffer defined by a bio (list) or
+ * (private) bio_vec array.
+ *
+ * @off is relative to the start of the data buffer.
+ */
+static void rbd_obj_zero_range(struct rbd_obj_request *obj_req, u32 off,
+ u32 bytes)
+{
+ dout("%s %p data buf %u~%u\n", __func__, obj_req, off, bytes);
+
+ switch (obj_req->img_request->data_type) {
+ case OBJ_REQUEST_BIO:
+ zero_bios(&obj_req->bio_pos, off, bytes);
+ break;
+ case OBJ_REQUEST_BVECS:
+ case OBJ_REQUEST_OWN_BVECS:
+ zero_bvecs(&obj_req->bvec_pos, off, bytes);
+ break;
+ default:
+ BUG();
+ }
+}
+
+static void rbd_obj_request_destroy(struct kref *kref);
+static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
+{
+ rbd_assert(obj_request != NULL);
+ dout("%s: obj %p (was %d)\n", __func__, obj_request,
+ kref_read(&obj_request->kref));
+ kref_put(&obj_request->kref, rbd_obj_request_destroy);
+}
+
+static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
+ struct rbd_obj_request *obj_request)
+{
+ rbd_assert(obj_request->img_request == NULL);
+
+ /* Image request now owns object's original reference */
+ obj_request->img_request = img_request;
+ dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
+}
+
+static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
+ struct rbd_obj_request *obj_request)
+{
+ dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
+ list_del(&obj_request->ex.oe_item);
+ rbd_assert(obj_request->img_request == img_request);
+ rbd_obj_request_put(obj_request);
+}
+
+static void rbd_osd_submit(struct ceph_osd_request *osd_req)
+{
+ struct rbd_obj_request *obj_req = osd_req->r_priv;
+
+ dout("%s osd_req %p for obj_req %p objno %llu %llu~%llu\n",
+ __func__, osd_req, obj_req, obj_req->ex.oe_objno,
+ obj_req->ex.oe_off, obj_req->ex.oe_len);
+ ceph_osdc_start_request(osd_req->r_osdc, osd_req);
+}
+
+/*
+ * The default/initial value for all image request flags is 0. Each
+ * is conditionally set to 1 at image request initialization time
+ * and currently never change thereafter.
+ */
+static void img_request_layered_set(struct rbd_img_request *img_request)
+{
+ set_bit(IMG_REQ_LAYERED, &img_request->flags);
+}
+
+static bool img_request_layered_test(struct rbd_img_request *img_request)
+{
+ return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
+}
+
+static bool rbd_obj_is_entire(struct rbd_obj_request *obj_req)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+
+ return !obj_req->ex.oe_off &&
+ obj_req->ex.oe_len == rbd_dev->layout.object_size;
+}
+
+static bool rbd_obj_is_tail(struct rbd_obj_request *obj_req)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+
+ return obj_req->ex.oe_off + obj_req->ex.oe_len ==
+ rbd_dev->layout.object_size;
+}
+
+/*
+ * Must be called after rbd_obj_calc_img_extents().
+ */
+static void rbd_obj_set_copyup_enabled(struct rbd_obj_request *obj_req)
+{
+ rbd_assert(obj_req->img_request->snapc);
+
+ if (obj_req->img_request->op_type == OBJ_OP_DISCARD) {
+ dout("%s %p objno %llu discard\n", __func__, obj_req,
+ obj_req->ex.oe_objno);
+ return;
+ }
+
+ if (!obj_req->num_img_extents) {
+ dout("%s %p objno %llu not overlapping\n", __func__, obj_req,
+ obj_req->ex.oe_objno);
+ return;
+ }
+
+ if (rbd_obj_is_entire(obj_req) &&
+ !obj_req->img_request->snapc->num_snaps) {
+ dout("%s %p objno %llu entire\n", __func__, obj_req,
+ obj_req->ex.oe_objno);
+ return;
+ }
+
+ obj_req->flags |= RBD_OBJ_FLAG_COPYUP_ENABLED;
+}
+
+static u64 rbd_obj_img_extents_bytes(struct rbd_obj_request *obj_req)
+{
+ return ceph_file_extents_bytes(obj_req->img_extents,
+ obj_req->num_img_extents);
+}
+
+static bool rbd_img_is_write(struct rbd_img_request *img_req)
+{
+ switch (img_req->op_type) {
+ case OBJ_OP_READ:
+ return false;
+ case OBJ_OP_WRITE:
+ case OBJ_OP_DISCARD:
+ case OBJ_OP_ZEROOUT:
+ return true;
+ default:
+ BUG();
+ }
+}
+
+static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
+{
+ struct rbd_obj_request *obj_req = osd_req->r_priv;
+ int result;
+
+ dout("%s osd_req %p result %d for obj_req %p\n", __func__, osd_req,
+ osd_req->r_result, obj_req);
+
+ /*
+ * Writes aren't allowed to return a data payload. In some
+ * guarded write cases (e.g. stat + zero on an empty object)
+ * a stat response makes it through, but we don't care.
+ */
+ if (osd_req->r_result > 0 && rbd_img_is_write(obj_req->img_request))
+ result = 0;
+ else
+ result = osd_req->r_result;
+
+ rbd_obj_handle_request(obj_req, result);
+}
+
+static void rbd_osd_format_read(struct ceph_osd_request *osd_req)
+{
+ struct rbd_obj_request *obj_request = osd_req->r_priv;
+ struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
+ struct ceph_options *opt = rbd_dev->rbd_client->client->options;
+
+ osd_req->r_flags = CEPH_OSD_FLAG_READ | opt->read_from_replica;
+ osd_req->r_snapid = obj_request->img_request->snap_id;
+}
+
+static void rbd_osd_format_write(struct ceph_osd_request *osd_req)
+{
+ struct rbd_obj_request *obj_request = osd_req->r_priv;
+
+ osd_req->r_flags = CEPH_OSD_FLAG_WRITE;
+ ktime_get_real_ts64(&osd_req->r_mtime);
+ osd_req->r_data_offset = obj_request->ex.oe_off;
+}
+
+static struct ceph_osd_request *
+__rbd_obj_add_osd_request(struct rbd_obj_request *obj_req,
+ struct ceph_snap_context *snapc, int num_ops)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ struct ceph_osd_request *req;
+ const char *name_format = rbd_dev->image_format == 1 ?
+ RBD_V1_DATA_FORMAT : RBD_V2_DATA_FORMAT;
+ int ret;
+
+ req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false, GFP_NOIO);
+ if (!req)
+ return ERR_PTR(-ENOMEM);
+
+ list_add_tail(&req->r_private_item, &obj_req->osd_reqs);
+ req->r_callback = rbd_osd_req_callback;
+ req->r_priv = obj_req;
+
+ /*
+ * Data objects may be stored in a separate pool, but always in
+ * the same namespace in that pool as the header in its pool.
+ */
+ ceph_oloc_copy(&req->r_base_oloc, &rbd_dev->header_oloc);
+ req->r_base_oloc.pool = rbd_dev->layout.pool_id;
+
+ ret = ceph_oid_aprintf(&req->r_base_oid, GFP_NOIO, name_format,
+ rbd_dev->header.object_prefix,
+ obj_req->ex.oe_objno);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return req;
+}
+
+static struct ceph_osd_request *
+rbd_obj_add_osd_request(struct rbd_obj_request *obj_req, int num_ops)
+{
+ rbd_assert(obj_req->img_request->snapc);
+ return __rbd_obj_add_osd_request(obj_req, obj_req->img_request->snapc,
+ num_ops);
+}
+
+static struct rbd_obj_request *rbd_obj_request_create(void)
+{
+ struct rbd_obj_request *obj_request;
+
+ obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
+ if (!obj_request)
+ return NULL;
+
+ ceph_object_extent_init(&obj_request->ex);
+ INIT_LIST_HEAD(&obj_request->osd_reqs);
+ mutex_init(&obj_request->state_mutex);
+ kref_init(&obj_request->kref);
+
+ dout("%s %p\n", __func__, obj_request);
+ return obj_request;
+}
+
+static void rbd_obj_request_destroy(struct kref *kref)
+{
+ struct rbd_obj_request *obj_request;
+ struct ceph_osd_request *osd_req;
+ u32 i;
+
+ obj_request = container_of(kref, struct rbd_obj_request, kref);
+
+ dout("%s: obj %p\n", __func__, obj_request);
+
+ while (!list_empty(&obj_request->osd_reqs)) {
+ osd_req = list_first_entry(&obj_request->osd_reqs,
+ struct ceph_osd_request, r_private_item);
+ list_del_init(&osd_req->r_private_item);
+ ceph_osdc_put_request(osd_req);
+ }
+
+ switch (obj_request->img_request->data_type) {
+ case OBJ_REQUEST_NODATA:
+ case OBJ_REQUEST_BIO:
+ case OBJ_REQUEST_BVECS:
+ break; /* Nothing to do */
+ case OBJ_REQUEST_OWN_BVECS:
+ kfree(obj_request->bvec_pos.bvecs);
+ break;
+ default:
+ BUG();
+ }
+
+ kfree(obj_request->img_extents);
+ if (obj_request->copyup_bvecs) {
+ for (i = 0; i < obj_request->copyup_bvec_count; i++) {
+ if (obj_request->copyup_bvecs[i].bv_page)
+ __free_page(obj_request->copyup_bvecs[i].bv_page);
+ }
+ kfree(obj_request->copyup_bvecs);
+ }
+
+ 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");
+}
+
+/*
+ * If an image has a non-zero parent overlap, get a reference to its
+ * parent.
+ *
+ * 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 = 0;
+
+ if (!rbd_dev->parent_spec)
+ return false;
+
+ if (rbd_dev->parent_overlap)
+ counter = atomic_inc_return_safe(&rbd_dev->parent_ref);
+
+ if (counter < 0)
+ rbd_warn(rbd_dev, "parent reference overflow");
+
+ return counter > 0;
+}
+
+static void rbd_img_request_init(struct rbd_img_request *img_request,
+ struct rbd_device *rbd_dev,
+ enum obj_operation_type op_type)
+{
+ memset(img_request, 0, sizeof(*img_request));
+
+ img_request->rbd_dev = rbd_dev;
+ img_request->op_type = op_type;
+
+ INIT_LIST_HEAD(&img_request->lock_item);
+ INIT_LIST_HEAD(&img_request->object_extents);
+ mutex_init(&img_request->state_mutex);
+}
+
+/*
+ * Only snap_id is captured here, for reads. For writes, snapshot
+ * context is captured in rbd_img_object_requests() after exclusive
+ * lock is ensured to be held.
+ */
+static void rbd_img_capture_header(struct rbd_img_request *img_req)
+{
+ struct rbd_device *rbd_dev = img_req->rbd_dev;
+
+ lockdep_assert_held(&rbd_dev->header_rwsem);
+
+ if (!rbd_img_is_write(img_req))
+ img_req->snap_id = rbd_dev->spec->snap_id;
+
+ if (rbd_dev_parent_get(rbd_dev))
+ img_request_layered_set(img_req);
+}
+
+static void rbd_img_request_destroy(struct rbd_img_request *img_request)
+{
+ struct rbd_obj_request *obj_request;
+ struct rbd_obj_request *next_obj_request;
+
+ dout("%s: img %p\n", __func__, img_request);
+
+ WARN_ON(!list_empty(&img_request->lock_item));
+ for_each_obj_request_safe(img_request, obj_request, next_obj_request)
+ rbd_img_obj_request_del(img_request, obj_request);
+
+ if (img_request_layered_test(img_request))
+ rbd_dev_parent_put(img_request->rbd_dev);
+
+ if (rbd_img_is_write(img_request))
+ ceph_put_snap_context(img_request->snapc);
+
+ if (test_bit(IMG_REQ_CHILD, &img_request->flags))
+ kmem_cache_free(rbd_img_request_cache, img_request);
+}
+
+#define BITS_PER_OBJ 2
+#define OBJS_PER_BYTE (BITS_PER_BYTE / BITS_PER_OBJ)
+#define OBJ_MASK ((1 << BITS_PER_OBJ) - 1)
+
+static void __rbd_object_map_index(struct rbd_device *rbd_dev, u64 objno,
+ u64 *index, u8 *shift)
+{
+ u32 off;
+
+ rbd_assert(objno < rbd_dev->object_map_size);
+ *index = div_u64_rem(objno, OBJS_PER_BYTE, &off);
+ *shift = (OBJS_PER_BYTE - off - 1) * BITS_PER_OBJ;
+}
+
+static u8 __rbd_object_map_get(struct rbd_device *rbd_dev, u64 objno)
+{
+ u64 index;
+ u8 shift;
+
+ lockdep_assert_held(&rbd_dev->object_map_lock);
+ __rbd_object_map_index(rbd_dev, objno, &index, &shift);
+ return (rbd_dev->object_map[index] >> shift) & OBJ_MASK;
+}
+
+static void __rbd_object_map_set(struct rbd_device *rbd_dev, u64 objno, u8 val)
+{
+ u64 index;
+ u8 shift;
+ u8 *p;
+
+ lockdep_assert_held(&rbd_dev->object_map_lock);
+ rbd_assert(!(val & ~OBJ_MASK));
+
+ __rbd_object_map_index(rbd_dev, objno, &index, &shift);
+ p = &rbd_dev->object_map[index];
+ *p = (*p & ~(OBJ_MASK << shift)) | (val << shift);
+}
+
+static u8 rbd_object_map_get(struct rbd_device *rbd_dev, u64 objno)
+{
+ u8 state;
+
+ spin_lock(&rbd_dev->object_map_lock);
+ state = __rbd_object_map_get(rbd_dev, objno);
+ spin_unlock(&rbd_dev->object_map_lock);
+ return state;
+}
+
+static bool use_object_map(struct rbd_device *rbd_dev)
+{
+ /*
+ * An image mapped read-only can't use the object map -- it isn't
+ * loaded because the header lock isn't acquired. Someone else can
+ * write to the image and update the object map behind our back.
+ *
+ * A snapshot can't be written to, so using the object map is always
+ * safe.
+ */
+ if (!rbd_is_snap(rbd_dev) && rbd_is_ro(rbd_dev))
+ return false;
+
+ return ((rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP) &&
+ !(rbd_dev->object_map_flags & RBD_FLAG_OBJECT_MAP_INVALID));
+}
+
+static bool rbd_object_map_may_exist(struct rbd_device *rbd_dev, u64 objno)
+{
+ u8 state;
+
+ /* fall back to default logic if object map is disabled or invalid */
+ if (!use_object_map(rbd_dev))
+ return true;
+
+ state = rbd_object_map_get(rbd_dev, objno);
+ return state != OBJECT_NONEXISTENT;
+}
+
+static void rbd_object_map_name(struct rbd_device *rbd_dev, u64 snap_id,
+ struct ceph_object_id *oid)
+{
+ if (snap_id == CEPH_NOSNAP)
+ ceph_oid_printf(oid, "%s%s", RBD_OBJECT_MAP_PREFIX,
+ rbd_dev->spec->image_id);
+ else
+ ceph_oid_printf(oid, "%s%s.%016llx", RBD_OBJECT_MAP_PREFIX,
+ rbd_dev->spec->image_id, snap_id);
+}
+
+static int rbd_object_map_lock(struct rbd_device *rbd_dev)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ CEPH_DEFINE_OID_ONSTACK(oid);
+ u8 lock_type;
+ char *lock_tag;
+ struct ceph_locker *lockers;
+ u32 num_lockers;
+ bool broke_lock = false;
+ int ret;
+
+ rbd_object_map_name(rbd_dev, CEPH_NOSNAP, &oid);
+
+again:
+ ret = ceph_cls_lock(osdc, &oid, &rbd_dev->header_oloc, RBD_LOCK_NAME,
+ CEPH_CLS_LOCK_EXCLUSIVE, "", "", "", 0);
+ if (ret != -EBUSY || broke_lock) {
+ if (ret == -EEXIST)
+ ret = 0; /* already locked by myself */
+ if (ret)
+ rbd_warn(rbd_dev, "failed to lock object map: %d", ret);
+ return ret;
+ }
+
+ ret = ceph_cls_lock_info(osdc, &oid, &rbd_dev->header_oloc,
+ RBD_LOCK_NAME, &lock_type, &lock_tag,
+ &lockers, &num_lockers);
+ if (ret) {
+ if (ret == -ENOENT)
+ goto again;
+
+ rbd_warn(rbd_dev, "failed to get object map lockers: %d", ret);
+ return ret;
+ }
+
+ kfree(lock_tag);
+ if (num_lockers == 0)
+ goto again;
+
+ rbd_warn(rbd_dev, "breaking object map lock owned by %s%llu",
+ ENTITY_NAME(lockers[0].id.name));
+
+ ret = ceph_cls_break_lock(osdc, &oid, &rbd_dev->header_oloc,
+ RBD_LOCK_NAME, lockers[0].id.cookie,
+ &lockers[0].id.name);
+ ceph_free_lockers(lockers, num_lockers);
+ if (ret) {
+ if (ret == -ENOENT)
+ goto again;
+
+ rbd_warn(rbd_dev, "failed to break object map lock: %d", ret);
+ return ret;
+ }
+
+ broke_lock = true;
+ goto again;
+}
+
+static void rbd_object_map_unlock(struct rbd_device *rbd_dev)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ CEPH_DEFINE_OID_ONSTACK(oid);
+ int ret;
+
+ rbd_object_map_name(rbd_dev, CEPH_NOSNAP, &oid);
+
+ ret = ceph_cls_unlock(osdc, &oid, &rbd_dev->header_oloc, RBD_LOCK_NAME,
+ "");
+ if (ret && ret != -ENOENT)
+ rbd_warn(rbd_dev, "failed to unlock object map: %d", ret);
+}
+
+static int decode_object_map_header(void **p, void *end, u64 *object_map_size)
+{
+ u8 struct_v;
+ u32 struct_len;
+ u32 header_len;
+ void *header_end;
+ int ret;
+
+ ceph_decode_32_safe(p, end, header_len, e_inval);
+ header_end = *p + header_len;
+
+ ret = ceph_start_decoding(p, end, 1, "BitVector header", &struct_v,
+ &struct_len);
+ if (ret)
+ return ret;
+
+ ceph_decode_64_safe(p, end, *object_map_size, e_inval);
+
+ *p = header_end;
+ return 0;
+
+e_inval:
+ return -EINVAL;
+}
+
+static int __rbd_object_map_load(struct rbd_device *rbd_dev)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ CEPH_DEFINE_OID_ONSTACK(oid);
+ struct page **pages;
+ void *p, *end;
+ size_t reply_len;
+ u64 num_objects;
+ u64 object_map_bytes;
+ u64 object_map_size;
+ int num_pages;
+ int ret;
+
+ rbd_assert(!rbd_dev->object_map && !rbd_dev->object_map_size);
+
+ num_objects = ceph_get_num_objects(&rbd_dev->layout,
+ rbd_dev->mapping.size);
+ object_map_bytes = DIV_ROUND_UP_ULL(num_objects * BITS_PER_OBJ,
+ BITS_PER_BYTE);
+ num_pages = calc_pages_for(0, object_map_bytes) + 1;
+ pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
+ if (IS_ERR(pages))
+ return PTR_ERR(pages);
+
+ reply_len = num_pages * PAGE_SIZE;
+ rbd_object_map_name(rbd_dev, rbd_dev->spec->snap_id, &oid);
+ ret = ceph_osdc_call(osdc, &oid, &rbd_dev->header_oloc,
+ "rbd", "object_map_load", CEPH_OSD_FLAG_READ,
+ NULL, 0, pages, &reply_len);
+ if (ret)
+ goto out;
+
+ p = page_address(pages[0]);
+ end = p + min(reply_len, (size_t)PAGE_SIZE);
+ ret = decode_object_map_header(&p, end, &object_map_size);
+ if (ret)
+ goto out;
+
+ if (object_map_size != num_objects) {
+ rbd_warn(rbd_dev, "object map size mismatch: %llu vs %llu",
+ object_map_size, num_objects);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (offset_in_page(p) + object_map_bytes > reply_len) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ rbd_dev->object_map = kvmalloc(object_map_bytes, GFP_KERNEL);
+ if (!rbd_dev->object_map) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ rbd_dev->object_map_size = object_map_size;
+ ceph_copy_from_page_vector(pages, rbd_dev->object_map,
+ offset_in_page(p), object_map_bytes);
+
+out:
+ ceph_release_page_vector(pages, num_pages);
+ return ret;
+}
+
+static void rbd_object_map_free(struct rbd_device *rbd_dev)
+{
+ kvfree(rbd_dev->object_map);
+ rbd_dev->object_map = NULL;
+ rbd_dev->object_map_size = 0;
+}
+
+static int rbd_object_map_load(struct rbd_device *rbd_dev)
+{
+ int ret;
+
+ ret = __rbd_object_map_load(rbd_dev);
+ if (ret)
+ return ret;
+
+ ret = rbd_dev_v2_get_flags(rbd_dev);
+ if (ret) {
+ rbd_object_map_free(rbd_dev);
+ return ret;
+ }
+
+ if (rbd_dev->object_map_flags & RBD_FLAG_OBJECT_MAP_INVALID)
+ rbd_warn(rbd_dev, "object map is invalid");
+
+ return 0;
+}
+
+static int rbd_object_map_open(struct rbd_device *rbd_dev)
+{
+ int ret;
+
+ ret = rbd_object_map_lock(rbd_dev);
+ if (ret)
+ return ret;
+
+ ret = rbd_object_map_load(rbd_dev);
+ if (ret) {
+ rbd_object_map_unlock(rbd_dev);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void rbd_object_map_close(struct rbd_device *rbd_dev)
+{
+ rbd_object_map_free(rbd_dev);
+ rbd_object_map_unlock(rbd_dev);
+}
+
+/*
+ * This function needs snap_id (or more precisely just something to
+ * distinguish between HEAD and snapshot object maps), new_state and
+ * current_state that were passed to rbd_object_map_update().
+ *
+ * To avoid allocating and stashing a context we piggyback on the OSD
+ * request. A HEAD update has two ops (assert_locked). For new_state
+ * and current_state we decode our own object_map_update op, encoded in
+ * rbd_cls_object_map_update().
+ */
+static int rbd_object_map_update_finish(struct rbd_obj_request *obj_req,
+ struct ceph_osd_request *osd_req)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+ struct ceph_osd_data *osd_data;
+ u64 objno;
+ u8 state, new_state, current_state;
+ bool has_current_state;
+ void *p;
+
+ if (osd_req->r_result)
+ return osd_req->r_result;
+
+ /*
+ * Nothing to do for a snapshot object map.
+ */
+ if (osd_req->r_num_ops == 1)
+ return 0;
+
+ /*
+ * Update in-memory HEAD object map.
