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| author | Benjamin Marzinski <bmarzins@redhat.com> | 2009-03-06 10:03:20 -0600 |
|---|---|---|
| committer | Steven Whitehouse <steve@dolmen.chygwyn.com> | 2009-03-24 11:21:26 +0000 |
| commit | 02ffad08e838997fad3de05c85560a57e5fd92de (patch) | |
| tree | feee17b1848957b1b42047ae6c4156d716adf4e8 | |
| parent | 229615def3f573fc448d20f62c6ec1bc9340cefb (diff) | |
| download | op-kernel-dev-02ffad08e838997fad3de05c85560a57e5fd92de.zip op-kernel-dev-02ffad08e838997fad3de05c85560a57e5fd92de.tar.gz | |
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: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| -rw-r--r-- | fs/gfs2/incore.h | 1 | ||||
| -rw-r--r-- | fs/gfs2/lock_dlm.c | 7 |
2 files changed, 5 insertions, 3 deletions
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h index 980a086..399d1b9 100644 --- a/fs/gfs2/incore.h +++ b/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; diff --git a/fs/gfs2/lock_dlm.c b/fs/gfs2/lock_dlm.c index a0bb7d2..46df988 100644 --- a/fs/gfs2/lock_dlm.c +++ b/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 gfs2_glock *gl, int req; u32 lkf; + gl->gl_req = req_state; req = make_mode(req_state); lkf = make_flags(gl->gl_lksb.sb_lkid, flags, req); |
