diff options
Diffstat (limited to 'drivers/block/rbd.c')
| -rw-r--r-- | drivers/block/rbd.c | 6215 |
1 files changed, 6215 insertions, 0 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c new file mode 100644 index 000000000..9f1265ce2 --- /dev/null +++ b/drivers/block/rbd.c @@ -0,0 +1,6215 @@ + +/* + 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/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_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_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 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, +}; + +/* + * Writes go through the following state machine to deal with + * layering: + * + * need copyup + * RBD_OBJ_WRITE_GUARD ---------------> RBD_OBJ_WRITE_COPYUP + * | ^ | + * v \------------------------------/ + * done + * ^ + * | + * RBD_OBJ_WRITE_FLAT + * + * Writes start in RBD_OBJ_WRITE_GUARD or _FLAT, depending on whether + * there is a parent or not. + */ +enum rbd_obj_write_state { + RBD_OBJ_WRITE_FLAT = 1, + RBD_OBJ_WRITE_GUARD, + RBD_OBJ_WRITE_COPYUP, +}; + +struct rbd_obj_request { + struct ceph_object_extent ex; + union { + bool tried_parent; /* 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; + }; + }; + struct bio_vec *copyup_bvecs; + u32 copyup_bvec_count; + + struct ceph_osd_request *osd_req; + + u64 xferred; /* bytes transferred */ + int result; + + 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 */ +}; + +struct rbd_img_request { + struct rbd_device *rbd_dev; + enum obj_operation_type op_type; + enum obj_request_type data_type; + unsigned long flags; + union { + u64 snap_id; /* for reads */ + struct ceph_snap_context *snapc; /* for writes */ + }; + union { + struct request *rq; /* block request */ + struct rbd_obj_request *obj_request; /* obj req initiator */ + }; + spinlock_t completion_lock; + u64 xferred;/* aggregate bytes transferred */ + int result; /* first nonzero obj_request result */ + + struct list_head object_extents; /* obj_req.ex structs */ + u32 obj_request_count; + u32 pending_count; + + struct kref kref; +}; + +#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; + u64 features; +}; + +/* + * 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; + wait_queue_head_t lock_waitq; + + 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 + * - BLACKLISTED is protected by rbd_dev->lock_rwsem + */ +enum rbd_dev_flags { + RBD_DEV_FLAG_EXISTS, /* mapped snapshot has not been deleted */ + RBD_DEV_FLAG_REMOVING, /* this mapping is being removed */ + RBD_DEV_FLAG_BLACKLISTED, /* our ceph_client is blacklisted */ +}; + +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; + +/* + * 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 rbd_add(struct bus_type *bus, const char *buf, + size_t count); +static ssize_t rbd_remove(struct bus_type *bus, const char *buf, + size_t count); +static ssize_t rbd_add_single_major(struct bus_type *bus, const char *buf, + size_t count); +static ssize_t rbd_remove_single_major(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_lock_owner(struct rbd_device *rbd_dev) +{ + 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 rbd_supported_features_show(struct bus_type *bus, char *buf) +{ + return sprintf(buf, "0x%llx\n", RBD_FEATURES_SUPPORTED); +} + +static BUS_ATTR(add, 0200, NULL, rbd_add); +static BUS_ATTR(remove, 0200, NULL, rbd_remove); +static BUS_ATTR(add_single_major, 0200, NULL, rbd_add_single_major); +static BUS_ATTR(remove_single_major, 0200, NULL, rbd_remove_single_major); +static BUS_ATTR(supported_features, 0444, rbd_supported_features_show, NULL); + +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); +static int rbd_dev_header_info(struct rbd_device *rbd_dev); +static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev); +static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev, + u64 snap_id); +static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id, + u8 *order, u64 *snap_size); +static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id, + u64 *snap_features); + +static int rbd_open(struct block_device *bdev, fmode_t mode) +{ + struct rbd_device *rbd_dev = bdev->bd_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, fmode_t mode) +{ + 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 int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg) +{ + int ro; + + if (get_user(ro, (int __user *)arg)) + return -EFAULT; + + /* Snapshots can't be marked read-write */ + if (rbd_dev->spec->snap_id != CEPH_NOSNAP && !ro) + return -EROFS; + + /* Let blkdev_roset() handle it */ + return -ENOTTY; +} + +static int rbd_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + struct rbd_device *rbd_dev = bdev->bd_disk->private_data; + int ret; + + switch (cmd) { + case BLKROSET: + ret = rbd_ioctl_set_ro(rbd_dev, arg); + break; + default: + ret = -ENOTTY; + } + + return ret; +} + +#ifdef CONFIG_COMPAT +static int rbd_compat_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + return rbd_ioctl(bdev, mode, cmd, arg); +} +#endif /* CONFIG_COMPAT */ + +static const struct block_device_operations rbd_bd_ops = { + .owner = THIS_MODULE, + .open = rbd_open, + .release = rbd_release, + .ioctl = rbd_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = rbd_compat_ioctl, +#endif +}; + +/* + * 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 *client_node; + bool found = false; + + if (ceph_opts->flags & CEPH_OPT_NOSHARE) + return NULL; + + spin_lock(&rbd_client_list_lock); + list_for_each_entry(client_node, &rbd_client_list, node) { + if (!ceph_compare_options(ceph_opts, client_node->client)) { + __rbd_get_client(client_node); + + found = true; + break; + } + } + spin_unlock(&rbd_client_list_lock); + + return found ? client_node : NULL; +} + +/* + * (Per device) rbd map options + */ +enum { + Opt_queue_depth, + Opt_lock_timeout, + Opt_last_int, + /* int args above */ + Opt_pool_ns, + Opt_last_string, + /* string args above */ + Opt_read_only, + Opt_read_write, + Opt_lock_on_read, + Opt_exclusive, + Opt_notrim, + Opt_err +}; + +static match_table_t rbd_opts_tokens = { + {Opt_queue_depth, "queue_depth=%d"}, + {Opt_lock_timeout, "lock_timeout=%d"}, + /* int args above */ + {Opt_pool_ns, "_pool_ns=%s"}, + /* string args above */ + {Opt_read_only, "read_only"}, + {Opt_read_only, "ro"}, /* Alternate spelling */ + {Opt_read_write, "read_write"}, + {Opt_read_write, "rw"}, /* Alternate spelling */ + {Opt_lock_on_read, "lock_on_read"}, + {Opt_exclusive, "exclusive"}, + {Opt_notrim, "notrim"}, + {Opt_err, NULL} +}; + +struct rbd_options { + int queue_depth; + unsigned long lock_timeout; + bool read_only; + bool lock_on_read; + bool exclusive; + bool trim; +}; + +#define RBD_QUEUE_DEPTH_DEFAULT BLKDEV_MAX_RQ +#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 parse_rbd_opts_ctx { + struct rbd_spec *spec; + struct rbd_options *opts; +}; + +static int parse_rbd_opts_token(char *c, void *private) +{ + struct parse_rbd_opts_ctx *pctx = private; + substring_t argstr[MAX_OPT_ARGS]; + int token, intval, ret; + + token = match_token(c, rbd_opts_tokens, argstr); + if (token < Opt_last_int) { + ret = match_int(&argstr[0], &intval); + if (ret < 0) { + pr_err("bad option arg (not int) at '%s'\n", c); + return ret; + } + dout("got int token %d val %d\n", token, intval); + } else if (token > Opt_last_int && token < Opt_last_string) { + dout("got string token %d val %s\n", token, argstr[0].from); + } else { + dout("got token %d\n", token); + } + + switch (token) { + case Opt_queue_depth: + if (intval < 1) { + pr_err("queue_depth out of range\n"); + return -EINVAL; + } + pctx->opts->queue_depth = intval; + break; + case Opt_lock_timeout: + /* 0 is "wait forever" (i.e. infinite timeout) */ + if (intval < 0 || intval > INT_MAX / 1000) { + pr_err("lock_timeout out of range\n"); + return -EINVAL; + } + pctx->opts->lock_timeout = msecs_to_jiffies(intval * 1000); + break; + case Opt_pool_ns: + kfree(pctx->spec->pool_ns); + pctx->spec->pool_ns = match_strdup(argstr); + if (!pctx->spec->pool_ns) + return -ENOMEM; + break; + case Opt_read_only: + pctx->opts->read_only = true; + break; + case Opt_read_write: + pctx->opts->read_only = false; + break; + case Opt_lock_on_read: + pctx->opts->lock_on_read = true; + break; + case Opt_exclusive: + pctx->opts->exclusive = true; + break; + case Opt_notrim: + pctx->opts->trim = false; + break; + default: + /* libceph prints "bad option" msg */ + return -EINVAL; + } + + return 0; +} + +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"; + 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); +} + +static int wait_for_latest_osdmap(struct ceph_client *client) +{ + u64 newest_epoch; + int ret; + + ret = ceph_monc_get_version(&client->monc, "osdmap", &newest_epoch); + if (ret) + return ret; + + if (client->osdc.osdmap->epoch >= newest_epoch) + return 0; + + ceph_osdc_maybe_request_map(&client->osdc); + return ceph_monc_wait_osdmap(&client->monc, newest_epoch, + client->options->mount_timeout); +} + +/* + * 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_nested(&client_mutex, SINGLE_DEPTH_NESTING); + 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 = wait_for_latest_osdmap(rbdc->client); + 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); +} + +/* + * Fill an rbd image header with information from the given format 1 + * on-disk header. + */ +static int rbd_header_from_disk(struct rbd_device *rbd_dev, + struct rbd_image_header_ondisk *ondisk) +{ + struct rbd_image_header *header = &rbd_dev->header; + bool first_time = header->object_prefix == NULL; + struct ceph_snap_context *snapc; + char *object_prefix = NULL; + char *snap_names = NULL; + u64 *snap_sizes = NULL; + u32 snap_count; + 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; + rbd_init_layout(rbd_dev); + } else { + ceph_put_snap_context(header->snapc); + kfree(header->snap_names); + kfree(header->snap_sizes); + } + + /* 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_snap_features(struct rbd_device *rbd_dev, u64 snap_id, + u64 *snap_features) +{ + rbd_assert(rbd_image_format_valid(rbd_dev->image_format)); + if (snap_id == CEPH_NOSNAP) { + *snap_features = rbd_dev->header.features; + } else if (rbd_dev->image_format == 1) { + *snap_features = 0; /* No features for format 1 */ + } else { + u64 features = 0; + int ret; + + ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, &features); + if (ret) + return ret; + + *snap_features = features; + } + return 0; +} + +static int rbd_dev_mapping_set(struct rbd_device *rbd_dev) +{ + u64 snap_id = rbd_dev->spec->snap_id; + u64 size = 0; + u64 features = 0; + int ret; + + ret = rbd_snap_size(rbd_dev, snap_id, &size); + if (ret) + return ret; + ret = rbd_snap_features(rbd_dev, snap_id, &features); + if (ret) + return ret; + + rbd_dev->mapping.size = size; + rbd_dev->mapping.features = features; + + return 0; +} + +static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev) +{ + rbd_dev->mapping.size = 0; + rbd_dev->mapping.features = 0; +} + +static void zero_bvec(struct bio_vec *bv) +{ + void *buf; + unsigned long flags; + + buf = bvec_kmap_irq(bv, &flags); + memset(buf, 0, bv->bv_len); + flush_dcache_page(bv->bv_page); + bvec_kunmap_irq(buf, &flags); +} + +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, ({ + zero_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, ({ + zero_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) +{ + 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: + rbd_assert(0); + } +} + +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 void rbd_img_request_get(struct rbd_img_request *img_request) +{ + dout("%s: img %p (was %d)\n", __func__, img_request, + kref_read(&img_request->kref)); + kref_get(&img_request->kref); +} + +static void rbd_img_request_destroy(struct kref *kref); +static void rbd_img_request_put(struct rbd_img_request *img_request) +{ + rbd_assert(img_request != NULL); + dout("%s: img %p (was %d)\n", __func__, img_request, + kref_read(&img_request->kref)); + kref_put(&img_request->kref, rbd_img_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; + img_request->obj_request_count++; + img_request->pending_count++; + 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(img_request->obj_request_count > 0); + img_request->obj_request_count--; + rbd_assert(obj_request->img_request == img_request); + rbd_obj_request_put(obj_request); +} + +static void rbd_obj_request_submit(struct rbd_obj_request *obj_request) +{ + struct ceph_osd_request *osd_req = obj_request->osd_req; + + dout("%s %p object_no %016llx %llu~%llu osd_req %p\n", __func__, + obj_request, obj_request->ex.oe_objno, obj_request->ex.oe_off, + obj_request->ex.oe_len, osd_req); + ceph_osdc_start_request(osd_req->r_osdc, osd_req, false); +} + +/* + * 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); + smp_mb(); +} + +static void img_request_layered_clear(struct rbd_img_request *img_request) +{ + clear_bit(IMG_REQ_LAYERED, &img_request->flags); + smp_mb(); +} + +static bool img_request_layered_test(struct rbd_img_request *img_request) +{ + smp_mb(); + 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; +} + +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: + return true; + default: + BUG(); + } +} + +static void rbd_obj_handle_request(struct rbd_obj_request *obj_req); + +static void rbd_osd_req_callback(struct ceph_osd_request *osd_req) +{ + struct rbd_obj_request *obj_req = osd_req->r_priv; + + dout("%s osd_req %p result %d for obj_req %p\n", __func__, osd_req, + osd_req->r_result, obj_req); + rbd_assert(osd_req == obj_req->osd_req); + + obj_req->result = osd_req->r_result < 0 ? osd_req->r_result : 0; + if (!obj_req->result && !rbd_img_is_write(obj_req->img_request)) + obj_req->xferred = osd_req->r_result; + else + /* + * 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. + */ + obj_req->xferred = 0; + + rbd_obj_handle_request(obj_req); +} + +static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request) +{ + struct ceph_osd_request *osd_req = obj_request->osd_req; + + osd_req->r_flags = CEPH_OSD_FLAG_READ; + osd_req->r_snapid = obj_request->img_request->snap_id; +} + +static void rbd_osd_req_format_write(struct rbd_obj_request *obj_request) +{ + struct ceph_osd_request *osd_req = obj_request->osd_req; + + 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_osd_req_create(struct rbd_obj_request *obj_req, unsigned int num_ops) +{ + struct rbd_img_request *img_req = obj_req->img_request; + struct rbd_device *rbd_dev = img_req->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; + + req = ceph_osdc_alloc_request(osdc, + (rbd_img_is_write(img_req) ? img_req->snapc : NULL), + num_ops, false, GFP_NOIO); + if (!req) + return NULL; + + 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; + + if (ceph_oid_aprintf(&req->r_base_oid, GFP_NOIO, name_format, + rbd_dev->header.object_prefix, obj_req->ex.oe_objno)) + goto err_req; + + if (ceph_osdc_alloc_messages(req, GFP_NOIO)) + goto err_req; + + return req; + +err_req: + ceph_osdc_put_request(req); + return NULL; +} + +static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req) +{ + ceph_osdc_put_request(osd_req); +} + +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); + 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; + u32 i; + + obj_request = container_of(kref, struct rbd_obj_request, kref); + + dout("%s: obj %p\n", __func__, obj_request); + + if (obj_request->osd_req) + rbd_osd_req_destroy(obj_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: + rbd_assert(0); + } + + 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; + + down_read(&rbd_dev->header_rwsem); + if (rbd_dev->parent_overlap) + counter = atomic_inc_return_safe(&rbd_dev->parent_ref); + up_read(&rbd_dev->header_rwsem); + + if (counter < 0) + rbd_warn(rbd_dev, "parent reference overflow"); + + return counter > 0; +} + +/* + * Caller is responsible for filling in the list of object requests + * that comprises the image request, and the Linux request pointer + * (if there is one). + */ +static struct rbd_img_request *rbd_img_request_create( + struct rbd_device *rbd_dev, + enum obj_operation_type op_type, + struct ceph_snap_context *snapc) +{ + struct rbd_img_request *img_request; + + img_request = kmem_cache_zalloc(rbd_img_request_cache, GFP_NOIO); + if (!img_request) + return NULL; + + img_request->rbd_dev = rbd_dev; + img_request->op_type = op_type; + if (!rbd_img_is_write(img_request)) + img_request->snap_id = rbd_dev->spec->snap_id; + else + img_request->snapc = snapc; + + if (rbd_dev_parent_get(rbd_dev)) + img_request_layered_set(img_request); + + spin_lock_init(&img_request->completion_lock); + INIT_LIST_HEAD(&img_request->object_extents); + kref_init(&img_request->kref); + + dout("%s: rbd_dev %p %s -> img %p\n", __func__, rbd_dev, + obj_op_name(op_type), img_request); + return img_request; +} + +static void rbd_img_request_destroy(struct kref *kref) +{ + struct rbd_img_request *img_request; + struct rbd_obj_request *obj_request; + struct rbd_obj_request *next_obj_request; + + img_request = container_of(kref, struct rbd_img_request, kref); + + dout("%s: img %p\n", __func__, img_request); + + for_each_obj_request_safe(img_request, obj_request, next_obj_request) + rbd_img_obj_request_del(img_request, obj_request); + rbd_assert(img_request->obj_request_count == 0); + + if (img_request_layered_test(img_request)) { + img_request_layered_clear(img_request); + rbd_dev_parent_put(img_request->rbd_dev); + } + + if (rbd_img_is_write(img_request)) + ceph_put_snap_context(img_request->snapc); + + kmem_cache_free(rbd_img_request_cache, img_request); +} + +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_req_setup_data(struct rbd_obj_request *obj_req, u32 which) +{ + switch (obj_req->img_request->data_type) { + case OBJ_REQUEST_BIO: + osd_req_op_extent_osd_data_bio(obj_req->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(obj_req->osd_req, which, + &obj_req->bvec_pos); + break; + default: + rbd_assert(0); + } +} + +static int rbd_obj_setup_read(struct rbd_obj_request *obj_req) +{ + obj_req->osd_req = rbd_osd_req_create(obj_req, 1); + if (!obj_req->osd_req) + return -ENOMEM; + + osd_req_op_extent_init(obj_req->osd_req, 0, CEPH_OSD_OP_READ, + obj_req->ex.oe_off, obj_req->ex.oe_len, 0, 0); + rbd_osd_req_setup_data(obj_req, 0); + + rbd_osd_req_format_read(obj_req); + return 0; +} + +static int __rbd_obj_setup_stat(struct rbd_obj_request *obj_req, + unsigned 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(obj_req->osd_req, which, CEPH_OSD_OP_STAT, 0); + osd_req_op_raw_data_in_pages(obj_req->osd_req, which, pages, + 8 + sizeof(struct ceph_timespec), + 0, false, true); + return 0; +} + +static void __rbd_obj_setup_write(struct rbd_obj_request *obj_req, + unsigned int which) +{ + struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev; + u16 opcode; + + osd_req_op_alloc_hint_init(obj_req->osd_req, which++, + rbd_dev->layout.object_size, + rbd_dev->layout.object_size); + + if (rbd_obj_is_entire(obj_req)) + opcode = CEPH_OSD_OP_WRITEFULL; + else + opcode = CEPH_OSD_OP_WRITE; + + osd_req_op_extent_init(obj_req->osd_req, which, opcode, + obj_req->ex.oe_off, obj_req->ex.oe_len, 0, 0); + rbd_osd_req_setup_data(obj_req, which++); + + rbd_assert(which == obj_req->osd_req->r_num_ops); + rbd_osd_req_format_write(obj_req); +} + +static int rbd_obj_setup_write(struct rbd_obj_request *obj_req) +{ + unsigned int num_osd_ops, which = 0; + 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->write_state = RBD_OBJ_WRITE_GUARD; + num_osd_ops = 3; /* stat + setallochint + write/writefull */ + } else { + obj_req->write_state = RBD_OBJ_WRITE_FLAT; + num_osd_ops = 2; /* setallochint + write/writefull */ + } + + obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops); + if (!obj_req->osd_req) + return -ENOMEM; + + if (obj_req->num_img_extents) { + ret = __rbd_obj_setup_stat(obj_req, which++); + if (ret) + return ret; + } + + __rbd_obj_setup_write(obj_req, which); + return 0; +} + +static void __rbd_obj_setup_discard(struct rbd_obj_request *obj_req, + unsigned int which) +{ + u16 opcode; + + if (rbd_obj_is_entire(obj_req)) { + if (obj_req->num_img_extents) { + osd_req_op_init(obj_req->osd_req, which++, + CEPH_OSD_OP_CREATE, 0); + opcode = CEPH_OSD_OP_TRUNCATE; + } else { + osd_req_op_init(obj_req->osd_req, which++, + CEPH_OSD_OP_DELETE, 0); + opcode = 0; + } + } else if (rbd_obj_is_tail(obj_req)) { + opcode = CEPH_OSD_OP_TRUNCATE; + } else { + opcode = CEPH_OSD_OP_ZERO; + } + + if (opcode) + osd_req_op_extent_init(obj_req->osd_req, which++, opcode, + obj_req->ex.oe_off, obj_req->ex.oe_len, + 0, 0); + + rbd_assert(which == obj_req->osd_req->r_num_ops); + rbd_osd_req_format_write(obj_req); +} + +static int rbd_obj_setup_discard(struct rbd_obj_request *obj_req) +{ + unsigned int num_osd_ops, which = 0; + int ret; + + /* reverse map the entire object onto the parent */ + ret = rbd_obj_calc_img_extents(obj_req, true); + if (ret) + return ret; + + if (rbd_obj_is_entire(obj_req)) { + obj_req->write_state = RBD_OBJ_WRITE_FLAT; + if (obj_req->num_img_extents) + num_osd_ops = 2; /* create + truncate */ + else + num_osd_ops = 1; /* delete */ + } else { + if (obj_req->num_img_extents) { + obj_req->write_state = RBD_OBJ_WRITE_GUARD; + num_osd_ops = 2; /* stat + truncate/zero */ + } else { + obj_req->write_state = RBD_OBJ_WRITE_FLAT; + num_osd_ops = 1; /* truncate/zero */ + } + } + + obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops); + if (!obj_req->osd_req) + return -ENOMEM; + + if (!rbd_obj_is_entire(obj_req) && obj_req->num_img_extents) { + ret = __rbd_obj_setup_stat(obj_req, which++); + if (ret) + return ret; + } + + __rbd_obj_setup_discard(obj_req, which); + return 0; +} + +/* + * For each object request in @img_req, allocate an OSD request, add + * individual OSD ops and prepare them for submission. The number of + * OSD ops depends on op_type and the overlap point (if any). + */ +static int __rbd_img_fill_request(struct rbd_img_request *img_req) +{ + struct rbd_obj_request *obj_req; + int ret; + + for_each_obj_request(img_req, obj_req) { + switch (img_req->op_type) { + case OBJ_OP_READ: + ret = rbd_obj_setup_read(obj_req); + break; + case