2005-04-16 15:20:36 -07:00
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2008-06-05 22:46:27 -07:00
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2005-04-16 15:20:36 -07:00
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2015-05-22 17:13:32 -04:00
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2005-04-16 15:20:36 -07:00
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2012-03-23 15:01:50 -07:00
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2005-04-16 15:20:36 -07:00
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2011-09-16 02:31:11 -04:00
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2009-02-25 10:44:19 +01:00
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2006-08-29 19:06:09 +01:00
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2005-04-16 15:20:36 -07:00
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2007-05-08 00:24:32 -07:00
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2011-09-16 02:31:11 -04:00
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2015-09-08 14:58:40 -07:00
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2016-05-07 11:40:28 -07:00
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2016-10-31 11:59:25 -06:00
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2016-10-11 13:51:11 -07:00
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2016-12-24 11:46:01 -08:00
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2006-09-30 20:52:18 +02:00
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2005-04-16 15:20:36 -07:00
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2008-02-18 13:48:31 +01:00
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2005-04-16 15:20:36 -07:00
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2015-06-26 13:58:32 +02:00
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2005-04-16 15:20:36 -07:00
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2016-05-10 10:23:52 -06:00
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2015-11-09 09:23:40 -07:00
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2015-01-14 10:42:33 +01:00
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2015-11-09 09:23:40 -07:00
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2015-01-14 10:42:33 +01:00
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2015-11-09 09:23:40 -07:00
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2015-01-14 10:42:33 +01:00
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2007-05-06 14:49:55 -07:00
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2011-09-16 02:31:11 -04:00
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2005-04-16 15:20:36 -07:00
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2011-09-16 02:31:11 -04:00
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2016-01-22 15:10:40 -08:00
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2007-05-06 14:49:55 -07:00
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2011-09-16 02:31:11 -04:00
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2007-05-06 14:49:55 -07:00
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2011-09-16 02:31:11 -04:00
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2005-04-16 15:20:36 -07:00
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2011-09-16 02:31:11 -04:00
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2011-09-21 11:56:28 -04:00
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2011-09-16 02:31:11 -04:00
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2005-04-16 15:20:36 -07:00
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2007-05-08 00:24:32 -07:00
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2005-04-16 15:20:36 -07:00
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2009-05-22 17:17:49 -04:00
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2005-04-16 15:20:36 -07:00
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2006-03-24 03:18:05 -08:00
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2005-04-16 15:20:36 -07:00
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2009-05-22 17:17:49 -04:00
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2005-04-16 15:20:36 -07:00
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2015-10-28 07:48:19 +09:00
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2016-11-17 17:50:47 +01:00
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2016-10-31 11:59:25 -06:00
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2016-11-16 23:11:42 -07:00
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2016-10-31 11:59:25 -06:00
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2016-11-22 08:12:39 -07:00
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2016-10-31 11:59:25 -06:00
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2016-11-16 23:11:42 -07:00
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2016-11-22 08:57:21 -07:00
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2016-10-31 11:59:25 -06:00
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2016-11-22 15:38:49 +09:00
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2016-10-31 11:59:25 -06:00
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2016-11-17 17:50:47 +01:00
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2016-10-31 11:59:25 -06:00
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2016-11-17 17:50:47 +01:00
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2016-10-31 11:59:25 -06:00
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2016-11-16 23:11:42 -07:00
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2016-10-31 11:59:25 -06:00
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2016-11-16 23:14:22 -07:00
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2007-02-03 01:14:01 -08:00
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2016-11-16 23:14:22 -07:00
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2007-02-03 01:14:01 -08:00
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2015-10-28 07:48:19 +09:00
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2016-11-16 23:14:22 -07:00
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2016-12-22 19:20:45 +01:00
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2016-11-16 23:14:22 -07:00
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2016-11-22 08:12:39 -07:00
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2016-11-16 23:14:22 -07:00
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2016-12-22 19:20:45 +01:00
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2016-11-16 23:14:22 -07:00
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2016-11-22 15:38:49 +09:00
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2016-11-16 23:14:22 -07:00
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2016-12-22 19:20:45 +01:00
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2016-11-16 23:14:22 -07:00
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2016-12-13 19:07:55 -08:00
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2016-11-16 23:14:22 -07:00
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2016-10-31 11:59:25 -06:00
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2007-02-03 01:14:01 -08:00
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2016-11-16 23:11:42 -07:00
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2016-10-31 11:59:25 -06:00
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2016-11-16 23:11:42 -07:00
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2016-10-31 11:59:25 -06:00
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2016-11-16 23:14:22 -07:00
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2007-02-03 01:14:01 -08:00
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2016-11-16 23:14:22 -07:00
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2007-02-03 01:14:01 -08:00
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2009-04-27 16:43:51 +02:00
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2009-02-25 10:44:19 +01:00
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2009-04-27 16:43:51 +02:00
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2009-02-25 10:44:19 +01:00
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2009-04-27 16:43:53 +02:00
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2009-02-25 10:44:19 +01:00
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2009-04-01 07:07:16 -04:00
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2009-02-25 10:44:19 +01:00
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2009-08-03 23:28:35 +02:00
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2009-02-25 10:44:19 +01:00
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2016-08-23 18:55:31 +03:00
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2009-08-03 23:28:35 +02:00
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fs: add freeze_super/thaw_super fs hooks
Currently, freezing a filesystem involves calling freeze_super, which locks
sb->s_umount and then calls the fs-specific freeze_fs hook. This makes it
hard for gfs2 (and potentially other cluster filesystems) to use the vfs
freezing code to do freezes on all the cluster nodes.
In order to communicate that a freeze has been requested, and to make sure
that only one node is trying to freeze at a time, gfs2 uses a glock
(sd_freeze_gl). The problem is that there is no hook for gfs2 to acquire
this lock before calling freeze_super. This means that two nodes can
attempt to freeze the filesystem by both calling freeze_super, acquiring
the sb->s_umount lock, and then attempting to grab the cluster glock
sd_freeze_gl. Only one will succeed, and the other will be stuck in
freeze_super, making it impossible to finish freezing the node.
To solve this problem, this patch adds the freeze_super and thaw_super
hooks. If a filesystem implements these hooks, they are called instead of
the vfs freeze_super and thaw_super functions. This means that every
filesystem that implements these hooks must call the vfs freeze_super and
thaw_super functions itself within the hook function to make use of the vfs
freezing code.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-11-13 20:42:03 -06:00
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2010-03-23 10:34:56 -04:00
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2009-02-25 10:44:19 +01:00
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2010-03-23 10:34:56 -04:00
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2009-02-25 10:44:19 +01:00
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2010-03-23 10:34:56 -04:00
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2009-08-03 23:28:35 +02:00
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2009-02-25 10:44:19 +01:00
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2009-08-03 23:28:06 +02:00
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2009-02-25 10:44:19 +01:00
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2009-08-03 23:28:35 +02:00
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2009-02-25 10:44:19 +01:00
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2009-08-03 23:28:35 +02:00
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2010-03-23 10:34:56 -04:00
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2009-08-03 23:28:35 +02:00
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2010-03-23 10:34:56 -04:00
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2009-08-03 23:28:35 +02:00
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2010-03-23 10:34:56 -04:00
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2009-08-03 23:28:35 +02:00
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|
fs: add freeze_super/thaw_super fs hooks
Currently, freezing a filesystem involves calling freeze_super, which locks
sb->s_umount and then calls the fs-specific freeze_fs hook. This makes it
hard for gfs2 (and potentially other cluster filesystems) to use the vfs
freezing code to do freezes on all the cluster nodes.
In order to communicate that a freeze has been requested, and to make sure
that only one node is trying to freeze at a time, gfs2 uses a glock
(sd_freeze_gl). The problem is that there is no hook for gfs2 to acquire
this lock before calling freeze_super. This means that two nodes can
attempt to freeze the filesystem by both calling freeze_super, acquiring
the sb->s_umount lock, and then attempting to grab the cluster glock
sd_freeze_gl. Only one will succeed, and the other will be stuck in
freeze_super, making it impossible to finish freezing the node.
To solve this problem, this patch adds the freeze_super and thaw_super
hooks. If a filesystem implements these hooks, they are called instead of
the vfs freeze_super and thaw_super functions. This means that every
filesystem that implements these hooks must call the vfs freeze_super and
thaw_super functions itself within the hook function to make use of the vfs
freezing code.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-11-13 20:42:03 -06:00
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2016-10-04 10:53:40 +02:00
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2010-03-23 10:34:56 -04:00
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2009-02-25 10:44:19 +01:00
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2016-10-04 10:53:40 +02:00
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2009-02-25 10:44:19 +01:00
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2005-04-16 15:20:36 -07:00
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2014-10-09 15:26:58 -07:00
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2007-10-16 01:25:04 -07:00
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2005-04-16 15:20:36 -07:00
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2010-06-04 11:29:58 +02:00
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2005-04-16 15:20:36 -07:00
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2007-10-16 01:25:04 -07:00
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2005-04-16 15:20:36 -07:00
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2007-10-16 01:25:04 -07:00
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mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 15:29:47 +03:00
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2007-10-16 01:25:04 -07:00
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2005-04-16 15:20:36 -07:00
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2013-01-23 17:07:38 -05:00
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2005-04-16 15:20:36 -07:00
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2012-12-17 15:59:39 -08:00
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2005-04-16 15:20:36 -07:00
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2015-10-28 07:48:19 +09:00
|
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2005-04-16 15:20:36 -07:00
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2016-01-22 15:40:57 -05:00
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2013-06-23 21:34:45 +04:00
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2016-01-22 15:40:57 -05:00
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2005-04-16 15:20:36 -07:00
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2011-07-16 20:44:56 -04:00
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2005-04-16 15:20:36 -07:00
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2015-10-28 07:48:19 +09:00
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|
fs/block_dev.c: fix performance regression in O_DIRECT|O_SYNC writes to block devices
We are seeing a large regression in database performance on recent
kernels. The database opens a block device with O_DIRECT|O_SYNC and a
number of threads write to different regions of the file at the same time.
A simple test case is below. I haven't defined DEVICE since getting it
wrong will destroy your data :) On an 3 disk LVM with a 64k chunk size we
see about 17MB/sec and only a few threads in IO wait:
procs -----io---- -system-- -----cpu------
r b bi bo in cs us sy id wa st
0 3 0 16170 656 2259 0 0 86 14 0
0 2 0 16704 695 2408 0 0 92 8 0
0 2 0 17308 744 2653 0 0 86 14 0
0 2 0 17933 759 2777 0 0 89 10 0
Most threads are blocking in vfs_fsync_range, which has:
mutex_lock(&mapping->host->i_mutex);
err = fop->fsync(file, dentry, datasync);
if (!ret)
ret = err;
mutex_unlock(&mapping->host->i_mutex);
commit 148f948ba877f4d3cdef036b1ff6d9f68986706a (vfs: Introduce new
helpers for syncing after writing to O_SYNC file or IS_SYNC inode) offers
some explanation of what is going on:
Use these new helpers for syncing from generic VFS functions. This makes
O_SYNC writes to block devices acquire i_mutex for syncing. If we really
care about this, we can make block_fsync() drop the i_mutex and reacquire
it before it returns.
Thanks Jan for such a good commit message! As well as dropping i_mutex,
Christoph suggests we should remove the call to sync_blockdev():
> sync_blockdev is an overcomplicated alias for filemap_write_and_wait on
> the block device inode, which is exactly what we did just before calling
> into ->fsync
The patch below incorporates both suggestions. With it the testcase improves
from 17MB/s to 68M/sec:
procs -----io---- -system-- -----cpu------
r b bi bo in cs us sy id wa st
0 7 0 65536 1000 3878 0 0 70 30 0
0 34 0 69632 1016 3921 0 1 46 53 0
0 57 0 69632 1000 3921 0 0 55 45 0
0 53 0 69640 754 4111 0 0 81 19 0
Testcase:
#define _GNU_SOURCE
#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define NR_THREADS 64
#define BUFSIZE (64 * 1024)
#define DEVICE "/dev/mapper/XXXXXX"
#define ALIGN(VAL, SIZE) (((VAL)+(SIZE)-1) & ~((SIZE)-1))
static int fd;
static void *doit(void *arg)
{
unsigned long offset = (long)arg;
char *b, *buf;
b = malloc(BUFSIZE + 1024);
buf = (char *)ALIGN((unsigned long)b, 1024);
memset(buf, 0, BUFSIZE);
while (1)
pwrite(fd, buf, BUFSIZE, offset);
}
int main(int argc, char *argv[])
{
int flags = O_RDWR|O_DIRECT;
int i;
unsigned long offset = 0;
if (argc > 1 && !strcmp(argv[1], "O_SYNC"))
flags |= O_SYNC;
fd = open(DEVICE, flags);
if (fd == -1) {
perror("open");
exit(1);
}
for (i = 0; i < NR_THREADS-1; i++) {
pthread_t tid;
pthread_create(&tid, NULL, doit, (void *)offset);
offset += BUFSIZE;
}
doit((void *)offset);
return 0;
}
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-23 13:18:06 -04:00
|
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2009-10-29 14:14:04 +01:00
|
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2011-08-02 02:17:48 +02:00
|
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2009-10-29 14:14:04 +01:00
|
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|
|
fs/block_dev.c: fix performance regression in O_DIRECT|O_SYNC writes to block devices
We are seeing a large regression in database performance on recent
kernels. The database opens a block device with O_DIRECT|O_SYNC and a
number of threads write to different regions of the file at the same time.
A simple test case is below. I haven't defined DEVICE since getting it
wrong will destroy your data :) On an 3 disk LVM with a 64k chunk size we
see about 17MB/sec and only a few threads in IO wait:
procs -----io---- -system-- -----cpu------
r b bi bo in cs us sy id wa st
0 3 0 16170 656 2259 0 0 86 14 0
0 2 0 16704 695 2408 0 0 92 8 0
0 2 0 17308 744 2653 0 0 86 14 0
0 2 0 17933 759 2777 0 0 89 10 0
Most threads are blocking in vfs_fsync_range, which has:
mutex_lock(&mapping->host->i_mutex);
err = fop->fsync(file, dentry, datasync);
if (!ret)
ret = err;
mutex_unlock(&mapping->host->i_mutex);
commit 148f948ba877f4d3cdef036b1ff6d9f68986706a (vfs: Introduce new
helpers for syncing after writing to O_SYNC file or IS_SYNC inode) offers
some explanation of what is going on:
Use these new helpers for syncing from generic VFS functions. This makes
O_SYNC writes to block devices acquire i_mutex for syncing. If we really
care about this, we can make block_fsync() drop the i_mutex and reacquire
it before it returns.