+ */
+ rbd_assert(osd_req->r_num_ops == 2);
+ osd_data = osd_req_op_data(osd_req, 1, cls, request_data);
+ rbd_assert(osd_data->type == CEPH_OSD_DATA_TYPE_PAGES);
+
+ p = page_address(osd_data->pages[0]);
+ objno = ceph_decode_64(&p);
+ rbd_assert(objno == obj_req->ex.oe_objno);
+ rbd_assert(ceph_decode_64(&p) == objno + 1);
+ new_state = ceph_decode_8(&p);
+ has_current_state = ceph_decode_8(&p);
+ if (has_current_state)
+ current_state = ceph_decode_8(&p);
+
+ spin_lock(&rbd_dev->object_map_lock);
+ state = __rbd_object_map_get(rbd_dev, objno);
+ if (!has_current_state || current_state == state ||
+ (current_state == OBJECT_EXISTS && state == OBJECT_EXISTS_CLEAN))
+ __rbd_object_map_set(rbd_dev, objno, new_state);
+ spin_unlock(&rbd_dev->object_map_lock);
+
+ return 0;
+}
+
+static void rbd_object_map_callback(struct ceph_osd_request *osd_req)
+{
+ struct rbd_obj_request *obj_req = osd_req->r_priv;
+ int result;
+
+ dout("%s osd_req %p result %d for obj_req %p\n", __func__, osd_req,
+ osd_req->r_result, obj_req);
+
+ result = rbd_object_map_update_finish(obj_req, osd_req);
+ rbd_obj_handle_request(obj_req, result);
+}
+
+static bool update_needed(struct rbd_device *rbd_dev, u64 objno, u8 new_state)
+{
+ u8 state = rbd_object_map_get(rbd_dev, objno);
+
+ if (state == new_state ||
+ (new_state == OBJECT_PENDING && state == OBJECT_NONEXISTENT) ||
+ (new_state == OBJECT_NONEXISTENT && state != OBJECT_PENDING))
+ return false;
+
+ return true;
+}
+
+static int rbd_cls_object_map_update(struct ceph_osd_request *req,
+ int which, u64 objno, u8 new_state,
+ const u8 *current_state)
+{
+ struct page **pages;
+ void *p, *start;
+ int ret;
+
+ ret = osd_req_op_cls_init(req, which, "rbd", "object_map_update");
+ if (ret)
+ return ret;
+
+ pages = ceph_alloc_page_vector(1, GFP_NOIO);
+ if (IS_ERR(pages))
+ return PTR_ERR(pages);
+
+ p = start = page_address(pages[0]);
+ ceph_encode_64(&p, objno);
+ ceph_encode_64(&p, objno + 1);
+ ceph_encode_8(&p, new_state);
+ if (current_state) {
+ ceph_encode_8(&p, 1);
+ ceph_encode_8(&p, *current_state);
+ } else {
+ ceph_encode_8(&p, 0);
+ }
+
+ osd_req_op_cls_request_data_pages(req, which, pages, p - start, 0,
+ false, true);
+ return 0;
+}
+
+/*
+ * Return:
+ * 0 - object map update sent
+ * 1 - object map update isn't needed
+ * <0 - error
+ */
+static int rbd_object_map_update(struct rbd_obj_request *obj_req, u64 snap_id,
+ u8 new_state, const u8 *current_state)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ struct ceph_osd_request *req;
+ int num_ops = 1;
+ int which = 0;
+ int ret;
+
+ if (snap_id == CEPH_NOSNAP) {
+ if (!update_needed(rbd_dev, obj_req->ex.oe_objno, new_state))
+ return 1;
+
+ num_ops++; /* assert_locked */
+ }
+
+ req = ceph_osdc_alloc_request(osdc, NULL, num_ops, false, GFP_NOIO);
+ if (!req)
+ return -ENOMEM;
+
+ list_add_tail(&req->r_private_item, &obj_req->osd_reqs);
+ req->r_callback = rbd_object_map_callback;
+ req->r_priv = obj_req;
+
+ rbd_object_map_name(rbd_dev, snap_id, &req->r_base_oid);
+ ceph_oloc_copy(&req->r_base_oloc, &rbd_dev->header_oloc);
+ req->r_flags = CEPH_OSD_FLAG_WRITE;
+ ktime_get_real_ts64(&req->r_mtime);
+
+ if (snap_id == CEPH_NOSNAP) {
+ /*
+ * Protect against possible race conditions during lock
+ * ownership transitions.
+ */
+ ret = ceph_cls_assert_locked(req, which++, RBD_LOCK_NAME,
+ CEPH_CLS_LOCK_EXCLUSIVE, "", "");
+ if (ret)
+ return ret;
+ }
+
+ ret = rbd_cls_object_map_update(req, which, obj_req->ex.oe_objno,
+ new_state, current_state);
+ if (ret)
+ return ret;
+
+ ret = ceph_osdc_alloc_messages(req, GFP_NOIO);
+ if (ret)
+ return ret;
+
+ ceph_osdc_start_request(osdc, req);
+ return 0;
+}
+
+static void prune_extents(struct ceph_file_extent *img_extents,
+ u32 *num_img_extents, u64 overlap)
+{
+ u32 cnt = *num_img_extents;
+
+ /* drop extents completely beyond the overlap */
+ while (cnt && img_extents[cnt - 1].fe_off >= overlap)
+ cnt--;
+
+ if (cnt) {
+ struct ceph_file_extent *ex = &img_extents[cnt - 1];
+
+ /* trim final overlapping extent */
+ if (ex->fe_off + ex->fe_len > overlap)
+ ex->fe_len = overlap - ex->fe_off;
+ }
+
+ *num_img_extents = cnt;
+}
+
+/*
+ * Determine the byte range(s) covered by either just the object extent
+ * or the entire object in the parent image.
+ */
+static int rbd_obj_calc_img_extents(struct rbd_obj_request *obj_req,
+ bool entire)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+ int ret;
+
+ if (!rbd_dev->parent_overlap)
+ return 0;
+
+ ret = ceph_extent_to_file(&rbd_dev->layout, obj_req->ex.oe_objno,
+ entire ? 0 : obj_req->ex.oe_off,
+ entire ? rbd_dev->layout.object_size :
+ obj_req->ex.oe_len,
+ &obj_req->img_extents,
+ &obj_req->num_img_extents);
+ if (ret)
+ return ret;
+
+ prune_extents(obj_req->img_extents, &obj_req->num_img_extents,
+ rbd_dev->parent_overlap);
+ return 0;
+}
+
+static void rbd_osd_setup_data(struct ceph_osd_request *osd_req, int which)
+{
+ struct rbd_obj_request *obj_req = osd_req->r_priv;
+
+ switch (obj_req->img_request->data_type) {
+ case OBJ_REQUEST_BIO:
+ osd_req_op_extent_osd_data_bio(osd_req, which,
+ &obj_req->bio_pos,
+ obj_req->ex.oe_len);
+ break;
+ case OBJ_REQUEST_BVECS:
+ case OBJ_REQUEST_OWN_BVECS:
+ rbd_assert(obj_req->bvec_pos.iter.bi_size ==
+ obj_req->ex.oe_len);
+ rbd_assert(obj_req->bvec_idx == obj_req->bvec_count);
+ osd_req_op_extent_osd_data_bvec_pos(osd_req, which,
+ &obj_req->bvec_pos);
+ break;
+ default:
+ BUG();
+ }
+}
+
+static int rbd_osd_setup_stat(struct ceph_osd_request *osd_req, int which)
+{
+ struct page **pages;
+
+ /*
+ * The response data for a STAT call consists of:
+ * le64 length;
+ * struct {
+ * le32 tv_sec;
+ * le32 tv_nsec;
+ * } mtime;
+ */
+ pages = ceph_alloc_page_vector(1, GFP_NOIO);
+ if (IS_ERR(pages))
+ return PTR_ERR(pages);
+
+ osd_req_op_init(osd_req, which, CEPH_OSD_OP_STAT, 0);
+ osd_req_op_raw_data_in_pages(osd_req, which, pages,
+ 8 + sizeof(struct ceph_timespec),
+ 0, false, true);
+ return 0;
+}
+
+static int rbd_osd_setup_copyup(struct ceph_osd_request *osd_req, int which,
+ u32 bytes)
+{
+ struct rbd_obj_request *obj_req = osd_req->r_priv;
+ int ret;
+
+ ret = osd_req_op_cls_init(osd_req, which, "rbd", "copyup");
+ if (ret)
+ return ret;
+
+ osd_req_op_cls_request_data_bvecs(osd_req, which, obj_req->copyup_bvecs,
+ obj_req->copyup_bvec_count, bytes);
+ return 0;
+}
+
+static int rbd_obj_init_read(struct rbd_obj_request *obj_req)
+{
+ obj_req->read_state = RBD_OBJ_READ_START;
+ return 0;
+}
+
+static void __rbd_osd_setup_write_ops(struct ceph_osd_request *osd_req,
+ int which)
+{
+ struct rbd_obj_request *obj_req = osd_req->r_priv;
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+ u16 opcode;
+
+ if (!use_object_map(rbd_dev) ||
+ !(obj_req->flags & RBD_OBJ_FLAG_MAY_EXIST)) {
+ osd_req_op_alloc_hint_init(osd_req, which++,
+ rbd_dev->layout.object_size,
+ rbd_dev->layout.object_size,
+ rbd_dev->opts->alloc_hint_flags);
+ }
+
+ if (rbd_obj_is_entire(obj_req))
+ opcode = CEPH_OSD_OP_WRITEFULL;
+ else
+ opcode = CEPH_OSD_OP_WRITE;
+
+ osd_req_op_extent_init(osd_req, which, opcode,
+ obj_req->ex.oe_off, obj_req->ex.oe_len, 0, 0);
+ rbd_osd_setup_data(osd_req, which);
+}
+
+static int rbd_obj_init_write(struct rbd_obj_request *obj_req)
+{
+ int ret;
+
+ /* reverse map the entire object onto the parent */
+ ret = rbd_obj_calc_img_extents(obj_req, true);
+ if (ret)
+ return ret;
+
+ obj_req->write_state = RBD_OBJ_WRITE_START;
+ return 0;
+}
+
+static u16 truncate_or_zero_opcode(struct rbd_obj_request *obj_req)
+{
+ return rbd_obj_is_tail(obj_req) ? CEPH_OSD_OP_TRUNCATE :
+ CEPH_OSD_OP_ZERO;
+}
+
+static void __rbd_osd_setup_discard_ops(struct ceph_osd_request *osd_req,
+ int which)
+{
+ struct rbd_obj_request *obj_req = osd_req->r_priv;
+
+ if (rbd_obj_is_entire(obj_req) && !obj_req->num_img_extents) {
+ rbd_assert(obj_req->flags & RBD_OBJ_FLAG_DELETION);
+ osd_req_op_init(osd_req, which, CEPH_OSD_OP_DELETE, 0);
+ } else {
+ osd_req_op_extent_init(osd_req, which,
+ truncate_or_zero_opcode(obj_req),
+ obj_req->ex.oe_off, obj_req->ex.oe_len,
+ 0, 0);
+ }
+}
+
+static int rbd_obj_init_discard(struct rbd_obj_request *obj_req)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+ u64 off, next_off;
+ int ret;
+
+ /*
+ * Align the range to alloc_size boundary and punt on discards
+ * that are too small to free up any space.
+ *
+ * alloc_size == object_size && is_tail() is a special case for
+ * filestore with filestore_punch_hole = false, needed to allow
+ * truncate (in addition to delete).
+ */
+ if (rbd_dev->opts->alloc_size != rbd_dev->layout.object_size ||
+ !rbd_obj_is_tail(obj_req)) {
+ off = round_up(obj_req->ex.oe_off, rbd_dev->opts->alloc_size);
+ next_off = round_down(obj_req->ex.oe_off + obj_req->ex.oe_len,
+ rbd_dev->opts->alloc_size);
+ if (off >= next_off)
+ return 1;
+
+ dout("%s %p %llu~%llu -> %llu~%llu\n", __func__,
+ obj_req, obj_req->ex.oe_off, obj_req->ex.oe_len,
+ off, next_off - off);
+ obj_req->ex.oe_off = off;
+ obj_req->ex.oe_len = next_off - off;
+ }
+
+ /* reverse map the entire object onto the parent */
+ ret = rbd_obj_calc_img_extents(obj_req, true);
+ if (ret)
+ return ret;
+
+ obj_req->flags |= RBD_OBJ_FLAG_NOOP_FOR_NONEXISTENT;
+ if (rbd_obj_is_entire(obj_req) && !obj_req->num_img_extents)
+ obj_req->flags |= RBD_OBJ_FLAG_DELETION;
+
+ obj_req->write_state = RBD_OBJ_WRITE_START;
+ return 0;
+}
+
+static void __rbd_osd_setup_zeroout_ops(struct ceph_osd_request *osd_req,
+ int which)
+{
+ struct rbd_obj_request *obj_req = osd_req->r_priv;
+ u16 opcode;
+
+ if (rbd_obj_is_entire(obj_req)) {
+ if (obj_req->num_img_extents) {
+ if (!(obj_req->flags & RBD_OBJ_FLAG_COPYUP_ENABLED))
+ osd_req_op_init(osd_req, which++,
+ CEPH_OSD_OP_CREATE, 0);
+ opcode = CEPH_OSD_OP_TRUNCATE;
+ } else {
+ rbd_assert(obj_req->flags & RBD_OBJ_FLAG_DELETION);
+ osd_req_op_init(osd_req, which++,
+ CEPH_OSD_OP_DELETE, 0);
+ opcode = 0;
+ }
+ } else {
+ opcode = truncate_or_zero_opcode(obj_req);
+ }
+
+ if (opcode)
+ osd_req_op_extent_init(osd_req, which, opcode,
+ obj_req->ex.oe_off, obj_req->ex.oe_len,
+ 0, 0);
+}
+
+static int rbd_obj_init_zeroout(struct rbd_obj_request *obj_req)
+{
+ int ret;
+
+ /* reverse map the entire object onto the parent */
+ ret = rbd_obj_calc_img_extents(obj_req, true);
+ if (ret)
+ return ret;
+
+ if (!obj_req->num_img_extents) {
+ obj_req->flags |= RBD_OBJ_FLAG_NOOP_FOR_NONEXISTENT;
+ if (rbd_obj_is_entire(obj_req))
+ obj_req->flags |= RBD_OBJ_FLAG_DELETION;
+ }
+
+ obj_req->write_state = RBD_OBJ_WRITE_START;
+ return 0;
+}
+
+static int count_write_ops(struct rbd_obj_request *obj_req)
+{
+ struct rbd_img_request *img_req = obj_req->img_request;
+
+ switch (img_req->op_type) {
+ case OBJ_OP_WRITE:
+ if (!use_object_map(img_req->rbd_dev) ||
+ !(obj_req->flags & RBD_OBJ_FLAG_MAY_EXIST))
+ return 2; /* setallochint + write/writefull */
+
+ return 1; /* write/writefull */
+ case OBJ_OP_DISCARD:
+ return 1; /* delete/truncate/zero */
+ case OBJ_OP_ZEROOUT:
+ if (rbd_obj_is_entire(obj_req) && obj_req->num_img_extents &&
+ !(obj_req->flags & RBD_OBJ_FLAG_COPYUP_ENABLED))
+ return 2; /* create + truncate */
+
+ return 1; /* delete/truncate/zero */
+ default:
+ BUG();
+ }
+}
+
+static void rbd_osd_setup_write_ops(struct ceph_osd_request *osd_req,
+ int which)
+{
+ struct rbd_obj_request *obj_req = osd_req->r_priv;
+
+ switch (obj_req->img_request->op_type) {
+ case OBJ_OP_WRITE:
+ __rbd_osd_setup_write_ops(osd_req, which);
+ break;
+ case OBJ_OP_DISCARD:
+ __rbd_osd_setup_discard_ops(osd_req, which);
+ break;
+ case OBJ_OP_ZEROOUT:
+ __rbd_osd_setup_zeroout_ops(osd_req, which);
+ break;
+ default:
+ BUG();
+ }
+}
+
+/*
+ * Prune the list of object requests (adjust offset and/or length, drop
+ * redundant requests). Prepare object request state machines and image
+ * request state machine for execution.
+ */
+static int __rbd_img_fill_request(struct rbd_img_request *img_req)
+{
+ struct rbd_obj_request *obj_req, *next_obj_req;
+ int ret;
+
+ for_each_obj_request_safe(img_req, obj_req, next_obj_req) {
+ switch (img_req->op_type) {
+ case OBJ_OP_READ:
+ ret = rbd_obj_init_read(obj_req);
+ break;
+ case OBJ_OP_WRITE:
+ ret = rbd_obj_init_write(obj_req);
+ break;
+ case OBJ_OP_DISCARD:
+ ret = rbd_obj_init_discard(obj_req);
+ break;
+ case OBJ_OP_ZEROOUT:
+ ret = rbd_obj_init_zeroout(obj_req);
+ break;
+ default:
+ BUG();
+ }
+ if (ret < 0)
+ return ret;
+ if (ret > 0) {
+ rbd_img_obj_request_del(img_req, obj_req);
+ continue;
+ }
+ }
+
+ img_req->state = RBD_IMG_START;
+ return 0;
+}
+
+union rbd_img_fill_iter {
+ struct ceph_bio_iter bio_iter;
+ struct ceph_bvec_iter bvec_iter;
+};
+
+struct rbd_img_fill_ctx {
+ enum obj_request_type pos_type;
+ union rbd_img_fill_iter *pos;
+ union rbd_img_fill_iter iter;
+ ceph_object_extent_fn_t set_pos_fn;
+ ceph_object_extent_fn_t count_fn;
+ ceph_object_extent_fn_t copy_fn;
+};
+
+static struct ceph_object_extent *alloc_object_extent(void *arg)
+{
+ struct rbd_img_request *img_req = arg;
+ struct rbd_obj_request *obj_req;
+
+ obj_req = rbd_obj_request_create();
+ if (!obj_req)
+ return NULL;
+
+ rbd_img_obj_request_add(img_req, obj_req);
+ return &obj_req->ex;
+}
+
+/*
+ * While su != os && sc == 1 is technically not fancy (it's the same
+ * layout as su == os && sc == 1), we can't use the nocopy path for it
+ * because ->set_pos_fn() should be called only once per object.
+ * ceph_file_to_extents() invokes action_fn once per stripe unit, so
+ * treat su != os && sc == 1 as fancy.
+ */
+static bool rbd_layout_is_fancy(struct ceph_file_layout *l)
+{
+ return l->stripe_unit != l->object_size;
+}
+
+static int rbd_img_fill_request_nocopy(struct rbd_img_request *img_req,
+ struct ceph_file_extent *img_extents,
+ u32 num_img_extents,
+ struct rbd_img_fill_ctx *fctx)
+{
+ u32 i;
+ int ret;
+
+ img_req->data_type = fctx->pos_type;
+
+ /*
+ * Create object requests and set each object request's starting
+ * position in the provided bio (list) or bio_vec array.
+ */
+ fctx->iter = *fctx->pos;
+ for (i = 0; i < num_img_extents; i++) {
+ ret = ceph_file_to_extents(&img_req->rbd_dev->layout,
+ img_extents[i].fe_off,
+ img_extents[i].fe_len,
+ &img_req->object_extents,
+ alloc_object_extent, img_req,
+ fctx->set_pos_fn, &fctx->iter);
+ if (ret)
+ return ret;
+ }
+
+ return __rbd_img_fill_request(img_req);
+}
+
+/*
+ * Map a list of image extents to a list of object extents, create the
+ * corresponding object requests (normally each to a different object,
+ * but not always) and add them to @img_req. For each object request,
+ * set up its data descriptor to point to the corresponding chunk(s) of
+ * @fctx->pos data buffer.
+ *
+ * Because ceph_file_to_extents() will merge adjacent object extents
+ * together, each object request's data descriptor may point to multiple
+ * different chunks of @fctx->pos data buffer.
+ *
+ * @fctx->pos data buffer is assumed to be large enough.
+ */
+static int rbd_img_fill_request(struct rbd_img_request *img_req,
+ struct ceph_file_extent *img_extents,
+ u32 num_img_extents,
+ struct rbd_img_fill_ctx *fctx)
+{
+ struct rbd_device *rbd_dev = img_req->rbd_dev;
+ struct rbd_obj_request *obj_req;
+ u32 i;
+ int ret;
+
+ if (fctx->pos_type == OBJ_REQUEST_NODATA ||
+ !rbd_layout_is_fancy(&rbd_dev->layout))
+ return rbd_img_fill_request_nocopy(img_req, img_extents,
+ num_img_extents, fctx);
+
+ img_req->data_type = OBJ_REQUEST_OWN_BVECS;
+
+ /*
+ * Create object requests and determine ->bvec_count for each object
+ * request. Note that ->bvec_count sum over all object requests may
+ * be greater than the number of bio_vecs in the provided bio (list)
+ * or bio_vec array because when mapped, those bio_vecs can straddle
+ * stripe unit boundaries.
+ */
+ fctx->iter = *fctx->pos;
+ for (i = 0; i < num_img_extents; i++) {
+ ret = ceph_file_to_extents(&rbd_dev->layout,
+ img_extents[i].fe_off,
+ img_extents[i].fe_len,
+ &img_req->object_extents,
+ alloc_object_extent, img_req,
+ fctx->count_fn, &fctx->iter);
+ if (ret)
+ return ret;
+ }
+
+ for_each_obj_request(img_req, obj_req) {
+ obj_req->bvec_pos.bvecs = kmalloc_array(obj_req->bvec_count,
+ sizeof(*obj_req->bvec_pos.bvecs),
+ GFP_NOIO);
+ if (!obj_req->bvec_pos.bvecs)
+ return -ENOMEM;
+ }
+
+ /*
+ * Fill in each object request's private bio_vec array, splitting and
+ * rearranging the provided bio_vecs in stripe unit chunks as needed.
