[PATCH 19/22] orangefs: add orangefs_revalidate_mapping

[hubcap@kernel.org]

From: Martin Brandenburg <martin@omnibond.com>

This is modeled after NFS, except our method is different.  We use a
simple timer to determine whether to invalidate the page cache.  This
is bound to perform.

This addes a sysfs parameter cache_timeout_msecs which controls the time
between page cache invalidations.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
---
 fs/orangefs/file.c            |  70 +++++++++-
 fs/orangefs/inode.c           | 250 +++++++++++++++++++++++++++++++---
 fs/orangefs/orangefs-kernel.h |   4 +
 fs/orangefs/orangefs-mod.c    |   1 +
 fs/orangefs/orangefs-sysfs.c  |  22 +++
 5 files changed, 328 insertions(+), 19 deletions(-)

diff --git a/fs/orangefs/file.c b/fs/orangefs/file.c
index 405449ce4b02..faa5b61cdfd6 100644
--- a/fs/orangefs/file.c
+++ b/fs/orangefs/file.c
@@ -241,18 +241,78 @@ ssize_t wait_for_direct_io(enum ORANGEFS_io_type type, struct inode *inode,
 	return ret;
 }
 
+int orangefs_revalidate_mapping(struct inode *inode)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct address_space *mapping = inode->i_mapping;
+	unsigned long *bitlock = &orangefs_inode->bitlock;
+	int ret;
+
+	while (1) {
+		ret = wait_on_bit(bitlock, 1, TASK_KILLABLE);
+		if (ret)
+			return ret;
+		spin_lock(&inode->i_lock);
+		if (test_bit(1, bitlock)) {
+			spin_unlock(&inode->i_lock);
+			continue;
+		}
+		if (!time_before(jiffies, orangefs_inode->mapping_time))
+			break;
+		spin_unlock(&inode->i_lock);
+		return 0;
+	}
+
+	set_bit(1, bitlock);
+	smp_wmb();
+	spin_unlock(&inode->i_lock);
+
+	unmap_mapping_range(mapping, 0, 0, 0);
+	ret = filemap_write_and_wait(mapping);
+	if (!ret)
+		ret = invalidate_inode_pages2(mapping);
+
+	orangefs_inode->mapping_time = jiffies +
+	    orangefs_cache_timeout_msecs*HZ/1000;
+
+	clear_bit(1, bitlock);
+	smp_mb__after_atomic();
+	wake_up_bit(bitlock, 1);
+
+	return ret;
+}
+
 static ssize_t orangefs_file_read_iter(struct kiocb *iocb,
     struct iov_iter *iter)
 {
+	int ret;
 	orangefs_stats.reads++;
-	return generic_file_read_iter(iocb, iter);
+
+	down_read(&file_inode(iocb->ki_filp)->i_rwsem);
+	ret = orangefs_revalidate_mapping(file_inode(iocb->ki_filp));
+	if (ret)
+		goto out;
+
+	ret = generic_file_read_iter(iocb, iter);
+out:
+	up_read(&file_inode(iocb->ki_filp)->i_rwsem);
+	return ret;
 }
 
 static ssize_t orangefs_file_write_iter(struct kiocb *iocb,
     struct iov_iter *iter)
 {
+	int ret;
 	orangefs_stats.writes++;
-	return generic_file_write_iter(iocb, iter);
+
+	if (iocb->ki_pos > i_size_read(file_inode(iocb->ki_filp))) {
+		ret = orangefs_revalidate_mapping(file_inode(iocb->ki_filp));
+		if (ret)
+			return ret;
+	}
+
+	ret = generic_file_write_iter(iocb, iter);
+	return ret;
 }
 