Thanks Jan for such a good commit message! As well as dropping i_mutex,
Christoph suggests we should remove the call to sync_blockdev():
> sync_blockdev is an overcomplicated alias for filemap_write_and_wait on
> the block device inode, which is exactly what we did just before calling
> into ->fsync
The patch below incorporates both suggestions. With it the testcase improves
from 17MB/s to 68M/sec:
procs -----io---- -system-- -----cpu------
r b bi bo in cs us sy id wa st
0 7 0 65536 1000 3878 0 0 70 30 0
0 34 0 69632 1016 3921 0 1 46 53 0
0 57 0 69632 1000 3921 0 0 55 45 0
0 53 0 69640 754 4111 0 0 81 19 0
Testcase:
#define _GNU_SOURCE
#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define NR_THREADS 64
#define BUFSIZE (64 * 1024)
#define DEVICE "/dev/mapper/XXXXXX"
#define ALIGN(VAL, SIZE) (((VAL)+(SIZE)-1) & ~((SIZE)-1))
static int fd;
static void *doit(void *arg)
{
unsigned long offset = (long)arg;
char *b, *buf;
b = malloc(BUFSIZE + 1024);
buf = (char *)ALIGN((unsigned long)b, 1024);
memset(buf, 0, BUFSIZE);
while (1)
pwrite(fd, buf, BUFSIZE, offset);
}
int main(int argc, char *argv[])
{
int flags = O_RDWR|O_DIRECT;
int i;
unsigned long offset = 0;
if (argc > 1 && !strcmp(argv[1], "O_SYNC"))
flags |= O_SYNC;
fd = open(DEVICE, flags);
if (fd == -1) {
perror("open");
exit(1);
}
for (i = 0; i < NR_THREADS-1; i++) {
pthread_t tid;
pthread_create(&tid, NULL, doit, (void *)offset);
offset += BUFSIZE;
}
doit((void *)offset);
return 0;
}
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-23 13:18:06 -04:00
|
|
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|
2010-09-16 20:51:46 +02:00
|
|
|
|
2009-10-29 14:14:04 +01:00
|
|
|
|
|
|
|
|
|
fs/block_dev.c: fix performance regression in O_DIRECT|O_SYNC writes to block devices
We are seeing a large regression in database performance on recent
kernels. The database opens a block device with O_DIRECT|O_SYNC and a
number of threads write to different regions of the file at the same time.
A simple test case is below. I haven't defined DEVICE since getting it
wrong will destroy your data :) On an 3 disk LVM with a 64k chunk size we
see about 17MB/sec and only a few threads in IO wait:
procs -----io---- -system-- -----cpu------
r b bi bo in cs us sy id wa st
0 3 0 16170 656 2259 0 0 86 14 0
0 2 0 16704 695 2408 0 0 92 8 0
0 2 0 17308 744 2653 0 0 86 14 0
0 2 0 17933 759 2777 0 0 89 10 0
Most threads are blocking in vfs_fsync_range, which has:
mutex_lock(&mapping->host->i_mutex);
err = fop->fsync(file, dentry, datasync);
if (!ret)
ret = err;
mutex_unlock(&mapping->host->i_mutex);
commit 148f948ba877f4d3cdef036b1ff6d9f68986706a (vfs: Introduce new
helpers for syncing after writing to O_SYNC file or IS_SYNC inode) offers
some explanation of what is going on:
Use these new helpers for syncing from generic VFS functions. This makes
O_SYNC writes to block devices acquire i_mutex for syncing. If we really
care about this, we can make block_fsync() drop the i_mutex and reacquire
it before it returns.
Thanks Jan for such a good commit message! As well as dropping i_mutex,
Christoph suggests we should remove the call to sync_blockdev():
> sync_blockdev is an overcomplicated alias for filemap_write_and_wait on
> the block device inode, which is exactly what we did just before calling
> into ->fsync
The patch below incorporates both suggestions. With it the testcase improves
from 17MB/s to 68M/sec:
procs -----io---- -system-- -----cpu------
r b bi bo in cs us sy id wa st
0 7 0 65536 1000 3878 0 0 70 30 0
0 34 0 69632 1016 3921 0 1 46 53 0
0 57 0 69632 1000 3921 0 0 55 45 0
0 53 0 69640 754 4111 0 0 81 19 0
Testcase:
#define _GNU_SOURCE
#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define NR_THREADS 64
#define BUFSIZE (64 * 1024)
#define DEVICE "/dev/mapper/XXXXXX"
#define ALIGN(VAL, SIZE) (((VAL)+(SIZE)-1) & ~((SIZE)-1))
static int fd;
static void *doit(void *arg)
{
unsigned long offset = (long)arg;
char *b, *buf;
b = malloc(BUFSIZE + 1024);
buf = (char *)ALIGN((unsigned long)b, 1024);
memset(buf, 0, BUFSIZE);
while (1)
pwrite(fd, buf, BUFSIZE, offset);
}
int main(int argc, char *argv[])
{
int flags = O_RDWR|O_DIRECT;
int i;
unsigned long offset = 0;
if (argc > 1 && !strcmp(argv[1], "O_SYNC"))
flags |= O_SYNC;
fd = open(DEVICE, flags);
if (fd == -1) {
perror("open");
exit(1);
}
for (i = 0; i < NR_THREADS-1; i++) {
pthread_t tid;
pthread_create(&tid, NULL, doit, (void *)offset);
offset += BUFSIZE;
}
doit((void *)offset);
return 0;
}
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-23 13:18:06 -04:00
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2009-10-29 14:14:04 +01:00
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2005-04-16 15:20:36 -07:00
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2010-04-06 14:35:00 -07:00
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2005-04-16 15:20:36 -07:00
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2014-06-04 16:07:46 -07:00
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2015-11-19 13:29:28 -08:00
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2015-05-12 13:48:53 -04:00
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2015-11-19 13:29:28 -08:00
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2015-11-26 09:13:05 +01:00
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2015-11-19 13:29:28 -08:00
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2016-08-05 08:11:04 -06:00
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2015-11-19 13:29:28 -08:00
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2014-06-04 16:07:46 -07:00
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2015-11-19 13:29:28 -08:00
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2015-05-12 13:48:53 -04:00
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2014-06-04 16:07:46 -07:00
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2015-11-26 09:13:05 +01:00
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2015-11-19 13:29:28 -08:00
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2014-06-04 16:07:46 -07:00
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2016-08-05 08:11:04 -06:00
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2014-06-04 16:07:46 -07:00
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2015-11-19 13:29:28 -08:00
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2014-06-04 16:07:46 -07:00
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2015-01-07 18:05:34 +02:00
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2016-01-15 16:55:59 -08:00
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2015-01-07 18:05:34 +02:00
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2016-01-15 16:55:59 -08:00
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2015-01-07 18:05:34 +02:00
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2016-01-15 16:55:59 -08:00
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2015-01-07 18:05:34 +02:00
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2015-07-03 10:40:43 -04:00
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2015-01-07 18:05:34 +02:00
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2016-06-23 17:05:50 -04:00
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2015-01-07 18:05:34 +02:00
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2016-02-24 14:02:11 -08:00
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2015-01-07 18:05:34 +02:00
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2016-01-15 16:55:56 -08:00
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2015-01-07 18:05:34 +02:00
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2016-05-10 10:23:53 -06:00
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2016-05-10 10:23:57 -06:00
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2005-04-16 15:20:36 -07:00
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2006-12-06 20:33:20 -08:00
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2005-04-16 15:20:36 -07:00
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2006-12-06 20:33:17 -08:00
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2005-04-16 15:20:36 -07:00
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2011-01-07 17:49:49 +11:00
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2005-04-16 15:20:36 -07:00
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2011-01-07 17:49:49 +11:00
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2005-04-16 15:20:36 -07:00
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2011-01-07 17:49:49 +11:00
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2008-07-25 19:45:34 -07:00
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2005-04-16 15:20:36 -07:00
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2007-05-16 22:10:57 -07:00
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2011-01-14 18:43:57 +01:00
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2007-05-16 22:10:57 -07:00
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2009-01-09 16:40:59 -08:00
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2005-04-16 15:20:36 -07:00
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2010-06-07 14:34:48 -04:00
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2005-04-16 15:20:36 -07:00
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2014-04-03 14:47:49 -07:00
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2010-06-07 14:34:48 -04:00
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2012-05-03 14:48:02 +02:00
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2005-04-16 15:20:36 -07:00
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2007-02-12 00:55:41 -08:00
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2005-04-16 15:20:36 -07:00
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2010-06-07 14:34:48 -04:00
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2005-04-16 15:20:36 -07:00
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2010-07-25 23:47:46 +04:00
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2005-04-16 15:20:36 -07:00
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2016-02-22 15:27:40 -07:00
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2016-08-22 12:47:43 +02:00
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2016-02-22 15:27:40 -07:00
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2005-04-16 15:20:36 -07:00
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2010-07-25 23:47:46 +04:00
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2005-04-16 15:20:36 -07:00
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2015-05-22 17:13:33 -04:00
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2005-04-16 15:20:36 -07:00
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2012-01-10 02:43:59 +03:00
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2008-12-01 14:34:56 -08:00
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2005-04-16 15:20:36 -07:00
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2006-03-24 03:16:06 -08:00
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2016-01-14 15:18:21 -08:00
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2007-07-20 10:11:58 +09:00
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2005-04-16 15:20:36 -07:00
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2012-01-10 02:43:59 +03:00
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2005-04-16 15:20:36 -07:00
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2008-12-01 14:34:56 -08:00
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2005-04-16 15:20:36 -07:00
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2011-06-30 11:01:45 +10:00
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2005-04-16 15:20:36 -07:00
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2009-07-29 21:07:55 +02:00
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2010-10-23 11:11:40 -04:00
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2009-07-29 21:07:55 +02:00
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2013-04-01 09:47:56 -07:00
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2009-07-29 21:07:55 +02:00
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2005-04-16 15:20:36 -07:00
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2007-07-15 23:40:23 -07:00
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2005-04-16 15:20:36 -07:00
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2007-07-15 23:40:23 -07:00
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2005-04-16 15:20:36 -07:00
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2006-06-22 14:47:21 -07:00
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2005-04-16 15:20:36 -07:00
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2006-06-22 14:47:21 -07:00
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2015-11-20 22:18:43 +01:00
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2005-04-16 15:20:36 -07:00
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2006-06-22 14:47:21 -07:00
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2005-04-16 15:20:36 -07:00
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2006-06-22 14:47:21 -07:00
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2010-10-23 11:11:40 -04:00
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2006-06-22 14:47:21 -07:00
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2015-11-20 22:18:43 +01:00
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2006-06-22 14:47:21 -07:00
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2005-04-16 15:20:36 -07:00
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2006-06-22 14:47:21 -07:00
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2005-04-16 15:20:36 -07:00
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2013-04-30 15:26:47 -07:00
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2016-07-19 13:16:52 -04:00
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2005-04-16 15:20:36 -07:00
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2006-06-22 14:47:21 -07:00
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2015-11-20 22:18:43 +01:00
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2005-04-16 15:20:36 -07:00
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2010-04-07 18:52:29 +09:00
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2011-03-30 22:57:33 -03:00
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2010-04-07 18:52:29 +09:00
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2005-04-16 15:20:36 -07:00
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2010-04-07 18:52:29 +09:00
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2005-04-16 15:20:36 -07:00
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2010-04-07 18:52:29 +09:00
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block_dev: don't test bdev->bd_contains when it is not stable
bdev->bd_contains is not stable before calling __blkdev_get().
When __blkdev_get() is called on a parition with ->bd_openers == 0
it sets
bdev->bd_contains = bdev;
which is not correct for a partition.
After a call to __blkdev_get() succeeds, ->bd_openers will be > 0
and then ->bd_contains is stable.
When FMODE_EXCL is used, blkdev_get() calls
bd_start_claiming() -> bd_prepare_to_claim() -> bd_may_claim()
This call happens before __blkdev_get() is called, so ->bd_contains
is not stable. So bd_may_claim() cannot safely use ->bd_contains.
It currently tries to use it, and this can lead to a BUG_ON().
This happens when a whole device is already open with a bd_holder (in
use by dm in my particular example) and two threads race to open a
partition of that device for the first time, one opening with O_EXCL and
one without.
The thread that doesn't use O_EXCL gets through blkdev_get() to
__blkdev_get(), gains the ->bd_mutex, and sets bdev->bd_contains = bdev;
Immediately thereafter the other thread, using FMODE_EXCL, calls
bd_start_claiming() from blkdev_get(). This should fail because the
whole device has a holder, but because bdev->bd_contains == bdev
bd_may_claim() incorrectly reports success.
This thread continues and blocks on bd_mutex.
The first thread then sets bdev->bd_contains correctly and drops the mutex.
The thread using FMODE_EXCL then continues and when it calls bd_may_claim()
again in:
BUG_ON(!bd_may_claim(bdev, whole, holder));
The BUG_ON fires.
Fix this by removing the dependency on ->bd_contains in
bd_may_claim(). As bd_may_claim() has direct access to the whole
device, it can simply test if the target bdev is the whole device.
Fixes: 6b4517a7913a ("block: implement bd_claiming and claiming block")
Cc: stable@vger.kernel.org (v2.6.35+)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-12 08:21:51 -07:00
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2010-04-07 18:52:29 +09:00
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2005-04-16 15:20:36 -07:00
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block: make blkdev_get/put() handle exclusive access
Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.
* blkdev_get/put() are the primary open and close functions.
* bd_claim/release() deal with exclusive open.
* open/close_bdev_exclusive() are combination of open and claim and
the other way around, respectively.
* bd_link/unlink_disk_holder() to create and remove holder/slave
symlinks.
* open_by_devnum() wraps bdget() + blkdev_get().
The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access. Reorganize the interface such that,
* blkdev_get() is extended to include exclusive access management.
@holder argument is added and, if is @FMODE_EXCL specified, it will
gain exclusive access atomically w.r.t. other exclusive accesses.