+ */
+ fctx->iter = *fctx->pos;
+ for (i = 0; i < num_img_extents; i++) {
+ ret = ceph_iterate_extents(&rbd_dev->layout,
+ img_extents[i].fe_off,
+ img_extents[i].fe_len,
+ &img_req->object_extents,
+ fctx->copy_fn, &fctx->iter);
+ if (ret)
+ return ret;
+ }
+
+ return __rbd_img_fill_request(img_req);
+}
+
+static int rbd_img_fill_nodata(struct rbd_img_request *img_req,
+ u64 off, u64 len)
+{
+ struct ceph_file_extent ex = { off, len };
+ union rbd_img_fill_iter dummy = {};
+ struct rbd_img_fill_ctx fctx = {
+ .pos_type = OBJ_REQUEST_NODATA,
+ .pos = &dummy,
+ };
+
+ return rbd_img_fill_request(img_req, &ex, 1, &fctx);
+}
+
+static void set_bio_pos(struct ceph_object_extent *ex, u32 bytes, void *arg)
+{
+ struct rbd_obj_request *obj_req =
+ container_of(ex, struct rbd_obj_request, ex);
+ struct ceph_bio_iter *it = arg;
+
+ dout("%s objno %llu bytes %u\n", __func__, ex->oe_objno, bytes);
+ obj_req->bio_pos = *it;
+ ceph_bio_iter_advance(it, bytes);
+}
+
+static void count_bio_bvecs(struct ceph_object_extent *ex, u32 bytes, void *arg)
+{
+ struct rbd_obj_request *obj_req =
+ container_of(ex, struct rbd_obj_request, ex);
+ struct ceph_bio_iter *it = arg;
+
+ dout("%s objno %llu bytes %u\n", __func__, ex->oe_objno, bytes);
+ ceph_bio_iter_advance_step(it, bytes, ({
+ obj_req->bvec_count++;
+ }));
+
+}
+
+static void copy_bio_bvecs(struct ceph_object_extent *ex, u32 bytes, void *arg)
+{
+ struct rbd_obj_request *obj_req =
+ container_of(ex, struct rbd_obj_request, ex);
+ struct ceph_bio_iter *it = arg;
+
+ dout("%s objno %llu bytes %u\n", __func__, ex->oe_objno, bytes);
+ ceph_bio_iter_advance_step(it, bytes, ({
+ obj_req->bvec_pos.bvecs[obj_req->bvec_idx++] = bv;
+ obj_req->bvec_pos.iter.bi_size += bv.bv_len;
+ }));
+}
+
+static int __rbd_img_fill_from_bio(struct rbd_img_request *img_req,
+ struct ceph_file_extent *img_extents,
+ u32 num_img_extents,
+ struct ceph_bio_iter *bio_pos)
+{
+ struct rbd_img_fill_ctx fctx = {
+ .pos_type = OBJ_REQUEST_BIO,
+ .pos = (union rbd_img_fill_iter *)bio_pos,
+ .set_pos_fn = set_bio_pos,
+ .count_fn = count_bio_bvecs,
+ .copy_fn = copy_bio_bvecs,
+ };
+
+ return rbd_img_fill_request(img_req, img_extents, num_img_extents,
+ &fctx);
+}
+
+static int rbd_img_fill_from_bio(struct rbd_img_request *img_req,
+ u64 off, u64 len, struct bio *bio)
+{
+ struct ceph_file_extent ex = { off, len };
+ struct ceph_bio_iter it = { .bio = bio, .iter = bio->bi_iter };
+
+ return __rbd_img_fill_from_bio(img_req, &ex, 1, &it);
+}
+
+static void set_bvec_pos(struct ceph_object_extent *ex, u32 bytes, void *arg)
+{
+ struct rbd_obj_request *obj_req =
+ container_of(ex, struct rbd_obj_request, ex);
+ struct ceph_bvec_iter *it = arg;
+
+ obj_req->bvec_pos = *it;
+ ceph_bvec_iter_shorten(&obj_req->bvec_pos, bytes);
+ ceph_bvec_iter_advance(it, bytes);
+}
+
+static void count_bvecs(struct ceph_object_extent *ex, u32 bytes, void *arg)
+{
+ struct rbd_obj_request *obj_req =
+ container_of(ex, struct rbd_obj_request, ex);
+ struct ceph_bvec_iter *it = arg;
+
+ ceph_bvec_iter_advance_step(it, bytes, ({
+ obj_req->bvec_count++;
+ }));
+}
+
+static void copy_bvecs(struct ceph_object_extent *ex, u32 bytes, void *arg)
+{
+ struct rbd_obj_request *obj_req =
+ container_of(ex, struct rbd_obj_request, ex);
+ struct ceph_bvec_iter *it = arg;
+
+ ceph_bvec_iter_advance_step(it, bytes, ({
+ obj_req->bvec_pos.bvecs[obj_req->bvec_idx++] = bv;
+ obj_req->bvec_pos.iter.bi_size += bv.bv_len;
+ }));
+}
+
+static int __rbd_img_fill_from_bvecs(struct rbd_img_request *img_req,
+ struct ceph_file_extent *img_extents,
+ u32 num_img_extents,
+ struct ceph_bvec_iter *bvec_pos)
+{
+ struct rbd_img_fill_ctx fctx = {
+ .pos_type = OBJ_REQUEST_BVECS,
+ .pos = (union rbd_img_fill_iter *)bvec_pos,
+ .set_pos_fn = set_bvec_pos,
+ .count_fn = count_bvecs,
+ .copy_fn = copy_bvecs,
+ };
+
+ return rbd_img_fill_request(img_req, img_extents, num_img_extents,
+ &fctx);
+}
+
+static int rbd_img_fill_from_bvecs(struct rbd_img_request *img_req,
+ struct ceph_file_extent *img_extents,
+ u32 num_img_extents,
+ struct bio_vec *bvecs)
+{
+ struct ceph_bvec_iter it = {
+ .bvecs = bvecs,
+ .iter = { .bi_size = ceph_file_extents_bytes(img_extents,
+ num_img_extents) },
+ };
+
+ return __rbd_img_fill_from_bvecs(img_req, img_extents, num_img_extents,
+ &it);
+}
+
+static void rbd_img_handle_request_work(struct work_struct *work)
+{
+ struct rbd_img_request *img_req =
+ container_of(work, struct rbd_img_request, work);
+
+ rbd_img_handle_request(img_req, img_req->work_result);
+}
+
+static void rbd_img_schedule(struct rbd_img_request *img_req, int result)
+{
+ INIT_WORK(&img_req->work, rbd_img_handle_request_work);
+ img_req->work_result = result;
+ queue_work(rbd_wq, &img_req->work);
+}
+
+static bool rbd_obj_may_exist(struct rbd_obj_request *obj_req)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+
+ if (rbd_object_map_may_exist(rbd_dev, obj_req->ex.oe_objno)) {
+ obj_req->flags |= RBD_OBJ_FLAG_MAY_EXIST;
+ return true;
+ }
+
+ dout("%s %p objno %llu assuming dne\n", __func__, obj_req,
+ obj_req->ex.oe_objno);
+ return false;
+}
+
+static int rbd_obj_read_object(struct rbd_obj_request *obj_req)
+{
+ struct ceph_osd_request *osd_req;
+ int ret;
+
+ osd_req = __rbd_obj_add_osd_request(obj_req, NULL, 1);
+ if (IS_ERR(osd_req))
+ return PTR_ERR(osd_req);
+
+ osd_req_op_extent_init(osd_req, 0, CEPH_OSD_OP_READ,
+ obj_req->ex.oe_off, obj_req->ex.oe_len, 0, 0);
+ rbd_osd_setup_data(osd_req, 0);
+ rbd_osd_format_read(osd_req);
+
+ ret = ceph_osdc_alloc_messages(osd_req, GFP_NOIO);
+ if (ret)
+ return ret;
+
+ rbd_osd_submit(osd_req);
+ return 0;
+}
+
+static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req)
+{
+ struct rbd_img_request *img_req = obj_req->img_request;
+ struct rbd_device *parent = img_req->rbd_dev->parent;
+ struct rbd_img_request *child_img_req;
+ int ret;
+
+ child_img_req = kmem_cache_alloc(rbd_img_request_cache, GFP_NOIO);
+ if (!child_img_req)
+ return -ENOMEM;
+
+ rbd_img_request_init(child_img_req, parent, OBJ_OP_READ);
+ __set_bit(IMG_REQ_CHILD, &child_img_req->flags);
+ child_img_req->obj_request = obj_req;
+
+ down_read(&parent->header_rwsem);
+ rbd_img_capture_header(child_img_req);
+ up_read(&parent->header_rwsem);
+
+ dout("%s child_img_req %p for obj_req %p\n", __func__, child_img_req,
+ obj_req);
+
+ if (!rbd_img_is_write(img_req)) {
+ switch (img_req->data_type) {
+ case OBJ_REQUEST_BIO:
+ ret = __rbd_img_fill_from_bio(child_img_req,
+ obj_req->img_extents,
+ obj_req->num_img_extents,
+ &obj_req->bio_pos);
+ break;
+ case OBJ_REQUEST_BVECS:
+ case OBJ_REQUEST_OWN_BVECS:
+ ret = __rbd_img_fill_from_bvecs(child_img_req,
+ obj_req->img_extents,
+ obj_req->num_img_extents,
+ &obj_req->bvec_pos);
+ break;
+ default:
+ BUG();
+ }
+ } else {
+ ret = rbd_img_fill_from_bvecs(child_img_req,
+ obj_req->img_extents,
+ obj_req->num_img_extents,
+ obj_req->copyup_bvecs);
+ }
+ if (ret) {
+ rbd_img_request_destroy(child_img_req);
+ return ret;
+ }
+
+ /* avoid parent chain recursion */
+ rbd_img_schedule(child_img_req, 0);
+ return 0;
+}
+
+static bool rbd_obj_advance_read(struct rbd_obj_request *obj_req, int *result)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+ int ret;
+
+again:
+ switch (obj_req->read_state) {
+ case RBD_OBJ_READ_START:
+ rbd_assert(!*result);
+
+ if (!rbd_obj_may_exist(obj_req)) {
+ *result = -ENOENT;
+ obj_req->read_state = RBD_OBJ_READ_OBJECT;
+ goto again;
+ }
+
+ ret = rbd_obj_read_object(obj_req);
+ if (ret) {
+ *result = ret;
+ return true;
+ }
+ obj_req->read_state = RBD_OBJ_READ_OBJECT;
+ return false;
+ case RBD_OBJ_READ_OBJECT:
+ if (*result == -ENOENT && rbd_dev->parent_overlap) {
+ /* reverse map this object extent onto the parent */
+ ret = rbd_obj_calc_img_extents(obj_req, false);
+ if (ret) {
+ *result = ret;
+ return true;
+ }
+ if (obj_req->num_img_extents) {
+ ret = rbd_obj_read_from_parent(obj_req);
+ if (ret) {
+ *result = ret;
+ return true;
+ }
+ obj_req->read_state = RBD_OBJ_READ_PARENT;
+ return false;
+ }
+ }
+
+ /*
+ * -ENOENT means a hole in the image -- zero-fill the entire
+ * length of the request. A short read also implies zero-fill
+ * to the end of the request.
+ */
+ if (*result == -ENOENT) {
+ rbd_obj_zero_range(obj_req, 0, obj_req->ex.oe_len);
+ *result = 0;
+ } else if (*result >= 0) {
+ if (*result < obj_req->ex.oe_len)
+ rbd_obj_zero_range(obj_req, *result,
+ obj_req->ex.oe_len - *result);
+ else
+ rbd_assert(*result == obj_req->ex.oe_len);
+ *result = 0;
+ }
+ return true;
+ case RBD_OBJ_READ_PARENT:
+ /*
+ * The parent image is read only up to the overlap -- zero-fill
+ * from the overlap to the end of the request.
+ */
+ if (!*result) {
+ u32 obj_overlap = rbd_obj_img_extents_bytes(obj_req);
+
+ if (obj_overlap < obj_req->ex.oe_len)
+ rbd_obj_zero_range(obj_req, obj_overlap,
+ obj_req->ex.oe_len - obj_overlap);
+ }
+ return true;
+ default:
+ BUG();
+ }
+}
+
+static bool rbd_obj_write_is_noop(struct rbd_obj_request *obj_req)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+
+ if (rbd_object_map_may_exist(rbd_dev, obj_req->ex.oe_objno))
+ obj_req->flags |= RBD_OBJ_FLAG_MAY_EXIST;
+
+ if (!(obj_req->flags & RBD_OBJ_FLAG_MAY_EXIST) &&
+ (obj_req->flags & RBD_OBJ_FLAG_NOOP_FOR_NONEXISTENT)) {
+ dout("%s %p noop for nonexistent\n", __func__, obj_req);
+ return true;
+ }
+
+ return false;
+}
+
+/*
+ * Return:
+ * 0 - object map update sent
+ * 1 - object map update isn't needed
+ * <0 - error
+ */
+static int rbd_obj_write_pre_object_map(struct rbd_obj_request *obj_req)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+ u8 new_state;
+
+ if (!(rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP))
+ return 1;
+
+ if (obj_req->flags & RBD_OBJ_FLAG_DELETION)
+ new_state = OBJECT_PENDING;
+ else
+ new_state = OBJECT_EXISTS;
+
+ return rbd_object_map_update(obj_req, CEPH_NOSNAP, new_state, NULL);
+}
+
+static int rbd_obj_write_object(struct rbd_obj_request *obj_req)
+{
+ struct ceph_osd_request *osd_req;
+ int num_ops = count_write_ops(obj_req);
+ int which = 0;
+ int ret;
+
+ if (obj_req->flags & RBD_OBJ_FLAG_COPYUP_ENABLED)
+ num_ops++; /* stat */
+
+ osd_req = rbd_obj_add_osd_request(obj_req, num_ops);
+ if (IS_ERR(osd_req))
+ return PTR_ERR(osd_req);
+
+ if (obj_req->flags & RBD_OBJ_FLAG_COPYUP_ENABLED) {
+ ret = rbd_osd_setup_stat(osd_req, which++);
+ if (ret)
+ return ret;
+ }
+
+ rbd_osd_setup_write_ops(osd_req, which);
+ rbd_osd_format_write(osd_req);
+
+ ret = ceph_osdc_alloc_messages(osd_req, GFP_NOIO);
+ if (ret)
+ return ret;
+
+ rbd_osd_submit(osd_req);
+ return 0;
+}
+
+/*
+ * copyup_bvecs pages are never highmem pages
+ */
+static bool is_zero_bvecs(struct bio_vec *bvecs, u32 bytes)
+{
+ struct ceph_bvec_iter it = {
+ .bvecs = bvecs,
+ .iter = { .bi_size = bytes },
+ };
+
+ ceph_bvec_iter_advance_step(&it, bytes, ({
+ if (memchr_inv(bvec_virt(&bv), 0, bv.bv_len))
+ return false;
+ }));
+ return true;
+}
+
+#define MODS_ONLY U32_MAX
+
+static int rbd_obj_copyup_empty_snapc(struct rbd_obj_request *obj_req,
+ u32 bytes)
+{
+ struct ceph_osd_request *osd_req;
+ int ret;
+
+ dout("%s obj_req %p bytes %u\n", __func__, obj_req, bytes);
+ rbd_assert(bytes > 0 && bytes != MODS_ONLY);
+
+ osd_req = __rbd_obj_add_osd_request(obj_req, &rbd_empty_snapc, 1);
+ if (IS_ERR(osd_req))
+ return PTR_ERR(osd_req);
+
+ ret = rbd_osd_setup_copyup(osd_req, 0, bytes);
+ if (ret)
+ return ret;
+
+ rbd_osd_format_write(osd_req);
+
+ ret = ceph_osdc_alloc_messages(osd_req, GFP_NOIO);
+ if (ret)
+ return ret;
+
+ rbd_osd_submit(osd_req);
+ return 0;
+}
+
+static int rbd_obj_copyup_current_snapc(struct rbd_obj_request *obj_req,
+ u32 bytes)
+{
+ struct ceph_osd_request *osd_req;
+ int num_ops = count_write_ops(obj_req);
+ int which = 0;
+ int ret;
+
+ dout("%s obj_req %p bytes %u\n", __func__, obj_req, bytes);
+
+ if (bytes != MODS_ONLY)
+ num_ops++; /* copyup */
+
+ osd_req = rbd_obj_add_osd_request(obj_req, num_ops);
+ if (IS_ERR(osd_req))
+ return PTR_ERR(osd_req);
+
+ if (bytes != MODS_ONLY) {
+ ret = rbd_osd_setup_copyup(osd_req, which++, bytes);
+ if (ret)
+ return ret;
+ }
+
+ rbd_osd_setup_write_ops(osd_req, which);
+ rbd_osd_format_write(osd_req);
+
+ ret = ceph_osdc_alloc_messages(osd_req, GFP_NOIO);
+ if (ret)
+ return ret;
+
+ rbd_osd_submit(osd_req);
+ return 0;
+}
+
+static int setup_copyup_bvecs(struct rbd_obj_request *obj_req, u64 obj_overlap)
+{
+ u32 i;
+
+ rbd_assert(!obj_req->copyup_bvecs);
+ obj_req->copyup_bvec_count = calc_pages_for(0, obj_overlap);
+ obj_req->copyup_bvecs = kcalloc(obj_req->copyup_bvec_count,
+ sizeof(*obj_req->copyup_bvecs),
+ GFP_NOIO);
+ if (!obj_req->copyup_bvecs)
+ return -ENOMEM;
+
+ for (i = 0; i < obj_req->copyup_bvec_count; i++) {
+ unsigned int len = min(obj_overlap, (u64)PAGE_SIZE);
+ struct page *page = alloc_page(GFP_NOIO);
+
+ if (!page)
+ return -ENOMEM;
+
+ bvec_set_page(&obj_req->copyup_bvecs[i], page, len, 0);
+ obj_overlap -= len;
+ }
+
+ rbd_assert(!obj_overlap);
+ return 0;
+}
+
+/*
+ * The target object doesn't exist. Read the data for the entire
+ * target object up to the overlap point (if any) from the parent,
+ * so we can use it for a copyup.
+ */
+static int rbd_obj_copyup_read_parent(struct rbd_obj_request *obj_req)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+ int ret;
+
+ rbd_assert(obj_req->num_img_extents);
+ prune_extents(obj_req->img_extents, &obj_req->num_img_extents,
+ rbd_dev->parent_overlap);
+ if (!obj_req->num_img_extents) {
+ /*
+ * The overlap has become 0 (most likely because the
+ * image has been flattened). Re-submit the original write
+ * request -- pass MODS_ONLY since the copyup isn't needed
+ * anymore.
+ */
+ return rbd_obj_copyup_current_snapc(obj_req, MODS_ONLY);
+ }
+
+ ret = setup_copyup_bvecs(obj_req, rbd_obj_img_extents_bytes(obj_req));
+ if (ret)
+ return ret;
+
+ return rbd_obj_read_from_parent(obj_req);
+}
+
+static void rbd_obj_copyup_object_maps(struct rbd_obj_request *obj_req)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+ struct ceph_snap_context *snapc = obj_req->img_request->snapc;
+ u8 new_state;
+ u32 i;
+ int ret;
+
+ rbd_assert(!obj_req->pending.result && !obj_req->pending.num_pending);
+
+ if (!(rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP))
+ return;
+
+ if (obj_req->flags & RBD_OBJ_FLAG_COPYUP_ZEROS)
+ return;
+
+ for (i = 0; i < snapc->num_snaps; i++) {
+ if ((rbd_dev->header.features & RBD_FEATURE_FAST_DIFF) &&
+ i + 1 < snapc->num_snaps)
+ new_state = OBJECT_EXISTS_CLEAN;
+ else
+ new_state = OBJECT_EXISTS;
+
+ ret = rbd_object_map_update(obj_req, snapc->snaps[i],
+ new_state, NULL);
+ if (ret < 0) {
+ obj_req->pending.result = ret;
+ return;
+ }
+
+ rbd_assert(!ret);
+ obj_req->pending.num_pending++;
+ }
+}
+
+static void rbd_obj_copyup_write_object(struct rbd_obj_request *obj_req)
+{
+ u32 bytes = rbd_obj_img_extents_bytes(obj_req);
+ int ret;
+
+ rbd_assert(!obj_req->pending.result && !obj_req->pending.num_pending);
+
+ /*
+ * Only send non-zero copyup data to save some I/O and network
+ * bandwidth -- zero copyup data is equivalent to the object not
+ * existing.
+ */
+ if (obj_req->flags & RBD_OBJ_FLAG_COPYUP_ZEROS)
+ bytes = 0;
+
+ if (obj_req->img_request->snapc->num_snaps && bytes > 0) {
+ /*
+ * Send a copyup request with an empty snapshot context to
+ * deep-copyup the object through all existing snapshots.
+ * A second request with the current snapshot context will be
+ * sent for the actual modification.
+ */
+ ret = rbd_obj_copyup_empty_snapc(obj_req, bytes);
+ if (ret) {
+ obj_req->pending.result = ret;
+ return;
+ }
+
+ obj_req->pending.num_pending++;
+ bytes = MODS_ONLY;
+ }
+
+ ret = rbd_obj_copyup_current_snapc(obj_req, bytes);
+ if (ret) {
+ obj_req->pending.result = ret;
+ return;
+ }
+
+ obj_req->pending.num_pending++;
+}
+
+static bool rbd_obj_advance_copyup(struct rbd_obj_request *obj_req, int *result)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+ int ret;
+
+again:
+ switch (obj_req->copyup_state) {
+ case RBD_OBJ_COPYUP_START:
+ rbd_assert(!*result);
+
+ ret = rbd_obj_copyup_read_parent(obj_req);
+ if (ret) {
+ *result = ret;
+ return true;
+ }
+ if (obj_req->num_img_extents)
+ obj_req->copyup_state = RBD_OBJ_COPYUP_READ_PARENT;
+ else
+ obj_req->copyup_state = RBD_OBJ_COPYUP_WRITE_OBJECT;
+ return false;
+ case RBD_OBJ_COPYUP_READ_PARENT:
+ if (*result)
+ return true;
+
+ if (is_zero_bvecs(obj_req->copyup_bvecs,
+ rbd_obj_img_extents_bytes(obj_req))) {
+ dout("%s %p detected zeros\n", __func__, obj_req);
+ obj_req->flags |= RBD_OBJ_FLAG_COPYUP_ZEROS;
+ }
+
+ rbd_obj_copyup_object_maps(obj_req);
+ if (!obj_req->pending.num_pending) {
+ *result = obj_req->pending.result;
+ obj_req->copyup_state = RBD_OBJ_COPYUP_OBJECT_MAPS;
+ goto again;
+ }
+ obj_req->copyup_state = __RBD_OBJ_COPYUP_OBJECT_MAPS;
+ return false;
+ case __RBD_OBJ_COPYUP_OBJECT_MAPS:
+ if (!pending_result_dec(&obj_req->pending, result))
+ return false;
+ fallthrough;
+ case RBD_OBJ_COPYUP_OBJECT_MAPS:
+ if (*result) {
+ rbd_warn(rbd_dev, "snap object map update failed: %d",
+ *result);
+ return true;
+ }
+
+ rbd_obj_copyup_write_object(obj_req);
+ if (!obj_req->pending.num_pending) {
+ *result = obj_req->pending.result;
+ obj_req->copyup_state = RBD_OBJ_COPYUP_WRITE_OBJECT;
+ goto again;
+ }
+ obj_req->copyup_state = __RBD_OBJ_COPYUP_WRITE_OBJECT;
+ return false;
+ case __RBD_OBJ_COPYUP_WRITE_OBJECT:
+ if (!pending_result_dec(&obj_req->pending, result))
+ return false;
+ fallthrough;
+ case RBD_OBJ_COPYUP_WRITE_OBJECT:
+ return true;
+ default:
+ BUG();
+ }
+}
+
+/*
+ * Return:
+ * 0 - object map update sent
+ * 1 - object map update isn't needed
+ * <0 - error
+ */
+static int rbd_obj_write_post_object_map(struct rbd_obj_request *obj_req)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+ u8 current_state = OBJECT_PENDING;
+
+ if (!(rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP))
+ return 1;
+
+ if (!(obj_req->flags & RBD_OBJ_FLAG_DELETION))
+ return 1;
+
+ return rbd_object_map_update(obj_req, CEPH_NOSNAP, OBJECT_NONEXISTENT,
+ &current_state);
+}
+
+static bool rbd_obj_advance_write(struct rbd_obj_request *obj_req, int *result)
+{
+ struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
+ int ret;
+
+again:
+ switch (obj_req->write_state) {
+ case RBD_OBJ_WRITE_START:
+ rbd_assert(!*result);
+
+ rbd_obj_set_copyup_enabled(obj_req);
+ if (rbd_obj_write_is_noop(obj_req))
+ return true;
+
+ ret = rbd_obj_write_pre_object_map(obj_req);
+ if (ret < 0) {
+ *result = ret;
+ return true;
+ }
+ obj_req->write_state = RBD_OBJ_WRITE_PRE_OBJECT_MAP;
+ if (ret > 0)
+ goto again;
+ return false;
+ case RBD_OBJ_WRITE_PRE_OBJECT_MAP:
+ if (*result) {
+ rbd_warn(rbd_dev, "pre object map update failed: %d",
+ *result);
+ return true;
+ }
+ ret = rbd_obj_write_object(obj_req);
+ if (ret) {
+ *result = ret;
+ return true;
+ }
+ obj_req->write_state = RBD_OBJ_WRITE_OBJECT;
+ return false;
+ case RBD_OBJ_WRITE_OBJECT:
+ if (*result == -ENOENT) {
+ if (obj_req->flags & RBD_OBJ_FLAG_COPYUP_ENABLED) {
+ *result = 0;
+ obj_req->copyup_state = RBD_OBJ_COPYUP_START;
+ obj_req->write_state = __RBD_OBJ_WRITE_COPYUP;
+ goto again;
+ }
+ /*
+ * On a non-existent object:
+ * delete - -ENOENT, truncate/zero - 0
+ */
+ if (obj_req->flags & RBD_OBJ_FLAG_DELETION)
+ *result = 0;
+ }
+ if (*result)
+ return true;
+
+ obj_req->write_state = RBD_OBJ_WRITE_COPYUP;
+ goto again;
+ case __RBD_OBJ_WRITE_COPYUP:
+ if (!rbd_obj_advance_copyup(obj_req, result))
+ return false;
+ fallthrough;
+ case RBD_OBJ_WRITE_COPYUP:
+ if (*result) {
+ rbd_warn(rbd_dev, "copyup failed: %d", *result);
+ return true;
+ }
+ ret = rbd_obj_write_post_object_map(obj_req);
+ if (ret < 0) {
+ *result = ret;
+ return true;
+ }
+ obj_req->write_state = RBD_OBJ_WRITE_POST_OBJECT_MAP;
+ if (ret > 0)
+ goto again;
+ return false;
+ case RBD_OBJ_WRITE_POST_OBJECT_MAP:
+ if (*result)
+ rbd_warn(rbd_dev, "post object map update failed: %d",
+ *result);
+ return true;
+ default:
+ BUG();
+ }
+}
+
+/*
+ * Return true if @obj_req is completed.
+ */
+static bool __rbd_obj_handle_request(struct rbd_obj_request *obj_req,
+ int *result)
+{
+ struct rbd_img_request *img_req = obj_req->img_request;
+ struct rbd_device *rbd_dev = img_req->rbd_dev;
+ bool done;
+
+ mutex_lock(&obj_req->state_mutex);
+ if (!rbd_img_is_write(img_req))
+ done = rbd_obj_advance_read(obj_req, result);
+ else
+ done = rbd_obj_advance_write(obj_req, result);
+ mutex_unlock(&obj_req->state_mutex);
+
+ if (done && *result) {
+ rbd_assert(*result < 0);
+ rbd_warn(rbd_dev, "%s at objno %llu %llu~%llu result %d",
+ obj_op_name(img_req->op_type), obj_req->ex.oe_objno,
+ obj_req->ex.oe_off, obj_req->ex.oe_len, *result);
+ }
+ return done;
+}
+
+/*
+ * This is open-coded in rbd_img_handle_request() to avoid parent chain
+ * recursion.
+ */
+static void rbd_obj_handle_request(struct rbd_obj_request *obj_req, int result)
+{
+ if (__rbd_obj_handle_request(obj_req, &result))
+ rbd_img_handle_request(obj_req->img_request, result);
+}
+
+static bool need_exclusive_lock(struct rbd_img_request *img_req)
+{
+ struct rbd_device *rbd_dev = img_req->rbd_dev;
+
+ if (!(rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK))
+ return false;
+
+ if (rbd_is_ro(rbd_dev))
+ return false;
+
+ rbd_assert(!test_bit(IMG_REQ_CHILD, &img_req->flags));
+ if (rbd_dev->opts->lock_on_read ||
+ (rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP))
+ return true;
+
+ return rbd_img_is_write(img_req);
+}
+
+static bool rbd_lock_add_request(struct rbd_img_request *img_req)
+{
+ struct rbd_device *rbd_dev = img_req->rbd_dev;
+ bool locked;
+
+ lockdep_assert_held(&rbd_dev->lock_rwsem);
+ locked = rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED;
+ spin_lock(&rbd_dev->lock_lists_lock);
+ rbd_assert(list_empty(&img_req->lock_item));
+ if (!locked)
+ list_add_tail(&img_req->lock_item, &rbd_dev->acquiring_list);
+ else
+ list_add_tail(&img_req->lock_item, &rbd_dev->running_list);
+ spin_unlock(&rbd_dev->lock_lists_lock);
+ return locked;
+}
+
+static void rbd_lock_del_request(struct rbd_img_request *img_req)
+{
+ struct rbd_device *rbd_dev = img_req->rbd_dev;
+ bool need_wakeup = false;
+
+ lockdep_assert_held(&rbd_dev->lock_rwsem);
+ spin_lock(&rbd_dev->lock_lists_lock);
+ if (!list_empty(&img_req->lock_item)) {
+ list_del_init(&img_req->lock_item);
+ need_wakeup = (rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING &&
+ list_empty(&rbd_dev->running_list));
+ }
+ spin_unlock(&rbd_dev->lock_lists_lock);
+ if (need_wakeup)
+ complete(&rbd_dev->releasing_wait);
+}
+
+static int rbd_img_exclusive_lock(struct rbd_img_request *img_req)
+{
+ struct rbd_device *rbd_dev = img_req->rbd_dev;
+
+ if (!need_exclusive_lock(img_req))
+ return 1;
+
+ if (rbd_lock_add_request(img_req))
+ return 1;
+
+ if (rbd_dev->opts->exclusive) {
+ WARN_ON(1); /* lock got released? */
+ return -EROFS;
+ }
+
+ /*
+ * Note the use of mod_delayed_work() in rbd_acquire_lock()
+ * and cancel_delayed_work() in wake_lock_waiters().