OBJ_OP_WRITE: + ret = rbd_obj_setup_write(obj_req); + break; + case OBJ_OP_DISCARD: + ret = rbd_obj_setup_discard(obj_req); + break; + default: + rbd_assert(0); + } + if (ret) + return ret; + } + + 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_request_submit(struct rbd_img_request *img_request) +{ + struct rbd_obj_request *obj_request; + + dout("%s: img %p\n", __func__, img_request); + + rbd_img_request_get(img_request); + for_each_obj_request(img_request, obj_request) + rbd_obj_request_submit(obj_request); + + rbd_img_request_put(img_request); +} + +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_img_request *child_img_req; + int ret; + + child_img_req = rbd_img_request_create(img_req->rbd_dev->parent, + OBJ_OP_READ, NULL); + if (!child_img_req) + return -ENOMEM; + + __set_bit(IMG_REQ_CHILD, &child_img_req->flags); + child_img_req->obj_request = 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: + rbd_assert(0); + } + } 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_put(child_img_req); + return ret; + } + + rbd_img_request_submit(child_img_req); + return 0; +} + +static bool rbd_obj_handle_read(struct rbd_obj_request *obj_req) +{ + struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev; + int ret; + + if (obj_req->result == -ENOENT && + rbd_dev->parent_overlap && !obj_req->tried_parent) { + /* reverse map this object extent onto the parent */ + ret = rbd_obj_calc_img_extents(obj_req, false); + if (ret) { + obj_req->result = ret; + return true; + } + + if (obj_req->num_img_extents) { + obj_req->tried_parent = true; + ret = rbd_obj_read_from_parent(obj_req); + if (ret) { + obj_req->result = ret; + return true; + } + 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. In both cases we update xferred + * count to indicate the whole request was satisfied. + */ + if (obj_req->result == -ENOENT || + (!obj_req->result && obj_req->xferred < obj_req->ex.oe_len)) { + rbd_assert(!obj_req->xferred || !obj_req->result); + rbd_obj_zero_range(obj_req, obj_req->xferred, + obj_req->ex.oe_len - obj_req->xferred); + obj_req->result = 0; + obj_req->xferred = obj_req->ex.oe_len; + } + + return true; +} + +/* + * 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(page_address(bv.bv_page) + bv.bv_offset, 0, + bv.bv_len)) + return false; + })); + return true; +} + +static int rbd_obj_issue_copyup(struct rbd_obj_request *obj_req, u32 bytes) +{ + unsigned int num_osd_ops = obj_req->osd_req->r_num_ops; + int ret; + + dout("%s obj_req %p bytes %u\n", __func__, obj_req, bytes); + rbd_assert(obj_req->osd_req->r_ops[0].op == CEPH_OSD_OP_STAT); + rbd_osd_req_destroy(obj_req->osd_req); + + /* + * Create a copyup request with the same number of OSD ops as + * the original request. The original request was stat + op(s), + * the new copyup request will be copyup + the same op(s). + */ + obj_req->osd_req = rbd_osd_req_create(obj_req, num_osd_ops); + if (!obj_req->osd_req) + return -ENOMEM; + + ret = osd_req_op_cls_init(obj_req->osd_req, 0, CEPH_OSD_OP_CALL, "rbd", + "copyup"); + if (ret) + return ret; + + /* + * 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 (is_zero_bvecs(obj_req->copyup_bvecs, bytes)) { + dout("%s obj_req %p detected zeroes\n", __func__, obj_req); + bytes = 0; + } + osd_req_op_cls_request_data_bvecs(obj_req->osd_req, 0, + obj_req->copyup_bvecs, + obj_req->copyup_bvec_count, + bytes); + + switch (obj_req->img_request->op_type) { + case OBJ_OP_WRITE: + __rbd_obj_setup_write(obj_req, 1); + break; + case OBJ_OP_DISCARD: + rbd_assert(!rbd_obj_is_entire(obj_req)); + __rbd_obj_setup_discard(obj_req, 1); + break; + default: + rbd_assert(0); + } + + rbd_obj_request_submit(obj_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); + + obj_req->copyup_bvecs[i].bv_page = alloc_page(GFP_NOIO); + if (!obj_req->copyup_bvecs[i].bv_page) + return -ENOMEM; + + obj_req->copyup_bvecs[i].bv_offset = 0; + obj_req->copyup_bvecs[i].bv_len = len; + obj_overlap -= len; + } + + rbd_assert(!obj_overlap); + return 0; +} + +static int rbd_obj_handle_write_guard(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). Use rbd_obj_issue_copyup() + * to re-submit the original write request -- the copyup + * operation itself will be a no-op, since someone must + * have populated the child object while we weren't + * looking. Move to WRITE_FLAT state as we'll be done + * with the operation once the null copyup completes. + */ + obj_req->write_state = RBD_OBJ_WRITE_FLAT; + return rbd_obj_issue_copyup(obj_req, 0); + } + + ret = setup_copyup_bvecs(obj_req, rbd_obj_img_extents_bytes(obj_req)); + if (ret) + return ret; + + obj_req->write_state = RBD_OBJ_WRITE_COPYUP; + return rbd_obj_read_from_parent(obj_req); +} + +static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req) +{ + int ret; + +again: + switch (obj_req->write_state) { + case RBD_OBJ_WRITE_GUARD: + rbd_assert(!obj_req->xferred); + if (obj_req->result == -ENOENT) { + /* + * 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. + */ + ret = rbd_obj_handle_write_guard(obj_req); + if (ret) { + obj_req->result = ret; + return true; + } + return false; + } + /* fall through */ + case RBD_OBJ_WRITE_FLAT: + if (!obj_req->result) + /* + * There is no such thing as a successful short + * write -- indicate the whole request was satisfied. + */ + obj_req->xferred = obj_req->ex.oe_len; + return true; + case RBD_OBJ_WRITE_COPYUP: + obj_req->write_state = RBD_OBJ_WRITE_GUARD; + if (obj_req->result) + goto again; + + rbd_assert(obj_req->xferred); + ret = rbd_obj_issue_copyup(obj_req, obj_req->xferred); + if (ret) { + obj_req->result = ret; + obj_req->xferred = 0; + return true; + } + return false; + default: + BUG(); + } +} + +/* + * Returns true if @obj_req is completed, or false otherwise. + */ +static bool __rbd_obj_handle_request(struct rbd_obj_request *obj_req) +{ + switch (obj_req->img_request->op_type) { + case OBJ_OP_READ: + return rbd_obj_handle_read(obj_req); + case OBJ_OP_WRITE: + return rbd_obj_handle_write(obj_req); + case OBJ_OP_DISCARD: + if (rbd_obj_handle_write(obj_req)) { + /* + * Hide -ENOENT from delete/truncate/zero -- discarding + * a non-existent object is not a problem. + */ + if (obj_req->result == -ENOENT) { + obj_req->result = 0; + obj_req->xferred = obj_req->ex.oe_len; + } + return true; + } + return false; + default: + BUG(); + } +} + +static void rbd_obj_end_request(struct rbd_obj_request *obj_req) +{ + struct rbd_img_request *img_req = obj_req->img_request; + + rbd_assert((!obj_req->result && + obj_req->xferred == obj_req->ex.oe_len) || + (obj_req->result < 0 && !obj_req->xferred)); + if (!obj_req->result) { + img_req->xferred += obj_req->xferred; + return; + } + + rbd_warn(img_req->rbd_dev, + "%s at objno %llu %llu~%llu result %d xferred %llu", + obj_op_name(img_req->op_type), obj_req->ex.oe_objno, + obj_req->ex.oe_off, obj_req->ex.oe_len, obj_req->result, + obj_req->xferred); + if (!img_req->result) { + img_req->result = obj_req->result; + img_req->xferred = 0; + } +} + +static void rbd_img_end_child_request(struct rbd_img_request *img_req) +{ + struct rbd_obj_request *obj_req = img_req->obj_request; + + rbd_assert(test_bit(IMG_REQ_CHILD, &img_req->flags)); + rbd_assert((!img_req->result && + img_req->xferred == rbd_obj_img_extents_bytes(obj_req)) || + (img_req->result < 0 && !img_req->xferred)); + + obj_req->result = img_req->result; + obj_req->xferred = img_req->xferred; + rbd_img_request_put(img_req); +} + +static void rbd_img_end_request(struct rbd_img_request *img_req) +{ + rbd_assert(!test_bit(IMG_REQ_CHILD, &img_req->flags)); + rbd_assert((!img_req->result && + img_req->xferred == blk_rq_bytes(img_req->rq)) || + (img_req->result < 0 && !img_req->xferred)); + + blk_mq_end_request(img_req->rq, + errno_to_blk_status(img_req->result)); + rbd_img_request_put(img_req); +} + +static void rbd_obj_handle_request(struct rbd_obj_request *obj_req) +{ + struct rbd_img_request *img_req; + +again: + if (!