* blkdev_put() is similarly extended. It now takes @mode argument and
if @FMODE_EXCL is set, it releases an exclusive access. Also, when
the last exclusive claim is released, the holder/slave symlinks are
removed automatically.
* bd_claim/release() and close_bdev_exclusive() are no longer
necessary and either made static or removed.
* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
is no longer necessary and removed.
* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
and blkdev_get(). It also has an unexpected extra bdev_read_only()
test which probably should be moved into blkdev_get().
* open_by_devnum() is modified to take @holder argument and pass it to
blkdev_get().
Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should). This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.
open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features. Well, let's leave them for another day.
Most conversions are straight-forward. drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:17 +01:00
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2010-04-07 18:52:29 +09:00
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2005-04-16 15:20:36 -07:00
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2010-04-07 18:52:29 +09:00
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2010-04-07 18:53:59 +09:00
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2010-08-04 17:59:39 +02:00
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2010-04-07 18:53:59 +09:00
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2010-05-26 01:51:19 +10:00
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2010-04-07 18:53:59 +09:00
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2011-06-13 12:45:48 +02:00
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2010-05-26 01:50:21 +10:00
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2010-04-07 18:53:59 +09:00
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2006-03-27 01:17:57 -08:00
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2011-01-14 18:43:57 +01:00
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[PATCH] blockdev.c: check driver layer errors
Check driver layer errors.
Fix from: "Jun'ichi Nomura" <j-nomura@ce.jp.nec.com>
In blockdevc-check-errors.patch, add_bd_holder() is modified to return error
values when some of its operation failed. Among them, it returns -EEXIST when
a given bd_holder object already exists in the list.
However, in this case, the function completed its work successfully and need
no action by its caller other than freeing unused bd_holder object. So I
think it's better to return success after freeing by itself.
Otherwise, bd_claim-ing with same claim pointer will fail.
Typically, lvresize will fails with following message:
device-mapper: reload ioctl failed: Invalid argument
and you'll see messages like below in kernel log:
device-mapper: table: 254:13: linear: dm-linear: Device lookup failed
device-mapper: ioctl: error adding target to table
Similarly, it should not add bd_holder to the list if either one of symlinking
fails. I don't have a test case for this to happen but it should cause
dereference of freed pointer.
If a matching bd_holder is found in bd_holder_list, add_bd_holder() completes
its job by just incrementing the reference count. In this case, it should be
considered as success but it used to return 'fail' to let the caller free
temporary bd_holder. Fixed it to return success and free given object by
itself.
Also, if either one of symlinking fails, the bd_holder should not be added to
the list so that it can be discarded later. Otherwise, the caller will free
bd_holder which is in the list.
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 01:58:56 -07:00
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2006-03-27 01:17:57 -08:00
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|
[PATCH] blockdev.c: check driver layer errors
Check driver layer errors.
Fix from: "Jun'ichi Nomura" <j-nomura@ce.jp.nec.com>
In blockdevc-check-errors.patch, add_bd_holder() is modified to return error
values when some of its operation failed. Among them, it returns -EEXIST when
a given bd_holder object already exists in the list.
However, in this case, the function completed its work successfully and need
no action by its caller other than freeing unused bd_holder object. So I
think it's better to return success after freeing by itself.
Otherwise, bd_claim-ing with same claim pointer will fail.
Typically, lvresize will fails with following message:
device-mapper: reload ioctl failed: Invalid argument
and you'll see messages like below in kernel log:
device-mapper: table: 254:13: linear: dm-linear: Device lookup failed
device-mapper: ioctl: error adding target to table
Similarly, it should not add bd_holder to the list if either one of symlinking
fails. I don't have a test case for this to happen but it should cause
dereference of freed pointer.
If a matching bd_holder is found in bd_holder_list, add_bd_holder() completes
its job by just incrementing the reference count. In this case, it should be
considered as success but it used to return 'fail' to let the caller free
temporary bd_holder. Fixed it to return success and free given object by
itself.
Also, if either one of symlinking fails, the bd_holder should not be added to
the list so that it can be discarded later. Otherwise, the caller will free
bd_holder which is in the list.
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 01:58:56 -07:00
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2006-03-27 01:17:57 -08:00
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2006-10-30 16:23:56 -05:00
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2010-11-13 11:55:17 +01:00
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2006-10-30 16:23:56 -05:00
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2011-01-14 18:43:57 +01:00
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2010-11-13 11:55:17 +01:00
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2006-03-27 01:17:57 -08:00
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2010-11-13 11:55:17 +01:00
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2006-03-27 01:17:57 -08:00
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2010-11-13 11:55:17 +01:00
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2006-03-27 01:17:57 -08:00
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2010-11-13 11:55:17 +01:00
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2006-03-27 01:17:57 -08:00
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2010-11-13 11:55:17 +01:00
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2006-03-27 01:17:57 -08:00
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2010-11-13 11:55:17 +01:00
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2006-03-27 01:17:57 -08:00
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2010-11-13 11:55:17 +01:00
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2006-03-27 01:17:57 -08:00
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2010-11-13 11:55:17 +01:00
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2006-03-27 01:17:57 -08:00
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2011-01-14 18:43:57 +01:00
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2010-11-13 11:55:17 +01:00
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2006-03-27 01:17:57 -08:00
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2006-12-08 02:36:13 -08:00
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2006-10-30 16:23:56 -05:00
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2011-01-14 18:43:57 +01:00
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2007-07-15 23:41:25 -07:00
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2010-11-13 11:55:17 +01:00
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2007-07-15 23:41:25 -07:00
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2011-01-14 18:43:57 +01:00
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2010-11-13 11:55:17 +01:00
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2011-01-14 18:43:57 +01:00
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2006-03-27 01:17:57 -08:00
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2011-01-14 18:43:57 +01:00
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2010-11-13 11:55:17 +01:00
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2006-03-27 01:17:57 -08:00
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2011-01-14 18:43:57 +01:00
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2011-02-24 09:56:32 +01:00
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2011-01-14 18:43:57 +01:00
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2010-11-13 11:55:17 +01:00
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2006-03-27 01:18:00 -08:00
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2010-11-13 11:55:17 +01:00
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2006-03-27 01:17:57 -08:00
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2010-11-13 11:55:17 +01:00
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2006-03-27 01:17:57 -08:00
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2011-01-14 18:43:57 +01:00
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2006-03-27 01:17:57 -08:00
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2011-01-14 18:43:57 +01:00
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2006-03-27 01:17:57 -08:00
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2011-01-14 18:43:57 +01:00
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2006-03-27 01:17:57 -08:00
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2011-01-14 18:43:57 +01:00
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2011-02-24 09:56:32 +01:00
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2011-01-14 18:43:57 +01:00
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2005-04-16 15:20:36 -07:00
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2011-01-14 18:43:57 +01:00
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2006-03-27 01:17:57 -08:00
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2005-04-16 15:20:36 -07:00
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2008-09-04 14:27:40 -06:00
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2011-02-26 10:54:00 -08:00
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2008-09-04 14:27:40 -06:00
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2011-02-24 17:25:47 +11:00
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2008-09-04 14:27:40 -06:00
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2011-02-24 17:25:47 +11:00
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2008-09-04 14:27:40 -06:00
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2015-04-13 16:31:34 +04:00
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2008-09-04 14:27:40 -06:00
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2011-08-23 20:01:04 +02:00
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2008-09-04 14:27:40 -06:00
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2008-09-04 14:27:25 -06:00
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2008-10-09 10:42:38 +02:00
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2008-09-04 14:27:25 -06:00
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2015-04-13 16:31:34 +04:00
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2008-09-04 14:27:25 -06:00
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2011-02-24 17:25:47 +11:00
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2008-09-04 14:27:25 -06:00
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2008-09-04 14:27:20 -06:00
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2008-10-09 10:42:38 +02:00
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2008-09-04 14:27:20 -06:00
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2008-09-04 14:27:25 -06:00
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2008-09-04 14:27:20 -06:00
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2015-10-21 13:19:49 -04:00
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2008-09-04 14:27:25 -06:00
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2013-02-21 16:42:01 -08:00
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2008-09-04 14:27:25 -06:00
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2008-09-04 14:27:20 -06:00
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2005-04-16 15:20:36 -07:00
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2009-09-21 17:01:13 -07:00
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implement in-kernel gendisk events handling
Currently, media presence polling for removeable block devices is done
from userland. There are several issues with this.
* Polling is done by periodically opening the device. For SCSI
devices, the command sequence generated by such action involves a
few different commands including TEST_UNIT_READY. This behavior,
while perfectly legal, is different from Windows which only issues
single command, GET_EVENT_STATUS_NOTIFICATION. Unfortunately, some
ATAPI devices lock up after being periodically queried such command
sequences.
* There is no reliable and unintrusive way for a userland program to
tell whether the target device is safe for media presence polling.
For example, polling for media presence during an on-going burning
session can make it fail. The polling program can avoid this by
opening the device with O_EXCL but then it risks making a valid
exclusive user of the device fail w/ -EBUSY.
* Userland polling is unnecessarily heavy and in-kernel implementation
is lighter and better coordinated (workqueue, timer slack).
This patch implements framework for in-kernel disk event handling,
which includes media presence polling.
* bdops->check_events() is added, which supercedes ->media_changed().
It should check whether there's any pending event and return if so.
Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and
DISK_EVENT_EJECT_REQUEST. ->check_events() is guaranteed not to be
called parallelly.
* gendisk->events and ->async_events are added. These should be
initialized by block driver before passing the device to add_disk().
The former contains the mask of all supported events and the latter
the mask of all events which the device can report without polling.
/sys/block/*/events[_async] export these to userland.
* Kernel parameter block.events_dfl_poll_msecs controls the system
polling interval (default is 0 which means disable) and
/sys/block/*/events_poll_msecs control polling intervals for
individual devices (default is -1 meaning use system setting). Note
that if a device can report all supported events asynchronously and
its polling interval isn't explicitly set, the device won't be
polled regardless of the system polling interval.
* If a device is opened exclusively with write access, event checking
is automatically disabled until all write exclusive accesses are
released.
* There are event 'clearing' events. For example, both of currently
defined events are cleared after the device has been successfully
opened. This information is passed to ->check_events() callback
using @clearing argument as a hint.
* Event checking is always performed from system_nrt_wq and timer
slack is set to 25% for polling.
* Nothing changes for drivers which implement ->media_changed() but
not ->check_events(). Going forward, all drivers will be converted
to ->check_events() and ->media_change() will be dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-08 20:57:37 +01:00
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2005-04-16 15:20:36 -07:00
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|
implement in-kernel gendisk events handling
Currently, media presence polling for removeable block devices is done
from userland. There are several issues with this.
* Polling is done by periodically opening the device. For SCSI
devices, the command sequence generated by such action involves a
few different commands including TEST_UNIT_READY. This behavior,
while perfectly legal, is different from Windows which only issues
single command, GET_EVENT_STATUS_NOTIFICATION. Unfortunately, some
ATAPI devices lock up after being periodically queried such command
sequences.
* There is no reliable and unintrusive way for a userland program to
tell whether the target device is safe for media presence polling.
For example, polling for media presence during an on-going burning
session can make it fail. The polling program can avoid this by
opening the device with O_EXCL but then it risks making a valid
exclusive user of the device fail w/ -EBUSY.
* Userland polling is unnecessarily heavy and in-kernel implementation
is lighter and better coordinated (workqueue, timer slack).
This patch implements framework for in-kernel disk event handling,
which includes media presence polling.
* bdops->check_events() is added, which supercedes ->media_changed().
It should check whether there's any pending event and return if so.
Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and
DISK_EVENT_EJECT_REQUEST. ->check_events() is guaranteed not to be
called parallelly.
* gendisk->events and ->async_events are added. These should be
initialized by block driver before passing the device to add_disk().
The former contains the mask of all supported events and the latter
the mask of all events which the device can report without polling.
/sys/block/*/events[_async] export these to userland.
* Kernel parameter block.events_dfl_poll_msecs controls the system
polling interval (default is 0 which means disable) and
/sys/block/*/events_poll_msecs control polling intervals for
individual devices (default is -1 meaning use system setting). Note
that if a device can report all supported events asynchronously and
its polling interval isn't explicitly set, the device won't be
polled regardless of the system polling interval.
* If a device is opened exclusively with write access, event checking
is automatically disabled until all write exclusive accesses are
released.
* There are event 'clearing' events. For example, both of currently
defined events are cleared after the device has been successfully
opened. This information is passed to ->check_events() callback
using @clearing argument as a hint.
* Event checking is always performed from system_nrt_wq and timer
slack is set to 25% for polling.
* Nothing changes for drivers which implement ->media_changed() but
not ->check_events(). Going forward, all drivers will be converted
to ->check_events() and ->media_change() will be dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-08 20:57:37 +01:00
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2005-04-16 15:20:36 -07:00
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2011-02-24 17:25:47 +11:00
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2005-04-16 15:20:36 -07:00
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2009-05-22 17:17:49 -04:00
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2005-04-16 15:20:36 -07:00
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2016-01-22 15:40:57 -05:00
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2013-02-21 15:16:42 -08:00
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2016-01-22 15:40:57 -05:00
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|
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 15:29:47 +03:00
|
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2005-04-16 15:20:36 -07:00
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2013-05-05 22:11:03 -04:00
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|
[PATCH] lockdep: simplify some aspects of bd_mutex nesting
When we open (actually blkdev_get) a partition we need to also open (get) the
whole device that holds the partition. The involves some limited recursion.
This patch tries to simplify some aspects of this.
As well as opening the whole device, we need to increment ->bd_part_count when
a partition is opened (this is used by rescan_partitions to avoid a rescan if
any partition is active, as that would be confusing).
The main change this patch makes is to move the inc/dec of bd_part_count into
blkdev_{get,put} for the whole rather than doing it in blkdev_{get,put} for
the partition.
More specifically, we introduce __blkdev_get and __blkdev_put which do exactly
what blkdev_{get,put} did, only with an extra "for_part" argument
(blkget_{get,put} then call the __ version with a '0' for the extra argument).
If for_part is 1, then the blkdev is being get(put) because a partition is
being opened(closed) for the first(last) time, and so bd_part_count should be
updated (on success). The particular advantage of pushing this function down
is that the bd_mutex lock (which is needed to update bd_part_count) is already
held at the lower level.
Note that this slightly changes the semantics of bd_part_count. Instead of
updating it whenever a partition is opened or released, it is now only updated
on the first open or last release. This is an adequate semantic as it is only
ever tested for "== 0".