 /*
@@ -341,6 +401,12 @@ static const struct vm_operations_struct orangefs_file_vm_ops = {
  */
 static int orangefs_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
+	int ret;
+
+	ret = orangefs_revalidate_mapping(file_inode(file));
+	if (ret)
+		return ret;
+
 	gossip_debug(GOSSIP_FILE_DEBUG,
 		     "orangefs_file_mmap: called on %s\n",
 		     (file ?
diff --git a/fs/orangefs/inode.c b/fs/orangefs/inode.c
index add9c569a7dc..7ed2ea093c4e 100644
--- a/fs/orangefs/inode.c
+++ b/fs/orangefs/inode.c
@@ -31,6 +31,7 @@ static int orangefs_writepage_locked(struct page *page,
 	len = i_size_read(inode);
 	if (PagePrivate(page)) {
 		wr = (struct orangefs_write_range *)page_private(page);
+		WARN_ON(wr->pos >= len);
 		off = wr->pos;
 		if (off + wr->len > len)
 			wlen = len - off;
@@ -79,6 +80,173 @@ static int orangefs_writepage(struct page *page, struct writeback_control *wbc)
 	return ret;
 }
 
+struct orangefs_writepages {
+	loff_t off;
+	size_t len;
+	kuid_t uid;
+	kgid_t gid;
+	int maxpages;
+	int npages;
+	struct page **pages;
+	struct bio_vec *bv;
+};
+
+static int orangefs_writepages_work(struct orangefs_writepages *ow,
+    struct writeback_control *wbc)
+{
+	struct inode *inode = ow->pages[0]->mapping->host;
+	struct orangefs_write_range *wrp, wr;
+	struct iov_iter iter;
+	ssize_t ret;
+	size_t len;
+	loff_t off;
+	int i;
+
+	len = i_size_read(inode);
+
+	for (i = 0; i < ow->npages; i++) {
+		set_page_writeback(ow->pages[i]);
+		ow->bv[i].bv_page = ow->pages[i];
+		ow->bv[i].bv_len = min(page_offset(ow->pages[i]) + PAGE_SIZE,
+		    ow->off + ow->len) -
+		    max(ow->off, page_offset(ow->pages[i]));
+		if (i == 0)
+			ow->bv[i].bv_offset = ow->off -
+			    page_offset(ow->pages[i]);
+		else
+			ow->bv[i].bv_offset = 0;
+	}
+	iov_iter_bvec(&iter, WRITE, ow->bv, ow->npages, ow->len);
+
+	WARN_ON(ow->off >= len);
+	if (ow->off + ow->len > len)
+		ow->len = len - ow->off;
+
+	off = ow->off;
+	wr.uid = ow->uid;
+	wr.gid = ow->gid;
+	ret = wait_for_direct_io(ORANGEFS_IO_WRITE, inode, &off, &iter, ow->len,
+	    0, &wr);
+	if (ret < 0) {
+		for (i = 0; i < ow->npages; i++) {
+			SetPageError(ow->pages[i]);
+			mapping_set_error(ow->pages[i]->mapping, ret);
+			if (PagePrivate(ow->pages[i])) {
+				wrp = (struct orangefs_write_range *)
+				    page_private(ow->pages[i]);
+				ClearPagePrivate(ow->pages[i]);
+				put_page(ow->pages[i]);
+				kfree(wrp);
+			}
+			end_page_writeback(ow->pages[i]);
+			unlock_page(ow->pages[i]);
+		}
+	} else {
+		ret = 0;
+		for (i = 0; i < ow->npages; i++) {
+			if (PagePrivate(ow->pages[i])) {
+				wrp = (struct orangefs_write_range *)
