From: Qu Wenruo <wqu@suse.com>
To: linux-btrfs@vger.kernel.org
Subject: [PATCH 16/27] btrfs: cleanup for extent_write_locked_range()
Date: Tue, 13 Jul 2021 14:15:05 +0800 [thread overview]
Message-ID: <20210713061516.163318-17-wqu@suse.com> (raw)
In-Reply-To: <20210713061516.163318-1-wqu@suse.com>
There are several cleanups for extent_write_locked_range(), most of them
are pure cleanups, but with some preparation for future subpage support.
- Add a proper comment for which call sites are suitable
Unlike regular synchronized extent write back, if async cow or zoned
cow happens, we have all pages in the range still locked.
Thus for those (only) two call sites, we need this function to submit
page content into bios and submit them.
- Remove @mode parameter
All the existing two call sites pass WB_SYNC_ALL. No need for @mode
parameter.
- Better error handling
Currently if we hit an error during the page iteration loop, we
overwrite @ret, causing only the last error can be recorded.
Here we add @found_error and @first_error variable to record if we hit
any error, and the first error we hit.
So the first error won't get lost.
- Don't reuse @start as the cursor
We reuse the parameter @start as the cursor to iterate the range, not
a big problem, but since we're here, introduce a proper @cur as the
cursor.
- Remove impossible branch
Since all pages are still locked after the ordered extent is inserted,
there is no way that pages can get its dirty bit cleared.
Remove the branch where page is not dirty and replace it with an
ASSERT().
Signed-off-by: Qu Wenruo <wqu@suse.com>
---
fs/btrfs/extent_io.c | 45 ++++++++++++++++++++++++++++----------------
fs/btrfs/extent_io.h | 3 +--
fs/btrfs/inode.c | 4 ++--
3 files changed, 32 insertions(+), 20 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 5ad15a092574..583cfc89f2af 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -5045,23 +5045,29 @@ int extent_write_full_page(struct page *page, struct writeback_control *wbc)
return ret;
}
-int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
- int mode)
+/*
+ * Submit the pages in the range to bio for call sites which delalloc range
+ * has already be ran (aka, ordered extent inserted) and all pages are still
+ * locked.
+ */
+int extent_write_locked_range(struct inode *inode, u64 start, u64 end)
{
+ bool found_error = false;
+ int first_error = 0;
int ret = 0;
struct address_space *mapping = inode->i_mapping;
struct page *page;
+ u64 cur = start;
unsigned long nr_pages = (end - start + PAGE_SIZE) >>
PAGE_SHIFT;
-
struct extent_page_data epd = {
.bio_ctrl = { 0 },
.extent_locked = 1,
- .sync_io = mode == WB_SYNC_ALL,
+ .sync_io = 1,
};
struct writeback_control wbc_writepages = {
- .sync_mode = mode,
.nr_to_write = nr_pages * 2,
+ .sync_mode = WB_SYNC_ALL,
.range_start = start,
.range_end = end + 1,
/* We're called from an async helper function */
@@ -5070,26 +5076,33 @@ int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
};
wbc_attach_fdatawrite_inode(&wbc_writepages, inode);
- while (start <= end) {
- page = find_get_page(mapping, start >> PAGE_SHIFT);
- if (clear_page_dirty_for_io(page))
- ret = __extent_writepage(page, &wbc_writepages, &epd);
- else {
- btrfs_writepage_endio_finish_ordered(BTRFS_I(inode),
- page, start, start + PAGE_SIZE - 1, 1);
- unlock_page(page);
+ while (cur <= end) {
+ page = find_get_page(mapping, cur >> PAGE_SHIFT);
+ /*
+ * All pages in the range are locked since
+ * btrfs_run_delalloc_range(), thus there is no way to clear
+ * the page dirty flag.