Having introduced these functions we remove the current bd_part_count updates
from do_open (which is really the body of blkdev_get) and call
__blkdev_get(... 1). Similarly in blkget_put we remove the old bd_part_count
updates and call __blkget_put(..., 1). This call is moved to the end of
__blkdev_put to avoid nested locks of bd_mutex.
Finally the mutex_lock on whole->bd_mutex in do_open can be removed. It was
only really needed to protect bd_part_count, and that is now managed (and
protected) within the recursive call.
The observation that bd_part_count is central to the locking issues, and the
modifications to create __blkdev_put are from Peter Zijlstra.
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 02:36:16 -08:00
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2007-02-20 13:58:18 -08:00
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2007-10-08 13:24:05 -04:00
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2005-04-16 15:20:36 -07:00
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2011-10-19 14:31:07 +02:00
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2008-06-05 22:46:27 -07:00
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2008-09-03 09:01:09 +02:00
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2008-06-23 08:30:55 -04:00
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2007-10-08 13:24:05 -04:00
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2008-06-23 08:30:55 -04:00
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2007-10-08 13:24:05 -04:00
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2008-06-23 08:30:55 -04:00
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2010-08-10 18:02:55 -07:00
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2008-08-01 05:32:04 -04:00
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2008-06-05 22:46:27 -07:00
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|
md: make devices disappear when they are no longer needed.
Currently md devices, once created, never disappear until the module
is unloaded. This is essentially because the gendisk holds a
reference to the mddev, and the mddev holds a reference to the
gendisk, this a circular reference.
If we drop the reference from mddev to gendisk, then we need to ensure
that the mddev is destroyed when the gendisk is destroyed. However it
is not possible to hook into the gendisk destruction process to enable
this.
So we drop the reference from the gendisk to the mddev and destroy the
gendisk when the mddev gets destroyed. However this has a
complication.
Between the call
__blkdev_get->get_gendisk->kobj_lookup->md_probe
and the call
__blkdev_get->md_open
there is no obvious way to hold a reference on the mddev any more, so
unless something is done, it will disappear and gendisk will be
destroyed prematurely.
Also, once we decide to destroy the mddev, there will be an unlockable
moment before the gendisk is unlinked (blk_unregister_region) during
which a new reference to the gendisk can be created. We need to
ensure that this reference can not be used. i.e. the ->open must
fail.
So:
1/ in md_probe we set a flag in the mddev (hold_active) which
indicates that the array should be treated as active, even
though there are no references, and no appearance of activity.
This is cleared by md_release when the device is closed if it
is no longer needed.
This ensures that the gendisk will survive between md_probe and
md_open.
2/ In md_open we check if the mddev we expect to open matches
the gendisk that we did open.
If there is a mismatch we return -ERESTARTSYS and modify
__blkdev_get to retry from the top in that case.
In the -ERESTARTSYS sys case we make sure to wait until
the old gendisk (that we succeeded in opening) is really gone so
we loop at most once.
Some udev configurations will always open an md device when it first
appears. If we allow an md device that was just created by an open
to disappear on an immediate close, then this can race with such udev
configurations and result in an infinite loop the device being opened
and closed, then re-open due to the 'ADD' even from the first open,
and then close and so on.
So we make sure an md device, once created by an open, remains active
at least until some md 'ioctl' has been made on it. This means that
all normal usage of md devices will allow them to disappear promptly
when not needed, but the worst that an incorrect usage will do it
cause an inactive md device to be left in existence (it can easily be
removed).
As an array can be stopped by writing to a sysfs attribute
echo clear > /sys/block/mdXXX/md/array_state
we need to use scheduled work for deleting the gendisk and other
kobjects. This allows us to wait for any pending gendisk deletion to
complete by simply calling flush_scheduled_work().
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:10 +11:00
|
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|
2008-08-25 19:56:12 +09:00
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2008-11-05 10:21:06 +01:00
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2008-09-03 09:01:09 +02:00
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2008-08-25 19:56:12 +09:00
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2010-08-07 18:25:34 +02:00
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2011-10-19 14:31:07 +02:00
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2005-04-16 15:20:36 -07:00
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2011-03-09 19:54:27 +01:00
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2006-12-08 02:36:16 -08:00
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2005-04-16 15:20:36 -07:00
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2012-01-12 17:20:34 -08:00
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2005-04-16 15:20:36 -07:00
|
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2016-02-26 15:19:43 -08:00
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2008-09-03 09:01:09 +02:00
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2008-11-05 10:21:06 +01:00
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2011-04-21 20:54:45 +02:00
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2005-04-16 15:20:36 -07:00
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2007-10-08 13:24:05 -04:00
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md: make devices disappear when they are no longer needed.
Currently md devices, once created, never disappear until the module
is unloaded. This is essentially because the gendisk holds a
reference to the mddev, and the mddev holds a reference to the
gendisk, this a circular reference.
If we drop the reference from mddev to gendisk, then we need to ensure
that the mddev is destroyed when the gendisk is destroyed. However it
is not possible to hook into the gendisk destruction process to enable
this.
So we drop the reference from the gendisk to the mddev and destroy the
gendisk when the mddev gets destroyed. However this has a
complication.
Between the call
__blkdev_get->get_gendisk->kobj_lookup->md_probe
and the call
__blkdev_get->md_open
there is no obvious way to hold a reference on the mddev any more, so
unless something is done, it will disappear and gendisk will be
destroyed prematurely.
Also, once we decide to destroy the mddev, there will be an unlockable
moment before the gendisk is unlinked (blk_unregister_region) during
which a new reference to the gendisk can be created. We need to
ensure that this reference can not be used. i.e. the ->open must
fail.
So:
1/ in md_probe we set a flag in the mddev (hold_active) which
indicates that the array should be treated as active, even
though there are no references, and no appearance of activity.
This is cleared by md_release when the device is closed if it
is no longer needed.
This ensures that the gendisk will survive between md_probe and
md_open.
2/ In md_open we check if the mddev we expect to open matches
the gendisk that we did open.
If there is a mismatch we return -ERESTARTSYS and modify
__blkdev_get to retry from the top in that case.
In the -ERESTARTSYS sys case we make sure to wait until
the old gendisk (that we succeeded in opening) is really gone so
we loop at most once.
Some udev configurations will always open an md device when it first
appears. If we allow an md device that was just created by an open
to disappear on an immediate close, then this can race with such udev
configurations and result in an infinite loop the device being opened
and closed, then re-open due to the 'ADD' even from the first open,
and then close and so on.
So we make sure an md device, once created by an open, remains active
at least until some md 'ioctl' has been made on it. This means that
all normal usage of md devices will allow them to disappear promptly
when not needed, but the worst that an incorrect usage will do it
cause an inactive md device to be left in existence (it can easily be
removed).
As an array can be stopped by writing to a sysfs attribute
echo clear > /sys/block/mdXXX/md/array_state
we need to use scheduled work for deleting the gendisk and other
kobjects. This allows us to wait for any pending gendisk deletion to
complete by simply calling flush_scheduled_work().
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:10 +11:00
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2012-01-12 17:20:34 -08:00
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md: make devices disappear when they are no longer needed.
Currently md devices, once created, never disappear until the module
is unloaded. This is essentially because the gendisk holds a
reference to the mddev, and the mddev holds a reference to the
gendisk, this a circular reference.
If we drop the reference from mddev to gendisk, then we need to ensure
that the mddev is destroyed when the gendisk is destroyed. However it
is not possible to hook into the gendisk destruction process to enable
this.
So we drop the reference from the gendisk to the mddev and destroy the
gendisk when the mddev gets destroyed. However this has a
complication.
Between the call
__blkdev_get->get_gendisk->kobj_lookup->md_probe
and the call
__blkdev_get->md_open
there is no obvious way to hold a reference on the mddev any more, so
unless something is done, it will disappear and gendisk will be
destroyed prematurely.
Also, once we decide to destroy the mddev, there will be an unlockable
moment before the gendisk is unlinked (blk_unregister_region) during
which a new reference to the gendisk can be created. We need to
ensure that this reference can not be used. i.e. the ->open must
fail.
So:
1/ in md_probe we set a flag in the mddev (hold_active) which
indicates that the array should be treated as active, even
though there are no references, and no appearance of activity.
This is cleared by md_release when the device is closed if it
is no longer needed.
This ensures that the gendisk will survive between md_probe and
md_open.
2/ In md_open we check if the mddev we expect to open matches
the gendisk that we did open.
If there is a mismatch we return -ERESTARTSYS and modify
__blkdev_get to retry from the top in that case.
In the -ERESTARTSYS sys case we make sure to wait until
the old gendisk (that we succeeded in opening) is really gone so
we loop at most once.
Some udev configurations will always open an md device when it first
appears. If we allow an md device that was just created by an open
to disappear on an immediate close, then this can race with such udev
configurations and result in an infinite loop the device being opened
and closed, then re-open due to the 'ADD' even from the first open,
and then close and so on.
So we make sure an md device, once created by an open, remains active
at least until some md 'ioctl' has been made on it. This means that
all normal usage of md devices will allow them to disappear promptly
when not needed, but the worst that an incorrect usage will do it
cause an inactive md device to be left in existence (it can easily be
removed).
As an array can be stopped by writing to a sysfs attribute
echo clear > /sys/block/mdXXX/md/array_state
we need to use scheduled work for deleting the gendisk and other
kobjects. This allows us to wait for any pending gendisk deletion to
complete by simply calling flush_scheduled_work().
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:10 +11:00
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2011-03-09 19:54:27 +01:00
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2011-10-19 14:31:07 +02:00
|
|
|
|
md: make devices disappear when they are no longer needed.
Currently md devices, once created, never disappear until the module
is unloaded. This is essentially because the gendisk holds a
reference to the mddev, and the mddev holds a reference to the
gendisk, this a circular reference.
If we drop the reference from mddev to gendisk, then we need to ensure
that the mddev is destroyed when the gendisk is destroyed. However it
is not possible to hook into the gendisk destruction process to enable
this.
So we drop the reference from the gendisk to the mddev and destroy the
gendisk when the mddev gets destroyed. However this has a
complication.
Between the call
__blkdev_get->get_gendisk->kobj_lookup->md_probe
and the call
__blkdev_get->md_open
there is no obvious way to hold a reference on the mddev any more, so
unless something is done, it will disappear and gendisk will be
destroyed prematurely.
Also, once we decide to destroy the mddev, there will be an unlockable
moment before the gendisk is unlinked (blk_unregister_region) during
which a new reference to the gendisk can be created. We need to
ensure that this reference can not be used. i.e. the ->open must
fail.
So:
1/ in md_probe we set a flag in the mddev (hold_active) which
indicates that the array should be treated as active, even
though there are no references, and no appearance of activity.
This is cleared by md_release when the device is closed if it
is no longer needed.
This ensures that the gendisk will survive between md_probe and
md_open.
2/ In md_open we check if the mddev we expect to open matches
the gendisk that we did open.
If there is a mismatch we return -ERESTARTSYS and modify
__blkdev_get to retry from the top in that case.
In the -ERESTARTSYS sys case we make sure to wait until
the old gendisk (that we succeeded in opening) is really gone so
we loop at most once.
Some udev configurations will always open an md device when it first
appears. If we allow an md device that was just created by an open
to disappear on an immediate close, then this can race with such udev
configurations and result in an infinite loop the device being opened
and closed, then re-open due to the 'ADD' even from the first open,
and then close and so on.
So we make sure an md device, once created by an open, remains active
at least until some md 'ioctl' has been made on it. This means that
all normal usage of md devices will allow them to disappear promptly
when not needed, but the worst that an incorrect usage will do it
cause an inactive md device to be left in existence (it can easily be
removed).
As an array can be stopped by writing to a sysfs attribute
echo clear > /sys/block/mdXXX/md/array_state
we need to use scheduled work for deleting the gendisk and other
kobjects. This allows us to wait for any pending gendisk deletion to
complete by simply calling flush_scheduled_work().
Signed-off-by: NeilBrown <neilb@suse.de>
2009-01-09 08:31:10 +11:00
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2005-04-16 15:20:36 -07:00
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2011-05-23 13:26:07 +02:00
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2016-09-14 11:56:13 +02:00
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2011-05-23 13:26:07 +02:00
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2011-04-21 20:54:45 +02:00
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2012-03-02 10:38:33 +01:00
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2015-11-30 10:20:29 -08:00
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2011-04-21 20:54:45 +02:00
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2005-04-16 15:20:36 -07:00
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2008-08-25 19:56:12 +09:00
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[PATCH] lockdep: simplify some aspects of bd_mutex nesting
When we open (actually blkdev_get) a partition we need to also open (get) the
whole device that holds the partition. The involves some limited recursion.
This patch tries to simplify some aspects of this.
As well as opening the whole device, we need to increment ->bd_part_count when
a partition is opened (this is used by rescan_partitions to avoid a rescan if
any partition is active, as that would be confusing).
The main change this patch makes is to move the inc/dec of bd_part_count into
blkdev_{get,put} for the whole rather than doing it in blkdev_{get,put} for
the partition.
More specifically, we introduce __blkdev_get and __blkdev_put which do exactly
what blkdev_{get,put} did, only with an extra "for_part" argument
(blkget_{get,put} then call the __ version with a '0' for the extra argument).
If for_part is 1, then the blkdev is being get(put) because a partition is
being opened(closed) for the first(last) time, and so bd_part_count should be
updated (on success). The particular advantage of pushing this function down
is that the bd_mutex lock (which is needed to update bd_part_count) is already
held at the lower level.
Note that this slightly changes the semantics of bd_part_count. Instead of
updating it whenever a partition is opened or released, it is now only updated
on the first open or last release. This is an adequate semantic as it is only
ever tested for "== 0".
Having introduced these functions we remove the current bd_part_count updates
from do_open (which is really the body of blkdev_get) and call
__blkdev_get(... 1). Similarly in blkget_put we remove the old bd_part_count
updates and call __blkget_put(..., 1). This call is moved to the end of
__blkdev_put to avoid nested locks of bd_mutex.
Finally the mutex_lock on whole->bd_mutex in do_open can be removed. It was
only really needed to protect bd_part_count, and that is now managed (and
protected) within the recursive call.
The observation that bd_part_count is central to the locking issues, and the
modifications to create __blkdev_put are from Peter Zijlstra.
