All of lore.kernel.org
 help / color / mirror / Atom feed
From: David Howells <dhowells@redhat.com>
To: Trond Myklebust <trondmy@hammerspace.com>,
	Anna Schumaker <anna.schumaker@netapp.com>,
	Steve French <sfrench@samba.org>,
	Dominique Martinet <asmadeus@codewreck.org>
Cc: dhowells@redhat.com, Jeff Layton <jlayton@redhat.com>,
	Matthew Wilcox <willy@infradead.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	linux-cachefs@redhat.com, linux-afs@lists.infradead.org,
	linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org,
	ceph-devel@vger.kernel.org, v9fs-developer@lists.sourceforge.net,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [RFC PATCH 64/76] afs: Extract writeback extension into its own function
Date: Fri, 20 Nov 2020 15:16:24 +0000	[thread overview]
Message-ID: <160588538471.3465195.782513375683399583.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <160588455242.3465195.3214733858273019178.stgit@warthog.procyon.org.uk>

Extract writeback extension into its own function to break up the writeback
function a bit.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/write.c |  109 ++++++++++++++++++++++++++++++++++----------------------
 1 file changed, 67 insertions(+), 42 deletions(-)

diff --git a/fs/afs/write.c b/fs/afs/write.c
index e1791de90478..89c804bfe253 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -490,47 +490,25 @@ static int afs_store_data(struct afs_vnode *vnode, struct iov_iter *iter,
 }
 
 /*
- * Synchronously write back the locked page and any subsequent non-locked dirty
- * pages.
+ * Extend the region to be written back to include subsequent contiguously
+ * dirty pages if possible, but don't sleep while doing so.
+ *
+ * If this page holds new content, then we can include filler zeros in the
+ * writeback.
  */
-static int afs_write_back_from_locked_page(struct address_space *mapping,
-					   struct writeback_control *wbc,
-					   struct page *primary_page,
-					   pgoff_t final_page)
+static void afs_extend_writeback(struct address_space *mapping,
+				 struct afs_vnode *vnode,
+				 long *_count,
+				 pgoff_t start,
+				 pgoff_t final_page,
+				 unsigned *_offset,
+				 unsigned *_to,
+				 bool new_content)
 {
-	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
-	struct iov_iter iter;
 	struct page *pages[8], *page;
-	unsigned long count, priv;
-	unsigned n, offset, to, f, t;
-	pgoff_t start, first, last;
-	loff_t i_size, pos, end;
-	int loop, ret;
-
-	_enter(",%lx", primary_page->index);
-
-	count = 1;
-	if (test_set_page_writeback(primary_page))
-		BUG();
-
-	/* Find all consecutive lockable dirty pages that have contiguous
-	 * written regions, stopping when we find a page that is not
-	 * immediately lockable, is not dirty or is missing, or we reach the
-	 * end of the range.
-	 */
-	start = primary_page->index;
-	priv = page_private(primary_page);
-	offset = afs_page_dirty_from(primary_page, priv);
-	to = afs_page_dirty_to(primary_page, priv);
-	trace_afs_page_dirty(vnode, tracepoint_string("store"), primary_page);
-
-	WARN_ON(offset == to);
-	if (offset == to)
-		trace_afs_page_dirty(vnode, tracepoint_string("WARN"), primary_page);
-
-	if (start >= final_page ||
-	    (to < PAGE_SIZE && !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)))
-		goto no_more;
+	unsigned long count = *_count, priv;
+	unsigned offset = *_offset, to = *_to, n, f, t;
+	int loop;
 
 	start++;
 	do {
@@ -551,8 +529,7 @@ static int afs_write_back_from_locked_page(struct address_space *mapping,
 
 		for (loop = 0; loop < n; loop++) {
 			page = pages[loop];
-			if (to != PAGE_SIZE &&
-			    !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags))
+			if (to != PAGE_SIZE && !new_content)
 				break;
 			if (page->index > final_page)
 				break;
@@ -566,8 +543,7 @@ static int afs_write_back_from_locked_page(struct address_space *mapping,
 			priv = page_private(page);
 			f = afs_page_dirty_from(page, priv);
 			t = afs_page_dirty_to(page, priv);
-			if (f != 0 &&
-			    !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) {
+			if (f != 0 && !new_content) {
 				unlock_page(page);
 				break;
 			}
@@ -593,6 +569,55 @@ static int afs_write_back_from_locked_page(struct address_space *mapping,
 	} while (start <= final_page && count < 65536);
 