+ */
+ dout("%s rbd_dev %p queueing lock_dwork\n", __func__, rbd_dev);
+ queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
+ return 0;
+}
+
+static void rbd_img_object_requests(struct rbd_img_request *img_req)
+{
+ struct rbd_device *rbd_dev = img_req->rbd_dev;
+ struct rbd_obj_request *obj_req;
+
+ rbd_assert(!img_req->pending.result && !img_req->pending.num_pending);
+ rbd_assert(!need_exclusive_lock(img_req) ||
+ __rbd_is_lock_owner(rbd_dev));
+
+ if (rbd_img_is_write(img_req)) {
+ rbd_assert(!img_req->snapc);
+ down_read(&rbd_dev->header_rwsem);
+ img_req->snapc = ceph_get_snap_context(rbd_dev->header.snapc);
+ up_read(&rbd_dev->header_rwsem);
+ }
+
+ for_each_obj_request(img_req, obj_req) {
+ int result = 0;
+
+ if (__rbd_obj_handle_request(obj_req, &result)) {
+ if (result) {
+ img_req->pending.result = result;
+ return;
+ }
+ } else {
+ img_req->pending.num_pending++;
+ }
+ }
+}
+
+static bool rbd_img_advance(struct rbd_img_request *img_req, int *result)
+{
+ int ret;
+
+again:
+ switch (img_req->state) {
+ case RBD_IMG_START:
+ rbd_assert(!*result);
+
+ ret = rbd_img_exclusive_lock(img_req);
+ if (ret < 0) {
+ *result = ret;
+ return true;
+ }
+ img_req->state = RBD_IMG_EXCLUSIVE_LOCK;
+ if (ret > 0)
+ goto again;
+ return false;
+ case RBD_IMG_EXCLUSIVE_LOCK:
+ if (*result)
+ return true;
+
+ rbd_img_object_requests(img_req);
+ if (!img_req->pending.num_pending) {
+ *result = img_req->pending.result;
+ img_req->state = RBD_IMG_OBJECT_REQUESTS;
+ goto again;
+ }
+ img_req->state = __RBD_IMG_OBJECT_REQUESTS;
+ return false;
+ case __RBD_IMG_OBJECT_REQUESTS:
+ if (!pending_result_dec(&img_req->pending, result))
+ return false;
+ fallthrough;
+ case RBD_IMG_OBJECT_REQUESTS:
+ return true;
+ default:
+ BUG();
+ }
+}
+
+/*
+ * Return true if @img_req is completed.
+ */
+static bool __rbd_img_handle_request(struct rbd_img_request *img_req,
+ int *result)
+{
+ struct rbd_device *rbd_dev = img_req->rbd_dev;
+ bool done;
+
+ if (need_exclusive_lock(img_req)) {
+ down_read(&rbd_dev->lock_rwsem);
+ mutex_lock(&img_req->state_mutex);
+ done = rbd_img_advance(img_req, result);
+ if (done)
+ rbd_lock_del_request(img_req);
+ mutex_unlock(&img_req->state_mutex);
+ up_read(&rbd_dev->lock_rwsem);
+ } else {
+ mutex_lock(&img_req->state_mutex);
+ done = rbd_img_advance(img_req, result);
+ mutex_unlock(&img_req->state_mutex);
+ }
+
+ if (done && *result) {
+ rbd_assert(*result < 0);
+ rbd_warn(rbd_dev, "%s%s result %d",
+ test_bit(IMG_REQ_CHILD, &img_req->flags) ? "child " : "",
+ obj_op_name(img_req->op_type), *result);
+ }
+ return done;
+}
+
+static void rbd_img_handle_request(struct rbd_img_request *img_req, int result)
+{
+again:
+ if (!__rbd_img_handle_request(img_req, &result))
+ return;
+
+ if (test_bit(IMG_REQ_CHILD, &img_req->flags)) {
+ struct rbd_obj_request *obj_req = img_req->obj_request;
+
+ rbd_img_request_destroy(img_req);
+ if (__rbd_obj_handle_request(obj_req, &result)) {
+ img_req = obj_req->img_request;
+ goto again;
+ }
+ } else {
+ struct request *rq = blk_mq_rq_from_pdu(img_req);
+
+ rbd_img_request_destroy(img_req);
+ blk_mq_end_request(rq, errno_to_blk_status(result));
+ }
+}
+
+static const struct rbd_client_id rbd_empty_cid;
+
+static bool rbd_cid_equal(const struct rbd_client_id *lhs,
+ const struct rbd_client_id *rhs)
+{
+ return lhs->gid == rhs->gid && lhs->handle == rhs->handle;
+}
+
+static struct rbd_client_id rbd_get_cid(struct rbd_device *rbd_dev)
+{
+ struct rbd_client_id cid;
+
+ mutex_lock(&rbd_dev->watch_mutex);
+ cid.gid = ceph_client_gid(rbd_dev->rbd_client->client);
+ cid.handle = rbd_dev->watch_cookie;
+ mutex_unlock(&rbd_dev->watch_mutex);
+ return cid;
+}
+
+/*
+ * lock_rwsem must be held for write
+ */
+static void rbd_set_owner_cid(struct rbd_device *rbd_dev,
+ const struct rbd_client_id *cid)
+{
+ dout("%s rbd_dev %p %llu-%llu -> %llu-%llu\n", __func__, rbd_dev,
+ rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle,
+ cid->gid, cid->handle);
+ rbd_dev->owner_cid = *cid; /* struct */
+}
+
+static void format_lock_cookie(struct rbd_device *rbd_dev, char *buf)
+{
+ mutex_lock(&rbd_dev->watch_mutex);
+ sprintf(buf, "%s %llu", RBD_LOCK_COOKIE_PREFIX, rbd_dev->watch_cookie);
+ mutex_unlock(&rbd_dev->watch_mutex);
+}
+
+static void __rbd_lock(struct rbd_device *rbd_dev, const char *cookie)
+{
+ struct rbd_client_id cid = rbd_get_cid(rbd_dev);
+
+ rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
+ strcpy(rbd_dev->lock_cookie, cookie);
+ rbd_set_owner_cid(rbd_dev, &cid);
+ queue_work(rbd_dev->task_wq, &rbd_dev->acquired_lock_work);
+}
+
+/*
+ * lock_rwsem must be held for write
+ */
+static int rbd_lock(struct rbd_device *rbd_dev)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ char cookie[32];
+ int ret;
+
+ WARN_ON(__rbd_is_lock_owner(rbd_dev) ||
+ rbd_dev->lock_cookie[0] != '\0');
+
+ format_lock_cookie(rbd_dev, cookie);
+ ret = ceph_cls_lock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
+ RBD_LOCK_NAME, CEPH_CLS_LOCK_EXCLUSIVE, cookie,
+ RBD_LOCK_TAG, "", 0);
+ if (ret && ret != -EEXIST)
+ return ret;
+
+ __rbd_lock(rbd_dev, cookie);
+ return 0;
+}
+
+/*
+ * lock_rwsem must be held for write
+ */
+static void rbd_unlock(struct rbd_device *rbd_dev)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ int ret;
+
+ WARN_ON(!__rbd_is_lock_owner(rbd_dev) ||
+ rbd_dev->lock_cookie[0] == '\0');
+
+ ret = ceph_cls_unlock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
+ RBD_LOCK_NAME, rbd_dev->lock_cookie);
+ if (ret && ret != -ENOENT)
+ rbd_warn(rbd_dev, "failed to unlock header: %d", ret);
+
+ /* treat errors as the image is unlocked */
+ rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
+ rbd_dev->lock_cookie[0] = '\0';
+ rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
+ queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
+}
+
+static int __rbd_notify_op_lock(struct rbd_device *rbd_dev,
+ enum rbd_notify_op notify_op,
+ struct page ***preply_pages,
+ size_t *preply_len)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ struct rbd_client_id cid = rbd_get_cid(rbd_dev);
+ char buf[4 + 8 + 8 + CEPH_ENCODING_START_BLK_LEN];
+ int buf_size = sizeof(buf);
+ void *p = buf;
+
+ dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op);
+
+ /* encode *LockPayload NotifyMessage (op + ClientId) */
+ ceph_start_encoding(&p, 2, 1, buf_size - CEPH_ENCODING_START_BLK_LEN);
+ ceph_encode_32(&p, notify_op);
+ ceph_encode_64(&p, cid.gid);
+ ceph_encode_64(&p, cid.handle);
+
+ return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, buf, buf_size,
+ RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
+}
+
+static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
+ enum rbd_notify_op notify_op)
+{
+ __rbd_notify_op_lock(rbd_dev, notify_op, NULL, NULL);
+}
+
+static void rbd_notify_acquired_lock(struct work_struct *work)
+{
+ struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
+ acquired_lock_work);
+
+ rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
+}
+
+static void rbd_notify_released_lock(struct work_struct *work)
+{
+ struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
+ released_lock_work);
+
+ rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
+}
+
+static int rbd_request_lock(struct rbd_device *rbd_dev)
+{
+ struct page **reply_pages;
+ size_t reply_len;
+ bool lock_owner_responded = false;
+ int ret;
+
+ dout("%s rbd_dev %p\n", __func__, rbd_dev);
+
+ ret = __rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_REQUEST_LOCK,
+ &reply_pages, &reply_len);
+ if (ret && ret != -ETIMEDOUT) {
+ rbd_warn(rbd_dev, "failed to request lock: %d", ret);
+ goto out;
+ }
+
+ if (reply_len > 0 && reply_len <= PAGE_SIZE) {
+ void *p = page_address(reply_pages[0]);
+ void *const end = p + reply_len;
+ u32 n;
+
+ ceph_decode_32_safe(&p, end, n, e_inval); /* num_acks */
+ while (n--) {
+ u8 struct_v;
+ u32 len;
+
+ ceph_decode_need(&p, end, 8 + 8, e_inval);
+ p += 8 + 8; /* skip gid and cookie */
+
+ ceph_decode_32_safe(&p, end, len, e_inval);
+ if (!len)
+ continue;
+
+ if (lock_owner_responded) {
+ rbd_warn(rbd_dev,
+ "duplicate lock owners detected");
+ ret = -EIO;
+ goto out;
+ }
+
+ lock_owner_responded = true;
+ ret = ceph_start_decoding(&p, end, 1, "ResponseMessage",
+ &struct_v, &len);
+ if (ret) {
+ rbd_warn(rbd_dev,
+ "failed to decode ResponseMessage: %d",
+ ret);
+ goto e_inval;
+ }
+
+ ret = ceph_decode_32(&p);
+ }
+ }
+
+ if (!lock_owner_responded) {
+ rbd_warn(rbd_dev, "no lock owners detected");
+ ret = -ETIMEDOUT;
+ }
+
+out:
+ ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
+ return ret;
+
+e_inval:
+ ret = -EINVAL;
+ goto out;
+}
+
+/*
+ * Either image request state machine(s) or rbd_add_acquire_lock()
+ * (i.e. "rbd map").
+ */
+static void wake_lock_waiters(struct rbd_device *rbd_dev, int result)
+{
+ struct rbd_img_request *img_req;
+
+ dout("%s rbd_dev %p result %d\n", __func__, rbd_dev, result);
+ lockdep_assert_held_write(&rbd_dev->lock_rwsem);
+
+ cancel_delayed_work(&rbd_dev->lock_dwork);
+ if (!completion_done(&rbd_dev->acquire_wait)) {
+ rbd_assert(list_empty(&rbd_dev->acquiring_list) &&
+ list_empty(&rbd_dev->running_list));
+ rbd_dev->acquire_err = result;
+ complete_all(&rbd_dev->acquire_wait);
+ return;
+ }
+
+ while (!list_empty(&rbd_dev->acquiring_list)) {
+ img_req = list_first_entry(&rbd_dev->acquiring_list,
+ struct rbd_img_request, lock_item);
+ mutex_lock(&img_req->state_mutex);
+ rbd_assert(img_req->state == RBD_IMG_EXCLUSIVE_LOCK);
+ if (!result)
+ list_move_tail(&img_req->lock_item,
+ &rbd_dev->running_list);
+ else
+ list_del_init(&img_req->lock_item);
+ rbd_img_schedule(img_req, result);
+ mutex_unlock(&img_req->state_mutex);
+ }
+}
+
+static bool locker_equal(const struct ceph_locker *lhs,
+ const struct ceph_locker *rhs)
+{
+ return lhs->id.name.type == rhs->id.name.type &&
+ lhs->id.name.num == rhs->id.name.num &&
+ !strcmp(lhs->id.cookie, rhs->id.cookie) &&
+ ceph_addr_equal_no_type(&lhs->info.addr, &rhs->info.addr);
+}
+
+static void free_locker(struct ceph_locker *locker)
+{
+ if (locker)
+ ceph_free_lockers(locker, 1);
+}
+
+static struct ceph_locker *get_lock_owner_info(struct rbd_device *rbd_dev)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ struct ceph_locker *lockers;
+ u32 num_lockers;
+ u8 lock_type;
+ char *lock_tag;
+ u64 handle;
+ int ret;
+
+ ret = ceph_cls_lock_info(osdc, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, RBD_LOCK_NAME,
+ &lock_type, &lock_tag, &lockers, &num_lockers);
+ if (ret) {
+ rbd_warn(rbd_dev, "failed to get header lockers: %d", ret);
+ return ERR_PTR(ret);
+ }
+
+ if (num_lockers == 0) {
+ dout("%s rbd_dev %p no lockers detected\n", __func__, rbd_dev);
+ lockers = NULL;
+ goto out;
+ }
+
+ if (strcmp(lock_tag, RBD_LOCK_TAG)) {
+ rbd_warn(rbd_dev, "locked by external mechanism, tag %s",
+ lock_tag);
+ goto err_busy;
+ }
+
+ if (lock_type != CEPH_CLS_LOCK_EXCLUSIVE) {
+ rbd_warn(rbd_dev, "incompatible lock type detected");
+ goto err_busy;
+ }
+
+ WARN_ON(num_lockers != 1);
+ ret = sscanf(lockers[0].id.cookie, RBD_LOCK_COOKIE_PREFIX " %llu",
+ &handle);
+ if (ret != 1) {
+ rbd_warn(rbd_dev, "locked by external mechanism, cookie %s",
+ lockers[0].id.cookie);
+ goto err_busy;
+ }
+ if (ceph_addr_is_blank(&lockers[0].info.addr)) {
+ rbd_warn(rbd_dev, "locker has a blank address");
+ goto err_busy;
+ }
+
+ dout("%s rbd_dev %p got locker %s%llu@%pISpc/%u handle %llu\n",
+ __func__, rbd_dev, ENTITY_NAME(lockers[0].id.name),
+ &lockers[0].info.addr.in_addr,
+ le32_to_cpu(lockers[0].info.addr.nonce), handle);
+
+out:
+ kfree(lock_tag);
+ return lockers;
+
+err_busy:
+ kfree(lock_tag);
+ ceph_free_lockers(lockers, num_lockers);
+ return ERR_PTR(-EBUSY);
+}
+
+static int find_watcher(struct rbd_device *rbd_dev,
+ const struct ceph_locker *locker)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ struct ceph_watch_item *watchers;
+ u32 num_watchers;
+ u64 cookie;
+ int i;
+ int ret;
+
+ ret = ceph_osdc_list_watchers(osdc, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, &watchers,
+ &num_watchers);
+ if (ret) {
+ rbd_warn(rbd_dev, "failed to get watchers: %d", ret);
+ return ret;
+ }
+
+ sscanf(locker->id.cookie, RBD_LOCK_COOKIE_PREFIX " %llu", &cookie);
+ for (i = 0; i < num_watchers; i++) {
+ /*
+ * Ignore addr->type while comparing. This mimics
+ * entity_addr_t::get_legacy_str() + strcmp().
+ */
+ if (ceph_addr_equal_no_type(&watchers[i].addr,
+ &locker->info.addr) &&
+ watchers[i].cookie == cookie) {
+ struct rbd_client_id cid = {
+ .gid = le64_to_cpu(watchers[i].name.num),
+ .handle = cookie,
+ };
+
+ dout("%s rbd_dev %p found cid %llu-%llu\n", __func__,
+ rbd_dev, cid.gid, cid.handle);
+ rbd_set_owner_cid(rbd_dev, &cid);
+ ret = 1;
+ goto out;
+ }
+ }
+
+ dout("%s rbd_dev %p no watchers\n", __func__, rbd_dev);
+ ret = 0;
+out:
+ kfree(watchers);
+ return ret;
+}
+
+/*
+ * lock_rwsem must be held for write
+ */
+static int rbd_try_lock(struct rbd_device *rbd_dev)
+{
+ struct ceph_client *client = rbd_dev->rbd_client->client;
+ struct ceph_locker *locker, *refreshed_locker;
+ int ret;
+
+ for (;;) {
+ locker = refreshed_locker = NULL;
+
+ ret = rbd_lock(rbd_dev);
+ if (!ret)
+ goto out;
+ if (ret != -EBUSY) {
+ rbd_warn(rbd_dev, "failed to lock header: %d", ret);
+ goto out;
+ }
+
+ /* determine if the current lock holder is still alive */
+ locker = get_lock_owner_info(rbd_dev);
+ if (IS_ERR(locker)) {
+ ret = PTR_ERR(locker);
+ locker = NULL;
+ goto out;
+ }
+ if (!locker)
+ goto again;
+
+ ret = find_watcher(rbd_dev, locker);
+ if (ret)
+ goto out; /* request lock or error */
+
+ refreshed_locker = get_lock_owner_info(rbd_dev);
+ if (IS_ERR(refreshed_locker)) {
+ ret = PTR_ERR(refreshed_locker);
+ refreshed_locker = NULL;
+ goto out;
+ }
+ if (!refreshed_locker ||
+ !locker_equal(locker, refreshed_locker))
+ goto again;
+
+ rbd_warn(rbd_dev, "breaking header lock owned by %s%llu",
+ ENTITY_NAME(locker->id.name));
+
+ ret = ceph_monc_blocklist_add(&client->monc,
+ &locker->info.addr);
+ if (ret) {
+ rbd_warn(rbd_dev, "failed to blocklist %s%llu: %d",
+ ENTITY_NAME(locker->id.name), ret);
+ goto out;
+ }
+
+ ret = ceph_cls_break_lock(&client->osdc, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, RBD_LOCK_NAME,
+ locker->id.cookie, &locker->id.name);
+ if (ret && ret != -ENOENT) {
+ rbd_warn(rbd_dev, "failed to break header lock: %d",
+ ret);
+ goto out;
+ }
+
+again:
+ free_locker(refreshed_locker);
+ free_locker(locker);
+ }
+
+out:
+ free_locker(refreshed_locker);
+ free_locker(locker);
+ return ret;
+}
+
+static int rbd_post_acquire_action(struct rbd_device *rbd_dev)
+{
+ int ret;
+
+ ret = rbd_dev_refresh(rbd_dev);
+ if (ret)
+ return ret;
+
+ if (rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP) {
+ ret = rbd_object_map_open(rbd_dev);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * Return:
+ * 0 - lock acquired
+ * 1 - caller should call rbd_request_lock()
+ * <0 - error
+ */
+static int rbd_try_acquire_lock(struct rbd_device *rbd_dev)
+{
+ int ret;
+
+ down_read(&rbd_dev->lock_rwsem);
+ dout("%s rbd_dev %p read lock_state %d\n", __func__, rbd_dev,
+ rbd_dev->lock_state);
+ if (__rbd_is_lock_owner(rbd_dev)) {
+ up_read(&rbd_dev->lock_rwsem);
+ return 0;
+ }
+
+ up_read(&rbd_dev->lock_rwsem);
+ down_write(&rbd_dev->lock_rwsem);
+ dout("%s rbd_dev %p write lock_state %d\n", __func__, rbd_dev,
+ rbd_dev->lock_state);
+ if (__rbd_is_lock_owner(rbd_dev)) {
+ up_write(&rbd_dev->lock_rwsem);
+ return 0;
+ }
+
+ ret = rbd_try_lock(rbd_dev);
+ if (ret < 0) {
+ rbd_warn(rbd_dev, "failed to acquire lock: %d", ret);
+ goto out;
+ }
+ if (ret > 0) {
+ up_write(&rbd_dev->lock_rwsem);
+ return ret;
+ }
+
+ rbd_assert(rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED);
+ rbd_assert(list_empty(&rbd_dev->running_list));
+
+ ret = rbd_post_acquire_action(rbd_dev);
+ if (ret) {
+ rbd_warn(rbd_dev, "post-acquire action failed: %d", ret);
+ /*
+ * Can't stay in RBD_LOCK_STATE_LOCKED because
+ * rbd_lock_add_request() would let the request through,
+ * assuming that e.g. object map is locked and loaded.
+ */
+ rbd_unlock(rbd_dev);
+ }
+
+out:
+ wake_lock_waiters(rbd_dev, ret);
+ up_write(&rbd_dev->lock_rwsem);
+ return ret;
+}
+
+static void rbd_acquire_lock(struct work_struct *work)
+{
+ struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
+ struct rbd_device, lock_dwork);
+ int ret;
+
+ dout("%s rbd_dev %p\n", __func__, rbd_dev);
+again:
+ ret = rbd_try_acquire_lock(rbd_dev);
+ if (ret <= 0) {
+ dout("%s rbd_dev %p ret %d - done\n", __func__, rbd_dev, ret);
+ return;
+ }
+
+ ret = rbd_request_lock(rbd_dev);
+ if (ret == -ETIMEDOUT) {
+ goto again; /* treat this as a dead client */
+ } else if (ret == -EROFS) {
+ rbd_warn(rbd_dev, "peer will not release lock");
+ down_write(&rbd_dev->lock_rwsem);
+ wake_lock_waiters(rbd_dev, ret);
+ up_write(&rbd_dev->lock_rwsem);
+ } else if (ret < 0) {
+ rbd_warn(rbd_dev, "error requesting lock: %d", ret);
+ mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
+ RBD_RETRY_DELAY);
+ } else {
+ /*
+ * lock owner acked, but resend if we don't see them
+ * release the lock
+ */
+ dout("%s rbd_dev %p requeuing lock_dwork\n", __func__,
+ rbd_dev);
+ mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
+ msecs_to_jiffies(2 * RBD_NOTIFY_TIMEOUT * MSEC_PER_SEC));
+ }
+}
+
+static bool rbd_quiesce_lock(struct rbd_device *rbd_dev)
+{
+ dout("%s rbd_dev %p\n", __func__, rbd_dev);
+ lockdep_assert_held_write(&rbd_dev->lock_rwsem);
+
+ if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED)
+ return false;
+
+ /*
+ * Ensure that all in-flight IO is flushed.
+ */
+ rbd_dev->lock_state = RBD_LOCK_STATE_RELEASING;
+ rbd_assert(!completion_done(&rbd_dev->releasing_wait));
+ if (list_empty(&rbd_dev->running_list))
+ return true;
+
+ up_write(&rbd_dev->lock_rwsem);
+ wait_for_completion(&rbd_dev->releasing_wait);
+
+ down_write(&rbd_dev->lock_rwsem);
+ if (rbd_dev->lock_state != RBD_LOCK_STATE_RELEASING)
+ return false;
+
+ rbd_assert(list_empty(&rbd_dev->running_list));
+ return true;
+}
+
+static void rbd_pre_release_action(struct rbd_device *rbd_dev)
+{
+ if (rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP)
+ rbd_object_map_close(rbd_dev);
+}
+
+static void __rbd_release_lock(struct rbd_device *rbd_dev)
+{
+ rbd_assert(list_empty(&rbd_dev->running_list));
+
+ rbd_pre_release_action(rbd_dev);
+ rbd_unlock(rbd_dev);
+}
+
+/*
+ * lock_rwsem must be held for write
+ */
+static void rbd_release_lock(struct rbd_device *rbd_dev)
+{
+ if (!rbd_quiesce_lock(rbd_dev))
+ return;
+
+ __rbd_release_lock(rbd_dev);
+
+ /*
+ * Give others a chance to grab the lock - we would re-acquire
+ * almost immediately if we got new IO while draining the running
+ * list otherwise. We need to ack our own notifications, so this
+ * lock_dwork will be requeued from rbd_handle_released_lock() by
+ * way of maybe_kick_acquire().