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 02:36:16 -08:00
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2007-10-08 13:24:05 -04:00
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2005-04-16 15:20:36 -07:00
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2008-08-25 19:56:12 +09:00
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2005-04-16 15:20:36 -07:00
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2008-11-05 10:21:06 +01:00
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2008-09-03 09:03:02 +02:00
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2008-11-05 10:21:06 +01:00
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2005-04-16 15:20:36 -07:00
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2008-08-25 19:56:12 +09:00
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2005-04-16 15:20:36 -07:00
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2008-11-05 10:21:06 +01:00
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2005-04-16 15:20:36 -07:00
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2011-04-21 20:54:45 +02:00
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2007-10-08 13:24:05 -04:00
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2011-04-21 20:54:45 +02:00
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2012-03-02 10:38:33 +01:00
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2011-04-21 20:54:45 +02:00
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2005-04-16 15:20:36 -07:00
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2011-03-09 19:54:27 +01:00
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2011-10-19 14:31:07 +02:00
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2005-04-16 15:20:36 -07:00
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|
[PATCH] lockdep: simplify some aspects of bd_mutex nesting
When we open (actually blkdev_get) a partition we need to also open (get) the
whole device that holds the partition. The involves some limited recursion.
This patch tries to simplify some aspects of this.
As well as opening the whole device, we need to increment ->bd_part_count when
a partition is opened (this is used by rescan_partitions to avoid a rescan if
any partition is active, as that would be confusing).
The main change this patch makes is to move the inc/dec of bd_part_count into
blkdev_{get,put} for the whole rather than doing it in blkdev_{get,put} for
the partition.
More specifically, we introduce __blkdev_get and __blkdev_put which do exactly
what blkdev_{get,put} did, only with an extra "for_part" argument
(blkget_{get,put} then call the __ version with a '0' for the extra argument).
If for_part is 1, then the blkdev is being get(put) because a partition is
being opened(closed) for the first(last) time, and so bd_part_count should be
updated (on success). The particular advantage of pushing this function down
is that the bd_mutex lock (which is needed to update bd_part_count) is already
held at the lower level.
Note that this slightly changes the semantics of bd_part_count. Instead of
updating it whenever a partition is opened or released, it is now only updated
on the first open or last release. This is an adequate semantic as it is only
ever tested for "== 0".
Having introduced these functions we remove the current bd_part_count updates
from do_open (which is really the body of blkdev_get) and call
__blkdev_get(... 1). Similarly in blkget_put we remove the old bd_part_count
updates and call __blkget_put(..., 1). This call is moved to the end of
__blkdev_put to avoid nested locks of bd_mutex.
Finally the mutex_lock on whole->bd_mutex in do_open can be removed. It was
only really needed to protect bd_part_count, and that is now managed (and
protected) within the recursive call.
The observation that bd_part_count is central to the locking issues, and the
modifications to create __blkdev_put are from Peter Zijlstra.
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 02:36:16 -08:00
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2006-03-23 03:00:28 -08:00
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2011-03-09 19:54:27 +01:00
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2005-04-16 15:20:36 -07:00
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2008-08-25 19:56:12 +09:00
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2008-11-05 10:21:06 +01:00
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2005-04-16 15:20:36 -07:00
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2008-08-25 19:56:12 +09:00
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2012-01-12 17:20:34 -08:00
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2005-04-16 15:20:36 -07:00
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2007-10-08 13:24:05 -04:00
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2005-04-16 15:20:36 -07:00
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2008-08-25 19:56:12 +09:00
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2006-03-23 03:00:28 -08:00
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2011-03-09 19:54:27 +01:00
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2008-08-25 19:56:12 +09:00
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2011-10-19 14:31:07 +02:00
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2011-03-19 13:53:31 +01:00
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2008-08-25 19:56:12 +09:00
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2005-04-16 15:20:36 -07:00
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2010-11-13 11:55:18 +01:00
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block: make blkdev_get/put() handle exclusive access
Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.
* blkdev_get/put() are the primary open and close functions.
* bd_claim/release() deal with exclusive open.
* open/close_bdev_exclusive() are combination of open and claim and
the other way around, respectively.
* bd_link/unlink_disk_holder() to create and remove holder/slave
symlinks.
* open_by_devnum() wraps bdget() + blkdev_get().
The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access. Reorganize the interface such that,
* blkdev_get() is extended to include exclusive access management.
@holder argument is added and, if is @FMODE_EXCL specified, it will
gain exclusive access atomically w.r.t. other exclusive accesses.
* blkdev_put() is similarly extended. It now takes @mode argument and
if @FMODE_EXCL is set, it releases an exclusive access. Also, when
the last exclusive claim is released, the holder/slave symlinks are
removed automatically.
* bd_claim/release() and close_bdev_exclusive() are no longer
necessary and either made static or removed.
* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
is no longer necessary and removed.
* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
and blkdev_get(). It also has an unexpected extra bdev_read_only()
test which probably should be moved into blkdev_get().
* open_by_devnum() is modified to take @holder argument and pass it to
blkdev_get().
Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should). This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.
open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features. Well, let's leave them for another day.
Most conversions are straight-forward. drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:17 +01:00
|
|
|
|
2005-04-16 15:20:36 -07:00
|
|
|
|
block: make blkdev_get/put() handle exclusive access
Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.
* blkdev_get/put() are the primary open and close functions.
* bd_claim/release() deal with exclusive open.
* open/close_bdev_exclusive() are combination of open and claim and
the other way around, respectively.
* bd_link/unlink_disk_holder() to create and remove holder/slave
symlinks.
* open_by_devnum() wraps bdget() + blkdev_get().
The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access. Reorganize the interface such that,
* blkdev_get() is extended to include exclusive access management.
@holder argument is added and, if is @FMODE_EXCL specified, it will
gain exclusive access atomically w.r.t. other exclusive accesses.
* blkdev_put() is similarly extended. It now takes @mode argument and
if @FMODE_EXCL is set, it releases an exclusive access. Also, when
the last exclusive claim is released, the holder/slave symlinks are
removed automatically.
* bd_claim/release() and close_bdev_exclusive() are no longer
necessary and either made static or removed.
* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
is no longer necessary and removed.
* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
and blkdev_get(). It also has an unexpected extra bdev_read_only()
test which probably should be moved into blkdev_get().
* open_by_devnum() is modified to take @holder argument and pass it to
blkdev_get().
Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should). This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.
open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features. Well, let's leave them for another day.
Most conversions are straight-forward. drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:17 +01:00
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2011-04-21 20:54:46 +02:00
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2010-11-13 11:55:17 +01:00
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implement in-kernel gendisk events handling
Currently, media presence polling for removeable block devices is done
from userland. There are several issues with this.
* Polling is done by periodically opening the device. For SCSI
devices, the command sequence generated by such action involves a
few different commands including TEST_UNIT_READY. This behavior,
while perfectly legal, is different from Windows which only issues
single command, GET_EVENT_STATUS_NOTIFICATION. Unfortunately, some
ATAPI devices lock up after being periodically queried such command
sequences.
* There is no reliable and unintrusive way for a userland program to
tell whether the target device is safe for media presence polling.
For example, polling for media presence during an on-going burning
session can make it fail. The polling program can avoid this by
opening the device with O_EXCL but then it risks making a valid
exclusive user of the device fail w/ -EBUSY.
* Userland polling is unnecessarily heavy and in-kernel implementation
is lighter and better coordinated (workqueue, timer slack).
This patch implements framework for in-kernel disk event handling,
which includes media presence polling.
* bdops->check_events() is added, which supercedes ->media_changed().
It should check whether there's any pending event and return if so.
Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and
DISK_EVENT_EJECT_REQUEST. ->check_events() is guaranteed not to be
called parallelly.
* gendisk->events and ->async_events are added. These should be
initialized by block driver before passing the device to add_disk().
The former contains the mask of all supported events and the latter
the mask of all events which the device can report without polling.
/sys/block/*/events[_async] export these to userland.
* Kernel parameter block.events_dfl_poll_msecs controls the system
polling interval (default is 0 which means disable) and
/sys/block/*/events_poll_msecs control polling intervals for
individual devices (default is -1 meaning use system setting). Note
that if a device can report all supported events asynchronously and
its polling interval isn't explicitly set, the device won't be
polled regardless of the system polling interval.
* If a device is opened exclusively with write access, event checking
is automatically disabled until all write exclusive accesses are
released.
* There are event 'clearing' events. For example, both of currently
defined events are cleared after the device has been successfully
opened. This information is passed to ->check_events() callback
using @clearing argument as a hint.
* Event checking is always performed from system_nrt_wq and timer
slack is set to 25% for polling.
* Nothing changes for drivers which implement ->media_changed() but
not ->check_events(). Going forward, all drivers will be converted
to ->check_events() and ->media_change() will be dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-08 20:57:37 +01:00
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2010-11-13 11:55:17 +01:00
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implement in-kernel gendisk events handling
Currently, media presence polling for removeable block devices is done
from userland. There are several issues with this.
* Polling is done by periodically opening the device. For SCSI
devices, the command sequence generated by such action involves a
few different commands including TEST_UNIT_READY. This behavior,
while perfectly legal, is different from Windows which only issues
single command, GET_EVENT_STATUS_NOTIFICATION. Unfortunately, some
ATAPI devices lock up after being periodically queried such command
sequences.
* There is no reliable and unintrusive way for a userland program to
tell whether the target device is safe for media presence polling.
For example, polling for media presence during an on-going burning
session can make it fail. The polling program can avoid this by
opening the device with O_EXCL but then it risks making a valid
exclusive user of the device fail w/ -EBUSY.
* Userland polling is unnecessarily heavy and in-kernel implementation
is lighter and better coordinated (workqueue, timer slack).
This patch implements framework for in-kernel disk event handling,
which includes media presence polling.
* bdops->check_events() is added, which supercedes ->media_changed().
It should check whether there's any pending event and return if so.
Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and
DISK_EVENT_EJECT_REQUEST. ->check_events() is guaranteed not to be
called parallelly.
* gendisk->events and ->async_events are added. These should be
initialized by block driver before passing the device to add_disk().
The former contains the mask of all supported events and the latter
the mask of all events which the device can report without polling.
/sys/block/*/events[_async] export these to userland.
* Kernel parameter block.events_dfl_poll_msecs controls the system
polling interval (default is 0 which means disable) and
/sys/block/*/events_poll_msecs control polling intervals for
individual devices (default is -1 meaning use system setting). Note
that if a device can report all supported events asynchronously and
its polling interval isn't explicitly set, the device won't be
polled regardless of the system polling interval.
* If a device is opened exclusively with write access, event checking
is automatically disabled until all write exclusive accesses are
released.
* There are event 'clearing' events. For example, both of currently
defined events are cleared after the device has been successfully
opened. This information is passed to ->check_events() callback
using @clearing argument as a hint.
* Event checking is always performed from system_nrt_wq and timer
slack is set to 25% for polling.
* Nothing changes for drivers which implement ->media_changed() but
not ->check_events(). Going forward, all drivers will be converted
to ->check_events() and ->media_change() will be dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-08 20:57:37 +01:00
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2010-11-13 11:55:17 +01:00
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implement in-kernel gendisk events handling
Currently, media presence polling for removeable block devices is done
from userland. There are several issues with this.
* Polling is done by periodically opening the device. For SCSI
devices, the command sequence generated by such action involves a
few different commands including TEST_UNIT_READY. This behavior,
while perfectly legal, is different from Windows which only issues
single command, GET_EVENT_STATUS_NOTIFICATION. Unfortunately, some
ATAPI devices lock up after being periodically queried such command
sequences.
* There is no reliable and unintrusive way for a userland program to
tell whether the target device is safe for media presence polling.
For example, polling for media presence during an on-going burning
session can make it fail. The polling program can avoid this by
opening the device with O_EXCL but then it risks making a valid
exclusive user of the device fail w/ -EBUSY.
* Userland polling is unnecessarily heavy and in-kernel implementation
is lighter and better coordinated (workqueue, timer slack).
This patch implements framework for in-kernel disk event handling,
which includes media presence polling.
* bdops->check_events() is added, which supercedes ->media_changed().
It should check whether there's any pending event and return if so.
Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and
DISK_EVENT_EJECT_REQUEST. ->check_events() is guaranteed not to be
called parallelly.
* gendisk->events and ->async_events are added. These should be
initialized by block driver before passing the device to add_disk().
The former contains the mask of all supported events and the latter
the mask of all events which the device can report without polling.
/sys/block/*/events[_async] export these to userland.
* Kernel parameter block.events_dfl_poll_msecs controls the system
polling interval (default is 0 which means disable) and
/sys/block/*/events_poll_msecs control polling intervals for
individual devices (default is -1 meaning use system setting). Note
that if a device can report all supported events asynchronously and
its polling interval isn't explicitly set, the device won't be
polled regardless of the system polling interval.
* If a device is opened exclusively with write access, event checking
is automatically disabled until all write exclusive accesses are
released.
* There are event 'clearing' events. For example, both of currently
defined events are cleared after the device has been successfully
opened. This information is passed to ->check_events() callback
using @clearing argument as a hint.
* Event checking is always performed from system_nrt_wq and timer
slack is set to 25% for polling.
* Nothing changes for drivers which implement ->media_changed() but
not ->check_events(). Going forward, all drivers will be converted
to ->check_events() and ->media_change() will be dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-08 20:57:37 +01:00
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2011-04-21 20:54:46 +02:00
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|
implement in-kernel gendisk events handling
Currently, media presence polling for removeable block devices is done
from userland. There are several issues with this.
* Polling is done by periodically opening the device. For SCSI
devices, the command sequence generated by such action involves a
few different commands including TEST_UNIT_READY. This behavior,
while perfectly legal, is different from Windows which only issues
single command, GET_EVENT_STATUS_NOTIFICATION. Unfortunately, some
ATAPI devices lock up after being periodically queried such command
sequences.
* There is no reliable and unintrusive way for a userland program to
tell whether the target device is safe for media presence polling.
For example, polling for media presence during an on-going burning
session can make it fail. The polling program can avoid this by
opening the device with O_EXCL but then it risks making a valid
exclusive user of the device fail w/ -EBUSY.
* Userland polling is unnecessarily heavy and in-kernel implementation
is lighter and better coordinated (workqueue, timer slack).
This patch implements framework for in-kernel disk event handling,
which includes media presence polling.