 no_more:
+	*_count = count;
+	*_offset = offset;
+	*_to = to;
+}
+
+/*
+ * Synchronously write back the locked page and any subsequent non-locked dirty
+ * pages.
+ */
+static int afs_write_back_from_locked_page(struct address_space *mapping,
+					   struct writeback_control *wbc,
+					   struct page *primary_page,
+					   pgoff_t final_page)
+{
+	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
+	struct iov_iter iter;
+	unsigned long count, priv;
+	unsigned offset, to;
+	pgoff_t start, first, last;
+	loff_t i_size, pos, end;
+	bool new_content = test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
+	int ret;
+
+	_enter(",%lx", primary_page->index);
+
+	count = 1;
+	if (test_set_page_writeback(primary_page))
+		BUG();
+
+	/* Find all consecutive lockable dirty pages that have contiguous
+	 * written regions, stopping when we find a page that is not
+	 * immediately lockable, is not dirty or is missing, or we reach the
+	 * end of the range.
+	 */
+	start = primary_page->index;
+	priv = page_private(primary_page);
+	offset = afs_page_dirty_from(primary_page, priv);
+	to = afs_page_dirty_to(primary_page, priv);
+	trace_afs_page_dirty(vnode, tracepoint_string("store"), primary_page);
+
+	WARN_ON(offset == to);
+	if (offset == to)
+		trace_afs_page_dirty(vnode, tracepoint_string("WARN"), primary_page);
+
+	if (start < final_page &&
+	    (to == PAGE_SIZE || new_content))
+		afs_extend_writeback(mapping, vnode, &count, start, final_page,
+				     &offset, &to, new_content);
+
 	/* We now have a contiguous set of dirty pages, each with writeback
 	 * set; the first page is still locked at this point, but all the rest
 	 * have been unlocked.



  parent reply	other threads:[~2020-11-20 15:16 UTC|newest]