__rbd_obj_handle_request(obj_req)) + return; + + img_req = obj_req->img_request; + spin_lock(&img_req->completion_lock); + rbd_obj_end_request(obj_req); + rbd_assert(img_req->pending_count); + if (--img_req->pending_count) { + spin_unlock(&img_req->completion_lock); + return; + } + + spin_unlock(&img_req->completion_lock); + if (test_bit(IMG_REQ_CHILD, &img_req->flags)) { + obj_req = img_req->obj_request; + rbd_img_end_child_request(img_req); + goto again; + } + rbd_img_end_request(img_req); +} + +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); + + 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) + return ret; + + rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED; + __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: %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) +{ + struct page **reply_pages; + size_t reply_len; + + __rbd_notify_op_lock(rbd_dev, notify_op, &reply_pages, &reply_len); + ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len)); +} + +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; +} + +static void wake_requests(struct rbd_device *rbd_dev, bool wake_all) +{ + dout("%s rbd_dev %p wake_all %d\n", __func__, rbd_dev, wake_all); + + cancel_delayed_work(&rbd_dev->lock_dwork); + if (wake_all) + wake_up_all(&rbd_dev->lock_waitq); + else + wake_up(&rbd_dev->lock_waitq); +} + +static int get_lock_owner_info(struct rbd_device *rbd_dev, + struct ceph_locker **lockers, u32 *num_lockers) +{ + struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc; + u8 lock_type; + char *lock_tag; + int ret; + + dout("%s rbd_dev %p\n", __func__, rbd_dev); + + 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) + return ret; + + if (*num_lockers == 0) { + dout("%s rbd_dev %p no lockers detected\n", __func__, rbd_dev); + goto out; + } + + if (strcmp(lock_tag, RBD_LOCK_TAG)) { + rbd_warn(rbd_dev, "locked by external mechanism, tag %s", + lock_tag); + ret = -EBUSY; + goto out; + } + + if (lock_type == CEPH_CLS_LOCK_SHARED) { + rbd_warn(rbd_dev, "shared lock type detected"); + ret = -EBUSY; + goto out; + } + + if (strncmp((*lockers)[0].id.cookie, RBD_LOCK_COOKIE_PREFIX, + strlen(RBD_LOCK_COOKIE_PREFIX))) { + rbd_warn(rbd_dev, "locked by external mechanism, cookie %s", + (*lockers)[0].id.cookie); + ret = -EBUSY; + goto out; + } + +out: + kfree(lock_tag); + return ret; +} + +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) + return ret; + + sscanf(locker->id.cookie, RBD_LOCK_COOKIE_PREFIX " %llu", &cookie); + for (i = 0; i < num_watchers; i++) { + if (!memcmp(&watchers[i].addr, &locker->info.addr, + sizeof(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 *lockers; + u32 num_lockers; + int ret; + + for (;;) { + ret = rbd_lock(rbd_dev); + if (ret != -EBUSY) + return ret; + + /* determine if the current lock holder is still alive */ + ret = get_lock_owner_info(rbd_dev, &lockers, &num_lockers); + if (ret) + return ret; + + if (num_lockers == 0) + goto again; + + ret = find_watcher(rbd_dev, lockers); + if (ret) { + if (ret > 0) + ret = 0; /* have to request lock */ + goto out; + } + + rbd_warn(rbd_dev, "%s%llu seems dead, breaking lock", + ENTITY_NAME(lockers[0].id.name)); + + ret = ceph_monc_blacklist_add(&client->monc, + &lockers[0].info.addr); + if (ret) { + rbd_warn(rbd_dev, "blacklist of %s%llu failed: %d", + ENTITY_NAME(lockers[0].id.name), ret); + goto out; + } + + ret = ceph_cls_break_lock(&client->osdc, &rbd_dev->header_oid, + &rbd_dev->header_oloc, RBD_LOCK_NAME, + lockers[0].id.cookie, + &lockers[0].id.name); + if (ret && ret != -ENOENT) + goto out; + +again: + ceph_free_lockers(lockers, num_lockers); + } + +out: + ceph_free_lockers(lockers, num_lockers); + return ret; +} + +/* + * ret is set only if lock_state is RBD_LOCK_STATE_UNLOCKED + */ +static enum rbd_lock_state rbd_try_acquire_lock(struct rbd_device *rbd_dev, + int *pret) +{ + enum rbd_lock_state lock_state; + + 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)) { + lock_state = rbd_dev->lock_state; + up_read(&rbd_dev->lock_rwsem); + return lock_state; + } + + 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)) { + *pret = rbd_try_lock(rbd_dev); + if (*pret) + rbd_warn(rbd_dev, "failed to acquire lock: %d", *pret); + } + + lock_state = rbd_dev->lock_state; + up_write(&rbd_dev->lock_rwsem); + return lock_state; +} + +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); + enum rbd_lock_state lock_state; + int ret = 0; + + dout("%s rbd_dev %p\n", __func__, rbd_dev); +again: + lock_state = rbd_try_acquire_lock(rbd_dev, &ret); + if (lock_state != RBD_LOCK_STATE_UNLOCKED || ret == -EBLACKLISTED) { + if (lock_state == RBD_LOCK_STATE_LOCKED) + wake_requests(rbd_dev, true); + dout("%s rbd_dev %p lock_state %d ret %d - done\n", __func__, + rbd_dev, lock_state, 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"); + /* + * If this is rbd_add_acquire_lock(), we want to fail + * immediately -- reuse BLACKLISTED flag. Otherwise we + * want to block. + */ + if (!(rbd_dev->disk->flags & GENHD_FL_UP)) { + set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags); + /* wake "rbd map --exclusive" process */ + wake_requests(rbd_dev, false); + } + } 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 requeueing 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)); + } +} + +/* + * lock_rwsem must be held for write + */ +static bool rbd_release_lock(struct rbd_device *rbd_dev) +{ + dout("%s rbd_dev %p read lock_state %d\n", __func__, rbd_dev, + rbd_dev->lock_state); + if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED) + return false; + + rbd_dev->lock_state = RBD_LOCK_STATE_RELEASING; + downgrade_write(&rbd_dev->lock_rwsem); + /* + * Ensure that all in-flight IO is flushed. + * + * FIXME: ceph_osdc_sync() flushes the entire OSD client, which + * may be shared with other devices. + */ + ceph_osdc_sync(&rbd_dev->rbd_client->client->osdc); + 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_dev->lock_state != RBD_LOCK_STATE_RELEASING) + return false; + + rbd_unlock(rbd_dev); + /* + * Give others a chance to grab the lock - we would re-acquire + * almost immediately if we got new IO during ceph_osdc_sync() + * otherwise. We need to ack our own notifications, so this + * lock_dwork will be requeued from rbd_wait_state_locked() + * after wake_requests() in rbd_handle_released_lock(). + */ + cancel_delayed_work(&rbd_dev->lock_dwork); + return true; +} + +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 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)) { + /* + * we already know that the remote client is + * the owner + */ + up_write(&rbd_dev->lock_rwsem); + return; + } + + rbd_set_owner_cid(rbd_dev, &cid); + downgrade_write(&rbd_dev->lock_rwsem); + } else { + down_read(&rbd_dev->lock_rwsem); + } + + if (!