* bdops->check_events() is added, which supercedes ->media_changed().
It should check whether there's any pending event and return if so.
Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and
DISK_EVENT_EJECT_REQUEST. ->check_events() is guaranteed not to be
called parallelly.
* gendisk->events and ->async_events are added. These should be
initialized by block driver before passing the device to add_disk().
The former contains the mask of all supported events and the latter
the mask of all events which the device can report without polling.
/sys/block/*/events[_async] export these to userland.
* Kernel parameter block.events_dfl_poll_msecs controls the system
polling interval (default is 0 which means disable) and
/sys/block/*/events_poll_msecs control polling intervals for
individual devices (default is -1 meaning use system setting). Note
that if a device can report all supported events asynchronously and
its polling interval isn't explicitly set, the device won't be
polled regardless of the system polling interval.
* If a device is opened exclusively with write access, event checking
is automatically disabled until all write exclusive accesses are
released.
* There are event 'clearing' events. For example, both of currently
defined events are cleared after the device has been successfully
opened. This information is passed to ->check_events() callback
using @clearing argument as a hint.
* Event checking is always performed from system_nrt_wq and timer
slack is set to 25% for polling.
* Nothing changes for drivers which implement ->media_changed() but
not ->check_events(). Going forward, all drivers will be converted
to ->check_events() and ->media_change() will be dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-08 20:57:37 +01:00
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2011-06-01 08:27:41 +02:00
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implement in-kernel gendisk events handling
Currently, media presence polling for removeable block devices is done
from userland. There are several issues with this.
* Polling is done by periodically opening the device. For SCSI
devices, the command sequence generated by such action involves a
few different commands including TEST_UNIT_READY. This behavior,
while perfectly legal, is different from Windows which only issues
single command, GET_EVENT_STATUS_NOTIFICATION. Unfortunately, some
ATAPI devices lock up after being periodically queried such command
sequences.
* There is no reliable and unintrusive way for a userland program to
tell whether the target device is safe for media presence polling.
For example, polling for media presence during an on-going burning
session can make it fail. The polling program can avoid this by
opening the device with O_EXCL but then it risks making a valid
exclusive user of the device fail w/ -EBUSY.
* Userland polling is unnecessarily heavy and in-kernel implementation
is lighter and better coordinated (workqueue, timer slack).
This patch implements framework for in-kernel disk event handling,
which includes media presence polling.
* bdops->check_events() is added, which supercedes ->media_changed().
It should check whether there's any pending event and return if so.
Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and
DISK_EVENT_EJECT_REQUEST. ->check_events() is guaranteed not to be
called parallelly.
* gendisk->events and ->async_events are added. These should be
initialized by block driver before passing the device to add_disk().
The former contains the mask of all supported events and the latter
the mask of all events which the device can report without polling.
/sys/block/*/events[_async] export these to userland.
* Kernel parameter block.events_dfl_poll_msecs controls the system
polling interval (default is 0 which means disable) and
/sys/block/*/events_poll_msecs control polling intervals for
individual devices (default is -1 meaning use system setting). Note
that if a device can report all supported events asynchronously and
its polling interval isn't explicitly set, the device won't be
polled regardless of the system polling interval.
* If a device is opened exclusively with write access, event checking
is automatically disabled until all write exclusive accesses are
released.
* There are event 'clearing' events. For example, both of currently
defined events are cleared after the device has been successfully
opened. This information is passed to ->check_events() callback
using @clearing argument as a hint.
* Event checking is always performed from system_nrt_wq and timer
slack is set to 25% for polling.
* Nothing changes for drivers which implement ->media_changed() but
not ->check_events(). Going forward, all drivers will be converted
to ->check_events() and ->media_change() will be dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-08 20:57:37 +01:00
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|
|
|
2011-04-21 20:54:46 +02:00
|
|
|
|
implement in-kernel gendisk events handling
Currently, media presence polling for removeable block devices is done
from userland. There are several issues with this.
* Polling is done by periodically opening the device. For SCSI
devices, the command sequence generated by such action involves a
few different commands including TEST_UNIT_READY. This behavior,
while perfectly legal, is different from Windows which only issues
single command, GET_EVENT_STATUS_NOTIFICATION. Unfortunately, some
ATAPI devices lock up after being periodically queried such command
sequences.
* There is no reliable and unintrusive way for a userland program to
tell whether the target device is safe for media presence polling.
For example, polling for media presence during an on-going burning
session can make it fail. The polling program can avoid this by
opening the device with O_EXCL but then it risks making a valid
exclusive user of the device fail w/ -EBUSY.
* Userland polling is unnecessarily heavy and in-kernel implementation
is lighter and better coordinated (workqueue, timer slack).
This patch implements framework for in-kernel disk event handling,
which includes media presence polling.
* bdops->check_events() is added, which supercedes ->media_changed().
It should check whether there's any pending event and return if so.
Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and
DISK_EVENT_EJECT_REQUEST. ->check_events() is guaranteed not to be
called parallelly.
* gendisk->events and ->async_events are added. These should be
initialized by block driver before passing the device to add_disk().
The former contains the mask of all supported events and the latter
the mask of all events which the device can report without polling.
/sys/block/*/events[_async] export these to userland.
* Kernel parameter block.events_dfl_poll_msecs controls the system
polling interval (default is 0 which means disable) and
/sys/block/*/events_poll_msecs control polling intervals for
individual devices (default is -1 meaning use system setting). Note
that if a device can report all supported events asynchronously and
its polling interval isn't explicitly set, the device won't be
polled regardless of the system polling interval.
* If a device is opened exclusively with write access, event checking
is automatically disabled until all write exclusive accesses are
released.
* There are event 'clearing' events. For example, both of currently
defined events are cleared after the device has been successfully
opened. This information is passed to ->check_events() callback
using @clearing argument as a hint.
* Event checking is always performed from system_nrt_wq and timer
slack is set to 25% for polling.
* Nothing changes for drivers which implement ->media_changed() but
not ->check_events(). Going forward, all drivers will be converted
to ->check_events() and ->media_change() will be dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-08 20:57:37 +01:00
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2010-11-13 11:55:17 +01:00
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block: make blkdev_get/put() handle exclusive access
Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.
* blkdev_get/put() are the primary open and close functions.
* bd_claim/release() deal with exclusive open.
* open/close_bdev_exclusive() are combination of open and claim and
the other way around, respectively.
* bd_link/unlink_disk_holder() to create and remove holder/slave
symlinks.
* open_by_devnum() wraps bdget() + blkdev_get().
The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access. Reorganize the interface such that,
* blkdev_get() is extended to include exclusive access management.
@holder argument is added and, if is @FMODE_EXCL specified, it will
gain exclusive access atomically w.r.t. other exclusive accesses.
* blkdev_put() is similarly extended. It now takes @mode argument and
if @FMODE_EXCL is set, it releases an exclusive access. Also, when
the last exclusive claim is released, the holder/slave symlinks are
removed automatically.
* bd_claim/release() and close_bdev_exclusive() are no longer
necessary and either made static or removed.
* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
is no longer necessary and removed.
* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
and blkdev_get(). It also has an unexpected extra bdev_read_only()
test which probably should be moved into blkdev_get().
* open_by_devnum() is modified to take @holder argument and pass it to
blkdev_get().
Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should). This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.
open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features. Well, let's leave them for another day.
Most conversions are straight-forward. drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:17 +01:00
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[PATCH] lockdep: simplify some aspects of bd_mutex nesting
When we open (actually blkdev_get) a partition we need to also open (get) the
whole device that holds the partition. The involves some limited recursion.
This patch tries to simplify some aspects of this.
As well as opening the whole device, we need to increment ->bd_part_count when
a partition is opened (this is used by rescan_partitions to avoid a rescan if
any partition is active, as that would be confusing).
The main change this patch makes is to move the inc/dec of bd_part_count into
blkdev_{get,put} for the whole rather than doing it in blkdev_{get,put} for
the partition.
More specifically, we introduce __blkdev_get and __blkdev_put which do exactly
what blkdev_{get,put} did, only with an extra "for_part" argument
(blkget_{get,put} then call the __ version with a '0' for the extra argument).
If for_part is 1, then the blkdev is being get(put) because a partition is
being opened(closed) for the first(last) time, and so bd_part_count should be
updated (on success). The particular advantage of pushing this function down
is that the bd_mutex lock (which is needed to update bd_part_count) is already
held at the lower level.
Note that this slightly changes the semantics of bd_part_count. Instead of
updating it whenever a partition is opened or released, it is now only updated
on the first open or last release. This is an adequate semantic as it is only
ever tested for "== 0".
Having introduced these functions we remove the current bd_part_count updates
from do_open (which is really the body of blkdev_get) and call
__blkdev_get(... 1). Similarly in blkget_put we remove the old bd_part_count
updates and call __blkget_put(..., 1). This call is moved to the end of
__blkdev_put to avoid nested locks of bd_mutex.
Finally the mutex_lock on whole->bd_mutex in do_open can be removed. It was
only really needed to protect bd_part_count, and that is now managed (and
protected) within the recursive call.
The observation that bd_part_count is central to the locking issues, and the
modifications to create __blkdev_put are from Peter Zijlstra.
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 02:36:16 -08:00
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2005-04-16 15:20:36 -07:00
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2010-11-13 11:55:18 +01:00
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2011-02-16 18:11:53 -05:00
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2010-11-13 11:55:18 +01:00
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2005-04-16 15:20:36 -07:00
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2007-10-08 13:24:05 -04:00
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2005-04-16 15:20:36 -07:00
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2006-10-28 10:38:33 -07:00
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2005-04-16 15:20:36 -07:00
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2007-10-08 13:24:05 -04:00
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block: make blkdev_get/put() handle exclusive access
Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.
* blkdev_get/put() are the primary open and close functions.
* bd_claim/release() deal with exclusive open.
* open/close_bdev_exclusive() are combination of open and claim and
the other way around, respectively.
* bd_link/unlink_disk_holder() to create and remove holder/slave
symlinks.
* open_by_devnum() wraps bdget() + blkdev_get().
The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access. Reorganize the interface such that,
* blkdev_get() is extended to include exclusive access management.
@holder argument is added and, if is @FMODE_EXCL specified, it will
gain exclusive access atomically w.r.t. other exclusive accesses.
* blkdev_put() is similarly extended. It now takes @mode argument and
if @FMODE_EXCL is set, it releases an exclusive access. Also, when
the last exclusive claim is released, the holder/slave symlinks are
removed automatically.
* bd_claim/release() and close_bdev_exclusive() are no longer
necessary and either made static or removed.
* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
is no longer necessary and removed.
* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
and blkdev_get(). It also has an unexpected extra bdev_read_only()
test which probably should be moved into blkdev_get().
* open_by_devnum() is modified to take @holder argument and pass it to
blkdev_get().
Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should). This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.
open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features. Well, let's leave them for another day.
Most conversions are straight-forward. drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:17 +01:00
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2005-04-16 15:20:36 -07:00
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2013-05-05 22:11:03 -04:00
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2006-12-08 02:36:13 -08:00
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[PATCH] lockdep: simplify some aspects of bd_mutex nesting
When we open (actually blkdev_get) a partition we need to also open (get) the
whole device that holds the partition. The involves some limited recursion.
This patch tries to simplify some aspects of this.
As well as opening the whole device, we need to increment ->bd_part_count when
a partition is opened (this is used by rescan_partitions to avoid a rescan if
any partition is active, as that would be confusing).
The main change this patch makes is to move the inc/dec of bd_part_count into
blkdev_{get,put} for the whole rather than doing it in blkdev_{get,put} for
the partition.
More specifically, we introduce __blkdev_get and __blkdev_put which do exactly
what blkdev_{get,put} did, only with an extra "for_part" argument
(blkget_{get,put} then call the __ version with a '0' for the extra argument).
If for_part is 1, then the blkdev is being get(put) because a partition is
being opened(closed) for the first(last) time, and so bd_part_count should be
updated (on success). The particular advantage of pushing this function down
is that the bd_mutex lock (which is needed to update bd_part_count) is already
held at the lower level.
Note that this slightly changes the semantics of bd_part_count. Instead of
updating it whenever a partition is opened or released, it is now only updated
on the first open or last release. This is an adequate semantic as it is only
ever tested for "== 0".
Having introduced these functions we remove the current bd_part_count updates
from do_open (which is really the body of blkdev_get) and call
__blkdev_get(... 1). Similarly in blkget_put we remove the old bd_part_count
updates and call __blkget_put(..., 1). This call is moved to the end of
__blkdev_put to avoid nested locks of bd_mutex.
Finally the mutex_lock on whole->bd_mutex in do_open can be removed. It was
only really needed to protect bd_part_count, and that is now managed (and
protected) within the recursive call.
The observation that bd_part_count is central to the locking issues, and the
modifications to create __blkdev_put are from Peter Zijlstra.
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 02:36:16 -08:00
|
|
|
|
2006-12-08 02:36:13 -08:00
|
|
|
|
2006-12-08 02:36:16 -08:00
|
|
|
|
[PATCH] lockdep: simplify some aspects of bd_mutex nesting
When we open (actually blkdev_get) a partition we need to also open (get) the
whole device that holds the partition. The involves some limited recursion.
This patch tries to simplify some aspects of this.
As well as opening the whole device, we need to increment ->bd_part_count when
a partition is opened (this is used by rescan_partitions to avoid a rescan if
any partition is active, as that would be confusing).
The main change this patch makes is to move the inc/dec of bd_part_count into
blkdev_{get,put} for the whole rather than doing it in blkdev_{get,put} for
the partition.
More specifically, we introduce __blkdev_get and __blkdev_put which do exactly
what blkdev_{get,put} did, only with an extra "for_part" argument
(blkget_{get,put} then call the __ version with a '0' for the extra argument).
If for_part is 1, then the blkdev is being get(put) because a partition is
being opened(closed) for the first(last) time, and so bd_part_count should be
updated (on success). The particular advantage of pushing this function down
is that the bd_mutex lock (which is needed to update bd_part_count) is already
held at the lower level.
Note that this slightly changes the semantics of bd_part_count. Instead of
updating it whenever a partition is opened or released, it is now only updated
on the first open or last release. This is an adequate semantic as it is only
ever tested for "== 0".