+ */
+ cancel_delayed_work(&rbd_dev->lock_dwork);
+}
+
+static void rbd_release_lock_work(struct work_struct *work)
+{
+ struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
+ unlock_work);
+
+ down_write(&rbd_dev->lock_rwsem);
+ rbd_release_lock(rbd_dev);
+ up_write(&rbd_dev->lock_rwsem);
+}
+
+static void maybe_kick_acquire(struct rbd_device *rbd_dev)
+{
+ bool have_requests;
+
+ dout("%s rbd_dev %p\n", __func__, rbd_dev);
+ if (__rbd_is_lock_owner(rbd_dev))
+ return;
+
+ spin_lock(&rbd_dev->lock_lists_lock);
+ have_requests = !list_empty(&rbd_dev->acquiring_list);
+ spin_unlock(&rbd_dev->lock_lists_lock);
+ if (have_requests || delayed_work_pending(&rbd_dev->lock_dwork)) {
+ dout("%s rbd_dev %p kicking lock_dwork\n", __func__, rbd_dev);
+ mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
+ }
+}
+
+static void rbd_handle_acquired_lock(struct rbd_device *rbd_dev, u8 struct_v,
+ void **p)
+{
+ struct rbd_client_id cid = { 0 };
+
+ if (struct_v >= 2) {
+ cid.gid = ceph_decode_64(p);
+ cid.handle = ceph_decode_64(p);
+ }
+
+ dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
+ cid.handle);
+ if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
+ down_write(&rbd_dev->lock_rwsem);
+ if (rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
+ dout("%s rbd_dev %p cid %llu-%llu == owner_cid\n",
+ __func__, rbd_dev, cid.gid, cid.handle);
+ } else {
+ rbd_set_owner_cid(rbd_dev, &cid);
+ }
+ downgrade_write(&rbd_dev->lock_rwsem);
+ } else {
+ down_read(&rbd_dev->lock_rwsem);
+ }
+
+ maybe_kick_acquire(rbd_dev);
+ up_read(&rbd_dev->lock_rwsem);
+}
+
+static void rbd_handle_released_lock(struct rbd_device *rbd_dev, u8 struct_v,
+ void **p)
+{
+ struct rbd_client_id cid = { 0 };
+
+ if (struct_v >= 2) {
+ cid.gid = ceph_decode_64(p);
+ cid.handle = ceph_decode_64(p);
+ }
+
+ dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
+ cid.handle);
+ if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
+ down_write(&rbd_dev->lock_rwsem);
+ if (!rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
+ dout("%s rbd_dev %p cid %llu-%llu != owner_cid %llu-%llu\n",
+ __func__, rbd_dev, cid.gid, cid.handle,
+ rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle);
+ } else {
+ rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
+ }
+ downgrade_write(&rbd_dev->lock_rwsem);
+ } else {
+ down_read(&rbd_dev->lock_rwsem);
+ }
+
+ maybe_kick_acquire(rbd_dev);
+ up_read(&rbd_dev->lock_rwsem);
+}
+
+/*
+ * Returns result for ResponseMessage to be encoded (<= 0), or 1 if no
+ * ResponseMessage is needed.
+ */
+static int rbd_handle_request_lock(struct rbd_device *rbd_dev, u8 struct_v,
+ void **p)
+{
+ struct rbd_client_id my_cid = rbd_get_cid(rbd_dev);
+ struct rbd_client_id cid = { 0 };
+ int result = 1;
+
+ if (struct_v >= 2) {
+ cid.gid = ceph_decode_64(p);
+ cid.handle = ceph_decode_64(p);
+ }
+
+ dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
+ cid.handle);
+ if (rbd_cid_equal(&cid, &my_cid))
+ return result;
+
+ down_read(&rbd_dev->lock_rwsem);
+ if (__rbd_is_lock_owner(rbd_dev)) {
+ if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED &&
+ rbd_cid_equal(&rbd_dev->owner_cid, &rbd_empty_cid))
+ goto out_unlock;
+
+ /*
+ * encode ResponseMessage(0) so the peer can detect
+ * a missing owner
+ */
+ result = 0;
+
+ if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) {
+ if (!rbd_dev->opts->exclusive) {
+ dout("%s rbd_dev %p queueing unlock_work\n",
+ __func__, rbd_dev);
+ queue_work(rbd_dev->task_wq,
+ &rbd_dev->unlock_work);
+ } else {
+ /* refuse to release the lock */
+ result = -EROFS;
+ }
+ }
+ }
+
+out_unlock:
+ up_read(&rbd_dev->lock_rwsem);
+ return result;
+}
+
+static void __rbd_acknowledge_notify(struct rbd_device *rbd_dev,
+ u64 notify_id, u64 cookie, s32 *result)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ char buf[4 + CEPH_ENCODING_START_BLK_LEN];
+ int buf_size = sizeof(buf);
+ int ret;
+
+ if (result) {
+ void *p = buf;
+
+ /* encode ResponseMessage */
+ ceph_start_encoding(&p, 1, 1,
+ buf_size - CEPH_ENCODING_START_BLK_LEN);
+ ceph_encode_32(&p, *result);
+ } else {
+ buf_size = 0;
+ }
+
+ ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, notify_id, cookie,
+ buf, buf_size);
+ if (ret)
+ rbd_warn(rbd_dev, "acknowledge_notify failed: %d", ret);
+}
+
+static void rbd_acknowledge_notify(struct rbd_device *rbd_dev, u64 notify_id,
+ u64 cookie)
+{
+ dout("%s rbd_dev %p\n", __func__, rbd_dev);
+ __rbd_acknowledge_notify(rbd_dev, notify_id, cookie, NULL);
+}
+
+static void rbd_acknowledge_notify_result(struct rbd_device *rbd_dev,
+ u64 notify_id, u64 cookie, s32 result)
+{
+ dout("%s rbd_dev %p result %d\n", __func__, rbd_dev, result);
+ __rbd_acknowledge_notify(rbd_dev, notify_id, cookie, &result);
+}
+
+static void rbd_watch_cb(void *arg, u64 notify_id, u64 cookie,
+ u64 notifier_id, void *data, size_t data_len)
+{
+ struct rbd_device *rbd_dev = arg;
+ void *p = data;
+ void *const end = p + data_len;
+ u8 struct_v = 0;
+ u32 len;
+ u32 notify_op;
+ int ret;
+
+ dout("%s rbd_dev %p cookie %llu notify_id %llu data_len %zu\n",
+ __func__, rbd_dev, cookie, notify_id, data_len);
+ if (data_len) {
+ ret = ceph_start_decoding(&p, end, 1, "NotifyMessage",
+ &struct_v, &len);
+ if (ret) {
+ rbd_warn(rbd_dev, "failed to decode NotifyMessage: %d",
+ ret);
+ return;
+ }
+
+ notify_op = ceph_decode_32(&p);
+ } else {
+ /* legacy notification for header updates */
+ notify_op = RBD_NOTIFY_OP_HEADER_UPDATE;
+ len = 0;
+ }
+
+ dout("%s rbd_dev %p notify_op %u\n", __func__, rbd_dev, notify_op);
+ switch (notify_op) {
+ case RBD_NOTIFY_OP_ACQUIRED_LOCK:
+ rbd_handle_acquired_lock(rbd_dev, struct_v, &p);
+ rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
+ break;
+ case RBD_NOTIFY_OP_RELEASED_LOCK:
+ rbd_handle_released_lock(rbd_dev, struct_v, &p);
+ rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
+ break;
+ case RBD_NOTIFY_OP_REQUEST_LOCK:
+ ret = rbd_handle_request_lock(rbd_dev, struct_v, &p);
+ if (ret <= 0)
+ rbd_acknowledge_notify_result(rbd_dev, notify_id,
+ cookie, ret);
+ else
+ rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
+ break;
+ case RBD_NOTIFY_OP_HEADER_UPDATE:
+ ret = rbd_dev_refresh(rbd_dev);
+ if (ret)
+ rbd_warn(rbd_dev, "refresh failed: %d", ret);
+
+ rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
+ break;
+ default:
+ if (rbd_is_lock_owner(rbd_dev))
+ rbd_acknowledge_notify_result(rbd_dev, notify_id,
+ cookie, -EOPNOTSUPP);
+ else
+ rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
+ break;
+ }
+}
+
+static void __rbd_unregister_watch(struct rbd_device *rbd_dev);
+
+static void rbd_watch_errcb(void *arg, u64 cookie, int err)
+{
+ struct rbd_device *rbd_dev = arg;
+
+ rbd_warn(rbd_dev, "encountered watch error: %d", err);
+
+ down_write(&rbd_dev->lock_rwsem);
+ rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
+ up_write(&rbd_dev->lock_rwsem);
+
+ mutex_lock(&rbd_dev->watch_mutex);
+ if (rbd_dev->watch_state == RBD_WATCH_STATE_REGISTERED) {
+ __rbd_unregister_watch(rbd_dev);
+ rbd_dev->watch_state = RBD_WATCH_STATE_ERROR;
+
+ queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
+ }
+ mutex_unlock(&rbd_dev->watch_mutex);
+}
+
+/*
+ * watch_mutex must be locked
+ */
+static int __rbd_register_watch(struct rbd_device *rbd_dev)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ struct ceph_osd_linger_request *handle;
+
+ rbd_assert(!rbd_dev->watch_handle);
+ dout("%s rbd_dev %p\n", __func__, rbd_dev);
+
+ handle = ceph_osdc_watch(osdc, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, rbd_watch_cb,
+ rbd_watch_errcb, rbd_dev);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ rbd_dev->watch_handle = handle;
+ return 0;
+}
+
+/*
+ * watch_mutex must be locked
+ */
+static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ int ret;
+
+ rbd_assert(rbd_dev->watch_handle);
+ dout("%s rbd_dev %p\n", __func__, rbd_dev);
+
+ ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
+ if (ret)
+ rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
+
+ rbd_dev->watch_handle = NULL;
+}
+
+static int rbd_register_watch(struct rbd_device *rbd_dev)
+{
+ int ret;
+
+ mutex_lock(&rbd_dev->watch_mutex);
+ rbd_assert(rbd_dev->watch_state == RBD_WATCH_STATE_UNREGISTERED);
+ ret = __rbd_register_watch(rbd_dev);
+ if (ret)
+ goto out;
+
+ rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
+ rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;
+
+out:
+ mutex_unlock(&rbd_dev->watch_mutex);
+ return ret;
+}
+
+static void cancel_tasks_sync(struct rbd_device *rbd_dev)
+{
+ dout("%s rbd_dev %p\n", __func__, rbd_dev);
+
+ cancel_work_sync(&rbd_dev->acquired_lock_work);
+ cancel_work_sync(&rbd_dev->released_lock_work);
+ cancel_delayed_work_sync(&rbd_dev->lock_dwork);
+ cancel_work_sync(&rbd_dev->unlock_work);
+}
+
+/*
+ * header_rwsem must not be held to avoid a deadlock with
+ * rbd_dev_refresh() when flushing notifies.
+ */
+static void rbd_unregister_watch(struct rbd_device *rbd_dev)
+{
+ cancel_tasks_sync(rbd_dev);
+
+ mutex_lock(&rbd_dev->watch_mutex);
+ if (rbd_dev->watch_state == RBD_WATCH_STATE_REGISTERED)
+ __rbd_unregister_watch(rbd_dev);
+ rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
+ mutex_unlock(&rbd_dev->watch_mutex);
+
+ cancel_delayed_work_sync(&rbd_dev->watch_dwork);
+ ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
+}
+
+/*
+ * lock_rwsem must be held for write
+ */
+static void rbd_reacquire_lock(struct rbd_device *rbd_dev)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ char cookie[32];
+ int ret;
+
+ if (!rbd_quiesce_lock(rbd_dev))
+ return;
+
+ format_lock_cookie(rbd_dev, cookie);
+ ret = ceph_cls_set_cookie(osdc, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, RBD_LOCK_NAME,
+ CEPH_CLS_LOCK_EXCLUSIVE, rbd_dev->lock_cookie,
+ RBD_LOCK_TAG, cookie);
+ if (ret) {
+ if (ret != -EOPNOTSUPP)
+ rbd_warn(rbd_dev, "failed to update lock cookie: %d",
+ ret);
+
+ /*
+ * Lock cookie cannot be updated on older OSDs, so do
+ * a manual release and queue an acquire.
+ */
+ __rbd_release_lock(rbd_dev);
+ queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
+ } else {
+ __rbd_lock(rbd_dev, cookie);
+ wake_lock_waiters(rbd_dev, 0);
+ }
+}
+
+static void rbd_reregister_watch(struct work_struct *work)
+{
+ struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
+ struct rbd_device, watch_dwork);
+ int ret;
+
+ dout("%s rbd_dev %p\n", __func__, rbd_dev);
+
+ mutex_lock(&rbd_dev->watch_mutex);
+ if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR) {
+ mutex_unlock(&rbd_dev->watch_mutex);
+ return;
+ }
+
+ ret = __rbd_register_watch(rbd_dev);
+ if (ret) {
+ rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
+ if (ret != -EBLOCKLISTED && ret != -ENOENT) {
+ queue_delayed_work(rbd_dev->task_wq,
+ &rbd_dev->watch_dwork,
+ RBD_RETRY_DELAY);
+ mutex_unlock(&rbd_dev->watch_mutex);
+ return;
+ }
+
+ mutex_unlock(&rbd_dev->watch_mutex);
+ down_write(&rbd_dev->lock_rwsem);
+ wake_lock_waiters(rbd_dev, ret);
+ up_write(&rbd_dev->lock_rwsem);
+ return;
+ }
+
+ rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
+ rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;
+ mutex_unlock(&rbd_dev->watch_mutex);
+
+ down_write(&rbd_dev->lock_rwsem);
+ if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
+ rbd_reacquire_lock(rbd_dev);
+ up_write(&rbd_dev->lock_rwsem);
+
+ ret = rbd_dev_refresh(rbd_dev);
+ if (ret)
+ rbd_warn(rbd_dev, "reregistration refresh failed: %d", ret);
+}
+
+/*
+ * Synchronous osd object method call. Returns the number of bytes
+ * returned in the outbound buffer, or a negative error code.
+ */
+static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
+ struct ceph_object_id *oid,
+ struct ceph_object_locator *oloc,
+ const char *method_name,
+ const void *outbound,
+ size_t outbound_size,
+ void *inbound,
+ size_t inbound_size)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ struct page *req_page = NULL;
+ struct page *reply_page;
+ int ret;
+
+ /*
+ * Method calls are ultimately read operations. The result
+ * should placed into the inbound buffer provided. They
+ * also supply outbound data--parameters for the object
+ * method. Currently if this is present it will be a
+ * snapshot id.
+ */
+ if (outbound) {
+ if (outbound_size > PAGE_SIZE)
+ return -E2BIG;
+
+ req_page = alloc_page(GFP_KERNEL);
+ if (!req_page)
+ return -ENOMEM;
+
+ memcpy(page_address(req_page), outbound, outbound_size);
+ }
+
+ reply_page = alloc_page(GFP_KERNEL);
+ if (!reply_page) {
+ if (req_page)
+ __free_page(req_page);
+ return -ENOMEM;
+ }
+
+ ret = ceph_osdc_call(osdc, oid, oloc, RBD_DRV_NAME, method_name,
+ CEPH_OSD_FLAG_READ, req_page, outbound_size,
+ &reply_page, &inbound_size);
+ if (!ret) {
+ memcpy(inbound, page_address(reply_page), inbound_size);
+ ret = inbound_size;
+ }
+
+ if (req_page)
+ __free_page(req_page);
+ __free_page(reply_page);
+ return ret;
+}
+
+static void rbd_queue_workfn(struct work_struct *work)
+{
+ struct rbd_img_request *img_request =
+ container_of(work, struct rbd_img_request, work);
+ struct rbd_device *rbd_dev = img_request->rbd_dev;
+ enum obj_operation_type op_type = img_request->op_type;
+ struct request *rq = blk_mq_rq_from_pdu(img_request);
+ u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
+ u64 length = blk_rq_bytes(rq);
+ u64 mapping_size;
+ int result;
+
+ /* Ignore/skip any zero-length requests */
+ if (!length) {
+ dout("%s: zero-length request\n", __func__);
+ result = 0;
+ goto err_img_request;
+ }
+
+ blk_mq_start_request(rq);
+
+ down_read(&rbd_dev->header_rwsem);
+ mapping_size = rbd_dev->mapping.size;
+ rbd_img_capture_header(img_request);
+ up_read(&rbd_dev->header_rwsem);
+
+ if (offset + length > mapping_size) {
+ rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
+ length, mapping_size);
+ result = -EIO;
+ goto err_img_request;
+ }
+
+ dout("%s rbd_dev %p img_req %p %s %llu~%llu\n", __func__, rbd_dev,
+ img_request, obj_op_name(op_type), offset, length);
+
+ if (op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_ZEROOUT)
+ result = rbd_img_fill_nodata(img_request, offset, length);
+ else
+ result = rbd_img_fill_from_bio(img_request, offset, length,
+ rq->bio);
+ if (result)
+ goto err_img_request;
+
+ rbd_img_handle_request(img_request, 0);
+ return;
+
+err_img_request:
+ rbd_img_request_destroy(img_request);
+ if (result)
+ rbd_warn(rbd_dev, "%s %llx at %llx result %d",
+ obj_op_name(op_type), length, offset, result);
+ blk_mq_end_request(rq, errno_to_blk_status(result));
+}
+
+static blk_status_t rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *bd)
+{
+ struct rbd_device *rbd_dev = hctx->queue->queuedata;
+ struct rbd_img_request *img_req = blk_mq_rq_to_pdu(bd->rq);
+ enum obj_operation_type op_type;
+
+ switch (req_op(bd->rq)) {
+ case REQ_OP_DISCARD:
+ op_type = OBJ_OP_DISCARD;
+ break;
+ case REQ_OP_WRITE_ZEROES:
+ op_type = OBJ_OP_ZEROOUT;
+ break;
+ case REQ_OP_WRITE:
+ op_type = OBJ_OP_WRITE;
+ break;
+ case REQ_OP_READ:
+ op_type = OBJ_OP_READ;
+ break;
+ default:
+ rbd_warn(rbd_dev, "unknown req_op %d", req_op(bd->rq));
+ return BLK_STS_IOERR;
+ }
+
+ rbd_img_request_init(img_req, rbd_dev, op_type);
+
+ if (rbd_img_is_write(img_req)) {
+ if (rbd_is_ro(rbd_dev)) {
+ rbd_warn(rbd_dev, "%s on read-only mapping",
+ obj_op_name(img_req->op_type));
+ return BLK_STS_IOERR;
+ }
+ rbd_assert(!rbd_is_snap(rbd_dev));
+ }
+
+ INIT_WORK(&img_req->work, rbd_queue_workfn);
+ queue_work(rbd_wq, &img_req->work);
+ return BLK_STS_OK;
+}
+
+static void rbd_free_disk(struct rbd_device *rbd_dev)
+{
+ put_disk(rbd_dev->disk);
+ blk_mq_free_tag_set(&rbd_dev->tag_set);
+ rbd_dev->disk = NULL;
+}
+
+static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
+ struct ceph_object_id *oid,
+ struct ceph_object_locator *oloc,
+ void *buf, int buf_len)
+
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ struct ceph_osd_request *req;
+ struct page **pages;
+ int num_pages = calc_pages_for(0, buf_len);
+ int ret;
+
+ req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_KERNEL);
+ if (!req)
+ return -ENOMEM;
+
+ ceph_oid_copy(&req->r_base_oid, oid);
+ ceph_oloc_copy(&req->r_base_oloc, oloc);
+ req->r_flags = CEPH_OSD_FLAG_READ;
+
+ pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
+ if (IS_ERR(pages)) {
+ ret = PTR_ERR(pages);
+ goto out_req;
+ }
+
+ osd_req_op_extent_init(req, 0, CEPH_OSD_OP_READ, 0, buf_len, 0, 0);
+ osd_req_op_extent_osd_data_pages(req, 0, pages, buf_len, 0, false,
+ true);
+
+ ret = ceph_osdc_alloc_messages(req, GFP_KERNEL);
+ if (ret)
+ goto out_req;
+
+ ceph_osdc_start_request(osdc, req);
+ ret = ceph_osdc_wait_request(osdc, req);
+ if (ret >= 0)
+ ceph_copy_from_page_vector(pages, buf, 0, ret);
+
+out_req:
+ ceph_osdc_put_request(req);
+ return ret;
+}
+
+/*
+ * 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 int rbd_dev_v1_header_info(struct rbd_device *rbd_dev,
+ struct rbd_image_header *header,
+ bool first_time)
+{
+ struct rbd_image_header_ondisk *ondisk = NULL;
+ u32 snap_count = 0;
+ u64 names_size = 0;
+ u32 want_count;
+ int ret;
+
+ /*
+ * The complete header will include an array of its 64-bit
+ * snapshot ids, followed by the names of those snapshots as
+ * a contiguous block of NUL-terminated strings. Note that
+ * the number of snapshots could change by the time we read
+ * it in, in which case we re-read it.
+ */
+ do {
+ size_t size;
+
+ kfree(ondisk);
+
+ size = sizeof (*ondisk);
+ size += snap_count * sizeof (struct rbd_image_snap_ondisk);
+ size += names_size;
+ ondisk = kmalloc(size, GFP_KERNEL);
+ if (!ondisk)
+ return -ENOMEM;
+
+ ret = rbd_obj_read_sync(rbd_dev, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, ondisk, size);
+ if (ret < 0)
+ goto out;
+ if ((size_t)ret < size) {
+ ret = -ENXIO;
+ rbd_warn(rbd_dev, "short header read (want %zd got %d)",
+ size, ret);
+ goto out;
+ }
+ if (!rbd_dev_ondisk_valid(ondisk)) {
+ ret = -ENXIO;
+ rbd_warn(rbd_dev, "invalid header");
+ goto out;
+ }
+
+ names_size = le64_to_cpu(ondisk->snap_names_len);
+ want_count = snap_count;
+ snap_count = le32_to_cpu(ondisk->snap_count);
+ } while (snap_count != want_count);
+
+ ret = rbd_header_from_disk(header, ondisk, first_time);
+out:
+ kfree(ondisk);
+
+ return ret;
+}
+
+static void rbd_dev_update_size(struct rbd_device *rbd_dev)
+{
+ sector_t size;
+
+ /*
+ * If EXISTS is not set, rbd_dev->disk may be NULL, so don't
+ * try to update its size. If REMOVING is set, updating size
+ * is just useless work since the device can't be opened.