Thread overview: 77+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-20 15:02 [RFC PATCH 00/76] fscache: Modernisation David Howells
2020-11-20 15:02 ` [RFC PATCH 01/76] nfs, cifs, ceph, 9p: Disable use of fscache prior to its rewrite David Howells
2020-11-20 15:02 ` [RFC PATCH 02/76] afs: Disable use of the fscache I/O routines David Howells
2020-11-20 15:03 ` [RFC PATCH 03/76] fscache: Add a cookie debug ID and use that in traces David Howells
2020-11-20 15:03 ` [RFC PATCH 04/76] fscache: Procfile to display cookies David Howells
2020-11-20 15:03 ` [RFC PATCH 05/76] fscache: Remove the old I/O API David Howells
2020-11-20 15:03 ` [RFC PATCH 06/76] fscache: Remove the netfs data from the cookie David Howells
2020-11-20 15:04 ` [RFC PATCH 07/76] fscache: Remove struct fscache_cookie_def David Howells
2020-11-20 15:04 ` [RFC PATCH 08/76] fscache: Remove store_limit* from struct fscache_object David Howells
2020-11-20 15:04 ` [RFC PATCH 09/76] fscache: Remove fscache_check_consistency() David Howells
2020-11-20 15:04 ` [RFC PATCH 10/76] fscache: Remove fscache_attr_changed() David Howells
2020-11-20 15:04 ` [RFC PATCH 11/76] fscache: Remove obsolete stats David Howells
2020-11-20 15:05 ` [RFC PATCH 12/76] fscache: Remove old I/O tracepoints David Howells
2020-11-20 15:05 ` [RFC PATCH 13/76] fscache: Temporarily disable fscache_invalidate() David Howells
2020-11-20 15:05 ` [RFC PATCH 14/76] fscache: Remove the I/O operation manager David Howells
2020-11-20 15:05 ` [RFC PATCH 15/76] fscache: Change %p in format strings to something else David Howells
2020-11-20 15:06 ` [RFC PATCH 16/76] cachefiles: " David Howells
2020-11-20 15:06 ` [RFC PATCH 17/76] iov_iter: Add ITER_XARRAY David Howells
2020-11-20 15:06 ` [RFC PATCH 18/76] vm: Add wait/unlock functions for PG_fscache David Howells
2020-11-20 15:06 ` [RFC PATCH 19/76] mm: Implement readahead_control pageset expansion David Howells
2020-11-20 15:06 ` [RFC PATCH 20/76] mm: Stop generic_file_buffered_read() from grabbing a superfluous page David Howells
2020-11-20 15:07 ` [RFC PATCH 21/76] vfs: Export rw_verify_area() for use by cachefiles David Howells
2020-11-20 15:07 ` [RFC PATCH 22/76] vfs: Provide S_CACHE_FILE inode flag David Howells
2020-11-20 15:07 ` [RFC PATCH 23/76] cachefiles: Remove tree of active files and use " David Howells
2020-11-20 15:07 ` [RFC PATCH 24/76] fscache: Provide a simple thread pool for running ops asynchronously David Howells
2020-11-20 15:07 ` [RFC PATCH 25/76] fscache: Replace the object management state machine David Howells
2020-11-20 15:08 ` [RFC PATCH 26/76] fscache: Rewrite the I/O API based on iov_iter David Howells
2020-11-20 15:08 ` [RFC PATCH 27/76] fscache: Keep track of size of a file last set independently on the server David Howells
2020-11-20 15:08 ` [RFC PATCH 28/76] fscache, cachefiles: Fix disabled histogram warnings David Howells
2020-11-20 15:08 ` [RFC PATCH 29/76] fscache: Recast assertion in terms of cookie not being an index David Howells
2020-11-20 15:08 ` [RFC PATCH 30/76] vfs, fscache: Force ->write_inode() to occur if cookie pinned for writeback David Howells
2020-11-20 15:09 ` [RFC PATCH 31/76] fscache: Allow ->put_super() to be used to wait for cache operations David Howells
2020-11-20 15:09 ` [RFC PATCH 32/76] netfs: Make a netfs helper module David Howells
2020-11-20 15:09 ` [RFC PATCH 33/76] netfs: Provide readahead and readpage netfs helpers David Howells
2020-11-20 15:09 ` [RFC PATCH 34/76] netfs: Use the cache David Howells
2020-11-20 15:10 ` [RFC PATCH 35/76] fscache: read-helper: Add tracepoints David Howells
2020-11-20 15:10 ` [RFC PATCH 36/76] cachefiles: Remove some redundant checks on unsigned values David Howells
2020-11-20 15:10 ` [RFC PATCH 37/76] cachefiles: trace: Log coherency checks David Howells
2020-11-20 15:10 ` [RFC PATCH 38/76] cachefiles: Split cachefiles_drop_object() up a bit David Howells
2020-11-20 15:11 ` [RFC PATCH 39/76] cachefiles: Implement new fscache I/O backend API David Howells
2020-11-20 15:11 ` [RFC PATCH 40/76] cachefiles: Merge object->backer into object->dentry David Howells
2020-11-20 15:11 ` [RFC PATCH 41/76] cachefiles: Implement a content-present indicator and bitmap David Howells