+				    page_private(ow->pages[i]);
+				ClearPagePrivate(ow->pages[i]);
+				put_page(ow->pages[i]);
+				kfree(wrp);
+			}
+			end_page_writeback(ow->pages[i]);
+			unlock_page(ow->pages[i]);
+		}
+	}
+	return ret;
+}
+
+static int orangefs_writepages_callback(struct page *page,
+    struct writeback_control *wbc, void *data)
+{
+	struct orangefs_writepages *ow = data;
+	struct orangefs_write_range *wr;
+	int ret;
+
+	if (!PagePrivate(page)) {
+		unlock_page(page);
+		/* It's not private so there's nothing to write, right? */
+		printk("writepages_callback not private!\n");
+		BUG();
+		return 0;
+	}
+	wr = (struct orangefs_write_range *)page_private(page);
+
+	ret = -1;
+	if (ow->npages == 0) {
+		ow->off = wr->pos;
+		ow->len = wr->len;
+		ow->uid = wr->uid;
+		ow->gid = wr->gid;
+		ow->pages[ow->npages++] = page;
+		ret = 0;
+		goto done;
+	}
+	if (!uid_eq(ow->uid, wr->uid) || !gid_eq(ow->gid, wr->gid)) {
+		orangefs_writepages_work(ow, wbc);
+		ow->npages = 0;
+		ret = -1;
+		goto done;
+	}
+	if (ow->off + ow->len == wr->pos) {
+		ow->len += wr->len;
+		ow->pages[ow->npages++] = page;
+		ret = 0;
+		goto done;
+	}
+done:
+	if (ret == -1) {
+		if (ow->npages) {
+			orangefs_writepages_work(ow, wbc);
+			ow->npages = 0;
+		}
+		ret = orangefs_writepage_locked(page, wbc);
+		mapping_set_error(page->mapping, ret);
+		unlock_page(page);
+		end_page_writeback(page);
+	} else {
+		if (ow->npages == ow->maxpages) {
+			orangefs_writepages_work(ow, wbc);
+			ow->npages = 0;
+		}
+	}
+	return ret;
+}
+
+static int orangefs_writepages(struct address_space *mapping,
+    struct writeback_control *wbc)
+{
+	struct orangefs_writepages *ow;
+	struct blk_plug plug;
+	int ret;
+	ow = kzalloc(sizeof(struct orangefs_writepages), GFP_KERNEL);
+	if (!ow)
+		return -ENOMEM;
+	ow->maxpages = orangefs_bufmap_size_query()/PAGE_SIZE;
+	ow->pages = kcalloc(ow->maxpages, sizeof(struct page *), GFP_KERNEL);
+	if (!ow->pages) {
+		kfree(ow);
+		return -ENOMEM;
+	}
+	ow->bv = kcalloc(ow->maxpages, sizeof(struct bio_vec), GFP_KERNEL);
+	if (!ow->bv) {
+		kfree(ow->pages);
+		kfree(ow);
+		return -ENOMEM;
+	}
+	blk_start_plug(&plug);
+	ret = write_cache_pages(mapping, wbc, orangefs_writepages_callback, ow);
+	if (ow->npages)
+		ret = orangefs_writepages_work(ow, wbc);
+	blk_finish_plug(&plug);
+	kfree(ow->pages);
+	kfree(ow->bv);
+	kfree(ow);
+	return ret;
+}
+
 static int orangefs_readpage(struct file *file, struct page *page)
 {
 	struct inode *inode = page->mapping->host;
@@ -93,6 +261,9 @@ static int orangefs_readpage(struct file *file, struct page *page)
 	bv.bv_offset = 0;
 	iov_iter_bvec(&iter, READ, &bv, 1, PAGE_SIZE);
 