+ */
+ if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
+ !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
+ size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
+ dout("setting size to %llu sectors", (unsigned long long)size);
+ set_capacity_and_notify(rbd_dev->disk, size);
+ }
+}
+
+static const struct blk_mq_ops rbd_mq_ops = {
+ .queue_rq = rbd_queue_rq,
+};
+
+static int rbd_init_disk(struct rbd_device *rbd_dev)
+{
+ struct gendisk *disk;
+ struct request_queue *q;
+ unsigned int objset_bytes =
+ rbd_dev->layout.object_size * rbd_dev->layout.stripe_count;
+ int err;
+
+ memset(&rbd_dev->tag_set, 0, sizeof(rbd_dev->tag_set));
+ rbd_dev->tag_set.ops = &rbd_mq_ops;
+ rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
+ rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
+ rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
+ rbd_dev->tag_set.nr_hw_queues = num_present_cpus();
+ rbd_dev->tag_set.cmd_size = sizeof(struct rbd_img_request);
+
+ err = blk_mq_alloc_tag_set(&rbd_dev->tag_set);
+ if (err)
+ return err;
+
+ disk = blk_mq_alloc_disk(&rbd_dev->tag_set, rbd_dev);
+ if (IS_ERR(disk)) {
+ err = PTR_ERR(disk);
+ goto out_tag_set;
+ }
+ q = disk->queue;
+
+ snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
+ rbd_dev->dev_id);
+ disk->major = rbd_dev->major;
+ disk->first_minor = rbd_dev->minor;
+ if (single_major)
+ disk->minors = (1 << RBD_SINGLE_MAJOR_PART_SHIFT);
+ else
+ disk->minors = RBD_MINORS_PER_MAJOR;
+ disk->fops = &rbd_bd_ops;
+ disk->private_data = rbd_dev;
+
+ blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
+ /* QUEUE_FLAG_ADD_RANDOM is off by default for blk-mq */
+
+ blk_queue_max_hw_sectors(q, objset_bytes >> SECTOR_SHIFT);
+ q->limits.max_sectors = queue_max_hw_sectors(q);
+ blk_queue_max_segments(q, USHRT_MAX);
+ blk_queue_max_segment_size(q, UINT_MAX);
+ blk_queue_io_min(q, rbd_dev->opts->alloc_size);
+ blk_queue_io_opt(q, rbd_dev->opts->alloc_size);
+
+ if (rbd_dev->opts->trim) {
+ q->limits.discard_granularity = rbd_dev->opts->alloc_size;
+ blk_queue_max_discard_sectors(q, objset_bytes >> SECTOR_SHIFT);
+ blk_queue_max_write_zeroes_sectors(q, objset_bytes >> SECTOR_SHIFT);
+ }
+
+ if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
+ blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
+
+ rbd_dev->disk = disk;
+
+ return 0;
+out_tag_set:
+ blk_mq_free_tag_set(&rbd_dev->tag_set);
+ return err;
+}
+
+/*
+ sysfs
+*/
+
+static struct rbd_device *dev_to_rbd_dev(struct device *dev)
+{
+ return container_of(dev, struct rbd_device, dev);
+}
+
+static ssize_t rbd_size_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ return sprintf(buf, "%llu\n",
+ (unsigned long long)rbd_dev->mapping.size);
+}
+
+static ssize_t rbd_features_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ return sprintf(buf, "0x%016llx\n", rbd_dev->header.features);
+}
+
+static ssize_t rbd_major_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ if (rbd_dev->major)
+ return sprintf(buf, "%d\n", rbd_dev->major);
+
+ return sprintf(buf, "(none)\n");
+}
+
+static ssize_t rbd_minor_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ return sprintf(buf, "%d\n", rbd_dev->minor);
+}
+
+static ssize_t rbd_client_addr_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+ struct ceph_entity_addr *client_addr =
+ ceph_client_addr(rbd_dev->rbd_client->client);
+
+ return sprintf(buf, "%pISpc/%u\n", &client_addr->in_addr,
+ le32_to_cpu(client_addr->nonce));
+}
+
+static ssize_t rbd_client_id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ return sprintf(buf, "client%lld\n",
+ ceph_client_gid(rbd_dev->rbd_client->client));
+}
+
+static ssize_t rbd_cluster_fsid_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ return sprintf(buf, "%pU\n", &rbd_dev->rbd_client->client->fsid);
+}
+
+static ssize_t rbd_config_info_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ return sprintf(buf, "%s\n", rbd_dev->config_info);
+}
+
+static ssize_t rbd_pool_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
+}
+
+static ssize_t rbd_pool_id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ return sprintf(buf, "%llu\n",
+ (unsigned long long) rbd_dev->spec->pool_id);
+}
+
+static ssize_t rbd_pool_ns_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ return sprintf(buf, "%s\n", rbd_dev->spec->pool_ns ?: "");
+}
+
+static ssize_t rbd_name_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ if (rbd_dev->spec->image_name)
+ return sprintf(buf, "%s\n", rbd_dev->spec->image_name);
+
+ return sprintf(buf, "(unknown)\n");
+}
+
+static ssize_t rbd_image_id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
+}
+
+/*
+ * Shows the name of the currently-mapped snapshot (or
+ * RBD_SNAP_HEAD_NAME for the base image).
+ */
+static ssize_t rbd_snap_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
+}
+
+static ssize_t rbd_snap_id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ return sprintf(buf, "%llu\n", rbd_dev->spec->snap_id);
+}
+
+/*
+ * For a v2 image, shows the chain of parent images, separated by empty
+ * lines. For v1 images or if there is no parent, shows "(no parent
+ * image)".
+ */
+static ssize_t rbd_parent_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+ ssize_t count = 0;
+
+ if (!rbd_dev->parent)
+ return sprintf(buf, "(no parent image)\n");
+
+ for ( ; rbd_dev->parent; rbd_dev = rbd_dev->parent) {
+ struct rbd_spec *spec = rbd_dev->parent_spec;
+
+ count += sprintf(&buf[count], "%s"
+ "pool_id %llu\npool_name %s\n"
+ "pool_ns %s\n"
+ "image_id %s\nimage_name %s\n"
+ "snap_id %llu\nsnap_name %s\n"
+ "overlap %llu\n",
+ !count ? "" : "\n", /* first? */
+ spec->pool_id, spec->pool_name,
+ spec->pool_ns ?: "",
+ spec->image_id, spec->image_name ?: "(unknown)",
+ spec->snap_id, spec->snap_name,
+ rbd_dev->parent_overlap);
+ }
+
+ return count;
+}
+
+static ssize_t rbd_image_refresh(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t size)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+ int ret;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ ret = rbd_dev_refresh(rbd_dev);
+ if (ret)
+ return ret;
+
+ return size;
+}
+
+static DEVICE_ATTR(size, 0444, rbd_size_show, NULL);
+static DEVICE_ATTR(features, 0444, rbd_features_show, NULL);
+static DEVICE_ATTR(major, 0444, rbd_major_show, NULL);
+static DEVICE_ATTR(minor, 0444, rbd_minor_show, NULL);
+static DEVICE_ATTR(client_addr, 0444, rbd_client_addr_show, NULL);
+static DEVICE_ATTR(client_id, 0444, rbd_client_id_show, NULL);
+static DEVICE_ATTR(cluster_fsid, 0444, rbd_cluster_fsid_show, NULL);
+static DEVICE_ATTR(config_info, 0400, rbd_config_info_show, NULL);
+static DEVICE_ATTR(pool, 0444, rbd_pool_show, NULL);
+static DEVICE_ATTR(pool_id, 0444, rbd_pool_id_show, NULL);
+static DEVICE_ATTR(pool_ns, 0444, rbd_pool_ns_show, NULL);
+static DEVICE_ATTR(name, 0444, rbd_name_show, NULL);
+static DEVICE_ATTR(image_id, 0444, rbd_image_id_show, NULL);
+static DEVICE_ATTR(refresh, 0200, NULL, rbd_image_refresh);
+static DEVICE_ATTR(current_snap, 0444, rbd_snap_show, NULL);
+static DEVICE_ATTR(snap_id, 0444, rbd_snap_id_show, NULL);
+static DEVICE_ATTR(parent, 0444, rbd_parent_show, NULL);
+
+static struct attribute *rbd_attrs[] = {
+ &dev_attr_size.attr,
+ &dev_attr_features.attr,
+ &dev_attr_major.attr,
+ &dev_attr_minor.attr,
+ &dev_attr_client_addr.attr,
+ &dev_attr_client_id.attr,
+ &dev_attr_cluster_fsid.attr,
+ &dev_attr_config_info.attr,
+ &dev_attr_pool.attr,
+ &dev_attr_pool_id.attr,
+ &dev_attr_pool_ns.attr,
+ &dev_attr_name.attr,
+ &dev_attr_image_id.attr,
+ &dev_attr_current_snap.attr,
+ &dev_attr_snap_id.attr,
+ &dev_attr_parent.attr,
+ &dev_attr_refresh.attr,
+ NULL
+};
+
+static struct attribute_group rbd_attr_group = {
+ .attrs = rbd_attrs,
+};
+
+static const struct attribute_group *rbd_attr_groups[] = {
+ &rbd_attr_group,
+ NULL
+};
+
+static void rbd_dev_release(struct device *dev);
+
+static const struct device_type rbd_device_type = {
+ .name = "rbd",
+ .groups = rbd_attr_groups,
+ .release = rbd_dev_release,
+};
+
+static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
+{
+ kref_get(&spec->kref);
+
+ return spec;
+}
+
+static void rbd_spec_free(struct kref *kref);
+static void rbd_spec_put(struct rbd_spec *spec)
+{
+ if (spec)
+ kref_put(&spec->kref, rbd_spec_free);
+}
+
+static struct rbd_spec *rbd_spec_alloc(void)
+{
+ struct rbd_spec *spec;
+
+ spec = kzalloc(sizeof (*spec), GFP_KERNEL);
+ if (!spec)
+ return NULL;
+
+ spec->pool_id = CEPH_NOPOOL;
+ spec->snap_id = CEPH_NOSNAP;
+ kref_init(&spec->kref);
+
+ return spec;
+}
+
+static void rbd_spec_free(struct kref *kref)
+{
+ struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);
+
+ kfree(spec->pool_name);
+ kfree(spec->pool_ns);
+ kfree(spec->image_id);
+ kfree(spec->image_name);
+ kfree(spec->snap_name);
+ kfree(spec);
+}
+
+static void rbd_dev_free(struct rbd_device *rbd_dev)
+{
+ WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
+ WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
+
+ ceph_oid_destroy(&rbd_dev->header_oid);
+ ceph_oloc_destroy(&rbd_dev->header_oloc);
+ kfree(rbd_dev->config_info);
+
+ rbd_put_client(rbd_dev->rbd_client);
+ rbd_spec_put(rbd_dev->spec);
+ kfree(rbd_dev->opts);
+ kfree(rbd_dev);
+}
+
+static void rbd_dev_release(struct device *dev)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+ bool need_put = !!rbd_dev->opts;
+
+ if (need_put) {
+ destroy_workqueue(rbd_dev->task_wq);
+ ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
+ }
+
+ rbd_dev_free(rbd_dev);
+
+ /*
+ * This is racy, but way better than putting module outside of
+ * the release callback. The race window is pretty small, so
+ * doing something similar to dm (dm-builtin.c) is overkill.
+ */
+ if (need_put)
+ module_put(THIS_MODULE);
+}
+
+static struct rbd_device *__rbd_dev_create(struct rbd_spec *spec)
+{
+ struct rbd_device *rbd_dev;
+
+ rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
+ if (!rbd_dev)
+ return NULL;
+
+ spin_lock_init(&rbd_dev->lock);
+ INIT_LIST_HEAD(&rbd_dev->node);
+ init_rwsem(&rbd_dev->header_rwsem);
+
+ rbd_dev->header.data_pool_id = CEPH_NOPOOL;
+ ceph_oid_init(&rbd_dev->header_oid);
+ rbd_dev->header_oloc.pool = spec->pool_id;
+ if (spec->pool_ns) {
+ WARN_ON(!*spec->pool_ns);
+ rbd_dev->header_oloc.pool_ns =
+ ceph_find_or_create_string(spec->pool_ns,
+ strlen(spec->pool_ns));
+ }
+
+ mutex_init(&rbd_dev->watch_mutex);
+ rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
+ INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);
+
+ init_rwsem(&rbd_dev->lock_rwsem);
+ rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
+ INIT_WORK(&rbd_dev->acquired_lock_work, rbd_notify_acquired_lock);
+ INIT_WORK(&rbd_dev->released_lock_work, rbd_notify_released_lock);
+ INIT_DELAYED_WORK(&rbd_dev->lock_dwork, rbd_acquire_lock);
+ INIT_WORK(&rbd_dev->unlock_work, rbd_release_lock_work);
+ spin_lock_init(&rbd_dev->lock_lists_lock);
+ INIT_LIST_HEAD(&rbd_dev->acquiring_list);
+ INIT_LIST_HEAD(&rbd_dev->running_list);
+ init_completion(&rbd_dev->acquire_wait);
+ init_completion(&rbd_dev->releasing_wait);
+
+ spin_lock_init(&rbd_dev->object_map_lock);
+
+ rbd_dev->dev.bus = &rbd_bus_type;
+ rbd_dev->dev.type = &rbd_device_type;
+ rbd_dev->dev.parent = &rbd_root_dev;
+ device_initialize(&rbd_dev->dev);
+
+ return rbd_dev;
+}
+
+/*
+ * Create a mapping rbd_dev.
+ */
+static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
+ struct rbd_spec *spec,
+ struct rbd_options *opts)
+{
+ struct rbd_device *rbd_dev;
+
+ rbd_dev = __rbd_dev_create(spec);
+ if (!rbd_dev)
+ return NULL;
+
+ /* get an id and fill in device name */
+ rbd_dev->dev_id = ida_simple_get(&rbd_dev_id_ida, 0,
+ minor_to_rbd_dev_id(1 << MINORBITS),
+ GFP_KERNEL);
+ if (rbd_dev->dev_id < 0)
+ goto fail_rbd_dev;
+
+ sprintf(rbd_dev->name, RBD_DRV_NAME "%d", rbd_dev->dev_id);
+ rbd_dev->task_wq = alloc_ordered_workqueue("%s-tasks", WQ_MEM_RECLAIM,
+ rbd_dev->name);
+ if (!rbd_dev->task_wq)
+ goto fail_dev_id;
+
+ /* we have a ref from do_rbd_add() */
+ __module_get(THIS_MODULE);
+
+ rbd_dev->rbd_client = rbdc;
+ rbd_dev->spec = spec;
+ rbd_dev->opts = opts;
+
+ dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
+ return rbd_dev;
+
+fail_dev_id:
+ ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
+fail_rbd_dev:
+ rbd_dev_free(rbd_dev);
+ return NULL;
+}
+
+static void rbd_dev_destroy(struct rbd_device *rbd_dev)
+{
+ if (rbd_dev)
+ put_device(&rbd_dev->dev);
+}
+
+/*
+ * Get the size and object order for an image snapshot, or if
+ * snap_id is CEPH_NOSNAP, gets this information for the base
+ * image.
+ */
+static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
+ u8 *order, u64 *snap_size)
+{
+ __le64 snapid = cpu_to_le64(snap_id);
+ int ret;
+ struct {
+ u8 order;
+ __le64 size;
+ } __attribute__ ((packed)) size_buf = { 0 };
+
+ ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, "get_size",
+ &snapid, sizeof(snapid),
+ &size_buf, sizeof(size_buf));
+ dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
+ if (ret < 0)
+ return ret;
+ if (ret < sizeof (size_buf))
+ return -ERANGE;
+
+ if (order) {
+ *order = size_buf.order;
+ dout(" order %u", (unsigned int)*order);
+ }
+ *snap_size = le64_to_cpu(size_buf.size);
+
+ dout(" snap_id 0x%016llx snap_size = %llu\n",
+ (unsigned long long)snap_id,
+ (unsigned long long)*snap_size);
+
+ return 0;
+}
+
+static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev,
+ char **pobject_prefix)
+{
+ size_t size;
+ void *reply_buf;
+ char *object_prefix;
+ int ret;
+ void *p;
+
+ /* Response will be an encoded string, which includes a length */
+ size = sizeof(__le32) + RBD_OBJ_PREFIX_LEN_MAX;
+ reply_buf = kzalloc(size, GFP_KERNEL);
+ if (!reply_buf)
+ return -ENOMEM;
+
+ ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, "get_object_prefix",
+ NULL, 0, reply_buf, size);
+ dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
+ if (ret < 0)
+ goto out;
+
+ p = reply_buf;
+ object_prefix = ceph_extract_encoded_string(&p, p + ret, NULL,
+ GFP_NOIO);
+ if (IS_ERR(object_prefix)) {
+ ret = PTR_ERR(object_prefix);
+ goto out;
+ }
+ ret = 0;
+
+ *pobject_prefix = object_prefix;
+ dout(" object_prefix = %s\n", object_prefix);
+out:
+ kfree(reply_buf);
+
+ return ret;
+}
+
+static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
+ bool read_only, u64 *snap_features)
+{
+ struct {
+ __le64 snap_id;
+ u8 read_only;
+ } features_in;
+ struct {
+ __le64 features;
+ __le64 incompat;
+ } __attribute__ ((packed)) features_buf = { 0 };
+ u64 unsup;
+ int ret;
+
+ features_in.snap_id = cpu_to_le64(snap_id);
+ features_in.read_only = read_only;
+
+ ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, "get_features",
+ &features_in, sizeof(features_in),
+ &features_buf, sizeof(features_buf));
+ dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
+ if (ret < 0)
+ return ret;
+ if (ret < sizeof (features_buf))
+ return -ERANGE;
+
+ unsup = le64_to_cpu(features_buf.incompat) & ~RBD_FEATURES_SUPPORTED;
+ if (unsup) {
+ rbd_warn(rbd_dev, "image uses unsupported features: 0x%llx",
+ unsup);
+ return -ENXIO;
+ }
+
+ *snap_features = le64_to_cpu(features_buf.features);
+
+ dout(" snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
+ (unsigned long long)snap_id,
+ (unsigned long long)*snap_features,
+ (unsigned long long)le64_to_cpu(features_buf.incompat));
+
+ return 0;
+}
+
+/*
+ * These are generic image flags, but since they are used only for
+ * object map, store them in rbd_dev->object_map_flags.
+ *
+ * For the same reason, this function is called only on object map
+ * (re)load and not on header refresh.
+ */
+static int rbd_dev_v2_get_flags(struct rbd_device *rbd_dev)
+{
+ __le64 snapid = cpu_to_le64(rbd_dev->spec->snap_id);
+ __le64 flags;
+ int ret;
+
+ ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, "get_flags",
+ &snapid, sizeof(snapid),
+ &flags, sizeof(flags));
+ if (ret < 0)
+ return ret;
+ if (ret < sizeof(flags))
+ return -EBADMSG;
+
+ rbd_dev->object_map_flags = le64_to_cpu(flags);
+ return 0;
+}
+
+struct parent_image_info {
+ u64 pool_id;
+ const char *pool_ns;
+ const char *image_id;
+ u64 snap_id;
+
+ bool has_overlap;
+ u64 overlap;
+};
+
+static void rbd_parent_info_cleanup(struct parent_image_info *pii)
+{
+ kfree(pii->pool_ns);
+ kfree(pii->image_id);
+
+ memset(pii, 0, sizeof(*pii));
+}
+
+/*
+ * The caller is responsible for @pii.
+ */
+static int decode_parent_image_spec(void **p, void *end,
+ struct parent_image_info *pii)
+{
+ u8 struct_v;
+ u32 struct_len;
+ int ret;
+
+ ret = ceph_start_decoding(p, end, 1, "ParentImageSpec",
+ &struct_v, &struct_len);
+ if (ret)
+ return ret;
+
+ ceph_decode_64_safe(p, end, pii->pool_id, e_inval);
+ pii->pool_ns = ceph_extract_encoded_string(p, end, NULL, GFP_KERNEL);
+ if (IS_ERR(pii->pool_ns)) {
+ ret = PTR_ERR(pii->pool_ns);
+ pii->pool_ns = NULL;
+ return ret;
+ }
+ pii->image_id = ceph_extract_encoded_string(p, end, NULL, GFP_KERNEL);
+ if (IS_ERR(pii->image_id)) {
+ ret = PTR_ERR(pii->image_id);
+ pii->image_id = NULL;
+ return ret;
+ }
+ ceph_decode_64_safe(p, end, pii->snap_id, e_inval);
+ return 0;
+
+e_inval:
+ return -EINVAL;
+}
+
+static int __get_parent_info(struct rbd_device *rbd_dev,
+ struct page *req_page,
+ struct page *reply_page,
+ struct parent_image_info *pii)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ size_t reply_len = PAGE_SIZE;
+ void *p, *end;
+ int ret;
+
+ ret = ceph_osdc_call(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
+ "rbd", "parent_get", CEPH_OSD_FLAG_READ,
+ req_page, sizeof(u64), &reply_page, &reply_len);
+ if (ret)
+ return ret == -EOPNOTSUPP ? 1 : ret;
+
+ p = page_address(reply_page);
+ end = p + reply_len;
+ ret = decode_parent_image_spec(&p, end, pii);
+ if (ret)
+ return ret;
+
+ ret = ceph_osdc_call(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
+ "rbd", "parent_overlap_get", CEPH_OSD_FLAG_READ,
+ req_page, sizeof(u64), &reply_page, &reply_len);
+ if (ret)
+ return ret;
+
+ p = page_address(reply_page);
+ end = p + reply_len;
+ ceph_decode_8_safe(&p, end, pii->has_overlap, e_inval);
+ if (pii->has_overlap)
+ ceph_decode_64_safe(&p, end, pii->overlap, e_inval);
+
+ dout("%s pool_id %llu pool_ns %s image_id %s snap_id %llu has_overlap %d overlap %llu\n",
+ __func__, pii->pool_id, pii->pool_ns, pii->image_id, pii->snap_id,
+ pii->has_overlap, pii->overlap);
+ return 0;
+
+e_inval:
+ return -EINVAL;
+}
+
+/*
+ * The caller is responsible for @pii.
+ */
+static int __get_parent_info_legacy(struct rbd_device *rbd_dev,
+ struct page *req_page,
+ struct page *reply_page,
+ struct parent_image_info *pii)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ size_t reply_len = PAGE_SIZE;
+ void *p, *end;
+ int ret;
+
+ ret = ceph_osdc_call(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
+ "rbd", "get_parent", CEPH_OSD_FLAG_READ,
+ req_page, sizeof(u64), &reply_page, &reply_len);
+ if (ret)
+ return ret;
+
+ p = page_address(reply_page);
+ end = p + reply_len;
+ ceph_decode_64_safe(&p, end, pii->pool_id, e_inval);
+ pii->image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
+ if (IS_ERR(pii->image_id)) {
+ ret = PTR_ERR(pii->image_id);
+ pii->image_id = NULL;
+ return ret;
+ }
+ ceph_decode_64_safe(&p, end, pii->snap_id, e_inval);
+ pii->has_overlap = true;
+ ceph_decode_64_safe(&p, end, pii->overlap, e_inval);
+
+ dout("%s pool_id %llu pool_ns %s image_id %s snap_id %llu has_overlap %d overlap %llu\n",
+ __func__, pii->pool_id, pii->pool_ns, pii->image_id, pii->snap_id,
+ pii->has_overlap, pii->overlap);
+ return 0;
+
+e_inval:
+ return -EINVAL;
+}
+
+static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev,
+ struct parent_image_info *pii)
+{
+ struct page *req_page, *reply_page;
+ void *p;
+ int ret;
+
+ req_page = alloc_page(GFP_KERNEL);
+ if (!req_page)
+ return -ENOMEM;
+
+ reply_page = alloc_page(GFP_KERNEL);
+ if (!reply_page) {
+ __free_page(req_page);
+ return -ENOMEM;
+ }
+
+ p = page_address(req_page);
+ ceph_encode_64(&p, rbd_dev->spec->snap_id);
+ ret = __get_parent_info(rbd_dev, req_page, reply_page, pii);
+ if (ret > 0)
+ ret = __get_parent_info_legacy(rbd_dev, req_page, reply_page,
+ pii);
+
+ __free_page(req_page);
+ __free_page(reply_page);
+ return ret;
+}
+
+static int rbd_dev_setup_parent(struct rbd_device *rbd_dev)
+{
+ struct rbd_spec *parent_spec;
+ struct parent_image_info pii = { 0 };
+ int ret;
+
+ parent_spec = rbd_spec_alloc();
+ if (!parent_spec)
+ return -ENOMEM;
+
+ ret = rbd_dev_v2_parent_info(rbd_dev, &pii);
+ if (ret)
+ goto out_err;
+
+ if (pii.pool_id == CEPH_NOPOOL || !pii.has_overlap)
+ goto out; /* No parent? No problem. */
+
+ /* The ceph file layout needs to fit pool id in 32 bits */
+
+ ret = -EIO;
+ if (pii.pool_id > (u64)U32_MAX) {
+ rbd_warn(NULL, "parent pool id too large (%llu > %u)",
+ (unsigned long long)pii.pool_id, U32_MAX);
+ goto out_err;
+ }
+
+ /*
+ * The parent won't change except when the clone is flattened,
+ * so we only need to record the parent image spec once.
+ */
+ parent_spec->pool_id = pii.pool_id;
+ if (pii.pool_ns && *pii.pool_ns) {
+ parent_spec->pool_ns = pii.pool_ns;
+ pii.pool_ns = NULL;
+ }
+ parent_spec->image_id = pii.image_id;
+ pii.image_id = NULL;
+ parent_spec->snap_id = pii.snap_id;
+
+ rbd_assert(!rbd_dev->parent_spec);
+ rbd_dev->parent_spec = parent_spec;
+ parent_spec = NULL; /* rbd_dev now owns this */
+
+ /*
+ * Record the parent overlap. If it's zero, issue a warning as
+ * we will proceed as if there is no parent.
