From: Matthew Wilcox <willy@infradead.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-fsdevel@vger.kernel.org,
Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>,
linux-nilfs@vger.kernel.org
Subject: [PATCH v9 15/61] xarray: Add xa_get_tag, xa_set_tag and xa_clear_tag
Date: Tue, 13 Mar 2018 06:25:53 -0700 [thread overview]
Message-ID: <20180313132639.17387-16-willy@infradead.org> (raw)
In-Reply-To: <20180313132639.17387-1-willy@infradead.org>
From: Matthew Wilcox <mawilcox@microsoft.com>
XArray tags are slightly more strongly typed than the radix tree tags,
but occupy the same bits. This commit also adds the xas_ family of tag
operations, for cases where the caller is already holding the lock, and
xa_tagged() to ask whether any array member has a particular tag set.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
include/linux/xarray.h | 41 +++++++
lib/xarray.c | 235 +++++++++++++++++++++++++++++++++++++++++
tools/include/linux/spinlock.h | 6 ++
3 files changed, 282 insertions(+)
diff --git a/include/linux/xarray.h b/include/linux/xarray.h
index 5845187c1ce8..1cf012256eab 100644
--- a/include/linux/xarray.h
+++ b/include/linux/xarray.h
@@ -11,6 +11,7 @@
#include <linux/bug.h>
#include <linux/compiler.h>
+#include <linux/gfp.h>
#include <linux/kconfig.h>
#include <linux/kernel.h>
#include <linux/rcupdate.h>
@@ -149,6 +150,20 @@ static inline int xa_err(void *entry)
return 0;
}
+typedef unsigned __bitwise xa_tag_t;
+#define XA_TAG_0 ((__force xa_tag_t)0U)
+#define XA_TAG_1 ((__force xa_tag_t)1U)
+#define XA_TAG_2 ((__force xa_tag_t)2U)
+#define XA_PRESENT ((__force xa_tag_t)8U)
+#define XA_TAG_MAX XA_TAG_2
+
+/*
+ * Values for xa_flags. The radix tree stores its GFP flags in the xa_flags,
+ * and we remain compatible with that.
+ */
+#define XA_FLAGS_TAG(tag) ((__force gfp_t)((1U << __GFP_BITS_SHIFT) << \
+ (__force unsigned)(tag)))
+
/**
* struct xarray - The anchor of the XArray.
* @xa_lock: Lock that protects the contents of the XArray.
@@ -195,6 +210,9 @@ struct xarray {
void xa_init_flags(struct xarray *, gfp_t flags);
void *xa_load(struct xarray *, unsigned long index);
+bool xa_get_tag(struct xarray *, unsigned long index, xa_tag_t);
+void xa_set_tag(struct xarray *, unsigned long index, xa_tag_t);
+void xa_clear_tag(struct xarray *, unsigned long index, xa_tag_t);
/**
* xa_init() - Initialise an empty XArray.
@@ -209,6 +227,19 @@ static inline void xa_init(struct xarray *xa)
xa_init_flags(xa, 0);
}
+/**
+ * xa_tagged() - Inquire whether any entry in this array has a tag set
+ * @xa: Array
+ * @tag: Tag value
+ *
+ * Context: Any context.
+ * Return: %true if any entry has this tag set.
+ */
+static inline bool xa_tagged(const struct xarray *xa, xa_tag_t tag)
+{
+ return xa->xa_flags & XA_FLAGS_TAG(tag);
+}
+
#define xa_trylock(xa) spin_trylock(&(xa)->xa_lock)
#define xa_lock(xa) spin_lock(&(xa)->xa_lock)
#define xa_unlock(xa) spin_unlock(&(xa)->xa_lock)
@@ -221,6 +252,12 @@ static inline void xa_init(struct xarray *xa)
#define xa_unlock_irqrestore(xa, flags) \
spin_unlock_irqrestore(&(xa)->xa_lock, flags)
+/*
+ * Versions of the normal API which require the caller to hold the xa_lock.