__rbd_is_lock_owner(rbd_dev)) + wake_requests(rbd_dev, false); + 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 unexpected owner, 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); + up_write(&rbd_dev->lock_rwsem); + return; + } + + rbd_set_owner_cid(rbd_dev, &rbd_empty_cid); + downgrade_write(&rbd_dev->lock_rwsem); + } else { + down_read(&rbd_dev->lock_rwsem); + } + + if (!__rbd_is_lock_owner(rbd_dev)) + wake_requests(rbd_dev, false); + 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) +{ + WARN_ON(waitqueue_active(&rbd_dev->lock_waitq)); + 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; + + WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED); + + 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. + */ + if (rbd_release_lock(rbd_dev)) + queue_delayed_work(rbd_dev->task_wq, + &rbd_dev->lock_dwork, 0); + } else { + __rbd_lock(rbd_dev, cookie); + } +} + +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 == -EBLACKLISTED || ret == -ENOENT) { + set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags); + wake_requests(rbd_dev, true); + } else { + queue_delayed_work(rbd_dev->task_wq, + &rbd_dev->watch_dwork, + RBD_RETRY_DELAY); + } + mutex_unlock(&rbd_dev->watch_mutex); + 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; +} + +/* + * lock_rwsem must be held for read + */ +static int rbd_wait_state_locked(struct rbd_device *rbd_dev, bool may_acquire) +{ + DEFINE_WAIT(wait); + unsigned long timeout; + int ret = 0; + + if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) + return -EBLACKLISTED; + + if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) + return 0; + + if (!may_acquire) { + rbd_warn(rbd_dev, "exclusive lock required"); + return -EROFS; + } + + do { + /* + * Note the use of mod_delayed_work() in rbd_acquire_lock() + * and cancel_delayed_work() in wake_requests(). + */ + dout("%s rbd_dev %p queueing lock_dwork\n", __func__, rbd_dev); + queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0); + prepare_to_wait_exclusive(&rbd_dev->lock_waitq, &wait, + TASK_UNINTERRUPTIBLE); + up_read(&rbd_dev->lock_rwsem); + timeout = schedule_timeout(ceph_timeout_jiffies( + rbd_dev->opts->lock_timeout)); + down_read(&rbd_dev->lock_rwsem); + if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) { + ret = -EBLACKLISTED; + break; + } + if (!timeout) { + rbd_warn(rbd_dev, "timed out waiting for lock"); + ret = -ETIMEDOUT; + break; + } + } while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED); + + finish_wait(&rbd_dev->lock_waitq, &wait); + return ret; +} + +static void rbd_queue_workfn(struct work_struct *work) +{ + struct request *rq = blk_mq_rq_from_pdu(work); + struct rbd_device *rbd_dev = rq->q->queuedata; + struct rbd_img_request *img_request; + struct ceph_snap_context *snapc = NULL; + u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT; + u64 length = blk_rq_bytes(rq); + enum obj_operation_type op_type; + u64 mapping_size; + bool must_be_locked; + int result; + + switch (req_op(rq)) { + case REQ_OP_DISCARD: + case REQ_OP_WRITE_ZEROES: + op_type = OBJ_OP_DISCARD; + break; + case REQ_OP_WRITE: + op_type = OBJ_OP_WRITE; + break; + case REQ_OP_READ: + op_type = OBJ_OP_READ; + break; + default: + dout("%s: non-fs request type %d\n", __func__, req_op(rq)); + result = -EIO; + goto err; + } + + /* Ignore/skip any zero-length requests */ + + if (!length) { + dout("%s: zero-length request\n", __func__); + result = 0; + goto err_rq; + } + + rbd_assert(op_type == OBJ_OP_READ || + rbd_dev->spec->snap_id == CEPH_NOSNAP); + + /* + * Quit early if the mapped snapshot no longer exists. It's + * still possible the snapshot will have disappeared by the + * time our request arrives at the osd, but there's no sense in + * sending it if we already know. + */ + if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) { + dout("request for non-existent snapshot"); + rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP); + result = -ENXIO; + goto err_rq; + } + + if (offset && length > U64_MAX - offset + 1) { + rbd_warn(rbd_dev, "bad request range (%llu~%llu)", offset, + length); + result = -EINVAL; + goto err_rq; /* Shouldn't happen */ + } + + blk_mq_start_request(rq); + + down_read(&rbd_dev->header_rwsem); + mapping_size = rbd_dev->mapping.size; + if (op_type != OBJ_OP_READ) { + snapc = rbd_dev->header.snapc; + ceph_get_snap_context(snapc); + } + 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_rq; + } + + must_be_locked = + (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) && + (op_type != OBJ_OP_READ || rbd_dev->opts->lock_on_read); + if (must_be_locked) { + down_read(&rbd_dev->lock_rwsem); + result = rbd_wait_state_locked(rbd_dev, + !rbd_dev->opts->exclusive); + if (result) + goto err_unlock; + } + + img_request = rbd_img_request_create(rbd_dev, op_type, snapc); + if (!img_request) { + result = -ENOMEM; + goto err_unlock; + } + img_request->rq = rq; + snapc = NULL; /* img_request consumes a ref */ + + if (op_type == OBJ_OP_DISCARD) + 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_request_submit(img_request); + if (must_be_locked) + up_read(&rbd_dev->lock_rwsem); + return; + +err_img_request: + rbd_img_request_put(img_request); +err_unlock: + if (must_be_locked) + up_read(&rbd_dev->lock_rwsem); +err_rq: + if (result) + rbd_warn(rbd_dev, "%s %llx at %llx result %d", + obj_op_name(op_type), length, offset, result); + ceph_put_snap_context(snapc); +err: + 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 request *rq = bd->rq; + struct work_struct *work = blk_mq_rq_to_pdu(rq); + + queue_work(rbd_wq, work); + return BLK_STS_OK; +} + +static void rbd_free_disk(struct rbd_device *rbd_dev) +{ + blk_cleanup_queue(rbd_dev->disk->queue); + blk_mq_free_tag_set(&rbd_dev->tag_set); + put_disk(rbd_dev->disk); + 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; + + ret = ceph_osdc_alloc_messages(req, GFP_KERNEL); + if (ret) + goto out_req; + + 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); + + ceph_osdc_start_request(osdc, req, false); + 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_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(rbd_dev, ondisk); +out: + kfree(ondisk); + + return ret; +} + +/* + * Clear the rbd device's EXISTS flag if the snapshot it's mapped to + * has disappeared from the (just updated) snapshot context. + */ +static void rbd_exists_validate(struct rbd_device *rbd_dev) +{ + u64 snap_id; + + if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) + return; + + snap_id = rbd_dev->spec->snap_id; + if (snap_id == CEPH_NOSNAP) + return; + + if (rbd_dev_snap_index(rbd_dev, snap_id) == BAD_SNAP_INDEX) + clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags); +} + +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(rbd_dev->disk, size); + revalidate_disk(rbd_dev->disk); + } +} + +static int rbd_dev_refresh(struct rbd_device *rbd_dev) +{ + u64 mapping_size; + int ret; + + down_write(&rbd_dev->header_rwsem); + mapping_size = rbd_dev->mapping.size; + + ret = rbd_dev_header_info(rbd_dev); + 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); + if (ret) + goto out; + } + + if (rbd_dev->spec->snap_id == CEPH_NOSNAP) { + rbd_dev->mapping.size = rbd_dev->header.image_size; + } else { + /* validate mapped snapshot's EXISTS flag */ + rbd_exists_validate(rbd_dev); + } + +out: + up_write(&rbd_dev->header_rwsem); + if (!ret && mapping_size != rbd_dev->mapping.size) + rbd_dev_update_size(rbd_dev); + + return