From 048786f1e6042022a8fb2035157a8c8c3a82a4f2 Mon Sep 17 00:00:00 2001 From: Adrian Bunk Date: Tue, 29 Jan 2008 00:11:34 +0200 Subject: [GFS2] make gfs2_glock_hold() static gfs2_glock_hold() can now become static. Signed-off-by: Adrian Bunk Signed-off-by: Steven Whitehouse --- fs/gfs2/glock.h | 1 - 1 file changed, 1 deletion(-) (limited to 'fs/gfs2/glock.h') diff --git a/fs/gfs2/glock.h b/fs/gfs2/glock.h index 2f9c6d136b37..ace5770760ce 100644 --- a/fs/gfs2/glock.h +++ b/fs/gfs2/glock.h @@ -79,7 +79,6 @@ static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl) int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, const struct gfs2_glock_operations *glops, int create, struct gfs2_glock **glp); -void gfs2_glock_hold(struct gfs2_glock *gl); int gfs2_glock_put(struct gfs2_glock *gl); void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags, struct gfs2_holder *gh); -- cgit v1.2.2 From 7afd88d9166a752b52517648bcbe923e05d393fc Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Fri, 22 Feb 2008 16:07:18 +0000 Subject: [GFS2] Fix a page lock / glock deadlock We've previously been using a "try lock" in readpage on the basis that it would prevent deadlocks due to the inverted lock ordering (our normal lock ordering is glock first and then page lock). Unfortunately tests have shown that this isn't enough. If the glock has a demote request queued such that run_queue() in the glock code tries to do a demote when its called under readpage then it will try and write out all the dirty pages which requires locking them. This then deadlocks with the page locked by readpage. The solution is to always require two calls into readpage. The first unlocks the page, gets the glock and returns AOP_TRUNCATED_PAGE, the second does the actual readpage and unlocks the glock & page as required. Signed-off-by: Steven Whitehouse --- fs/gfs2/glock.h | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'fs/gfs2/glock.h') diff --git a/fs/gfs2/glock.h b/fs/gfs2/glock.h index ace5770760ce..cdad3e6f8150 100644 --- a/fs/gfs2/glock.h +++ b/fs/gfs2/glock.h @@ -32,24 +32,23 @@ #define GLR_TRYFAILED 13 #define GLR_CANCELED 14 -static inline int gfs2_glock_is_locked_by_me(struct gfs2_glock *gl) +static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl) { struct gfs2_holder *gh; - int locked = 0; struct pid *pid; /* Look in glock's list of holders for one with current task as owner */ spin_lock(&gl->gl_spin); pid = task_pid(current); list_for_each_entry(gh, &gl->gl_holders, gh_list) { - if (gh->gh_owner_pid == pid) { - locked = 1; - break; - } + if (gh->gh_owner_pid == pid) + goto out; } + gh = NULL; +out: spin_unlock(&gl->gl_spin); - return locked; + return gh; } static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl) -- cgit v1.2.2