Having introduced these functions we remove the current bd_part_count updates
from do_open (which is really the body of blkdev_get) and call
__blkdev_get(... 1). Similarly in blkget_put we remove the old bd_part_count
updates and call __blkget_put(..., 1). This call is moved to the end of
__blkdev_put to avoid nested locks of bd_mutex.
Finally the mutex_lock on whole->bd_mutex in do_open can be removed. It was
only really needed to protect bd_part_count, and that is now managed (and
protected) within the recursive call.
The observation that bd_part_count is central to the locking issues, and the
modifications to create __blkdev_put are from Peter Zijlstra.
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 02:36:16 -08:00
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2006-12-08 02:36:13 -08:00
|
|
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|
2010-11-13 11:55:17 +01:00
|
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|
2006-12-08 02:36:13 -08:00
|
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block: detach bdev inode from its wb in __blkdev_put()
Since 52ebea749aae ("writeback: make backing_dev_info host
cgroup-specific bdi_writebacks") inode, at some point in its lifetime,
gets attached to a wb (struct bdi_writeback). Detaching happens on
evict, in inode_detach_wb() called from __destroy_inode(), and involves
updating wb.
However, detaching an internal bdev inode from its wb in
__destroy_inode() is too late. Its bdi and by extension root wb are
embedded into struct request_queue, which has different lifetime rules
and can be freed long before the final bdput() is called (can be from
__fput() of a corresponding /dev inode, through dput() - evict() -
bd_forget(). bdevs hold onto the underlying disk/queue pair only while
opened; as soon as bdev is closed all bets are off. In fact,
disk/queue can be gone before __blkdev_put() even returns:
1499 static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
1500 {
...
1518 if (bdev->bd_contains == bdev) {
1519 if (disk->fops->release)
1520 disk->fops->release(disk, mode);
[ Driver puts its references to disk/queue ]
1521 }
1522 if (!bdev->bd_openers) {
1523 struct module *owner = disk->fops->owner;
1524
1525 disk_put_part(bdev->bd_part);
1526 bdev->bd_part = NULL;
1527 bdev->bd_disk = NULL;
1528 if (bdev != bdev->bd_contains)
1529 victim = bdev->bd_contains;
1530 bdev->bd_contains = NULL;
1531
1532 put_disk(disk);
[ We put ours, the queue is gone
The last bdput() would result in a write to invalid memory ]
1533 module_put(owner);
...
1539 }
Since bdev inodes are special anyway, detach them in __blkdev_put()
after clearing inode's dirty bits, turning the problematic
inode_detach_wb() in __destroy_inode() into a noop.
add_disk() grabs its disk->queue since 523e1d399ce0 ("block: make
gendisk hold a reference to its queue"), so the old ->release comment
is removed in favor of the new inode_detach_wb() comment.
Cc: stable@vger.kernel.org # 4.2+, needs backporting
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Tested-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-20 22:22:34 +01:00
|
|
|
|
|
|
|
|
|
2015-01-14 10:42:33 +01:00
|
|
|
|
block: detach bdev inode from its wb in __blkdev_put()
Since 52ebea749aae ("writeback: make backing_dev_info host
cgroup-specific bdi_writebacks") inode, at some point in its lifetime,
gets attached to a wb (struct bdi_writeback). Detaching happens on
evict, in inode_detach_wb() called from __destroy_inode(), and involves
updating wb.
However, detaching an internal bdev inode from its wb in
__destroy_inode() is too late. Its bdi and by extension root wb are
embedded into struct request_queue, which has different lifetime rules
and can be freed long before the final bdput() is called (can be from
__fput() of a corresponding /dev inode, through dput() - evict() -
bd_forget(). bdevs hold onto the underlying disk/queue pair only while
opened; as soon as bdev is closed all bets are off. In fact,
disk/queue can be gone before __blkdev_put() even returns:
1499 static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
1500 {
...
1518 if (bdev->bd_contains == bdev) {
1519 if (disk->fops->release)
1520 disk->fops->release(disk, mode);
[ Driver puts its references to disk/queue ]
1521 }
1522 if (!bdev->bd_openers) {
1523 struct module *owner = disk->fops->owner;
1524
1525 disk_put_part(bdev->bd_part);
1526 bdev->bd_part = NULL;
1527 bdev->bd_disk = NULL;
1528 if (bdev != bdev->bd_contains)
1529 victim = bdev->bd_contains;
1530 bdev->bd_contains = NULL;
1531
1532 put_disk(disk);
[ We put ours, the queue is gone
The last bdput() would result in a write to invalid memory ]
1533 module_put(owner);
...
1539 }
Since bdev inodes are special anyway, detach them in __blkdev_put()
after clearing inode's dirty bits, turning the problematic
inode_detach_wb() in __destroy_inode() into a noop.
add_disk() grabs its disk->queue since 523e1d399ce0 ("block: make
gendisk hold a reference to its queue"), so the old ->release comment
is removed in favor of the new inode_detach_wb() comment.
Cc: stable@vger.kernel.org # 4.2+, needs backporting
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Tested-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-20 22:22:34 +01:00
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|
2011-09-10 17:20:21 +10:00
|
|
|
|
block: detach bdev inode from its wb in __blkdev_put()
Since 52ebea749aae ("writeback: make backing_dev_info host
cgroup-specific bdi_writebacks") inode, at some point in its lifetime,
gets attached to a wb (struct bdi_writeback). Detaching happens on
evict, in inode_detach_wb() called from __destroy_inode(), and involves
updating wb.
However, detaching an internal bdev inode from its wb in
__destroy_inode() is too late. Its bdi and by extension root wb are
embedded into struct request_queue, which has different lifetime rules
and can be freed long before the final bdput() is called (can be from
__fput() of a corresponding /dev inode, through dput() - evict() -
bd_forget(). bdevs hold onto the underlying disk/queue pair only while
opened; as soon as bdev is closed all bets are off. In fact,
disk/queue can be gone before __blkdev_put() even returns:
1499 static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
1500 {
...
1518 if (bdev->bd_contains == bdev) {
1519 if (disk->fops->release)
1520 disk->fops->release(disk, mode);
[ Driver puts its references to disk/queue ]
1521 }
1522 if (!bdev->bd_openers) {
1523 struct module *owner = disk->fops->owner;
1524
1525 disk_put_part(bdev->bd_part);
1526 bdev->bd_part = NULL;
1527 bdev->bd_disk = NULL;
1528 if (bdev != bdev->bd_contains)
1529 victim = bdev->bd_contains;
1530 bdev->bd_contains = NULL;
1531
1532 put_disk(disk);
[ We put ours, the queue is gone
The last bdput() would result in a write to invalid memory ]
1533 module_put(owner);
...
1539 }
Since bdev inodes are special anyway, detach them in __blkdev_put()
after clearing inode's dirty bits, turning the problematic
inode_detach_wb() in __destroy_inode() into a noop.
add_disk() grabs its disk->queue since 523e1d399ce0 ("block: make
gendisk hold a reference to its queue"), so the old ->release comment
is removed in favor of the new inode_detach_wb() comment.
Cc: stable@vger.kernel.org # 4.2+, needs backporting
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Tested-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-20 22:22:34 +01:00
|
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|
2006-12-08 02:36:13 -08:00
|
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2013-05-05 21:52:57 -04:00
|
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|
2006-12-08 02:36:13 -08:00
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|
2008-08-25 19:56:12 +09:00
|
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|
2006-12-08 02:36:13 -08:00
|
|
|
|
[PATCH] lockdep: simplify some aspects of bd_mutex nesting
When we open (actually blkdev_get) a partition we need to also open (get) the
whole device that holds the partition. The involves some limited recursion.
This patch tries to simplify some aspects of this.
As well as opening the whole device, we need to increment ->bd_part_count when
a partition is opened (this is used by rescan_partitions to avoid a rescan if
any partition is active, as that would be confusing).
The main change this patch makes is to move the inc/dec of bd_part_count into
blkdev_{get,put} for the whole rather than doing it in blkdev_{get,put} for
the partition.
More specifically, we introduce __blkdev_get and __blkdev_put which do exactly
what blkdev_{get,put} did, only with an extra "for_part" argument
(blkget_{get,put} then call the __ version with a '0' for the extra argument).
If for_part is 1, then the blkdev is being get(put) because a partition is
being opened(closed) for the first(last) time, and so bd_part_count should be
updated (on success). The particular advantage of pushing this function down
is that the bd_mutex lock (which is needed to update bd_part_count) is already
held at the lower level.
Note that this slightly changes the semantics of bd_part_count. Instead of
updating it whenever a partition is opened or released, it is now only updated
on the first open or last release. This is an adequate semantic as it is only
ever tested for "== 0".
Having introduced these functions we remove the current bd_part_count updates
from do_open (which is really the body of blkdev_get) and call
__blkdev_get(... 1). Similarly in blkget_put we remove the old bd_part_count
updates and call __blkget_put(..., 1). This call is moved to the end of
__blkdev_put to avoid nested locks of bd_mutex.
Finally the mutex_lock on whole->bd_mutex in do_open can be removed. It was
only really needed to protect bd_part_count, and that is now managed (and
protected) within the recursive call.
The observation that bd_part_count is central to the locking issues, and the
modifications to create __blkdev_put are from Peter Zijlstra.
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 02:36:16 -08:00
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2006-12-08 02:36:13 -08:00
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2011-10-19 14:31:07 +02:00
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2006-12-08 02:36:13 -08:00
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[PATCH] lockdep: simplify some aspects of bd_mutex nesting
When we open (actually blkdev_get) a partition we need to also open (get) the
whole device that holds the partition. The involves some limited recursion.
This patch tries to simplify some aspects of this.
As well as opening the whole device, we need to increment ->bd_part_count when
a partition is opened (this is used by rescan_partitions to avoid a rescan if
any partition is active, as that would be confusing).
The main change this patch makes is to move the inc/dec of bd_part_count into
blkdev_{get,put} for the whole rather than doing it in blkdev_{get,put} for
the partition.
More specifically, we introduce __blkdev_get and __blkdev_put which do exactly
what blkdev_{get,put} did, only with an extra "for_part" argument
(blkget_{get,put} then call the __ version with a '0' for the extra argument).
If for_part is 1, then the blkdev is being get(put) because a partition is
being opened(closed) for the first(last) time, and so bd_part_count should be
updated (on success). The particular advantage of pushing this function down
is that the bd_mutex lock (which is needed to update bd_part_count) is already
held at the lower level.
Note that this slightly changes the semantics of bd_part_count. Instead of
updating it whenever a partition is opened or released, it is now only updated
on the first open or last release. This is an adequate semantic as it is only
ever tested for "== 0".
Having introduced these functions we remove the current bd_part_count updates
from do_open (which is really the body of blkdev_get) and call
__blkdev_get(... 1). Similarly in blkget_put we remove the old bd_part_count
updates and call __blkget_put(..., 1). This call is moved to the end of
__blkdev_put to avoid nested locks of bd_mutex.
Finally the mutex_lock on whole->bd_mutex in do_open can be removed. It was
only really needed to protect bd_part_count, and that is now managed (and
protected) within the recursive call.
The observation that bd_part_count is central to the locking issues, and the
modifications to create __blkdev_put are from Peter Zijlstra.
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 02:36:16 -08:00
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2008-02-22 20:40:24 -05:00
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2006-12-08 02:36:13 -08:00
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2013-05-05 22:11:03 -04:00
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[PATCH] lockdep: simplify some aspects of bd_mutex nesting
When we open (actually blkdev_get) a partition we need to also open (get) the
whole device that holds the partition. The involves some limited recursion.
This patch tries to simplify some aspects of this.
As well as opening the whole device, we need to increment ->bd_part_count when
a partition is opened (this is used by rescan_partitions to avoid a rescan if
any partition is active, as that would be confusing).
The main change this patch makes is to move the inc/dec of bd_part_count into
blkdev_{get,put} for the whole rather than doing it in blkdev_{get,put} for
the partition.
More specifically, we introduce __blkdev_get and __blkdev_put which do exactly
what blkdev_{get,put} did, only with an extra "for_part" argument
(blkget_{get,put} then call the __ version with a '0' for the extra argument).
If for_part is 1, then the blkdev is being get(put) because a partition is
being opened(closed) for the first(last) time, and so bd_part_count should be
updated (on success). The particular advantage of pushing this function down
is that the bd_mutex lock (which is needed to update bd_part_count) is already
held at the lower level.
Note that this slightly changes the semantics of bd_part_count. Instead of
updating it whenever a partition is opened or released, it is now only updated
on the first open or last release. This is an adequate semantic as it is only
ever tested for "== 0".
Having introduced these functions we remove the current bd_part_count updates
from do_open (which is really the body of blkdev_get) and call
__blkdev_get(... 1). Similarly in blkget_put we remove the old bd_part_count
updates and call __blkget_put(..., 1). This call is moved to the end of
__blkdev_put to avoid nested locks of bd_mutex.
Finally the mutex_lock on whole->bd_mutex in do_open can be removed. It was
only really needed to protect bd_part_count, and that is now managed (and
protected) within the recursive call.
The observation that bd_part_count is central to the locking issues, and the
modifications to create __blkdev_put are from Peter Zijlstra.
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 02:36:16 -08:00
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2011-07-01 16:17:47 +02:00
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block: make blkdev_get/put() handle exclusive access
Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.
* blkdev_get/put() are the primary open and close functions.
* bd_claim/release() deal with exclusive open.
* open/close_bdev_exclusive() are combination of open and claim and
the other way around, respectively.
* bd_link/unlink_disk_holder() to create and remove holder/slave
symlinks.
* open_by_devnum() wraps bdget() + blkdev_get().
The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access. Reorganize the interface such that,
* blkdev_get() is extended to include exclusive access management.
@holder argument is added and, if is @FMODE_EXCL specified, it will
gain exclusive access atomically w.r.t. other exclusive accesses.
* blkdev_put() is similarly extended. It now takes @mode argument and
if @FMODE_EXCL is set, it releases an exclusive access. Also, when
the last exclusive claim is released, the holder/slave symlinks are
removed automatically.
* bd_claim/release() and close_bdev_exclusive() are no longer
necessary and either made static or removed.
* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
is no longer necessary and removed.
* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
and blkdev_get(). It also has an unexpected extra bdev_read_only()
test which probably should be moved into blkdev_get().
* open_by_devnum() is modified to take @holder argument and pass it to
blkdev_get().
Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should). This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.
open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features. Well, let's leave them for another day.
