Commit 02ffad08 authored by Benjamin Marzinski's avatar Benjamin Marzinski Committed by Steven Whitehouse

GFS2: Fix locking bug in failed shared to exclusive conversion

After calling out to the dlm, GFS2 sets the new state of a glock to
gl_target in gdlm_ast().  However, gl_target is not always the lock
state that was requested. If a conversion from shared to exclusive
fails, finish_xmote() will call do_xmote() with LM_ST_UNLOCKED, instead
of gl->gl_target, so that it can reacquire the lock in exlusive the next
time around.  In this case, setting the lock to gl_target in gdlm_ast()
will make GFS2 think that it has the glock in exclusive mode, when
really, it doesn't have the glock locked at all.  This patch adds a new
field to the gfs2_glock structure, gl_req, to track the mode that was
requested.
Signed-off-by: default avatarBenjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent 229615de
...@@ -203,6 +203,7 @@ struct gfs2_glock { ...@@ -203,6 +203,7 @@ struct gfs2_glock {
unsigned int gl_target; unsigned int gl_target;
unsigned int gl_reply; unsigned int gl_reply;
unsigned int gl_hash; unsigned int gl_hash;
unsigned int gl_req;
unsigned int gl_demote_state; /* state requested by remote node */ unsigned int gl_demote_state; /* state requested by remote node */
unsigned long gl_demote_time; /* time of first demote request */ unsigned long gl_demote_time; /* time of first demote request */
struct list_head gl_holders; struct list_head gl_holders;
......
...@@ -46,11 +46,11 @@ static void gdlm_ast(void *arg) ...@@ -46,11 +46,11 @@ static void gdlm_ast(void *arg)
BUG(); BUG();
} }
ret = gl->gl_target; ret = gl->gl_req;
if (gl->gl_lksb.sb_flags & DLM_SBF_ALTMODE) { if (gl->gl_lksb.sb_flags & DLM_SBF_ALTMODE) {
if (gl->gl_target == LM_ST_SHARED) if (gl->gl_req == LM_ST_SHARED)
ret = LM_ST_DEFERRED; ret = LM_ST_DEFERRED;
else if (gl->gl_target == LM_ST_DEFERRED) else if (gl->gl_req == LM_ST_DEFERRED)
ret = LM_ST_SHARED; ret = LM_ST_SHARED;
else else
BUG(); BUG();
...@@ -147,6 +147,7 @@ static unsigned int gdlm_lock(struct gfs2_glock *gl, ...@@ -147,6 +147,7 @@ static unsigned int gdlm_lock(struct gfs2_glock *gl,
int req; int req;
u32 lkf; u32 lkf;
gl->gl_req = req_state;
req = make_mode(req_state); req = make_mode(req_state);
lkf = make_flags(gl->gl_lksb.sb_lkid, flags, req); lkf = make_flags(gl->gl_lksb.sb_lkid, flags, req);
......
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