diff options
Diffstat (limited to 'fs/ceph/mds_client.h')
| -rw-r--r-- | fs/ceph/mds_client.h | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h new file mode 100644 index 00000000000..d66d63c7235 --- /dev/null +++ b/fs/ceph/mds_client.h @@ -0,0 +1,365 @@ +#ifndef _FS_CEPH_MDS_CLIENT_H +#define _FS_CEPH_MDS_CLIENT_H + +#include <linux/completion.h> +#include <linux/kref.h> +#include <linux/list.h> +#include <linux/mutex.h> +#include <linux/rbtree.h> +#include <linux/spinlock.h> + +#include <linux/ceph/types.h> +#include <linux/ceph/messenger.h> +#include <linux/ceph/mdsmap.h> + +/* + * Some lock dependencies: + * + * session->s_mutex + * mdsc->mutex + * + * mdsc->snap_rwsem + * + * inode->i_lock + * mdsc->snap_flush_lock + * mdsc->cap_delay_lock + * + */ + +struct ceph_fs_client; +struct ceph_cap; + +/* + * parsed info about a single inode. pointers are into the encoded + * on-wire structures within the mds reply message payload. + */ +struct ceph_mds_reply_info_in { + struct ceph_mds_reply_inode *in; + u32 symlink_len; + char *symlink; + u32 xattr_len; + char *xattr_data; +}; + +/* + * parsed info about an mds reply, including information about the + * target inode and/or its parent directory and dentry, and directory + * contents (for readdir results). + */ +struct ceph_mds_reply_info_parsed { + struct ceph_mds_reply_head *head; + + struct ceph_mds_reply_info_in diri, targeti; + struct ceph_mds_reply_dirfrag *dirfrag; + char *dname; + u32 dname_len; + struct ceph_mds_reply_lease *dlease; + + struct ceph_mds_reply_dirfrag *dir_dir; + int dir_nr; + char **dir_dname; + u32 *dir_dname_len; + struct ceph_mds_reply_lease **dir_dlease; + struct ceph_mds_reply_info_in *dir_in; + u8 dir_complete, dir_end; + + /* encoded blob describing snapshot contexts for certain + operations (e.g., open) */ + void *snapblob; + int snapblob_len; +}; + + +/* + * cap releases are batched and sent to the MDS en masse. + */ +#define CEPH_CAPS_PER_RELEASE ((PAGE_CACHE_SIZE - \ + sizeof(struct ceph_mds_cap_release)) / \ + sizeof(struct ceph_mds_cap_item)) + + +/* + * state associated with each MDS<->client session + */ +enum { + CEPH_MDS_SESSION_NEW = 1, + CEPH_MDS_SESSION_OPENING = 2, + CEPH_MDS_SESSION_OPEN = 3, + CEPH_MDS_SESSION_HUNG = 4, + CEPH_MDS_SESSION_CLOSING = 5, + CEPH_MDS_SESSION_RESTARTING = 6, + CEPH_MDS_SESSION_RECONNECTING = 7, +}; + +struct ceph_mds_session { + struct ceph_mds_client *s_mdsc; + int s_mds; + int s_state; + unsigned long s_ttl; /* time until mds kills us */ + u64 s_seq; /* incoming msg seq # */ + struct mutex s_mutex; /* serialize session messages */ + + struct ceph_connection s_con; + + struct ceph_authorizer *s_authorizer; + void *s_authorizer_buf, *s_authorizer_reply_buf; + size_t s_authorizer_buf_len, s_authorizer_reply_buf_len; + + /* protected by s_cap_lock */ + spinlock_t s_cap_lock; + u32 s_cap_gen; /* inc each time we get mds stale msg */ + unsigned long s_cap_ttl; /* when session caps expire */ + struct list_head s_caps; /* all caps issued by this session */ + int s_nr_caps, s_trim_caps; + int s_num_cap_releases; + struct list_head s_cap_releases; /* waiting cap_release messages */ + struct list_head s_cap_releases_done; /* ready to send */ + struct ceph_cap *s_cap_iterator; + + /* protected by mutex */ + struct list_head s_cap_flushing; /* inodes w/ flushing caps */ + struct list_head s_cap_snaps_flushing; + unsigned long s_renew_requested; /* last time we sent a renew req */ + u64 s_renew_seq; + + atomic_t s_ref; + struct list_head s_waiting; /* waiting requests */ + struct list_head s_unsafe; /* unsafe requests */ +}; + +/* + * modes of choosing which MDS to send a request to + */ +enum { + USE_ANY_MDS, + USE_RANDOM_MDS, + USE_AUTH_MDS, /* prefer authoritative mds for this metadata item */ +}; + +struct ceph_mds_request; +struct ceph_mds_client; + +/* + * request completion callback + */ +typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc, + struct ceph_mds_request *req); + +/* + * an in-flight mds request + */ +struct ceph_mds_request { + u64 r_tid; /* transaction id */ + struct rb_node r_node; + struct ceph_mds_client *r_mdsc; + + int r_op; /* mds op code */ + int r_mds; + + /* operation on what? */ + struct inode *r_inode; /* arg1 */ + struct dentry *r_dentry; /* arg1 */ + struct dentry *r_old_dentry; /* arg2: rename from or link from */ + char *r_path1, *r_path2; + struct ceph_vino r_ino1, r_ino2; + + struct inode *r_locked_dir; /* dir (if any) i_mutex locked by vfs */ + struct inode *r_target_inode; /* resulting inode */ + + struct mutex r_fill_mutex; + + union ceph_mds_request_args r_args; + int r_fmode; /* file mode, if expecting cap */ + + /* for choosing which mds to send this request to */ + int r_direct_mode; + u32 r_direct_hash; /* choose dir frag based on this dentry hash */ + bool r_direct_is_hash; /* true if r_direct_hash is valid */ + + /* data payload is used for xattr ops */ + struct page **r_pages; + int r_num_pages; + int r_data_len; + + /* what caps shall we drop? */ + int r_inode_drop, r_inode_unless; + int r_dentry_drop, r_dentry_unless; + int r_old_dentry_drop, r_old_dentry_unless; + struct inode *r_old_inode; + int r_old_inode_drop, r_old_inode_unless; + + struct ceph_msg *r_request; /* original request */ + int r_request_release_offset; + struct ceph_msg *r_reply; + struct ceph_mds_reply_info_parsed r_reply_info; + int r_err; + bool r_aborted; + + unsigned long r_timeout; /* optional. jiffies */ + unsigned long r_started; /* start time to measure timeout against */ + unsigned long r_request_started; /* start time for mds request only, + used to measure lease durations */ + + /* link unsafe requests to parent directory, for fsync */ + struct inode *r_unsafe_dir; + struct list_head r_unsafe_dir_item; + + struct ceph_mds_session *r_session; + + int r_attempts; /* resend attempts */ + int r_num_fwd; /* number of forward attempts */ + int r_resend_mds; /* mds to resend to next, if any*/ + u32 r_sent_on_mseq; /* cap mseq request was sent at*/ + + struct kref r_kref; + struct list_head r_wait; + struct completion r_completion; + struct completion r_safe_completion; + ceph_mds_request_callback_t r_callback; + struct list_head r_unsafe_item; /* per-session unsafe list item */ + bool r_got_unsafe, r_got_safe, r_got_result; + + bool r_did_prepopulate; + u32 r_readdir_offset; + + struct ceph_cap_reservation r_caps_reservation; + int r_num_caps; +}; + +/* + * mds client state + */ +struct ceph_mds_client { + struct ceph_fs_client *fsc; + struct mutex mutex; /* all nested structures */ + + struct ceph_mdsmap *mdsmap; + struct completion safe_umount_waiters; + wait_queue_head_t session_close_wq; + struct list_head waiting_for_map; + + struct ceph_mds_session **sessions; /* NULL for mds if no session */ + int max_sessions; /* len of s_mds_sessions */ + int stopping; /* true if shutting down */ + + /* + * snap_rwsem will cover cap linkage into snaprealms, and + * realm snap contexts. (later, we can do per-realm snap + * contexts locks..) the empty list contains realms with no + * references (implying they contain no inodes with caps) that + * should be destroyed. + */ + struct rw_semaphore snap_rwsem; + struct rb_root snap_realms; + struct list_head snap_empty; + spinlock_t snap_empty_lock; /* protect snap_empty */ + + u64 last_tid; /* most recent mds request */ + struct rb_root request_tree; /* pending mds requests */ + struct delayed_work delayed_work; /* delayed work */ + unsigned long last_renew_caps; /* last time we renewed our caps */ + struct list_head cap_delay_list; /* caps with delayed release */ + spinlock_t cap_delay_lock; /* protects cap_delay_list */ + struct list_head snap_flush_list; /* cap_snaps ready to flush */ + spinlock_t snap_flush_lock; + + u64 cap_flush_seq; + struct list_head cap_dirty; /* inodes with dirty caps */ + int num_cap_flushing; /* # caps we are flushing */ + spinlock_t cap_dirty_lock; /* protects above items */ + wait_queue_head_t cap_flushing_wq; + + /* + * Cap reservations + * + * Maintain a global pool of preallocated struct ceph_caps, referenced + * by struct ceph_caps_reservations. This ensures that we preallocate + * memory needed to successfully process an MDS response. (If an MDS + * sends us cap information and we fail to process it, we will have + * problems due to the client and MDS being out of sync.) + * + * Reservations are 'owned' by a ceph_cap_reservation context. + */ + spinlock_t caps_list_lock; + struct list_head caps_list; /* unused (reserved or + unreserved) */ + int caps_total_count; /* total caps allocated */ + int caps_use_count; /* in use */ + int caps_reserve_count; /* unused, reserved */ + int caps_avail_count; /* unused, unreserved */ + int caps_min_count; /* keep at least this many + (unreserved) */ + spinlock_t dentry_lru_lock; + struct list_head dentry_lru; + int num_dentry; +}; + +extern const char *ceph_mds_op_name(int op); + +extern struct ceph_mds_session * +__ceph_lookup_mds_session(struct ceph_mds_client *, int mds); + +static inline struct ceph_mds_session * +ceph_get_mds_session(struct ceph_mds_session *s) +{ + atomic_inc(&s->s_ref); + return s; +} + +extern void ceph_put_mds_session(struct ceph_mds_session *s); + +extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc, + struct ceph_msg *msg, int mds); + +extern int ceph_mdsc_init(struct ceph_fs_client *fsc); +extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc); +extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc); + +extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc); + +extern void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc, + struct inode *inode, + struct dentry *dn, int mask); + +extern void ceph_invalidate_dir_request(struct ceph_mds_request *req); + +extern struct ceph_mds_request * +ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode); +extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc, + struct ceph_mds_request *req); +extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc, + struct inode *dir, + struct ceph_mds_request *req); +static inline void ceph_mdsc_get_request(struct ceph_mds_request *req) +{ + kref_get(&req->r_kref); +} +extern void ceph_mdsc_release_request(struct kref *kref); +static inline void ceph_mdsc_put_request(struct ceph_mds_request *req) +{ + kref_put(&req->r_kref, ceph_mdsc_release_request); +} + +extern int ceph_add_cap_releases(struct ceph_mds_client *mdsc, + struct ceph_mds_session *session); +extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc, + struct ceph_mds_session *session); + +extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc); + +extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base, + int stop_on_nosnap); + +extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry); +extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session, + struct inode *inode, + struct dentry *dentry, char action, + u32 seq); + +extern void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, + struct ceph_msg *msg); + +extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc, + struct ceph_mds_session *session); + +#endif |