Most conversions are straight-forward. drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:17 +01:00
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2010-11-13 11:55:17 +01:00
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implement in-kernel gendisk events handling
Currently, media presence polling for removeable block devices is done
from userland. There are several issues with this.
* Polling is done by periodically opening the device. For SCSI
devices, the command sequence generated by such action involves a
few different commands including TEST_UNIT_READY. This behavior,
while perfectly legal, is different from Windows which only issues
single command, GET_EVENT_STATUS_NOTIFICATION. Unfortunately, some
ATAPI devices lock up after being periodically queried such command
sequences.
* There is no reliable and unintrusive way for a userland program to
tell whether the target device is safe for media presence polling.
For example, polling for media presence during an on-going burning
session can make it fail. The polling program can avoid this by
opening the device with O_EXCL but then it risks making a valid
exclusive user of the device fail w/ -EBUSY.
* Userland polling is unnecessarily heavy and in-kernel implementation
is lighter and better coordinated (workqueue, timer slack).
This patch implements framework for in-kernel disk event handling,
which includes media presence polling.
* bdops->check_events() is added, which supercedes ->media_changed().
It should check whether there's any pending event and return if so.
Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and
DISK_EVENT_EJECT_REQUEST. ->check_events() is guaranteed not to be
called parallelly.
* gendisk->events and ->async_events are added. These should be
initialized by block driver before passing the device to add_disk().
The former contains the mask of all supported events and the latter
the mask of all events which the device can report without polling.
/sys/block/*/events[_async] export these to userland.
* Kernel parameter block.events_dfl_poll_msecs controls the system
polling interval (default is 0 which means disable) and
/sys/block/*/events_poll_msecs control polling intervals for
individual devices (default is -1 meaning use system setting). Note
that if a device can report all supported events asynchronously and
its polling interval isn't explicitly set, the device won't be
polled regardless of the system polling interval.
* If a device is opened exclusively with write access, event checking
is automatically disabled until all write exclusive accesses are
released.
* There are event 'clearing' events. For example, both of currently
defined events are cleared after the device has been successfully
opened. This information is passed to ->check_events() callback
using @clearing argument as a hint.
* Event checking is always performed from system_nrt_wq and timer
slack is set to 25% for polling.
* Nothing changes for drivers which implement ->media_changed() but
not ->check_events(). Going forward, all drivers will be converted
to ->check_events() and ->media_change() will be dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-08 20:57:37 +01:00
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2011-07-01 16:17:47 +02:00
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implement in-kernel gendisk events handling
Currently, media presence polling for removeable block devices is done
from userland. There are several issues with this.
* Polling is done by periodically opening the device. For SCSI
devices, the command sequence generated by such action involves a
few different commands including TEST_UNIT_READY. This behavior,
while perfectly legal, is different from Windows which only issues
single command, GET_EVENT_STATUS_NOTIFICATION. Unfortunately, some
ATAPI devices lock up after being periodically queried such command
sequences.
* There is no reliable and unintrusive way for a userland program to
tell whether the target device is safe for media presence polling.
For example, polling for media presence during an on-going burning
session can make it fail. The polling program can avoid this by
opening the device with O_EXCL but then it risks making a valid
exclusive user of the device fail w/ -EBUSY.
* Userland polling is unnecessarily heavy and in-kernel implementation
is lighter and better coordinated (workqueue, timer slack).
This patch implements framework for in-kernel disk event handling,
which includes media presence polling.
* bdops->check_events() is added, which supercedes ->media_changed().
It should check whether there's any pending event and return if so.
Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and
DISK_EVENT_EJECT_REQUEST. ->check_events() is guaranteed not to be
called parallelly.
* gendisk->events and ->async_events are added. These should be
initialized by block driver before passing the device to add_disk().
The former contains the mask of all supported events and the latter
the mask of all events which the device can report without polling.
/sys/block/*/events[_async] export these to userland.
* Kernel parameter block.events_dfl_poll_msecs controls the system
polling interval (default is 0 which means disable) and
/sys/block/*/events_poll_msecs control polling intervals for
individual devices (default is -1 meaning use system setting). Note
that if a device can report all supported events asynchronously and
its polling interval isn't explicitly set, the device won't be
polled regardless of the system polling interval.
* If a device is opened exclusively with write access, event checking
is automatically disabled until all write exclusive accesses are
released.
* There are event 'clearing' events. For example, both of currently
defined events are cleared after the device has been successfully
opened. This information is passed to ->check_events() callback
using @clearing argument as a hint.
* Event checking is always performed from system_nrt_wq and timer
slack is set to 25% for polling.
* Nothing changes for drivers which implement ->media_changed() but
not ->check_events(). Going forward, all drivers will be converted
to ->check_events() and ->media_change() will be dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-08 20:57:37 +01:00
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2011-03-09 19:54:27 +01:00
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|
implement in-kernel gendisk events handling
Currently, media presence polling for removeable block devices is done
from userland. There are several issues with this.
* Polling is done by periodically opening the device. For SCSI
devices, the command sequence generated by such action involves a
few different commands including TEST_UNIT_READY. This behavior,
while perfectly legal, is different from Windows which only issues
single command, GET_EVENT_STATUS_NOTIFICATION. Unfortunately, some
ATAPI devices lock up after being periodically queried such command
sequences.
* There is no reliable and unintrusive way for a userland program to
tell whether the target device is safe for media presence polling.
For example, polling for media presence during an on-going burning
session can make it fail. The polling program can avoid this by
opening the device with O_EXCL but then it risks making a valid
exclusive user of the device fail w/ -EBUSY.
* Userland polling is unnecessarily heavy and in-kernel implementation
is lighter and better coordinated (workqueue, timer slack).
This patch implements framework for in-kernel disk event handling,
which includes media presence polling.
* bdops->check_events() is added, which supercedes ->media_changed().
It should check whether there's any pending event and return if so.
Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and
DISK_EVENT_EJECT_REQUEST. ->check_events() is guaranteed not to be
called parallelly.
* gendisk->events and ->async_events are added. These should be
initialized by block driver before passing the device to add_disk().
The former contains the mask of all supported events and the latter
the mask of all events which the device can report without polling.
/sys/block/*/events[_async] export these to userland.
* Kernel parameter block.events_dfl_poll_msecs controls the system
polling interval (default is 0 which means disable) and
/sys/block/*/events_poll_msecs control polling intervals for
individual devices (default is -1 meaning use system setting). Note
that if a device can report all supported events asynchronously and
its polling interval isn't explicitly set, the device won't be
polled regardless of the system polling interval.
* If a device is opened exclusively with write access, event checking
is automatically disabled until all write exclusive accesses are
released.
* There are event 'clearing' events. For example, both of currently
defined events are cleared after the device has been successfully
opened. This information is passed to ->check_events() callback
using @clearing argument as a hint.
* Event checking is always performed from system_nrt_wq and timer
slack is set to 25% for polling.
* Nothing changes for drivers which implement ->media_changed() but
not ->check_events(). Going forward, all drivers will be converted
to ->check_events() and ->media_change() will be dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-08 20:57:37 +01:00
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2011-07-01 16:17:47 +02:00
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2013-05-05 22:11:03 -04:00
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|
[PATCH] lockdep: simplify some aspects of bd_mutex nesting
When we open (actually blkdev_get) a partition we need to also open (get) the
whole device that holds the partition. The involves some limited recursion.
This patch tries to simplify some aspects of this.
As well as opening the whole device, we need to increment ->bd_part_count when
a partition is opened (this is used by rescan_partitions to avoid a rescan if
any partition is active, as that would be confusing).
The main change this patch makes is to move the inc/dec of bd_part_count into
blkdev_{get,put} for the whole rather than doing it in blkdev_{get,put} for
the partition.
More specifically, we introduce __blkdev_get and __blkdev_put which do exactly
what blkdev_{get,put} did, only with an extra "for_part" argument
(blkget_{get,put} then call the __ version with a '0' for the extra argument).
If for_part is 1, then the blkdev is being get(put) because a partition is
being opened(closed) for the first(last) time, and so bd_part_count should be
updated (on success). The particular advantage of pushing this function down
is that the bd_mutex lock (which is needed to update bd_part_count) is already
held at the lower level.
Note that this slightly changes the semantics of bd_part_count. Instead of
updating it whenever a partition is opened or released, it is now only updated
on the first open or last release. This is an adequate semantic as it is only
ever tested for "== 0".
Having introduced these functions we remove the current bd_part_count updates
from do_open (which is really the body of blkdev_get) and call
__blkdev_get(... 1). Similarly in blkget_put we remove the old bd_part_count
updates and call __blkget_put(..., 1). This call is moved to the end of
__blkdev_put to avoid nested locks of bd_mutex.
Finally the mutex_lock on whole->bd_mutex in do_open can be removed. It was
only really needed to protect bd_part_count, and that is now managed (and
protected) within the recursive call.
The observation that bd_part_count is central to the locking issues, and the
modifications to create __blkdev_put are from Peter Zijlstra.
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 02:36:16 -08:00
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|
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|
2006-12-08 02:36:13 -08:00
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2005-04-16 15:20:36 -07:00
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2015-10-28 07:48:19 +09:00
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2013-05-05 22:11:03 -04:00
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2005-04-16 15:20:36 -07:00
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2005-06-23 00:10:15 -07:00
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2005-04-16 15:20:36 -07:00
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2015-10-28 07:48:19 +09:00
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2008-09-19 03:17:36 -04:00
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2008-11-05 14:58:42 +01:00
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2008-09-19 03:17:36 -04:00
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2008-11-05 14:58:42 +01:00
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2008-09-19 03:17:36 -04:00
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2005-04-16 15:20:36 -07:00
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2009-08-20 17:43:41 +02:00
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2014-04-03 03:21:50 -04:00
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2009-08-20 17:43:41 +02:00
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2015-10-28 07:48:19 +09:00
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2015-04-07 11:35:14 -04:00
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2012-08-02 09:50:39 +02:00
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2009-08-20 17:43:41 +02:00
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2015-04-07 11:28:12 -04:00
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2015-04-07 11:35:14 -04:00
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2015-04-07 11:28:12 -04:00
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2015-04-07 11:35:14 -04:00
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2015-04-07 11:28:12 -04:00
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2015-04-07 11:35:14 -04:00
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2009-08-20 17:43:41 +02:00
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2012-08-02 09:50:39 +02:00
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2014-04-03 03:21:50 -04:00
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2016-04-07 08:52:01 -07:00
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2012-08-02 09:50:39 +02:00
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2009-08-20 17:43:41 +02:00
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2014-04-03 03:21:50 -04:00
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2009-08-20 17:43:41 +02:00
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2014-09-29 10:21:10 -04:00
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2012-12-07 16:48:39 -08:00
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2015-10-28 07:48:19 +09:00
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2012-12-07 16:48:39 -08:00
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2014-04-02 20:02:21 -04:00
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2012-12-07 16:48:39 -08:00
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2014-04-02 20:02:21 -04:00
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2012-12-07 16:48:39 -08:00
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2014-09-29 10:21:10 -04:00
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2012-12-07 16:48:39 -08:00
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2009-01-03 09:47:09 -05:00
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2016-02-26 15:19:55 -08:00
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2008-02-18 13:48:31 +01:00
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2005-04-16 15:20:36 -07:00
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2014-10-09 15:26:58 -07:00
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2005-04-16 15:20:36 -07:00
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2007-10-16 01:25:04 -07:00
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2016-02-26 15:19:55 -08:00
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2009-01-03 09:47:09 -05:00
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2005-04-16 15:20:36 -07:00
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2013-07-03 15:02:05 -07:00
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2005-04-16 15:20:36 -07:00
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2016-10-11 13:51:11 -07:00
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2006-03-28 01:56:42 -08:00
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2005-04-16 15:20:36 -07:00
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2014-04-02 20:02:21 -04:00
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2014-04-03 03:21:50 -04:00
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2016-05-07 11:40:28 -07:00
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2010-04-06 14:35:00 -07:00
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2005-06-23 00:10:15 -07:00
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2005-04-16 15:20:36 -07:00
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2012-11-29 10:49:50 -08:00
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2014-04-05 04:27:08 -04:00
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2016-10-11 13:51:11 -07:00
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2005-04-16 15:20:36 -07:00
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2008-09-19 03:17:36 -04:00
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2005-04-16 15:20:36 -07:00
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2009-01-06 14:41:15 -08:00
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2005-04-16 15:20:36 -07:00
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2008-10-09 10:42:38 +02:00
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2005-04-16 15:20:36 -07:00
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2008-08-02 01:04:36 -04:00
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2005-04-16 15:20:36 -07:00
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2008-08-02 01:04:36 -04:00
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2005-04-16 15:20:36 -07:00
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2008-08-02 01:04:36 -04:00
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2005-04-16 15:20:36 -07:00
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2008-08-02 01:04:36 -04:00
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2005-04-16 15:20:36 -07:00
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2015-03-17 22:26:21 +00:00
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2005-04-16 15:20:36 -07:00
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2016-06-09 15:34:02 -05:00
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2005-04-16 15:20:36 -07:00
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2008-08-02 01:04:36 -04:00
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2005-04-16 15:20:36 -07:00
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2008-08-01 05:00:11 -04:00
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2005-04-16 15:20:36 -07:00
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2011-02-24 17:25:47 +11:00
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2006-08-29 19:06:11 +01:00
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2011-02-24 17:25:47 +11:00
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2006-08-29 19:06:11 +01:00
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2007-05-06 14:49:54 -07:00
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2006-08-29 19:06:11 +01:00
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2012-07-03 16:45:31 +02:00
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2015-03-04 12:37:22 -05:00
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2012-07-03 16:45:31 +02:00
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2016-12-01 09:18:28 +01:00
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2012-07-03 16:45:31 +02:00
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2015-03-04 12:37:22 -05:00
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2012-07-03 16:45:31 +02:00
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2015-03-04 12:37:22 -05:00
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2012-07-03 16:45:31 +02:00
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2015-03-04 12:37:22 -05:00
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2012-07-03 16:45:31 +02:00
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2016-12-01 09:18:28 +01:00
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2012-07-03 16:45:31 +02:00
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2016-12-01 09:18:28 +01:00
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2012-07-03 16:45:31 +02:00
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2015-03-04 12:37:22 -05:00
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2012-07-03 16:45:31 +02:00
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2015-03-04 12:37:22 -05:00
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2012-07-03 16:45:31 +02:00
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