ret; +} + +static int rbd_init_request(struct blk_mq_tag_set *set, struct request *rq, + unsigned int hctx_idx, unsigned int numa_node) +{ + struct work_struct *work = blk_mq_rq_to_pdu(rq); + + INIT_WORK(work, rbd_queue_workfn); + return 0; +} + +static const struct blk_mq_ops rbd_mq_ops = { + .queue_rq = rbd_queue_rq, + .init_request = rbd_init_request, +}; + +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; + + /* create gendisk info */ + disk = alloc_disk(single_major ? + (1 << RBD_SINGLE_MAJOR_PART_SHIFT) : + RBD_MINORS_PER_MAJOR); + if (!disk) + return -ENOMEM; + + 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->flags |= GENHD_FL_EXT_DEVT; + disk->fops = &rbd_bd_ops; + disk->private_data = rbd_dev; + + 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 | BLK_MQ_F_SG_MERGE; + rbd_dev->tag_set.nr_hw_queues = 1; + rbd_dev->tag_set.cmd_size = sizeof(struct work_struct); + + err = blk_mq_alloc_tag_set(&rbd_dev->tag_set); + if (err) + goto out_disk; + + q = blk_mq_init_queue(&rbd_dev->tag_set); + if (IS_ERR(q)) { + err = PTR_ERR(q); + goto out_tag_set; + } + + 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, objset_bytes); + blk_queue_io_opt(q, objset_bytes); + + if (rbd_dev->opts->trim) { + blk_queue_flag_set(QUEUE_FLAG_DISCARD, q); + q->limits.discard_granularity = objset_bytes; + 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)) + q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES; + + /* + * disk_release() expects a queue ref from add_disk() and will + * put it. Hold an extra ref until add_disk() is called. + */ + WARN_ON(!blk_get_queue(q)); + disk->queue = q; + q->queuedata = rbd_dev; + + rbd_dev->disk = disk; + + return 0; +out_tag_set: + blk_mq_free_tag_set(&rbd_dev->tag_set); +out_disk: + put_disk(disk); + 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); +} + +/* + * Note this shows the features for whatever's mapped, which is not + * necessarily the base image. + */ +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", + (unsigned long long)rbd_dev->mapping.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_client *rbdc, + 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); + init_waitqueue_head(&rbd_dev->lock_waitq); + + 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); + + rbd_dev->rbd_client = rbdc; + rbd_dev->spec = spec; + + 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(rbdc, spec); + if (!rbd_dev) + return NULL; + + rbd_dev->opts = opts; + + /* 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); + + 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_image_size(struct rbd_device *rbd_dev) +{ + return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP, + &rbd_dev->header.obj_order, + &rbd_dev->header.image_size); +} + +static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev) +{ + void *reply_buf; + int ret; + void *p; + + reply_buf = kzalloc(RBD_OBJ_PREFIX_LEN_MAX, 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, RBD_OBJ_PREFIX_LEN_MAX); + dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret); + if (ret < 0) + goto out; + + p = reply_buf; + rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p, + p + ret, NULL, GFP_NOIO); + ret = 0; + + if (IS_ERR(rbd_dev->header.object_prefix)) { + ret = PTR_ERR(rbd_dev->header.object_prefix); + rbd_dev->header.object_prefix = NULL; + } else { + dout(" object_prefix = %s\n", rbd_dev->header.object_prefix); + } +out: + kfree(reply_buf); + + return ret; +} + +static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id, + u64 *snap_features) +{ + __le64 snapid = cpu_to_le64(snap_id); + struct { + __le64 features; + __le64 incompat; + } __attribute__ ((packed)) features_buf = { 0 }; + u64 unsup; + int ret; + + ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid, + &rbd_dev->header_oloc, "get_features", + &snapid, sizeof(snapid), + &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; +} + +static int rbd_dev_v2_features(struct rbd_device *rbd_dev) +{ + return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP, + &rbd_dev->header.features); +} + +struct parent_image_info { + u64 pool_id; + const char *pool_ns; + const char *image_id; + u64 snap_id; + + bool has_overlap; + u64 overlap; +}; + +/* + * 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); + + 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); + + return 0; + +e_inval: + return -EINVAL; +} + +static int get_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_v2_parent_info(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 = get_parent_info(rbd_dev, &pii); + if (ret) + goto out_err; + + 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); + + 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 image has been flattened\n", + rbd_dev->disk->disk_name); + } + + goto out; /* No parent? No problem. */ + } + + /* The ceph file layout needs to fit pool id in 32 bits */ + + ret = -EIO; + if (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, already handled that). So we only need to + * record the parent spec we have not already done so. + */ + if (!rbd_dev->parent_spec) { + 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_dev->parent_spec = parent_spec; + parent_spec = NULL; /* rbd_dev now owns this */ + } + + /* + * We always update the parent overlap. If it's zero we issue + * a warning, as we will proceed as if there was no parent. + */ + if (!pii.overlap) { + if (parent_spec) { + /* refresh, careful to warn just once */ + if (rbd_dev->parent_overlap) + rbd_warn(rbd_dev, + "clone now standalone (overlap became 0)"); + } else { + /* initial probe */ + rbd_warn(rbd_dev, "clone is standalone (overlap 0)"); + } + } + rbd_dev->parent_overlap = pii.overlap; + +out: + ret = 0; +out_err: + kfree(pii.pool_ns); + kfree(pii.image_id); + rbd_spec_put(parent_spec); + return ret; +} + +static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev) +{ + struct { + __le64 stripe_unit; + __le64 stripe_count; + } __attribute__ ((packed)) striping_info_buf = { 0 }; + size_t size = sizeof (striping_info_buf); + void *p; + 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; + + p = &striping_info_buf; + rbd_dev->header.stripe_unit = ceph_decode_64(&p); + rbd_dev->header.stripe_count = ceph_decode_64(&p); + return 0; +} + +static int rbd_dev_v2_data_pool(struct rbd_device *rbd_dev) +{ + __le64 data_pool_id; + int ret; + + ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid, + &rbd_dev->header_oloc, "get_data_pool", + NULL, 0, &data_pool_id, sizeof(data_pool_id)); + if (ret < 0) + return ret; + if (ret < sizeof(data_pool_id)) + return -EBADMSG; + + rbd_dev->header.data_pool_id = le64_to_cpu(data_pool_id); + WARN_ON(rbd_dev->header.