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Diffstat (limited to 'fs/gfs2/glock.h')
| -rw-r--r-- | fs/gfs2/glock.h | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/fs/gfs2/glock.h b/fs/gfs2/glock.h new file mode 100644 index 000000000..5e12220cc --- /dev/null +++ b/fs/gfs2/glock.h @@ -0,0 +1,303 @@ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. + * + * This copyrighted material is made available to anyone wishing to use, + * modify, copy, or redistribute it subject to the terms and conditions + * of the GNU General Public License version 2. + */ + +#ifndef __GLOCK_DOT_H__ +#define __GLOCK_DOT_H__ + +#include <linux/sched.h> +#include <linux/parser.h> +#include "incore.h" +#include "util.h" + +/* Options for hostdata parser */ + +enum { + Opt_jid, + Opt_id, + Opt_first, + Opt_nodir, + Opt_err, +}; + +/* + * lm_lockname types + */ + +#define LM_TYPE_RESERVED 0x00 +#define LM_TYPE_NONDISK 0x01 +#define LM_TYPE_INODE 0x02 +#define LM_TYPE_RGRP 0x03 +#define LM_TYPE_META 0x04 +#define LM_TYPE_IOPEN 0x05 +#define LM_TYPE_FLOCK 0x06 +#define LM_TYPE_PLOCK 0x07 +#define LM_TYPE_QUOTA 0x08 +#define LM_TYPE_JOURNAL 0x09 + +/* + * lm_lock() states + * + * SHARED is compatible with SHARED, not with DEFERRED or EX. + * DEFERRED is compatible with DEFERRED, not with SHARED or EX. + */ + +#define LM_ST_UNLOCKED 0 +#define LM_ST_EXCLUSIVE 1 +#define LM_ST_DEFERRED 2 +#define LM_ST_SHARED 3 + +/* + * lm_lock() flags + * + * LM_FLAG_TRY + * Don't wait to acquire the lock if it can't be granted immediately. + * + * LM_FLAG_TRY_1CB + * Send one blocking callback if TRY is set and the lock is not granted. + * + * LM_FLAG_NOEXP + * GFS sets this flag on lock requests it makes while doing journal recovery. + * These special requests should not be blocked due to the recovery like + * ordinary locks would be. + * + * LM_FLAG_ANY + * A SHARED request may also be granted in DEFERRED, or a DEFERRED request may + * also be granted in SHARED. The preferred state is whichever is compatible + * with other granted locks, or the specified state if no other locks exist. + * + * LM_FLAG_PRIORITY + * Override fairness considerations. Suppose a lock is held in a shared state + * and there is a pending request for the deferred state. A shared lock + * request with the priority flag would be allowed to bypass the deferred + * request and directly join the other shared lock. A shared lock request + * without the priority flag might be forced to wait until the deferred + * requested had acquired and released the lock. + */ + +#define LM_FLAG_TRY 0x0001 +#define LM_FLAG_TRY_1CB 0x0002 +#define LM_FLAG_NOEXP 0x0004 +#define LM_FLAG_ANY 0x0008 +#define LM_FLAG_PRIORITY 0x0010 +#define GL_ASYNC 0x0040 +#define GL_EXACT 0x0080 +#define GL_SKIP 0x0100 +#define GL_NOCACHE 0x0400 + +/* + * lm_async_cb return flags + * + * LM_OUT_ST_MASK + * Masks the lower two bits of lock state in the returned value. + * + * LM_OUT_CANCELED + * The lock request was canceled. + * + */ + +#define LM_OUT_ST_MASK 0x00000003 +#define LM_OUT_CANCELED 0x00000008 +#define LM_OUT_ERROR 0x00000004 + +/* + * lm_recovery_done() messages + */ + +#define LM_RD_GAVEUP 308 +#define LM_RD_SUCCESS 309 + +#define GLR_TRYFAILED 13 + +#define GL_GLOCK_MAX_HOLD (long)(HZ / 5) +#define GL_GLOCK_DFT_HOLD (long)(HZ / 5) +#define GL_GLOCK_MIN_HOLD (long)(10) +#define GL_GLOCK_HOLD_INCR (long)(HZ / 20) +#define GL_GLOCK_HOLD_DECR (long)(HZ / 40) + +struct lm_lockops { + const char *lm_proto_name; + int (*lm_mount) (struct gfs2_sbd *sdp, const char *table); + void (*lm_first_done) (struct gfs2_sbd *sdp); + void (*lm_recovery_result) (struct gfs2_sbd *sdp, unsigned int jid, + unsigned int result); + void (*lm_unmount) (struct gfs2_sbd *sdp); + void (*lm_withdraw) (struct gfs2_sbd *sdp); + void (*lm_put_lock) (struct gfs2_glock *gl); + int (*lm_lock) (struct gfs2_glock *gl, unsigned int req_state, + unsigned int flags); + void (*lm_cancel) (struct gfs2_glock *gl); + const match_table_t *lm_tokens; +}; + +extern struct workqueue_struct *gfs2_delete_workqueue; +static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl) +{ + struct gfs2_holder *gh; + struct pid *pid; + + /* Look in glock's list of holders for one with current task as owner */ + spin_lock(&gl->gl_lockref.lock); + pid = task_pid(current); + list_for_each_entry(gh, &gl->gl_holders, gh_list) { + if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) + break; + if (gh->gh_owner_pid == pid) + goto out; + } + gh = NULL; +out: + spin_unlock(&gl->gl_lockref.lock); + + return gh; +} + +static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl) +{ + return gl->gl_state == LM_ST_EXCLUSIVE; +} + +static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl) +{ + return