From: Goldwyn Rodrigues <rgoldwyn@suse.de>
To: linux-fsdevel@vger.kernel.org
Cc: jack@suse.com, hch@infradead.org, linux-block@vger.kernel.org,
linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org,
linux-xfs@vger.kernel.org, sagi@grimberg.me, avi@scylladb.com,
axboe@kernel.dk, linux-api@vger.kernel.org,
Goldwyn Rodrigues <rgoldwyn@suse.com>
Subject: [PATCH 02/10] fs: Introduce filemap_range_has_page()
Date: Thu, 11 May 2017 14:17:02 -0500 [thread overview]
Message-ID: <20170511191710.31959-3-rgoldwyn@suse.de> (raw)
In-Reply-To: <20170511191710.31959-1-rgoldwyn@suse.de>
From: Goldwyn Rodrigues <rgoldwyn@suse.com>
filemap_range_has_page() return true if the file's mapping has
a page within the range mentioned. This function will be used
to check if a write() call will cause a writeback of previous
writes.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
include/linux/fs.h | 2 ++
mm/filemap.c | 33 +++++++++++++++++++++++++++++++++
2 files changed, 35 insertions(+)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 869c9a6fe58d..2e6fc6a23f91 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2513,6 +2513,8 @@ extern int filemap_fdatawait(struct address_space *);
extern void filemap_fdatawait_keep_errors(struct address_space *);
extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
loff_t lend);
+extern int filemap_range_has_page(struct address_space *, loff_t lstart,
+ loff_t lend);
extern int filemap_write_and_wait(struct address_space *mapping);
extern int filemap_write_and_wait_range(struct address_space *mapping,
loff_t lstart, loff_t lend);
diff --git a/mm/filemap.c b/mm/filemap.c
index 1694623a6289..fae5a361befb 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -376,6 +376,39 @@ int filemap_flush(struct address_space *mapping)
}
EXPORT_SYMBOL(filemap_flush);
+/**
+ * filemap_range_has_page - check if a page exists in range.
+ * @mapping: address space structure to wait for
+ * @start_byte: offset in bytes where the range starts
+ * @end_byte: offset in bytes where the range ends (inclusive)
+ *
+ * Find at least one page in the range supplied, usually used to check if
+ * direct writing in this range will trigger a writeback.
+ */
+int filemap_range_has_page(struct address_space *mapping,
+ loff_t start_byte, loff_t end_byte)
+{
+ pgoff_t index = start_byte >> PAGE_SHIFT;
+ pgoff_t end = end_byte >> PAGE_SHIFT;
+ struct pagevec pvec;
+ int ret;
+
+ if (end_byte < start_byte)
+ return 0;
+
+ if (mapping->nrpages == 0)
+ return 0;
+
+ pagevec_init(&pvec, 0);
+ ret = pagevec_lookup(&pvec, mapping, index, 1);
+ if (!ret)
+ return 0;
+ ret = (pvec.pages[0]->index <= end);
+ pagevec_release(&pvec);
+ return ret;
+}
+EXPORT_SYMBOL(filemap_range_has_page);
+
static int __filemap_fdatawait_range(struct address_space *mapping,
loff_t start_byte, loff_t end_byte)
{
--
2.12.0
next prev parent reply other threads:[~2017-05-11 19:17 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-11 19:17 [PATCH 0/10 v8] No wait AIO Goldwyn Rodrigues
2017-05-11 19:17 ` [PATCH 01/10] fs: Separate out kiocb flags setup based on RWF_* flags Goldwyn Rodrigues
2017-05-11 19:17 ` Goldwyn Rodrigues [this message]
[not found] ` <20170511191710.31959-1-rgoldwyn-l3A5Bk7waGM@public.gmane.org>
2017-05-11 19:17 ` [PATCH 03/10] fs: Use RWF_* flags for AIO operations Goldwyn Rodrigues
2017-05-11 19:17 ` [PATCH 04/10] fs: Introduce RWF_NOWAIT Goldwyn Rodrigues
[not found] ` <20170511191710.31959-5-rgoldwyn-l3A5Bk7waGM@public.gmane.org>
2017-05-15 9:47 ` Jan Kara
2017-05-11 19:17 ` [PATCH 05/10] fs: return if direct write will trigger writeback Goldwyn Rodrigues
2017-05-11 19:17 ` [PATCH 06/10] fs: Introduce IOMAP_NOWAIT Goldwyn Rodrigues
2017-05-11 19:17 ` [PATCH 07/10] fs: return on congested block device Goldwyn Rodrigues
2017-05-11 19:17 ` [PATCH 08/10] ext4: nowait aio support Goldwyn Rodrigues
2017-05-11 19:17 ` [PATCH 09/10] xfs: " Goldwyn Rodrigues
2017-05-11 19:17 ` [PATCH 10/10] btrfs: " Goldwyn Rodrigues
2017-05-24 16:41 [PATCH 0/10 v9] No wait AIO Goldwyn Rodrigues
2017-05-24 16:41 ` [PATCH 02/10] fs: Introduce filemap_range_has_page() Goldwyn Rodrigues
2017-05-25 8:25 ` Jan Kara
2017-06-05 5:35 [PATCH 0/10 v10] No wait AIO Goldwyn Rodrigues
2017-06-05 5:35 ` [PATCH 02/10] fs: Introduce filemap_range_has_page() Goldwyn Rodrigues
2017-06-06 11:19 [PATCH 0/10 v11] No wait AIO Goldwyn Rodrigues
2017-06-06 11:19 ` [PATCH 02/10] fs: Introduce filemap_range_has_page() Goldwyn Rodrigues
2017-06-15 15:59 [PATCH 0/10 v12] No wait AIO Goldwyn Rodrigues
2017-06-15 15:59 ` [PATCH 02/10] fs: Introduce filemap_range_has_page() Goldwyn Rodrigues
[not found] ` <20170615160002.17233-3-rgoldwyn-l3A5Bk7waGM@public.gmane.org>
2017-06-15 18:25 ` Andrew Morton
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=20170511191710.31959-3-rgoldwyn@suse.de \
--to=rgoldwyn@suse.de \
--cc=avi@scylladb.com \
--cc=axboe@kernel.dk \
--cc=hch@infradead.org \
--cc=jack@suse.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-xfs@vger.kernel.org \
--cc=rgoldwyn@suse.com \
--cc=sagi@grimberg.me \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).