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) +{ + 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); + + ceph_put_snap_context(rbd_dev->header.snapc); + rbd_dev->header.snapc = 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) +{ + bool first_time = rbd_dev->header.object_prefix == NULL; + int ret; + + ret = rbd_dev_v2_image_size(rbd_dev); + if (ret) + return ret; + + if (first_time) { + ret = rbd_dev_v2_header_onetime(rbd_dev); + if (ret) + return ret; + } + + ret = rbd_dev_v2_snap_context(rbd_dev); + if (ret && first_time) { + kfree(rbd_dev->header.object_prefix); + rbd_dev->header.object_prefix = NULL; + } + + return ret; +} + +static int rbd_dev_header_info(struct rbd_device *rbd_dev) +{ + rbd_assert(rbd_image_format_valid(rbd_dev->image_format)); + + if (rbd_dev->image_format == 1) + return rbd_dev_v1_header_info(rbd_dev); + + return rbd_dev_v2_header_info(rbd_dev); +} + +/* + * 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. + */ + 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; +} + +/* + * 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 parse_rbd_opts_ctx pctx = { 0 }; + struct ceph_options *copts; + 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 + 1; + 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; + + /* 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->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; + + copts = ceph_parse_options(options, mon_addrs, + mon_addrs + mon_addrs_size - 1, + parse_rbd_opts_token, &pctx); + if (IS_ERR(copts)) { + ret = PTR_ERR(copts); + goto out_err; + } + kfree(options); + + *ceph_opts = copts; + *opts = pctx.opts; + *rbd_spec = pctx.spec; + + return 0; +out_mem: + ret = -ENOMEM; +out_err: + kfree(pctx.opts); + 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_unlock(rbd_dev); + up_write(&rbd_dev->lock_rwsem); +} + +static int rbd_add_acquire_lock(struct rbd_device *rbd_dev) +{ + int ret; + + if (!(rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK)) { + rbd_warn(rbd_dev, "exclusive-lock feature is not enabled"); + return -EINVAL; + } + + /* FIXME: "rbd map --exclusive" should be in interruptible */ + down_read(&rbd_dev->lock_rwsem); + ret = rbd_wait_state_locked(rbd_dev, true); + up_read(&rbd_dev->lock_rwsem); + if (ret) { + rbd_warn(rbd_dev, "failed to acquire exclusive lock"); + return -EROFS; + } + + 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, RBD_IMAGE_ID_LEN_MAX); + 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) +{ + struct rbd_image_header *header; + + rbd_dev_parent_put(rbd_dev); + + /* Free dynamic fields from the header, then zero it out */ + + header = &rbd_dev->header; + ceph_put_snap_context(header->snapc); + kfree(header->snap_sizes); + kfree(header->snap_names); + kfree(header->object_prefix); + memset(header, 0, sizeof (*header)); +} + +static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev) +{ + int ret; + + ret = rbd_dev_v2_object_prefix(rbd_dev); + if (ret) + goto out_err; + + /* + * Get the and check features for the image. Currently the + * features are assumed to never change. + */ + ret = rbd_dev_v2_features(rbd_dev); + if (ret) + goto out_err; + + /* If the image supports fancy striping, get its parameters */ + + if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) { + ret = rbd_dev_v2_striping_info(rbd_dev); + if (ret < 0) + goto out_err; + } + + if (rbd_dev->header.features & RBD_FEATURE_DATA_POOL) { + ret = rbd_dev_v2_data_pool(rbd_dev); + if (ret) + goto out_err; + } + + rbd_init_layout(rbd_dev); + return 0; + +out_err: + rbd_dev->header.features = 0; + kfree(rbd_dev->header.object_prefix); + rbd_dev->header.object_prefix = NULL; + return ret; +} + +/* + * @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->rbd_client, 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. + */ + __rbd_get_client(rbd_dev->rbd_client); + rbd_spec_get(rbd_dev->parent_spec); + + 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_dev_mapping_clear(rbd_dev); + 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; + + ret = rbd_dev_mapping_set(rbd_dev); + if (ret) + goto err_out_disk; + + set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE); + set_disk_ro(rbd_dev->disk, rbd_dev->opts->read_only); + + ret = dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id); + if (ret) + goto err_out_mapping; + + set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags); + up_write(&rbd_dev->header_rwsem); + return 0; + +err_out_mapping: + rbd_dev_mapping_clear(rbd_dev); +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_dev_image_release(struct rbd_device *rbd_dev) +{ + if (rbd_dev->opts) + 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) +{ + 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 (!depth) { + ret = rbd_register_watch(rbd_dev); + if (ret) { + if (ret == -ENOENT) + 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); + goto err_out_format; + } + } + + if (!depth) + down_write(&rbd_dev->header_rwsem); + + ret = rbd_dev_header_info(rbd_dev); + if (ret) + goto err_out_probe; + + /* + * 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) + 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); + goto err_out_probe; + } + + if (rbd_dev->header.features & RBD_FEATURE_LAYERING) { + ret = rbd_dev_v2_parent_info(rbd_dev); + if (ret) + goto err_out_probe; + + /* + * Need to warn users if this image is the one being + * mapped and has a parent. + */ + if (!depth && rbd_dev->parent_spec) + rbd_warn(rbd_dev, + "WARNING: kernel layering is EXPERIMENTAL!"); + } + + 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 (!depth) + 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 ssize_t do_rbd_add(struct bus_type *bus, + 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 */ + + 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 we are mapping a snapshot it must be marked read-only */ + if (rbd_dev->spec->snap_id != CEPH_NOSNAP) + rbd_dev->opts->read_only = true; + + rc = rbd_dev_device_setup(rbd_dev); + if (rc) + goto err_out_image_probe; + + if (rbd_dev->opts->exclusive) { + rc = rbd_add_acquire_lock(rbd_dev); + if (rc) + goto err_out_device_setup; + } + + /* Everything's ready. Announce the disk to the world. */ + + rc = device_add(&rbd_dev->dev); + if (rc) + goto err_out_image_lock; + + add_disk(rbd_dev->disk); + /* see rbd_init_disk() */ + blk_put_queue(rbd_dev->disk->queue); + + 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_image_lock: + rbd_dev_image_unlock(rbd_dev); +err_out_device_setup: + 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 rbd_add(struct bus_type *bus, + const char *buf, + size_t count) +{ + if (single_major) + return -EINVAL; + + return do_rbd_add(bus, buf, count); +} + +static ssize_t rbd_add_single_major(struct bus_type *bus, + const char *buf, + size_t count) +{ + return do_rbd_add(bus, 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(struct bus_type *bus, + const char *buf, + size_t count) +{ + struct rbd_device *rbd_dev = NULL; + struct list_head *tmp; + 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(tmp, &rbd_dev_list) { + rbd_dev = list_entry(tmp, struct rbd_device, 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_set_queue_dying(rbd_dev->disk->queue); + } + + 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 rbd_remove(struct bus_type *bus, + const char *buf, + size_t count) +{ + if (single_major) + return -EINVAL; + + return do_rbd_remove(bus, buf, count); +} + +static ssize_t rbd_remove_single_major(struct bus_type *bus, + const char *buf, + size_t count) +{ + return do_rbd_remove(bus, buf, count); +} + +/* + * create control files in sysfs + * /sys/bus/rbd/... + */ +static int rbd_sysfs_init(void) +{ + int ret; + + ret = device_register(&rbd_root_dev); + if (ret < 0) + return ret; + + ret = bus_register(&rbd_bus_type); + if (ret < 0) + device_unregister(&rbd_root_dev); + + return ret; +} + +static void rbd_sysfs_cleanup(void) +{ + bus_unregister(&rbd_bus_type); + device_unregister(&rbd_root_dev); +} + +static int 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"); |