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: Benjamin Marzinski <[email protected]> --- fs/gfs2/incore.h | 1 + fs/gfs2/lock_dlm.c | 7 ++++--- 2 files changed, 5 insertions(+), 3 deletions(-) Index: gfs2-2.6-nmw/fs/gfs2/incore.h =================================================================== --- gfs2-2.6-nmw.orig/fs/gfs2/incore.h +++ gfs2-2.6-nmw/fs/gfs2/incore.h @@ -203,6 +203,7 @@ struct gfs2_glock { unsigned int gl_target; unsigned int gl_reply; unsigned int gl_hash; + unsigned int gl_req; unsigned int gl_demote_state; /* state requested by remote node */ unsigned long gl_demote_time; /* time of first demote request */ struct list_head gl_holders; Index: gfs2-2.6-nmw/fs/gfs2/lock_dlm.c =================================================================== --- gfs2-2.6-nmw.orig/fs/gfs2/lock_dlm.c +++ gfs2-2.6-nmw/fs/gfs2/lock_dlm.c @@ -46,11 +46,11 @@ static void gdlm_ast(void *arg) BUG(); } - ret = gl->gl_target; + ret = gl->gl_req; 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; - else if (gl->gl_target == LM_ST_DEFERRED) + else if (gl->gl_req == LM_ST_DEFERRED) ret = LM_ST_SHARED; else BUG(); @@ -147,6 +147,7 @@ static unsigned int gdlm_lock(struct gfs int req; u32 lkf; + gl->gl_req = req_state; req = make_mode(req_state); lkf = make_flags(gl->gl_lksb.sb_lkid, flags, req);