+	if (PageDirty(page))
+		orangefs_launder_page(page);
+
 	ret = wait_for_direct_io(ORANGEFS_IO_READ, inode, &off, &iter,
 	    PAGE_SIZE, inode->i_size, NULL);
 	/* this will only zero remaining unread portions of the page data */
@@ -170,22 +341,42 @@ static int orangefs_write_begin(struct file *file,
 	set_page_private(page, (unsigned long)wr);
 	get_page(page);
 okay:
-
-	if (!PageUptodate(page) && (len != PAGE_SIZE)) {
-		unsigned from = pos & (PAGE_SIZE - 1);
-
-		zero_user_segments(page, 0, from, from + len, PAGE_SIZE);
-	}
 	return 0;
 }
 
 static int orangefs_write_end(struct file *file, struct address_space *mapping,
     loff_t pos, unsigned len, unsigned copied, struct page *page, void *fsdata)
 {
-	int r;
-	r = simple_write_end(file, mapping, pos, len, copied, page, fsdata);
+	struct inode *inode = page->mapping->host;
+	loff_t last_pos = pos + copied;
+
+	/*
+	 * No need to use i_size_read() here, the i_size
+	 * cannot change under us because we hold the i_mutex.
+	 */
+	if (last_pos > inode->i_size)
+		i_size_write(inode, last_pos);
+
+	/* zero the stale part of the page if we did a short copy */
+	if (!PageUptodate(page)) {
+		unsigned from = pos & (PAGE_SIZE - 1);
+		if (copied < len) {
+			zero_user(page, from + copied, len - copied);
+		}
+		/* Set fully written pages uptodate. */
+		if (pos == page_offset(page) &&
+		    (len == PAGE_SIZE || pos + len == inode->i_size)) {
+			zero_user_segment(page, from + copied, PAGE_SIZE);
+			SetPageUptodate(page);
+		}
+	}
+
+	set_page_dirty(page);
+	unlock_page(page);
+	put_page(page);
+
 	mark_inode_dirty_sync(file_inode(file));
-	return r;
+	return copied;
 }
 
 static void orangefs_invalidatepage(struct page *page,
@@ -200,6 +391,7 @@ static void orangefs_invalidatepage(struct page *page,
 		set_page_private(page, 0);
 		ClearPagePrivate(page);
 		put_page(page);
+		return;
 	/* write range entirely within invalidate range (or equal) */
 	} else if (page_offset(page) + offset <= wr->pos &&
 	    wr->pos + wr->len <= page_offset(page) + offset + length) {
@@ -209,6 +401,7 @@ static void orangefs_invalidatepage(struct page *page,
 		put_page(page);
 		/* XXX is this right? only caller in fs */
 		cancel_dirty_page(page);
+		return;
 	/* invalidate range chops off end of write range */
 	} else if (wr->pos < page_offset(page) + offset &&
 	    wr->pos + wr->len <= page_offset(page) + offset + length &&
@@ -240,6 +433,7 @@ static void orangefs_invalidatepage(struct page *page,
 		 * should we just ignore this and write it out anyway?
 		 * it hardly makes sense
 		 */
+		return;
 	/* non-overlapping ranges */
 	} else {
 		/* WARN if they do overlap */
@@ -251,7 +445,15 @@ static void orangefs_invalidatepage(struct page *page,
 			printk("write range offset %llu length %zu\n",
 			    wr->pos, wr->len);
 		}
+		return;
 	}
+
+	/*
+	 * Above there are returns where wr is freed or where we WARN.
+	 * Thus the following runs if wr was modified above.
+	 */
+
+	orangefs_launder_page(page);
 }
 
 static int orangefs_releasepage(struct page *page, gfp_t foo)
@@ -404,6 +606,7 @@ static ssize_t orangefs_direct_IO(struct kiocb *iocb,
 static const struct address_space_operations orangefs_address_operations = {
 	.writepage = orangefs_writepage,
 	.readpage = orangefs_readpage,
+	.writepages = orangefs_writepages,
 	.set_page_dirty = __set_page_dirty_nobuffers,
 	.write_begin = orangefs_write_begin,
 	.write_end = orangefs_write_end,
@@ -418,9 +621,18 @@ vm_fault_t orangefs_page_mkwrite(struct vm_fault *vmf)
 {
 	struct page *page = vmf->page;
 	struct inode *inode = file_inode(vmf->vma->vm_file);
-	vm_fault_t ret = VM_FAULT_LOCKED;
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	unsigned long *bitlock = &orangefs_inode->bitlock;
+	vm_fault_t ret;
 	struct orangefs_write_range *wr;
 
+	sb_start_pagefault(inode->i_sb);
+
+	if (wait_on_bit(bitlock, 1, TASK_KILLABLE)) {
+		ret = VM_FAULT_RETRY;
+		goto out;
+	}
+
 	lock_page(page);
 	if (PageDirty(page) && !PagePrivate(page)) {
 		/*
@@ -429,7 +641,7 @@ vm_fault_t orangefs_page_mkwrite(struct vm_fault *vmf)
 		 * orangefs_writepage_locked.
 		 */
 		if (orangefs_launder_page(page)) {
-			ret = VM_FAULT_RETRY;
+			ret = VM_FAULT_LOCKED|VM_FAULT_RETRY;
 			goto out;
 		}
 	}
@@ -442,14 +654,14 @@ vm_fault_t orangefs_page_mkwrite(struct vm_fault *vmf)
 			goto okay;
 		} else {
 			if (orangefs_launder_page(page)) {
-				ret = VM_FAULT_RETRY;
+				ret = VM_FAULT_LOCKED|VM_FAULT_RETRY;
 				goto out;
 			}
 		}
 	}
 	wr = kmalloc(sizeof *wr, GFP_KERNEL);
 	if (!wr) {
-		ret = VM_FAULT_RETRY;
+		ret = VM_FAULT_LOCKED|VM_FAULT_RETRY;
 		goto out;
 	}
 	wr->pos = page_offset(page);
@@ -461,11 +673,10 @@ vm_fault_t orangefs_page_mkwrite(struct vm_fault *vmf)
 	get_page(page);
 okay:
 