+ */
+ ASSERT(PageDirty(page));
+ clear_page_dirty_for_io(page);
+ ret = __extent_writepage(page, &wbc_writepages, &epd);
+ ASSERT(ret <= 0);
+ if (ret < 0) {
+ found_error = true;
+ first_error = ret;
}
put_page(page);
- start += PAGE_SIZE;
+ cur += PAGE_SIZE;
}
- ASSERT(ret <= 0);
- if (ret == 0)
+ if (!found_error)
ret = flush_write_bio(&epd);
else
end_write_bio(&epd, ret);
wbc_detach_inode(&wbc_writepages);
+ if (found_error)
+ return first_error;
return ret;
}
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 62027f551b44..3f7f83a91976 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -183,8 +183,7 @@ int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
struct btrfs_bio_ctrl *bio_ctrl,
unsigned int read_flags, u64 *prev_em_start);
int extent_write_full_page(struct page *page, struct writeback_control *wbc);
-int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
- int mode);
+int extent_write_locked_range(struct inode *inode, u64 start, u64 end);
int extent_writepages(struct address_space *mapping,
struct writeback_control *wbc);
int btree_write_cache_pages(struct address_space *mapping,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7931c4a5bc5d..94449a6da16b 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -873,7 +873,7 @@ static int submit_one_async_extent(struct btrfs_inode *inode,
*/
if (!page_started && !ret)
extent_write_locked_range(&inode->vfs_inode, start,
- end, WB_SYNC_ALL);
+ end);
else if (ret && async_chunk->locked_page)
unlock_page(async_chunk->locked_page);
kfree(async_extent);
@@ -1460,7 +1460,7 @@ static noinline int run_delalloc_zoned(struct btrfs_inode *inode,
__set_page_dirty_nobuffers(locked_page);
account_page_redirty(locked_page);
- extent_write_locked_range(&inode->vfs_inode, start, end, WB_SYNC_ALL);
+ extent_write_locked_range(&inode->vfs_inode, start, end);
*page_started = 1;
return 0;
--
2.32.0
next prev parent reply other threads:[~2021-07-13 6:15 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-13 6:14 [PATCH 00/27] btrfs: limited subpage compressed write support Qu Wenruo
2021-07-13 6:14 ` [PATCH 01/27] btrfs: remove unused parameter @nr_pages in add_ra_bio_pages() Qu Wenruo
2021-07-13 6:14 ` [PATCH 02/27] btrfs: remove unnecessary parameter @delalloc_start for writepage_delalloc() Qu Wenruo
2021-07-13 6:14 ` [PATCH 03/27] btrfs: use async_chunk::async_cow to replace the confusing pending pointer Qu Wenruo
2021-07-13 7:36 ` Nikolay Borisov
2021-07-13 6:14 ` [PATCH 04/27] btrfs: don't pass compressed pages to btrfs_writepage_endio_finish_ordered() Qu Wenruo
2021-07-13 6:14 ` [PATCH 05/27] btrfs: make add_ra_bio_pages() to be subpage compatible Qu Wenruo
2021-07-13 6:14 ` [PATCH 06/27] btrfs: introduce compressed_bio::pending_sectors to trace compressed bio more elegantly Qu Wenruo
2021-07-13 6:14 ` [PATCH 07/27] btrfs: add subpage checked_bitmap to make PageChecked flag to be subpage compatible Qu Wenruo
2021-07-16 7:54 ` Qu Wenruo
2021-07-13 6:14 ` [PATCH 08/27] btrfs: handle errors properly inside btrfs_submit_compressed_read() Qu Wenruo
2021-07-13 6:14 ` [PATCH 09/27] btrfs: handle errors properly inside btrfs_submit_compressed_write() Qu Wenruo
2021-07-13 6:14 ` [PATCH 10/27] btrfs: introduce submit_compressed_bio() for compression Qu Wenruo
2021-07-13 6:15 ` [PATCH 11/27] btrfs: introduce alloc_compressed_bio() " Qu Wenruo
2021-07-13 6:15 ` [PATCH 12/27] btrfs: make btrfs_submit_compressed_read() to determine stripe boundary at bio allocation time Qu Wenruo
2021-07-13 6:15 ` [PATCH 13/27] btrfs: make btrfs_submit_compressed_write() " Qu Wenruo
2021-07-13 6:15 ` [PATCH 14/27] btrfs: remove unused function btrfs_bio_fits_in_stripe() Qu Wenruo
2021-07-13 6:15 ` [PATCH 15/27] btrfs: refactor submit_compressed_extents() Qu Wenruo
2021-07-13 6:15 ` Qu Wenruo [this message]
2021-07-13 6:15 ` [PATCH 17/27] btrfs: make compress_file_range() to be subpage compatible Qu Wenruo
2021-07-13 6:15 ` [PATCH 18/27] btrfs: make btrfs_submit_compressed_write() " Qu Wenruo
2021-07-13 6:15 ` [PATCH 19/27] btrfs: make end_compressed_bio_writeback() to be subpage compatble Qu Wenruo
2021-07-13 6:15 ` [PATCH 20/27] btrfs: make extent_write_locked_range() to be subpage compatible Qu Wenruo
2021-07-13 6:15 ` [PATCH 21/27] btrfs: extract uncompressed async extent submission code into a new helper Qu Wenruo
2021-07-13 6:15 ` [PATCH 22/27] btrfs: rework lzo_compress_pages() to make it subpage compatible Qu Wenruo
2021-07-13 6:15 ` [PATCH 23/27] btrfs: teach __extent_writepage() to handle locked page differently Qu Wenruo
2021-07-13 6:15 ` [PATCH 24/27] btrfs: allow page to be unlocked by btrfs_page_end_writer_lock() even if it's locked by plain page_lock() Qu Wenruo
2021-07-13 6:15 ` [PATCH 25/27] btrfs: allow subpage to compress a range which only covers one page Qu Wenruo
2021-07-13 6:15 ` [PATCH 26/27] btrfs: don't run delalloc range which is beyond the locked_page to prevent deadlock for subpage compression Qu Wenruo
2021-07-13 6:15 ` [PATCH 27/27] btrfs: only allow subpage compression if the range is fully page aligned Qu Wenruo
2021-07-16 9:11 ` [PATCH 00/27] btrfs: limited subpage compressed write support Qu Wenruo
2021-07-20 5:00 ` Qu Wenruo
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