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04b933f27b
In Testing the previously posted and accepted patch for https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=228540 I uncovered some gfs2 badness. It turns out that the current gfs2 code saves off a process pointer when glocks is taken in both the glock and glock holder structures. Those structures will persist in memory long after the process has ended; pointers to poisoned memory. This problem isn't caused by the 228540 fix; the new capability introduced by the fix just uncovered the problem. I wrote this patch that avoids saving process pointers and instead saves off the process pid. Rather than referencing the bad pointers, it now does process lookups. There is special code that makes the output nicer for printing holder information for processes that have ended. This patch also adds a stub for the new "sprint_symbol" function that exists in Andrew Morton's -mm patch set, but won't go into the base kernel until 2.6.22, since it adds functionality but doesn't fix a bug. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
144 lines
4.0 KiB
C
144 lines
4.0 KiB
C
/*
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* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
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* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
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*
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* This copyrighted material is made available to anyone wishing to use,
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* modify, copy, or redistribute it subject to the terms and conditions
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* of the GNU General Public License version 2.
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*/
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#ifndef __GLOCK_DOT_H__
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#define __GLOCK_DOT_H__
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#include "incore.h"
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/* Flags for lock requests; used in gfs2_holder gh_flag field.
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From lm_interface.h:
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#define LM_FLAG_TRY 0x00000001
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#define LM_FLAG_TRY_1CB 0x00000002
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#define LM_FLAG_NOEXP 0x00000004
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#define LM_FLAG_ANY 0x00000008
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#define LM_FLAG_PRIORITY 0x00000010 */
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#define GL_ASYNC 0x00000040
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#define GL_EXACT 0x00000080
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#define GL_SKIP 0x00000100
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#define GL_ATIME 0x00000200
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#define GL_NOCACHE 0x00000400
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#define GL_NOCANCEL 0x00001000
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#define GLR_TRYFAILED 13
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#define GLR_CANCELED 14
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static inline int gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
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{
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struct gfs2_holder *gh;
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int locked = 0;
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/* Look in glock's list of holders for one with current task as owner */
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spin_lock(&gl->gl_spin);
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list_for_each_entry(gh, &gl->gl_holders, gh_list) {
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if (gh->gh_owner_pid == current->pid) {
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locked = 1;
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break;
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}
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}
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spin_unlock(&gl->gl_spin);
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return locked;
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}
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static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
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{
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return gl->gl_state == LM_ST_EXCLUSIVE;
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}
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static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
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{
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return gl->gl_state == LM_ST_DEFERRED;
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}
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static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
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{
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return gl->gl_state == LM_ST_SHARED;
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}
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static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl)
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{
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int ret;
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spin_lock(&gl->gl_spin);
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ret = test_bit(GLF_DEMOTE, &gl->gl_flags) || !list_empty(&gl->gl_waiters3);
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spin_unlock(&gl->gl_spin);
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return ret;
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}
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int gfs2_glock_get(struct gfs2_sbd *sdp,
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u64 number, const struct gfs2_glock_operations *glops,
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int create, struct gfs2_glock **glp);
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void gfs2_glock_hold(struct gfs2_glock *gl);
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int gfs2_glock_put(struct gfs2_glock *gl);
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void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
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struct gfs2_holder *gh);
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void gfs2_holder_reinit(unsigned int state, unsigned flags,
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struct gfs2_holder *gh);
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void gfs2_holder_uninit(struct gfs2_holder *gh);
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int gfs2_glock_nq(struct gfs2_holder *gh);
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int gfs2_glock_poll(struct gfs2_holder *gh);
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int gfs2_glock_wait(struct gfs2_holder *gh);
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void gfs2_glock_dq(struct gfs2_holder *gh);
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void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
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int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
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u64 number, const struct gfs2_glock_operations *glops,
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unsigned int state, int flags, struct gfs2_holder *gh);
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int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
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void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
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void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
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/**
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* gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
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* @gl: the glock
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* @state: the state we're requesting
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* @flags: the modifier flags
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* @gh: the holder structure
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*
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* Returns: 0, GLR_*, or errno
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*/
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static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
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unsigned int state, int flags,
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struct gfs2_holder *gh)
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{
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int error;
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gfs2_holder_init(gl, state, flags, gh);
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error = gfs2_glock_nq(gh);
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if (error)
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gfs2_holder_uninit(gh);
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return error;
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}
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/* Lock Value Block functions */
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int gfs2_lvb_hold(struct gfs2_glock *gl);
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void gfs2_lvb_unhold(struct gfs2_glock *gl);
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void gfs2_glock_cb(void *cb_data, unsigned int type, void *data);
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void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
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void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
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void gfs2_scand_internal(struct gfs2_sbd *sdp);
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void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait);
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int __init gfs2_glock_init(void);
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int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
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void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
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int gfs2_register_debugfs(void);
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void gfs2_unregister_debugfs(void);
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#endif /* __GLOCK_DOT_H__ */
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