linux-toradex.git/fs/gfs2/glock.c, branch v4.4.81

gfs2: Fix glock rhashtable rcu bug

2017-07-15T09:57:46+00:00

commit 961ae1d83d055a4b9ebbfb4cc8ca62ec1a7a3b74 upstream.

Before commit 88ffbf3e03 "GFS2: Use resizable hash table for glocks",
glocks were freed via call_rcu to allow reading the glock hashtable
locklessly using rcu.  This was then changed to free glocks immediately,
which made reading the glock hashtable unsafe.  Bring back the original
code for freeing glocks via call_rcu.

Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Bob Peterson 
Signed-off-by: Greg Kroah-Hartman

gfs2: Add missing rcu locking for glock lookup

2017-03-12T05:37:29+00:00

commit f38e5fb95a1f8feda88531eedc98f69b24748712 upstream.

We must hold the rcu read lock across looking up glocks and trying to
bump their refcount to prevent the glocks from being freed in between.

Signed-off-by: Andrew Price 
Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Bob Peterson 
Signed-off-by: Greg Kroah-Hartman

gfs2: Remove gl_spin define

2015-10-29T17:57:48+00:00

Commit e66cf161 replaced the gl_spin spinlock in struct gfs2_glock with a
gl_lockref lockref and defined gl_spin as gl_lockref.lock (the spinlock in
gl_lockref).  Remove that define to make the references to gl_lockref.lock more
obvious.

Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Bob Peterson

gfs2: A minor "sbstats" cleanup

2015-09-03T18:34:14+00:00

It seems cleaner to avoid the temporary value here.

Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Bob Peterson

gfs2: Make statistics unsigned, suitable for use with do_div()

2015-09-03T18:33:32+00:00

None of these statistics can meaningfully be negative, and the
numerator for do_div() must have the type u64.  The generic
implementation of do_div() used on some 32-bit architectures asserts
that, resulting in a compiler error in gfs2_rgrp_congested().

Fixes: 0166b197c2ed ("GFS2: Average in only non-zero round-trip times ...")

Signed-off-by: Ben Hutchings 
Signed-off-by: Bob Peterson 
Acked-by: Andreas Gruenbacher

GFS2: Use resizable hash table for glocks

2015-09-03T18:33:24+00:00

This patch changes the glock hash table from a normal hash table to
a resizable hash table, which scales better. This also simplifies
a lot of code.

Signed-off-by: Bob Peterson 
Signed-off-by: Andreas Gruenbacher 
Acked-by: Steven Whitehouse

GFS2: Move glock superblock pointer to field gl_name

2015-09-03T18:33:09+00:00

What uniquely identifies a glock in the glock hash table is not
gl_name, but gl_name and its superblock pointer. This patch makes
the gl_name field correspond to a unique glock identifier. That will
allow us to simplify hashing with a future patch, since the hash
algorithm can then take the gl_name and hash its components in one
operation.

Signed-off-by: Bob Peterson 
Signed-off-by: Andreas Gruenbacher 
Acked-by: Steven Whitehouse

gfs2: Simplify the seq file code for "sbstats"

2015-09-03T18:33:05+00:00

Don't use struct gfs2_glock_iter as the helper data structure for iterating
through "sbstats"; we are not iterating through glocks here.

Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Bob Peterson

GFS2: Don't add all glocks to the lru

2015-06-18T17:17:59+00:00

The glocks used for resource groups often come and go hundreds of
thousands of times per second. Adding them to the lru list just
adds unnecessary contention for the lru_lock spin_lock, especially
considering we're almost certainly going to re-use the glock and
take it back off the lru microseconds later. We never want the
glock shrinker to cull them anyway. This patch adds a new bit in
the glops that determines which glock types get put onto the lru
list and which ones don't.

Signed-off-by: Bob Peterson 
Acked-by: Steven Whitehouse

gfs2: incorrect check for debugfs returns

2015-03-30T14:13:29+00:00

debugfs_create_dir and debugfs_create_file may return -ENODEV when debugfs
is not configured, so the return value should be checked against ERROR_VALUE
as well, otherwise the later dereference of the dentry pointer would crash
the kernel.

Signed-off-by: Chengyu Song 
Signed-off-by: Bob Peterson 
Acked-by: Steven Whitehouse