+ */
+void __xa_set_tag(struct xarray *, unsigned long index, xa_tag_t);
+void __xa_clear_tag(struct xarray *, unsigned long index, xa_tag_t);
+
/* Everything below here is the Advanced API. Proceed with caution. */
/*
@@ -534,6 +571,10 @@ static inline bool xas_retry(struct xa_state *xas, const void *entry)
void *xas_load(struct xa_state *);
+bool xas_get_tag(const struct xa_state *, xa_tag_t);
+void xas_set_tag(const struct xa_state *, xa_tag_t);
+void xas_clear_tag(const struct xa_state *, xa_tag_t);
+
/**
* xas_reload() - Refetch an entry from the xarray.
* @xas: XArray operation state.
diff --git a/lib/xarray.c b/lib/xarray.c
index 195cb130d53d..ca25a7a4a4fa 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -5,6 +5,7 @@
* Author: Matthew Wilcox <mawilcox@microsoft.com>
*/
+#include <linux/bitmap.h>
#include <linux/export.h>
#include <linux/xarray.h>
@@ -24,6 +25,55 @@
* @entry refers to something stored in a slot in the xarray
*/
+static inline struct xa_node *xa_parent(struct xarray *xa,
+ const struct xa_node *node)
+{
+ return rcu_dereference_check(node->parent,
+ lockdep_is_held(&xa->xa_lock));
+}
+
+static inline struct xa_node *xa_parent_locked(struct xarray *xa,
+ const struct xa_node *node)
+{
+ return rcu_dereference_protected(node->parent,
+ lockdep_is_held(&xa->xa_lock));
+}
+
+static inline void xa_tag_set(struct xarray *xa, xa_tag_t tag)
+{
+ if (!(xa->xa_flags & XA_FLAGS_TAG(tag)))
+ xa->xa_flags |= XA_FLAGS_TAG(tag);
+}
+
+static inline void xa_tag_clear(struct xarray *xa, xa_tag_t tag)
+{
+ if (xa->xa_flags & XA_FLAGS_TAG(tag))
+ xa->xa_flags &= ~(XA_FLAGS_TAG(tag));
+}
+
+static inline bool node_get_tag(const struct xa_node *node, unsigned int offset,
+ xa_tag_t tag)
+{
+ return test_bit(offset, node->tags[(__force unsigned)tag]);
+}
+
+static inline void node_set_tag(struct xa_node *node, unsigned int offset,
+ xa_tag_t tag)
+{
+ __set_bit(offset, node->tags[(__force unsigned)tag]);
+}
+
+static inline void node_clear_tag(struct xa_node *node, unsigned int offset,
+ xa_tag_t tag)
+{
+ __clear_bit(offset, node->tags[(__force unsigned)tag]);
+}
+
+static inline bool node_any_tag(struct xa_node *node, xa_tag_t tag)
+{
+ return !bitmap_empty(node->tags[(__force unsigned)tag], XA_CHUNK_SIZE);
+}
+
/* extracts the offset within this node from the index */
static unsigned int get_offset(unsigned long index, struct xa_node *node)
{
@@ -118,6 +168,85 @@ void *xas_load(struct xa_state *xas)
}
EXPORT_SYMBOL_GPL(xas_load);
+/**
+ * xas_get_tag() - Returns the state of this tag.
+ * @xas: XArray operation state.
+ * @tag: Tag number.
+ *
+ * Return: true if the tag is set, false if the tag is clear or @xas
+ * is in an error state.
+ */
+bool xas_get_tag(const struct xa_state *xas, xa_tag_t tag)
+{
+ if (xas_invalid(xas))
+ return false;
+ if (!xas->xa_node)
+ return xa_tagged(xas->xa, tag);
+ return node_get_tag(xas->xa_node, xas->xa_offset, tag);
+}
+EXPORT_SYMBOL_GPL(xas_get_tag);
+
+/**
+ * xas_set_tag() - Sets the tag on this entry and its parents.