+ */
+ if (!pii.overlap)
+ rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
+ rbd_dev->parent_overlap = pii.overlap;
+
+out:
+ ret = 0;
+out_err:
+ rbd_parent_info_cleanup(&pii);
+ rbd_spec_put(parent_spec);
+ return ret;
+}
+
+static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev,
+ u64 *stripe_unit, u64 *stripe_count)
+{
+ struct {
+ __le64 stripe_unit;
+ __le64 stripe_count;
+ } __attribute__ ((packed)) striping_info_buf = { 0 };
+ size_t size = sizeof (striping_info_buf);
+ int ret;
+
+ ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, "get_stripe_unit_count",
+ NULL, 0, &striping_info_buf, size);
+ dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
+ if (ret < 0)
+ return ret;
+ if (ret < size)
+ return -ERANGE;
+
+ *stripe_unit = le64_to_cpu(striping_info_buf.stripe_unit);
+ *stripe_count = le64_to_cpu(striping_info_buf.stripe_count);
+ dout(" stripe_unit = %llu stripe_count = %llu\n", *stripe_unit,
+ *stripe_count);
+
+ return 0;
+}
+
+static int rbd_dev_v2_data_pool(struct rbd_device *rbd_dev, s64 *data_pool_id)
+{
+ __le64 data_pool_buf;
+ int ret;
+
+ ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, "get_data_pool",
+ NULL, 0, &data_pool_buf,
+ sizeof(data_pool_buf));
+ dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
+ if (ret < 0)
+ return ret;
+ if (ret < sizeof(data_pool_buf))
+ return -EBADMSG;
+
+ *data_pool_id = le64_to_cpu(data_pool_buf);
+ dout(" data_pool_id = %lld\n", *data_pool_id);
+ WARN_ON(*data_pool_id == CEPH_NOPOOL);
+
+ return 0;
+}
+
+static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
+{
+ CEPH_DEFINE_OID_ONSTACK(oid);
+ size_t image_id_size;
+ char *image_id;
+ void *p;
+ void *end;
+ size_t size;
+ void *reply_buf = NULL;
+ size_t len = 0;
+ char *image_name = NULL;
+ int ret;
+
+ rbd_assert(!rbd_dev->spec->image_name);
+
+ len = strlen(rbd_dev->spec->image_id);
+ image_id_size = sizeof (__le32) + len;
+ image_id = kmalloc(image_id_size, GFP_KERNEL);
+ if (!image_id)
+ return NULL;
+
+ p = image_id;
+ end = image_id + image_id_size;
+ ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
+
+ size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
+ reply_buf = kmalloc(size, GFP_KERNEL);
+ if (!reply_buf)
+ goto out;
+
+ ceph_oid_printf(&oid, "%s", RBD_DIRECTORY);
+ ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
+ "dir_get_name", image_id, image_id_size,
+ reply_buf, size);
+ if (ret < 0)
+ goto out;
+ p = reply_buf;
+ end = reply_buf + ret;
+
+ image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
+ if (IS_ERR(image_name))
+ image_name = NULL;
+ else
+ dout("%s: name is %s len is %zd\n", __func__, image_name, len);
+out:
+ kfree(reply_buf);
+ kfree(image_id);
+
+ return image_name;
+}
+
+static u64 rbd_v1_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
+{
+ struct ceph_snap_context *snapc = rbd_dev->header.snapc;
+ const char *snap_name;
+ u32 which = 0;
+
+ /* Skip over names until we find the one we are looking for */
+
+ snap_name = rbd_dev->header.snap_names;
+ while (which < snapc->num_snaps) {
+ if (!strcmp(name, snap_name))
+ return snapc->snaps[which];
+ snap_name += strlen(snap_name) + 1;
+ which++;
+ }
+ return CEPH_NOSNAP;
+}
+
+static u64 rbd_v2_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
+{
+ struct ceph_snap_context *snapc = rbd_dev->header.snapc;
+ u32 which;
+ bool found = false;
+ u64 snap_id;
+
+ for (which = 0; !found && which < snapc->num_snaps; which++) {
+ const char *snap_name;
+
+ snap_id = snapc->snaps[which];
+ snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
+ if (IS_ERR(snap_name)) {
+ /* ignore no-longer existing snapshots */
+ if (PTR_ERR(snap_name) == -ENOENT)
+ continue;
+ else
+ break;
+ }
+ found = !strcmp(name, snap_name);
+ kfree(snap_name);
+ }
+ return found ? snap_id : CEPH_NOSNAP;
+}
+
+/*
+ * Assumes name is never RBD_SNAP_HEAD_NAME; returns CEPH_NOSNAP if
+ * no snapshot by that name is found, or if an error occurs.
+ */
+static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
+{
+ if (rbd_dev->image_format == 1)
+ return rbd_v1_snap_id_by_name(rbd_dev, name);
+
+ return rbd_v2_snap_id_by_name(rbd_dev, name);
+}
+
+/*
+ * An image being mapped will have everything but the snap id.
+ */
+static int rbd_spec_fill_snap_id(struct rbd_device *rbd_dev)
+{
+ struct rbd_spec *spec = rbd_dev->spec;
+
+ rbd_assert(spec->pool_id != CEPH_NOPOOL && spec->pool_name);
+ rbd_assert(spec->image_id && spec->image_name);
+ rbd_assert(spec->snap_name);
+
+ if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) {
+ u64 snap_id;
+
+ snap_id = rbd_snap_id_by_name(rbd_dev, spec->snap_name);
+ if (snap_id == CEPH_NOSNAP)
+ return -ENOENT;
+
+ spec->snap_id = snap_id;
+ } else {
+ spec->snap_id = CEPH_NOSNAP;
+ }
+
+ return 0;
+}
+
+/*
+ * A parent image will have all ids but none of the names.
+ *
+ * All names in an rbd spec are dynamically allocated. It's OK if we
+ * can't figure out the name for an image id.
+ */
+static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
+{
+ struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ struct rbd_spec *spec = rbd_dev->spec;
+ const char *pool_name;
+ const char *image_name;
+ const char *snap_name;
+ int ret;
+
+ rbd_assert(spec->pool_id != CEPH_NOPOOL);
+ rbd_assert(spec->image_id);
+ rbd_assert(spec->snap_id != CEPH_NOSNAP);
+
+ /* Get the pool name; we have to make our own copy of this */
+
+ pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, spec->pool_id);
+ if (!pool_name) {
+ rbd_warn(rbd_dev, "no pool with id %llu", spec->pool_id);
+ return -EIO;
+ }
+ pool_name = kstrdup(pool_name, GFP_KERNEL);
+ if (!pool_name)
+ return -ENOMEM;
+
+ /* Fetch the image name; tolerate failure here */
+
+ image_name = rbd_dev_image_name(rbd_dev);
+ if (!image_name)
+ rbd_warn(rbd_dev, "unable to get image name");
+
+ /* Fetch the snapshot name */
+
+ snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
+ if (IS_ERR(snap_name)) {
+ ret = PTR_ERR(snap_name);
+ goto out_err;
+ }
+
+ spec->pool_name = pool_name;
+ spec->image_name = image_name;
+ spec->snap_name = snap_name;
+
+ return 0;
+
+out_err:
+ kfree(image_name);
+ kfree(pool_name);
+ return ret;
+}
+
+static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev,
+ struct ceph_snap_context **psnapc)
+{
+ size_t size;
+ int ret;
+ void *reply_buf;
+ void *p;
+ void *end;
+ u64 seq;
+ u32 snap_count;
+ struct ceph_snap_context *snapc;
+ u32 i;
+
+ /*
+ * We'll need room for the seq value (maximum snapshot id),
+ * snapshot count, and array of that many snapshot ids.
+ * For now we have a fixed upper limit on the number we're
+ * prepared to receive.
+ */
+ size = sizeof (__le64) + sizeof (__le32) +
+ RBD_MAX_SNAP_COUNT * sizeof (__le64);
+ reply_buf = kzalloc(size, GFP_KERNEL);
+ if (!reply_buf)
+ return -ENOMEM;
+
+ ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, "get_snapcontext",
+ NULL, 0, reply_buf, size);
+ dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
+ if (ret < 0)
+ goto out;
+
+ p = reply_buf;
+ end = reply_buf + ret;
+ ret = -ERANGE;
+ ceph_decode_64_safe(&p, end, seq, out);
+ ceph_decode_32_safe(&p, end, snap_count, out);
+
+ /*
+ * Make sure the reported number of snapshot ids wouldn't go
+ * beyond the end of our buffer. But before checking that,
+ * make sure the computed size of the snapshot context we
+ * allocate is representable in a size_t.
+ */
+ if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
+ / sizeof (u64)) {
+ ret = -EINVAL;
+ goto out;
+ }
+ if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
+ goto out;
+ ret = 0;
+
+ snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
+ if (!snapc) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ snapc->seq = seq;
+ for (i = 0; i < snap_count; i++)
+ snapc->snaps[i] = ceph_decode_64(&p);
+
+ *psnapc = snapc;
+ dout(" snap context seq = %llu, snap_count = %u\n",
+ (unsigned long long)seq, (unsigned int)snap_count);
+out:
+ kfree(reply_buf);
+
+ return ret;
+}
+
+static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
+ u64 snap_id)
+{
+ size_t size;
+ void *reply_buf;
+ __le64 snapid;
+ int ret;
+ void *p;
+ void *end;
+ char *snap_name;
+
+ size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
+ reply_buf = kmalloc(size, GFP_KERNEL);
+ if (!reply_buf)
+ return ERR_PTR(-ENOMEM);
+
+ snapid = cpu_to_le64(snap_id);
+ ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
+ &rbd_dev->header_oloc, "get_snapshot_name",
+ &snapid, sizeof(snapid), reply_buf, size);
+ dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
+ if (ret < 0) {
+ snap_name = ERR_PTR(ret);
+ goto out;
+ }
+
+ p = reply_buf;
+ end = reply_buf + ret;
+ snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
+ if (IS_ERR(snap_name))
+ goto out;
+
+ dout(" snap_id 0x%016llx snap_name = %s\n",
+ (unsigned long long)snap_id, snap_name);
+out:
+ kfree(reply_buf);
+
+ return snap_name;
+}
+
+static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev,
+ struct rbd_image_header *header,
+ bool first_time)
+{
+ int ret;
+
+ ret = _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
+ first_time ? &header->obj_order : NULL,
+ &header->image_size);
+ if (ret)
+ return ret;
+
+ if (first_time) {
+ ret = rbd_dev_v2_header_onetime(rbd_dev, header);
+ if (ret)
+ return ret;
+ }
+
+ ret = rbd_dev_v2_snap_context(rbd_dev, &header->snapc);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int rbd_dev_header_info(struct rbd_device *rbd_dev,
+ struct rbd_image_header *header,
+ bool first_time)
+{
+ rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
+ rbd_assert(!header->object_prefix && !header->snapc);
+
+ if (rbd_dev->image_format == 1)
+ return rbd_dev_v1_header_info(rbd_dev, header, first_time);
+
+ return rbd_dev_v2_header_info(rbd_dev, header, first_time);
+}
+
+/*
+ * Skips over white space at *buf, and updates *buf to point to the
+ * first found non-space character (if any). Returns the length of
+ * the token (string of non-white space characters) found. Note
+ * that *buf must be terminated with '\0'.
+ */
+static inline size_t next_token(const char **buf)
+{
+ /*
+ * These are the characters that produce nonzero for
+ * isspace() in the "C" and "POSIX" locales.
+ */
+ static const char spaces[] = " \f\n\r\t\v";
+
+ *buf += strspn(*buf, spaces); /* Find start of token */
+
+ return strcspn(*buf, spaces); /* Return token length */
+}
+
+/*
+ * Finds the next token in *buf, dynamically allocates a buffer big
+ * enough to hold a copy of it, and copies the token into the new
+ * buffer. The copy is guaranteed to be terminated with '\0'. Note
+ * that a duplicate buffer is created even for a zero-length token.
+ *
+ * Returns a pointer to the newly-allocated duplicate, or a null
+ * pointer if memory for the duplicate was not available. If
+ * the lenp argument is a non-null pointer, the length of the token
+ * (not including the '\0') is returned in *lenp.
+ *
+ * If successful, the *buf pointer will be updated to point beyond
+ * the end of the found token.
+ *
+ * Note: uses GFP_KERNEL for allocation.
+ */
+static inline char *dup_token(const char **buf, size_t *lenp)
+{
+ char *dup;
+ size_t len;
+
+ len = next_token(buf);
+ dup = kmemdup(*buf, len + 1, GFP_KERNEL);
+ if (!dup)
+ return NULL;
+ *(dup + len) = '\0';
+ *buf += len;
+
+ if (lenp)
+ *lenp = len;
+
+ return dup;
+}
+
+static int rbd_parse_param(struct fs_parameter *param,
+ struct rbd_parse_opts_ctx *pctx)
+{
+ struct rbd_options *opt = pctx->opts;
+ struct fs_parse_result result;
+ struct p_log log = {.prefix = "rbd"};
+ int token, ret;
+
+ ret = ceph_parse_param(param, pctx->copts, NULL);
+ if (ret != -ENOPARAM)
+ return ret;
+
+ token = __fs_parse(&log, rbd_parameters, param, &result);
+ dout("%s fs_parse '%s' token %d\n", __func__, param->key, token);
+ if (token < 0) {
+ if (token == -ENOPARAM)
+ return inval_plog(&log, "Unknown parameter '%s'",
+ param->key);
+ return token;
+ }
+
+ switch (token) {
+ case Opt_queue_depth:
+ if (result.uint_32 < 1)
+ goto out_of_range;
+ opt->queue_depth = result.uint_32;
+ break;
+ case Opt_alloc_size:
+ if (result.uint_32 < SECTOR_SIZE)
+ goto out_of_range;
+ if (!is_power_of_2(result.uint_32))
+ return inval_plog(&log, "alloc_size must be a power of 2");
+ opt->alloc_size = result.uint_32;
+ break;
+ case Opt_lock_timeout:
+ /* 0 is "wait forever" (i.e. infinite timeout) */
+ if (result.uint_32 > INT_MAX / 1000)
+ goto out_of_range;
+ opt->lock_timeout = msecs_to_jiffies(result.uint_32 * 1000);
+ break;
+ case Opt_pool_ns:
+ kfree(pctx->spec->pool_ns);
+ pctx->spec->pool_ns = param->string;
+ param->string = NULL;
+ break;
+ case Opt_compression_hint:
+ switch (result.uint_32) {
+ case Opt_compression_hint_none:
+ opt->alloc_hint_flags &=
+ ~(CEPH_OSD_ALLOC_HINT_FLAG_COMPRESSIBLE |
+ CEPH_OSD_ALLOC_HINT_FLAG_INCOMPRESSIBLE);
+ break;
+ case Opt_compression_hint_compressible:
+ opt->alloc_hint_flags |=
+ CEPH_OSD_ALLOC_HINT_FLAG_COMPRESSIBLE;
+ opt->alloc_hint_flags &=
+ ~CEPH_OSD_ALLOC_HINT_FLAG_INCOMPRESSIBLE;
+ break;
+ case Opt_compression_hint_incompressible:
+ opt->alloc_hint_flags |=
+ CEPH_OSD_ALLOC_HINT_FLAG_INCOMPRESSIBLE;
+ opt->alloc_hint_flags &=
+ ~CEPH_OSD_ALLOC_HINT_FLAG_COMPRESSIBLE;
+ break;
+ default:
+ BUG();
+ }
+ break;
+ case Opt_read_only:
+ opt->read_only = true;
+ break;
+ case Opt_read_write:
+ opt->read_only = false;
+ break;
+ case Opt_lock_on_read:
+ opt->lock_on_read = true;
+ break;
+ case Opt_exclusive:
+ opt->exclusive = true;
+ break;
+ case Opt_notrim:
+ opt->trim = false;
+ break;
+ default:
+ BUG();
+ }
+
+ return 0;
+
+out_of_range:
+ return inval_plog(&log, "%s out of range", param->key);
+}
+
+/*
+ * This duplicates most of generic_parse_monolithic(), untying it from
+ * fs_context and skipping standard superblock and security options.
+ */
+static int rbd_parse_options(char *options, struct rbd_parse_opts_ctx *pctx)
+{
+ char *key;
+ int ret = 0;
+
+ dout("%s '%s'\n", __func__, options);
+ while ((key = strsep(&options, ",")) != NULL) {
+ if (*key) {
+ struct fs_parameter param = {
+ .key = key,
+ .type = fs_value_is_flag,
+ };
+ char *value = strchr(key, '=');
+ size_t v_len = 0;
+
+ if (value) {
+ if (value == key)
+ continue;
+ *value++ = 0;
+ v_len = strlen(value);
+ param.string = kmemdup_nul(value, v_len,
+ GFP_KERNEL);
+ if (!param.string)
+ return -ENOMEM;
+ param.type = fs_value_is_string;
+ }
+ param.size = v_len;
+
+ ret = rbd_parse_param(&param, pctx);
+ kfree(param.string);
+ if (ret)
+ break;
+ }
+ }
+
+ return ret;
+}
+
+/*
+ * Parse the options provided for an "rbd add" (i.e., rbd image
+ * mapping) request. These arrive via a write to /sys/bus/rbd/add,
+ * and the data written is passed here via a NUL-terminated buffer.
+ * Returns 0 if successful or an error code otherwise.
+ *
+ * The information extracted from these options is recorded in
+ * the other parameters which return dynamically-allocated
+ * structures:
+ * ceph_opts
+ * The address of a pointer that will refer to a ceph options
+ * structure. Caller must release the returned pointer using
+ * ceph_destroy_options() when it is no longer needed.
+ * rbd_opts
+ * Address of an rbd options pointer. Fully initialized by
+ * this function; caller must release with kfree().
+ * spec
+ * Address of an rbd image specification pointer. Fully
+ * initialized by this function based on parsed options.
+ * Caller must release with rbd_spec_put().
+ *
+ * The options passed take this form:
+ * <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
+ * where:
+ * <mon_addrs>
+ * A comma-separated list of one or more monitor addresses.
+ * A monitor address is an ip address, optionally followed
+ * by a port number (separated by a colon).
+ * I.e.: ip1[:port1][,ip2[:port2]...]
+ * <options>
+ * A comma-separated list of ceph and/or rbd options.
+ * <pool_name>
+ * The name of the rados pool containing the rbd image.
+ * <image_name>
+ * The name of the image in that pool to map.
+ * <snap_id>
+ * An optional snapshot id. If provided, the mapping will
+ * present data from the image at the time that snapshot was
+ * created. The image head is used if no snapshot id is
+ * provided. Snapshot mappings are always read-only.
+ */
+static int rbd_add_parse_args(const char *buf,
+ struct ceph_options **ceph_opts,
+ struct rbd_options **opts,
+ struct rbd_spec **rbd_spec)
+{
+ size_t len;
+ char *options;
+ const char *mon_addrs;
+ char *snap_name;
+ size_t mon_addrs_size;
+ struct rbd_parse_opts_ctx pctx = { 0 };
+ int ret;
+
+ /* The first four tokens are required */
+
+ len = next_token(&buf);
+ if (!len) {
+ rbd_warn(NULL, "no monitor address(es) provided");
+ return -EINVAL;
+ }
+ mon_addrs = buf;
+ mon_addrs_size = len;
+ buf += len;
+
+ ret = -EINVAL;
+ options = dup_token(&buf, NULL);
+ if (!options)
+ return -ENOMEM;
+ if (!*options) {
+ rbd_warn(NULL, "no options provided");
+ goto out_err;
+ }
+
+ pctx.spec = rbd_spec_alloc();
+ if (!pctx.spec)
+ goto out_mem;
+
+ pctx.spec->pool_name = dup_token(&buf, NULL);
+ if (!pctx.spec->pool_name)
+ goto out_mem;
+ if (!*pctx.spec->pool_name) {
+ rbd_warn(NULL, "no pool name provided");
+ goto out_err;
+ }
+
+ pctx.spec->image_name = dup_token(&buf, NULL);
+ if (!pctx.spec->image_name)
+ goto out_mem;
+ if (!*pctx.spec->image_name) {
+ rbd_warn(NULL, "no image name provided");
+ goto out_err;
+ }
+
+ /*
+ * Snapshot name is optional; default is to use "-"
+ * (indicating the head/no snapshot).
+ */
+ len = next_token(&buf);
+ if (!len) {
+ buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
+ len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
+ } else if (len > RBD_MAX_SNAP_NAME_LEN) {
+ ret = -ENAMETOOLONG;
+ goto out_err;
+ }
+ snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
+ if (!snap_name)
+ goto out_mem;
+ *(snap_name + len) = '\0';
+ pctx.spec->snap_name = snap_name;
+
+ pctx.copts = ceph_alloc_options();
+ if (!pctx.copts)
+ goto out_mem;
+
+ /* Initialize all rbd options to the defaults */
+
+ pctx.opts = kzalloc(sizeof(*pctx.opts), GFP_KERNEL);
+ if (!pctx.opts)
+ goto out_mem;
+
+ pctx.opts->read_only = RBD_READ_ONLY_DEFAULT;
+ pctx.opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
+ pctx.opts->alloc_size = RBD_ALLOC_SIZE_DEFAULT;
+ pctx.opts->lock_timeout = RBD_LOCK_TIMEOUT_DEFAULT;
+ pctx.opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
+ pctx.opts->exclusive = RBD_EXCLUSIVE_DEFAULT;
+ pctx.opts->trim = RBD_TRIM_DEFAULT;
+
+ ret = ceph_parse_mon_ips(mon_addrs, mon_addrs_size, pctx.copts, NULL,
+ ',');
+ if (ret)
+ goto out_err;
+
+ ret = rbd_parse_options(options, &pctx);
+ if (ret)
+ goto out_err;
+
+ *ceph_opts = pctx.copts;
+ *opts = pctx.opts;
+ *rbd_spec = pctx.spec;
+ kfree(options);
+ return 0;
+
+out_mem:
+ ret = -ENOMEM;
+out_err:
+ kfree(pctx.opts);
+ ceph_destroy_options(pctx.copts);
+ rbd_spec_put(pctx.spec);
+ kfree(options);
+ return ret;
+}
+
+static void rbd_dev_image_unlock(struct rbd_device *rbd_dev)
+{
+ down_write(&rbd_dev->lock_rwsem);
+ if (__rbd_is_lock_owner(rbd_dev))
+ __rbd_release_lock(rbd_dev);
+ up_write(&rbd_dev->lock_rwsem);
+}
+
+/*
+ * If the wait is interrupted, an error is returned even if the lock
+ * was successfully acquired. rbd_dev_image_unlock() will release it
+ * if needed.
+ */
+static int rbd_add_acquire_lock(struct rbd_device *rbd_dev)
+{
+ long ret;
+
+ if (!(rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK)) {
+ if (!rbd_dev->opts->exclusive && !rbd_dev->opts->lock_on_read)
+ return 0;
+
+ rbd_warn(rbd_dev, "exclusive-lock feature is not enabled");
+ return -EINVAL;
+ }
+
+ if (rbd_is_ro(rbd_dev))
+ return 0;
+
+ rbd_assert(!rbd_is_lock_owner(rbd_dev));
+ queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
+ ret = wait_for_completion_killable_timeout(&rbd_dev->acquire_wait,
+ ceph_timeout_jiffies(rbd_dev->opts->lock_timeout));
+ if (ret > 0) {
+ ret = rbd_dev->acquire_err;
+ } else {
+ cancel_delayed_work_sync(&rbd_dev->lock_dwork);
+ if (!ret)
+ ret = -ETIMEDOUT;
+
+ rbd_warn(rbd_dev, "failed to acquire lock: %ld", ret);
+ }
+ if (ret)
+ return ret;
+
+ /*
+ * The lock may have been released by now, unless automatic lock
+ * transitions are disabled.
+ */
+ rbd_assert(!rbd_dev->opts->exclusive || rbd_is_lock_owner(rbd_dev));
+ return 0;
+}
+
+/*
+ * An rbd format 2 image has a unique identifier, distinct from the
+ * name given to it by the user. Internally, that identifier is
+ * what's used to specify the names of objects related to the image.
+ *
+ * A special "rbd id" object is used to map an rbd image name to its
+ * id. If that object doesn't exist, then there is no v2 rbd image
+ * with the supplied name.
+ *
+ * This function will record the given rbd_dev's image_id field if
+ * it can be determined, and in that case will return 0. If any
+ * errors occur a negative errno will be returned and the rbd_dev's
+ * image_id field will be unchanged (and should be NULL).
+ */
+static int rbd_dev_image_id(struct rbd_device *rbd_dev)
+{
+ int ret;
+ size_t size;
+ CEPH_DEFINE_OID_ONSTACK(oid);
+ void *response;
+ char *image_id;
+
+ /*
+ * When probing a parent image, the image id is already
+ * known (and the image name likely is not). There's no
+ * need to fetch the image id again in this case. We
+ * do still need to set the image format though.