-	sb_start_pagefault(inode->i_sb);
 	file_update_time(vmf->vma->vm_file);
 	if (page->mapping != inode->i_mapping) {
 		unlock_page(page);
-		ret = VM_FAULT_NOPAGE;
+		ret = VM_FAULT_LOCKED|VM_FAULT_NOPAGE;
 		goto out;
 	}
 
@@ -476,6 +687,7 @@ vm_fault_t orangefs_page_mkwrite(struct vm_fault *vmf)
 	 */
 	set_page_dirty(page);
 	wait_for_stable_page(page);
+	ret = VM_FAULT_LOCKED;
 out:
 	sb_end_pagefault(inode->i_sb);
 	return ret;
@@ -553,13 +765,15 @@ int __orangefs_setattr(struct inode *inode, struct iattr *iattr)
 			} else {
 				gossip_debug(GOSSIP_UTILS_DEBUG,
 					     "User attempted to set sticky bit on non-root directory; returning EINVAL.\n");
-				return -EINVAL;
+				ret = -EINVAL;
+				goto out;
 			}
 		}
 		if (iattr->ia_mode & (S_ISUID)) {
 			gossip_debug(GOSSIP_UTILS_DEBUG,
 				     "Attempting to set setuid bit (not supported); returning EINVAL.\n");
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out;
 		}
 	}
 
@@ -741,6 +955,8 @@ static int orangefs_set_inode(struct inode *inode, void *data)
 	ORANGEFS_I(inode)->refn.khandle = ref->khandle;
 	ORANGEFS_I(inode)->attr_valid = 0;
 	hash_init(ORANGEFS_I(inode)->xattr_cache);
+	ORANGEFS_I(inode)->mapping_time = jiffies - 1;
+	ORANGEFS_I(inode)->bitlock = 0;
 	return 0;
 }
 
diff --git a/fs/orangefs/orangefs-kernel.h b/fs/orangefs/orangefs-kernel.h
index 336a3ec0b83e..87beab10326a 100644
--- a/fs/orangefs/orangefs-kernel.h
+++ b/fs/orangefs/orangefs-kernel.h
@@ -193,9 +193,11 @@ struct orangefs_inode_s {
 	sector_t last_failed_block_index_read;
 
 	unsigned long getattr_time;
+	unsigned long mapping_time;
 	int attr_valid;
 	kuid_t attr_uid;
 	kgid_t attr_gid;
+	unsigned long bitlock;
 
 	DECLARE_HASHTABLE(xattr_cache, 4);
 };
@@ -390,6 +392,7 @@ bool __is_daemon_in_service(void);
 /*
  * defined in file.c
  */
+int orangefs_revalidate_mapping(struct inode *);
 ssize_t wait_for_direct_io(enum ORANGEFS_io_type, struct inode *, loff_t *,
     struct iov_iter *, size_t, loff_t, struct orangefs_write_range *);
 ssize_t do_readv_writev(enum ORANGEFS_io_type, struct file *, loff_t *,
@@ -427,6 +430,7 @@ int orangefs_normalize_to_errno(__s32 error_code);
 extern struct mutex orangefs_request_mutex;
 extern int op_timeout_secs;
 extern int slot_timeout_secs;
+extern int orangefs_cache_timeout_msecs;
 extern int orangefs_dcache_timeout_msecs;
 extern int orangefs_getattr_timeout_msecs;
 extern struct list_head orangefs_superblocks;
diff --git a/fs/orangefs/orangefs-mod.c b/fs/orangefs/orangefs-mod.c
index 85ef87245a87..82cf8b3e568b 100644
--- a/fs/orangefs/orangefs-mod.c
+++ b/fs/orangefs/orangefs-mod.c
@@ -30,6 +30,7 @@ static ulong module_parm_debug_mask;
 __u64 orangefs_gossip_debug_mask;
 int op_timeout_secs = ORANGEFS_DEFAULT_OP_TIMEOUT_SECS;
 int slot_timeout_secs = ORANGEFS_DEFAULT_SLOT_TIMEOUT_SECS;
+int orangefs_cache_timeout_msecs = 50;
 int orangefs_dcache_timeout_msecs = 50;
 int orangefs_getattr_timeout_msecs = 50;
 