+ * @xas: XArray operation state.
+ * @tag: Tag number.
+ *
+ * Sets the specified tag on this entry, and walks up the tree setting it
+ * on all the ancestor entries. Does nothing if @xas has not been walked to
+ * an entry, or is in an error state.
+ */
+void xas_set_tag(const struct xa_state *xas, xa_tag_t tag)
+{
+ struct xa_node *node = xas->xa_node;
+ unsigned int offset = xas->xa_offset;
+
+ if (xas_invalid(xas))
+ return;
+
+ while (node) {
+ if (node_get_tag(node, offset, tag))
+ return;
+ node_set_tag(node, offset, tag);
+ offset = node->offset;
+ node = xa_parent_locked(xas->xa, node);
+ }
+
+ if (!xa_tagged(xas->xa, tag))
+ xa_tag_set(xas->xa, tag);
+}
+EXPORT_SYMBOL_GPL(xas_set_tag);
+
+/**
+ * xas_clear_tag() - Clears the tag on this entry and its parents.
+ * @xas: XArray operation state.
+ * @tag: Tag number.
+ *
+ * Clears the specified tag on this entry, and walks back to the head
+ * attempting to clear it on all the ancestor entries. Does nothing if
+ * @xas has not been walked to an entry, or is in an error state.
+ */
+void xas_clear_tag(const struct xa_state *xas, xa_tag_t tag)
+{
+ struct xa_node *node = xas->xa_node;
+ unsigned int offset = xas->xa_offset;
+
+ if (xas_invalid(xas))
+ return;
+
+ while (node) {
+ node_clear_tag(node, offset, tag);
+ if (node_any_tag(node, tag))
+ return;
+
+ offset = node->offset;
+ node = xa_parent_locked(xas->xa, node);
+ }
+
+ if (xa_tagged(xas->xa, tag))
+ xa_tag_clear(xas->xa, tag);
+}
+EXPORT_SYMBOL_GPL(xas_clear_tag);
+
/**
* xa_init_flags() - Initialise an empty XArray with flags.
* @xa: XArray.
@@ -160,6 +289,112 @@ void *xa_load(struct xarray *xa, unsigned long index)
}
EXPORT_SYMBOL(xa_load);
+/**
+ * __xa_set_tag() - Set this tag on this entry while locked.
+ * @xa: XArray.
+ * @index: Index of entry.
+ * @tag: Tag number.
+ *
+ * Attempting to set a tag on a NULL entry does not succeed.
+ *
+ * Context: Any context. Expects xa_lock to be held on entry.
+ */
+void __xa_set_tag(struct xarray *xa, unsigned long index, xa_tag_t tag)
+{
+ XA_STATE(xas, xa, index);
+ void *entry = xas_load(&xas);
+
+ if (entry)
+ xas_set_tag(&xas, tag);
+}
+EXPORT_SYMBOL_GPL(__xa_set_tag);
+
+/**
+ * __xa_clear_tag() - Clear this tag on this entry while locked.
+ * @xa: XArray.
+ * @index: Index of entry.
+ * @tag: Tag number.
+ *
+ * Context: Any context. Expects xa_lock to be held on entry.
+ */
+void __xa_clear_tag(struct xarray *xa, unsigned long index, xa_tag_t tag)
+{
+ XA_STATE(xas, xa, index);
+ void *entry = xas_load(&xas);
+
+ if (entry)
+ xas_clear_tag(&xas, tag);
+}
+EXPORT_SYMBOL_GPL(__xa_clear_tag);
+
+/**
+ * xa_get_tag() - Inquire whether this tag is set on this entry.
+ * @xa: XArray.
+ * @index: Index of entry.
+ * @tag: Tag number.
+ *
+ * This function uses the RCU read lock, so the result may be out of date
+ * by the time it returns. If you need the result to be stable, use a lock.
