From: Jan Kara <jack@suse.cz>
To: linux-fsdevel@vger.kernel.org
Cc: linux-ext4@vger.kernel.org, linux-mm@kvack.org,
Ross Zwisler <ross.zwisler@linux.intel.com>,
Dan Williams <dan.j.williams@intel.com>,
linux-nvdimm@lists.01.org, Matthew Wilcox <willy@linux.intel.com>,
Jan Kara <jack@suse.cz>
Subject: [PATCH 15/18] dax: Allow DAX code to replace exceptional entries
Date: Mon, 18 Apr 2016 23:35:38 +0200 [thread overview]
Message-ID: <1461015341-20153-16-git-send-email-jack@suse.cz> (raw)
In-Reply-To: <1461015341-20153-1-git-send-email-jack@suse.cz>
Currently we forbid page_cache_tree_insert() to replace exceptional radix
tree entries for DAX inodes. However to make DAX faults race free we will
lock radix tree entries and when hole is created, we need to replace
such locked radix tree entry with a hole page. So modify
page_cache_tree_insert() to allow that.
Signed-off-by: Jan Kara <jack@suse.cz>
---
include/linux/dax.h | 1 +
mm/filemap.c | 18 +++++++++++-------
2 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/include/linux/dax.h b/include/linux/dax.h
index bef5c44f71b3..fd4aeae65ed7 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -3,6 +3,7 @@
#include <linux/fs.h>
#include <linux/mm.h>
+#include <linux/radix-tree.h>
#include <asm/pgtable.h>
/* We use lowest available exceptional entry bit for locking */
diff --git a/mm/filemap.c b/mm/filemap.c
index f2479af09da9..3effd5c8f2f6 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -597,14 +597,18 @@ static int page_cache_tree_insert(struct address_space *mapping,
if (!radix_tree_exceptional_entry(p))
return -EEXIST;
- if (WARN_ON(dax_mapping(mapping)))
- return -EINVAL;
-
- if (shadowp)
- *shadowp = p;
mapping->nrexceptional--;
- if (node)
- workingset_node_shadows_dec(node);
+ if (!dax_mapping(mapping)) {
+ if (shadowp)
+ *shadowp = p;
+ if (node)
+ workingset_node_shadows_dec(node);
+ } else {
+ /* DAX can replace empty locked entry with a hole */
+ WARN_ON_ONCE(p !=
+ (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY |
+ RADIX_DAX_ENTRY_LOCK));
+ }
}
radix_tree_replace_slot(slot, page);
mapping->nrpages++;
--
2.6.6
WARNING: multiple messages have this Message-ID (diff)
From: Jan Kara <jack@suse.cz>
To: linux-fsdevel@vger.kernel.org
Cc: linux-ext4@vger.kernel.org, linux-mm@kvack.org,
Ross Zwisler <ross.zwisler@linux.intel.com>,
Dan Williams <dan.j.williams@intel.com>,
linux-nvdimm@lists.01.org, Matthew Wilcox <willy@linux.intel.com>,
Jan Kara <jack@suse.cz>
Subject: [PATCH 15/18] dax: Allow DAX code to replace exceptional entries
Date: Mon, 18 Apr 2016 23:35:38 +0200 [thread overview]
Message-ID: <1461015341-20153-16-git-send-email-jack@suse.cz> (raw)
In-Reply-To: <1461015341-20153-1-git-send-email-jack@suse.cz>
Currently we forbid page_cache_tree_insert() to replace exceptional radix
tree entries for DAX inodes. However to make DAX faults race free we will
lock radix tree entries and when hole is created, we need to replace
such locked radix tree entry with a hole page. So modify
page_cache_tree_insert() to allow that.