gl->gl_state == LM_ST_DEFERRED; +} + +static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl) +{ + return gl->gl_state == LM_ST_SHARED; +} + +static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl) +{ + if (gl->gl_ops->go_flags & GLOF_ASPACE) + return (struct address_space *)(gl + 1); + return NULL; +} + +extern int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, + const struct gfs2_glock_operations *glops, + int create, struct gfs2_glock **glp); +extern void gfs2_glock_hold(struct gfs2_glock *gl); +extern void gfs2_glock_put(struct gfs2_glock *gl); +extern void gfs2_glock_queue_put(struct gfs2_glock *gl); +extern void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, + u16 flags, struct gfs2_holder *gh); +extern void gfs2_holder_reinit(unsigned int state, u16 flags, + struct gfs2_holder *gh); +extern void gfs2_holder_uninit(struct gfs2_holder *gh); +extern int gfs2_glock_nq(struct gfs2_holder *gh); +extern int gfs2_glock_poll(struct gfs2_holder *gh); +extern int gfs2_glock_wait(struct gfs2_holder *gh); +extern void gfs2_glock_dq(struct gfs2_holder *gh); +extern void gfs2_glock_dq_wait(struct gfs2_holder *gh); +extern void gfs2_glock_dq_uninit(struct gfs2_holder *gh); +extern int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, + const struct gfs2_glock_operations *glops, + unsigned int state, u16 flags, + struct gfs2_holder *gh); +extern int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs); +extern void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs); +extern void gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl); +#define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { gfs2_dump_glock(NULL, gl); BUG(); } } while(0) +extern __printf(2, 3) +void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...); + +/** + * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock + * @gl: the glock + * @state: the state we're requesting + * @flags: the modifier flags + * @gh: the holder structure + * + * Returns: 0, GLR_*, or errno + */ + +static inline int gfs2_glock_nq_init(struct gfs2_glock *gl, + unsigned int state, u16 flags, + struct gfs2_holder *gh) +{ + int error; + + gfs2_holder_init(gl, state, flags, gh); + + error = gfs2_glock_nq(gh); + if (error) + gfs2_holder_uninit(gh); + + return error; +} + +extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state); +extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret); +extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp); +extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip); +extern void gfs2_glock_thaw(struct gfs2_sbd *sdp); +extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl); +extern void gfs2_glock_free(struct gfs2_glock *gl); + +extern int __init gfs2_glock_init(void); +extern void gfs2_glock_exit(void); + +extern int gfs2_create_debugfs_file(struct gfs2_sbd *sdp); +extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp); +extern int gfs2_register_debugfs(void); +extern void gfs2_unregister_debugfs(void); + +extern const struct lm_lockops gfs2_dlm_ops; + +static inline void gfs2_holder_mark_uninitialized(struct gfs2_holder *gh) +{ + gh->gh_gl = NULL; +} + +static inline bool gfs2_holder_initialized(struct gfs2_holder *gh) +{ + return gh->gh_gl; +} + +/** + * glock_set_object - set the gl_object field of a glock + * @gl: the glock + * @object: the object + */ +static inline void glock_set_object(struct gfs2_glock *gl, void *object) +{ + spin_lock(&gl->gl_lockref.lock); + if (gfs2_assert_warn(gl->gl_name.ln_sbd, gl->gl_object == NULL)) + gfs2_dump_glock(NULL, gl); + gl->gl_object = object; + spin_unlock(&gl->gl_lockref.lock); +} + +/** + * glock_clear_object - clear the gl_object field of a glock + * @gl: the glock + * @object: the object + * + * I'd love to similarly add this: + * else if (gfs2_assert_warn(gl->gl_sbd, gl->gl_object == object)) + * gfs2_dump_glock(NULL, gl); + * Unfortunately, that's not possible because as soon as gfs2_delete_inode + * frees the block in the rgrp, another process can reassign it for an I_NEW + * inode in gfs2_create_inode because that calls new_inode, not gfs2_iget. + * That means gfs2_delete_inode may subsequently try to call this function + * for a glock that's already pointing to a brand new inode. If we clear the + * new inode's gl_object, we'll introduce metadata corruption. Function + * gfs2_delete_inode calls clear_inode which calls gfs2_clear_inode which also + * tries to clear gl_object, so it's more than just gfs2_delete_inode. + * + */ +static inline void glock_clear_object(struct gfs2_glock *gl, void *object) +{ + spin_lock(&gl->gl_lockref.lock); + if (gl->gl_object == object) + gl->gl_object = NULL; + spin_unlock(&gl->gl_lockref.lock); +} + +#endif /* __GLOCK_DOT_H__ */ |