diff --git a/fs/orangefs/orangefs-sysfs.c b/fs/orangefs/orangefs-sysfs.c
index 19739aaee675..3627ea946402 100644
--- a/fs/orangefs/orangefs-sysfs.c
+++ b/fs/orangefs/orangefs-sysfs.c
@@ -62,6 +62,14 @@
  *			Slots are requested and waited for,
  *			the wait times out after slot_timeout_secs.
  *
+ * What:		/sys/fs/orangefs/cache_timeout_msecs
+ * Date:		Mar 2018
+ * Contact:		Martin Brandenburg <martin@omnibond.com>
+ * Description:
+ *			Time in milliseconds between which
+ *			orangefs_revalidate_mapping will invalidate the page
+ *			cache.
+ *
  * What:		/sys/fs/orangefs/dcache_timeout_msecs
  * Date:		Jul 2016
  * Contact:		Martin Brandenburg <martin@omnibond.com>
@@ -221,6 +229,13 @@ static ssize_t sysfs_int_show(struct kobject *kobj,
 				       "%d\n",
 				       slot_timeout_secs);
 			goto out;
+		} else if (!strcmp(attr->attr.name,
+				   "cache_timeout_msecs")) {
+			rc = scnprintf(buf,
+				       PAGE_SIZE,
+				       "%d\n",
+				       orangefs_cache_timeout_msecs);
+			goto out;
 		} else if (!strcmp(attr->attr.name,
 				   "dcache_timeout_msecs")) {
 			rc = scnprintf(buf,
@@ -277,6 +292,9 @@ static ssize_t sysfs_int_store(struct kobject *kobj,
 	} else if (!strcmp(attr->attr.name, "slot_timeout_secs")) {
 		rc = kstrtoint(buf, 0, &slot_timeout_secs);
 		goto out;
+	} else if (!strcmp(attr->attr.name, "cache_timeout_msecs")) {
+		rc = kstrtoint(buf, 0, &orangefs_cache_timeout_msecs);
+		goto out;
 	} else if (!strcmp(attr->attr.name, "dcache_timeout_msecs")) {
 		rc = kstrtoint(buf, 0, &orangefs_dcache_timeout_msecs);
 		goto out;
@@ -818,6 +836,9 @@ static struct orangefs_attribute op_timeout_secs_attribute =
 static struct orangefs_attribute slot_timeout_secs_attribute =
 	__ATTR(slot_timeout_secs, 0664, sysfs_int_show, sysfs_int_store);
 
+static struct orangefs_attribute cache_timeout_msecs_attribute =
+	__ATTR(cache_timeout_msecs, 0664, sysfs_int_show, sysfs_int_store);
+
 static struct orangefs_attribute dcache_timeout_msecs_attribute =
 	__ATTR(dcache_timeout_msecs, 0664, sysfs_int_show, sysfs_int_store);
 
@@ -861,6 +882,7 @@ static struct orangefs_attribute perf_time_interval_secs_attribute =
 static struct attribute *orangefs_default_attrs[] = {
 	&op_timeout_secs_attribute.attr,
 	&slot_timeout_secs_attribute.attr,
+	&cache_timeout_msecs_attribute.attr,
 	&dcache_timeout_msecs_attribute.attr,
 	&getattr_timeout_msecs_attribute.attr,
 	&readahead_count_attribute.attr,
-- 
2.20.1