Signed-off-by: Jan Kara <jack@suse.cz>
---
include/linux/dax.h | 1 +
mm/filemap.c | 18 +++++++++++-------
2 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/include/linux/dax.h b/include/linux/dax.h
index bef5c44f71b3..fd4aeae65ed7 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -3,6 +3,7 @@
#include <linux/fs.h>
#include <linux/mm.h>
+#include <linux/radix-tree.h>
#include <asm/pgtable.h>
/* We use lowest available exceptional entry bit for locking */
diff --git a/mm/filemap.c b/mm/filemap.c
index f2479af09da9..3effd5c8f2f6 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -597,14 +597,18 @@ static int page_cache_tree_insert(struct address_space *mapping,
if (!radix_tree_exceptional_entry(p))
return -EEXIST;
- if (WARN_ON(dax_mapping(mapping)))
- return -EINVAL;
WARNING: multiple messages have this Message-ID (diff)
From: Jan Kara <jack@suse.cz>
To: linux-fsdevel@vger.kernel.org
Cc: linux-ext4@vger.kernel.org, linux-mm@kvack.org,
Ross Zwisler <ross.zwisler@linux.intel.com>,
Dan Williams <dan.j.williams@intel.com>,
linux-nvdimm@lists.01.org, Matthew Wilcox <willy@linux.intel.com>,
Jan Kara <jack@suse.cz>
Subject: [PATCH 15/18] dax: Allow DAX code to replace exceptional entries
Date: Mon, 18 Apr 2016 23:35:38 +0200 [thread overview]
Message-ID: <1461015341-20153-16-git-send-email-jack@suse.cz> (raw)
In-Reply-To: <1461015341-20153-1-git-send-email-jack@suse.cz>
Currently we forbid page_cache_tree_insert() to replace exceptional radix
tree entries for DAX inodes. However to make DAX faults race free we will
lock radix tree entries and when hole is created, we need to replace
such locked radix tree entry with a hole page. So modify
page_cache_tree_insert() to allow that.
Signed-off-by: Jan Kara <jack@suse.cz>
---
include/linux/dax.h | 1 +
mm/filemap.c | 18 +++++++++++-------
2 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/include/linux/dax.h b/include/linux/dax.h
index bef5c44f71b3..fd4aeae65ed7 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -3,6 +3,7 @@
#include <linux/fs.h>
#include <linux/mm.h>
+#include <linux/radix-tree.h>
#include <asm/pgtable.h>
/* We use lowest available exceptional entry bit for locking */
diff --git a/mm/filemap.c b/mm/filemap.c
index f2479af09da9..3effd5c8f2f6 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -597,14 +597,18 @@ static int page_cache_tree_insert(struct address_space *mapping,
if (!radix_tree_exceptional_entry(p))
return -EEXIST;
- if (WARN_ON(dax_mapping(mapping)))
- return -EINVAL;
-
- if (shadowp)
- *shadowp = p;
mapping->nrexceptional--;
- if (node)
- workingset_node_shadows_dec(node);
+ if (!dax_mapping(mapping)) {
+ if (shadowp)
+ *shadowp = p;
+ if (node)
+ workingset_node_shadows_dec(node);
+ } else {
+ /* DAX can replace empty locked entry with a hole */
+ WARN_ON_ONCE(p !=
+ (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY |
+ RADIX_DAX_ENTRY_LOCK));
+ }
}
radix_tree_replace_slot(slot, page);
mapping->nrpages++;
--
2.6.6
--
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next prev parent reply other threads:[~2016-04-18 21:35 UTC|newest]
Thread overview: 122+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-18 21:35 [RFC v3] [PATCH 0/18] DAX page fault locking Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` [PATCH 01/18] ext4: Handle transient ENOSPC properly for DAX Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` [PATCH 02/18] ext4: Fix race in transient ENOSPC detection Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` [PATCH 03/18] DAX: move RADIX_DAX_ definitions to dax.c Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` [PATCH 04/18] dax: Remove complete_unwritten argument Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` [PATCH 05/18] ext2: Avoid DAX zeroing to corrupt data Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-29 16:30 ` Ross Zwisler
2016-04-29 16:30 ` Ross Zwisler
2016-04-29 16:30 ` Ross Zwisler