+ *
+ * Context: Any context. Takes and releases the RCU lock.
+ * Return: True if the entry at @index has this tag set, false if it doesn't.
+ */
+bool xa_get_tag(struct xarray *xa, unsigned long index, xa_tag_t tag)
+{
+ XA_STATE(xas, xa, index);
+ void *entry;
+
+ rcu_read_lock();
+ entry = xas_start(&xas);
+ while (xas_get_tag(&xas, tag)) {
+ if (!xa_is_node(entry))
+ goto found;
+ entry = xas_descend(&xas, xa_to_node(entry));
+ }
+ rcu_read_unlock();
+ return false;
+ found:
+ rcu_read_unlock();
+ return true;
+}
+EXPORT_SYMBOL(xa_get_tag);
+
+/**
+ * xa_set_tag() - Set this tag on this entry.
+ * @xa: XArray.
+ * @index: Index of entry.
+ * @tag: Tag number.
+ *
+ * Attempting to set a tag on a NULL entry does not succeed.
+ *
+ * Context: Process context. Takes and releases the xa_lock.
+ */
+void xa_set_tag(struct xarray *xa, unsigned long index, xa_tag_t tag)
+{
+ xa_lock(xa);
+ __xa_set_tag(xa, index, tag);
+ xa_unlock(xa);
+}
+EXPORT_SYMBOL(xa_set_tag);
+
+/**
+ * xa_clear_tag() - Clear this tag on this entry.
+ * @xa: XArray.
+ * @index: Index of entry.
+ * @tag: Tag number.
+ *
+ * Clearing a tag always succeeds.
+ *
+ * Context: Process context. Takes and releases the xa_lock.
+ */
+void xa_clear_tag(struct xarray *xa, unsigned long index, xa_tag_t tag)
+{
+ xa_lock(xa);
+ __xa_clear_tag(xa, index, tag);
+ xa_unlock(xa);
+}
+EXPORT_SYMBOL(xa_clear_tag);
+
#ifdef XA_DEBUG
void xa_dump_node(const struct xa_node *node)
{
diff --git a/tools/include/linux/spinlock.h b/tools/include/linux/spinlock.h
index 4ec4d2cbe27a..622266b197d0 100644
--- a/tools/include/linux/spinlock.h
+++ b/tools/include/linux/spinlock.h
@@ -10,6 +10,12 @@
#define __SPIN_LOCK_UNLOCKED(x) (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER
#define spin_lock_init(x) pthread_mutex_init(x, NULL)
+#define spin_lock(x) pthread_mutex_lock(x)
+#define spin_unlock(x) pthread_mutex_unlock(x)
+#define spin_lock_bh(x) pthread_mutex_lock(x)
+#define spin_unlock_bh(x) pthread_mutex_unlock(x)
+#define spin_lock_irq(x) pthread_mutex_lock(x)
+#define spin_unlock_irq(x) pthread_mutex_unlock(x)
#define spin_lock_irqsave(x, f) (void)f, pthread_mutex_lock(x)
#define spin_unlock_irqrestore(x, f) (void)f, pthread_mutex_unlock(x)
--
2.16.1
next prev parent reply other threads:[~2018-03-13 13:25 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-13 13:25 [PATCH v9 00/61] XArray v9 Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 01/61] mac80211_hwsim: Use DEFINE_IDA Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 02/61] radix tree: Use GFP_ZONEMASK bits of gfp_t for flags Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 03/61] arm64: Turn flush_dcache_mmap_lock into a no-op Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 04/61] unicore32: " Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 05/61] Export __set_page_dirty Matthew Wilcox
2018-03-27 0:28 ` Darrick J. Wong
2018-03-13 13:25 ` [PATCH v9 06/61] fscache: Use appropriate radix tree accessors Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 07/61] xarray: Add the xa_lock to the radix_tree_root Matthew Wilcox
2018-04-12 20:59 ` Ross Zwisler
2018-04-12 21:10 ` Matthew Wilcox
2018-04-12 21:16 ` Ross Zwisler
2018-04-12 21:22 ` Matthew Wilcox
2018-04-12 21:27 ` Ross Zwisler
2018-03-13 13:25 ` [PATCH v9 08/61] page cache: Use xa_lock Matthew Wilcox
2018-03-16 18:06 ` Josef Bacik
2018-03-13 13:25 ` [PATCH v9 09/61] xarray: Replace exceptional entries Matthew Wilcox
2018-03-16 18:53 ` Josef Bacik
2018-03-16 19:06 ` Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 10/61] xarray: Change definition of sibling entries Matthew Wilcox
2018-03-16 19:00 ` Josef Bacik
2018-03-13 13:25 ` [PATCH v9 11/61] xarray: Add definition of struct xarray Matthew Wilcox
2018-03-16 19:05 ` Josef Bacik
2018-03-13 13:25 ` [PATCH v9 12/61] xarray: Define struct xa_node Matthew Wilcox
2018-03-16 19:11 ` Josef Bacik
2018-03-13 13:25 ` [PATCH v9 13/61] xarray: Add documentation Matthew Wilcox
2018-03-16 19:12 ` Josef Bacik
2018-03-13 13:25 ` [PATCH v9 14/61] xarray: Add xa_load Matthew Wilcox
2018-03-13 13:25 ` Matthew Wilcox [this message]