+ */
+ if (rbd_dev->spec->image_id) {
+ rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;
+
+ return 0;
+ }
+
+ /*
+ * First, see if the format 2 image id file exists, and if
+ * so, get the image's persistent id from it.
+ */
+ ret = ceph_oid_aprintf(&oid, GFP_KERNEL, "%s%s", RBD_ID_PREFIX,
+ rbd_dev->spec->image_name);
+ if (ret)
+ return ret;
+
+ dout("rbd id object name is %s\n", oid.name);
+
+ /* Response will be an encoded string, which includes a length */
+ size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
+ response = kzalloc(size, GFP_NOIO);
+ if (!response) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /* If it doesn't exist we'll assume it's a format 1 image */
+
+ ret = rbd_obj_method_sync(rbd_dev, &oid, &rbd_dev->header_oloc,
+ "get_id", NULL, 0,
+ response, size);
+ dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
+ if (ret == -ENOENT) {
+ image_id = kstrdup("", GFP_KERNEL);
+ ret = image_id ? 0 : -ENOMEM;
+ if (!ret)
+ rbd_dev->image_format = 1;
+ } else if (ret >= 0) {
+ void *p = response;
+
+ image_id = ceph_extract_encoded_string(&p, p + ret,
+ NULL, GFP_NOIO);
+ ret = PTR_ERR_OR_ZERO(image_id);
+ if (!ret)
+ rbd_dev->image_format = 2;
+ }
+
+ if (!ret) {
+ rbd_dev->spec->image_id = image_id;
+ dout("image_id is %s\n", image_id);
+ }
+out:
+ kfree(response);
+ ceph_oid_destroy(&oid);
+ return ret;
+}
+
+/*
+ * Undo whatever state changes are made by v1 or v2 header info
+ * call.
+ */
+static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
+{
+ rbd_dev_parent_put(rbd_dev);
+ rbd_object_map_free(rbd_dev);
+ rbd_dev_mapping_clear(rbd_dev);
+
+ /* Free dynamic fields from the header, then zero it out */
+
+ rbd_image_header_cleanup(&rbd_dev->header);
+}
+
+static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev,
+ struct rbd_image_header *header)
+{
+ int ret;
+
+ ret = rbd_dev_v2_object_prefix(rbd_dev, &header->object_prefix);
+ if (ret)
+ return ret;
+
+ /*
+ * Get the and check features for the image. Currently the
+ * features are assumed to never change.
+ */
+ ret = _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
+ rbd_is_ro(rbd_dev), &header->features);
+ if (ret)
+ return ret;
+
+ /* If the image supports fancy striping, get its parameters */
+
+ if (header->features & RBD_FEATURE_STRIPINGV2) {
+ ret = rbd_dev_v2_striping_info(rbd_dev, &header->stripe_unit,
+ &header->stripe_count);
+ if (ret)
+ return ret;
+ }
+
+ if (header->features & RBD_FEATURE_DATA_POOL) {
+ ret = rbd_dev_v2_data_pool(rbd_dev, &header->data_pool_id);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * @depth is rbd_dev_image_probe() -> rbd_dev_probe_parent() ->
+ * rbd_dev_image_probe() recursion depth, which means it's also the
+ * length of the already discovered part of the parent chain.
+ */
+static int rbd_dev_probe_parent(struct rbd_device *rbd_dev, int depth)
+{
+ struct rbd_device *parent = NULL;
+ int ret;
+
+ if (!rbd_dev->parent_spec)
+ return 0;
+
+ if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
+ pr_info("parent chain is too long (%d)\n", depth);
+ ret = -EINVAL;
+ goto out_err;
+ }
+
+ parent = __rbd_dev_create(rbd_dev->parent_spec);
+ if (!parent) {
+ ret = -ENOMEM;
+ goto out_err;
+ }
+
+ /*
+ * Images related by parent/child relationships always share
+ * rbd_client and spec/parent_spec, so bump their refcounts.
+ */
+ parent->rbd_client = __rbd_get_client(rbd_dev->rbd_client);
+ parent->spec = rbd_spec_get(rbd_dev->parent_spec);
+
+ __set_bit(RBD_DEV_FLAG_READONLY, &parent->flags);
+
+ ret = rbd_dev_image_probe(parent, depth);
+ if (ret < 0)
+ goto out_err;
+
+ rbd_dev->parent = parent;
+ atomic_set(&rbd_dev->parent_ref, 1);
+ return 0;
+
+out_err:
+ rbd_dev_unparent(rbd_dev);
+ rbd_dev_destroy(parent);
+ return ret;
+}
+
+static void rbd_dev_device_release(struct rbd_device *rbd_dev)
+{
+ clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
+ rbd_free_disk(rbd_dev);
+ if (!single_major)
+ unregister_blkdev(rbd_dev->major, rbd_dev->name);
+}
+
+/*
+ * rbd_dev->header_rwsem must be locked for write and will be unlocked
+ * upon return.
+ */
+static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
+{
+ int ret;
+
+ /* Record our major and minor device numbers. */
+
+ if (!single_major) {
+ ret = register_blkdev(0, rbd_dev->name);
+ if (ret < 0)
+ goto err_out_unlock;
+
+ rbd_dev->major = ret;
+ rbd_dev->minor = 0;
+ } else {
+ rbd_dev->major = rbd_major;
+ rbd_dev->minor = rbd_dev_id_to_minor(rbd_dev->dev_id);
+ }
+
+ /* Set up the blkdev mapping. */
+
+ ret = rbd_init_disk(rbd_dev);
+ if (ret)
+ goto err_out_blkdev;
+
+ set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
+ set_disk_ro(rbd_dev->disk, rbd_is_ro(rbd_dev));
+
+ ret = dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
+ if (ret)
+ goto err_out_disk;
+
+ set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
+ up_write(&rbd_dev->header_rwsem);
+ return 0;
+
+err_out_disk:
+ rbd_free_disk(rbd_dev);
+err_out_blkdev:
+ if (!single_major)
+ unregister_blkdev(rbd_dev->major, rbd_dev->name);
+err_out_unlock:
+ up_write(&rbd_dev->header_rwsem);
+ return ret;
+}
+
+static int rbd_dev_header_name(struct rbd_device *rbd_dev)
+{
+ struct rbd_spec *spec = rbd_dev->spec;
+ int ret;
+
+ /* Record the header object name for this rbd image. */
+
+ rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
+ if (rbd_dev->image_format == 1)
+ ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
+ spec->image_name, RBD_SUFFIX);
+ else
+ ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
+ RBD_HEADER_PREFIX, spec->image_id);
+
+ return ret;
+}
+
+static void rbd_print_dne(struct rbd_device *rbd_dev, bool is_snap)
+{
+ if (!is_snap) {
+ pr_info("image %s/%s%s%s does not exist\n",
+ rbd_dev->spec->pool_name,
+ rbd_dev->spec->pool_ns ?: "",
+ rbd_dev->spec->pool_ns ? "/" : "",
+ rbd_dev->spec->image_name);
+ } else {
+ pr_info("snap %s/%s%s%s@%s does not exist\n",
+ rbd_dev->spec->pool_name,
+ rbd_dev->spec->pool_ns ?: "",
+ rbd_dev->spec->pool_ns ? "/" : "",
+ rbd_dev->spec->image_name,
+ rbd_dev->spec->snap_name);
+ }
+}
+
+static void rbd_dev_image_release(struct rbd_device *rbd_dev)
+{
+ if (!rbd_is_ro(rbd_dev))
+ rbd_unregister_watch(rbd_dev);
+
+ rbd_dev_unprobe(rbd_dev);
+ rbd_dev->image_format = 0;
+ kfree(rbd_dev->spec->image_id);
+ rbd_dev->spec->image_id = NULL;
+}
+
+/*
+ * Probe for the existence of the header object for the given rbd
+ * 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.
+ *
+ * On success, returns with header_rwsem held for write if called
+ * with @depth == 0.
+ */
+static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
+{
+ bool need_watch = !rbd_is_ro(rbd_dev);
+ int ret;
+
+ /*
+ * Get the id from the image id object. Unless there's an
+ * error, rbd_dev->spec->image_id will be filled in with
+ * a dynamically-allocated string, and rbd_dev->image_format
+ * will be set to either 1 or 2.
+ */
+ ret = rbd_dev_image_id(rbd_dev);
+ if (ret)
+ return ret;
+
+ ret = rbd_dev_header_name(rbd_dev);
+ if (ret)
+ goto err_out_format;
+
+ if (need_watch) {
+ ret = rbd_register_watch(rbd_dev);
+ if (ret) {
+ if (ret == -ENOENT)
+ rbd_print_dne(rbd_dev, false);
+ goto err_out_format;
+ }
+ }
+
+ if (!depth)
+ down_write(&rbd_dev->header_rwsem);
+
+ ret = rbd_dev_header_info(rbd_dev, &rbd_dev->header, true);
+ if (ret) {
+ if (ret == -ENOENT && !need_watch)
+ rbd_print_dne(rbd_dev, false);
+ goto err_out_probe;
+ }
+
+ rbd_init_layout(rbd_dev);
+
+ /*
+ * If this image is the one being mapped, we have pool name and
+ * id, image name and id, and snap name - need to fill snap id.
+ * Otherwise this is a parent image, identified by pool, image
+ * and snap ids - need to fill in names for those ids.
+ */
+ if (!depth)
+ ret = rbd_spec_fill_snap_id(rbd_dev);
+ else
+ ret = rbd_spec_fill_names(rbd_dev);
+ if (ret) {
+ if (ret == -ENOENT)
+ rbd_print_dne(rbd_dev, true);
+ goto err_out_probe;
+ }
+
+ ret = rbd_dev_mapping_set(rbd_dev);
+ if (ret)
+ goto err_out_probe;
+
+ if (rbd_is_snap(rbd_dev) &&
+ (rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP)) {
+ ret = rbd_object_map_load(rbd_dev);
+ if (ret)
+ goto err_out_probe;
+ }
+
+ if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
+ ret = rbd_dev_setup_parent(rbd_dev);
+ if (ret)
+ goto err_out_probe;
+ }
+
+ ret = rbd_dev_probe_parent(rbd_dev, depth);
+ if (ret)
+ goto err_out_probe;
+
+ dout("discovered format %u image, header name is %s\n",
+ rbd_dev->image_format, rbd_dev->header_oid.name);
+ return 0;
+
+err_out_probe:
+ if (!depth)
+ up_write(&rbd_dev->header_rwsem);
+ if (need_watch)
+ rbd_unregister_watch(rbd_dev);
+ rbd_dev_unprobe(rbd_dev);
+err_out_format:
+ rbd_dev->image_format = 0;
+ kfree(rbd_dev->spec->image_id);
+ rbd_dev->spec->image_id = NULL;
+ return ret;
+}
+
+static void rbd_dev_update_header(struct rbd_device *rbd_dev,
+ struct rbd_image_header *header)
+{
+ rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
+ rbd_assert(rbd_dev->header.object_prefix); /* !first_time */
+
+ if (rbd_dev->header.image_size != header->image_size) {
+ rbd_dev->header.image_size = header->image_size;
+
+ if (!rbd_is_snap(rbd_dev)) {
+ rbd_dev->mapping.size = header->image_size;
+ rbd_dev_update_size(rbd_dev);
+ }
+ }
+
+ ceph_put_snap_context(rbd_dev->header.snapc);
+ rbd_dev->header.snapc = header->snapc;
+ header->snapc = NULL;
+
+ if (rbd_dev->image_format == 1) {
+ kfree(rbd_dev->header.snap_names);
+ rbd_dev->header.snap_names = header->snap_names;
+ header->snap_names = NULL;
+
+ kfree(rbd_dev->header.snap_sizes);
+ rbd_dev->header.snap_sizes = header->snap_sizes;
+ header->snap_sizes = NULL;
+ }
+}
+
+static void rbd_dev_update_parent(struct rbd_device *rbd_dev,
+ struct parent_image_info *pii)
+{
+ if (pii->pool_id == CEPH_NOPOOL || !pii->has_overlap) {
+ /*
+ * 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 !pii.has_overlap, the parent image spec is not
+ * applicable. It's there to avoid duplication in each
+ * snapshot record.
+ */
+ if (rbd_dev->parent_overlap) {
+ rbd_dev->parent_overlap = 0;
+ rbd_dev_parent_put(rbd_dev);
+ pr_info("%s: clone has been flattened\n",
+ rbd_dev->disk->disk_name);
+ }
+ } else {
+ rbd_assert(rbd_dev->parent_spec);
+
+ /*
+ * Update the parent overlap. If it became zero, issue
+ * a warning as we will proceed as if there is no parent.
+ */
+ if (!pii->overlap && rbd_dev->parent_overlap)
+ rbd_warn(rbd_dev,
+ "clone has become standalone (overlap 0)");
+ rbd_dev->parent_overlap = pii->overlap;
+ }
+}
+
+static int rbd_dev_refresh(struct rbd_device *rbd_dev)
+{
+ struct rbd_image_header header = { 0 };
+ struct parent_image_info pii = { 0 };
+ int ret;
+
+ dout("%s rbd_dev %p\n", __func__, rbd_dev);
+
+ ret = rbd_dev_header_info(rbd_dev, &header, false);
+ if (ret)
+ goto out;
+
+ /*
+ * If there is a parent, see if it has disappeared due to the
+ * mapped image getting flattened.
+ */
+ if (rbd_dev->parent) {
+ ret = rbd_dev_v2_parent_info(rbd_dev, &pii);
+ if (ret)
+ goto out;
+ }
+
+ down_write(&rbd_dev->header_rwsem);
+ rbd_dev_update_header(rbd_dev, &header);
+ if (rbd_dev->parent)
+ rbd_dev_update_parent(rbd_dev, &pii);
+ up_write(&rbd_dev->header_rwsem);
+
+out:
+ rbd_parent_info_cleanup(&pii);
+ rbd_image_header_cleanup(&header);
+ return ret;
+}
+
+static ssize_t do_rbd_add(const char *buf, size_t count)
+{
+ struct rbd_device *rbd_dev = NULL;
+ struct ceph_options *ceph_opts = NULL;
+ struct rbd_options *rbd_opts = NULL;
+ struct rbd_spec *spec = NULL;
+ struct rbd_client *rbdc;
+ int rc;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (!try_module_get(THIS_MODULE))
+ return -ENODEV;
+
+ /* parse add command */
+ rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
+ if (rc < 0)
+ goto out;
+
+ rbdc = rbd_get_client(ceph_opts);
+ if (IS_ERR(rbdc)) {
+ rc = PTR_ERR(rbdc);
+ goto err_out_args;
+ }
+
+ /* pick the pool */
+ rc = ceph_pg_poolid_by_name(rbdc->client->osdc.osdmap, spec->pool_name);
+ if (rc < 0) {
+ if (rc == -ENOENT)
+ pr_info("pool %s does not exist\n", spec->pool_name);
+ goto err_out_client;
+ }
+ spec->pool_id = (u64)rc;
+
+ rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
+ if (!rbd_dev) {
+ rc = -ENOMEM;
+ goto err_out_client;
+ }
+ rbdc = NULL; /* rbd_dev now owns this */
+ spec = NULL; /* rbd_dev now owns this */
+ rbd_opts = NULL; /* rbd_dev now owns this */
+
+ /* if we are mapping a snapshot it will be a read-only mapping */
+ if (rbd_dev->opts->read_only ||
+ strcmp(rbd_dev->spec->snap_name, RBD_SNAP_HEAD_NAME))
+ __set_bit(RBD_DEV_FLAG_READONLY, &rbd_dev->flags);
+
+ rbd_dev->config_info = kstrdup(buf, GFP_KERNEL);
+ if (!rbd_dev->config_info) {
+ rc = -ENOMEM;
+ goto err_out_rbd_dev;
+ }
+
+ rc = rbd_dev_image_probe(rbd_dev, 0);
+ if (rc < 0)
+ goto err_out_rbd_dev;
+
+ if (rbd_dev->opts->alloc_size > rbd_dev->layout.object_size) {
+ rbd_warn(rbd_dev, "alloc_size adjusted to %u",
+ rbd_dev->layout.object_size);
+ rbd_dev->opts->alloc_size = rbd_dev->layout.object_size;
+ }
+
+ rc = rbd_dev_device_setup(rbd_dev);
+ if (rc)
+ goto err_out_image_probe;
+
+ rc = rbd_add_acquire_lock(rbd_dev);
+ if (rc)
+ goto err_out_image_lock;
+
+ /* Everything's ready. Announce the disk to the world. */
+
+ rc = device_add(&rbd_dev->dev);
+ if (rc)
+ goto err_out_image_lock;
+
+ rc = device_add_disk(&rbd_dev->dev, rbd_dev->disk, NULL);
+ if (rc)
+ goto err_out_cleanup_disk;
+
+ spin_lock(&rbd_dev_list_lock);
+ list_add_tail(&rbd_dev->node, &rbd_dev_list);
+ spin_unlock(&rbd_dev_list_lock);
+
+ pr_info("%s: capacity %llu features 0x%llx\n", rbd_dev->disk->disk_name,
+ (unsigned long long)get_capacity(rbd_dev->disk) << SECTOR_SHIFT,
+ rbd_dev->header.features);
+ rc = count;
+out:
+ module_put(THIS_MODULE);
+ return rc;
+
+err_out_cleanup_disk:
+ rbd_free_disk(rbd_dev);
+err_out_image_lock:
+ rbd_dev_image_unlock(rbd_dev);
+ rbd_dev_device_release(rbd_dev);
+err_out_image_probe:
+ rbd_dev_image_release(rbd_dev);
+err_out_rbd_dev:
+ rbd_dev_destroy(rbd_dev);
+err_out_client:
+ rbd_put_client(rbdc);
+err_out_args:
+ rbd_spec_put(spec);
+ kfree(rbd_opts);
+ goto out;
+}
+
+static ssize_t add_store(const struct bus_type *bus, const char *buf, size_t count)
+{
+ if (single_major)
+ return -EINVAL;
+
+ return do_rbd_add(buf, count);
+}
+
+static ssize_t add_single_major_store(const struct bus_type *bus, const char *buf,
+ size_t count)
+{
+ return do_rbd_add(buf, count);
+}
+
+static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
+{
+ while (rbd_dev->parent) {
+ struct rbd_device *first = rbd_dev;
+ struct rbd_device *second = first->parent;
+ struct rbd_device *third;
+
+ /*
+ * Follow to the parent with no grandparent and
+ * remove it.
+ */
+ while (second && (third = second->parent)) {
+ first = second;
+ second = third;
+ }
+ rbd_assert(second);
+ rbd_dev_image_release(second);
+ rbd_dev_destroy(second);
+ first->parent = NULL;
+ first->parent_overlap = 0;
+
+ rbd_assert(first->parent_spec);
+ rbd_spec_put(first->parent_spec);
+ first->parent_spec = NULL;
+ }
+}
+
+static ssize_t do_rbd_remove(const char *buf, size_t count)
+{
+ struct rbd_device *rbd_dev = NULL;
+ int dev_id;
+ char opt_buf[6];
+ bool force = false;
+ int ret;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ dev_id = -1;
+ opt_buf[0] = '\0';
+ sscanf(buf, "%d %5s", &dev_id, opt_buf);
+ if (dev_id < 0) {
+ pr_err("dev_id out of range\n");
+ return -EINVAL;
+ }
+ if (opt_buf[0] != '\0') {
+ if (!strcmp(opt_buf, "force")) {
+ force = true;
+ } else {
+ pr_err("bad remove option at '%s'\n", opt_buf);
+ return -EINVAL;
+ }
+ }
+
+ ret = -ENOENT;
+ spin_lock(&rbd_dev_list_lock);
+ list_for_each_entry(rbd_dev, &rbd_dev_list, node) {
+ if (rbd_dev->dev_id == dev_id) {
+ ret = 0;
+ break;
+ }
+ }
+ if (!ret) {
+ spin_lock_irq(&rbd_dev->lock);
+ if (rbd_dev->open_count && !force)
+ ret = -EBUSY;
+ else if (test_and_set_bit(RBD_DEV_FLAG_REMOVING,
+ &rbd_dev->flags))
+ ret = -EINPROGRESS;
+ spin_unlock_irq(&rbd_dev->lock);
+ }
+ spin_unlock(&rbd_dev_list_lock);
+ if (ret)
+ return ret;
+
+ if (force) {
+ /*
+ * Prevent new IO from being queued and wait for existing
+ * IO to complete/fail.
+ */
+ blk_mq_freeze_queue(rbd_dev->disk->queue);
+ blk_mark_disk_dead(rbd_dev->disk);
+ }
+
+ del_gendisk(rbd_dev->disk);
+ spin_lock(&rbd_dev_list_lock);
+ list_del_init(&rbd_dev->node);
+ spin_unlock(&rbd_dev_list_lock);
+ device_del(&rbd_dev->dev);
+
+ rbd_dev_image_unlock(rbd_dev);
+ rbd_dev_device_release(rbd_dev);
+ rbd_dev_image_release(rbd_dev);
+ rbd_dev_destroy(rbd_dev);
+ return count;
+}
+
+static ssize_t remove_store(const struct bus_type *bus, const char *buf, size_t count)
+{
+ if (single_major)
+ return -EINVAL;
+
+ return do_rbd_remove(buf, count);
+}
+
+static ssize_t remove_single_major_store(const struct bus_type *bus, const char *buf,
+ size_t count)
+{
+ return do_rbd_remove(buf, count);
+}
+
+/*
+ * create control files in sysfs
+ * /sys/bus/rbd/...
+ */
+static int __init rbd_sysfs_init(void)
+{
+ int ret;
+
+ ret = device_register(&rbd_root_dev);
+ if (ret < 0) {
+ put_device(&rbd_root_dev);
+ return ret;
+ }
+
+ ret = bus_register(&rbd_bus_type);
+ if (ret < 0)
+ device_unregister(&rbd_root_dev);
+
+ return ret;
+}
+
+static void __exit rbd_sysfs_cleanup(void)
+{
+ bus_unregister(&rbd_bus_type);
+ device_unregister(&rbd_root_dev);
+}
+
+static int __init rbd_slab_init(void)
+{
+ rbd_assert(!rbd_img_request_cache);
+ rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
+ if (!rbd_img_request_cache)
+ return -ENOMEM;
+
+ rbd_assert(!rbd_obj_request_cache);
+ rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
+ if (!rbd_obj_request_cache)
+ goto out_err;
+
+ return 0;
+
+out_err:
+ kmem_cache_destroy(rbd_img_request_cache);
+ rbd_img_request_cache = NULL;
+ return -ENOMEM;
+}
+
+static void rbd_slab_exit(void)
+{
+ rbd_assert(rbd_obj_request_cache);
+ kmem_cache_destroy(rbd_obj_request_cache);
+ rbd_obj_request_cache = NULL;
+
+ rbd_assert(rbd_img_request_cache);
+ kmem_cache_destroy(rbd_img_request_cache);
+ rbd_img_request_cache = NULL;
+}
+
+static int __init rbd_init(void)
+{
+ int rc;
+
+ if (!libceph_compatible(NULL)) {
+ rbd_warn(NULL, "libceph incompatibility (quitting)");
+ return -EINVAL;
+ }
+
+ rc = rbd_slab_init();
+ if (rc)
+ return rc;
+
+ /*
+ * The number of active work items is limited by the number of
+ * rbd devices * queue depth, so leave @max_active at default.
+ */
+ rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
+ if (!rbd_wq) {
+ rc = -ENOMEM;
+ goto err_out_slab;
+ }
+
+ if (single_major) {
+ rbd_major = register_blkdev(0, RBD_DRV_NAME);
+ if (rbd_major < 0) {
+ rc = rbd_major;
+ goto err_out_wq;
+ }
+ }
+
+ rc = rbd_sysfs_init();
+ if (rc)
+ goto err_out_blkdev;
+
+ if (single_major)
+ pr_info("loaded (major %d)\n", rbd_major);
+ else
+ pr_info("loaded\n");
+
+ return 0;
+
+err_out_blkdev:
+ if (single_major)
+ unregister_blkdev(rbd_major, RBD_DRV_NAME);
+err_out_wq:
+ destroy_workqueue(rbd_wq);
+err_out_slab:
+ rbd_slab_exit();
+ return rc;
+}
+
+static void __exit rbd_exit(void)
+{
+ ida_destroy(&rbd_dev_id_ida);
+ rbd_sysfs_cleanup();
+ if (single_major)
+ unregister_blkdev(rbd_major, RBD_DRV_NAME);
+ destroy_workqueue(rbd_wq);
+ rbd_slab_exit();
+}
+
+module_init(rbd_init);
+module_exit(rbd_exit);
+
+MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
+MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
+MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
+/* following authorship retained from original osdblk.c */
+MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
+
+MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-06 07:25:41 +0000