2016-04-18 21:35 ` [PATCH 06/18] dax: Remove dead zeroing code from fault handlers Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-29 16:48 ` Ross Zwisler
2016-04-18 21:35 ` [PATCH 07/18] ext4: Refactor direct IO code Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` [PATCH 08/18] ext4: Pre-zero allocated blocks for DAX IO Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-29 18:01 ` Ross Zwisler
2016-04-29 18:01 ` Ross Zwisler
2016-04-29 18:01 ` Ross Zwisler
2016-05-02 13:09 ` Jan Kara
2016-05-02 13:09 ` Jan Kara
2016-04-18 21:35 ` [PATCH 09/18] dax: Remove zeroing from dax_io() Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-29 18:56 ` Ross Zwisler
2016-04-29 18:56 ` Ross Zwisler
2016-04-18 21:35 ` [PATCH 10/18] dax: Remove pointless writeback from dax_do_io() Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-29 19:00 ` Ross Zwisler
2016-04-29 19:00 ` Ross Zwisler
2016-04-29 19:00 ` Ross Zwisler
2016-04-18 21:35 ` [PATCH 11/18] dax: Fix condition for filling of PMD holes Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-29 19:08 ` Ross Zwisler
2016-04-29 19:08 ` Ross Zwisler
2016-04-29 19:08 ` Ross Zwisler
2016-05-02 13:16 ` Jan Kara
2016-05-02 13:16 ` Jan Kara
2016-04-18 21:35 ` [PATCH 12/18] dax: Remove redundant inode size checks Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` [PATCH 13/18] dax: Make huge page handling depend of CONFIG_BROKEN Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-29 19:53 ` Ross Zwisler
2016-04-29 19:53 ` Ross Zwisler
2016-05-02 13:19 ` Jan Kara
2016-05-02 13:19 ` Jan Kara
2016-05-02 13:19 ` Jan Kara
2016-04-18 21:35 ` [PATCH 14/18] dax: Define DAX lock bit for radix tree exceptional entry Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-29 20:03 ` Ross Zwisler
2016-04-29 20:03 ` Ross Zwisler
2016-04-29 20:03 ` Ross Zwisler
2016-04-18 21:35 ` Jan Kara [this message]
2016-04-18 21:35 ` [PATCH 15/18] dax: Allow DAX code to replace exceptional entries Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-29 20:29 ` Ross Zwisler
2016-04-29 20:29 ` Ross Zwisler
2016-04-18 21:35 ` [PATCH 16/18] dax: New fault locking Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-27 4:27 ` NeilBrown
2016-04-27 4:27 ` NeilBrown
2016-05-06 4:13 ` Ross Zwisler
2016-05-06 4:13 ` Ross Zwisler
2016-05-06 4:13 ` Ross Zwisler
2016-05-10 12:27 ` Jan Kara
2016-05-10 12:27 ` Jan Kara
2016-05-11 19:26 ` Ross Zwisler
2016-05-11 19:26 ` Ross Zwisler
2016-05-12 7:58 ` Jan Kara
2016-05-12 7:58 ` Jan Kara
2016-04-18 21:35 ` [PATCH 17/18] dax: Use radix tree entry lock to protect cow faults Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-19 11:46 ` Jerome Glisse
2016-04-19 11:46 ` Jerome Glisse
2016-04-19 11:46 ` Jerome Glisse
2016-04-19 14:33 ` Jan Kara
2016-04-19 14:33 ` Jan Kara
2016-04-19 14:33 ` Jan Kara
2016-04-19 15:19 ` Jerome Glisse
2016-04-19 15:19 ` Jerome Glisse
2016-04-19 15:19 ` Jerome Glisse
2016-04-19 15:19 ` Jerome Glisse
2016-04-18 21:35 ` [PATCH 18/18] dax: Remove i_mmap_lock protection Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-04-18 21:35 ` Jan Kara
2016-05-06 3:35 ` [RFC v3] [PATCH 0/18] DAX page fault locking Ross Zwisler
2016-05-06 3:35 ` Ross Zwisler
2016-05-06 20:33 ` Ross Zwisler
2016-05-06 20:33 ` Ross Zwisler
2016-05-09 9:38 ` Jan Kara
2016-05-09 9:38 ` Jan Kara
2016-05-09 9:38 ` Jan Kara
2016-05-10 15:28 ` Jan Kara
2016-05-10 15:28 ` Jan Kara
2016-05-10 15:28 ` Jan Kara
2016-05-10 20:30 ` Ross Zwisler
2016-05-10 20:30 ` Ross Zwisler
2016-05-10 20:30 ` Ross Zwisler
2016-05-10 22:39 ` Ross Zwisler
2016-05-10 22:39 ` Ross Zwisler
2016-05-11 9:19 ` Jan Kara
2016-05-11 9:19 ` Jan Kara
2016-05-11 9:19 ` Jan Kara
2016-05-11 15:52 ` Ross Zwisler
2016-05-11 15:52 ` Ross Zwisler
2016-05-11 15:52 ` Ross Zwisler
2016-05-09 21:28 ` Verma, Vishal L
2016-05-10 11:52 ` Jan Kara
2016-05-10 11:52 ` Jan Kara
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