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From: Jan Kara <jack@suse.cz>
To: linux-fsdevel@vger.kernel.org
Cc: Jan Kara <jack@suse.cz>,
	linux-nvdimm@lists.01.org, linux-mm@kvack.org,
	linux-ext4@vger.kernel.org
Subject: [PATCH 14/18] dax: Define DAX lock bit for radix tree exceptional entry
Date: Mon, 18 Apr 2016 23:35:37 +0200	[thread overview]
Message-ID: <1461015341-20153-15-git-send-email-jack@suse.cz> (raw)
In-Reply-To: <1461015341-20153-1-git-send-email-jack@suse.cz>

We will use lowest available bit in the radix tree exceptional entry for
locking of the entry. Define it. Also clean up definitions of DAX entry
type bits in DAX exceptional entries to use defined constants instead of
hardcoding numbers and cleanup checking of these bits to not rely on how
other bits in the entry are set.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/dax.c            | 17 +++++++++++------
 include/linux/dax.h |  3 +++
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 388327f56fa8..3e491eb37bc4 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -32,14 +32,19 @@
 #include <linux/pfn_t.h>
 #include <linux/sizes.h>
 
-#define RADIX_DAX_MASK	0xf
-#define RADIX_DAX_SHIFT	4
-#define RADIX_DAX_PTE  (0x4 | RADIX_TREE_EXCEPTIONAL_ENTRY)
-#define RADIX_DAX_PMD  (0x8 | RADIX_TREE_EXCEPTIONAL_ENTRY)
-#define RADIX_DAX_TYPE(entry) ((unsigned long)entry & RADIX_DAX_MASK)
+/*
+ * We use lowest available bit in exceptional entry for locking, other two
+ * bits to determine entry type. In total 3 special bits.
+ */
+#define RADIX_DAX_SHIFT	(RADIX_TREE_EXCEPTIONAL_SHIFT + 3)
+#define RADIX_DAX_PTE (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 1))
+#define RADIX_DAX_PMD (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 2))
+#define RADIX_DAX_TYPE_MASK (RADIX_DAX_PTE | RADIX_DAX_PMD)
+#define RADIX_DAX_TYPE(entry) ((unsigned long)entry & RADIX_DAX_TYPE_MASK)
 #define RADIX_DAX_SECTOR(entry) (((unsigned long)entry >> RADIX_DAX_SHIFT))
 #define RADIX_DAX_ENTRY(sector, pmd) ((void *)((unsigned long)sector << \
-		RADIX_DAX_SHIFT | (pmd ? RADIX_DAX_PMD : RADIX_DAX_PTE)))
+		RADIX_DAX_SHIFT | (pmd ? RADIX_DAX_PMD : RADIX_DAX_PTE) | \
+		RADIX_TREE_EXCEPTIONAL_ENTRY))
 
 static long dax_map_atomic(struct block_device *bdev, struct blk_dax_ctl *dax)
 {
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 0591f4853228..bef5c44f71b3 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -5,6 +5,9 @@
 #include <linux/mm.h>
 #include <asm/pgtable.h>
 
+/* We use lowest available exceptional entry bit for locking */
+#define RADIX_DAX_ENTRY_LOCK (1 << RADIX_TREE_EXCEPTIONAL_SHIFT)
+
 ssize_t dax_do_io(struct kiocb *, struct inode *, struct iov_iter *, loff_t,
 		  get_block_t, dio_iodone_t, int flags);
 int dax_clear_sectors(struct block_device *bdev, sector_t _sector, long _size);
-- 
2.6.6

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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 14/18] dax: Define DAX lock bit for radix tree exceptional entry
Date: Mon, 18 Apr 2016 23:35:37 +0200	[thread overview]
Message-ID: <1461015341-20153-15-git-send-email-jack@suse.cz> (raw)
In-Reply-To: <1461015341-20153-1-git-send-email-jack@suse.cz>

We will use lowest available bit in the radix tree exceptional entry for
locking of the entry. Define it. Also clean up definitions of DAX entry
type bits in DAX exceptional entries to use defined constants instead of
hardcoding numbers and cleanup checking of these bits to not rely on how
other bits in the entry are set.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/dax.c            | 17 +++++++++++------
 include/linux/dax.h |  3 +++
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 388327f56fa8..3e491eb37bc4 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -32,14 +32,19 @@
 #include <linux/pfn_t.h>
 #include <linux/sizes.h>
 