2018-03-13 13:25 ` [PATCH v9 16/61] xarray: Add xa_store Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 17/61] xarray: Add xa_cmpxchg and xa_insert Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 18/61] xarray: Add xa_for_each Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 19/61] xarray: Add xa_extract Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 20/61] xarray: Add xa_destroy Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 21/61] xarray: Add xas_next and xas_prev Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 22/61] xarray: Add xas_create_range Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 23/61] xarray: Add MAINTAINERS entry Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 24/61] page cache: Rearrange address_space Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 25/61] page cache: Convert hole search to XArray Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 26/61] page cache: Add and replace pages using the XArray Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 27/61] page cache: Convert page deletion to XArray Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 28/61] page cache: Convert page cache lookups " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 29/61] page cache: Convert delete_batch " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 30/61] page cache: Remove stray radix comment Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 31/61] page cache: Convert filemap_range_has_page to XArray Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 32/61] mm: Convert page-writeback " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 33/61] mm: Convert workingset " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 34/61] mm: Convert truncate " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 35/61] mm: Convert add_to_swap_cache " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 36/61] mm: Convert delete_from_swap_cache " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 37/61] mm: Convert __do_page_cache_readahead " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 38/61] mm: Convert page migration " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 39/61] mm: Convert huge_memory " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 40/61] mm: Convert collapse_shmem " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 41/61] mm: Convert khugepaged_scan_shmem " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 42/61] pagevec: Use xa_tag_t Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 43/61] shmem: Convert replace to XArray Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 44/61] shmem: Convert shmem_confirm_swap " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 45/61] shmem: Convert find_swap_entry " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 46/61] shmem: Convert shmem_add_to_page_cache " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 47/61] shmem: Convert shmem_alloc_hugepage " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 48/61] shmem: Convert shmem_free_swap " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 49/61] shmem: Convert shmem_partial_swap_usage " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 50/61] memfd: Convert shmem_tag_pins " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 51/61] memfd: Convert shmem_wait_for_pins " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 52/61] shmem: Comment fixups Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 53/61] btrfs: Convert page cache to XArray Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 54/61] fs: Convert buffer " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 55/61] fs: Convert writeback " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 56/61] nilfs2: Convert " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 57/61] f2fs: " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 58/61] lustre: " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 59/61] dax: " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 60/61] page cache: Finish XArray conversion Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 61/61] radix tree: Remove unused functions Matthew Wilcox
2018-03-26 22:36 ` [PATCH v9 00/61] XArray v9 Andrew Morton
2018-03-26 23:26 ` Matthew Wilcox
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