2020-11-20 15:11 ` [RFC PATCH 42/76] cachefiles: Shape requests from the fscache read helper David Howells
2020-11-20 15:11 ` [RFC PATCH 43/76] cachefiles: Round the cachefile size up to DIO block size David Howells
2020-11-20 15:12 ` [RFC PATCH 44/76] cachefiles: Implement read and write parts of new I/O API David Howells
2020-11-20 15:12 ` [RFC PATCH 45/76] cachefiles: Add I/O tracepoints David Howells
2020-11-20 15:12 ` [RFC PATCH 46/76] fscache: Display cache-specific data in /proc/fs/fscache/objects David Howells
2020-11-20 15:12 ` [RFC PATCH 47/76] fscache: Remove more obsolete stats David Howells
2020-11-20 15:12 ` [RFC PATCH 48/76] fscache: Always create /proc/fs/fscache/stats if configured David Howells
2020-11-20 15:13 ` [RFC PATCH 49/76] netfs: Stats David Howells
2020-11-20 15:13 ` [RFC PATCH 50/76] fscache: New stats David Howells
2020-11-20 15:13 ` [RFC PATCH 51/76] fscache, cachefiles: Rewrite invalidation David Howells
2020-11-20 15:13 ` [RFC PATCH 52/76] fscache: disable cookie when doing an invalidation for DIO write David Howells
2020-11-20 15:13 ` [RFC PATCH 53/76] fscache: Implement "will_modify" parameter on fscache_use_cookie() David Howells
2020-11-20 15:14 ` [RFC PATCH 54/76] fscache: Provide resize operation David Howells
2020-11-20 15:14 ` [RFC PATCH 55/76] fscache: Remove the update operation David Howells
2020-11-20 15:14 ` [RFC PATCH 56/76] afs: Pass page into dirty region helpers to provide THP size David Howells
2020-11-20 15:14 ` [RFC PATCH 57/76] afs: Print the operation debug_id when logging an unexpected data version David Howells
2020-11-20 15:14 ` [RFC PATCH 58/76] afs: Move key to afs_read struct David Howells
2020-11-20 15:15 ` [RFC PATCH 59/76] afs: Don't truncate iter during data fetch David Howells
2020-11-20 15:15 ` [RFC PATCH 60/76] afs: Log remote unmarshalling errors David Howells
2020-11-20 15:15 ` [RFC PATCH 61/76] afs: Set up the iov_iter before calling afs_extract_data() David Howells
2020-11-20 15:15 ` [RFC PATCH 62/76] afs: Use ITER_XARRAY for writing David Howells
2020-11-20 15:16 ` [RFC PATCH 63/76] afs: Wait on PG_fscache before modifying/releasing a page David Howells
2020-11-20 15:16 ` David Howells [this message]
2020-11-20 15:16 ` [RFC PATCH 65/76] afs: Prepare for use of THPs David Howells
2020-11-20 15:16 ` [RFC PATCH 66/76] afs: Use the fs operation ops to handle FetchData completion David Howells
2020-11-20 15:17 ` [RFC PATCH 67/76] afs: Use new fscache read helper API David Howells
2020-11-20 15:17 ` [RFC PATCH 68/76] netfs: Add write_begin helper David Howells
2020-11-20 15:17 ` [RFC PATCH 69/76] fscache: Add support for writing to the cache David Howells
2020-11-20 15:17 ` [RFC PATCH 70/76] afs: Use the fscache_write_begin() helper David Howells
2020-11-20 15:18 ` [RFC PATCH 71/76] afs: Copy local writes to the cache when writing to the server David Howells
2020-11-20 15:18 ` [RFC PATCH 72/76] afs: Invoke fscache_resize_cookie() when handling ATTR_SIZE for setattr David Howells
2020-11-20 15:18 ` [RFC PATCH 73/76] afs: Add O_DIRECT read support David Howells
2020-11-20 15:18 ` [RFC PATCH 74/76] afs: Skip truncation on the server of data we haven't written yet David Howells
2020-11-20 15:19 ` [RFC PATCH 75/76] afs: Make afs_write_begin() return the THP subpage David Howells
2020-11-20 15:19 ` [RFC PATCH 76/76] afs: Fix speculative status fetch going out of order wrt to modifications David Howells

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=160588538471.3465195.782513375683399583.stgit@warthog.procyon.org.uk \
    --to=dhowells@redhat.com \
    --cc=anna.schumaker@netapp.com \
    --cc=asmadeus@codewreck.org \
    --cc=ceph-devel@vger.kernel.org \
    --cc=jlayton@redhat.com \
    --cc=linux-afs@lists.infradead.org \
    --cc=linux-cachefs@redhat.com \
    --cc=linux-cifs@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-nfs@vger.kernel.org \
    --cc=sfrench@samba.org \
    --cc=trondmy@hammerspace.com \
    --cc=v9fs-developer@lists.sourceforge.net \
    --cc=viro@zeniv.linux.org.uk \
    --cc=willy@infradead.org \
    --subject='Re: [RFC PATCH 64/76] afs: Extract writeback extension into its own function' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.