-#define RADIX_DAX_MASK	0xf
-#define RADIX_DAX_SHIFT	4
-#define RADIX_DAX_PTE  (0x4 | RADIX_TREE_EXCEPTIONAL_ENTRY)
-#define RADIX_DAX_PMD  (0x8 | RADIX_TREE_EXCEPTIONAL_ENTRY)
-#define RADIX_DAX_TYPE(entry) ((unsigned long)entry & RADIX_DAX_MASK)
+/*
+ * We use lowest available bit in exceptional entry for locking, other two
+ * bits to determine entry type. In total 3 special bits.
+ */
+#define RADIX_DAX_SHIFT	(RADIX_TREE_EXCEPTIONAL_SHIFT + 3)
+#define RADIX_DAX_PTE (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 1))
+#define RADIX_DAX_PMD (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 2))
+#define RADIX_DAX_TYPE_MASK (RADIX_DAX_PTE | RADIX_DAX_PMD)
+#define RADIX_DAX_TYPE(entry) ((unsigned long)entry & RADIX_DAX_TYPE_MASK)
 #define RADIX_DAX_SECTOR(entry) (((unsigned long)entry >> RADIX_DAX_SHIFT))
 #define RADIX_DAX_ENTRY(sector, pmd) ((void *)((unsigned long)sector << \
-		RADIX_DAX_SHIFT | (pmd ? RADIX_DAX_PMD : RADIX_DAX_PTE)))
+		RADIX_DAX_SHIFT | (pmd ? RADIX_DAX_PMD : RADIX_DAX_PTE) | \
+		RADIX_TREE_EXCEPTIONAL_ENTRY))
 
 static long dax_map_atomic(struct block_device *bdev, struct blk_dax_ctl *dax)
 {
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 0591f4853228..bef5c44f71b3 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -5,6 +5,9 @@
 #include <linux/mm.h>
 #include <asm/pgtable.h>
 
+/* We use lowest available exceptional entry bit for locking */
+#define RADIX_DAX_ENTRY_LOCK (1 << RADIX_TREE_EXCEPTIONAL_SHIFT)
+
 ssize_t dax_do_io(struct kiocb *, struct inode *, struct iov_iter *, loff_t,
 		  get_block_t, dio_iodone_t, int flags);
 int dax_clear_sectors(struct block_device *bdev, sector_t _sector, long _size);
-- 
2.6.6

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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 14/18] dax: Define DAX lock bit for radix tree exceptional entry
Date: Mon, 18 Apr 2016 23:35:37 +0200	[thread overview]
Message-ID: <1461015341-20153-15-git-send-email-jack@suse.cz> (raw)
In-Reply-To: <1461015341-20153-1-git-send-email-jack@suse.cz>

We will use lowest available bit in the radix tree exceptional entry for
locking of the entry. Define it. Also clean up definitions of DAX entry
type bits in DAX exceptional entries to use defined constants instead of
hardcoding numbers and cleanup checking of these bits to not rely on how
other bits in the entry are set.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/dax.c            | 17 +++++++++++------
 include/linux/dax.h |  3 +++
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 388327f56fa8..3e491eb37bc4 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -32,14 +32,19 @@
 #include <linux/pfn_t.h>
 #include <linux/sizes.h>
 
-#define RADIX_DAX_MASK	0xf
-#define RADIX_DAX_SHIFT	4
-#define RADIX_DAX_PTE  (0x4 | RADIX_TREE_EXCEPTIONAL_ENTRY)
-#define RADIX_DAX_PMD  (0x8 | RADIX_TREE_EXCEPTIONAL_ENTRY)
-#define RADIX_DAX_TYPE(entry) ((unsigned long)entry & RADIX_DAX_MASK)
+/*
+ * We use lowest available bit in exceptional entry for locking, other two
+ * bits to determine entry type. In total 3 special bits.
+ */
+#define RADIX_DAX_SHIFT	(RADIX_TREE_EXCEPTIONAL_SHIFT + 3)
+#define RADIX_DAX_PTE (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 1))
+#define RADIX_DAX_PMD (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 2))
+#define RADIX_DAX_TYPE_MASK (RADIX_DAX_PTE | RADIX_DAX_PMD)
+#define RADIX_DAX_TYPE(entry) ((unsigned long)entry & RADIX_DAX_TYPE_MASK)
 #define RADIX_DAX_SECTOR(entry) (((unsigned long)entry >> RADIX_DAX_SHIFT))
 #define RADIX_DAX_ENTRY(sector, pmd) ((void *)((unsigned long)sector << \
-		RADIX_DAX_SHIFT | (pmd ? RADIX_DAX_PMD : RADIX_DAX_PTE)))
+		RADIX_DAX_SHIFT | (pmd ? RADIX_DAX_PMD : RADIX_DAX_PTE) | \
+		RADIX_TREE_EXCEPTIONAL_ENTRY))
 
 static long dax_map_atomic(struct block_device *bdev, struct blk_dax_ctl *dax)
 {
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 0591f4853228..bef5c44f71b3 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -5,6 +5,9 @@
 #include <linux/mm.h>
 #include <asm/pgtable.h>
 
+/* We use lowest available exceptional entry bit for locking */
+#define RADIX_DAX_ENTRY_LOCK (1 << RADIX_TREE_EXCEPTIONAL_SHIFT)
+
 ssize_t dax_do_io(struct kiocb *, struct inode *, struct iov_iter *, loff_t,
 		  get_block_t, dio_iodone_t, int flags);
 int dax_clear_sectors(struct block_device *bdev, sector_t _sector, long _size);
-- 
2.6.6


  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 ` Jan Kara [this message]
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
2016-04-29 20:03   ` Ross Zwisler
2016-04-29 20:03     ` Ross Zwisler
2016-04-29 20:03     ` Ross Zwisler
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
2016-04-18 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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